United States
             Environmental Protection
             Agency
             Off ice of Water
             Program Operations (WH-547)
             Washington DC 20460
Off ice of
Research and Development (MERL)
Cincinnati, OH 45268
             Water
                          430/9-78-009
                                       February 1980
&EPA
Innovative and Alternative
Technology Assessment
Manual
                                            CD-53

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         INNOVATIVE AND ALTERNATIVE

           TECHNOLOGY ASSESSMENT

                  MANUAL
    OFFICE OF WATER  PROGRAM OPERATIONS
   U.S.  ENVIRONMENTAL  PROTECTION AGENCY
          WASHINGTON,  D.C.  20460
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
     OFFICE  OF  RESEARCH  AND  DEVELOPMENT
    U.S.  ENVIRONMENTAL PROTECTION AGENCY
          CINCINNATI, OHIO  45268

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                                 DISCLAIMER
This manual has been prepared by the Office of Research and Development's
Municipal Environmental Research Laboratory in cooperation with the Office
of Water and Waste Management's Municipal Construction and Facilities
Requirements Divisions.

The baseline cost and energy information contained in the Municipal Treatment
Technology Fact sheets (Appendix A) was developed by Burns and Roe, Consulting
Engineers; Paramus, New Jersey  using substantial input from previous EPA
cost estimating publications, including the Areawide Assessment Procedures
Manual published by EPA in July, 1976.

In approving this manual, both the Office of Research and Development and
the Office of Water and Waste Management wish to emphasize that the base-
line cost and energy information contained herein is based on the best
available information using both detailed standard estimating techniques
and field verification from as built cost records.  This cost information
is deemed acceptable for use in verifying comparative technology cost esti-
mates within the accuracy limits shown, but should not be used as an absolute
cost reference.

The contents of the manual are intended to be instructive and informational,
providing interpretative insights into both Congressional and Agency goals
in the formulation and administration of the innovative and alternative
technology provisions of the Clean Water Act of 1977.  It is intended to
be used as an aid to both the developers and reviewers of facility plans
submitted for federal grant assistance under the innovative and alternative
technology provisions of the Clean Water Act of 1977.

                                    NOTES

   To order this publication,  MCD-53, "Innovative &  Alternative Technology
   Assessment Manual,"  write to:
                  General Services Administration (8BRC)
                  Centralized Mailing List Services
                  Building 41,  Denver Federal  Center
                  Denver, Colorado  80225

   Please indicate the MCD number and title of publication.   Multiple copies
   may be purchased from:
                  National  Technical  Information Service
                  Springfield,  Viriginia  22151

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TO:  Users of the Innovative and Alternative Technology Assessment Manual


Enactment of Public Law 95-217 has marked a significant milestone in meeting
the Nation's environmental quality goals.  The provisions of the Act and its
legislative history have clearly established the Congressional intent of
meeting the Nation's water quality goals by much greater use of systems that
reclaim and reuse wastewater, productively recycle wastewater constituents,
and otherwise eliminate the discharge of pollutants or recover energy.

The keystones of the new Act in achieving these goals are the provisions for
the identification and use of innovative and alternative municipal treatment
technology.

The Environmental Protection Agency in accepting this challenge has moved
forward swiftly in developing the regulations and guidelines necessary to
achieve the goals of the Act while still maintaining the momentum of the
Construction Grants Program.

This Innovative and Alternative Technology Assessment Manual, produced
jointly by EPA's Office of Research and Development and Office of Water
and Waste Management, has been designed specifically to aid Federal and
State review authorities in the administration of the innovative and alter-
native technology requirements of the Construction Grants Program as well
as to provide the same basic methodological and technological information
to the engineering and planning personnel preparing facility plans.

The manual contains a user's guide, an innovative and alternative technology
screening methodology, cost and energy effectiveness analysis criteria and
procedures a's well as a set of comprehensive fact sheets for commonly employed
and emerging municipal technology processes, systems and subsystems.  Each
fact sheet addresses the applicable regulatory criteria for innovative and
alternative technology including estimated cost and energy utilization figures.
Edcardt C. Beck     'I                   Stephen
Assistant Administrator                 Assistant Administrator
Office of Water and Waste Management    Office of Research and Development
                                     m

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                                  ABSTRACT
This four chapter, six appendix manual presents the procedures and methodology
as well as the baseline cost and energy information necessary for the analysis
and evaluation of innovative and alternative technology applications submitted
for federal grant assistance under the innovative and alternative technology
provisions of the Clean Water Act of 1977.

The manual clarifies and interprets the intent of Congress and the Environ-
mental Protection Agency in carrying out the mandates of the innovative and
alternative provisions of the Clean Water Act of 1977.

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                                  FOREWORD
The innovative and alternative technology provisions of the Clean Water Act
of 1977 clearly established the Congressional and Environmental Protection
Agency's intent to encourage the development and use of innovative and
alternative technology for the treatment of the Nation's municipal wastewaters,

Alternatives to conventional treatment and discharge, and innovative designs
leading to greater cost and energy savings have been strongly encouraged by
the provisions of increased federal assistance and guarantee of system success
during the first two years of operation.  Major emphasis has been placed in
the planning, design, and construction of cost effective municipal treatment
works that maximize the recycle and reclamation of water, nutrients, and
energy while minimizing adverse environmental and public health impacts.

The new emphasis toward innovative solutions to environmental control prob-
lems under PL 95-217 presents a challenging opportunity for contemporary
planners and engineers to depart from traditional practice by the development
and construction of acceptable higher risk, higher benefit municipal waste-
water treatment facilities.

This Innovative and Alternative Technology Assessment Manual, produced
jointly by EPA's Office of Research and Development and Office of Water
and Waste Management, has been designed specifically to aid Federal and
State review authorities in the administration of the innovative and alter-
native requirements of the Construction Grants Program as well as providing
the same basic methodological and technological information to the engineering
and planning personnel preparing facility plans.

This manual was published in draft form in September, 1978, and has been
subjected to extensive public review during the past year including a public
review meeting held in Washington, D.C. on June 25, 1979.  This final version
reflects careful Agency consideration and incorporation of comments received
during this public comment period.  The body of the manual including the
methodological approach and use of the Innovative and Alternative Technology
Guidelines remains substantially the same.  The Municipal Treatment Tech-
nology Fact Sheets have been extensively updated to reflect new cost, per-
formance, and energy utilization information received during the public
comment period.
                                  Francis T. Mayo
                                  Municipal Environmental Resear

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                              ACKNOWLEDGEMENTS


This manual has been prepared by the Environmental Protection Agency, Office
of Research and Development, Municipal Environmental Research Laboratory,
Cincinnati, Ohio, in collaboration with the Office of Water and Waste Manage-
ment, Municipal Construction and Facilities Requirements Divisions.

Significant technical contribution and direction has been provided by the
following EPA programs.

     Municipal Environmental Research Laboratory  (Cincinnati, Ohio)

       Wastewater Research Division
         Urban Systems Management Section
         Physical-Chemical Treatment Section
         Biological  Treatment Section
         Ultimate Disposal Section
         Systems and Economic Analysis Section

     Robert S. Kerr  Environmental Research Laboratory  (Ada, Oklahoma)

       Wastewater Management Branch

     Office of Water Program Operations  (Washington, D.C.)

       Municipal Construction Division
       Facilities Requirements Division

In addition to EPA staff contributions, Appendix A of this manual has been
partially prepared by Burns and Roe, Consulting Engineers, Paramus, New Jersey;
under Contract No. WA-77-B037.

In publishing this manual in final form the Environmental Protection Agency
wishes to acknowledge those individuals and organizations furnishing comments
and participating in the June 25, 1979 public meeting.
                                     VI

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                                  CONTENTS


Chapter                                                                 Page

          DISCLAIMER                                                    ii

          TRANSMITTAL LETTER                                            iii

          ABSTRACT                                                      iv

          FOREWORD                                                      v

          ACKNOWLEDGEMENTS                                              vi

   1      INTRODUCTION

          1.0  General                                                  1-1
          1.1  User's Guide                                             1-2
               1.1.1  Intended Users                                    1-2
               1.1.2  Applicability for Plan Development and Review     1-3
               1.1.3  Organization                                      1-3

   2      INNOVATIVE AND ALTERNATIVE TECHNOLOGY DECISION METHODOLOGY

          2.1  General Classification and Screening Approach            2-1
          2.2  Innovative and Alternative Decision Methodology          2-1
               2.2.1  Description of Methodology                        2-1
               2.2.2  Detailed Description of Decision Points           2-4
                      2.2.2.1  Decision Point A - Developed             2-4
                               Technology Not Fully Proven for
                               Contemplated Use
                      2.2.2.2  Innovative Criteria                      2-6
                      2.2.2.3  Qualification of Technology as           2-11
                               Innovative by Regional Administrator
                      2.2.2.4  Cost Effectiveness Analysis              2-14
                      2.2.2.5  Partial  Project Eligibility Based        2-16
                               on Time
          2.3  Other Considerations                                     2-16
               2.3.1  Individual  and On-Site Systems                    2-16

   3      IMPROVED APPLICATION CRITERIA FOR ALTERNATIVE TECHNOLOGY

          3.1  General                                                  3-1
          3.2  Improved Operational  Reliability                         3-1
          3.3  Improved Toxics Management                               3-3


                                      vii

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                            CONTENTS  (Continued)


Chapter                                                                 Page

               3.3.1  Loss of Toxic Organic Compounds to the            3-11
                      Atmosphere During Conventional Wastewater
                      Treatment or Application to  Land
               3.3.2  Transformation of Toxics Through Biological        3-13
                      Treatment Processes Used as  a Part of
                      Alternative Technology Treatment Systems
                      3.3.2.1  Inorganics                               3-13
                      3.3.2.2  Organics                                 3-14
                      3.3.2.3  Analytical Considerations                3-16
               3.3.3  Activated Carbon Used as a Part of Alternative    3-16
                      Technology Systems
               3.3.4  The Fate and Effects of Toxic Substances on  Soil  3-18
                      3.3.4.1  General                                  3-18
                      3.3.4.2  Site Selection for  Improved Toxics        3-23
                               Management
                      3.3.4.3  Effect of Soil Properties on Fate of     3-24
                               Organic and Inorganic Toxicants
                      3.3.4.4  Addition of Inorganic Elements in        3-27
                               Sludge to Soils
                      3.3.4.5  The Fate and Effects of Toxic Organic    3-30
                               Wastes Added to Soils
          3.4  Increased Environmental Benefits                         3-31
               3.4.1  General                                           3-31
          3.5  Improved Joint Treatment of Municipal and Industrial     3-33
               Wastes
               3.5.1  General                                           3-33
          3.6  References                                               3-36

   4      INNOVATIVE TECHNOLOGY CONCEPTS AND APPLICATIONS

          4.1  General                                                  4-1
          4.2  Risk Versus Potential State-of-the-Art Advancement        4-1
          4.3  Innovative Planning and Design Approach                  4-2
               4.3.1  Innovative Processes                              4-2
               4.3.2  Innovative Concept Development                    4-3
               4.3.3  Innovative Equipment                              4-3
Appendix
          MUNICIPAL TREATMENT TECHNOLOGY FACT SHEETS  (See A-5 thru     A-l
          A-8 for Index of 117 Separate Fact Sheets)
                                     vim

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                            CONTENTS  (Continued)


Appendix                                                               Page

   B       LEGISLATION, REGULATIONS, AND PROGRAM GUIDANCE INFORMATION  B-l
           PERTAINING TO INNOVATIVE AND ALTERNATIVE TECHNOLOGY UNDER
           PL 95-217 (See B-ii for Separate Index)

   C       COST INDEXING                                               C-1

   D       ENERGY UTILIZATION CURVES AND CONVERSION FACTORS            D-l
           (See D-i for Separate Index)

   E       INNOVATIVE AND ALTERNATIVE TECHNOLOGY GUIDELINES            E-l

   F       COST EFFECTIVE ANALYSIS GUIDELINES                          F-l
                                     IX

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                                  CHAPTER  1

                                INTRODUCTION
1.0  General

The Clean Water Act of 1977 clearly established the intent of Congress to
encourage the use of innovative and alternative technology in the Environ-
mental Protection Agency's multi-billion dollar Municipal Treatment Construc-
tion Grant Program.

The legislation contains specific sections that refer to innovative and
alternative technology.  These provisions are included in Appendix B of
this manual.  The Environmental Protection Agency, in fulfilling its man-
date under the Clean Water Act of 1977, has published final regulations
pertaining to innovative and alternative technology.  These are also pre-
sented in Appendix B.

Extensive review of the legislative history of the Act along with consider-
ation of the voluminous public comment and results of public hearings have
led to the formulation of the Innovative and Alternative Technology Guide-
lines identified as Appendix E of the final regulations and also presented
as Appendix E of this manual.

The underlying concept of the Innovative and Alternative Guidelines is the
provision of a basic monetary incentive, i.e., a grant increase from 75% to
85% for the design and construction of municipal treatment technology that
represents an advancement of the current state-of-the-art technology with
respect to meeting the specific national goals of:  (a) greater recycling
and reuse of water, nutrients, and natural resources; (b) increased energy
recovery and conservation, reuse, and recycling; (c) improved cost effec-
tiveness in meeting specific water quality goals; and (d) improved toxics
management.

The legislation, guidelines, and Agency policy have been structured to pro-
vide additional incentives to both the public and private segments of the
municipal construction industry most directly responsible for implementation
of improved wastewater management systems.  Specific efforts have been made
to encourage the use of innovative concepts in the planning and design of
municipal treatment facilities by providing indemnification of risk through
the provision of 100% Federal grants for modification or replacement of
facilities which fail within the first two years of operation.  Additionally,
the Agency is presently in the process of clarifying the applicability of
the standard government patent provisions (40 CFR Part 30, Subpart D) to
innovative technology developed under Section 35.908 of the Innovative and
Alternative Technology Guidelines for a three-year  period  beginning

                                     1-1

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October 1, 1978.  As of this writing, a final decision on the patent issue
has not been reached.  This information will be provided as a separate
guidance document when available.

For conventional concepts of treatment, innovative technology must meet a 15%
life cycle cost reduction or a 20% net primary energy reduction over non-
innovative alternatives.  The criteria for qualifying alternative technology
as innovative includes either the above-mentioned cost or energy reduction
criteria or any one of the four additional criteria of:  (a) improved toxics
management; (b) improved operational reliability; (c) improved environmental
benefit; or (d) improved joint industrial municipal treatment potential.
These last four criteria are referred to as improved applications criteria
and are fully described in Chapter 3.

Supplementing these basic economic incentives is the latitude granted the
EPA Regional Offices in administering the Innovative and Alternative Tech-
nology Program.  The regulations provide for discretionary authority to
approve as innovative technology facility plans that provide substantial
public benefit.  Additional guidance for use of this discretionary authority
is provided in Chapter 2.  The regulations further provide for maximum state
and local government participation including modification of state priority
lists to allow eligibility of innovative or alternative technology projects.

It must be emphasized that because of the comprehensive nature of the inno-
vative and Alternative Technology Guidelines ultimate success of the program
will depend on the highest possible standards of engineering excellence and
judgement on the part of both the designers and reviewers of innovative and
alternative technology applications.

1.1  User's Guide

     1.1.1  Intended Users

This Innovative and Alternative Technology Assessment Manual has been pre-
pared specifically as an aid to State and Federal review authorities charged
with the responsibility of reviewing the conformance of facility plans for
the construction of municipal treatment works initiated after September 30, 1978,
with the Innovative and Alternative Technology Guidelines contained  in
Appendix E of the regulations and also included as Appendix E of this manual.

Because of the short three year time frame for implementation of the inno-
vative and alternative provisions of the Act and the Environmental Protec-
tion Agency's desire for maximum participation and understanding of  the
requirements, the manual will be concurrently distributed to planners,
engineers, and other interested parties engaged  in the formulation,  develop-
ment, design, and construction of municipal treatment works.

The manual is  intended to  be informative rather than prescriptive in nature.
The basic objectives are to provide a concise description and interpretation
of the enabling legislation, Agency regulations, program guidelines, and
information needed to efficiently implement the provision of the Act.


                                      1-2

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The manual  has  been designed  for the  use of  planners,  engineers,  and  analysts
engaged  in  the  development  and review of facility plans  for the construction
of municipal wastewater treatment facilities.  Emphasis  has been  placed  on:
(a) describing  and interpreting the applicable EPA regulations and guidelines;
(b) presenting  a  sequential classification and screening methodology;  and
(c) identifying,  collecting,  and presenting  state of the art cost and  energy
information needed to judge the conformance  of proposed  designs against  the
applicable  qualifying criteria.

Because  of  the  emphasis on  cost and energy considerations  in the  guidelines,
a major  effort  has been devoted in Appendix  A of this  manual to the develop-
ment and presentation of baseline cost  and energy data for the most commonly
used municipal  treatment technologies.

     1.1.2  Applicability for Plan Development and Review

As stated earlier, this manual is intended both for those engaged in the
development and review of facility plans.  It must be  emphasized  that  the
information contained herein, especially that related  to baseline cost and
energy is not to  be used as an absolute reference, but rather as  a general
guideline for the development of cost and energy estimates consistent with
the levels of sensitivity normally employed  in Step 1  facility plans.Con-
formance with the estimates presented herein should not  be interpreted by
either the designer or reviewer as a  guarantee of approval or satisfaction
of the Agency's requirements for meeting cost or energy  qualifying criteria.
Substantial deviation from the estimates, however, should be used as a guide
for requiring further documentation of the cost or energy estimates presented.
Final decisions regarding the conformance with qualifying criteria will be
made by  the State or Federal review staff based on their comprehensive anal-
ysis of  individual facility plans.  It should be noted that State or Federal
review staffs will require greater documentation and more detailed develop-
ment of  cost and energy estimates for Step 1 plans submitted to qualify as
innovative technology.  These requirements are further discussed  in Chapter 2.

Recognizing that the cost and energy estimating sensitivity at the Step 1
stage may be less than that ultimately required for some of the innovative
technology qualifying criteria, the final innovative and alternative tech-
nology regulations have been modified to include the right to reject or
modify Step 1 innovative qualifying decisions during subsequent Step 2
review.

     1.1.3  Organization

This manual contains four chapters and six supporting appendices.   The
development of both the main body of the manual and the  appendices are user
oriented.  Textual material  has been minimized while emphasis has  been
placed on graphical displays,  simplified equations,  example calculations,
logic and process flow diagrams,  and tabular information.  Although the
manual contains an extensive bibliography and is well referenced,  a special
attempt has been made to identify, extract,  and summarize available infor-
mation on applicable regulations  and guidelines and  state-of-the-art  baseline


                                     1-3

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cost and energy information needed for the efficient analysis and review of
facility plans.

Listed below is a synopsis of Chapters 2 through 4 and Appendices A through
F.

Chapter 2    Innovative and Alternative Technology Decision Methodology

This chapter contains a discussion and summary of the innovative screening
criteria as required by the innovative and alternative regulations, along
with a graphically displayed decision methodology to allow the recommended
portion(s) of facility plans to be screened and a decision reached as to
their classification as innovative or alternative technologies.  Each step
of the decision methodology is described in detail and refers to other sec-
tions or appendices of the report and to other documents for information
such as typical cost and energy utilization for commonly used and engineering
technology.  This chapter also includes a discussion of the window of accept-
able risk and guidance for the use of the Regional Administrators' discre-
tionary authority.

Chapter 3    Improved Application Criteria

This chapter contains an extensive discussion of Appendix E's improved
applications criteria (reliability, toxics management, improved joint treat-
ment, and environmental impact) for qualifying alternative technology as
innovative.  Emphasis is placed on improved toxics management including
discussion and quantification of adsorbability, volatility, biodegradability,
and transformations of toxic materials in soils.  This chapter also describes
the September 13, 1979, RCRA requirements as they apply to improved appli-
cations of alternative technology.

Chapter 4    Innovative Technology Concepts and Applications

This chapter includes a discussion and elaboration of specific criteria and
requirements for  innovative technology with emphasis on innovative planning
approaches, concept development, risk-benefit analysis, and the incorporation
of novel equipment in innovative process and system designs.

Appendix A   Municipal Treatment Technology Fact Sheets

This appendix contains a series of two-page municipal treatment technology
fact sheets.  Each fact sheet contains a process description, discussion of
process applicability, common process modifications, technology status, pro-
cess limitations, typical equipment, performance and design criteria, a
discussion of  improved application criteria (toxics management, environmental
impact, O&M, and  joint treatment) along with a flow diagram, energy balance,
construction cost curve, and O&M cost curve.

Appendix B   Legislation, Regulations, and Program Guidance Summary

A concise presentation of the  legislation, regulations, and program guidance
information pertaining to innovative and alternative technology.   Program

                                    1-4

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requirement memorandum modifying and clarifying Agency position and policy on
land application and small wastewater systems are presented.

Appendix C   Cost and Locality Factor Index

The construction and operation and maintenance (O&M) costs presented in this
manual have all been adjusted to a September 1976 (constant dollar) base
except as noted.  The EPA Sewage Treatment Plant Construction Cost Index
and O&M Cost Index needed to adjust this data to the date of analysis is
presented in this appendix.

In addition to adjusting to current dollars, Locality Factors have been
calculated from available statistics which permit the localizing of national
average cost data for construction labor, construction materials, total
construction cost, operation and maintenance labor, and power costs.  The
use of the Locality Factors to modify national average costs will result in
more accurate cost estimates than possible using the national average indexes
alone.

Appendix D   Energy Utilization Curves and Conversion Factors

This appendix summarizes the energy utilization of the more energy intensive
municipal treatment unit processes such as pumping and aeration, as well as
specific energy utilization and recovery curves for the analysis of the
energy recovery alternative technologies identified in Appendix E of the
Innovative and Alternative Technology Guidelines.  The appendix contains
a list of commonly used cost and energy conversion factors, a specific set
of energy utilization and recovery curves for anaerobic digestion, sludge
dewatering, and incineration processes.  This appendix also contains example
calculations illustrating the use of the energy curves and figures along with
a table of factors needed to compute the present worth of constant and variable
O&M costs.

Appendix E   Innovative and Alternative Technology Guidelines

A reprint of the final version of innovative and alternative guidelines
(Appendix E of Regulations).

Appendix F   Cost Effectiveness Analysis Guidelines (CEAG)

A reprint of the final cost effectiveness guidelines (Appendix A of
Regulations).
                                     1-5

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                                  CHAPTER 2

         INNOVATIVE AND ALTERNATIVE TECHNOLOGY DECISION METHODOLOGY


2.1  General Classification and Screening Approach

Section 201(g)5 of the Clean Water Act of 1977 requires all facility plans
initiated after September 30, 1978, to consider innovative and alternative
technology.  Figure 2-1 presents a generalized classification scheme for
review and analysis of these plans.  Referring to Figure 2-1, all potentially
innovative technology facility designs are classified as alternative tech-
nology or conventional concepts of treatment.  Facility designs classified
as alternative technology may qualify as innovative technology by meeting
any one of the six qualifying criteria shown.  Facility designs classified
as conventional concepts of treatment must meet either the cost or energy
criteria to qualify as innovative technology.

Alternative technologies are fully proven methods which provide for the
reclaiming and reuse of water, productively recycle wastewater constituents,
or otherwise eliminate the discharges of pollutants, or recover energy.  All
alternative technologies identified in the guidelines are listed in Figure 2-1.

Conventional concepts of treatment are generally defined as biological or phys-
ical chemical processes conventionally used for the treatment of wastewater
and which result in a point source discharge to surface waters.

2.2  Innovative and Alternative Decision Methodology

     2.2.1  Description of the Methodology

Presented in Figure 2-2 is a basic decision methodology to be used in the
analysis and evaluation of facility plans (Step 1) or plans and specifi-
cations (Step 2) submitted for consideration as innovative and alternative
technology.

A simplified three-step procedure for determining the classification and
funding eligibility of proposed projects is described below first for alter-
native technology, then for conventional concepts of treatment.

Referring to the upper portion of Figure 2-2, the procedure for alternative
technology is as follows:

     Beginning  with  Point  A

     A  -  Determine  if  the  proposed  alternative  technology  has  been  proven  in
                                     2-1

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                                                                FIGURE  2-1

                       GENERALIZED CLASSIFICATION  OF  INNOVATIVE AND ALTERNATIVE  TECHNOLOGY
ALTERNATIVE TECHNOLOGY

Specifically  identified forms  of  treatment and  unit
processes
          Effluent Treatment

          - land treatment
          - aquifer recharge
          - aquaculture
          - silviculture
          - direct reuse
             (non potable)
          - horticulture
          - revegetation of
ro           disturbed land
          - containment ponds
          - treatment and storage
             prior to land
             application
          - preapplication treat-
             ment
  - land application
  - composting prior to
     land application
  - drying prior to
     land application
                                 Energy Recovery

                                 - co-disposal  of
                                   sludge and  refuse
                                 - anaerobic digestion
                                   with >90% methane
                                   recovery
                                 - self-sustaining
                                   incineration

                                 Individual and On-
                                 Site Systems

                                 - on-site treatment
                                 - septage treatment
                                 - alternative  col-
                                   lection systems
                                   for smal1 com-
                                   munities
   CONVENTIONAL CONCEPTS OF CENTRALIZED TREATMENT

   Generally defined biological   or physical chemical
   processes with direct point source discharges to
   surface waters
  Improved Applications
of Alternative Technology
 (Any 6 Criteria)
             Conventional
               Concepts
                  Must Meet
                Cost or Energy
                                        QUALIFYING CRITERIA
Improved operational
 reliability
Improved toxics
 management
Increased environ-
 mental benefit
Improved joint treat-
 ment potential
                                                                        Innovative
                                                                        Technology
15% LCC reduction
20% net primary
 energy reduction

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                        FIGURE  2-2



INNOVATIVE AND ALTERNATIVE TECHNOLOGY DECISION METHODOLOGY
Fully Proven Meet Innovative Classification ani
in cir>-iin«Mqce90% methane
- direct reuse recovery
(non potable) - self-sustaining
- horticulture incineration
- revegetation of
disturbed land Individual and On-
- containment ponds Site Systems
- treatment and storage
prior to land - on-site treatment
application - septage treatment
- preapplication treat- - alternative col-
ment lection systems
for small com-
Sludge muni ties
- land application
- composting prior to
land application
- drying prior to
land application

CONVENTIONAL CONCEPTS OF CENTRALIZED TREATMENT

processes with direct point source discharges to
surface waters

YES
NO
YES

I 115% cost pre-
YES JL r ference for
un V publicly owned
NO ]

[>A YES Xr l155L"sL?re"
1 NO | publicly owned
YES Ar
NO Y

YES Jl^ r no cost
un V preference
nU 1

1 YF<. 1 115% cost pre-
NO ] publicly owned
j energy criteria
YES In I 1s met
. 85% alternative
not funded
- 86% innovative
not funded
not funded
75% conventional
- not funded
_ 85% innovative
if
not funded
                                              NO
                                                                              not funded

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         the circumstances  of its  intended  use.
         If YES - Proceed to Point  C
         If NO  - Proceed to Point  B

     B - Determine if the technology  meets  any one  of the  six qualifying
         criteria for innovative technology listed  in Figure 2-1.
         If YES - Proceed to Point  C
         If NO  - Not Funded

     C - Determine if the technology  cost is within 115% of the most cost-
         effective alternative.
         If YES - 85% Funding
         If NO  - Not Funded

Referring to the lower portion of  Figure 2-2, the procedure for conventional
concepts of treatment is as follows:

     Beginning at Point A

     A - Determine if the proposed technology has been proven in the circum-
         stances of its intended use.
         If YES - Proceed to Point C
         If NO  - Proceed to Point B

     B - Determine if the proposed technology meets either the 15% life cycle
         cost reduction jp_r_ the 20% net primary energy reduction criteria.
         If YES - Proceed to Point D
         If NO  - Not Funded

     C - Determine if the technology  is the most cost-effective alternative.
         If YES - 75% Funding
         If NO  - Not Funded

     D - For technologies that have met the energy criteria, determine if
         they are within 115% of the  cost of the most cost-effective alter-
         native.
         If YES - 85% Funding
         If NO  - Not Funded

Technologies that reach Point D by achieving a 15% life cycle cost reduction
have already demonstrated cost effectiveness.

     2.2.2  Detailed Description of Decision Points A, B,  C, and D

            2.2.2.1  Decision Point A - Developed Technology Not Fully
                     Proven for Contemplated Use

Traditional engineering practice has always dictated a very  low element  of
risk for the construction of full  scale public works projects supported  by
federal expenditures.  In passing Public Law 95-217, Congress clearly  intended
                                     2-4

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that a higher degree of risk be permitted for the set-aside funds for inno-
vative technology.  This intent should be recognized in judging the state
of development of potentially innovative technology.  The permitted degree
of risk should be compared to the potential for significant state-of-the-art
advancement.  High risk, high potential state of the art advancement projects
may be judged acceptable where high risk, low potential state of the art
advancement projects may be deemed unacceptable.

The first decision point in the methodology (Point A) is a determination
whether the proposed technology is developed but is not proven in the cir-
cumstances of its contemplated use.  This is a two-part determination.  The
first is to insure that the technology is developed to the extent that the
risk of full-scale use is acceptable, while the second part, i.e., the
test for fully-proven technology is intended to eliminate those technologies
that are fully proven and should not be granted the incentive of an inno-
vative grant increase.

The goal of the Innovative and Alternative Technology Program is to encourage
the use of technologies that lie between these two extremes as shown by the
window of acceptable risk in Figure 2-2(a) below.

A determination of whether processes and techniques are fully developed re-
quires consideration of the stage of development of a particular unit process
or specific piece of equipment,  as well as the degree of change in the appli-
cation of processes, techniques, or equipment that is substantially different
                                FIGURE 2-2(a)

                          WINDOW OF ACCEPTABLE RISK
                                        WINDOW OF ACCEPTABLE RISK
                                        FOR INNOVATIVE TECHNOLOGY
                   TECHNOLOGY
                      NOT
                     FULLY
                   DEVELOPED
                       STAGE OF TECHNOLOGY DEVELOPMENT
                                     2-5

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from the original intended use.  Technologies to the left of the window of
acceptable risk in Figure 2-2(a) are considered not fully developed.  For
technologies within the window of acceptable risk,  the development should
have progressed beyond the laboratory or bench scale stage and have been
successfully tested or demonstrated in a field application or pilot plant
program that has met the following general requirements.

     1.  The size of the principle components must  be such that physical,
         chemical, or biological processes are accurately simulated.

     2.  Process variables normally expected in full-scale application
         have been simulated.

     3.  All recycle streams have been considered.

     4.  Variations in influent characteristics substantially affecting
         performance in full-scale application have been anticipated
         and simulated.

     5.  The time of testing has been adequate to insure process equilibrium.

     6.  Full control of all major process variables has been demonstrated.

     7.  The service life of high maintenance or replacement items has been
         accurately estimated.

     8.  Basic process safety, environmental, and health risks have been
         considered and found to be within reasonable limits.

     9.  Type and amount of  all required process additives have been
         determined.

Where full-scale application requires multiple components, the size of the
units under No. 1 above should be judged in comparison to the smallest size
anticipated in modular or multiple system designs.

Technologies meeting the "developed" criteria above but are not considered
fully proven (i.e., are within the window of acceptable risk) in the pro-
posed application and represent an advancement in the state of the art
should be further considered as potentially innovative and proceed to
Step B in the methodology.  The state-of-the-art advancement must represent
a benefit commensurate with  the increased risk.  The risk/benefit assess-
ment of potentially innovative technology is further described in Chapter 4
of this manual.

     2.2.2.2  Innovative Criteria

              2.2.2.2.1  General

The second  step  in the decision methodology is to determine  if the proposed
technologies meet the innovative criteria specified  in the Appendix E  guide-
lines.  As  shown  in Figure 2-1, projects or portions of projects that  are

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originally classified as alternative technology can qualify as innovative by
meeting any one of the six qualifying criteria while those projects classified
as conventional concepts of treatment must meet either the 20% net primary
energy reduction or the 15% life cycle cost reduction.

The improved applications criteria of:  (a) improved operational reliability;
(b) improved toxics management; (c) improved environmental benefit; and
(d) improved joint treatment potential differ from the cost and energy cri-
teria in that there are no quantitative levels of improvement specified in
the guidelines as being necessary for qualification as innovative technology.
These four criteria are fully described in Chapter 3.

              2.2.2.2.2  Cost Criteria

For both the cost and energy criteria, specific reference is made in the
guidelines to comparison of innovative designs with non-innovative alter-
natives.  The specific language of these guidelines is shown below.

     1.   The life cycle cost of the eligible portions of the treatment works
         excluding conventional sewer lines is at least 15% less than that
         for the most cost effective alternative which does not incorporate
         innovative wastewater treatment processes and techniques (i.e., is
         no more than 85% of the life cycle of the most cost effective non-
         innovative alternative).

     2.   The net primary energy requirements for the operation and maintenance
         of the eligible portions  of the treatment works excluding conventional
         sewer lines are at least  20% less than the net energy requirements of
         the least net energy alternative which does not incorporate innovative
         wastewater treatment processes and techniques (i.e.,  the net energy
         requirements are no more  than 80% of those for the least net energy
         non-innovative alternative).   The least net energy non-innovative
         alternative must be one of the alternatives selected  for analysis
         under Section 5 of Appendix "A"!(Appendix A of 40 CFR Part 35 is
         included as Appendix F of this manual.

In the above life cycle cost comparisons,  the following apply.

     1.   The non-innovative alternative must be clearly identified.  Where an up-
         grading or expansion of an existing treatment works is encountered, only
         the portions associated with the increased capacity or level of treatment
         shall  be considered in the cost analysis.

     2.   The cost effectiveness of the non-innovative alternative will  be
         judged against the best available state of the art cost information.
         The construction cost information contained in Appendix A of this
         manual  and the referenced material  contained therein  may be used as
         a general  estimating guide in the analysis,  but in no way should be
         taken  as an absolute construction cost standard.

     3.   The basis  of the comparison is the  lowest present worth cost with
         the cost effective analysis for each  system being conducted in
         accordance with  the Cost  Effectiveness Analysis Guidelines.

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     4.  Aggregation of component cost savings is permitted providing all appli-
         cable provisions of the Cost Effectiveness Analysis Guidelines are met.
         Each separate component included  in the aggregation must include risk
         as described in decision point A.

     5.  The cost comparison between the proposed innovative and non-innovative
         alternatives must be made on a completed treatment works basis (grant
         eligible portions excluding conventional sewer  lines) even though the
         proposed potentially innovative portion is a sub-system or component.

     6.  In the  comparative analysis, both systems must  provide equivalent
         levels  of  pollutant control^Equivalency of the following factors
         must be considered.

         - Design minimum effluent quality standards
         - System reliability with respect to effluent quality
           and residual disposal
         - Residual  treatment and disposal
         - Level of toxic material control
         - Environmental benefit

         For cases  where innovative  sub-system components are analyzed  or aggre-
         gated  in the total plant cost comparison, only  the cost of the appur-
         tenant  equipment uniquely necessary for the proper functioning of
         the candidate  innovative or alternative technology component or piece
         of equipment should be  included as a part of the component cost.
         For example,  if an activated sludge plant with  a potentially innovative
         air diffusing  system  is compared  to a conventional activated sludge
         plant  on a total plant  basis as required by  item  (5) above,  an air
         cleaning or filtering  system uniquely necessary to pretreat  air for
          a proposed innovative  air diffusing system may  be  included  as  a part
         of the  aeration component while  items such as blowers,  portions of
         plant  electrical distribution  system, etc., would  not  be  eligible.
         A good  test for determining if  a  component  is uniquely necessary  is
         on the  basis  of whether  it  would  have to be modified or replaced
         to correct a  failure  of the innovative  system.

In the  above total system cost  comparison,  the  present worth cost of  the pro-
posed design with innovative components must be a minimum of 15% less  than
that of the most  cost effective  non-innovative  alternative  to  qualify as inno-
vative  technology.

              2.2.2.2.3   Energy  Criteria

The energy analysis  compares  the net  primary energy  utilization  of  the proposed
innovative  alternative  with  that of  the  least net  primary energy utilization
non-innovative  alternative.   In  this  analysis,  the required  20%  net primary
energy savings  must  be  made  on  the  total  treatment works  basis (eligible por-
tions excluding conventional  sewer  lines)   including  treatment  and disposal  of
all residuals  except where  an  upgrading  or expansion of  an  existing treatment
works is encountered.  In  this  case,  only the  treatment  works  associated with
the increased  capacity  and/or  level  of  treatment  shall  be considered for inclu-
sion in the energy analysis.   All  increases in  energy use in other  portions  of

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the plant must be accounted for in the above net 20% energy savings calculation.
The energy audits for the potentially innovative and non-innovative alternative
technologies must be made on an equivalent basis.  The following general require-
ments and conditions should be considered.

     1.  The boundaries and boundary conditions of system or system components
         receiving energy audits must be fully described including all flow
         streams entering or leaving the treatment works.

     2.  A materials balance for all significant influent and effluent streams
         including flow, mass, temperature, etc., must be included in the analysis

     3.  Differences in hydraulic profile required of different treatment
         systems must be accounted for in the energy analysis.

     4.  The system's energy balance must include the treatment and disposal
         (including transportation) of all residuals.

     5.  In determining the energy consumed to dewater sludge, the energy
         balance point is the sludge stream entering the dewatering process
         or the thickening process when thickening is required.  All  energy
         balances required to document energy recovery will be based  on annual
         values.  The sludge mass to be used in the analysis is the average
         annual sludge mass projected over the project planning period.

     6.  The energy utilization and heat transfer efficiency of commonly
         cited components or unit processes of similar size and design must
         be equivalent.

     7.  For processes where the energy utilization is a function of  influent
         flow, the energy analysis must consider the increase in plant flow
         over the project planning period as permitted by the cost effective
         analysis guidelines.  In the absence of a detailed analysis  of pro-
         jected flow increases and energy use, the average annual daily flow
         over the project planning period may be used in the analysis.

     8.  The net primary energy reduction of 20% specified in the innovative
         and alternative technology guidelines does not distinguish the form
         or location of the energy savings.  The savings should be computed
         at the boundary of the proposed treatment works in BTU or KwH/year.
         The conversion efficiency of fossil fueled electrical power  genera-
         tion and distribution to the plant site may be taken as a 32.5%.  A
         heat to electrical power conversion of 10,500 BTU/KwH may be used.
         See Tables D-4 and D-5 of Appendix D for other representative energy
         conversion and representative heat of fuels values.

     9.  Energy savings credit may be granted for lower grade fuel substi-
         tutions.  The credit basis must be approved through the EPA  regional
         office.

    10.  Net primary energy is the net energy consumed for the complete
         treatment of wastewater,  including the transportation and ultimate
         disposal of all  residuals.

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    11.  Aggregation of energy savings may be permitted if adequately doc-
         umented and other factors such as degree of technology advancement,
         increased risk, and energy recycle aspects are present for each
         aggregated component.

The non-innovative alternative that is to be used as the least net primary
energy using alternative baseline must be one of the alternatives selected
for analysis under Section 5(c) of the cost effectiveness analysis guidelines.
Section 5(c) is presented below.

     5(c)  Selection of Alternatives (From Cost Effectiveness Analysis
     Guidelines


     The identified alternatives shall be initially screened and analyzed
     to determine which systems have cost effectiveness potential and which
     should be fully evaluated according to the cost effectiveness analysis
     procedures established in the guidelines.

This requirement ensures that the baseline energy technology would have
roughly comparable cost effectiveness for the particular application, thus
basing the energy savings analysis on a reasonable comparison.

For facility planning begun after September 30, 1978, Regulation 35.917-l(d)9
requires an analysis of the primary energy requirements for each alternative
system considered.  The alternatives selected shall propose adoption of meas-
ures to reduce energy consumption or to increase recovery as long as such meas-
ures are cost effective.  This regulation further requires a detailed energy
analysis for those processes and techniques claiming innovation under the energy
criteria.  Although the above energy analysis requirements originate under dif-
ferent sections of the regulations, they are consistent in encouraging energy
reduction and conservation while still maintaining total project cost effec-
tiveness.

Appendix E guidelines mention two specific processes, anaerobic digestion and
incineration that, under certain energy-related conditions, qualify as alter-
native technology.  The condition that must be met for anaerobic digestion is
that greater than 90% of the methane gas produced must be recovered and used
as fuel.  Although the most common fuel use is for digester heating, all
other uses that reduce the net primary energy requirements of the treatment
works, including on-site as well as any off-site use qualify as meeting this
requirement.  Export of fuel that meets the requirements of applicable program
requirements memoranda may also be eligible.  The condition for eligibility of
incineration as alternative technology is that the energy recovered and pro-
ductively used is greater than the energy required to dewater the sludge to an
autogenous state.  Productive use of the energy is defined as any use that
reduces the net primary energy requirements of the treatment works, including
that used for disposal of the effluent or residuals generated during treatment.
Export and reuse of energy that meets the requirements of the applicable pro-
gram requirements memoranda may also be considered eligible.

Because of the large number of energy reuse and conservation possibilities

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that exist within the sludge handling and disposal portions of conventional
and alternative treatment technologies, and also because contemporary de-
signers do not have broad experience in energy optimization, Appendix D of
this manual has been prepared as a specific aid for the energy analysis of
potentially innovative and alternative applications required by Appendix E.

            2.2.2.3  Qualification of Technology as Innovative by
                     Regional Administrator

                     2.2.2.3.1  General

In accordance with Paragraph 6(a) of the Innovative and Alternative Technology
Guidelines (40 CFR Part 35, Appendix E), certain treatment systems may qualify
as innovative technology because they:  (a) incorporate unique design and
operational features due to local variations in geographic or climatic con-
ditions; or (b) because the design achieves significant public benefit through
the advancement of technology that would not otherw^:? be possible.

Qualification by these mechanisms will be made by the regional administrator
on a selective basis for those projects that exhibit high potential towards
achieving the goals of the Clean Water Act of 1977 but due to the unique
nature of the technology or system design may not strictly qualify under the
cost, energy, or improved application criteria.

In all cases, the present worth cost of the proposed innovative designs must
be within 115% of that for the least cost non-innovative alternative.

                     2.2.2.3.2  Unique Design Features Due to Climatic and
                                Geographic Conditions

Qualification by this mechanism recognizes that some conventional and many
newly developed alternative technologies, especially those that use natural
processes, are dependent on both climatic and geographical conditions of the
particular site or the more general conditions that prevail in a given region
or local area.

For these systems, the present worth cost, overall annual performance, risk
of system failure, and potential benefits are related to design and opera-
tional features that are governed by geographic and climatic factors.  Tech-
nologies considered proven under certain physical constraints and natural
conditions may exhibit increased risk when applied under more extreme or
substantially different climatic or geographic conditions.

These technologies may be judged innovative by the regional administrator
where increased risk is demonstrated and where the potential benefits derived
from the wider applicability or translocation of the technology justifies the
increased levels of risk on a regional or local basis.  In making the above
determination, the regional administrator will consider the overall appli-
cability of the technology for cost effectively meeting water quality goals
of the region as required by the Clean Water Act of 1977.  In some cases,
approval of moderate or low risk technology may be justified due to high


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potential benefits to the particular region or a potential for transference
to other regions.

                     2.2.2.3.3  Advancement of the State of the Art and
                                Significant Public Benefit

Projects qualifying under these criteria must fully document and quantify
both the:  (a) technological advancement; and (b) the achievable public
benefit.

The description of the technology advancement must include the following:

     1.  Identification of project element(s) contributing to state-of-the
         art advancement

     2.  Description of advancement by comparison to the most cost effective
         non-innovative design

     3.  Relationship of technological advancement to one or more of the
         following national goals for innovative and alternative technologies.

         . Cost reduction
         • Increased energy conservation or recovery
         . Greater recycling and conservation of water resources
         . Reclamation or reuse of effluents and resources
         . Improved efficiency and/or reliability of municipal
           treatment processes
         . Beneficial use of sludge or effluent constituents
         . Improved management of toxic materials
         • Increased environmental benefit

To be considered significant, the public benefits derived from innovative
technologies under this criteria must:   (a) be specifically identified; with
applicability and benefits extending beyond the proposed project.

This advancement of the state-of-the-art criteria may be applied to individual
unit processes or other sub-system components that are a part of the eligible
portion of treatment works as well as to total treatment systems.

The Agency intent in permitting qualification under this criteria  is to
encourage the development and use of all innovative methods of treatment
including conceptional advances, unit process advances, and the  integration
of improved unit processes into innovative treatment systems.

In judging qualification of innovative technology under this criteria,
priority consideration will be given to  new process and total treatment
concept development versus specific unit process, equipment, and individual
component development.

It is  recognized that for equipment intensive unit processes and other
proprietary devices, advances in the state of the art are an integral part


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of competition in the market place.  Although the use of  improved equipment,
devices, and unit processes is encouraged as a part of  innovative design,
qualification of these unit processes or proprietary equipment  items  indi-
vidually will be given lower priority than their incorporation  into new
concepts of treatment or to the development of totally  new treatment  pro-
cesses.

The following is recommended as a general priority guide  in qualifying inno-
vative technology under the state of the art advancement  and significant
public benefit criteria.
Technology Priority Class

(1) Development of new concepts
    of treatment
(1) Development of totally new
    treatment systems
(2) Development of proprietary
    processes
(2) Development of unit processes
(3) Development of unit process
    components or improved
    efficiency of existing processes
NOTE:  (1) to (3)—highest to lowest
Critical Factor Assessment

• Novel, approach
. New solution to problem
• Departure from conventional practices
. Incorporates more than one stated EPA
  goal for innovative technology
• Process advantage over conventional
. Widely applicable
. Recognized potential benefits
• High potential for transference to
  other applications

. Entire unit process but not a total
  treatment system
• Advance in technology has market
  potential
• Lower total treatment system cost
  or energy savings potential
. Some potential for transference to
  other processes

. Equipment or device improvement
. Advance has market potential
. Least total treatment system cost
  or energy savings potential
• Limited potential for transference
  to other processes
Although any of the three technology priority classes may be determined
innovative for a particular application by the regional administrator, a
greater judgmental latitude is justified by the higher priority classes
because of the greater inherent benefits that are potentially achievable
through the use of conceptual innovation as opposed to retrofitting or
modification of more conventional approaches with improved unit processes,
equipment, or devices.  In all cases, increased risks and benefits must be
assessed and documented to the satisfaction of the regional administrator.

In conjunction with the above, the regional administrators shall use the

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following criteria as a guide in their decisions.  These criteria are appli-
cable to projects proposed for innovative technology on the basis of cost or
energy reductions but which do not achieve the respective 15% or 20% cost or
energy savings over the entire treatment works as specified in Appendix E of
40 CFR Part 35.

     1.  Unit processes or operations which contain proposed innovative
         components must, as a minimum, achieve 15% total present worth
         cost savings or 20% net primary energy savings when compared to
         the replaced unit processes in the most cost effective or least
         net primary energy non-innovative alternative, respectively.

     2.  The project shall contain two or more distinctly separate innovative
         components.  Preferably, these components should be located in dif-
         ferent unit processes or operations.

     3.  Any increase in the total present worth cost or net primary energy
         requirements in other parts of the plant (i.e., as a result of
         sidestreams, recycle flows within the treatment works, etc.) must
         be included in the net cost and energy calculations in No. 1 above.
         Preferably, energy-saving projects qualified in accordance with
         these criteria should also be the most cost effective without
         adding the 15% cost preference.

            2.2.2.4  Cost Effectiveness Analysis

The Step C and D cost effectiveness analysis is the same as that normally
used for facility plans and the same guidelines should be used except that
all projects originating from the alternative technology category (upper
portion of Figure 2-2) and projects originating from the conventional con-
cepts of treatment category (lower portion) that meet the energy saving
criteria (Step D) are granted a 115% cost preference in the analysis.  The
cost effectiveness analysis must be completed in accordance with the Cost
Effectiveness Analysis Guidelines in Appendix F of this manual.

For those cases where innovative or alternative unit processes would serve
in lieu of conventional unit processes in a conventional wastewater treat-
ment plant, and the present worth costs of the non-conventional unit pro-
cesses are less than 50% of the present worth costs of the treatment plant,
multiply the present worth costs of the replaced conventional processes by
115% and add the cost of non-replaced unit processes.  In cases where alter-
native energy sources are substituted for power derived from unrenewable
energy sources, the present worth cost of the replaced conventional compo-
nents may be taken as the present worth cost of the conventionally supplied
power.  The portion of the project eligible for the cost effectiveness pre-
ference noted above should not be confused with the portion of projects
eligible for grant increases.  Table 2-1 summarizes both the cost effec-
tiveness and grant increase eligibilities.
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Many proposed  designs include  a mix  of conventional,  alternative, and pro-
posed  innovative processes, components, and equipment.   For these cases, the
facility plan  must clearly identify  all cost components  in  each category
indicating  those eligible for  the  115% cost effectiveness preference as
described  in Appendix E and shown  in Figure 2-2.

For systems involving individual and on-site systems,  only  the publicly owned
portion of  the proposed project may  be given the 115% cost  effectiveness
preference.  Further information regarding the eligibility  of these individual
and on-site systems is provided in PRM 79-8 shown in  Appendix B.


The cost effectiveness analysis of the proposed innovative  or alternative
components  with other alternative  designs contained in the  application
should be conducted as a part  of Step C or D of the decision methodology
shown  in Figure 2-2.  Another  critical part of this analysis is the com-
parison of  the estimated costs of  the alternatives contained in the appli-
cation to the  best available state of the art cost estimates for the tech-
nologies under consideration.  The Municipal Treatment Technology Fact
Sheets in Appendix A of this manual  have been prepared for  this purpose.
These  cost  estimates are general in  nature but can be  used  for comparative
analysis within the accuracy limits  shown.  They should  not be used as an
absolute cost  standard.  Care  must be exercised in recognizing and accounting
for the differences between the design basis of the alternatives under con-
sideration  and that used in the development of the fact  sheets.  Details of
the fact sheet cost estimates  are  provided in Pages A-l  thru A-5 of Appendix A
of this manual.

                                   TABLE  2-1

      COST  EFFECTIVENESS AND  GRANT INCREASE  PROJECT  PORTION ELIGIBILITY
Project
Project Portion
Preference
or Eligibility
115% Cost Effective-
ness Preference for
Innovative and
Alternative (I&A)
Technology
75% to 85% Grant
Increase for
Innovative or
Alternative (I&A)
Technology
Portion of Total Project That
Is Eligible (a)
Kor Project Portion
Less Than 50% of
Total Project
Only
I&A
Portion
Only
I&A
Portion
For Project Portion
Greater Than 50% of
Total Project
Entire
Project
Only
I&A
Portion
Authority
or
Reference
CEAG
Paragraph 7
Appendix A
202(a)2
202(a)4
§35.908(b)
Preamble
        (a)  Project eligibility is based on present worth cost of total project eligible
            portions excluding sewer related costs except for projects qualifying as
            alternatives to small  communities (a municipality with a population of 3,500
            or less or a highly dispersed section of a larger conmunity).

        (b)  Conventional concepts  of treatment qualifying as innovative under the energy
            criteria must meet the overall  115% cost effectiveness criteria to be
            eligible for funding.
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Appendix C of this manual has also been provided to permit easy indexing of
construction and O&M cost data from differing time periods.  This appendix
further contains cost locality factors for construction labor and materials.

            2.2.2.5  Partial Project Eligibility Based on Time

The decision methodology described thus far has dealt with the analysis of
innovative and alternative plant components proposed for the entire project
planning period as well as for specific project portions previously described.

For these latter cases, equivalent project eligibility for increased grant
assistance may be determined by multiplying the fraction of the normal plant
components eligible for a grant increase by the ratio of the total flow
treated over the project planning period by the innovative or alternative
technology to the total flow treated by the innovative or alternative tech-
nology plus that treated by non-innovative technology over the project
planning period.  For a phased project, the total flow treated is the aver-
age flow per phase times the length of each phase.

For a single phase project, the equivalent project eligibility is given by
the following expression:


                     FP  -  F     Ql/A
                                QI/A + QNI

         where   Fe  =  Equivalent fraction of plant components
                        eligible for grant increase in percent

                 Fn  =  Fraction of plant components normally
                        eligible as innovative or alternative
                        technology for entire planning period
                        in percent

               Ql/A  =  Total flow treated by innovative or
                        alternative technology over the project
                        planning period

                QNI  =  Total flow treated by non-innovative or
                        alternative technology over the project
                        planning period

The above procedure may be extended for any number of phases and for differing
innovative and alternative eligible portions for each phase.  A similar anal-
ysis for the equivalent fraction of eligible components may be used for inno-
vative or alternative components used for treatment or disposal of residuals.

2.3  Other Considerations

     2.3.1  Individual and On-Site Systems (Reader is also Referred to
            Program Requirements Memorandum 79-8 in Appendix B for
            Additional Information on Individual and On-Site Systems)

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Along with promulgation of the Innovative and Alternative Technology Guide-
lines, the Clean Water Act of 1977 substantially extended the basic eligi-
bility of the Construction Grants Program to include individual systems.
Under the Individual System Regulations (35.918, 35.918-1, 35.918-2, and
35.918-3), 4% of the construction grant funds have been set aside exclusively
for funding "alternatives to conventional treatment works" in communities
having a population of 3,500 or less and in highly dispersed sections of
larger communities.  The population density qualifying as highly dispersed
will be made by the regional administrator.

Individual systems are defined as privately owned alternative wastewater
treatment works serving one or more principal residences or commercial
establishments which are neither connected into nor a part of any conven-
tional treatment works.

On-site systems may be publicly or privately owned and include all wastewater
treatment alternatives for single family, multiple family, or clustered
residential or commercial developments that are not connected to centralized
wastewater collection systems.  On-site technology may include treatment with
surface or subsurface discharge, recycle and reuse, or evaporation systems.
On-site systems characteristically provide treatment and disposal of waste-
waters in the immediate locality of generation.

Commonly used on-site technology is listed as follows:

         Qn-Site Technology

         1.  Septic Tank - Soil Absorption Systems
         2.  Aerobic Treatment - Soil Absorption Systems
         3.  Sand Filtration, Polishing and Disinfecting
         4.  Mound Systems
         5.  Evapotranspiration Systems
         6.  Evaporation Systems
         7.  Waterless Toilets/Greywater Systems (only the
             treatment and treatment residual disposal portion
             are grant eligible.  See 35.918-2(a))
         8.  On-Site Recycle Systems
         9.  Combinations of 1 thru 8

In addition to the individual and on-site systems, alternative collection
systems and septage treatment have been identified as alternative technology
by the Appendix E guidelines and thereby are eligible for the grant increase
and the 115% cost effectiveness preference if publicly owned, which would
normally be the case.  Alternative collection and septage treatment systems
are listed below.

         Alternative Collection Systems (also see PRM 79-8 in Appendix B)

         1.  Pressure Sewers (limited to small  communities or highly dispersed
             sections of larger communities)
         2.  Vacuum Sewers (limited to small communities or highly dispersed
             sections of larger communities)

                                     2-17

-------
         3.  Small Diameter Gravity Sewers (except if used for conveyance of
             raw wastewater to a centralized plant)

         Septage Treatment

         1.  Separate Septage Treatment
         2.  Septage Disposal

All individual and on-site systems, alternative collection systems, and sep-
tage treatment systems have been identified as alternative technology in the
Innovative and Alternative Technology Guidelines and are, therefore, eligible
for the 75% to 85% grant increase.  These individual systems may also qualify
as innovative technology by meeting any of the six Appendix E qualifying
criteria.  Publicly owned portions of the above alternative technologies
are eligible for the 115% cost effectiveness preference.  Land used for treat-
ment purposes for publically owned on-site systems serving more than one prin-
ciple residence or commercial establishment is grant eligible.  Acquisition
of easement and legal fees associated with such acquisitions for purposes of
obtaining access to on-site technology components are not grant eligible.

Because much of the on-site technology is new and very site specific, the
cost and energy data bases needed to judge conformance with the innovative
technology qualifying criteria are not as well developed as with the more
conventional technologies.  Also, many planners and design engineers are
unfamiliar with the formulation and development of facility plans incor-
porating this technology.  Recognizing an increased need for the dissemina-
tion of  information on the cost and applicability of on-site technology, the
Office of Research and Development, in cooperation with the Office of Water
and Waste Management, sponsored two intensive one-week training seminars:
one in Cincinnati, Ohio, and one in Denver, Colorado, during August of 1978
to familiarize both state and federal review authorities with the use of
this technology in future facility plans.  This information has been used
where applicable in the development of the fact sheet cost and energy curves
and is appropriately referenced on the individual fact sheets.

Of particular importance in judging the overall cost effectiveness of on-site
technologies is the provision for adequate system maintenance and management
budgets.  These systems which may include combinations of individual home
treatment units, clustered units, small centralized treatment with surface or
subsurface disposal, along with various combinations of pressure or vacuum
sewer collection, are generally more widely dispersed than conventional
treatment systems and therefore require greater than normal attention to
operation and maintenance requirements, especially as related to large
numbers of small mechanical equipment items.  Complete documentation of
expected equipment lifetimes and recommended preventative maintenance prac-
tices should be included in the facility plan.
                                    2-18

-------
                                  CHAPTER  3

          IMPROVED APPLICATION CRITERIA FOR ALTERNATIVE TECHNOLOGY
3.1  General

Alternative technologies such as land treatment and application of waste-
water and sludge are encouraged as fully proven technologies (See Chap-
ter 2).  In order to be classified as innovative, these fully proven tech-
nologies must be analyzed in Step 2 of the screening process (See Sec-
tion 2.2.2.2 on Page 2.6).  In addition to the specific cost and energy
criteria, alternative technology leading to:  (a) improved operational
reliability; (b) better management of toxic materials; (c) increased envi-
ronmental benefits; or (d) new or improved joint treatment of municipal
and industrial wastes qualifies as innovative technology.  The intent of
these four criteria is to encourage the use of new or improved applications
of already proven alternative technologies such as reuse, reclamation,
recycle, and energy saving systems that offer an advantage over the current
state of the art in one or more of the above categories.   As described in
Chapter 2, the new or improved applications of alternative technology must
include elements of increased risk.

These criteria differ from the cost and energy criteria in that no specific
target levels have been provided to quantitatively judge  conformance or
level of conformance.  The intent, however, is to encourage alternative
system designs that maximize the above benefits over contemporary practice.
Each of the improved application criteria is discussed in the subsequent
sections.  Subjective qualitative analyses will be required to demonstrate
compliance with these criteria.  In these analyses, comparisons must be made
on a total treatment works or system basis including all  appurtenant equip-
ment and processes, sludge handling and disposal processes and techniques.
The systems to be used as a basis of comparison must be functionally similar
alternative processes that are potentially cost effective as defined by
Paragraph 5(c) of the Cost Effectiveness Analysis Guidelines.  The period
of comparison is the project planning period.

3.2  Improved Operational Reliability

Alternative technology contributing towards improved operational reliability
must meet one of the following conditions to qualify as innovative.

     1.   Provide  decreased  susceptibility to upsets or interference
         (Also  see  Section  3.3.2)

     2.   Result  in  reduced  occurrence  (frequency x  duration)  of inadequately
         treated  discharges


                                     3-1

-------
     3.   Provide  decreased  levels of  required operator  attention  and skills

In the comparative analysis, claimed advantages for decreased susceptibility
to upsets or interferences must be  fully documented.  As a minimum,  the
specific reason(s) for reduced susceptibility must be identified.  For
example, greater system reliability due to reliability of mechanical  com-
ponents must be documented with evidence such as greater mean time between
failure data.  It must be clearly identified if the increased operational
reliability is due to:

     1.   Greater  mechanical  reliability
     2.   Greater  inherent physical,  chemical, or biological  process
         stability or reliability,  including processes  and  transformations
         taking place in  the soils  of land  application  systems
     3.   Improved system  design
     4.   Increased standby or backup  facilities
     5.   Continuous monitoring alert  or diversion systems
     6.   Combinations of  1  through  5

Upsets would include any reduction in the system ability to meet the design
effluent quality requirements continuously at flows up to design capacity.
Interferences  include influent stream factors as well as the impact of all
internally generated streams or environmentally  imposed conditions within
the treatment  system leading to total system or  system component failure.
The comparative  analysis must include a reasonable range of potential  pro-
cess upsets and  interferences, including the probable frequency of these
occurring and  their relative magnitude.  The basic level of reliability
against which  the  improvement is judged is the greater of:  (1) that required
by EPA Reliability Guidelines (Report EPA 430-99-74-001); (2) the minimum
level specified  in the NPDES permit; or (3) that required to meet effluent
quality or reuse/reclamation criteria for non-discharging systems.

Reduced occurrence of the discharge of  inadequately treated effluent must be
made on a mass pollutant basis accounting for the frequency and magnitude of
the excessive  discharge(s) of the pollutant(s) of concern.  The pollutants
of concern, unless otherwise  identified, are those contained in the NPDES
permit for discharging systems including the requirements of BPWWT where
applicable.

For non-discharging systems, the pollutants of concern are the major pollu-
tants that the system is designed to remove to meet a pollution control
objective or the pollutant(s) that must be removed to  insure reuse quality.

For systems employing land  application  or land utilization practices,
criteria for groundwater protection are contained in Alternative Waste
Management Techniques for Best Practicable Waste Treatment  (BPWPT),
(EPA-430/9-75-013).  The objective of the BPWPT  criteria for land appli-
cation systems is  to protect  groundwater for drinking water purposes and
other beneficial  uses.   In  the case of  groundwater protection for drinking
water supplies,  the pollutants of concern are  those contained in the
appropriate  sections of  the  National Primary Drinking Water Standards.


                                      3-2

-------
Applications which claim reduction in process upsets or interferences, and/or
reductions in the occurrences of inadequately treated discharges simply
through use of increased equipment redundancy or abnormally low loading
will not normally be considered innovative.  Innovative technology may
include use of unique operational procedures, land application schedules,
materials, and/or equipment which meets the requirements of:  (1) decreased
susceptibility; or (2) reduced occurrence previously mentioned.

Alternative systems or system components that claim decreased levels of
required operator attention and skills must clearly document the differences
in system operating and/or maintenance procedures and characteristics that
justify the savings.  The system upon which the comparison is based must be
a functionally similar alternative technology that is potentially cost
effective in accordance with Section 5(c) of the Cost Effectiveness Guide-
lines.

Claims for reduced operator attention due to increased use of automation
and instrumentation for alternative technologies must fully document in
annual person hours and dollars the savings for all required operator func-
tions including but not limited to:

     1.   Process  monitoring
     2.   Routine  process observations and control  changes
     3.   Effluent quality monitoring
     4.   Unique process control  changes
     5.   Preventative maintenance activities,  including instrument
         calibration
     6.   Corrective maintenance  activities, including instrument  repair
     7.   Mechanical component maintenance
     8.   Operation management and supervision
     9.   Maintenance management  and supervision

This trade-off analysis must include documentation of all  automated equip-
ment service lifetimes, and maintenance costs under the conditions of their
anticipated use.

3.3  Improved Toxics Management

Alternative technology contributing toward better or improved management of
toxic materials are those processes, techniques, and practices that reduce
the direct or indirect exposure of known toxicants to man  or his environment
beyond that normally expected in contemporary practice.  Better management
can also be demonstrated through enhanced controls such as in improved mon-
itoring.  Reduction in exposure may be brought about by chemical, physical,
or biological mechanisms that reduce or eliminate the recycling of toxicants
within or between media.  Reduction of recycling and exposure potential may
be achieved by:

     1.   Isolation
     2.   Modification of the chemical  form (detoxification)
     3.   Destruction by such methods  as thermal  or  biological  oxidation


                                     3-3

-------
 Applications qualifying  alternative technology as  innovative due to  improved
toxics management must:   (a)  identify  the significant exposure  pathways for
the specific system under consideration;  (b)  document the mechanism(s)  of
improved management; and (c)  identify  the specific toxic compound(s)  or
classes of organic compounds  that are  reduced or  better controlled.   Although
the priority pollutants  shown in Table 3-1 are of primary concern,  the
requirements (a), (b),  and (c) above also apply to other known  or identified
toxic materials.

The intent of the improved management  of toxic material criteria is to
encourage the use of specific exposure reduction  mechanisms that result
in improvement over the  current state-of-the-art  wastewater management  and
disposal techniques.  Generalized claims of improved toxics management  not
meeting the requirements of items (a), (b), and (c) will not be considered
as meeting the criteria.

The more common pathways of toxics movement in urban areas are  shown in
Figure 3-1.  Toxic substances originate from four sources:  industrial,
residential, commercial  or institutional, and non-point.  They  can be
disposed of in the air,  on the land, or in surface or ground water.  Man
can be affected by inhalation or ingestion of affected water or food pro-
ducts, or by exposure.   Controlling legislation is found in the Clean Air
Act (CAA), Clean Water Act (CWA), and  Resource Conservation and Recovery Act
 (RCRA), and any proposed technology would have to comply with applicable
sections of these laws or regulations  promulgated as a result of the laws.

Figure 3-1 is comprehensive in nature, covering all aspects of  toxics
movement, but alternative technology which provides for improved toxics
management and that would be eligible for funding under the CWA excludes
portions of this chart.   Generally, only publicly owned treatment works and
on-site systems would become  involved in funding under the Construction Grants
Program.  For example,  stormwater control projects are not innovative sol-
utions to toxics mangement and are limited in eligibility.  Also, bypasses
are not allowed and would not be considered innovative.

 Improved toxics management opportunities applicable to alternative tech-
nology are identified as major control points and are denoted by the
darnkened dots.  In general,  better management of toxics can be found in
 improved source control, i.e., improved pretreatment of industrial wastes
 and improved removal at the plant prior to sludge treatment and disposal
or prior to effluent disposal.  As is  apparent from the figure, once toxic
materials reach the plant, the toxics  management question usually involves
 a comparison of trade-offs because the toxic materials which are present
will be found either in the sludge or effluent unless they are detoxified or
 destroyed.

While  it is not currently possible to quantitatively describe all possible
 transformations of the priority pollutants in Table 3-1,  it is possible to
 describe many of the physical, chemical, and biological characteristics of
 broad  classes of toxic materials that permit qualitative  prediction  and
                                     3-4

-------
                      TABLE  3-1



HENRY'S LAW CONSTANTS FOR EPA PRIORITY POLLUTANTS

1.
2.
3.
4.
5.
6.




7.
8.
9.




10.
11.
12.
13.
14.
15.
16.


17.
18.
19.

20.




21.
22.
23.
24.

25.
26.
27.

*acenaphthene
*acrolein
*acrylonitrile
*benzene
*benzidine
*carbon tetrachloride
( tetrachl oromethane )
*chlorinated benzenes
(other than
dichlorobenzenes)
chlorobenzene
1 ,2,4-trichlorobenzene
hexachlorobenzene
*chlorinated ethanes (including
1 ,2-dichloroethane, 1,1,1-
trichloroethane and hexachloro-
ethane)
1 ,2-dichloroethane
1 ,1 ,1-trichloroethane
hexachloroethane
1 ,1-dichloroethane
1 ,1 ,2-trichloroethane
1 ,1 ,2,2-tetrachloroethane
chloroethane
*chloroalkyl ethers (chloromethyl,
chloroethyl and mixed ethers)
bis (chloromethyl ) ether
bis(2-chloroethyl ) ether
2-chloroethyl vinyl ether (mixed)
*chlorinated naphthalene
2-chl oronaphtha 1 ene
*chlorinated phenols (other than
those listed elsewhere; includes
trichlorophenols and chlorinated
cresols)
2,4,6-trichlorophenol
parachlorometa cresol
*chloroform (trichloromethane)
*2-chlorophenol
*dichlorobenzenes
1 ,2-dichlorobenzene
1 ,3-dichlorobenzene
1 ,4-dichlorobenzene
HO)
C,009(c)
0.0046(b)
0.0030(b)
0.22(b)


1 .2(c)



0.19(d)






0.050(c)
0.17(b)
0.05(c)
0.24(c)
0.037(c)
0.020(c)
VP(2)
(mmHg)
Solubility (3)
(mg/£)
3.0xlO"Z 3.88
300.
100.
95.2


91.3



15.






82.
100.
0.33
226.
25.
6.5
0.73(c) 1200.













0.16(c)
0.001 (b)

0.081 (b)
0.13(c)
0.10(c)













192.
5.0

1.0
2.0
1.0
200,000.
93,000.
1780.


800.



448.






8700.
4400.
8.
5100.
4420.
3000.
5700.













7840.
28,000.

100.
123.
79.
                        3-5

-------
                             TABLE 3-1(Continued)
                                                       VP(2)    Solubility(3)
                                             H(l)     (mmHg)       (rng/a)
     *di chlorobenzi di ne
28.     3,3'-dich1orobenzidine
     *dichloroethylenes (1,1-dichloroeth-
        ylene and 1,2-dichloroethylene)
29.     1,1-dichloroethylene
30.     1,2-trans-dichloroethylene
31.  *2,4-dichlorophenol
     *dichloropropane and dichloro-
        propene
32.     1,2-dichloropropane
33.     1,2-dichloropropylene (1,3-
          dichloropropene)
34.  *2,4-dimethylphenol
     *dinitrotoluene
35.     2,4-dinitrotoluene
36.     2,6-dinitrotoluene
37.  *1,2-diphenylhydrazine
38.  *ethylbenzene
39.  *fluoranthene
     *haloethers (other than those
        listed elsewhere)
40.     4-chlorophenyl phenyl ether
41.     4-bromophenyl phenyl ether
42.     bis(2-chloroisopropyl) ether
43.     bis(2-chloroethoxy) methane
     *halomethanes (other than those
        1isted elsewhere)
44.     methylene chloride (dichloro-
          methane)
45.     methyl chloride (chloromethane)
46.     methyl bromide (bromomethane)
47.     bromoform (tribromomethane)
48.     dichlorobromomethane
49.     trichlorofluoromethane
50.     dichlorodifluoromethane
51.     chlorodibromomethane
52.  *hexachlorobutadiene
53.  *hexachlorocyclopentadiene
54.  *isophorone
55.  *naphthalene
56.  *nitrobenzene
     *nitrophenols (including 2,4-
        dinitrophenol and dinitrocresol)
57.     2-nitrophenol
58.     4-nitrophenol
59.    *2,4-dinitrophenol
 7.80      598.
 0.27      326.
 0.002       1.0
 0.095(b)   42.

 0.095(b)   43.
 0.27(b)
   7.
 0.005
   0.85
 0.12(c)   438.
 0.38(c)   760.
 4.39(b)   760.
 0.030(d)    5.
  .
98.8(c)
 760.
4250.
 0.0036(b)   1.0
               400.
              6300.
              4500.
              2700.

              2700.
   152.
  1700.
16,700.
  5380.
   900.
  3190.

  1100.
   280.
0.0002(b)
O.OU(c)
0.0005(b)
0.38
0.87
0.15
12,000
30
1900
              2100.
                                     3-6

-------
TABLE 3-1 (Continued)

60.

61.
62.
63.
64.
65.

66.
67.
68.
69.
70.
71.

72.

73.
74.
75.

76.
77.
78.
79.

80.
81.
82.

83.

84.
85.
86.
87.
88.

89.
90.
91.


92.
93.
94.

4,6-dinitro-o-cresol
*nitrosamines
N-nitrosodimethylamine
N-nitrosodiphenylamine
N-ni trosodi -n-propyl amine
*pentachlorophenol
*phenol
*phthalate esters
bis(2-ethylhexyl) phthalate
butyl benzyl phthalate
di-n-butyl phthalate
di-n-octyl phthalate
diethyl phthalate
dimethyl phthalate
*polynuclear aromatic hydrocarbons
benzo(a)anthracene (1,2-
benzanthracene)
benzo(a)pyrene (3,4-benzopyrene)
3,4-benzofluoranthene
benzo(k)fluoranthane (11,12-
benzofluoranthene)
chrysene
acenaphthylene
anthracene
benzo(ghi)perylene (1,12-
benzoperylene)
fluorene
phenanthrene
dibenzo(a,h)anthracene (1 ,2,5,6-
dibenzanthracene)
indeno (1 ,2,3-cd)pyrene (2,3-o-
phenylenepyrene)
pyrene
*tetrachl oroethyl ene
*toluene
*trichl oroethyl ene
*vinyl chloride (chloroethylene)
pesticides and metabolites
*aldrin
*dieldrin
*chlordane (technical mixture
& metabolites)
*DDT and metabolites
4,4'-DDT
4,4'-DDE (p.p'-DDX)
4,4'-DDD (p,p'-TDE)
H(D
8xlO'6(a)




0.0001 (b)
1.3xlO-5(c)



0.0030(c)


0.00002(b)









0.067(c)


O.OlO(c)
0.006(c)





l.l(c)
0.27(c)
0.48(c)
VP(2)
(mmHg)
IxlO"4



_A
1.1x10 ^
0.20



0.1


0.01









0.04


0.012
3.4x10-3





18.6
28.
74.
301. (c) 2660.

0.10(c)
8.2xlO-b



0.0016(c)


/i
1.4xlO"J
5.4xin"°



1.9X10'7


Solubility(3)
(mg/n)
130.




14.
82,000.



500.


5000.









0.075


1.90
1.18





150.
515.
1000.
60.

0.027
0.19



S.lxlO-3


         3- 7

-------
TABLE 3-1(Continued)
                          VP(2)     Solubility(3)
                         (mmHg)        (mg/£)

95.
96.
97.

98.
99.

100.
101.

102.
103.
104.
105.

106.
107.
108.
109.
110.
111.
112.
113.
114.
115.
116.
117.
118.
119.
120.
121.
122.
123.
124.
125.
126.
127.
128.
129.

(1)
(2)
(3)
*endosulfan and metabolites
a-endosul fan-Alpha
b-endosul fan-Beta
endosulfan sulfate
*endrin and metabolites
endrin
endrin aldehyde
*heptachlor and metabolites
heptachlor
heptachlor epoxide
*hexachl orocycl ohexane (all isomers)
a-BHC-Alpha
b-BHC-Beta
r-BHC (lindane) -Gamma
g-BHC-Delta
*polychlorinated biphenyls (PCB's)
PCB-1242 (Arochlor 1242)
PCB-1254 (Arochlor 1254)
PCB-1221 (Arochlor 1221)
PCB-1232 (Arochlor 1232)
PCB-1248 (Arochlor 1248)
PCB-1260 (Arochlor 1260)
PCB-1016 (Arochlor 1016)
*toxaphene
*antimony (total)
*arsenic (total)
*asbestos (fibrous)
*beryllium (total)
*Cadmium (total )
*chromium (total )
*copper (total)
*cyanide (total)
*lead (total)
*mercury (total)
*nickel (total)
*selenium (total )
*silver (total)
^thallium (total)
*zinc (total)
2,3,7,8-tetrachlorodibenzo-p-
dioxin (TCDD)
H is calculated Henry's Law Constant
VP is vapor pressure of compound
Solubility is compound solubility in







A
0.11 (c) 3x10"^ 0.056


0.094(c) 0.06 10.
0.53(£) 0.17 5.
1.5xl0~ic) 9.4xlO-6 10.

n
0.023(c) 4.1x10"^ 0.24
0.11 (c) 7.7xlO-5 0.012

A 9
0.14(c) 4.9x10"^ 5.4x10",
0.29(c) 4.1x10"° 2.7X10"-3

2.97(c) .40 3.0

















*Specific compounds and chem-
ical classes as listed in
water the consent degree
        3-8

-------
                            TABLE 3-1   (Continued)
(a)  = 288°K(15°C)
(b)  = 293°K(20°C)
(c)  = 298°K(25°C)
(d)  = 303°K(30°C)
Henry's Law Constant Calculation:
                            16.04  PM
                       H =
H = Henry's Law Constant (dimensionless)
P = vapor pressure of compound (mmHg)
M = molecular weight of compound
S = solubility of compound (mg/&)
T = temperature "Kelvin
References

Handbook of Environmental Data on Organic Chemicals - Van Nostrand Reinhold
  Company 1977 (Karel Verschuren)

Handbook of Physics and Chemistry (CRC 58th Edition)

International Critical Tables (Volumes 3,4)

Physical Chemistry (Textbook), Morrison & Boyd, Allyn and Bucan, Inc., Second
  Edition 1966.

"Rate of Evaporation of Low-Solubility Contaminants from Water Bodies to
  Atmosphere," Mackay and Leinonen, Environmental Science and Technology,
  Vol. 9, Number 13, December 1975, pp. 1178 - 1180.

"Interphase Transfer Processes, II, Evaporation Rates of Chloromethanes,
  Ethanes, Ethylenes, Propanes, Propylenes from Dilute Aqueous Solutions
  Comparison with Theoretical Predictions," Wendell L. Dilling, Environ-
  mental Science and Technology, Vol. 11, Number 4, April 1977, pp. 405-409.

"Partition Coefficient and Bioaccumulation of Selected Organic Chemicals,"
  Chiou, Freed, Schmedding, and Kohnert, Environmental Science and Technology,
  Vol. 11, Number 5, May 1977, pp. 475-478.

"Pesticide Manual," British Crop Protection Council, Fourth Edition, 1974.
                                     3-9

-------
                                                FIGURE  3-1
                                PATHWAYS FOR TOXICS MOVEMENT IN URBAN AREAS
             SOURCES
PATHWAYS & TRANSFORMATIONS
  MEDIA
RECEPTORS
HUMAN EXPOSURE
    VECTORS
 I
o
                                                                    RCRA-
                                                                                      Tout* Catin.61.

-------
judgement of their behavior in the more common alternative technology pro-
cesses and techniques.  The loss of toxic organic compounds to the atmosphere
during aeration of wastewater, the transformation of inorganic and organic
toxicants by common biological treatment processes, the adsorbability of
toxicants by activated carbon, and the transformation and effect on selected
inorganic and organic toxicants by soil systems are discussed in the following
sections of this chapter.  The loss of toxic organic compounds to the atmos-
phere during aeration, the transformations during biological treatment and
adsorbability are included since many land application and reclamation
systems include these processes.

     3.3.1   Loss  of  Toxic Organic  Compounds  to the  Atmosphere  During  Conventional
            Wastewater Treatment or Application to Land

In any process of aeration, wherein air-liquid contact is provided, the
opportunity exists for transfer of organic compounds from the liquid phase
to the gas phase.  Thus, in wastewater treatment processes such as aerated
lagoons, activated sludge, fixed film contacting systems or spray irrigation
application systems, the potential of stripping as a removal mechanism for
certain toxic organic compounds should be recognized.  Stripping may be
caused by air-liquid contact due to bubble diffusion, mechanical aeration,
spraying or any point where significant surface turbulence occurs.

In the proposed design, it must be shown that improvement by loss of toxics
to the atmosphere is part of the design and not a happenstance occurrence.
Also, the ultimate fate of the toxics in the atmosphere must be addressed.

The extent of removal of a compound by stripping is governed chiefly by two
factors.  One factor is the tendency of the compound to establish an equilib-
rium between the gas and liquid phases.  This is the principle of Henry's Law
which states that the partial pressure of the compound (a measure of the
concentration in the gas phase) is equal to a constant (Henry's Law constant)
times the concentration of the compound in the liquid phase.  Henry's Law
constant can be considered a partition coefficient which describes the
relative tendency for the compound to partition between the gas and liquid
at equilibrium in accordance with the following equation:


                              H = £i                                (3-1)
        where  H   = Dimensionless Henry's Law constant
               Cg  = Concentration in gas phase
               Ce  = Concentration in liquid phase

Henry's Law constant is a property of the compound which can be calculated
by dividing the compound's vapor pressure (P) by its solubility (S).  H can
also be determined experimentally.  The calculated values for H, vapor
pressure, and solubility for 59 of the 129 priority pollutants are shown
in Table 3-1.  Recently published data on several organic compounds have
shown fairly close agreement between calculated and experimentally determined

                                     3-11

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values.  Temperature obviously affects the value of H, since both solubility
and especially vapor pressure are temperature dependent.   The presence of
electrolytes, surface active agents, lipids and particulate matter in sewage
may all affect the equilibrium to some extent.  Examples  of calculated values
of H at 25°C in clean water, taken from the literature are:  chloroform - 0.16,
carbon tetrachloride - 1.2, 1,2-dichloroethane - 0.05, benzene - 0.22,
DDT - 1.6 x lO'3, dieldrin - 8.2 x 10'6, Arochlor 1260 -  0.29.  Examining
the values for dieldrin and Arochlor, both with very low  vapor pressures, it
is seen that the PCB is much more likely to be stripped than is the pesticide,
because its extremely low solubility (in pure water) results in a fairly
high Henry's Law constant.  A more soluble PCB, Arochlor  1242, has a cal-
culated H of 0.023.  Laboratory experiments using Arochlor 1242 showed only
minimal loss by stripping, in keeping with its low value  of H.  It should
be remembered that very little data are available which experimentally
verify the calculation of H from solubility and vapor pressure.  Thus, the
calculated values should be used with caution.  However,  this calculated
value is at least a tool which can be used to provide an  estimation of a
compound's tendency to be stripped from solution in a given water or waste-
water.

The air-liquid partition coefficient, H, can be determined by fairly simple
laboratory equilibration tests providing analytical methods are available
for the compound of interest in wastewater.  Thus, the amenability of a
compound to removal from any wastewater can be observed.

The removal of a strippable compound depends not only on  its equilibrium
partition ratio but also on the contact opportunity or the intensity and
duration of the aeration.  In a diffused air suspended growth system, the
removal of a compound by stripping can be estimated assuming that the air
leaving the process is saturated with the compound in accordance with
Henry's Law with the process at steady state.  The resulting expression is:


                                                              (3"2)
                         Ci   1 + (Qa/Qi) H

        where  C  is the effluent concentration, mg/1
               C-j is the influent concentration, mg/1
            Qa/Qi is the air to water ratio, m3/hr/m3/hr

As an example, if a suspended growth process is operated at one standard
cubic foot of air per gallon of wastewater, and the partition coefficients
at 25°C given above apply, the removal of chloroform would be estimated at
55%, carbon tetrachloride at 90% and 1-2-dichloroethane at 23%.

Transfer of compounds with high values of H (>0.1) is controlled by the
resistance in the liquid film side of the air-water interface.  Liquid film
resistance also controls the rate of oxygen dissolution during aeration.
Therefore, a reasonable assumption is that the more efficient the aeration
device the more efficient will be the stripping of volatile compounds.

Aerated grit chambers, hydraulic jumps, overflow weirs, clarifier surfaces,


                                     3-12

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turbulent flow in open channels all provide some air-wastewater contact
opportunity and thus have potential for loss of volatile compounds from
solution.

Very little data on removal of volatile compounds by alternative wastewater
treatment processes or processes used as pretreatment for land application
systems are available.  There have been very few compounds for which Henry's
Law constants have been experimentally determined.  The best estimate for
removal that can be made for most compounds now is based on calculated
values of the partition coefficient from published solubility and vapor
pressure data summarized in Table 3-1 and simple mathematical relationships
based on mass balances at steady state.

The above methodology can be used for estimating the relative loss of organic
compounds to the atmosphere from commonly used wastewater aeration systems.
The same procedures may also be used for land application systems where air/
water contact through aerosol formation may be significant.  For these cases,
equation 3-2 would be modified with a similar expression describing the air/
water contact opportunity.

There could be another mechanism involved also, that is, loss of compound by
discharge in the aerosol.  This is probably not significant for the more
volatile compounds but could be for other compounds, especially those that
tend to accumulate at the air-water interface.

     3.3.2   Transformation  of Toxics  Through  Biological  Treatment  Processes
            Used as a Part of Alternative Technology Treatment Systems

In discussing the fate and effects of toxics during biological treatment,
toxic materials can be arranged into two broad classes:  one consisting of
inorganics and the other synthetic organics.

            3.3.2.1  Inorganics

Generally, inorganic toxics are represented by such elements as copper,
nickel, zinc, chromium, lead, silver, arsenic, cadmium, and mercury.  Also
included in this class is the cyanide radical due to its association with
metal plating operations.

Innovative suggestions for enhanced inorganic control should recognize that
certain metals can cycle between several valence states that can influence
removal or concentration of the element through the treatment process,
depending on the prevailing oxidation-reduction level of the process.
Chromium, for instance, exists in the soluble hexavalent form in aerobic
processes and insoluble trivalent chromium in anaerobic environments.
Additionally, elements such as mercury, can cycle between an inorganic form
and a volatile organic form such as methyl mercury.

In the case of inorganics, as well as the inorganics to be discussed below,
the phenomenon of acclimation in biological systems can be encountered.  Upon
the first introduction of a toxicant into a biological  system, a deteriorated


                                     3-13

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performance is noted; however, with continued dosage of the toxicant up to
some upper concentration, the system gains the ability to tolerate the
toxicant and normal performance returns.  Response to the cyanide radical is
typical of this type of toxicant stress.

Generally, biological secondary treatment processes can tolerate up to
5 mg/1 of the inorganic toxicants without noticeable impairment of treatment
efficiency.  The composition of municipal wastewater and the chemistry of
the inorganic toxics is such that re-allocation of the inorganics occurs
during treatment and the materials are conservative in nature.  Thus, if
the inorganics enter the POTW at concentrations of 1 to 5 mg/1 in the raw
wastewater and removal occurs to yield low effluent residuals, the inorganics
will be found in concentrated sidestreams such as primary sludge, waste
biological sludge, digested sludge, digester supernatant, or lagoon bottom
sediment.  Mainly, the inorganics will exist as insoluble products in
these sidestreams or sludge deposits.  Assessment of potentially innovative
technology to enhance inorganic toxics control must be based on the overall
environmental trade-off of low final effluent residuals versus concentration
of the inorganics in the sludge or sludge handling operations of municipal
treatment systems and their subsequent fate during ultimate disposal prac-
tices in accordance with the overall requirements described in Section 3.1.

            3.3.2.2  Organics

The situation with potentially innovative processes for enhanced control of
organic toxics is more complicated than the inorganic class.  In addition
to loss to the atmosphere previously discussed, the organic toxics could
yield the following type response upon introduction into either an aerobic
or anaerobic treatment process:

     1.   Inhibition  - the organic compound  interferes  with  the  proper
         functioning of the biological  process and  treatment efficiency
         deteriorates.

     2.   Non-biodegradability - the organic compound does not effect the
         treatment efficiency but passes substantially unchanged  through
         the treatment system.

     3.   Primary degradation - the biological  process  transforms  the
         organic compound into a different  material  which no longer
         responds to the specific analytical  test  procedure.

     4.   Ultimate degradation - the organic compound is mineralized into
         oxidized forms such as carbon dioxide and  water and cellular mass.

     5.   Acclimation - initial  introduction of the  organic  compounds does
         not show degradation but continued exposure causes a population
         shift which eventually results in  degradation of the toxicant.
                                     3-14

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    6.   Sorption  - the organic compound  is removed from the mainstream  by
         sorption  onto soil particules, primary sludge, or mixed  liquor
         particles without  any biodegradation occurring.

Innovative suggestions will probably center on  controlling one or more of
the above type responses.   Likely candidate process selections or modifi-
cations are as follows:

    1.   Inhibition Control - Aeration  (previously  described)

    2.   Chemical  Oxidation Before  the  Secondary  Process with  Chemicals
         Like  Ozone or Chlorine Dioxide - This  approach is probably  not
         cost  effective due to the  presence of  high concentrations of
         competing organic  materials  in the wastewater.

    3.   Non-Degradable Control -  Likely  suggestions  would be  chemical
         oxidation before the secondary process.  Probably not cost
         effective due to high concentrations of  other organics.   Pre-
         chemical  oxidation might  produce toxic compounds  from innocuous
         materials.   Laboratory documentation of  specified approaches
         should  be furnished.

    4.   Primary,  Ultimate  Degradation  and  Acclimation - Several  control
         approaches can be  considered for enhancing these  reactions.
         Most  will probably center  on sludge  age  (solids retention
         time) control to encourage adaptive  or constitute enzymatic
         population shifts. Also  staged  sequential reactors  to
         manage  the F/M ratios or  environmental conditions for
         isolated  biomass are a likely  suggestion.

    5.   Proprietary  Materials -  There  is an  emerging interest in
         proprietary  materials generically  listed as  biocatalytic
         additives.   These  are specifically prepared  enzyme  and/or
         microorganism cultures packaged  in concentrated form for
         addition  to  treatment processes.   To date  there exists
         very  little  information  on the real  benefit  of these type
         additives.   Any  suggested  innovative process utilizing
         these type additives should  be documented  with results
         of pilot  studies employing adequate  controls.  The  diverse
         life  forms in activated  sludge and the huge  mass  of volatile
         solids  under aeration make it  unlikely that  an  additive
         could economically have  a sustained  beneficial  impact
         upon  treatment  efficiency.

    6.   Sorptive  Materials - Addition  of sorptive  materials such as
         activated carbon may  be  suggested  for  enhanced toxic control.
         The main  decision  point  for these  type approaches will be
         on the  economics of  replenishment  of the sorptive agent
         and/or  its regeneration  to an  active form.  Comprehensive
         analytical documentation of the  fate of  toxics through
         the system would  be  necessary  for  evaluation.

                                     3-15

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     7.   Sorption  -  Primary sludge,  soil  particles,  waste  biological  and
         activated sludges  have  very high surface  areas  which  favor
         sorption  of organics.   Many toxic organics  which  are  only slightly
         soluble can be  sorbed to  these  surfaces and show  removal through
         the  treatment process even  though there was no  biodegradation.
         Pesticides  in particular  have been found  to preferentially
         accumulate  in fat  and grease scum layers.   Schemes  for  enhanced
         treatment of toxics should  be documented  by studies employing
         mass balances of complete treatment systems.

           3.3.2.3   Analytical  Considerations

The priority pollutants  can be classified into five general  groups  (other
than the inorganics and  cyanide) as follows:

     1.   Carcinogenic, potentially carcinogenic  and  teratogenic  compounds
     2.   Polycyclic  aromatic hydrocarbons
     3.   Xenobiotics (new synthesized compounds  such as  pesticides)
     4.   Aromatic  compounds and  their halogenated  and nitro  derivatives
     5.   Halogenated alkyl  compounds

Analytical procedures for mixtures of these materials in trace amounts is at
the frontier stage of development.  Highly specialized equipment such as gas
chromatography and mass  spectrography coupled with computer capability is
necessary for coherent results.   Any proposed innovative process for enhanced
toxic control should be  documented by comprehensive analytical data.  The
laboratory furnishing such data should be certified by the  Environmental
Monitoring and Support Laboratory as to  its capability to perform such
tedious analyses.

     3.3.3 Activated Carbon Used  as a Part of Alternative Technology Systems

It is possible that some reuse/reclamation projects could employ activated
carbon for removal of organic materials  including toxic compounds.   The use
of activated carbon has  been shown to be a feasible unit process for removal
of toxic organic compounds  from water and wastewater.  An additional benefit
of the use of activated  carbon is the safe ultimate disposal of the toxic
compound when the  exhausted carbon is thermally regenerated for recycle.

Activated carbon is a highly porous material having a surface area of
approximately 1,000 square meters per gram.  Adsorption is  a phenomenon
in which the molecules being adsorbed are attached to the surface of the
carbon.  A number  of forces are involved in the adsorption  process.   These
include:

     1.   Attraction  of carbon for  the solute
     2.   Attraction  of carbon for  the solvent
     3.   Solubilizing power of the solvent
     4.   Association
     5.   lonization
     6.   Effect of solvent  on orientation at the  interface
                                     3-16

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     7.   Competition  from other  solutes  in  solution
     8.   Co-adsorption
     9.   Molecular  size
    10.   Carbon  pore  size distribution of the carbon
    11.   Surface area of the  carbon

More recently, it is recognized that biological  activity plays a major role
in the removal of organics  by activated  carbon.

Efficiency of adsorption of organic compounds depends on the relative
adsorbability of the individual components.  Based on the factors listed
above, some generalizations can be made  regarding the adsorbability of
certain compounds.   Solubility of the organic contaminant in water is a
very important factor.   As  solubility decreases, adsorption capacity
increases.  Factors such as pH, concentration,  temperature, and ionic
strength which affect solubility will also affect adsorption.  Molecular
weight and polarity have a pronounced effect.  Usually an increase in
molecular weight improves adsorption.  Non-polar molecules are more
strongly adsorbed than polar molecules.   Molecular structure is another
important factor.  The influence of substituent groups on adsorbability
can be described in general terms.  Hydroxyl usually reduces adsorbability
because of increased polarity.  Amino groups have a similar but greater
effect than hydroxyl.  Many amino acids  are, in fact, not adsorbed to any
appreciable extent.  Carbonyl groups have a variable effect depending on
the host molecule.   Sulfonic groups are  polar and decrease adsorbability.
Nitro groups often increase adsorbability.   Generalizations based on
molecular structure can also be made.  Aromatic and substituted aromatic
compounds are,  in general,  more adsorbable than aliphatic compounds.  Amines,
ethers, and halogenated aliphatic compounds adsorb more efficiently than low
molecular weight alcohols,  glycols, or low molecular weight straight chain
unsubstituted aliphatic compounds.

The quantitative effect of the factors discussed above can be expressed by
the Freundlich  adsorption equation:

                            X/M  =  KCf1/"                      (3-3)

        where:  X =  C0-Cf which is the amount of compound adsorbed from a
                     given volume of solution
                M    is the weight of carbon
                C0   is the initial amount of compound in the untreated solution
                Cf   is the amount of compound remaining after carbon treatment
                K and 1/n are empirical  constants

Graphically, K  is the X/M intercept of the  isotherm plot at  Cf  =  1 and 1/n
is the slope of the  line when the equation  is plotted on logarithmic paper.
The intercept is roughly an  indicator of adsorption capacity and  the slope
of adsorption intensity.  The concentration of compound on the  carbon in
equilibrium with a concentration Cf is expressed by the X/M  value.  Since
X/M values are  dependent on the initial concentration of compound, comparisons
among compounds must be made  at similar concentrations.

                                     3-17

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The effect of substitutions on the benzene ring on adsorption capacity is
illustrated in Table 3-2.

Many of the compounds identified as pesticides and herbicides on the
Environmental Protection Agency's List of Priority Pollutants are chlori-
nated aromatic hydrocarbons.  This group of compounds is readily adsorbed
on activated carbon.  Table 3-3 presents a summary of adsorption capacities
at an initial concentration of 0.01 mg/1.

Adsorption capacities for several chemical carcinogens are summarized in
Table 3-4.  Polynuclear aromatic hydrocarbons, many of which are known
carcinogens, are also strongly adsorbed on carbon.

Although activated carbon is very efficient for removal of many types of
organic compounds from wastewater, it does not remove all classes of com-
pounds.  Table 3-5 lists some compounds which are not appreciably adsorbed
by activated carbon.

Inorganic compounds also exhibit a wide range of adsorbability.  Strongly
dissociated salts, such as sodium chloride, are not adsorbed by activated
carbon.  Iodine, gold permanganates, dichromates, mercuric salts, molybdates,
ferric salts, arsenates, and silver salts are adsorbed on activated carbon.
Some of the metal salts are actually chemically reduced to elemental metal
by activated carbon.

In summary, adsorption on activated carbon is an effective method for re-
moval of many of the toxic compounds on the list of priority pollutants.

     3.3.4  The  Fate and Effects of Toxic Substances  on Soil

            3.3.4.1   General

Toxic substances which are present in wastewater can find their way into
soil by means of land application of effluent, sludge, and septage after
various stages of treatment.  The regulations published on September 13,
1979, "Criteria for Classification of Solid Waste Disposal Facilities,"
do not affect land application of municipal effluents or location or oper-
ation of septic tanks but do affect in a major way the land application of
sludges and septic tank pumpings/septage.  The following discussion addresses
both as sludge.   Also, discussion is on sludge application rather than
application of effluents since many of the same principles are applicable
to both practices.  For more information on land treatment and disposal of
wastewater, refer to the process design manual for Land Treatment of Municipal
Wastewater, October 1977.
                                     3-18

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                                  TABLE 3-2

       ADSORPTION CAPACITIES FOR BENZINE AND SUBSTITUTED BENZENES (2)
COMPOUND
                                  STRUCTURE
      ADSORPTION CAPACITY (mg/g)(l)
BENZENE
                                                               0.7
PHENOL
ETHYLBENZENE
NITROBENZENE
                            >- OH
                                       H    H
                                      C
                                      i
                                      H
C -H
i
H
                  21
                                                              53
                                                              68
CHLOROBENZENE
                                      Cl
                                                              93
STYRENE
                         c-
                             LH
                  120
                                          Cl
1-CHLORO-2-NITROBENZENE
                                                             130
(1)  Measured at 1  mg/1  initial  concentration

(2)  R. A. Dobbs, R.  J.  Middendorf and J.  M.  Cohen
     "Carbon Adsorption  Isotherms for Toxic Organics,"
     Municipal Environmental  Research Laboratory
     U.S. Environmental  Protection Agency
     Cincinnati, Ohio  45268   (May 1978).
                                    3-19

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                                  TABLE 3-3

    ADSORPTION OF PESTICIDES AND RELATED COMPOUNDS ON ACTIVATED CARBON (2)
COMPOUND
                                  STRUCTURE
                        ADSORPTION CAPACITY
q
ALDRIN X

k

H ICl
x*x
1
N 3.5
Cl
' Cl
C1 -S
DIELDRIN 0 [H
X/

N-ci
Cl] 9.3
^ n
ENDRIN
DDT
ODD
DDE
                                           Cl
                               Cl
Cl
               CHC1,
                                                      Cl
                  Cl    Cl
                                    24
                                     7.3
                                                              27
                                     4.8
TOXAPHENE


AROCLOR 1242



AROCLOR 1254

ci 2
^U

r
\j
Cl



Cl
LI Cl
21

Cl
IV \-/ \ 19
\ 	 / \ /
— ^ci

6

(1)  Measured at 0.01  mg/1 initial concentration

(2)  F.  Bernandin, Jr., and E. M.  Froelich, "Practical Removal of Toxicity by
     Adsorption," Presented 30th Annual Purdue Industrial Waste Conference,
     Purdue University, Lafayette, Indiana, May 8-9, 1978
                                    3-20

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                                 TABLE  3-4



              ADSORPTION CAPACITIES  FOR CHEMICAL CARCINOGENS
COMPOUND
      STRUCTURE      ADSORPTION CAPACITY (mg/g)(l)
NAPHTHALENE
                                169
1, 1-DIPHENYLHYDRAZINE
                                150
3-NAPTHYLAMINE
4-4'-METHYLENE-BIS

(2-CHLOROANILINE)
         GO
   Cl      H     Cl


HoN f~Vc -f
                                 10
                                240
o
<-  x=
BENZIDINE
               NH
                                173
(1)   Measured  at 1.0 mg/1 initial  concentration
                                   3-21

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                                  TABLE 3-5


               COMPOUNDS NOT ADSORBED BY ACTIVATED CARBON (1)


                             Di methylni trosami ne

                             Acetone Cyanohydrin

                             Butyl amine

                             Choline Chloride

                             Cyclohexylamine

                             Diethylene Glycol

                             Ethylenediamine

                             Triethanolamine

                             Ethanol
               (1)  R. A. Dobbs, R. J. Middendorf and J. M. Cohen
                    "Carbon Adsorption Isotherms for Toxic Organics,"
                    Municipal Environmental Research Laboratory
                    U.S. Environmental Protection Agency
                    Cincinnati, Ohio  45268  (May 1978).
Application of sludge to land, especially agricultural lands, must be examined
in terms of protection of human health and future land productivity.  This
is due to the present limited knowledge as to the full extent to which this
practice could result in the entry of toxics substances in toxic amounts
into the human food chain.  There is strong potential for improved toxics
management of alternative technologies in these areas.  Better management
of the toxic substances listed in Table 3-1 would qualify as innovative;
however, the September 13, 1979 regulations establish maximum acceptable
levels of two toxic substances—cadmium and PCB's.  These should be addressed
as minimum requirements.  Better management of toxic substances could be an
improved method of meeting these minimum criteria.

Significant quantities of potentially toxic substances can be applied to
soil without developing phytotoxicity, producing crops with harmful concen-
trations or causing ground or surface water pollution or contamination if
municipal sewage sludge is applied at fertilizer rates and good crop and
soil management practices are followed.  Proper sludge disposal practice
has the benefit of providing a soil conditioner and conserving and recycling
                                     3-22

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organic matter, N, P, and trace elements.  In recent years, the intentional
application of persistent pesticides and the incidental application of indus-
trial compounds and elements that are potentially toxic to plants, animals,
or man have occurred without adequate research to define the ultimate effects.
Municipal wastewater sludge can be applied to soil, but it should be done in
a way that will preserve the present and future integrity of soils and protect
them from impairment of their capacity to produce a wide variety of adapted
crops and protect public health.  Beneficial use of sludge will require
careful sludge and site selection and site management.  Following the require-
ments of the September 13, 1979 regulations and the guidance provided in the
Sludge Management Bulletin ("Municipal Sludge Management:  Environmental
Factors, EPA 430/9-77-004; October 1977; MCD-28 and various Agency technical
reports) will help to insure that sludge is applied in a safe and beneficial
manner.

           3.3.4.2  Site  Selection  for Improved  Toxics Management

A soil performs many functions that are important to its role as an assimilator
of wastes.  It transforms wastes by chemical, physical, and biological means.
It filters, buffers, and adsorbs.  The efficiency with which the soil accepts
and transforms toxic wastes into innocuous or beneficial compounds and elements
is determined by  its physical and chemical properties.  The soil is a natural
body at the earth's surface that supports or is capable of supporting plant
growth.  It consists of a complex mixture of organic and mineral matter, air,
and water.  Optimum conditions for plant growth exist when pore space con-
stitutes about half of the soil.  The soil is inhabited by a heterogenous
population of organisms including bacteria, actinomycetes, fungi,  protozoa,
algae, micro and macro animals, and higher plants.

Careful site selection can prevent many of the problems that can result from
an improperly designed and managed system.  Soil properties vary widely, so
it is important to manage wastewater and sludge utilization sites according
to soil characteristics.

An ideal site for improved management of sludge borne toxicants would have
the following soil, geologic, and landscape characteristics:  (Careful
engineering design and site management can compensate for some undesirable
characteristics):

     1.   Gentle slopes  that  are short  with  a closed drainage system
     2.   Moderate infiltration  rate
     3.   Permeable to water  and roots
     4.   Thick  soil  with  no  zones  that remain  saturated for  extensive
         time  periods,  and no highly porous material  within  a depth
         of five  feet
     5.   High  cation adsorption capacity.   Soils high  in  organic
         matter and  cation exchange  capacity have  substantial  capacity
         to adsorb cations and  prevent increases of available metals  in
         the soil  solution.
                                     3-23

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     6.  Neutral to moderately alkaline pH.
     7.  Well-drained soil with high moisture-carrying capacity

The  steepness,  length,  and shape of  slopes  influence  the rate of runoff  and
thus the risk of erosion  from  a tract  of  land.  Slopes of  less than 3% are
desirable.  Those  of 3% to 8%  present  some  risk of erosion and require some
soil erosion control conservation practices.  Slopes  steeper than 8%  should
be used only with  a carefully  designed system to control runoff and erosion.

In addition to  the above, an ideal site would be remote from public access
or water supply.   Also, the future use of  the site beyond  the expected life  for
application purposes would be  considered.

     3.3.4.3   Effect of Soil  Properties  on Fate of Organic and
               Inorganic Toxicants

Physical, chemical, and biological properties of soils help determine their
capacity to assimilate  wastewater and  sludge constituents  and attenuate
their  pollution potential.  The following  basic properties determine water
intake and movement; moisture-air relationships; availability, adsorption,
and movement of some nutrients and other elements; and plant root distribution
under  given climatic and  land  use conditions.

Texture is an important consideration for selection of a site for sludge
spreading.   The proportion of sand,  silt, and clay strongly influences moisture
holding capacity,  permeability, infiltration rates, and adsorption capacity.
Clay has a much greater surface area than the silt or sand, so it gives to a
soil  the capacity to adsorb ions and hold moisture.  Most physical and chemical
reactions in soils are determined by the  amount and kind of clay and organic
matter present.

Bulk density, porosity, and soil  structure strongly influence water and air
movement, moisture-holding capacity, and  plant root distribution.   Cation
exchange capacity, pH, the percentage of  cation exchange sites occupied by
bases, and the kinds of ions adsorbed influence the acceptable application
rate and the effects of many sludge components when they are added to soil.

The rate at which soils will  take in water is a function of the size, shape,
and number of their pores.  Fine-textured soils have many pores, but they
are usually small  and disconnected and transmit water slowly, whereas coarse-
textured soils have fewer pores that are  larger and may be continuous, thus
water can infiltrate more readily.    Infiltration in fine  and medium-textured
soils  is influenced by tillage and soil management practices.  Proper tillage
will help break crusts  and create a  roughness and porosity of the soil surface
that favors infiltration.  A dense vegetative cover protects the soil surface
from sealing due to direct impact of water droplets.  Organic matter in the
surface soil promotes aggregation,  increases infiltration, and provides slow
release nitrogen for plant growth.

The permeability of subsoils varies with texture, structure, density, and
porosity.  Restricted permeability in a subsoil layer may cause poor drainage
and saturated zones above the  restrictive  layer which may result in runoff

                                      3-24

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and/or erosion.  Temporary anaerobic conditions have a potential for causing
odors and plant toxicity.  Drainage systems may be needed if sludge is applied
to poorly drained soils.  If soils with poor natural drainage are used, adverse
effects can be minimized by applying sludge when the soil is dry.  Coarse,
sandy, and gravelly soils are usually rapidly permeable; however, they gen-
erally transmit water very rapidly and may not remove all of the suspended
materials before they reach groundwater.  Adsorption of nutrients, metals,
and organisms is generally limited.  The available moisture-holding capacity
of these soils is low.

Depth of soil that is favorable for adsorption of elements, pathogenic orga-
nisms, and organic substances is an important consideration.  The distribution
of plant roots in the soil is also important.  With nearly neutral pH and no
inhibiting chemical conditions, many plants extend their roots to a depth of
three feet or more in well aerated, permeable soils.  Soils that inhibit
root penetration may cause greater plant uptake of metals.  The most severe
limitations of soil depth are caused by bedrock, coarse sand and gravel, or
a high water table.

Soil cation exchange capacity (CEC) is a measure of the net negative charge
and is expressed as   milli-equivalents   (meq) per 100 g of soil.  Soil CEC
has been proposed as a measure for controlling metal applications to soil,
although it is a nonspecific sorption reaction.  The general consensus is
that only a small proportion of the metals (Cd, Cr, Cu, Pb, Hg, Ni, and Zn)
take part in cation exchange reactions between soil and soil solution.

Additionally, sorption studies with intact soil and soil components indicate
that sorption sites with higher activation energies than that of cation
exchange are involved.  Further, it has been shown that removal of metals by
soil materials in greater quantities than the CEC does occur.  It becomes
evident then that the CEC itself is not the controlling factor in metal
retention in soil.  However, the CEC of the soil may permit a first approx-
imation of the soil's ability to retain metals in insoluble forms because it
acts as a temporary storage system for soluble ions and represents a rough
indicator of the clay and organic matter content of the soil (which are
important in precipitation and sorption of metals).

The organic fraction of soils has a significant effect on the solubility of
heavy metals and organics in soils.  This conclusion is the result of the
observations that:  (a) humic and fulvic acids (the complex heterogenous
mixture which is the nucleus of soil organic matter) and plant extracts
exhibit chelation tendencies; (b) biochemical compounds having chelating
characteristics are continuously produced and degraded in soils; and (c) sorp-
tion of heavy metals and organics is often related to the organic matter con-
tent of soils.

The management of soil organic matter is important because of its involvement
in the chemistry of metals and organic toxicants in soil.  Production prac-
tices (crop rotation, manure crops, organic matter addition, etc.) which
maintain or add organic matter to soil should reduce the solubility of
metals.
                                     3-25

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Superimposed on the aforementioned  soil  variables  is  the  soil  pH.   Soil  pH
has a significant effect on the other variables.   It  has  been  demonstrated
numerous times that soil pH has a significant  effect  on heavy  metal  adsorp-
tion and uptake by plants.   This pH effect  could be the result of  the
decrease  in solubility of  metals as the pH increases.  Figure 3-2  which
shows the effect of solution pH on  soluble  Cd  concentration  in the  presence
of various solid phases and demonstrates the interaction  between soil
material and pH on sorption of Cd.   These data provide an understanding  for
the observations that the Cd content of  crops  is a function  of pH  in that as
the pH is increased,  the concentration of Cd in the plant tissue decreases.
Soil pH can also affect virus removal.   As  a general  rule, viruses  are readily
desorbed by a high pH.   Virus absorption and removal  by soil is therefore
reduced as the pH increases above 7.0.   The optimum pH for soil treatment
and disposal systems  must include both toxics  management  and public  health
considerations.  Disease control requirements  are  described  in the  9/13/79
RCRA and BPT regulations.

                                 FIGURE 3-2

                 DISTRIBUTION OF Cd BETWEEN SOIL MATERIAL AND
                   EQUILIBRIUM SOLUTION  AS  A FUNCTION OF  pH
        25 T
         20 -•
      en
      ZJ
      U
         15 --
      Q  10 +
      H-
      ID
      o
      (S)
          5  ••
                                                           CONTROL
ILLITIC CLAY SOIL
                     —t-
                      4
                           6

                          PH
8
                                     3-26

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     3.3.4.4   Addition  of  Inorganic  Elements  in  Sludge  to Soils

Many elements are not of much environmental significance because of their
low concentrations in sludge, low solubility, strong adsorption by soils,
low tendency to be taken up by plants, or low toxicity to plants and animals.
Unusually high concentrations of elements in sludge, poor site selection,
and poor site management could render the application of less significant
elements hazardous.  Elements of most concern are cadmium, copper, molybdenum,
nickel, and zinc.  Copper, nickel, and zinc are of concern because when
added at high levels to soil, they can become available to plants in concen-
trations that are toxic to the plant.  Cadmium is of concern because it is
taken up by plants and may increase the dietary cadmium intake of animals
 and  man.   Cadmium accumulates  in  the kidney  and  liver  of humans  and  may
 constitute a health  risk.   Cadmium  is controlled  by the  9/13/79  (RCRA)
 regulations.   Lead is  an  accumulative poison  that is strongly
 adsorbed  by  soils,  but  could be  a problem  from  direct  ingestion  of  surface
 contaminated crops.

 The  principal  pathways  of  the  toxic  substances  are  the contamination of
 soil  causing:  (a)  plant uptake or uptake of  soil  directly by animals and
 transmission through the  food  chain  to humans;  (b)  runoff and contamination
 of  surface water;  or  (c)  leaching  and contamination of  groundwater.   Metals
 in  sewage  sludge added  to  soil generally have not leached significantly.

 The  complexity of the  reactions  of metals  in  soil  and  the difficulty in
 making  precise predictions of  their  fate is  illustrated  in Figure 3-3.
 Mechanisms for removal  of  the  metals from  the soil  include plant  uptake,
 leaching,  and  volatilization.

 The  form  of  the metal  added  (sulfide, hydroxide,  carbonate,  phosphate,
 etc.)  will have a significant  effect on  its  initial  solubility  in soil
 and  therefore  its  initial  impact  on  plant  growth.   Crop  yields  have  been
 affected  more  by inorganic metal  additions than  by  the addition  of  an
 equivalent amount  of metals  from  a  sewage  sludge.

 The  adverse  effects  of  potentially toxic constituents  of sludge  can  be
 controlled by  good management  practices  such  as:  (a) controlling  the rate
 and  amount of  sludge application;  (b) controlling soil  pH;  (c) maintaining
 organic matter at  high  levels;  (d) selecting  crops  that  exclude  the  elements
 of  concern;  and  (e)  using soil  conservation  practices to control runoff
 and  erosion.

 In  terms  of  recycling,  the rate  of sludge  application  that has  been  his-
 torically  recommended  is  based on supplying the  nitrogen  needs  of the  crop.
 Sludges vary in nitrogen  content  and crops vary  in  nitrogen  requirement,
 but  the annual  sludge  application to supply the  available  nitrogen that
 would  be  supplied  by mineral  fertilizer usually  ranges between  5  and 40
 metric  tons  per hectare.   However, the rate and  amount of  applied sludge
 cannot  violate the 9/13/79 regulations,  i.e., cadmium  and  PCB controls
 are  needed.   Other toxic  substances  should also  be  controlled as  appropriate.

 Total  accumulative metal  loadings based on a  cation exchange capacity  of

                                      3-27

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soils, and controlled soil pH  6.5 is shown in Table 3-6.
the limits are different.   Lower rates are preferred.
                            For pH   6.5,
                                 FIGURE 3-3
                    PATHWAYS OF TOXIC SUBSTANCES IN SOIL
WASTE ADDITION
                                                              RUN OFF TO
                                                             SURFACE WATER
     EXCHANGEABLE IONS
        AND SURFACE
        ADSORPTION
                        SOLID PHASES
                            AND
                          MINERALS
      MICROORGANISMS
           AND
        CHELATES
                        PLANT UPTAKE|
                  LEACHING
                                        CROP REMOVAL
                                     3-28

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                                 TABLE 3-6
   ACCUMULATIVE METAL LOADINGS BASED ON CATION EXCHANGE CAPACITY OF SOILS
                       FOR SLUDGE APPLICATION TO LAND

               Soil cation exchange capacity (mi11iequivalent per 100 g) (a)
Metal               0-5	      5-15	^              15
                   Amount of metal (kilogram per hectare^
Pb
Zn
Cu
Ni
500
250
125
50
1,000
500
250
100
2,000
1,000
500
200
      Note:   For information on land disposal  and treatment of
              wastewater refer to the EPA Process Design Manual
              for Land Treatment of Municipal Wastewater,
              October, 1977

 Cadmium (Cd) is specifically controlled by regulation, and in this respect,
 the new (9/13/79)  RCRA requirements update all  previous recommended limits
 for Cd.  The regulation includes two approaches for the control  of Cd.
 Under the first approach,  controls are placed  on both annual  application
 rates and the maximum cumulative loadings.  The pH must be at 6.5 or more
 at the time of each application (unless Cd is<2 mg/kg in the sludge).   The
 annual application rate for accumulator crops  (tobacco, leafy, or root
 crops for human consumption) shall not exceed  0.5 kg/ha.  The annual  rate for
 other crops will be phased until, by 1/1/87, the rate limit will  also be
 0.5 kg/ha.

 Limits on cumulative loadings depend on pH of  the soil.  If the  background
 pH of the soil is£6.5, or where natural soil  background is pH<6.5 but
 safeguards exist at the site which will assure  pH will be maintained£6.5
 for as long as food chain  crops are grown, the  maximum limits vary from
 5 to 20 kg/ha, depending on the soil cation exchange capacity.  In all
 other situations,  the maximum cumulative loading may not exceed  5 kg/ha.

 The second approach allows unlimited application of Cd provided  that:  the
 crop is only grown for use as animal feed; the  pH must be maintained at
 26.5 as long as food chain crops are grown; an operating plan must be
 developed describing how the feed will be distributed to prevent  human
 ingestion and describing measures to prevent Cd from entering the human
 food chain from alternate  future land uses; future homeowners must be
 provided notice that there are high Cd levels  in the soil and that food
 chain crops should not be  grown.
                                     3-29

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     3.3.4.5  The Fate and Effects of Toxic Organic Wastes Added to Soils

A great number of organic pesticides have been used in agriculture with
great advantage to society.  Organic substances used in industries, many of
which are recognized toxicants, are discharged into sewers and find their
way into municipal sludge and ultimately are applied to soils.  Only
recently have aggressive studies been initiated to identify the toxic organic
substances in sludge.  Some of the known organic constituents of sludge
that are potentially toxic include:  (a) phenolic compounds (b) chlorinated
hydrocarbons  (c) chlorinated biphenyls  (d) detergent residues, and  (e)
petroleum residues (3).  Many of the organic compounds are reduced during
wastewater treatment by biologic activity, volatilization or adsorption as
previously described.

The pathways by which organic substances in sludge applied to cropland
could reach animals and man includes:

     1.  Volatilization and rainout on land or water
     2.  Plant uptake from soils by food chain crops or direct ingestion
         of soil
     3.  Contamination of soil leading to phytotoxity
     4.  Leaching into aquifers used for water supply

The soil may adsorb, precipitate, transport, or decompose toxic organic
substances.  The degree of adsorption depends upon the characteristics of
the soil and the adsorbate.  Some of the most important soil properties
favoring adsorption are large surface area, high organic content, and high
cation exchange capacity.  Some characteristics of the organic substance
that affect it's adsorption are molecular size and structure, pH, water
solubility, and polarity (4).  The organic substances may be degraded
photochemically, chemically, or microbially.  Photochemical decomposition
occurs while the chemical is at the soil surface and may play a minor role
in degradation of sludge born toxic organics.  Chemical decomposition is an
important and widespread phenomenon.  It is a complex process that is
influenced by soil properties and properties of the organic substance.
Microbial decomposition plays an important role in soil attenuation of
toxic organic substances.  Extensive research on pesticides has shown that
soil microbes can degrade even those considered to be persistent and
relatively non-biodegradable.  Some of the important soil factors
determining rate of degradation include soil moisture, pH, temperature,
organic matter content, redox potential and nutrient availability.  The
chemical nature of the organic substances also determines the decomposition
rate.  Of most concern for sludge applications are the persistent organics
which resist degradation and accumulate in the soil when they are applied
at high rates.  Phenolic compounds are rather stable, but they have been
shown to decompose biologically when the soil adsorbs the compound and
allows sufficient time for microbial activity (3).  Chlorinated hydrocarbon
pesticides also degrade biologically when present in soils at low concen-
trations.

Persistent pesticides and PCBs are relatively stable and strongly adsorbed
by soils.  They are sorbed by plant roots and transmitted to areal portions

                                    3-30

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at negligible rates.  Organics present more of a hazard from direct ingestion
than from plant uptake, so direct ingestion of sludges by dairy animals
should be avoided  (5).

The application of sewage sludge containing low levels of pesticides or
PCBs and other toxic organic substances from industrial discharges should
not pose a reasonable probability of adverse effects on health or the
environment when sludge is applied according to the 9/13/79 RCRA regulations
and the EPA Sludge Technical Bulletin.  There is not enough experimental
data to justify applying sludges high in toxic organics, to poor sites, or
under poor management.  The 9/13/79 RCRA regulations control the applica-
tion of sludge containing PCBs.  Sludge containing concentrations of PCB
210 mg/kg (dry weight) must be incorporated into the soil when applied
to land used for producing animal feed including pasture crops for animals
raised for milk.   Incorporation is not required if the PCB content^O.2 mg/kg
(actual weight) in animal feed or less than 1.5 mg/kg (fat basis) in milk.


3.4  Increased Environmental Benefits

     3.4.1  General

Projects or subsystems identified as alternative technology may be determined
to be innovative as a result of increased environmental benefits.  Unlike
the cost and energy criteria, Agency regulations do not provide specific
numerical comparisons between the environmental  impacts of the alternative
approaches and baseline technology.

The inclusion of the "increased environmental  benefits" criteria for alter-
native technologies recognizes the need to consider the trade offs between
environmental effects and other evaluation criteria.  The analysis of
improved environmental benefits for proposed innovative portions of alter-
native projects should be done at the same time and within the context of
the overall environmental assessment and analysis activity.

The level of detail must be increased and reporting format modified specifi-
cally to compare the benefits of potentially innovative to non-innovative
processes.  Added benefits attributed to innovative designs must be separately
identified and documented.

Environmental effects should be considered in  alternatives design, eval-
uation, and plan selection (7, 13).   Such environmental assessments should
include not only the relative contribution to  water quality enhancement,
but also other related primary and secondary environmental impacts such
as: (a) air quality; (b) public health; (c) water supply; (d)  land use
(including induced growth); (e) aesthetics; (f)  housing availability; and
(g) sensitive areas.   Socio-economic considerations such as changes in
employment and population characteristics should also be included in the
analysis (8,  9).   Environmental effects that occur: (a)  during construction;
(b) under normal  facility operations; and  (c)  under various system failure
conditions should be identified and  evaluated.   The expected frequency and


                                    3-31

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duration of such failure conditions should also be estimated.   The identifi-
cation of potential environmental effects should be used to improve system
design and to develop emergency control and other methods to mitigate adverse
environmental impacts.

In general, environmental impacts may be associated with project siting,
sizing, phasing, construction methods and materials, treatment and disposal
options, and proposed methods of operation and maintenance.  Only those
impacts which are deemed to be relevant to the total project comparison
of potentially innovative and non-innovative alternative systems or system
components should be highlighted.  These factors will vary significantly
among proposed innovative projects.  Therefore, as appropriate during
Step I and 2 preparation, the design engineer should identify relevant
criteria for the consideration of environmental benefits of the potentially
innovative portion of specific projects.  Similar criteria may be developed
for other alternatives.  The state and EPA regional project engineers
should review the appropriateness of the identified environmental criteria
and assessment techniques for the individual applications submitted.

Appendix E of the regulations lists five specific examples of potential
environmental benefits that could be derived:  (a) water conservation;
(b) more effective land use; (c) improved air quality; (d) improved ground-
water quality; and   (e) reduced resource requirements for facility construc-
tion and operation.  Each of these potential benefits should be assessed
in addition to other potential environmental impacts outlined in more com-
prehensive Agency environmental assessment guidelines.

Water conservation practices should include consideration of methods or
techniques over that required in the Cost Effectiveness Analysis Guidelines
where these approaches are practicable.  More effective land use should
include:

     1.  Growth management and other regulatory measures to minimize
         induced growth and adverse secondary impacts of development
         (i.e., more efficient land development patterns)

     2.  Increased agricultural productivity (increased yields through
         nutrient additions)

     3.  Protection of environmentally sensitive areas (e.g., floodplains,
         aquifers, prime agricultural areas, historic and cultural  areas,
         wetlands, habitats, recreation  areas)

     4.  Relative consumption of land for the wastewater system

     5.  Erosion control

     6.  Potential off site "nuisance" factors for  land uses abutting  the
         facility  (e.g., odor, noise, dust, glare,  traffic)
                                     3-32

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Air quality impacts should normally consider potential discharges resulting
from evaporation, stripping, volatilization, incineration, and aerosol
effects, as well as automotive air pollutants associated with resultant
development patterns and more specific transport requirements of alter-
native treatment and disposal practices.  Consideration of groundwater
should include estimation of relative expected changes in quantity,
quality, and flow characteristics resulting from contamination from landfill
leachate, infiltration from land application, as well as replenishment
benefits (e.g., water supply, prevention of salt water intrusion, subsidence
protection).  Relative resource requirements should be considered both for
construction and operation,   including chemicals, construction materials,
energy, and manpower.

Potential environmental impacts are generally identified on the process
fact sheets in Appendix A in this manual.  The design engineer should
identify in more detail relevant environmental impacts.  The reader should
be aware, however, that the estimated impacts from a particular project
will depend upon specific design characteristics and various local con-
ditions.  The state and EPA regional reviewers should very carefully examine
the specific process and site designs proposed.   With regard to many of the
potential environmental effects described above, proper siting and design
of an installation is far more important than a non-site specific comparison
of generic technologies.

Although an alternative may rate high in one or more environmental effect
categories, it may, at the same time, rate low in others (10).  Therefore,
it is necessary to determine the "net environmental benefits" (15).  The
user may find appropriate the use of a scalar rating system with both positive
and negative values (benefits and costs) (11).  In addition, to reflect the
relative importance of various factors, varying weights may be assigned
(12, 14).  The design engineer should clearly identify and justify his
selected technique for comparing the innovative and non-innovative application
of the alternative technology.  (Note that the engineer will have previously
conducted a broader environmental assessment for all alternatives considered
during Step 1.)  For each relevant environmental criteria, the design engineer
should document the environmental impacts for both the baseline alternative
technology and the proposed innovative application(s) using a comparison
matrix similar to that shown in Table 3-7.

3.5  Improved Joint Treatment of Municipal and Industrial Wastes

     3.5.1  General

Alternative technology that provides for new or improved methods of joint
treatment and management of municipal and industrial wastes discharged into
municipal systems may qualify as innovative technology.

Improved joint treatment refers to: (a) treatment of industrial wastes
discharged into municipal wastewater collection systems for treatment at
Publicly Owned Treatment Works; and  (b) the joint treatment and disposal
of municipal and industrial residuals resulting from the joint or independent

                                    3-33

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                                                   TABLE  3-7


                       IMPROVED  ENVIRONMENTAL  IMPACT  COMPARISON  MATRIX


                                                           Control  Alternatives (1)

                           	Baseline	Innovative  "ft"	Innovative "8"	Etc.

Environmental  Impacts  (2)     Weight     Score     Weighted     Score     Weighted     Score     Weighted
                               (3)       (4)      Score (5)               Score                  Score

 A.  Water Conservation
     Criteria  1
     Criteria  2
     Etc.


 B.  Effective Land  Use
     Criteria  1
     Criteria  2
     Etc.


 C.  Air Quality
     Criteria  1
     Criteria  2
     Etc.


 0.  Groundwater
     Criteria  1
     Criteria  2
     Etc.


 E.  Resource  Requirements
     Criteria  1
     Criteria  2
     Etc.


 F.  Other
     Criteria  1
     Criteria  2
     Etc.
TOTAL NET  SCORE
Notes:

(1)  The innovative applications of the  alternative technology being  considered must be clearly described  in  the
     facilities plan text.  There may be more than one proposed innovative application for a specific subsystem.
     If there  are several different innovative proposals, each should be  compared separately with the appropriate
     baseline  alternative technology.

(2)  The five  environmental impact categories listed in Appendix E should be considered as a minimum.  The relevant
     aspects of each of these impact categories for the specific alternative technology should be identified  by the
     design engineer.

(3)  The relative importance of this environmental impact criteria should be assigned by the design engineer.  Weights
     are best  set by allocating a given  number of points (e.g., 100)  over the entire set of impact categories.  The
     engineer  may first want to determine  the relative importance of  the  impact categories and then distribute those
     points within each category.

(4)  Different scoring systems are possible.  Recommended is the following:     +2  very positive benefit
                                                                             +1  positive benefit
                                                                              0  little or no impact
                                                                             -1  negative effect
                                                                             -2  very negative effect

(5)  Product of the raw score and the associated criteria weight.


                                                        3-34

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 treatment  of  liquid wastes.


 Facility plans  qualifying  for  innovative technology under  this criteria
 must meet  EPA's  General  Pretreatment  Regulations,40 CFR, Part 403,  for
 existing and  new sources of  pollutants  promulgated under Section  307 of the
 CWA of  1977,  and must document  the  specific  improved joint  treatment
 benefit compared to non-innovative  alternative wastewater management
 approaches.

 Improved joint  treatment efficiency may result from the use of industrial
 waste or waste  products  to improve  municipal collection, treatment, or
 residual disposal efficiency as well  as the  use of municipal residuals for
 improved industrial waste  processing  and residual disposal.

 Examples of the  more common  potential beneficial industrial/municipal
 recycling  and joint treatment  opportunities  are listed below:

     1.  Use  of  industrial waste heat to improve liquid or  solids
         processing efficiency.

     2.  Use  of  high nutrient  industrial waste to supplement
         nutrient deficient  municipal wastes or vice versa.

     3.  Addition of industrial liquid  wastes or residuals to
         control  or alleviate  corrosion of municipal collection systems.

     4.  Use  of  industrial wastes or  by-products as organic supplements or
         treatment aids  for  biological  treatment processes.

     5.  Use  of  industrial waste products as source of chemical additives
         or bulking agents for  physical, chemical, or biological  liquid or
         residual processes.

     6.  Co-mixing or neutralization  of combinations of industrial  and
         municipal wastes  to improve  treatment efficiency or reduce the
         need for auxiliary  sources of  energy.

     7.  Industrial use of municipal  treatment residuals.

     8.  Use of  industrial waste products to alleviate municipal treatment
         process  operating problems or  improve treatment efficiency.

The above  list is intended to  illustrate potential beneficial joint treat-
ment opportunities and in  no way should be considered inclusive.  The overall
objective  is to  encourage  joint industrial/municipal wastewater management
facilities that  maximize cost effectiveness of treatment, equitably dis-
tributes the cost, and achieves improved management and control of toxic
materials  and industrial wastes.
                                    3-35

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3.6  References

1.  Ryan, J. A., "Factors Affecting Plant Uptake of Heavy Metals from Land
    Application of Residuals," In:  Proceedings of National  Conference on
    Disposal of Residues on Land

2.  Witty, J. E., and Flach, K. W., "Site Selection as Related to Utilization
    and Disposal of Organic Wastes," Soils for Management of Organic Wastes
    and Waste Waters, Soil Science Society of America, American Society of
    Agronomy, Crop Science Society of America, Madison, Wisconsin, 1977,
    pgs. 327-345

3.  Miller, R. H., "The Soil as a Biological Filter," Recycling Treated
    Municipal Wastewater and Sludge Through Forest and Cropland, W. E.
    Sopper and L. T. Kardos Eds., Pennsylvania State University Press,
    University Park, Pennsylvania, 1973, pgs. 71-94

4.  Leonard, R. A., Bailey, and Swank, R. R., Jr., "Transport, Detoxification,
    Fate and Effects of Pesticides in Soil and Water Environments,"  Land
    Application of Waste Materials, Soil Conservation Society of America,
    Ankeny, Iowa, 1976, pgs. 48-78

5.  Pahren, H. R., Lucas, 0. B., Ryan, J. A., and Dotson, G. K., "An
    Appraisal of the Relative Health Risks Associated with Land Application
    of Municipal Sludge," Journal Water Pollution Control Federation, in press

6.  Anon, "Municipal Sludge Management Environmental Factors," EPA 430/9-77-004,
    MCD-28, U.S. Environmental Protection Agency, Washington, D.C., 1977, pg. 30

7.  Manual for Preparation of Environmental Impact Statements for Wastewater
    Treatment Works, Facilities Plans, and 208 Areawide Waste Treatment
    Management Plans:  Office of Federal Activities, EPA, Washington, D.C.,
    July 1974

 8.   Consideration  of Secondary  Environmental  Effects  in  the Construction
     Grants  Process,  Program Guidance  Memo  No.  50,  EPA, Washington,  D.C.,
     June 1975

 9.   Environmental  Assessment of  Water Quality Management Plans,  EPA,
     Washington,  D.C.,  October 1976

10.   Environmental  Impact Assessment,  Council  of State Governments,
     Lexington,  Kentucky,  January 1977

11.   Dee, Norbert,  et al,  "An Environmental  Evaluation System for Water
     Resource Planning,"  Water Resources Research,  9,  3,  June 1973,  pgs. 523-535

12.   Bennington, G., et al, Resource and Land Investigations (RALI)  Program:
     Methodologies  for Environmental  Analysis, Vol. I:  Environmental
     Assessment, Mitre Corporation for U.S.  Geological Survey, Washington,D.C.,
     August 1974

                                      3-36

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13.   Environmental  Assessment Guidance:   Municipal  Sewage  Treatment  Works
     Program, Region 5,  EPA,  Chicago,  Illinois,  February 1977

14.   Jain,  R. K.,  et al,  Environmental  Impact Analysis  - A New Dimension  in
     Decision Making, Van Nostrand Reinhold Co.,  New York, 1977

15.   Burchell, Robert W., and Listokin,  David, The  Environmental  Impact
     Handbook, Center for Urban Policy  Research,  Rutgers - The State
     University,  New Brunswick, New Jersey, 1975
                                     3-37

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                                  CHAPTER 4

               INNOVATIVE TECHNOLOGY CONCEPTS AND APPLICATIONS
4.1  General
The methodology and criteria presented in previous chapters of this manual
have described a stepwise procedure for screening and classification of
facility plans as well as a discussion of the criteria to be used in the
final analysis.  The appended information summarized the legislation, regu-
lations, and guidelines to be followed in the analysis along with the best
available information on the cost and energy utilization of commonly employed
municipal treatment technology.

The intent of this chapter is to provide additional  insights into the concep-
tion, development, and formulation of innovative municipal  treatment system
designs that satisfy the regulatory requirements  while also demonstrating
accelerated progress toward meeting the national goals of greater cost effec-
tiveness, energy conservation, reclamation of water and wastewater constituents,
and improved management of toxic materials.

4.2  Risk Versus Potential State-of-the-Art Advancement

Both the Congressional and Agency intent in administering the innovative and
alternative technology provisions of the Act is to encourage the design and
construction of more efficient municipal treatment technology by advocating
departure from the traditional engineering and design practices.  Implicit in
this objective is a willingness to accept a greater degree  of risk in order
to achieve a greater potential for a significant advancement in the state of
the art as evidenced by lower cost, greater reliability, or other similar
design objectives.  This trade off in the two objectives is illustrated in
Figure 4-1.

                                 FIGURE 4-1

        RISK-POTENTIAL BENEFIT OF MUNICIPAL TREATMENT FACILITY DESIGNS
   Increasing
      Risk
                         Increasing  Potential  for
                      State-of-the-Art  Advancement
                                    4-1

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Under the new Innovative and Alternative Technology Guidelines,  first quad-
rant designs (moving toward the right and upward,  i.e.,  greater  potential
advancement with greater risk) are encouraged whereas the past traditional
design and engineering practices tended to discourage this acceptance of
greater risk with potentially greater benefit.  Although definitive quanti-
fication of the risk/technology advance relationship has not been provided,
the 15% cost savings and 20% energy savings,  as well as  the improved applica-
tion criteria, may be viewed as a measurement of the advance or  benefit
expected, while the 100% two year replacement provision  §35.908(e) may be
viewed as a measure of the increased risk that will be tolerated.

In addition to shifting the traditional risk  benefit balance point to en-
courage process design innovation, the innovative and alternative regulations
have also provided added incentive for the development and use of innovative
equipment.

4.3  Innovative Planning and Design Approach

     4.3.1.  Innovative Processes

While it is difficult to explicitly define the boundaries or to  prescribe
universal guidelines leading to innovative processes or system designs, it
is possible to outline and categorize successful approaches based on the
history of past development efforts in the wastewater treatment  field.

Innovative designs may originate in a number of ways, the most common of
which are listed below.

     1.  Greater integration and use of natural processes.

     2.  Maximum consideration and beneficial use of available physical
         surroundings.

     3.  New process invention or development.

     4.  New equipment invention or development.

     5.  Modification, adaptation, or improvement of fundamental biological,
         chemical, or physical processes.

     6.  Improved efficiency or control of known processes.

     7.  The application of proven processes or equipment originally
         developed for another purpose for the treatment of municipal
         wastewater.

     8.  Unique combinations of processes and techniques that recognize
         and maximize inter-process compatability or synergistic effects.

The above elements of innovative designs are not inclusive, nor are the
elements completely exclusive of one another.  The degree to which they


                                     4-2

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may be included in a particular project depends on such factors as design
objectives, physical constraints, etc.

A major emphasis of innovative systems under the CWA of 1977 is the greater
attention placed on multi-objective planning, inter-media impact considera-
tions, and total systems design.  Satisfaction of these objectives requires
a higher level of discipline in the systematic screening and evaluation of
alternatives than has been generally employed in the past.  More important,
however, is the much greater effort needed in concept development and the
formulation of innovative alternatives.

     4.3.2  Innovative Concept Development

Past experience with the review of facility plans has indicated a strong
tendency for contemporary designers to consider a narrow range of alterna-
tives, both with respect to liquid processing technology and also for
residual treatment and disposal.  Innovative design concepts should include
a broad range of reuse, beneficial recycling, and energy conservation and
recovery opportunities, as well as the specific methods or technologies of
treatment.  A partial list of recycling, reclamation, and energy recovery
opportunities that might be incorporated into an innovative concept of
treatment is shown in Table 4-1.

Conceptually, innovative designs may embody a number of the above mentioned
recycle/reclamation or reuse opportunities depending on the particular site
variables and design objectives.  Maximum consideration should be given to
the identification of all potential conceptual approaches early in the Step 1
planning process, especially those system designs incorporating alternative
technologies that exhibit significant recycle, reclamation, energy recovery,
or revenue generating potential.

Specific questions regarding state and regional policies and priorities on
innovative concepts should be discussed with the appropriate review author-
ities during the Step 1 pre-application conference.  Current Agency policy
regarding the eligibility of multiple purpose projects is described in
Program Requirements Memorandum No.  77-4.

     4.3.3  Innovative Equipment

Equipment incorporated into the construction of wastewater treatment facili-
ties under the CWA of 1977 will be considered innovative based on its appli-
cation in a particular facility system design.  Specific equipment items or
classes of equipment will not be given a blanket qualification as innovative
based on inherent characteristics.  The intent of the above determination is
to encourage the integrated use of the most efficient equipment in an overall
system design that meets one or more of the innovative technology qualifying
criteria.  Systems may meet either the cost or energy criteria due to unique
design features using standard equipment, novel equipment, or any combination
that provides the required system cost or energy savings.  The equipment so
used may be developed specifically for municipal  wastewater or residual  treat-
ment in conjunction with an innovative process design or may be originally


                                      4-3

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                            TABLE 4-1

EXAMPLES OF REUSE, RECLAMATION AND ENERGY RECOVERY OPPORTUNITIES


                    Effluent Reuse Recycling

1.  Irrigation for nutrient or water value
2.  Industrial recycle for nutrient, water, or heat value
3.  Commercial recycle for nutrient, water, or heat value
4.  Aquaculture uses including all farming and production operations
5.  Groundwater injection as supplemental source, intrusion barriers,
    subsidence prevention

                      Beneficial Sludge Use

1.  Land spreading of municipal sludges
2.  Joint treatment, blending and disposal of municipal sludge,
    solid wastes and industrial sludges
3.  Use of municipal sludges as new material(s) for industrial
    or commercial production of saleable products

          Energy Conservation. Reclamation and Recycle

1.  Use of solar energy to accelerate temperature sensitive
    processes
2.  Use of solar energy for space heating
3.  Use of heat pumps to extract heat from effluents
4.  Use of digester gas for in-plant or off-plant uses including
    sale for industrial or commercial use
5.  Gas recovery from landfill operation
6.  Accelerated plant growth and harvesting for energy recovery
7.  Waste heat recovery and reuse for thermal  and combustion
    processes

         Industrial  and Commercial Reuse or Reclamation

1.  Industrial use of wastewater
2.  Industrial use of waste heat from municipal treatment systems
3.  Municipal  use of waste industrial heat
4.  Commercial use of wastewater effluents
5.  Joint industrial municipal  disposal  of effluents or residuals
6.  Use of industrial  waste products, including off gases for
    beneficial municipal  use
7.  Use of municipal waste products,  including off gases, for
    beneficial industrial  uses
                               4-4

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developed for use in another industry and modified for use in an innovative
municipal treatment plant design.

The non-restrictive specifications §35.936-13(a)(l) presented in Appendix B
prohibits the use of proprietary, exclusionary, or discriminatory bid speci-
fications other than those based on performance or those necessary to demon-
strate a specific thing or provide for necessary interchangeability...The
above reference to...demonstrate a specific thing...recognizes the possibil-
ity of permitting the use of unique equipment items when incorporated into
an overall system design meeting the innovative technology qualifying criteria.
Sufficient justification for use of such proprietary specifications must be
prepared and approved on a case by case basis.

The decision to allow exclusion will normally be made at the Step 1 review
stage by state or federal review authorities and will be subject to confir-
mation during the Step 2 review stage.  If the innovative qualifying criteria
is based on cost savings, verification will take place as a part of the Step 3
interim and final audits.  If the savings is based on the energy criteria,
post construction verification and documentation may be requested as a part
of the general requirement of Section 202(a)(3) of the CWA of 1977 as speci-
fied in §35.908(c).

Equipment used in the context of the innovative and alternative provision
includes the following:

     1.  All equipment used for liquid stream processing (includes pumping
         facilities that are a part of the treatment works)

     2.  All equipment needed for the treatment and disposal of residuals
         including energy recycling or reuse.

     3.  All automation and instrumentation equipment needed for equipment
         or process control.

For Item 3 above, the use of plant instrumentation and automation equipment
to achieve greater cost or energy savings must clearly document the cost
effectiveness of the automated level of control over manual control.  Judge-
ments regarding conformance with the qualifying innovative cost and energy
criteria will be based on the overall system cost or energy savings including
all processes and equipment items.  For systems judged to have met the inno-
vative qualifying criteria; the portion of the project qualifying for in-
creased grant assistance must be explicitly identified by the applicant as
previously discussed.
                                      4-5

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                                 APPENDIX A

                 MUNICIPAL TREATMENT TECHNOLOGY FACT SHEETS


A.I  General

This appendix provides a series of two-page capsule summaries of processes
and techniques commonly used in the United States for treatment and disposal
of wastewater and its residuals.  While it is expected that these fact sheets
will be used extensively for the non-innovative cost and energy analysis and
evaluation, the technologies contained in this appendix should not be used
as an inclusive list of non-innovative or baseline technology.  The inclusion
or exclusion of processes and techniques in Tables A-3 and A-4 is not a direct
indication of whether the technology is innovative or alternative in a particular
application"!Those processes employed to a more limited extent are identified
with an asterisk.  The cost and energy data presented in the appendix are gen-
eralized rather than site specific and are intended primarily for comparative
analysis.  The accuracy of the cost and energy estimating curves and infor-
mation have been noted on the fact sheets where available.  The user of the
appendix is cautioned against considering the estimates as absolute.  The esti-
mates are to be used for comparative estimating purposes during the Step 1 re-
view process and as a general guide for determining the adequacy of proposed
cost and energy values.

The fact sheets also serve to provide basic information on a number of com-
monly used technologies which have been identified in the Innovative and
Alternative Technology Guidelines  (Appendix E of the Construction Grant
Regulations) as alternative technology for the purpose of increased construc-
tion grant funding and other incentives provided under the Clean Water Act
of  1977.  These processes and systems are indicated by an "A" in parenthesis.

Portions of other systems may be considered alternative technology depending
on  the method of ultimate sludge disposal, degree of energy recovery, or other
special design considerations.

The bibliography for this appendix contains numerous publications which are
readily available to the manual user from EPA and other sources.  The user
should consider obtaining copies of selected material as a supplement to the
fact sheet  information.

A.2  Fact Sheet Format

The first of two sheets of the  fact sheet sets has been designed to provide
the following  information for each process:

     - Description                    - Typical Equipment/No. Mfrs.
     - Common Modifications           - Performance
     - Technology Status              - Design Considerations
     - Applications                   - Reliability
     - Limitations                    - References

                                    A-l

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In addition, the following information has been included when applicable to
the process under consideration:

     - Chemicals Required             - Potential  for Increased Environmental
     - Residuals Generated                Benefits
     - Potential of Improved          - Joint Treatment Potential
         Toxics Management

The second page of each fact sheet set contains the following information:

     - Flow or Schematic Diagram      - Construction Costs
     - Energy Notes                   - Operation  and Maintenance Costs

Design criteria and assumptions used to develop the energy and cost estimates
have been fully described on each fact sheet to provide the user with a base
to adjust the information to specific project designs where required.

The information provided under Typical Equipment/No. Mfrs. has been supplied
to provide the user an understanding of the relative availability of equip-
ment for the process.  The heading refers to well-known directories of
equipment for manufacturers' names and numbers.  These directories are
annual publications and, therefore, become a renewable resource of infor-
mation describing the state of the art.

Reference listings on the fact sheets have been shown in two forms; namely,
general listings at the lower part of each page, and in parentheses where
applicable to a particular subject being discussed.

Toxics management has been addressed in the fact sheets in several ways,
depending on the characteristics of the progress and the contribution the
process makes to toxics management.  This information is supplementary to
the discussion and tabular information presented in Chapter 3.  If a process
is passive with respect to improved toxics management opportunities, no
statement has been made concerning the subject.  On the other hand, if the
process provides toxic management in the form of incidental removal, a state-
ment has been made concerning this effect in the description of the process.

When applicable and where data is available, comments have also been made
showing concentrations of toxics in the process sidestreams.  A specific
toxics management statement has been provided for those processes providing
high levels of toxic control.

Energy information has been developed for each of the processes from pub-
lished information or by derivation for the process being discussed.  In
certain cases, curves of energy requirements per year versus treatment plant
flow have been provided.  In these cases, the efficiencies of energy-using-
devices have been shown to permit adjustment where needed.  In other cases,
particularly where pumping energy is involved, a simple equation has been
used to show the energy requirements at a given pumping head for an annual
flow rate.  The user can then, by simple correction to his conditions of
flow and head, determine the energy needs for his specific design.  Curves

                                     A-2

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have also been provided in Appendix D to aid in this analysis.

The energy information presented has been based on the assumption that the
process will be operated as proposed and that equipment used will be main-
tained in a representative good operating condition.  In certain cases, wide
variations in energy consumption can be expected to occur due to equipment
wear or corrosion, changes in flow rate, heat transfer efficiency, poor
operation techniques, inadequate controls or other factors influencing oper-
ation at the optimum conditions.  The impact of these off-design operating
conditions can be expected to vary widely with the process and the type of
equipment being used.  Additional energy information for specific alternative
technology processes along with often needed conversion factors, and equivalent
fuel and energy values is presented in Appendix D.

Cost data presented in the fact sheets have been derived from EPA publications,
open literature, construction grant files, and manufacturers' information.
These data exhibit a level of accuracy dependent upon the degree of usage of
the process.  Therefore,  processes using well-known types of equipment,
facilities and operating methods can be expected to have a higher level of
accuracy.  Those processes with few examples of usage beyond the demonstra-
tion stage must be considered as individual cases with the potential for
wider variation in costs when applied in a generalized fashion.

A large number of the construction and operation and maintenance curves used
in the development of the fact sheets have been obtained or derived from the
Areawide Assessment Procedures Manual (3).  This information is the result
of cost estimates developed over a period of years by several contractors
from detailed conceptual  designs, process and equipment layouts in accordance
with standard estimating techniques plus verification using normalized "as
built" costs where available.  Fact sheets for processes having limited "as
built" cost data bases contain single or multiple case history costs as
available.  In some cases costs have been tabulated rather than displayed
graphically.

     All  cost curves are based on cost elements described in Table A-l unless
specifically noted otherwise in a given fact sheet.  Conversion of the con-
struction costs shown in the fact sheets may be made to capital cost by use
of the outline in Table A-2.  Construction and O&M costs for Appendix A
curves have been indexed to September 1976 (ENR 2475) unless otherwise noted.
Appendix C provides information for adjusting the costs to other time and
regional  bases.
                                     A-3

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                              TABLE  A-l

       GENERAL  COST  AND  DESIGN  BASIS  FOR  COST  CURVES
           (Used for  All  Fact Sheets Unless  Noted)
Basis of Costs

     1.   ENR  =  2475, September 1976

     2.   Labor  rate, including fringe benefits  = $7.50/hr

         Note:   Labor costs are based on a man-year of 1,500 hours.  This
                represents:  a 5-day work week; an average of 29 days for
                holidays, vacations, and sick  leave; and 6 1/2 hours of
                productive work time per day.
     3.   Energy  Costs

         a.   Electric Power
         b.   Fuel Oil
         c.   Gasoline

     4.   Land

     5.   Chemical Costs

         a.   Liquid Oxygen
         b.   Methanol
         c.   Chlorine     150-lb cylinder
                         1-ton cylinder
                         Tank Car
         d.   Quicklime
         e.   Hydrated Lime
         f.   Polymer (Dry)
         g.   Ferric Chloride
         h.   Alum
         i.   Activated Carbon (Granulated)
         j.   Sulfuric Acid (66°  Be)
         k.   Sodium Hexametaphosphate
         1.   SOj         150-lb cylinder
                         1-ton cylinder
                         Tank Car
=  $0.02/KwH
=  $0.37/gallon
=  $0.60/gallon

=  $l,000/acre
   $65/Ton
   $0.50/gallon
   $360/Ton
   $260/Ton
   $160/Ton
   S25/Ton
   $30/Ton (as CaO)
   $1.50/lb
   $lOO/Ton
   $72/Ton
   $0.50/lb
   $50/Ton
   $0.25/lb
   S450/Ton
   $215/Ton
   $155/Ton
Design Basis

1.  Construction  costs and operation and maintenance  costs are based on design
    average flow  unless otherwise noted.

2.  Operation  and maintenance costs include:

    a.  Labor  costs for operation, preventive maintenance, and minor repairs.
    b.  Materials costs to include replacement parts  and major repair work
        (normally performed by outside contractors).
    c.  Chemical  costs.
    d.  Fuel costs.
    e.  Electrical power costs.

3.  Construction  costs do not include external piping,  electrical, instrumentation,
    land costs,  site work, miscellaneous structures,  contingency, or engineering
    and fiscal fees.
                                   A-4

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                                  TABLE  A-2

                        DEVELOPMENT OF CAPITAL COSTS
Conversion from construction costs to capital costs can be made by using the
following tabulation.
Component Installed Construction  Costs

     Unit Processes
                                                   $ 2,5o OOP
                                                   $ _
                                                   $
     Miscellaneous Structures
     (administrative offices, laboratories,
     shop and garage facilities)

     Subtotal 1

Non-Component Costs

     Piping
     Electrical
     Instrumentation
     Site Preparation

     SubtotalsZ^,  I

Non-Construction Costs

     Engineering and Construction
     Supervision @ 15%**
     Contingencies @ 15%**

     Subtotals 3y L^ 1

Total Capital Cost
                                                   $
                                                                        OOP
Avg.*
T05T
8%
5%
5%
Range*
5-125%
3-10%
1-10%
$
$
$
$
*
2.5 oOQ
I2.o1 oo O
fL^W
ft, foO
i
                                                                $ 3 Z o, 00 O
                                             $
                                                        ooQ
                                                   $ ^# oo O
                                                      6, oo Q
                                                                       QQ Q
*  Range due to level of complexity,  degree of instrumentation,  subsoil
   conditions, configuration of site, etc., percentage of Subtotal  1

** Percentage of Subtotals 1 plus 2
                                    A-5

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                                  TABLE  A-3

                             LIST  OF  FACT SHEETS
Fact
Sheet No.     Title

1.1.1         Force Mains, Transmission
1.1.2         Lift Stations, Raw Wastewater
1.1.3         Sewers, Gravity
1.1.4(A)      Sewers, Pressure
1.1.5(A)      Sewers, Vacuum

1.2.1(A)      Aquaculture - Water Hyacinth*                          A-  24
1.2.2(A)      Aquaculture - Wetlands*                                A-  26
1.2.3(A)      Rapid Infiltration, Underdrained                       A-  28
1.2.4(A)      Rapid Infiltration, Not Underdrained                   A-  30
1.2.5(A)      Land Treatment, Slow Rate, Sprinkler, Underdrained     A-  32
1.2.6(A)      Land Treatment, Slow Rate, Sprinkler, Not Underdrained  A-  34
1.2.7(A)      Land Treatment, Slow Rate, Gravity, Not Underdrained   A-  36
1.2.8(A)      Land Treatment, Slow Rate, Gravity, Underdrained       A-  38
1.2.9(A)      Overland Flow, Gravity, Not Underdrained*              A-  40

2.1.1         Activated Sludge, Conventional, Diffused Aeration      A-  42
2.1.2         Activated Sludge, Conventional, Mechanical Aeration    A-  44
2.1.3         Activated Sludge, High Rate, Diffused Aeration         A-  46
2.1.4         Activated Sludge, Pure Oxygen, Covered                 A-  48
2.1.5         Activated Sludge, Pure Oxygen, Uncovered               A-  50
2.1.6         Activated Sludge with Nitrification                    A-  52
2.1.7         Bio-Filter, Activated (with Aerator)*                  A-  54
2.1.8         Contact Stabilization, Diffused Aeration               A-  56
2.1.9         Denitrification, Separate Stage, with Clarifier        A-  58
2.1.10        Extended Aeration, Mechanical  and Diffused Aeration    A-  60
2.1.11        Lagoons, Aerated                                       A-  62
2.1.12        Lagoons, Anaerobic                                     A-  64
2.1.13        Lagoons, Facultative                                   A-  66
2.1.14        Nitrification, Separate Stage, with Clarifier          A-  68
2.1.15        Oxidation Ditch                                        A-  70
2.1.17        Phostrip*                                              A-  72

2.2.1         Biological  Contactors, Rotating (RBC)                  A-  74
2.2.2         Denitrification Filter, Coarse Media                   A-  76
2.2.3         Denitrification Filter, Fine Media                     A-  78
2.2.4         Intermittent Sand Filtration,  Lagoon Upgrading         A-  80
2.2.5         Polishing Filter for Lagoon, Rock Media                A-  82
                                     A-6

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                           TABLE A-3  (Continued)
Fact
Sheet No,

2.2.6
2.2.7
2.2.8

3.1.1
3.1.2
3.1.3
3.1.4
3.1.5
3.1.6
 ,1.7
 ,1.9
 ,1.10
3.1.11
3.1.12
3.1.13
3.1.16
3.1.17
3.
3.
3.
4.1.1
4.1.2
4.1.3
4.1.4
4.2.1
4.2.2
4.3.1

4.4.1
4.4.2
4.4.3

4.5.1
4.5.2
4.5.3

5.1.1
5.1.2
5.1.5
5.1.6
5.1.7
              Title

              Trickling Filter,
              Trickling Filter,
              Trickling Filter,
                  Plastic Media
                  High Rate, Rock Media
                  Low Rate, Rock Media
Clarifier,
Clarifier,
Clarifier,
Clarifier,
Clarifier,
Dissolved
Filtration, Dual Media
Flow Equalization
Mixing/Chlorine Contact,
Post Aeration
Preliminary Treatment
Pump Stations, In-Plant
Screen, Horizontal Shaft
Screen, Wedge Wire
                         Primary, Circular with Pump
                         Primary, Rectangular with Pump
                         Secondary, Circular
                         Secondary, Rectangular
                         Secondary, High Rate Trickling Filter
                        Air Flotation
High Intensity
                                       Rotary
              Ammonia Stripping
              ARRP (Ammonia Removal and Recovery Process)*
              Breakpoint Chlorination
              Ion Exchange (for Ammonia Removal)*

              Lime Recalcination
              Two-Stage Tertiary Lime Treatment, without
                Recalcination

              Independent Physical/Chemical Treatment

              Tertiary Granular Activated Carbon Adsorption
              Activated Carbon Thermal Regeneration
              Ozone Oxidation (Air and Oxygen)*

              Chlorination (Disinfection)
              Dechlorination (Sulfur Dioxide)
              Ozone Disinfection (Air and Oxygen)

              Alum Addition
              Ferric Chloride Addition
              Lime Clarification of Raw Wastewater
              Polymer Addition
              Powdered Carbon Addition
A- 84
A- 86
A- 88

A- 90
A- 92
A- 94
A- 96
A- 98
A-100
A-102
A-104
A-106
A-108
A-110
A-112
A-114
A-116

A-118
A-120
A-122
A-124

A-126
A-128
                                                       A-130

                                                       A-132
                                                       A-134
                                                       A-136

                                                       A-138
                                                       A-140
                                                       A-142

                                                       A-144
                                                       A-146
                                                       A-148
                                                       A-150
                                                       A-152
                                    A-7

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                           TABLE A-3  (Continued)
Fact
Sheet No.     Title                                                   Page

6.1.1         Dewatered Sludge Transport (Rail)                      A-154
6.1.2         Dewatered Sludge Transport (Truck)                     A-156
6.1.3(A)      Land Application of Sludge                             A-158
6.1.4         Sludge Landfilling - Area Fill                         A-160
6.1.5         Liquid Sludge Transport (Pipeline)                     A-162
6.1.6         Liquid Sludge Transport (Rail)                         A-164
6.1.7         Liquid Sludge Transport (Truck)                        A-166
6.1.8         Sludge Pumping                                         A-168
6.1.9         Sludge Storage                                         A-170
6.1.10        Sludge Landfilling - Sludge Trenching                  A-172
6.1.11        Sludge Lagoons                                         A-174

6.2.1         Co-Incineration of Sludge, Sludge Incinerator          A-176
6.2.2         Co-Incineration of Sludge, Solid Waste Incinerator     A-178
6.2.3(A)      Composting Sludge, Static Pile                         A-180
6.2.4(A)      Composting Sludge, Windrow                             A-182
6.2.5         Incineration of Sludge, Fluidized Bed Furnace (FBF)    A-184
6.2.6         Incineration of Sludge, Multiple Hearth Furnace (MHF)  A-186
6.2.7         Co-Disposal by Starved Air Combustion*                 A-188
6.2.8         Starved Air Combustion of Sludge*                      A-190
6.2.9         Sludge Drying                                          A-192

6.3.1         Centrifugal Dewatering                                 A-194
6.3.2         Drying Beds, Sludge                                    A-196
6.3.3         Filter, Belt                                           A-198
6.3.4         Filter Press, Diaphragm                                A-200
6.3.5         Conventional Filter Press                              A-202
6.3.6         Thickening, Dissolved Air Flotation                    A-204
6.3.7         Thickening, Gravity                                    A-206
6.3.8         Centrifugal Thickening                                 A-208
6.3.9         Vacuum Filtration, Sludge                              A-210

6.4.1         Digestion, Aerobic                                     A-212
6.4.2         Digestion, Autothermal Thermophilic Aerobic (Air)      A-214
6.4.3         Digestion, Autothermal Thermophilic Oxygen (Oxygen)    A-216
6.4.4         Digestion, Two Stage Anaerobic                         A-218
6.4.5         Digestion, Two Stage Thermophilic Anaerobic            A-220
6.4.6         Disinfection (Heat)*                                   A-222
6.4.7         Heat Treatment of Sludge                               A-224
6.4.8         Lime Stabilization                                     A-226

7.1.1(A)      Aerobic Treatment and Absorption Bed                   A-228
7.1.2(A)      Aerobic Treatment and Surface Discharge                A-230
7.1.3(A)      Disinfection for On-Site Surface Discharge             A-232
                                     A-8

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                           TABLE A-3  (Continued)
Fact
Sheet No.     Title                                                   Page

7.1.4(A)      Evaporation Lagoons                                    A-234
7.1.5(A)      Evapotranspiration Systems                             A-236
7.1.6(A)      Septic Tank Absorption Bed                             A-238
7.1.7(A)      Septic Tank Mound Systems                              A-240
7.1.8(A)      Septic Tank Polishing, Surface Discharge               A-242
7.1.9(A)      Septage Treatment and Disposal                         A-244

7.2.1         In-the-Home Treatment and Recycle*                     A-246
7.2.2         Non-Water Carriage Toilets*                            A-248


NOTE:  (A) Denotes process and systems identified in the Innovative and
           Alternative Guidelines as Alternative Technology for incentives
           under the Clean Water Act of 1977.

        *  Denotes processes which have had limited use as  of 10/79.
                                    A-9

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                                  TALBE  A-4

                      ALPHABETIZED LIST OF FACT SHEETS               Fact

Title                                                                Sheet No.
Activated Carbon Thermal Regeneration                                4.4.2
Activated Sludge, Conventional, Diffused Aeration                    2.1.1
Activated Sludge, Conventional, Mechanical Aeration                  2.1.2
Activated Sludge, High Rate, Diffused Aeration                       2.1.3
Activated Sludge, Pure Oxygen, Covered                               2.1.4
Activated Sludge, Pure Oxygen, Uncovered                             2.1.5
Activated Sludge with Nitrification                                  2.1.6
Aerobic Treatment and Absorption Bed                                 7.1.1
Aerobic Treatment and Surface Discharge                              7.1.2
Alum Addition                                                        5.1.1
Ammonia Stripping                                                    4.1.1
Aquaculture - Water Hyacinth                                         1.2.1
Aquaculture - Wetlands                                               1.2.2
ARRP (Ammonia Removal and Recovery Process)                          4.1.2
Bio-Filter, Activated (with Aerator)                                 2.1.7
Biological Contactors, Rotating (RBC)                                2.2.1
Breakpoint Chlorination                                              4.1.3
Centrifugal Dewatering                                               6.3.1
Centrifugal Thickening                                               6.3.8
Chlorination (Disinfection)                                          4.5.1
Clarifier, Primary, Circular with Pump                               3.1.1
Clarifier, Primary, Rectangular with Pump                            3.1.2
Clarifier, Secondary, Circular                                       3.1.3
Clarifier, Secondary, High Rate Trickling Filter                     3.1.5
Clarifier, Secondary, Rectangular                                    3.1.4
Co-Disposal by Starved Air Combustion                                6.2.7
Co-Incineration of Sludge, Sludge Incinerator                        6.2.1
Co-Incineration of Sludge, Solid Waste Incinerator                   6.2.2
Composting Sludge, Static Pile                                       6.2.3
Composting Sludge, Windrow                                           6.2.4
Contact Stabilization, Diffused Aeration                             2.1.8
Conventional Filter Press                                            6.3.5
Dechlorination (Sulfur Dioxide)                                      4.5.2
Denitrification Filter, Coarse Media                                 2.2.2
Denitrification Filter, Fine Media                                   2.2.3
Denitrification Separate Stage, with Clarifier                       2.1.9
Dewatered Sludge Transport (Rail)                                    6.1.1
Dewatered Sludge Transport (Truck)                                   6.1.2
Digestion, Aerobic                                                   6.4.1
Digestion, Autothermal Thermophilic Aerobic  (Air)                    6.4.2
Digestion, Autothermal Thermophilic Oxygen (Oxygen)                  6.4.3
Digestion, Two Stage Anaerobic                                       6.4.4


                                     A-10

-------
                           TABLE A-4   (Continued)
Title                                                                Sheet No.
Digestion, Two Stage Thermophilic Anaerobic                          6.4,5
Disinfection  (Heat)                                                  6.4.6
Disinfection  for On-Site Surface Discharge                           7.1.3
Dissolved Air Flotation                                              3.1.6
Drying Beds,  Sludge                                                  6.3.2
Evaporation Lagoons                                                  7.1.4
Evapotranspiration Systems                                           7.1.5
Extended Aeration, Mechanical and Diffused Aeration                  2.1.10
Ferric Chloride Addition                                             5.1.2
Filter, Belt                                                         6.3.3
Filter Press, Diaphragm                                              6.3.4
Filtration, Dual Media                                               3.1.7
Flow Equalization                                                    3.1.9
Force Mains,  Transmission                                            1.1.1
Heat Treatment of Sludge                                             6.4.7
Incineration  of Sludge, Fluidized Bed Furnace  (FBF)                  6.2.5
Incineration  of Sludge, Multiple Hearth Furnace  (MHF)                6.2.6
Independent Physical/Chemical Treatment                              4.3.1
Intermittent  Sand Filtration, Lagoon Upgrading                       2.2.4
In-the-Home Treatment and Recycle                                    7.2.1
Ion Exchange  (for Ammonia Removal)                                   '4.1.4
Lagoons, Aerated                                                     2.1.11
Lagoons, Anaerobic                                                   2.1.12
Lagoons, Facultative                                                 2.1.13
Land Application of Sludge                                           6.1.3
Land Treatment, Slow Rate, Gravity, Not Underdrained                 1.2.7
Land Treatment, Slow Rate, Gravity, Underdrained                     1.2.8
Land Treatment, Slow Rate, Sprinkler, Not Underdrained               1.2.6
Land Treatment, Slow Rate, Sprinkler, Underdrained                   1.2.5
Lift Stations, Raw Wastewater                                        1.1.2
Lime Clarification of Raw Wastewater                                 5.1.5
Lime Recalcination                                                   4.2.1
Lime Stabilization                                                   6.4.8
Liquid Sludge Transport (Pipeline)                                   6.1.5
Liquid Sludge Transport (Rail)                                       6.1.6
Liquid Sludge Transport (Truck)                                      6.1.7
Mixing/Chlorine Contact, High Intensity                              3.1.10
Nitrification, Separate Stage, with Clarifier                        2.1.14
Non-Water Carriage Toilets                                           7.2.2
Overland Flow, Gravity, Not Underdrained                             1.2.9
Oxidation Ditch                               •                       2!l!l5
Ozone Disinfection (Air and Oxygen)                                  4.*5i3
Ozone Oxidation (Air and Oxygen)                                     4.4.3
Phostrip                                                             2!l!l7
Polishing Filter for Lagoon, Rock Media                              2.*2.*5
Polymer Addition                                                     5\l'.6
Post Aeration                                                        3.*1.*11
Powdered Carbon Addition                                             s'.l'j


                                    A-ll

-------
                           TABLE A-4  (Continued)                    r  .
                                                                     r act
Title                                                                Sheet No.
Preliminary Treatment                                                3.1.12
Pump Stations, In-Plant                                              3.1.13
Rapid Infiltration, Not Underdrained                                 1.2.4
Rapid Infiltration, Underdrained                                     1.2.3
Screen, Horizontal Shaft Rotary                                      3.1.16
Screen, Wedge Wire                                                   3.1.17
Septage Treatment and Disposal                                       7.1.9
Septic Tank Absorption Bed                                           7.1.6
Septic Tank Mound Systems                                            7.1.7
Septic Tank Polishing, Surface Discharge                             7.1.8
Sewers, Gravity                                                      1.1.3
Sewers, Pressure                                                     1.1.4
Sewers, Vacuum                                                       1.1.5
Sludge Drying                                                        6.2.9
Sludge Lagoons                                                       6.1.11
Sludge Landfilling - Area Fill                                       6.1.4
Sludge Landfilling - Sludge Trenching                                6.1.10
Sludge Pumping                                                       6.1.8
Sludge Storage                                                       6.1.9
Starved Air Combustion of Sludge                                     6.2.8
Tertiary Granular Activated Carbon Adsorption                        4.4.1
Thickening, Dissolved Air Flotation                                  6.3.6
Thickening, Gravity                                                  6.3.7
Trickling Filter, High Rate, Rock Media                              2.2.7
Trickling Filter, Low Rate, Rock Media                               2.2.8
Trickling Filter, Plastic Media                                      2.2.6
Two-Stage Tertiary Lime Treatment, without Recalcination             4.2.2
Vacuum Filtration, Sludge                                            6.3.9
                                     A-12

-------
FACT SHEETS
    A-13

-------
FORCE  MAINS,  TRANSMISSION                                                      FACT SHEET 1,1,1
Description - A  force main conveys wastewater under pressure from the discharge side of a pump or lift station to
a point of gravity  flow downstream.  The purpose of the force main  (also referred to as rising main or pressure
main) is  to convey  the wastewater from a low level area to a high level system.  Energy for movement of the
wastewater is provided by a pumping system.  Wastewater often first enters a storage well which serves as a
suction well for  the pump(s).  The size of the force main is a compromise between the most cost effective pipe and
pump  size and the need to provide suitable wastewater velocity to insure proper scouring of the pipe during
operation.

Common Modifications  - Mains may be aerated or the wastewater chlorinated to maintain freshness or prevent
septicity.   Installation of wye cleanouts on longer lines.  Various pipe materials are used.

Technology Status - Widespread use, fully demonstrated.
Typical Equipment(23) - Pipe/18.
Applications - To convey wastewater from a low level area to a high level system where a gravity sewer is not
feasible.

Limitations - Often the dissolved oxygen content of the wastewater is depleted in the storage well and the sub-
sequent passage through the force main results in the discharge of septic wastewater which is not only devoid of
oxygen but often contains sulfides.  Frequent cleaning and maintenance of force mains is required to remove slimes
and solids buildup.

Design Criteria - Desirable force main velocities are from 3.5 to 5 ft/s to assure adequate scouring.  Under
certain circumstances, velocities as low as 2 ft/s can be used, provided precautions are used to increase the
velocity from time to time.  This increased velocity for scouring is commonly obtained by operating the spare and
active pump simultaneously on at least a weekly basis.  Pipe of 4-inch diameter is commonly used for small ejector
stations, and pipe of 6-inch or larger is used for installations fed by a pumping station.

Force main design is intimately tied to pump station selection to insure a cost effective design.  Wetwell size
must be coordinated with the force main size and length to determine the methods needed for sulfide control.

                                              Force Main Capacity

Diameter, inches    	V = 2 ft/s	         	V = 3. 5 ft/s                  V = 5.0 ft/s
       6            176 gpm    .25 Mgal/d         308 gpm     .44 Mgal/d        440 gpm     .63 Mgal/d
       8            313 gpm    .45 Mgal/d         548 gpm     .79 Mgal/d        780 gpm    1.12 Mgal/d
      10            490 gpm    .71 Mgal/d         860 gpm    1.24 Mgal/d      1,230 gpm    1.77 Mgal/d

A peaking factor allowance ranging from 3 for average flows of 1 Mgal/d and less, to 2 for average flows in excess
of 10 Mgal/d, should be used in sizing the force main pipe diameter.

If continuous pumping is desired it may be necessary to have two or three sizes of pumps, some of which may be
constant-speed units and some variable-speed units.

Force mains should be designed with proper provision for the release of air and/or gases and should enter the
gravity sewer system at a point not more than 2 ft above the flow line of the receiving manhole.  Special design
consideration must be given to valve and pump selection and the elevation and slope of the force main to avoid
water hammer problems.

Characteristics of some of the more common pipe materials are given below.

Material               Application               Advantages               Disadvantages               C Values
Cast or ductile        General use; high         Less expensive than      Undergoes corrosion,           100
iron, unlined          pressures                 most                     grease build-up
Cast or ductile        General use; high         No corrosion,  slow       More expensive than           120
iron, cement-lined     pressures                 grease build-up          unlined
Steel, cement-lined    General use; high         No corrosion,  slow       More expensive than           120
                       pressures                 grease build-up          unlined steel
Cement-asbestos        General use, moderate     No corrosion,  slow       Relatively brittle            120
                       pressures                 grease build-up
Fiberglass-reinforced  General use;              No corrosion,  slow       As expensive as glass-        140
epoxy pipe             moderate pressures        grease build-up          lined pipe
Plastic                General use;              No corrosion,  slow                                     140
                       lower pressures           grease build-up

Reliability - Very reliable if properly designed and maintained.
Environmental Impact - Subject to odors, especially during service interruptions.   Involves less  land use dis-
ruption and capital expenditures than excessively deep sewering in many areas.

References - 7, 20, 30, 229

                                                     _-

-------
FORCE MAINS,  TRANSMISSION
                                                                              FACT SHEET 1,1,1
 FLOW DIAGRAM
                                                                                          Manhole
                      Pump
                    Station
                                                                                                 Gravity Sewer
ENERGY NOTES - The energy required to convey wastewater through the  force main  is derived from the pump station.

COSTS - Assumptions:  Costs have been adjusted to third quarter 1977 dollars; ENR Index =  2611.
1.   Capital costs* have been derived from reference 228.  Operating and maintenance costs have been obtained
     from reference 3.

     Capital costs include construction costs for force main in-place (including materials and labor)  and non-
     construction costs (administrative/legal costs; land, structures and right-of-way costs;  architect/engineer
     fees; bond interest, contingency and indirect costs).  Because of the wide variety of construction con-
     ditions under which force mains are built, capital costs shown here do not include allowances for appurte-
     nances, or site-specific requirements such as stream or thoroughfare crossings, extensive rock excavation,
     etc.  Also not included is the cost of pump station.
3.
If adequate information about pipe size is not available,  the following  table  can  be  used to  approximate the
pipe size, assuming a velocity of 3.5 ft/s and a peaking factor of  3.
      6 inch diameter - .15 Mgal/d
      10 inch diameter - .4  Mgal/d
                                   12 inch diameter -  .59 Mgal/d
                                   18 inch diameter - 1.35 Mgal/d
                         CAPITA^ COS1
 24 inch diameter - 2.37 Mgal/d
 30 inch diameter - 3.7  Mgal/d

OPERATION & MAINTENANCE COST
       160


       140


       120


       100


        80


        60


        40


        20
                                                                001
                                                        Q 0001
                                                        o
                                                        - 0 0001
                        12     18     24

                        Pipe Diameter, in
                                             30
                                                             01
                                                                           1 0            10
                                                                          Wastewater Flow, Mgal/d
                                                                                                     100
 REFERENCES  -  3,228
 *Capital (rather than construction)  costs  are  shown since the development of capital costs shown in Table A-2 is
  not readily applicable to force mains.
                                                       A-15

-------
LIFT STATIONS,  RAW  WASTEWATER                                                 FACT  SHEET  1,1,2
Description - An arrangement of pumps, electric motor sets/  piping/  valves,  strainers,  controls,  and alarms.
usually with ventilation fan, sump pump, dehumidifier,  lights,  and space heater,  assembled in an enclosed struc-
ture which consists of a wet well (wastewater receiver, equipped with a screen and sometimes  also a comminutor)
and a dry well (pump and motor room).   The pump station can be  field-installed or factory pre-fabricated or
packaged.  The capacities range from 20 gal/min and over.   The  packaged unit generally has a  capacity up to 10,000
gal/min.  The total dynamic head varies.

Common Modifications - When separate wet and dry wells  are not  provided as described above, the following pump
configurations may be used:   pump set submersible;  liquid end of pump is submersible,  with extended shaft for
motor drive and controls outside of wet well but in weather-proof enclosure;  liquid end of pump,  piping,  and
valves are above wastewater level but pump has extended,  submerged suction pipe,  with  motor drive and controls
outside of wet well but in weather-proof enclosure.

Pneumatic ejector, with separate or integral collection chamber acting as a wet well when connected to sanitary
line, can be substituted for pumps in a dry well configuration and are economically feasible for capacities up to
300 gal/min.  Above 300 gal/min space requirements  and equipment and power costs  become excessive.

Use of various pump capacities in a multiple unit system to match diurnal flow characterisitcs.

Provision for emergency power supply.

Oxygenation, aeration, or chemical feeding equipment is sometimes included for the stated purpose of reducing H S
at force main discharge.

Technology Status - Widespread use in wastewater application.
Application - Lifts wastewater to a higher elevation when the continuance of the  gravity flow line at reasonable
slopes would involve excessive depths of trench;  lifts wastewater from areas too low to drain into an available
sanitary sewer line; boosts wastewater elevation  where there is insufficient head in the incoming gravity flow
line for gravity flow through a treatment plant.

Limitations - Potential exists for odor problems  and H S generation when wastewater flow conditions are not
properly controlled.  Need for emergency power under certain conditions.   Single pump units are not recommended.
Wet well mounted units may have inspection and maintenance problems in the wet well.

Typical Equipment/Ho, of Mfrs. (23)  - Pump sets/34;  valves/39;  screens/20; comminutors/12;  heaters/7;  ventilating
fans/7; controls and alarms/29.

Design Criteria - Wet well maximum detention time 10 to 30 min;  minimum slope wet well bottom 2:1;  dry well and
wet well must be ventilated; effective volume of the wet well may include  incoming sewerlines;  wet well floor
should always remain covered with liquid to reduce odor problems;  bar screens should be provided;  pump suction and
discharge nozzle velocities should range between 10 and 14 ft/s;  minimum solid capacity of pump,  3 inch diameter;
high water alarm; minimum number of pumps, 2; suitable water level controls for pump motor operation;  emergency
power provisions; pumping capacity must equal the maximum flow condition with the largest pump  unit out of service.

Reliability - Reliable with a 10 to 20 year life expectancy consistent with cost effective guidelines  provided
manufacturer1s maintenance procedures are followed.   Reliability highly dependent upon power source and number of
pumps.  Regular operation and maintenance required.

Environmental Impact - Low impact on air and water.   Moderate impact on land during installation.   Potential for
water pollution and health risk under failure conditions.   Potential for noise,  odor.

References - 3, 7, 22, 23, 30, 195, 196, 197, 198
                                                      A-16

-------
 LIFT STATIONS,  RAW  WASTEWATER
          FACT SHEET 1,1,2
FLOW DIAGRAM -
                          Suction
                                                   Discharge
                                                   Q = 20 gal/min and over
                                                   TDK = varies
ENERGY NOTES - Primary energy consumption for a lift station is related  to  the pumping  requirements.  Pumping
energy can be computed from the following equation:
     kWh/yr = 1140 (Mgal/d X TDK)
              Wire to Water Efficiency
Assuming a wire to water efficiency of 67 percent,  a power consumption  of  17,500 kWh/Mgal/d/yr would be expected
at a TDK of 10 feet.   Small additional energy needs  are required for  controls,  lights, and mechanical screening
(if used).
COSTS -Assumptions: ENR Index = 2475
1.   Construction cost includes fully enclosed wet well/dry well pit  structure; pumping equipment capable of
     meeting the peak flow with largest unit out of service; standby  pumping  facilities; piping and valves within
     structure; bar screens - mechanically cleaned.   TDK = 10 ft.
2.   Power costs based on ?0.02/kWh.
         100
          10
         001
                        CONSTRUCTION , COST
            Poekogt Station!~
                                                                10
                                                          =   2
                                                          =   o
                        10           10

                    Wastewater  Flow, Mgal/d
                                                  100
                                                              0001
                                                                 01






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                                001   I
                                     «
                                     o
                                     2
                                     i

                                     1
                                     a.

                                0001  I
    10            10
Wastewater Flow, Mgal/d
                                00001
                               100
REFERENCE - 3
 *To  convert construction cost to capital cost see Table A-2.
                                                       A-17

-------
SEWERS,  GRAVITY
                                                            FACT  SHEET 1,1.3
Description - Gravity sewers are used for the transport of sanitary and industrial wastewater, stormwater and any
combination of wastewaters by proper slope design, which results in a flow due to gravity.  Access to a gravity
sewer is made by manholes every 300 to 500 ft or at changes in slope or direction.

Common Modifications - Addition of corrosion protection coatings (coal based tar, PVC based tar),  chemical grout-
ing and slip-in liners (for pipes with diameters of less than 12")  for rehabilitation of in-place sewers, inverted
syphons, lift stations for hilly or excessively flat terrain, diversion regulators for combined sewers.  Drop
manholes.  Various types of joint materials are used,  such as rubber, lead, plastic and various forms of masonry.

In rural communities where topography is favorable, small diameter gravity sewers which transport septic tank
effluent to central treatment works have been employed in Australia and, to a limited extent, in the United
States.  Generally, these sewers have a minimum pipe diameter of 4 in.  All installations to date have employed
PVC pipe, owing to its light weight, long lengths and ease of laying.  Curvilinear alignments in the vertical and
horizontal planes are allowable, and manholes or meter boxes (depending on line depth)  may be kept to a minimum
(400 to 600 ft spacing).

Applications - Gravity sewers are used for the transport of wastewater wherever gravity flow is cost effective.

Technology Status - Oldest and most common wastewater transport system existing.   Technology advancement limited
principally to improvement in materials and methods of construction.  Small diameter systems are undergoing design
improvements with applications.  Present gradient and size requirements are conservative.

Limitations - High capital cost in rural areas, in areas requiring removal of ledge rock and where depths greater
than 15 feet are required.  Possible explosion hazard due to production of gas or improper discharge of combus-
tibles into the system.   Severe internal corrosion of piping materials can occur due to improper hydraulic design
of a sewer.  Stoppage due to grease, sedimentation, tree root development and, in the case of combined sewers,
debris.  Excessive infiltration and inflow are the most common problems for both old and new systems.
Material
                        Diameters Available
                                                            Favorable
                                                                                          Unfavorable
(1) Asbestos Cement     4" to 42"
(2) Clay Pipe
                        4" to 42"
(3) Concrete
    (Reinforced)        12" to 144"
    (Non-reinforced)    4" to 24"
                       light weight,  ease of handling,
                       long laying lengths,  tight joints
                       Resists corrosion from acids and
                       alkalies, resists erosion and scour
                       Strength,  availability of sizes/
                       widely used
                                     Subject to corrosion where
                                     acids and hydrogen sulfide
                                     are present

                                     Limited range of sizes and
                                     strength, brittle, short length:
                                     many joints.

                                     Subject to corrosion where
                                     acids or hydrogen sulfide are
                                     present.  Short pipe lengths.
                                     Large number of joints.
(4) Cast Iron
(5) Solid Wall
    (Plastic Pipe)
    Truss Pipe
2" to 48"



Up to 12"

8" to 15"
Long laying lengths, tight joints,   Corrosion by acid, highly
withstands high external loads,      septic wastewater or
corrosion resistant in neutral soils corrosive soils
Light weight, tight joints, long
laying lengths, some cases -
corrosion resistant
                                                                                    Thin walls, susceptibility
                                                                                    to sunlight and low temper-
                                                                                    ature which affect shape
                                                                                    and strength,  limited sizes,
                                                                                    limited experience, continu-
                                                                                    ous lateral support is
                                                                                    essential.

Design Criteria - Size:  Dependent upon flow,  minimum 6 inch inside diameter for all laterals in collection
systems.  Slope:  Dependent upon size and flow.   Velocity:   Minimum of 2.0 ft/sec at full depth.  Material: Must
meet service application requirements.  Additional Requirements:   Adequate ground cover, minimum scouring (self-
cleaning) velocity; infiltration shall not exceed 200 gal/d/in diameter/mile (lower in certain jurisdictions).
Small diameter gravity sewers transport septic tank effluent,-, have a minimum diameter of 4 in. , and are designed
for 1/2-full peak flow (corresponding to a gradient of 0.67 percent for a 4-in.  sewer).
Unit Process Reliability - Highly reliable,
parts.
                    with a long life expectancy.   System is not dependent upon moving
Environmental Impact - Low impact on air and water.  Considerable impact on land during installation. The instal-
lation of sewers in roadways adjacent to vacant properties leads to an increase in the rate of development of the
land.  Small diameter gravity sewers in rural areas would result in a reduction in the magnitude of the land and
secondary development impacts for conventional gravity sewers, and they may also reduce the land requirements for
subsequent treatment processes where organic loading is the principal design parameter.

References - 3, 7, 103, 228
                                                     A-18

-------
   SEWERS,  GRAVITY
                                                                                  FACT SHEET 1.1.3
ENERGY NOTES - Since, by definition, the process is gravity operated,  no energy is consumed in its operation.
1.   Capital costs* are third quarter 1977 dollars (based on EPA Complete Urban Sewer System Cost Index)  and
     have been derived from reference 228.  Operating and Maintenance costs represent September 1976 Figures
     (ENR=2475),  and have been obtained from reference 3.

     Capital costs include:  construction costs for in-place sewer pipe;  appurtenances and non-pipe costs;
     and non-construction costs.  Construction costs for in-place pipe include material and labor.   Appur-
     tenances and non-pipe costs include manholes, thoroughfare crossings,  pavement removal and replacement,
     rock excavation (minimal),  special pipe bedding and miscellaneous appurtenances.  Non-construction costs
     include administrative/legal costs; land, structures s right-of-way  costs; architect/engineer  fees,
     bond interest, contingency, indirect and miscellaneous costs.

3.   Data base for capital costs consisted of over 13,000 bid items for 455 construction projects.   Pipe materials
     used on these projects included PVC, asbestos cement, vitrified clay,  cast iron, reinforced concrete and
     ductile iron.  Typical capital costs shown here do not include costs for special or site specific require-
     ments such as extensive rock excavation, dewatering, shoring, or local cost indices.
4.   If adequate information about pipe diameters is not available, the following table may be used as a guide
     to convert a given design wastewater flow to pipe diameter.

                                     Sizing of Collector and Interceptor Sewers
Pipe Diameter
  (Inches)
                      Minimum Slope for
                       Pipe Velocity of
                      2 ft/sec  8 ft/sec
                       Design Wastewater Flow (Mgal/d)  with
                      	Pipe Flowing Full	
                      	Velocity, ft/sec	
     10
     12
     15
     18
     21
     24
     27
     30
     36
     42
     48
     54
      400
      300
       200
       100
         0
                      0.0060
                      0.0038
                      0.0030
                      0.0022
                      0.0015
                      0.0012
                      0.0010
                      0.00078
                      0.00065
                      0.00058
                      0.00045
                      0.00038
                      0.00032
                      0.00026
0.075
0.045
0.035
0.026
0.020
0.016
0.013
0.011
0.0095
0.0080
0.0060
0.0050
0.0045
0.0039
                                                     0.26
                                                     0.48
                                                     0.72
 1.04
 1.69
 2.41
 3.38
 4.10
 5.20
 6.50
 9.75
13.00
16.25
20.80
 0.36
 0.69
 1.04
 1.46
 2.47
 3.45
 4.94
 6.24
 7.80
 9.75
14.63
19.50
24.70
31.85
 0.47
 0.91
 1.37
 1.94
 3.25
 4.42
 6.37
 8.13
10.08
13.00
18.20
25.36
31.85
39.65
                                                                                                0.91
                                              76
                                              54
 3.51
 5.84
 9.43
12.35
15.28
18.85
24.05
37.05
48.10
59.80
84.50
                        CAPITAL COST
                                                                        OPERATION & MAINTENANCE COST
           —1.  Depth < 8 f t
           —2.  Depth = 8-15 ft
           —3.  Depth > 15 ft

                                                               10
                                                               0 1
                                                              0 01
                                                                                                            001
                                                                                                                o
                                                                                                           0001  -
                                                                0 1
                                                                              1 0            10
                                                                             Wastewater Flow, Mgal/d
                                                                                                        100
                                                                                                           00001
          0    6    12   18   24  30    36   42   48  54
                     Pipe Diameter,  Inches
REFERENCES - 3, 228, 261
*Capital rather than construction costs are provided since Table A-2 is not readily applicable to gravity sewers.


                                                      A-19

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SEWERS,  PRESSURE                                                                 FACT  SHEET
October 1978
Description (38) - Pressure sewers are used to reduce costs relative to gravity sewer systems  in less populated
areas.  The pressure sewer embodies a number of pressurizing inlet points and a single outlet to a treatment
facility or to a gravity sewer, depending on the application.

The two major types of pressure sewer systems are the grinder pump (GP)  system and the septic tank effluent pump
(STEP) system.  The major differences between the alternative systems are in the on-site equipment and layout.
Neither pressure sewer system alternative requires any modification of household plumbing.

In both designs household wastes are collected in the sanitary drain and conveyed by gravity to the pressurization
facility.  The on-lot piping arrangement includes at least one check valve and one gate valve to permit isolation
of each pressurization system from the main sewer.  GP's can be installed in the basement of a home to provide
easier access for maintenance and greater protection from vandalism.

In STEP systems, wastewater receives intermediate treatment in a septic tank.  The septic tank effluent then flows
to a holding tank which houses the pressurization device, control sensors, and valves required for a STEP system.
Normally, small centrifugal pumps are employed for the STEP systems.   These pumps are submersible and range in
size from 1/4 to 2 hp.  Pump total head requirements generally range from 25 to 90 ft.  Impellers can be made of
plastic to reduce corrosion problems.  Also included within the holding tank are level controls, valves and
piping.  The effluent holding tank can be made of properly cured precast or cast-in-place reinforced concrete,  or
they may be made of molded fiberglass or reinforced polyester resin.   Tank size is based on accessibility for
repairs and maintenance.

Pump control switches are either a pressure sensing type, or the mercury float switch type.

Service connection lines between the pump and the pressure main are generally made of 1 to 2 inch PVC pipe  (Sched-
ule 40, SDR-21, or SDR-26) with PVC drain, waste, and vent fittings.   Pressure mains are usually 2 to 12 in
diameter PVC pipe, depending on hydraulic requirements.  Pipes must only be buried deep enough to avoid freezing.
Head loss due to pipe friction generally is in the range of 1 to 4 ft H2O/100 ft of pipe.

Common Modifications  (38) - On GP systems an emergency (i.e., power failure, etc.) overflow tank may be provided.
Measures such as standpipes and pressure control valves are sometimes used to maintain a positive pressure on the
system.  Air release valves are also provided to eliminate gas pockets in the system.  Polyethylene pipe, pneu-
matic ejectors, and mainline check valves have been used in some designs.

Technology Status - More than 30 pressure sewer systems have been operated in the United States to date.  At least
70 more are either being designed or constructed.

Applications - Pressure sewers are most applicable where population density is low, severe rocky conditions exist.
high ground water or unstable soils prevail, and/or where undulating terrain predominates.

Limitations - High operation and maintenance costs related to the use of mechanical equipment at each point of
entry to the system.  In GP systems, the wastewater conveyed to the treatment facility may be more concentrated
than normal wastewater.  In STEP systems, a weaker, more septic waste is generated.  Therefore, both systems
require special care in system design and in treatment facility design.

Typical Equipment/No, of Mfrs.dO, 38) - Pressurization pumps/27; Septic tanks and distribution piping/locally
supplied; air release valves/8; pressure sustaining valves/9; grinder pumps/8

Design Criteria - Dendriform systems are generally used instead of grids.  Pump requirements vary with the type of
pump employed and its location in the system.  Flushing provisions are necessary.  Pipe design is based on Hazen-
Williams friction coefficient of 130 to 140.  For GP systems a minimum velocity of about 3 ft/s at least one time
per day is used to prevent deposition of solids.  Meter boxes generally suffice in place of manholes.

Process Reliability  (38) - Severe corrosion can cause mechanical and electrical problems.  Accumulations of grease
and fiber can cause  reductions in pipe cross-sectional areas of GP systems during partial flow conditions.  Esti-
mated  life of current pump designs exceeds ten years.  Centralized maintenance is generally required for optimum
service.

Environmental Impact - During construction, there is potentially less noise impact, fugitive dust problems and
erosion than with conventional sewers because of smaller equipment and less excavation requirements. In aquifer
areas, the smaller and shallower trench and water tight piping will minimize the trench draining effect that is
normally associated  with sewer pipes in aquifer areas. Fewer pumping station requirements improve aesthetics. Some
odor potential  is inherent in pressure sewers, but judicious design has been successful in controlling it.
Pressure sewers generally run along road right-of-ways, resulting in less traffic disruption during construction
and repair operations.  Without proper emergency backup and warning systems, in-house overflows may occur.

References - 10,  38, 103
                                                        A-20

-------
BOS,  PRESSURE
                                                                                   FACT SHEET 1.1,
'LOW  DIAGRAM -
 Grinder Pump
                                                                             Pressure Sewer
                                                                              PVC Piping
                     Tank
  Septic Tank
  Effr
:ic Tanx         .	•
uent Pumping    |   |<
                                                           *• Drainage Field
                              Existing Septic Tank


         Overflow Level Sensor

    On-Off Level Sensor

Junction Box and High Level Alarm
       ^—2-inch plastic pipe for electricity
                                                                                 PVC plastic main
         From House
                             Existing  or New
                                Septic  Tank
                                                                 -inch pla:
                                                                  service
                                                             Ball or Gate Valve

                                                         ^""""24-inch Concrete Pipe with Floor and Lid

                                                                  1/3-hp Sump Pump
                                                   Check Valve
ENERGY NOTES - Required kWh/yr/home = 50 to 200
COSTS*  (1978 dollars) ENR  Index = 2776
Components**
1. Mainline Piping (PVC)
   a. 1-3 in diameter
   b. 4 in
   c. 6 in
                                       Construction Cost

                                          $3.00/lin ft
                                          $3.50/lin ft
                                          $4.65/lin ft
                                                   Operation  & Maintenance  Cost
                                                   $100-200/year/mile
                                   TOTAL
2. On-lot Septic Tank Effluent Pumping (STEP)
   a. Pump, controls, etc.
   b. Service line  (100 ft @ $2/ft)
   c. Corporation cocks, valves, etc.
   d. Septic tank (optional)
   e. Connection fee
                                   TOTAL
   On-lot Grinder Pump  (GP)
   a. GP unit, controls, etc.
   b. Service line  (100 ft @ ?2/ft)
   c. Cocks, valves, etc.
   d. Connection fee
                                   TOTAL
                                          900-1,500
                                          200
                                            50
                                          250
                                            50-100

                                        $1,200-2,100
                                        $1,300-2,000
                                           200
                                            50
                                            50-100

                                        $1,600-2,350
                                                                                $100-200/year/mile
                                                                                     $40/year
                                                        $10/year
                                                                                     $50/year
                                                                                $75/year
                                                                                     $75/year
     To convert construction cost to capital cost, refer to Table A-2.
 **   Local economics, climate, geology, soils, etc. make any such effort to give specific, accurate costs for these
     components extremely difficult.  The above costs are considered typical for gross estimating purposes only.
REFERENCES - 38, 103
                                                       A-21

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SEWERS, VACUUM                                                                   FACT  SHEET 1,1,5
Description - Vacuum sewers employ a central vacuum source which is maintained at 15 to 25 in Hg vacuum.   A
gravity vacuum interface valve separates atmospheric pressure in the home service line or toilets from the vacuum
in the collection mains.  When the interface valve opens,  a volume of wastewater enters the main, followed by a
volume of atmospheric air.  After a preset interval, the valve closes.   The packet of liquid,  called a slug, is
propelled into the main by the differential pressure of vacuum in the main and the higher atmospheric pressure air
behind the slug.  After a distance, the slug is broken down by shear and gravitational forces,  allowing the higher
pressure air behind the slug to slip past the liquid.  With no differential pressure across it, the liquid then
flows to the lowest local elevation and vacuum is restored to the interface valve for the subsequent operation.
When the next upstream interface valve operates,  identical actions occur, with that slug breaking down and air
rushing across the second slug.  That air then impacts the first slug and forces it further down the system.
After a number of operations, the first slug arrives at the central vacuum station.  When sufficient liquid volume
accumulates in the collection tank at the central vacuum station, a sewage pump is actuated to deliver the accumu-
lated sewage to a treatment plant.

There are significant differences in the designs of the four types of currently installed systems:  Lil;jendahl-
Electrolux, Colt Envirovac, AIRVAC, and Vac-Q-Tec.  The major differences lie in the extent to which each system
uses separate black (toilet) and gray (the balance) water collection mains.  Electrolux uses separate systems for
these sources; Colt uses vacuum toilets and only one main, and AIRVAC and Vac-Q-Tec take the normal household
combined waste.  Other differences relate to the location of the gravity/vacuum interface (i.e. in the house or
outside) and to the design of pumps and vacuum valves.

Wastewater piping in all four designs is 3 to 6 inches in diameter PVC except where separate black and gray lines
are used, which are Ih to 3 inches.  Joints are made with solvent welds or special "O" ring seals.  Piping pro-
files vary in each system depending on terrain.  Traps are located where the designer wishes to reform a slug of
water for transport purposes or to gain elevation within the limits available; i.e., 15 to 25 in Hg.

Vacuum toilets are flushed after each use, while a vacuum valve opens automatically when a predetermined volume of
water has accumulated behind it, provided there is adequate vacuum available.  The valve is actuated by a pneu-
matic or electrical controller, depending on the design.

Vacuum pump construction has been both sliding vane and liquid ring.  Liquid ring pumps have been used more fre-
quently.   The contents in the vacuum collection tank are transferred to a treatment facility by non-clog waste-
water pumps.  It is important to use pumps whose shaft seals close against vacuum.  The Vac-Q-Tec system utilizes
a pneumatic ejector for this service.

Common Modifications - Vacuum reserve tanks are often installed to reduce vacuum pump cycling thereby extending
pump life.  On-lot tanks can be used to hold accumulated liquid or the existing building sewer can be used.

Technology Status - Vacuum sewage systems are in limited commercial use (15 to 20 systems have been installed) ,
and many designs and component fabrication improvements have been made in recent years to improve their perform-
ance.

Applications - Vacuum sewers are most applicable in areas with scarce water supply, high ground water, impermeable
soil, rocky conditions, and low population density.

Limitations - Vacuum systems are limited in the lift available and are therefore more suitable to flat terrain.
These systems may be adversely affected by low initial use/design use ratio because of inefficient operation and
high cost/unit volume of sewage transported.  Generally, all system malfunctions result in on-lot wastewater
accumulation.

Typical Equipment/No, of Mfrs. (38, 23) - Vacuum valves/4, vacuum toilets/2, pumps/34.
Design Criteria- Trap spacing = 200 to 400 ft(max.).  Minimum line velocity = 2 ft/s at 0.7 of full pipe flow.
Wastewater flow = 50 to 75 gal/d/capita.  Vacuum receiver pressure 15 to 25 in Hg.  Air flow volume into system
equals the wastewater volume, but expansion under vacuum increases the air/wastewater ratio.

Process Reliability - Valves will generally require a yearly inspection, scheduled major maintenance every 6 years
and unscheduled repair every four to eight years.  Vacuum and discharge pumps will require major repair or replace-
ment every ten years.  Vacuum system malfunctions have occurred in the valves, piping system and collection
stations.  Moisture in sensor lines and valve boot ruptures have been major sources of valve problems.

Environmental Impact - There is potentially less noise impact, fewer problems with fugitive dust, and less erosion
potential than conventional sewers during construction because of smaller equipment requirements.  There is
potentially  less chance of disturbing natural areas, such as streambeds and low-lying wetlands, because of lack of
gravity  flow requirements.  In aquifer areas, the smaller and shallower trench will minimize the trench draining
effect that  is normally associated with sewer pipes in aquifer areas.  Less growth inducement potential because of
considerably less  reserve capacity in sewer lines.  Air pollution potential at vacuum stations due to exhaust air
has not  been quantified.

References - 23, 38, 103
                                                        A-22

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 SEWERS,  VACUUM
         FACT SHEET  1.1,5
 FLOW DIAGRAM -
 ENERGY NOTES - Electrical power requirements have been  shown to vary from 0.0024 to 0.44 kWh/gal of wastewater
 transported (103).   Elevation head loss per  trap  =  1.5  ft HO  (varies with design); Dynamic head loss = 1 to 5 ft
 H 0/1000 ft of pipe length;  vacuum valve  head  loss  =  5  ft HO.
COSTS* (1978 dollars);  ENR Index = 2776.

                                     Estimated Construction Costs per Home

         (Flat terrain; design population 500; 3.5 persons/home; one valve/home)   (Ideal Conditions)
     Valve and Appurtenances
     Service Line (100 ft)
     Mainline (120 ft)
     Pocket and Cleanouts (@ $100 each)
     Vacuum Station (@ $85,000)
     Discharge Pipe
Cost
$1,000
   200
   660
    50
   595
    15
                                                                TOTAL     $2,520

                             Estimated Operation  and Maintenance Costs per Home
Approximate Range
   $  800-1,100
      150-  300
      600-1,200
       30-  100
      400-2,000
       10-   50
   $1,990-4,750
     Preventive Maintenance (4 h @  $10/h)
     Power (175 gal/d @ $0.02/kWh and 13.2  gal/kWh)
     Repair and Replacement
     Mainline Operation and Maintenance
iEPERENCES 38, 103
                                                                TOTAL
$40/year
 26
 14
  2-5

$82-85/year
To convert construction cost to capital cost, refer to Table A-2.
                                                       A-23

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AQUACULTURE -  WATER HYACINTH                                                   FACT  SHEET 1,2,1
Description - Aquaculture, or the production of aquatic organisms (both flora and fauna)  under controlled condi-
tions has been practiced for centuries, primarily for the generation of food, fiber and fertilizer.   The water
hyacinth (Eichhornia crassipes) appears to be the most promising organism for wastewater treatment and has re-
ceived the most attention.  However, other organisms are being studied.  Among them are duckweed,  seaweed, midge
larvae, alligator weeds and a host of other organisms.  Water hyacinths are large fast-growing floating aquatic
plants with broad, glossy green leaves and light lavender flowers.   A native of South America, water hyacinths are
found naturally in waterways, bayous, and other backwaters throughout the South.  Insects and disease have little
effect on the hyacinth, and they thrive in raw, as well as partially treated, wastewater.  Wastewater treatment by
water hyacinths is accomplished by passing the wastewater through a hyacinth-covered basin, where  the plants
remove nutrients, BOD  , suspended solids, metals, etc.  Batch treatment and flow-through systems,  using single and
multiple cell units, are possible.  Hyacinths harvested from these systems have been investigated  as a fertil-
izer/soil conditioner  after composting, animal feed, and a source of methane when anaerobically digested.

Common Modifications - Generally used in combination with (following) lagoons, with or without chemical P removal.
Artificial and natural wetlands are also being studied (see Fact Sheet 1.2.2).

Technology Status - Developmental stage.  A number of full-scale experimental and demonstration systems are in
operation; exact design and economic data have not been developed.

Applications - Most often considered for nutrient removal and additional treatment of secondary effluent.   Also,
research is being conducted on the use of water hyacinths for raw and primary treated wastewater or industrial
wastes, but present data favor combination systems.  Very good heavy metal uptake by the hyacinth has been
reported.  Hyacinth treatment may be suitable for seasonal use in treating wastewaters from recreational facil-
ities and those generated from processing of agricultural products.  Other organisms and methods with wider
climatological applicability are being studied.  The ability of hyacinths to remove nitrogen during active growth
periods and some phosphorus and retard algae growth provides potential applications in the upgrading of lagoons,
renovation of small lakes and reservoirs, pretreatment of surface waters used for domestic supply, storm water
treatment, demineralization of water, recycling fish culture water and for biomonitoring purposes.

Limitations - Climate or climate control is the major limitation.  Active growth begins when the water temperature
rises above 10 C. and flourishes when the water temperature is approximately 21 C.  Plants die rapidly when the
water temperature approaches the freezing point; therefore, greenhouse structures are necessary in northern
locations.  Water hyacinths are sensitive to high salinity.  Removal of phosphorus and potassium is restricted to
the active growth period of the plants.

Metals such as arsenic, chromium, copper, mercury, lead, nickel and zinc can accumulate in hyacinths and limit
their suitability as a fertilizer or feed material.  The hyacinths may also create small pools of stagnant surface
water which can breed mosquitoes.  Mosquito problems can generally be avoided by maintaining mosquito fish in the
system.  The spread of the hyacinth plant itself must be controlled by barriers since the plant can spread and
grow rapidly and clog affected waterways.  Hyacinth treatment may prove impractical for large treatment plants due
to land requirements.  Removal must be at regular intervals to avoid heavy intertwined growth conditions.  Evapo-
transpiration can be increased by 2 to 7 times greater than evaporation alone.

Typical Equipment - Ponds, channels or basins (in northern climates covers and heat would be required); harvesting
equipment; processing  (macerating, etc.) equipment; water hyacinths - locally acquired.

Performance - In tests on five different wastewater streams the following removals were reported:
Feed Source         BOD,. Reduction      COD Reduction       TSS Reduction       N Reduction    Phosphate Reduction
Secondary Effluent            35%            -                   -                   44%            74%
Secondary Effluent            83%            61%                 83%                 72%            31%
Raw Wastewater                97%            -                   75%                 92%            60%
Secondary Effluent         60-79%            -                   71%                 47%            11%
There is some evidence that coliform, heavy metals, organics are also reduced, as well as pH neutralization.

Residuals Generated - Hyacinth harvesting may be continuous or intermittent.  Studies indicate that average
hyacinth production  (including 95 percent water) is on the order of 1,000 to 10,000 Ib/d/acre.  Basin cleaning at
least once per year  results in harvested hyacinths.

Design Criteria - Experimental data vary widely.  Ranges below refer to hyacinth treatment as a tertiary process
on  secondary effluent.  Depth should be sufficient to maximize plant rooting and plant absorption.  Detention
time:  depends on effluent requirements and flow; 4-15 days average; phosphorus reduction: 10 to 75 percent;
nitrogen reduction:   40 to 75 percent; land requirement:  2 to 15 acres/Mgal/d.

Overall Reliability  - Additional data is required.  Process appears reliable from mechanical and process stand-
points, subject  to temperature constraints.

Environmental  Impact - Reduces the nutrient and contaminant levels of wastewater effluent and subsequent eutro-
phication potential.  Land use is high.  Metal uptake by hyacinths may limit the harvested culture's end use, but
provide  removal  from wastewater effluent.

References -  57,  74, 174, 200, 209
                                                        A-24

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 AQUA CULTURE - WATER HYACINTH
                     FACT  SHEET 1.2.1
 FLOW DIAGRAM -
                                                  Water Hyacinth Cover
                            Pretreated
                            Wastewater
                                                                              Effluent
                                                     Aquaculture Basin
ENERGY NOTES - Operation is by gravity flow and requires no energy.  Hyacinth growth energy is supplied by sun-
light.  All experimental data is from southern climates where no auxiliary heat was needed.  Data is not available
on heating requirements for northern climates, but it can be assumed proportional to northern latitude of location
and  to the desired growth rate of hyacinths.
COSTS - Assumptions:
1.   Design basis: used as tertiary treatment; average detention time = 5 days, average depth = 4  ft.   Costs based
     on September  1976 prices  (ENR = 2475).
2.   Construction  costs include excavation, grading and other earthwork,  service roads, hyacinth seeding.   Costs
     do not include land, pumping, harvesting equipment or covers/auxiliary heat for northern climates.
3.   Operation and maintenance costs include labor at $7.50/h, including fringe benefits.   Does not include costs
     for harvesting, processing or disposal of hyacinths.  No credit is indicated for value of harvested hyacinths.
                         CONSTRUCTION COST
                                                                             OPERATION & MAINTENANCE  COST
           0 1
       8
       o
          001
         0001
               10

Wastewater Flow, Mgal/d
                                                                 o  01
                                                                 Q
2
"w
O  001
1
                                                     100
                                                                  0001
                                                                     0.1           1            10

                                                                               Wastewater Flow, Mgal/d
                                              100
REFERENCES - 3, 174
*To convert construction cost to capital  cost  see  Table A-2.
                                                        A-25

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AQUACULTURE -  WETLANDS                                                    FACT  SHEET 1,2,2
Description - Aquaculture systems for wastewater treatment include natural and artificial wetlands as well as
other aquatic systems involving the production of algae and higher plants  (both submergent and emergent),  inver-
tebrates , fish and integrated polyculture foodchain systems.   Natural wetlands, both marine and freshwater, have
inadvertently served as natural waste treatment systems for centuries; however, in recent years marshes,  swamps,
bogs and other wetland areas have been successfully utilized as managed natural "nutrient sinks" for polishing
partially treated effluents under relatively controlled conditions.   Constructed artificial wetlands can  be
designed to meet specific project conditions while providing new wetland areas that also improve available wild-
life wetland habitats and the other numerous benefits of wetland areas.   Managed plantings of reeds (e.g., Phrag-
mites spp.)  and rushes (e.g., Scirpus spp. and Schoenoplectus spp.)  as well as managed natural and constructed
marshes, swamps, and bogs have been demonstrated to reliably provide pH neutralization and some reduction of
nutrients, heavy metals, organics, BOD ,  COD, SS, fecal coliforms and pathogenic bacteria.  Wastewater treatment
by natural and constructed artificial wetland systems is generally accomplished by sprinkling or flood irrigating
the wastewater into the wetland area or by passing the wastewater through a system of shallow ponds, channels,
basins or other constructed areas where the emergent aquatic vegetation has been planted or naturally occurs and
is actively growing.  The vegetation produced as a result of the system's operation may or may not be removed and
can be utilized for various purposes e.g., composted for use as a source of fertilizer/soil conditioner,  dried or
otherwise processed for use as animal feed supplements, or digested to produce methane.

Common Modifications-  Tie-ins with cooling water from power plants to recover waste heat have potential  for
extending growing seasons in colder climates.  Enclosed and covered systems are possible for very small flows.

Technology Status - Developmental stage.  Several full-scale,  demonstration, and experimental systems are in
operation or under construction; a limited amount of tested design and economic data have been developed to date.

Applications - Useful for polishing treated effluents.   Has potential as a low cost, low energy consuming alter-
native or addition to conventional treatment systems, especially for smaller flows.  Has been successfully used in
combination with chemical addition and overland flow land treatment systems.  Wetland systems may also be suitable
for seasonal use in treating wastewaters from recreational facilities, some agricultural operations, or other
waste-producing units where the necessary land area is available.  Potential application as an alternative to
lengthy outfalls extended into rivers, etc. and as a method of pretreatment of surface waters for domestic supply,
storm water treatment, recycling fish culture water and biomonitoring purposes.

Limitations - Temperature (climate) is a major limitation since effective treatment is linked to the active growth
phase of the emergent vegetation.  Herbicides and other materials toxic to the plants can affect their health and
lead to poor treatment.   Duckweeds are prized as food for waterfowl and fish and can be seriously depleted by
these species.  Winds may blow duckweeds to the shore if wind screens or deep trenches are not employed.  Small
pools of stagnant surface water which can allow mosquitoes to breed can develop, but problems can generally be
avoided by maintaining mosquito fish or a healthy mix of aquatic flora and fauna in the system.  Wetland systems
may prove impractical for large treatment plants due to the large land requirements.  May cause evapotranspiration
increases.

Typical Equipment - Natural or artificial marshes, swamps, bogs, shallow ponds, channels, or basins.  Irrigation,
harvesting and processing equipment optional.  Aquatic vegetation locally acquired.

performance - In test units and operating artificial marsh facilities using various wastewater streams, the fol-
lowing removals have been reported for secondary effluent treatment  (10 day detention):  BOD5/ 80 - 95 percent;
TSS, 29 - 87 percent; COD, 43 - 87 percent; nitrogen, 42 - 94 percent;  (depending upon vegetative uptake and
frequency of harvesting); Total P, 0-94 percent (high levels possible with warm climates and harvesting);
coliforms, 86 - 99 percent; heavy metals, highly variable depending on species.  There is also evidence of reduc-
tions in wastewater concentrations of chlorinated organics and pathogens, as well as pH neutralization without
causing detectable harm  to the wetland ecosystem.

Chemical, Physical and Biological Aids - Sunlight, proper temperature.

Residuals Generated - Dependent upon type of system and whether or not harvesting is employed.  Duckweed, for
example, yields 50 - 60  Ib/acre/d  (dry weight) during peak growing period to about half of this figure during
colder months.

Design Criteria - Design criteria are very site and project specific.  Experimental data are sparse and vary
widely.  Values below refer to one type of artificial system used as a tertiary process on secondary effluent:
     Detention Time:  13 days
     Land Requirement: 8 acres/Mgal/d
     Depth may vary with type of system, generally 1 to 5 ft.

Overall Reliability - Additional data is required.  Process appears  reliable from mechanical and performance
standpoints,  subject to  seasonality of  vegetation growth.  Low operator attention is required if properly designed

Environmental Impact - Reduces pollutant levels of sewage effluent while enhancing  available wetland wildlife
habitat.  Land use is  high.

References -  214,  215, 216, 217,  218, 219, 220.
                                                        JV-26

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AQUACULTURE - WETLANDS FACT SHEET 1.2.2
FLOW DIAGRAM -


— ^\ f\ JT*
	 PLAN VIEW
/~~
\ ^ ^ ^^ ^ _ /
K 	 N£^ v-®$ < .» -t'i'.- ;<•*£- f- * % *$$ IsK^M ^
ELEVATION
ENERGY NOTES - Operation by gravity flow and requires negligible energy due to minimal
supplied by sunlight. Enclosed systems in northern climates will require supplemental
but no data are available.
*
COSTS - Assumptions:
1. Second
2. Constr
Costs
3. 0/M cc
proces
1 0
„ 0 1
(0
O
Q
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REFERENCES -
*To convert

Effluent
Duckweeds
/
/
	 fc- V Ffflnpnt-
headloss . Growth energy
heating during cold months.
ary effluent feed; nominal detention time = 5 days; average depth 4 feet; ENR = 2475
uction costs include excavation, grading and other earth work, service roads, vegetation seeding.
do not include land, pumping, harvesting equipment, or covers/auxiliary heat for northern climates.
sts include labor at $7.50/h» including fringe benefits, but do not include costs for harvesting,
sing or disposal of vegetation. No credit is given for potential value of harvested vegetation
CONSTRUCTION COST OPERATION & MAINTENANCE COST
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0.1 1 10 100
Wastewater Flow, Mgal/d
Waslewater Flow Mgal/d
3, 174
construction cost to capital cost see Table A-2.
A-27

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RAPID INFILTRATION,  UNDERDRAINED                                        FACT  SHEET  1,2.3
Description - Wastewater is applied to deep and permeable deposits  such as  sand or  sandy  loam usually by dis-
tributing in basins or infrequently by sprinkling,  and is treated as it travels  through the  soil matrix by filtra-
tion, adsorption, ion exchange precipitation,  and microbial action.   Most metals are  retained on the soil, many
toxic organics are degraded or adsorbed.   An underdrainage system consisting of  a network of drainage pipe buried
below the surface serves to recover the effluent, to control groundwater mounding,  or to minimize trespass of
wastewater onto adjoining property by horizontal subsurface flow.  To recover renovated water for reuse or dis-
charge underdrains are usually intercepted at one end of the field by a ditch.   If groundwater is shallow, under-
drains are placed at or in the groundwater to remove the appropriate volume of water.  Thus, the designed soil
depth, soil detention time and underground travel distance to achieve the desired water quality can be controlled.
Effluent can also be recovered by pumped wells.

Basins or beds are constructed by removing the fine textured top soil from which shallow banks are constructed.
The underlying sandy soil serves as the filtration  media.  Underdrainage is provided  by using plastic, concrete
(sulfate resistant if necessary), or clay tile lines.   The distribution system  applies wastewater at a rate which
constantly floods the basin throughout the application period of several hours to a couple of weeks.  The waste
floods the bed and then drains uniformly away, driving air downwards through the soil and drawing fresh air from
above.  A cycle of flooding and drying maintains the infiltration capacity of the soil material.  Infiltration
diminishes slowly with time due to clogging.  Full  infiltration is readily restored by occasional tillage of the
surface layer and, when appropriate, removal of several inches from the surface  of the basin.  Preapplication
treatment to remove solids improves distribution system reliability, reduces nuisance conditions, and may reduce
clogging rates.  Common preapplication treatment practices include the following: primary treatment for isolated
locations with restricted public access;  biological treatment for urban locations with controlled public access.
Storage is sometimes provided for flow equalization and for non-operating periods.

Common Modifications - Nitrogen removals are improved by establishing specific operating procedures to maximize
denitrification, including adjusting application cycles, supplying an additional carbon source,  using vegetated
basins (at low rates),  recycling portions of wastewater containing high nitrate concentrations and reducing
application rates.

Technology Status - Was developed approximately 100 years ago and has remained unaltered since then.   Has been
widely used for municipal and certain industrial wastewaters throughout the world.

Application - A simple wastewater treatment system that is less land intensive than other land application systems
and provides a means of controlling groundwater levels and lateral subsurface flow.   Also provides a means of
recovering renovated water for reuse or for discharge to a particular surface water  body.  Is suitable for small
plants where operator expertise is limited.  Is applicable for primary and secondary effluent and for many types
of industrial wastes, including those from breweries, distilleries, paper mills,  and wool scouring plants.   In
very cold weather the ice layer floats atop the effluent and also protects the soil  surface from freezing.

Limitations - Process is limited by soil type, soil depth, the hydraulic capacity of the soil, the underlying
geology, and the slope of the land.  Nitrate and nitrite removals are low unless special management practices are
used.

Typical Equipment/No, of Mfrs. (23) - Storage tanks/2, pipe/9, pumps/34.
Performance  (9) - Effluent quality is generally excellent where sufficient soil depth exists and is not normally
dependent on the quality of wastewater applied within limits.  Well designed systems provide for high quality
effluent that may meet or exceed primary drinking water standards.  Percent removals for typical, pollution para-
meters are:  BOD  and TSS, 95 to 99 percent; Total N, 25 to 90 percent; Total P, 0 to 90 percent until flooding
exceeds adsorptive capacity; Fecal Coliform, 99.9 to 99.99+ percent.

Chemicals Required - None
Residuals Generated - Occasional removals of top layer of soil are sometimes required.  This material is disposed
of on-site.
Design Criteria - Field area 3 to 56 acres/Mgal/d; application rate 20 to 400 ft/yr, 4 to 92 in/wk; BOD5 loading
rate 20 to 100 Ib/acre/d; soil depth 10 to 15 ft or more; soil permeability 0.6 in/h or more; hydraulic loading
cycle 9 h to 2 wks application period, 15 h to 2 wks resting period; soil texture - sands, sandy loams; basin size
1 to 10 acres, at least 2 basins/site; height of dikes 4 ft; underdrains 6 or more ft deep, well or drain spacing
site specific; application techniques - flooding or sprinkling; preapplication treatment - primary or secondary.

Process Reliability - Extremely reliable, as long as sufficient resting periods are provided.
Environmental Impact - Potential for contamination of groundwater by nitrates.  Heavy metals are eliminated by
pretreatment techniques as necessary.  Monitoring for metals and toxic organics is needed where they are not
removed by pretreatment.  Requires long term commitment of relatively large land areas, although small by compari-
son  to other land treatment systems.

References - 6,  9, 23, 40, 41
                                                       A-28

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RAPID  INFILTRATION,  UNDERDRAINED
       FACT SHEET 1.2.3
'LOW DIAGRAM -
                              Pretreated
                                                             To reuse or
                             Wastewater
                                                               Discharge
ENERGY NOTES - Gravity distribution methods consume  no  energy but do require head availability; sprinkler appli-
cation energy requirements are included in 1.2.5
COSTS -Assumptions:
     Costs are based on February 1973 (EPA Index 194.2)  figures. ENR Index = 1850
     Labor rates including fringe benefits « $5/hr;  application rate 182 ft/yr.
     Construction costs include field preparations  (removal  of brush and trees) for multiple unit infiltration
     basins with 4 ft dike formed from native excavated  material,  and  storage  is not assumed necessary.
     Drain pipes buried 6 to 8 ft with 400 ft spacing, interception ditch along length of field, and weir for
     control of discharge; gravel service roads  and  4-ft stock fence around perimeter.
     OSM cost includes inspection and unclogging of  drain pipes at outlets; annual rototilling of infiltration
     surface and major repair of dikes after 10  years; high  pressure jet cleaning of drain pipes every 5 yr,
     annual cleaning of interceptor ditch, and major repair  of ditches, fences and roads after 10 yr.
     Costs of pretreatment monitoring wells, land and transmission to and from pretreatment facility not in-
     cluded .
                          CONSTRUCTION COSTS
                                                                         OPERATION  & MAINTENANCE COST
          1 0
      o
      i
          o 1
         0 01
                                      II
                                           V
                                         z.
                                                                 1 o
                                                                 01
                                                                001
                                                                0001
            o.i          i.o           10

                       Wastewater Flow, Mgal/d


REFERENCE - Curves derived from Reference 6.
                                                     100
                                                                   0.1
  1.0           10

Wastewater Flow, Mgal/d
                                                                                                          100
*To convert construction cost to capital cost see Table  A-2.
                                                      A-29

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RAPID INFILTRATION,  NOT  UNDERDRAINED                                         FACT  SHEET 1.2.4
Description - Wastewater is applied to deep and permeable deposits such as sand or sandy loam usually by dis-
tributing in basins or infrequently by sprinkling,  and is treated as it travels through the soil matrix by filtra-
tion, adsorption, ion exchange precipitation,  and microbial action.   Most  metals are retained on the soil, many
toxic organics are degraded or adsorbed.   The  treated effluent eventually  reaches the groundwater.

Basins or beds are constructed by removing the fine textured top soil from which shallow banks are  constructed and
the underlying sandy soil serves as the filtration media.  The distribution system applies  wastewater at a rate
which constantly floods the basin throughout the application period of several hours to a couple of weeks.  The
waste floods the bed and then drains uniformly away, driving air downwards through the soil and drawing fresh air
from above.  A cycle of flooding and drying helps maintain the infiltration capacity of the soil material. Infil-
tration diminishes slowly with time due to clogging.  Full infiltration is readily restored by occasional tillage
of the surface layer and, when appropriate, removal of several inches from the surface of the basin.

Preapplication treatment to remove solids improves distribution system reliability,  reduces nuisance conditions,
and may reduce clogging rates.  Common preapplication treatment practices  include the following: Primary treat-
ment for isolated locations with restricted public access; biological treatment for urban locations with con-
trolled public access.  Storage is sometimes provided for flow equalization and for non-operating periods.

Common Modifications - Nitrogen removals are improved by establishing specific operating procedures to maximize
denitrification including adjusting application cycles,  supplying an additional carbon source,  using vegetated
basins (at low rates), recycling portions of wastewater containing high nitrate concentrations  and reducing appli-
cation rates.

Technology Status - Was developed approximately 100 years ago and has remained unaltered since  then.  Has been
widely used for municipal and certain industrial wastewaters throughout the world.

Application - A simple wastewater treatment system that is less land intensive than other land application systems
and provides a means of groundwater recharge.   Is useful for temporary storage of renovated water in the aquifer.
If groundwater quality is being degraded by salinity intrusion, groundwater recharge can help to reverse the
hydraulic gradient and protect the existing groundwater.  Process is useful for the reclamation of sterile or
stripmined soil.  Is suitable for small plants where operator expertise is limited.  Is applicable for primary and
secondary effluent and for many types of industrial wastes including those from breweries,  distilleries, paper
mills, and wool scouring plants.  In very cold weather the ice layer floats atop the effluent and also protects
the soil surface from freezing.

Limitations - Process is limited by soil type, soil depth, the hydraulic capacity of the soil, the underlying
geology, and the slope of the land.  Adverse conditions cause improper treatment results.   Nitrate and nitrite
removals are low unless special management practices are used.   Crops grown and harvested from basins and ground-
water below basins require monitoring for heavy metal content,  unless metal removal practiced in pretreatment
step.

Typical Equipment/No, of Mfrs. (23) - Storage tanks/2, pipe/9,  pumps/34.
Performance  (9, 40) - Effluent quality is generally excellent where sufficient soil exists and is not normally
dependent on the wastewater applied (within limits).   Well designed systems provide for high quality effluent that
may meet or exceed primary drinking water standards.   Percent removals for typical pollution parameters aret   BOD,_
and TSS, 95 to 99 percent; Total N, 25 to 90 percent; Total P, 0 to 90 percent (until flooding exceeds adsorptive
capacity); Fecal Coliforms, 99.9 to 99.99+ percent.

Chemicals Required  - None
Residuals Generated - Occasional removal of top layer of soil is sometimes required.   This material is disposed of
on-site.

Design Criteria - Field area 3 to 56 acres/Mgal/d; application rate 20 to 400 ft/yr, 4 to 92 in/wk; BOD  loading
rate 20 to 100 Ib/acre/d; soil depth 10 to 15 ft or more, soil permeability 0.6 in/h or more;  hydraulic loading
cycle 9 h to 2 wks application period, 15 h to 2 wks resting period; soil texture - sands,  sandy loams; basin size
1 to 10 acres, at least 2 basins/site; height of dikes 4 ft; application techniques - flooding or sprinkling;
preapplication treatment - primary or secondary.

Process Reliability - Extremely reliable, as long as sufficient resting periods are provided.
Environmental Impact - Potential for contamination of groundwater by nitrates.  Heavy metals are
eliminated by pretreatment techniques as necessary.  Monitoring for metals and toxic organics is needed where they
are not removed by pretreatment.  Requires long term commitment of relatively large land area, although small by
comparison to other land treatment systems.  Water resources are diverted to groundwaters.   Crops grown and
harvested from basins and groundwater below basins require monitoring for heavy metal content, unless metal
removal practiced in pretreatment step.

References - 6, 9, 23, 40, 41
                                                        A-30

-------
 RAPID  INFILTRATION, NOT UNDERDRAINED
                                                                             FACT SHEET
October 1978
 FLOW DIAGRAM •-
                                Pretreated
                                                             To Groundwater  Recharge
                                Wastewater
ENERGY NOTES - Gravity distribution methods consume  no  energy, but do require sufficient head availability;
sprinkler application energy requirements are included  in  1.2.5  .
COSTS -Assumptions: ENR Index = 1850
1.   Costs are based on February 1973 (EPA Index 194.2)  figures; application rate 182 ft/yr; no storage required.
2.   Labor rates, including fringe benefits = $5/hr.
3.   Construction costs include field preparations  (removal  of brush and trees) for multiple unit infiltration
     basins with 4 ft dikes formed from native excavated material; gravel service roads; and 4-ft stock fence
     around perimeter.
4.   Materials cost includes annual rototilling of  infiltration surface and major repairs of dikes, fences and
     roads after 10 yr.
5.   Costs of pretreatment, monitoring wells, land  and  transmission from treatment facility to application site
     not included.
6.   Storage assumed unnecessary.
                         CONSTRUCTION COST
                                                                           OPERATION S MAINTENANCE COST
           10
           1 0
o

^   01
          001
                                                      S2
                                                      5   0 1
                                                      o
                                                      D
                                                             8  0 01
            0.1           1.0          10
                     Wastewater Flow, Mgal/d



  REFERENCE - Curves derived from reference 6.


*To convert construction cost to capital cost see Table  A-2.
                                                               0 001
                                                     100           0.1
                                                                          1.0           10

                                                                        Wastewater  Flow,  Mgal/d
                                                                                                           100
                                                          A-31

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 LAND TREATMENT, SLOW RATE, SPRINKLER, UNDERDRMNED            FACT  SHEET 1.2.5
Description - Wastewater is applied by sprinkling to vegetated soils that are slow to  moderate in permeability
(clay loams to sandy loams) and is treated as it travels through the soil matrix by filtration,  adsorption,  ion
exchange, precipitation, microbial action and by plant uptake.  An underdrainage system consisting of a network of
drainage pipe buried below the surface serves to recover the effluent,  to control groundwater, or to minimize
trespass of leachate onto adjoining property by horizontal subsurface flow.   To recover renovated water for  reuse
or discharge, underdrains are usually intercepted at one end of the field by a ditch.   Underdrainage for ground-
water control is installed as needed to prevent waterlogging of the application site or to  recover the renovated
water for reuse.  Proper crop management also depends on the drainage conditions.   Sprinklers  can be categorized
as hand moved, mechanically moved, and permanent set, the selection of which includes  the following considera-
tions:  field conditions (shape,  slope, vegetation,  and soil type), climate, operating conditions, and economics.
Vegetation is a vital part of the process and serves to extract nutrients, reduce erosion and  maintain soil
permeability.  Considerations for crop selection include:  (1) suitability to local climate and soil conditions;
(2) consumptive water use and water tolerance;  (3)  nutrient uptake and sensitivity to  wastewater constituents;
(4) economic value and marketability; (5) length of growing season; (6)  ease of management;  (7)  public health
regulations.  Common preapplication treatment practices include the following:  primary treatment for isolated
locations with restricted public access and when limited to crops not for direct human consumption;  biological
treatment plus control of coliform to 1000 MPN/100 ml for agricultural irrigation, except for  human food crops to
be eaten raw; secondary treatment plus disinfection to 200 MPN/100 ml fecal coliform for public access areas
(parks).  Wastewaters high in metal content should be pretreated to avoid plant and soil contamination.

Modifications - Forestland irrigation is more suited to cold weather operation, since  soil  temperatures are  gen-
erally higher, but nutrient removal capabilities are less than for most field crops.

Technology Status - Has been widely and successfully utilized for more than 100 years.

Application - Slow rate systems produce the best results of all the land treatment systems.  Advantages of sprink-
ler application over gravity methods include:  more uniform distribution of water and  greater  flexibility in range
of application rates, applicability to most crops,  less susceptibility to topographic  constraints, and reduced
operator skill and experience requirements.   Underdrainage provides a means of recovering  renovated water for
reuse or for discharge to a particular surface water body when dictated by senior water rights and a means of
controlling groundwater.  The system also provides the following benefits:  (1) an economic return from the  use of
water and nutrients to produce marketable crops for forage; and (2) water and nutrient conservation when utilized
for irrigating landscaped areas.

Limitations - Process is limited by soil type and depth, topography, underlying geology, climate, surface and
groundwater hydrology and quality, crop selection and land availability.  Crop water tolerances, nutrient require-
ments, and the nitrogen removal capacity of the soil-vegetation complex limit hydraulic loading rate.  Climate
affects growing season and will dictate the period of application and the storage requirements.   Application
ceases during period of frozen soil conditions.  Once in operation, infiltration rates can  be  reduced by sealing
of the soil.  Limitations to sprinkling include adverse wind conditions and clogging of nozzles.  Slopes should be
less than 15 percent to minimize runoff and erosion.  Pretreatment for removal of solids and oil and grease
serves to maintain reliability of sprinklers and to reduce clogging.  Many states have regulations regarding
preapplication disinfection, minimum buffer areas,  and control of public access for sprinkler  systems.

Typical Equipment/No, of Mfrs. (23) - Pipe/9; pumps/34; valves/39; gates/9;  spray nozzles/3; irrigation systems/1;
plus farm equipment.

Performance  (9) - Effluent quality is generally excellent and consistent regardless of the  quality of wastewater
applied.  Percent removals for typical pollution parameters when wastewater is applied through more than 5 ft of
unsaturated soil are:  BOD  and TSS, 90 to 99 percent plus; Total N, 50 to 95 percent,  depending on N uptake of
vegetation; Total P, 80 to 99 percent, until adsorptive capacity is exceeded; Fecal Coliform,  99.99 percent  plus
when applied levels are more than 10  MPN/100 ml.

Chemicals Required, Residuals Generated - None

Design Criteria - Field area 56 to 560 acres/Mgal/d; application rate 2 to 20 ft/yr, 0.5 to 4  in/wk; BOD5 loading
rate 0.2 to 5 Ib/acre/d; soil depth 2 to 5 ft or more; soil permeability 0.06 to 2.0 in/h;  minimum preapplication
treatment - primary; lower temperature limit 25 F;  particle size of solids less than 1/3 sprinkler nozzle dia-
meter,- any common pressure pipe material is suitable.  Further details on sprinkler system  characteristics are
included in 1.2.6.  Underdrains 4 to 8 inch diameter, 4 to 10 ft deep, 50 to 500 ft apart,  pipe material plastic,
concrete (sulfate-resistant, if necessary), or clay.

Environmental Impact - Requires long term commitment of large land area; i.e., largest land requirement of all
land treatment processes.  N and P are conserved.  Concerns with aerosol carriage of pathogens,  potential vector
problems, and crop contamination have been identified, but are generally controllable  by proper design and man-
agement .

References - 6, 9, 23
                                                      A-32

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LAND  TREATMENT,  SLOW RATE,  SPRINKLER, UNDERDRAINED
                                                                                    FACT  SHEET  1.2.5
FLOW DIAGRAM -
                 Spray Irrigation
                                                                                      To reuse or discharge
                   of Wastewater
ENERGY NOTES - Solid set
                         spray distribution requires 2,100 kWh/yr/ft of TDH/Mgal/d capacity.   Center pivot  spray-
ing requires an additional 0.84 X 10  kWh/yr/acre (based on 3.5 d/wk operation)  for 1 Mgal/d  or  larger  facilities
(below 1 Mgal/d, additional power = 0.84 - 1.35 X 10  kWh/yr/acre).


COSTS - Assumptions: (EPA Index = 194.2) (Yearly average application rate = 0.33 in./d)
~.   Costs are based on February 1973 figures; EN-R  Index  = 1850; labor  rates, including fringe benefits =  ?5/h.
2.   Clearing costs are for brush with few trees using bulldozer-type equipment.
3.   Solid set spraying construction costs include:  lateral spacing, 100 ft; sprinkler spacing,  80 ft along
     laterals; 5.4 sprinklers/acre; application rate, 0.20 in/h; 16.5 gal/min flow to sprinklers at 70  psi; flow
     to laterals controlled by hydraulically operated automatic valves; laterals buried 18 in; mainlines buried 36
     in; all pipe 4 in diameter and smaller is PVC;  all larger pipe is asbestos  cement (TDK = 150 ft).
4.   Center pivot spraying construction costs include: heavy-duty center pivot rig with electric drive; multiple
     units for field areas over 40 acres; maximum area per unit, 132 acres; distribution pipe buried 36 in.
5.   Underdrains are spaced 250 ft between drain pipes.  Drain pipes are buried  6 to 8 ft  deep with interception
     ditch along length of field and weir for control of discharge.
6.   Distribution pumping construction costs include: structure built into dike  of storage reservoir; continuously
     cleaned water screens; pumping equipment with normal standby facilities; piping and valves  within  structure;
     controls and electrical work.
7.   Labor costs include inspection and unclogging of drain pipes at outlets and dike maintenance.
8.   Materials costs include for solid set spraying: replacement of sprinklers and air compressors for  valve
     controls after 10 yr; for center pivot spraying, minor repair parts and major overhaul of center pivot rigs
     after 10 yr; high pressure jet cleaning of drain pipes every 5 yr, annual cleaning of interceptor  ditch,  and
     major repair of ditches after 10 yr; distribution pumping repair work performed by outside  contractor  and
     replacement parts; scraping and patching of storage receiver liner every 10 yr.
9.   Storage for 75 days is included; 15 ft dikes (12-ft wide at crest) are formed from native materials  (inside
     slope 3:1, outside 2:1); rectangular shape on level ground; 12-ft water depth; multiple  cells for  more than
     50 acre size; asphaltic lining; 9-in riprap on inside slope of dikes.
     Cost of pretreatment, monitoring wells, land, and transmission to and from  land treatment facility not
     included.
10
                          CONSTRUCTION COST
                                                                           OPERATION & MAINTENANCE COST
           100
            10
           1 0
            0 1
                   Solid Set Spray s
                   *
                                  Center Pivot
                                                                  1 0
                                                                  001
                                                                 0001
                                                                      Center Pivot Spray.
                                                                                 tt
                                                                                                    y
                                                                                       Solid Set Spray
                                                                                              I
             .01
                          0.1           10

                         Wastewater Flow, Mgal/d

REFERENCE - Curves derived from Reference 6.
                                                      100
                                                                    .01
                                                                                 1.0          10

                                                                               Wastewater Flow, Mgal/d
                                                                                                            100
 *To  convert construction cost to capital cost see Table A-2.
                                                       A-33

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 LAND TREATMENT,  SLOW  RATE,  SPRINKLER,  NOT  UNDERDRAINED             FACT SHEET 1.2.6
Description - Wastewater is applied by sprinkling to vegetated soils that are slow to moderate in permeability
 (clay loams to sandy loams) and is treated as it travels through the soil matrix by filtration,  adsorption,  ion
exchange, precipitation, microbial action and also by plant uptake.   Sprinklers can be categorized as hand moved,
mechanically moved, and permanent set, the selection of which includes the following considerations:   field  con-
ditions  (shape, slope, vegetation, and soil type), climate, operating conditions,  and economics.   Vegetation is a
vital part of the process and serves to extract nutrients,  reduce erosion and maintain soil permeability.  Common
preapplication treatment practices include the following: primary treatment for isolated locations with restricted
public access and when limited to crops not for direct human consumption; biological treatment plus control  of
coliform to 1000 MPN/100 ml for agricultural irrigation except for human food crops to be eaten  raw;  secondary
treatment plus disinfection to 200 MPN/100 ml fecal coliform for public access areas (parks).  Wastewaters high
in metal content should be pretreated to avoid plant and soil contamination.

Modifications - Forestland irrigation is more suited to cold weather operation since soil temperatures are gen-
erally higher, but nutrient removal capabilities are less than for most field crops.

Technology Status - Has been widely and successfully utilized for more  than 100  years.
Application - Slow rate systems produce the best results of all the  land treatment systems.  Advantages  of  sprinkler
application over gravity methods include:  more uniform distribution of  water and greater  flexibility in range  of
application rates, applicability to most crops, less susceptibility to  topographic  constraints,  and reduced opera-
tor skill and experience requirements.   Provides following benefits:  water conservation when  utilized for  irri-
gating landscaped areas, marketable crops, or forage;  reuse of nitrogen,  phosphorus,  and  other plant nutrients.

Limitations - Process is limited by soil type and depth,  topography,  underlying  geology,  climate,  surface  and
groundwater hydrology and quality, crop selection and land availability.   Crop water  tolerances,  nutrient  require-
ments, and the nitrogen removal capacity of the soil-vegetation complex  limit hydraulic  loading rate.   Climate
affects growing season and will dictate the period of application and the  storage  requirements.   Application
ceases during periods of frozen soil conditions.   Once in operation,  infiltration  rates  can be reduced  by  sealing
of the soil.  Limitations to sprinkling include adverse wind conditions  and clogging  of  nozzles.   Slopes should  be
less than 15 percent to minimize runoff and erosion.   Pretreatment for removal of  solids and  oil  and grease neces-
sary to maintain reliability of sprinklers.  Many states have regulations  regarding preapplication disinfection,
minimum buffer areas, and control of public access for sprinkler systems.

Typical Equipment/No, of Mfrs. (23)  - Pipe/9;  pumps/34;  valves/39;  gates/9;  spray  nozzles/3;  irrigation system/1;
plus farm equipment.

Performance (9) - Effluent quality is generally excellent and consistent  regardless  of  the  quality  of  the waste-
water applied.  Percent removals for typical pollution parameters  when  wastewater  is  applied  through more  than  5
ft of unsaturated soil are: BOD  and TSS,  90 to 99 percent plus; Total  N,  50  to  95 percent, depending upon N
uptake of vegetation; Total P,  80 to 99 percent until adsorptive capacity  is  exceeded;  Fecal  Coliforms,  99.99
percent plus, when applied levels are more than 10  MPN/100 ml.

Chemicals Required, Residuals Generated -  None
Design Criteria - Field area 56 to 560 acres/Mgal/d;  application  rate  2  to  20  ft/yr,  0.5  to  4  in/wk; BOD   loading
rate 0.2 to 5 Ib/acre/d; soil depth 2 to 3 ft or more;  soil permeability  0.06  in/h or more; minimum preapplication
treatment - primary; lower temperature limit 25 F;  particle size  of  solids  less  than 1/3  sprinkler nozzle diameter;
any common pressure pipe material is suitable.
                                                 Sprinkler  System Characteristics
                 Application    Outlets per   Nozzle P       Size  of       Shape  of        Maximum    Maximum Crop
	Rate,  in/h	Lateral	Ib/in	Area, acres	Field	Slope, %   Height,    ft
Hand moved
  Portable pipe   0.1-2.0         Multiple     30-60         1-40          Any  shape         15
  Stationary gun  0.25-2.0        Single       50-100       20-40          Any  shape         15
Mechanically moved
  End tow         0.1-2.0         Multiple     30-60        20-40          Rectangular       5-10
  Traveling gun   0.25-1.0        Single       50-100       40-100         Rectangular    Unlimited   —
  Side wheel roll 0.10-2.0        Multiple     30-60        20-80          Rectangular       5-10      3-4
  Center pivot    0.20-1.0        Multiple     15-60        40-160         Circular3         5-15      8-10
Permanent
  Solid set	0.05-2.0	Multiple	30-60	Unlimited	Any  shape	Unlimited
a.  Travelers are available to allow irrigation of any shape  field.

Process Reliability - Extremely reliable.
Environmental Impact - Water resources are diverted to groundwater.   Requires  long term commitment of  large  land
area; i.e., largest land requirement of land treatment systems.   Concerns with aerosol  carriage of
pathogens, vectors, and crop contamination have been identified,  but  are  generally controllable by proper design
and management.

References - 6,  9, 23
                                                       A-34

-------
  LAND  TREATMENT,  SLOW  RATE,  SPRINKLER,  NOT  UNDERDRAINED
  October 1978
                                 FACT  SHEET  1.2.6
 FLOW DIAGRAM -
                  Spray Irrigation
                  of Wastcwater
Land
Treatment
                                                                            To groundwater recharge
ENERGY
       NOTES - Solid set spray distribution requires 2,100 kWh/yr/ft of TDH/Mgal/d capacity.   Center pivot  spray-
ing requires an additional 0.84 X 10  kWh/yr/acre (based on 3.5 d/wk operation)  for 1 Mgal/d or larger  facilities
(below 1 Mgal/d, additional power = 0.84 - 1.35 X 10  kWh/yr/acre).


COSTS * - Assumptions: EPA Index = 194.2; ENR Index = 1850; Yearly average application rate = 0.33 in/d.
                                                            including fringe benefits
                                  $5/h.
Costs are based on February 1973 figures; labor rates,
Clearing costs are for brush with few trees using bulldozer-type equipment.
Solid set spraying construction costs include:  lateral  spacing,  100  ft;  sprinkler  spacing, 80 ft along
laterals; 5.4 sprinklers/acre;  application rate,  0.20 in/h;  16.5 gal/min flow to sprinklers at  70 psi;  flow
to laterals controlled by hydraulically operated automatic valves; laterals buried 18  in; mainlines buried
36 in; all pipe 4 in. diameter and smaller is PVC;  all  larger pipe is  asbestos cement.   (TDK =  150 ft)
Center pivot spraying construction costs include: heavy-duty center  pivot rig with electric drive; multiple
units for field areas over 40 acres;  maximum area per unit,  132  acres; distribution pipe buried 36 in.
Distribution and storage costs are included as  discussed in  1.2.5C;
OSM costs include:  for solid set spraying-replacement  of sprinklers and air  compressors for valve controls
after 10 yr; for center pivot spraying - minor  repair parts  and  major  overhaul of  center pivot  rigs after 10
yr; dike maintenance; and scraping and patching of storage reservoir liner every 10 yrs.
Cost of pretreatment, monitoring wells, land and transmission of pretreated waste  to land treatment site are
not included.
                          CONSTRUCTION COSTS
                                                                           OPERATION & MAINTENANCE COST
            100
            10
        &
        •5
         o

        2   1 0
            0 1
                  Solid Set Spray%
                                     Center Pivot Spray
                                                                 1 0
         o
         D  0 1
         B
         £
         o
                                                               • 001
                                                                0001
                                                                       Center Pivot Spray
                                                                                       ;Solid Set  Spray
              0.1
                           1.0            10

                         Wastewater Flow, Mgal/d
100
                                                                   0.1
                                                                            1.0          10

                                                                           Wastewater Flow, Mgal/d
                                                                                                            100
REFERENCE - Curves derived from Reference 6.
*To convert construction cost to  capital  cost  see Table A-2.
                                                          A-35

-------
LAND TREATMENT, SLOW RATE, GRAVITY,  NOT UNDERDRAINED                FACT  SHEET 1.2.7
Description - Wastewater is applied by gravity flow to vegetated soils that are slow to moderate in  permeability
(clay loams to sandy loams) and is treated as it travels through the soil matrix by filtration, adsorption,  ion
exchange, precipitation, microbial action and also by plant uptake.   Part of the water is lost to evaporation and
plant transpiration, part is stored in plant tissue, and the remainder percolates to groundwater.  Organics  are
reduced substantially by biological oxidation, and most mineral components become part of the soil matrix
or are extracted by plant uptake.  Nitrogen is removed primarily by crop uptake which varies with the type of crop
grown and the crop yield.  Phosphorus is removed by soil adsorption, precipitation and crop uptake.  Surface
distribution employs gravity flow from piping systems or open ditches to flood the application area with several
inches of water.  Application techniques include ridge and furrow and surface flooding (border strip flooding).
Ridge and furrow irrigation consists of running irrigation streams along small channels (furrows) bordered by
raised beds (ridges) upon which crops are grown.  Surface flooding irrigation consists of directing a sheet flow
of water along border strips or cultivated strips of land bordered by small levees.  The latter method is suited
to close-growing crops such as grasses that can tolerate periodic inundation at the ground surface.  A tailwater
return system for wastewater runoff from excess surface application is usually employed.  It consists of a small
pond, a pump, and return pipeline.  Flooding basins or furrows vary in size and shape depending upon the crops
grown, slope and grade of the land, quantity of flow, soil permeability, compatibility with farm implements, and
installation and operating costs.  Once in operation infiltration rates can be reduced by sealing.  Remedies includ
disking or harrowing of the soil every year and the use of normal or deep plowing  (ripping) of heavier soils at
2 to 4 year intervals.  High flotation tires are recommended for farm vehicles.  Vegetation is a vital part of the
process and serves to extract nutrients, reduce erosion and maintain soil permeability.  Considerations for crop
selection include:   (1) suitability to local climate and soil conditions; (2) consumptive water use and water
tolerance; (3)  nutrient uptake and sensitivity to wastewater constituents;  (4) economic value and marketability;
(5) length of growing season; (6) ease of management;  (7) public health regulations.  Common preapplication treat-
ment practices include the following:  primary treatment for isolated locations with restricted public access and
when limited to crops not  for direct human consumption; biological treatment plus control of coliform to 1000 MPN/
100 ml for agricultural irrigation except for food crops to be eaten raw; secondary treatment plus disinfection to
200 MPN/100 ml fecal coliform for public access areas  (parks).  Wastewater high in metal content should be pre-
treated to avoid soil and plant contamination.

Modifications - Forestland irrigation is more suited to cold weather operation since soil temperatures are gen-
erally higher, but nutrient removal capabilities are less than for most field crops.

Technology Status - Has been widely and successfully utilized for more than 100 years.
Application - Slow rate systems are capable of producing the best results of all the land treatment systems.
Gravity distribution is less costly, better suited to heavy soils and less capable of uniform wastewater distribu-
tion than sprinkler application.   It also provides the following benefits:   (1) an economic return from the reuse
of water and nutrients to produce marketable crops or forage;  (2) water conservation when utilized for irrigating
landscaped areas; and  (3) groundwater recharge.

Limitations - Process is limited by soil type and depth, topography, underlying geology, climate, surface and
groundwater hydrology and quality, crop selection and land availability.  Crop water tolerances, nutrient require-
ments, and the nitrogen removal capacity of the soil-vegetation complex limit hydraulic loading rate.  Graded land
is essential; excessive slope increases runoff and erosion.  Climate affects growing season and will dictate the
period of application and the storage requirements.  Application ceases during periods of frozen soil conditions.
Regions where prolonged wet spells limit application include Gulf states and the Pacific Northwest coastal region.
Border strip flooding has the following limitations:  (1) It requires operator skill and experience to ensure
uniform distribution and minimal runoff, and (2) Crop must be  able to withstand periods of inundation.  Many
states have regulations regarding preapplication disinfection  and minimum buffer areas.

Typical Equipment/No, of Mfrs.  (23) - Pipes/9, pumps/34, valves/39, gates/9, plus farm equipment.
Performance  (9) - Effluent quality  is generally excellent and consistent regardless of quality of wastewater
applied.Percent removals for typical pollution parameters when wastewater is applied through more than  5 ft of
	1	.4-^^  ~«*T ava.  onrt  anH TQQ qn *-n QQ marr^n-h nliis: Tntal K. 550 to 95 oercent. denendincr on N uptake of
applied.  Percent removals ror typical pollution parametera wxicu wasuewaL-ej. x» a^pj.j.c^ L.JU.VJU^U MI^J.^ L.UMU ^ *..- v
unsaturated soil are:  BOD  and TSS, 90 to 99 percent plus; Total N, 50 to 95 percent, depending on N uptake of
vegetation; Total P, 80 to 99 percent, diminishes when P uptake exhausted; Fecal Coliforms, 99.99 percent plus
(when applied counts more than 10  MPN/100 ml).

Chemicals Required, Residuals Generated - None

Design Criteria - Field area 56 to 560 acres/Mgal/d; application rate 2 to 20 ft/yr, 0.5 to 4 in/wk; BOD5 loading
rate 0.2 to 5 lb/acre/d; soil depth 2 to 3 ft or more; soil permeability 0.06 in/h or more; minimum preapplication
treatment - primary; lower temperature limit -25°F; tailwater return system capacity 10 to 50 percent applied
surficial flow.

Process Reliability - Extremely reliable.

Environmental Impact - Requires long term commitment of large land area; i.e., largest land requirement of all
land treatment systems.  Water resources are diverted to groundwater.    Concerns with vectors and crop
contamination have been identified, but are generally controllable with proper design and management.

References - 6, 9, 23
                                                       A-36

-------
  LAND TREATMENT,  SLOW  RATE,  GRAVITY, NOT UNDERDRAINED
                                                                                     FACT SHEET  1.2.7
  FLOW DIAGRAM  -  Surface Flooding
                 of Wastewater
                                             Land  Treatment
                                                                        Effluent to grouiidwater
                                                     J_
                                                                        recharge
                                                                                     TAILWATER RETURN
                                             Tailwater Return
                                                                    10
 ENERGY NOTES - Gravity distribution methods
 consume no energy.  Tailwater return energy
 usage is indicated assuming: pump efficiency
 (wire to water)  = 60 percent, total head = 30
 ft; operation 8760 h/yr.   Energy cost = $.02/kWh.

                                                                     .
                                                                   10
                                                                   10"
                                                                        .01
                                                                             Flow of Recovered Water, Mgal/d
                                                            194.2)  (Yearly average application rate =  0.33  in./d)
COSTS -Assumptions: ENR Index = 1850
1.   Costs are based on February 1973 figures (EPA Index
2.   Labor rates, including fringe benefits = $5/hr.
3.   Clearing costs are for brush with few trees using bulldozer-type equipment.
4.   Levelling costs are for moving 500 yd /acre.
5.   Distribution is by surface flooding using border strips or ridge and furrow  methods.   Border  strips  are  40  ft
     wide by 1150 ft long; have concrete lined trapezoidal distribution ditches with 2  slide  gates per  strip
     Ridge and furrow-gated aluminum pipe distribution based on 1200 ft long furrows, rectangular  shaped  fields
6.   Tailwater return-construction costs include drainage collection ditches;  pumping station forebay 1/3 acre-
     pumping station with shelter and multiple pumps,  piping to nearest point  of  distribution mainline  (230 ft)•
     assumed rate of return = 20 percent of applied wastewater.                                                 '
7.   OSM cost (border strip)  includes reordering  every 2 yr and major relining of  ditches  after 10 yrs.  OSM cost
     (ridge and furrow)  includes replacement of  gated  pipe after 10  yr.
8.   OSM cost includes major repair of pumping station after 10  yr;  dike maintenance; and scraping and patching of
     storage reservoir liner every 10 yrs.                                                             panning 01
9.   Storage for 75 days included (See Fact Sheet  1.2.5 ).
                         '  m°nit0ring Wells<  land  and  transmission of  wastewater  to  land application site not
                                                                                                                 10
             1 0
                            CONSTRUCTION COSTS
       o

       5
          0001
              0.1
                           1.0           10
                           Wastewater Flow. Mgal/d
                                                                    1 0
                                                                              OPERATION  &  MAINTENANCE  COST
                                                                    0 1
                                                                   0 01
                                                     100
                                                                  0001





































Ri



^











dg















e &


^*'
*'"







1



Fun

t.s*
,s
*J











o\

^>







"s

/








^
/








— 4 -
<







//
//
A~ 	 1







'/














































jBorder Strip Flooding^




























































•1





                                                                    0.1
                                                                                  1.0           10
                                                                                 Wastewater Flow, Mgal/d
100
REFERENCE - Derived from figures in Reference 6.

*To convert construction cost  to capital  cost see Table A-2.
                                                          A-37

-------
LAND  TREATMENT,  SLOW RATE,  GRAVITY,  UNDERDRAINED                    FACT SHEET  1.2.8
Description - Wastewater is applied by gravity flow to vegetated soils that are slow to moderate in permeability
and  is treated as it travels through the soil matrix by filtration, adsorption, ion exchange, precipitation,
microbial action and also by plant uptake.  An underdrainage system consisting of a network of drainage pipe
buried below the surface serves to recover the effluent, to control groundwater, or to minimize trespass of waste-
water onto adjoining property by horizontal subsurface flow.  To recover renovated water for reuse or discharge,
underdrains are usually intercepted at one end  of the field by a ditch.  Underdrainage for groundwater control is
installed as necessary to prevent waterlogging soils of the application site and to recover renovated water for
further reuse.  Proper crop management also depends on the drainage conditions.  Surface distribution employs
gravity flow from piping systems or open ditches to flood the application area with several inches of water.
Application techniques include ridge and furrow and surface flooding (border strip flooding).  Ridge and furrow
irrigation consists of running irrigation streams along small channels  (furrows) bordered by raised beds (ridges)
upon which crops are grown.  Surface flooding irrigation consists of directing a sheet flow of water along border
strips or cultivated strips of land bordered by small levees.  The latter method is suited to close-growing crops
such as grasses that can tolerate periodic inundation at the ground surface.  A tailwater return system for waste-
water runoff from excess surface application is usually employed.  It consists of a small pond, a pump, and return
pipeline.  Flooding basins or furrows vary in size and shape depending upon the crops grown, characteristics of
the  land, quantity of flow, soil permeability, compatibility with farm implements, and installation and operating
costs.  Once in operation, infiltration rates can be reduced by sealing.  Sealing results from compaction from
farm machinery, raindrops, or formation of a clay crust.  Remedies include disking or harrowing of the soil every
year and normal or deep plowing (ripping) of heavier soils at two to four year intervals.  The use of high flota-
tion farm equipment is recommended.   Vegetation is a vital part of the process and serves to extract nutrients,
reduce erosion and maintain soil permeability.  Considerations for crop selection include:  (1) suitability to
local climate and soil conditions; (2) consumptive water use and water tolerance; (3) nutrient uptake and sensi-
tivity to wastewater constituents; (4) economic value and marketability;  (5) length of growing season; (6)  ease of
management;  (7) public health regulations.  Common preapplication treatment practices include the following:
primary treatment for isolated locations with restricted public access and when limited to crops not for direct
human consumption; biological treatment plus control of coliform to 1000 MPN/100 ml for agricultural irrigation
except for human food crops to be eaten raw; secondary treatment plus disinfection to 200 MPN/100 ml fecal
coliforms for public access areas (parks).  Wastewaters high in metal content should be pretreated to avoid soil
and  plant contamination.

Modifications - Forestland irrigation is more suited to cold weather operation since soil temperatures are gen-
erally higher, but nutrient removal capabilities are less than for most field crops.

Technology Status - Has been widely and successfully utilized for more than 100 years.
Application - Slow rate systems are capable of producing the best results of all,the land treatment systems.
Gravity systems cost less and are better suited to heavier soils than sprinkler systems.  It also provides the
following benefits:  (1) an economic return from the reuse of water and nutrients to produce marketable crops or
forage; (2) water conservation when utilized for irrigating landscaped areas; (3) a means of recovering renovated
water for reuse or for discharge; and  (4) a means of controlling groundwater.  Surface flooding is more difficult
to apply uniformly than by sprinkler application, but is preferred for flat topography.

Limitations - Process is limited by soil type and depth, topography, underlying geology, climate, surface and
groundwater hydrology and quality, crop selection and land availability. Crop water tolerances, nutrient require-
ments, and the nitrogen removal capacity of the soil-vegetation complex limit hydraulic loading rate.  Graded land
is essential; excessive slope increases runoff and erosion.  Climate affects growing season and will dictate the
period of application and the storage requirements.  Application ceases during periods of frozen soil conditions.
Regions where prolonged wet spells limit application include Gulf states and the Pacific Northwest coastal region.
Border strip flooding has the following limitations:  (1) It requires operator skill and experience to ensure
uniform distribution and minimal runoff, and  (2) Crop must be able to withstand periods of inundation.  Pretreat-
ment by primary  settling will reduce clogging, odors and health hazards.  Many states have regulations regarding
preapplication disinfection, and minimum buffer areas.

Typical Equipment/No, of Mfrs.(23) - Pipe/9; pumps/34; valves/39; gates/9; plus farm equipment.
Performance  (9) - Effluent quality is generally excellent and consistent regardless of quality of wastewater
applied.  Percent removals for typical pollution parameters when wastewater is applied through more than 5 ft
unsaturated  soil are:  BOD  and TSS, 90 to 99 percent plus; Total N, 50 to 95 percent (depending on N uptake of
vegetation); Total P, 80 to 99 percent  (diminishes when P uptake exhausted); Fecal Coliforms, 99.99 percent plus
 (when applied counts 7-10 / 100ml) .

Design Criteria - Field area 56 to 560 acres/Mgal/d; application rate 2 to 20 ft/yr, 0.5 to 4 in/wk; BOD  loading
rate  0.2 to  5  Ib/acre/d; soil depth 2 to 3 ft or more; soil permeability 0.06 in/h or more; minimum preapplication
treatment -  primary; lower temperature limit 25 F; tailwater return system capacity 10 to 50 percent applied
surficial flow; underdrains, 4 to 8 in dia, 3 to 10 ft deep, 30 to 500 ft apart; soil texture - clay loams to
sandy loams.

Process Reliability - Extremely reliable.
Environmental Impact - Requires  long term commitment of large land area, i.e., largest land requirement of all
land treatment systems.            Concerns with vectors and crop contamination have been identified; but are
generally controllable with proper design  and operation.
References: 6, 9, 23

                                                       A-38

-------
 LAND TREATMENT,  SLOW  RATE,  GRAVITY, UNDERDRAWS)
                                                                               FACT SHEET 1.2.8
 FLOW DIAGRAM -
                       Surface Flooding
                           of
                       Wastewater
                                          Land Treatment
                                                                       Underdrains
                                                    Runoff
                                                                                 To reuse or
                                                                                  Discharge
                                         Tailwater Return
ENERGY NOTES - Gravity distribution methods consume no energy,
return energy requirements are included in 1.2.7
                                                          as long as sufficient head available;  tailwater
COSTS -Assumptions: ENR Index = 1850
1.   Costs are based on February 1973 figures;  (EPA Index
     Labor rates including fringe  benefits = ?5/hr.
     Storage for 75 days included  (see Fact Sheet 1.2.5).
                                                       194.2)  (Yearly average application rate  =  0.33  in./d)
10.
11.
Clearing costs are for brush with few trees using bulldozer-type equipment.
Levelling costs are for moving 500 yd /acre.
Distribution is by surface flooding using border strips or ridge and  furrow  methods.  Border  strips are 40 ft
wide by 1150 ft long; have concrete lined trapezoidal distribution ditches with  2  slide gates per  strip.
Ridge and furrow-gated aluminum pipe distribution based on 1200 ft long  furrows, rectangular  shaped fields.
Drain pipes (100-ft spacing)  are buried 6 to 8 ft with interception ditch along  length of  field and weir  for
control of discharge.
OSM cost (border strip) includes rebordering every 2 yr and major relining of  ditches after 10 yrs.  OSM  cost
(ridge and furrow) includes replacement of gated pipe after 10 yrs.   Also included are dike maintenance;
scraping and patching storage liner every 10 yrs; and inspection and  cleaning, underdrains, ditches, etc.
Materials cost includes high pressure jet cleaning of drain pipes every  5 yrs, annual cleaning of  interceptor
ditch, and major repair of ditches after 10 yrs.
A tailwater return rate of 20 percent is included (refer to 1.2.7 ).
Cost of pretreatment, monitoring wells, land and wastewater transmission costs to  and from site are not
included.
                         CONSTRUCTION COSTS
                                                                         OPERATION S MAINTENANCE COST
           10
          1 0
         001
            o.i
                         i.o           10

                         Wastewater Flow, Mgal/d
                                                                 1 0
                                                                 0 1
                                                             o
                                                             o
                                                             '5
                                                             8
                                                                001
                                                               0001
                                                                             and Furrow
                                                                                             ,  y
                                                                                           Border Stri
                                                100
0.1           1.0          10

            Wastewater Flow. Mgal/d
                                                                                                      100
 REFERENCE  -  Derived  from figures in reference 6.
To convert construction cost to capital cost see Table A-2.
                                                         A-39

-------
OVERLAND  FLOW,  GRAVITY                                                          FACT  SHEET  1.2.9
Description - Wastewater is applied over the upper reaches of sloped terraces  and is  treated  as  it  flows  across
the vegetated surface to runoff collection ditches.   The wastewater is renovated  by physical,  chemical  and  bio-
logical means as it flows in a thin film down the relatively impermeable  slope.   A secondary objective  of the
system is for crop production.  Perennial grasses (Reed Canary,  Bermuda,  Red Top, tall  fescue  and Italian Rye)
with long growing seasons, high moisture tolerance and extensive root formation are best suited to overland flow.
Harvested grass is suitable for cattle feed.  Biological oxidation, sedimentation and grass filtration  are  the
primary removal mechanisms for organics and suspended solids.  Nitrogen removal is attributed  primarily to  nitri-
fication/denitrification and plant uptake.  Loading rates and cycles are  designed to maintain  active  microorganism
growth on the soil surface.  The operating principles are similar to a conventional trickling  filter  with inter-
mittent dosing.  The rate and length of application is controlled to minimize severe anaerobic conditions that
result from overstressing the system.  The resting period should be long  enough to prevent surface ponding, yet
short enough to keep the microorganisms in an active state.   Surface methods of distribution include  the use of
gated pipe or bubbling orifice.  Gated surface pipe, which is attached to aluminum hydrants, is aluminum pipe with
multiple outlets.  Control of flow is accomplished with slide gates or screw adjustable orifices at each outlet.
Bubbling orifices are small diameter outlets from laterals used  to introduce flow.  Gravel may be necessary to
dissipate energy and ensure uniform distribution of water from these surface methods.  Slopes  must be steep enough
to prevent ponding of the runoff, yet mild enough to prevent erosion and  provide  sufficient detention time  for the
wastewater on the slopes.  Slopes must have a uniform cross  slope and be  free from gullies to  prevent channeling
and allow uniform distribution over the surface.  The network of slopes and terraces that make up an  overland
system may be adapted to natural rolling terrain.  The use of this type of terrain will minimize land preparation
costs.  Storage must be provided for non-operating periods.   Runoff is collected  in open ditches.  When unstable
soil conditions are encountered or flow velocities are erosive,  gravity pipe collection systems may be required.
Common preapplication practices include the following: screening or comminution for isolated sites with no  public
access; screening or comminution plus aeration to control odors  during storage or application  for urban locations
with no public access.  Wastewaters high in metal content should be pretreated to avoid soil and plant contamina-
tion.

Common Modifications - A common method of distribution is with sprinklers.  Recirculation of collected effluent  is
sometimes provided and/or required.  Secondary treatment prior to overland flow permits reduced  (as much as 2/3
reduction) land requirements.  Effluent disinfection is required where stringent  fecal  coliform criteria exist.

Technology Status - Relatively new.  Extensively used in the food processing industry.   Very few municipal  plants
in operation, and most are in warm, dry areas.

Application - Because overland flow is basically a surface phenomenon, soil clogging is not a  problem.   High BOD
and suspended solids removals have been achieved with the application of  raw comminuted municipal wastewater.
Thus, preapplication treatment is not a prerequisite where other limitations are  not operative.  Depth to ground-
water is less critical than with other land systems.   It also provides the following benefits:  an economic
return from the reuse of water and nutrients to produce marketable crops  or forage; and a means of recovering
renovated water for reuse or discharge.  Is preferred for gently sloping  terrain  with impermeable soils.

Limitations - Process is limited by soil type, crop water tolerances, climate, and slope of  the land.  Steep
slopes reduce travel time over the treatment area and thus,  treatment efficiency.  Flat land may require extensive
earthwork to create slopes.  Ideally, slope should be 2 to 8 percent.  High flotation tires  are required for
equipment.  Cost and impact of the earthwork required to obtain terraced  slopes  can be  major constraints.   Appli-
cation is restricted during rainy periods and stopped during very cold weather.   Many states have regulations
regarding preapplication disinfection, minimum buffer zones and control of public access.

Typical Equipment/No, of Mfrs. (23) - Pipes/9; pumps/34; valves/39; gates/9; plus farm equipment.

Performance - Percent removals for comminuted or screened municipal wastewater over about 150  ft of 2 to 6  percent
slope: BOD  and suspended Solids, 80 to 95 percent; Total N, 75 to 90 percent; Total P, 30 to  60 percent, Fecal
coliform 90 to 99.9 percent.

Chemicals Required - Normally none.  Addition of alum. Fed  or CaCO3 prior to application increases  phosphorus
removals.

Design Criteria - Field area required, 35 to 100 acres/Mgal/d; terraced slopes 2  to 8 percent; application  rate,
11 to 32 ft/yr, 2.5 to 16 in/wk; BOD  loading rate 5 to 50 Ib/acre/d; soil depth, sufficient to form slopes that
are uniform and to maintain a vegetative cover; soil permeability 0.2 in/h or less; hydraulic  loading cycle 6 to 8
hr application period, 16 to 18 hr resting period; operating period 5 to 6 d/wk;  soil texture  clay and clay loams.
Below are representative application rates for 2 to 8 percent sloped terraces:
               in/wk                              Pretreatment                  Terrace Length,  ft
               2.5 to 8                           untreated or primary               150
               6 to 16                            lagoon or secondary                120
Generally, 40 to 80 percent of applied wastewater reaches collection structures,  lower percent in summer and
higher in winter  (southwest data).

Environmental Impact - Requires long term commitment of large land area.   Potential odor and vector problems
exist, but careful design and operation generally can control them.

References - 6, 9, 23



                                                      A-40

-------
 OVERLAND FLOW, GRAVITY
                                                                                    FACT SHEET 1.2.9
 FLOW DIAGRAM  -
                                  Evaporation      Plant Uptake
                      Wastewater
                                          Overland Flow
                                                             Collection, Disinfection (if required)
                                                                           fc  and Discharge
                                           Percolation


ENERGY NOTES - Overland flow surface distribution consumes no energy if sufficient head available.   If sprinklers
employed, see Fact Sheet 1.2.5 .
COSTS -Assumptions: ENR Index = 1850
1.   Costs are based on February 1973 figures (EPA Index = 194.2);  labor rates,  including fringe benefits = ?5/h.
2.   Storage for 75 days included (See Fact Sheet 1.2.5 ).
3.   Site cleared of brush and trees using bulldozer-type equipment;  terrace construction:  175 to 250 ft wide with
     2.5 percent slope (1400 yd /acre of cut).  Costs include surveying, earthmoving,  finish grading, ripping two
     ways, disking, landplaning, equipment mobilization.
4.   Distribution system: application rate, 0.064 in/h; yearly average rate of 3 in /wk (8 h/d;  6 d/wk); flow to
     sprinklers, 13 gal/min at 50 psi; laterals 70 ft from top of terrace,  buried 18 in;  flow to laterals con-
     trolled by hydraulically operated automatic valves;  mainlines  buried 36 in; all pipe 4 in  diameter and
     smaller is PVC: all larger pipe is asbestos cement.
5.   Open Ditch Collection: network of unlined interception ditches sized for a 2 in/h storm;  culverts under
     service roads; concrete drop structures at 1,000 ft intervals.
6.   Gravity Pipe Collection: network of gravity pipe interceptors  with inlet/manholes every 250 ft along sub-
     mains; storm runoff is allowed to pond at inlets;  each inlet/manhole serves 1,000 ft of collection ditch;
     manholes every 500 ft along interceptor mains.
7.   OSM cost includes replacement of sprinklers and air compressors  for valve controls after 10 yr and either
     biannual cleaning of open ditches with major repair after 10 yr  or the periodic cleaning of inlets and
     normal maintenance of gravity pipe.  Also includes dike maintenance and scraping and patching of storage
     basin liner every 10 yr.
     Costs for pretreatment, land, transmission to site,  disinfection and service roads and fencing not included.
8.
                        CONSTRUCTION  COSTS
                                                                           OPERATION & MAINTENANCE COSTS
          10
          1 0
         001
                  Gravit
                          Pipe
                                    Open Ditch
                                                                   01
                                                                  001
                                                                 0001
                                                                              Open Ditch,
                                                                                             Gravity
                                                                                                     Pipe
           0.1           1.0          10

                     Wastewater Flow, Mgal/d


REFERENCE  -  Derived  from figures of Reference 6.
                                                    100
                                                                    0.1
                                                                                 1.0           10

                                                                                 Wastewater Flow. Mgal/d
100
*To convert construction cost to capital cost see Table A-2.
                                                      A-41

-------
ACTIVATED SLUDGE,  CONVENTIONAL DIFFUSED AERATION                          FACT  SHEET  2,1.1
Description - Activated sludge is a continuous flow, biological treatment process  characterized  by  a  suspension
of aerobic microorganisms, maintained in a relatively homogeneous state  by the mixing and turbulence  induced
by aeration.  The microorganisms are used to oxidize soluble and colloidal organics  to CO and HO  in the
presence of molecular oxygen.  The process is generally,  but not always, preceded by primary  sedimentation.
The mixture of microorganisms and wastewater formed in the aeration basins,  called mixed liquor,  is transferred
to gravity clarifiers for liquid-solids separation.  The  major portion of the  microorganisms  settling out  in
the clarifiers is recycled to the aeration basins to be mixed with incoming wastewater,  while the excess,
which constitutes the waste sludge, is sent to the sludge handling facilities.  The  rate and  concentration of
activated sludge returned to the aeration basins determines the mixed liquor suspended solids (MLSS)  level
developed and maintained in the basins.   During the oxidation process,  a certain amount of the organic
material is synthesized into new cells, some of which then undergoes auto-oxidation  (self-oxidation,  or
endogenous respiration)  in the aeration basins, the remainder forming net growth or  excess sludge.  Oxygen is
required in the process to support the oxidation and synthesis reactions.  Volatile  compounds are driven off
to a certain extent in the aeration process.  Metals will also be partially removed, with accumulation in  the
sludge.  Activated sludge systems are classified as high  rate, conventional, or extended aeration (low rate)
based on the organic loading.  In the conventional activated sludge plant,  the wastewater is  commonly aerated
for a period of four to eight hours (based on average daily flow)  in a plug flow hydraulic mode.  Either
surface or submerged aeration systems can be employed to  transfer oxygen from  air to wastewater.  Compressors
are used to supply air to the submerged systems, normally through a network of diffusers, although  newer
submerged devices which don't come under the general category of diffusers (e.g.,  static aerators and jet
aerators) are being developed and applied.  Diffused air  systems may be  classified as fine bubble or  coarse
bubble.  Diffusers commonly used in activated sludge service include the following:   porous ceramic plates
laid in the basin bottom (fine bubble), porous ceramic domes or ceramic  or plastic tubes connected  to a pipe
header and lateral system (fine bubble), tubes covered with synthetic fabric or wound filaments  (fine or
coarse bubble), and specially designed spargers with multiple openings (coarse bubble).

Common Modifications - Step aeration;  contact stabilization; and complete mix  flow regimes.   Alum or  ferric
chloride is sometimes added to the aeration tank for phosphorus removal.

Technology Status- Activated sludge is the most versatile and widely used biological process  in wastewater
treatment.

Typical Equipment/No, of Mfrs. (23, 97)  - Equipment normally associated with diffused air,  activated sludge
systems include the following:  air diffusers/19;  compressors/44.

Applications - Domestic wastewater and biodegradable industrial wastewater.   The main advantage  of  the  conven-
tional activated sludge system is the lower initial cost of the system,  particularly where  a  high quality
effluent is required.  Industrial wastewater (including some "priority pollutants")  which is  amenable  to
biological treatment and degradation may be jointly treated with domestic wastewater in a conventional activated
sludge system.

Limitations - Limited BOD  loading capacity; poor organic load distribution;  required aeration time of four
to eight hours; plant upset with extreme variations in hydraulic,  organic,  and toxic  loadings;  operational
complexity; operating costs; energy consuming mechanical compressors;  and diffuser maintenance.

Performance (26, 39) -   BOD, Removal (conventional activated sludge)            85-95 percent
                         NH -N removal (non-nitrified systems)                   10-20 percent

Residuals Generated - The following table illustrates the anticipated  increase in excess sludge,  volatile
suspended solids (VSS) production from the conventional activated sludge  process as  settled wastewater food-
to-microorganism (F/M) loadings increase:
          F/M (Ib BOD /d/lb MLVSS)                      Excess VSS (secondary effluent plus waste sludge)
          0.3                                          0.5 Ib/lb BOD  removed
          0.5                                          0.7

Design Criteria (26, 31, 30) - A partial listing of design criteria for the conventional activated sludge
process is summarized as follows:
                                   Volumetric loading,  Ib BOD5/d/1000 ft                  25-50
                                   Aeration detention time,  h (based on avg.  daily flow)   4-8
                                   MLSS,  mg/1                                             1500-3000
                                   F/M, Ib BOD /d/lb MLVSS                                0.25-0.5
                                   Air required,  std.  ft /Ib BOD  removed                 800-1500
                                   Sludge retention time, days                            5-10

Unit Process Reliability (31)  - Good.
Environmental Impact - Sludge disposal; odor potential;  and energy consumption.
References - 23, 26, 28, 30, 31, 39, 97
                                                       A-42

-------
  ACTIVATED SLUDGE, CONVENTIONAL  DIFFUSED  AERATION
                                                                                    FACT SHEET 2.1.1
 FLOW DIAGRAM -
                        Primary Effluent
                       	fc
                                                       Aeration Tank
                                                                             To Final Clarifier
                                       Return Sludge
                               Excess Sludge
ENERGY NOTES -Assumptions:
The hydraulic head loss through the aeration tank
is negligible.  Sludge recycle and sludge wasting
pumping energy are a part of clarifier operation.
                                  Clarifier
                                  Effluent (mg/1)
                                      20
                                      20
Water Quality:
                 Influent (mg/1)
                    130
Suspended Solids    100
Oxygen Transfer Rate (wire to water)  in wastewater
for:
Fine Bubble Diffusion =2.5  Ib O /hph
Coarse Bubble Diffusion =  1.5  Ib 0 /hph
Average oxygen requirement - 1300  Ib/d/Mgal/d
COSTS * - Assumptions:
Service life = 40 years.  ENR Index = 2475
Construction cost includes aeration basins,  air
supply and dissolution equipment and piping,  and
slower building.   Clarifier and recycle pumps are
not included.
removed. MLVSS
                1.1 Ib O2 supplied/lb BOD
                 2100  mg/1.   F/M =  0.25  Ib BOD /
d/lb MLVSS.  Detention time =  6 hours (based on
average daily flow).   Volumetric loading  = 32 Ib
BOD /d/1,000 ft .  Power costs are for an
 iverage energy requirement of
2.0 Ib 02/hph @S.02Awh.
           10
        i
        o
                         CONSTRUCTION  COST
            01
REFERENCES 3,  4
                         10            10
                       Wastewater Flow, Mgal/d
                                                    Sludge  from Final Clarifier
                                                   IOO
*To convert construction  cost to capital cost see Table A-2.
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                                                       A-43

-------
ACTIVATED  SLUDGE,  CONVENTIONAL  MECHANICAL AERATION                       FACT SHEET 2,1.2
Description - The activated sludge system in general,  and the  conventional  activated  sludge plant in particular,
are described in Fact Sheet 2.1.1. Mechanical aeration methods include the  submerged  turbine with compressed air
spargers (agitator/sparger system) and the surface-type mechanical  entrainment aerators.  The surface-type
aerators entrain atmospheric air by producing a region of intense turbulence  at the surface around their periphery.
They are designed to pump large quantities of liquid,  thus dispersing the entrained air and agitating and mixing
the basin contents.  The agitator/sparger system consists of a radial-flow  turbine located below the mid-depth of
the basin, with compressed air supplied to the turbine through a sparger.   Volatile compounds are driven off to a
certain extent in the aeration process.  Metals will also be partially removed, with  accumulation in the sludge.

Common Modifications - In addition to the modifications listed on Fact Sheet  2.1.1 for conventional activated
sludge plants, the following mechanical aeration modifications should also  be considered.  The  submerged turbine
aeration system affords a convenient and relatively economical method for upgrading overloaded  activated sludge
plants.  To attain optimum flexibility of oxygen input,  the surface aerator can be combined with the submerged
turbine aerator.  Several manufacturers supply such equipment, with both aerators mounted on the same vertical
shaft.  Such an arrangement might be advantageous if space limitations require the use of deep  aeration basins.
In addition, mechanical aerators may be either the floating or fixed installation type.

Technology Status - Highly developed and widely used,  particularly  in the industrial  wastewater treatment field.
Since 1950, the submerged turbine (widely used in the  chemical industry) has  come into use for  activated sludge
aeration.

Typical Equipment/No, of Mfrs. (23)  - Equipment normally associated with mechanical aeration conventional
activated sludge systems include the following:  aerators/30;  package treatment plants/21.

Applications - See Fact Sheet 2.1.1.  Has been used primarily  in industrial waste activated sludge treatment
plants and is considered an attractive aeration system for very deep basins (with bottom mixers or spargers plus
surface aerators), for activated sludges having high oxygen uptake  rates, and for high concentrations of MLSS as
in aerobic digesters.

Limitations - Limited BOD loading capacity; poor organic load  distribution; required  aeration time of four to
eight hours; plant upset with extreme variations in hydraulic  and organic loadings; operational complexity and
the resulting operating costs; energy consuming mechanical aerators; aerator  maintenance; and potential for ice
formation around surface aerators.

Performance -
BOD Removal  (conventional activated sludge system)                                 85 to 95 percent
NH -N Removal (Non-nitrified systems)                                              10 to 20 percent

Residuals Generated - See Fact Sheet 2.1.1.

Design Criteria - A partial listing of design criteria for the mechanically-aerated conventional activated
sludge process is summarized as follows:

          Volumetric loading, Ib BOD /d/1000 ft                        25-50
          Aeration detention time, h (based on average daily flow)      4-8
          MLSS, mg/1                                                   1500-3000
          F/M, Ib BOD /d/lb MLVSS                                      0.25-0.5
          Air required, std. ft /Ib BOD  removed                       800-1500  (agitator-sparger system only)
          Sludge retention time, days                                  5-10
            lixing equipment for aeration or oxygen transfer must be sized to keep the  solids  in  uniform suspen-
            times.  Depending on basin shape and depth, 4000 mg/1 of MLSS require about  0.75  to  1.0 hp/1000  ft
Note:  The m.
sion at all ^J_»H*-H.
(0.02 to 0.03 kW/m )  of basin volume to prevent settling if mechanical aerators are employed.  However, the power
required to transfer the necessary oxygen will  usually  equal or exceed this value.

Process Reliability - See Fact Sheet 2.1.1.   Reliability of mechanical aeration equipment is dependent on the
quality of manufacture and a planned maintenance program.

Environmental Impact - Sludge disposal, aerosol and odor potential,  and energy consumption.

References - 23, 26,  28, 30, 31,  39
                                                      A-44

-------
 ACTIVATED  SLUDGE, CONVENTIONAL,  MECHANICAL AERATION
                                                                                    FACT  SHEET 2.1.2 .
FLOW DIAGRAM-  gee Fact Sheet 2.1.1  for typical flow diagram.

                         Driv
                 Mechanical Surface Aerator
 ENERGY NOTES - Assumptions:
The hydraulic head loss through the aeration
tank is negligible.  Sludge recycle and sludge
wasting pumping energy are a part of clarifier
operation.                         Clarifier
Water Quality:    Influent (mg/1)   Effluent (mg/1)
  >D5                130                 20
Suspended Solids    100                 20

Assumed Oxygen Transfer Rate  = 1.8  Ib 0 /hph for high-
speed surface aerator and 1.6 Ib 0^/hph for turbine
sparger (wire to water)  in wastewater.   Conventional
activated sludge oxygen requirement = 1.1  Ib o /Ib BOD
removed.                                       2       5
COSTS -
Design Basis: ENR Index = 2475
1.   Construction cost includes aeration basins and
     surface aerators.  Clarifier and recycle pumps
     are not included.
     Volumetric loading = 32 Ib BOD /d/1,000 ft3.
     1-1 Ib 02 supplied/lb BOD,, removed;  Oxygen Trans-
     fer Rate -1.8 lb/hph.(high speed surface  aerators)
     MLVSS = 2100 mg/1
     F/M = 0.25 Ib BOD /d/lb MLVSS
     Detention time = 6 h (based on average  daily  flow).
         10 =
         10
        oo
                     t-^ONSTRUCTION COS
                       - — -- --- "-
                       10            10            loo
                  Wastewater Flow, Mqal/d
ffiFERENCES -3,4
To convert construction cost to capital cost see Table  A-2.
                                                                         Drive
                                                                                            .Compressor
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                                                                          Wastewater Flow, Mgal/d
                                                       A-45

-------
ACTIVATED SLUDGE,  HIGH  RATE,  DIFFUSED AERATION                             FACT  SHEET  2.1.3
Description - A description of the activated sludge process in general  is presented in Fact Sheet  2.1.1.   Acti-
vated sludge systems have traditionally been classified as high rate,  conventional,  or  extended aeration  (low
rate) based on organic loading.   The term modified aeration has been adopted to  apply to  those  high rate  air
activated sludge systems with design F/M loadings in the range of 0.75 to  1.5 Ib BOD /d/lb MLVSS.   Modified
aeration systems are characterized by low MLSS concentrations, short aeration detention times,  high' volumetric
loadings, low air usage rates, and intermediate levels of BOD,, and suspended solids  removal  efficiencies.   Prior
to enactment of nationwide secondary treatment regulations, modified aeration was utilized as an independent
treatment system for plants where BOD  removals of 50 to 70 percent would  suffice.   With  present-day treatment
requirements, modified aeration no longer qualifies as a "stand-alone" activated sludge option.

Modified aeration basins are normally designed to operate in either complete mix or  plug  flow hydraulic configu-
rations.  Either surface or submerged aeration systems can be employed to  transfer oxygen from  air  to wastewater,
although submerged equipment is specified more frequently for this process.   Compressors  are used to supply air
to submerged aeration systems.  A description of diffuser alternatives and other submerged aeration devices is
presented in Fact Sheet 2.1.1.  Volatile compounds are driven off to a certain extent in  the aeration process.
Metals will also be partially removed, with accumulation in the sludge.

Common Modifications - Recently, due primarily to rapidly escalating -power costs,  interest has  been expressed in
the development of high rate,  diffused aeration systems which would produce a high quality  secondary  effluent.
As with modified aeration, aeration detention times would remain low and volumetric loadings  high.  In  contrast
to modified aeration systems,  high MLSS concentrations would have to be  utilized to permit  F/M loadings to  be
maintained at reasonable levels.   The key to development of efficient high rate  air systems is the  availability
of submerged aeration equipment that could satisfy the high oxygen demand rates  that accompany high MLSS levels
and short aeration times.  New innovations in fine bubble diffuser and jet aeration technology offer  potential
for uniting high efficiency oxygen transfer with high rate air activated sludge  flow regimes  to achieve acceptable
secondary treatment as independent "stand alone" processes.  Research evaluations and field studies currently
underway should provide performance and cost data on this subject in the next several years.

Technology Status - Was more widely used in the 1950's and 1960's than it is today because  of the less  stringent
effluent standards in effect during these periods.

Typical Equipment/No. of Mfrs. - Equipment normally associated with diffused air, activated sludge  systems  in
general, include the following:  air diffusers/19; compressors/44.

Applications - See Fact Sheet 2.1.1. Since the early 1970's, employed generally  as a pretreatment or  roughing
process in a two-stage activated sludge system, where the second stage is used for biological nitrification.
Alum or one of the iron salts is sometimes added to modified aeration basins preceding second-stage nitrification
units for phosphorus removal.

Limitations - High rate activated sludge alone does not produce an effluent with BOD  and suspended solids  concen-
trations suitable for discharge into most surface waters in the United States.  (Cannot assure that 30  mg/1 BOD
and SS in the final effluent will be achieved).

Performance -
BOD  Removal for modified aeration - 5O to 70 percent; for high solids,  high rate air system  - 85 to  95 percent
(tentative).
NH -N Removal - 5 to 10 percent.

Residuals Generated - One modified air aeration system fed with degritted raw wastewater produced on  the average
over a two-year period 1.11 Ib excess VSS (secondary effluent plus waste sludge)/Ib BOD5 removed at an  average
F/M ratio loading of 1.17 Ib BOD5 /d/lb MLVSS.

Design Criteria (39) - A partial listing of design criteria for the two  high rate air activated sludge  process
options are summarized as follows:
                                                        Modified Aeration     High Solids,  High Rate  Aeration
                                                                                       (tentative)
Volumetric loading, Ib BOD /d/1000 ft                       50 - 100                   50 - 125
MLSS, mg/1                                                  800 - 2000                 3000 - 5000
Aeration detention time, hours (based on influent flow)     2-3                      2-4
F/M, Ib BOD /d/lb MLVSS                                     0.75 - 1.5                 0.4  -  0.8
Std ft  air?lb BOD  removed                                 400 - 800                  800  -  1200
Lb 02/lb BOD  removed                                       0.4 - 0.7                  0.9  -  1.2
Sludge retention time, days                                 0.75-2                   2-5
Recycle ratio (R)                                            0.25 - 1.0                 0.25 - 0.5
Volatile fraction of MLSS                                   0.7-0.85                 0.7-0.8

Process Reliability - Requires close operator attention.

Environmental Impact- See Fact Sheet 2.1.1.
References - 23, 26, 31, 39, 263
                                                        A-46

-------
 ACTIVATED SLUDGE,  HIGH  RATE,  DIFFUSED  AERATION
                                                                                   FACT SHEET 2,1,3
LOW DIAGRAM -
   Effluent Feed
egritted
or Primary




'
t
t
Complete Mix
1 1 » 1 t 1
t i , , , ,
Aeration Tank

i '
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To Final Clarifier
From Final Clarifi
1 Was
                                                                                              Waste  Sludge
ENERGY NOTES - Assumptions:   The hydraulic  head  loss
through the aeration tank is negligible.  Sludge
recycle and sludge wasting pumping energy are  a  part
of clarifier operation.   Oxygen Transfer Rate  with
coarse bubble diffusers = 1.5  Ib O /hph  (wire to
water) in wastewater.  Other parameters in  accordance
with cost assumptions.

COSTS* - Assumptions: ENR Index = 2475. Construction
cost includes aeration basins, air supply equipment
and piping, and a blower building.  Clarifier  and
recycle pumps are not included.  Basins sized  with  50
percent recycle flow.  Detention time= 3 h  (based on
average daily flow).  F/M = 1.0 Ib BOD5/d/lb MLVSS.
0.7 Ib 0  applied per Ib BOD  removed.  MLVSS  =  1050
mg/1.  Service life = 40 years.
fied aeration.
                                 Costs  are  for modi-
                    Influent
                      mg/1
                      130
                                   Effluent
                                     mg/1
                                      40
            1.0
          I
          Z 01
           001
                          -CONSTRUCTION COST
                           10            10
                      Wastewater Flow, Mgal/d
                                                     100
                                                                  in
REFERENCES -3,4

*To convert construction cost to capital cost see  Table A-2.



                                                      A-47
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-------
ACTIVATED SLUDGE,  PURE OXYGEN,  COVERED                                       FACT  SHEET 2,1,4
Description - The use of pure oxygen for activated sludge treatment has become competitive with the use of air due
to the development of efficient oxygen dissolution systems.   The covered oxygen system is a high rate activated
sludge system.  The main benefits cited for the process include reduced power requirements for dissolving oxygen
in the wastewater, reduced aeration tank volume requirements, and improved biokinetics of the activated sludge
system.  In the covered system, oxygenation is performed in a staged,  covered reactor in which oxygen gas is
recirculated within the system until it reaches a reduced level of purity and a decreased undissolved mass at
which it can no longer be used and is vented to the atmosphere.  High-purity oxygen gas (90 to 100 percent volume)
enters the first stage of the system and flows concurrently with the wastewater being treated through the oxygena-
tion basin.  Pressure under the tank covers is essentially atmospheric, being held at 2 to 4 inches water column,
sufficient to maintain oxygen gas feed control and prevent backmixing  from stage to stage.  Effluent mixed liquor
is separated in conventional gravity clarifiers, and the thickened sludge is recycled to the first stage for
contact with influent wastewater.

Mass transfer and mixing within each stage are accomplished either with surface aerators or with a submerged-
turbine rotating-sparge system.  In the first case, mass transfer occurs in the gas space; in the latter, oxygen
is sparged into the mixed liquor where mass transfer occurs from the oxygen bubbles to the bulk liquid.  In both
cases, the mass-transfer process is enhanced by the high oxygen-partial pressure maintained under the tank covers
in each stage.

Volatile compounds are driven off to a certain extent in the oxygenation process and removed in the vent gas.
Metals may also be expected to be partially removed, with accumulation in the sludge.   High purity oxygen may be
produced on-site by cryogenic or PSA (Pressure Swing Adsorption) generators, or purchased as liquid oxygen pro-
duced off-site and stored at the treatment plant.  Cost effectiveness  of oxygen source depends upon plant size and
process train.

Common Modifications - Although flexibility is claimed to permit operation in any of the normally used flow
regimes, i.e., plug flow, complete mix, step aeration, and contact stabilization, the method of oxygen contact
employed favors the plug flow mode.  Process may be designed to achieve: optimum carbonaceous oxidation only,
combined carbonaceous and nitrogenous oxidation, or optimum nitrogenous oxidation as a separate stage after
secondary treatment.

Technology Status - Pilot and full scale plant studies since 1969; presently over 100 municipal and industrial
plants.

Typical Equipment/No, of Mfrs. (23) - Oxygen activated sludge systems/5; Oxygen generators/1; Liquid oxygen
storage tank (for standby and peak load capacity)/I; and aerators/30.

Applications - Domestic and biologically degradable industrial wastewaters; upgrading existing air activated
sludge plants; new facilities - to reduce construction cost where effective odor control is required, where high
effluent dissolved oxygen is required, where reduced quantity and higher concentration of waste sludge is required
and where reduced aeration detention time is required.

Limitations - Complexity of operation.

Performance (46) - Certain pilot test performance data are summarized  here:
                                                            Location A   Location B   Location C   Location D
Carbonaceous Oxidation:
COD, percent removal                                             77          76            73          80
BOD , percent removal                                            89          95            91          95
Suspended solids, percent removal                                89          64            75          76

Nitrogenous Oxidation; NH -N percent removals:
Single stage with carbonaceous oxidation                         20% - 90%
Separate stage nitrification after carbonaceous oxidation        80% - 98%

Residuals Generated  (46) - Pilot test systems have generated between 0.42 and 1.0 Ib VSS per Ib BOD5 removed.

Design Criteria  (Carbonaceous BOD  Oxidation) -                 ,
                           Volumetric loading, Ib BOD /d/1000 ft                100 to 200
                           F/M Ib BOD /d/lb MLVSS                               0.5 to 1.0
                           Oxygen requirement, Ib 0 /Ib COD removed             0.6 to 0.8
                           MLSS, mg/1                                           3,000 to 6,000
                           Aeration detention time, hours                       1 to 3
                           Mixed liquor dissolved oxygen, mg/1                  4 to 8
                           Oxygen required, Ib 02/lb BOD5 removed               0.9-1.3

Process Reliability - Complex operation, high level of operator/maintenance attention required.

Environmental Impact - Sludge disposal; energy consumption.

References - 22, 26, 28, 46
                                                     A-48
-------
 ACTIVATED SLUDGE,  PURE  OXYGEN COVERED
                                                         FACT SHEET 2.1.4
FLOW DIAGRAM -
                                                         Aeration
                                                        Tank
                                 Oxygen Feed Gas
                               eration               l~ Surface Ae
                               nk  Cover    \.        I          r-

                               n	\ n   /         n
Surface Aerator
          Mixer Drive
            Screened and Degritted Raw Wastewater
            or Primary Effluent Feed
                                   Return Sludge
ENERGY NOTES  (4)  - Assumptions: Carbonaceous Oxidation.
Operating Parameters:  Oxygen activated sludge oxygen re-
quirement = 1.2  Ib O2/lb BOD   removed.
Water Quality:         Influent  (mg/1) Effluent  (mg/1)
                                                                                                       Exhaust Gas
                                                                    J—   Mixed Liquor
                                                                    T"   to Clarifier
                                                           Submerged propeller  (Optional)
 BOD,.
                              130
                                             20
Oxygen Transfer  Rate  (OTR)  includes  oxygen production  and      ^
oxygen dissolution.                                           ^
1. With  cryogenic  oxygen gas  generation  and  surface  aerators, 3
OTR  = 2.5  Ib 0 /hph  (wire to  water)  in wastewater
 2. With pressure  swing  adsorption  (PSA)  oxygen  gas  generation T>
 and  surface  aerators, OTR
 wastewater.
2.0 Ib O /hph (wire to water)  in
 3. Liquid  0   supply and surface  aerators,
 O /hph (wire  to  water)  in wastewater.
                                           OTR =  6.5  Ib
COSTS*  - Design  Basis:  January 1979 dollars; ENR  Index =     c
2872.   Assumptions:   Carbonaceous Oxidation.
1.  Construction cost includes oxygenation basins, dissolution18
equipment, oxygen generators and liquid oxygen feed/storage   -jj
facilities, instrumentation  (where applicable), and licensing *•
fees.                                                         
-------
ACTIVATED SLUDGE,  PURE  OXYGEN,  UNCOVERED                                    FACT  SHEET 2.1.5
De scription - The use of pure oxygen for activated sludge treatment has become competitive with the use of air due
to the development of efficient oxygen dissolution systems.   The open tank oxygen system is a high rate activated
sludge system.  The main benefits cited for the process include reduced power requirements for dissolving oxygen
in the wastewater, reduced aeration tank volume requirements, and improved biokinetics of the activated sludge
system.  In the uncovered system, oxygenation is performed in an open reactor in which extremely fine porous
diffusers are utilized to develop small oxygen gas bubbles that are completely dissolved before breaking surface
in normal-depth tanks.  The basic principles which apply in the transfer of oxygen in conventional diffused air
systems also apply to the open tank pure oxygen system.

The pure oxygen open tank system produces ultra-fine bubbles with a correspondingly high gas surface area.  These
ultra-fine bubbles are of micron size, whereas "fine bubbles" normally produced in diffused air systems are in
millimeter sizes.  The complete oxygenation system is composed of an oxygen dissolution system comprised of
rotating diffusers; a source of high-purity oxygen gas (normally, an on-site oxygen generator); and an oxygen
control system which balances oxygen supply with oxygen demand through use of basin-located dissolved oxygen
probes and control valves.  High purity oxygen may be produced on-site by cryogenic or PSA (Pressure Swing Adsorp-
tion) generators, or purchased as liquid oxygen produced off-site and stored at the treatment plant.  Selection of
cost effective oxygen source depends upon plant size and treatment train.

The influent to the system enters the oxygenation tank and is mixed with return activated sludge.   The mixed
liquor is continuously and thoroughly mixed using low energy mechanical agitation deep in the mixed liquor.
Mixing is produced by radial turbine impellers located on both surfaces (top and bottom)  of the rotating diffusion
discs.  Pure oxygen gas in the form of micron-size bubbles is simultaneously introduced into the tank to accom-
plish mass oxygen transfer.  The rotating diffuser is a gear-driven disc-shaped diffusion device equipped with a
porous medium to assist in the diffusion process.  As the diffuser rotates at constant speed in the mixed liquor,
hydraulic shear wipes bubbles from the medium before they have an opportunity to coalesce and enlarge.

Common Modifications - Operation in any of the normally-used flow regimes, i.e., plug flow, complete mix, step
aeration, and contact stabilization, can be used as conditions dictate since the method of oxygen contact employed
does not favor one particular operating mode.  System may be designed to optimize carbonaceous (BOD ) oxidation,
combined carbonaceous (BOD ) and nitrogenous (NOD) oxidation as a single stage, or nitrogenous oxidation as a
separate stage after secondary treatment.

Technology Status - Recently developed; supplied under proprietary status.

Applications - Domestic and biologically degradable industrial wastewaters; plant flows greater than 1 Mgal/d;
upgrading existing air activated sludge plants; new facilities - to reduce construction cost where high effluent
dissolved oxygen is required, where reduced quantity and higher concentration of waste sludge is required, and
where reduced aeration detention time is required.

Limitations - Complexity of operation.

Performance - Removal efficiencies of various pollutants are similar to those of activated sludge and vary with
mode of operation, aeration detention time, and character of influent wastewater.  Examples of operational and
pilot test data have demonstrated the following removals:

          Carbonaceous Oxidation:
               BOD                                          75-95%
               COD                                          60-85%
               SS                                           60-90%
               Single stage nitrification, NH4~N            20-90%
               carbonaceous oxidation, NH -N                80-98%
          Nitrogenous Oxidation:
               Single stage nitrd

               Separate stage nitrification after
               carbonaceous oxidation,  NH -N

Residuals Generated - Between 0.42 ane  1.00 Ib VSS per Ib BOD5 removed.

Design Criteria -                    Volumetric Loading              100  to  200  Ib  BOD  /d/1000  ft
                                     F/M                             0.5  to  1.0  Ib  BOD5/d/lb  MLVSS
                                     Oxygen requirement,
                                        Ib 0 /Ib BOD  removed         0.9-1.3
                                        Ib 0 /Ib COD removed          0.6  to  0.8
                                     Aeration Detention Time         1  to 3  h (based on avg.  daily  flow)
                                     Mixed Liquor D.O.                2  to 6  mg/1
                                     MLSS                            3,000 to 6,000 mg/1

Process Reliability - Not yet fully established.

Environmental Impact - Sludge disposal; odor potential;  and energy consumption.

References - 26, 185, 186
                                                        A-50
-------
ACTIVATED SLUDGE,  PURE  OXYGEN, UNCOVERED
                                                                                    FACT SHEET 2.1,5
FLOW DIAGRAM -
                                                             .—  Motor/Gear
                                                            /	Reducer  Assembly
                                                                               D.O.  Analyzer
                                                                                    Typical Open Basin
                                                                                         .-] Mixed Liquor to Clarifier
                     LOX
                   Storage (Stand-By) N—Vaporizer
ENERGY NOTES (4) - Assumptions: Carbonaceous Oxidation.
Operating Parameters: Oxygen activated sludge oxygen re-
quirement = 1.2 Ib 0 /Ib BOD  removed.
Water Quality:         Influent (mg/1) Effluent (mg/1)


























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        10








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        0 1	
         01            10           10           100
                      Wastewater Flow, Mgal/d
REFERENCES - 3, 4, 259
*To convert  construction cost to capital cost,  see  Table A-2.
                                                          A-51

                             130            20
Oxygen Transfer Rate  (OTR) includes oxygen production and
oxygen dissolution.
1. With cryogenic oxygen gas generation and surface aerators,
OTR = 2.5 Ib 02/hph  (wire to water) in wastewater.
2. With pressure swing adsorption  (PSA) oxygen gas generation
and surface aerators, OTR - 2.0 Ib O /hph (wire to water) in
wastewater.
3. Liquid 0  supply and surface aerators, OTR = 6.5 Ib
0 /hph (wire to water) in wastewater.
COSTS* - Design Basis: January 1979 dollars; ENR Index «
2872. Assumptions: Carbonaceous Oxidation.
1. Construction cost includes oxygenation basins, dissolution
equipment, oxygen generators and liquid oxygen feed/storage facil-
ities, instrumentation (where applicable),  and licensing fees.
2. Oxygen was assumed to be delivered as liquid oxygen for
plants from 0.1 to 1 Mgal/d size. For plants from 1.0 to 100
Mgal/d, oxygen was assumed to be generated on-site.
   1.2 Ib O  supplied per Ib BOD  removed.
4. MLVSS = 3100 mg/1.  F/M = 0.5 Ib BOD /d/lb MLVSS.
5. Volumetric loading = 97 Ib BOD5/d/1000 ft .
6. Detention time = 2 h (based on average daily flow).
 . Electricity @ $.05Awh, labor @ $ll/h, liquid 0  @ $100/t.
                      CONSTRUCTION COST           2
        100
                                                                       10
                                                                   3
                                                                    *
                                                                       10
                                                                       10

                                                                                            Z PSA
                                                                                   Liquid Oxygen
                                                                                   I I Mil  II   II
                                                                                                    Cryogen
                                                                                                           w
                                                                          Liquid Oxygen;
                                                                    o

                                                                      0001
                                                                                      10            10
                                                                                      Wastewater Flow Mgal/d


                                                                                OPERATION & MAINTENANCE COST
                                                                                                                 100
                                                                                            -PSA-
                                                                                                       Cryogemc ~»

                                                                                     v<±
                                                                                           J_
                                                                         01
                                                                   Total 	
                                                                   Power	Materials
                                                                                      1 0            10            100
                                                                                     Wastewater Flow, Mgal/d

                                                                                    —   Labor 	 	 	
-------
ACTIVATED SLUDGE WITH NITRIFICATION                                          FACT  SHEET  2.1.6
Description - This process is also referred to as single-stage nitrification,  because  ammonia and carbonaceous
materials are oxidized in the same aeration unit.   As in any aerobic biological process,  carbonaceous  materials
are oxidized by heterotrophic aerobes.  In addition, a special group of autotrophic aerobic  organisms  called
nitrifiers oxidize ammonia in two stages:  Nitrosomonas bacteria convert ammonia to nitrite  and Nitrobacter
convert nitrite to nitrate.  The optimal conditions for nitrification,  in general,  are:   temperature of about
30°C; pH of about 7.2 to 8.5; F/M of about 0.05 to 0.15; relatively long aeration detention  time as nitrifiers
have a lower growth rate than other aerobes; and sludge retention time  of about 20  to 30  days,  depending upon
temperature.

The degree of nitrification depends mainly on three factors, SRT, mixed liquor DO concentration and wastewater
temperature, of which SRT is of primary importance because of the slow  growth rate  of nitrifiers. If  the sludge
is wasted at too high a rate, the nitrifiers will be eliminated from the system.  Generally,  nitrification begins
at an SRT of about five days, but does not become appreciable until the SRT reaches about 15 days, depending  upon
temperature.  The aeration system is designed to provide the additional oxygen needed to  oxidize the ammonia
nitrogen.

The conventional and high rate modifications of the activated sludge process do not provide  the necessary hydrau-
lic and sludge detention time.  Besides, the F/M ratio is higher.  As a result, single stage nitrification cannot
be achieved in these configurations, although they effect a small reduction, about  20 percent in ammonia.

Common Modifications - Any low rate modification of the activated sludge process such as  the extended  aeration  and
the oxidation ditch can be used.  In addition, the use of powdered activated carbon has the potential to enhance
ammonia removal, although its application is in a state of infancy.

Technology Status - Over all, the process is fully  demonstrated.   There are nearly 650 shallow oxidation ditch
installations in the U.S. and Canada.  In addition, pre-engineered extended aeration plants are also widely used.

Typical Equipment/No, of Mfrs. (23) - Aerators/30; extended aeration package treatment plants/21;  air diffusers/19;
compressors/44; oxidation ditch equipment (brush aerators, etc.)/6;  hydraulic controls/29.

Application - Applicable during warm weather if levels of 1 to 3 mg/1 of ammonia nitrogen in the effluent is
permitted.

Limitations - Biological nitrification is very sensitive to temperature,  resulting in poor reduction in colder
months.  In addition, heavy metals such as Cd, Cr, Cu, Ni, Pb and Zn,  phenolic compounds,  cyanide and halogenated
compounds can inhibit nitrification reactions.

Performance - A well-established extended aeration process will decrease ammonia-nitrogen  to around 1 mg/1 if the
aerator temperature is about 55 F.

Residuals Generated - This process produces no primary sludge.   The secondary sludge is lesser in quantity and
better stabilized than the high rate and conventional activated sludge process,  which minimizes the magnitude of
the disposal problem considerably.

Design Criteria -                                                Extended Aeration   Oxidation Ditch
     Volumetric loading, Ib BOD /d/1000 ft                       5 to 10             10 to 15
     MLSS, mg/1                                                  3,000 to 6,000      3,000 to 5,000
     F/M, Ib BOD /d/lb MLVSS                                     0.05 to 0.15        0.03 to 0.10
     Aeration detention time (based on average daily flowjh,     18 to 36            24
     Air supplied, std. ft /Ib BOD_ applied                      3,000 to 4,000
     Ib O /Ib BOD  applied                                       2.0 to 2.5          2.0 to 2.5
     Sludge Retention Time, d                                    20 to 30            20 to 30
     Recycle Ratio                                               0.7 to 1.5          0.25 to 0.75
     Volatile fraction of MLSS, mg/1                             0.6 to 0.7          0.6 to 0.7
Process Reliability - Good.
Environmental Impact - From the solid waste point of view, the impact is very minimal compared to high rate and
conventional activated sludge processes.  However, odor and air pollution problems are very similar to other
activated sludge processes.

References - 28, 29
                                                        A-52
-------
ACTIVATED  SLUDGE WITH NITRIFICATION
                                                           FACT SHEET 2.1,6
FLOW DIAGRAM -
                   Screened and Degritted
                            Wastewater
                            with or
                            without
                            Primary
                        Sedimentation
                                              Aerator
                                                     Return Sludge
                                                                                 Excess  Sludge
 ,NERGY NOTES - Assumptions:  The hydraulic head loss through the aeration tank is negligible.   Sludge recycle  and
 sludge wasting pumping energy are part of clarifier operation.
      Water  Quality

          Ammonia as N
          BOD,.
                Influent, mg/1           Effluent,  mg/1
                                    Warm Months    Cold Months
                     15                  1.0       Up to 12.0
                    130                 20.0             20.0
 Oxygen  Requirement =  1.5 Ib O /lb BOD  removed + 4.6 Ib 02/lb NH4-N removed.

 Oxygen Transfer Rate (wire to water)  in  wastewater:
      Extended Aeration
          Coarse Bubble Diffusion = 1.08 lb O2/hph
          Fine Bubble Diffusion   = 1.44 lb 02/hph
          Mechanical  aeration     = 1.08 lb 0 /hph
      Oxidation Ditch
                                    1.8 lb 02/hph
 COSTS* {1976 dollars)  - Assumptions:   Construction cost includes  building, laboratory, outdoor sludge drying beds,
 but excludes land, engineering,  legal and financing during construction. ENR Index = 2401.
                        CONSTRUCTION COSTS
                                                                            OPERATION AND MAINTENANCE COSTS
           10
           1 0
       o
       at
       §

       I
          001
                   Oxidation Ditch
                            -Extended  Aeration-
                                                                     1 0
                                                                     0 1
                                                                 5  001
           o.oi
 o.i           i.o
Wastewater Flow, Mgal/d
                                                    10
                                                                   0001
                                                                                Oxidation Ditch'
                                                                                       • Extended Aeration
                                                                     0.01
 0.1           1.0

Wastewater Flow, Mgal/d
                                                                                                               10
 REFERENCES  -  3,  4,  16
 *To convert construction cost to capital cost see Table A-2.
                                                            A-53
-------
BIO-FILTER, ACTIVATED  (WITH  AERATOR)                                         FACT  SHEET  2,1.7
Description - Activated bio filters (ABF)  are a recent innovation in the biological treatment field.   This process
has been developed and promoted by one manufacturer,  and it consists of  the series combination of  an  aerobic  tower
(bio-cell) with wood packing material, followed by an activated sludge aeration tank and  secondary clarifier.
Settled sludge from the clarifier is recycled to the  top of the tower.  In addition, the  mixture of wastewater  and
recycle sludge passing  through the tower is also recycled around the tower, in a similar manner to a high rate
trickling filter.  No intermediate clarifier is utilized.   Forward flow  passes directly from the tower discharge to
the aeration tank.   The use of  the two forms of biological  treatment combines  the  effects of  both  fixed and sus-
pended growth processes in one  system.  The  microorganisms  formed  in the fixed growth phase  are passed along  to the
suspended growth unit,  whereas the suspended growth microorganisms are recycled to the  top of the  fixed media unit.

The bio-media in the bio-cell consists of individual  racks  made of wooden laths fixed to  supporting rails.  The
wooden laths are placed in the horizontal direction,  permitting wastewater to  pass downward,  and air  horizontally
and vertically.  The horizontal surfaces reduce premature sloughing of biota.   Droplet  formation and  breakup
induced by wastewater dripping from lath to  lath enhances oxygen transfer.  The aeration  basin is  a short detention
unit that can be designed for either plug  flow or  complete  mix  operation.   The effluent from the aeration basin
passes to a secondary clarifier where the activated sludge  is collected  and recycled to the  top of the bio-cell
tower and to waste.

Common Modifications - ABF units can be used for the  removal of either carbonaceous material or for carbonaceous
removal plus nitrification by appropriately modifying  the  detention  time of  the aeration basin.   When  nitrification
is desired, the bio-cell acts as a first-stage roughing unit and the aeration basin as a  second-stage  nitrification
unit.  ABF bio-cells can be either rectangular or  round.   Various types of aeration equipment can be used in the
aeration system, including both surface and diffused aerators.   The  detention time of  the  aeration tank can be
modified, depending on influent quality and desired  effluent quality.  ABF units can be supplied  with  mixed media
effluent filters for enhanced treatment.

Technology Status - This technology has been  developed recently,  with full scale units first built approximately
five years ago.  Presently, only one manufacturer is producing  these  units,  and  claims  over  65 installations
operating or under construction.

Typical Equipment/No, of Mfrs. - Activated bio  filter systems/1.
Applications - Domestic wastewater and biodegradable industrial wastewater.   Can be used when both BOD  removal and
nitrification are required.   Is applicable where  land  availability  is  low.  Can be used where  raw wastewater
organic loadings fluctuate greatly,  due to its  ability to  handle  shock conditions.  Existing trickling  filter
facilities and overloaded existing secondary plants can be upgraded to ABF  at reduced cost.

Limitations - Will only treat biodegradable substances.   Limited  data  are available on metals  removal and sludge
characteristics.

Performance - ABF systems can treat standard municipal, combined municipal/industrial,  or industrial wastewaters to
BOD  and suspended solids levels of 20 mg/1 or less.   One test study on a package system produced the following
results:
                                                                    Average Values
                                                       Influent,  mg/1           Effluent, mg/1
                    BOD                                     153                      14
                    COD                                     330                      58
                    TSS                                     222                      20
                    NH.-N (when used for nitrification)      20                       1

Chemicals Required - None
Residuals Generated - Sludge.  One study showed that 0.25 to 1.0 pounds of waste VSS are produced per pound of BOD
removed.  The mean yield over the course of the pilot study was 0.60 pounds VSS per pound of BOD  removed.

Design Criteria -  Bio-cell  organic load                     100 to 200 Ib BOD /d/1000 ft
                  Return sludge rate                        25 to 100 percent
                  Bio-cell recycle rate                     0 to 100 percent
                  Bio-cell hydraulic load                   1 to 5.5 gal/min/ft
                  Aeration basin detention time             0.5 to 7.5 h (0.5-3.0,  BOD  removal only;  5.8-7.5,
                                                            two-stage nitrification)
                  System F/M                                0.25 to 1.5 Ib BOD /d/lb  MLVSS  for BOD  removal
                                                            (defined as influent BOD   to bio-cell/a/MLVSS in
                                                            aeration basin);  about 0718 Ib BOD5/d/lb MLVSS
                                                            for two-stage nitrification

Unit Process Reliability - The mechanical and operational simplicity allows for a high unit reliability.  Short
term data indicate that the process reliability is also high.

Environmental Impact - Sludge will be generated, as described above.   Volatile materials will be stripped due to
the aeration action of the bio-cell.  ABF systems require less land than traditional attached growth biological
treatment systems that do not employ a suspended growth element.

References - 178, 179, 180, 181, 182, 183, 184, 227, 259


                                                      A-54
-------
BIO-FILTER,
ACTIVATED
(WITH AERATOR) FACT SHEET 2.1.7
FLOW DIAGRAM -
ENERGY NOTES -
0.5 Q/RAS
@ 14' medi
water) ; bi
ft ; ABF a
0 /lb BOD
1.8 lb 02?
speed surf
requirement
0/lb NH4-
energy in
Water Qual
BOD
SS
(Nitrifica
NH4-N
COSTS* - J
tions : Con
filter, bi
equipment.
been deriv
from refer
from refer
2.5 h for
fication (
100
10
tfi
o
O
~5
ased on average daily flow) .
CONSTRUCTION COST


























































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Wastewa er Flow, Mga /d
OPERATION & MAINTENANCE COST

























































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Wastewater Flow, Mgal/d Wastewa er Fiow Mgal/d
- 259





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*To convert construction cost to capital cost see Table A-2.
A-55
-------
CONTACT STABILIZATION, DIFFUSED AERATION                                    FACT SHEET 2,1,8
Description - Contact stabilization is a modification of the activated  sludge process  (described more completely
in Fact Sheet 2.1.1).  In this modification,  the adsorptive capacity  of  the  floe  is  utilized  in the contact tank
to adsorb suspended, colloidal, and some dissolved organics.   The  hydraulic  detention time  in the contact tank is
only 30 to 60 minutes (based on average daily flow) .   after the biological sludge is separated from the waste-
water in the secondary clarifier, the concentrated sludge is  separately  aerated in the  stabilization tank with a
detention time of 2 to 6 hours (based on sludge recycle flow) .   The adsorbed organics undergo oxidation in the
stabilization tank and are synthesized into microbial cells.   If the  detention  time  is  long enough in the stabili-
zation tank, endogenous respiration will occur, along with a  concomitant decrease in excess biological sludge
production.  Following stabilization, the reaerated sludge is mixed with incoming wastewater  in the contact tank
and the cycle starts anew.  Volatile compounds are driven off to a certain extent by aeration in the contact and
stabilization tanks.  Metals will also be partially removed,  with accumulation  in the sludge.

This process requires smaller total aeration volume than the  conventional activated  sludge  process.  It also can
handle greater organic shock and toxic loadings because of the biological buffering  capacity  of the stabilization
tank and the fact that at any given time the majority of the  activated sludge is  isolated from the main stream of
the plant flow.  Generally, the total aeration basin volume (contact  plus stabilization basins) is only 50 - 75
percent of that required in the conventional activated sludge system.  A description of diffused aeration tech-
niques is presented in Fact Sheet 2.1.1.

Common Modifications - Used in a package treatment plant with clarification  and chlorination  facilities in one
vessel.  Other modifications include raw wastewater feed to aeration tank;  flow equalization;  integral  aerobic
digester.

Technology Status - Contact stabilization has evolved as an outgrowth of activated sludge  technology  since  1950
and seen common usage in package plants and some usage for on-site constructed plants.

Typical Equipment/Mo, of Mfrs. - Air diffusers/19; compressors/44; package treatment plants/21.
Applications - Wastewaters that have an appreciable amount of BOD  in the form of suspended and colloidal  solids;
upgrading of an existing, hydraulically overloaded conventional activated sludge plant;  new installations,  to
take advantage of low aeration volume requirements; where the plant might be subject to  shock organic  or toxic
loadings; where larger, more uniform flow conditions are anticipated (or if the flows to the plant have  been
equalized).

Limitations - It is unlikely that effluent standards can be met using contact stabilization in plants  smaller
than 50,000 gal/d without some prior flow equalization.  Other limitations include operational complexity,  high
operating costs, high energy consumption and high diffuser maintenance.   As the fraction of soluble BOD  in the
influent wastewater increases, the required total aeration volume of the contact stabilization process approaches
that of the conventional process.
Performance -
BOD  Removal                                      80 to 95 percent
NH -N Removal                                     10 to 20 percent

Residuals Generated - See Fact Sheet 2.1.1.
Design Criteria  (39) - A partial listing of design criteria for the contact stabilization process is summarized
as follows:
     F/M,  Ib BOD /d/lb MLVSS               3  0.2 to 0.6
     Volumetric loading, Ib BOD /d/1,000 ft   30 to 50 (based on contact and stabilization volume)
     MLSS, mg/1                               1,000 to 2,500, contact tank; 4,000 to 10,000, stabilization tank
     Aeration time, h                         0.5 to 1.0, contact tank (based on average daily flow)
                                              2 to 6, stabilization basin  (based on sludge recycle flow)
     Sludge retention time, days              5 to 10
     Recycle ratio  (R)                        0.25 to 1.0
     Std.  ft  air/lb BOD  removed             800 to 2,100
     Ib O  /Ib BOD   removed                    0.7 to 1.0
         ati
     Volatile  fraction of MLSS                0.6 to 0.8

Process Reliability - Requires close operator attention.
Environmental  Impact - See Fact Sheet 2.1.1
 References -  23,  26,  31,  39
                                                       A-56
-------
CONTACT STABILIZATION,DIFFUSED AERATION
                                                                                  FACT SHEET 2.1.8
'LOW DIAGRAM -
                Screened and  Degritted
                   Raw Wastewacer
                or Primary Effluent
                                         -*—j-
                                                  Contact
                                                    'ank
                                                                                            Effluent
                                Alternate Excess
                                   Sludge
                                Draw-Off Point


ENERGY NOTFS - Assumptions: Air requirements are
                                                    Stabilization
                                                        Tank
based on 2100 ft~Vlb BOD  removed  (2 Ib BOD./
1000 gal/d).  Positive displacement blowers witn
100% standby are provided.  Electricity = S.03/KWh.
Includes energy requirements for entire package  plant.
COSTS* - Assumptions:   Costs  are  in  1976  dollars; ENR
Index = 2401.
1. Construction  cost  is for package  plants  and  includes
tankage and  equipment  in place  for aeration cnambers,
chlonnation equipment,  clarification  and sludge
stabilization.   Costs  include concrete  and  yardwork,
15%  contingency,  electrical and instrumentation,  and
contractor's overnead  and profit  at  25% of  equipment
costs but  exclude land,  engineering, legal  or finan-
cing during  construction.
2. O&M costs are based on a labor rate  of S9/h,
including  fringe benefits, with 7 d/wk  staffing and
electricity  @  S.03/kwh.  Maintenance materials  include
cnlorine.
                      CONSTRUCTION COST
         10
         01
        001
          001
REFERENCE - 16
                       01            10
                      Wastewater Flow Mgal/d
                                                 10
                                                     A-57
                                                                     Return Sludge
                                                                                    ' Excess
                                                                   10
                                                                   10
                                                                   10"
                                                                   10,
                                                                     0.01
                                                                                   0.1
                                                                                                1.0
                                                                                                             10
                                                                               Wastewater Flow,  Mgal/d
                                                                             OPERATION & MAINTENANCE COST
                                                                     1 0
                                                                    0 1
                                                                    001
                                                                   0001
                                                                                                       SPower:
                                                                                                         Total
                                                                                                        Labor:
                                                                     001
                                                                                   01           10
                                                                                  Wastewater Fiow Mgal/d
                                                                                                             10
-------
DENITRIFICATION, SEPARATE STAGE, WITH CLARIFIER                           FACT SHEET 2.1.9
Description and Common Modifications - Denitrification  involves  the reduction of nitrates and nitrites to nitrogen
gas through the action of facultative heterotrophic bacteria.   In  suspended growth, separate stage denitrification
processes, nitrified wastewater containing primarily  nitrates  is passed through a mixed anaerobic vessel con-
taining denitrifying bacteria.   Since the nitrified feedwater  contains very little carbonaceous material, a sup-
plemental source of carbon is required to maintain the denitrifying biomass.  This supplemental energy is provided
by feeding methanol to the biological reactor along with  the nitrified wastewater.  Mixing in the anaerobic
denitrification reaction vessel may be accomplished using low  speed paddles analogous to standard flocculation
equipment.  Following the reactor,  the denitrified effluent is aerated for a short period  (5 to 10 min) to strip
out gaseous nitrogen formed in the  previous step which might otherwise inhibit sludge settling.  Clarification
follows the stripping step with the collected sludge  being either  returned to the head end of the denitrification
system, or wasted.

Common modifications include the use of alternate energy  sources such as sugars, acetic acid, ethanol or other
compounds.  Nitrogen deficient materials such as brewery  wastewater may also be used.  An  intermediate aeration
step for stabilization (about 50 min) between the denitrification  reactor and the stripping step may be used to
guard against carryover of carbonaceous materials.  The denitrification reactor may be covered but not air tight
to assure anaerobic conditions by minimizing surface  reaeration.   See Fact Sheets 2.2.2 and 2.2.3 for information
on attached growth denitrification  systems.

Technology Status - Well developed  at full scale but  not  in widespread use.
Typical Equipment/No, of Mfrs.  (23)  - Clarifier equipment/38;  controls/29;  air diffusers/19; aeration tanks/1;
controls/29; instrumentation/9;  chemical feed equipment/25;  flocculators/32.

Applications - Used almost exclusively to denitrify municipal  wastewaters  that have undergone carbon oxidation and
nitrification.  May also be used to reduce nitrate in industrial  wastewaters.

 Imitations - Specifically acts on nitrate and nitrite.   Will  not affect other  forms of nitrogen.
Performance - Capable of reducing 80 to 98 percent of the nitrate and  nitrite  entering  the  system  to gaseous
nitrogen.  Overall nitrogen removals of 70 to 95 percent are achievable.   Typical wastewater characteristics for
NO -N:  influent 19 mg/1, effluent 1 mg/1.

Chemicals Required - An energy source is needed and usually supplied  in  the  form of methanol.  Methanol  feed
concentration may be estimated using the following values per  mg/1  of  the material at  the  inlet  to the process.

                    mg/1 CH OH     per       mg/1 of

                         2.47                NO -N
                         1.53                NO -N
                         0.87                D.O.

Residuals Generated - If supplemental energy feed rates  are controlled,  very  little  excess sludge is generated.
Sludge production 0.6 to .8 Ib/lb NH -N reduced.

Design Criteria -
?low Scheme                        Plug Flow (preferable,  but  not mandatory)
Optimum pH                         6.5 to 7.5
MLVSS                              1000 to 3000 mg/1
Mixer power requirement            0.25 to 0.5 HP/1000 ft
Clarifier depth                    12 to 15 ft        2
Clarifier surface loading rate     400 to 600 gal/d/ft
Solids loading                     20 to 30 Ib/d/ft
Return sludge rate                 50 to 100 percent
Sludge generation                  0.2 Ib/lb CH OH or 0.7  Ib/lb NH -N reduced
Detention time                     0.2 to 2 h
Cell residence time                1 to 5 d

Unit Process Reliability - Under controlled pH, temperature, loading,  and  chemical  feed,  high levels  of  relia-
bility are achievable.

Environmental Impact - Reduces the nitrogen loading on receiving stream.

References - 3, 7, 23, 28, 45, 95
                                                    A-58
-------
DENITRIFICATION,  SEPARATE  STAGE,  WITH  CLARIFIER
                                                                                    FACT SHEET 2.1.9
'LOW DIAGRAM -
             MuLhanol
            Nitrified
             Effluent
                            Anaerobic Mixed
                              Denitrification
                                  Reactor
                                                           Aerated  Nitrogen
                                                           Stripping  channel
                                                                T=5 min
Denitrified
 Effluent
                                                                                                  Waste
                                               Return sludge
INERGY NOTES - Assumptions:
    CH3OH/N - 3:1
:.  Same design basis as in costs.
COSTS - Assumptions: ENR Index = 2475.
     Construction costs include denitrification
     tanks (uncovered), mixers, methanol feed,
     clarifiers, sludge recycle and waste pumps,  but
     do not include reaeration facility.

     Two hours detention time in denitrification
     tank.
3.   MLVSS = 2,000 mg/1.
4.   Denitrification recycle pumps sized for 100
     percent recycle, operated at 50% recycle.    2
     Final clarifier overflow rate = 600 gal/d/ft .
     3 Ib methanol/lb of nitrate nitrogen removed.
     Methanol storage - 30 d supply with a minimum
     tank size of 500 gal.
     Wastewater characteristics
               Influent (mg/1)  Effluent (mg/1)
     NO -N          19               1
     NH -N           1               1
                                                                 •a
                                                                 a

       &
         I0
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          O.I
                        •CONSTRUCTION  COST:
                                                            0
                                                            O
                                                                0.1
                        10            10
                       Wastewater Flow, Mgal/d
                                                  100
                                                               0.01
                                                                 oi
 REFERENCES  -  3,  28

 *To convert construction cost to capital cost see Table A-2.
                                                     A-59
                                                                     io
                                                                     10
                                                                     io
                                                                     io
                                                                         0.1
                                                                                      1.0            10
                                                                                   Wastewater Flow, Mgal/d
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-------
EXTENDED  AERATION,  MECHANICAL  AND DIFFUSED AERATION                 FACT SHEET 2.1.10
Description - Extended aeration is the "low rate"  modification  of the activated sludge process.  The F/M loading
is in the range of 0.05 to 0.15 Ib BOD /d/lb MLVSS,  and  the  detention time is about 24 hours.  Primary clarifi-
cation is rarely used.  The extended aeration system operates  in  the endogenous respiration phase of the bacterial
growth cycle, because of the low BOD  loading.   The  organisms  are starved and forced to undergo partial auto-
oxidation.  Volatile compounds are driven off to a certain extent in the aeration process.  Metals will also be
partially removed, with accumulation in the sludge.

In the complete mix version of the extended aeration process,  all portions of the aeration basin are essentially
homogeneous, resulting in a uniform oxygen demand throughout the  aeration tank.  This condition can be accom-
plished fairly simply in a symmetrical (square or circular)  basin with a single mechanical aerator or by diffused
aeration.  The raw wastewater and return sludge enter at a point  (e.g., under a mechanical aerator) where they are
quickly dispersed throughout the basin.   In rectangular  basins with mechanical aerators or diffused air, the
incoming waste and return sludge are distributed along one side of the basin and the mixed liquor is withdrawn
from the opposite side.

Common Modifications - Step aeration, contact stabilization, and  plug flow regimes.  Alum or ferric chloride is
sometimes added to the aeration tank for phosphorus  removal.

Technology Status - Extended aeration plants have  evolved  since  the  latter part of the 1940's.  Pre-engineered,
package plants have been widely utilized for this  process.

Typical Equipment/No, of Mfrs.  - aerators/30;  package  treatment plants/21; air diffusers/19; compressors/44.
Applications - Commonly flows of less than 50,000 gal/d;  emergency or temporary treatment needs; and biodegradable
wastewater.

Limitations - High power costs,  operation costs,  and capital  costs  (for  large permanent installations where the
pre-engineered plants would not be appropriate).

Performance
BOD5 Removal                                                                                  85-95%
NH4 - N Removed  (Nitrification)                                                                50-90%

Residuals Generated - Because of the low F/M loadings and long  hydraulic detention times employed, excess sludge
production for the extended aeration process (and the closely related oxidation ditch process) is the lowest of
any of the activated sludge process alternatives, generally in  the  range of  0.15 to 0.3 Ib excess total  suspended
solids/lb BOD  removed.

Design Criteria  (39) - A partial listing of design criteria for the extended aeration modification of the acti-
vated sludge process is summarized as follows:

     Volumetric loading, Ib BOD /d/1,000 ft       5 to 10
     MLSS, mg/1                                   3,000 to 6,000
     F/M, Ib BOD /d/lb MLVSS                      0.05 to 0.15
     Aeration detention time, hours (based on     18 to 36
       average daily flow)
     Standard ft  air/lb BOD  applied             3,000 to 4,000
     Ib O /Ib BOD  applied                        2.0 to 2.5  (based on 1.5 Ib O./lb BOD5 removed + 4.6  Ib O-/
                                                  Ib NH -N removed)
     Sludge retention time, days                  20 to 40
     Recycle ratio  (R)                            0.75 to 1.5
     Volatile fraction of MLSS                    0.6 to 0.7

Process Reliability - Good

Environmental Impact - See Fact Sheet 2.1.1

References - 23, 26, 31, 39
                                                       A-60
-------
EXTENDED  AERATION, MECHANICAL AND  DIFFUSED AERATION
             FACT SHEET 2.1.10
FLOW DIAGRAM -
    Screened and
    Degritted Raw
    Wastewater



Complete Mix
Aeration Tank
Return Sludge


Clarif ier



Sludge
1 Excess
Sludge
Chlorination

Aerobic
Digestion
Effluent
To Disposal

ENERGY NOTES - Assumptions:  The hydraulic head  loss  through the
aeration tank is negligible.  Sludge recycle  and sludge wasting
pumping energy are included.
Water Quality:      Influent(mg/1)  Effluent(mg/l)
BOD                      210            20
Suspended Solids         230            20
NH -N                     20             1
Oxygen Transfer Rate (wire to water)  in  wastewater for:
     Mechanical Aeration = 1.8 Ib O /hph
     Diffused Aeration
          Coarse Bubble Diffusion - 1.5  Ib O  /hph
          Fine Bubble Diffusion = 2.5 Ib O2/Rph
Oxygen Requirement:
     1.5 Ib 0 /Ib BOD  removed plus 4.6  Ib O2/lb of
     NH -N removed
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                                                        A-61
-------
LAGOONS,  AERATED                                                                 FACT SHEET 2,1,11
Description - Aerated lagoons are medium-depth basins designed for the biological treatment of wastewater on a
continuous basis.  In contrast to stabilization ponds, which obtain oxygen from photosynthesis and surface re-
aeration, they employ aeration devices which supply supplemental oxygen to the system.  The aeration devices may
be mechanical (i.e., surface aerator), or diffused air systems.  Surface aerators are divided into two types:
cage aerators and the more common turbine and vertical shaft aerators.  The many diffused air systems utilized in
lagoons consist of plastic pipes supported near the bottom of the cells with regularly spaced sparger holes
drilled in the tops of the pipes.  Because aerated lagoons are normally designed to achieve partial mixing only,
aerobic-anaerobic stratification will occur, and a large fraction of the incoming solids and a large fraction of
the biological solids produced from waste conversion settle to the bottom of the lagoon cells.  As the solids
begin to build up, a portion will undergo anaerobic decomposition.  Volatile toxics can potentially be removed by
the aeration process, and incidental removal of other toxics can be expected to be similar to an activated sludge
system.  Several smaller aerated lagoon cells in series are more effective than one large cell.  Tapering aeration
intensity downward in the direction of flow promotes settling out of solids in the last cell.  A non-aerated
polishing cell following the last aerated cell is an optional, but recommended, design technique  to enhance
suspended solids removal prior to discharge.

Common Modifications - The lagoons may be lined with concrete or an impervious flexible lining, depending on soil
conditions and environmental regulations.  Use of various types of aeration.  When high-intensity aeration pro-
duces completely mixed  (all aerobic) conditions, a final settling tank is required.  Solids are recycled to
maintain about 800 mg/1 MLVSS in this mode.

Technology Status - While not as widely used when compared with the large number of stabilization ponds in common
use throughout the U. S., it has been fully demonstrated, and used for years.

Applications - Used  for domestic and industrial wastewater of low and medium strength.  Commonly used where land
is inexpensive and costs and operational control are to be minimized.  It is relatively simple to upgrade existing
oxidation ponds, lagoons, and natural bodies of water to this type of treatment.  Aeration increases the oxidation
capacity of the pond and is useful in overloaded ponds that generate odors.  Useful when supplemental oxygen
requirements are high or when the requirements are either seasonal or intermittent.

Limitations - In very cold climates aerated lagoons may experience reduced biological activity and treatment
efficiency, and the formation of ice.

Typical Equipment/No. Mfrs.  (23) - Lining systems/6; Aerators/30; Hydraulic Controls/29

Performance

                                                  	Influent        * Removed
                              BOD                   200 - 500 mg/1     60 - 90
                              COD                       -              70-90
                              TSS                   200 - 500 mg/1     70 - 90

Residuals - Settled solids on pond bottom may require clean-out every 10 to 20 years, or possibly more often if a
polishing pond is used behind the aerated pond.

Design Criteria  (12, 67)

Operation:  One or more aerated cells,        Water Temperature range:  0 to 40 C
followed by a settling  (unaerated) cell       Optimum Hater Temperature:  20 C
Detention time: 3 to 10 days                  Oxygen requirement:  0.7 to 1.4 times the amount of BOD  removed
Depth, ft:  6 to 20                           Organic Loading:  10 to 300 Ib BOD5/acre/d
pH:   6.5 to 8.0

Energy requirements:
      For aeration:  6 to  10 hp/million gallons capacity
      To maintain all solids in suspension:  60 to 100 hp/million gallons capacity
      To maintain some solids in suspension:  30 to 40 hp/million gallons capacity

Process Reliability - The service life of a lagoon is estimated at 30 years or more.  The reliability of equipment
and  the process is high.  Little operator expertise is required.

Environmental Impacts - There is opportunity for volatile organic material and pathogens in aerated lagoons to
enter the air as with any aerated wastewater treatment process.  This opportunity depends on air/water contact
afforded by the aeration  system.  There  is potential for seepage of wastewater into ground water unless a lagoon
is lined.  Compared to  other secondary treatment processes, aerated lagoons generate less solid residue.

Toxics - Volatile toxics  will be removed, and incidental removal of other toxics can be expected to be similar to
an activated sludge system.

References - 7, 12, 13, 18,  23, 67
                                                          A-62
-------
LAGOONS,  AERATED
                                                                                    FACT SHEET 2,1.11
 FLOW DIAGRAM -
                        Influent
                                         Aerated
                                         Lagoon(s)
                                                                        To
                                                                     .Polishing
                                                                       Pond
                                                                    10
ENERGY NOTES (4) -
Low speed mechanical surface aerators; motor
efficiency = 90%; aerator efficiency =1.8
Ib 02/hph (wire to water),-  head loss negli-
gible.  Type of energy required: electrical

For additional information on energy
requirements and transfer efficiency
of selected aeration devices, refer
to Table D-l.
                                                                    10
                                                                    10
                                                                   10
                                                                                          z
                                                                       1.0
                                                                                    10           100

                                                                                     AERATOR,  hp
COSTS (3) -Assumptions:
1. Service life, 30 years; ENR Index = 2475
2. Theoretical detention time = 7 d; 15-ft water depth; floating mechanical aerators;
3. Horsepower required = 36 hp/Mgal of capacity; power @ $.02/kWh;
4. Construction cost includes excavation, embankment, and seeding of lagoon/slopes (3 cells);  service road and
fencing; riprap embankment protection; hydraulic control works; aeration equipment and electrical equipment.
Wastewater Characteristics:                        In            Out
                                                   210           25
                                                   400           50
          TSS, mg/1                                230           40
          Total-P, mg/1                             11            8
          NH3-N, mg/1                               20           18

To adjust construction cost for detention time other than above, enter curve at effective flow (Q )

                  X New Design Detention Time
                                                                                                             1,000
          BOD ,  mg/1
          COD,  mg/1
           ^r-T™
           DESIGN
                             7 days
   10
2
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                        CONSTRUCTION  COST:
          01
                                                            1
                                                                  10
                                                             =
                                                             O    01
                                                             of
                                                             — b
                                                                 001
                                                  100
                        10            10
                    Wastewater Flow, Mgal/d

REFERENCES -3,4

 To convert construction cost to capital cost see Table A-2.
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                                                                              Wastewater Flow, Mgal/d
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                                                       A-63
-------
LAGOONS,  ANAEROBIC                                                               FACT  SHEET 2.1.12
Description - Anaerobic lagoons are relatively deep (up to 20 ft)  ponds with steep sidewalls in which anaerobic
conditions are maintained by keeping loading so high that complete deoxygenation is prevalent.   Although some oxy-
genation is possible in a shallow surface zone, once greases form an impervious surface layer,  complete anaerobic
conditions develop.  Treatment or stabilization results from thermophilic anaerobic digestion of organic wastes.
The treatment process is analogous to that occurring in single stage untreated anaerobic digestion of sludge in
which acid forming bacteria break down organics.   The resultant acids are then converted to carbon dioxide,
methane, cells and other end products.

In the typical anaerobic lagoon, raw wastewater enters near the bottom of the pond (often at the center)  and mixes
with the active microbial mass in the sludge blanket, which is usually about 6 ft deep.  The discharge is located
near one of the sides of the pond, submerged below the liquid surface.  Excess undigested grease floats to the
top, forming a heat retaining and relatively air tight cover.  Wastewater flow equalization and heating are
generally not practiced.  Excess sludge is washed out with the effluent.  Recirculation of waste sludge is not
required.

Anaerobic lagoons are capable of providing treatment of high strength wastewaters and are resistant to shock
loads.

Common Modifications- Anaerobic lagoons are customarily contained within earthen dikes.  Depending on soil
characteristics, lining with various impervious materials such as rubber,  plastic or clay may be necessary.   Pond
geometry may vary, but surface area to volume ratios are minimized to enhance heat retention.

Technology Status - Although anaerobic processes are common for sludge digestion, anaerobic lagoons for wastewater
treatment have found only limited application.  The process is well demonstrated for stabilization of highly con-
centrated organic wastes.

Typical Equipment/Mo.of Mfrs.(23) -
Lining Systems/6; Hydraulic controls/29

Applications - Typically used in series with aerobic or facultative lagoons.  Anaerobic lagoons are effective as
roughing units prior to aerobic treatment of high strength wastes.

Limitations - May generate odors.  Requires relatively large land area.  For efficient operation, water tempera-
tures above 75 F should be maintained.

Performance -BOD  removals of 50 to 70 percent are achievable depending on loading and temperature conditions.
TSS concentrations may increase, especially if the influent BOD5 is primarily dissolved. Generally does not
produce an effluent suitable for direct discharge to receiving waters.

Residuals Generated - In anaerobic lagoons excess sludge is usually washed out in the effluent.  Since anaerobic
lagoons are often used for preliminary treatment recirculation'or removal of sludge not generally required.

Chemicals Required - Nutrients as needed to make up deficiencies in raw wastewater.  No other chemicals required.
Design Criteria -
Operation:     Parallel or series
Detention Time:     20 to 50 d
Depth, ft:     8 to 20
pH:  6.8 to 7.2                   Q
Water Temperature Range: 35 to 120 F
Optimum Water Temperature:    86 F
Organic loading: 200 to 2200 Ib BOD5/acre/d

Unit Process Reliability - Generally resistant to upsets.  Highly reliable if pH in the relatively narrow optimum
range  is maintained.

Environmental  Impact - May create odors.  Have relatively high land requirements.  There is potential for seepage
 of wastewater  into groundwater unless lagoon is lined.

 Joint Treatment Potential - Valuable as a. preliminary treatment process for combined industrial and municipal
 wastes  containing high  concentrations of organic materials.  Can be used preceding most standard biological
 treatment processes.

 References -  7,  16,  18,  20,  23, 67, 107, 110
                                                     A-64
-------
 LAGOONS,  ANAEROBIC
                                  FACT  SHEET  2.1.12
FLOW DIAGRAM -
             Inlet
                                                                                               X Outlet
                                                                               Liner (if necessary)
ENERGY NOTES - Anaerobic lagoons are operated by gravity flow and therefore have no energy requirements other  than
any pumping that may be necessary to lift the influent wastewater into the lagoons.

COSTS* - Assumptions: January  1979 dollars; ENR Index = 2872.
Service Life:  50 years
Average detention  time = 35 days; depth = 10 ft; BOD  loading = 466 Ib/acre/d.  Construction cost includes exca-
vating, grading and other  earthwork and service roads.  Costs do not include land  and pumping.  Liner cost not
included in estimate.  Operation and maintenance costs consist of labor and material.
 Wastewater Characteristics
     BOD,
Influent,  mg/1
     600
Effluent, mg/1
     240
 To  adjust  costs  for other BOD5 loadings and/or detention times, enter curve at effective flow (Q ):
     0  _  _          (466 Ib/acre/d)(New detention time)
     UE    ^DESIGN     (New Design Loading)  (35 days)
                      CONSTRUCTION COST
                                                                          OPERATION & MAINTENANCE COST
        01
       001
                                                             D   0 1
                                                                001
          0 1
                       1 0           10
                      Wastewater Flow. Mgal/d
                                                                0001
                                                                   0 1
                              1 0           10
                             Wastewater How Mgal/d
                                                        100
REFERENCE - Curves derived from reference 3.
*To convert construction cost to capital cost see  Table  A-2.
                                                       A-65
-------
LAGOONS,  FACULTATIVE                                                           -FACT  SHEET  2lL13
Description - Facultative lagoons are intermediate depth (3 to 8 feet)  ponds  in which the  wastewater is  stratified
into three zones.  These zones consist of an anaerobic bottom layer,  an aerobic  surface  layer,  and an intermediate
zone.  Stratification is a result of solids settling and temperature-water density variations.   Oxygen in the
surface stabilization zone is provided by reaeration and photosynthesis.   This is  in contrast to aerated lagoons
in which mechanical aeration is used to create aerobic surface conditions.  In general,  the  aerobic surface  layer
serves to reduce odors while providing treatment of soluble organic by-products  of the anaerobic processes opera-
ting at the bottom.

Sludge at the bottom of facultative lagoons will undergo anaerobic digestion producing carbon dioxide,  methane  and
cells.  The photosynthetic activity at the lagoon surface produces oxygen diurnally,  increasing the dissolved
oxygen during daylight hours, while surface oxygen is depleted at night.

Facultative lagoons are often and for optimum performance should be operated in  series.   When three or more  cells
are linked, the effluent from either the second or third cell may be  recirculated  to the first.   Recirculation
rates of 0.5 to 2.0 times the plant flow have been used to improve overall performance.

Common Modifications - Facultative lagoons are customarily contained  within earthen dikes.   Depending on soil
characteristics, lining with various impervious materials such as rubber,  plastic  or  clay  may be  necessary.   Use
of supplemental top layer aeration can improve overall treatment capacity,  particularly in northern climates  where
icing over of facultative lagoons is common in the winter.

Technology Status -Fully demonstrated and in moderate use especially for  treatment of relatively  weak municipal
wastewater in areas where real estate costs are not a restricting factor.

Applications - Used for treating raw, screened, or primary settled domestic wastewaters  and  weak biodegradable
industrial wastewaters.  Most applicable when land costs are  low and operation and maintenance costs  are  to be
minimized.

Limitations - In very cold climates, facultative lagoons may  experience reduced biological  activity and treatment
efficiency.  Ice formation can also hamper operations.   In overloading situations,  odors  can  be a problem.

Typical Equipment/No, of Mfrs. (23)  - Lining systems/6;  Hydraulic controls/29.
Performance - BOD5reductions of 75 to 95 percent have been reported.   Effluent suspended solids  concentrations  of
20 to 150 mg/1 can be expected, depending on the degree of algae separation achieved in the last cell.   Effi-
ciencies are strongly related to pond depth, detention time and temperature.

Chemicals Required - If wastewater is nutrient deficient,  a source  of supplemental  nitrogen or phosphorus  may  be
needed.  No other chemicals are required.

Residuals - Settled solids may require clean out and removal once every 10 to 20  years.
Design Criteria -
Operation: At least three cells in series.   Parallel trains of, cells may be used for larger  systems.
Detention time: 20 to 180 days.
Depth, ft:  3 to 8, although a portion of the anaerobic zone of the first cell may be up to  12  ft deep to accom-
            modate large initial solids deposition.
pH:  6.5 to 9.0
Water temperature range:  35 to 90 F for municipal applications
Optimum water temperature:  68 F
Organic loading:  10 to 100 Ib BOD5/acre/d

Process Reliability - The service life of the lagoon is estimated to be 50 years.   Little operator expertise is
required.  Overall, the system is highly reliable.

Environmental Impact - There is potential for seepage of wastewater into ground water unless  lagoon  is  lined.
Compared to other secondary processes, relatively small quantities of sludge are  produced.

References - 3, 7, 18, 23, 67, 109, 110
                                                    A-66
-------
 LAGOONS, FACULTATIVE
                                                                                    FACT SHEET 2.1.13
 FLOW DIAGRAM -
                                                                     Effluent Discharge Sump with
                                                                     Multiple Drawoff Level Discharge
                                                                     Capability (to minimize algae
                                                                     concentrations in discharge)
                       Intermediate (Facultative) Zone
            Inlet (typically near 1/3 point)
                                                                                      ~  Transfer Pipe to
                                                                                                Secondary Cell
                                                                                          lif necessarv'
                                                          Sludge Storage Zone (for
                                                          primary cells only without
                                                          prior primary sedimentation)
ENERGY NOTES - Facultative lagoons  are operated by gravity and therefore have no energy requirements other than
any pumping that may be necessary to lift the influent wastewater into the lagoons.
COSTS -Assumptions:
1.   Warm climate - lagoon loading = 40 Ib BOD /acre/d.
2.   Cool climate (northern U.S.) - lagoon loading = 20 Ib BOD /acre/d.
3.   Water depth = 4 ft.
4.   Construction cost includes excavating, grading, and other earthwork required for normal subgrade preparation
     and service roads.  Costs do not include land and pumping.
     Process performance:                     Wastewater Characteristics
                                                                                Out
                                                                                 30
                                                                                100
                                   BOD ,  mg/1
                                   COD,  mg/1
                                   TSS, mg/1
                                   Total-P, mg/1
                                   NHj-N, mg/1
In
210
400
230
 11
 20
                                                                                 60
                                                                                  8
                                                                                 15 (cool climate)
                                                                                  1 (warm climate)
     No liner included in cost estimate.
7.   ENR Index = 2475
Adjustment Factor:  To adjust costs for loadings other than those above, enter curve at effective flow (Q ).
     Warm Climates
QE = DESIGN X 40 lb BOD /acre/day
               New Design Loading
                       CONSTRUCTION COST
                                                            Cool Climates
                                                            QE = °.DESIGN x 20 lb BOD^/acre/day
                                                                           New Design Loading
         01
        001
                  Cool Climat
                  7"

                           5Z
                               Warm Climate
                                                                  1 0
                                                                           OPERATION & MAINTENANCE COST
                                                              D   0 1
                                                              O
                                                              ~5  001
          0 1

REFERENCE  - 3
                       1 0            10
                       Wastewater Flow, Mgal/d
                                                                0001
          1 0            10
         Wastewater Flow, Mgal/d
                                     100
*To convert construction cost to capital cost see Table A-2.

                                                      A-67
-------
NITRIFICATION, SEPARATE STAGE, WITH CLARIFIER                              FACT SHEET 2.1,14
Description - The process by which ammonia is converted to nitrate in wastewater is referred to as nitrification.
In the process, Nitrosomonas and Nitrobacter act sequentially to oxidize ammonia (and nitrite)  to nitrate.   The
biological reactions involved in these conversions may take place during activated sludge treatment or as a
separate stage following removal of carbonaceous materials.  Separate stage nitrification may be accomplished via
suspended growth or attached growth unit processes.  In either case, the nitrification step is preceded by a
pretreatment sequence to reduce the carbonaceous demand.  Possible pretreatment schemes include: activated sludge,
trickling filter, roughing filter, primary treatment with chemical addition and physical chemical treatment.   In
general, if the pretreatment effluent has a BOD5/TKN ratio of less than 3.0, sufficient carbonaceous removal has
occurred such that the following nitrification process may be classified as a separate stage.  Low BOD is required
to assure a high concentration of nitrifiers in the nitrification biomass.

The most common separate stage nitrification process is the plug flow suspended growth configuration with clari-
fication.  In this process, pretreatment effluent is pH adjusted (as required)  and aerated, in a plug flow mode.
Because the carbonaceous demand is low, nitrifiers predominate.   A clarifier follows aeration,  and nitrification
sludge is returned to the aeration tank.  A possible modification is the use of pure oxygen in place of conven-
tional aeration during the plug flow operation.

Common Modifications - Less prevalent are attached growth separate stage nitrification processes.  These processes
may be operated analogously to trickling filter, packed bed or rotating biological disc systems.   Since the
biomass is attached to the reactor surface and solids synthesis is low, a clarifier may not be required.   Final
filtration is sometimes practiced to reduce effluent suspended solids,  although this is often not required.   Refer
to Fact Sheet 2.2.6 for costs of nitrification utilizing the attached growth process.

Technology Status - Nitrification is a well known phenomenon in biological treatment processes.   Separate  stage
nitrification has been well demonstrated throughout the United States and England in numerous  pilot studies  and
several full-scale designs.  Separate stage suspended growth systems outnumber separate  stage  attached growth
systems in these applications by about four to one.

Typical Equipment/No. Mfrs (23)  - Air diffusers/19; aeration tanks/1; clarifier equipment/38,-  controls/29; filter
equipment/35; instrumentation/9.

Applications - Applicable for conversion of ammonia to nitrate,  particularly as  a preliminary  step prior  to
denitrification.  Commonly used as an add-on process after secondary treatment.

Limitations - Sensitive to toxicant upset.   Design should compensate for reduced efficiency  at low temperature.
Only oxidizes ammonia to nitrate.   Cannot remove nitrogen effectively;  does  not significantly  treat organic
nitrogen.

Performance - Conversions of ammonia (and nitrite)  to nitrate of up to  98  percent are  achievable.   Properly
designed systems have effluent ammonia in the 1 to  3 mg/1 range.   BOD  reductions are  generally  70  to 80 percent
(influent BOD  assumed as approximately 50 mg/1).

Chemicals Required - Acid or alkali for pH control  as needed.
Residuals Generated - A separate nitrification sludge is generated as  a result  of  separate  stage  suspended growth
systems.   Attached growth systems may generate a filter backwash wastewater.

3esign Criteria -
               Suspended Growth Systems
               Flow Scheme                        Plug Flow (preferable, but not mandatory)
               Optimum pH                         8.2-8.6
               MLVSS                              1200-2400 mg/1
               Min.  Aeration Tank D.O.             2.0  mg/1
               Clarifier Surface Loading Rate      400-600 gal/d/ft^
               Solids Loading                     20 to 30  Ib/d/ft
               Return Sludge Rate                 50 to 100 percent
               Detention Time                     0.5  to 3  hr
               Mean Cell Residence Time           10 to 20  d

               Attached Growth Systems  (Trickling  Filters)
               Media Area                         3,000-10,000  ft /lb NH -N oxidized/d
               Recirculation Rate                 up to 100 percent  (variable)

LTnit Process Reliability - Under controlled pH,  temperature, loading and toxicant conditions, high levels of
reliability are achievable.

Environmental Impact - Nitrification sludge  by  itself  is  relatively difficult to dewater.  However, it is usually
combined with other sludges,  resulting in  a very  small  impact  on overall dewaterability.  Other environmental
impacts are similar to those  of standard biological  treatment.

References 7,  23,  28,  45,  95,  262
                                                       A-68
-------
NITRIFICATION,  SEPARATE  STAGE,  WITH CLARIFIER
                        FACT SHEET 2.1,14
FLOW DIAGRAM -
Nitrification
           Influent
                                                                                                Effluent
                          ••Sludge Recycle

                           Waste
                                                     Waste
                                                                 10
ENERGY NOTES -
Suspended Growth
Assumptions:
Mechanical Aeration
02 Transfer Rate =  1.8  Ib O2/hph

O2 required = 4.6 Ib  02/lb NH4-N, 1.0 Ib O2/lb BOD

          In ( mg/1)  Out (mg/1)
NH -N         19         1
BOD           40        10
       10
                                                                 10
                                                                 10
                                                                                       -f~H-
                                                                                     ;ILL
                                                                   0 1
                                                                                 10           10            100
                                                                                Wastewater Flow  Mgal d
COSTS -ENR Index = 2475
Design Basis (suspended  growth):
1.   Construction costs  include nitrification tanks, aeration devices,  clarifiers, and sludge recycle and waste
     pumps,  but not pH adjustment facilities.
1.   System to follow high-rate activated sludge system.
3.   Detention time = 3  hours.
4.   O. requirements: 1.5  Ib 0 /Ib BOD  removed, pluS 4.6 Ib 0 /Ib NH.-N  oxidized.
5.   Sludge return pumps sized  for 100 percent regycle.  Operated at 50 percent  recycle.
6.   Final clarifier overflow rate = 600 gal/d/ft   (30 Ib/ft /d)
7.   Power @ $.02/kWh

Millions of Dollars
2 5
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                                                           8
                                                           II
          01            ID            10           100
                   Wastewater Flow, Mgal/d
 REFERENCES -  3,  4,  45
 *To convert construction cost  to capital  cost see Table A-2.
                                                     A-69
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-------
OXIDATION DITCH                                                                  FACT  SHEET 2.1,15
Description - An oxidation ditch is an activated sludge biological treatment process;  commonly operated in the
extended aeration mode, although conventional activated sludge treatment is also possible.  Typical oxidation ditch
treatment systems consist of a single or closed loop channel 4 to 6 ft deep,  with 45  sloping sidewalls.

Some form of preliminary treatment such as screening, comminution or grit removal normally  precedes the process.
After pretreatment  (primary clarification is usually not practiced)  the wastewater is aerated in the ditch using
mechanical aerators which are mounted across the channel.  Horizontal brush,  cage or disc-type aerators,  specially
designed for oxidation ditch applications are normally used.  The aerators provide mixing and circulation in the
ditch, as well as sufficient oxygen transfer.  Mixing in the channels is uniform, but zones of low dissolved
oxygen concentration can develop.  Aerators operate in the 60 to 110 RPM range and provide  sufficient velocity to
maintain solids in  suspension.  A high degree of nitrification may occur in the process without special modifi-
cation because of the long detention times and high solid retention times (10 to 50 d)  utilized.  Secondary set-
tling of the aeration ditch effluent is provided in a separate clarifier.

Common Modifications - Ditches may be constructed of various materials, including concrete,  gunite, asphalt, or
impervious membranes.  Concrete is the most common.  Ditch loops may be oval or circular in shape.  "Ell" and
"horseshoe" configurations have been constructed to maximize land usage.  Conventional activated sludge treatment,
in contrast to extended aeration, may be practiced.  Oxidation ditch systems with depths of 10 ft or more with
vertical sidewalls  and vertical shaft aerators may also be used.

Technology Status - There are nearly 650 shallow oxidation ditch installations in the United States and Canada.
Numerous shallow and deep oxidation ditch systems are in operation in Europe.  The overall  process is fully demon-
strated for carbon  removal, as a. secondary treatment process.

Typical Equipment/No, of Mfrs. (16, 23) - Oxidation ditch equipment (brush aerators, etc.)/6; hydraulic controls/
29.

Applications - Oxidation ditch technology is applicable in any situation where activated sludge treatment  (con-
ventional or extended aeration) is appropriate.  The process cost of treatment is generally less than other
biological processes in the range of wastewater flows between 0.1 and 10 Mgal/d.

Limitations - Oxidation ditches offer an added measure of reliability and performance over other biological
processes but are subject to some of the same limitations that other activated sludge treatment processes  face.

Performance - The average performance of 29 shallow oxidation ditch plants is summarized below:
                              Effluent, mg/1                     Removal, Percent
                         Winter    Summer    Annual Avg.         Winter    Summer    Annual flvg.
BOD                      15.2      1.2       12.3                92        94        93
Suspended Solids         13.6      9.3       10.5                93        94        94

40 to 80 percent ammonia nitrogen removal has been achieved.

Chemicals Required  - None

Residuals Generated - No primary sludge is generated.  Sludge produced is less volatile due to higher oxidation
efficiency and increased solids retention times.

Design Criteria -  (Extended Aeration Mode)
BOD  Loading:  8.6  to 15 Ib BOD5/1000  ft  of aeration volume/d; Sludge Age:      10 to 33 d;
Channel Depth: 4 to 6 ft
Channel Geometry:   45 degree or vertical sidewalls
Aeration Channel Detention Time:   1 d

Unit Process Reliability - The average reliability of 12 shallow oxidation ditch plants is summarized below:
                              Percent of Time Effluent Concentration mg/1 Less Than
                            10 mg/1                  20 mg/1                  30 mg/1
                         TSS_       BOD            TSS       BOD            TSS       BOD
Average of all plants    65~       65              85        90             94        96

Environmental Impact - Solid waste, odor and air pollution  impacts  are  similar to  those encountered with  standard
activated sludge processes.

Toxics Management - The same potential for  sludge  contamination, upsets  and  pass through of toxic  pollutants
exists for oxidation ditch plants  as standard  activated  sludge processes.

References -  7,  16, 20, 23, 110, 259
                                                    A-70
-------
OXIDATION DITCH
                                                                                    FACT SHEET 2.1,15
FLOW DIAGRAM
                  SCREENED AND
                  DEGRITTED RAW
                  WASTEWATER
ENERGY NOTES - Assumptions:
Energy requirement based on:
Water Quality       Influent (mg/1)
  IT                   136
                                        Effluent  (mg/1)
                                            20
Design Assumptions -
Oxygen transfer efficiency = 1.8 Ib O /hph  (wire to
water).  No appreciable nitrification occurs.

Operating Parameters -
Oxygen requirement = 1.5 Ib O /Ib BOD  removed

Type of Energy Required:  Electrical
COSTS* - 3rd quarter 1976 dollars; ENR Index = 2445.
Assumptions: Construction cost includes oxidation
ditch, clanfier, pumps, building, laboratory, out-door
sludge drying beds, but excludes land, engineering,
legal and financing during construction.  OSM costs
include labor, utilities, chemicals, maintenance
materials.
                       CONSTRUCTION COSTS
           10
          1 0
       o
       Q
          01
          001
           0.01
 REFERENCES - 4,  16
                         0.1            1.0
                        Wastewater Flow. Mgal/d
                                                    10
*To convert construction cost to capital cost see Table A-2.
                                                                       10
                                                                                  Wastewater Flow, Mgal/d

                                                                         7      0.1          1.0           10
                                                                       10
                                                                       10"
                                                                      10
                                                                        ion
                                                                                     ],oor       io,non      100,000
                                                                                 Oxygen Requirement, Ib/day
                                                                            OPERATION AND MAINTENANCE COSTS
                                                                     1 0
                                                                     0 1
                                                                 o
                                                                 O
                                                                 •5  001
                                                                   0001
                                                                     0.01
                                                                                   0.1           1.0
                                                                                  Wastewater Flow, Mgal/d
                                                                                                               10
                                                         A-71
-------
PHOSTRIP                                                                           FACT  SHEET  2,1,17
Description - "PhoStrip" is a combined biological-chemical precipitation process based on the use of activated
sludge microorganisms to transfer phosphorus from incoming wastewater to a small concentrated substream for pre-
cipitation.  The activated sludge is subjected to anoxic conditions to induce phosphorus release into the sub-
stream and to provide phosphorus uptake capacity when the sludge is returned to the aeration tank.   Settled
wastewater is mixed with return activated sludge in the aeration tank.  Under aeration/ sludge microorganisms can
be induced to take up dissolved phosphorus in excess of the amount required for growth.  The mixed liquor then
flows to the secondary clarifier where liquid effluent, now largely free of phosphorus, is separated from the
sludge and discharged.  A portion of the phosphorus-rich sludge is transferred from the bottom of the clarifier to
& thickener-type holding tank: the phosphate stripper.   The settling sludge quickly becomes anoxic and, thereupon,
the organisms surrender phosphorus, which is mixed into the supernatant.  The phosphorus-rich supernatant, a low
volume, high concentration substream, is removed from the stripper and treated with lime for phosphorus precipi-
tation.  The thickened sludge, now depleted in phosphorus, is returned to the aeration tank for a new cycle.

Modifications - The PhoStrip process has demonstrated a compatibility with the conventional activated sludge
process and appears to be compatible with modifications of it.  The process can operate in various flow schemes,
including full or split flow of return activated sludge through the phosphate stripper, use of an elutriate to aid
in the release of phosphorus from the anoxic zone of the stripper, or returning lime-treated stripper supernatant
to the primary clarifier for removal of chemical sludge.

Technology Status - This technique is a new development in municipal wastewater treatment and has been demon-
strated in pilot plant and full-scale studies.  Notable large scale evaluations have been conducted at Seneca
Falls, New York and, more recently, Reno/Sparks, Nevada.  Nearly a dozen commercial installations are reported to
be in the design or construction phase now.   (190)

Typical Equipment - The equipment package for this proprietary process includes phosphate stripper tanks, chemical
feeders, mixers, and precipitator tanks.

Applications - This method, which involves a modification of the activated sludge process, can be used in removing
phosphorus from municipal wastewaters to comply with most effluent standards.  Direct chemical treatment is simple
and reliable, but it has the two disadvantages of significant sludge production and high operating costs.  The
PhoStrip system reduces the volume of the substream to be treated, thereby reducing the chemical dosage required,
the amount of chemical sludge produced, and associated costs.  Lime is used to remove phosphorus from the stripper
supernatant at lower pH levels (8.5 to 9.0) than normally required.  The cycling of sludge through an anoxic phase
may also assist in the control of bulking by the destruction of filamentous organisms to which bulking is gen-
erally attributed.

Limitations - More equipment and automation, along with a greater capital investment, are normally required than
for conventional chemical addition systems.  Since this method relies on activated sludge microorganisms for
phosphorus removal, any biological upset that hinders uptake ability will also affect effluent concentrations.  It
has been found that sludge in the stripper tank is very sensitive to the presence of oxygen.  Anoxic conditions
must be maintained for phosphorus release to occur.

Performance - Pilot and full-scale studies of the process have shown it to be capable of reducing the total
phosphorus concentration of typical municipal wastewaters to 1 mg/1 or less.  A plant-scale evaluation of the
method treating 6 Mgal/d of municipal wastewater at the Reno/Sparks Joint Water Pollution Control Plant in Nevada
demonstrated satisfactory performance for achieving greater than 90 percent phosphorus removal.  Results showed
that the process enhanced the overall operation and performance of the activated sludge process, since it produced
a more stable, better settling sludge.   (191)

Chemicals Required - Lime  (CaO).

Residuals Generated - Chemical sludge containing hydroxyapatite is formed from lime treatment.

Design Criteria - The fraction of the total sludge flow which must be processed through the stripper tank is
 determined by the phosphorus concentration in the influent wastewater to the treatment plant and the level
required in the treated effluent.  Required detention time in the stripper tank ranges from five to fifteen hours.
Typical phosphorus concentrations produced in the stripper are in the range of 40 to 70 mg/1.  The volume of the
phosphorus-rich supernatant stream to be lime treated is 10 to 20 percent of the total flow.

Process Reliability - As yet, the process has not been evaluated over a long period of time.  Regular maintenance
of mechanical equipment, including pumps and mixers, is necessary to ensure proper functioning of entire  system.

Environmental Impact - Controlling the discharge of phosphorus can arrest eutrophication of receiving waters.
Less chemical sludge requiring disposal is produced than from other phosphorus removal methods.

References - 188-193
                                                        A-72
-------
 PHOSTRIP
                                                                                      FACT  SHEET 2.1,17
 FLOW DIAGRAM -
nndary
idge
Return
Sludge


Phosphate
Stripper
V S
P-R
Lime Storage
and Feed

ich
Supernatant




O

6



Supernatant
Precipitator
X. Tank s^
   Waste/Return
      Sludge
                                                                   Mixer
                              Return ^noxic
                                Sludge to
                              Aeration Tank
ENERGY NOTES - Assumptions:  Power required  for  operation
                                                                                    Chemical
                                                                                     Sludge
                                                                      10
of pumps, lime mixing equipment and clarifiers.
COSTS -Assumptions:
                                                                  "?,  10
ENR Index = 2475
Service Life:   40 years

1.   Construction costs include:  stripper  (10 h detention
     time at 50% of return sludge); flash mixer; flocculator-
     clarifier;  thickeners; lime feed and storage facilities.

     Operation and maintenance costs include:  labor for
     operation,  preventive maintenance, and minor repairs
     at $7.50/h, including benefits; materials to include
     replacement parts and major repair work; lime cost basec
     on $25/ton and 225 Ib/Mgal; power cost at 50.02/k'Jh.
                                                                   c
                                                                   H
                                                                      10
                                                                      10
         100
                       CONSTRUCTION COST
                                                                         °-l           1.0           10
                                                                                   Wastewater Flow, Mgal/d

                                                                         OPERATION & MAINTENANCE COST
          10
         1 0
         01
          0 1
EFERENCE  - 3
                                                                1 O
                                                          Q jn
                                                          »- ro
                                                          o c
                                                          ° 5
                                                          o J.
                                                          O S
                                                               001
                        1 0           10
                       Wastewater Flow. Mgal/d
                                                              0001
                                                                                       -Po<
                                                                                                Chemica s
                                                                                          ;MatenaJs!
                                                                                                     Total
                                                                                                      :i_abo
                                                                                                             0 1
                                                                                                             001
                                                                                                            0001 .
                                                  100
                                                                 01
                                                                              1 0            10
                                                                              Wastewater Flow, Mgal/d
                                                                                                         100
                                                                                                           0 0001
*To convert construction cost to capital cost see Table A-2.
                                                       A-73
-------
BIOLOGICAL CONTACTORS,  ROTATING (RBC)                                       FACT SHEET  2.2.1
Description - The process is a fixed film biological reactor consisting  of plastic  media mounted on  a horizontal
shaft and placed in a tank.   Common media forms are disc type made of  styrofoam and a  denser  lattice type made of
polyethylene.  While wastewater flows through the tank,  the media are  slowly  rotated,  about 40% immersed, for
contact with the wastewater for removal of organic matter by the biological film that  develops on  the media.
Rotation results in exposure of the film to the atmosphere as a means  of aeration.   Excess biomass on the media
is stripped off by rotational shear forces and the stripped solids are maintained in suspension by the mixing
action of the rotating media.  Multiple staging of RBC's increases treatment  efficiency and could  aid in achieving
nitrification year round.  A complete system could consist of two or more parallel  trains with each  train con-
sisting of multiple stages in series.

Common Modifications - Multiple staging; use of dense media for latter stages in train; use of molded covers or
housing of units; various methods of pretreatment and after treatment  of wastewater; use in combination with
trickling filter or activated sludge processes; use of air driven system in lieu of mechanically driven system;
addition of air to the tanks; addition of chemicals for  pH control;  and  sludge recycle to enhance  nitrification.

Technology Status- The process has only been in use in the United States since 1969 and thus  is not  yet in wide-
spread use in this country.   However, because of its characteristic  modular construction, low hydraulic head loss
and shallow excavation, which make it adaptable to new or existing treatment  facilities, its  use is  growing.

Application - Treatment of domestic and compatible industrial wastewater amenable to aerobic  biological treatment
in conjunction with suitable pre and post treatment.  Can be used for  nitrification, roughing, secondary treat-
ment and polishing.

Limitations - Can be vulnerable to climatic changes and  low temperatures if not housed or covered.  Performance
may diminish significantly at temperatures below 55 F.  Enclosed units can result in considerable  wintertime
condensation if heat is not added to the enclosure.  High organic loadings can result  in first stage septicity
and supplemental aeration may be required.  Use of dense media for early stages can result in media  clogging.
Alkalinity deficit can result from nitrification;  supplemental alkalinity source may be required.

Typical Equipment/No. Hfrs.  (10)  - Rotating Disc Systems/5

Performance - Four stage system with final clarifier and preceded by primary  treatment (percent removal).

BOD , 80-90%          SS, 80-90%          Phosphorus, 10-30%        NH  -N, Up to 95%*

*Dependent upon temperature, alkalinity, organic loading, and unoxidized nitrogen loading.

Residuals Generated - Sludge in the secondary clarifier.  3000 to 4000 gal sludge/Mgal wastewater, 500 to 700 Ib
dry solids/Mgal wastewater.

Design Criteria -
Organic Loading - Without nitrification - 30 to 60 Ib BOD /d/1000 ft  media,  with nitrification -  15 to 20 Ib
                  BOD /d/1000 ft  media
Hydraulic Loading - Without nitrification - 0.75 to 1.5  gal/d/ft  of media surface  area, with nitrification - 0.3
                  to 0.6 gal/d/ft  cf media surface area
Number of stages per train - 1-4 depending upon treatment objectives
Number of parallel trains -  Recommended at least two
Rotational Velocity - Peripheral velocity = 60 ft/mm for mechanically driven, 30-60 ft/min for air  driven
Typical media surface area - Disc type - 20-25 ft /ft ,  standard lattice type - 30-40  ft /ft  ; high  density
  lattice - 50-60 ft /ft
Percent media submerged - 40%
Tank volume =0.12 gal/ft  of disc area
Detention time based on 0.12 gal/ft  - Without nitrification - 40-120  minutes, with nitrification  -  90-250
  minutes
Secondary clarifier overflow rate - 500-800 gal/d/ft
HP - 3.0-5.0 consumed/25 ft shaft; 5-7.5 connected/25 ft shaft

Process and Mechanical Reliability - Moderately reliable in absence  of high organic loading and temperatures
below 55°F.Mechanical reliability is generally high provided first stage of system is designed to  hold large
biomass.  Dense media in first stage can result in clogging and structural failure.

Toxics Management - Little data exists concerning removal of toxics  by this process.   As with any  fixed film
process, this process is presumably sensitive to variable inputs of  toxics.   Treatability studies  are advisable
to determine degree of toxics removal.

Environmental Impact - Negative impacts have not been documented.  Presumably, odor can be a  problem if septic
conditions develop in the first stage.

References - 3, 4, 22, 28, 54, 60, 61, 62, 63, 233
                                                         A-74
-------
 BIOLOGICAL CONTACTORS, ROTATING,  (RBO
          FACT SHEET 2.2.1
 FLOW DIAGRAM -
                                         TYPICAL  STAGED RBC CONFIGURATION

                                               Shaft Drive
                  Primary Effluent
                                                                               to  Secondary Clarifier
                                    *Alternate shaft orientation is parallel to
                                    direction of flow with a common drive for all
                                    the stages in a single train.
ENERGY NOTES - Approximate drive  energy for operating the contactors can be determined from the following relation-
ship:
               kwh/yr= K x(Effective  surface  area of the biological contactor)
               where K is 0.3 for standard media and 0.2 for dense media.
COSTS -  Assumptions:  (ENR Index = 2475)                             2
1.   Construction cost includes RBC shafts  (standard media, 100,000 ft /shaft), motor drives (5 hp/shaft),
     molded fiberglass covers,  and reinforced  concrete basins.
2.   Cost does not include primary and secondary  clarifiers.
3.   Loading rate - 1.0 gal/d/ft .
4.   Treatment is for carbonaceous oxidation.
100
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                     Wastewater Flow,  Mgal/d


REFERENCES -3,4


**To convert construction cost to  capital cost see  Table A-2.
                                                                 01
                                                                               10
                                                                                            10
                                                                                                         100
Wastewater Flow,  Mgal/d
-------
DENITRIFICATION FILTER,  COARSE MEDIA                                          FACT  SHEET 2.2.2
Description and Common Modifications - During denitrification,  nitrates and nitrites  are  reduced to nitrogen  gas
through the action of facultative heterotrophic bacteria.   Coarse media denitrification  filters  are  attached
growth biological processes in which nitrified wastewater  is passed through submerged beds  containing  natural
(gravel or stone) or synthetic (plastic) media. The systems may be pressure or gravity.  Minimum  media  diameter  is
about 15 mm.  Anaerobic or near anaerobic conditions are maintained in the  submerged bed, and  since  the  nitrified
wastewater is usually deficient in carbonaceous materials  a supplemental carbon source (usually  methanol)  is
required to maintain the attached denitrifying slime.  Because of the high  void percent  and low  specific surface
area characteristic of high porosity coarse denitrification filters, biomass (attached slime)  continuously sloughs
off.  As a result, the coarse media column effluent is usually moderately high in suspended solids (20-40 mg/1),
requiring a final polishing step.  (See Fact Sheet 2.2.3 on fine media denitrification filters.)

A wide variety of media types may be used as long as high  void volume and low specific volume  are maintained.
Both dumped plastic media and corrugated sheet media have  been used.  Backwashing is infrequent  and  is usually
done to control effluent suspended solids rather than pressure drop.  Alternate energy sources such  as sugars,
volatile acids, ethanol, or other organic compounds, as well as nitrogen deficient materials such as brewery
wastes may be used.  Nitrogen gas filled coarse media denitrification filters are a possible modification. See
Fact Sheet 2.1.9 for information on suspended growth denitrification systems.

Technology Status - Well developed at full scale, but not  in widespread use.
Typical Equipment/No, of Mfrs. (23) - Filter Equipment/35;  Controls/29;  Instrumentation/9;  Chemical Feed Equip-
ment/25; Clarifier Equipment/38.

Applications - Used almost exclusively to denitrify municipal wastewater that has undergone carbon oxidation and
nitrification.  May also be used to reduce nitrate in industrial wastewater.

Limitations - Specifically acts on nitrate and nitrite, will not affect other forms of nitrogen.
Performance - Capable of converting nearly all nitrate in a nitrified secondary effluent to gaseous nitrogen.
Overall nitrogen removals of 70-90 percent are achievable.

Chemicals Required - The amount of the most common energy source, methanol, required may be estimated using the
following values per mg/1 of the material in the inlet to the process.

          mg/1  CH OH         per            mg/1 of


            2.47                             N03-N

            1.53                             N02~N

            0.87                             D.O.

Residuals Generated - With controlled supplemental carbon feed rates, little excess sludge is generated.  Sludge
production 0.6-0.8 Ib/lb NH3~N reduced.
Degign Criteria  (28, 204) - Optimum PH.- 6.5 to 7.5.  Voids - 70 to 96 percent.  Specific surface - 6§4to 274
 ft /ft  .  Loading Rate Ib NO -N rem/ft  packing surface/d is a function of temperature up to 0.5 x 10   at 5 C,
 0.2  to  0.8 X 10   at 15°C and 0.8 to 1.3 X 10" at 25°C.  Surface loading rate of 2.5 and 4.1 gal/ft /d for a flow
 of 0.3  and 0.5 Mgal/d respectively have been found to apply at El Lago, Texas facility.

 Unit Process Reliability - Under controlled pH, temperature, loading and chemical feed high levels of reliability
 are  achievable.  Less operator attention required than with fine media systems.

 Environmental  Impact - Reduction of nitrogen loading on streams; less land requirement than suspended growth
 system.

 References  -  7,  23,  28,  45, 95, 204
                                                       A-76
-------
DENITRIFICATION FILTER,  COARSE MEDIA
                                       FACT  SHEET  2,2,2
FLOW DIAGRAM -
                             Backwash  Water
                         to head of plant
                          Denitrification
                              Column
                                                               Effluent to
                                                                  polishing
                          Denitrification
                             Column
                       Dumped Media
                         (Typical)
                                                                       ^Backwash Pump
                                 Methanol
ENERGY NOTES - Pumping energy can be  computed from the following equation:
     kWh/yr = 1140 (Mgal/d    X  ft  of  total average head
                   wire to water efficiency

For a 0,5 Mgal/d plant treating  14  mg/1 of NO -N two 10-ft diameter by 10-ft deep tanks would  be  required.
Therefore, using 15 ft of total  head and  a wire to water efficiency of 0.60, 14,250 kWh will be required  for
wastewater pumping.

Backwashing at a rate of 20 gal/min/ft once a month for four hours would require an additional energy  consumption
of 1425 kWh/yr.

Upflow and downflow operations consume roughly the same amount of energy.


COSTS* - Assumptions: Mid 1972 costs;  ENR Index - 1761.  For an 0.5 Mgal/d plant treating 14 mg/1 NO -N,  two  10-ft
diameter by 10-ft deep tanks would  be  required.  Construction costs for such a system would be approximately
$200,000  (28).

Operation and maintenance costs  would  be  as follows:

     Item
     Chemicals (Methanol)
     Labor at $5/h
                              Total
O/M Costs per 1000 gal  Treated
          $0.03
           0.03
          $0.06/1000  gal
*To convert construction cost to capital  cost see Table A-2.
 REFERENCES  -  4,  28, 204
                                                       A-77
-------
DENITRIFICATION FILTER,  FINE  MEDIA                                             FACT  SHEET 2.2.3
Description - In the denitrification process,  nitrates and nitrites in nitrified wastewater  are  converted to
nitrogen gas by the action of facultative heterotrophic bacteria.   The fine  media denitrification filter is  an
attached growth biological process in which nitrified wastewater is passed through a pressurized  submerged bed  of
sand or other fine filter media (up to about 15 mm in diameter)  in which anoxic  conditions  are  maintained.   The
nitrified wastewater contains very little carbonaceous material, and consequently requires  a  supplemental energy
source (usually methanol) to maintain the attached denitrifying  slime.  Because  of the  relatively fine  media used,
physical filtration analogous to that occuring in a pressure filter takes place.   As a  result,  a  clear  effluent is
produced, eliminating the need for final clarification.  Backwashing is required to maintain  an acceptable pressure
drop.  Surface loading rates may be somewhat lower than those common for pressure filtration.   Development of the
denitrifying slime, and consequent denitrification efficiency are a function of  the specific  surface  area of the
filter, and in practice fine media denitrification filters convert nitrates  to nitrogen gas at  a  much higher rate
than suspended growth systems.  The coarser the media, the less  frequent the backwashing, although the  effluent
may be more turbid.  (See Fact Sheet 2.2.2 on coarse media denitrification filters.)

Common Modifications - Common modifications include the use of various media such as garnet sand, silica sand or
anthracite coal with varying size distributions.   Multimedia systems have  also been used.   Alternate  energy
sources such as sugars, volatile acids, ethanol or other organic compounds as well as nitrogen deficient materials
such as brewery wastewater may be used.  An air scour may be incorporated  into the backwashing cycle;  however,
temporary inhibition of denitrification may result.  Various types of underdrains may be used.   A bumping pro-
cedure (short periodic flow reversals)  has been used to remove entraped nitrogen gas bubbles produced during
denitrification.  Denitrification may be combined with refractory organic  removal. Upflow systems utilizing fine
media (sand or activated carbon) have been operated as fluidized bed reactors.

Technology Status - Well demonstrated but not in widespread use.
Typical Equipment/No, of Mfrs.  (23) - Filter Equipment/35;  Controls/29;  Instrumentation/9;
Chemical Feed Equipment/25.

Applications - Used almost exclusively to denitrify municipal wastewaters that have undergone carbon oxidation and
nitrification.  May also be used to reduce nitrate in industrial wastewater.

Limitations - Specifically acts on nitrate and nitrite and  will not affect other forms of nitrogen.
Performance - Capable of converting nearly all nitrate and nitrite in a nitrified secondary effluent to gaseous
nitrogen.  Overall nitrogen removals of 75-90 percent are achievable.   Suspended solids removals of up to 93 per-
cent have been achieved.

Chemicals Required - An energy source is commonly supplied in the form of methanol.   Methanol feed concentrations
may be estimated using the following values per mg/1 of the material at the inlet to the process.

          mg/1  CH3OH         per            mg/1 of
            2.47                             N03-N

            1.53                             N02~N

            0.87                             D.O.

Residuals Generated - If supplemental energy feed rates are controlled, little excess sludge is generated.
Design Criteria  (28) -
Flow Scheme                                       Downflow (although upflow systems with different design criteria
                                                       have been utilized (28))
Optimum pH                       ,                6.5-7.5
Surface Loading Rates, gal/min/ft                 0.5-7.0
Media Diameter  (d  ) mm                           2-15                                  2   3
Column Depth, ft                                  3-20 (function of specific surface  ft /ft   and contact time)
                         2                             (28)
Backwash Rate, gal/min/ft                         8-25
Backwash Cycle Frequency, d                       0.5-4.0
Specific Surface ft /ft                           85-300
Voids, %                                          40-50

Unit Process Reliability - Under controlled pH, temperature, loading and chemical feed high levels of reliability
 are  achievable.

 Environmental Impact - High nitrogen removal efficiency; smaller structures (land use)  than suspended growth
 systems.

 References  -  7,  23,  28, 45, 95
                                                      A-78
-------
*To convert construction cost to capital cost see Table A-2
0.1 1.0
Wastewater Flow,
REFERENCES - 4, 28, 204
£ °
I-1
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Millions of Dollars
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COSTS* (204) - Assumptions:
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Temperature is 15 °C 4
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DENITRIFICATION FILTER, FINE MEDIA FACT SHEET 2.2.3
-------
INTERMITTENT  SAND FILTRATION,  LAGOON UPGRADING                             FACT SHEET  2.2.4
Description - The intermittent sand filter is an outdoor,  gravity,  filtration system that capitalizes on the
availability of land area.   It is a biological and physical wastewater treatment mechanism consisting of an
underdrained bed of granular material, usually sand.   The  filter surface  is flooded intermittently with lagoon
effluent at intervals which permit the surface to drain between applications.   It is recommended that the flow be
directed to one filter for 24 hours.   That filter is  then  allowed to drain and dry for one to two days,  and the
flow goes to an adjacent filter.   It is preferable to have three filter beds where good operation and treatment
may be accomplished over a three-day cycle.

The filter contains drainage pipes that are  laid with open joints at depths of 3 to 4 ft and surrounded with
layers of coarse stone and gravel graded from coarse  to fine to keep sand out.   When the filter is located in
natural sand deposits, the percolating waters may reach the groundwater table,  and no effluent may come to view.
In areas where percolation to the groundwater is not  permitted, the filter must be provided with an impermeable
base or lining.  Influent wastewater is piped to the  beds  for discharge into a protective stone or concrete apron
or into a concrete flume distributor.   Surface accumulations of solids are periodically removed and disposed  of as
fill or by some other means.  Filters must be resanded when they become too shallow as a result of the periodic
surface cleaning.  In cold weather the beds  are plowed into ridges  and furrows (1 to 1.5 ft deep)  to keep them
from freezing and opening up cracks through  which the applied wastewater  can escape with little treatment.  To
form protective sheets of ice spanning the furrows and keep the beds warm, furrowed beds are dosed deeply on  cold
nights.

Common Modifications - Continuous application; series application where effluent is applied to filter beds of
progressively smaller size; e.g., #1 e.s.  =  0.72 mm,  #2 e.s. = 0.40 mm, #3 e.s. = 0.17 mm.

Technology Status - Practiced for many years where land is available;  proven performance; current emphasis on
development of scientific basis and optimum  design criteria through pilot research and demonstration activities.

Typical Equipment - Piping; graded sand and  gravel.

Applications - Polishing of domestic wastewater stabilization pond  effluent; also for final treatment of bio-
degradable industrial wastewater stabilization pond effluent; where minimum maintenance is required.

Limitations - High land requirements;  unsuitable for  anaerobic lagoon effluents; suitable for aerated lagoons if
aerated lagoons followed by facultative lagoon.

Performance  (12) -

     Filter effluent quality (treatment of domestic wastewater stabilization pond):
     BOD , mg/1 - less than 10.
     SS, mg/1 - less than 10.
     Nitrogen - nearly complete nitrification except  during winter  when cold temperatures can retard nitrifi-
          cation.
     Phosphorus - negligible removal

Residuals Generated  (12) - For an average loading of  500,000 gal/acre/d (490,000 m /m .d) the filters would
operate approximately 30 to 60 days before cleaning would  be required. Therefore, it might be expected that  two
to three inches of surface material will need to be disposed of after 30  to 60 days of operation.   Disposal is
usually to landfill.

Design Criteria  (39) -

     Filter drain - open joint or perforated tiles, at least 4 inches, laid on impervious layer.
     Sand depth - 30 to 36 inches (0.75 to 0.90 m)
     Sand characteristics - graded, effective size between 0.15 to 0.75 mm.
     Loading rate (24 h application), 400,000 to 600,000 gal/acre/d

Process Reliability - Highly reliable; requires minimal operator attention.

Environmental Impact  - Land area requirements are great;  odor potential  exists; public acceptance may be dif-
ficult due to potential adverse effects to surrounding land uses.

References - 12, 14,  39, 133, 137, 149
                                                        A-80
-------
INTERMITTENT  SAND  FILTRATION,LAGOON UPGRADING
                                   FACT  SHEET  2.2.4
 PLOW DIAGRAM
              msm
                        Underdrains
                          Profi1P
                                                                             Plan
ENERGY NOTES - Assuming influent pumping requirements  of 30  ft TDK  and pumping operation of 3 h/d, with gravity
discharge, an energy requirement of 35,000 kWh will be required per Mgal/d.



COSTS (137) - Costs for this process are particularly  site specific due to the land requirements.  Generalized
cost curves are therefore not available.   Presented below is  a capital cost estimate for a particular application
where influent pumping and impervious lining are  required. November 1974  dollars. ENR = 2094.

Single intermittent filters (duplicate facilities).

Design flow rate: 0.5 Mgal/acre/day
Locally available sand: 0.17 nan effective size @  30 inch bed  depth  (760 ran)
Initial Construction Cost (in place):

Granular media (sand)
Gravel
6 inch lateral drains (10 ft spacing)
Ductile iron pipe
Pumps (3 h application,  1 pump for each filter,
  plus 1 standby, 2 800  gal/min and timer,
  30 ft TDK)
Excavation and embankment (Slopes 3:1  interior,
  2:1 exterior; line with clay type impervious
  material; 10 ft wide at top of dike)
Building
Distribution system
Pipe distribution
Land
Total Capital Cost

Annual Operating and Maintenance Costs

Maintenance cost:
Manpower cost: (at $10,000/yr)
Power: 22 hp or 16 kW
  16 kW  (3 h/d)  (365 d/yr)  = 17,520 kWh/yr
  17,520 kWh/yr X $0.03/kWh

Total Operating and Maintenance Costs
REFERENCE - 137
                Unit Cost
,380
 500
13, 828 yd
 1
 2
  1000 ft
  6 acres
                     4.40
                     4.40
                     1.00
                     9.50
                $3,200.00
                     1.00
$2,000.00
$1,000.00
$    2.00
$1,000.00
               Total Cost
               $27,500
               $ 9,770
               $ 7,380
               $ 4,750
               $ 9,600
                               $13,830
                                                                               $84,830
                $l,000/yr
                 4,500
                 3,500

                   526
                $9,526/yr
                                                     A-81
-------
POLISHING FILTER FOR LAGOON,  ROCK  MEDIA                                     FACT  SHEET 2.2,5
Description (173) - The rock filter, as an alternative for the removal of algae  from lagoon  effluents,  consists  of
a submerged bed of rocks (5 to 20 cm diameter)  through which the lagoon effluent is passed  vertically  or  hori-
zontally, allowing the algae to become attached to the rock surface and thereby be removed.   The  basic simplicity
of operation and maintenance are the key advantages of this process.   The  effluent quality  achievable  and the
dependability of long-term operation, however,  have not yet been proven.

This fact sheet is based upon a full-scale rock filter which was designed  and constructed as  part of a lagoon
expansion and upgrading project at Veneta, Oregon in 1975.   The system treats wastewater  from a population of
approximately 2200 with no industrial wastewater contribution.   The lagoon effluent enters  the bottom  of  the
filter through an influent channel.  The lagoon effluent then rises from the influent channel and moves hori-
zontally toward the discharge weirs where it flows into a covered effluent channel.   Finally, the flow from each
side of the rock filter is combined,chlorinated, and discharged.   The rock surface is approximately 0.30  m (1.0
ft)  above the water elevation to prevent growth of algae on the rock filter.

Common Modifications - Not applicable,- only one plant in operation.
Technology Status - Experimental stage of development.
application - Polishing of domestic wastewater stabilization pond effluent;  also for final  treatment of biode-
gradable industrial wastewater stabilization pond effluent;  where low maintenance is  required.

Limitations - Effluent quality and operational dependability are not yet proven.
Performance - The following table is a summary of performance data for the demonstration filter at Veneta,  Oregon:

                    	Weekly Averages	
Parameter           Wk. 1          Wk. 2          We.  3          Wk.  4          Wk.  5          Wk. 6          Wk.  7
                    I*   E*        IE 	     I    E	I    E	I    E	I    E	I    E
DO (rag/1)           10.1 4.5    15.4  6.2      11.2   3.2     10.8   3.0     10.8   3.2      17.4   2.9      6.9  1.8
TSS  (mg/1)          42   9      29    14       28     10      22     9       44     7       43     9        105  10
BOD  (rag/1)         20   9      27    14       20     10      21     15      39     19      42     18       43   11
COD  (mg/1)          121  77     67    45       51     36      61     44      147    80      159    104
NH +-N (mg/1)       0.8  1.7    3.5   2.9      15.5   12.4    15.9   14.3    3.8    5.5      2.6    7.2      0.2  3.5
Org-N (mg/1)        4.1  3.4    5.8   5.4      5.7    1.4     3.9    3.3     8.8    4.5      8.4    5.2
NO ~-N (mg/1)       1.5  2.1    1.0   1.6      0.8    1.1     1.1    0.8     1.7    1.5      2.3    1.0      1.9  1.2
Soluble P  (mg/1)    4.8  3.9    1.7   1.6      2.5    3.1     2.1    3.5     6.0    4.6      3.7    4.9
Total P  (mg/1)      5.2  4.1    2.1   1.6      3.2    3.4     2.7    3.1     6.8    5.0      5.6    5.4
Chlorophyll a (ug/1)  -    -    340   160      260    72      160    32      690    13      210    34
Chlorophyll b (ug/1)  -    -    39    23       59     15      17     3       348    12      240    38
Chlorophyll c (ug/1)  -    -    23    15       29     6       19     5       148    22      380    80

*I = rock filter influent; *E = rock filter effluent.

Residuals Generated - Sludge accumulation and periodic clean out requirements should be  anticipated.
Design Criteria - The following is a list of design data from the Veneta, Oregon facility:
     Influent pump capacity, 1/s (gal/min)       22               25 <400)
     Effective surface area of the rock filter, m  (ft )               5,400 (58,000)
     Effective volume, m  (ft )                                       8,200 (290,000)
     Rock size, cm (inches)                                            7.6 to 15.2 (3  to 6)
     Porosity, in situ average, percent                               42
     Hydraulic loading, m  water/m  rock filter/d                     0.07 to 0.28

Process Reliability - Short-term data favorable; minimum operator attention required.
Environmental Impact - Potential odors; large land requirements

Reference  - 173
                                                       A-82
-------
POLISHING  FILTER FOR  LAGOON,  ROCK MEDIA
FACT  SHEET 2.2,5
    FLOW DIAGRAM
                                    Rock Filter located at Veneta, Oregon.
                                  Effluent
                        T nf luent
                                                            Effluent
                                              Influent
                                                nine
                                                                                Effluent weir
                              Effluent weir
                                      Influent  Dine
                                                      PROFILE
  FNERGY NOTES -
  Depending on site conditions,  the influent to the filter may require pumping;   otherwise,  there  are no energy
  requirements.   Pumping energy  requirements may be approximated by using the following equation;  kWhr/year=
  1900 x Mgal/day x discharge head ft., assuming a wire to water efficiency of 60%.   For the typical head
  requirements of 6 ft.  for this process, an energy requirement of 11,400 kwhr/year/Mgal/day can be expected.



  COSTS (177)  -
  There are no generalized cost data for the rock filter.   The best data presently available is on the Veneta,
  Oregon facility,  which is currently the only such filter in operation.  This facility was  constructed in 1976
  at a cost of 11*  per gal/d of design capacity.  It is estimated that with a design  flow of 300 gal/min, the
  filter cost  was $47,500.  In terms of generalized costs, it may also be estimated that the rock media present-
  day cost (1978)  is  $8/yd3,ENR  Index = 2776


  REFERENCES - 173,  177
                                                  A-83
-------
TRICKLING FILTER,  PLASTIC MEDIA                                               FACT  SHEET  2.2.6
Description - The process consists of a fixed bed of plastic media over which wastewater is applied for aerobic
biological treatment.  Zoogleal slimes form on the media which assimilate and oxidize substances in the waste-
water.  The bed is dosed by a distributor system, and the treated wastewater is collected by an underdrain system.
Primary treatment is normally required to optimize trickling filter performance,  whereas post-treatment is gen-
erally not required to meet secondary standards.

The rotary distributor has become the standard because of its reliability and ease of maintenance,  however, fixed
nozzles are often used in roughing filters.  Plastic media is comparatively light with a specific weight 10 to 30
times less than rock media.  Its high void space (approximately 95 percent)  promotes better oxygen transfer during
passage through the filter than rock media with its approximate 50 percent void space.  Because of its light
weight, plastic media containment structures are normally constructed as elevated towers 20 to 30 feet high.
Excavated containment structures for rock media can sometimes serve as a foundation for elevated towers for con-
verting an existing facility to plastic media.

Plastic media trickling filters can be employed to provide independent secondary treatment or roughing ahead of a
second-stage biological process.  When used for secondary treatment, the media bed is generally circular in plan
and dosed by a rotary distributor.  Roughing applications often utilize rectangular media beds with fixed nozzles
for distribution.

The organic material present in the wastewater is degraded by a population of microorganisms attached to the
filter media.  As the microorganisms grow, the thickness of the slime layer increases.  Periodically, the liquid
will wash some slime off the media, and a new slime layer will start to grow.  This phenomenon of losing the slime
layer is called sloughing and is primarily a function of the organic and hydraulic loadings on the filter.  Filter
effluent recirculation is vital with plastic media trickling filters to ensure proper wetting of the media and to
promote effective sloughing control compatible with the high organic loadings employed.

Common Modifications - Recirculation flow schemes, rate of recirculation, multistaging, electrically powered
distributors, forced ventilation, filter covers, and use of various methods of pretreatment and post treatment of
wastewater.  Can also be used as a roughing filter at flow rates above 1400 gal/d/ft .   Can be used as a separate
stage nitrification process.  Discussion of this application is presented in Fact Sheet 2.1.14.

Technology Status - Has been used as a modification of rock media filters for 10 to 20 years.
Applications - Treatment of domestic and compatible industrial wastewaters amenable to aerobic biological treat-
ment.  Industrial and  joint wastewater treatment facilities may use the process as a roughing filter prior to
activated sludge or other unit processes.  Existing rock filter facilities can be upgraded via elevation of the
containment  structure  and conversion to plastic media.  Can be used for nitrification following prior  (first-
stage) biological treatment.

Limitations  - Vulnerable to below freezing weather, recirculation may be restricted during cold weather due to
cooling effects, marginal treatment capability in single stage operation.  It is less effective in treatment of
wastewater containing high concentrations of soluble organics.  Has limited flexibility and control in comparison
with  competing processes, and has potential for vector and odor problems although they are not as prevalent as
with  low  rate rock media trickling filters.  Long recovery times with upsets.

Typical Equipment/No, of Mfrs.(23) - Underdrains/3; Distributors/10; Filter covers/2; Plastic media/5.
Performance - Employing the  loadings  listed below for secondary treatment and using a single-stage configuration
with  filter  effluent  recirculation and primary and secondary clarification (percent removal)
BOD   -  80  to 90 percent

Chemicals  Required -  None
BOD  - 80 to 90 percent    Phosphorus - 10 to 30 percent      NH4~N -  20  to 30  percent     SS -  80 to 90 percent
 Residuals  Generated -  Sludge  is withdrawn from the secondary clarifier at a rate of 3000 to 4000 gal/Mgal of
wastewater,  containing  500  to  700  Ib dry  solids.

Design Criteria -
 Hydraulic  loading (with  recirculation)                 Organic loading
 a.    Secondary treatment -  15  to 90  Mgal/acre/d        a.   Secondary treatment - 450 to 1750 Ib BOD /d/acre ft
                            350 to 2050 gal/d/ft                                   10 to 40 Ib BOD5/d/1000 ft
 b.    Roughing - 60 to 200 Mgal/acre/d                 b.   Roughing - 4500 to 22,000 Ib BOD /d/acr| ft
                 1400 to  4600 gal/d/ft                                 100 to 500 Ib BOD5/d/IOOO ft
 Recirculation ratio - 0.5:1 to 5:1                    Bed Depth - 20 to  30 ft
 Dosing interval - Not more  than 15 sec (continuous)    Power requirements - 10 to 50 hp/Mgal
 Sloughing  -  continuous                                Underdrain minimum slope = 1%

 Process and  Mechanical Reliability  - The  process  can  be  expected to have a high degree of reliability if operat-
 ing conditions minimize  variability  and the  installation  is in a climate where wastewater temperatures do not fall
 below 13°C for prolonged periods. Mechanical  reliability is high.  The process is simple to operate.

 Environmental Impact - Air: Odor problems if  improperly  operated.

 References - 7, 10, 22,  26, 27, 28,  29, 30,  31,  259


                                                          A-84
-------
 TRICKLING  FILTER, PLASTIC MEDIA
                                                                 FACT  SHEET  2.2.6
FLOW DIAGRAM -
                       Pump Station
                                                 Recirculation
              Raw
          Wastewater
         Prirr.ary
        Clarificr

r^

Plastic
Media
Trickling
Filter





Filial
Clarif ier


Effluent ^
1
                                                                         Waste Sludge
                         Raw Sludge
                                                       Recirculation
ENERGY NOTES - Pumping energy requirements may be approximated by using the following equation:
kWh/yr = 1900 x Mgal/d x discharge head ft, assuming a wire-to-water efficiency of 60 percent.   For  the  typical
head requirement of 23 ft for this process, and assuming an average recirculation ratio of 2:1, an energy
requirement of 131,000 kWh/yr/Mgal/d can be expected.  Mgal =  Influent Flow + Recirculation Flow.
Water Quality:
     BODC
Filter Influent(mg/1)
     130
     Suspended Solids
                         100
Effluent (mg/1)
     25
     20
COSTS* - Assumptions: January 1979 dollars.  ENR Index = 2872.
1.   Construction costs shown are for carbonaceous oxidation and are based on: bed depth = 21 ft; hydraulic
     loading approximately 0.65 gal/min/ft  at an average recirculation ratio of 2:1; at organic loading =
     20 Ib BOD /1000 ft ,- concrete enclosures are precast concrete; foundations and supports are poured-
     in-place.
2.   Construction cost includes plastic media, underdrains, distributors, and tower containment structures.
     Clarifiers and recirculation equipment not included.
3.   Construction costs for single stage nitrification range 23-25% higher than those for carbonaceous oxidation.
4.   OSM Costs shown are for carbonaceous oxidation and do not include energy requirements associated with recir-
     culation.  There is no energy requirement for the plastic media trickling filter itself.
5.   Labor including fringes = $ll/h.
6.   O&M costs for nitrification are approximately 12-15% higher than those for carbonaceous oxidation.
           100
                         CONSTRUCTION COST
                                                                            OPERATION & MAINTENANCE COST
            10
           1 0
           01
                                                                   0 1
                                                                   001
                                                                  0001
             0 1
                          1 0            10
                         Wastewater Flow Mgal/d
                                                                 00001
                                                                                               Total
                                                                                                 Labo
                                                                                               Materials—
                                                              1 0            10
                                                             Wastewater how Mgal/d
REFERENCE - 259

*To convert construction cost to capital cost see Table A-2.



                                                    A-85
-------
TRICKLING FILTER,  HIGH  RATE,  ROCK MEDIA                                     FACT  SHEET 2.2.7
Description - The process consists of a fixed bed of rock media over which wastewater is applied for aerobic bio-
logical treatment.  Zoogleal slimes form on the media which assimilate and oxidize substances in the wastewater.
The bed is dosed by a distributor system, and the treated wastewater is collected by an underdrain system.
Primary treatment is normally required to optimize trickling filter performance, and post-treatment is often
necessary to meet secondary standards or water quality limitations.

The rotary distributor has become the standard because of its reliability and ease of maintenance.  It consists of
two or more arms that are mounted on a pivot in the center of the filter.   Nozzles distribute the wastewater as
the arms rotate due to the dynamic action of the incoming primary effluent.  Continuous recirculation of filter
effluent is used to maintain a constant hydraulic loading to the distributor arms.

Underdrains are manufactured from specially designed vitrified-clay blocks that support the filter media and pass
the treated wastewater to a collection sump for transfer to the final clarifier.

The filter media consists of 1- to 5-inch stone.  The high rate trickling filter media bed generally is circular
in plan, with a depth of 3 to 6 feet.  Containment structures are normally made of reinforced concrete and
installed in the ground to support the weight of the media.

The organic material present in the wastewater is degraded by a population of microorganisms attached to the
filter media.  As the microorganisms grow, the thickness of the slime layer increases.  As the slime layer
increases in thickness, the absorbed organic matter is metabolized before it can reach the microorganisms near the
media face.  As a result, the microorganisms near the media face enter into an endogenous phase of growth.   In
this phase, the microorganisms lose their ability to cling to the media surface.  The liquid then washes the slime
off the media, and a new slime layer will start to grow.  This phenomenon of losing the slime layer is called
sloughing and is primarily a function of the organic and hydraulic loadings on the filter.  Filter effluent recir-
culation is vital with high rate trickling filters to promote the flushing action necessary for effective slough-
ing control, without which media clogging and anaerobic conditions could develop due to the high organic loading
rates employed.

Common Modifications - Various recirculation methods, rate of recirculation, multistaging, electrically powered
distributors, forced ventilation, and filter covers.

Technology Status - In widespread use since 1936.  A modification of the low rate trickling filter process.
Applications - Treatment of domestic and compatible industrial wastewaters amenable to aerobic biological treat-
ment in conjunction with suitable pre- and post-treatment.   Industrial and joint wastewater treatment facilities
may use the process as a roughing filter prior to activated sludge or other unit processes.  The process is
effective for removal of suspended or colloidal materials and is less effective for removal of soluble organics.

Limitations - Vulnerable to below freezing weather, recirculation may be restricted during cold weather due to
cooling effects, marginal treatment capability in single stage operation.   It is less effective in treatment of
wastewater containing high concentrations of soluble organics.  Has limited flexibility and control in comparison
with competing processes, and has potential for vector and odor problems although they are not as prevalent as
with low-rate trickling filters.   Long recovery times with upsets.  Limited to 60-80% BOD  removal.

Typical Equipment/No, of Mfrs.   (23)  - Underdrains/3; Distributors/10;  Filter covers/2.
Performance - Single-stage configuration with filter effluent recirculation and primary and secondary clarification
(percent removal).

BOD5  - 60 to 80 percent  Phosphorus - 10 to 30 percent   NH4~N - 20 to 30 percent   SS - 60 to 80 percent

Chemicals Required - None
Residuals Generated - Sludge is withdrawn from the secondary clarifier at a rate of 2500 to 3000 gal/Mgal waste-
water containing 400 to 500 Ib dry solids.

Design Criteria -
Hydraulic loading (with recirculation)  - 10 to 50 Mgal/acre/d      Organic loading - 900 to 2600 Ib BOD /d/acre ft
                                         230 to 1150 gal/d/ft                        20 to 60 Ib BOD /d/1000 ft
Recirculation ratio - 0.5:1 to 4:1                                 Bed Depth - 3 to 6 ft
Dosing interval - Not more than 15 sec (continuous)                 Power requirements - 10 to 50 hp/Mgal
Sloughing - continuous                                             Underdrain minimum slope = 1 percent Media -
Rock, 1" to 5", (using square mesh screen.   Must meet
  sodium sulfate soundness test)

Process and Mechanical Reliability  - The process can be expected to have a high degree of reliability if opera-
ting conditions minimize variability and the installation is in a climate where wastewater temperatures do not
fall below 13°C for prolonged periods.   Mechanical reliability is high.   The process is simple to operate.

Environmental Impact - Air:  Odor problems if improperly operated.
References - 7, 10, 22, 26, 27, 28, 29, 30, 31
                                                     A-86
-------
 I
CD
*To convert construction cost to capital cost see Table A-2.
1 10 1(
Wastewater Flow, Mga
REFERENCES - 207, 259

c
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stewater Flow, Mga
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*
COSTS Assumptions: ENR = 2494.
kWh/yr = 1900 x Mgal/d x discharge head ft, assuming a wire-to-water efficiency of
head requirement of 10 ft for this process and assuming an average recirculation ra
energy requirement of 95,000 kWh/yr/Mgal/d can be expected. Mgal = Influent Flow +
Water Quality: Filter Influent (mg/1) Ef fluent (mg/]
50 percent. For the typical
tio of 4:1, an
Recirculation Flow.
)
Raw S]
ENERGY NOTES - Pumping energy req
c c -• 	
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Waste Sludge
l_ J
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Raw Wastewater
Primary
,. Clarifier


High Rate,
Rock Media
Trickling
Filter
fc
Final
Clarifier
•ti
3
t
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Recirculation
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-------
TRICKLING FILTER,  LOW  RATE,  ROCK MEDIA                                       FACT  SHEET  2,2,8
Description - The process consists of a fixed bed of rock media over which wastewater is applied for aerobic  bio-
logical treatment.  Zoogleal slimes form on the media which assimilate and oxidize substances in the wastewater.
The bed is dosed by a distributor system, and the treated wastewater is collected by an underdrain system.   Recir-
culation is usually not used.  Primary treatment is normally required to optimize trickling filter performance.

The rotary distributor has become the standard because of its reliability and ease of maintenance.  In contrast  to
the high rate trickling filter which uses continuous recirculation of filter effluent to maintain a constant
hydraulic loading to the distributor arms, either a suction-level controlled pump or a dosing siphon is employed
for that purpose with a low rate filter.  Nevertheless, programmed rest periods may be necessary at times because
of inadequate influent flow.

Underdrains are manufactured from specially designed vitrified-clay blocks that support the filter media and pass
the treated wastewater to a collection sump for transfer to the final clarifier.   The filter media consists of 1-
to 5-inch stone.  Containment structures are normally made of reinforced concrete and installed in the ground to
support the weight of the media.

The low rate trickling filter media bed generally is circular in plan, with a depth of 5 to 10 feet.  Although
filter effluent recirculation is generally not utilized, it can be provided as a standby tool to keep filter media
wet during low flow periods.

The organic material present in the wastewater is degraded by a population of microorganisms attached to the
filter media.   As the microorganisms grow, the thickness of the slime layer increases.  Periodically, wastewater
washes the slime off the media, and a new slime layer will start to grow.  This phenomenon of losing the slime
layer is called sloughing and is primarily a function of the organic and hydraulic loadings on the filter.

Common Modifications - Addition of recirculation, multistaging, electrically powered distributors, forced ven-
ilation, filter covers, and use of various methods of pretreatment and post-treatment of wastewater.

Technology Status - In widespread use, this process is highly dependable in moderate climates.   Use of after-
treatment or multistaging has frequently been found necessary to insure uniform compliance with effluent limit-
ations in colder regions.  Being superseded by changes to plastic media systems.

Applications - Treatment of domestic and compatible industrial wastewaters amenable to aerobic biological treat-
ment in conjunction with suitable pretreatment.   This process is good for removal of suspended or colloidal
materials and is somewhat less effective for removal of soluble organics.  Can be used for nitrification following
prior (first-stage) biological treatment or as a stand-alone process in warm climates if the organic loading is
low enough.

Limitations - Vulnerable to climate changes and low temperatures, filter flies and odors are common, periods of
inadequate moisture for slimes can be common, less effective in treatment of wastewater containing high concen-
trations of soluble organics, limited flexibility and process control in comparison with competing processes,  high
land and capital cost requirements, and recovery times of several weeks with upsets.

Typical Equipment/No, of Mfrs. (23) - Underdrains/3; Distributors/10; Filter covers/2.
Performance - Single-stage configuration with primary and secondary clarification and no recirculation (percent
removal).   BOD  - 75 to 90%        Phosphorus - 10 to 30%        NH4-N - 20 to 40%         SS - 75 to 90%

Residuals Generated - Sludge is withdrawn from the secondary clarifier  at a rate of 3,000 to 4,000 gal/Mgal of
wastewater, containing 500 to 700 Ib dry solids.

Design Criteria -                                        2
Hydraulic Loading - 1 to 4 Mgal/acre/d; 25 to 90 gal/d/ft             Recirculation ratio - 0
Organic Loading   - 200 to 900 Ib BOD /d/acre ft;                     Depth - 5 to 10 ft
                    5 to 20 Ib BOD /d/1000 ft                         Sloughing - Intermittent
Dosing interval   - Continuous for majority of daily operating        Underdrain minimum slope = 1%
                    schedule, but may become intermittent (not
                    more than 5 min)  during low flow periods
Effluent channel minimum velocity = 2 ft/s at average daily flow
Media - Rock, 1" to 5", must meet sodium sulfate soundness test

Process and Mechanical Reliability - Highly reliable under conditions of moderate climate.  Mechanical reliability
high.  Process operation requires little skill.

Environmental Impact - Odor problems; high land requirement relative to many alternative processes; and filter
flies.

References- 7, 10, 22, 26, 27, 28, 29, 30, 31
                                                       A-88
-------
1
03
*To convert construction cost to capital cost see Table A-2.
$ Millions of Dollars
8 r £
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*
COSTS - Assumptions: U
er Influent (mg/1) Effluent (mg/1)
130 25
100 25
ranuary 1977 prices) ENR = 2494.. 3
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Waste Sludge
ess requires a hydraulic head for operation. Pumping energy requirements may
g eqution: kwh/yr = 1900 (Mgal/d) x (discharge head, ft) , assuming a wire-to-
the typical head requirement of 10 ft for this process, an energy requirement
ected. Mgal = Influent flow + Recirculation flow (although recirculation
) .
I
^ Primary
Clarifier


TricXIing
Filter


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-------
CLARIFIER,  PRIMARY,  CIRCULAR  WITH  PUMP                                       FACT  SHEET  3.1,1
Description - Primary clarification involves a relatively long period of quiescence  in a basin (depths  of  10  to
15 ft) where most of the settleable solids fall out of suspension by gravity;  a  chemical  coagulant  may be  added.
The solids are mechanically collected on the bottom and pumped as a sludge underflow.

The conical bottom (1 in per ft slope)  is equipped with a rotating mechanical  scraper  that  plows  sludge to a
center hopper.  An influent feed well located  in the center distributes  the influent  radially, and a  peripheral
weir overflow system carries the effluent.  Floating scum is trapped inside a  peripheral  scum  baffle and squeegeed
 .nto a scum discharge box.   The unit contains a center motor-driven turntable  drive  supported  by  a  bridge  spanning
the top of the tank,  or supported by a vertical steel center pier.  The turntable gear rotates a  vertical  cage  or
torque tube, which in turn rotates the truss arms (preferably two long arms).  The truss  arms  carry multiple
flights (plows)  on the bottom chord which are set at a 30  angle of attack and literally  "plow" heavy  fractions
of sludge and grit along the bottom slope toward the center blowdown hopper.   An inner diffusion  chamber receives
influent flow and distributes this flow (by means of about 4-in H 0 head  loss) inside  of  the large  diameter feed-
well skirt.  Approximately  three percent of the clarifier surface area is used  for  the feed well.   The depth of
the feed wells are generally about one-half of the tank depth.  The center sludge hopper  should be  less than  two
 :t deep and less than four ft  in cross section.

Common Modifications - Two short auxiliary scraper arms are added perpendicular  to the two  long arms on medium  to
large tanks.   This makes practicable the use of deep spiral flights which aid in center region plowing where
ordinary  shallow straight plows (30  angle of attack)  are nearly useless.   Peripheral feed systems are sometimes
used in lieu of central feed.   Also, central effluent weirs are used sometimes.   Flocculating feed wells may  also
 >e provided if coagulants are  to be added to assist sedimentation.

Technology Status - Very widely used.
Applications - Removal of readily settleable solids and floating material to reduce suspended solids content and
BOD .   Can accept high solids loading.   Primary clarifiers are generally employed as a preliminary step to further
 irocessing.

 imitations - Maximum diameter is 200 ft.   Larger tanks are subject to unbalanced radial diffusion and wind
action, both of which can reduce efficiency.   Horizontal velocities in the clarifier must be limited to prevent
'scouring" of settled solids from the sludge  bed and eventual escape in the effluent.

'ypical Equipment/No, of Mfrs.  (10)  - Clarifier/35;  Sludge Pumps/20
 erformance - Efficiently designed and operated primary clarifiers should remove 50 to 65 percent of the TSS and
25 to 40 percent of the BOD  while producing an underflow sludge solids concentration of about 5 percent.   Skimmings
 •olumes rarely exceed 1.0 ft /Mgal.

Chemicals Required -  Coagulants such as alum,  ferrous sulfate and lime may be added to aid sedimentation.   The
dosage is determined from jar tests.

Design Criteria - Surface loading rates equal to 600 to 1200 gal/d/ft  for untreated wastewater;  360 to 600 for
alum floe; 540 to 800 for iron floe;  540 to 1200 for lime floe.   Detention times = 1.5 to 3.0 hours.   Weir
loadings = 10.000 to 30,000 gal/d/lin ft.   Sludge collector tip  speed = 10 to 15 ft/min.   Heads of 2-3 ft HO are
required to overcome losses at inlet  and effluent controls and in connecting pipes.   Forward velocity should be
 .ess than 9-15 times the particle settling velocity to avoid scour.   Scum handling equipment should be sized for
  ft /Mgal of free decanted water.   Sludge pumping rates range between 2,500 to 20,000 gal/d/Mgal depending upon
chemical addition and service.

Unit Process Reliability - Generally, reliability is high.  However,  clarification of solids into a packed
central mass may cause collector arm stoppages.   Attention to design of center area bottom slope,  number of arms,
and center area scraper blade design is required to prevent such problems.

Environmental Impact - Scum on surface is a source of odors which can be controlled by masking with chemical
 .dditives and aerosols.   Large land use requirement for degree of treatment imparted,  even more so than rectangular
units.

References - 3, 4, 7, 10, 64, 99
                                                        A-90
-------
 CLARIFIED  PRIMARY,  CIRCULAR KITH PUMP
                                                               FACT SHEET 3,1,1
         Scum Trough'
FLOW DIAGRAM -
                                                                                                cum Baffle
                                                                                                •Effluent Weir

                                                                                                       Effluent
                                                                                                       —>-
                                                                                               Side Water Depth
                                  Sludge
                                  Draw-off Pipe
                                         Influent Pipe
                                                  fi
                                                                     10
ENERGY NOTES - Cost design assumptions applicable.
Energy usage shown on energy curve is for sludge
pumps, sludge scrapers and skimmers.

Energy required for providing the head loss of 2 to
3 ft through the clarifier can be approximated by the
following equation: kWh/yr - 1625 (Mgal/d x TDK) at a
wire-to water efficiency of 70 percent.
COSTS - Assumptions:  Service Life = 50 years; ENR = 2475.
                                                                     10"
Design Basis:
                                                   .1             1             10
                                                             Wastewater  Flow,  Hgal/d
                                                                                                                100
1.    Clarifier designed for surface  overflow rate  of  800  gal/d/ft   (based on average Q).
2.    Costs include primary sludge  pumps;  sludge  concentration of 4 percent solids; pump head assumed as 10 ft TDK.
3.    Power Cost = $0.02/kWh
4.    To adjust construction cost for alternative surface  overflow rate,  enter  curve at  effective  flow  (Q  )

     Q  = o       X 	800  gal/d/ft2	
     *E   ^DESIGN   New Design Surface  Overflow  Rate
                     CONSTRUCTION COST
        10
                                                                        OPERATION & MAINTENANCE COST
        1 0
       0 1
      001
                                      o v>
                                     Q m
                                     o &
                                     li
                                     II
                                                               01
                                                              001
        0 1

REFERENCE - 3
 1 0           10
Wastewater Flow Mgal/d
                                                100
                                                             0001
                                                                                              Labor,
                                                                                              Materials
                                                                                                            0001
                                                                                                           00001
 1 0           10
Waslewater Flow, Mgal/d
                                                                                                          0 00001
 *To  convert construction cost to capital cost see Table A-2.
                                                  A-91
-------
CLARIFIER,  PRIMARY,  RECTANGULAR WITH PUMP                             FACT  SHEET  3.1.2
Description - Primary clarification involves a relatively long period of  quiescence  in  a basin (depths  of
10 to 15 ft) where most of the settleable solids in a pretreated wastewater fall  out of suspension by  gravity.
The solids are mechanically transported along the bottom of the tank by  a  scraper mechanism  and  pumped as  a sludge
underflow.

The maximum length of rectangular tanks has been approximately 300 ft.   Where widths of greater  than 20 ft are
required, multiple bays with individual cleaning equipment may be employed, thus  permitting  tank widths up to 80
ft or more.  Influent channels and effluent channels should be located at  opposite  ends of the tank.

Sludge removal equipment usually consists of a pair of endless conveyor  chains.   Attached to the chains at about
10-ft intervals are wooden crosspieces or flights, extending the full width of the  tank or bay.   Linear conveyor
speeds of 2 to 4 ft/min are common.   The settled solids are scraped to sludge hoppers in small tanks and to trans-
verse troughs in large tanks.  The troughs,  in turn, are equipped with cross collectors, usually  of the same type
as the longitudinal collectors, which convey solids to one or more sludge  hoppers.   Screw conveyors have been used
for the cross collectors.

Scum is usually collected at the effluent end of rectangular tanks by the  flights returning  at the liquid  surface.
The scum is moved by the flights to a point where it is trapped by baffles before removal or it  can also be moved
along the surface by water sprays.  The scum is then scraped manually up an inclined apron,  or it can be removed
hydraulically or mechanically, and for this process a number of means have been developed (rotating slotted pipe,
transverse rotating helical wiper, chain and flight collectors, scum rakes).

Common Modifications - Tanks may also be cleaned by a bridge-type mechanism which travels up and down the  tank
on rails supported on the sidewalls.   Scraper blades are suspended from the bridge and are lifted clear of the
sludge on the return travel.  Chemical coagulants may be added to

Technology Status - Rectangular clarifiers are in widespread use.
sludge on the return travel.   Chemical coagulants  may  be  added  to  improve BOD   and SS removals  and  remove  P.
Applications - Removal of readily settleable solids and floating material to reduce  TSS and BOD .   Can accept high
solids loading.  Primary clarifiers are generally employed as a preliminary step to further processing.   Rectangu-
lar tanks also lend themselves to nesting with preaeration tanks and aeration tanks in activated sludge  plants.

Limitations - Horizontal velocities in the clarifier must be limited to prevent "scouring"  of settled solids
from the sludge bed and their eventual escape in the effluent.

Typical Equipment/No, of Mfrs. (10) - Clarifiers/35; Sludge Pumps/20.
Performance - Efficiently designed and operated primary clarifiers should remove 50 to  65  percent of the TSS  and
25 to 40 percent of the BOD  while producing a sludge solids concentration of about 5 percent.   Skimmings volume
rarely exceeds 1.0 ft /Mgal.

Chemicals Required - Coagulants such as alum,  ferrous sulfate and lime may be added to aid sedimentation.  The
dosage is determined from jar tests.

Design Criteria - Average surface loading rates = 600 to 1200 gal/d/ft  for untreated wastewater.   If
chemicals are used, the ranges are 360 to 600 for alum,  540 to 800 for iron, 540 to 1200 for lime.   Detention
times = 1.5 to 3.0 hours.  Weir loadings = 10,000 to 30,000 gal/d/lin ft.    Individual bays  of rectangular tanks
should have a length to width ratio of at least 4.   Forward velocities should be less than 9-15 times settling
velocity to avoid scour.  Scum handling equipment should be sized for 6 ft /Mgal of free decanted water.   Sludge
pumping rates range between 2500 to 20,000 gal/d/Mgal, depending upon chemical addition and  service.

Unit Process Reliability - Generally, reliability is very high.   However,  broken links in collector drive chain
can cause outages.  Plugging of sludge hoppers has also been a problem when cross collectors are not provided.

Environmental Impact - Multiple rectangular tanks require less area than multiple circular tanks and for  this
reason are used where ground area is at a premium.   However,  they require relatively large space for the level of
treatment imparted.

References - 3, 7, 10, 64, 99
                                                        A-92
-------
CLARIFIER,  PRIMARY,  RECTANGULAR WITH PUMP
                                                                                     FACT SHEET 3.1.2
 PLOW DIAGRAM -
                             Power
                                               Water level
                                                                              Adjustable
                                                                                weirs
                                                                                     Effluent
                                    Sludge Hopper
 ENERGY NOTES - Cost design assumptions applicable.
                                                                    io
Energy  usage shown on  the energy curve is for sludge
pumps,  sludge  scrapers and skimmers.

Energy  required for providing the head loss of 2 to
3 ft through the clarifier can be approximated by the
following equation: kwh/yr = 1625 (Mgal/d x TDK) at a
wire-to-water efficiency of 70 percent.

                                                              n
                                                              a;
                                                              c
                                                              a


COSTS - Assumptions:
                              Life = 50 years;  ENR = 2475.
                                                                     .1           1             10

                                                                              Wastewater Flow,  Mgal/d
                                                                                                               100
 Jesign Basis:
     Clarifier designed for surface overflow rate  of 800 gal/d/ft2  (based on  average  Q).
     Costs include primary sludge pumps;  sludge concentration  of  4  percent  solids; pump head assumed as  10  ft TDK
3.   Power Cost = $0.02AWh
4.   To adjust construction cost for alternative surface overflow rate,  enter curve at effective flow  (Q )

     Q  = Q       x 	800 gal/d/ft2	
      E   ^DESIGN   New Design Surface  Overflow Rate

                       CONSTRUCTION COST

        001

                                                                      OPERATION & MAINTENANCE COST

                                                        i
                                                        O o
          01
                      1 0           10
                     Wastewater Flow, Mgal/d
                                                  100
                                                            0001
                                                                                   Tola
                                                                                              Labor
                                                                                           / Materials



                                                                            1 0            10
                                                                           Wastewater Flow, Mgal/d
                                                                                                       100
                                                                                                         000001
 REFERENCE - 3

 *To convert construction cost to capital cost see Table A-2.
                                                    A-93
-------
CLARIFIER,  SECONDARY, CIRCULAR                                          FACT  SHEET  3.1.3
Description - Circular clarifiers have been constructed with diameters ranging from 12 to 200 ft,  depths
of 12 to 15 ft.  There are two types to choose from:  the center-feed and the rim-feed.   Both utilize a revolving
mechanism to transport and remove the sludge from the bottom of the clarifier.  Mechanisms are of two types:   those
that scrape or plow the sludge to a center hopper similar to the types used in primary sedimentation tanks (see
Fact Sheet 3.1.1), and those that remove the sludge directly from the tank bottom through suction orifices that
 erve the entire bottom of the tank in each revolution.  In one type of the latter,  the  suction is maintained by
reduced static head on the individual drawoff pipes.  In another patented suction system, sludge is removed through
a manifold either hydrostatically or by pumping.

Circular clarifiers are made with effluent overflow weirs located near the center or near the perimeter of the
tank.  Skimming facilities are now required on all federally funded projects.

Vhile the design is similar to primary clarifiers, the large volume of flocculent solids in the mixed liquor
requires that special consideration be given to the design of activated-sludge clarifiers.  The sludge pump capa-
city and the size of the settling tank are larger.  Further, the mixed liquor, on entering the tank, has a tendency
to flow as a density current interfering with the separation of the solids and the thickening of the sludge.   To
cope successfully with these characteristics, factors that must be considered in the design of these tanks include:
type of tank to be used, surface loading rate, solids loading rate, flow-through velocities, weir placement and
loading rates, and scum removal.

Technology Status - Circular secondary clarifiers are in widespread use.
Applications - To separate the activated sludge solids from the mixed liquor, to produce the concentrated solids
 for  the return flow required to sustain biological treatment, and to permit settling of solids resulting from low-
 rate trickling filter treatment.

 Limitations - Must operate at relatively low hydraulic loadings (large space requirements).  Maximum diameter is
 200  ft.Larger tanks are subject to unbalanced radial diffusion and wind action, both of which can reduce effici-
 ency.  Horizontal velocities in the clarifier must be limited to prevent "scouring" of settled solids from the
 sludge bed and eventual escape with the effluent.

 Typical Equipment/No, of Mfrs.  (10) - Clarifier/35; Sludge Pumps/20
 Performance - Underflow solids concentrations in activated sludge systems range from 0.5 to 2.0 percent depending
 on  settling and  compaction characteristics of sludge.  Trickling filter (low-rate) underflows generally vary from
 3 to  7 percent solids.  Effluent SS have been measured at 11 to 14 mg/1 (99), however, 20 to 30 mg/1 are more
 likely.

 Design Criteria  -  Inlet baffle diameter = 15 to 20 percent of tank diameter.  (Baffle should not extend more
 than  3 ft  below  surface.)  Weir loading rates = 10,000 to 30,000 gal/d/lin ft.  Maximum upflow velocity in vicinity
 of  weir  =  12 to  24 ft/h.  Other typical design parameters are as shown below:

                                                     Hydraulic Loading            Solids Loading*
 Type  of  Treatment                                 Average         . Peak       Average        Pgak
 	~~                                               gal/d/ft               Ib solids/d/ft
 Settling following trickling  filtration           400-600        1000-1200
 Settling following air activated sludge
 (excluding extended aeration)                     400-800        1000-1200       20-30         50          12-15
 Settling following extended aeration              200-400           800          20-30         30          12-15
 Settling following oxygen activated sludge
 with  primary settling                             400-800        1000-1200       25-35         50          12-15

 *Allowable solids  loadings are generally governed by sludge thickening characteristics associated with cold
 weather  operations.

 The sludge recirculation rate in an activated sludge process ranges from 15 percent to 200 percent of the plant
 flow  depending upon the modification  employed.

 Unit  Reliability - Generally, the  reliability is very high.  However, rising sludge due to denitrification and
 sludge bulking may cause problems, which may be overcome by proper operational techniques.
 Environmental Impact - Circular  units require  greater  land area than rectangular units.
 References - 3,  7,  10,  99
                                                      A-94
-------
 CLARIFIER,  SECONDARY, CIRCULAR
            FACT SHEET 3.1.3
 FLOW  DIAGRAM -
             Activated  Sludge
                                                                                        Trickling Filter
                                              Effluent
nfluent

Trickling
Filter


                                                                                            Clarifier
                                                                                                         Effluent
                                    Waste
ENERGY NOTES - Cost design assumptions applicable.
Energy usage is for sludge pumps, sludge scrapers
and skimmers.  In the activated sludge case, the
sludge return pump energy is included.

Energy required for providing the head loss of 2 to
3 ft through the clarifier can be approximated by the
following equation: kWh/yr = 1625 (mgal/d plant flow
+ Mgal/d return sludge flow)  TDH at a wire-to-water
efficiency of 70 percent.
                                                                                                  Sludge
                                                                                Plant Capacity,  Mgal/d
                                                                         0-1           1.0           10
COSTS - Assumptions:  Service Life = 40 years; ENR Index = 2475
1.   Flocculator-type clarifier.
2.   Overflow rate of 600 gal/d/ft2  used for the development of costs.
io6
(
io5
io4



10J









^f











- —~2
*"











^'




ff-
i-







	 ^
Activated Sludge/*"


. \
/
x^







—









n


^-'
Trie





j:;^:


. •*'*
cllnq




/

	 > ^
s

Filter

















3.
                                                                                  1,000        10,000
                                                                                  Surface  Area,  ft2
     Costs include sludge return and waste pumps.   Sludge concentrations of 1 percent solids.   Pump  TDH at 10
      t.  Spare pumps included as necessary.   Pump capacity 350 gal/min/Mgal/d of plant capacity.  Nonclog
     centrifugal pumps.
4.   Maximum clarifier diameter = 200 ft.
5.   To adjust for alternate overflow rates,  enter the curve at effective flow.
                                   100,000
          = Q
             DESIGN	„--,-,— ~ NEW DESIQN

                   CONSTRUCTION COST
                                                                    OPERATION & MAINTENANCE COST
     1 0
     0 1
     001
                                                           1 0
                                                           0 1
                                                                                                      Total

                                                                                                      Materials
                                                                                                      Labor
       0 1
                    1 0            10
                   Wastewater Flow, Mgal/d
                                              100
                                                            0 1
 1 0            10           100
Wastewater Flow, Mgal/d
REFERENCES -3,4

  *To convert construction cost to capital cost see Table A-2.



                                                    A-95
-------
 CLARIFIED  SECONDARY,  RECTANGULAR                                            FACT SHEET  3.1.4
 'ascription - The design of secondary clarifiers is similar to primary clarifiers except that the large volume of
flocculant solids in the mixed liquor must be considered during the design of activated-sludge clarifiers and in
sizing of sludge pumps.  Further, the mixed liquor,  on entering the tank,  has a tendency to flow as a density
current interfering with the separation of the solids and the thickening of the sludge.   To cope successfully
with these characteristics, factors that must be considered in the design  of these tanks include:  (1)  type of
tank to be used, (2) surface loading rate, (3) solids loading rate, (4)  flow-through velocities, (5)  weir place-
ment and loading rates, and (6)  scum removal.

 low through rectangular tanks enters at one end, passes a baffle arrangement, and traverses the length of the
 :ank to effluent weirs.  The maximum length of rectangular tanks has been  approximately  300 ft with depths of 12
to 15 ft.  Where widths of greater than 20 ft are required, multiple bays  with individual cleaning equipment may
be employed, thus permitting tank widths up to 80 ft or more.

Sludge removal equipment usually consists of a pair  of endless conveyor  chains.  Attached to the chains at 10 ft
intervals are 2-in thick wooden crosspieces or flights, 6 to 8 in deep,  extending the full width of the tank or
bay.  Linear conveyor speeds of 2 to 4 ft/min are common.  The settled solids are scraped to sludge hoppers in
small tanks and to transverse troughs in large tanks.  The troughs, in turn, are equipped with cross collectors,
usually of the same type as the longitudinal collectors, which convey solids to one or more sludge hoppers.
Screw conveyors have also been used for the cross collectors.  Tanks may also be cleaned by a bridge-type mechanism
which travels up and down the tank on rails supported on the sidewalls.  Scraper blades  are suspended from the
bridge and are lifted clear of the sludge on the return travel.  For very  long tanks, it is desirable to use two
sets of chains and flights in tandem with a central  hopper to receive the  sludge.  Tanks in which mechanisms that
move the sludge toward the effluent end in the same  direction as the density current have shown superior per-
formance in some instances.

Scum is usually collected at the effluent end of rectangular tanks by the  flights returning at the liquid surface.
The scum is moved by the flights to a point where it is trapped by baffles before removal, or it can also be
moved along the surface by water sprays.  The scum is then scraped manually up an inclined apron, or it can be
removed hydraulically or mechanically, and for this  process a number of  means have been  developed (rotating
transverse rotating helical wiper, chain and flight  collectors, scum rakes).

 Common Modifications  - Multiple  inlets  with  balanced  flow  at various spacings  and with  target baffles  to reduce
 velocity  of  streams;  hydraulic balancing between parallel clarifier units; Control of wind effects on water
 surface;  Sludge  hopper  collection  systems; Flocculation inlet structures; Use of traveling bridge sludge col-
 lectors and  skimmers, as an alternate to chain and flight systems; Use of steeply inclined tube settlers to
 enhance SS removal  in either new or rehabilitated clarifiers; Use of wedge wire settler panels at peak hydraulic
 loading of less  than  800 gal/d/ft  for improved SS removal.


 Technology Status - Rectangular clarifiers are in widespread use.
 Applications  -  Secondary clarifiers are used for solids separation and for the production of a concentrated
 return sludge  flow  to  sustain biological treatment.  Multiple rectangular tanks require less area than multiple
 circular  tanks and  for this reason are used where ground area i's at a premium.  Rectangular tanks also lend
 themselves more readily to nesting with primary tanks and aeration tanks in activated sludge plants.  They are
 also  used generally where tank roofs or covers are required.

 Limitations  -  Must  operate at relatively low hydraulic loadings  (large space requirements).  The maximum length
 of  tank has been  about  300 ft. Horizontal velocities in the clarifier must be limited to prevent "scouring" of
 settled solids  from  the sludge bed and their eventual escape with the effluent.

 Typical Equipment/No, of Mfrs.   (10) - Clarifiers/35; Sludge Pumps/20.
 Performance  - Maximum practical solids concentrations of sludge from secondary clarifiers in activated sludge
 systems range  from  0.5 to 2.0 percent depending on settling and compaction characteristics of the sludge (99).
 Effluent  TSS = 20 to  30 mg/1  (7).

 3esign Criteria -  Average hydraulic loading in activated sludge systems varies from 400 to 800 gal/d/ft  and
 peak  loadings range  from 700 to 1200 gal/d/ft  depending on mixed liquor suspended solids concentration and
 percent  sludge  recycle.  Average solids loadings of 0.6 to 1.2 Ib/h/ft  and peak loadings of 1.25 to 2.0 Ib/h/ft
 have  been  suggested  for activated sludge plants.  Weir loading1 = 10,000 to 30,000 gal/d/lin ft.  Maximum inflow
 velocity in vicinity of weir = 12 to 24 ft/h.  Depths are normally 12 to 15 ft.

 Unit  Process Reliability - Mechanical reliability can be considered high provided suitable preventive maintenance
 and  inspection procedures are observed.  Plugging of sludge hoppers has been a problem when cross collectors are
 not  provided.  Process reliability is highly dependent upon the upstream performance of the aerator for the pro-
 duction of good  settling sludge with acceptable compactability.  Rising sludge caused by denitrification of the
 sludge is a problem  in certain cases.

 Environmental Impact - Although it requires large land areas, it offers a higher space efficiency than circular
 clarifiers.

 References -  3,  7,  10,  99
                                                         A-96
-------
CLARIFIER,  SECONDARY, RECTANGULAR
                                                                                    FACT  SHEET 3.1.4
 LOW DIAGRAM -
              PRIMARY EFFLUENT
             	*—
                                                                                    SECONDARY
                                                                                    CLARIFIER
                                                    RECYCLE
                                                                                                 SECONDARY EFFLUENT
 :NERGY NOTES - Cost design assumptions applicable.
 Inergy usage shown on energy curve is for sludge
 •eturn and waste pumps,  sludge scrapers and skimmers.

 Inergy required for providing the head loss for 2-3 ft
 :hrough the clarifier can be approximated by the following
 ;quation:  kWh/yr = 1625  (Mgal/d plant flow + Mgal/d return
 ludge flow)(TDH)at a wire to water efficiency of 70 percent.
                                                                     io
                                                                     10
 OSTS -  Assumptions:
,ervice Life:   40 years,  ENR = 2475  (Sept.  1976),
:ost:  $0.02/kWh.
Design Basis:
                                                  Power
     Flocculator-type clarifier:  600  gal/d/ft
     Costs include sludge return  and  waste  pumps.
                                                   Sludge
                                                                     10
                                         Pump  TDK at  10  ft.
                                         (non-clog centri-
     concentration of 1  percent  solids.
     Spare pumps  included as  necessary.
     fugal pumps).
     To adjust construction cost for  alternative  flow
     rates,  enter  the curve at effective flow  (Q_)  -
     0 „„,-_.. x 600 gal/d/ft  x (I/New Design Overflow
      DESIGN
     Rate) .
                                                                     10
                                                                                       1             10
                                                                                   Wastewater Flow, Mgal/d

                     CONSTRUCTION COST
                                                                         0.1


                                                                         OPERATION & MAINTENANCE COST
                                                                                                                 100
        1 0
        01
       001
                                                            O2
         01            10            10            100
                       1 0            10
                      Wastewater Flow, Mgal/d
                                                               0001




                                                                                10            10
                                                                               Wastewater F'ow, Mgai/d
                                                                                                            0 QQ01
                                                                                                          100
  REFERENCE  - 3

  *To convert  construction  cost  to capital  cost see Table A-2.
                                                     A-97
-------
CLARIFIED  SECONDARY,  HIGH RATE TRICKLING  FILTER                          FACT SHEET 3.1.5
Description  (7, 99)  - The design of clarifiers  that  follow high rate trickling filters is similar to that of
primary clarifiers, (see Fact Sheets 3.1.1  and  3.1.2  for description) except that the surface loading rate is
based on the plant flow plus the effluent recycle  flow minus the underflow  (often neglected).  These clarifiers
differ from secondary clarifiers following  activated  sludge processes in that the sludge recirculation is not
used.  Also, solids loading limits are not  involved in the sizing.  Recirculation of the supernatant from the
clarifier to the trickling filter can range from one  to four times the plant influent flow rate.  See Fact Sheets
2.2.6 and 2.2.7 for further details on recirculation  flow requirements.  Under suitable trickling filter operating
conditions it is more economical to recirculate the clarifier  influent to reduce the flow sizing requirements in
the clarifier.

Technology Status - In widespread use.
Applications - To control suspended solids levels  in  the effluent and to provide the recirculated water flow
required to maintain the high rate trickling filter process.

Limitations - Effluent quality is limited by the performance of the trickling filter not that of the clarifier
(99).  See Fact Sheets 3.1.1 and 3.1.2 for other  limitations.

Typical Equipment/No,  of Mfrs.  (10)  -  Clarifiers/35;  Sludge Pumps/20; Recirculation Pumps/45
Performance - See predicted performance for trickling  filters on Fact Sheets 2.2.6, 2.2.7, and 2.2.8.
Chemicals Required - None
Design Criteria (99)  -  Average hydraulic loading  (including recirculated flow) = 800 gal/d/ft  ; peak hydraulic
loading = 1000 to 1200 gal/d/ft ;  depth = 10 to 12  ft.   Other  criteria same as shown on Fact Sheets 3.1.1 and
3.1.2.

Unit Process Reliability - Generally,  the reliability  of the clarifier itself is very high.  However, its per-
formance is dependent upon the trickling filter.

Environmental Impact - Requires large land area.   However,  rectangular clarifiers are more space efficient than
circular clarifiers.

References - 3, 7, 10, 99
                                                      A-98
-------
 CLARIFIER,  SECONDARY, HIGH  RATE TRICKLING  FILTER
                                                                                     FACT SHEET  3.1.5
 FLOW DIAGRAM -
                                                              Recirculation
             Plant Influent

Primary
Clarifier

Trickling
Filter
~w

Secondary
Clarifier


Plant Eff

                                   Waste
                                   Sludge
                                                                             Waste
                                                                             Sludqe
                                                                +  P
                                                     udge pumps    Recirculation
ENERGY NOTES (3)  - Power required for operation = P_,  ,          .  .                .  ,.  ,
	                                       Sludge  pumps    Recirculation     Skimmers  &  Sludge Scrapers.
At an effluent recycling rate of 3 times average plant wastewater  flow,  this  power requirement can be  estimated to
be kWh/yr = 160,000 (Mgal/d plant flow).  Clarifier head loss  is  2 to  3  ft.   Influent pumping  energy can be
estimated by the  use of the following equation:  kWh/yr  =  1625 (Plant  flow Mgal/d + effluent recycle flow Mgal/d)
(TDK)  at a wire-to-water efficiency of 70 percent.
COSTS* - Assumptions:  Service Life = 40 years;  ENR = 2475.
Design Basis
     Construction costs include  sJudge  pumps,  effluent  recycle pumps,  Clarifier  mechanisms  and  internal piping.
     Overflow rate = 800 gal/d/ft  at average  design  flow.
     Recycle pumping capacity =  3 times average  wastewater  flow.
     Maximum clarifier diameter  = 200 ft.
     Power cost = $0.02/kWh
     To adjust construction cost for  alternative loading  rates,  enter  curve  at effective  flow  (Q  )

     0=0       X       800 gal/d/ft2
     WE   ^DESIGN   New Design Overflow Rate
       10
                    CONSTRUCTION COST
       1 0
      001
                                                                  I 0
                                                                           OPERATION & MAINTENANCE COST
                                                                  0 1
                                                              re  001
        0 1
                     1 0            10
                     Wastewater Flow  Mgal/d
                                                100
                                                                0001
                                                                         -Materials
                                                                                    3ower
                                                                                               Total
                                                                                                Labor
                                                                   0 1
                                                                                1 0            10
                                                                                Wastewater Flow, Mgal/d
                                                                                                           100
.EFERENCE - 3


To convert construction cost to capital cost see Table A-2.
                                                       A-99
-------
DISSOLVED AIR FLOTATION                                                          FACT SHEET 3.1.6
Description - Dissolved air flotation  (DAP) is used to remove suspended solids by flotation (rising)  by decreasing
their apparent density.  Dissolved air flotation consists of saturating a portion or all of the wastewater feed,
or a portion of recycled effluent with air at a pressure of 25 to 70 Ib/in g.   The pressurized wastewater is held
at this pressure for 0.5 to 3.0 minutes in a retention tank and then released to atmospheric pressure to the
flotation chamber.  The sudden reduction in pressure results in the release of microscopic air bubbles which
attach themselves to oil and suspended particles in the wastewater in the flotation chamber.  This results in
agglomeration  which, due to the entrained air, have greatly increased vertical rise rates of about 0.5 to 2.0
ft/min.  The floated materials rise to the surface to form a froth layer.  Specially designed flight scrapers or
other skimming devices continuously remove the froth.  The retention time in the flotation chambers is usually
about 20 to 60 minutes.  The effectiveness of dissolved air flotation depends upon the attachment of bubbles to
the suspended oil and other particles which are to be removed from the waste stream.  The attraction between the
air bubble and particle is primarily a result of the particle surface charges and bubble-size distribution.

The more uniform the distribution of water and microbubbles, the shallower the flotation unit can be.  Generally,
the depth of effective flotation units is between 4 and 9 feet.

The surface sludge layer can in certain cases attain a thickness of many inches and can be relatively stable for  a
short period.  The layer thickens with time, but undue delays in removal will cause a release of particulates back
to the liquid.

Common Modifications - Units can be round, square or rectangular.  In addition, gases other than air can be  used.
The petroleum industry has used nitrogen, with closed vessels, to reduce the possibilities  of fire.

Technology Status - Dissolved air flotation has been used for many years to treat industrial wastewaters.   It has
commonly been used to treat sludges generated by municipal wastewaters (see Fact Sheet No.  6.3.6),  however is not
widely used to treat municipal wastewaters.

Typical Equipment/No, of Mfrs. (23) - Dissolved air flotation units/24;  Air compressors/8;  Skimmers/over 20.
Applications - DAF is used to remove lighter suspended materials whose specific gravity is only slightly in excess
of 1.0.  Usually used to remove oil and grease materials.  Sometimes used when existing clarifiers are overloaded
hydraulically by converting to DAF which requires less surface area.

Limitations - Will only be effective on particles with densities near or smaller than water.
Performance  (99) -
                    Percent Removal (w/o chemicals)               Percent Removal (w.  chemicals)
Suspended Solids            40 to 65                                       80 to 93
Oil and Grease              60 to 80                                       85 to 99

Chemicals Required - Alum (Al (SO ) .14H O), ferric chloride (Fed ),  and polymers can be added to aid in the
coagulation process prior to the actual flotation step.

Residuals Generated - A froth layer is generated, which is skimmed off the top of the unit and is generally denser
than clarifier sludge.

Design Criteria (99) -
                              Parameter                               Range
                              Pressure, Ib/in g                       25 to 70
                              Air to Solids Ratio, Ib/lb              0.01 to 0.1
                              Float Detention, min                    20 to 60
                              Surface Hydraulic Loading, gal/d/ft     500-8,000
                              Recycle, percent (where employed)        5 to 120

Unit Process Reliability - DAF systems have been found to be reliable.   However chemical pretreatment is essential.
without which DAF units are subject to variable influent conditions,  resulting in widely varying performance.

Environmental Impact - Requires very little use of land.  The air released in the unit is unlikely to strip vola-
tile organic material into the air.  The air compressors will need silencers to control the noise generated.   The
sludge generated will need methods for disposal.   This sludge will contain high levels of chemical coagulants
used.

References - 23, 99, 108, 111
                                                      A-100
-------
DISSOLVED AIR  FLOTATION
               FACT  SHEET  3,1.6
FLOW DIAGRAM -
                                                       Sludge Removal Mechanism
               Recirculation  (^  Recycle
                                                                                                Sludge
                                                                                               Discharge
                  Pump
ENERGY NOTES - Assumptions:   Energy consumption
includes that required for wastewater  recycle,
air injection, and chemical feed pumping.
COSTS* - Assumptions:   Costs  are  based  on  1976 dollars;
         ENR Index = 2475.
                                                                                  \
                                                                                     Recycle Flow
                                                                  Retention Tank
                                                                  Air Dissolution
1.   Construction costs  include  DAF  unit  and  chemical
    feed equipment.

2.   Operating costs  include  chemical  feed' alum  @  $72/t;
    polymer @ $1.50/lb,  labor @ $20,000/my including  fringes.

Design Basis:
Air Injection = 1.25 ftj/1000 gal
33 percent recycle
Detention time = 25 min
Area flow rate = 2 to 3 gal/min/ft
                    CONSTRUCTION COSTS
        10
       1 0
    &
    O
    2   01
         .01
                      .1           1.0
                     Wastewater Flow, Mgal/d
                                                10
 REFERENCES -  99,  112
*To convert construction cost to capital cost see  Table A-2.
                                                                    10
                                                                    10
10
10
                                                                      0 1
                                                                     001
                                                                     0001
                                                                        .01
                                                      A-101
                                                                        .01          .1            1-0

                                                                                   Wastewater Flow,  Mgal/d



                                                                                 OPERATION  AND MAINTENANCE
                                                                                                                 10
                 .1            1.0
                Wastewater Flow. Mgal/d
                                                                                                                 10
-------
 ILTRATION,  DUAL  MEDIA                                                          FACT SHEET 3.1,7
Description - Dual media filtration-gravity is one of the most economical forms of granular  media  filtration.
Granular media filtration involves the passage of water through a bed of  filter media  with resulting  deposition
of solids.  Eventually,  the pressure drop across the bed becomes excessive or the  ability  of  the  bed  to  remove
suspended solids is impaired.  Cleaning is then necessary to restore operating head and effluent  quality.   The
time in service between cleanings is termed the run length.   The head loss at which filtration  is interrupted for
cleaning is called the terminal head loss/ and this head loss is maximized by the  judicious choice of media
sizes.

Dual media filtration involves the use of both sand and anthracite as filter media,  with anthracite being placed
on top of the sand. Gravity filters operate by either using  the available head from the previous  treatment  unit,
or by pumping to a flow split box after which the wastewater flows by gravity to the filter cells. Pressure
filters utilize pumping to increase the available head.

Normally filter systems include multiple filter compartments.  This allows for the filtration system  to  continue
to operate while one compartment is being backwashed.

A filter unit generally consists of a containing vessel, the filter media, structures  to support  the  media, dis-
tribution and collection devices for influent, effluent and  backwash water flows,  supplemental  cleaning  devices
(see "Common Modifications"), and necessary controls for flows, water levels and backwash  sequencing.

Common Modifications - Filtration systems can be constructed out of concrete or steel, with single or multiple
compartment units.  Steel units can be either horizontal or vertical and are generally used for pressure  filters.
Systems can be manually or automatically operated.

Backwash sequences can include air scour or surface wash steps.   Backwash water can be stored separately  or in
chambers that are integral parts of the filter unit.  Backwash water can be pumped through the unit or can be
supplied through gravity head tanks.

Technology Status - Has been used for many years in the potable water industry,  and has been used in the  waste-
water treatment field for 10 to 15 years.

Typical Equipment/No, of Mfrs.  (23)  - Dual media filters/20;  blowers/7;  controls/29.
Applications - Removal of residual biological floe in settled effluents from secondary treatment and removal  of
residual chemical-biological floe after alum,  iron,  or lime precipitation in tertiary or independent physical-
chemical waste treatment.

In these applications filtration may serve both as an intermediate process to prepare wastewater for further
treatment (such as carbon adsorption, clinoptilolite ammonia exchange columns, or reverse osmosis)  or as a final
polishing step following other processes.

Limitations - Economics are highly dependent on consistent pretreatment quality and flow modulations.  Increasing
suspended solids loading will reduce run lengths,  and large flow variations will deleteriously effect effluent
quality in chemical treatment sequences.

Performance -
                    Filter Influent                          Filter Effluent mg/1
                    High Rate Trickling Filter                    10 to 20
                    2-Stage Trickling Filter                       6 to 15
                    Contact Stabilization                          6 to 15
                    Conventional Activated Sludge                   3 to 10
                    Extended Aeration                              1 to 5

Chemicals Required - Alum and iron salts, and polymers can be added as coagulant aids directly ahead of fil-
tration units.  This, however, will generally reduce run lengths.

Residuals Generated - Backwash water, which generally approximates two to ten percent of the throughput.   Back-
wash water can be returned to the head of the plant.

Design Criteria (99) -
Filtration rate 2 to 8 gal/min/ft ;  bed depth 24 to 48 inches (depth ratios of 1:1-4:1 sand to anthracite);  back-
wash rate 15 to 25 gal/min/ft ;  air scour rate 3 to 5 stdft /min/ft ; filter run length 8 to 48 hours;  terminal
head loss 6 to 15 ft.

Unit Process Reliability- Dual media filtration systems are very reliable from both a process and unit stand-
point.

Environmental Impact - Requires relatively little use of land.   Backwash water will need further treatment,  with
an ultimate production of solids which will need disposal.  Air scour blowers usually need silencers to control
noise.  No air pollution generated.

References - 23, 26, 39, 44, 99
                                                   A-102
-------
 FILTRATION, DUAL MEDIA
                   FACT  SHEET  3.1.7
 FLOW  DIAGRAM -
                                               Operating Level
                                        Backwash      __
                                         .• •• I, • . * »
                                          Anthracite
                                             Sand
                                          Underdrain
             Spent Backwash to
                 Headworks
ENERGY NOTES - If sufficient head available, no
influent pumping required.  However, usually a feed
pump is employed to provide necessary head.
Assumptions:
1.  Gravity filters @ 4 gal/min/ft
    a.  TDK for backwash and feed pumps 14 ft
    b.  Run length = 12 h; 15 min backwash @ 15
        gal/min/ft
    c.  Pump efficiency 70%; motor efficiency, 93%
2.  Centrifugal pumps
COSTS* - Assumptions:  ENR Index = 2475
1.  Same as above, with air scour assist for back-
    wash
2.  Backwash holding tank = capacity of two back-
    wash cycles.
3.  Construction cost includes facilities for back-
    wash storage, all feed and backwash pumps,
    piping, and building.
4.  Power at $.02/kWh.
5.  Labor at $7.50/h, including fringe benefits.
          01
         001
                         'CONSTRUCTION COST
                                                           o «>
                                                           SI
                                                                                    Backwash
                                                                                    Storage
                                                                                               Effluent
                                                                  Backwash Pump
1
0)
^
-rH

D1
                                                                 10
                                                                 01
                                                                001
                        IO            10
                      Wastewater Flow. Mgal/d
                                                               0001
                                                                  01
REFERENCES - 3, 4, 39

*To convert construction cost  to  capital  cost  see  Table  A-2.


                                                      A-103
                                                                      10
                                                                     10"
                                                                      10
                                                                               7
                           7
                                                                      10
                                                                        10
                                                                                    100

                                                                                   Surface Area, ft
                                1,000

                                  2
                                                                                                             10,000











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                                                                                                           01
                                                                                                           001
                                                                                                           0001
                                                                                                           oooa
              10           10
            Wastewater Flow, Mgal/d
                                                                                                          100
-------
FLOW EQUALIZATION                                                          FACT  SHEET  3.1.9
Description - Wastewater flows into treatment facilities are subjected to diurnal and seasonal fluctuation in
quality and in quantity.  Most waste treatment processes are sensitive to such changes.   An equalization basin
serves to balance the extreme quality and quantity of these fluctuations to allow normal contact time in the
treatment facility.  This Fact Sheet addresses equalization basins that are used only to equalize flow;  however,
it should be noted that the quality of the wastewater will also equalize to some degree.

Equalization basins may be designed as either in-line or side-line units.  In the in-line design, the basin
receives the wastewater directly from the collection system, and the discharge from the  basin through the treat-
ment plant is kept essentially at a constant rate.  In the side-line design, flows in excess of the average are
diverted to the equalization basin and, when the plant flow falls below the average,  wastewater from the basin is
discharged to the plant to bring up the flow to the average level.  The basins are sufficiently sized to hold the
peak flows and to discharge at a constant rate.

Pump stations may or may not be required to discharge into or out of the equalization basin, depending upon the
available head.  Where pumping is found necessary, the energy requirements will be based on total flow for in-line
basins and on excess flow for side-line basins.

Aeration of the wastewater in the equalization basin is normally required for mixing and maintaining aerobic
conditions.

Common Modifications - There are various methods of aeration, pumping and flow control.   Tanks or basins can be
manufactured out of steel or concrete, or can be excavated and be of the lined or unlined earthen variety.

Technology Status - Has been used in the municipal and industrial sectors for many years.  Over 200 municipal
 installations  in the United States.

 Typical Equipment/No, of Mfrs.  (23) - Lift pumps/34( air compressors/8; basin liners/6; flow controllers/29,-
aerators/30.

Applications - Can be used to equalize the extremes of diurnal and wet weather flow fluctuations.  The secondary
benefits are equalization of quality and the potential for the protection from toxic upsets.

Limitations -  Its application to equalize diurnal fluctuation is rather limited because the cost may be high
when  compared  to  the benefits.  It may require substantial land area.

Performance -  Flow  equalization basins are easily designed to achieve the objective.  Use of aeration, in com-
bination with  the relatively long detention times afforded can produce BOD5 reductions of 10 to 20 percent.

Residuals Generated -  Due to the settling characteristics of influent wastewater solids, some materials will
 collect at  the bottom of the basin, and will need to be periodically discarded.  Provisions must be made to accom-
 modate this need.

 Design Criteria  (122) - Design of an equalization basin is highly site specific and dependent upon the type and
magnitude of  the  input  flow variations and facility configuration.  The pumping/flow control mode, aeration,
mixing  and  flushing methods are dependent upon the size and site conditions.  Grit removal should be provided
upstream of the basin.  Mechanical mixing at 20 to 40 hp/Mgal of storage.  Aeration at 1.25 to 2 ft /min/1,000 gal
of  storage.

Process Reliability - These units have been found to be reliable from both a unit and process standpoint and are
 used  to  increase  the reliability of the flow-sensitive treatment processes that follow.

 Environmental  Impact - Can consume large land areas.  Impact upon air quality and noise levels are minimal.  There
may be  some  sludge generated that will require disposal.

References -  23,  26, 113, 114, 122
                                                       A-104
-------
FLOW EQUALIZATION
                                                                FACT SHEET  3,1.9
FLOW DIAGRAM -
                 IN-LINE
                                                         Controlled
                                                         Flow Pumpinc
                                                         Station

nfluent
Grit
Removal
1


Equalization
Basin
1

«•«
                                                                Sludge-Processing
                                                                  Recycle Flows
                 SIDE-LINE
              Influent .
Grit
Removal
\
oiled
ion



Overflow
Structure
\
r
Equalization
Basin
1


^ Flow Meter and ^
i
*J
r Control Device
Sludge-Processing

                                                                                                   To
                                                                                                   Treatment
ENERGY NOTES - Pumping energy requirements may be approximated by using the following equation:
     kWh/yr  = 1900  X Mgal/d* X discharge head ft, assuming 60% wire to water efficiency *
For  the typical head requirements of 10 ft for this process, an energy requirement of 19,000 kWh/yr/Mgal/d can be
expected. ^^  ^^  case Q£  in_fiow basins,  the  flow  through  the plant and  in  the case  of side-line basins,
            the excess  flow.
COSTS** - Assumptions:  Construction costs are based on concrete basin for design flows less than 1 Mgal/d and 6-
inch concrete lined earthen basin for design flows greater than 1 Mgal/d.  Detention  time = 1.0 d.  Mixing require-
 lents = 20 to 40 hp/Mgal of storage volume.  Costs include basin and mechanical mixing equipment.  Pumping is not
included.  ENR Index = 2475.
                                                                      OPERATION & MAINTENANCE COST
                                                             1 0
CONSTRUCTION COST
       0 1
      001
                                                            001
                                                            0001
                                                                                             Power
                                                                                          Labor
                                                                                            Materials
         01
 REFERENCE - 3
  1 0            10            100
 Wastewater Flow. Mgal/d
 1 0            10
Wastewater Flow, Mgal/d
                                                                                                       100
**To  convert  construction cost to capital cost see Table A-2.
                                                    A-105
-------
MIXING/CHLORINE CONTACT,  HIGH  INTENSITY                               FACT SHEET 3.1,10
Description - Standard chlorine disinfection systems involve  the  addition  of gaseous chlorine, followed by a
baffled contact chamber which usually provides a 15 to 30 minute  detention  time.  These contact chambers afford
plug flow conditions, but do not encourage rapid contact between  the  chlorine and the microorganisms to be killed.

High intensity mixing systems have been under investigation for the past  several years.  These systems involve the
use of mixing tanks with extremely high velocity gradients.   These flash  mixing devices cause the disinfectant to
come into contact with many more microorganisms than standard contact devices.  Therefore, small detention times
can be used, on the order of 1 to 5 minutes.

High intensity mixing systems can be manufactured in two forms.   One  design uses standard mixing devices, with
high energy input per unit volume.  The second design involves the use of closely spaced baffles or static type
mixers, with high energies supplied by pumping.

The effluent from the mixing chamber is generally checked for chlorine residual, which is used to adjust the rate
of chlorine feed.

Common Modifications - Standard mixing devices, closely spaced baffles, or  static mixers can be used, often in
conjunction with (post)  aeration.   Various disinfecting agents,  other  than gaseous chlorine, can be used.  These
include hypochlorite, ozone, and chlorine dioxide.

Chemical feed rates can be adjusted automatically or manually.

Technology Status - The use of high intensity mixing devices  for disinfection has been tested only on the pilot
and bench scales.

Typical Equipment/No. Mfrs. (23)  - Mixing devices/26.
Applications - For the purpose of this fact sheet,  high intensity mixing  devices are used for the application of
chlorine to combined sewer overflows.

Limitations - Due to the simplicity of the process,  and the use  of  proven  equipment  such as mixers,  it is expected
that there are few, and most likely minor, mechanical limitations.

In regard to the process of disinfection by chlorine, chlorinated hydrocarbons may  be  formed.   Some of these
compounds are known to be carcinogenic.   The effectiveness  of chlorination  is greatly  dependent upon pH and temper-
ature of the wastewater being treated.  Chlorine gas is hazardous material,  and  it  requires  sophisticated handling
procedures.  Chlorine will preferentially react with certain chemicals  in the wastewater,  leaving  only the resi-
dual amounts of chlorine for disinfection.  These compounds include  ammonia, hydrogen  sulfide  and  metals present
in their reduced states.

Performance - High rate chlorination can result in 99.9 percent  removal of  viruses  and over  99 percent removal of
total and fecal coliforms.

Chemicals Required - Chlorine, sodium hypochlorite,  or calcium hypochlorite.
Design Criteria - Detention times of 1 to 5 minutes  are generally  sufficient, with detentions up  to  10 minutes
possibly required in some applications.  Velocity gradients  of  at least  300  s   are  generally  required.   Mixing
horsepower requirements are (at a 2-minute detention)  approximately 1.25 hp/Mgal/d  of  throughput(wire to water).

Residuals - None
Process Reliability - Due to its lack of use on a full scale,  the process  reliability  cannot be  adequately deter-
mined.  However, due to the simplicity of operation,  and the  use  of proven  equipment  such  as mixers,  the  relia-
bility is expected to be high.

Environmental Impact - This process is designed to reduce the land-use  and  chemical requirements  for  disinfection
processes.  However, chlorination can cause the formation of  chlorinated hydrocarbons.   In addition,  chlorine  gas
may be released to the atmosphere.

References - 154, 155, 163, 164,  165, 166
                                                        A-106
-------
 MIXING/CHLORINE  CONTACT,  HIGH INTENSITY
                FACT SHEET 3.1.10
 FLOW  DIAGRAM -
                                   Chlorine
                                   Influent
                                                                       Effluent
 ENERGY NOTES - Energy required  (kwh/yr) = 8750 X HP (wire to water)/I.339;  for temperature  =  15°C, detention time =
               2 MIN, G = 300 sec
                                  •L
 COSTS  -  Assumptions: ENR Index =  2475
 1.   Service  life of mixer, approximately 10 yr.
 2.   Costs  are based on 2 minute detention time and on velocity gradient (G)  of 300 SEC  .
 3.   Construction costs include concrete mixing basin and stainless steel mixers.
 4.   Miscellaneous costs such as chlorine storage area,  hoist and evaporator  are not included.
 5.   Labor  costs at $7.50/h and power at $.02/kwh.
 6.   Power  requirement is 1.25 hp/Mqal/c1 (w\re to water) .
           1 0
                        CONSTRUCTION COST
                                                                               OPERATION  & MAINTENANCE
       5  001
         0001
                                                                  001
                         10           100
                        Wastewater Flow, Mgal/d
                                                  1000
                                                               0 00001
0.1
             1.0          10            100
            Wastewater Flow. Mgal/d
REFERENCES -  3,155
 *To convert construction cost to capital cost  see Table A-2.
                                                       A-107
-------
POST AERATION                                                                      FACT  SHEET 3.1.11
Description - There are many regulations requiring the maintenance of minimum dissolved oxygen (DO)  concentrations
in wastewater treatment plant effluents.  Plant effluents from secondary clarifiers normally contain 0.5 to 2.0
mg/1 of DO.  Many effluent quality standards, depending on the intended water use,  specify a minimum DO concen-
tration of 4.0 mg/1.  Post aeration is designed to provide the additional oxygen to effluents prior to their
discharge to receiving waters.  There are at least four methods available for post  aeration of treatment plant
effluents:

Diffused Aeration - Diffused air aerators can be obtained in a number of variations, with all accomplishing the
same goal.  The purpose of diffused aerators is to carry the air supplied by blowers or compressors to a subsurface
level in an aeration basin, distribute the air, and create as small a bubble as possible.

Mechanical Aeration - Mechanical aerators are generally grouped in two broad categories:  turbine types and pump
types.  In both, oxygen transfer occurs through a vortexing action and/or from the  interfacial exposure of large
volumes of liquid sprayed over the surface.  To optimize aeration and mixing, and to avoid interference between
units, aerator manufacturers have developed criteria for minimum areas and depths,  depending on the horsepower of
the aerator and the configuration of the impeller.

Cascade Aeration - Cascade aeration generally takes advantage of effluent discharge head and employs a series of
steps or weirs over which the flow moves in fairly thin layers.  The objective is the maximization of turbulence to
increase oxygen transfer.  Head requirements vary from three to ten feet, depending upon the initial DO and the
desired increase.  If the necessary head is not available, effluent pumping is required.

U-Tube Aeration - The U-tube aerator consists of two basic components;  a conduit to provide a vertical U-shaped
flow path and a device for entraining air into the stream flow in the down leg of the conduit.  The entrainment
device is one of two types:   (1) aspirator,- or (2) compressor and diffuser.  In either case, the entrained air is
carried along the down flow leg of the tube because the water velocity exceeds the buoyant rising velocity of the
air bubbles.

Technology Status - Except for U-tube aeration, post aeration systems have been widely used in both the municipal
and industrial sectors.  U-tube aeration has been utilized for sanitary force main aeration.

Typical Equipment/tto. of Mfrs.  (23) - Blowers/7; Aeration equipment/30.

Applications - Post aeration is used when the dissolved oxygen (DO) content in the effluent from the wastewater
treatment plant does not meet effluent standards.  The choice of an aeration method is dependent upon local con-
ditions and economics.

Common Modifications - Post aeration can be accomplished in high-intensity mixing chlorination systems, which
preclude the necessity of a separate post aeration system.

Limitations - Usually limited to secondary or tertiary effluents.

Performance - Post aeration systems can achieve oxygen concentrations in the effluent approaching the saturation
concentration.

Chemicals Required - None

Residuals Generated - None

Design Criteria - Diffused Aeration - Post aeration systems are designed on the basis of required oxygen-transfer
rate  (26).  General aeration requirements range from 0.5 to 5 Sft /min of air per square foot of tank area (26).

Mechanical Aeration - Mechanical aeration systems are also designed using oxygen-transfer rates which are then
converted to horsepower ratings.  Normal horsepower ratings can range from 0.03 to 0.1 hp/1000 gal of tank capacity
(26).

Cascade Aeration - As mentioned above, cascade aeration takes advantage of water falling over a series of weirs.
The cumulative height of these weirs is between 3 and 10 feet, depending on the DO increase required.


U-Tube Aeration - Various design considerations include air-to-water ratio, tube cross-sectional area, and depth.
The hydraulic head requirements for plants of 5 Mgal/d or less should be less than five feet.  If sufficient head
is not available, the flow may be pumped through the U-tube.

Unit  Process Reliability - Due to their inherent simplicity, post aeration systems are extremely reliable.

Environmental Impact - Degree of land usage required varies with type chosen, but generally, it is small. Volatiles
remaining in the treated effluent may be stripped by the aeration process.  There are no sludges generated.

Reference  - 26
                                                         A-108
-------
 POST AERATION
                                                                      FACT  SHEET  3.1.11
         Oxygen Source or
               Air _, Compressor
 FLOW DIAGRAM        /
 	       o
                                                                                  Venturi
                                                                                  'Aspirator
            Diffused Aeration
                                 Turbine Type Aerator
                                  Mechanical Aeration

Cas
1-
icade t
h
0*
"/

deration
Head
Loss

^
t
J
>\.

f
t

Effluent
Channel
                                                                                           U-Tube Aeration
ENERGY NOTES (26) - Energy consumption for post aeration  systems is highly dependent upon basin geometry and
the dissolved oxygen deficit.  Diffused and mechanical aeration and power requirement can be calculated as  follows:
Power  (kWh/yr) =
                  272  (SOR)
                 N  F  n
                  o  g
with SOR =
     N.  =     0  transfer  efficiency under standard conditions  in  tap water,  Ib  0 /hph (See Appendix D)
Standard oxygen-transfer rate, Ib 0 /d
     F°  =     Correction factor related to basin geometry
     n   =     Aerator efficiency correction

Cascade aerators consume power by the loss of head.   The equivalent energy requirement can be calculated as follows:

Energy (kWh/yr) = 1900 (Mgal/d X ft head loss), assuming a wire to water efficiency of 60 percent, with normal
operating head loss at approximately 5 feet, Energy  (kWh/y) = 9500 X  (Mgal/d)
U-tube aerators:                                                                         .
      Optimum U-tube (requiring pumping) designs require 0.9-1.3 kWh/lb D.O. added at 24  C


     *
COSTS  (3) - Assumptions:   ENR Index = 2475
1.   Construction costs include aeration equipment and post aeration basin for mechanical aeration.
2.   Designed to increase dissolved oxygen from 1 mg/1 to 5 mg/1.
3.   Detention time = 20 minutes.
4.   Power information based on transfer of 34 Ib of 02/Mgal of wastewater treated.
5.   Power @ $.02/kWh

Note:   Total costs  have  been derived from the  power, labor and materials  costs given in reference 3.

                        CONSTRUCTION COST                             OPERATION & MAINTENANCE COST
           10
           01
          001
                                                              1 0
                                                              01
                                                          5 S
                                                             001
            0 1
 REFERENCES -  3,  26
                         1 0            10
                         Wastewaler Flow  Mgal/d
                                                             0001
                                                                                             -Total-
                                                                                            Labor
                                                                                          Materials
                                                                                          in  ii
                                                                                                            0 1
                                                                                                           001
                                                                                                          0001
                                                0 1
                                                              1 0            10
                                                             Wastewater Flow, Mgal/d
                                                                                        100
                                                                                                          00001
*To convert construction cost to capital cost see Table A-2.
                                                       A-109
-------
PRELIMINARY TREATMENT                                                                  FACT  SHEET  3.1.12
Description - The purpose of preliminary treatment is to remove large  objects,  such  as  rocks,  logs, and  cans,  as
well as grit, in order to prevent damage to subsequent treatment  and  process  equipment.   Objects normally removed
by preliminary treatment steps can be extremely harmful to pumps,  and can  increase  downtime due to pipe clogging
and clarifier scraper mechanism failures.

Preliminary treatment usually consists of two separate and distinct unit operations -  bar screening  and grit
removal.  There are two types of bar screens (or racks).   The  most commonly used, and  oldest  technology, consists
of hand-cleaned bar racks.  These are generally used in smaller treatment  plants.   The second type of bar screen is
the type that is mechanically cleaned, which is commonly used  in  larger facilities.

Grit is most commonly removed in chambers, which are capable of settling out  high density solid materials,  such as
sand, gravel and cinders.  There are two types of grit chambers:   (1)  horizontal flow,  and (2) aerated.  In both
types the settleables collect at the bottom of the unit.   The  horizontal units  are  designed to maintain a rela-
tively constant velocity by use of proportional weirs or flumes in order to prevent settling  of organic solids,
while simultaneously obtaining relatively complete removal of  inorganic particles  (grit).

The aerated type produces spiral action whereby the heavier particles remain  at the bottom of the tank to be
removed, while organic particles are maintained in suspension  by  rising air bubbles.   One main advantage of aerated
units is that the amount of air can be regulated to control the grit/ organic solids separation, and less offensive
odors are generated.  The aeration process also facilitates cleaning  of the grit.   The grit removed  from horizontal
flow units usually needs additional cleaning steps prior to disposal.

Common Modifications - Many plants also use comminutors.   These are mechanical  devices that cut up the material
normally removed in the screening process.   Therefore, these solids remain in the wastewater to be removed in
downstream unit operations, rather than being removed immediately from the wastewater.

In recent years, the use of static or rotating wedge-wire screens has increased to remove large organic  particu-
lates ]ust prior to degritting.  These units have been found to be superior to comminutors in that they  remove the
material immediately from the waste instead of creating additional loads downstream.   Other grit chamber designs
are available including swirl concentrators and square tanks.

Technology Status - Preliminary treatment has been widely used since the early days of municipal wastewater treat-
ment.  Wedge-wire screens are newer technology (approximately 13 years old).

Typical Equipment (23) - Screens/20; grinders/9;  comminutors/12; sedimentation equipment/28;  wedge-wire screens/2.
Applications - Should be used at all municipal wastewater treatment plants,  and also are normally used prior to
wastewater pumping stations.

Limitations - None for normal municipal wastes.  Operational problems have been experienced with comminutors at
certain installations due to heavy influx of plastic objects.

Performance - Bar screens are designed to remove all large debris, such as stones, wood,  cans,  etc.   Grit chambers
are designed to remove virtually all inorganic particles, such as sand and gravel.  Wedge-wire  screens remove up to
25 percent SS and associated BOD, and possibly reduce digester scum.

Chemicals Required - None

Residuals Generated - All unit operations, except for comminutors, will generate solids that will need disposal.
Wedge-wire screens remove up to 1 yd  of 12 to 15 percent solids/Mgal.  The grit and other solids are often land-
filled.

Design Criteria - Bar Screens:  Bar size, 1/4 to 5/8 in width by 1 to 3 in depth; spacing, 0.75 to 3 in; slope from
vertical, 0 to 45°; velocity, 1.5 to 3 ft/s.  Wedge-wire Screens:  See Fact Sheet 3.1.17.

Grit Chambers:  Horizontal velocities of 0.5 to 1.25 ft/s, sufficiently long to settle lightest and smallest
 (usually 0.2 mm) grit particles with an additional factor of safety  (up to 50 percent).  Weir crests are generally
set 4 to 12 in above bottom.
 Un
   it Process Reliability - Preliminary treatment systems are extremely reliable and, in fact, are designed to
 improve the reliability of downstream treatment systems.

 Environmental  Impact - Requires relatively little use of land.  Requires minimal amounts of energy.  Solids will be
 generated, requiring disposal.  Odors are common when removed grit contains excess organic solids and is not
 disposed of within a short time after removal.

 Reference  - 7
                                                      A-110
-------
   PRELIMINARY TREATMENT
                                                                                       FACT SHEET  3.1.12
   FLOW DIAGRAM
                                                      Metering
,r j jient

Bar
Screen




Comminutor
(optional)

  ENERGY NOTES -
                                                                          To treatment
  Grit Chamber  (non-aerated)
  Grit removal includes screw pumps.
  Velocity =0.55 ft/s.
  Detention time (at peak flow of 2:1) = 1 min.
                                                                Grit
  Grit Chamber (aerated)
  Grit removal includes screw pumps.
  Air Rate = 3 ft /min/ft of length
  Detention time (at peak flow of 2:1)
              5
                                         3 min.
            10
           10
           10
           10
                         Aerated
                          tt
Mechanically  Cleaned Bar Screen
Run time of 10 min/h; worm gear drive,
50 percent efficiency; bar spacing, 3/4 inch.
    10
                                  Non-aerated
                                                                    5   10
                                                                       10"
                                                                        10
             100
                           1,000         10,000       100,000
                          Grit Chamber Volume,  ft3
                                                                        0.1            1.0           10
                                                                                   Wastewater Plow, Mgal/d
                                                                                                                  100
COSTS - Assumptions:  ENR Index = 2475*
orifoh^h^ C°^S in°lude:
-------
PUMP STATIONS,  IN-PLANT                                                         FACT SHEET  3,1,13
Description - Due to terrain and design  conditions, wastewater after partial treatment may require pumping to
subsequent or previous treatment processes, and the  final effluent after complete treatment may need pumping to
the receiving body of water.   These  in-plant pump stations are usually less costly than those for raw wastewater
due to the relatively clear water handled which requires neither screens nor comminutors; and to the use of
relatively small wet wells.   The assembly,  installation, and testing of the station which includes pumps, motors,
piping, valves,  controls,  and alarms are  generally completed on the site.

Common Modifications - Some larger systems employ Archimedes screw pumps which may not require a wet well.
Chemical addition equipment is  sometimes  needed according to the treatment requirements.  Multiple pumps or
variable-speed pumps are used to match the  variations of flow.

Technology Status - Widespread  use in wastewater  application.
Application - Lifts wastewater when there  is  not  sufficient head for gravity flow to a subsequent or a previous
process, or to a receiving body of water.

Limitations - May need emergency power under  certain  conditions.
Typical Equipment/ No.  of Mfrs.  (23)  - Pump  sets/34; valves/39; ventilating fans/7; controls and alarms/29.
Design Criteria - Minimum slope wet well  bottom  2:1;  dry well and wet well must be ventilated; wet well floor
should always remain covered with liquid to reduce odor problems; high water alarm; minimum number of pumps, 2;
suitable water level controls for pump motor operation; emergency power provisions.

Reliability - Reliability is closely related to  maintenance and power supply.
Environmental Impact - Low impact on air and water.  Potential  for water pollution and health risk under failure
conditions.  Potential for noise.

References - 3, 7, 22, 23, 30,  201
                                                      A-112
-------
 'UMP  STATIONS,  IN-PLANT
                                                                              FACT SHEET  3.1.13
FLOW DIAGRAM -
                               Suction
                                                       Discharge
                                                       Q is variable
                                                       TDH varies
ENERGY NOTES - Pumping  energy requirements can be computed  from  the following equation:
     kWh/yr =  114°  (Mgal/d    )(ft of  total head)
                    wire  to water efficiency


Using a wire to water efficiency of 67% and a TDH of 30 ft, about 51,000 kWh/yr are required for a 1 Mgal/d station
COSTS -  Assumptions: ENR Index = 2475
1.  Costs are based on September 1976 figures.

2.  Construction cost includes normal earthwork, structure, electrical, heating, ventilating, controls and other
    equipment essential to a complete pump station.  TDH = 30 ft.
3.  Power costs based on $0.02/kWh.





Note:   Total cost  has been  derived from labor,  materials  and  power costs  provided  in reference  201.
                         CONSTRUCTION  COST
                                                                         OPERATION & MAINTENANCE COST
          1 0
Q

O


O


5
          01
         0 01
          0.1
                                                                 1 0
                                                             ».   o 1
                                                             o
                                                             V)
                                                             c
                                                             o _
                                                             = ffl

                                                             if
                                                             o
                                                             O
                        i.o           10

                        Wastewater Flow, Mgal/d
                                                               0001
                                                   100
                                                                                                               0 1
                                                                                                              0001
                                                                                                             00001
                                                           o.i
                                                                         i.o            10
                                                                        Wastewater Flow, Mgal/d
                                                                                                     100
 REFERENCE  - 201



  *To  convert construction cost to capital  cost  see Table A-2.





                                                       -——
-------
  SCREEN,  HORIZONTAL SHAFT  ROTARY                                              FACT SHEET 3.1.16
Description - An intermittently or continuously rotating drum covered with a plastic or stainless steel screen of
uniform  sized openings, installed and partially submerged in a chamber.  The chamber is designed to permit the
entry of wastewater to the interior of the drum and collection of filtered (or screened)  wastewater from the
exterior side of the drum.  With each revolution, the solids are flushed by sprays from the exposed screen surface
into a collecting trough.  Coarse screens have openings of 1/4 inch or more; fine screens have openings of less
than 1/4 inch.  Screens with openings of 20 to 70 microns are called microscreens or microstrainers.  Drum
diameters are 3 to 5 ft with 4 to 12 ft lengths.

Common Modifications -
     Tile chamber, reinforced concrete chamber, steel chamber.
     Variable speed drive for drum.
     Addition of backwash storage and pumping facilities.
     Addition of ultra-violet light slime growth control equipment.
     Addition of chlorinating equipment.

Technology Status - Widespread use for roughing pretreatment, and for secondary biological plant effluent polishing
Applications - Removal of coarse wastewater solids from the wastewater treatment plant influent after bar screen
treatment; screen openings 150 microns to 0.4 inches.  For polishing activated sludge effluent,  screen openings 20
to 70 microns.

Limitations - Dependence on pretreatment and inability to handle solids fluctuations in tertiary applications.
Reducing the speed of rotation of the drum and less frequent flushing of the screen has resulted in increased
removal efficiencies, but reduced capacities.

Typical Equipment/No, of Mfrs. (23)  - Screens/20; mechanical equipment/at least 3.
Performance  (3, 7, 22) - For tertiary applications with head loss of 0.3 to 2 ft:

               Pollutant                               Typical Percent Removals

                 BOD                                          40 to 60
                 SS                                           50 to 70

Note:     Solids removed by fine screens have amounted to approximately 5 to 30 ft /Mgal of wastewater treated,
          equivalent to 5 to 15 percent of suspended matter.

Residuals Generated - Sidestream of solids accumulations backwashed from screen.   (2  to  5 percent of influent with
SS concentration of 200 to 500 rag/1).

Design Criteria -
     Screen submergence 70 to 80 percent.
     Loading Rate: 2 to 10 gal/min/ft  of submerged area depending on pretreatment and mesh  size.
     Screen openings: 150 microns to 0.4 inches for pretreatment;  20 to 70  microns for tertiary  treatment.
     Drum r/min:  0 to 7.
     Screen Materials:  Stainless steel or plastic cloth.
     Washwater = 2 to 5 percent of flow being treated.
     Performance of fine screen device varies considerably on influent solids  type,  concentration and  loading
     patterns; mesh size;  hydraulic head and degree of biological  conditioning of  solids.

Unit Process Reliability - High degree of reliability for both the process  and mechanical  areas.  The  process is
simple to operate.  Mechanical equipment is generally simple and straightforward.  Occasional problems may arise
because of incomplete solids removal by flushing.   Hand cleaning with  acid  solution may be required  for  stainless
steel cloths.  Blinding by grease can be a problem in pretreatment applications.

Environmental Impact - Air:  odor problems around equipment may be created  if  solids are not flushed frequently
enough from the screen (pretreatment).   Disposal of solids  by incineration  can  affect air quality.  Land:  Dis-
posal of solids in landfill has neglibible impact.   Water:   None.

References - 3, 7, 22, 23, 39, 52, 99
                                                       A-114
-------
 SCREEN,  HORIZONTAL SHAFT ROTARY
                                   FACT SHEET  3.1.16
 FLOW DIAGRAM -
                                                    Effluent Weir
                                                                    10
                                                                 •d
                                                                 a;    g
                                                                 *J  10
                                                                  $
                                                                  H    5

                                                                 _,  10
                                                     Effluent Cha-nber
           Influent Chamber
                                                                    10
                                                                      10
                                                                                     100           1000


                                                                                                         2
                                                                                Submerged Screen area, ft
                                                           10,000
ENERGY MOTES (4) - Assumptions:  Electrical energy requirements include backwash water pumping and screen drive.
COSTS* - Assumptions:  ENR Index = 2475
Design Basis:

Construction costs include tanks, drums, screens, backwash equipment, drive motors, and building.  Instrumentation

for automatic operation is included.  Hydraulic load = 2.5 gal/min/ft  at average flow.  Screen mesh = 25 microns.

Peripheral drum speed = 15 ft/rain at 3 inch head loss.  Backwash 3 percent of throughput at 35 psi
                        CONSTRUCTION COST
                                                                           OPERATION S MAINTENANCE COST
        10
       1.0
    r


    g

    
-------
 ;CREEN, WEDGEWIRE                                                               FACT SHEET  3.1.17
Description - A device onto which wastewater is directed across  an  inclined  stationary  screen  or  a  drum  screen of
uniform sized openings.   Solids are trapped on the  screen surface while  the wastewater  flows through the openings.
The solids are moved either by gravity (stationary)  or by mechanical means  (rotating drum) to  a  collecting  area
for discharge.  Stationary screens introduce the  wastewater as  a thin  film  flowing downward with a minimum  of
turbulence across the wedgewire screens,  which is generally in  three sections  of progressively flatter  slope.  The
drum screen employs the  same type of wedgewire wound around its periphery.  Wastewater  is  introduced as a thin
film near the top of the drum and flows through the hollow drum and out  the bottom.  The solids  retained by the
peripheral screen follow the drum rotation until  removed by a doctor blade  located at about 120   from the intro-
duction point.

Common Modifications - Wedgewire spacing can be varied to best  suit the  application.  For  municipal wastewater
applications spacings are generally between 0.01 and 0.06 inches (0.25  to  1.5 mm).   Inclined  screens  can be housed
in stainless steel or fiberglass;  wedgewires may be curved or straight;  the  screen  face may be  a  single multi-
angle unit, three separate multi-angle pieces,  or a single curved unit.  Rotary  screens can have  a single  rotation
speed drive or a variable speed drive.

Technology Status - In use in industry since 1965 and in municipal wastewater treatment since 1967. Over 100
installations to date.

Applications - Stationary and rotary drum screens are ideally suited and usually employed after bar screens and
prior to grit chambers.  They have also been employed for primary treatment,  scum dewatering,  sludge  screening,
and digester cleaning and for storm water overflow treatment.   Generally,  the rotary drum unit is  preferred where
grease problems are evident due to the increased frequency of  cleaning required for stationary units.

Limitations - Require regular cleaning and prompt residuals disposal.
Typical Equipment/No. Mfrs.(23)  - Screen systems/3
Performance - Screenings removed by fine screens (.01 to .06 in.)  have amounted to approximately 1 to 2 yd /Mgal
of wastewater treated.  Head loss can be 4 to 8 ft.   Pollutant removals are:

     Pollutant                  Typical Percent Removal
     BOD5 to 20
     SS                                5 to 25

Residuals Generated - Solids trapped on the screen surface (1 - 2 yd /Mgal)
Design Criteria - Screening of raw wastewater - (0.05 - 36 Mgal/d)
               Parameter                         Stationary                      Rotary Drum
               Screen opening                    0.01 - 0.06 in                  0.01 - 0.06 in
               Head required                     4 - 7 ft                        2.5 - 4.5 ft
               Space required                    10 - 750 ft                     10 - 100 ft
               Motor size                        -                               0.5 - 3 hp

Unit Process Reliability - Very high reliability for process and mechanical areas when maintained.
Environmental Impact - Air:  Can create odors if screenings are not disposed of properly.   Land:  Practically nil.
Screenings are generally disposed of in a landfill or by incineration.  Water:  None

References - 3, 7, 22, 27, 39, 52, 53, 99
                                                     A-116
-------
 SCREEN,  WEDGEWIRE
                                                                                    FACT SHEET 3.1.17
 FLOW DIAGRAM
                                                  Feed
      Sludge
                                                                     Water Level
                                                            Influent
                                                           Effluent
ENERGY NOTES - Energy requirements of the stationary screens  are  dependent upon  the head  loss through  the screen
system which may amount to 4 to 8 ft TDK.   Energy requirements  are  kWh/yr =  1900 (Mgal/d  X TDK) at a wire to water
efficiency of 60 percent.   With a representative head of 4.5  ft,  8,550  kWh/yr  would be  required per Mgal/d.
Operation of rotary drum units requires about 3,300 kWh/yr for up to 1  Mgal/d; 5,000  kWh/yr for 1 to  6 Mgal/d;
10,000 to 20,000 kWh/yr for 6 to 8 Mgal/d; and about 2,000 kWh/yr/Mgal/d for higher flows in addition to
pumping energy for 2.5 to 4.5 ft of static head.


COSTS* - Assumptions:  Last quarter 1978 dollars. ENR Index = 2860
     Construction cost includes wedgewire stainless steel screen 0.06 inch opening; equipment and installation,
     including electrical.  Equipment provides suitable weirs for flow control.
     Cost does not include flumes or piping for effluent or sludge, or pumping equipment.
     Operation cost based on labor costs at $7.50/h; power at $0.02/kWh;  pumping head for stationary screen
     4.5 Ft.
                        CONSTRUCTION COST
                                                                           OPERATION & MAINTENANCE COST
          Q
          ~0
          5 001
            0001
-- — 1


























=















a^








Stati





- = :








onar
!





mi








f




/





Sc:



/



	 H



---±
1:'
,


--
--'-





>k/
f'l1-
''—?










S






Rotary Screen


















/

-/















/











*/5
7 I

t









i

                                                                  1 0
                                                              I
                                                              Q  0 1
                                                              8
                                                              •s  001
                                                                 0001
Stationary Screen>
                                                                              Rotary Screen
               .1            1.0          10.0            100
                          Wastewater Flow, Mgal/d

REFERENCES - 3,  99


 *To  convert construction cost to capital cost see Table A-2.
       1.0           10.0
      Wastewater Flow. Mgal/d
                                                                                                             100
                                                        A-117
-------
AMMONIA  STRIPPING
                                         FACT SHEET 4.1,1
Description - Ammonia Stripping is a simple desorption process  used  to  lower  the ammonia content of  a wastewater
stream.  In the process, wastewater at elevated pH is  pumped to the  top of  a  packed  tower with  a countercurrent
flow of air drawn through the bottom openings.
into the air stream which is then discharged to the atmosphere.
     Free ammonia (NHJ is stripped from the falling water droplets
Lime or caustic soda is added prior to the stripping to raise the pH  of  the  wastewater  to  the range of  10.8  to
11.5 converting essentially all ammonium ions to ammonia gas which  can be  stripped  by air.   Process controls
required for the operation are the proper pH adjustment of the influent  wastewater,  and maintenance of  proper air
and water flows.

Ammonia removal efficiency is highly dependent on air temperature and air/water ratios. As  the air temperature
decreases, the efficiency drops significantly.  The most common operating  problem of this  process  is  the occa-
sional formation of calcium carbonate scale.  The influent should always be  clarified before stripping.

Common Modifications - Tower packing materials, plastic and wood; operation  of the  stripping gas in a closed
system with an ammonia absorption unit for removal of the CO  from  the  stripping gas stream  to  reduce scaling
problems; reclamation of ammonia from the closed cycle absorption unit;  use  of high pH  holding  ponds, followed  by
a cross flow spray tower and final removal of the residual ammonia  by breakpoint chlorination.

Technology Status - The process is considered fully demonstrated but not widely used.
Applications - Good for wastewater with high ammonia content (more than 10 mg/1).   For higher ammonia content
 (more than 100 mg/1), it may be economical to use alternate ammonia removal techniques.  See Fact Sheet No.  4.1.2.

Limitations - Poor efficiency in cold weather locations (0  - 10 C).   Cannot operate in freezing conditions    3
 (unless sufficient heated air is available).  Ammonia is discharged to atmosphere usually at low level (6 mg/m ).
This may be objectionable in certain locations.  Nitrite, nitrate and organic nitrogen are not removed.  Poor
efficiency when ammonia concentration is low  (less than 10 mg/1).  Scale formation can be removed hydraulically
in most cases but not in all, resulting in a need to pilot test at most locations.

Typical Equipment - Stripping tower closely resembles a conventional cooling tower, with 24 manufacturers (77).
Performance - The operation is unaffected by toxic compounds which can disrupt the performance of a biological
system.However, volatile toxics will be stripped during the process.  Operating efficiency is highly dependent
on air temperature as follows:
                              Air Temperature
                                   10 C
                                   20°C
             NH  Removal  Efficiency
                  75  percent
                  90  to 95 percent
Efficiency may be reduced by severe scaling in the tower.
ammonia  concentrations  are  in the 1 to 3 mg/1 range.
                                                           However, under normal operating conditions, residual
Chemicals  Required - Lime or caustic soda is needed to raise the pH of the wastewater to the range of 10.8 to
11.5.   For wastewater with high calcium content, an inhibiting polymer may be added to ease the scaling problem.
Effluent from the stripping may need pH readjustment to neutral condition with an acid (H2S°4 at 1-75 parts for
one part of  lime added) or recarbonation followed by clarification.
 Design Criteria -
      Wastewater loading:   1  to  2 gal/min/ft 3
      Stripping air flow rate:   300  to  500  ft /gal
      Packing depth:   20  to  25  ft
      pH of  wastewater:   10.8 to 11.5
      Air pressure drop:   0.015" to 0.019"
of water/ft
Packing material:  plastic or wood
packing spacing: approx.  2" horizontal and
vertical
Providing:  uniform water distribution
Providing:  scale removal and clean-up
Land requirement:  small
 Reliability -  The operation is simple  and reliable, and not subject to upset by the wastewater fluctuation, if pH
 and air temperature are  stable.   Occasional  clean-up of scale may be required.

 Environmental  Impact -

 Air: Normal operational  discharge of less than  6 mg/m  does not present an odor problem.  NH3 washout to downwind
 water bodies;  minor noise pollution from motor, fan and water splashing.

 References - 3, 4, 23, 28, 31, 39, 44, 47
                                                      A-118
-------
 AMMONIA  STRIPPING
         FACT SHEET
 FLOW DIAGRAM -
                                                               Outlet
                             Water Inlet
                                Air Inlet
                                Outlet
                                                                          Drift
                                                                          .Eliminators
                                                                         'Distribution
                                                                             System
                                                                          Air  Inlet
Water Collecting
     Basin
                                                 Countercurrent Tower
 ENERGY NOTES  (4)  -  Pumping  energy  requirements  can be approximated by the use of the following equation:
      kwh/yr  =  1140  (Mgal/d     x  ft of  total  head)
                    Wire  to water Efficiency

 For  a TDK of 50  feet,  a  wire  to  water  efficiency of 60 percent and a 1 Mgal/d flow would amount to 95,000
 kwh/yr.   Assuming a fan  energy requirement of 0.0765 hp/1,000 gal  (400 ft /gal), a 1 Mgal/d facility would
 require  500,000  kwh/yr,  resulting  in a total energy requirement  of 600,000  kwh/yr
COSTS* - Assumptions:  ENR 2475, Sept 1976
 Design Assumptions:   Tower,  20 ft high, packed with 1/2 in diameter Schedule 80  Pvc  pipe  at  3  in centers
 horizontally with alternate  layers placed at right angles  at  2  in centers  vertically;  Pump,  50  ft TDH;  Loading,
 1 gal/min/ff1;  Air Flow,  400 ftj/gal;  Concentration of NH3,  influent 18  mg/1,  effluent 3  mg/1;  pH to  11-11.5
 Operation Assumptions:  Labor, at $7.50/h, including benefits;  Power, at  $.02/kwh;  Lime, at  530/ton
 Note: Total OsM costs have been derived from the power, materials,  chemicals and labor costs provided in  Ref.  3.
                      CONSTRUCTION COST
        10
                                                                        OPERATION & MAINTENANCE COST
        1 0
        0 1
       001
         0 1
REFERENCES - 3,  4
                       1 0            10
                      Wastewater Flow Mgal/d
                                                 100
                            100
                                                                                                          0.001
                                                                             Waitewater Flow, Mgal/d
*To convert construction cost to  capital  cost  see  Table  A-2.
                                                   A-119
-------
ARRP (AMMONIA REMOVAL AND RECOVERY  PROCESS)                                FACT SHEET  4.1.2
Description - ARRP consists of two packed towers for stripping and absorption.   In the  stripping  tower, waste-
water flows downward against an upflow gas stream.   Ammonia in the wastewater is  stripped  into  the  gas  stream.
The gas stream is then directed to the absorption tower,  in which an absorption solution is  sprayed downward.
With good countercurrent contact,  most of the ammonia transferred to the  gas stream is  absorbed by  the  solution.
The gas stream is then recycled back to the stripping tower for reuse.

Lime or caustic soda is usually added to the wastewater prior to ARRP to  convert  the ammonium ion in  the waste-
water to free ammonia.  Air is used as the stripping gas.   Water or a dilute acid (sulfuric  acid) is  frequently
selected as the absorption solution, so that the process produces an aqueous ammonia solution or an ammonium
sulfate solution.

Common Modifications - For wastewaters with high ammonium ion concentrations (greater than 300  mg/1), steam may
be economically used as the stripping gas.   Steam is injected at the bottom of the stripping tower and is  con-
densed as it exits.  A wastewater feed-effluent heat exchanger is often used to minimize  energy consumption.

Technology Status - Steam stripping and absorption operations are commonly used in chemical  and fertilizer indus-
tries.  In wastewater treatment, air stripping is considered fully demonstrated,  but not widely used.   ARRP  is  a
relatively untried process.

Applications - Economically attractive for treatment of wastewater, with a high ammonium ion concentration (greater
than 100 mg/1).  This approach is being used for stripping ammonia from selective ion exchange  regenerant.   May
produce a waste ammonia stream with some value.

Limitations - Less competitive as ammonium ion concentration decreases.   Highly susceptible to  the ammonia  market
to become cost effective.

Typical Equipment/No, of Mfrs. (77) - Stripping towers/28;  absorption towers/46
Performance - Ammonia removal efficiency can be expected to be higher than with ambient air stripping towers in
the colder climates, since the stripping gas temperature approximates the wastewater temperature.   Removal
efficiencies are projected to range from 90 to 95 percent with water temperatures of 20°C to 75 percent at water
temperatures of 10 C.  Scaling problems are reduced when compared to NH  air stripping towers.

Chemicals Required -
Sulfuric acid (H SO ):  at 2.72 parts per one part of ammonium ion recovered,  if an (NH )  SO  solution is the
desired product.  No sulfuric acid is needed if water is used as the absorption solution.

Lime  (CaO): Sufficient lime to raise pH to 10.8 to 11.5 (see Fact Sheet 4.2.2).

Acid  for pH readjustment:  may be needed for neutralization of the residual alkali.

Design Criteria  (28,  47) -
                Stripping Operation                                        Absorption Operation

     Wastewater loading:  1 to 2 gal/min/ft  (air stripping)      Product solution:   1 to 30% (aqueous ammonia)
                          7 gal/min/ft  (steam stripping)                            to 50% ((NH4>  SO4 solution)
     Gas flow rate:  300 to 500 ft /gal (air stripping)           Tower diameter:   50 to 75% flooding velocity
                     15 lb/1000 gal (steam stripping)             Degree of recovery:  about 90%
     Packing depth:  20 to 25 ft                                 Packing depth:   15 to 20 ft
     Wastewater pH:  10.8 to 11.5                                Gas pressure drop:  2 to 3" of water

     Tower diameter is set to a gas flow of 50 to 75 percent of flooding velocity for both the stripper and
absorber.

Reliability - Can be expected to have a moderately high degree of reliability, as demonstrated in the chemical
industry.  Occasional clean-up of scale in the stripping tower and heat exchanger may be required.

Environmental Impact - Air:  No impact without leakage.
Water:  Effluent would have a slightly higher solids content due to pH adjustment.

References - 3, 28, 47, 77
                                                     A-120
-------
 ARRP (AMMONIA  REMOVAL AND  RECOVERY PROCESS)
                                                                                    FACT  SHEET  4,1,2
 FLOW DIAGRAM -
          Wastewater containing
          dissolved ammonia (NH )
                                         Gas stream with ammonia increased
                                                                                             Motor
                                                                                             D
                                                                                                Ducting (Typical)
                                                                                           Acid and water makeup


                                                                                             Recycled
                                                                                             Absorbent
                                                                                             Liquid
                                 u
                                 V
                                     Gas stream-ammonia  ,
                                   Deduced by absorption^
                                         Wastewater stripped of nearly
                                         all or part of ammonia (NH )
                                                                                  Ammonium salt blowdown
                                                                                  or discharge to stripper
ASSUMPTION - For lack of information  on  the  adsorption unit, it is assumed to be two-thirds the size  of  the
stripping unit.   A further assumption is that  the  construction cost, operation and maintenance cost,  and energy
requirements are also two-thirds of that for the stripping unit.
ENERGY NOTES-               1140 X Mgal/d X TDH
Stripper: Pumping - kWh/yr = wire to %ater ef£iciency     3
          Fan     - kWh/yr = 76.5 hp/Mgal/d at 400 std. ft  air/gal of wastewater
Absorber: Pumping - kWh/yr = 0.67 X Energy Required for Stripper Pumping
          Fan     - kWh/yr = 0.67 X Energy Required for Stripper Fan
For wastewater flow of 1 Mgal/d,  TDH of  50 ft  and wire to water efficiency of 60 percent.   The total  energy
required is: Pumping = 160,000 kWh/yr; Fan = 835,000 kWh/yr; Total = 995,000 kWh/yr
COSTS*- Assumptions: ENR Index =  2475
     Construction cost includes ammonia stripping  tower  (20 ft high packed with 1/2 in.  diameter  schedule  80  PVC
     pipe at 3 in.  centers horizontally with alternate layers placed at right angles at 2 in.  centers  vertically);
     pumps (50 ft TDH);  lime  feed  facilities to raise pH to 11 to 11.5 and sulfuric acid facilities  to subse-
     quently neutralize  the treated effluent. No credit for sale of NH .
     Hydraulic loading:  1.0 gal/min/ft  ; Air/water ratio: 400 ft /gal.
     Process performance:          Wastewater Characteristics
                                            In        Out
                             NH
                                3'
                                  mg/1
                                            18
                         CONSTRUCTION COST
                                                                           OPERATION S MAINTENANCE COST
         10
                                                                   10
                                                              S    1.0
                                                             a
                                                             •3
                                                             a
                                                                  O.l
REFERENCE - 3
                         10             100

                     Wastewater Flow, Mgal/d
                                                                                 10           100

                                                                               Wastewater Flow,  Mgal/d
 *To  convert  construction cost to capital cost see Table A-2.
                                                   A-121
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BREAKPOINT CHLORINATION                                                         FACT SHEET  4.1.3
Description - Breakpoint chlorination is a chemical treatment for ammonium ion removal.   In  the  process,  chlorine
is added to a wastewater containing ammonium ion in a mixing tank,  where practically all  the  ammonium ions  are
oxidized to nitrogen gas.  Amount of chlorine addition is precisely adjusted to a level  (the  breakpoint) which  is
sufficient for the oxidation and results in minimal residual chlorine and by-product formation.   Hydrochloric acid
is co-produced during the oxidation and must be neutralized by adding lime or caustic soda.   Equipment needs are
relatively simple but control requirements for chlorine dosage and pH adjustment are sophisticated and important.

Common Modifications- A downstream de-chlorination step for the removal of residual chlorine  is  usually adopted.
This can be a SO  addition (see Fact Sheet 4.5.2),  or an activated carbon adsorption (see Fact  Sheet 4.4.1).
Sodium hypochlonte  (NaOCl) may be used for the oxidation, instead of chlorine with no  HC1 co-production.  In  this
case, no lime or caustic soda addition is needed.

Technology Status -  Demonstrated on a large scale,  but not widely used.

Applications - It is economically attractive for wastewater with low ammonium ion concentrations (less  than 5
mg/1) and can be employed as a polishing step following other ammonium ion removal processes.   It is especially
attractive in a cold weather location.

Limitations - The process is rated low in capital costs, but high in operating costs,  especially at ammonium  ion
concentrations above 16 mg/1.  Potential for formation of chlorinated hydrocarbons in  the effluent.

Typical Equipment/No, of Mfrs. (77) Chlorine analyzers/25;  pH controllers/25; Control computers/42; Chemical
feeders/27; Mixers/26.

Performance - Can reduce ammonium ion concentration to 0.1 mg/1 or less,  and convert to nitrogen gas and to insig-
nificant amounts of  by-products  (nitrate at 0.2 to 0.45 mg/1 and NCI  at  0 to 0.25 mg/1)  under  normal operation.
Performance is not affected by temperature fluctuation or toxic compounds.  However, pH and chlorine dosage have
significant effects  on by-product formations as follows:

     pH_              6_       1_       £                Cl? dosage   Breakpoint               50% excess
     NCI , mg/1      0.33    0.05                     NCl , mg/1   Trace                     0.63
     NO , mg/1       0.70            1.0              NO", mg/1    0.15                     0.6

     Organic nitrogen compound is only slightly reduced.

Chemicals Required-
 Chlorine  (Cl  ):  8  to 13 parts per one part of ammonium ion (or NaOCl at 9 to 14 parts, instead of C12)
 Lime  (CaO):   0.9 to 1.1 Ib per one Ib of Cl2 or 1.5 Ib of NaOH per one Ib of C12 (No need if NaOCl is used instead
 of cl  )
 SO  for dechlonnation:  See Fact Sheet 4.5.2.

 Design Criteria   (28) ,  (47) -

                    Chlorination                             Activated Carbon Dechlorination
                    pH range:  6 to  7                        Loading rate: 1 to 2 gal/min/ft
                    Contact time:  1-2 min.                  Carbon charge: 0.3 to 2 ft /Mgal
                    Cl  control:  quick response             Contact time:  10 min.

 Reliability - Process reliability is medium.  Computer control for quick and close dosage of chlorine and pH
 adjustment may be required to improve reliability and to minimize by-product formation.

 Environmental Impact  -
 Air:   Chlorine and  by-products such as NCI. and H  may escape into the atmosphere, but the amounts are normally
 neglibible without  process upset.  Aeration operation for de-chlorination may not be acceptable in certain
 locations if  the exit air is discharged directly into atmosphere.

 Aqueous: Effluent TDS would increase significantly at 8.5, 12.2 or 14.8 times the amount of the ammonium ion
 reduced, depending  on whether NaOCl, lime or caustic soda is used in the process.

 References -  3, 23, 28, 31, 47
                                                    A-122
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BREAKPOINT CHLORINATION
                      FACT SHEET 4.1,3
FLOW DIAGRAM -
T
                                                                                Effluent
 ENERGY  NOTES  - Mixing energy - Approximately 135,000 kWh/yr/Mgal/d (Mixing power at 0.37 kWh/1000 gal)
COSTS - Assumptions :
Service Life:  15 years
Equipment:  Chlorine storage and feed system,  lime  storage and  feed system, mixing tank (30 min)
 hemicals:  C12 (13 Ib/lb of ammonium ion)  at  $160/ton
           Lime (0.9 Ib/lb of Cl )  at $30/ton
Concentration: Ammonium ion input 23 mg/1, output  2.6 mg/1
Labor Rate: $7.50/h including benefits
Power Cost: $.02/kWh
Index: ENR 2475, Sept. 1976
            10

           001
                          CONSTRUCTION  COST
                                            -+
                                                           u
             O.I
 REFERENCE  - 3
                          10           10

                          Wastewater Flow, Mgal/d
                                                    100
                   Wastewater Flow, Mgal/d
*To convert construction cost to capital cost see Table  A-2.
                                                      A-123
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ION  EXCHANGE  (FOR AMMONIA REMOVAL)                                      FACT  SHEET  H.l.
Description - The ion exchange process can be utilized to reduce the ammonium ion  concentration in wastewater.
The medium is usually clinoptilolite,  a natural ion exchange material.   Wastewater,  following  filtration  to reduce
suspended solids, is passed downflow through the ion-exchange bed until  the  bed reaches  the  point  of exhaustion.
The bed is considered exhausted when the ammonia concentration in the effluent reaches a predetermined value.   The
exhausted bed can be regenerated with 2 percent NaCl solution.  The effluent from the regeneration process  is
called spent regenerant, and it amounts to 2.5 to 5 percent of the wastewater stream and may contain more than 300
mg/1 of ammonia.  The key to the application of the ion exchange process is  the method of handling of the spent
regenerant.

The process for individual beds is batch but, by using multiple beds, continuous operation can be  accomplished.

The spent regenerant requires some form of processing for separation of  ammonia so that  the  regenerant can  be
reused.  The alternative processes available for regenerant recovery are air stripping or steam stripping (Fact
Sheet 4.1.2)  at high pH and electrolysis treatment.  The stripped ammonia can be vented  to the atmosphere or
absorbed in dilute acid solution and sold as fertilizer.  Steam stripping produces a 1 percent aqueous ammonia
solution as a waste product.  Electrolysis converts chloride in the spent regenerant to  chlorine which oxidizes
ammonium to nitrogen gas.

Common Modifications - Any ion exchange material which has high selectivity  for ammonium over  other cations can be
substituted for clinoptilolite.

Technology Status - The process is considered fully demonstrated,  but not widely used.
Applications - The process may be employed for one or more of the following reasons:   (1)  Where cold weather
limits the application of stripping as the sole process of ammonia removal (Fact Sheet 4.1.2),  (2)  reduction from
a feed with low concentration of ammonium ion, 10 to 50 mg/1,  (3)  potential for the reduction  of ammonia emission
to atmosphere, (4) where limited increase in TDS is allowable.

Limitations - Relatively high capital cost compared to the other two ammonia removal processes,  stripping or
breakpoint chlorination.  Nitrite, nitrate and organic nitrogen compounds are not removed.

Typical Equipment/No, of Mfrs. (77) - Ion exchangers/15;  mixers/26;  cycle controllers/36.
Performance - High ammonium ion removal efficiency,  93 to 97 percent,  not significantly impaired by temperature
fluctuation, and unaffected by toxic compounds.  Residual ammonium ion concentrations are in the one to three mg/1
range  (down to 0.22 mg/1 is possible at higher costs).   Wastewater TDS would be increased by about 50 mg/1.

Chemicals Required -
     Salt (NaCl): about 0.1 lb/1000 gallons of wastewater as makeup for purge and regenerant loss.
     Caustic soda (NaOH): at 1.15 parts per one part of ammonium ion (or lime (CaO)  at 1.6 parts per part of
     ammonium ion),  if air or steam stripping is used for ammonia recovery.

Design Criteria -
     Ion Exchange Operation                                      Regeneration
     Clinoptilolite size = 20 x 50 mesh                          Solution = 2% NaCl
     Bed height = 4 to 6 ft                                      Solution flow rate =4 to 10 bed volume/h
     Wastewater suspended solids = 35 mg/1 max.                  or 4 to 8 gal/min/ft
     Wastewater loading rate = 7.5 to 20 bed volume/h            Total solution volume = 2.5 to 5% of treated
     Pressure drop = 8.4 in. of water/ft                         wastewater or 10 bed volumes
     Cycle time = 100 to 150 bed volumes for one 6 ft bed;       Cycle time = 1 to 3 hour,s
     200 to 250 bed volumes for two 6 ft beds in series          Backwash = 8 gal/min/ft

Reliability - Moderate.  Operation is usually on automatic control, requiring occasional monitoring, inspection
and maintenance.  There is a potential scaling problem for wastewater with high magnesium and/or calcium contents.

Environmental Impact -
Air:  None, unless regenerant air is stripped for NH  removal (see Fact Sheet 4.1.1).
Aqueous:  A small purge stream (about 0.3 gal/1000 gal of wastewater), containing two percent NaCl, small amounts
of calcium and magnesium salts and possibly some toxic metal ions (if any in the wastewater) must be disposed of.
When a clarification step is employed, a low volume sludge stream, mainly Mg(OH)2 and CaCO. must be disposed of.
Effluent from the process would have a slightly higher solids content (addition of about 50 mg/1 of salt).

References - 3, 23, 28, 47, 77
                                                  A-124
-------
  ION EXCHANGE  (FOR  AMMONIA REMOVAL)
                      FACT  SHEET  it.l.
FLOW DIAGRAM -
                                  Neutral pH
                                     Spent
                Influent          Regenerant
                           to one of the following:
                                   I	-
                                                                      Air
                                                                    Stripping
                                                                Ammonia Removal
                                                                 and Recovery
                                                                 Process  (ARRP)
                   Effluent
                               Fresh and makeup
                                Regenerant
                                                                 Electrolysis
                                                                    Cells
                               NH  to
                               Atmosphere
                               Sludge

                               Recovered
                               Ammonia as

                               Sludge


                               H  and N


                               Sludge
 ENERGY  NOTES  -  From  the example below, power for operation of the regenerator amounts to 11,500 kWh/yr/Mgal/d.
 COSTS * - Assumptions: ENR index = 2475
 1.   Construction  costs include:
     a.    Gravity  feed clinoptilolite  beds with loading rate of 5.25 gal/min/ft  at 4 ft depth.
     b.    Backwash regeneration  facilities at 8 gal/min/ft .
     c.    Sodium chloride regeneration facilities using 2 percent NaCl solution, 40 bed volumes/regeneration, and
           1  regeneration/24 h.
     d.    Closed-loop air stripping tower for regenerant recovery.
     e.    Clarifier for spent regenerant.
 2.   Chemical  costs include makeup clinoptilolite and makeup regenerant.
 3.   Ammonium  sulfate produced by this system may be sold to offset operation and maintenance costs;  however,
     it  was  not included in this cost  estimate.
Note:   Totals have been derived from the power, labor, materials and chemicals costs provided in reference  3.
          01
REFERENCE  -  3
                         10            IO
                      Wastewater Flow. Mgal/d
                                                                                                                 I
0.01
   Ol
                 10            10
              Wastewater Flow, Mgal/d
*To convert construction  cost  to capital cost see Table A-2.
                                                   A-125
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LIME RECALCINATION                                                         FACT  SHEET  4.2,1
Description - In the recalcination process, lime sludge is subjected to thermal decomposition to produce quick
lime (CaO) and CO .   This process is very similar to the calcination process,  except for the raw material,  which
is sludge.  Primary or tertiary sludge where lime is used for coagulation can  be recalcined.  The application of
the process reduces the volume for sludge disposal and for lime make-up requirements.

In a typical recalcination system, the lime sludges from chemical clarifiers and recarbonation reaction basins are
thickened and centrifugally classified.  The thickening process increases the  solids concentration to 20 to 40
percent and the centrifugation reduces the inert content.  The inert materials are made up largely of magnesium
hydroxide and hydroxyapatite, and their presence will make the lime recovery and reuse more difficult.  The cakes
after centrifugation are ready for recalcination in the open hearth or fluidized bed furnace.

The tertiary plant serving South Lake Tahoe provides the most significant experience with open hearth furnace and
the following details pertain to this plant.  The cake after passing through solid bowl concurrent flow centri-
fuges is carried by a belt conveyor to a six-hearth furnace.  The optimum temperature of operation appears  to be
1900 F on the fourth and fifth hearths at 1.5 to 2.0 rabble rate.  At this temperature, the available CaO increased
by 5 percent as compared to a temperature of 1800 F.  At a lower temperature,  1600 F,  the product showed a  tendency
to agglomerate into particles of 1/4 to 3/4 inches in diameter with centers of unburned organic sludge in many of
them.  The recalcined lime is conveyed out of the furnace by gravity through a crusher to a thermal disc cooler
where the lime temperature is lowered from 700 F to 100 to 150 F.  From there  it is conveyed to a rotary air lock
and then to the storage bin.  The product is in the form of lime dust.  A portion of the stack gas is recycled to
the recarbonation system to adjust the pH to about 7.  The rest is scrubbed in a multiple tray scrubber before
exhausting to the atmosphere.  Although the cost of recalcined lime is slightly higher than new lime, the magnitude
of sludge disposal reduced from 34 tons/d of liquid sludge to 1.5 tons/d of dry solids, thereby effecting a sub-
stantial cost saving.

A fluidized bed furnace may also be used.  The filter cake is fed to a mixer along with dry recycled fines  and
quench water.  From there it goes to a cage mill disintegrator where the pre-cooled calciner stack gas at 1000 F
dries and disintegrates the moist solids.  The resultant fine carbonate is conveyed by the exhaust gas to a
cyclone separator.  From the cyclone separator, a portion is recycled to the mixer and the other portion is fed to
the calciner bin from where it enters the furnace.  The furnace contains two compartments.  The upper fluid bed is
used for low temperature calcination (1500 to 1600 F) and the lower third bed  to cool the product.  The product is
in the form of pelletized particles of 6 to 20 mesh size which is the primary  advantage over the dusty product of
open hearth furnace.

Commod Modifications - When large quantities of inert materials are involved,  a dry classification device may be
used after the recalcination furnace in addition to the wet centrifugal devices mentioned above.

Technology Status - At least six United States plants have utilized recalcination of lime sludge  from treatment of
wastewater.

Applications - Minimize makeup lime requirements and the amount of sludge for disposal.
Limitations - Economic feasibility of the process at a given site is dependent upon such factors as the quantity
of lime used, sludge disposal costs and fuel costs and indirectly the expertise of the personnel available for
satisfactory operation.

Typical Equipment/No, of Mfrs.  (10, 23) - Calcination Reactor/12; Stack Gas scrubbers/3; Sludge cake conveyors/7;
Sludge pumps/7; Air fans/42.

Performance - The recalcination of lime sludge reduces by a factor of 20 the amount of water and sludge for
disposal.  Seventy-two percent of the plant lime requirements can be obtained from the recovery process; 3.7
percent by weight of the usable calcium entering the furnace is lost as fly ash and captured in the wet scrubber.

Residuals Generated - Inerts from the centrifugal classifier in the form of magnesium hydroxide and hydroxyapatite
and a portion of the lime.  Wet scrubber sludge containing recalcined lime and particulates from combustion.

Design Criteria  - Hearth loading rate = 5 Ib/ft /h of wet solids (approximately).   Dry solids concentra-
tion = 20 to 40 percent.  Excess air = 75 to 100 percent.  Shaft cooling air flow = 1/3 to 1/2 of combustion air
flow.

Environmental Impact - Particulate collection efficiencies of 96 to 97 percent are required to meet current EPA
standards.  Available data indicate that other air and water pollutant emissions are acceptable, however addi-
tional testing  is required to confirm this.

References - 3, 8, 10, 23, 43, 77, 208
                                                    A-126
-------
	 , 	 	 	
LIME RECALCINATION FACT SHEET 4.2.1
FLOW DIAGRAM -
ENERGY NOTES - E
Electrical enerc
Mgal/d
1
10
100
Fuel requirement
To determine en
COSTS* - Assumpt
Primary or
Tertiary
Sludge
•" 1

hickener
*
Supernatant
ased on Design Assumptions below.
y -
kWh/yr
150 x 10
650 X 10
4,500 x 10
-s 1.78 x 1010 Btu/Mgal/d/yr
ergy requirements for centrifuge o
.ions: Service Life = 30 years; E!

Classification
I High
inert to CaC°3 Cake
Landfill
peration see Fact Sheet 6.3.
« Index = 2475
1
Gc
Fur

IS
V
nace
1 .
Scrubber
Drain
Lime to
Storage Bin
Design Basis:
1. Quantity of lime sludge: 4,500 lb/Mgal; 30 percent solids (from two-stage tertiary lime treatment).
2. Operations:
Furnace Hearth
Flow Wet Solids Days/Week Hours/Day Loading Area
Mgal/d Ib/h; 24 h/d Operating Operating Ib/h ft
0.1 62.5 1 20 525 112
1.0 625 6 16 1,095 256
10.0 6,250 7 20 7,500 2 at 760
100.0 62,500 7 20 75,000 3 at 5,070
3. Fuel requirements (No. 2 fuel oil): 129,000 gal/yr/Mgal/d - 1.78 x 10 Btu/Mgal/d/yr
4. Construction costs include recalcination furnace, sludge conveyors, storage, hoppers, building.
Fuel cost = S2. 66/10 Btu. Power cost = $0.02/kWh.
CONSTRUCTION COST OPERATION & MAINTENANCE COST
mn 	 	 10 1 0





o — i
O 	

o
2 10-




0 1
REFERENCE - 3







s'
^'









_ . . . — y* 	
,.•











- - - • c 	
O
5 if
(0 to "^

1 1 1 1|| < r | | r [>"[

"***!
n m / I I







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n;^==i

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Labor
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/?--


, ' PO>




	 , .
.'it
' '/
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wer «




10 10 100 01 10 10 100
Wastewater Flow Mgal d Wastewater Flow, Mgal/d
*To convert construction cost to capital cost see Table A-2.
A-127
-------
TWO-STAGE TERTIARY  LIME  TREATMENT, WITHOUT  RECALCINATION                  FACT  SHEET  4.2,2
Description - Lime treatment of secondary effluent for the removal of phosphorus  and suspended solids  is  essen-
tially the same process as high-lime clarification of raw wastewater.   Calcium carbonate  and magnesium hydroxide
precipitate at high pH along with phosphorus hydroxyapatite and other suspended solids.   In  the two stage system,
the first stage precipitation generally is controlled around a pH of 11,  which is approximately one pH unit  higher
than that used in the single stage process.  After precipitation and clarification in the first stage, the waste-
water is recarbonated with carbon dioxide, forming a calcium carbonate precipitate which  is  removed in the second
clarification stage.

Lime is generally added to a separate rapid-mixing tank or to the mixing  zone of  a solids contact or sludge
blanket clarifier.  After mixing, the wastewater is flocculated to allow  for the  particles to increase in size  to
aid in clarification.  The clarified wastewater is recarbonated in a separate tank following the first clarifier,
after which it is re-clarified in a second clarifier.  Final pH adjustment may be required to meet allowable
discharge limits.

Common Modifications - Treatment systems can consist of separate units for flash  mixing,  flocculation, and clari-
fication; or they can consist of specially designed solids contact or sludge blanket units which contain  flash
mix, flocculation, and clarification zones in one unit.  The calcium carbonate sludge formed in the second stage
can be recalcined (see Fact Sheet No. 4.2.1).  Final effluent can be neutralized  with sulfuric acid, as well as
other acids.

Technology Status  - The use of these systems for water softening have been used  for many decades, however their
use for phosphorus removal has been prominent only since the mid-1960'a.   There are presently many large  scale
systems in operation.

Typical Equipment/No, of Mfrs. (23) - Clarifier equipment/38; chemical feeders/6; flocculators/32,- mixers/26;
ins trumentation/9.

Applications - Used for the removal of phosphorus from wastewaters.  Will also remove some BOD5 and suspended
solids as well as hardness present in the wastewater.  Will also remove metals.

Limitations - Will generate relatively large amounts of chemical sludge.   High operator skill required.  In  some
cases polymer or coagulant is required to assist second-stage clarification.

Performance -
                                                    Influent                                Effluent
Phosphorus as P                      Generally 15 to 40 mg/1, but not limiting in           0.01 to 1 mg/1
                                     regard to effluent quality

Chemicals Required - Lime (CaO), C02 or H2S04, sometimes polymer or coagulant

Residuals Generated - First stage -  Sludge containing hydroxyapatite, calcium carbonate, magnesium hydroxide,  and
organic solids -  1 to 1.5 pounds of dry solids per pound of lime added.  Second stage - sludge may contain calcium
carbonate, aluminum or ferric hydroxide, depending upon the coagulant used.  The  quantities  generated are: 2.27
pounds CaCo  per pound of CO  ; 4 pounds per pound of Al in alum or 2.5 pounds per pound of Fe in ferric chloride.

Design Criteria - Clarifier settling rate - 1,000 to 1,400 gal/d/ft

Secondary Effluent                                Approximate Lime
    Alkalinity           Clarifier pH                 Dose
 (mg/1 as CaCO )                                     (mg/1 of CaO)
    300                       11.0                   400-450
    400                       11.0                   450-500

Carbon Dioxide -  Feed tank -  5 to  15 minutes
                  Feed rate -  1.2 mg/l/mg/1 of Ca to be precipitated

Unit Process Reliability - These systems are reliable from both a unit and process standpoint with skilled oper-
ator attention.

Environmental Impact - Will generate relatively large amounts of sludge which will need to be handled in some
manner.  Will have  little or  no effect on  air pollution, noise levels, or odor.  In comparison to secondary
systems, little  land use is required.

References - 29,  95
                                                     A-128
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 TWO-STAGE  TERTIARY LIME TREATMENT,  WITHOUT RECALCINATION
                       FACT SHEET 4.2.2
FLOW DIAGRAM -
  Wastewater
   Feed
                                            Treated


Rapid Mix


Slaker


Flocculator



Settler
Sludge



Recarbonator
t
Carbon
Dioxide


Settler

1
Sludge
Water •

                Lime
 ENERGY NOTES -
See design basis under COSTS.
 COSTS -  Assumptions:   ENR -  2475
 1.   Typical  secondary  effluent as  feed  to  two-
     stage  lime  treatment.
 2.   Lime dosage rate = 400 mg/1 or 3,340 Ib/Mgal
     as CaO.
 3.   Clarifier overflow rate  = 1,000 gal/d/ft  .
 4.   Construction cost  includes: lime storage  and
     feed facilities, rapid-mix facilities, floc-
     culator/clarifiers,  flow and pH controls,
     and  recarbonation  facilities.
 5.   Costs  do not include recalcination  facilities.
 6.   Electric power  = $.02/kWh
 7-   Lime costs  - $25/ton,  quick lime
        100
                      CONSTRUCTION COST
         10
    o
    Q
         1 0
         01
          01
REFERENCE  - 3,
                       1 0            10
                      Wastewater Flow, Mgal/d
                                                 100
                                                                Sludge  to  Recalcinator
                                                                     or Disposal
                                                                     10
                                                                 X
                                                                 •a
n
s
w
t-i
ID
O
•H
H
4J
O
                                                                    10"
        10
        10'
          0.1          1.0          10           100

                    Wastewater Flow,  Mgal/d
                                                                 10
                                                                         OPERATION & MAINTENANCE COST
of
o E
                                                                 10
                                                             ȣ 01
                                                                001
                                                                     Total
                                                                                          Material
                                                                                                 lemicals
                                                                                                    .abor
                                                                                                             01
                                                                                                             001
                                                                                                            0001
      01
                   1 0           10
                  Wastewater Flow, Mgal/d
                                                                                                          100
                                                                                                            00001
*To convert construction cost to capital cost see Table A-2.
                                                        A-129
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INDEPENDENT PHYSICAL/CHEMICAL  TREATMENT
                                                                                   FACT SHEET  4.3.
Description - Independent Physical-Chemical Treatment (IPC)  utilizes methods other than  biological treatment to
obtain secondary, or better, removals of BOD ,  COD and TSS.   Typically,  these systems  use  combinations  of clari-
fication with chemical addition, filtration, and activated carbon.   This Fact Sheet includes  nitrate  addition to
the activated carbon system to prevent H S formation by biological action in the carbon contactor.

Common Modifications - The following are some typical flow trains that can be used:   Clarification,  filtration,
activated carbon (downflow);  clarification, activated carbon (upflow),  filtration.   Additional  treatment steps  can
be added to obtain better than secondary treatment levels,  such as ammonia removal  and part of  phosphate clari-
fication.
Technology Status - A number of full scale systems have been started up.
operation.  It has not been used on a wide scale.
                                                                          Several mechanical problems have plagued
Typical Equipment -
Clarification, filtration, preliminary treatment - See Fact Sheets 3.1.1 through 3.1.5.
Chemical addition - See Fact Sheets in Section 5.
Thickening and dewatering - See Fact Sheets 6.3.1 through 6.3.9.
Activated Carbon - See Fact Sheets 4.4.1,  and 4.4.2.
Chlorination - See Fact Sheet 4.5.1.
Transportation and disposal - See Fact Sheets 6.1.1 through 6.1.11.

Applications - IPC can be used in some applications where standard biological treatment  applies,  namely typical
municipal wastewater.  IPC is a very flexible process and can be  tailored to specific pollutant problems,  such as
high background levels of metals or refractory organic materials.   Phosphorus and some toxic chemicals  will  also
be removed.  (See Fact Sheet 4.4.1.)

Limitations - The large quantities of sludge produced by the process may result in disposal problems.

Performance (50)  - Application of screened degritted wastewater can result in the following estimated process
effluent quality:
     Unit Process
     Combinations
     C,S
     C,S,F
     C,S,F,AC
     C,S,NS,F,AC
                                                   TURB
                                                   (JTU)
                                                   5-20
                                                   1-2
                                                   1-2
                                                   1-2
 P°4
(mg/1)
 1-4
 0.5-2
 0.5-2
 0.5-2
  SS
(mg/1)
10-30
2-10
2-10
2-10
Color
(Units)
30-60
30-60
5-20
5-20
NH -N
(mg/1)
20-30
20-30
20-30
1-10
C,S = coagulation and sedimentation; F = mixed-media filtration;
AC = activated carbon adsorption; NS = ammonia stripping.
Lower effluent NH  value at 18 C; upper value at 13 C.
Chemicals Required - NaNO  for H S control.
the first stage clarification process.  These include alum (AL (SO )   14H O) ,  ferric chloride (Fed ) ,  polymers,
                                                             its.
                                             In addition,  chemicals  are  used  to  aid  in  suspended solids  removal in
                                            :  include  alum (A1-.
and lime (CaO).   In small plants carbon dominates chemical cosl
Residuals Generated  - Sludge will be generated in the preliminary clarification step.   This sludge is quite
voluminous  (see Fact Sheet 5.1.5 for lime and 4.2.2 for alum and ferric chloride).   Filter backwash water (see
Fact Sheets 3.1.7 and 3.1.8)  and spent activated carbon and carbon backwash water (see  Fact Sheet 4.4.1)  will also
be generated.  Carbon from regeneration will be recycled within the plant and the ash fines must be disposed of in
an acceptable manner.

Design Criteria  - See associated Fact Sheets for individual pieces of equipment.  (Refer to listing of processes
under "Typical Equipment" as shown above.)

Unit Process Reliability - Because this process is a combination of many processes,  the reliability is a function
of the individual unit process reliabilities.  See Individual Fact Sheets as indicated  above.
Toxics Management - Removes many, but not all, non-degradable organic compounds.
high molecular weight, slightly soluble compounds.
                                                                                  Most effective for non-polar,
EPA has developed activated carbon adsorption isotherms for 60 toxic organic materials (86).   The isotherms
demonstrate removal of 51 of these organic compounds by activated carbon technology.   Another study (87)  demon-
strated that PCB levels can be reduced from 50 micrograms per liter to less than 1 microgram per liter,  and other
work showed that aldrin, dieldrin, endrin, DDE, DDT, ODD, toxaphene, and Aroclors 1242 and 1254 can be renoved to
values less than 1 microgram per liter (88).   Toxicity measured by bioassays was also significantly reduced.

Environmental Impact- See Fact Sheets for individual processes.  In general, however, this process requires much
less land area than conventional biological secondary treatment systems.  Phosphorus  removal is inherent in this
system.

References - 50, 86, 87, 88, 95
                                                  A-130
-------
INDEPENDENT PHYSICAL/CHEMICAL  TREATMENT
                                                          FACT SHEET 1.3,1
LOW DIAGRAM -
                               Sludge Thickening
                                 S Dewatering
                                                          Backwash
                               Sludge to Disposal

i:\ERGY NOTES - Energy (kWh/yr)  = 7,500,000 (Mgal/d) .
COSTS -*(ENR Index = 2475) Assumptions:
1.   Processes include lift pumps, preliminary treatment,  two-stage  lime/  gravity  filtration,  interstage pumping,
     carbon adsorption, chlorination,  gravity thickener,  vacuum filters, miscellaneous  structures, support per-
     sonnel .
2    Lime dosage at 400 mg/1 as CaO.
3.   Carbon adsorption without regeneration at plant sizes less than 3  Mgal/d;  carbon adsorption with regeneration
     at plant size greater than 3 Mgal/d.
           100,-
                        CONSTRUCTION COST
            10
           10
           0 1
                                                              100
                                                                       OPERATION & MAINTENANCE COST
                                                           0   10
                                                           15  1 0
             0 1
 1 0           10
Wastewater Flow, Mgal/d
                                                    100
                                                               0 1
                                                                    **
                                                                                          emicals
                                                                                            Total:
                                                                                            s^r
                                                                                                Labo
                                                                                 10


                                                                                    «
                                                                                    I

                                                                                 1 0  g
                                                                                 01 E
                                                                                    3
 1 o           10
Wastewater Flow, Mgal/d
                                                                                                        100
                                                                                                          001
REFERENCE - 3
*To convert constr
                  uction cost to capital cost see Table A-2.
                                                    A-131
-------
TERTIARY  GRANULAR ACTIVATED CARBON  ADSORPTION                         FACT SHEET  H.U.l
Description  - Granular activated carbon is used in wastewater treatment to adsorb soluble organic materials.
Granular carbon systems generally consist of vessels in which the carbon is placed,  forming a "filter" bed.
These systems can also include carbon storage vessels and thermal regeneration facilities.   Vessels are usually
circular for pressure systems or rectangular for gravity flow systems.   Once the carbon adsorptive capacity  has
been fully utilized, it must be disposed of or regenerated.  Usually multiple carbon vessels are used to allow
continuous operation.  Columns can be operated in series or parallel modes.  All vessels must be equipped with
carbon removal and loading mechanisms to allow for the removal of spent carbon and the addition of new material.
Flow can be either upward or downward through the carbon bed.  Vessels  are backwashed periodically.  Surface wash
and air scour systems can also be used as part of the backwash cycle.
Small systems usually dispose of spent carbon or regenerate it offsite.  Systems above about 3 to 5 Mgal/d us
provide on-site regeneration of carbon for economic reasons.  (See Fact Sheet No.4.4.2)
                                                                                                           isually


Technology Status - Has been used for municipal wastewater  treatment on a  limited basis since the mid-1960's.
 Applications - Used directly following secondary clarifier, primarily when nitrification obtained in secondary
 treatment.  Often preceded by chemical clarification of secondary effluent.  In either case,  a high quality
 influent  is sought.

 Limitations - Wastewater should be filtered prior to treatment to remove suspended solids.   Requires more sophis-
 ticated  operation  than  standard secondary treatment systems.  Under certain conditions, granular carbon beds
 provide  favorable  conditions for the production of hydrogen sulfide, creating odors, and corrosion problems.
 More mechanical operations - difficult corrosion control - materials handling.  Most applicable to low strength
 or  toxic wastewaters.

 Typical  Equipment/No, of Mfrs.  (23) - Activated carbon material/5  (90),  granular carbon systems/15
 Performance
                         Influent  (mg/1)                      Effluent (mg/1)
 BOD                     10 to 50                             5 to 20
 COD                     20 to 100                            10 to 50
 TSS                     5 to 10                              2 to 10

 Side  Streams:
 Spent Carbon  -  3  to  10  Ib/lb of COD removed for Tertiary treatment
 Backwash Water  -  1 to 5 percent of wastewater throughput, TSS 100 to 250 mg/1

 Design Criteria -
                         Size - Vessels  2 to 12 ft diameter commonly used
                         Area Loading -  2 to 10 gal/min/ft
                         Organic Loading - 0.1 to 0.3 Ib BOD  or COD/lb carbon
                         Backwash - 12 to 20 gal/min/ft
                         Air Scour - 3 to 5 ft /min/ft
                         Bed Depth - 5 to 30 ft
                         Contact Time -  10 to 50 min.
                         Land Area - minimal

 Reliability - Moderately reliable both mechanically and operationally depending on design construction and man-
 ufactured equipment  quality.

 Toxics  Management -  Removes many, but not all, non-degradable organic compounds.  Most effective for non-polar.
 high molecular  weight,  slightly  soluble compounds.

 EPA has developed  activated  carbon  adsorption isotherms for 60 toxic organic materials (86).  The isotherms
 demonstrate  removal  of  51  of these  organic compounds by activated carbon technology.  Another study (87) demon-
 strated that PCB levels can  be reduced from  50 micrograms per liter to less than 1 microgram per liter, and other
 work showed  that aldrin, dieldrin,  endrin, DDE, DDT, ODD, Toxaphene, and Aroclors 1242 and 1254 can be removed to
 values  less  than 1 microgram per liter(88).  Toxicity measured by bioassays was also significantly reduced.

 Environmental Impact -  Very  little  use of land.  There is air pollution generated as a result of regeneration.
 Under certain conditions,  granular  activated carbon beds may generate hydrogen sulfide which has an unpleasant
 odor.   NaNO   or chlorine may be  applied to the influent to inhibit or control these conditions.  Spent carbon may
 be a land disposal problem,  unless  regenerated.

 Improved Joint  Treatment Potential  - Will remove pollutants discharged by industrial sources that are generally
 not treated by normal secondary  systems  such as refractory organic materials and some metals.

 References  - 4, 23,  50,  84,  85,  86,  87,  88, 89, 90
                                                    A-132
-------
TERTIARY GRANULAR ACTIVATED CARBON
FLOW DIAGRAM
-



ADSORPTION FACT SHEET 4. 4. 1
Spent Backwash
to Headworks
Secondary
Effluent
Activated
Carbon
*
	 *


Back-
wash
Tank
O
Backwash Pump
ENERGY NOTES - The energy consumption curve
the energy require
Sheet 4.4.2 for re
Carbon: 8 to 30 me
Downflow Pressure
ft ; terminal head
15 min; backwash f
Downflow Gravity -
d
ge
sh
I2
lo
for
nera
siz
Head
ss =
Dumping onl
tion energy
a .
Loss = 37 f
rkwash rate
20 ft; bac
requency =
Hydraulic
ft"; terminal headless =
18 gal/min/ft ; backwash
frequency = 1/d; backwasl
pump and motor efficiency
COSTS* - Assumptions: El
6 f
tim
i pu
t -
TO I
]
]
t,
e
mi
7C
nc
./d.
oad
back
= 15
head
perc
lex =
y. See
requir
t; hydr
- 18 c
kwash t
3.5 gal
wash ra
min; ba
loss -
ent.
2475
E
en
at
al
in
/n
te
ck
23
gi
ac
len
li
/m
ie
in
—
wa
f
ves
t
t.
c
in/
/
sh
t;


Effluent
io6
Electrical Energy Required, kWh/yr
£ H t-
o5
o4
33
C












/



.1









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7
/
/ j
^/
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Downflow Pressurized Contac
Downflow Grav






-rttrt— t-
ity Cont


II



	
actor '



1.0 10
Flow, Mgal/d

' ' r
i {
1








tor





100-
1. Construction cost includes vessels, media, pumps, carbon storage tanks, controls, and operations building ;
loading rate = 30 Ib carbon per Mgal; contact time = 30 min; disposal costs not included.
2. 0/M cost includes pumping ($.02/kWh), labor ($7.50/h, including fringes) and maintenance.
3. No regeneration is included.
CONSTRUCTION COST OPERATION & MAINTENANCE COST
	 1 	 pa.- 	 ! 	 r-rt 	 -— 	 -r-r-- — h — t— — — r--r- r" — ' 	 ^ 	 L
10
o
D
"o
VI
C
0
2 1 0
0 1
(
REFERENCES -














*













x
X













'











	

x












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'













S













— 7 "












s
, *
-J-J4- —












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S













— 7











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nj
o
7 c
o
—

o

::::: <



0 01











^
/



























x




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	 :












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f|4-|










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./r

















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x 1





	 \ .1 ...LJ If
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3.1 1.0 10 100 o.l 1.0 10 100
Wastewater Flow, Mgal/d Wastewater Flow, Mgal/d
3, 84
*To convert construction cost to capital cost see Table A-2.
A-133
-------
ACTIVATED CARBON  THERMAL REGENERATION                                         FACT SHEET H.H.2
Description - To make granular activated carbon economically feasible for wastewater treatment in most applications.
the exhausted carbon must be regenerated and reused.  When the plant effluent quality reaches the minimum effluent
quality standards or when a predetermined carbon dosage is achieved, spent carbon is removed from the columns to be
regenerated.  The most common method of thermal regeneration of carbon is with the use of multiple hearth furnaces.
Rotary kiln furnaces are also in use.  In either case, a typical sequence for thermal regeneration of carbon is as
follows:

The granular carbon is hydraulically transported (pumped) in a water slurry to the regeneration station for de-
watering.
After dewatering, the carbon is fed to a furnace which requires an external source of steam and is heated to 1500
to 1700 F in a controlled atmosphere which volatilizes and oxidizes the adsorbed impurities.
The hot regenerated carbon is quenched in water.
The cooled regenerated carbon is washed to remove carbon fines and hydraulically transported to the adsorption
equipment or to storage.
The furnace off-gases are scrubbed, (the scrubber water is returned to the plant for processing)  and may also pass
through an afterburner.

The thermal regeneration grocess itself involves four steps.  The first step is drying, which occurs by evaporation
at temperatures up to 300 F.  The second step involves volatilization of light organic materials.  This occurs at
300 to 600 F.  Those organic compounds which are not removed by volatilization are thermally decomposed at tem-
peratures of 600 to 1200 F.  The last step involves reactivation, which is the removal of char from the pores of
the carbon.  The total regeneration process requires approximately 30 minutes.  Regeneration systems usually
require spent carbon holding tanks, regenerated carbon holding tanks, dewatering screws, quench tanks,  steam
generators, and air pollution control equipment.

Common Modifications - Multiple hearth furnaces, rotary kiln furnaces.
Technology Status - Thermal regeneration of carbon is a well-established and demonstrated technology.
Typical Equipment/No, of Mfrs. (23, 100) - Carbon regeneration furnaces/3;  conveyors/4;  air scrubbers/over 50.
Applications - Can be used whenever disposal of carbon is uneconomical or environmentally impractical,  generally at
large facilities.

Limitations - Is usually not practical for small activated carbon systems.   Should generally be operated on a
24 h/d basis, which requires around-the-clock operator attention.

Performance - The quality of the carbon exiting the regeneration system will not equal that of virgin carbon.
However, the actual amount of degradation is greatly dependent upon the carbon used and the organic materials
removed.  In general, there will be a reduction in iodine number,  molasses index,  with an associated increase in
ash content.  In addition, there will be a loss in carbon due to oxidation and crushing.   This generally totals 2
to 10 percent of the carbon being regenerated,  with 5 percent being the general average value.

Chemicals Required - Acid may be used to strip metals from regenerated carbon, in  special cases.
Residuals Generated - Some amount of ash and carbon fines will be generated,  which will greatly depend upon the
quality of carbon and the type of wastewater treated.   Exhaust air from the furnace will require scrubber treat-
ment, resulting in the recycling of solids to the plant and eventual inclusion in sludges.

Design Criteria - The theoretically required furnace capacity can be determined by multiplying the carbon dosage
(in Ib carbon/Mgal) by the daily flow rate in Mgal/d.   This will determine the Ib carbon/d that must be regen-
erated.  An allowance of 40 percent downtime should then be included.   Multiple hearth furnaces used for regen-
erating carbon generally include a hearth area of about 1 ft /40 Ib carbon/d to be regenerated.   A storage tank
should be sized to hold all of the carbon contained in the largest carbon adsorber.   This  tank would be used to
hold the carbon prior to regeneration.  A tank of equal size is needed to hold the regenerated carbon prior to its
use in a previously emptied adsorber.  A steam generator (0.4 to 1.0 Ib steam/lb carbon) is also required in con-
junction with the furnace.  All ancillary equipment, such as conveyors and quenchers,  should be designed for the
maximum throughput of the furnace.

Unit Process Reliability - Carbon regeneration systems are reliable from a process standpoint.  However, they are
subject to more mechanical failures than other wastewater treatment processes.   Therefore,  high maintenance costs,
relative to the unit's construction cost, can be expected.

Environmental Impact - Very little use of land is required.   Air emissions from the furnace will be polluted with
volatiles stripped from the carbon and with carbon monoxide formed from incomplete combustion.   Therefore,  after-
burners and scrubbers are usually required to treat the exhaust gases.   The induced draft fan of a MHF could
produce a noise problem, if not controlled.  It should be noted that carbon regeneration will eliminate a solids
handling problem caused by the spent carbon (See Fact Sheet 4.4.1).

References 50, 115
                                                    A-134
-------
 ACTIVATED CARBON THERMAL REGENERATION
                                                                      FACT  SHEET 4,1,2
FLOW DIAGRAM
              Make-up Carbon
                      r-tX-
                                                                                      Spent  Carbon
                            XX
                          A    A
T\TX
       \  Regener
         ^ I art A C f-/>
                                    Water Back
                                        ^		
                                    to Process
                                     [R
                                   ^la
                                 rated Carbon Defining
J

,



Lning







1






Spent Carbon Drain i
Storage Tanks


^

I
I
ind
JI



\

' Cart






o






n
IAir
Poll

Fuel S
<
Steam

Reaener
                                     and Storage  Tanks
                                                                                              Furnace
           Carbon Fines
ENERGY NOTES  (116) -
Electricity = 0.004-0.046 kWh/lb of carbon
regenerated.   Rate decreases with increasing
scale.
Fuel = 4300-6800 Btu/lb.  Rate  decreases with
increasing scale.
Steam = 0.6 Ib/lb
                                     Regenerated  Carbon

                                       120,000
                                     •g  30,000 —^^~
                                                   1,000 -
                                                                                                         9 r-l
                                                             10    2U     30    40    50     60    70
                                                            Thousand Ib/d of Carbon Regenerated
COSTS*  (116) - Assumptions:  1977 dollars;  ENR Index = 2577
1.   Carbon  loss 5 percent per regeneration.
2.   Equipment includes dewatering feed screw,  quench tank, afterburner, scrubber,  furnace and controls,  two
     storage tanks and steam generator.
3.   Operating costs are based on maintenance costs of 15 percent  of constructed costs/yr.  Carbon
     make-up - $.50/lb.
                     CONSTRUCTION COSTS
                                                                        OPERATION  & MAINTENANCE COSTS
      1000
       600
       200
                                  ^_
                                                            1000
                                                             800
                                                             600
                                                             400
0    10     20    30   40    50    60    70
    Thousand Ib/d of Carbon Regenerated
REFERENCES  - 50, 116

*To convert construction cost  to capital cost see Table A-2.



                                                A-135
                                                                      10    20    30    40    50     60    70
                                                                     Thousand Ib/d of Carbon Regenerated
-------
OZONE OXIDATION  (AIR AND OXYGEN)                                          FACT SHEET
Description - Ozone (0 )  is a very strong oxidant.  At dosages of 10 to 300 mg/1,  ozone may be used to remove
residual dissolved organics in secondary effluent.  Ozone has also been experimentally used to treat raw wastewatej
and wastewater after various stages of treatment.  The rate of oxidation is both temperature and pH dependent.
Reaction rates increase with increasing temperature.  Because there is a wide range of ozone reactivity with the
diverse organic content of wastewater, both the required ozone dose and reaction time are dependent on the quality
of the influent to the ozonation process.  Generally, higher doses and longer contact times are required for ozone
oxidation reactions than are required for wastewater disinfection using ozone.   Ozone tertiary treatment may
eliminate the need for a final disinfection step.  Ozone breaks down to elemental  oxygen in a relatively short
period of time (half life about 20 minutes).  Consequently, it must be generated on site using either air or oxygei
as the feed gas.  Ozone generation utilizes a silent electric arc or corona through which air or oxygen passes,  and
yields an ozone in air/oxygen mixture, the percentage of ozone being a function of voltage, frequency, gas flow
rate and moisture.  Automatic devices are commonly applied to control and adjust the ozone generation rate.

Common Modifications - Systems have been designed which utilize staged contactors  (injection type)  with recycle of
the ozone/oxygen off-gas.  On these systems, provision must be made for the removal of nitrogen gas from the
influent wastewater stream and for the removal of reaction-produced carbon dioxide from the off-gas stream in thos<
situations that warrant it.

Technology Status - It is a developing technology.  Recent developments and cost reduction in ozone generation and
ozone dissolution technology make the process more competitive.  A full scale application is currently in the
start-up stage.

Applications - The process is feasible as a tertiary treatment for oxidation of residual dissolved organics,
cyanides, organic N compounds and other toxics susceptible to the highly active oxidation characteristics of
ozone.  If oxygen-activated sludge is employed in the system, ozone treatment may  be economically attractive, sinc<
a source of pure oxygen is available facilitating ozone production.

Limitations - For poor quality wastewater with high COD, BOD  and/or TOC contents  (greater than 300 mg/1) , ozone
treatment may be uneconomical due to high ozone consumption.  COD removal is generally limited to around 70 per-
cent.  May not be effective in oxidizing some halogenated hydrocarbons.

Typical Equipment/No,  of Mfrs.(77, 130)  - Oxygen generator/5; Columns-towers/60; Ozone auxiliary equipment/8; Ozom
generator/10.

Performance - The following table shows the reduction of overall COD, BOD , and TOC, achieved in laboratory tests
after a 90 minute contact time with ozone (128).

                                              COD, mg/1               BOD , mg/1                 TOC, mg/1
     Ozone Dosage, mg/1                  Influent   Effluent      Influent   Effluent       Influent   Effluent
            50                             318        262           142        110             93         80
           100                             318        245           142        100             93         77
           200                             318        200           142         95             93         80
           325                             318        159           142         60             93         50
            50                              45         27            13          7             20.5       15.5
           100                              45         11            13          3             20.5        9
           200                              45          5.5          13          1.5           20.5        5

Beyond the 70 percent COD removal level, the oxidation rate is significantly slowed.  In laboratory tests, COD
removal never reaches 100 percent even at a high ozone dose of 300 mg/1.

Chemicals Required - Air or pure oxygen may be used as the feed gas to the ozone generator.

Design Criteria -
     Contact time:    1 to 90 min            Ozone production    4.5 kWh/lb from oxygen, 7.5 kWh/lb from air
     Dosage rate:     10 to 300 mg/1         pH range:           5 to 11 (6 to 8 optimum)

Reliability - Mechanical reliability is good.

Environmental Impact - Ozone in off gases which are not destroyed is an air pollutant in the lower atmosphere whicl
can discolor or kill vegetation coming in contact with it.  Inhalation toxicology  of ozone is both exposure dura-
tion and concentration dependent.

Toxics Management - Ozone has been found to be a good oxidant for removal of cyanide, phenol and other dissolved
toxic organic materials.

References - 77,  95, 128, 130,  132, 172
                                                    A-136
-------
 OZONE  OXIDATION  (AIR  AND  OXYGEN)
                FACT SHEET
FLOW DIAGRAM -
                                             Air
                                                                               Purge
                                                                                  J,    Catalytic
                                                                                       Ozone
                                                                                       Decomp.
ENERGY NOTES - 1,927,200 kWh/yr/Mgal/d are the estimated energy requirements for a 75 mg/1 ozone dosage derived
from an oxygen feed.
COSTS* - Assumptions:   1971  prices; ENR Index = 1581
JT.  Construction  costs are based on an ozone dosage of 75 mg/1 derived from an oxygen feed.
2.  Construction  costs include deaerators, process pumps, injector and mixers, reactors and holding tanks, oxygen
compressors, dryers, ozone generators, sumps and draws, ozone decomposer.
3.  Total operation and maintenance costs include electricity, oxygen, maintenance and labor.
4.  Labor =  $5/hr plus 30 percent for overhead and supervision; electricity = $.02/kWh.
                        CONSTRUCTION COSTS
                                                                           OPERATION & MAINTENANCE COSTS
           100
           10
           01
                                                                   10
                                                               _  01
             o.i
                          1.0           10
                         Wastewater Flow, Mgal/d
                                                                 001
                                                                         Total
                                                                        -Electricity»
                                                                                                     rOxygen
                                                      100
0.1
             1.0           10
            Wastewater Flow, Mgal/d
                                        100
REFERENCES -  3, 95, 172
*To convert  construction cost to capital cost see Table  A-2.



                                                     A-137
-------
CHLORINATION  (DISINFECTION)
                                          FACT SHEET  H.5.1
Description - Chlorination is the most commonly used wastewater disinfection process.   This process  involves  the
addition of elemental chlorine or hypochlorite  to the wastewater.   When chlorine  is  used, it  combines with water
to form hypochlorous (HOC1)  and hydrochloric (HC1) acids.   Hydrolysis goes virtually  to completion at pH  values
and concentrations normally experienced in municipal wastewater applications.   Hypochlorous acid will ionize  to
hypochlorite (OC1) ion, with the amount greatly affected by pH.  However,  hypochlorous  acid is the primary disin-
fectant in water.  In wastewater, the primary disinfectant species  is monochloramine.    Therefore, the tendency of
hypochlorous acid to dissociate to hypochlorite ion should be discouraged by maintaining a pH  below  7.5.

The amount of chlorine added is determined by cylinder weight loss.   Chlorine demand  is determined by the dif-
ference between the chlorine added and the measured residual concentration after a certain period has passed  from
the time of addition.  This is usually 15-30 minutes.  The chlorine or hypochlorite is  rapidly mixed with the
wastewater, after which it passes through a detention tank, which normally contains baffled zones to prevent  short
circuiting of wastewater.

Common Modifications - Chlorine or hypochlorite salts can be used.   The two most common hypochlorite salts are
calcium and sodium hypochlorite.  Dechlorination may be used, which generally involves  the addition  of sulfur
dioxide (see Fact Sheet 4.5.2), aeration, or even activated carbon, when chlorine  residual standards are  strict.

Technology Status - Chlorination of water supplies on an emergency  basis has been  practiced since about  1850.
Presently, Chlorination of both water supplies and wastewaters is an extremely wide-spread practice.

Typical Equipment/No, of Mfrs.  (77)- Chlorine analyzers/25; pH controllers/25; Chemical feeders/27;  Mixers/26.
Applications - Chlorination for disinfection is used to prevent the spread of waterborne diseases and to control
algae growth and odors.
Limitations - May cause the formation of chlorinated hydrocarbons,  some of which are known to be carcinogenic
compounds.  The effectiveness of Chlorination is greatly dependent on pH and temperature of the wastewater.
Chlorine gas is a hazardous material, and requires sophisticated handling procedures.  Chlorine will react with
certain chemicals in the wastewater, leaving only the residual amounts of chlorine for disinfection.  Chlorine
will oxidize ammonia, hydrogen sulfide, as well as metals present in their reduced states.

Performance - It should be noted that disinfection is designed to kill harmful organisms, and generally does not
result in a sterile water  (free of all microorganisms).   The following tablg presents coliform remaining after 30
minutes of chlorine contact time assuming primary effluent contains 35 x 10  total coliform/100 ml prior to dis-
infection, and secondary effluent contains 1 x 10  total coliform/100 ml prior to disinfection.  The values given
are dependent upon good mixing in a highly turbulent regime followed by ideal plug flow conditions in the contact
chamber.  If these conditions do not exist, a definitive relation between C12 residual and coliform reduction
cannot be expected.  Predictability of results from Chlorination is also affected by wastewater characteristics
and treatment processes used.
                                                           Total Coliform MPN/100 ml
Chlorine Residual, mg/1
   0.5 - 1.5
   1.5 - 2.5
   2.5 - 3.5
   3.5 - 4.5
Primary Effluent
24,000 - 400,000
 6,000 -  24,000
 2,000 -   6,000
 1,000 -   2,000
Secondary Effluent
1,000 - 12,000
  200 -  1,000
   60 -    200
   30 -     60
In normal low dose disinfection treatment, the COD,
changed.
                                                    BOD , and TOC of the treated wastewater are not measurably
Chemicals Required - Chlorine, sodium hypochlorite, or calcium hypochlorite.

Design Criteria - Generally a contact period of 15-30 minutes at peak flow is required.  Detention tanks should be
designed to prevent short circuiting.  This usually involves the use of baffling.  Baffles can either be the over-
and-under or the end-around varieties.  Residuals of at least 0.5 mg/1 are generally required.  The following
table presents typical dosages for disinfection:
                                                                            Dosage range,
                              Effluent From                                   mg/1	
               Untreated wastewater(prechlorination)
               Primary sedimentation
               Chemical-precipitation plant
               Trickling-filter plant
               Activated-sludge plant
               Multimedia filter following activated-sludge plant

Unit Process Reliability - Extremely reliable.
                                      6-25
                                      5-20
                                      3-10
                                      3-10
                                      2-8
                                      1-5
Environmental Impact - Can cause the formation of chlorinated hydrocarbons.  Chlorine gas may be released to the
atmosphere.  Relatively small land requirements.

References - 3, 26, 7, 11, 77, 126, 127, 129, 140, 146.


                                                  A-138
-------
 CHLORINATION (DISINFECTION)
      FACT  SHEET 4.5.1
 LOW DIAGRAM -
                                                      Chlorinator
                                     Chlorine gas
                Solution water
                                                                 Chlorine
                               Eductor
                               Influent
                                                                                         Effluent
                                                                        Contact Tank
                                                Mixing  Tank
                                                 (Optional)
  L.K^Y i4L>'''r_S - energy requirements lor chlorination are derived principally froi.i water used for the vacuum eductors
and the evaporators when used.  For the example below,  total energy requirements are 10,000 kWh/yr/Mgal/d, 1,200
kWh/yr/Mgal/d and 200 kWh/yr/Mgal/d,  respectively, for a 1 Mgal/d, 10 Mgal/d and 100 Mgal/d facility.  Eductor
water requirements can vary widely from site to site.  Facilities using more than 1,000 Ib chlorine/d generally use
electrically heated evaporators for conversion of the liquid chlorine to gas.  The heat of vaporization of chlorine
is 111 Btu/lb @ 60°F.  Approximate energy required for the evaporator can be computed by the following equation:
kWh/yr = 11.8 X Ib chlorine/d. Mixing  is  not included.
COSTS - Assumptions:
    Service life: 15 years
    Equipment:  Including chlorine supply, chlorinator, and contact chamber
    Dosage = 10 mg/1; contact time = 30 minutes  for  average  flow
    Labor rate = ?7.50/h, including benefits
    Power cost = $.02/kWh; chlorine cost = $160/ton
    Index: ENR = 2475, September 1976.
                                                                 10
                                 -4-44.4444—4-1-a-4
                          CONSTRUCTION  COST±±rrt4-
                          10            10
                        Wastewater Flow, Mgal/d
                                                                                                                i
                                                               0001
                                                                  0
 10            10
Wastewater Flow, Mgal/d
 REFERENCE   -  3
 •To convert construction cost to capital cost see Table A-2.
                                                     A-139
-------
DECHLORINATION (SULFUR  DIOXIDE)                                               FACT  SHEET  4,5,2
Description  - Since about 1970, much attention has been focused on the toxic effects of chlorinated effluents.
Both free chlorine and chloramine residuals are toxic to fish and other aquatic organisms.   Dechlorination
involves the addition of sulfur dioxide to the wastewater, whereby the following reactions  occur:

          SO2 + HOC1 + H20 = SO4+  + Cl" + 3H+  (For free chlorine)

          SO  + NH Cl + 2H20 = S04+2 + Cl~  + 2H+ + NH4+  (For combined chlorine)

As can be seen, small amounts of sulfuric and hydrochloric acids are formed;  however, they  are generally neutral-
ized by the buffering capacity of the wastewater.  Dechlorination can also be used in conjunction  with super-
chlorination.  Since superchlorination involves the addition of excess chlorine, dechlorination is required to
eliminate this residual.  Sulfur dioxide is the most common chemical used.  It is fed as a  gas, using the same
equipment as chlorine systems.  Because the reaction of sulfur dioxide with free or combined chlorine is practi-
cally instantaneous, the design of contact systems are less critical than that of chlorine  contact systems.
Detention of less than 5 minutes is quite adequate, and in-line feed arrangements may also  be acceptable under
certain conditions.

Common Modifications - Metabisulfite, bisulfite, or sulfite salts can be used.  Automatic or manually fed systems
can also be used.  If chlorine is used at the site, sulfur dioxide is preferred, since identical equipment can be
used for the addition of both chemicals.  Alternative dechlorination systems  include activated carbon, HO, and
ponds (sunlight and aeration).

Technology Status  - The technology of dechlorination with sulfur dixoide is  established, but is not in widespread
use.  A few plants in California and at least one in New York are known to be practicing effluent dechlorination
with SO  on either a continuous or intermittent basis.

Typical Equipment/No, of Mfrs.  (23) - Chemical feeders/27; mixers/26; Automatic controls/over 50.

Applications - Can be used whenever a chlorine residual is undesirable.  This usually occurs when the receiving
water contains aquatic life sensitive to free chlorine. Is generally required when superchlorination is practiced
or stringent effluent chlorine residuals are dictated.

Limitations  - Will not destroy chlorinated hydrocarbons already formed in the wastewater.   It has been reported
that about 1 percent of the chlorine ends up in a variety of stable organic compounds when  municipal wastes are
chlorinated.

Performance  - Available chlorine residuals can be reduced to essentially zero by sulfur dioxide dechlorination.

Chemicals Required  - Sulfur dioxide  (SO.) and Sulfite salts are the most common chemicals  used.  Sodium meta-
bisulfite  (Na S 0 ) can also be used, but is much less common.  In fact, any reducing agent can be considered,
depending on cost and availability.

Residuals Generated  - None

Design Criteria  - Contact Time:  1-5 minutes: Sulfur Dixoide Feed Bate:  1.1 pounds per pound of residual chlo-
rine; Sodium Sulfite Feed Rate:  0.57 pound per pound of chlorine; Sodium Bisulfite Feed Rate:  0.68 pound per
pound of chlorine;  Sodium Thiosulfate Feed Rate:  1.43 pounds per pound of chlorine.

Unit Process Reliability  - Sulfur dioxide addition for dechlorination purposes is reasonably reliable from a
mechanical standpoint.  The greatest problems are experienced with analytical control which may lower the process
reliability.

Environmental Impact  - Requires very little use of land, and no residuals are generated.  It is used to eliminate
the environmental impact of chlorine residuals.  Overdosing can result in low pH and low DO effluents, however.

References - 7, 48
                                                     A-140
-------
DECHLORINATION  (SULFUR DIOXIDE)
                                                           FACT SHEET 4,5,2
FLOW DIAGRAM -
                                                               Sulfonator
 ENERGY NOTES - Energy requirements  for SO. dechlorination are  derived principally  from water used  for  the  vacuum
 eductors and the evaporators when used.   For the example below,  total energy requirements  are  10,000 kWh/yr/
 Mgal/d, 1,200 kWh/yr/Mgal/d and 200 kWh/yr/Mgal/d,  respectively,  for a  1  Mgal/d, 10  Mgal/d and 100 Mgal/d  facil-
 ity.   Eductor water requirements can vary widely from site to  site.  Facilities using  more than 1,000  Ib SO /d
 generally use electrically heated evaporators for conversion of  the liquid  S02 to  gas.   The heat of vaporization
 of SO  is 158 Btu/lb @ 60 F.  Approximate energy required for  the evaporator can be  computed by the following
 equation: kWh/yr = 16.8 X Ib SO /d. Mixing is not included
 COSTS* - Design Basis:  Assumptions:  ENR Index - 2475
 Y.Construction costs  include S02 feed facilities, reaction tank (1 minute detention time),  mixer, and storage
 facilities; building space not included.
 2. S02 costs are based on 20 Ib/Mgal (1.1 rag/1 of SO   required per mg/1 of chlorine residual).
 3. No control instrumentation included.
 SO  Costs -
 150 Ib cylinder     $450/t
 2,000 Ib. cylinder   215/t
 Tank Car             155/t
           1 0
                        CONSTRUCTION COST
                                                                      OPERATION & MAINTENANCE COST
           01
       Q
       o
          001
         0001
                                                              1 0
                                                          Q   0 1
                                                          Si
                                                             001
            0 1

  REFERENCE -  3
 1 0           10
Wastewater Flow, Mgal/d
                                                    100
                                                            0001
                                                                                           Total
                                                                                        Labor7
                                                                                              -Materials
                                                                                            "Power"
                                                                                                          0 1
                                                                                                          001 £
                                                                                                             o
                                                                                                         0001 *
 1 0            10
Wastewater Flow, Mgal/d
                                                                                                       100
                                                                                                         00001
 *To convert construction cost to capital cost see Table  A-2.
                                                    A-141
-------
OZONE DISINFECTION  (AIR  AND OXYGEN)                                           FACT SHEET  4.b.
Description and Common Modifications - Ozone (0 )  may be used for the  final  disinfection  step  in  a wastewater
treatment process.  As a disinfectant (dosages of 3 to 10 mg/1  are  common),  ozone  is  an  effective  agent  for
deactivating common forms of bacteria,  bacterial spores and vegetative  microorganisms found  in wastewater, as
well as eliminating harmful viruses.  Additionally, ozone acts  to chemically oxidize  materials found  in  the
wastewater and can reduce the BOD  and COD,  forming oxygenated  organic  intermediates  and end products.   Further,
ozone treatment reduces wastewater color and odor.

Ozone breaks down to elemental oxygen in a relatively short period  of time  (half life about  twenty minutes).
Consequently, it is generated on site using either air or oxygen as the raw  material.  The ozone generation
process utilizes a silent electric arc or corona through which  air  or oxygen passes yielding a certain percentage
of ozone.  Automatic devices are commonly applied to control voltage treatment, frequency, gas flow and  moisture,
all of which influence the ozone generation rate.  Ozone injection  into the  wastewater flow  may be accomplished
via mechanical mixing devices, countercurrent or co-current flow columns, porous diffusers or jet  injectors.
Ozone acts quickly and consequently requires a relatively short contact time.  Ozonation as  a tertiary treatment
process to reduce BOD  and COD is covered in Fact Sheet 4.4.3.

Technology Status - Fully demonstrated but not widely used in the united States because  of relatively high cost
of ozone.  Recent developments in ozone generation have lowered the cost and thus  make  it more  competitive with
other disinfection methods.

Applications - Applicable in cases where chlorine disinfection may produce  potentially  harmful  chlorinated organic
compounds. If oxygen-activated sludge is employed in the system,  ozone disinfection  is  economically  attractive,
since a source of pure oxygen is available facilitating ozone production.

Limitations - Ozone disinfection does not form a residual that will persist and can  be  easily measured  to  assure
adequate dosage.  Ozonation may not be economically competitive with chlorination under  non-restrictive  local
conditions.

Effluents containing high levels of suspended solids may require filtration to  make  ozone  disinfection more  cost-
effective.

Typical Equipment/No, of Mfrs. (77, 130)  - Oxygen Generator/5;  Columns-Towers/60;  Ozonation  auxiliary equipment/8;
Ozone Generator/10.

Performance - Easily oxidizable wastewater organic materials consume ozone  at a faster  rate  than disinfection;
therefore, effectiveness of disinfection is inversely correlated with effluent quality but directly proportional
to ozone dosage.  When sufficient ozone is introduced, ozone is a more complete disinfectant  than chlorine.

Results of disinfection by Ozonation have been reported by various sources as follows (11):

     Influent            Dose, mg/1          Contact Time, minutes    Effluent Residual
     Secondary effluent  5.5-6.0             Less than or equal to 1  Less than 2 fecal coliforms/100 ml
     Secondary effluent  10                             3             99% inactivation of fecal coliform
     Secondary effluent  1.75-3.5                       13.5          Less than 200 fecal coliform/100 ml
     Drinking water      4                              8             Sterilization of virus

Chemicals Required - Air or pure oxygen may be used as the raw material for the ozone generation.
Design Criteria  (131) -
     Contact time:  1 to 16 minutes
     Dosage: 5 to 10 mg/1

Reliability - Mechanically highly reliable.  Highly reliable in deactivating microorganisms.
Toxics Management  (132) - Ozone has been found to be a good oxidant for removal of cyanide,  phenol and other
dissolved toxic organic materials.  Combination of ozonation and activated carbon treatment can achieve 95 percent
chloroform and other trihalomethanes removals.

Environmental Impact - Ozone is an air pollutant which can discolor or kill vegetation coming in contact with it.
Residual ozone in off-gas streams must be processed for ozone decomposition prior to release.   Ozone is toxic
when inhaled in sufficient concentration.

References - 3, 10, 11, 39, 77, 126, 128, 129, 130, 131, 132
                                                    A-142
-------
 OZONATION  DISINFECTION  (AIR  AND OXYGEN)
                                                              FACT  SHEET 4.5.3
FLOW DIAGRAM -
Secondary Effluent _

tor






i

03 Out Thermal j


Ozone
Contactor

Effluent

                                                                                            Vent
ENERGY NOTES - The energy requirement  is  750  kWh/Mgal  of wastcwacer i.reatea if ozone is generaujd from air and 550
kWh/Hgal if ozone is generated  from  oxygen.   These  requirements are based on the assumption that the energy
required for tue production of  ozone is  7.5  kWh/lb  of ozone when generated from air and 4.5 kWh/lb when generated
from oxygen.
COSTS* - Assumptions:  Service  Life  = 30 years
Design Basis:
TIEquipment: 0  storage  or  air  supply ozonator,  injector,  contact chamber, aeration chamber.
2.   O  requirements:  3  Ib/lb  of O ,  ozone  dosage:  8 mg/1.
3.   Labor rate: $7.50/h, including benefits,  power cost:  $.02/kWh.
4.   Index: ENR =  2475,  September  1976.
Ozonation — Air
          10
                       CONSTRUCTION COST
                                                                        OPERATION & MAINTENANCE COST
          1 0
      O
      Q
          01
         001

                                   s
                                                            t 001
                                                              0001
                                                                                   Tola
                                                                                             Power—
                                                                                            Matena



           0 1

Ozonalion — Oxygen
          10
 1 0           10
Wastewater Flow, Mgal/d

CONSTRUCTION COST
                                                   100
01            10           10
             Wastewater Flow, Mgal/d
       OPERATION & MAINTENANCE COST
                                                                                                         100
                                                                                                           0.0001
llars
0
          01
         001

                                                                                                            001
                                                                                                         :! 0001
           01
                                                    100
                         1 0            10
  REFERENCE - 3         Wastewater Flow, Mgal/d
  *To convert construction  cost to capital cost see Table A-2.
                                                              0001
                                                                                                           00001
                                                                 01
                                                       1 0            10
                                                      Wastewater Flow, Mgal/d
                                                                                                         100
                                                    A-143
-------
ALUM ADDITION                                                                     FACT SHEET 5,1,1
Description and Common Modifications -  Alum or filter alum, Al (SO )   .  14H O, is a coagulant which when added to
wastewater reacts with available alkalinity (carbonate, bicarbonate and hydroxide) and phosphate to form insoluble
aluminum salts.  The combination of alum with alkalinity or phosphate are competing reactions which are pH depen-
dent.  Alum is an offwhite crystal which when dissolved in water produces acidic conditions.  As a solid, alum may
be supplied in lumps, or in ground, rice or powdered form.  Shipments may be in small bags (100 Ib), in drums or
in bulk quantities (over 40,000 Ib).  In liquid form, alum is commonly supplied as a 50 percent solution delivered
in minimum loads of 4000 gal.  The choice between liquid or dry alum use is dependent on factors such as availa-
bility of storage space, method of feeding and economics.  In general, purchase of liquid alum is justified only
when the supplier is close enough to make differences in transportation costs negligible.  Dry alum is stored in
mild steel or concrete bins with appropriate dust collection equipment.  Since dry alum is slightly hydroscopic,
provisions are made to avoid moisture which could cause caking and corrosive conditions.  Before addition to
wastewater, dry alum must be dissolved, forming a concentrated solution.  Bulk stored or hopper filled alum is
transported by either bucket elevator, screw conveyor or a pneumatic device to a feeder mechanism.  Three basic
types of feeders are in common use:  volumetric, belt gravimetric and loss-in-weight gravimetric.  The feeder
supplies a controlled quantity of dry alum (accuracy ranges from about 1-7%) to a mixed dissolver vessel.  The
quantity supplied depends on the concentrate strength desired and the temperature, since alum solubility is
temperature dependent.  Because alum solution is corrosive, the dissolving chamber as well as following storage
tanks, pumps, piping and surfaces that may come in contact with the solution or generated fumes must be constructed
of resistant materials such as type 316 stainless steel, fiberglass reinforced plastic  (FRP)  or plastics.  Rubber
or saran lined pipes are commonly used.  Liquid alum, which crystallizes at about 30 F and freezes at about 18 F,
is stored and shipped in insulated type 316 stainless steel or rubber-lined vessels.  Feeding of liquid alum (pur-
chased or made up on site) to wastewater treatment unit processes may be accomplished by gravity, via pumping or
by using a roto dip-type feeder.  Diaphragm pumps and valves are common.

Technology Status - Alum addition has been used for decades for coagulation and turbidity reduction in water
treatment.  Application to wastewater treatment is more recent and the technology well demonstrated.

Applications - Alum is used in wastewater treatment (sometimes in conjunction with polymers) for suspended solids
and/or phosphorus removal.  Alum coagulation may be incorporated into independent physical-chemical treatment,
tertiary treatment schemes or as an add-on to existing treatment processes.  In independent physical-chemical
treatment    (or tertiary treatment), alum is added directly to the wastewater, which is intensely mixed, floc-
culated and settled.  Solids contact clarifiers may be used.  In existing wastewater treatment process, alum may
be added directly to primary clarifiers, secondary clarifiers or aeration vessels to improve performance.  It
should not be dosed directly to trickling filters because of possible deposition of chemical precipitates on the
filter media.  Alum has also been used as a filter aid in tertiary filtration processes and has been used to
upgrade stabilization pond effluent quality.

Limitations - Alum solution is a corrosive material.  Appropriate dosages are not stoichoimetric and must be re-
confirmed frequently.  Alkalinity is required for proper coagulation, and where inadequate, supplemental alka-
linity must be provided (usually by lime addition).   Alum sludge is voluminous and difficult to dewater.

Typical Equipment/No. Mfrs. (97-100) - Bins/over 50; Hoppers/over 40; Conveyors and Elevators/over 50; Liquid
Storage tanks/over 50; Dry and Wet Feeders/over 50:  pH instrumentation/over 50.
Performance - Typical performance for existing treatment plants using alum for upgrading are as follows:
Treatment System Type    Trickling Filter    Trickling Filter    Activated sludge    Activated Sludge
Point of Addition        Final Clarifier    Primary Clarifier    Final Clarifier     Aeration Tank
Effluent BOD , mg/1           10-25               20-30               10-25               15-25
Effluent SS, mg/1             15-30               20-40               10-30               15-30
Effluent P, mg/1             0.5-2.0             1.0-3.0             0.2-1.5             0.5-1.5

Chemicals Required - The amount of alum required depends on multiple factors such as alkalinity and pH of waste-
water, phosphate level and point of injection.  Accurate dosages should be determined by jar tests and confirmed
by field trials.

Residuals Generated - Alum sludges are substantially different in character from biological sludges in that
volumes are greater and dewatering is more difficult.  Alum sludge also has a tendency to induce undesirable
stratification in anaerobic digesters.

Design Criteria  (99) - Dosage:  Determined by jar testing, generally in the range of 5-20 mg/| as Al; Mixing:  G =
(approximately) 300/s, t is less than or equal to 30 s; Flocculation:  GT = (approximately)  10  or, GCT = (approx-
imately) 100; Sedimentation:  Overflow Rate = 500 to 600 gal/d/ft  (average), 800 to 900 ga/d/ft  (peak).

Unit Process Reliability - Reduces phosphate and suspended solids to low levels, although the effluent quality may
vary unless filtration follows the clarification step.

Toxics Management - Alum is an effective chemical for precipitating and removing many heavy metals in wastewater.
Among the metals reduced in concentration by more than 50 percent by alum coagulation are zinc, copper, barium,
lead, chromium  (III) and arsenic.

References - 29, 95, 97, 99, 100
                                                    A-144
-------
ALUM ADDITION
                                                                                    FACT  SHEET 5,1,1
FLOW DIAGRAM
              Dry  Alum
              Storage
                                                                  Mixer
r .
Conveyor


Feeder



°£
Dissolver


Holding
Tank
                                                                                   Metering Pump

                                                                                     I	
                                                                                   Liquid  Alum
ENERGY NOTES - Assumptions:
1. Power consumption based on the operation
   of pumps, mixers and feeders.
2. Alum dosage = 200 mg/1 as Al {SO )  .14 H
3. Type of energy: Electrical
COSTS - Assumptions:
T.   Alum dosage =  200 mg/1 as A12(SO4)3.14 H2O.
Phosphorus removal  for other dosages, see
adjustments below.
2.   The rapid mix  tank is constructed of concrete,
and multiple basins are used for volumes greater
than 1,500 ft .
3.   Costs include  liquid alum (8.3% Al 0 ) ,
chemical feed equipment sized for twice the
average feed rate and storage of at least 15 days.
Price of building is included except for plants
with a capacity of  less than 1 Mgal/d.  Rapid mix
tank includes stainless steel mixer.
4.   Service life = 20 years.
5.   ENR Index = 2475.
                                                       Dry Alum
                                                                      10
                                                                      10'
                                                                   ^  10
                                                                      10
                                                                                                    7
                                                                                                        7
 Adjustment  factor:   To adjust cost curves  for other alum dosages,
 enter cost  curve at  effective flow  (Q  ) :
                                                                       0.1            1.0           10

                                                                                Uastewater Flow, Mqal/d
                                                                                                                100
      E   ^DESIGN
           10
                  X Alum Dose
                    200 mg/1
                                                           s
                                                           o
                                                           I
                         10            10
                       Wastewater Flow. Mgal/d
                                                                                !0            10
                                                                               Wastewater Flow, Mgal/d
 REFERENCE  -  3
 *To convert construction cost to capital  cost see  Table  A-2.
                                                      A-145
-------
 FERRIC CHLORIDE  ADDITION                                                       FACT SHEET 5.1.2
Description and Common Modifications- Ferric chloride (Fed )  is a chemical coagulant which when added to waste-
 water  reacts  with alkalinity and phosphates,  forming insoluble iron salts.  The colloidal particle size of insol-
 uble FePO   is small,  requiring  excess dosages of FeCl  to produce a well flocculated iron hydroxide precipitate
 which  carries the phosphate precipitate.  Large excesses of ferric chloride, and corresponding quantities of
 alkalinity, are  required  to assure phosphate  removal.  Exact ferric chloride dosages are usually best determined
 by jar tests  and full scale evaluations.  Ferric chloride is available in either dry (hydrated or anhydrous) or
 liquid form.   Liquid  ferric chloride is a dark brown oily-appearing solution supplied in concentrations ranging
 between 35  and 45 percent FeCl  .  Because higher concentrations of ferric chloride have higher freezing points,
 lower  concentrations  are  supplied during winter.  Liquid ferric chloride is shipped in 3,000 to 4,000 gallon bulk
 truckload lots,  in 4,000  to 10,000 gallon carloads and in 5 to 13 gallon carboys.  Ferric chloride solution
 stains surfaces  it comes  in contact with and  is highly corrosive  (a 1 percent solution has a pH of 2.0).  Conse-
 quently, it must be stored and  handled with care.  Storage tanks are equipped with vents and vacuum relief valves.
 Tanks  are constructed of  fiberglass reinforced plastic, rubber lined steel and plastic lined steel.  Because of
 freezing potential, ferric chloride solutions are either stored in heated areas or in heated and insulated vessels
 in northern climates.  Ferric chloride solution should not be diluted because of possible unwanted hydrolysis.
 Consequently,  feeding at  the concentration of the delivered product is common.  The stored solution is transferred
 to a day tank using graphite or rubber lined  self-priming centrifugal pumps with corrosion resistant Teflon
 seals.   From  the day  tank, controlled quantities are fed to the unit process using rotodip feeders or diaphragm
 metering pumps.   Rotometers are not used for  ferric chloride flow measurement because of its tendency to deposit
 on and stain  the glass tubes.   All pipes, valves or surfaces that come in contact with ferric chloride must be
 made of corrosion resistant materials such as rubber or Saran lining, Teflon or vinyl.   Similar treatment results
 are obtainable by substituting  ferrous chloride, ferric sulfate, ferrous sulfate or spent pickle liquor for
 ferric chloride.   Details of storage feeding  and control for these materials are similar to those for ferric
 chloride.   Dry ferric chloride  may also be dissolved on site before use in treatment.

 Technology  Status - Ferric chloride is commonly used in water treatment as a coagulant for turbidity reduction.
 Its  use  in wastewater  treatment is more recent and well demonstrated.

 Applications  - Ferric  chloride  (sometimes with polymer addition) is used in wastewater treatment for suspended
 solids removal and/or phosphate removal.  FeCl  coagulation may be incorporated into independent physical-chemical
 treatment and tertiary treatment  schemes.  In these applications, solids contact clarifiers or separate floccula-
 tion vessels are used for the treatment of either raw wastewater or secondary effluent.  Ferric chloride coagu-
 lation may also be applied to existing treatment systems.  Addition of ferric chloride before primary and second-
 ary clarifiers has been practiced in both activated sludge and trickling filter plants.

 Limitations - Ferric chloride is  an extremely corrosive material which must be stored and transported in special
 corrosion resistant equipment.  Dosages are not stoichiometric and must be rechecked frequently via jar tests.
 Ferric chloride coagulation requires a source of alkalinity, and in soft wastewaters, the pH of the clarified
 effluent might be decreased to a point requiring pH adjustment by addition of a supplemental base such as lime or
 caustic soda.  Iron concentrations in plant effluents may become unacceptably high.

 Typical Equipment/No, of Mfrs.  (97, 100) - Liquid storage tanks/over 50; Dry and Wet feeders/over 50; pH instru-
mentation/over  50.

Performance  (230) - Phosphorus removal studies at Baltimore, Maryland showed the following P  (mg/1) levels:
               Primary Effluent Prior        	Secondary Effluent  (After Fe Addition)	
                  to Fe Addition	        Activated Sludge	% Removal	Trickling Filter	% Removal
                          7762.1              72                7.2               5
                          8.2                       0.85             90                5.8              29
                          8.0                       0.58             93                3.8              53
                          8.6                       0.29             97                3.9              55
                          7.7                       0.32             96                3.3              57

Chemicals Required - The  amount of ferric chloride required depends on variable factors including pH and alka-
 linity of the wastewater, phosphate level, point of injection and mixing modes.  Accurate doses should be deter-
 mined by jar tests and confirmed by field evaluations.  Base addition may be required when treating soft waste
 waters.

 Residuals Generated - Used in standard biological processes, ferric chloride addition will increase the volume of
 sludge generated.  Based on a full-scale study conducted in Baltimore, Maryland, the additional sludge generated
 by adding  15 mg/1 Fe was 0.6 wet tons/Mgal.  Iron coagulants' produce sludges that are significantly different
 from biological  sludges, especially in terms of dewatering characteristics.

 Design Criteria  (99) - Dosage:  Determined by jar testing.  Dosages of 20-100 mg/1 FeCl  are common.
                       Mixing:  G =  (approximately) 300/s; t is less than or equal to 30/s.
 Reliability - Reduces phosphate and suspended solids to low levels, although the effluent quality may vary unless
 filtration follows  the clarification step.

 Toxics Management - Ferric chloride is an effective chemical for precipitating and removing many heavy metals in
wastewaters.  Among the metals reduced in concentration by more than 50 percent by ferric chloride coagulation
are  zinc, copper, barium, lead, chromium  (III) and arsenic.

References -  29, 95,  97, 99, 100, 230

•~"~~-                                   ~~    A-146
-------
 FERRIC  CHLORIDE  ADDITION
                      FACT SHEET  5.1.2
FLOW DIAGRAM -
                                 Ferric
                                Chloride
                                Solution
                                 Storage
                                                                   Diaphragm Metering
                                                                          Pump
                  Rubber-Lined,  Self-Priming
                  Centrifugal Pump with
                      Teflon  Seals
ENERGY NOTES - Assumptions:
Power consumption based on the operation of
pumps, mixers and feeders.  Fed  dosage =
100 mg/1.  Type of energy: Electrical.
                                                              10
10
                                                               10
                                                               10
                                                                                                 z
COSTS - Assumptions:
                                                                 0 1
1.   FeCl  dosage =  100 mg/1.
                1 0            10
               Wastewa'er F i./w Mgal/d
2.   The rapid mix  tank  is  constructed of concrete,  and multiple basins are used for volumes greater than
     1,500 ft .
3.   Costs include  liquid ferric  chloride,  chemical  feed equipment sized for twice the average feed rate, and
     storage of at  least 15 days.   Price  of building is included except for plants with a capacity of less than
     1 Mgal/d.  Rapid mix tank  includes stainless steel mixer.
4.   Service life = 20 years.
5.   ENR Index = 2475.
Adjustment factor:   To adjust cost curves for other  FeCl  dosages, enter cost curve at effective
flow  (QE) :
     QE ' ^DESIGN x FeC13  fse
                    100 mg/1
            10
                           CONSTRUCTION  COST


                                                                 001
                                                               0001
                                                                          OPERATION a  MAINTENANCE
                                                                                    Labor
                                                                                  ' Power
            01
REFERENCE - 3
                           10            10
                         Wastewater Flow, Mgal/d
                                                                  01
                  10            10
                 Wastewater Flow, Mgal/d
                                                                                                            01
                                                                                                            0001
                                                                                                            00001
                                                                                                           100
*To convert construction cost to capital  cost  see Table A-2.
                                                    A-147
-------
LIME CLARIFICATION  OF  RAW WASTEWATER                                         FACT  SHEET 5.1.5
Description and Common Modifications - Lime clarification of raw wastewater  removes  suspended solids, while  also
removing phosphates.  There are two basic processes,  the low-lime system and the high-lime  system.   The low-lime
process consists of the addition of lime to obtain a pH of approximately 9 to 10.  Generally,  a subsequent bio-
logical treatment system is capable of readjusting the pH through natural recarbonation.  The  high-lime process
consists of the addition of lime to obtain a pH of approximately 11 or more.  In this case, the pH  generally
requires readjusting with carbon dioxide or acid to be acceptable to the secondary treatment system.

Lime can be purchased in many forms, with quicklime (CaO) and hydrated lime (Ca(OH)  )  being the most prevalent
forms.  In either case, lime is usually purchased in the dry state, in bags or in bulk.   Bulk  lime  can be  (1)
shipped by trucks that are generally equipped with pneumatic unloading equipment; or (2)  shipped by rail cars,
which consist of covered hoppers.  The rail cars are emptied by opening a discharge gate  which discharges  to a
screw conveyor.  The bulk lime is then transferred by the screw conveyor to a bucket elevator  which empties into
the elevated storage tank.  Bulk storage usually consists of steel or concrete bins.  Storage  vessels should be
water and air tight to prevent the lime from "slaking."

Lime is generally made into a wet suspension or slurry before being introduced into the  treatment system.   The
precise steps involved in converting from the dry to the wet stage will vary according to the  size  of operation and
type and form of limes used.  In the smallest plants, bagged hydrated lime is often charged manually into  a batch
mixing tank with the resulting "milk-of-lime" (or slurry) being fed via a so-called solution feeder to the process.
Where bulk hydrate is used, some type of dry feeder charges the lime continuously to either a  batch or continuous
mixer, thence via solution feeder to point of application.  With bulk quicklime, a dry feeder  is also used which  in
turn feeds a slaking device, where the oxides are converted to hydroxides, producing a paste or slurry. The slurry
is then further diluted to milk-of-lime before being piped by gravity or pumped to the process.  Dry feeders can  be
of the volumetric or gravimetric type.

Technology Status - Established.
Typical Equipment  (97, 100) - Bins/over 50; Hoppers/over 40; Conveyors and Elevators/over 50; Liquid Storage
Tanks/ over 50; Dry and Wet Feeders/over 50; Lime Slakers/6; pH Instrumentation/over 50.

Applications - Lime addition to a primary clarifier is used for improved removal of suspended solids and the
removal of phosphates.   (The primary use of this process is for the removal of phosphates.)  Will also remove toxic
metals.

Limitations - Will generate additional amounts of sludge, over and above that generated by the normal primary
clarification process  (approximately twice the volume for low-lime and 5 to 6 times for high lime).  Lime feed
systems can require intensive operator attention.  Even low-lime could present biological problems to fixed-growth
systems with no pH adjustment.  Increases operator safety needs.

Performance (29) - The following table presents data from one POTW-.
                                Lime Treatment to pH 11 mg/1
                         Influent            Effluent       % Removal
     BOD,                     192                 60             69
     SS                       195                 47             76
     Total Phosphorus         9.2                 2.3            75

Chemicals Required - Lime  (CaO or Ca(OH)2>; COj or H2SO4 for high-lime.
Residuals Generated - Sludge, which will contain 1 to 1.5 pounds of dry solids per pound of lime added, plus the
usual amount of solids produced in the primary settling process.

Design Criteria  (29) - Lime requirements:
Feed Water Alkalinity               Clarifier pH               Approximate Lime Dose
    (mg/1  as CaCO  )                                                  (mg/1 of CaO)
        300                             9.5                             185
        300                            10.5                             270
        400                             9-5                             230
        400                            10.5                             380

Unit Process Reliability - The process is highly reliable from a process standpoint, however increased operator
attention and  cleaning requirements are necessary to maintain mechanical reliability of the lime feed system.
Environmental  Impact - Will generate  relatively large amounts of inorganic sludge that will need disposal.
References - 29,  97,  100,  102
                                                    A-148
-------
 LIME CLARIFICATION  OF RAW WASTEWATER
                       FACT SHEET  5.1.5
FLOW DIAGRAM -
                                                                                          To Secondary
                                                                                            Treatment
Lime
Feed


Lime
Storage
ENERGY NOTES - Assumptions:
Design Assumptions:
1.  Slaked lime used for 0.1 to 10 Mgal/d capacity
    plants
2.  Quicklime used for 10 to 100 Mgal/d capacity
    plants

Operating Parameters:
1.   350 mg/1, low lime as Ca(OH)
2.   600 mg/1, high lime as Ca(OHT2
3.   Electrical energy at $.02/kwh
COSTS* - Assumptions: October 1973 dollars;  ENR Index = 1933.
Construction costs include:
1.   Chemical storage and feeding equipment
2.   Hydrated lime for 0.1 to 10 Mgal/d plants
3.   Pebble quicklime for 10 to 100 Mgal/d plants
4.   Lime feed rates are based on a dosage of
     150 mg/1 and allow for peak rates of twice
     this capacity
5.   Storage was provided for at least 15 days at the
     average rate.
6.   Piping and buildings to house the feeding equipment
     are not included.
                       CONSTRUCTION   COSTS
         1 0
         0 1
      D
      "o
      5  001
        0001
            .1
REFERENCES - 3, 4, 29
                        1.0          10
                       Wastewater Flow, Mgal/d
                                                  100
*To convert construction cost  to  capital  cost see Table A-2.
                                                A-149
                                                                       -0.1
                                                                                     PLANT CAPACITY, Mgal/d
                                                                            )..!          l.|)	10 HIGH LIME
                                                                                     1.0
                                                                                                 10
                                                                                                        LOW LIME
                                                                    10
      10
                                                                    10
       10'
          10
                       100         1000

                      Feed  Rate, Ib/hr
                                              10,000
  Operating  costs  include:
  1.    Lime  cost,  $27.50/ton
  2.    Operating  costs  include only the cost of lime.
       They  do  not include depreciation of equipment.

             OPERATION & MAINTENANCE COST
Q   0 1
"o
c
o

2

o
O
w  001
                                                                0001
                                                                   0 1
                   1 0            10
                  Wastewater How  Mgal/d
                                                                                                           100
-------
POLYMER ADDITION                                                                 FACT SHEET  5.1.6
Description and Common Modifications - Polymers or polyelectrolytes are high molecular  weight  compounds  (usually
synthetic) which, when added to wastewater,  can be used as coagulants,  coagulant aids,  filter  aids, or  sludge
conditioners.  In solution, polymers may carry either a positive,  negative or neutral  charge and,  as  such,  they  are
characterized as cationic, anionic or nonionic.  As a coagulant or coagulant aid,  polymers  act as  bridges,  reducing
charge repulsion between colloidal and dispersed floe particles, increasing settling velocities.   As  a  filter  aid,
polymers strengthen fragile floe particles controlling filter penetration and reducing particle breakthrough.
Filterability and dewatering characteristics of sludges may similarly be improved through the  use  of  polyelectro-
lytes.  Polymers are available in predissolved liquid or dry form.   Dry polymers are supplied  in relatively small
quantities (up to about 100 pound bags or barrels) and must be dissolved on site prior to use.  A  stock solution,
usually about 0.2 to 2.0 percent concentration, is made up for subsequent feeding to the treatment process.
Preparation involves automatic or batch wetting, mixing and aging.   Stock polymer solutions may be very viscous.
Surfaces coining in contact with the polymer stock solution should be constructed of resistant  materials such as  316
stainless steel, fiberglass reinforced plastic or other plastic lining materials.   Polymers may be supplied as a
prepared stock solution ready for feeding to the treatment process.   Many competing polymer formulations with
differing characteristics are available, requiring somewhat differing handling procedures.  Manufacturers  should be
consulted for optimum practices.  Polymer stock solutions are generally fed to unit processes  using equipment
similar to that commonly in service for dissolved coagulant addition.   (See Fact Sheets 5.1.1  and  5.1.2 on Alum  and
Ferric Chloride Addition.)  Because of the high viscosity of stock solutions, special  attention should  be  paid to
the diameter and slopes of pipes, as well as the size of orifices used in the feed systems.

Technology Status - Polymer or polyelectrolyte usage in wastewater and water treatment has  gained  widespread
acceptance.  The technology for its use is well demonstrated and is common throughout the  wastewater and water
treatment fields.

Applications - Polymers are utilized in a variety of applications in wastewater treatment  ranging from flocculation
of suspended or colloidal materials either alone or in conjunction with other coagulants such as lime,  alum or
ferric chloride, to use as a filter aid or sludge conditioner.   Polyelectrolytes may be added alone or  with other
coagulants to raw wastewater prior to primary treatment to effect or aid in suspended solids  and BOD removal.
Similarly, polymers may be used to aid coagulation or as a primary coagulant in treatment of  secondary  effluent.
As a filter aid, polyelectrolytes effectively strengthen fragile chemical floes, facilitating more efficient filter
operations.

Limitations - Frequent jar tests are necessary to assure proper dosages.  Overdosages (1.0 to 2.0 mg/1)  can some-
times work against the treatment process.

Typical Equipment - Bins/over 50; hoppers/over 40; liquid storage tanks/over 50;  dry and wet feeders/over 50.
Performance - Generally, improvement in unit process performance has been achieved using polymer.   But the per-
formance varies depending upon its use as coagulant, coagulant aid or filter aid.   Actual performance is best
determined on a case by case basis.

Chemicals Required - Accurate dosages should be determined by bench scale evaluation.
Residuals Generated - Sludges generated in conjunction with polymer addition will be somewhat different from, but
not necessarily more difficult to handle than biological sludges or chemical sludges generated without polymers.

Design Criteria - Dosage determined by jar testing.  Materials contacting polymer solutions should be of the
type 316 stainless steel, fiberglass reinforced plastic or plastic construction.   Storage place must be cool and
dry.  Storage periods should be minimized.  Viscosity considerations must be made in feeding system design.

Reliability - With proper control, capable of producing consistently high quality effluents.
Environmental Impact - May improve sludge dewaterability;  operator safety should be carefully considered.
References - 23, 29, 95, 99
                                                     A-150
-------
 i
M
U1
ruct
                                            Millions of Dollars
                          §
w, M
                                                                         ;8|
                                     Annua  Cost, Millions of Dollars
                                         (Total- Labor- Chemicals)
                                                                                                       Energy  Required,  kWh/yr
                                             (Power - Matena s)
                                                                                                                               N
                                                                                                                                                                                                   C3
                                                                                                                                                                                                   C3
                                                                                                                                                                                                   CO

                                                                                                                                                                                                   m
-------
POWDERED  CARBON ADDITION
                                                        FACT  SHEET  5,1.7
Description - Powdered activated carbon is used in wastewater facilities to adsorb soluble organic materials  and
to aid in the clarification process.  Powdered carbon is fed to a treatment system using chemical feed equipment
similar to those used for other chemicals that are purchased in dry form.   The spent carbon is removed with the
sludge and can then be discarded or regenerated.  Regeneration can be accomplished in a furnace or wet air oxi-
dation system.

Powdered carbon can be fed to primary clarifiers directly, or to a separate sludge recirculation type clarifier
which enhances the contact between the carbon and the wastewater.  Powdered carbon can also be fed to tertiary
clarifiers to remove additional amounts of soluble organics.  Powdered carbon, when added to a sludge recircu-
lation type clarifier, has been shown to be capable of achieving secondary removal efficiencies.

Powdered carbon can be fed in the dry state using volumetric or gravimetric feeders or can be fed in slurry form.

Modifications - A new technology has been developed over the past several  years that consists of the addition of
powdered activated carbon to the aeration basins of biological systems.  This application is capable of the
following: high BOD  and COD reduction, despite hydraulic and organic overloading; aiding solids settling in  the
clarifiers,- a high degree of nitrification due to extended sludge age; a substantial reduction in phosphorus;
adsorbing coloring materials such as dyes and toxic compounds; and adsorbing detergents and reducing foam (211,
212).

Technology Status - Two new municipal plants using powdered carbon addition to activated sludge are currently
under construction.  Several more are planned.
Typical Equipment (2, 3, 97,
50; Slurry feeders/over 50.
100)  - Powdered carbon - major producers/2;  Volumetric and gravimetric  feeders/over
applications - Has been used in the clarifiers and has the potential use in aeration basins to adsorb soluble
organic materials, thus removing BOD  and COD, as well as some toxic materials.

Limitations - Will increase the amount of sludge generated.   Regeneration will be necessary at higher dosages in
order to maintain reasonable costs.  Most powdered carbon systems will require post-filtration to capture  any
residual carbon particles.  Some sort of flocculating agent such as an organic polyelectrolyte is usually  required
to maintain efficient solids capture in the clarifier.

Performance - Physical/chemical treatment (two contact type clarifiers in series)  (106)
                                                                  Neutralized
         Average                      Raw         Chemical         Chemical            Plant
 Process Treatment Results         Wastewater     Effluent         Effluent          Effluent
Turbidity, JTU
Suspended Solids, mg/1
Total P, mg/1 P
Soluble Total P, mg/1 P
Total PO , mg/1 P
Soluble, PO , mg/1 P
COD, mg/1
           4'
           33
           87
           4,50
           3.16
           2.82
           2.25
           136
4
14
0.29
0.14
0.10
0.04
4
10

0.15
0.06
0.05
55
3
5
0.20
0.11
0.11
0.08
14
Limited pilot and field scale data are available for powdered activated carbon addition to biological treatment
units and its use in municipal treatment systems.

Chemicals Required - Powdered activated carbon, polyelectrolytes.
Residuals Generated - Sludge: 1 pound of dry sludge per pound of carbon added.   If regeneration is practiced,
carbon sludge is reactivated and reused with only a small portion removed to prevent buildup of inerts.
Design Criteria - The amount of powdered carbon fed to a system greatly depends on the characteristics of the
wastewater and the desired effluent quality.  However, powdered carbon will generally be fed at a rate between 50
and 300 mg/1.

Process Reliability - Powdered activated carbon systems are reasonably reliable from both a unit and process
standpoint.  In fact, powdered carbon systems can be used to improve process reliability of existing systems.

Environmental Impact - Land use requirements vary with application.   Air pollution may result from regeneration.
Spent carbon may be a land disposal problem unless regenerated.

References - 71, 106, 150
                                                    A-152
-------
 I
M
t/1
*To convert construction cost to capital cost see Table A-2.
101 10 10 100 0 1 1
Wastewater Flow. Mgal/d Wa
REFERENCE -34
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-------
DEWATERED SLUDGE  TRANSPORT  (RAIL)                                             FACT  SHEET 6.1.1
Description - The movement by covered hopper cars, of dewatered sludge having a minimum solids content of 12
percent, from its point of origin, such as the treatment plant, to a distant designated site by common carrier
railroad.  The site has been selected for the particular sludge and is proximate to an existing railroad.

Modifications -

1.   Open hopper cars  (not recommended for other than well digested sludge).
2.   Gondola cars (not recommended for other than well digested sludge).
3.   Reduced costs are possible if cars are owned by shipper (justifiable for larger plants).

Technology Status (101) -

Not in widespread use even though railroad technology is highly developed for hauling freight in countless in-
dustries.

Limitations (8, 101) - The fixed position of a railroad limits disposal site locations.   Generally,  a minimum of
40 miles one way for each trip and a total load of 1000 ton/d is needed to compete with truck transportation.
Scheduled deliveries of cars are difficult to predict if non-unit train operation is used.

Design Criteria (3,  101)  -

     Rail line should be near or next to the site to reduce length of spur or siding.
     Sludge should have a density to achieve the approximate payload of the rail car.
     Cars should be covered to avoid odor impact.
     Cars should be gravity loaded from storage tank above car at POTW, and gravity unloaded into a  hopper below
     car at site.
     Movement of up to 74,000 yd  of sludge should be done with 50 yd  (approx.  50 ton)  cars (unit train  concept).
     Movement of greater than 75,000 yd  of sludge should be done with 100 yd  (approx.  100  ton)  cars (unit train
     concept) .

Typical Equipment/No.  Mfrs.  (23)  - Sludge handling and control/32; conveyors/4 (83);  cars, dump/27;  cars,  hopper/16
Reliability (8, 101)  - Delivery by unit train can provide a high level of reliability through good delivery
schedules.

Environmental Impact - None for air and water.   Only potential impact would result from use  of open hopper or
gondola cars.   Moderate impact on land because of rail spur to site,  and unloading equipment and storage  area  at
site.

Comments (8, 101)  - By virtue of its existing right of way, the railroad in many instances  can provide  the oppor-
tunity to use marginal or poor land of the type that can be reclaimed in some way by application of  a  non-specific
sludge.

Transport to the site should be one element of an integrated design for the production and ultimate  disposal  of
the sludge.   Other important elements of this design are the methods and equipment to be used for unloading,
storage,  and distributing the sludge over the site.

References - 3, 8,  83, 101,  104,  142
                                                 A-154
-------
 DEWATERED SLUDGE  TRANSPORT  (RAIL)
                                                                                     FACT SHEET 6,1.1
FLOW DIAGRAM -
                  V.
                        Loading
                        Storage
                         Tank
                Loading at Treatment Plant
                                                                           Unloading at Site
                                          Dewatered Sludge Loading and Unloading

ENERGY NOTES (161) - Rail transport can be considered to require approximately 25 percent of the energy in Btu/ton
mile when compared to truck transport.  See Fact Sheet 6.1.2  for truck energy requirements for large vehicles
handling dewatered sludge.
                               • 2475
                                construction of loading facilities;  loading storage tank sized for one carload
COSTS - Assumptions: ENR Index
1. Construction cost includes:
(cars are gravity loaded).
2.  Railroad provides hopper cars.
3.  Construction cost does not include any construction work and equipment at site.
4.  Operation and maintenance costs include:  rail haul charges, labor,  electric power,  and supplies for the
loading facilities; 50 yd  cars for 0 to 74,000 yd  of sludge;  100 yd  cars for greater  than 75,000 yd  of sludge.
5.  Rail haul charges based on travel distances of 40, 80, 160  mi one way in the central and north central areas
of the country.  Adjustments for other areas of the country:
     Area                Approximate RR Rate Variation, (adjust accordingly)
                              25% higher than average
                              25% lower than average
                              10% lower than average
                              10% higher than average
     Northeast
     Southeast
     Southwest
     West Coast
    Costs based on eight hours operation per day.
    Unloading costs not included.
                        CONSTRUCTION COST
           10
           1 0
           0 1
          001
                                                                   10
                                                                           OPERATION & MAINTENANCE COST
                                                               Q   1 0
                                                              O
                                                               B   0 1
           "10            10            100          1000
                     Annual Sludge Volume, 1000 cu yd
 REFERENCES - 3, 142, 161


 *To convert  construction cost  to  capital  cost  see Table A-2.


                                                     A-155
                                                                 0 01
                                                                               80 Mile
                                                                                        160 M
                                                                                                   4  M le
                                                                    1 0
                                                                                 10           100          1000
                                                                              Annual Sludge Volume, 1000 cu yd
-------
DEWATERED  SLUDGE TRANSPORT (TRUCK)                                           FACT SHEET  6.1.2
 Description  - The movement over highways and roads by canvas covered, hydraulic lift, dump vehicles,  of dewatered
 sludge  having a minimum  total solids content of 12 percent, from its point of origin, such as the treatment plant,
 to  a  distant designated  site.  The site has been selected for the particular sludge and is accessible to a road or
 highway.

 Common  Modifications  (22, 96) -

 1.    Depending on state  road laws, the type of vehicle would vary:
          Two axle and three axle trucks.
          Two axle tractor with one axle semi-trailer.
          Two axle tractor with two-axle semi-trailer.
          Three axle  tractor with two axle semi-trailer.
          Two or three axle truck with a two or three axle trailer.

 2.    Gasoline or diesel  engine power.  Diesel engine power preferred because of cheaper fuel and lower maintenance
 costs.

 Technology Status - Highly developed and in widespread use.

 Limitations  (7, 8, 96) -

 State road laws which limit load of vehicle.  In Ohio, for example, the maximum payloads would be:

      Vehicle                              Payload, tons
      3-axle  tractor,  2 axle semi-trailer          22
      3-axle  truck                                 10
      2-axle  truck                                 7-1/2

 Generally, highway and road loadings are in accordance with American Association of State Highway Officials Class
 Standards H10, HIS, and  H20.

 Load  limits  may be restricted by practical on-site road conditions.

 While truck  transport generally has a lower initial investment cost, it will have higher operating cost relative
 to  rail for  most levels  of design volume.

 Vehicles carrying sludge should be able to reach the site without passing through heavily populated areas or
 business districts.

 Design  criteria  (3, 22,  73) -

 Dewatered sludge should  have a minimum of 12 percent total solids.

 Vehicle should be loaded by gravity from a storage tank and gravity unloaded at site.

 Loading equipment should be sized to fill vehicle in 20 minutes maximum.

 Size  of vehicle should be selected so that density and solid content^ of sludge3achieves approximate payload of
 the vehicle. For a 25 percent solid content, vehicle sizes of 10 yd  and 30 yd  are most cost-effective.

 Loading tank should be sized to fill at least one vehicle.

 Typical Equipment - Trucks and trailer equipment widely available.

 Reliability  - Very reliable, but dependent upon disposal site road conditions.

 Environmental Impact  - Small for land if temporary roads are built from highway to unloading area in site.
 Potential for air pollution due to traffic of heavy trucks, especially from large plants.

 Comments - Highway vehicles offer flexibility of movement to various sites when compared to rail.  Transport to
 the site should be one element of an integrated design for the production and ultimate disposal of the sludge.
 Other important elements of this design are the methods and equipment to be used for unloading, storage, and
 distributing the sludge  over the site.

 References - 3, 7, 8, 22, 73, 96, 142
                                                  A-156
-------
Ul
REFERENCE
                                                        Millions  Of  Dollors
o
o
                                                 Annua  Cos!, Millons  Of  Dollars


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-------
LAND  APPLICATION OF  SLUDGE                                                     FACT  SHEET 6.1,3
 Description -  Techniques for applying liquid sludge, dried  sludge  and  sludge  cake to  the  land  include tank truck,
 injection,  ridge and furrow spreading,  spray irrigation.  Sludge can be  incorporated  into the  soil by plowing,
 discing,  or other similar methods.   Ridge  and furrow methods  involve spreading  sludge in  the furrows and planting
 crops on  the ridges,   utilization of this  technique is  generally best  suited  to relatively  flat  land and is well
 suited to certain row crops.   Spray irrigation systems  are  more flexible,  require less  soil preparation and can be
 used with a wider variety of crops.   High  application rates are commonly used to reclaim  strip mine spoils or
 other low quality land.   Sludge  spreading  in forests has  been limited, but offers opportunities  for improved soil
 fertility and  increased  tree growth.

 Applications - Is popular as a disposal method because  it is  simple.   Also serves as  a  utilization measure since
 it is beneficial as a soil conditioner for agricultural,  marginal, or  drastically disturbed land.  It contains
 considerable quantities  of organic matter, all of  the essential plant  nutrients, and  a  capacity  to produce water
 retaining humus.

 Limitations -  Constituents of sludge may limit the acceptable rate of  application, the  crop that can be grown, or
 the management or location of the site.  Trace elements added to soil  may  accumulate  in a concentration that is
 toxic to  plants or is taken up and concentrated in edible portions of  plants  in a concentration  that is harmful to
 animals or man.   Trace elements  problem can be prevented  by limiting the amount of sludge to be  applied, indus-
 trial pretreatment,  selection of tolerant  or non-accumulating crops, selection  of crops not used in the human food
 chain, and adapting appropriate  agronomic  practices such  as liming of  the  soil.  Where  population is concentrated,
 and agricultural land limited, sufficient  land for sludge application  may  not be available.  Terrain must be
 carefully selected;  steep slopes and low lying fields are less suitable  and require more  careful management.
 Equipment with standard  tires can cause ruts, compacted soil  and crop  damage  or get  stuck in muddy  terrain.

 Typical Equipment/No. Mfrs.  (21)  - Farm equipment  or tank trucks with  standard  tires  can  be adapted for sludge
 application.  However, specially designed  sludge application  equipment with high flotation  tires and apparatus for
 applying  liquid or dry sludge, or for subsurface injection  is now  available.  This equipment has a 15 Ib/in
 compaction factor with an 8-ton  payload and does minimize rutting, compaction or crop damage when sludge applica-
 tions are made under proper soil moisture  conditions.

 Performance -  Municipal  sludge contains all of the essential  plant nutrients.   It can be  applied at rates which
 will supply all the nitrogen and phosphorus needed by most  crops.  It  may  also  increase the concentration in
 plants of certain elements which are at or near deficiency  levels  for  animals.  For instance,  animal diets are
 often deficient in trace elements such as  zinc,  copper, nickel, chromium,  and selenium.   Thus  sludge application
 may improve the quality  of feeds and forages used  for animal  consumption.  Sludge as  fertilizer  can provide the
 following agricultural needs:
      Sludge                                    Nitrogen                   Phosphate               Potash
      1 ton dry sludge provides                 60  Ibs  (50%  avail)          40 Ibs                   5 Ibs
      Typical corn fertilizer provides (Ib/acre)    180                      50                     60
      If 6 tons dry sludge/acre
      were applied, would provide (Ib/acre)     180 (avail)                 240  (avail)             30  (avail)

 Design Criteria -
      Application rates depend on sludge composition, soil characteristics  (usually 3%N; 2%P; 0.25%K), climate,
 vegetation, and cropping practices.   Annual application rates have varied  from  0.5 to more  than  100 tons per acre.
      Applying  sludge at  a rate to support  the nitrogen  needs  of a  crop of  about 5 to  10 tons of  digested solids in
 the liquid form, avoids  problems associated with overloading  the soil. Rates  based on phosphorus needs are lower.
      A pH of 6.5 or greater will minimize  heavy metal uptake  by most crops.

 Unit Process Reliability - As a  disposal process,  very  reliable; as a  utilization process,  careful control should
 be exercised.

 Toxics Management - Soil has a variable capacity to filter, buffer, absorb, and chemically  and biologically react
 with a sludge's constituents. Toxics may  pass through  the  soil unchanged, be degraded  by microorganisms, react
 with organic or inorganic compounds to form soluble or  insoluble compounds, be  adsorbed on  soil  colloids, or be
 volatilized from the soil.  Factors influencing these pathways include the physical and chemical state of the
 material  and of soil constituents,  microbial population,  solubility, pH, the  cation exchange capacity, soil
 aeration, moisture and temperature.   Generally,  most heavy  metals  applied  to  the surface  are bound in the soil.

 Environmental  Impact - Potential for toxics and pathogens to  contaminate soil,  water, air,  vegetation, and animal
 life, and ultimately to  be hazardous to humans.  Accumulation of toxics  in the  soil may cause  phytotoxic effects,
 the degree of  which varies with  the tolerance level of  the  particular  plant specie and  variety.  Toxic substances
 such as cadmium that accumulate  in plant tissues can subsequently  enter  the food chain, reaching human beings
 directly  by ingestion or indirectly through animals. If available  nitrogen exceeds plant  requirements, it can be
 expected  to reach groundwater in the nitrate form.  Toxic materials and  pathogens can contaminate groundwater
 supplies  or can be transported by runoff or erosion to  surface waters  if improper loading occurs.  Aerosols which
 contain pathogenic organisms may be present in the air  over a landspreading site, particularly where spray irri-
 gation is the  means of sludge application.  Some pathogens  remain  viable in the soil  and  on plants for periods of
 several months; some parasitic ova can survive for a number of years.  Other  potential  impacts include public
 acceptance and odor.

 References - 8, 11,  20,  21,  25,  33,  34,  66, 98
                                                      A-158
-------
LAND APPLICATION OF SLUDGE
                                                      FACT SHEET 6.1.3
ENERGY NOTES  (98) - Energy required to apply sludge to  land  is  approximately  1.2  million Btu/dry ton sludge or
58,000 Btu/wet ton sludge @ 5 percent solids, excluding  transport  of  sludge  to  the  site.
      it
 COSTS - (3)  Assumptions:
 Service Life 30 years; ENR = 2476

 1.   Construction costs include: storage lagoon  (6 weeks);  land preparation, monitoring wells  (3  at 0.1  Mgal/d,  5
      at 1 Mgal/d, 8 at 10 Mgal/d, 25 at 100 Mgal/d) and service roads.
 2.   Costs are for application of digested biological sludge - 900  Ib/Mgal at  4 percent solids.
 3.   Transport of sludge to site is not included.
 4.   Sludge application rate - 10 ton  (dry)/acre/yr.
 5.   Land costs are not included.
 6.   Sludge application is by subsurface injection - unit attached  to haul truck.
 7.   Operation and maintenance costs include:  labor costs  for sludge operation, preventive  maintenance, and minor
      repairs; material costs to include replacement of parts and  repair performance  by outside  contractors.
 8.   If costs are desired for different application rates,  enter  curve at effective  flow  (Qg).
      CE = C^CTr.M X      10 ton  (dry)/acre/yr
           "DESIGN
Note:  Total  costs
                     New Design Application  Rate

                   have been derive,', from the material and labor costs given in reference 3.
                     CONSTRUCTION COST
                                                                      OPERATION & MAINTENANCE COST
        0 1
    o

    5  0 01
       0001
                           Total.
. Land Preparation Cost
                                                             1 0
                                                             0 1
                                                         2 V
                                                            001
         0 1
                       1 0            10            100
                      Wastewater Flow, Mgal/d
                                                            0001
                                                                Materials.
                                                                          Labor-
                                                                                                          001
                                                                           0001
                                                               0 1
                                              1 0            10
                                             Wastewater Flow, Mgal/d
                                                                                                       100
                                                                                                         00001
   An example of  the costs  for one project  that  utilizes  high  flotation  equipment is  provided (98).
   Assumptions and Equipment Characterics

   1.   Equipment operates  50 wk/yr,  40 h/wk  or  2000  hr/yr
   2.   Application  rate  8000 gal/h,  5 percent dry  solids
        = 400 gal dry  solids/h X  8.34 Ib/gal  = 3336 Ib/h
        = 3336 dry ton/yr.
   3.   Eight ton payload has 15  Ib/in  compaction  factor.
   4.   Haul distance  from  sludge source to spreading site
        = 1/4 mile
   5.   Fuel consumption: diesel  - 6  gal/h; gas  - 9 gal/h
   6.   Service  life - 10 yr.
   7.   Prices  as of November  1977.  ENR Index = 2659

   REFERENCES -   3, 8,  98


 *To  convert construction cost  to capital  cost see Table A-2.
                                 Operating Estimates  of High Flotation  Equipment
                                 Maintenance  S  Repair       2,000
                                 Fuel Cost
                                   Diesel @ 60-?/gal         7,200
                                   Gas @ 65
-------
SLUDGE  LANDFILLING - AREA FILL
                                                       FACT SHEET 6.1.4
Description - A sludge disposal operation in which sludge is placed above the original earth cover and subsequently
:overed with soil.  To achieve stability and soil bearing capacity, sludge is mixed with a bulking agent,  usually
loll.  The soil absorbs excess moisture from the sludge and increases its workability.  The large quantities of
loil required may require hauling from elsewhere.  Provisions must be made to keep the stockpiled soil dry.
installation of a liner is generally required for groundwater control and provisions made for surface drainage
:ontrol, gas migration, dust, vectors and/or aesthetics.  Area fills are more specifically categorized as  follows:
     Area Fill Mound - Sludge is mixed with a bulking agent, usually soil, and the mixture is hauled to the  filling
area, where it is stacked in mounds approximately 6 ft high.  Cover material is then applied in a 3 ft thickness.
This cover thickness may be increased to 5 ft if additional mounds are applied atop the first lift.  The appropriate
sludge/soil bulking ratio and soil cover thickness depend upon the solids content of the sludge as received, the
leed for mound stability and bearing capacity as dictated by the number of lifts and equipment weight.  Lightweight
equipment with swamp pad tracks is appropriate for area fill mound operations; heavier wheel equipment is  appro-
iriate in transporting bulking material to and from stockpiles.  Construction of earthen containments is useful to
minimize mound slumping; and for sloping sites.
     Area Fill Layer - Sludge is mixed with soil on or off site and spread evenly in consecutive layers 0.5  to 3 ft
thick.  Interim cover between layers may be applied in 0.5 to 1 ft thick applications.  Layering may continue to an
 ndefinite height before final cover is applied.  Lightweight equipment with swamp pad tracks is appropriate for
,rea fill layer operations; heavier wheel equipment is appropriate for hauling soil.  Slopes should be relatively
:lat to prevent sludge from flowing downhill.  However, if sludge solids content is high and/or sufficient bulking
soil is used, the effect can be prevented and layering performed on mildly sloping terrain.
     Diked Containment - Dikes are constructed on level ground around all four sides of a containment area.
Alternatively, the containment area may be placed at the toe of the hill so that the steep slope can be utilized as
 ontainment on one or two sides.  Dikes would then be constructed around the remaining sides.  Access is provided
to the top of the dikes so that haul vehicles can dump sludge directly into the containment. A 1-3 ft interim cover
may be applied at certain points during the filling; a 3-5 ft final cover should be applied when filling is  dis-
continued.  Cover material is applied either by a dragline based on solid ground atop the dikes or by track dozers
directly on top of the sludge, depending upon sludge bearing capacity.  Usually, operations are conducted without
the addition of soil bulking agents, but occasionally soil bulking is added. Typical dimensions:  50-100 ft  wide,
100-200 ft long, 10-30 ft deep.

Modifications - Codisposal:  sludge/refuse
Technology Status - Relatively new, not in widespread use.
Applications - Suitable when subsurface placement is impossible due to shallow groundwater or bedrock.
     Area Fill Mound - Suitable for stabilized sludge; good land utilization; higher manpower and equipment
requirements due to the constant need to push and stack slumping mounds.   Area Fill Layer - Suitable for stabi-
lized sludge; poor land utilization; less manpower and equipment requirements. Diked Containment - Efficient land
use; suitable for stabilized or unstabilized sludge; less soil requirement.

 imitations - Rainfall causes mounds to slump.  Operating difficulties in wet and freezing weather.
Typical Equipment/No. of Hfrs. - Front-end loader/7; bulldozer/19;  scraper/25; backhoe/45; dragline/13; grader/25.
Chemicals Required - Lime and masking agents to control odors.
Residuals Generated - None
Design Criteria -
Sludge solids content
Sludge characteristics
Ground slopes

Bulking required
Bulking ratio soil: sludge
Sludge application rate
Equipment
                              Area Fill Mound
                              Greater than 20%.
                         Area Fill Layer
                         Greater than 15%.
Stabilized.
No limitation if
suitably prepared.
Yes.
0.5 to 2 soil:l sludge.
3000 to 14000 yd /acre.
Track loader, backhoe
with loader, track dozer.
Stabilized.
Level ground preferred.

Yes.
0.25 to 1 soil:l sludge.
2000 to 9000 yd /acre.
Track dozer, grader,
Diked Containment
20 to 28% for land-based
equipment; more than
28% for sludge-based
equipment.
Stabilized or unstabilized.
Level ground or steep terrain
if suitably prepared.
Occasionally.
0 to 0.5 soil:l sludge.
4800 to 15000 yd /acre.
Dragline, track dozer, scraper.
                                                             track loader.
 Process Reliability - Very reliable sludge disposal method.
Environmental Impact - Potential soil erosion, dust, vectors, noise and odor problems.  Leachate and gas continue
to be produced  for many  years  after the  fill  is  completed;  leachate must be properly  controlled to avoid ground-
water and surface water  contamination; gas  is explosive  and can migrate to nearby structures, or can stunt or kill
vegetation if not properly controlled.   Mud can  be  transferred to local roads by transport vehicles, can be allevi-
ated by a wash  pad located near the exit gate.   Area fill  layer relatively land intensive.

References - 148, 168
                                                      A-160
-------
 SLUDGE  LANDFILLING -  AREA  FILL
                                                                                 FAC1  SHEET
FLOW DIAGRAM
                                                                           GAS ,  LEACHATE  TO TREATMENT
ENERGY  NOTES  (171)  -  Actual fuel consumption varies considerably with specific sludge,  site  and  operating con-
ditions.   Fuel  consumption rates for some typical construction equipment performing  light  to medium work is given
1~ -. 1 A. .
Equipment
Caterpillar  D-6
Caterpillar  D-8
Excavator - !

       Hi to IS
       l»s to 2
Wheel Loader IS
             2
             3
             4
             5
             7
               yd,
                ^3
                ^3
                Y^3
                yd..
                yd
                    Average Diesel
                    Fuel, gal/hr
                         5.2
                        10.8
                         3.4
                         5.0
                         8.8
                        11.1
                         3.0
                         3.7
                         4.6
                         6.2
                         9.0
                        13.2
Equipment
Grader - 25,000 Ob
         28,000 Ib
         30,000 Ib
         40,000 Ib
         54,000 Ib
Track Loader - 1 yd
               2  yd
               2.5 Xd
                                                                  3
                                                                  4
                                                   Tractor-Scraper,
                   yd

                 Y3
                 yd
                 small
                 medium
                 large
Average Diesel
Fuel, gal/hr
     4.4
     4.8
     5.2
     6.0
     7.9
     2.4
     3.4
     4.2
     5.7
     7.4
    11.3
     4.9
    11.4
    15.8
 One  case  study  that used a sludge landfill operation was estimated to consume  700,000  Btu/dry  ton  sludge (1 gal
 diesel  fuel  = 140,000 Btu).

 COSTS*  (168)  -  Assumptions:  First quarter 1978 dollars; ENR Index =  2681.
 3.
Site and equipment costs include land  ($2500/acre),  site  preparation (clearing, grubbing, surface water
control ditches and ponds, monitoring wells,  soil  stockpiles,  roads and facilities), equipment purchase,
engineering  (6%).  Actual fill area consumes  50 percent of total  site area.
Operating costs include labor  ($8/hr, including fringe, overhead,  administration), equipment fuel, main-
tenance and parts; utilities;  laboratory  analysis  of water samples; supplies and materials.
Actual costs vary considerably with specific  sludge  and site  conditions.
                         SITE AND EQUIPMENT COSTS
                                                                                OPERATION s MAINTENANCE COSTS
                       20  30 40 50
                                            200  300 400 500
                                                                              20  30  40 50
                                                                                                    200 300 400 500
                           Sludge Quantity Received
                                (Wet Tons/Day)
 REFERENCES - 168,  171

 *To convert construction cost to capital cost see Table A-2.




                                                    A-161
                                                                             Sludge Quantity Received
                                                                                  (Wet Tons/Day)
-------
LIQUID  SLUDGE TRANSPORT (PIPELINE)
                                                                FACT SHEET 6.1.5
Description  (8, 22) - The movement of liquid sludge having a maximum total solids content of 5 percent, by centri-
fugal pumps  through a pipeline of two miles, minimum length, from the point of origin, such as a wastewater treat-
ment plant,  to a designated site selected for the particular sludge.  Depending on the terrain and length of the
line, intermediate dry well pumping stations (factory packaged or field constructed)  may be required to maintain
the flow to  the site.

Common Modifications (3, 8, 72, 105) -
Carbon steel pipe unlined and cement lined.
Cast iron pipe, unlined, and cement and glass lined.  Ductile iron pipe, unlined and cement lined.
Cement-asbestos.
Fiberglass-reinforced epoxy pipe.  Plastic pipe.
Depending on the length and pressure drop of the line, intermediate lift stations are provided.
Depending on the sludge utilization procedure to be followed at the site, dewatering at the site may be necessary.

Technology Status - Highly developed and in relatively widespread use.

Limitations  (26, 73) - Relatively high capital cost; long construction period; site must be available for a long
period of time; flushing or "pigging" of entire line may become necessary requiring shut-down of line.

Design Criteria (22, 105)  - Sludges are thixotropic.  The most economical sludge pumping occurs at the critical
velocity where turbulent flow begins, and where the mixing and agitation reduce the viscosity (and head loss).
Some critical velocities at 4 percent solids for various pipe diameters are:
                            Critical Velocity (ft/s)
                Dia.          Lower           Upper         Maintaining the operating velocity in the lower
                 8            3.58            4.52          portion of the turbulent flow zone results in
                10            3.55            4.42          maximum economy.  Critical velocity is a function
                14            3.45            4.31          of solids content as well as pipe size.
                20            3.40            4.23
Increasing the velocity is one method for causing turbulence, viscosity reduction,  and self-cleaning.  However
velocities much above the critical will involve an excessive head loss because of friction.   Head losses attribu-
table to the sludge characteristics increase when:  the solids concentration increases; size of the coarse sludge
particles increase; the volatile content increases; the temperature decreases; the  velocities are too high or too
low.  Effective grit removal is necessary for economical pumping.   Grit increases viscosity and settles out during
periods of little or no flow causing a temporary increase in pipe roughness and head loss.   Pumping anaerobically
digested sludge results in lower head loss as a result of friction than pumping raw primary sludge of the same
solids content (dry basis)  and flow condition.    Turbulent flow tends to prevent deposition of grease. Pipeline
materials and linings influence head losses as a result of differing friction flow  factors.   Mechanical and chemi-
cal aids such as macerators, in-line mixers, and polymers are sometimes used to reduce viscosity and head loss.
Operating controls usually are float control, density gauges, flow meters, pressure switches and pressure gauges.
The literature indicates that the hydraulic characteristics of wastewater sludges have not  been well defined
because of their indefinite nature and that finite predictions of head losses are impossible to make.  The
approach has been to provide an adequate safety factor when designing sludge pump and piping systems.
Brief characteristics of Pipeline and Pumping
Description
Pipe

Pipe

Pipe

Pipe

Pipe

Pipe

Pipe

Pipe

Pumping Station
Packaged
Pumping Station
Field Const.
Material
Cast or ductile iron,
unlined
Cast or ductile iron,
cement-lined
C.I. glass lined

Steel, unlined

Steel, cement-lined

Cement-asbestos

Fiberglass-reinforced
epoxy pipe
Plastic

Various

Various
Stations (105)  -
  Application
  General use;  high
  pressures
  General use;  high
  pressures
  Not in general use.

  General use;  high
  pressures
  General use;  high
  pressures
  General use;  moderate
  pressures
  Not in general use;
  moderate pressures
  Not in general use;
  lower pressures
  In general use

  In general use
Advantages
Less expensive than
most
No corrosion, slow
grease build-up
No corrosion, slow
grease build-up
Less expensive than
most
No corrosion, slow
grease build-up
No corrosion, slow
grease build-up
No corrosion, slow
grease build-up
No corrosion, slow
grease build-up
Less costly than
field constructed
High capacity, high
heads
Disadvantages
Undergoes corrosior
grease build-up
More expensive thar
unlined
Most expensive

Undergoes corrosior

More expensive thar
unlined steel
Relatively brittle

As expensive as
glass-lined pipe
Expensive

10,000 gal/min max.
200 ft head max.
Field constructed
more expensive
Reliability - Very reliable if properly installed.
Environmental Impact - None for air and water;  considerable impact on land during installation.   Potential for
ground water pollution if leak develops.

References - 3, 8, 22, 26,  72, 105
                                                    A-162
-------
 LIQUID  SLUDGE TRANSPORT (PIPELINE)
         FACT SHEET  6.1.5
FLOW DIAGRAM -
Pump
Station
Pipeline

Booster
Pump
Station
(Optional)
Pipeline __

Disposal
Site
ENERGY NOTES - Each pipeline is highly site specific  due  to  static head  and  the  dynamic head  requirements dictated
by the pipe material and size and the characteristics of  the sludge  being pumped.   Approximate energy requirements
for a pipeline can be computed from the equation kWh/yr = 1900  (Mgal/d/yr X  ft of  total head) after  actual con-
ditions have been determined, when assuming a wire to water  efficiency of 60 percent  for  the  pump  station.
COSTS (3)  - Assumptions: ENR Index =  2475
1.   Construction cost includes:   pipeline and pumping  stations, one major highway crossing per mile, one single
     rail crossing per 5 miles,  nominal number of  driveways  and minor road crossings.

     Pipeline is buried 3 to 6 ft.  (add 15 percent for  6  to  10 ft.), no  elevation change in pipeline.

3.   Pipeline is cement-lined cast or ductile  iron,  4 inch minimum  pipe  size.

4.   Pumps are dry-pit, horizontal or vertical,  non-clog  centrifugal  (1780 r/min).

     Construction cost does not include:   rock excavation or major  unusual problems  (add 70 percent to cost for
     hard rock).

     Operation cost includes:  labor, supplies,  and electrical power for pump  stations; 12 hours pumping per day;
     flow velocity of 4 ft/s.
                   CONSTRUCTION COST
                                                                        OPERATION & MAINTENANCE COST
      10
      0 1
                                                20 miles

                                                10 miles

                                                 5 miles
                                                              001
       10
REFERENCE  - 3
                    100          1000          10000
                  Sludge Pumping Rale, gal/mm
                                                                 10
   100         1000
Sludge Pumping Rate, gal/mm
                                                                                                       10000
 *To convert construction cost  to capital  cost see Table A-2.
                                                    A-163
-------
LIQUID SLUDGE  TRANSPORT  (RAIL)                                                FACT SHEET  6.1.6
Description - Liquid sludge having a maximum total solids content  of  six percent may be  transported by railroad
tank cars from point of Origin, such as a wastewater treatment plant  or pipeline  terminus,  to a designated site.
The site may be adjacent to the railroad or joined by pipeline to the unloading site.  The  cars used may be owned
or rented by the operator depending upon the economics of the location.

By virtue of its existing right-of-way, the railroad in many instances can provide  the opportunity  for use of
selected land for sludge disposal.  Transport to the site from the railroad  terminus may be a major element in the
development of an integrated disposal system.  Other important considerations  include the methods and equipment to
be used for unloading, storage, and distributing the sludge at the site.

Technology Status - Not in widespread use even though railroad technology is highly developed.
Limitations - Fixed position of railroad limits site selection.   Relative  transportation  costs  ($/ton dry solids
basis) indicate that railroad tank cars are the most expensive method of transporting  sludge  for  distances up to
approximately 150 miles when compared to a tank truck and up to approximately  200  miles when  compared  to a pipe-
line.  For greater distances, rail tank car transportation is least expensive.   May  not be applicable  for small
operation.

Design Criteria - Rail line should be near or next to the site to reduce length of spur,  siding,  or pipeline.
Sludge storage at wastewater treatment plant should equal one day's production.

Cars should be 20,000 gallon capacity, and pumping station filling rate should be  1.5,  2,  3,  and  15 hours,  respect'
ively, for 1, 10, 20, and 100 car groups.

Cars should be gravity unloaded at the terminus for pumping to storage and/or disposal.

Typical Equipment/ No. of Mfrs. (23)  - Sludge handling and control/32; cars,  dump/14.
Reliability - With respect to scheduled deliveries to the site:   very reliable  for unit  train;  not  reliable  for
single or few cars, since railroads would tend to preferentially select equipment for use  in  heavy  tonnage hauls
of other commodities.

Environmental Impact - None for air and water unless leak in car.
References - 3, 7, 8, 23, 72, 83, 101, 104, 142
                                                        A-164
-------
 LIQUID SLUDGE  TRANSPORT  (RAIL)
                                                               FACT SHEET 6.1.6
 FLOW DIAGRAM -
                    Treatment Plant
                                                                              Site


 ENERGY NOTES (161)  - Rail transport can be considered to require approximately  25 percent of  the energy  in Btu/ton
 mile when compared to truck transport.   See Fact Sheet 6.1.7 for truck energy requirements for  large  vehicles.
 Pumping energy for loading is insignificant compared to the transport energy.

COSTS - Construction cost includes loading facilities: storage for one day's production; pump and piping system
sized to fill 1, 10, 20 and 100 tank cars each with 20,000 gal capacity to be filled in 1.5, 2,  3, and 15 h,
respectively.  Solids content at 4 percent.  Construction cost does not include storage at unloading area.
Operation cost includes 8 h/d operation; car lease, labor, electrical energy, supplies maintenance (Full car
maintenance annual lease rate is assumed at $525/car); travel distances of 40, 80 and 160 miles  one way;  rail haul
charges based on the following:
     Area
     North Central and Central
     Northeast
     Southeast
     Southwest
     West Coast
                  Approximate  R.R.  Rate Variation  (adjust Accordingly)
                  Average Rate - Approximately  $0.06/ton mile
                  25 percent higher than average
                  25 percent lower  than average
                  10 percent lower  than average
                  10 percent higher than average
ENR Index =  2475.
         10
                      CONSTRUCTION COST
         1 0
         0 1
        001
                                                                  100
                                                                           OPERATION & MAINTENANCE COST
                                                                   10
                                                               15   1 0
          1 0
  10            100
Annual Sludge Volume. Mgal
                                                 1000
                                                                   0 1
                                                                                      160 Mile
                                                                                80 Mile
                                                                                                <-• -40 Mile
                                                                                  10            100
                                                                                Annual Sludge Volume. Mgal
                                                                                                           1000
 REFERENCES - 3, 161,  142
'To convert construction cost to capital cost see Table A-2.
                                                      A-165
-------
LIQUID  SLUDGE TRANSPORT (TRUCK)                                               FACT SHEET 6.1.7
 lescription - The movement over highways and roads by tank trucks,  of liquid sludge  having  a maximum total  solids
 :ontent of 6 percent, from its point of origin, such as a wastewater treatment plant,  to  a  distant designated
 lite selected for the particular sludge.  The site is next to a road or highway.

Common Modifications (96) -
 spending upon state road laws, the type of vehicle would vary between the following:

     .Two axle and three axle tank trucks.
     .Two axle tractor with one axle semi-tank trailer.
     .Two axle tractor with two axle semi-tank trailer.
     .Three axle tractor with two axle semi-tank trailer.
     .Two or three axle tank truck with a two or three axle tank trailer.

Gasoline or diesel engine power.  Diesel engine power preferred because of cheaper fuel  and lower maintenance
costs.

 'echnology Status - Highly developed and in widespread use.
 .imitations (7, 8, 21, 73, 96) -
 tate road laws which limit load of vehicle.  In Ohio,  for example,  the maximum payloads  would be:

     Vehicle                                                          Payload,  Gal (Tons)
     2 axle tank truck (Note a.)                                            1200      (  5)
     3 axle tank truck (Note b.)                                            2500      (10)
     5 axle tractor semi-trailer tank (Note c.)                             5800      (24)

     Note a.   Most commonly used vehicle for hauling and, if the site surface  is suitable,  for spreading as
               well.  Normally, special off-road tank vehicles are used for spreading.
     Note b.   Some wastewater treatment plants use vehicles of this type,  with only a  fraction of  the legal
               loads, to provide better flotation over soft ground.
     Note c.   Montgomery County, Ohio uses this vehicle with about a 5000  gal  (21 ton)  capacity to haul and
               spread.

Generally, highway and road loadings are in accordance with American Association of State Highway Officials Class
Standards H10, H15, H20,  HS15, and HS20.

 'ransportation of sludge by pipeline is generally more economical and more  convenient than tank truck handling,
although it does have higher capital costs and is inflexible.  Relative transportation  costs (S/ton dry solids
 iasis) indicate that tank trucks are the most expensive method for transporting sludge  for distances of approx-
imately 150 miles and over when compared to pipeline and railroad tank car.  For less than 150 miles it is less
expensive than railroad tank car, assuming that both require unloading at the disposal  site.

Truck transport generally  has  a  lower initial investment  cost but will have higher operating costs relative to
rail  or pipeline  transport for most  levels  of design volume.  Trucks are very  flexible.

 Design Criteria  (3)  -
 Liquid  sludge  should have a maximum  solids content of 6 percent.

 Vehicle should be  loaded by gravity  from a storage tank and gravity unloaded at the site.

 Loading equipment  should be sized  to fill vehicle in 20 minutes maximum.

 Typical Equipment/No,  of Mfrs.-  See  Society of Automotive Engineers (SAE) roster of truck and trailer manufac-
 turers.

 Reliability  -  Very  reliable.
 Environmental  Impact  - None  for air  and water unless a leak develops in the tank.  Small for land if temporary
 roads  are built from highway  to unloading area within disposal site. Noise and general disruption due to truck
 traffic may constitute  a  nuisance.

 Comments  (8)  -  Highway  vehicles offer  some  flexibility of movement to various sites when compared to rail.
 Transport to  the  site  should be one  element of an integrated design for the production and ultimate disposal of
 the sludge.   Other  important elements  of  this design are  the methods and equipment to be used for unloading,
 storage,  and  distributing  the  sludge at the site.

 References -  3, 7,  8,  21,  73,  96
                                                   A-166
-------
 LIQUID SLUDGE  TRANSPORT  (TRUCK)
                                                                   FACT  SHEET  6.1.7
 FLOW DIAGRAM -
                                                                                  Site
 ENERGY NOTES (142) - Approximate average annualgBtu used per Mgal  sludge per  one-way  tripmile for 1,200, 2,500,
 and 5,500 gal trucks are,  respectively,  51 x 10 ;  22 x 10 ;  14  x 10   Btu.  Electrical energy required for pumping
 is insignificant with respect to transportation energy needs.


      *
 COSTS - Assumptions: ENR Index = 2475
 1.   Construction cost includes load/unload facilities and purchase of the most cost  effective size trucks per
      volume of sludge transported;  i.e., 1200 gal,  2500 gal,  and 5500 gal.  Does not  include storage at unloading
      site.
 2.   Equipment is sized to fill truck in 20 rain, maximum.
 3.   Sludge = 4 percent solids.
 4.   Operation and maintenance costs include truck  maintenance  and operation  and supplies for the loading
      facility.
 5.   Fuel cost (Gasoline)  = $0.60/gal; electrical power @ $.02/kWh.
 6.   Labor  @ $7.50/h.
 7.   Most cost effective size trucks per volume of  sludge transported; i.e.,  1200 gal, 2500 gal, 5500 gal.
 8.   8  h/d  operation; 360  d/yr.
 9.   Travel distances of 10,  20,  or 40 miles one way to disposal site.
             10
                          CONSTRUCTION COST
             1 0
         Q
         ~O
         £
         O

         s
             0 1
            001
                       40 Miles ;
20 Miles
    7*
           '?
              • 10 Miles
                                                                   10
                                                                            OPERATION & MAINTENANCE COST
                                                                   1 0
              1 0
 REFERENCES -  3, 142
                            10           100          1000
                           Sludge Volume,  Mgal/yr
                                                                  001
                                                                               40 Miles :;_
                                                         20 Miles.
z
                                                                             10
                                                                     1 0
                                                                 10           100          1000
                                                               Sludge Volume, Mgal/yr
*To convert construction cost  to  capital  cost  see Table A-2.
                                                          A-167
-------
SLUDGE  PUMPING
                                                                  FACT  SHEET  6.1,8
Description  (22) - Sludges, scum, screenings, and sludge cakes have different viscosities and solids  content at
different locations.  Pumps are employed to move these materials where gravity flow is not possible or where the
receiving location requires a specific flow and pressure of the pumped fluid.   Capacities up to 80,000 gal/min and
210 ft head with fluids having up to 20 percent solids content are required.

Common Modifications  (22) - Electric motor or internal combustion engine power.   Variable speed belt,  chain, and
fluid drives. Materials of pump internal parts construction vary according to the properties of the fluids pumped.

Technology Status - Highly developed.
Applications  (22, 52) - Stormwater treatment facilities where gravity return of residuals to the dry weather sewer
is not possible.  Wastewater treatment plants to convey residuals from process to process.   Wastewater treatment
plants to convey sludge from plant to disposal site by pipeline.

Typical Equipment/No, of Mfrs.  (23) - Pump units/34.
Design Criteria  (7, 22, 52) - Sludge pumping equipment is selected on the basis of sludge concentration and the
operation intended:
                  Max.Solids   Max.Suction   Capacity   Max.Head   Typ.Eff.
Pump Type
Centrifugal,
2 port,
non-clog
Centrifugal,
vortex flow

Mixed flow
Air lift

Screw lift

Positive Displ.
progressing cavity,
plunger, and
diaphragm
Handled, %
   2
   6

   6

  20
Lift, ft
   15




   15


   15


   NA

    0

   28
gal/min
50-20,000
20-5,000


1000-80,000


30-150

100-70,000

30-700
                                                           ft
200




210


 60


 60

 40

500+
60-85




55-65


80-88


low

70-80

30-80
Typical Applications
Raw wastewater, primary and
secondary settled sludges, land
application, chem. treated sludge,
incinerator slurries.

Sludge recirculation, effluents with
stringy material.

Sludge recirculation, land appli-
cation.

Raw wastewater, return sludge, scum.

Raw wastewater, return sludge.

Primary settled, thickened, digested,
incinerated, heat conditioned, and
chemically treated sludges, scum.
Viscosity limit for efficiently operated centrifugal type pumps is 3000 to 3500 sSu

Non-clog, low r/min, low head centrifugal pumps are used for pumping return activated sludge because the sludge is
dilute, contains only fine solids, and the sludge's flocculent solids would not be significantly sheared by the
pump.

Plunger and progressing-cavity pumps are best for concentrated sludges to overcome high friction-head losses in
discharge lines.  However solids should be reduced to small aize (max. 1.5" for progressing cavity).

Screw lift pumps are good for variable capacity operation because the rate of discharge is controlled by the fluid
level at the inlet to the screw.  Variable speed drive not required.

In general, the centrifugal and screw lift pumps are used to handle larger sludge flows with lower solids content
and where precise control of flow is not required.

Air lift pumps, though of simple design and construction and not susceptible to clogging,  are difficult to throttle
and control and require large amounts of air.

Flow conditions can be improved by adding certain types of polymers to reduce viscosity of the fluid.

Reliability - Ten to 20 year expectancy provided manufacturer's maintenance procedures are followed.  Reliability
highly dependent on power source.

Environmental Impact - Low impact on air and water.  Small impact on land for pumps which are in process lines.
Potential for pollution under failure conditions.

References - 7, 22, 52
                                                      A-168
-------
SLUDGE  PUMPING
                                                                                    FACT SHEET  6.1.3
FLOW DIAGRAM - Possible locations for major sludge pumps in a wastewater treatment plant:
        Bar Screen
                                                                                                       or  Disposal
                                                                                  Pump
ENERGY NOTES - Each pump application is highly site specific due to static head and the dynamic head requirements
dictated by the piping configuration and the characteristics of the sludge being pumped.  Approximate energy
requirements for a pump installation can be computed by the following equation:

             1140 (Mgal/d X ft of total head)
    kWh/yr «   Wire to Water Pump Efficiency

Wire to water efficiencies may vary from 75 percent to less than 40 percent, depending upon the type pump used and
its size.  Use of variable speed drives at speeds other than 100 percent speed generally lowers the wire to water
efficiency.

COSTS -  ENR INDEX = 2475 *
1.   Costs are based on a sludge loading of 1900 Ib/Mgal at 4% solids, i.e., 5700 gal of sludge/Mgal for combined
     primary and secondary sludge after thickening.
2.   Non-clog centrifugal pumps.  Service  life:  10  years.
3.   To adjust costs for alternative sludge quantities and characteristics, enter curves at effective flow  (Q£)=

     Q  = QnFt;TrN X NEW DESIGN  SLUDGE MASS. LB/MGAL X 	4%	
                         1,900  Ib/Mgal                 NEW DESIGN  CONCENTRATION  (%)

Note: New Design concentration should not exceed 5%.
4.   Power at 2C/kWh.
                    CONSTRUCTION COST
                                                                        OPERATION & MAINTENANCE COST
   2
   ^
   i
   B
   tn
   c
   O
   5  0 01
     0001
                                                              0 1
                                                              001
Q 5
o £
                                                         •s -f 0001
                                                         31
        01
                     1 0            10
                     Wastewater Flow  Mgal/d
                                                100
                                                            00001
                      Matenals-
                                                                                                  Tola ,
                                                                                                             001
                                                                                                            0001
                                                  00001
                                                                                                          000001
                                                                01
                     1 0           10
                    Wastewater Flow, Mgal/d
                                                                                                        100
 REFERENCES - 3, 22

  *To convert construction cost to capital cost see Table A-2.


                                                    A-169
-------
 iLUDGE  STORAGE                                                                    FACT SHEET 6.1,9
Ascription (7,8)  - For the purposes of this fact sheet,  sludge  storage  is  the  retention and blending of thickened
 trimary and secondary sludges in an open tank.   The purposes  of sludge  storage  are to reduce the pathogen popu-
 ation by aeration and mixing, to further stabilize the sludge,  to  equalize  short-term peak loads, and to either
 repare the sludge for further processing or provide the means  for  loading the  sludge into a disposal system.   (The
 letention afforded by sludge storage can be used to further thicken the sludge.)

Common Modifications (22)  - Rectangular or cylindrical tanks  can be used, and agitators can be used for mixing.
Sludge can also be mixed by the use of recycle.   Air or pure oxygen  can  be  used  for aeration and mixing.

Sludge storage can also be used for chemical,  tertiary, as well  as other sludges.  Sludge scraper mechanisms with
 icket arms would then be required.

 'echnology Status - In widespread use.
Typical Equipment/No,  of Mfrs.  (23)  -
 ,gitators/10; air compressors/8;  blowers/7;  mixers/26.

 ipplications - Can be applicable  where separate thickening processes  for primary  and  activated  sludges are used.
It is also used between multiple sludge treatment processes so that each  unit can  b« batch  operated.

Limitations - Potential for odor problems.
Chemicals Required - None.
Residuals Generated - None.
Design Criteria (8,22) - Tank floor slope is generally 1:12.   This increased depth near  the  center  of  the  tank  can
serve to compact the sludge.  Sludge concentration increases as a function  of the  depth  of  the  sludge  blanket.
Effluent line should draw compressed solids out of the bottom of the tank.   Mixing by air diffusion  requires  at
least 25 ft /min/1000 ft .   Mixing by agitators (mixers)  requires approximately 1.0 hp/1000 ft  .

 'rocess and Mechanical Reliability - High degree of reliability provided regular maintenance procedures  for the  air
and mixing equipment are followed.

Environmental Impact - Can create odor problems if breakdown of air system occurs.   Land:   Moderate—depends  on
size of tank.  No residuals are generated.

References - 7, 8, 22, 23
                                                  A-170
-------
SLUDGE STORAGE
                                                                                    FACT  SHEET  6.1.9
I'LOW DIAGRAM
                           Decant Line-*-.
                           Sludge Inlet->
                                                                      I     ^Sludge  Ou
tlet
                                                                                 .Blower
                                            Air Sparger
                                                               Drain Line
                                                 Sludge  Storage  Tank
ENERGY NOTES -
  Based upon the "Cost" assumptions shown below, kWh/yr = 4242 x million gallons per day of plant throughput
  assuming that all conventional activated sludge plant sludges pass through the storage tank.
COSTS -Assumptions:  ENR Index  =  2475
1.  Construction cost includes storage tank and air-supply system.
2.  Operation cost includes storage of thickened primary and secondary sludge (1900 Ib/Mgal;  at 4% solids);
    mixing by diffused air  (25 CFM/1000 ft3 or approximately 130 hp/Mgal of sludge.
3.  To adjust costs for other sludge quantities and concentrations,  enter the curves at effective flow (QE).
10
1 0
o
0
"6
c
o
J 01
001
REFERENCES
CONSTRUCTION COST














—^
































,*-















»*• '
— '



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- 3, 4, 22











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1900 Ib/Mgal







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: §1

5 5
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ro o

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10 10 100
Wastewater Flow Mgal/d
                                                               New Design Sludge Concentrations
                                                                      OPERATION & MAINTENANCE COST
01
tf)
0^ 001
tn cp
II
2 5
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-------
SLUDGE LANDFILLING  - SLUDGE  TRENCHING                                        FACT  SHEET 6,1.10
Description - Stabilized or unstabilized sludge is placed within a subsurface excavation and covered with soil.
Trench operations are more specifically categorized as follows:  narrow trench and wide  trench.   Narrow trenches  are
defined as having widths less than 10 ft; wide trenches are defined as having widths greater  than 10 ft.   The width
of the trench is determined by the solids content of the receiving sludge and its capability  of supporting cover
material and equipment.  Distances between trenches should be large enough to provide sidewall  stability,  as well
as space for soil stockpiles, operating equipment and haul vehicles.  Design considerations should include pro-
visions to control leachate and gas migration, dust, vectors, and/or aesthetics.   Leachate  control measures include
the maintenance of 2 to 5 ft of soil thickness between trench bottom and highest  groundwater  level or bedrock (2 ft
for clay to 5 ft for sand), or membrane liners and leachate collection and treatment system.   Installation of gas
control facilities may be necessary if inhabited structures are  nearby.

Narrow trench - Sludge is disposed in a single application and a single layer of  cover  soil is  applied atop this
sludge.  Trenches are usually excavated by equipment based on solid ground adjacent to the trench,  and equipment
does not enter the excavation.  Backhoes, excavators and trenching machines are particularly useful.   Excavated
material is usually immediately applied as cover over an adjacent sludge-filled trench.  Sludge is  placed in
trenches either directly from haul vehicles, through a chute extension,  or by pumping.   The main advantage of a 2
to 3 ft narrow trench is its ability to handle sludge with a relatively  low solids content (15 to 20  percent).
Instead of sinking to the bottom of the sludge, the cover soil bridges over the trench and receives support from
undisturbed soils along each side of the trench.  A 3 to 10 ft width is  more appropriate for sludge with solids
content of 20 to 28 percent, which is high enough to support cover soil.

Wide trench - Usually excavated by equipment operating inside the trench.   Track loaders,  draglines,  scrapers and
track dozers are suitable.  Excavated material is stockpiled on solid ground adjacent to the trench for subsequent
application as cover material.  If sludge is incapable of supporting equipment,  cover is applied by equipment
based on solid undisturbed ground adjacent to the trench.  A front-end loader is suitable for trenches up to
10 ft wide; a dragline is suitable for trench widths up to 50 ft.   If sludge can support equipment, a track dozer
applies cover from within the trench.  Sludge is placed in trenches by one of the following methods: from haul
vehicles directly entering the trench and haul vehicles dumping from the top of  the trench.  Dikes can be used to
confine sludge to a specific area in a continuous trench.

After maximum settlement has occurred in approximately one year, the area should be regraded to ensure proper
drainage.

Common Modifications - Codisposal: Sludge/refuse
Technology Status - Fully demonstrated.
Applications - A relatively simple sludge disposal method suitable for stabilized or unstabilized sludge.   Does
not require special expertise beyond the skills necessary to operate the above-mentioned equipment, plus adminis-
trative skills.  Narrow trench system particularly well suited for smaller communities.

Limitations - Frozen soil conditions and precipitation cause operating difficulties.
Typical Equipment/Ho, of Mfrs. (83) - Front-end loader/7; bulldozer/19;  scraper/25;  backhoe/45; dragline/13;
trencher/4; grader/25.

Chemicals Required - Lime and masking agents to control odors.
Residuals Generated - None
Design Criteria -
                              Narrow Trench (less than 10 ft)    Wide Trench (more than 10 ft)
Sludge Solids Content         15 to 20 percent for 2 to 3 ft     20 to 28 percent for land-based equipment;
                              widths; 20 to 28 percent for       more than 28 percent for sludge based
                              3 to 10 ft widths.                 equipment.
Ground Slopes                 Less than 20 percent.              Less than 10 percent.
Cover Soil Thickness          2 to 3 ft for 2 to 3 ft widths;    3 to 4 ft for land based equipment; 4 to
                              3 to 4 ft for 3 to 10 ft widths.   5 ft for sludge based equipment.
Sludge Application Rate       1,200 to 5,600 yd /acre.           3,200 to 14,500 yd /acre.
Equipment                     Backhoe with loader, excavator.    Track loader, dragline, scraper, track
                              trenching machine.                 dozer.

Process Reliability - Very reliable sludge disposal method.
Environmental Impact - Potential soil erosion and odor problems.  Leachate and gas continue to be produced for
many years after the fill is completed; leachate must be properly controlled to avoid groundwater and surface
water contamination; gas is explosive or can stunt or kill vegetation if not properly controlled.  The narrow
trench method  is relatively more land  intensive.

References - 148, 168
                                                     A-172
-------
SLUDGE LANDFILLING - SLUDGE TRENCHING
FLOW DIAGRAM



FACT SHEET 6.1.10
GAS AND LEACHATE MAY BE


COLLECTED AND TREATED
ENERGY NOTL'S (171) - Actual iuol coiuiuiiipuiun varies considerably with specific sludge, site and operating con-
ditions. Fuel consumption rates for some typical construction equipment performing light to medium work is given
below.
Average Diesel Average Diesel
Equipment Fuel , gal/hr Equipment Fuel , gal/hr
Caterpillar D-6 5.2 Grader - 25,000 Ib 4.4
Caterpillar D-8 10.8 28,000 Ib 4.8
Excavator - >s yd 3.4 30,000 Ib 5.2
1 yd 5.0 40,000 Ib 6.0
1-1/4 to 1-1/2 yd 8.8 54,000 Ib 7.9
1-1/2 to 2 yd 11.1 Track Loader - 1 yd 2.4
Wheel Loader 1-1/2 yd 3.0 1-1/2 yd 3.4
2 yd 3.7 2 yd 4.2
3 yd 4.6 2.5 yd 5.7
4 yd 6.2 3 yd 7.4
5 yd3 9.0 4 yd 11.3
7 yd 13.2 Tractor-Scraper, small 4.9
medium 11.4
large 15.8
*
COSTS, 1978 dollars (168) - ENR Index = ?77fi
1. Site and equipment costs include land ($2500/acre) , site preparati
control ditches and ponds, monitoring wells, soil stockpiles, roac
engineering (6%). Actual fill area consumes 50 percent of total E
2. Operating costs include labor ($8/hr, including fringe, overhead,
and parts; utilities; laboratory analysis of water samples; suppl:
3. Actual costs varv considerably with specific sludge and site condi
SITE s EQLIFKENT CCSTS
50.00 | 50.00 •
40.00 T 40.00
30.00 •' 30.00
o 20.00 -f co 20.00
r~ f-
" 15.00 i " 15.00 •
a S
~ 10.30 ~ 10.00
1 , 	 J>
j 4.00 T ^^^~~^-^^^^ 	 	 w 4.00
° 3.30 N^ " 	 . 3 3.00
wide Trer.cn
2.00 * 2.00
1 - on 1111 1 i i i i ' ""
10 20 30 40 50 100 200 300 400 500 j
(Wee Tons/Day)
REFERENCES - 168, 171
*To convert construction cost to capital cost see Table A-2.
on (clearing, grubbing, surface water
s and facilities), equipment purchase,
ite area.
administration), equipment fuel, maintenance
es and materials.
tions.
OPERATION & MAINTENANCE COSTS
\~" ~^^ ^.Narrow Trench
'Wide Trench ^ 	
0 20 30 40 50 100 200 300 400 500
Sludge Quantity Received
(Wet Tons/Day)
A-173
-------
SLUDGE LAGOONS                                                                    FACT  SHEET 6,1,11
Process Description (8, 56) - Digested sludge has often been applied to sludge lagoons adjacent to or in the proxi-
mity of treatment facilities.  These sludge lagoons are primarily designed to accomplish long-term drying of the
digested sludge through the physical processes of percolation and evaporation, primarily the latter.   This method
of sludge processing has been extremely popular in the U.S.  due to its relatively low cost (when inexpensive land
is plentiful) and minimal O&M requirements, especially at smaller wastewater treatment facilities.  The process i:
relatively simple, requiring periodic decanting of supernatant back to the head of the plant and occasional mechan-
ical excavation of dewatered or dried sludge for transportation to its ultimate disposal location.  Lagoons can be
a very useful process step.  Supernatant is far better (low SS) than supernatant from a secondary digester or even
a thickener.  Ultimate disposal of the product solids often is as a soil conditioner or for landfilling.

Sludge lagoons may also be used as contingency units at treatment plants to store and/or process sludges when
normal processing units are either overloaded or out of service.

The drying time to 30 percent solids is generally quite lengthy and may require years.  Climatic conditions and
pre-lagoon sludge processing greatly influence lagoon performance.  In warmer, drier climates well-digested sludges
are economically and satisfactorily treated by sludge-drying lagoons because of their inherent simplicity of
operation and flexibility.  Complete freezing causes sludge to agglomerate so when it thaws supernatant decants or
drains away easily.   Well-digested sludges minimize potential odor problems which are inherent in this type of
system.  Multiple-cells are required for efficient operation.

Common Modifications (56) - Methods and patterns of loading, supernatant recycling techniques and mechanical
cleaning techniques vary with location, climate, and type of sludge to be processed.

Technology Status - This technology is widely used for industrial and municipal sludge processing throughout the
world.

Limitations - There is a high potential for odors and nuisance insect breeding if feed sludges are not well-di-
gested.  Odor and nuisance control chemicals are not entirely satisfactory.  Also, definitive data on performance
and design parameters are lacking despite the popularity of this approach.

Typical Equipment/No. Mfrs  (23) - Front-end loaders/7,- bulldozers/19; dragline/13.
Applications - A simple sludge drying method for digested sludge in smaller communities by virtue of the fact that
large inexpensive land areas are required.

Chemicals Required - Lime or other odor control chemicals may be required if digestion is incomplete.
Residuals Generated - Generally, the residuals resulting from a well-operated lagoon will be in the range of 30
percent solids and are suitable for use as a soil conditioner or for landfilling.

Design Criteria  (8, 56) -
Dikes:              Slopes of 1:2 exterior and 1:3 interior to permit maintenance and mowing and to prevent eros-
                    ion; width sufficient to allow vehicle transport during cleaning.
Depth:              1.5 to 4.0 feet of sludge depth  (depending upon climate)
Bottom:             Separation from groundwater is dependent upon application depths and soil characteristics, but
                    should not be less than 4 feet to prevent groundwater contamination.
Cells:              A minimum of two cells is required.                              2
Loading Rates:      2.2 to 2.4 Ib sglids/yr/ft  of capacity.  1.7 to 3.3 Ib solids/ft  of surface/30 days of bed
                    use.  1 to 4 ft /capita  (depending on climate).
Decant:             Single or multiple level decant  forAperiodic returning supernatant to head of plant.
Sludge Removal:     Approximately 1.5 to 3 yr intervals.

Process Reliability - Where properly designed, process reliability is function of reliability of upstream proc-
 essing  (digestion).

 Environmental  Impact  - Odor  and vector potential high unless properly designed and operated; land-use requirement
 high,-  groundwater  pollution potential high unless proper site characterization incorporated into design.

 References  -  8,  56,  83
                                                    A-174
-------
 SLUDGE  LAGOONS
                        FACT  SHEET  6,1.11
FLOW DIAGRAM -
                                                                  •Supernatant to  Wet Well
ENERGY NOTES - No external energy required other than possible sludge pumping  from digester
Sheet 6.1.8) and supernatant pumping (see Fact Sheet 3.1.13).
 COSTS -
                                                                                             (see Fact
 1.   Costs = 2nd quarter, 1977 dollars-ENR Index = 2515
 2.   Construction costs includes process  piping,  equipment,  concrete,  steel and excavation.
 3.   Sizing = 4 acres/Mgal/d, 1.5 ft depth of sludge
 4.   Operation and maintenance includes materials,  supplies, maintenance,  operation and residuals removal.
 5.   Labor = $7.50/h
                       CONSTRUCTION COSTS
                                                                          OPERATION AND MAINTENANCE
          10
         1 0
         0 1
        0 01
                                                                1 0
o
o
                         10           100

                        LAGOON AREA, ACRES
                                                   1,000
                                                               0001
      100          1,000        10,000

            DRIED SOLIDS APPLIED, TONS/YR
100,000
 REFERENCES - 5,  56,  201

*To convert construction  cost to capital cost see Table A-2.
                                                       A-175
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CO-INCINERATION OF  SLUDGE - SLUDGE  INCINERATOR                             FACT  SHEET  6.2.1
Description - Co-incineration is incineration using a combination of wastewater sludge and a combustible material,
other than natural gas or fuel oil, in a single furnace.   By combining sludge with other materials,  a combined
furnace feed can be formed which has both a low water content and a heating value high enough to eliminate the
need for supplemental furnace fuel.  Some (of the combustible)  materials are:  municipal solid waste, coal,  wood
wastes, textile wastes, bagasse, and farm wastes, such as corn stalks, rice husks, etc.

Co-incineration was first demonstrated in this country in Franklin, Ohio,  utilizing a fluidized bed  furnace.   The
fuel consisted of the rejected organic waste stream from the solid waste fiber recovery operation and wastewater
sludge.  Organic residue from the fiber recovery system,  a 20 percent solids slurry,  is mixed with 5 percent
solids sludge, dewatered to 45 percent solids in a. cone press,  and combusted in the fluidized bed incinerator.
The incinerator requires about 3000 Btu per pound of as-received material  to sustain combustion and  as the combi-
nation of solid waste and sludge contain about 3600 Btu per pound, autogenous conditions are maintained.  However,
with only 600 Btu per pound available as excess energy, the potential for  energy recovery is low.

Co-incineration using a multiple hearth sludge incinerator has been tested both in the United States and in
Europe. Early testing in Europe using raw solid waste proved less than successful.  However, converting the
organic portion of solid waste into a fluff to fuel the multiple hearth proved technically viable.  This technique
was demonstrated at a wastewater treatment plant in Concord (central Contra Costa County), California, in an EPA-
supported demonstration.  In the demonstration, an existing multiple hearth sludge incinerator (16 ft dia.,  6
hearth) was modified to accept refuse-derived fuel (RDF)  as a fuel.  (The  RDF mixed with the sludge  having a
solids content of 16 percent was introduced into the top hearth, or fed directly into the third hearth.  The latter
method proved more efficient.  Approximately 70 to 100 percent excess air  was used.  The system was  operated eight
hours per day for two months with a combined wet feed rate of up to 10 ton/hr.   Autogenous combustion could be
maintained with an RDF/sludge ratio of 1:2 using a sludge solids content of 16 percent.   The unit operated either
in the incineration mode (all excess air added to furnace proper) or the starved air combustion mode (oxygen
deficient in the furnace, excess air added at afterburner).  The latter mode was preferred.

In a bench-scale study recently completed, the addition of pulverized coal to liquid sludge showed that the coal
improves filtration efficiency slightly and results in a higher solids content in the filter cake than if the coal
is added directly to the sludge cake.  Addition of the coal to the liquid sludge prior to filtration results in a
furnace feed which has a higher solids content and heat value than pure sludge.  This reduces or eliminates the
supplemental fuel demand.  This approach solves the problem of solids content versus fuel value in one step.
Coal, of course, is not a waste material of little value.  However, it substitutes a fossil fuel of  great abun-
dance for scarce fuel oil and gas.

Technology Status - Technical feasibility of co-incineration in sludge incinerators with solid waste has been
demonstrated; however, there were only three municipal plants in operation in United States as of December,  1976
(91).

Applications - To provide a new low cost fuel source for existing sludge disposal facilities; derivation of
wastewater treatment plant power from a new energy source; use of same device to dispose of two waste products
thereby realizing capital and operating cost benefits, as well as reduced land requirement for disposal.

Limitations - Shredders are required to produce a nominal 1 inch refuse size.  More excess air is required with
co-incineration versus separate sludge incineration.  In addition, institutional constraints may have to be
resolved such as: existing long term refuse disposal contracts, jurisdictional disputes between currently separate
wastewater treatment and solid waste disposal government agencies.

Typical Equipment/No, of Mfrs.  (10, 25, 77) -
Multiple Hearth Furnace System - Multiple Hearth Furnaces/10, Sludge Dewatering Devices/15, Flapgate Valves/6,
Cooling and Combustion Air Fans/42, Sludge Conveyors/7, Gas Scrubbers/3, Ash Handling System/1,  Fluid Bed
Furnace System - Screw Feeders  (Sludge)/7, Combustion Air Fans/42, Recuperative Air Heaters/29, Exhaust Gas
Scrubbers/3, Ash Handling System/1, Combustible Material Preparation and Feed Systems.

Environmental Impact - The impact is a strong function of feed material and sludge composition.  The probable
uncontrolled particulate emissions from a co-incineration MHF furnace are about 10 percent greater than those from
sludge incineration alone.  Available data indicate that toxic organics can be destroyed during incineration and
that the bulk of metals, except Hg, can be removed by particulate collectors (91).  Hg emissions appear to be
acceptable but must be compared to allowable ambient concentrations at time of design.

References - 8, 25, 43, 65, 10, 77, 91
                                                   A-176
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 CO-INCINERATION  OF SLUDGE  - SLUDGE  INCINERATOR
                                                                                    FACT SHEET 6.2.1
FLOW DIAGRAM -
      Gas  Exhaust
      To Atmosphere
                             Multiple  Hearth Furnace
                                                                                  iiuid Bed Furnace
                                           Feed  System
Water In
Feed
System
                      Blender & 1
                      Flapgate
                      Valve
                                                             Waste
                                              ._ Combustion
                                             *TjAir Fan
                                                 Pooling Air
                                                 Fan
                                                                                      Feed System
                                             Sludge
                                                                                      Feed System
                                                                                                         Waste
                                                                                                            RDF
       L-H
      Blender

Furnace
Exhaus t

FBF


1

<

>
i.

_^ Recuper
t'
1A
	 »•
f
                                                                                                     Exhaust Gas  t(
                                                                                                     Atmosphere
                                                                                                         Ash Out
                                                                                 Air    Scrubber

                                                                          Co-incineration in Fluid  Bed  Furnace  (FBF)
           Ce-incineration in Multiple Hearth Furnace (MHF)

ENERGY NOTES  (91) - Using the power and fuel cost/ton cited below, the electrical energy usage is 100 kwh/ton,  and
the auxiliary fuel requirement is approximately 59,000 Btu/ton.
 COSTS  (91) - Co-incineration/Multiple Hearth Furnace  (Capacity 600 ton/d refuse; 224 ton/d sludge at 20 percent
 solids)- Costs, Mid  1975.  Assumptions for the cost estimate:  Capital costs include equipment,  labor and ma-
 terials for installation, construction overhead and contingency (15 percent of equipment modules only).   Manpower
 includes four  shifts/d,  seven d/wk operation with supervision and maintenance.  Salary/overhead  ranges from
 $10,000 to S20,000/yr  ($17,000 for operators and senior maintenance people).  Twenty percent is  added to total
 manpower cost  for overtime, vacations, holidays, etc.  Power costs = $.027/kWh.  Fuels costs = $2.73/(10 )  Btu.
 Water  and sewer costs  =  $0.37/1,000 gal.  Residue disposal cost = $4.00/ton.ENR Index = 2205
                       CAPITAL  COST

 Item                                    Cost
 Shredder:
   Two Primary Shredders                 $   562,000
   Two Screen & Mag.  Separators             746,000
   Two Secondary Shredders                  628,000
   Conveyors                                930,000
      Subtotal                           $  2,866,000
 Pneumatic Conveying System                 366,000
 Storage Silo (166,000 ft )                 1,541,000
 Four Feed Conveyors (Storage to Furnace)   648,000
 Four Multiple-Hearth Furnaces            13,800,000
   (22 ft diameter X 11 ft hearth)
 Building                                  4,314,000
 Direct Construction Cost  (DCC)          $23,535,000
 Design, Construction Management,          3,530,000
   Start-Up  (15% DCC)
 Land  ($50,000/acre)                         350,000
 Legal Fees  (3% DCC)                        706,000
 Bond Discount  (3% Total Cost)               844,000
 Total Facility Cost                     $28,965,000
 Facility Cost Per ton/d                 5    35,200
     (Design  Cap.)

 REFERENCE   - 91
                                                                              OPERATING COST
Item
Manpower
  (45 employees)
Power
  (2885 kWh/h)
Water/Sewer
  (1310 gal/min)
Auxiliary Fuel
  (85,300 gal/yr)
Maintenance
                       Cost per Ton*  Total  Ann.  Cost
$ 3.40
  2.72
  1.02
  0.16
  3.20
   (2.5% Incinerator DCC)
   (5% Shredder DCC)
Overhead                   1•14
   (1% DCC)
Residue                    0-94
   (161 ton/d)            	
   Total Operating Cost   $12.58
699,000

561,200

209,400

 32,300

660,000


235,400

193,200
               $2
 "Costs based on 824 ton/d facility with a
 refuse:sludge at approximately 3:2.
                  591,100

                  ratio of
                                                     A-177
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CO-INCINERATION OF  SLUDGE - SOLID  WASTE  INCINERATOR                       FACT  SHEET  6.2.2
Description - Co-incineration is incineration using a combination of wastewater sludge  and another combustible
material, other than natural gas or oil, in a single furnace.   Some other combustible materials include:   munic-
ipal solid waste, coal, wood wastes, textile wastes, and farm wastes.

One approach to co-disposal, that of using a solid waste incinerator as the volume  reduction unit, was tried many
times.  In the past 50 years, many municipal incinerators were used for rudimentary co-disposal.   The problems  of
material handling, feeding, and firing were never successfully addressed, and as a  result the concept was  gen-
erally abandoned.  As the technology of municipal solid waste incineration matured  into efficient, sophisticated
devices, co-incineration was again considered and great strides were made.  A number of incinerators  and waterwall
combustion units have been tested as co-incineration devices,  and some plants are operating on a day-to-day basis.
These plants use the heat released from the solid waste combustion to dewater or dry the sludge to its autogenous
point.  The form of the heat is either hot flue gas, steam from the waterwall combustion unit or waste heat
boiler, or heat from the fire itself.  Mechanical dewatering devices in the co-disposal plants can be driven by
steam or electricity generated within the plant itself.  The drying can take place  in the furnace or  in a  separate
vessel.

Two plants in this country use flue gas to dry the sludge and then burn the sludge  solids in the furnace.
Ansonia, Connecticut has a 200 ton/d (design) refractory incinerator.   About 55 ton/d of refuse are disposed of in
an eight-hour shift.  Sludge from the integrated wastewater treatment plant at about four percent solids is dried
in a high speed disk co-current spray dryer.  Hot flue gases from the secondary combustion chamber at 1200 F are
introduced into the spray dryer.  Vapors and dry solids are blown into the furnace  above the second grate  where
the solids burn in suspension.  However, the dried sludge is presently not burned but used for fertilizer  by local
residents.

Another small refractory incinerator, 50 ton/d average throughput, in Holyoke, Massachusetts, uses the same gen-
eral technique but the sludge, after mechanical dewatering to 28 percent solids, is dried in a rotary dryer. Hot
flue gas from the incinerator is used to directly heat the sludge in the dryer.  The dried solids are then burned
in suspension above the refuse grates.   No exportable energy is recovered in either of  these plants.

A different technique was tested in Norwalk, Connecticut.  The tests proved the viability of the idea and  it is
being replicated in Glen Cove, New York.  In this approach, the heat of the burning solid waste directly dries  the
sludge and the dried solids burn along with the waste.  This is accomplished by spraying the sludge at about five
percent solids into the charging chute forming a layer of sludge on the solid waste. As the solid waste  flows
into the furnace from the charging chute, the sludge layer remains on top of the solid  waste.  In the furnace,  the
heat from the burning solid waste first drives off the moisture from the sludge, and then the dry sludge  solids
burn along with the solid waste on the grates.  The plant at Glen Cove will have waste  heat boilers installed and
the steam will be used to generate electricity.

Two co-incineration plants are currently operating in Europe.  One is at Dieppe, France, the other at Krefeld,
West Germany.  Both utilize a waterwall combustion unit to burn the solid waste and wastewater sludge.

Technology Status - At least five co-incineration plants are operating worldwide (three in the United States)
utilizing solid waste incinerators.  Thus, the technical viability of this approach has been demonstrated on a
full scale basis, but, it is not widely used.

Applications - Use of a single device to dispose of both sludge and another solid waste material, thus reducing
capital and operating costs; derivation of wastewater treatment plant power and fuel requirements from a more
economical waste energy source; reduction of land requirements for disposal.

Limitations - A number of institutional constraints have to be resolved such as the existence of contracts with
private firms which define ownership of the solid refuse.  Also, wastewater treatment  and solid waste disposal are
often controlled by different government agencies.  The co-incineration plant site must be within pumping distance
of the wastewater treatment plant.  The minimum excess air rate for co-incineration in  refuse incinerators is 150
percent  (91).  The minimum flue gas temperature suitable for odor destruction is 1400  F.

Typical Equipment/No. of Mfrs. (10,  77) -

Incinerator/10, Stokers/5, Air Supply Fans/40, Exhaust Gas Scrubbers/3, Ash Handling System/1, Refuse Handling and
Feed System/9.

Performance - Volume and weight reductions for co-incineration will be about the same  as for separate incineration
of both materials.

Environmental Impact - Data  is required to establish  impact with various  feed combinations; however,  uncontrolled
particulate emission from  a  refuse  incinerator would  roughly double with  co-incineration.  Emission of SO^, NO^,
HC1 and CO is usually insignificant but must be evaluated in terms of the feed composition and the emission inven-
tory of the region  (91).  Available data indicate that toxic organics  (PCB's, pesticides, etc.) will  either be
destroyed by the  thermal condition or will be retained in the particulate collection equipment and ash (91).
Volatile Hg emissions are usually  low, but must be  evaluated in relation  to the ambient concentrations at the time
of design.

References - 8, 43, 65, 10,  77, 91
                                                   A-178
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CO-INCINERATION OF  SLUDGE - SOLID  WASTE  INCINERATOR
                           FACT SHEET 6.2,2
FLOW DIAGRAM -
                                                                                         To Atmosphere
                Combustion
                  Air Fan
                                                                                                       Scrubber
                                        Water
ENERGY NOTES (91)  - Using the power  and  fuel  cost/ton cited below, the electrical energy usage is 44 kWh/ton,  and
the auxiliary fuel requirement is  approximately  73,000 Btu/ton.
COSTS (91)  - Based on mid-1975 costs  for an  incinerator with design capacity of 600 ton/d refuse, 224 tons/d
sludge. ENR  Index = 2205
1.   Capital costs include equipment,  labor  and  material   for installation, construction overhead and contingency
     (15 percent on equipment modules  only).
2.   Manpower includes four shifts,  seven d/wk operation with supervision and maintenance.  Salary/overhead ranges
     from $10,000 to $20,000/yr ($17,000 for operators and senior maintenance people).  Twenty percent is added to
     total manpower cost for overtime, vacations, holidays, etc.
3.   Power costs:  $.027/kWh.  Fuel  costs:   $2.73/(10  Btu).  Water and Sewer costs:  $0.37/1000 gal.  Residue
     disposal cost: $4.00/ton.
                 CAPITAL COST
                                                                               OPERATING  COST
Item
                                     Cost
                                                         Item
                                                                                           Cost Per*   Total Annual
                                                                                             Ton          Cost
Incinerator DCC                      $15,291,000
Drier Circuit:
  Rotary Drier, Fan, Cyclone         $  1,477,000
  Ductwork                               138,000
  Conveyors & Pug Mill                   278,000
       Subtotal                        1,893,000
  Additional Building                  1,370,000
       Direct Construction Cost      $18,554,000
Design, Construction Management,
  Start-up (15% of DCC)                2,783,000
Land {50,000 per acre)                   500,000
Legal Fees (3% DCC)                      557,000
Bond Discount  (3% Total Cost)             672,000
Total Facility Cost                  $23,066,000
Facility Cost per ton/d                  $28,000
   (Design Capacity)
REFERENCE - 91
Manpower
  (46 employees)
Power
  (1265 kWh/h)
Water/Sewer
  (435 gal/min)
Auxiliary Fuel S Heating
  (128,800 gal/yr)
Maintenance
  (2.5% DCC)
Overhead
  (1% DCC)
Residue Disposal
  (161 ton/d)
Total Operating Cost
$3.61

 1.20

 0.29

 0.20

 2.25

 0.90

 0.94

$9.39
$  744,000

   247,700

    59,700

    41,200

   463,800

   185,500

   193,200

$1,935,100
                                                          *Based  on  824  tons of combined refuse/sludge
                                                          feed  in a  ratio of approximately 3:2.
                                                    A-179
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COMPOSTING SLUDGE,  STATIC PILE                                                FACT  SHEET 6.2.3
Description - Wastewater sludge is converted to compost in approximately eight weeks in a four-step process:
     Preparation - sludge is mixed with a bulking material such as wood chips or leaves,  in order to facilitate
handling, to provide the necessary structure and porosity for aeration, and to lower the  moisture content of the
biomass to 60 percent or less.  Following mixing, the aerated pile is constructed and positioned over porous pipe
through which air is drawn.  The pile is covered for insulation.
     Digestion - The aerated pile undergoes decomposition by thermophilic organisms, whose activity generates a
concomitant elevation in temperature to 60 C (140 F) or more.  Aerobic composting conditions are maintained by
drawing air through the pile at a predetermined rate.  The effluent air stream is conducted into a small pile of
screened, cured compost where odorous gases are effectively absorbed.  After about 21 days the composting rates
and temperatures decline, and the pile is taken down, the plastic pipe is discarded, and the compost is either
dried or cured depending upon weather conditions.
     Drying and Screening - Drying to 40 to 45 percent moisture facilitates clean separation of compost from wood
chips.  The unscreened compost is spread out with a front end loader to a depth of 12 inches.  Periodically a
tractor-drawn harrow is employed to facilitate drying.  Screening is performed with a rotary screen.  The chips
are recycled.
     Curing - The compost is stored in piles for about 30 days to assure no offensive odors remain and to com-
plete stabilization.  The compost is then ready for utilization as a low grade fertilizer, a soil amendment, or
for land reclamation.

Modifications - 1.  Extended high pile - pile height is extended to 18 ft using a crane (still experimental). Can
result in savings of space and materials.  2.  Aerated Extended Pile - each day's pile is constructed against the
shoulder of the previous day's pile, forming a continuous or extended pile.  Can result in savings of space and
materials.

Technology Status - Successfully demonstrated at four locations and projected to be capable of serving large
cities.  Experiments are ongoing on various operating parameters.

Applications - Suitable for converting digested and undigested sludge cake to an end product of some economic
value.  Insulation of the pile and a controlled aeration rate enable better odor and quality control than the
windrow process from which it evolved.

Limitations - The drying process is weather-dependent and requires at least two rainless days.  The use of compost
on land is limited by the extent to which sludge is contaminated by heavy metals and industrial chemicals.  In-
dustrial pretreatment of wastewater treatment plant influent should increase the availability of good quality
sludges for composting.

Typical Equipment/No, of Mfrs. (83) - Front-end loader/16 or crane/more than 100; four inch perforated plastic
pipe/more than 100; blower/more than 100; timer/more than 100; tractor-drawn/23; harrow/42; rotary screen/55.

Performance - Sludge is generally stabilized after 21 days at elevated temperatures.  Maximum temperatures of
between 60° to 80°C are produced during the first three to five days, during which time odors, pathogens and weed
seeds are destroyed.  Temperatures above 55 C (131 F) for sufficient periods can effectively destroy most human
pathogens.  The finished compost is a humus-like material, free of malodors, and useful as a soil conditioner
containing low levels of essential plant macronutrients such as nitrogen and phosphorus and often adequate levels
of micronutrients such as copper and zinc.

Chemicals Required - None

Residuals Generated - Final product is compost.

Design criteria (79) - Construction of the pile for a 10 dry ton/d  (43 wet tons) operation: 1.  A 6-in. layer of
unscreened compost for base.  2. A. 94 ft loop of 4-in. dia. perforated plastic pipe is placed on top (hole dia.
0.25 in.).  3.  Pipe is covered with 6-in. layer of unscreened compost or wood chips.  4. Loop is connected to a
1/3 hp blower by 14 ft of solid pipe fitted with water trap to collect condensate.  5-3 Timer is set for cycle of
4 minutes on and 16 minutes off.  6. Blower is connected to conical scrubber pile (2yd  wood chips covered with
10yd  screened compost) by 16 ft of solid pipe.  7. Sludge  (wet) - wood chip mixture in a volumetric ratio of
1:2.5 is placed on prepared base.  8.  A 12-in. layer of screened compost is placed on top for insulation.
Air Flow:  100 ft /h/ton of sludge; land area requirement for 10 dry tons processed daily:  3.5 acres, including
runoff collection pond, bituminous surface for roads, mixing, composting, drying, storage, and administration
area.  Pile dimension: 53 ft X 12  ft X 8 ft high.   Population equivalent, 100,000.

Process Reliability - High degree of process reliability through simplicity of operation.  Thoroughness  (percent
stabilization) is a function of recycle scheme, porosity distribution  in pile, and manifold design.

Toxics Management - Heavy metals entering the process remain  in the  final product.  The degree of removal of
organic  toxic substances is not defined.

Environmental Impact - Potential odor problems can  occur for  a brief period between the time a malodorous sludge
arrives  at  site,  is mixed  and is covered by  the  insulating  layer.   Human pathogen generation and aerosol distribu-
tion potential dictates  careful attention to downwind land  use.

References  -  78,  79, 80, 81,  82
                                                    A-180
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  COMPOSTING  SLUDGE, STATIC  PILE
                                          FACT SHEET 6.2,3
 FLOW DIAGRAM
                    SCREENED
                    COMPOST
                                 WOOOCHIPS
                                 AND SLUDGE
                                             PERFORATED
                                             PIPE
                                                                               FILTER PILE
                                                                               SCREENED COMPOST
 ENERGY NOTES -
      Electricity consumed for a 10 dry ton/d operation = 75,000 kWh/yr or 7500 kwh/yr/dry ton sludge.
      Fuel consumed for a 10 dry ton/d operation =2.29 billion kWh/yr or 229 MkWh/yr/dry ton sludge.
 COSTS  (1976  dollars) ENR Index = 2401
 1.   Quantity processed,  10  dry tons/d;  compost distribution  will  realize no net  revenues or costs to the
     municipality.
 2.   Blower  is  1/3  hp;  front-end loader  is  equipped with  3.5  yd  bucket.
 3.   Sewer line installation -  400  ft  of 8  inch sewer  line  @  $35/ft.
 4.   Asphalt composting pad  costs include grading, 12  inch  crushed stone, 4 inches of asphalt.
 5.   Site is operated  8 h/d, 7  d/wk; staff  includes 1  Superintendent,  4 equipment operators; labor costs include:
     5 wks off  for  paid sick leave,  vacations,  holidays;  $400/person for health insurance; 6% FICA; 0.3 man yr of
     overtime.   Superintendent  receives  $7.50/h;  operators  receive $6/h.
 6.   Equipment  maintenance 6 percent purchase price; insurance estimated 1 percent purchase price.
 7.   Gasoline 57
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COMPOSTING  SLUDGE,  WINDROW                                                     FACT SHEET 6.2.4
Description - Composting is the microbial degradation of sludge and other putrescible organic solid material by
aerobic metabolism in piles or windrows on a surfaced outdoor area.  The piles are turned periodically to provide
oxygen for the microorganisms to carry out the stabilization and to carry off the excess heat that is generated by
the process.  When masses of solids are assembled, and conditions of moisture, aeration and nutrition are favor-
able  for microbial activity and growth, the temperature rises spontaneously.  As a result of biological self-
heating, composting masses easily reach 60°C (140°F) and commonly exceed 70°C (150°F).   Peak composting tempera-
tures approaching 90 C  (194 F) have been recorded.  Temperatures of 140 to 160 F serve to kill pathogens, insect
larvae and weed  seeds.  Nuisances such as odors, insect breeding and vermin harborage are controlled through rapid
destruction of putrescible materials.  Sequential steps involved in composting are preparation, composting, curing
and finishing.

Preparation - To be compostable, a waste must have at least a minimally porous structure and a moisture content of
45 to 65 percent.  Therefore, sludge cake, which is usually about 20 percent solids, cannot be composted by itself
but must be combined with a bulking agent, such as soil, sawdust, wood chips, refuse, or previously manufactured
compost.  Sludge and refuse make an ideal process combination.  Refuse brings porosity to the mix, while sludge
provides needed  moisture and nitrogen, and both are converted synergistically to an end product amenable to
resource recovery.  The sludge is suitably prepared and placed in piles or windrows.

Composting - The composting period is characterized by rapid decomposition.  Air is supplied by periodic turnings.
The reaction is  exothermic, and wastes reach temperatures of 140°F to 160°F or higher.   Pathogen kill and the
inactivation of  insect larvae and weed seeds are possible at these temperatures.  The period of digestion is
normally about six weeks.

Curing - This is characterized by a slowing of the decomposition rate.  The temperature drops back to ambient, and
the process is brought to completion.  The period takes about two more windrow weeks.

Finishing - If municipal solid waste fractions containing non-digestible debris have been included, or if the
bulking agent such as wood chips is to be separated and recycled, some sort of screening or other removal pro-
cedure is necessary.  The compost may be pulverized with a shredder, if desired.

Common Modifications - Composting by the static pile method is discussed in Fact Sheet 6.2.3.  Composting within
a vessel is an emerging technology.

Technology Status - Successfully demonstrated.

applications - A sludge treatment method that successfully kills pathogens, larvae and weed seeds.  Is suitable
for converting undigested primary and/or secondary sludge to an end product amenable to resource recovery with a
minimum capital  investment and relatively small operating commitment.

Limitations - A  small porous windrow may permit such rapid air movement that temperatures remain too low for
effective composting.  The outside of the pile may not reach temperatures sufficiently high for pathogen des-
truction.  Pathogens may survive and regrow.  Sale of product may be difficult.

Typical Equipment/No, of Mfrs. (83) - Commonly available equipment can be used,  including front-end loaders/16;
traotor-drawn/23; harrow/42; rotary screen/55.   Equipment is currently being developed specifically for sludge
composting.

Performance - Sludge is converted to a relatively stable organic residue, reduced in volume by 20 to 50 percent.
The residue loses its original identity with respect to appearance, odor and structure.  The end product is
humified, has earthy characteristics; pathogens, weed seeds and insect larvae are destroyed.

Chemical Requirements - None

Residuals Generated - None

Design Criteria  - Approximate land requirement: 1/3 acre/dry ton sludge daily production, which is roughly equiv-
alent to a population of 10,000 with primary and secondary treatment.   Windrows can be 4 to 8 ft high, 12 to 25 ft
wide  at the base, and variable length.  Sludge cannot be composted by itself but must be combined with a bulking
agent to provide the biomass with the necessary porosity and moisture content.  Biomass criteria: moisture con-
tent, 45 to 65 percent; C/N ratio between 30 to 35:1; C/P, 75 to 150:1; air flow 10 to 30 ft  air/d/lb VS.
Detention time,  six weeks to 1 year.

Process Reliability - Highly reliable.  Ambient temperatures and moderate rainfall do not affect the process.

Environmental Impact - Is relatively land intensive; potential for odors; may be aesthetically unacceptable.  The
compost product  represents an environmental benefit when used as a soil amendment.  Other uses include wallboard
production, livestock feed, litter for the chicken industry, and adsorbent for oil spill cleanup.  Human pathogen
generation and aerosol distribution potential dictates careful attention to downwind land use.

References - 8,  20,  33, 202, 203,  205
                                                A-182
-------
 COMPOSTING SLUDGE,  WINDROW
                 FACT  SHEET 6.2.4
FLOW DIAGRAM -
                                            Air
Sludge


Mixing



Composting



Curing



T
| 	 (if woodchips are recycled)
Screening

Compost _

non-digestible
ENERGY NOTES - Actual fuel consumption varies with specific site and operating conditions.  Fuel consumption for
some typical construction equipment that can be utilized for sludge composting is presented in Fact Sheet 6.1.10
A mixer-separator has been developed that mixes sludge and bulking agent and also separates compost from the
bulking agent.  The 125 yd /h mixer-separator consumes approximately 3 gal/h of diesel fuel.
 COSTS -  Assumptions: ENR Index = 2475
 1.   Service  life,  17 years
 2.   Construction costs  include  asphalt pads, roads, sewer, drainage pond, electrical work, engineering.
 3.   Sludge production rate =  900 Ib/Mgal  (dry solids),  digested.
 4.   Land  requirement, 0.35 acres/(ton/day).  Assumed land cost = $10,500/acre.
 5.   Costs apply to  composting of digested er raw bi9logical sludge.
 6.   Adjustment factor:  To adjust for sludge composting rates different from 900 Ib/Mgal, enter cost curves at
     effective flow  (QE>.
                                        ^DESIGN X (New Design Sludge Mass)
                                                        900 Ib/Mgal
Note:  Costs other than labor are not given in Reference 3 but are assumed to include materials, fuel,  etc.
                        CONSTRUCTION COST
           10
          1 0
         001
                                                                  1 0
                                                                           OPERATION & MAINTENANCE COST
                                                              Q
                                                              o
                                                                  0 1
           01
                        1 0            10
                        Wastewater Flow. Mgal/d
                                                   100
                                                                0001
                                                                                                   Total
0 1
              1 0            10
             Wastewater Flow, Mgal/d
                                        100
REFERENCES - 3,  205

To convert construction cost to capital cost see Table A-2.
                                                       A-183
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INCINERATION  OF SLUDGE,  FLUIDIZED  BED  FURNACE (FBF)                       FACT  SHEET  6.2.5
Description - Sludge incineration is a two-step process involving drying and combustion after  preliminary  dewater-
ing.  A typical sludge contains 75 percent water and 75 percent volatiles in dry solids.   Self-sustained combus-
tion without supplementary fuel is often possible with dewatered raw sludges having a solids concentration greater
than 30 percent.

The FBF is a vertically oriented,  cylindrically shaped, refractory lined, steel shell which contains  a  sand bed
and fluidizing air distributor.  The FBF is normally available in diameters of 9 to 25 feet and heights of 20 to
60 feet.  There is one industrial unit operating with a diameter of 53 feet.   The sand bed is  approximately 2.5
feet thick and rests on a refractory lined air distribution grid containing tuyeres through which  air is injected
at a pressure of 3 to 5 Ib/in  to fluidize the bed.   Bed expansion is approximately 80 to  100  percent.  Tempera-
ture of the bed is controlled between 1400  F and 1500  F by auxiliary burners and/or a water  spray or  heat
removal system above the bed.  Ash is carried out the top of the furnace and is removed by air pollution control
devices, usually wet venturi scrubbers.   Sand is lost by attrition at an approximate rate  of five  percent  of the
bed volume every 300 hours of operation.  Furnace feed can be introduced either above or directly  into  the bed
depending on the type of feed.  Generally, sludge is fed directly into the bed.

Excess air requirements for the FBF vary from 20 to 40 percent.  It requires less supplementary fuel than a multiple
hearth furnace.   An oxygen analyzer in the stack controls the air flow into the reactor and the auxiliary fuel
feed rate is controlled by a bed temperature controller.

Start-up fuel requirements are very low, and no fuel is required for start-up following an overnight  shutdown.
The FBF is very attractive for intermittent operation.  Afterburners are not required to comply with  air pollution
regulations.

Common Modifications - An air preheater is used in conjunction with a fluidized bed to reduce  fuel costs.   Also,
cooling tubes may be submerged in the bed for purposes of energy recovery.

Technology Status  - The first fluidized bed wastewater sludge incinerator was installed in 1962.  There are now
many units operating in the United States with capacities of 200 to 1000 Ib/h of dry solids.

Applications - Reduction of sludge volume, thereby reducing land requirements for disposal.  Energy recovery
potential.  Most suitable where hauling distances to disposal sites are long, or where regulations concerning
alternative methods are prohibitive.

Limitations - Since a minimum amount of air is always required for bed fluidization,  fan energy savings during
load turndown  (i.e. sludge feed reduction)  are minor.  Generally not cost effective for small plants.

Typical Equipment/No, of  Mfrs. - FBF/6, Screw Pumps/4, Air Fans/42, Gas Scrubbers/3, Ash  Handling Systems/I

Performance - The mass of dry solids is reduced to 25 to 35 percent of the amount entering the unit.

Design Criteria - Bed loading rate = 50 to 60 Ib wet solids/ft /hr.  Superficial bed velocity  = 0.4 to  0.6 ft/s.
Sand effective size = 0.2 to 0.3 mm (uniformity coeff = 1.8), Operating temperature = 1400 to  1500 F  (normal) -
2200°F+ (maximum), bed expansion = 80 to 100 percent, sand loss = 5 percent of bed volume  per  300  hours of oper-
ation.

Unit Process Reliability - Some extensive maintenance problems have occurred with air preheaters.  Scaling of the
venturi scrubbers has also been a problem.  Screw feeds and screw pump feeds are both subject  to jamming because
of either overdrying of the sludge feed at the incinerator or because of silt carried into the feed system with
the sludge.  Another frequent problem has been the burnout of spray nozzles or thermocouples in the bed.

Environmental Impact - Particulate collection efficiencies of 96 to 97 percent are required to meet current
emission standards.  There are very few data on the amount of toxic metals which are volatilized and  discharged.
Limited test data  (8) indicate that 4 to 35 percent of the mercury entering an incinerator with emission controls
will volatilize and be emitted to the atmosphere (excluding particulate forms).  Gaseous emissions of CO,  HC1,
SO  and NO  may be appreciable; additional air pollution control measures may be necessary.  Pesticides and PCB's
are found in the sludge, but tests indicate that they can be destroyed during incineration and should not  be a
problem.

References:  - 3, 8, 10, 25, 43, 56, 77
                                                    A-184
-------
 INCINERATION  OF  SLUDGE,  FLUIDIZED BED FURNACE  (FBF)
                                                                        FACT  SHEET 6.2.5
FLOW DIAGRAM -
                                      Furnace Exhaust
                                                                           Gas  Exhaust
                   Bed Coils for
                   Heat Recovery
                   (not used in
                   this analysis
                     Radiation
                   Supplemental
                      Fuel
                 Sludge Feed
                       Fluid
                        Bed
                      Furnace
rv
/Wenturi
Recycle Water
X
« Sc
* Wa
sh
Makeup Water
                                                                                      Wet  Scrubber

                                                                                       Scrubber
                                                                                         Drain
ENERGY NOTES - Using the design basis below, electrical energy requirements are approximately 90,000 kWh/yr/dry  &
ton/d or 85,000 kWh/yr/Mgal/d plant flow; fuel requirements are approximately 90 gal/dry ton of sludge or 13 x 10
Btu/dry ton.  Fuel requirements are very sensitive to the moisture content of the sludge and other factors.   As a
result, adjustments should only be made after detailed study for each case.
COSTS -Assumptions: ENR Index = 2475
Design Basis:
Construction costs include reactor, air blowers, and accessories, preheaters, scrubbers, fuel pumps,  and building.
Costs are for undigested dewatered primary and secondary sludge  (1,900 Ib/Mgal at 20 percent solids;  75 percent
volatile) .
Operations:
Fuel cost
     100
             Plant flow,  Mgal/d
                  0.1
                  1.0
                 10.0
                100.0

$2.66/MBtu.   Power cost = $0.02/kWh.

       CONSTRUCTION COST
                                                       Operating,  d/wk
                                                            1
                                                            7
                                                            7
                                                            7
Operating, h/d
     20
     20
     20
     20
                                                                      OPERATION & MAINTENANCE COST
      10
     1 0
                                                              1 0
                                                              0 1
                                                           1-001
                    1 0            10
                   Wastewater Flow, Mgal/d
                                               100
                                                            0001
                                                                      Total
                                                                                       ,Labor_
                                                                                                          0,1
                                                                                                          001
                                                                                                         0.001
                                                               0 1
                                                                1 0            10
                                                               Wastewater Flow, Mgal/d
                                                                                                       100
                                                                                                         0.0001
REFERENCE - 3
*To convert construction cost to capital cost see Table A-2.
                                                  A-185
-------
INCINERATION OF SLUDGE,  HULTIPLE HEARTH  FURNACE (NHF)                    FACT SHEET  6.2.6
Description - Sludge incineration is a. two-step process involving drying  and  combustion after preliminary dewater-
ing.  A typical sludge is 80 percent water and has a dry solids volatility  of 75 percent.  Self-sustained combus-
tion without supplementary fuel is often possible with dewatered raw primary  sludges which can  frequently be
dewatered to 30 percent solids.

The MHF is a vertically oriented, cylindrically shaped, refractory lined, steel shell  {diameter =  4  to 25 ft)
containing 4 to 13 horizontal hearths positioned one above the other.   The  hearths  are constructed of high heat
duty fire brick and special fire brick shapes.  Sludge is raked radially  across the hearths by  rabble arms which
are supported by a central rotating shaft that runs the height of the furnace.  The cast  iron shaft  is motor
driven with provision for speed adjustment from 1/2 to 1-1/2 r/min.   Sludge is fed  to  the top hearth and proceeds
downward through the furnace from hearth to hearth.  Inflow hearths have  a  central  port through which sludge
passes to the next lower hearth.  Outflow hearths have ports on their periphery.  These ports tend to regulate
gas velocities also.  The central shaft contains internal concentric flow passages  through which air is routed to
cool the shaft and rabble arms.  The flow of combustion air is countercurrent to  that  of  the sludge.  Gas or oil
burners are provided on some hearths for start-up and/or supplemental use as  required.

The rabble arms provide mixing action as well as movement to the sludge so  that a maximum sludge surface is
exposed to the hot furnace gases.  Because of the irregular surface left  by the rabbling  action, the surface area
of sludge exposed to the hot gases is as much as 130 percent of the hearth  area.  While there is significant
solids-gas contact time on the hearths, the overall contact time is actually  still  greater, due to the fall of
the sludge from hearth to hearth through the countercurrent flow of hot gases.

The various phases of the incineration process occur in three zones of the  MHF.   The drying zone consists of the
upper hearths, the combustion zone consists of the central hearths, and the lower hearths comprise the cooling
zone.  Temperatures in each zone are:

     Drying zone - sludge about 100 F; air about 800 F
     Burning zone - sludge and air about 1500 F
     Cooling zone - sludge about 400 F, air about 350 F.

Common Modifications -  An after burner fired with oil or gas is provided where required  by local  air pollution
regulations to eliminate unburned hydrocarbons and other combustibles.

Technology Status - The MHF is the most widely used wastewater sludge incinerator in the  United States today.  As
of 1970, 120 units have been installed.

Applications - Reduction of sludge volume thereby reducing land requirements  for  disposal.  Energy recovery
potential.  Used in plants that have long hauling distances to land or ocean  disposal  sites or  where regulations
prohibit these alternate disposal methods.

Limitations - capacities of MHF's vary from 200 to 8,000 Ib/h of dry sludge.   Maximum  operating temperatures are
limited to 1700°F. With high energy feeds there may be operational problems.   The MHF  requires  24  -  30 hours for
furnace warm-up or cool-down to avoid refractory problems.  Failure of rabble arms  and hearths  have  also been
encountered.  Nuisance shutdowns have also occurred due to ultraviolet flame  scanner malfunctions.  Thickening
and dewatering pretreatment is required.

Typical Equipment/No, of Mfrs.  (10, 77) - MHF/6; flapgate valves/6; cooling and  combustion  air  fans/42,-  sludge
conveyors/7; gas scrubber/3.

Performance - Dry solids are reduced to 20 to 25 percent of the mass entering the unit.   The  recoverable heat
ranges from 18 percent of the total heat input  (sludge and supplementary fuel) at 20 percent  solids  concentration
to 45 percent of the total heat input at 40 percent solids concentration.

Design Criteria - Maximum operating temperature = 1700°F.  Hearth Loading Rate =  6  to  10  Ib wet solids/ft  /h
with a dry solids concentration of 20 to 40 percent.  Combustion air flow = 12 to 13  Ib/lb dry  solids.   Shaft
cooling air flow = 1/3 to 1/2 of combustion air flow.  Excess Air = 75 percent to 100  percent  (43).

Environmental Impact - Particulate collection efficiencies of 96 to 97 percent are  required  to  meet  current
emission standard.  There are very few data on the amount of toxic metals which  are volatilized and  discharged.
Limited test data (8) indicate that 4 to 35 percent of the mercury entering an incinerator with emission controls
will volatilize and be emitted to the atmosphere (excluding particulate forms).   Gaseous  emissions of CO,  HC1,
SO  and NO  are expected to be acceptable.  Pesticides and PCB's are found  in the sludge, but tests  indicate that
they can be destroyed during incineration and should not be a problem.

References - 3, 8, 10, 25, 43, 77
                                                     A-186
-------
 INCINERATION  OF SLUDGE,  MULTIPLE HEARTH  FURNACE (MHF)
                              FACT SHEET  6,2,6
FLOW DIAGRAM -
                                                                    Gas Exhaust
                                                      Shaft  Cooling Air Not Returned
                                   Shaft Cooling
                                      Air
                                     Cooling Air
ENERGY NOTES - Using the design assumptions  below,  electrical energy requirements are approximately 31,000,
135,000 and 1,250,000 kwh/yr for 1,  10 and 100 Mgal/d plant  flow.  Fuel requirements for startup and incineration
amount to approximately 4,500 x 10  Btu/yr/Mgal/d.   Fuel requirements are very sensitive to the moisture content
of the sludge and other factors.  As a result, adjustments should only be made after detailed study of the case.
COSTS - Assumptions: ENR Index = 2475
Design Basis:
Construction costs include incinerator,  building,  sludge  conveyor, ash handling equipment, gas scrubbers.  Costs
are for undigested dewatered primary and secondary sludge  (1,900 Ib/Mgal at 20 percent solids; 75 percent volatile).
Operations:
                         Plant flow,  Mgal/d
                              0.1
                              1.0
                             10.0
                            100.0
Operating, d/wk
     1
     7
     7
     7
Operating, h/d
     20
     20
     20
     20
Fuel requirements for warm-up and incineration  are  4,500 x  10  Btu/yr/Mgal/d.
Fuel cost = $2.66/MBtu.   Power cost = $0.02/kWh.
         100
                       CONSTRUCTION COST
                                                                      OPERATION & MAINTENANCE COST
          10
         1 0
         0 1
           01
                        1 0            10
                        Waslewater Flow, Mgal/d
                                                   100
                                                                                                          0 1
                                                                                                          001
                                                                                                         0001
                                                            0001
                      1 0           10
                     Wastewater Flow, Mgal/d
                                                100
                                                                                                        00001
BEFE HENCE - 3


*To convert construction cost to capital cost see Table A-2.
                                                   A-187
-------
CO-DISPOSAL BY STARVED AIR COMBUSTION                                        FACT  SHEET  6.2.7
Description - Co-disposal of sludge by starved air combustion (SAC)  is an extension of the process described in
Fact Sheet 6.2.8 using waste materials such as municipal solid waste,  wood wastes,  farm wastes,  etc.  as fuel
additives to allow operation of the unit without auxiliary fossil fuel in the case  of high moisture content sludge
or sludges with low solids heating value.

At a test run at the Central Contra Costa Sanitary District operated wastewater treatment plant in Concord, Cali-
fornia, a 16-ft diameter, 6-hearth, multiple hearth furnace (MHF) processed a combination of sludge and refuse
derived fuel (RDF).   Mixed municipal refuse was shredded, classified,  and screened  prior to addition to the MHF
where the RDF was the light fraction from the air classifier.   The sludge had a solids content of 16 percent,  a
volatile solids content of 75 percent, and a heating value of 9,000 Btu/lb dry solids, whereas the RDF had a
solids content of 75 percent, very few inerts, and a heating value of 7,500 Btu/lb  of dry solids.  The furnace
feed rate was varied from pure sludge to pure RDF.  A combustible gas was produced  with a heating value of 130
Btu/sdft .  This combustible gas could be fired in a waste heat boiler for steam production, used as the fuel  for
a lime recalcination furnace, or used for space heating.

During the test, the RDF could be fed to hearths 3 or 1.  Sludge was always fed to  hearth 1.  Temperatures were
maintained by controlling the amount of air fed to the furnace.  The off-gases from the furnace were allowed to
burn in an afterburner with the introduction of combustion air.  Afterburner temperatures were approximately
2200°F, although the gas could be combusted to produce a temperature as high as 2500 F with no supplemental fuel
addition.

The major shaft furnace systems available, the Purox (oxygen enrichment) and Torrax (regenerative heat recovery)
units by Union Carbide Co. and The Carborundum Co., respectively, have similar basic operating principles.  Refuse
is charged at the top of the refractory lined shaft, providing a seal, and, as it descends through the furnace,
hot pyrolytic gases from the slagging and combustion zones move in a countercurrent direction, thus providing  pre-
ignition and drying of the sludge and refuse.  Preheated air or oxygen-enriched air is injected into the com-
bustion zone at the base of the shaft furnace, where combustion of the pyrolyzed char occurs.

Preheating and oxygen enrichment serve essentially the same purpose: maintaining a  furnace temperature high enough
(2500-3000°F) to form a slag and to produce a pyrolysis gas with as high a heating  value as possible.  The slag
formed is virtually free of combustibles.  The cooled gases (low heating value), after preliminary cleaning, can
be burned in a secondary combustion chamber with energy recovery in the form of a waste-heat boiler.

Technology Status - Technical feasibility has been demonstrated, however, there are no plants in commercial use.

Applications - Reduction in volume of two solid waste streams and energy conservation; use a single device to
dispose of two waste products, thereby realizing capital and operating cost benefits.

Limitations -  Institutional constraints may hamper implementation; for instance, in many localities, wastewater
treatment and solid waste disposal are controlled by different governmental agencies.  Many communities have long-
term  (15 to 20 years) contracts with private firms for refuse handling and disposal which define ownership of the
refuse.  See Fact Sheets on Multiple Hearth Furnaces and Fluid Bed Furnaces for other limitations.  In shaft
furnaces, proper temperatures in the slag tap area must be maintained to prevent slag freezing.  The Purox system
and the MHF require a shredded refuse feed.

Typical Eguipment/No. of Mfrs. (10, 77, 97) - SAC reactors/10; scrubbers/3; ash disposal system/1; fans/42; waste
heat boiler/27; sludge dewatering device/15; sludge conveyors/7; combustible material preparation and feed sys-
tem/25.

Performance - Quantity of dry solids  (combined sludge and PDF) is reduced to 19 to 26 percent of amount entering
reactor  (43).

Design Parameters - For Multiple Hearth Furnaces  (43):

     Hearth Sludge Loading Rate = 11 to  13 Ib wet solids/(h)(ft  )

Unit Process Reliability - No data available.  MHF units have experienced failures of rabble arms and hearths
along with nuisance trips due to flame scanner malfunction.  Fluid bed units have experienced scaling of scrubbers
with bed media and plugging of sludge feed systems.  Freezing of slag bed and contamination of slag bed with
refuse have been experienced on shaft furnace systems.

Environmental Impact - Data required  to  evaluate  is not available for this process.  However, the impact will
depend on compositions of feed material  and operating conditions.  Hydrocarbons and CO emissions are not of
concern  since product fuel gas is  sought.  SO- and NO  emission  from reactor may be reduced relative to co-
incineration due to deficiency of oxygen; however, higher temperatures  in the afterburner could  cause a N0x
problem.

References - 43,  10, 77, 91, 97, 148, 221, 222, 223, 224, 226
                                                      A-188
-------
 CO-DISPOSAL BY STARVED AIR  COMBUSTION
                                                                                    FACT  SHEET 6.2.7
FLOW DIAGRAM

«<
e
r~
Waste
Heat
Raibci

*1



Dust
Collector


To AUacsph
               Preheated Air
               or Oxygen
    Water to
Treatment Plant
                                                                  Solids to Disposal
ENERGY NOTES - From the estimate below, electrical  power  requirements are  51  kWh/t of refuse and sludge.
Auxiliary fuel requirements are 6.2 gal of fuel oil or  780,000  btu/t of  refuse and sludge.
COSTS - Mid-1975 dollars;  ENR Index  = 2212,  Co-incineration/SAC  (sludge and refuse).  Design capacity
600 ton/d refuse; 224 ton/d sludge,  annual  capacity  206,000  tons.
Capital Costs Include:   Equipment, labor  and materials for installation, construction overhead and contingency at
15 percent of each equipment module.
Manpower Costs Include:   Four shifts,  seven  days per week operation; supervision and maintenance.  Salary and
overhead ranged from $10,000 to $20,000  ((operators and  senior maintenance people at $17,000 per year).   Twenty
percent is added for overtime,  vacations,  holidays, etc.
Power Costs:   $0.027/kwh
                                     Water  and  Sewer Costs:   $0.37/1000 gal
                                                                                 Fuel Costs:  $2.73/10 Btu
Residue Disposal Cost:   $4/ton
Item
                 Capital  Cost
                                                        Item
                                        Cost
                                                           Operating Cost
                                                                      Cost Per
                                                                        Ton*
Total Annual
    Cost
Two Shaft Furnaces                  $18,125,000
Additional Building                   1,541,000
Direct Construction Cost            $19,666,000
Design, Construction Management       2,950,000
  Start-Up (15% DCC)
Land  ($50,000/acre)                     250,000
Legal Fees (3% DCC)                     590,000
Bond Discount  (3% Total Cost)       	704,000
Total Facility Cost                 $24,160,000
Facility Cost Per ton/d             $29,300
   (Design Cap.)
                                        Manpower                       $ 3.15      $648,000
                                           (42 employees)
                                        Power                            1.37       282,000
                                           (1450 kWh/h)
                                        Water/Sewer                      0.23        48,000
                                           (300 gal/min)
                                        Auxiliary Fuel & Heating         2.14       440,700
                                           (1,057, 400 gal/yr)
                                        Maintenance                      2.37       491,600
                                           (2.5% DCC)
                                        Overhead                          .95       196,700
                                           (1% DCC)
                                        Residue                          0.71       146,500
                                           (488 ton/d                   	      	
                                        Total Operating Cost
                                                                                       $10.92    $2,253,600
                                                                      *  Based on Annual Throughput.
       REFERENCE -  91
                                                    A-189
-------
STARVED  AIR  COMBUSTION  OF SLUDGE                                              FACT  SHEET 6.2.8
Description - The process utilizes equipment and process flows similar to incineration except that less than the
theoretical amount of air for complete combustion is supplied.  Autogenous starved air combustion (SAC)  can be
achieved with a sludge solids concentration greater than 25 percent.   For lower concentrations,  an auxiliary fuel
may be required, depending on the percent volatiles in the solids.  High temperatures decompose or vaporize the
solid components of this sludge. The gas phase reactions are pyrolytic or oxidative, depending on the concen-
tration of oxygen remaining in the stream.  Under proper control, the gas leaving the vessel is a low Btu fuel gas
that can be burned in an afterburner to produce power and/or thermal energy.  Some processes utilize pure oxygen
instead of air and thus produce a higher Btu fuel gas.  The solid residue is a char with more or less residual
carbon, depending on how much combustion air had to be supplied to reach the proper operating temperatures.  Since
the process is neither purely pyrolytic nor purely oxidative, it is called starved-air combustion or thermal gasi-
fication, rather than pyrolysis,  other processes still in the development stage use indirect heating, rather than
the partial combustion.  These are true pyrolysis processes.  SAC reduces the sludge volumes and sterilizes the
end product.  Unlike incineration, it offers the potential advantages of producing useful by-products and of
reducing the volume of sludge without large amounts of supplementary fuels.  The gas which is produced has a heat
value up to 130 Btu/standard dry cubic foot using air for combustion and is suitable for use in local applications,
such as combustion in an afterburner or boiler or for fuel in another furnace.  SAC has a higher thermal efficiency
than incineration due to the lower quantity of air required for the process.  In addition, capital economies can
be realized due to the smaller gas handling requirements.

Furnaces may be operated in one of three modes resulting in substantially different heat generation and residue
characteristics.  The Low Temperature Char (LTC) mode only pyrolyzes the volatile material thereby producing a
charcoal-like residue with a high ash content, the High Temperature Char (HTC) mode produces a charcoal-like
material converted to fixed carbon and ash, and the Char Burned (CB)  mode reacts away all carbon and produces ash
as a residue.  Heat recovered is maximum for the CB mode, less for the HTC mode, and substantially less for the
LTC mode of operation.

SAC operation has shown the following advantages in addition to those discussed above:  easier to control than a
standard incinerator; more stable operation with little response to changes in feed; more feed capacity as com-
pared to an equal area for incineration; all equipment used is currently being manufactured; less air pollutants
and easier air pollution control management; lower sludge solids content required for autogenous operation.

Technology Status - Autogenous SAC of sludge has been demonstrated at a full scale Multiple Hearth Furnaces (MHF)
project at the Central Contra Costa Sanitary District in California.  One SAC unit for disposal of sludge from a
40 Mgal/d industrial wastewater treatment plant is reported to have gone on stream in 1978 and other units are out
for bid.

Applications - Reduction of sludge volume and production of fuel gas for a nearby combustor or furnace. Most
existing MHF's can easily be retrofitted to operate in the SAC mode.

Limitations - There are significant disadvantages, such as:
     Need for afterburner may limit use in existing installations due to space problems.
     Relatively large amount of instrumentation is required.
     Must be very careful of bypass stack exhaust since furnace exhaust is high in hydrocarbons and may be com-
     bustible in air.  This may result in bypassing only after afterburning with appropriate emergency controls in
     some areas.
     Corrosivity of furnace exhaust gases.
     Combustibles in ash may create ultimate disposal problems.
     Sludge volume reduction lower than with incineration.
     Requires recovery of the energy in the product gas to fully realize the improved efficiency.

Typical Equipment/No, of Mfrs. (10, 77, 97) - SAC Reactor/10, Waste Heat Boiler/27, Exhaust Gas Scrubbers/3,
Sludge Dewatering Devices/15, Afterburner/10.

Performance - Unit can operate without auxiliary fuel, including afterburner, with sludge dewatered to the range
of 29 to 39 percent solids.  Based on a limited number of pilot scale tesljS, the off-gas from an MHF unit oper-
ating in the SAC mode, with sludge alone, ranges from 18 to 73 Btu/std ft .

Design Criteria - MHF systems - Hearth loadings of 9 to 15 Ib wet  (22 percent) solids/ft /h; for autogenous com-
bustion, sludge solids content 25 to 39 percent depending upon volatility.  Off-gas heating value dependent upon
operating mode.

Unit Process Reliability - Mechanical function of MHF units under the SAC mode is expected to be similar to the
conventional operating modes.  Increased operating stability is expected to result in higher process reliability.
Environmental Impact - Air pollution can be expected to be less of a problem due to the lower air flows and the
potential for particulate carryover.  Data to date indicate conventional equipment can achieve acceptable con-
trols.  Depending upon the mode of operation, heavy metals in the sludge can be retained in the residue.

References - 8, 43, 10, 77, 97, 148, 220, 221, 222, 223, 224.
                                                  A-190
-------
STARVED AIR COMBUSTION OF SLUDGE
FLOW DIAGRAM -



C
t ,
Shaft Cooling Air
Returned to Furnace
Sludge Dewatering
and
Feed System
Sludge
r Feed
H
Shaft


Multiple
Hearth
Pyrolytic
Reactor
^
i
Cooling Air
ENERGY NOTES - Using assumptions below, the electric*
startup fuel requirements are 3.1 gal fuel oil or 0.
COSTS - Third quarter 1978 dollars. ENR Index = 2829
FACT SHEET 6.2.8
Gas Exhaust
t ,
Shaft Cooling Air Not Returned ^
Shaft Cooling Air
l 'Returned to After -
ombustion__
"Air 	 *"
Furnace Afterburner
Exhaust /V
Boiler
ArLeLLuiauy rSi^u'st" 1
	 Exhaust. 	 	 1.. __^.I.. Wut f-crubbor
Waste V
Heat A
„ . , / \ Scrubber
Boiler / \ ,<______
Mv
Recoverable Heat I
Supplemental | Draitl >
Fuel
Radiation ~~ Precooler and
Combustion Venturi Water
Air Connected Power
Ash
al energy requirements are 23 kWh/ton, and the auxiliary or
13 X 10 Btu/ton of sludge.
1. 324 ton/d design capacity at 40 percent dry solids. Annual throughput 80,000 tons.
2. Direct construction cost includes Multiple Hearth Furnace installed, with drives, fans, motor controls, gas
scrubber, external afterburner, ash handling system, auxiliary fuel system, instrumentation, piping, paint-
ing, initial operation and test. .
3. Manpower costs = $17,500/yr average; power cost = $0.02AWh; fuel cost = $2.73/10 Btu; water and sewer costs
= $0.37/1,000 gal; residue disposal = $5/ton.
Capital Cost Operating Cost
Direct Construction Cost (DCC) $2,325,000
Design, Construction Manage-
ment (20% DCC) 465,000
Land ($50,000/acre) 250,000
Legal fee (3% DCC) 69,750
Bond discount (3% Total Cost) 99,000
Total Cost $3,325,000
REFERENCES - 91, 225


Cost/ton* Annual Cost
Manpower, 20 employees $4.37 $350,000
Power, 210 kWh/h .46 36,800
Water/sewer @ 385 gal/min) .89 70,800
Auxiliary fuel (250,000 gal/yr) 1.19 95,500
Maintenance (2.5% DCC) 1.03 83,100
Overhead (1% DCC) .42 33,250
Residual disposal .94 75,000
Total Cost $9.30 $744,450
*Based on 80,000 ton/yr throughput
A-191
-------
SLUDGE  DRYING                                                                    FACT SHEET 6.2.9
Description - In this process the moisture in the sludge is reduced by evaporation to 8 to 10 percent by the
application of hot air, without combusting the solid materials.  For economic reasons, the moisture content of the
sludge must be reduced as much as possible through mechanical means prior to heat drying.   The five available heat
treating techniques are flash, rotary, toroidal, multiple hearth and atomizing spray.

Flash drying is the instantaneous vaporization of moisture from solids by introducing the sludge into a hot gas
stream.  The system is based on several distinct cycles which can be adjusted for different drying arrangements.
The wet sludge cake is first blended with some previously dried sludge in a mixer to improve pneumatic conveyance.
The blended sludge and hot gases from the furnace at about 1200°F to 1400°F (650 to 760 C) are mixed and fed into
a cage mill in which the mixture is agitated and the water vapor flashed.  The residence time in the cage mill is
only a matter of seconds.  The dry sludge with eight to ten percent moisture is separated from the spent drying
gases in a cyclone, with part of it being recycled with incoming wet sludge cake and another part being screened
and sent to storage.

A rotary dryer consists of a cylinder which is slightly inclined from the horizontal and revolves at about five to
eight r/min.  The inside of the dryer usually is equipped with flights or baffles throughout its length to break
up the sludge.  Wet cake is mixed with previously heat dried sludge in a pug mill.  The system may include cyclones
for sludge and gas separation, dust collection scrubbers, and a gas incineration step.

The toroidal dryer uses the jet mill principle, which has no moving parts, dries and classifies sludge solids
simultaneously.  Dewatered sludge is pumped into a mixer where it is blended with previously dried sludge.  The
blended material is fed into a doughnut-shaped dryer, where it comes into contact with heated air at a temperature
of 800 F to 1100 F.  The particles are dried and broken up into fine pieces and are carried out of the dryer by
the air stream.  The dried, powdered sludge is supplemented with nitrogen and phosphorus and formed into bri-
quettes which are crushed and screened to produce final products.

The multiple hearth furnace is adapted for heat drying of sludge by incorporating fuel burners at the top and
bottom hearths, plus down draft of the gases.  The dewatered sludge cake is mixed in a pug mill with previously
dried sludges before entering the furnace. QAt the point of exit from the furnace, the solids temperature is about
100 F, and the gas temperature is about 325 F.

Atomizing drying involves spraying liquid sludge in a vertical tower through which hot gases pass downward.  Dust
carried with hot gases is removed by a wet scrubber or dry dust collector.  A high-speed centrifugal bowl can also
be used to atomize the liquid sludge into fine particles and to spray them into the top of the drying chamber
where moisture is transferred to the hot gases.

Technology Status - Heat drying of sludge was developed more than 50 years ago; however, it is not widely used.
Application - It is an effective way for ultimate sludge disposal and resource conservation when the end products
are applied on land for agricultural and horticultural uses.  Although it is an expensive process, it can become a
viable alternative, if the product can be successfully marketed.

Limitations - Cost and high operator skill.
Typical Equipment/Ho, of Mfrs. - Complete heat drying systems are generally proprietory.  The major equipment
includes mixers, furnaces, cyclones, screens, dryers, wet scrubbers, dust collectors, air blowers, heaters,
spraying devices, sludge feed pumps and handling equipment.

Performance - Heat drying destroys most of the bacteria in the sludge.   However, undigested heat dried sludge is
susceptible to putrefaction if it is allowed to get wet in thick layers on the ground.   Heat drying does not cause
any significant decrease of the heavy metals concentration in the sludge.   In general,  heat dried sludge contains
nutrients which are only about one-fifth of those contained in chemical fertilizers.   Heat dried sludge is there-
fore useful only as a fertilizer supplement and a soil conditioner.

Physical, Chemical and Biological Aids - Heat; nitrogen and phosphorus may be added to increase nutrient values of
the dried sludge.

Residuals generated - All the solids captured in the wet scrubbers and dry solids collectors are recycled and
incorporated in the end products.

Design Criteria - Approximately 1,400 Btu are needed to vaporize one pound of water, based on a thermal efficiency
of 72 percent.  Less fuel would be required with additional heat recovery. Chemical scrubbers are used, or chem-
icals are added prior to heat drying.  Excessive drying tends to produce a sludge that is dusty or contains many
fine particles, which is less acceptable for marketing, and should be avoided.   Het scrubbers and/or solids
collectors are needed.  Standby heat drying equipment is needed for continuous  operation.

Environmental Impact - Potential for explosion and air pollution if the system  is not properly operated and
maintained.

Reference - 213
                                                  A-192
-------
 SLUDGE  DRYING
                                      FACT SHEET 6.2.9
FLOW DIAGRAM -
watered
Sludge
!
Mix

er

*


Dryer

*~


Collector



Screen

Dried
Sludge "~
ENERGY NOTES  (4) - Assumptions:  Dryer efficiency - 72 percent; product moisture  content « 10 percent; power
includes blowers, fans, conveyors;  continuous operation.
                  100,000,000
                   1,000.000
                     100,000

                        7
                        6
                        9
                        4

                        S

                        2
                                            PERCENT INPUT SOLIDS CONCENTRATION •
Z2
    ^
                                                                  //
                                                                         W-?£^
                                                                          5l3£
                                                                          xy^sssr
                                                                          /  f 7  v
                                                                               ELECT I ITY
                                                                               FUEL

                              	]	   i  B                •»     I  i 4 9 4799     i  349 6799  •

                                         100             1,000             10,000            100,000



                                            ANNUAL DRY SOLIDS PRODUCT - ton/rr
COSTS -
1.   City of Houston, production cost unknown, $21/dry ton revenue  (1972 F.O.B.  Houston).
2.   City of Milwaukee, $90/dry ton production, $54/dry ton revenue, $36/dry ton net  cost  (1975).
3.   City of Chicago, $60/dry ton production,  $15/dry ton revenue,  $45/dry ton net cost  (1968).
 REFERENCES - 3,  4,  7,  22, 23, 30, 201
                                                  A-193
-------
CENTRIFUGAL DEWATERING                                                         FACT SHEET 6.3.1.
Description  (8) - Centrifuges are used to dewater municipal sludges.  They use centrifugal force to increase the
sedimentation rate of sludge solids.  The three most common types of units are the solid bowl type, the disc type,
and the basket type.

The solid bowl continuous centrifuge assembly consists of a. bowl and conveyor joined through a planetary gear
system, designed to rotate the bowl and the conveyor at slightly different speeds.  The solid cylindrical bowl, or
shell, is supported between two sets of bearings and includes a conical section at one end.  This section forms
the dewatering beach over which the helical conveyor screw pushes the sludge solids to outlet ports and then to a
sludge cake discharge hopper.  The opposite end of the bowl is fitted with an adjustable outlet weir plate to
regulate the level of the sludge pool in the bowl.  The centrate flows through outlet ports either by gravity or
by a centrate pump attached to the shaft at one end of the bowl.  Sludge slurry enters the unit through a sta-
tionary feed pipe extending into the hollow shaft of the rotating bowl and passes to a baffled, abrasion-protected
chamber for acceleration before discharge through the feed ports in the rotating conveyor hub into the sludge
pool.  Due to the centrifugal forces, the sludge pool takes the form of a concentric annular ring on the inside of
the bowl.  Solids settle through this ring to the wall of the bowl where they are picked up by the conveyor scroll.
Separate motor sheaves or a variable speed drive can be used for adjusting the bowl speed for optimum performance.

Bowls and conveyors can be constructed from a large variety of metals and alloys to suit special applications.
For dewatering of wastewater sludges, mild steel or stainless steel normally has been used.  Because of the
abrasive nature of many sludges, hardfacing materials are applied to the leading edges and tips of the conveyor
blades, the discharge ports, and other wearing surfaces.  Such wearing surfaces may be replaced by welding when
required.

In the continuous concurrent solid bowl centrifuge, incoming sludge is carried by the feed pipe to the end of the
bowl opposite the discharge.  Centrate is skimmed off and cake proceeds up beach for removal.  As a result,
settled solids are not disturbed by incoming feed.

In the disc centrifuge the incoming stream is distributed between a multitude of narrow channels formed by stacked
conical discs.  Suspended particles have only a short distance to settle, so that small and low density particles
are readily collected and discharged continuously through fairly small orifices in the bowl wall.  The clarifi-
cation capability and throughput range are high, but sludge concentration is limited by the necessity of dis-
charging through orifices of 0.050 inches to 0.100 inches in diameter.  Therefore, it is generally considered a
thickener rather than a dewatering device.

In the basket centrifuge, flow enters the machine at the bottom and is directed toward the outer wall of the
basket.  Cake continually builds up within the basket until the centrate, which overflows a weir at the top of the
unit, begins to increase in solids.  At that point, feed to the unit is shut off, the machine decelerates, and a
skimmer enters the bowl to remove the liquid layer remaining in the unit.  A knife is then moved into the bowl to
cut out the cake which falls out the open bottom of the machine.  The unit is a batch device with alternate
charging of feed sludge and discharging of dewatered cake.

Technology Status - Solid bowl and disc centrifuges are in widespread use.   Basket centrifuges are fully demon-
strated for small plants, but not widely used.

Applications - Solid bowl and disc types are generally used for dewatering sludge in larger facilities where space
is limited or where sludge incineration is required.  Basket type is used primarily for partial dewatering at
small plants.  Disc centrifuges are more useful for thickening and clarification than dewatering.

Limitations  (7) - Centrifugation requires sturdy foundations because of the vibration and noise that result from
centrifuge operation.  Adequate electric power must also be provided since large motors are required.   The major
difficulty encountered in the operation of centrifuges has been the disposal of the centrate,  which is relatively
high in suspended, nonsettling solids.  With disc type units, the feed must be degritted and screened to prevent
pluggage of discharge orifices.

Typical Equipment/Ko. of Mfrs. (10) - Centrifuge/Si Sludge feed pump/7; Solids conveyor/7; Centrate pumps/40.
Performance (8) - Solid bowl centrifuge solids recovery = 50 to 75 percent without chemical addition and 80 to 95
percent with chemical addition.  Solids concentration = 15 to 40 percent depending on type of sludge.  For basket
centrifuges solids capture = 90 to 97 percent without chemical addition and cake solids concentrations = 9 to 14
percent.  Disc centrifuges can dewater a 1 percent sludge to six percent solids concentration.

Design Criteria - Each installation is site specific and dependent upon a manufacturers' product line.  Maximum
capacities of about 100 tons/h of dry solids are available in solid bowl units with diameters up to 54 inches and
power requirements up to 175 hp.  Disc units are available with capacities up to 400 gal/min of concentrate.

Unit Reliability - Pluggage of discharge orifices is a problem on disc type units if feed to the centrifuge is
stopped, interrupted, or reduced below a minimum value.  Wear is a serious problem with solid bowl centrifuges.

Environmental Impact - Centrate is relatively high in suspended, non-settling solids which, if returned to treat-
ment units, could reduce effluent quality from primary settling system.  Noise may require some control measures.

References - 3, 7, 8, 10
                                                A-194
-------
 CENTRIFUGAL DEWATERING
                                                               FACT SHEET 6.3.1
FLOW DIAGRAM -
                    Differential  p=
                  Speed Gear Box
                                                              —       -.
                                                                         ~ -
                                              Main Drive Sheave
                                                        Chemicals
                                                        •for Conditioning

                                                           Shutdown
                                                           Flush
                                Centrate
                                Discharge

ENERGY NOTES - Energy requirements in the form
of electricity can be highly site specific due
to the sizing and type of centrifuges used.  For
the cost examples below, an energy usage of
approximately 18,000 kwh/yr/ton of dry solids/d
for lime sludges and 31,500 for biological sludges
are noted.
COSTS - ENR = 2475
                             Sludge  Cake
                              Discharge
                                                                                               Sludge
                                                                          Sludge Pump
                                                            CONSTRUCTION  COST
                                             10
                                                                 1.0
Design Basis: Construction costs include centrifuges
(solid bowl), with minimum of one spare; sludge pumps
and piping; cake conveyors; internal electrical and
building cost.
Sludge quantity = 4,500 Ib/Mgal at 10 percent solids
for lime sludge and 900 Ib/Mgal at 4 percent for
digested biological sludge.
Operation = 8 h/d
Costs do not include centrate handling.
For biological sludge, cationic polymer cost is based
On 10 Ib/ton dry basis.
Power cost = $0.02/kwh.
                                        -  0.1
                                          0.01













































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udge



                                                                     0.1
                                                                                  1.0
                                                                                                10
                         Lime Sludge
                OPERATION & MAINTENANCE COST
                                                          Wastewater Flow, Mgal/d

                                                        Digested Biological Sludge
                                                   OPERATION & MAINTENANCE COST
    °S
    VI *-
      0001
                       Total
                         Pow
                                    enals
                                            Labo
                                                     0 1
                                                                 1 0
                                                     001
                                                             Q  0 1
                                  I
                                                    0001
         0 1
 REFERENCE  -  3
 1 0            10
Wastewater Flow, Mgal/d
                                                   00001
                                                 100
                                                               0001
                                                                      Mate
                                                                          las
                                                                               .. -'Labor
                                                                                       -To al
                                                                                              Chem
                                                                                                   ca
                                                                                                             100
                                                                                                              01
                                                                                                             0001
                                                                  0 1
 1 0            10
Wastewater Flow, Mgal/d
                                                                                                          100
                                                                                                            00001
 *To  convert construction cost to capital cost see Table A-2.
                                                      A-195
-------
DRYING BEDS,  SLUDGE                                                             FACT SHEET 6.3.2
Description - Drying beds are used to dewater sludge both by drainage through the sludge mass and by evaporation
from the surface exposed to the air.  Collected filtrate is usually returned to the treatment plant.  Drying beds
usually consist of 4 to 9 inches of sand which is placed over 8 to 18 inches of graded gravel or stone.   The sand
typically has an effective size of 0.3 to 1.2 mm and a uniformity coefficient of less than 5.0.   Gravel  is nor-
mally graded from 1/8 to 1.0 inch.  Drying beds have underdrains that are spaced from 8 to 20 feet apart.   Under-
drain piping is often vitrified clay laid with open joints, has a minimum diameter of 4 inches,  and has  a minimum
slope of about 1 percent.

Sludge is placed on the beds in an 8 to 12 inch layer.  The drying area is partitioned into individual beds,
approximately 20 ft wide by 20 to 100 ft long, of a convenient size so that one or two beds will be filled by a
normal withdrawal of sludge from the digesters.  The interior partitions commonly consist of two or three creo-
soted planks, one on top of the other, to a height of 15 to 18 inches, stretching between slots  in precast con-
crete posts.  The outer boundaries may be of similar construction or earthen embankments for open beds,  but
concrete foundation walls are required if the beds are to be covered.

Piping to the sludge beds is generally made of cast iron and designed for a minimum velocity of  2.5 ft/s.   It is
arranged to drain into the beds and provisions are made to flush the lines and to prevent freezing in cold cli-
mates.  Distribution boxes are provided to divert sludge flow to the selected bed.  Splash plates are used at the
sludge inlets to distribute the sludge over the bed and to prevent erosion of the sand.

Sludge can be removed from the drying bed after it has drained and dried sufficiently to be spadable.  Sludge
removal is accomplished by manual shoveling into wheelbarrows or trucks or by a scraper or front-end loader.
Provisions should be made for driving a truck onto or along the bed to facilitate loading.  Mechanical devices can
remove sludges of 20 to 30 percent solids while cakes of 30 to 40 percent generally require hand removal.

Paved drying beds with limited drainage systems permit the use of mechanical equipment for cleaning.  Field
experience indicates that the use of paved drying beds results in shorter drying times as well as more economical
operation when compared with conventional sandbeds because, as indicated above, the use of mechanical equipment
for cleaning permits the removal of sludge with a higher moisture content than in the case of hand cleaning.
Paved beds have worked successfully with anaerobically digested sludges but are less desirable than sandbeds for
aerobically digested activated sludge.

Common Modifications - Sandbeds can be enclosed by glass.  Glass enclosures protect the drying sludge from rain,
control odors and insects,  reduce the drying periods during cold weather, and can improve the appearance of a
wastewater treatment plant.

Wedge wire drying beds have been used successfully in England.  This approach prevents the rising of water by
capillary action through the media and the construction lends itself well to mechanical cleaning.  The first
United States installations have been made at Rollinsford, New Hampshire, and in Florida.  It is possible, in
small plants, to place the entire dewatering bed in a tiltable unit from which sludge may be removed merely by
tilting the entire unit mechanically.

Technology Status - Over 6,000 plants use open or covered sandbeds.

Applications - Sandbeds are generally used to dewater sludges in small plants.   They require little operator
attention or skill.

Limitations - Air drying is normally restricted to well digested or stabilized sludge, because raw sludge is
odorous, attracts insects,  and does not dry satisfactorily when applied at reasonable depths. Oil and grease clog
sandbed pores and thereby seriously retard drainage.   The design and use of drying beds are affected by  weather
conditions, sludge characteristics,  land values and proximity of residences.   Operation is severely restricted
during periods of prolonged freezing and rain.

Typical Equipment/No-  of Mfrs.(83)  - Front-end loader/16; Scraper/42.

Performance - A cake of 40 to 45 percent solids may be achieved in two to six weeks in good weather and  with a
well digested waste activated,  primary or mixed sludge.   With chemical conditioning, dewatering  time may be
reduced by 50 percent or more.   Solids contents of 85 to 90 percent have been achieved on sand beds, but normally
the times required are impractical.

Design Criteria-  Open bed area = 1.0 to 1.5 ft /capita (primary digested sludge); 1.75 to 2.5 ft /capita (pri-
mary and activated sludge);  2.0 to 2.5 ft /capita (alum or iron precipitated sludge).  Experience has shown that
enclosed beds require 60 to 75 percent of the open bed area.  Solids loading rates vary from 10  to 28 Ib/ft /yr
for open beds and 12 to 40 Ib/ft /yr for closed beds.  Sludge beds should be located at least 200 ft from dwell-
ings to avoid odor complaints due to poorly digested sludges.

Environmental Impact - Land requirements are large.   Odors can be a problem with poorly digested sludges and in-
adequate buffer zone areas.

References - 3, 7, 8,  22, 83
                                               A-196
-------
DRYING  BEDS, SLUDGE
                      FACT SHEET 6.3.2
FLOW DIAGRAM -
                   sludge
                                                          3-m coarse sand
                                                          3-in fine gravel
                                                          3-in medium grave!
                                                          3 to 6 irt coarse gravel
             - Pipe column foi
               glass-over
                                                       2 in coarse sand
                                                                                  n underdram laid
                                                                                  vith open joints
ENERGY NOTES  (4)  - Em = E   ,   .   .        .   + E    ,     ,         + E    .     (when required)
	        T    mechanical scraping    sand  replacement    pumping

E   is estimated  to be 3.2 X 10  Btu/yr/Mgal/d plant  flow  @ 900 Ib dry splids/Mgal plant  flow.
E   is estimated  to be 10 percent of the mechanical scraping or .32 X 10  Btu/Mgal/d plant  flow.

         _  1140  (Mgal/d X TDK)
 pumping    Wire to Water Efficiency

With a sludge  flow of 0.5 X 10  gal/d, a TDK of 40  ft and  a wire-to-water efficiency of 60  percent,  the pumping
energy requirement would be 38,000 kwh/yr.
COSTS - Service  Life:  20 years.  ENR = 2475
1.   Construction  costs include: sand beds, sludge  inlets,  underdrains, cell dividers, sludge piping,  underdrain
     return,  and other structural elements of the beds.   All costs are in mid-1976 dollars.
2.   Bed loading:  900  Ib of sludge/Mgal; 20 Ib/ft /yr.
Adjustment Factor  -  To adjust costs for bed loading  rates,  sludge quantities, or characteristics,  enter curve at
effective flow  (Q  ).

        _            New Design Sludge Mass   20  Ib/ft  /yr	
     QE ~ ^DESIGN       900 Ib/Mgal           New Design  Bed Loading
                         CONSTRUCTION COST
           10
                                                                        OPERATION & MAINTENANCE COST
           1 0
           0 1
          001
                                                               1 0
                                                           D   0 1
                          1 0            10
                         Wastewaler Flow Mgal/d
                                                              0001
                                                                      Labo
                                                                            ,M
                                                                                rials
                                                                                   Total, f
                                                                                                              0 1
                                                                                                             001
                                                                                                            0001
01
              1 0            10
             Wastewater how, Mgal/d
                                         100
                                                                                                           00001
REFERENCES -3,4

*To convert construction  cost to capital cost see Table A-2.
                                                         A-197
-------
FILTER,  BELT                                                                       FACT SHEET 6.3.:
Description (8) - Belt filters consist of an endless filter belt that runs over a drive and guide roller at each
end like a conveyor belt.  The upper side of the filter belt is supported by several rollers.   Above the filter
belt is a press belt that runs in the same direction and at the same speed; its drive roller is coupled with the
drive roller of the filter belt.  The press belt can be pressed on the filter belt by means of a pressure roller
system whose rollers can be individually adjusted horizontally and vertically.  The sludge to be dewatered is fed
on the upper face of the filter belt and is continuously dewatered between the filter and press belts.   After
having passed the pressure zone, further dewatering in a reasonable time cannot be achieved by only applying
static pressures.  However, a superimposition of shear forces can effect this further dewatering.  The  supporting
rollers of the filter belt and the pressure rollers of the pressure belt are adjusted in such a way that the belts
and the sludge between them describe an S-shaped curve.  Thus, there is a parallel displacement of the  belts
relative to each other due to the differences in the radii.  After further dewatering in the shear zone, the sludge
is removed by a scraper.

Some units consist of two stages where the initial draining zone is on the top level followed by an additional
lower section wherein pressing and shearing occur.  A significant feature of the belt filter press is that it
employs a coarse mesh, relatively open weave, metal medium fabric.  This is feasible because of the rapid and
complete cake formation obtainable when proper flocculation is achieved. Belt filters do not need vacuum systems
and do not have the sludge pickup problem occasionally experienced with rotary vacuum filters.  The belt filter
press system includes auxiliaries such as polymer solution preparation equipment and automatic process  controls.

Common Modifications - Some belt filters include the added feature of vacuum boxes in the free drainage zone.
About 6 inches Hg vacuum are applied to obtain higher cake solids.   A "second generation" of belt filters have
extended shearing or pressure stages that produce substantial increases in cake solids,  but are more costly.

Technology Status (8, 118)  - 67 units were installed in Europe as of 1971.  At that time, several units were  also
being installed in the United States.  In 1975 a belt filter press was installed in a 0.9 Mgal/d (average)  plant in
Medford Township, NJ.

Applications - Hard-to-dewater sludges can be handled more readily.  Low cake moisture permits incineration of
primary/secondary sludge combinations without auxiliary fuel.   A large filtration area can be installed in a
minimum of floor area.

Limitations - To avoid penetration of the filter belt by sludge, it is usually necessary to coagulate the sludge
(generally with synthetic, high polymeric flocculants).

Typical Equipment/No, of Mfrs.dO, 23) - Belt filter/7;  Chemical feed equipment/25;  Cake conveyors/7;  Sludge
Pumps/7

Performance (206) - The following table shows performance achieved in pilot studies:
Feed Solids    Secondary:Primary   Polymer   Pressure  Cake Solids       Solids      Capacity
     %              Ratio	   dosage (1)  Ib/in g(2)      %          Recovery %       (3)
   9.5           100% primary        1.6        100         41           97-99         2706
   8.5               1:5             2.4        100         38           97-99         2706
   7.5               1:2             2.7      25-100      33-38          95-97         1485
   6.8               1:1             2.9         25         31           95             898
   6.5               2:1             3.1         25         31           95             858
   6.1               3:1             4.1         25         28           90-95          605
   5.5           100% secondary      5.5         25         25           95             546

(1) pounds per ton dry solids
(2) pounds per square inch, gauge
(3) pound dry solids per hour per meter

In addition, reports from the Medford, NJ plant indicate that belt filter solids capture of 98 percent or more can
be achieved with filtrate TSS under 100 p/m.  Sludge is dewatered from 96 to 97 percent moisture to 81 to 83 per-
cent moisture.  Polymer addition has been 5 to 6 gal/ton.  (118)

Design Criteria (117) - The following loadings are based on active belt area:
                                             Sludge Loading                     Dry Solids Loading
          Sludge Type                        gal/ft /h                          Ib/ft /h	
          Raw Primary                           27-34                              13.5-17
          Digested Primary                      20-24                              20.5-24
          Digested Mixed/Secondary              13-17                              6.7-8.4

Environmental Impact - Relatively high chemical and energy requirements.
Unit Reliability (118) - Almost one year of trouble-free operation had been achieved on the Medford, NJ plant as of
October, 1977.  The two meter wide filter belt showed only slight discoloration and remained clean and free from
blinding or other'signs of wear.

References - 8, 10, 23, 117, 118, 125, 206
                                                 A-198
-------
 FILTER,  BELT
                                                           FACT  SHEET  6,3.3
 FLOW DIAGRAM -
                    Sludge  Inlet    Press Belt
                             Press Rolls     Drive Roll
                                                                                  Cake Discharge
                                                                                Drive Roll
                                               Filtrate
ENERGY NOTES (125)  -
     Plant Loading
   (lb dry solids/d)
         16,000
         40,000
         66,000
               Machine Capacity
               (lb dry solids/d)
                    24,000
                    60,000
                    99,000
                                  Energy Usage
                               kwh/ton dry solids
                                       13
COSTS - 1977 dollars;  ENR Index = 2577
Type of sludge:  Primary and secondary  (anaerobically digested) - 5 percent solids concentration.
Sludge production:  7 d/wk
Dewatering operation:  7 d/wk;  16 h/d
Construction costs  include belt filter press, sludge feed pumps, polymer pumps, and control  panels.
Labor cost:  $15/manhour.   Power cost:  $0.02/kWh.
Plant Sludge Loading
  (lb dry solids/d)
     16,000
     40,000
     66,000
Construction
	Cost
$ 97,000
 120,000
 165,000
Power
Cost
$ 800/yr
 1200/yr
 1700/yr
Labor
Cost
$ll,000/yr
 11,000/yr
 11,000/yr
Maintenance
	Cost
$1400/yr
 1700/yr
 2300/yr
REFERENCES - 8, 125
*To convert construction cost to  capital  cost see Table A-2.
                                                     A-199
-------
FILTER PRESS,  DIAPHRAGM                                                         FACT  SHEET  6.3.4
Description - The diaphragm filter press is a recent extension of filter press technology to increase the through-
put of a press and provide a higher solids content in wastewater filter cake.   (See Fact Sheet 6.3.5 for dis-
cussion of conventional filter presses.)  The press makes use of a rubber diaphragm with pressurized water to
provide a high pressure on the partially dewatered sludge cake in the press after conventional dewatering methods
have been used.

This diaphragm provides the support for the filter cloth on one side of the press cavity.  Filtration of the
sludge is accomplished by charging the chambers of the press with sludge under pump pressure in the conventional
manner, but at a generally lower pressure, and allowing a cake to develop.  The time alloted to this cycle is
dependent upon the characteristics of the sludge, but is scheduled to continue only as long as high filtration
rates are in progress.  This cycle usually is in the 10 to 30 minute range.  The pump pressurizing system is then
turned off, and water pressure is applied inside the diaphragm.  This pressure, in the 200 psi range, applies a
uniform pressure over the cake and further reduces the water content.  The squeezing cycle has been shown to
substantially reduce the overall cycle time for the press, yet produces a low moisture content cake.  The filter
cake produced is thinner than in the conventional press but has a uniform moisture content in contrast to the
conventional press.  The reduction in operating time for the sludge pumps is reported to substantially reduce wear
and the required maintenance.  The pressurized water for the diaphragm actuation is a closed recycle system;
therefore, components operate under predictable conditions and no effluent is produced.   Diaphragm presses are
designed to make use of a number of automation features to reduce labor and recycle time.

Common Modifications - Opening of the filter press to allow simultaneous discharge of filter cake from all cav-
ities.  Rejection of the sludge cake by physical movement of the filter cloth by vibration or actual movement of
the cloth in a forced rejection mode by partial withdrawal of the filter cloth loop.  Automatic washing of filter
cloths at each cycle or as conditions dictate.  Air purging of feed and filtrate lines between cycles.   Full
automation of press operation.

Technology Status - The diaphragm filter press originates as Japanese or European technology.  Several  hundred
presses were reported to be in operation in Japan's wastewater industry.   The press is new to the United States
and is being demonstrated by the use of portable pilot units.  Fourteen full-scale units are to be scheduled for
installation in 1979.

Applications - Dewatering of a wide variety of wastewater sludges to a high level of solids content.  Production
of an auto-combustible filter cake.  Used where a large filtration area is required in a minimum of floor area.

Limitations - Relatively high operator skill is required.  Life of filter cloths and diaphragms is limited.
Moisture content of sludge highly dependent upon proper sludge conditioning.

Typical Equipment/No- of Mfrs. (148) - Diaphragm filter presses/2.  (10)  - Sludge pumps/7; cake conveyors/7;
sludge conditioning tanks/3.

Performance  (210) - Pilot test runs on full scale diaphragm presses using a 2:1 mix of secondary to primary sludge
has shown cake solids in the 34 to 42 percent range.  Lime addition at 12 to 25 percent and Fed  at 4 to 8.5
percent were used as a chemical sludge conditioner.  Cycle times ranged from 5 to 20 minutes pumping and 8 to 30
minutes squeeze.

Chemicals Required - For sludge conditioning, when necessary, lime, FeCl  and other materials found by test to be
suitable for the sludge being processed.
                                           2
Design Criteria - Filter areas = 5 to 40 ft /chamber, cake thickness 1/2 to 3/4 inch, sludge yield 0.4 to 0.8
Ib/ft  of filter area, total cycle time 20 to 50 minutes.

Process Reliability - Reliability is expected to be high and similar to that of conventional filter presses.
Process expected to show greater tolerance to impact of hard-to-dewater sludges.

Environmental Impact - Consistent production of a high solids cake, even with hard-to-dewater sludge, can be
expected to aid in an environmentally optimum disposal of sludge.

References - 10, 148, 210
                                                      A-200
-------
 FILTER PRESS,  DIAPHRAGM
          FACT SHEET  6.3.4
 FLOW DIAGRAM  -
                                                                                      Cake
                                                                                                    Drain
                                    -Conditioning Tank
ENERGY NOTES (210) - Energy requirements per dry ton for  the  process based on  the assumptions below are:  37
cWh/ton for press operation + 29.7 kWh/ton for operation  of the  lime and Fed   systems, sludge pumping, sludge
conditioning equipment and the cake conveyors, resulting  in a total power requirement of 66.7 kWh/ton.
COSTS (210)  - A cost estimate has been derived for use  of  a diaphragm  filter press in a large multiple press
installation with a sludge cake production of 250 dry ton/d.   Sludge was assumed  to be a mix of 2:1 secondary to
primary with a feed solids of 5 percent.   Sludge conditioning  was  assumed  to be lime at 20 percent and FeCl  at 7
percent dry sludge solids.  Lime cost was assumed at $44/ton and FeCl   at  $130/ton.  Pricing is based on the
largest size presses available.  The total number includes one spare.   The capital cost (1978 dollars) includes
the chemical feed system, sludge feed pumps,  dewatering unit with  all  necessary accessories and a conveyor system
to transport cake to the next process.  The total installation cost was obtained  by utilizing a multiplication
factor of 3 which includes installation,  piping, utilities, building and engineering.  Labor is assumed at
$21,000/manyear.  ENR Index = 2577
                              Cost Summary
                              Capital Cost
                              Lime System
                              FeCl3 System
                              Conveyors
                                                       Total
                              Annual Costs
                              Amortization at 9%
                              Chemicals
                              Power at 66.7 kWh/ton and $0.04/kWh
                              Water 12 x 10  gallons
                              Labor - Operation

                              Maintenance -
                              Cloth and diaphragm replacement-materials
                              Labor replacement
                              Equipment maintenance  at  2% of purchase cost
$19,500,000
  1,000,000
    500,000
  2,000,000

$23,000,000
  2,070,000
  1,633,000
    243,000
      6,400
    504,000
   312,000
    31,500
   153,000
                                                      Total annual costs  $ 4,953,000

                               Unit cost/dry ton  of sludge  cake            $    54.28
REFERENCE  - 210
To  convert  construction cost to capital cost see Table A-2.
                                                   A-201
-------
CONVENTIONAL  FILTER PRESS                                                      FACT  SHEET  6.3.5
Description - The conventional filter press for dewatering wastewater sludges is the recessed plate press.   This
press consists of vertical recessed plates up to 5 ft in diameter (or 5 ft on a side,  if square)  which are held
rigidly in a frame and which are pressed together between a fixed and moving end.   On  the face of each individual
plate is mounted a filter cloth.  The sludge is fed into the press at pressures up to  225 Ib/in g and passes
through feed holes in the trays along the length of the press.  The water passes through the cloth,  while the
solids are retained and form a cake on the surface of the cloth.  Sludge feeding is stopped when the cavities or
chambers between the plates are completely filled.  Drainage ports are provided at the bottom of each press
chamber.  The filtrate is collected in these, taken to the end of the press, and discharged to a common drain.   At
the commencement of a processing cycle, the drainage from a large press can be in the  order of 2,000 to 3,000
gallons per hour. This rate falls rapidly to about 500 gallons per hour as the cake begins formation and, when the
cake completely fills the chamber, the rate is virtually nothing.  The dewatering step is completed when the
filtrate is near zero.  At this point, the pump feeding sludge to the press is stopped, and any back pressure in
the piping is released through the bypass valve.  The electrical closing gear is then  operated to open the press.
The individual plates are next moved in turn over the gap between the plates and the moving end.   This allows the
filter cakes to fall out.  The plate moving step can be either manual or automatic. When all the plates have been
moved and the cakes released, the complete pack of plates is then pushed back by the moving end and closed by the
electrical closing gear.   The valve to the press is than opened, the sludge feed pump  started, and the next
dewatering cycle commences.  Thus, a cycle includes the time required for filling, pressing, cake removal, media
washing, and press closing.

A monofilament filter media is now used which, unlike multifilament filter cloth,  resists blinding in service.
Many systems utilize an efficient precoat system which deposits a protective layer of  porous material (fly ash,
cement kiln dust, buffing dust) on the filter media to prevent blinding and to facilitate cake release.
                                                                         2
Whilj in; Sludge Feed Rate = approximately 2 Ib/cycle/ft  (dry solids basis).

Unit Reliability - Pressure filter plate warpage has been a major problem.   Plate gasket deterioration (sometimes
caused by plate warpage) has also been a problem requiring maintenance.

References - 8, 10, 64
                                                      A-202
-------
 CONVENTIONAL  FILTER PRESS
                             FACT SHEET  6.3.5
 LOW DIAGRAM -
                                                                                Cake
SNERGY NOTES (4) - Power consumption based on con-
tinuous operation, 225 Ib/in  operating pressure.
Curve includes feed pump  (hydraulically driven,
positive displacement piston pump), opening and
closing mechanism.

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                                                                        10
                                                                                    100
COSTS  (3) - ENR Index =  2475;  Service  life  =  15  years.
                                                                                Filter Press Volume, ft
                                                                                                 1000         10,000
                                                                                                       3
1.   Construction  cost  for biological  sludge  includes  filter  presses,  pressure pumps,  conveyor equipment,  chenical
     feed and  storage facilities,  conditioning  tanks,  sludge  storage  tanks,  and building.
2.   Sludge  loading: digested primary  +  secondary =  900  Ib/Mgal  @  2.5%
3.   Cake characteristics:   density =  68 Ib/ft  ;  solids  content  =  40%.
4.   Operations:    For 0.1  to  1 Mgal/d  plant =   20 cycles/wk
                    For 1 to 10 Mgal/d plant  =   48 cycles/wk
                    For 10 to 100  Mgal/d plant  =   84 cycles/wk
5.   Conditioning  chemicals:  FeCl =  35 Ib/Mgal;  CaO  =  90 Ib/Mgal
6.   For filter press costs  for lime sludge,  please  refer to  reference 3.

Adjustment Factor  - To  develop  cost for  sludge  quantities, concentration,  characteristics  or cycles per week dif-
 ferent  than  those  used  to  develop  these  curves,  enter  curve  at effective  flow (Q ).

 Q  = Q   ~Tr    New Design    New Design          New Design Cycle
               Sludge Mass X Cycles  Per  Week    X 	Time	
                900  Ib/Mgal    Or.ig.inal  Desinn
                              Cycles Per Week
                                                     2  hours
      100
       10
    1
    0
       10
      0.1
                     CONSTRUCTION  COST:
                          DigMted
                                Biological Sludgt
f   I
i   i
X   u
!   i
        01
                     10            10
                   Wastewater Flow. Mgal/d
                                                               OOOI
                                                                                                             0.01
                                                                001
                                                                                                             0.001
                                                                                                             0.0001
          01
                        10            10
                     Wastewater Flow, Mgal/d
 REFERENCES  -  Curves  derived from references  3 and 4.
 *To convert construction cost to capital cost see Table A-2.
                                                   A-203
-------
THICKENING, DISSOLVED AIR FLOTATION
                                                                FACT SHEET 6.3.6
Description and Common Modifications - In a Dissolved Air Flotation (DAF)  system, a recycled subnatant flow is
pressurized from 30 to 70 Ib/in g and then saturated with air in a pressure tank.  The pressurized effluent is
then mixed with the influent sludge and subsequently released into the flotation tank.  The excess dissolved air
then separates from solution, which is now under atmospheric pressure, and the minute {average diameter 80 microns)
rising gas bubbles attach themselves to particles which form the floating sludge blanket.  The thickened blanket is
skimmed off and pumped to the downstream sludge handling facilities while the subnatant is returned to the plant.
Polyelectrolytes are frequently used as flotation aids, to enhance performance and create  a thicker sludge blanket.
A description of the DAF process in general is presented in Fact Sheet 3.1.6.

Technology Status - DAF is the most common form of flotation thickening in use in the United States and has been
used for many years to thicken waste activated sludges, and to a lesser degree to thicken  combined sludges.  DAF
has widespread industrial wastewater applications.
Applications - The use of air flotation is limited primarily to thickening of sludges prior to dewatering or
digestion.  Used in this way, the efficiency of the subsequent dewatering units can be increased and the volume of
supernatant from the subsequent digestion units can be decreased.  Existing air flotation thickening units can be
upgraded by the optimization of process variables, and by the utilization of polyelectrolytes.  Air flotation
thickening is best applied to waste activated sludge.  With this process, it is possible to thicken the sludge to
6 percent solids, while the maximum concentration attainable by gravity thickening without chemical addition is 2
to 3 percent solids.  The DAF process can also be applied to mixtures of primary and waste activated sludge.  DAF
also maintains the sludge in aerobic condition and potentially has a better solids capture than gravity thick-
ening.  There is some evidence that activated sludges from pure oxygen systems are more amenable to flotation
thickening than sludges from conventional systems.

Limitations - DAF has high operating costs (primarily for power for aeration and chemicals) and is therefore
generally limited to waste activated sludges.  The variability of sludge characteristics requires that some pilot
work be done prior to design of a DAF system.

Typical Equipment/No, of Mfrs. (23) - Dissolved air flotation units/24; Air compressors/8.
Performance  (26) - A summary of data from various air flotation units indicates that solids recovery ranges from
83 to 99 percent at solids loading rates of 7 to 48 Ib/ft /d.

A summary of operating data from 14 sewage treatment plants  (8) is as follows:  Influent suspended solids 3,000 to
20,000 mg/1  (median 7,300), supernatant suspended solids 31 to 460 mg/1 (median 144), suspended solids removal 94
to 99+ percent  (median 98.7), flfiat solids 2.8 to 12.4 percent (median 5.0), loading 1.3 to 7.7 Ib/h/ft  (median
3.1), flow 0.4  to 1.8 gal/min/ft  (median 1.0).

Chemicals Required - Flotation aids (generally polyelectrolytes)  are usually used to enhance performance.
Residuals Generated - Supernatant (effluent) quality:
treatment plant.
                                   Approximately 150 mg/1 SS, returned to mainstream of the
Design Criteria - Pressure 30 to 70 Ib/in g; effluent recycle ratio 30 to 150 percent of influent flow; air to
solids ratio 0.02 Ib air/lb solids; solids loading 5 to 55 Ib/ft /d (depending on sludge type and whether flota-
tion aids are used); polyelectrolyte addition (when used) 5 to 10 Ib/ton of dry solids; solids capture 70 to 98+
percent; total solids* unthickened sludge 0.3 to 2.0 percent, thickened solids 3 to 12 percent; hydraulic loading
0.4 to 2.0 gal/min/ft .
Sludge Type
Primary + WAS
Primary +  (WAS + Fed )
  (Primary + FeCl ) + WAS
WAS
WAS + FeCl3
Digested Primary + WAS
Digested Primary +
Tertiary, Alum
(WAS  +  FeCl  )
 Feed Solids
Concentration
  (Percent)

     2.0
     1.5
     1.8
     1.0
     1.0
     4.0
     4.0
     1.0
Typical Loading Rate
  Without Polymer
  (Ib/sq ft/day)

        20
        15
        15
        10
        10
        20
        15
         8
Typical Loading Rate
    with Polymer
  (Ib/sq ft/day)

        60
        45
        45
        30
        30
        60
        45
        24
 Float Solids
Concentration
  (Percent)

      5.5
      3.5
      4.0
      3.0
      2.5
     10.0
      8.0
      2.0
Reliability - DAF systems are reliable from a mechanical standpoint.  Variations in sludge characteristics can
affect process  (treatment) reliability, and may require operator attention.

Environmental Impact - Requires less land than gravity thickeners.  A subnatant stream is returned to the head of
the treatment plant, although it should be compatible with other wastewater.  The air released to the atmosphere
may strip volatile organic material from the sludge.  The volume of sludge requiring ultimate disposal may be
reduced, although its composition will be altered if chemical flotation aids are used.  The air compressors will
require  shielding to control the noise generated.

References - 3,  7, 8, 23, 26, 95, 111
                                                   A-204
-------
THICKENING,  DISSOLVED AIR  FLOTATION
                                                            FACT  SHEET 6.3.6
FLOW DIAGRAM -
                                SKIMMER MECHANISM
                                                                   PRESSURE TANK
                                                                                 AIR
            SUBNATANT
ENERGY NOTES  (4) - See table in design section
of 6.3.6  for typical loading rates.
                                                                    10
                                                                o   10-
                                                                    10
                                                                       10
COSTS  (3) -Assumptions:
                                                                                    100           1,000
                                                                                  Surface Area, sq ft
                                                                                                              in ooo
T.	Construction costs include: flotation chamber  (2-h detention based on sludge flow); pressure tanks
     (60 Ib/in g); recycle pumps (100% recycle).
2.   Costs for thickening of, secondary sludge only: 820 Ib/Mgal.
3.   Loading rate = 2 Ib/ft /h
4.   Operating hours: 0.1 and 1 Mgal/d = 40 h/wk; 10 Mgal/d = 100 h/wk; 100 Mgal/d = 168 h/wk.


Adjustment Factor: To determine costs at loading rates or sludge quantities other than above, enter curve effec-
tive flow Q.                   2
  g  _ Q   E  x 	2 Ib/ft /h	X New Design Sludge Mass
   E    DESIGN  New Design Mass Loading Rate     820 Ib/d/Mgal
                        CONSTRUCTION COST
          10 		  l-L^UU              01
                                                   OPERATION & MAINTENANCE COST
          01
          001
            0 1
REFERENCES -  3,  4,  26
                                                               D  0 01
                                                                  0001
 1 0           10

Wastewater Flow Mgal/d
                           100
                                                                 00001
                                                                                          Total
                                                                                      Labor.
                                                                                        Materials
                                            01
 1 0            10

Wastewater Flow, Mgal/d
                                                                                    100
*To convert construction cost to capital cost see Table A-2.
                                                      A-205
-------
THICKENING,  GRAVITY                                                              FACT SHEET 6.3.7
Description - Thickening of sludge consists of the removal of supernatant,  thereby reducing the volume of sludge
that requires disposal or further treatment.   Gravity thickening takes advantage of the difference in specific
gravity between the solids and water.

A gravity thickener normally consists of two truss-type steel scraper arms mounted on a hollow pipe shaft keyed to
a motorized hoist mechanism.  A truss-type bridge is fastened to the tank walls or to steel or concrete columns.
The bridge spans the tank, and supports the entire mechanism.  The thickener resembles a conventional circular
clarifier with the exception of having a greater bottom slope.   Sludge enters at the middle of the thickener and
the solids settle into a sludge blanket at the bottom.  The concentrated sludge is very gently agitated by the
moving rake which dislodges gas bubbles and prevents bridging of the sludge solids.  It also keeps the sludge
moving toward the center well from which it is removed.  Supernatant liquor passes over an effluent weir around
the circumference of the thickener.  It has been shown that in the operation of gravity thickeners it is desirable
to keep a sufficiently high flow of fresh liquid entering the concentrator to prevent septic conditions and
resulting odors from developing.

Gravity thickening is characterized by zone settling.  The four basic settling zones in a thickener are:

.The clarification zone at the top containing the relatively clear supernatant.

.The hindered settling zone where the suspension moves downward at a constant rate and a layer of settled solids
begins building from the bottom of the zone.

.The transition zone characterized by a decreasing solids settling rate.

-The compression zone where consolidation of sludge results solely from liquid being forced upward around the
solids.

Common Modifications - Tanks can be square or round, with the round variety being much more prevalent.  Tanks can
be manufactured of concrete or steel.  Chemicals can be added to aid in the sludge dewatering.

Technology Status - Has been in wide use for many years.
Typical Equipment/No, of Mfrs. (23) - Sedimentation Equipment/28;  Chemical feed equipment/25.
Applications - Used to thicken primary, secondary, and digested sludges.
Limitations - Does not perform satisfactorily on most waste activated,  mixed primary-waste activated,  and alum or
iron sludges.  Is highly dependent on the dewaterability of the sludges being treated.

Performance - (No chemical conditioning)
                                         Solids Surface           Thickened Sludge
                                            Loading                   Solids
Type of Sludge                            (Ib/d/ft )               Concentration (%)
  Primary                                  20 to 30                   8 to 10
  Waste Activated                           5 to 6                    2.5 to 3
  Trickling filter                          8 to 10                   7 to 9
  Limed tertiary                           60                        12 to 15
  Primary and activated                     6 to 10                   4 to 7
  Primary and trickling filter             10 to 12                   7 to 9
  Limed primary                            20 to 25                   7 to 12

Chemicals Required - Lime (CaO) and/or polymers may be added to aid in the dewatering and settling of the sludge.
Chlorine can be added to prevent septicity.

Residuals Generated - Supernatant volume is directly related to the increase in solids concentration in the
thickener.  The supernatant will contain varying amounts of solids,  ranging from tens to hundreds of milligrams
per liter.

Design Criteria - See "Performance."  Detentions of one to three days are usually used.   Sludge blankets of at
least three feet are common.  Side water depths of at least ten feet are general practice.

Unit Process Reliability - Gravity thickeners are mechanically reliable, but are greatly affected by the quality
of sludge received.  Therefore, they may be upset due to a radical change in the raw wastewater or digested sludge
quality.

Environmental Impact - Requires relatively little use of land.  The supernatant will need disposal.   This can be
accomplished by recycling it to the head end of the plant for further treatment.   Odor problems frequently result
from septic conditions.

References - 8, 26, 34
                                                   A-206
-------
THICKENING,  GRAVITY
                                                                    FACT SHEET 6.3.7
FLOW
                            Influent
                                           Hopper Plow
                                                                   Under-   Scraper Blades
                                                                    flow
ENERGY NOTES - Assumptions:
Design basis included in "Performance".
COSTS -Assumptions: ENR Index = 2475
1.   Construction costs include thickener and
     all related mechanical equipment.  Pumps
     are not included.
2.   Costs are based on thickening of secondary
     sludge (820 Ib/Mgal; loading = 6 Ib/ft /d).
     See adjustment factors for other sludge
     loadings.
3.   O&M costs do not include polymer addition.

Adjustment Factor:  To adjust costs for alter-
native sludge quantities, concentrations, and
thickening properties, enter curves at effective
flow 
-------
CENTRIFUGAL THICKENING
                                                                   FACT  SHEET 6.3.3
Description (8) - Centrifuges may be used to thicken municipal  sludges.   They  use  centrifugal  force  to  increase the
sedimentation rate of sludge solids.  The three most common types  of  units  are the continuous  solid  bowl type, the
disc type, and the basket type.   Refer to Fact Sheet No.  6.3.1  for unit  descriptions.

Technology Status (8) - There has been limited use of centrifuges  for thickening excess activated  sludges  (EAS).
Field trials have been conducted at two facilities.   Disc type  units  have been selected for three  treatment plants.

Applications (8) - Centrifuges may be used for thickening of excess activated  sludge where space limitations or
sludge characteristics make other methods unsuitable.   Further,  if a  particular sludge can be  effectively  thickened
by gravity or by flotation thickening without chemicals,  centrifuge thickening is  not economically feasible.

Limitations (8) - Centrifugal thickening processes can have significant  maintenance and power  costs.  Adequate
chemical conditioning may be required in order to achieve 90 percent  solids capture and 4 percent  solids concen-
tration with activated sludge in a bowl type unit.  Disc  type units require prescreening to prevent  pluggage of
discharge nozzles, especially if flow is interrupted or reduced.   Rotating  parts of disc units must  be  manually
cleaned every two weeks. (144)

Typical Equipment/No, of Mfrs. - See Fact Sheet No.  6.3.1.
Performance (8) - Typical performance data for the disc,  basket,  and  solid  bowl  centrifuges when  they  are  employed
in the thickening of EAS, are presented in the following  table.   Note that  chemical  addition  is not  always required.
In general, underflow solids concentration from disc units is lower than  from solid  bowl units  (3 to 5 percent
versus 5 to 7 percent).  (144).
Type of Sludge
Centrifuge
   Type
Capacity
(gal/min)
                                                 Feed Solids
                                                                  Underflow
                                                                    Solids
                                  Solids
                                 Recovery
                               Polymer
                             Requirement
                              (Ib/ton)
EAS
EAS
EAS (after Roughing
Filter)
EAS (after Roughing
Filter)
EAS
EAS
EAS
EAS
   Disc
   Disc

   Disc

   Disc
   Basket
   Solid Bowl
   Solid Bowl
   Solid Bowl
   150
   400

 50-80

 60-270
 33-70
 10-12
 75-100
110-160
                                                 0.75-1.0
   0.7

   0.7
   0.7
   1.5
0.44-0.78
 0.5-0.7
5-5.5
  4.0

  5-7

  6.1
 9-10
 9-13
  5-7
  5-8
  90+
  80

93-87

97-80
90-70
  90
90-80
  65
  85
  90
  95
None
None

None

None
None

None
None
Less than
5-10
10-15
Design Criteria - See Fact Sheet No.  6.3.1.   Maximum available capacity per  unit  is  500  to  600 gal/min  for disc
units and 400 gal/min for solid bowl  units.  (144,145)

Unit Reliability - Pluggage of discharge orifices is a problem on disc type  units if feed to the  centrifuge  is
stopped, interrupted, or reduced below a minimum value.

Environmental Impact - For some sludges, odor controls may be required.  Noise  control is always  required.

References - 8, 144, 145
                                                       A-208
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-------
VACUUM  FILTRATION, SLUDGE                                                      FACT SHEET  6.3,9
Description  (8) - Vacuum filters are used to dewater sludges so as to produce a cake having the physical handling
characteristics and moisture contents required for subsequent processing.  A rotary vacuum filter consists of a
cylindrical drum rotating partially submerged in a vat or pan of conditioned sludge.  The drum is divided radially
into a number of sections, which are connected through internal piping to ports in a valve body  (plate) at the
hub.  This plate rotates in contact with a fixed valve plate with similar ports, which are connected to a vacuum
supply, a compressed air supply, and an atmospheric vent.  As the drum rotates each section is thus connected to
the appropriate service.  Various operating zones are encountered during a complete revolution of the drum.  In
the pickup or form section, vacuum is applied to draw liquid through the filter covering  (media) and form a cake
of partially dewatered sludge.  As the drum rotates the cake emerges from the liquid sludge pool, while suction is
still maintained to promote further dewatering.  A lower level of vacuum often exists in the cake drying zone.  If
the cake tends to adhere to the media, a scraper blade may be provided to assist removal.
     The three principal types of rotary vacuum filters are the drum type, coil type, and the belt type.  The
filters differ primarily in the type of covering used and the cake discharge mechanism employed.  Cloth media are
used on drum and belt types while stainless steel springs are used on the coil type.  Infrequently, a metal media
is used on belt types.  The drum filter also differs from the other two in that the cloth covering does not leave
the drum but is washed in place, when necessary.  The design of the drum filter provides considerable latitude in
the amount of cycle time devoted to cake formation, washing, and dewatering; while it minimizes  inactive time.
     A variation of the conventional drum filter is the top feed drum filter.  In this case, sludge is fed to the
vacuum filter through a hopper located above the filter.  The potential advantages are that gravity aids in cake
formation; capital costs may be lower since the feed hopper is smaller and no sludge agitator and related drive
equipment are required; and "blinding" of the media may be reduced.
     The coil type vacuum filter uses two layers of stainless steel coils arranged in corduroy fashion around the
drum.  After a dewatering cycle, the two layers of springs leave the drum and are separated from each other so
that the cake is lifted off the lower layer of springs and discharged from the upper layer.  Cake release is
essentially free of problems.  The coils are then washed and reapplied to the drum.  The coil filter has been and
is widely used for all types of sludge.  However, sludge with particles that are both extremely  fine and resistant
to flocculation dewater poorly on coil filters.
    Media on the belt type filter leaves the drum surface at the end of the drying zone and passes over a small
diameter discharge roll to facilitate cake discharge.  Washing of the media next occurs before it returns to the
drum and to the vat for another cycle.  This type filter normally has a small diameter curved bar between the
point where the belt leaves the drum and the discharge roll which aids in maintaining belt dimensional stability.
In practice it is frequently used to insure adequate cake discharge.
     A great many types of filter media are available for the belt and drum filters. There is some question
whether increases in yield due to operating vacuums greater than 15 inches of mercury are justifiable.  The cost
of a greater filter area must be balanced against the higher power costs for higher vacuums.  An increase from 15
to 20 inches of vacuum is reported to have provided about 10 percent greater yield in three full-scale installa-
tions.

Common Modifications - Chemical conditioning is often employed to agglomerate a large number of small particles.
It is almost universally applied with mixed sludges.

Technology Status - Is the most common method of mechanical sludge dewatering utilized in the United States.
Applications - Generally used in larger facilities where space is limited, or when incineration is necessary for
maximum volume reduction.

Limitations - Relatively high operating skill required.  Operation is sensitive to type of sludge and conditioning
procedures.  As raw sludge ages (3 to 4 hours) after thickening, vacuum filter performance decreases.  Poor
release of the filter cake from the belt is occasionally encountered.  Chemical conditioning costs can sometimes
be extremely large if a sludge is hard to dewater.

Typical Equipment/Mo, of Mfrs. (10, 77) - Rotary vacuum filter/11; Vacuum pump/27; Filtrate receiver/10; Filtrate
pump/40; Sludge conditioning apparatus/3; Sludge conveyors/7.

Performance (8, 10) - Solids capture ranges from 85 to 99.5 percent and cake moisture is usually 60 to 90 percent
depending on feed type, solids concentration, chemical conditioning, machine operation and management.  Dewatered
cake is suitable for landfill, heat drying, incineration or land spreading.

Chemicals Required (10) - Fed  and/or lime, or polymer dosing is a function of type of sludge and vacuum filter
characteristics.

Design Criteria (8) - Typical loadings in pounds dry solids/h/ft  are 7 to 15 for raw primary sludges, 4 to 7 for
digested primary sludges, and 3.5 to 5 for mixed digested sludges.  The loading is a function of feed solids
concentrations, subsequent processing requirements and chemical preconditioning.

Environmental Impact - Relatively high chemical and energy requirements.
Unit Process Reliability - Large doses of lime may require frequent washings of drum filter media.  Remedial
measures are frequently required to obtain operable cake releases from belt filters.  High operating skill re-
quired to maintain high level of reliability.

References - 3, 8, 10, 77
                                                        A-210
-------
 VACUUM FILTRATION,  SLUDGE
      FACT  SHEET 6.3.9
 FLOW  DIAGRAM -
                                               Tank    Sludge Cake  Filtrate      CONSTRUCTION COST (3)
                                                                      10
ENERGY NOTES  - Assumptions:
Electrical energy for operation of the vacuum
pumps, filtrate and other pumps and mechanical
equipment can be estimated on the basis of
11,000 kWh/yr/Mgal/d for biological sludge and
42,000 kWh/yr/Mgal/d for lime sludge.
                                                                     1 0
                                                                     01
 Lime  Sludge
                                                                                               Biological  Sludge
                                                                                               linn  ii   i i  mi
COSTS  -  ENR-2475  Assumptions:
                                                                       0-1
                                                                                    1.0
                                                                                                  10
                                                                                                               100
Design Basis:                                                                   Wastewater Flow,  Mgal/d
Construction costs include:  pumps,  internal piping and electrical controls,  mechanical  equipment,  conveyors,
and sludge cake storage hopper,  building,  chemical handling and storage  facilities.   Costs are  for dewatering
of combined primary and secondary digested sludge consisting of 900  Ib dry  solids/Mgal  plant  flow or  lime
sludge consisting of 4.500 Ib dry solids/Mgal plant flow.
Filter yield = 5 Ib/ft  for  biological sludge and 8 Ib/ft   for  lime  sludge.
Operation time (excluding downtime  for maintenance):  6 h/d for  1 Mgal/d  plant  or  less;  12  h/d for 10  Mgal/d
plant; 18 h/d for a 100 Mgal/d plant.
Chemical dosage:   FeCl, = 35 Ib/Mgal;  CaO  = 90 Ib/Mgal.
Power Cost:  $0.02/kWh.
         10
      0001
REFERENCES - 3
        ooi
                                                                  001
                                                                 0001
                                                                            OPERATION 8  MAINTENANCE  COST:
                                                                               ffi
                                                                                    Lime Sludge
                                                                                        /Po«»r
                                                                                            Mat

                                                                                                              01
                                                                                                             OOOOI
                                                                                                            IOO
                     Wastewater Flow, Mgal/d
Wastewater Flow, Mgal/d
To convert construction cost to capital cost see Table A-2.
                                                   A-211
-------
DIGESTION, AEROBIC
                                                      FACT SHEET  6.4.1
Description - Aerobic digestion is a method of sludge stabilization in an open tank that can be regarded as a
modification of the activated sludge process.  Microbiological activity beyond cell synthesis is stimulated by
aeration, oxidizing both the biodegradable organic matter and some cellular material into CO ,  HO and NO .  The
oxidation of cellular matter is called endogenous respiration and is normally the predominant reaction occurring
in aerobic digestion.  Stabilization is not complete until there has been an extended period of primarily endoge-
nous respiration  (typically 15 to 20 days).  Major objectives of aerobic digestion include odor reduction, reduc-
tion of biodegradable solids and improved sludge dewaterability.   Aerobic bacteria stabilize the sludge more
rapidly than anaerobic bacteria, although a less complete breakdown of cells is usually achieved.   Oxygen can be
supplied by surface aerators or by diffusers.  Other equipment may include sludge recirculation pumps and piping,
mixers and scum collection baffles.  Aerobic digesters are designed similarly to rectangular aeration tanks and
use conventional aeration systems, or employ circular tanks and use an eductor tube for deep tank aeration.
Common Modifications - Both one and two tank systems are used.  Small plants often use a one tank batch system
with a complete mix cycle followed by settling and decanting  (to help thicken the sludge).   Larger plants may
consider a separate sedimentation tank to allow continuous flow and facilitate decanting and thickening. Air may
be replaced with oxygen  (see Fact Sheet 6.4.3).

Technology Status - Primarily used in small plants and rural plants, especially where extended aeration or con-
tact stabilization are practiced.

Applications - Suitable  for waste primary sludge, waste biological sludges  (activated sludge or trickling filter
sludge) or a combination of any of these.  Advantages of aerobic digestion over anaerobic digestion include, sim-
plicity of operation, lower capital cost, lower BOD concentrations in supernatant liquid, recovery of more of the
fertilizer value of sludge, fewer effects from interfering substances (such as heavy metals), and no danger of
methane explosions.  The process also reduces grease content and reduces the level of pathogenic organisms,
reduces the volume of the sludge and sometimes produces a more easily dewatered sludge  (although it may have poor
characteristics for vacuum filters).  Volatile solids reduction is generally not as good as anaerobic digestion.

Limitations - High operating costs  (primarily to supply oxygen) make the process less competitive at large plants.
The required stabilization time is highly temperature sensitive, and aerobic stabilization may require excessive
periods in cold areas or will require sludge heating, further increasing its cost.  No useful by-products, such
as methane, are produced.  The process efficiency also varies according to sludge age, and sludge characteristics,
and pilot work should be conducted prior to design.  Improvement in dewaterability frequently does not occur.

Typical Equipment/No, of Mfrs. (23) - Sludge handling and control/32; Pumps/34; Mixers/26;  Aeration equipment/30.
Performance
     Total solids
     Volatile solids
     Pathogens
Influent
2-7%
50 - 80% of above
                                                     Effluent
                                                     3 - 12%
Reduction

30 - 70% (typical 35 - 45%)
Up to 85%
Physical Chemical and Biological Aids- pH adjustment may be necessary.  Depending on the buffering capacity of
the system, the pH may drop below 6 at long detention times, and although this may not inhibit the process over
long periods, alkaline additions may be made to raise the pH to neutral.

Residuals Generated - Supernatant Typical Quality:  SS 100 to 12,000 mg/1, BOD  50 to 1700 mg/1, soluble BOD   4
to 200 mg/1, COD 200 to 8000 mg/1, Kjeldahl N 10 to 400 mg/1,
5.5 to 7.7, Digested sludge.
                                                              Total P 20 to
                                                                            25B
                                                  mg/1. Soluble P 2 to 60 mg/1, pH
Design Criteria - Solids retention time  (SRT) required for 40% VSS reduction: 18 to 20 days at 20 C for mixed
sludges from AS or TF plant, 10 to 16 days for waste activated sludge only, 16 to 18 days average for activated
sludge from plants without primary settling; volume allowance: 3 to 4 ft /capita; VSS loading:  0.02 to 0.4
Ib/ft /d; air requirements, 20 to 60 ft /min/1000 ft ; minimum DO: 1 to 2 mg/1; energy for mechanical mixing:
0.75 to 1.25 hp/1000 ft ; oxygen requirements:  2 Ib/lb of cell tissue destroyed (includes nitrification demand),
1.6 to 1.9 Ib/lb of BOD removed in primary sludge.

Reliability  - Less sensitive to environmental factors than anaerobic digestion.  Requires less laboratory con-
trol and daily maintenance.  Relatively resistant to variations in loading, pH and metals interference.  Lower
temperatures require much longer detention times to achieve a fixed level of VSS reduction.  However, performance
loss does not necessarily cause an odorous product.  Maintenance of the DO at 1 to 2 mg/1 with adequate detention
results in a sludge that is often easier to dewater (except on vacuum filters).

Environmental Impact - The supernatant stream is returned to head of plant with high organic loadings.  Sludge
stabilization reduces the adverse impact of land disposal of sludge.  Process has high power requirements.  Odor
controls may be required.

References - 3, 5, 7, 8, 10, 23, 26, 111, 119
                                                      A-212
-------
 DIGESTION,  AEROBIC
                                                                                    FACT SHEET  6.4.1
FLOW DIAGRAM
                      Primary  Sludge
Excess Activated or
Trickling Filter Slu
I

11
w
'l '' ?*,«
r
-
-T~-=~  . * ~ ~
—^*\' •''."•"C"1 *\ •/ >J~»%v" CV*^*""1. ^ \ ^
\- -• ' *i • \ /• /T T V*j-V ' 1
TJ ' C


Clea
r 1
1
\
                                                                         Clear  Oxidized  Overflow
                                                                                  to  Plant
                                  Settled  Sludge  Returned  tc  Digester  -7
                                                                     10
                                                                                -^-  Waste  Sludge
ENERGY NOTES - Assumptions:
1.    Energy based on oxygen supply requirements;
     mixing assumed to be satisfied.
2.    Mechanical aeration based on 1.5 pounds  O
     transfer/hph.
3.    Diffused aeration based on 0.9  pounds
     transfer/hph.
4.    Sludge temperature 20 C.
5.    Oxygen requirements for nitrification not
     included.
                                             2
                                                                                                             10,OCO
      *                                                                                Dnn   _ 1K /A
 COSTS -Assumptions: ENR Index = 2475
 1.    Construction costs include  basins  (20  d detention  time),  sludge  flow  =  5,700  gal/Mgal  (1900  Ib/Mgal  at  4
      percent),  and floating mechanical  aerators.
 2.    Mixing requirement:   134 hp/Mgal sludge;  oxygen  requirements:  1.6  lb O2/lb VSS  destroyed  (nitrification  not
      included).
 3.    Adjustment Factor:  To adjust costs  for design factors  different from those above,  enter curves  at effective
      flow (QE) .
      2E
           ^DESIGN
                   X New Design Retention Time  X New Design Sludge  Mass   X
                                                                                       4 percent
                              20  days

                       CONSTRUCTION COST
                                                   1,900 Ib/Mgal          New Design Sludge Concentration

                                                                      OPERATION & MAINTENANCE COST

         001
                                                          c i_
                                                          O dj
                                                          = i

           01            10            10
REFERENCES - 3, 4, 8   Wastewater Flow, Mgal/d
                                                            0001
                                                                 ''Labor
                                                                            Powe
                                                                                        Ma
                                                                                                  //
                                                               01
                                                                             1 0           10
                                                                            Wastewater F.OW, Mgal/d
                                                                                                       100
                                                                                                         00001
 *To convert construction cost to capital cost see Table A-2.
                                                     A-213
-------
DIGESTION,  AUTOTHERMAL THERMOPHILIC AEROBIC  (AIR)                          FACT  SHEET  6.4.2
Description - Autothermal thermophlic aerobic digestion using air is a form of aerobic digestion (See Fact Sheets
6.4.1 and 6.4.3) that operates in the thermophilic temperature range (greater than 45°C)  using air as the source
of oxygen to aerate the sludge.  The operation is autothermal; that is,  the heat required for the increase in tem-
perature is supplied completely from the exothermic breakdown of organic and cellular material occurring during
aerobic digestion.  The increased temperature, in turn, reduces the required retention time for a given amount of
solids reduction.  The digester tanks are covered and insulated to minimize heat losses from the system.

Common Modifications - Use of oxygen in place of air (See Fact Sheet 6.4.3).
Technology Status - In development stage with essentially no commercial use.   One full-scale unit has been
operated since May 18, 1977 at the Binghamton-Johnson City,  New York wastewater treatment plant,  supplemented by
laboratory scale batch and continuous reactor experiments.   Preliminary results indicate the feasibility of this
process from a technical standpoint.  Additional operating experience will be required to optimize design con-
ditions and determine the process' competitiveness with other sludge treatment processes.  These  studies have
provided the data presented below.

Applications - Autothermal aerobic digestion can be applied to sludges with solids concentrations of 1.5 percent
or greater.  More dilute sludges will not reach thermophilic temperatures without supplemental heat.   The high
temperatures reached in the digester may result in virtually complete destruction of pathogens and eliminate the
need for further disinfection.  Thermophilic conditions can be reached in most climates and will require a much
shorter retention time than unheated aerobic digestion or anaerobic digestion.  At temperatures above 50°C, a high
degree of digestion and of solids removal can be achieved with less than 8 days' retention.   The high temperatures
also decrease oxygen requirements because of the inhibition of nitrification.   In general,  aerobic digestion
produces a supernatant with lower organic loadings than anaerobic digestion.   The process may improve the settle-
ability and dewatering characteristics of sludge.   The simplicity of operation may be suitable for use by small
treatment plants.  May have application in cold climates where conventional aerobic digestion is ineffective or
requires excessively long detention times.


Limitations - The process is not applicable to conventional waste activated sludges (WAS)  because of  the large
amount of heat required to raise WAS (at 0.5 percent solids)  to thermophilic temperatures.   The process has high
operating costs, primarily to supply oxygen.  The oxygen transfer efficiencies required to  maintain thermophilic
conditions with air may be as high as 15 percent, to avoid losing too much heat through the exhaust air.   No
useful by-products such as methane are produced.   The economic data for this process is not well developed, and it
is not clear whether the process is competitive with other digestion processes.

Typical Equipment/No, of Mfrs. (23) - Sludge handling and control/32; pumps/34,  mixers/26;  aeration equipment/30.
To achieve the high oxygen transfer efficiencies required,  the system used was proprietary in nature;  the "Liacom
System" by DeLaval, Inc., which utilized a self-aspirating aerator.   The digestion tanks will require  covers and
jacketing to contain the heat.

Performance  (143) - Based on full scale system-steady state performance.  Selected parameters.   1000 ft  reactor.
                                                                                   Retention Time
                                                                                7.7d	5.4d
TVS loading rate (Ib/ft /d)                                                      O.17           0.26
Treatment efficiency (percent TVS removed)                                       37.2           22,1
pH Feed sludge                                                                   5.4            6.05
pH reactor                                                                       7.6            7.9
pH effluent                                                                      7.6            7.6
Ambient temperature                                                             25 C           15 C
Sludge feed temperature                                                         20°C           20°C
Reactor temperature                                                             48 C           52 C
Oxygen transfer efficiency                                                       8.7%           15.1%
Airflow                                3                                         0.91  ft /s      0.78 ft /s Maximum
Maximum oxidation rate of sludge (Ib/ft /day)                                     0.43  (laboratory scale data)

Physical, Chemical and Biological Aids - Air,  pH adjustment,  if required,  mechanical foam cutting.
Residuals Generated - Supernatant.   Quality data not provided.   See  Fact Sheet 6.4.1 for quality of supernatant
from mesophilic aerobic digestion with air,  which may be similar.

Design Criteria - Temperature:     45 to 70 C;  Retention Time:    2 to 10  d.   Sufficient data is not available for
determination of detailed design criteria.

Reliability - The full-scale demonstration project indicated few problems with process  or equipment reliability.
During winter conditions (ambient: -20 C)  the digester remained in the thermophilic range.   There were no opera-
tional problems with the self-aspirating aerator system.   There are indications that the  aerobic digestion process
is generally more stable than anaerobic digestion and more easily able to recover from extreme  conditions.

Environmental Impact - The process requires less space than conventional digestion and, by  stabilizing and dis-
infecting sludge, reduces the adverse impact of land disposal.

References - 23, 143


                                               A-214
-------
DIGESTION, AUTOTHERMAL THERMOPHILIC AEROBIC (AIR)
FACT SHEET  6.4.2
FLOW DIAGRAM -  Single Stage unit is shown.
in a batch mode.
                                           Two or  more stages may be preferable with one  or more  stages operating
                                     Sludge
                                                      Digester
                                                                       Digested  Sludge
ENERGY NOTES - Energy requirements for O  supply and mixing were  approximately 3.5 kWh/h for 1000  ft reactor,
loaded at 130 to 210 ft /d.  Ongoing experiments with self-aspirating aerators will provide additional  information
for determining the energy requirements for air supply and mixing.
COSTS - No cost data for  the existing demonstration unit have  been developed.  However, a single stage digester
utilizing thermophilic aerobic digestion will require approximately 60 percent less volume than a mesophilic
aerobic digester,  but will  require insulation and a cover.   Other equipment will be similar to that of  aerobic
digestion (See Fact Sheet 6.4.1).  No information on other  operating costs is available.
REFERENCES - 143,  147
                                                  A-215
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DIGESTION,  AUTOTHERMAL THERMOPHILIC (OXYGEN)                                FACT  SHEET  6,1,3
Description - Autothermal thermophilic oxygen digestion using oxygen is a form of aerobic digestion (see Fact
Sheet 6.4.1) that operates in the thermophilic (more than 45 C)  temperature range and utilizes pure oxygen instead
of air to aerate the sludge.  The operation is autothermal; that is,  the heat required for the increase in tempera-
ture is supplied completely from the exothermic breakdown of organic and cellular material occurring during aerobic
digestion.  The increased temperatures, in turn,  reduce the required retention times in the digesters to achieve a
given amount of SS reduction.  The digester tanks are covered to minimize heat losses from the system.   Heat Ios3es
are also reduced in pure oxygen systems because there is little exhaust gas to remove the heat generated by the
process.  The equipment for pure oxygen thermophilic aerobic digestion is similar to that of aerobic digestion
(Fact Sheet 6.4.1} with the addition of digester covers and an oxygen generator.

Technology Status - Still in development stage with essentially no commercial use.  Pilot plant tests have been
completed.  Two preliminary full scale studies (Denver, Colorado and Speedway, Indiana)  have been conducted using
pure oxygen aerobic digestion.  Both achieved a significant temperature increase in the digester, but both
operated in the mesophilic temperature range.  Data presented on this process for thermophilic conditions are
largely from pilot studies by Union Carbide  (138).  Several units are in design or construction phase,  and addi-
tional data will be forthcoming.

Applications - May have greatest applications where pure oxygen activated sludge processes are used.   The high
temperatures used by the process may result in virtually complete destruction of pathogens, and eliminate the need
for further disinfection.  In colder climates the process will have much shorter retention times than other di-
gestion processes.  At temperatures above 45 C a high degree of digestion can be obtained with less than five days
retention.  The high temperatures decrease oxygen requirements because of the inhibition of nitrification.  In
general, aerobic digestion produces a supernatant with lower organic loadings than anaerobic digestion.  The danger
of methane explosions is also reduced.

Limitations - May not be applicable to conventional unthickened waste activated sludges because of the large amount
of heat required to raise WAS (at 0.5 percent solids) to thermophilic temperatures.  The process has high operating
costs  (primarily to supply oxygen).  No useful by-products such as methane are produced.  Oxygen aerobic digestion
in the mesophilic temperature range does not appear to be cost effective, but in the thermophilic range the reduced
O  requirements and smaller reactor volume may enable the process to be competitive with other forms of digestion,
particularly when a pathogen-free sludge is desired.

Typical Equipment/No. of Mfrs.  (23) - Sludge handling and control/32; pumps/34, mixers/26; aeration equipment/30;
oxygen generators/1.

Performance  (138) - Pilot plant results:
Single Stage System               Phase I              Phase IA              Phase II              Phase III
Sludge Description                O  step feed         O- step feed          O  activated sludge   primary + O  AS
  Temperature  (°C)                13-18              17-19               17.4 - 22             16 - 22
  pH                              6.0 - 6.3            5.9 - 6.4             5.9 - 6.4             5.5 - 6.1
  TSS  (mg/1)                      25,000 - 33,000      30,000 - 34,000       25,000 - 40,000
  VSS  (mg/1)                      21,000 - 27,000      22,000 - 27,000       20,000 - 30,000
  TS  (mg/1)                       -                    -                     -                     30,000 - 49,000
  TVS  (mg/1)                      -                    -                     -                     22,000 - 35,000
Retention time  (days)             4.2                  4.2                   4.2                   4.0
Digester temperature  ( C)         47.3                 46.4                  50.4                  50.2
VSS loading rate  (Ib/ft /d)       0.36                 0.38                  0.37                  0.45
VSS reduction  (percent)           37                   30                    40                    30

Two Stage System  -  (multiple test runs combined)
                                                 o  Waste Activated Sludge        Primary plus Secondary Sludge
Temperature (°C)                                 12 - 2412 - 30
pH                                               5.9 - 6.9                        6.0 - 6.(i
TS  (mg/1)                                        26,000 - 50,000                  23,000 - 60,000
TVS  (mg/1)                                       18,000 - 38,000                  18,000 - 41,000
Retention time  (days)                            3.7  - 5.0                       3-5
Digester temperature  (°C)                        48.7 - 57.8                      45.3 - 52.0
VS loading rate  (Ib/ft /d)                       0.32-0.46                      0.38-0.53
Overall VSS reduction  (percent)                  29 - 42                          30 - 45

Physical, Chemical  and Biological Aids - pH adjustment if necessary

Residuals Generated - Supernatant.  Quality similar to that of aerobic digestion with air (Fact Sheet 6.4.1).

Design Criteria - Single or two stage systems:  Retention time - five days or less, temperature 45 to 60 C.
Additional operating results are necessary to develop firm design criteria.

Reliability -  Process appears  stable and more easily able to recover from extremes than anaerobic digestion.

Environmental  Impact - Process requires less space than conventional digestion, and by stabilizing and disinfecting
sludge reduces adverse impact  of land disposal.

References - 23,  119,  138



                                                     A-216
-------
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-------
DIGESTION,  TWO STAGE ANAEROBIC                                                FACT  SHEET  6.4.4
Description - A two vessel system of sludge stabilization, where the first tank is  used for  digestion  and is
equipped with one or more of the following:  heater, sludge recirculation pumps,  methane gas recirculation,
mixers and scum breaking mechanisms.  The second tank is used for storage and concentration  of  digested
sludge and for formation of a supernatant.  Anaerobic digestion results in the breakdown of  the sludge into
methane, carbon dioxide, unusable intermediate organics and a relatively small amount of cellular protoplasm.
This process consists of two distinct simultaneous stages of conversion of organic  material  by  acid forming
bacteria and gasification of the organic acids by methane forming bacteria.   The methane producing  bacteria
are very sensitive to conditions of their environment and require careful control of temperature, pH,  excess
concentrations of soluble salts, metal cations, oxidizing compounds and volatile acids.  They also  show  an
extreme substrate specificity.  Can operate at various loading rates and is therefore not always clearly
defined as either standard or high rate.  Digester requires periodic cleanout (from 1 to 2 years) due  to
buildup of sand and gravel on digester bottom.

Technology Status - Widespread use  (60 to 70 percent)  for primary or primary and secondary sludge in plants having
a capacity of 1 Mgal/d or more.

Applications - Suitable for primary sludge or combinations of primary sludge and limited amounts of secondary
sludges.  Digested sludge is reduced in volume and pathogenic organism content, is  less odorous and easily de-
watered, and is suitable for ultimate disposal.   Advantages over single stage digestion include increased gas
production, a clearer supernatant liquor, necessity for heating a smaller primary tank thus  economizing  in heat,
and more complete digestion.  Process also lends itself to modification changes, such as to  high-rate  digestion.

Limitations - Is relatively expensive, about twice the capital cost of single-stage digestion.   It  is  the most
sensitive operation in the POTW and is subject to upsets by interfering substances, e.g., excessive quantities  of
heavy metals, sulfides, chlorinated hydrocarbons.  The addition of activated and advanced waste treatment sludges
can cause high operating costs and poor plant efficiencies.  The additional solids  do not readily settle after
digestion.  Digester requires periodic cleanout due to buildup of sand and gravel on digester bottom.

Typical Equipment/No, of Mfrs. - Sludge handling and control/32, pumps/34, heating  equipment/7 , digestion tank
equipment/18, gas holders/6.

Performance -                     Influent          Effluent          Reduction
Total Solids                      2 to 7%           2.5 to 12%        33 to 58%
Volatile Solids                                                       35 to 50%
Pathogen                                                              85 to less than 100%
Odor Reduction
Sidestream - Gas Production
     Quantity - 8 to 12 ft /lb volatile solids added, or 12 to 18 ft /lb volatile solids destroyed  or  0.6 to  1.25
                ft /cap, or 11 to 12 ft /lb total solids digested.
     Quality -  65 to 70% methane     N ,  H_, H_S,  NH ,  et al - trace     25 to 30% CO      550 to 600 Btu/ft
     -                           £   £   £     J                                f.
Physical, Chemical and Biological Aids - Heat;  maintain pH with lime,  also ammonia, soda ash,  bicarbonate of
soda, and lye are used; addition of powder activated carbon may improve stability of overstressed digesters;
precipitate heavy metals with ferrous or ferric sulfate; control odors  with hydrogen peroxide.

Residuals Generated -
Supernatant - Quality:  SS 200-15,000 mg/1, BOD,. 500-10,000 mg/1, COD 1,000-30,000 tag/1,  TKN 300-1,000 rag/1,  Total
P  (50-1,000 mg/1) , scum, sludge, gas.

Design Criteria - Solids Retention Times (SRT) required at various temperatures (22)
                            Mesophilic Range
     Temperature, °F       50  67  75  85  95
     SRT, days             55  40  30  25  20

Volume Criteria, (ft /capita):  Primary sludge 1.3-3, Primary and Trickling Filter Sludges 2.6-5, Primary and Waste
Activated Sludges 2.6-6.  Tank Size  (ft) :  diameter, 20-115; depth 25-45; bottom slope 1 vertical/4 horizontal.
Solids Loading (lb vss/ft /d) :  0.04-0.40.   Volumetric Loading (ft /cap/d) : 0.038-0.1.  Wet Sludge Loading (lb
/cap/d) : 0.12-0.19.  pH 6.7-7.6.

Overall Reliability - Successful operation subject to a variety of physical, chemical and biological phenomena,
e.g., pH, alkalinity, temperature, concentrations of toxic substances of digester contents.   Sludge digester bio-
mass is relatively intolerant to changing environmental conditions.  Under one set of conditions particular con-
centrations of a substance can cause upsets, while under another set of conditions higher concentrations of the
same substance are harmless.  Requires careful monitoring of pH, gas production, and volatile acids.

Environmental Impact - Return of supernatant to head of plant, may cause plant upsets.  The adverse environmental
impact of sludge disposal on land is reduced as a result of the process.

Miscellaneous Information - Digester gas can be used for on-site generation of electricity and/or for any in-plant
purpose requiring fuel.  Can also be used off-site in a natural gas supply system.  Off-site use usually requires
treatment to remove impurities such as hydrogen sulfide and moisture.  Removal of CO2 further increases the heat
value of the gas.  Utilization is more successful when a gas holder is  provided.

References - 7,  8, 10, 20, 22, 94


                                                  A-218
-------
DIGESTION
j
TWO
FLOW DIAGRAM
ENERGY NOTES (4) -
to heat incc
Btu = (-
C = specifi
mi
Lb
: r
nc
o
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for 1-10% solid
Energy is requi
losses during t
Btu/1000 ft
Correction fact<
Northern U.S. 1
U.S. 0.3.
Energy is genera
plant flow):
Gas Produced, s
Heat Available,
Electrical ener
assuming contim
release of gas,
COSTS* (3) (1976
1. Service life
2. Includes die
3. Feed to dige
(75% volati]
operating tt
4. Power costs
5. To adjust cc
QE = Q

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REFERE1TCES-
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STAGE ANAEROBIC
FACT SHEET 6A4
GAS I I GAS . ,
RELEASE 1 	 . 	 RELEASE II 	 _^^
/ GAS N^ / GAS ^^\
SLUDGE
INLET _
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Energy is
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al locati
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5,175
3.1
ed for mixing
on, 20 ft. subi
lency 85-93%.
ssumptions :
-exchanger , gas
nbined primary
t from digestei
85 to 110°F; c
3ing rates difi
=w Design Sludc
1,
TRUCT









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ION COST







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SUPERNATANT
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OPERATI
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104 105 106
DIGESTER VOLUME, ftj
ding.
,900 Ib/Mgal at 4% solids
ading rate - 0.16 Ib/ft /d;
, excess is not utilized.
ter curve at effective flow (QE> .
ON & MAINTENANCE COST
i — n — n 1 1 1 1 IL i i i i 1 1 1 LH °01




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3,4,8 Wastewater Flow Mgal/d Wastewater Flow, Mgal/d
construction cost to capital cost see Table A-2.
A-219
-------
DIGESTION,  TWO STAGE THERMOPHILIC  ANAEROBIC                                 FACT  SHEET 6,1.5
Description - Digestion is a fermentation process in which several groups of anaerobic and facultative organisms
assimilate and break down organic matter into primarily CO  and methane.   The process takes place in two tanks in
series; the first for digestion and the second for storage and concentration of sludge and formation of a super-
natant.  Thermophilic digestion operates at a temperature of approximately 46 to 57 C (115 to 135 F).  The methane-
producing bacteria essentially control the process and are very sensitive to pH, excess concentrations of soluble
salts, metal cations, temperature, and substrate concentration.  For additional details on anaerobic digestion
see Fact Sheet 6.4.4.

Technology Status - Full-scale studies of thermophilic digestion are in progress at the Hyperion plant (Los
Angeles, California) and serve as the basis for the data presented.

Applications - Thermophilic digestion may be a viable alternative to mesophilic anaerobic digestion for primary
or combined primary and waste activated sludges (WAS).   The high cost of heating the sludge may rule out its use
on WAS alone.  Thermophilic digestion enhances sludge dewaterability and methane production and achieves a greater
reduction of volatile solids, and reduces polymer dosage and pathogens.

Limitations - The higher temperatures require additional heat input; however,  this may be offset by higher methane
production.  Thermophilic bacteria are more sensitive to loading and temperature changes than mesophilic bacteria
and more severe temperature limitations.  Thermophilic digestion may solubilize some heavy metals, and the result-
ing recycle supernatant streams are higher in certain metals and in organic loadings than those from mesophilic
operations.  The digestion process itself is relatively expensive, and is highly sensitive to interferences such
as heavy metals, sulfides and chlorinated hydrocarbons.  There is some new data on thermophilic digestion as
applied to WAS or a combination of WAS and primary sludge, but analysis is not complete.  Thermophilic digestion
requires additional operator expertise and attention because of process sensitivities.

Typical Equipment/No, of Mfrs. (23) - Physically similar to conventional anaerobic digestion.  Sludge handling
and control/32; pumps/34; heating equipment for digestors/7; digestion tank equipment/18;  gas holders/6.

Performance (124) -
                              Influent          Effluent          Reduction     Notes
Total Solids  (percent)           6.1              2.1                66%        Includes reductions from dilution
Volatile Solids  (Percent)         78               65                70%        with steam used to heat sludge.
pH                               5.1              7.6
Alkalinity  (mg/1)               1600             4100
Temperature,  F                  77°             120°

Other:  Gas production 12.7 ft /lb VS added; gas quality 63 percent methane; volatile solids in sludge 600 mg/1;
detention time 18.2 days.  Salmonella and virus removals are greatly increased over mesophilic digesters, but
ascaris removals were negligible in both cases.

Effect of thermophilic digestion on dewatering (124):
                                              Chemical          Solids          Cake          Centrate
                                               Dosage           Capture       (Percent)
Dewatering Method          Feed Rate           (Ib/ton)         (Percent)       Solids)
Solid bowl centrifuge      25 gal/min            8                92             32
Basket bowl centrifuge     40 gal/min            6                38             31

Physical, Chemical and Biological Aids - Heat, lime for maintaining pH, sodium bicarbonate, ammonia, soda ash,
caustic, etc., nutrients to aid digestion if required, inorganic salts for metal precipitation, hydrogen peroxide
for odor control, polyelectrolytes for subsequent thickening.

Residuals Generated - Data on separate supernatant stream is not available (see Fact Sheet 6.4.4 for supernatant
from mesophilic range).  Filtrate quality (in mg/1) SS 1000, TDS 1500, COD 2700, N(total)  1400, PO  700, grease
1400, copper, cadmium, zinc, nickel, chromium, all measurable at less than 1 mg/1.

Design Criteria - Solids retention times required at various temperatures (22)  - 20 d at 100 F, 15 d at 110 to
130 F.  Loading rate 0.1 to 0.2 lb VS/ft /d, pH 6.6 to 7.4, tank diameter 20 to 115 ft, center depth 25 to 45 ft,
minimum bottom slope 1 vertical to 4 horizontal.  Process design criteria are not fully developed and require
more operating experience with various sludges and under different environmental conditions.

Overall Reliability - Limited operating data indicates a great deal of complexity of operation.  The process
requires a long time to achieve steady state conditions, and maintenance of these conditions is subject to a
variety of physical, chemical, and biological phenomena such as pH, alkalinity, temperature, interfering sub-
stances, loadings, etc.  High operator attention and monitoring required.

Environmental Impact - Recycle streams sent to head of plant may cause upsets.  Reduced sludge generation reduces
the adverse impact on the environment.  Boiler blowdown and air pollutants from boiler fuel may result.

References - 7, 8, 10, 22, 23, 26, 124, 136
                                                    A-220
-------
DIGESTION,  TWO  STAGE THERMOPHILIC ANAEROBIC
                                                                FACT  SHEET  6.4.5
FLOW DIAGRAM -
                                                    Release 1
Sludge
Inlet
Fuel

»
Sludge
Heater


Zone of
r^
1 Mixing
Actively
Digesting .s
Mixed
Liquor


Supernatant
Digested
^Sludge .
Supe
Remo

                                             Sludge Drawoff
                                                                      To further processing
ENERGY NOTES - Fuel requirements shown are for northern states.   For  central  locations, multiply by 0.5; for
southern locations, multiply by 0.3;  digester temperature  =  130  F;  energy credits for anaerobic digester gas
production  (124) = 18,000 ft /Mgal; 63 percent methane;  6.8  MBtu/Mgal.
    io6
    io
 o*   4
    10
    10
         1 Primary
         2 Primary + FeCl
         3 Primary + Low Lime
         4 Primary + High Lime
5 Primary + W A S
6 Primary + (W A S  +  FeCl  )
7 (Primary + FeCl  ) + W A  S
•8W A S
III  	Mil II   I  I III
       io
                                              io
                                                                   10
                                                                             IO     3     IO
                                                                  Digester Volume ft
                   10            10
COSTS'-              Solids,  Ib/day
1.   Costs include:   digester,  heat-exchanger,  gas-collection equipment, control building (ENR Index = 2475).
2.   Feed to digesters is combined primary  and  is thickened  feed = 1,900 Ib/Mgal at 4 percent solids (75 percent
     volatile) .                                                                          3
3.   Effluent from digesters  is 900 Ib/gal;  at  2.5% solids; loading rate = 0.16 Ib VSS/ft /d; operating tempera-
     ture = 130°F.
4.   Adjustment Factor; To adjust costs  for loading rates different than those presented here, enter curve at
     effective, flow (P-E)-NPW  Deslqn sludge  Mass
          CE   ^DESIGN  "       1,900  Ib/Mgal
                   CONSTRUCTION COST
                                                                      OPERATION S MAINTENANCE COSTS
     10
    1-0
    0.1

                                                       to id
                                                       O   -H
                                                       •H  - a
                                                       r-t rH +J
                                                       fH flj O
                                                       ST!"

                      1             10
                  Wastewater Flow,  Mgal/d
                                         .001
                                            .1
                                                                              Total
                                                                                     Material
                                                                             Labor


                                                                                                               8
                                                          1            10
                                                       Wastewater Flow, Mgal/d
  0001
100
REFERENCES - 3, 4, 8, 124 Costs  adjusted  from mesophilic operation to thermophilic operation from references.

*To convert construction cost to capital  cost  see Table A-2.


                                                   A-221
-------
DISINFECTION  (HEAT)                                                             FACT SHEET 6.4.6
Description - Heating to pasteurization temperatures is a well known method of destroying pathogenic organisms
that has been applied successfully to disinfecting sludge.  Pasteurization implies heating to a specific tem-
perature for a time period sufficient to destroy undesirable organisms in sludge and to make sludge suitable for
land disposal on cropland.  Usually heat is applied at 70 to 75 C for a period of 20 to 60 minutes.  Treatment can
be applied to raw liquid sludge (thickened or unthickened), or stabilized or digested sludge.

Pasteurization is usually a batch process, consisting of a reactor to hold sludge, a heat source, and heat exchange
equipment, pumping and piping and instrumentation for automated operation.  Pasteurization has little effect on
sludge composition or structure because the sludge is only heated to a relatively moderate temperature.

Technology Status - Not widely used.  More common in Europe than in the United States.  In West Germany and Swit-
zerland, there are regulations (actually seldom followed) that require pasteurization when sludge is spread on
pastures during summer growth periods.  May find increased application with the renewed interest of land disposal
of sludges.

Applications (119) - Can be applied to a wide variety of sludges in various forms.  Pasteurization may be redun-
dant where sludges are treated by other processes which destroy pathogenic matter.  Largest potential application
is to otherwise untreated sludges which are disposed of on land.  Studies show that liquid sludge need only be
cooled to 60 C for application to land with no adverse effects from temperature.  Small treatment plants can
pasteurize liquid digested sludge in a tank truck with steam injection.

Limitations - Pasteurization has little or no effect on metals or other toxic materials.  Pasteurized but undi-
gested sludges still have considerable risk of foul smelling fermentation after land applications.  Limited data
is available on interferences and other process controls required for optimizing the process.  Heating unthickened
sludge requires excessive amounts of heat.  Because of the low temperatures involved, heat recovery is not cost
effective unless the sludge flow is at least 50,000 gal/d.  At this level, one-stage heat recuperation may be cost
effective.  Two stage recuperation is not cost effective until a flow of over 100,000 gal/d of sludge is reached.

Typical Equipment/No, of Mfrs. (23)  - Sludge handling and control/32; Heating equipment/7; Instrumentation/9.

Performance (111,119) - Seventy-five degrees Centigrade for 60 minutes will reduce coliform indicators below 1,000
counts per 100 ml.  Seventy degrees Centigrade for 30 to 60 minutes is effective for destroying pathogens in di-
gested sludge.   Seventy degrees Centigrade for 20 minutes is effective for destroying pathogens in raw sludge.
Heat treatment also appears to destroy viruses.  The table below indicates the time required for 100 percent elim-
ination of various typical pathogenic organisms found in sludge at various temperatures:
                                                                            o
                                               	Temperature  C	
Organism	50	55	60	65	70
Time Required for 100% Reduction (minutes)
Cysts of Entamoeba histolytica                  5
Eggs of Ascaris lumbricoides                   60         7
Brucella abortus                                         60                   3
Corynebacterium diphtheriae                              45                             4
Salmonella typhosa                                                 30                   4
Escherichia coli                                                   60                   5
Micrococcus pyrogene var. aureus                                                       20
Mycobacterium tuberculosis var.                                                        20
Viruses                                                                                25

See Reference 119 for detailed experimental data on destruction of pathogens as a function of time and temperature.

Physical, Chemical and Biological Aids - Heat, typical boiler feedwater pretreatment chemicals (scale and/or cor-
rosion) .

Residuals Generated - Boiler blowdown, air pollution from the boiler.

Design Criteria - Temperature 70 to 75 C; time 20 to 60 minutes; heat required 4-6 x 10  Btu/ton of sludge  solids.
Two units or more are usually designed in parallel so one unit can be filling while the other is holding sludge
for the required length of time.  Units can share a common boiler.

Unit Process Reliability - Mechanical and process reliability high.  Pasteurization can be fully automated  and
requires minimum operator attention.   There is little operating experience in the United States.

Environmental Impact - Reduces the adverse impact of sludge disposal to cropland.   If steam injection is used to
heat the sludge, chemicals used for feedwater pretreatment must be acceptable for land spreading of sludge.

Miscellaneous Information - Digested sludge heat can reduce the need for supplemental energy.   Methane from
anaerobic digestion can provide the required fuel for pasteurization.

References - 8, 23, 111, 119
                                                       A-222
-------
DISINFECTION  (HEAT)
                                                                                   FACT SHEET  6,4,6
FLOW DIAGRAM -
                    feed Water
                                        Boiler
                                    Sludge
                                                        Holding Tank
                                                                           Pasteurized Sludge
ENERGY NOTES - Fuel requirements  for heating  (119); 4.6 X 10  Btu/ton of sludge (assuming 5 percent solids and 53
temperature rise requirement).   At 250 tons/d  or more, heat recovery may reduce the fuel requirement;  anaerobic
digesters could provide this energy.   Electrical requirements.  Approximately 14 kwh/ton of sludge for pumps and
mixing.
COSTS (1978)  -Assumptions: ENR  Index = 2776
2.
1.    Design Basis:   Sludge  temperature,  17 C; sludge solids, 5 percent; pasteurization temperature,  70  C;  pas-
     teurization time,  1 h.
     Construction cost  includes:  steam boiler, pasteurization tanks, sludge pumping and automatic controls.
3.    Single tank up to  10 tons  of sludge solids per day; two tanks above.
4.    Labor was estimated at $6/ton of  sludge  solids  for small plants, decreasing to 52/ton of sludge solids  for
     very large plants.
5.    Fuel, $2.80/MBtu.
                          CONSTRUCTION COSTS
                                                                             OPERATION AND MAINTENANCE
              1 0
              0 1
           5 001
            0001
                                                                   1 0
                                                                 Q  0 1
                                                                 o
                                                                   0001
                                                                            s
                                                                           1  Operating  Costs.
                                                                                                1
                                                                                           •Labor
                                                                                                 ruel,
                             10           100
                            Tons of Sludge/Day
                                                      1000
                                                                                   10           100
                                                                                   Tons of  Sludge/Day
                                                                                                              1000
REFERENCES - 111, 119
 *To  convert construction cost to capital cost see Table A-2.
                                                        A-223
-------
HEAT TREATMENT OF  SLUDGE                                                       FACT SHEET 6.4.7
Description and Common Modifications - The heat treatment process involves heating sludge to 144 to 210°C for
short periods of time under pressure of 150 to 400 Ib/in g.  It is essentially a conditioning process which pre-
pares sludge for dewatering on vacuum filters or filter presses without the use of chemicals.  In addition, the
sludge is sterilized and generally stabilized and rendered inoffensive.  Heat treatment results in coagulation of
solids, a breakclowr, in the cell structure of sludge and a reduction of the water affinity of sludge solids.

Several proprietary variations exist for heat treatment.  In these systems, sludge is passed through a heat ex-
changer into a reactor vessel, where steam is injected directly into the sludge to bring the temperature and
pressure into the necessary ranges.  In one variation air is also injected into the reactor vessel with the
sludge.  The detention time in the reactor is approximately 30 minutes.  After heat treatment, the sludge passes
back through the heat exchanger to recover heat, and then is discharged to a thickener-decant tank.  The thickened
sludge may be dewatered by filtration or centrifugation to a solids content of 30 to 50 percent.  The sludge may
be ground prior to heat treatment.

Technology Status - The process of heat treating sludge was first introduced in 1935,  but has only become common
during the last decade.  About 100 units are currently in operation in the United States.

Applications - Heat treatment is practiced as a sludge conditioning method to reduce the costs of sludge dewater-
ing and ultimate disposal.  The benefits of heat treatment include:  (1)  Improved dewatering characteristics of
treated sludge without chemical conditioning; (2)  Generally innocuous and sterilized sludge suitable for ultimate
disposal by a variety of methods including land application in some cases; (3)  few nuisance problems, (4)  suitable
for many types of sludge which cannot be stabilized biologically; (5)  reduction in subsequent incineration energy
requirements; and (6) reduction in size of subsequent vacuum filters and incinerators.

Limitations - The process has very high capital and operating costs, and may not be economical at small treatment
plants.  Specialized supervision and maintenance are required due to the high temperatures and pressures involved.
Expensive material costs are necessary to prevent corrosion and withstand the operating conditions.  Heavy metal
concentrations in sludges are not reduced by heat treatment and further treatment of sludges with high metals
concentrations may be required if the sludge is to be applied to crop land.   The sludge supernatant and filtrate
recycle liquor are strongly colored and contain a very high concentration of soluble organic compounds and ammonia
nitrogen, and in some cases must be pretreated prior to return to the head of the treatment plant.

Typical Equipment/No, of Mfrs. - Complete heat treatment systems are generally proprietary, and the most common
systems are supplied by five manufacturers.  The major equipment common to these processes are grinders, sludge
feed pumps and handling equipment, heat exchangers, reactors, boilers, and separators.

Performance - Heat treatment is a conditioning process, and is intended to enhance the  performance of subsequent
operations.  Within the process itself pathogens are destroyed and 30 to 40 percent of the VSS are solubilized.
Dewatering efficiency can be increased to a solids capture of over 95 percent and a solids content of up to 50
percent.

Physical, Chemical and Biological Aids - Heat; Chemicals for dewatering are not normally required.  Corrosion
control aids may be required for the boiler and/or the process.

Residuals Generated - Sidestream (recycle liquor)  50 percent of sludge flow (by volume);  quality - BOD,  5,000 to
15,000 mg/1; COD, 10,000 to 30,000 mg/1; NH -N, 500 to 800 mg/1;  P, 140 to 250 mg/1;  TSS,  9,000 to 12,000 mg/1;
VSS, 8,000 to 10,000 mg/lj pH, 4 to 6.

This stream is generally amenable to biological treatment but can contribute up to 30 to 50 percent of the organic
loading to a treatment plant.   If the plant has not been designed for this additional load, pretreatment prior to
return may be necessary.  Some non-condensable gases may be generated which will require combustion or disposal.
Boiler blowdown and/or water treatment residuals (for boiler feedwater)  may result.

Design Criteria - Temperature 140 to 210 C, pressure 150 to 400 Ib/in g, detention time 30 to 90 minutes, steam
consumption 600 lb/1000 gal of sludge.

Overall Reliability - Limited operating data is available.   Mechanical and process reliability appear adequate
after some initial operational problems.   Careful operator attention is required.

Environmental Impact - Recycle liquor sent to head of plant can cause plant upsets due to very high organic load-
ings.  The process can result in offensive odor production if proper odor control is not practiced.   A colored
effluent may also result, requiring additional processing where discharge standards prohibit this condition.

Miscellaneous Information - The composition of the recycle liquor can vary among the various processes.   Some
liquors may contain a high proportion of non-biodegradable matter.   This matter is largely humic acids,  which can
give rise to unpleasant odors and taste if present in water which has been chlorinated prior to use for domestic
supply.  If industrial wastes of various types are included in the wastewater to be treated, the actual chemical
composition of the liquor resulting from heat treatment of the sludge should be determined by a detailed chemical
analysis.  A possible treatment process for a highly polluted liquor can consist of filtration, aeration and
activated carbon adsorption for non-biodegradable organics.

References - 3, 7, 8, 26, 31, 95, 111, 199
                                                     A-224
-------
 HEAT  TREATMENT  OF SLUDGE
                                                                                    FACT SHEET 6.4.7
ENERGY NOTES - Assumptions:   Reactor Conditions;  300 Ib/in g at 350°F;  Heat  exchangers   T =  50°F; continuous
operation; electrical includes all pumping,  grinding,  air compressing  artd post  thickening drives; fuel is to
produce steam to bring reactor to operating temperature.
           5
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                                      10           10°             iu 1.0          10           100          1,000
                                         ' gal/min                       Thermal Treatment Capacity,  gal/min
:OSTS  ' Construction costs include:  sludge  feed pumps,  grinders,  heat exchangers,  reactors, boilers, gas separators
and buildings.  Costs are related to average  wastewater flow by  the following:  Sludge quantity = 1900 lb/ Mgal (un-'
digested, combined thickened primary plus  secondary sludge);  solids concentration  = 4.5 percent; sludge flow = 3.8
gal/min/Mgal/d based on 8,000 operating  h/yr.   Fuel costs  are for steam generation. ENR Index  =  2475
Adjustment Factor: To adjust costs for design factors  different  than for  those  above, enter curve at effective flow
  E '
         QE = QDESIGN X (New Desl8n  Sludge  Mass)/(1,900 lb/Mgal)
           100
                        CONSTRUCTION COST
                                                                         OPERATION & MAINTENANCE COST
           10
           10
           01

                                                             Q
                                                             B
                                                             O
            0 1
                         10            10
                         Wastewater Flow  Mgal/d
                                                    100
                                                               0001
                                                                                         Fuel
                                                                                               Tot \
                                                                  01
REFE^NCES-3 ,4,8
*To convert construction cost to capital cost see Table A-2.
                                                                               10            10            100
                                                                              Wastewa er Flow, Mgal/d
                                                       A-225
-------
LIME STABILIZATION                                                                FACT  SHEET 6.4.8
Description - The addition of lime, in sufficient quantities to maintain a high pH stabilizes sludge and destroys
pathogenic bacteria.  Lime stabilized sludges dewater well on sandbeds without odor problems.   Sludge filterability
can also be improved with the use of lime.  Lime is also used prior to land application of sludges.   Mixing of lime
with liquid sludges is best accomplished with air mixing.  For a detailed description of lime  handling and feeding
systems, see Fact Sheet No. 5.1.5.

Applications - Lime addition to raw or digested sludges to a stable (several hours)  pH of over 12 or greater
effectively stabilizes sludge for land application.   Pathogens  viruses and bacteria are destroyed,  but worm eggs
are resistant.  Disinfection is superior to that obtained by mesophilic anaerobic digestion.   Hydrated lime is
often used in conjunction with metal salts to improve dewaterability.   Though lime has some slight dehydration
effect on colloids, its use in conditioning is mainly for pH control,  odor reduction, disinfection and filter aid
effect.

Limitations - Lime treatment produces essentially no organic destruction.   Therefore caution is required when
sludge cake disposal to land is practiced.  Disposal in thick layers could create a situation where the pH could
fall to near 7 prior to the sludge drying out, causing regrowth of organisms and resulting noxious odors.   Main-
tenance of a pH of 11 for two weeks or more can minimize these problems.   Lime handling and feed systems can
require a high degree of operator attention.

Technology Status  - Lime has been in widespread use for over 100 years,  and the shipping, handling and feeding of
lime is a well proven technology.  Polymers recently have been replacing lime in some sludge conditioning appli-
cations prior to mechanical dewatering.  Lime may have an increasing role as land application of sludges becomes
more common.

Typical Equipment/No, of Mfrs. (23, 97) - Bins/over 50; Hoppers/over 40; Conveyors and elevators/over 50; Lime
slakers/6; Chemical feed equipment/25; pH instrumentation/over 50;  Sludge handling and control/32.

Performance (8) - A full scale study indicated the following effects of lime treatment on pathogenic bacteria
(initial pH = 12.5, maintained above pH = 11.5 for 24 hours).   Units - organisms/100 ml of sample.
     Sludge                   Salmonella               Fecal Strep.              Fecal Coli
     Raw primary                  62                   39 x 10                  8.3 x 10
     Limed raw primary        Less than 3              6 x 10                   5.9 x 10
     Waste activated sludge        6                   1x10                   2.7x 10
     Limed waste activated    Less than 3              6.7 x 10                 1.6 x 10
     Septage                       6                   6.7 x 102                1.5 x 10^
     Limed septage            Less than 3              6.7x10                 2.6x10

The effect of lime stabilization on vacuum filterability of sludge from a laboratory test is presented below
(Filter leaf test yield:  Ib/h/ft ).
     Sludge                              Al   Dose (mg/1)                    Fe   Dose (mg/1)
     Before lime addition                 .98   .94   .95                    1.06       1.57
     After lime addition                 1.97  2.10  2.58                    1.57       2.40
Note:  Cake moisture (before and after) in all cases was essentially unchanged at 4.0 Ib water/lb dry solids - 10
percent.

Chemicals Required - Lime (CaO or Ca(OH) )
Residuals Generated - None
Design Criteria (73) - Lime requirements to raise pH in sludges are as follows:
Sludge - Percent Solids           1%          2%          3%          3.5%          4.4%
pH=ll Ca(OH)  dosage, mg/1       1400        2500        3700         6000          8200
pH=12 CafOH)^ dosage, mg/1       2600        4300        5000         9000          9500

Lime dosage required to maintain sludge at pH greater than or equal 11.0 for at least 14 days.
Sludge Type                            Dosej  Ib Ca (OH) ,,/ton
Primary                                    200 - 300
Septage                                    200 - 600
Biological                                 600 - 1000
Al(Secondary) Precipitation                800 - 1200
Fe(Secondary) Precipitation                700 - 1200
Al(Primary & Secondary) Precipitation      500 - 800

Unit Process Reliability - Highly reliable from a process standpoint.   However,  above average operator attention
and cleaning requirements are necessary to maintain the mechanical reliability of the lime feed.

Environmental Impact - The volume of sludge generated may be increased,  although lime can reduce  the pathogenic
bacteria and odor of sludge rendering it more suitable for land disposal.   Improved dewaterability can result in
less land use demand through smaller sized sand bed requirements.   Disposal of sludge  with high pH.

References - 3, 7, 8, 23, 26, 73
                                                   A-226
-------
LIME  STABILIZATION
                                                                                    FACT SHEET 6,4,8
FLOW DIAGRAM -
                                                                Sludge
                                                    pH control
Lime

1

/ "
^T
Lime sluzry pot
Lime slurry

- 1 /
^

/

                                                                                       Stabilized sludge
                                                                   10
 INERGY NOTES - Assumptions:  Pump feed of slaked lime; mix lime
and sludge for 60 seconds at G = 600/s; sludge pumping not
included.
                                                                 TJ
                                                                 01   5
                                                                 .Jj 10
                                                                 3
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                                                                      100
                                                                                  1,000
                                                                                                10,000
                                                                                                             100,000
COSTS* - January 1978 dollars;  ENR Index = 2672                                 Sludge Quantity, Ib/d
T.  Construction cost includes:  bulk lime  storage bin  (hydrated  lime  for  1 Kqal/d,-pebble  quicklime for 4 and 40
    Mgal/d), augers, volumetric feeder,  slurry  tank,  line  slaker,  sludge mixing  S  thickening  tank,  sludge grinder,
    transfer pumps, all weather treatment building, and  sludge  holding lagoon  with 60 day  detention time.
    Operation and .Maintenance Costs; labor  rates  are  $6.50 per  hour; lime  costs  are $44.50 per  ton  for 46.8 per-
    cent CaO hydrated lirae and  $40 per ton  for  85 percent  CaO quicklime.
    Lime dosage required per unit dry solids  as 100 rc-c^-- Ca(OH)?  is 0.20 Ib/lb.
                            CONSTRUCTION COST
                                                                         OPERATION & MAINTENANCE COST
              01
             001
                                                            Q  o 1
                                                            o|
                                                             To l~001
                0 1
 1 0           10
Wastewater Flow, Mgal/d
                           -LU      0001
                           100        0 1
                                                                                 -Labor
                                                                                            Total /
                                                                                                     Maten
                                                                                                              0 1
                                                                                                             0 01
                                                                                                             0001
 1 0            10
Wastewater How, Mgal/d
                                                                                                            00001
                                                                                                          100
 REFERENCED-4,73,232


  *To convert construction cost to capital cost see Table A-2.
                                                         A-227
-------
AEROBIC TREATMENT  AND ABSORPTION BED                                   FACT  SHEET  7,1,1
Description - An aerobic treatment unit followed by a soil absorption bed is  an  on-site  system for  the  treatment
and disposal of domestic wastewater.  Various aerobic suspended and fixed growth processes  are available  alterna-
tives to the conventional septic tank (see Fact Sheet 7.1.6).   The activated  sludge process employs high  concen-
trations of microorganisms under aerobic conditions in a batch or flow-through/  extended aeration operation.
Forced air diffusion or mechanical aeration is followed by clarification, whereby the biomass  is separated  from
the treated wastewater.  A portion of the separated biomass is recycled back  to  the aeration chamber in the flow-
through mode.  Fixed film treatment processes employ a large surface area upon which  microorganisms will  grow and
over which wastewater is distributed so that the biomass may contact and metabolize pollutants within the waste
streams.  Aeration may be provided by natural convection, mechanical aeration, or forced air ventilation.   A
solid-liquid separation step normally follows, along with recycling of treated wastewater back to the fixed media.
Examples of fixed film systems include the packed tower, rotating contactor,  and submerged  media system.  Treated
effluent can then be discharged to a soil absorption field for disposal.  Distribution piping  surrounded  by gravel
is buried in a seepage bed or a series of absorption trenches, designed on the basis  of  site and soil charac-
teristics.  Wastewater is spread throughout the field and conducted into the  subsoil. (See  Fact Sheet 7.1.6)

Modifications - The aerobic unit may be preceded by a septic tank or trash trap  to remove grease, floating  solids,
and large debris or a surge tank to equalize flow.  Clarifiers, tube and plate settlers, or surface filtration are
alternatives for solids separation following aeration.  Solids return in flow-through operations can be provided
by either gravity, air lift pumps, or draft tubes.

Technology Status -  Aerobic units are used extensively in package plants for institutional and commercial  on-site
treatment, but their share of the individual home treatment market is quite small.

Typical Equipment/No, of Mfrs. - Package aerobic unit, including tank, aeration  equipment,  and controls/more than
20;  distribution piping/locally supplied.

Applications - Used as alternative  to the conventional septic tank for on-site  treatment of household wastewater.
Aerobic units, when properly operated and maintained can result in a higher effluent  quality than septic  tanks and
can reduce clogging in coarse (sandy) soils.  Although pretreatment can potentially be improved, subsurface
drainage beds should be limited to sites with recommended soil depths and permeability,  as  with septic tanks.

Limitations - On-site aerobic processes potentially produce a higher degree of treatment than  septic tanks, but
periodic carryover of solids due to sludge bulking, toxic chemical addition,  or  excessive sludge buildup  can
result in substantial variability in effluent quality.  Regular, semi-skilled operation and maintenance is
required to ensure proper functioning of moderately complex equipment, and inspections every two months are
recommended.  Power is required to operate aeration equipment and pumps.  Absorption  beds are  dependent upon site
and soil conditions, and are generally limited to sites with percolation rates less than 60 min/in, depth to water
table or bedrock of 2 to 4 ft, and level or slightly sloping topography.  (See Fact Sheet 7.1.6).

Performance - Aerobic units can achieve higher BOD removals than septic tanks, but SS removals, which are highly
dependent on the solids separation methods utilized, are similar.  Nitrification is normally achieved, but  little
reduction in phosphorus is effected.  Field studies indicate that suspended growth units can provide from 70 to 90
percent BOD  and SS reductions for combined household wastewater, yielding effluent BOD  and SS concentrations in
the range or 30 to 70 mg/1 and 40 to 100 mg/1, respectively.  Limited data for fixed  growth units  tested with
municipal or synthetic wastewater show effluent BOD  and SS concentrations of 30 to 50 mg/1 and 40  to 60  mg/1,
respectively (149).  A properly designed and constructed soil absorption bed  will effectively  remove pollutants,
including bacteria, viruses, and heavy metals, by natural adsorption in the soil zone adjacent to  the field.
However, nitrate movement through many soils to groundwater may be substantial.

Chemicals Required - None.

Residuals Generated - Excess sludge containing organics, grease, hair, grit,  and pathogens  must be  removed  from
aerobic units and disposed of every 8 to 12 months.  If a septic tank is used for pretreatment, sludge may  be
wasted to the tank, reducing offsite pumping frequency.

Design Criteria - Design peak flow:  75 gal/d/person.  Commercial designs must be evaluated in light of site
specific requirements.  The absorption area requirements shown on Fact Sheet  7.1.6 apply for finer  textured soils;
some size reduction is possible for coarser soil types with aerobic treatment.

Reliability - Aerobic processes are sensitive to microbial upsets and effluent quality is dependent upon  super-
vised operation.  Proper design and maintenance of mechanical equipment is necessary  for effective  treatment.

Environmental Impact - Sludge is generated, requiring approved treatment and disposal.  Effluent can contaminate
groundwaters when pollutants are not effectively removed by the aerobic unit or  the soil system.  Aeration  equip-
ment can be noisy.  Poorly maintained units may produce odors.

References - 14, 149, 152, 160
                                                     A-228
-------
AEROBIC  TREATMENT AND ABSORPTION BED
FACT  SHEET 7.1.1
 FLOW DIAGRAM -
                                        Q
   Wastewater
                    ///SCUM
                      TRASH
                      TRAP
                    /', SLUDGE''
                                        cfc
                                      AERATION
  ABSORPTION FIELD
        (PLAN)
                        EXTENDED AERATION UNIT
                               (PROFILE)
 ENERGY NOTES -  700  to  3,600 kWh/yr for aeration and pumping.
COSTS* - 1978 dollars; ENR Index =  2776.   The  following are cost estimates for a household aerobic  unit  and soil
absorption system:
          Aerobic treatment unit, including design, permit and installation  with              $1,000 to $3,500
          20 year service  life  for  shell and 10 years for equipment
          Soil absorption  system  (300 to 750 ft )  with 20 to 30 year service  life
          ($1 to $2.10/ft  )

                                                           Construction costs

          Maintenance of aerobic unit, including sludge removal (routine and
          unscheduled)
              375  to   2,100


           $1,375  to  $5,600

           $    50  to  $  150
          Power ($0.02/kWh)
                                                                                                 15 to
                                                                                                           75
                                                        Annual operating costs
                                                                                                 65 to $  225
Soil absorption system construction cost includes excavation, gravel,  pipe, backfill,  and miscellaneous labor.
This cost can vary significantly, depending upon site and soil characteristics,  size  and type of bed, and local
material and labor costs.
REFERENCES - 103, 152
To convert construction cost to  capital cost see Table A-2.
                                                      A-229
-------
AEROBIC  TREATMENT  AND SURFACE DISCHARGE                               FACT  SHEET 7.1.2
Description - Surface discharge of aerobically treated domestic wastewater is an alternative on-site  disposal
method that can be used when the conventional soil absorption system would be inadequate as  a treatment and dis-
posal medium.  If an appropriate receiving water is available, the level of treatment required may vary depending
on local regulations, stream water quality requirements, and other site-specific conditions.   Numerous  field
studies have shown that well-maintained aerobic units produce effluents containing concentrations somewhat in
excess of secondary treatment requirements of 30 mg/1 of BOD  and SS.   To attain this standard, some  form of
additional treatment is necessary.  Granular filtration, with its simplicity and low operation and maintenance
requirements, has proven effective for this purpose.  Various aerobic suspended and fixed growth processes are
available as alternatives to the conventional septic tank.   The activated sludge process in  batch or  flow-through
extended aeration designs and fixed film processes, which distribute wastewater over large surface areas of micro-
organisms, can produce higher quality effluents than septic tanks if properly maintained and operated (see Fact
Sheet 7.1.1).  The intermittent sand filter, successfully tested in the field, consists of a 2 to 3 ft  deep sand
bed which remains aerobic and removes SS and dissolved organics.  The filter surface is flooded intermittently
with pretreated wastewater at intervals which permit the surface to drain between applications.  Filtrate is
collected by underdrains for final discharge.  A sand filter preceded by aerobic treatment does not normally
require alternating units, as is necessary for a filter following septic tank pretreatment.   However, the filter
surface with accumulated solids should be removed and replaced with clean sand every 6 months.  Alternative
filters are described in Fact Sheet 7.1.8.

Modifications - A septic tank to remove grease, floating solids, and large debris or a surge tank to  equalize  flow
may precede an aerobic unit.  A dosing pump and chamber can be used to distribute effluent over the filter surface,
Covered, insulated filters are used in areas with extended periods of sub-freezing weather.   Disinfection of
filtrate or nutrient removal may be required to comply with direct discharge standards (see  Fact Sheet  7.1.3).

Technology Status - Many aerobic treatment units followed by filtration for surface discharge are in  operation in
the u. S. today.  The available field data on performance are meager,  however.

Typical Equipment/No, of Mfrs. - Package aerobic unit, including tank, aeration equipment, and controls/more
than 20; dosing tank and pump/more than 5; distribution and underdrain piping/locally supplied.

Applications - Direct discharge of effluent from an aerobic unit-sand filter system is an on-site option that  can
be utilized where unfavorable site or soil conditions render subsurface disposal impractical or infeasible and
where a receiving water is available.

Limitations - Studies under household conditions have shown that aerobic units are not as stable as conventional
septic tanks and periodic biological and hydraulic upsets can result in substantial variability in quality of  fil-
ter influent.  Although the effluent qualities of aerobic unit-sand filter and septic tank-sand filter  systems
have shown to be similar for comparable loading conditions, the difference in influent organic strength can affect
filter operation in terms of required surface area, length of loading and resting periods, and maintenance.  The
higher level of organic removal is obtainable with regular maintenance of aeration equipment and pumps.  Filter
surfaces need to be restored or replaced when clogging occurs to avoid serious ponding conditions. Discharge
permits, with sampling and inspection, may be required by regulatory authorities.

Performance (14) - Effluent quality data from field studies of an extended aeration unit-intermittent sand filter
system with 3.8 gal/d/ft  average loading rate, 0.19 mm effective size, and 3.31 uniformity  coefficient:
     Parameter                               Aerobic Unit Effluent              Sand Filter  Effluent
     BOD_, mg/1                                     31.0                                3.5
     TSS, mg/1                                      41.0                                9.4
     Total nitrogen (N), mg/1                       37.8                               34.8
     Ammonia-nitrogen, mg/1                          1.4                                0.3
     Nitrate-nitrogen, mg/1                         32.3                               33.8
     Total phosphorus (P), mg/1                     29.5                               20.3
     Fecal coliforms, log  #/l                       5.3                                4.0
     Fecal streptococci, log  #/l                    4.4                                3.2

Chemicals Required - None, unless chemical disinfection is required.

Residuals Generated - Sand with putrescible organic matter must be removed from filter surface when clogging
occurs.  Excess sludge from aerobic unit should be wasted every 8 to 12 months.  (see Fact Sheet 7.1.1)

Design Criteria - General:  Design peak flow = 75 gal/d/person.  Aerobic unit:  Available commercial  designs must
be evaluated with site specific requirements.  Intermittent sand filter:  design loading rate = 5 gal/d/ft ;
effective size = 0.2 to 0.6 mm; uniformity coefficient less than 4.0.

Reliability - Aerobic units are subject to biological upsets due to toxic chemical addition,  surge flows, or cold
climates.  Semi-skilled OSM is necessary to ensure proper functioning of modarately complex  equipment.   Sand
filtration is a relatively reliable process which is not greatly affected by normal pretreatment variations.

Environmental Impact - Potential for nutrient or pathogen addition to surface waters.  Poorly maintained aerobic
units may produce odors.  Disposal of excess sludge and sand residuals is required.

References - 14, 103, 152, 162
                                                   A-230
-------
 AEROBIC  TREATMENT  AND SURFACE DISCHARGE
                                         FACT SHEET 7.1.2
 FLOW DIAGRAM -
 Wastewater
                                                               Cover
                                    Sump
                                    Pump'

_£_
*— «•£


i



Open
W7r^/77>
•• •Orav^T~^r>
Un
^ r
— — i
                   .Underdrains

                    '      I Discharge
                   Aerobic
               Treatment Unit
Pumoing
Chamber
Intermittent
    Sand
   niter
    I	I
Disinfection
    Unit
(if required)
                                                           Receivj ng
                                                             Water
ENERGY NOTES - 70u to 3600 kWh/yr for operation of  aerobic  unit.   50 to 250 kWh/yr for sump pump.
COSTS* -  1978 dollars; ENR Index » 2776.  The following are cost estimates for an on-site  surface  discharge  system
consisting of an aerobic treatment unit, pumping chamber, and intermittent sand filter with  gravity  discharge:
     Construction cost:
     Aerobic treatment unit, including installation                             $1,000 to  $3,500
     Pumping chamber with 1/2 hp sump pump and controls to dose filter             600 to  1,000
       {optional, often included in design)
     Intermittent sand filter, 50 ft  surface area, with 25 ft gravity             500 to     750
      discharge line  (See Fact Sheet 7.1.8)                                      	
                                                       Total
     Annual operation and maintenance cost:
     Maintenance of aerobic unit (including sludge removal)  and pumping
      chamber  (routine and unscheduled repairs)
     Periodic raking and replacement rof sand surface to restore
      hydraulic capacity of filter (every 6 months)
     Power for aeration and pumping  ($0.02/kWh)
                                                       Total
                                     $2,100 to $5,250


                                     $    50 to $  150

                                         75 to    100

                                         15 to     80
                                     $   140 to $  330
Critical factors determining the cost of a sand filter include the type of filter,  the  amount of required surface
area, and the availability of quality filter sand, which is sensitive to location.   Also, available package
filter units may significantly reduce the construction cost cited above, as can the type of aerobic unit.  How-
ever, the performance of such units will not be comparable to the performance cited in  this fact  sheet.    The
cost of surface discharge depends on site specific factors such as distance to the  receiving water, ease of
excavation, and local material and labor costs.  This cost increases  if further pumping is required and effluent
monitoring is included.
REFERENCES - 103,  162
*To convert construction cost  to  capital cost see Table A-2.
                                                     A-231
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DISINFECTION FOR ON-SITE  SURFACE DISCHARGE                                 FACT SHEET  7,1,3
Description -  Direct discharge to an available  receiving water is an on-site alternative for the disposal of
lomestic wastewater,  as discussed in Fact  Sheet  7.1.8.  The required level of treatment depends upon stream water
juality requirements,  local  regulations, and other  site-specific conditions.  A properly maintained aerobic treat-
ment unit or septic tank followed by a polishing sand  filter  is capable of producing an effluent that complies
*ith secondary treatment standards of 30 mg/1  BOD  and SS.  However, disinfection may be required to reduce total
and fecal coliform levels below the maximums of  1000/100 ml and 200/100 ml, respectively, recommended for recre-
ational waters.(14)   Disinfection methods  that have proven effective against bacterial and viral pathogens for on-
site application include tablet chlorination,  iodine crystals, and ultraviolet irradiation.

rhe stacked-solid tablet feeder,  with a hypochlorite storage  chamber and flow-through mixing provision, followed
by a contact chamber is a typical chlorination system  for small waste flows.  Iodine, which is only slightly
soluble in water, is normally used in the  crystalline  form.   A saturator holding crystals serves as the feed
ievice.  The appropriate dosage to be added to the  effluent can be controlled by pumping a designated sidestream
through the iodinator and reblending it with the main  flow.   An ultraviolet disinfection unit for on-site applica-
tion consists of a high intensity lamp in  a radiation  chamber, through which a thin layer of wastewater is injected
for treatment.  Ultraviolet  light is germicidal  in  the wave length range of 230 to 300 nm, with optimum efficiency
at 257 nm.  The  dosage of UV irradiation required depends on  lamp intensity, wastewater transmissivity, exposure
time and flow pattern through the unit.

todifications -  A dry feed chlorination system can  be  improved with the use of a surge tank and siphon or pump for
nore accurate dosage control.   Ultraviolet units  can  be  equipped with automatic cleansing devices for lamp sleeves
to maintain radiation transmission and with meters  to measure  intensity.

 technology Status - Chlorination of wastewater has  been  practiced  for many years.   Iodine and ultraviolet irradi-
ation,  which have been shown to be effective water  supply disinfectants, are  relatively new for on-site wastewater
treatment applications.

typical Equipment/Ho.  Mfrs.  - Dry feed chlorinator/approx.  10;  iodine  saturator/more  than  2; UV disinfection unit
*ith controls/approx.  6.

applications - These on-site disinfection methods  are used to destroy  disease-causing organisms  in  the  effluents
from household treatment units prior to disposal by direct discharge  to meet  environmental and public health
requirements.

Limitations -  Dry feed chlorinators with gravity flow-through provisions  lack sufficient dosage  control, which can
cause excessive levels of residual chlorine to be present in final effluents.   Field  evaluations  found  the  actual
dosage to be an inverse function of flow rate with an average dosage  of  20 mg/1.(103)   Overdosing may result  from
the variability of influent flows, causing a wide range in chlorine residuals.   The presence of chlorinated organic
compounds could render disinfected effluents environmentally undesirable for surface  discharge.   More expensive
iodine is less subject to excessive overdosing, but the environmental effect of residuals  is uncertain.   Power is
required by UV units for lamp operation and pumping,  but residual toxicity potential  is eliminated when this
disinfection method is compared to the other options.   Both iodination and chlorination units must be periodically
inspected and recharged to insure sufficient protection against public health risks caused by insufficient  dosing.
Homeowner performance of these tasks has been shown to be unacceptable.

Performance - Currently available, well maintained (by central authority) dry feed chlorinators,  iodine saturators.
and UV units have been shown to provide consistently high levels of disinfection (greater than 97  percent reduction
of indicator organisms)  of domestic wastewaters following aerobic or septic tank treatment and slow sand filtration,
Bacteria are readily killed, while viruses,  spores,  and cysts are somewhat more resistant. With proper halogen
dosage and contact time or sufficient ultraviolet exposure,  water quality objectives  (less than 200 fecal coli/100
ml)  are achievable.

Chemicals Required - Calcium hypochlorite tablets,  iodine crystals.
Design Criteria - Typical halogen dosage requirements for sand filtered effluents  range  from 1 to 5  mg/1  for
chlorine and 5 to 10 mg/1 for iodine.   Contact chambers for small flow systems  should be designed to provide 30
minutes of contact time at peak flow (reasonable chamber sizes are 30 to 40  gal).   Disinfection requirements for
UV irradiation are based on total exposure of the liquid to the UV light energy.   USPHS  minimum exposure  require-
ments for drinking water are 16,000 mW sec/cm .   All disinfection units should  be  housed for protection from the
elements and vandals.

Reliability - Proper maintenance of on-site units by central authorities is  necessary for effective disinfection.
Tablet chlorinators require chemical refills two to four times per year, but more  frequent feed chamber cleaning may
be necessary to prevent tablet caking.  UV units require periodic lamp replacement (every 7,500 hours of  contin-
uous operation) and cleaning of accumulated materials Cat least 3 times per  year)  to restore transmissivity of the
UV lamp and sleeve.  Iodination units require yearly inspection and crystal  replenishment.

Environmental Impact - Chlorine disinfection can result in the production of toxic chlorinated organics in final
effluents being discharged to surface waters.

References - 14, 103, 149, 152, 162
                                                     A-232
-------
 DISINFECTION FOR ON-SITE SURFACE DISCHARGE
                              FACT SHEET  7.1.3
FLOW DIAGRAM -
   L'f fluent from Aerome
   Unit/Septic 'T "ik a'iu
   San 1 r'i li-er
Pump


Dry Feud
Chlorinator


Contact
Chamber


Pump


Iodine
Saturator



Tank


                                       Discharge
                                          to
                                       Rere iv ing
                                         Water
                                             Ultraviolet  Irradiation  Unit
                                                    DISINFECTION METHODS
ENERGY NOTES - Dry feed chlorinators normally employ gravity flow-through mixing.   Minimum power (50 to 250 kWh/yr)
required for small pump used with iodine saturator.  Field studies indicate that power requirements for a UV unit
(2 to 4 gal/nun with 15 W lamp) range from 25 kWh/yr for intermittent operation (70 min/d)  to 550 kWh/yr for con-
tinuous operation.
 C°STS  -  1978 dollars;  i;NR Index  -  2776.   The  following  cost  estimates  are presented  to  illustrate  the major com-
 ponents  of  three  on-site  disinfection  methods  for  the individual household.   (Labor  cost  S7.50/h,  including fringe
 benefits):
 I.   Dry feed chlorination system with gravity flow-through mixing:
     Construction cost:                                               Annual operation and maintenance cost:
       Chlorination unit with tablet feed chamber     $200-$800         Chlorine tablets ($1.98/lb)      $15-35
       housing, piping, and contact chamber (The                        Routine maintenance require-      15-30
       high end of the cost range reflects pumping.)  	         ments (2 to 4 h/yr)              	
                                        Total
                                                       $200-$800

II.  lodination system with pump to maintain flow and pressure through the iodine saturator:
                                                                                               Total
                                                  $30-65
     Construction cost:
       Iodine saturator with pump and holding
       tank
                                        Total
$600-1,000
                                                       $600-1,000
Annual operation and maintenance cost:
  Iodine crystals (3-5 Ib/yr @     $35-60
  $11.95/lb)
  Routine maintenance requirements   9-20
  1-3 h/yr)
  Power for pumping ($0.02/kWh)       1-5
                                                                                               Total
                                                                                                         $45-85
III. Ultraviolet disinfection unit with 15W lamp and 3 gal/min operation;
     Construction cost:
       UV disinfection unit with controls,
       surge tank, and pump
                                        Total
               Annual operation and maintenance cost:
$800-1,500       Maintenance requirements, in-    $69-120
                 eluding lamp replacement and
                 radiation chamber cleaning
                 Power for pumping and UV           1-10
	       operation ($0.02/kWh)            	
$800-1,500                              Total     $70-130
NOTE - See Fact Sheet 7.1.2 and 7.1.8 for cost and energy data on aerobic  and septic  tank treatment followed by
sand filtration.
REFERENCES - 103, 149, 152
 *To convert construction  cost to  capital  cost  see  Table  A-2.
                                                  A-2 3 3
-------
EVAPORATION  LAGOONS                                                             FACT  SHEET 7,1.4
Description - The evaporation lagoon may be described as an open holding facility which depends solely on climatic
conditions such as evaporation, precipitation, temperature, humidity, and wind velocity to effect dissipation
(evaporation) of on-site wastewater.  Individual lagoons may be considered as an alternate means of wastewater
disposal on individual pieces of property.  The basic impetus to consider this system is to allow building and
other land uses on properties which have soil conditions not conducive to the workability and acceptability of the
conventional on-site drainfield or leachbed disposal systems.

Generally, if the annual evaporation rate exceeds the annual precipitation, this method of disposal may at least
be considered.  The deciding factor then becomes the required land area and holding volume.  It should be noted
that for unlined on-site installations such as homes and small industrial applications, there may also be a
certain amount of infiltration or percolation in the initial period of operation.  However, after a time, it may
be expected that solids deposition will eventually clog the surface to the point where infiltration is eliminated.
The potential impact of wastewater infiltration to the groundwater, and particularly on-site water supplies,
should be evaluated in any event and, if necessary, lagoon lining may be utilized to alleviate the problem.

Often preceded by septic tanks or aerobic units in order to provide a more acceptable influent to and minimize
sludge removal from the lagoon.

Technology Status - The "technology" of evaporation is well developed in terms of our scientific understanding and
application of climatological and meteorologic data.

Applications - The on-site utilization of evaporation lagoons for the disposal of domestic wastewater, from homes
and smaller industrial or commercial facilities may be applicable where access to a municipal sanitary sewer is
not available; where subsurface methods are not feasible (see Fact Sheets 7.1.5, 7.1.6, and 7.1.7); and where
effluent polishing for surface discharge is not practical (see Fact Sheet 7.1.8).

Limitations - Local health ordinances; potential for odors and health hazard when not properly designed; land area
requirements; dependence on meteorologic and climatological conditions.   May require provision to add makeup water
to maintain a minimum depth during dry, hot seasons.   Public access restrictions are necessary.

Performance - The performance of evaporation lagoons is necessarily site-specific; therefore, the following data
are presented on the basis of net annual evaporation rate which may exist in a certain area:
     Net Annual Evaporation (inches)                              Lagoon Performance
(true annual evaporation - annual precipitation)             (gal of water evaporated/ft /yr)
                    5                                                 3.1
                   10                                                 6.2
                   15                                                 9.4
                   20                                                12.5
                   40                                                24.9
                   60                                                37.4

Residuals Generated - Periodic pump out of accumulated sludge is required from pretreatment unit and/or lagoon.

Design Criteria (170)  - The hydraulic loading is the primary sizing criteria for an individual home total reten-
tion lagoon.   In order to size the system properly the following information is needed:
     a.  Anticipated flow of wastewater;
     b.  Evaporation rates   (10-yr minimum of monthly data)
     c.  Precipitation rates   "      "          "       "
The rate of wastewater flow may be anticipated to be in the range of 50 gallons par person per day, depending on
individual site location.   Precipitation and evaporation data for most areas can be readily found in weather
bureau records.   A 12-month mass balance should be utilized to properly determine design sizing.  Design criteria
include:  depth 2 to 4 ft;  level bottom; banks more than 2 feet higher than maximum water level.

The following tables are taken from an individual retention system design for Spokane County, Washington, and are
presented here to illustrate the procedure utilized in the design of a 60.5 foot diameter lagoon.

                                          Water Mass Balance Analysis
Month
April
May
June
Gallons
Wastewater
Flow
5400
5580
5400
Average
Evap (in.)
5.54
7.79
9.26
Average
Precip.
1.0
1.0
1.2
Net Evaporation
Gal/
Inches ft
4.54
6.79
8.06
2.83
4.23
5.02
ft to Excess
Evap Evap
Wastewater Gals
1908
1319
1076
2694
5757
8052
Process Reliability - Good,  however should be closely controlled to prevent health hazard.

Environmental Impact - Potential odors;  potential health hazard; land area requirements  may be large;  may adverse-
ly affect surrounding property values.

Reference - 170
                                                  A-234
-------
 EVAPORATION  LAGOONS
                           FACT SHEET 7.1.4
 FLOW DIAGRAM -
         Wastewater
                           w/^c^^^
ENERGY NOTES _ Lagoon is gravity fed from source.  where pumping  is required, energy requirements may be approx-
imated by using the following equation: kwh/yr =  .0019 x gal/d x  discharge head ft, assuming a wire  to water
efficiency of 60 percent.
COSTS - 1978 dollars; ENR Index = 2776.  Land costs associated with the individual total retention lagoon are
site specific and not listed here.  Typical excavation and liner (plastic) costs associated with a two-bedroom
residence may be estimated as follows:
     Construction cost

       Excavation and hauling  (750 yd )
       Liner  (10 mil PVC) (21,000  ft2)
       Supervision and hand  labor
              Subtotal
Unit Price

S0.76/yd2
$0.11/ft
Cost

$  570
 2,310
   620
$3,700
(To the above must be added  fencing, septic tank and ancillary  costs)

     Operating Costs- Septic Tank  Pumpout




       Pumping of septic tank

       Maintenance costs of  lagoons not included.




 REFERENCE  - 170


To  convert construction cost to capital cost, see Table A-2.
                                      $10/yr
                                                  A-235
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EVAPOTRANSPI RATION  SYSTEMS                                               FACT  SHEET 7.1.5
Description - Evapotranspiration (ET) is a means of on-site wastewater disposal that may be utilized in some
localities where site conditions preclude soil absorption.   Evaporation of moisture from the soil surface and/or
transpiration by plants is the mechanism of ultimate disposal.   Thus,  in areas where the annual evaporation rate
equals or exceeds the rate of annual added moisture from rainfall and wastewater application, ET systems can
provide a means of liquid disposal without danger of surface or groundwater contamination.

If evaporation is to be continuous, three conditions must be met.  First, there must be a continuous supply of
heat to meet the latent heat requirement (approximately 590 cal/g of water evaporated at 15°C).  Second, a vapor
pressure gradient must exist between the evaporative surface and the atmosphere to remove vapor by diffusion,
convection, or both.  Meteorological factors, such as air temperature, humidity, wind velocity, and radiation
influence both energy supply and vapor removal.  Third, there must be a continuous supply of water to the evapo-
rative surface.  The soil material must be fine textured enough to draw up the water from the saturated zone to
the surface by capillary action but not so fine as to restrict the rate of flow to the surface.  Evapotranspira-
tion is also influenced by vegetation on the disposal field and can theoretically remove significant volumes of
effluent in late spring, summer, and early fall, particularly if large silhouette, good transpiring bushes and
trees are present.

A typical ET bed system consists of a Vt to 3 foot depth of selected sand over an impermeable plastic liner.  A
perforated plastic piping system with rock cover is often used to distribute pretreated effluent in the bed.  The
bed may be square-shaped on relatively flat land, or a series of trenches on slopes.  The surface area of the  bed
must be large enough for sufficient ET to occur to prevent the water level in the bed from rising to the surface.

Beds are preceded by septic tanks or aerobic units to provide the necessary pretreatment.

Common Modifications - Given the proper subsurface conditions,  systems can be designed to perform as both evapo-
transpiration and absorption beds (See Fact Sheet 7.1.6).   Nearly 3/4 of all the ET beds in operation were designed
to use both disposal methods.  Mechanical evaporators have been developed,  but not used at full scale.

Technology Status - There are estimated to be 4,000 to 5,000 year-round evapotranspiration beds in operation in
the United States, particularly in the semi-arid regions of the Southwest.

Typical Equipment/No, of Mfrs. (100)  - Liner/24; septic tank and distribution piping/locally supplied;  aerobic
unit/more than 20.

Applications - Used as an alternative to subsurface disposal in areas where these methods are either undesirable
due to groundwater pollution potential or not feasible due to certain geological or physical constraints of land.
The ET system can also be designed to supplement soil absorption for sites with slowly permeable soils.   The use
of ET systems for summer homes extends the range of application, which is otherwise limited by annual ET rates.
Since summer evaporation rates are generally higher and plants with high transpiration rates are in an active
growing state, many areas of the country can utilize ET beds for this seasonal application.

Limitations - The use of an evapotranspiration system is limited by climate and its effect on the local ET rate.
In practice, lined ET bed systems are generally limited to areas of the country where pan evaporation exceeds
annual rainfall by at least 24 inches.  The decrease of ET in winter at middle and high latitudes greatly limits
its use.  Snow cover reflects solar radiation, which reduces ET.  In addition, when temperatures are below freezing
more heat is required to change frozen water to vapor.  When vegetation is dormant, both transpiration and evap-
oration are reduced.  An ET system requires a large amount of land in most areas.   Salt accumulation may eventually
eliminate vegetation and thus, transpiration.  Bed liner (where needed)  must be kept water-tight to prevent the
possibility of groundwater contamination.  Therefore, proper construction methods  should be employed to keep the
liner from being punctured during installation.

Performance - Performance is a function of climate conditions, volume of wastewater, and physical design of the
system.  Evapotranspiration is an effective means of domestic wastewater disposal.

Chemicals Required - None
Residuals Generated - See Fact Sheet 7.1.6.
Design Criteria - Design of an evapotranspiration bed is based on the local annual weather cycle.  The total
expected inflow based on household wastewater generation rate and on rainfall (use a 10 year expectancy year to
provide sufficient surface area) is compared with an average design evaporation value established from the annual
pattern.  A mass balance is used to establish the storage requirements of the bed.  Vegetative cover can substan-
tially increase the ET rate during the summer growing season; but may reduce evaporation during the non-growing
season.  Uniform sand in the size range of D   of approximately 0.10 mm is capable of raising water about 3 ft.
Liner  (polyethylene) thickness typically greater than or equal to 10 mil.  Surface runoff must be excluded from
the bed proximity by proper lot grading.

Reliability - An ET system that has been properly designed and constructed is an efficient method for the disposal
of pretreated wastewater and requires a minimum of maintenance.

Environmental Impact - Healthy vegetative covers aesthetically pleasing.   Large land requirement conserves open
space, but limits use of land.

References - 14, 36, 103
                                                   A-236
-------
EVAPOTRANSPIRATIOfi  SYSTEMS
            FACT SHEET  7.1.5
  FLOW DIAGRAM
                                                                  4-inch plastic
                                                                  perforated
                                                                  pipe .
        T
                         ^-^<^^F&^v^rq^^u-&^oc>v»crZf^^C^c]Q
-------
SEPTIC TANK ABSORPTION  BED                                                     FACT  SHEET 7.1.6
Description - A septic tank followed by a soil absorption bed is the traditional on-site system for the treatment
and disposal of domestic wastewater from individual households or establishments.  The system consists of a buried
tank where wastewater is collected and scum, grease, and settleable solids are removed by gravity separation, and
a sub-surface drainage system where clarified effluent percolates into the soil.   Precast concrete tanks with a
capacity of 1000 gallons are commonly used for household systems.  Solids are collected and stored in the tank,
forming sludge and scum layers.  Anaerobic digestion occurs in these layers, reducing the overall volume.  Efflu-
ent is discharged from the tank to one of three basic types of subsurface systems, adsorption trenches, seepage
bed, or seepage pits.  Sizes are usually determined by percolation rates, soil characteristics, and site size and
location. Distribution pipes are laid in a field of absorption trenches to leach tank effluent over a large area.
Required absorption areas are dictated by state and local codes.  Trench depth is commonly about 24 inches to
provide minimum gravel depth and earth cover.  Clean, graded gravel or similar aggregate, varying in size from h
to 2S inches, should surround the distribution pipe and extend at least two inches above and six inches below the
pipe.  The maintenance of at least a 2 ft separation between the bottom of the trench and the high water table is
required to minimize groundwater contamination.  Piping typically consists of agricultural drain tile, vitrified
clay sewer pipe, or perforated, non-metallic pipe.  Absorption systems having trenches wider than 3 ft are
referred to as seepage beds.  Given the appropriate soil conditions (sandy soils), a wide bed makes more efficient
use of available land than a series of long, narrow trenches.

Common Modifications - Many different designs may be used in laying out a subsurface disposal field.  In sloping
areas, serial distribution can be employed with absorption trenches by arranging the system so that each trench is
utilized to its capacity before liquid flows into the succeeding trench.  A dosing tank can be used to obtain
proper wastewater distribution throughout the disposal area and give the absorption bed a chance to rest or dry
out between dosings.  Providing two separate alternating beds is another method used to restore the infiltrative
capacity of a system.  Aerobic units may be substituted for septic tanks with no changes in soil absorption system
requirements (see Fact Sheet 7.1.1).

Technology Status - Septic tank-soil absorption systems are the most widely used method of on-site domestic waste
disposal.  Almost one-third of the United States population depends on such systems.

Typical Equipment/No, of Mfrs. - Septic tanks and distribution piping are locally supplied.

Applications - Used primarily in rural and suburban areas where economics are favorable.  Properly designed and
installed systems require a minimum of maintenance and can operate in all climates.

Limitations - Dependent on soil and site conditions, the ability of the soil to absorb liquid, depth to ground-
water, nature of and depth to bedrock, seasonal flooding, and distance to well or surface water. A percolation
rate of 60 min/in is often used as the lower limit of permeability.  The limiting value for seasonal high ground-
water should be 2 ft below the bottom of the drainfield.  When a soil system loses its capacity to absorb septic
tank effluent, there is a potential for effluent surfacing, which often results in odors and, possibly, health
hazards.

Performance - Performance is a function of the design of the system components, construction techniques employed,
rate of hydraulic loading, areal geology and topography, physical and chemical composition of the soil mantle, and
care given to periodic maintenance.  Pollutants are removed from the effluent by natural adsorption and biological
processes in the soil zone adjacent to the field.  BOD, SS, bacteria, and viruses, along with heavy metals and
complex organic compounds, are adsorbed by soil under proper conditions.  However, chlorides and nitrates may
readily penetrate coarser, aerated soils to groundwater.

Residuals Generated - The sludge and scum layers accumulated in a septic tank must be removed every 3 to 5 years.
 (See Fact Sheet 7.1.9)

Design criteria (134) - Absorption area requirements for individual residences:
                                                   2                                                           2
Percolation Rate  (min/in)     Reg. Area/Bedroom  (ft )       Percolation Bate  (min/in)     Reg. Area/Bedroom (ft )
     1 or less                     70                            15                            190
     3                            100                            30                            250
     5                            125                            45                            300
    10                            165                            60                            330

Process Reliability - Properly designed, constructed, and operated septic tank systems have demonstrated an
efficient and economical alternative to public sewer systems, particularly in rural and sparsely developed areas.
System life for properly sited, designed, installed and maintained systems may equal ot exceed 20 years.

Environmental Impact - Leachate can contaminate groundwaters when pollutants are not effectively removed by the
soil system.  In many well aerated soils, significant densities of homes with septic tank - soil absorption
systems have resulted in increasing nitrate content of the ground water.  Soil clogging may result in surface
ponding with potential aesthetic and public health problems.

References - 12, 14, 36, 134, 135
                                               A-238
-------
 SEPTIC  TANK  ABSORPTION  BED
                                                                              FACT SHEET 7,1.6
 FLOW DIAGRAM -   (typical)
 INLET
                       OUTLET
            SEPTIC  TANK
            (PROFILE)
                                          ' TILE DRAINAGE
                                                  LINES
                                        V	ABSORPTION
                                            TRENCHES
                                          ABSORPTION FIELD
                                              (PLAN)
                                                                               Tar paper joint  covering
                                                                     Marsh hay, fabric or untreated
                                                                             building paper
                                                                                                           Gravel
                                                                               fil, „<„    &8gS
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SEPTIC TANK MOUND  SYSTEMS                                                      FACT  SHEET 7.1.7
Description - A septic tank and mound system is a method of on-site treatment and disposal of domestic wastewater
that can be used as an alternative to the conventional septic tank-soil absorption system.  (See Fact Sheet
7.1.6.) In areas where problem soil conditions preclude the use of subsurface trenches or seepage beds, mounds can
be installed to raise the absorption field above ground, provide treatment, and distribute the wastewater to the
underlying soil over a wide area in a uniform manner.

The three main elements of the system are the septic tank, dosing chamber,  and the mound.  The relative dimensions
and location of the septic tank, the type of control structures, the size and loading of inspection ports, and the
materials of construction are dictated by State and local codes.  A pressure distribution network should be used
for uniform application of clarified tank effluent to the mound.  A subsurface chamber can be installed with a
pump and high water alarm to dose the mound through a series of perforated pipes.  Where sufficient head is
available, a dosing siphon may be used.

The design of a mound is based on the expected daily wastewater volume it will receive and the natural soil
characteristics.  As with the conventional subsurface disposal system, pollutants are removed by natural adsorp-
tion and biological processes in the soil zone adjacent to the seepage bed.  The mound must provide an adequate
amount of unsaturated soil and spread septic tank effluent over a wide enough area so that distribution and
purification can be effected before the water table is reached.

A clean, medium sand is normally used as fill in which gravel trenches or beds are excavated consisting of 1 to 1*5
inch stones to surround distribution pipes.  As in any seepage system, a clogging mat will develop at the gravel-
sand interface.  The equilibrium flow rate through this zone has been shown to be 1.25 gpd/ft .   Sufficient inter-
facial area must therefore be available for the design flow.  The total effective basal area of the mound must be
sized to permit the effluent to percolate into the native soil.  Infiltration rates into the natural soil are
based on the hydraulic conductivity characteristics of the least permeable soil horizon below the proposed site.

Common Modifications - Different types and arrangements of seepage systems may be installed within a mound,
depending upon the characteristics of the underlying soil.  One or more trenches may be used above wet, slowly
permeable subsoil to spread percolating liquid over a large area and to prevent ponding.  When the permeability of
the natural soil is not a limiting factor, rectangular seepage beds are usually more suitable than trenches.
Although some mound designs do not employ dosing systems, these designs are not normally suitable for proper
performance of a mound.

Technology Status - Septic tank mound systems have proven to be successful alternatives for difficult soil condi-
tions.  They have been in use for more than twenty years in various forms and for nearly ten years with the design
described herein.

Typical Equipment/No, of Mfrs. - Pump chamber with controls/more than 50; Septic tank and piping/locally supplied.

Applications - Used as alternative to septic tank-soil absorption system in problem soil conditions.  Spreads
percolating liquid over wide area to slowly permeable (60-120 min/in percolation rate) subsoil.   Increases amount
of soil over shallow, permeable subsoil on creviced bedrock or high water table to provide sufficient contact time
for purification before effluent reaches groundwater.

Limitations - Requires more space and periodic maintenance than conventional subsurface disposal system, along
with higher construction costs.  System cannot be installed on steep slopes, nor over highly ( 120 min/in.)
impermeable subsurface. Seasonal high groundwater must be deeper than two feet to prevent surfacing at the edge of
the mound. Pumping is usually required to distribute tank effluent throughout mound, necessitating O/M require-
ments.

Performance - As with other soil absorption systems, performance is a function of several factors, including
design, construction, maintenance, waste characteristics, and soil conditions.  BOD, SS, heavy metals, complex
organic compounds, bacteria, and viruses are effectively removed by soil under proper conditions.  However,
nitrates are unaffected and often discharged to groundwaters.

Chemicals Required - None.

Residuals Generated - Septage is generated, requiring treatment and disposal.  See Fact Sheet 7.1.9.  Volume equal
to septic tank capacity every 3 to 5 years.

Design Criteria -  Design flow basis:  75 gal/person/d; 150 gal/bedroom/d.  Basal area based on percolation rates
up to 120 min/in.  Mound height at center approximately 3.5 to 5 ft.  Pump  (centrifugal) must accommodate appro-
ximately 30 gal/min at required TDK.  Pump controls: level or timer.

Process Reliability -  Septic tank-mound systems that are properly designed and constructed are viable alter-
natives to centralized treatment facilities.  Dosing equipment should be routinely maintained, and septic tanks
must be periodically pumped out for systems to operate effectively.  Long term service life data is not available
as yet, but projections suggest mound life to be about the same as that of properly designed soil system.

Environmental Impact - Visual impact can raise major aesthetic issues, particularly in suburban areas/ due to the
shape, size and proximity of mound systems.  Drainage patterns and land use flexibility may also be affected.

References - 14, 36, 134, 135



                                                 A-240
-------
SEPTIC TANK MOUND SYS1EMS
                    FACT SHEET 7.1.7

                                                             Sand fill
                                                                                                  Topsoi1
                                              I  I'   ll       \\Stom-fill  '      X            .
                                                                                         ('lowed surface
                                                      "Hiqh water
                                                       alarm switch

                                                      Pump with controls
                    SEPTIC TANK
                                       PIlMrlNI,  CHAMBER
                                                                                  MOUND
 ENERGY NOTES -  Minimum power
 (50 to 250 kWh/yr)  required
 to operate small  sump  pump for
 cosing mound.
                                                                    i     T  ^
                                                                . SEEPAGE TRENC
                                                                 5/8 to 1 inch stone\
I  1  inch perforated
1  PVC pipev      """
          -\-,    -,
— i                   ppe
— I  cvrzi.~ir~.rz.~ir.
   I  i
                                                                  l>j to 2 inch PVC pipe
                                                                           PLAN VIFW
 COSTS*  -  1978 dollars; ENR Index = 2776.  The following site specific  costs serve to illustrate the major com-
 ponents of a 300 gal/d household mound with two level trenches  3  x 41  ft, 65  x 42 ft basal area, and a peak
 mcund height of 3.5 ft.
      Construction  Cost
      Building sewer  and  1000 gal septic tank, design and permit
      Pumping chamber with  1/2 hp sump pump and controls ($600 to $1000)
      Mound system
                                                                 Total

      Annual Operating and  Maintenance Cost
      Operation and maintenance of pumping chamber ($20 to $50 per year)
      Pumping septage from  septic tank  (every 3 to 5 years)
                                                                 Total
                 $  700
                    800
                  2,400
                 $3,900
                     30
                     15
                     45
 The construction cost  for  this mound system includes 12 tons gravel,  265 tons sand,  110 tons clay fill/topsoil, 48
 ft of 2-in PVC pipe, 82  ft of 1-in perforated PVC pipe, hay to cover  trenches,  and labor.  This cost can vary
 significantly depending  upon site characteristics and local material  and labor  costs.  Mound systems of this type
 are quoted to cost anywhere from $2,500 to $5,000.  The range of mound costs  has  also been expressed as $0.75 to
 $3.0C/ft  of basal area.
 REFERENCES - 14, 103

*Tr convert construction cost  to  capital  cost see Table A-2.
                                                    A-241
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SEPTIC TANK POLISHING, SURFACE DISCHARGE                                    FACT  SHEET  7.1.8
 Description -  Surface discharge of septic tank effluent is a method of on-site disposal of domestic wastewater
 that  can be used  as  an alternative to the conventional soil absorption system  (See Fact Sheet 7.1.6).  Where
 permitted  by code, surface discharge units can be employed in areas where subsurface disposal systems are not
 feasible.  Since  septic  tank effluent quality is clearly unacceptable for direct discharge, additional processing
 is  required which should be consistent with the principles of on-site treatment, i.e., simplicity and low O/M.
 Filtration, with  its positive removal mechanisms, is particularly well suited for this purpose.  Sand filter
 trenches are similar to  absorption trenches, but contain an intermediate layer of sand as filtering material and
 underdrains for carrying off the  filtered sewage.  Buried sand filters, which require less area than trenches, are
 typically  installed  with underdrains in 1 ft of coarse gravel, covered with 2 ft of sand  (0.4 to 0.6mm effective
 size  with  uniformity coefficient  less than 4.0), followed by influent drain tile or perforated pipe in another
 foot  of gravel, and  covered with  at least 6 in of topsoil.  Intermittent slow sand filters are divided into two or
 more  units, which are alternately loaded and rested.  Wastewater is applied over a bed of sand (0.2 to 0.6 mm
 effective  size with  uniformity coefficient less than 4.0) 2 to 3 ft deep and the filtrate is collected by under-
 drains contained  in  a layer of gravel.  The sand remains aerobic and serves as a biological filter, removing SS
 and dissolved  organics.  Because  of smaller sand size and higher loading rates, these units require accessibility
 for periodic servicing.  The recirculating filter system consists of a septic tank and a recirculation tank,
 containing a timer-controlled sump pump for dosing onto a sand filter.  The filter bed contains 3 ft of coarse
 sand  (0.6  to 1.5mm effective size with less than 2.5 uniformity coefficient) and 1 ft of gravel surrounding the
 underdrain system.   A recirculation ratio of 4:1 (recycled filter effluent to forward flow) is recommended.  If
 the tank effluent requires disinfection, alternatives that are likely with on-site systems include tablet chlor-
 ination, iodine crystals, and ultraviolet irradiation.   (See Fact Sheet 7.1.3.)

 Common Modifications - Buried sand filters should be constructed in two sections, which are dosed separately by a
 tank  with  alternating siphons.  Above ground sand filters (intermittent or recirculating) can be installed in
 areas where subsurface construction is impossible.  Dosing tanks and pumps feed these filters, which may be open
 or  covered, but must be  accessible for cleaning.  Covering and insulation are recommended for intermittent and
 recirculating  filters to minimize freezing in cold weather and potential health risks and nuisances in warm
 weather.

 Technology Status -  Sand filtration has traditionally been employed to treat septic tank effluent.  The recircu-
 lating and sand filter is a relatively new type of on-site filter, but has enjoyed success in Illinois and Oregon.

 Typical Equipment/No, of Mfrs. -  Septic tank and distribution piping/locally supplied; dosing tank and pump/more
 than  5; dry chlorine feeder/approx. 10; iodination unit/more than 2; UV water purification unit/approx. 6.

 Applications - Surface discharge  systems are alternative designs to be used where site conditions, including
 geology, hydrology,  and  lot size, preclude the use of the soil as a treatment and disposal medium.  Centralized
 management, rather than  homeowners, are normally required for successful operation.

 Limitations -  Because of additional processing involved, these systems are more expensive than conventional on-
 site  systems.  Filter surfaces and disinfection equipment require periodic maintenance.  Buried sand beds are
 inaccessible.  Power is  required  for pumping and some disinfection units.  State or Federal discharge permits
 along with sampling  and  monitoring are required.

 Performance  (14)- Effluent quality data from experimental septic tank-intermittent sand filter systems with 5
 gal/d/ft   average loading rate, 0.45mm effective size, and 3.0 uniformity coefficient:
      Parameter                             Septic Tank Effluent   Sand Filter Effluent   Chlorinated Effluent
      BOD,  mg/1                                      123                     9                     3
      TSS,  mg/1                                       48                     6                     6
      Total nitrogen  (N), mg/1                       23.9                  24.5                  19.9
      Ammonia-nitrogen, mg/1                         19.2                   1.0                   1.6
      Nitrate-nitrogen, mg/1                            .3                  20.0                  18.9
      Total phosphorus  (P), mg/1                     10.g                   9.0                   8.4
      Fecal coliforms (number per  100 ml)       5.9 x 105             1.1.x 10*                     2
      Total coliforms (number per  100 ml)       9.0 x 10              6.5 x 10                      3

 Residuals  Generated  - See Fact Sheet 7.1.9 for septic tank residuals.  .Sand with putrescible organic matter must
 be  removed from intermittent and  recirculating filter surfaces when clogging occurs and may be buried on-site or
 require  off-site  disposal.

 Design  Criteria - Recommended loading rates in gal/d/ft  :  Buried sand filter  0.75 to 1.5, intermittent sand
 filter  5,  recirculating  sand filter 3  (based on forward  flow alone).

 Reliability -  Sand filters perform well, unless overloaded.  Periodic inspection is required to obtain proper
 functioning of chlorination, UV,  and iodination units.  (See Fact Sheet 7.1.3).

 Environmental  Impact - Treated effluents are discharged  to surface waters.  Processing and disposal of septage is
 required.  Odors  may emanate from open filters, and potential health risks increase without proper fencing or
 other access  control.

 References -  14,  36, 103,  134
                                                    A-242
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 SEPTIC  TANK  POLISHING,  SURFACE  DISCHARGE
                                                                                     FACT  SHEET 7.1.8
FLOW DIAGRAM -
I r



•s

                               Pimping Chamber
                                                                    Intermittent
                                                                    Sand  Filter
_^J)ischarge
T
 I with or without
                          »   Recirculation Tank
                                                                     Recirculating
                                                                      Sand Filter
                                                                                               is infection
ENERGY NOTES - Minimum power (50 to 250 kWh/yr)  required  for  operation of  small sump pump for dosing intermittent
slow sand filter and recirculating sand filter.   Dosing siphons  are  often  used with buried sand filters.

COSTS* - 1978 dollars; ENR Index = 2776.  The following  site  specific costs serve to  illustrate  the  major  com-
ponents of three types of filters normally employed to treat septic tank effluent for on-site,  surface  discharge.

I.   Buried sand filter: 300 gal/d;  17 ft x 17 ft filter;  vertical  profile  of  12  in.  gravel, 2  ft sand and 12 in.
     gravel;2 ft soil cover for depth necessary to operate  dosing  siphon;  25  ft  from discharge.
     Construction cost:                     ,                    Annual  operation and maintenance cost:
       Excavation,  backf ill, hauling (^60 yd )         $  400      None
       Sand (22 yd )  and gravel (22  yd )                   200
       Filter pipe (100 ft)  and ancillary pipe (25 ft)     100
       Siphon                                             500
       Supervision and labor                              300
                                             Total     $1,500

     The construction cost for the buried sand filter above  lies at the  low end of a  reported range of  $1,500 to
     $3,000 for these units.  However, dual systems are recommended because of their  permanence and inaccessibility.
     cessibility.
                                                                 Annual  operation and  maintenance  cost:
                                                                   Pumping chamber maintenance  and
                                                                   restoration of filter  capacity    $100-150
II.   Intermittent slow sand filter:  250 gal/d;  two  50  ft   covered filters; vertical profile of 30 in. sand and
     16 in.  gravel;  pump dosing system; 25  ft from  discharge.
     Construction cost:
       Excavation 140 yd )                              $    30
       Sand  (10 yd )  and gravel (5 yd )                    70
       Filter pipe (100 ft)  and ancillary pipe (25  ft)      80
       Two 1500 gal tanks for filter housing              600
       Insulated covers, splash plates, etc.               220
       Pump  chamber with 1/2 hp sump pump and controls    800
       Supervision and labor                              200
                                             Total      $2,000

     The construction cost of the above sand filter, without the pump  chamber,  is  $12/ft  , which is consistent
     with a  reported range of $10 to $15/ft .  In mild climates, it  is possible that an excavated, plastic-
     lined housing could be substituted for the tanks  included  above.
                                                 2
III. Recirculating sand filter: 300 gal/d;  100 ft  open filter; vertical profile  3 ft  sand and  1  ft  gravel;
     25 ft from discharge.
     Construction cost:                                          Annual  operation and  maintenance cost:
                                                                   Pump maintenance and
                                                                   restoration of filter capacity   $50 -  $100
       Excavation 122 yd )                              $   20
       Sand  (12 yd ) and gravel (4 yd )                    80
       Internal  (100 ft) and external  (25 ft) piping      100
       Recirculation tank  (1000 gal)                      250
       Filter housing                                     600
       Pump, controls, fittings                           450
       Supervision and labor                              200
                                             Total     $1,700

     The construction cost for the above recirculating sand filter does not include the cost of covers  and
     insulation, which will be required for cold weather application.

NOTE - See Fact Sheets 7.1.3 and 7.1.6 for disinfection and septic tank cost and energy data.
 REFERENCES -  14,  103
'*To  convert  construction cost to capital cost see Table A-2.
                                                  A-243
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SEPTAGE TREATMENT AND DISPOSAL                                                FACT  SHEET  7.1.9
Description - Common methods of septage treatment and disposal include land application,  disposal at wastewater
treatment plants, and disposal at separate septage treatment facilities.   Septage is a highly variable,  high
strength organic slurry characterized by an obnoxious odor,  resistance to settling and dewatering,  potential to
foam, and often significant contents of grease,  grit and hair.   The concentration of metals is considerably lower
than that of domestic sludge; consequently, heavy metals in septage do not constitute a serious problem.   Signifi-
cant numbers of indicator organisms and pathogens may be found in septage.  Several parasites have  also  been
identified in septage.  Proper handling, treatment, and disposal of septage is necessary to eliminate a  potential
threat to public health.

Land Disposal - Septage is applied to land by the same methods used for disposal of municipal treatment  plant
sludge.  Fact Sheets which are most applicable to land disposal of septage are:   Land Application of Sludge
(6.1.3) and Sludge Lagoons (6.1.11).   Septage is also disposed of at landfills by a variety of techniques.   How-
ever, the low solids content of septage often makes this practice undesirable.

Disposal at Sewage Treatment Plants - Septage treatment and disposal is achieved by addition to the plant liquid
or sludge streams at various points in the process train.  For plants with primary clarification, addition upstream
of the clarifier is preferable, as it effectively achieves septage solids concentration and incorporation into the
sludge stream without upsetting effluent quality.  Other plant configurations may require direct addition to the
biological treatment process or to sludge handling processes such as thickening,  digestion, dewatering,  etc.
Addition of septage to the liquid stream of a wastewater treatment plant may cause upsets in plant  performance due
to temporary hydraulic or organic overloads, clogging or fouling of plant equipment, or by exceeding the solids
handling capacity of the plant.  For this reason, a septage receiving station may be added to allow easy and safe
transfer of septage from the hauler truck, to provide some form of pretreatment (e.g., screening) to protect
equipment, and to allow controlled addition from a holding tank into the desired process.   Most wastewater treat-
ment processes are able to treat septage; however, some are more effective than others.  Conventional activated
sludge, preceded by a buffering primary clarifier, can effectively treat septage.   Extended aeration plants of
sufficient capacity are able to handle septage relatively well.  Trickling filter plants are potential acceptors
of septage; however, odor generation, filter fly proliferation, and media clogging may be a problem at increased
organic loading.  Contact stabilization processes without primary clarification appear to be least  amenable to
septage treatment due to short contact time.  Septage addition to the reaeration zone or digester would  be the
preferred approach for such plants.  Addition of septage to the sludge stream of a wastewater treatment  plant
avoids possible problems with pumping, biological overloading,  and greater sludge volumes for final disposal.
Fact Sheets applicable to disposal of septage at wastewater treatment plants are:   Clarifier, Primary, Circular
with Pump (3.1.1); Clarifier, Primary, Rectangular with Pump (3.1.2); Activated Sludge, Conventional, Diffused
Aeration  (2.1.1); Activated Sludge, Conventional, Mechanical Aeration (2.1.2); Activated Sludge with Nitrification
(2.1.6); Contact Stabilization, Diffused Aeration (2.1.8); Extended Aeration, Mechanical and Diffused Aeration
(2.1.10); Lagoons, Aerated (2.1.11); Oxidation Ditch (2.1.15);  Trickling Filter, Plastic Media (2.2.6);  Trickling
Filter, High Rate, Rock Media  (2.2.7); Trickling Filter, Low Rate, Rock Media (2.2.8).

Disposal at Separate Facilities - In rural areas where land disposal is not feasible and no wastewater treatment
plant is available, septage may be collected and treated at separate septage treatment facilities.   Several con-
ventional processes for treating sludge can be used to stabilize and dispose of septage.  Supernatant from sepa-
ration processes must be treated prior to disposal.  Applicable processes and Fact Sheets are:  Sludge Lagoons
(6.1.11); Lime Stabilization (6.4.8); Composting  (6.2.3, 6.2.4); Chemical Treatment (4.3.1); Dewatering (6.3.1,
6.3.2, 6.3.3, 6.3.4, 6.3.5, 6.3.9).  In addition, chlorine oxidation for stabilization of septage has also been
used.

Technology Status - Land disposal practice for septage is generally uncontrolled surface application on remote
land with little or no stabilization.  Land application of septage is by far the most widely used means  of septage
disposal.  Estimates regarding fraction of septage disposed of on land range from 60-90 percent of  total septage
generated.  Septage disposal at the treatment plant is limited to plants which have excess capacity to handle the
additional solids and BOD  load due to septage.   Disposal at treatment plants is estimated to account for up to  25
percent of the total septage slated for disposal.  Septage treatment and disposal at separate facilities is prac-
ticed in areas where high densities of septic tank systems exist and large volumes of septage are handled.   Chem-
ical treatment, composting, and lagoons are in full-scale use.   Some septage treatment methods have not  gained
economic acceptance.  Septage has also been improperly disposed of by surreptitious disposal into sewers, receiv-
ing streams, or by dumping on land.

Limitations - Refer to individual fact sheets referenced above.

Design Criteria - Septage generation rates for a particular area may be estimated by several methods. Accurate
records kept by septage haulers may provide reasonable estimates of annual septage production rate.  Alterna-
tively, assuming the number of dwellings using septic tanks is known, a tank volume (e.g., 1000 gal) and pumping
frequency (e.g., every 4 years) can be assumed,  allowing a simple calculation of generation rates  (e.g., 500 homes
x 1000 gal/4 years = 125,000 gal/yr).  A crude estimate of septage generation rate may be made by assuming a per
capita septage production of 60-80 gal/cap/year.

Typical characteristics of domestic septage are:  TS - 3,600-106,000 mg/1; SS - 1,770-22,600 mg/1;  BOD^  - 1,460-
18,600 mg/1; COD - 2,200-190,000 mg/1; TKN - 66-1,560 mg/1; NH -N 6-385 mg/1; Total P - 24-760 mg/1; Grease -
604-23,468 mg/1.  As indicated, septage characteristics are highly variable.

Environmental Impact - Refer to individual fact sheets referenced above.

References - 12, 14, 135, 234, 235, 236-258


                                                    A-244
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SEPTAGE TREATMENT AND DISPOSAL
                                                     FACT  SHEET  7.1.9
FLOW DIAGRAMS - Refer to individual fact sheets referenced in text for flow  diagrams of pertinent processes.
ENERGY NOTES - Refer to individual fact sheets referenced in text for  energy  requirements for various methods of
septage treatment and disposal.

COSTS* (1st quarter 1978 dollars);   ENR = 2681
Septage Treatment and/or      Cost per 1000 gal
	Disposal Method
Land Application

  Surface Spreading


  Subsurface Disposal

  Trench Disposal
   of Septage



$1.25-$17.00


$20-$35

$20-$30
  Sanitary Landfill Disposal  $5-$10
Disposal at Wastewater
 Treatment Plants
                              $20-$30
Separate Septage Facilities

  Lagoon Disposal             $5-$20
  Lime Stabilization
  Chlorine Oxidation
  Composting
  Chemical Treatment/
  Dewatering

REFERENCE - 234
                              $10-$20
                              $30-$35

                              $30-$60
                              530-$60
                              $30-$50
Transportation costs incurred by septage  hauler  to  and
from the disposal site not included.

Transportation costs not included.

Transportation costs not included.   Site  life  is assumed
to be 10 years.   Facility capacity  varies from 100,000
gal/yr to 250,000 gal/yr.

Accurate cost data not available.   Septage often not
accepted at landfills due to low solids content.
                         Costs  shown are total treatment costs, including
                         amortization of capital expenditure for a receiving
                         station.
                         Costs may vary considerably depending upon land
                         costs and costs of solids removal from lagoon.

                         Includes land spreading of limed liquid sludge.
                         Includes sand drying bed dewatering.

                         Process has high chlorine requirement and the
                         operating costs are dependent on fluctuations in the
                         price of chlorine.

                         Revenues from sale of compost product not included.   Unit
                         cost of bulking materials may be critical.  Dewatering prior
                         to  composting may be desirable.

                         Includes costs of chemical clarification, solids condition-
                         ing/dewatering, and effluent polishing/disposal.
 *To convert construction cost to capital cost see Table A-2.
                                                       A-245
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IN-THE-HOME TREATMENT AND RECYCLE                                             FACT  SHEET 7,2.1
Description - The waste stream from one or more household fixtures can be treated to provide  the  water supply  for
water uses, such as laundry, toilet, lawn sprinkling, car washing,  etc.   The primary purpose  of the  in-the-home-
treatment and recycle system is to reduce the quantity of water used and/or wastewater generated.  Numerous  waste-
water reuse options are available. Recycle systems are presently marketed which involve the treatment of various
fractions of the waste stream to satisfy a variety of uses.   One purports to have a complete  recycle-closed  loop
process.  However, little reliability and cost data are available.   A system can be assembled from existing
components.

Treatment  methods for recycle include ion exchange, aeration, adsorption, clarification,  filtration and disin-
fection.  One of the major options involves the recycling of bathing and laundry water for flushing  of water
carriage toilets (BL/T).   This system may consist of a holding tank, filtration device (paper cartridge,  sand,
diatomaceous earth, etc.), a disinfection process (chlorine or iodine),  and a pump-pressure tank combination for
supplying the treated water.  Makeup water (tap water) is brought in as  required when demand  exceeds supply.   In
general, pressurized media filtration systems are of moderate hardware complexity and require maintenance per-
formed by semi-skilled servicemen.  Routine adjustment of filtration equipment generally is required two to  four
times per year.  Unscheduled maintenance is required infrequently.   Disinfection is necessary to control odors and
bacterial growth.  The most common type of disinfection feeder for small waste flows has been the stacked-solid
tablet feeder employing Ca(OCl)2-  Dosage is controlled by flow control  weirs or by diversion of a portion of the
waste through the unit.  See Fact sheet 7.1.3.  Maintenance also includes cleaning of storage reservoirs, mainten-
ance of mechanical equipment, including pumps and residual disposal.

Modifications - Numerous options for recycle and reuse are possible. Most systems which recycle to the toilet are
dyed in some manner for aesthetic reasons.

Technology Status - Many complete systems are currently being tested.  Most systems are assembled from existing
components.

Typical Equipment/No. Mfrs. (23)  - Filters/20; tanks/2; pumps/34;  automatic feeders/4;  controls/310;  disinfection
units/more than 15; ion exchange equipment/15.

Applications - A flow reduction measure, which is suitable for increasing the life or improving the performance of
on-site soil disposal systems.   It occasionally permits the use of subsurface disposal systems where available
land area is very limited but soils have acceptable percolation characteristics or where land is available with a
limited ability to accept wastewater.  Involves semi-skilled to skilled labor,  depending on system.

Limitations - Operation and maintenance requirements are substantial and should be performed by centralized man-
agement personnel to prevent potential health risks.

Performance - Variable levels of flow reduction and treatment are achieved depending upon system developed.
Recycling bath and laundry wastes to toilet (BL/T)  reduces flow about 30 to 35 percent.   Analysis of bath and
laundry wastewaters after filtration through three units is summarized below:   (159)
     Filter System                 Average Effluent Turbidity,  ppm    Average  Effluent Suspended Solids,  mg/1
     Diatomite                               23                                      21
     Cartridge, Surface Type                 60                                      31
     Cartridge, Depth Type                   62                                      43

Chemicals Required - Disinfectants; may require coagulants, polymers for solids and scale control.
Residuals Generated - Sludge, scum.
Design Criteria - The following reuse water quality objectives are suggested to determine the level of wastewater
treatment necessary prior to on-site reuse.  (152)
                                        Suggested Reuse Water Quality Criteria
Grade                                        BOD (mg/1)     SS (mg/1)       Turbidity (TU)
Toilet Flushing                                 20              20              25
Utility (lawn watering, irrigation, car         15              15              20
and house washing, toilet flushing)
Body Contact (laundry, shower, fire             10              10               1
fighting, plus all of the above)
There should be no disagreeable colors, odors or visible oil and grease;  pH 6.5-8.5;  and caution should be used in
lawn watering, irrigation, etc.,  owing to certain constituents,  e.g.,  boron which adversely affects plant growth.

Process Reliability - Reliability data on recycle systems not available,  but significant maintenance can be anti-
cipated as a direct function of system complexity.

Environmental Impact - Odors may be generated and water quality may be aesthetically objectionable when systems
malfunction or are overstressed.  User acceptance may be difficult.   Potential health risks  exist but may be kept
at an acceptable level by proper centralized arrangements.

References - 149, 152, 159
                                                     A-246
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IN-THE-HOME TREATMENT  AND  RECYCLE
                                               FACT SHEET 7,2.1
 FLOW DIAGRAM
 Numerous recycling options  are possible.  One example is given below:
                      Disinfectant
                         Feeder
    Bath and
   aundrv Wastes
Storage
Tank




Filter







Pressure
Tank
                                           Makeup Water


                                                  »  To toilet or lawn

                                                  *  Overflow to disposal
 ENERGY NOTES - Minimum power (60 to 600 kWh/yr)  required  for  operation of small pump.
  COSTS* -  1974  dollars;  ENR =  2020.
                                    Prototype Recycle Systems     Projection for Mass Produced Recycle System
                                Diatomite Filter  Cartridge Filter              Diatomite Filter
  Installed Cost
       Storage system               $175             $175                             $ 70
       Filter                       135               60                              100
       Pressurization system        115              115                               85
       Disinfectant feeder            20               20                               20
       Valves, pipe,  fittings          95               80                               75
            Total Material Cost     540              450                              350
            Labor Cost              100               90                             	50_
            Total                   $640             $540                             $400
  Costs of  system housing and major  retrofitting requirements are not included.
  Annual Operating Cost
       Filter Media                   3.50            38.80                             3.50
       Electric Power               12.00             1.20                             7.00
       Disinfectant                   5.50             5.50                             5.50
            Total                   $21.00           $45.50                           $16.00
  Electric Costs = $.02 kWh.  Calculations  based on  a 16-h  "on",  8-h "off" cycle for the recirculation pump.
  Total Annual Cost
                                                                                     15
       Expected life,  yrs
       Total Cost/yr
15
$63.50
                                                  15
                                                  $81.50
                                                                                   $43.00
   Installation of a recycle system for toilet flushwater can result in a cost  saving  in the installation of on-site
   disposal systems since there are reduced capacity requirements.   Assuming a  1/3  reduction in flow, the following
   savings can be realized:  (103)
  Disposal Method
                                     Costs without Recycling  minus  Costs  with  Recycling equals Saving
Septic Tank-Soil Adsorption System $2275  (1000  ft  )
Septic Tank-Evapotranspiration      5000  (5000  ft  )
Septic Tank-Intermittent Sand       2800  (100 ft )
  Filter
                                                                   $1775  (667  ft  1
                                                                    3600  (3333 ft )
                                                                    2500  (67 ft )
                                                             $  500
                                                              1400
                                                               300
  Water costs would generally be reduced, but exact figures are  site  specific.
    REFERENCES - 103, 149, 159
   *To convert construction cost to capital cost see  Table  A-2.
                                                       A-247
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NON-WATER CARRIAGE  TOILETS                                               FACT  SHEET 7.2.2
Description - Non-water carriage toilets serve to eliminate the toilet contribution (black wastes)  to the house-
hold wastewater.   Methods include: thermal (incineration, evaporation-condensation),  freezing,  oil recirculating,
composting  (small, large), holding (packaging).   Descriptions of those systems for which there is available on-
site hardware and performance information follow:
     Incinerating Toilets - Small self-contained units which utilize the process of incineration to volatilize the
organic components of solid wastes and evaporate the liquid.  Wastes are deposited into a combustion chamber and
are incinerated upon a signal.  The process is fueled by gas, fuel oil or electricity.   Units are equipped with
appropriate exhaust gas vent and blower.  Ash residue should be removed using a vacuum cleaner or dustpan and
brush once/wk.  Routine cleaning of toilet bowl or replacement of toilet bowl liner is required.
     Composting Toilets - Organic matter from feces, urine and sometimes garbage undergoes aerobic composting and
is converted to humus which may be dispersed on the soil.  Two basic varieties of toilet systems are available,
those in which the point of use is removed from the decomposition chamber (separated)  and those in which the point
of use is directly attached to the chamber (non-separated).   Separated units are generally larger and rely on low
rate, generally aerobic biological action.  The non-separated units are equipped with  an electric heating element
and a mechanical stirring mechanism.  These smaller units depend upon both thermal dehydration and high rate
aerobic biological activity.  Operation and maintenance requirements: Separate units - removal of compost residue
approximately once/yr; periodic addition of organic solids to prevent compost mass compaction may be required, and
infrequent maintenance of mechanical parts.  Non-separated units - removal of compost  residue at least 4 times/yr;
mixing of compost daily; periodic maintenance of mechanical parts including fan, heater and stirrers.
     Oil Recirculating Toilets - Toilet wastes are carried by a recirculating petroleum base flushing liquid,
separated, and stored for subsequent removal and disposal.  System requirements include toilet bowl, waste sepa-
ration and purification system, pump and controls.  Removal and disposal of residuals  is required annually.
Maintenance includes the replacement of exhausted adsorbent, disinfection and filtration media and lost flushing
oil.  With all non-water carriage toilets, the remaining household wastewater (65 to 70 percent of combined
volume) must be treated and disposed of in an environmentally acceptable manner.

Technology Status - Relatively new.  Evaluation of performance in households is inadequate in United States.
applications - Non-water carriage toilets, as part of total household wastewater alternative, may be economically
viable in areas where water supplies are limited and other wastewater alternatives are environmentally limited.

Limitations - Incinerating toilets, gas and oil fired require more frequent maintenance than electric; electric
have higher energy costs.  Toilet capacity less than or equal to 3 uses/h.  Composting - non-separated unit is
subject to hydraulic overloads and has a unit capacity less than or equal to 3 persons.  Larger, separated units
have a capacity less than or equal to 5 persons.  Continuous nature of both process types provides potential for
short circuiting and contamination of stabilized compost by "fresh" waste materials.  Oil recirculating - large
space requirements.  Incomplete separation of aqueous base liquids from flushing oil due to the formation of oil-
water emulsions.  Flushing oil deteriorates.  Costs are quite high.  All units are limited to toilet wastes (1/3
total waste flow), and graywater treatment and disposal must be provided.  Also, user acceptance is an important
factor.  All systems require commitment of the user to sustain the process.

Typical Equipment/No. Mfrs. - Incinerating/more than 8; small composting/more than 12, large composting/more than
3, oil recirculating/more than 3.

Performance  (14) - The effect of eliminating blackwater from household wastewater discharges (% reduction): Flow
30 to 35; BOD, 10 to 35; SS, 20 to 60; Total P, 15 to 40; TKN, 40 to 90; Pathogenic organisms, considerable.

Chemicals Required - Incinerating - none.  Composting - peat "starters" are normally required to maintain good
moisture distribution, prevent compaction and facilitate aeration; fibrous dry organic materials are added per-
moisture distribution, prevent compaction ana racumane aeration; iicrous ary urganxc materxcixs aie auueu pei-
iodically with separated type.   Oil recirculation - Makeup oil (up to 8 gal/yr) may be required; filter, coa-
lescer, adsorbent and disinfectant cartridges.

Residuals - Incinerating - an inert sterile ash; Composting - a humus suitable as a soil conditioner; Oil recircu-
lating - oil coated residue, exhausted filtration media.

Design Criteria  (149) - Typical toilet waste loadings (g/cap/d): BOD, 16.7; SS, 27; TKN, 8.7; Total P, 1.2;
Incinerating - gas  fired requires propane or natural gas, combustion/cooling cycle 20-25 minutes; electric unit
requires 115 or 220 volts AC or 12 volts DC, combustion/cooling cycle 45 minutes; Composting - separated unit
space requirement 30 to 70 ft ; non-separated unit requires 2 to 5 ft ; Oil recirculation - 53 ft  holding tank
space requirement.

Environmental Impact - Commitment of water resources to toilet is eliminated; volume and pollutant ioadings to on-
site disposal systems are reduced.  Incinerating - potential odor or air pollution problems, potential fire or
explosion hazard, high energy use; Composting - nutrient elements in sewage are conserved, potential odor problems
and health hazards due to vectors and incompletely composted residue contacts;  Oil recirculating - potential odor
and discoloration problems; disposal of residuals may be a problem due to their oily character.

References - 14, 149, 152
                                                        A-248
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-WATER CARRIAGE TOILETS
                                                                               FACT SHEET  7.2.2
  FLOW DIAGRAM
  i let WasLes
Toilet Wastes
 Toilet Wastes


J
Toilet


                                                 Compos t   _


Ol 1
Recirculating



Treatment
Wastes


Storage
To disposal

                                            oil
ENERGY NOTES (149)  -

Incinerating Toilets - Gas  (propane)
Incinerating Toilets - Electricity
Composting - Small
Composting - Large
Oil Recirculating Toilet
                                        4,000  to 6,000 Btu/use  (17.5 to 26.2 X 10  Btu/yr)
                                        0.06 to 1.2 kWh/use  (262 to 5,250 kWh/yr)
                                        1-7 kWh/d                 (365 to 2,555 kWh/yr)
                                        1-8 kWh/d                 (365 to 2,920 kWh/yr)
                                        0.657  kWh/d               (240 kWh/yr)
COSTS  (103) (149) -

1.   Labor rates @ S10/hr                                       6                    6
2.   Energy consumption estimates based on:  Gas  (propane)  @  $8/10  Btu; Oil @ $3.42/10  Btu;
     Electricity @ $.02/kWh.
3.   Cost estimates based on 1978 dollars; ENR Index - 2776.
                    Incinerating

               Gas/Oil        Electric

               800 to 1200    600 to 1000
                                             Installed Costs  ($)

                                                       Composting

                                                  Small         Large

                                                  700 to 1200    1500 to  3200
                                      Operation and Maintenance  ($/yr)

                               80                  80              40

                                5 to 110           7  to 51           7  to  5Q
                               85 to 190
                                                 87 to 131
Maintenance     80

Energy          55 to 230

Total          135 to 310



REFERENCES - 103,  149,  152


*To convert construction  cost  to  capital cost see Table A-2.
                                                                   47  to  98
                                                                                    Oil Recirculating
                                                                                         4500 to 6000
 180

	5_

 185
                                                A-249
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BIBLIOGRAPHY
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                                                         A-250
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BIBLIOGRAPHY  (CONTINUED)
29.  U.S.  EPA Technology Transfer,  "Process Design Manual for Phosphorus  Removal",  Report  No.  625/1-76-OOla
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                                                   A-251
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BIBLIOGRAPHY  (CONTINUED)
55.  U.S. EPA, "Analysis of Operations & Maintenance Cost for Municipal Wastewater Treatment Systems", Report
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                                                      A-252
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31.   Willson,  G.  B.,  et al,  "Recent Advances in Compost Technology", Proceedings of the Third National Conference
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89.   Hager, D. G.  and J.L. Rizzo,  "Removal of Toxic Organics from Wastewater by Adsorption with Granular Activated
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30.   Chemical Week,  1978 Buyers Guide Issue (October 26, 1977).

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92.   U.S. EPA, " Urban Stormwater Management and Technology, An Assessment", Report No. 670/2-74-040,  (Dec. 1974).

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97.   "Chemical Engineering,  Eguipment Buyers's Guide Issue," Part Two, Vol. 85, No. 16, (July 17, 1978).

98.   Communication with Ken Decker, Big Wheels, Inc., P.O. Box 113, Paxton, IL 60957.

99.   U.S. EPA Technology Transfer, "Process Design Manual for Suspended Solids Removal,"  (January 1975).

100. "Pollution Equipment News," 1975 Catalog and Buyers Guide,  (November 1977).

101. U.S. EPA, "Sanitary Landfilling," Report on a Joint Conference Sponsored by the National Solid Waste Manage-
     ment Association and the U.S. EPA November 14 - 15, 1972, Kansas City, MO  (U.S. EPA 1973).

102. "Lime, Handling, Application and Storage," Natural Lime Association, rmlot'-n 213, 1949.

103. Kreissl, James F. , Robert Smith, James A. Heidman, "The Cost of Sma.1  '.: •  unity Waste'"ater M'-<;rnatives," U.S.
     EPA August 1978.

104. "Car Builders Cyclopedia," Compiled and Edited for the AAR-Mech. Div., Simmons-Boardman Publishing Corp., New
     York, NY.

105. Sparr, Anton E.  , "Pumping Sludge Long Distances,'1 .... ;>al Water Pollution Control Federation, Vol.  -   ,'o. 8,
     August 1971, pp.   1702-1711.

106. U.S. EPA, "Physical-Chemical Treatment of a Municipal Wastewater Using Powdered Carbon, No. II," Report No.
     600/2-76-235 (November 1976)
                                                     A-253
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 BIBLIOGRAPHY  (CONTINUED)
107. Conference Notes, Sam Perri, from Robinson Pipe Cleaning Co.,  Newark,  NJ,  (June  20,  1978).

108. U.S.  EPA,  "Development Document for Effluent Limitations Guidelines  and New  Source  Performance  Standards  for
     the Petroleum Refinery Point Source Category,"  Report No.  400/1-74-014-a (April  1974).

109. Eckenfelder, W.W., "Industrial Water Pollution  Control," McGraw-Hill.

110. Clark, J.w., W. Veissman and M.J. Hammer,  "Water Supply and Pollution  Control,"  International Textbook Co.

111. "Water Treatment Handbook," Gulf Degremont, 1973.

112. U.S.  EPA,  "Supplement for Pretreatment to  the Development Document for the Petroleum Refinery Industry,
     Existing Point Source Category," Report No. 440/1-76-083 (December 1976).

113. "Developing a Methodology for Design of Equalization Basins,"  Water  and Sewage Works,  (November 1977).

114. New Compressed Air and Gas Data, Jngersoll-Rand, 1971.

115. Heuther, Charles H.,  and Stanton B. Smith, "Regeneration of Granular Activated Carbon."  Westvaco Publication,
     (May 31, 1973).

116. Hutchen, R.A., "Thermal Regeneration Costs", Chemical Engineering Progress,  Vol.  71, No.  5  (May 1975).

117. "Carter Water and Waste Treatment Equipment," Catalog 0662, Ralph B. Carter  Company.

118. Pichmann,  B.W., "Dewatering Machine Solves Sludge Drying Problems,"  Water and Sewage Works,  p 99 (October
     1977).

119. American Society of Civil Engineers, U.S.  EPA,  Municipal Sludge Management,  Proceedings  of  the National
     Conference of Municipal Sludge Management, Pittsburgh, PA  (June 11-13, 1974).

120. U.S.  EPA,  Residual Waste, Best Management  Practices, A Water Planner's Guide to  Land Disposal," Report No.
     440/9-76-022  (August 1976).

121. U.S.  EPA,  "Thermal Regeneration of Activated Carbon," Report No. 600/2-78-013 (May  1978).

122. U.S.  EPA,  "Flow Equalization Evaluation of Applications in Municipal Sewage  Treatment,"Second Review Draft,
     Contract No.  68-03-2512  (January 1978).

123. Communication with (via letter) Dennis M.  Howard, Passavant Corp., Birmingham, AL,  Subject:   Equipment Lists
     and Prices for Passavant Filter Press Systems to Dewater Waste Activated Sludge  - Activated Carbon Sludges.
     September 8,  1977.

124. U.S.  EPA Municipal Sludge Management and Disposal, Proceedings of the  1975  National Conference, Anaheim,
     California, August 18-20, 1975.

125. Communication with (via telephone) Dale Bentley, Ralph B. Carter Company, Hackensack,  New Jersey, Subject:
     Costs for Belt Filter Press, September 14, 1977.

126. U.S.  EPA,  " Microstraining and Disinfection of Combined Sewer Overflows - Phase  III," Report No. 670/2-75-021,
     April 1975.

127. U.S.  EPA,  "Bench-Scale High-Rate Disinfection of Combined Sewer Overflows with Chlorine  and Chlorine Dioxide,"
     Report No. 670/2-75-021, April 1975.

128. U.S.  EPA,  "Laboratory Ozonation of Municipal Wastewaters," Report No.  670/2-73-075, September 1973.

129. Cochrane Division, Crane Co., "Microstraining and Disinfection of Combined Sewer Overflows," U.S. Department
     of the Interior, Federal Water Quality Administration, Contract No.  14-12-136.

130. "Ozone Gives  Wastewater the Treatment," Chemical Week, June 21, 1978,  p. 49.

131. "Ozone Use Grows as Effluent Disinfectant," ENR, May 11, 1978, p. 18.

132. Stopka, Karel, "Ozone-Activated Carbon Can Remove Organics," Water and Sewage Works, May 1978, p. 88.

133. Fair, G.M., J.C. Geyer, and D.A. Okun, "Water and Wastewater Engineering, John Wiley and Sons, 1968.

134. U.S. Department  of Health, Education and Welfare, "Manual of Septic Tank Practice," PHS  Publication No. 526,
     1972.
                                                       A-254
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BIBLIOGRAPHY  (CONTINUED)
135. U.S. EPA, "Environmental Effects of Septic Tank Systems," Report No.  600.3-77-096 (August 1977).

136. Garber, W.F, et.al, "Thermophilic Digestion at the Hyperion Treatment Plant," Journal Water Pollution Control
     Federation,  Vol. 47, No. 5, May 1975, p. 950.

137. Harris, S.E., et.al, "Intermittent Sand Filtration for Upgrading Waste Stabilization Pond Effluents," Journal
     Water Pollution Control Federation, Vol. 49, No. 1, January 1977.

138. Matsch, L.C., R. F. Dmevich, "Autothermal Aerobic Digestion," Journal Water Pollution Control Federation,  Vol.
     49, No. 2, February 1977, p. 286.

139. Communication (via telephone)  with Steven Caliento, Passavant Corporatiop,  Connecticut,  Subject:   Belt Filter
     Press Costs, September 15, 1978.

140. Solio, F.N., et. al,"Disinfection of Sewage Effluents," Illinois State Water Survey, PB-222 355,  July 1973.

141. Clow Waste Treatment Division "Engineering Manual, Wastewater Handling and Treatment Systems," Clow Corpo-
     ration, Florence, Kentucky.

142. U.S. EPA, "Transport of Sewage Sludge," EPA-600/2-77-216, EPA Technology Series, December 1977.

143. Jewell, William T., and Randolph M. Kabrick, "Autoheated Aerobic Thermophilic Digestion  with Air  Aeration,"
     Department of Agricultural Engineering, Cornell University, Ithaca,  New York.

144. Communication (via telephone)  with Dick Sobel, Sharpies-Stokes, New York, September 26,  1978, Subject:  Cost
     Data for Thickening; Solid Bowl and Disc Centrifugal.

145. Communication (via telephone)  with Bob Honeychurch, Dorr-Oliver, Stanford,  CT, September 26, 1978,  Subject:
     Lost Data for Thickening; Solid Bowl and Disc Centrifugal.

146. Sawyer, Clair N., and Perry L. McCarty, Chemistry for Sanitary Engineers, McGraw-Hill Company, 1967.

147. Communication (via telephone)  with Dr. William Jewell, September 27,  1978.  Subject:   Thermophilic Aerobic
     Digestion With Air.

148. Walsh, James J., Coppel, Wayne, "Seminar Sludge Treatment and Disposal, Part II, Sludge  Disposal,"  U. S.
     EPA, March 1978.

149. Otis, Richard J. , W. C. Boyle, "U.S. EPA Training Seminar for Wastewater Alternatives For Small Communities,
     OnSite Alternatives," August 14-1 8, 1978; August 28 - September 1,  1978.

150. U. S. EPA "Appraisal of Powdered Activated Carbon Processes For Municipal Wastewater Treatment,"  Report No.
     600/2-77-156 (September 1977).

151. Communication (Via Telephone)  with G. Burde, Burde Associates, Paramus, N.  J.  Subject:   Package  Plant Treat-
     ment Costs, Extended Aeration and Contact Stabilization.

152. Bauer, David H.  et. al., "Identification, Evaluation and Comparison of On-Site Wastewater Alternatives,"
     Draft Final Report, U. S. EPA, August 1978.

153. Rand Development Corporation,  "Rapid Flow Filters For Sewer Overflows," August, 1969.

154. U. S. EPA, "Urban Stormwater Management and Technology, An Assessment," Report No.  670/2-74-040 (December
     1974).

155. U. S. EPA, "Cost Estimating Manual-Combined Sewer Overflow Storage and Treatment,"  Report No. 600/2-76-286,
     (December 1976).

156. Kalinske, A. A., "Comparison of Air and Oxygen Activated Sludge Systems," Journal Water  Pollution Control
     Federation.   Vol. 48, No. 11,  November 1976, pp. 2472-2485.

157. Chamman, T.  D.,  L. G. Matsch,  and E. H. Zander, "Effect of High Dissolved Oxygen Concentration in Activated
     Sludge Systems,  " Journal Water Pollution Control Federation, Vol. 48, No.  11, November  1976, pp.  2486-2510.

158. Parker, D. S.,  M. S. Merrill,  "Oxygen and Air Activated Sludge:  Another View,"  Journal Hater Pollution
     Control Federation, Vol. 48, No. 11, November 1976, pp. 2511-2528.

159. U. S. EPA, "Demonstration of Wasteflow Reduction From Households," Report No. 670/2-74-071, September 1974.
                                                        A-255
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BIBLIOGRAPHY  (CONTINUED)
160. Otis, R. J., W. C. Boyle, "Performance of Single Household Treatment Units," Journal Environmental
     Engineering Division, American Society of Civil Engineers, Vol. 102, No. EE1,  February 1976, pp. 175-189.

161. "Exploring Energy Choices,"  Ford Foundation Report-1974.

162. Saver, O.K. et. al, "Intermittent Sand Filtration of Household Wastewater," Journal Environmental Engineering
     Division, American Society of Civil Engineers, Vol. 102, No. EE4, August 1976, pp. 789-803.

163. Drewhing, Frank J., et. al.,  "Disinfection/Treatment of Combined Sewer Overflows," Municipal Environmental
     Research Laboratory, Office of Research and Development, U. S. EPA, Cincinnati, Ohio, Project No. 5802400.

164. "Combined Sewer Overflow Abatement Program, Vol. I," Monroe County Division of Pure Waters, Rochester, New
     York, March 1978.

165. Cochrane Division, Crane Co., "Microstraining and Disinfection of Combined Sewer Overflows," Federal Water
     Quality Administration, U. S. Dept. of the Interior, Program No. 11023 EVO, June 1970.

166. Glover, George E., George R.  Herbert, "Microstraining and Disinfection of Combined Sewer Overflows-Phase
     II," Office of Research and Monitoring, U. S. EPA and Philadelphia Water Department, Philadelphia, P.A.  EPA-
     R2-73-124, January, 1973.

167. Lager, John A., et. al, "Urban Water Management and Technology:  Update and Users Guide,"  Office of
     Research and Development, U.S. EPA-600/8-77-014 (September 1977).

168. U. S. EPA, "Process Design Manual—Municipal Sludge Landfills," Technology Transfer, Report No. 625/1-78-010
     SW-705  (October 1978).

169. Spray Irrigation Manual, Pennsylvania Department of Environmental Resources, Bureau of Water Quality Manage-
     ment, Publication No. 31, 1972 Edition.

170. Pickett, Edward M., "Evapotranspiration and Individual Lagoons," Proceedings of the Northwest On-Site Waste
     Water Disposal Short Course," University of Washington, December 8-9, 1976.

171. Communication  (via telephone) with Walter Kuntz, Foley Machinery, Piscataway,  New Jersey, Subject:  Sludge
     Trenching.

172. U.S. EPA, "Pilot Plant for Tertiary Treatment of Wastewater with Ozone," Report No. EPA-R2-73-146, January
     1973.

173. Williamson, K.J., G. R. Swanson, "Field Evaluation of Rock Filters for Removal of Algae from Lagoon Effluents,
     Dr. R. Lewis of U.S. EPA, Cincinnati, Ohio, October 16, 1978.

174. Duffer, W.R., J. E. Moyer, "Municipal Wastewater Aquaculture," U.S. EPA-600/2-78-110, June 1978.

175. "Advanced Wastewater Treatment Nature's Way," Environmental Science and Technology, Vol. 12, No. 9, September
     1978.

176. Fairfield Service Co., Vendor Literature, Fairfield Engineering Co., P.O. Box 354, Marion, OH 43302.

177. Communication  (via telephone) with R. Walters; Schandt, Siemm, Walters, Inc.,  Eugene, Oregon, Subject: Veneta
     Rock Filter.

178. Neptune Microfloc, "ABF Biomedia, Superior Fixed Growth Media for Biological Treatment," Equipment Manufact-
     urers Literature on ABF Systems, Copyright 1975.

179. Williams, Charles, R., et. al., "Results of Pilot Studies on Biological Treatment of Combined Food Processing/
     Domestic Wastewater at Tracy, California," YTO S Associates, Walnut Creek, California.

180. Slechta, A., G. Mattli, "Activated Bio-Filter Process for Biological Wastewater Treatment," Nepture Microfloc,
     Inc.

181. Mattli, G., A. Slechta, " Final Report, City of Turlock, California, 1975 Pilot Plant Study, ABF System," CH
     2M-Hill, Inc.

182. City of Helena, Montana, Application for Federal Assistance, "Evaluation of Activated Bio-Filter Wastewater
     Treatment Process at Helena,  Montana," EPA Project Control No. R806047 01, March 31, 1978.

183. Slechta, Alfred, "Final Report, City of Rochester, Minnesota, 1974 Pilot Plant Study, ABF Nitrification
     System," Kirkham-Michael S Assoc., Wallace, Holland, Kastler, Schmitz S Co., Copyright, 1974.
                                                     A-256
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BIBLIOGRAPHY  (CONTINUED)
184. Neptune Microfloc, "ABF," Bulletin No. KD 7400-1 Secondary Biological Wastewater Treatment Systems.

185. Stetzer, R.H., "FMC Pure Oxygen, An Effective Solution to Wastewater Treatment and Process Applications,"
     paper presented at 70th Annual AICHE Meeting, November 15, 1977, New York, NY.

186. Pearlman, S.R. , and D. G. Fullerton, "Full Scale Demonstration of Open Tank Oxygen Activated Sludge  Treat-
     ment," U.S. EPA Grant No. S803910, draft report to Municipal Environmental Research Laboratory, Office of
     Research and Development, U.S. EPA, Cincinnati, OH.

187. Gulp, Wessler and Gulp, Suspended Growth Biological Wastewater Treatment - Construction, Operating and Main-
     tenance Cost Estimates, Vol. 2, unpublished EPA Document, El Dorea HiJ.ls, CA.

188. Buck, B.J., L.M.  LaClair, and M.R. Morlino, "Recent Advances in the Biological Removal of Phosphorus," paper
     presented at meeting of Water Pollution Control Association of PA, Hershey, PA, June 15-17, 1977.

189. Sheridan, D.L. and R. W. Regan, "Phosphorus Release by PhoStrip Activated Sludge, paper presented at the
     National Conference on Environmental Engineering sponsored by the American Society of Civil Engineers,
     Environmental Engineering Division, Kansas City, MO, July 10-12, 1978.

190. Communication with (via letter) Louis M. LaClair, Product Manager, Union Carbide Corp., Tonawanda, NY, Sub-
     ject: PhoStrip Process.

191. Peirano, L.E., "Low Cost Phosphorus Removal at Seno/Sparks, Nevada," Journal Water Pollution Control Fed-
     eration, Vol. 49, No. 4, April 1977, pp. 568 - 574.

192. Drnevich, R.F., and L. M. LaClair, "New System Cuts Phosphorus for Less Cost," Water s Water Engineering,
     Vol. 13, No. 9, September 1976, pp. 104-108.

193. Levin, G.V., G. J. Topol, and A.G. Tarnay, "Operation of Full-Scale Biological Phosphorus Removal  Plant,"
     Journal Water Pollution Control Federation, Vol. 47, No.  3, March 1975, pp. 577-590.

194. Vendor literature, "Metro-Waste Composting System," Resource Conversion Systems, Inc., 9039 Katy Freeway,
     Suite No. 300, Houston, TX 77024.

195. Vendor literature, Smith s Loveless, Lenexa, KS 66215

196. Vendor literature. Clow Corp., Florence, KY 41042.

197. Vendor literature, Chicago Pump, Chicago,  IL 60647.

198. Vendor literature, Carlgen, Inc.,  Walden NY 12586.

199. Ewing, Lewis, et.al., "Effects of Thermal Treatment of Sludge on Municipal Wastewater Treatment Costs,"  U.S.
     EPA-600/2-78-073  (June 1978).

200. "Compiled Data on Vascular Aquatic Plant Program 1975-1977, NASA-NSTL Station  Mississippi,  39529".

201. U.S. EPA, "Estimating Costs and Manpower Requirements for Conventional Wastewater Treatment Facilities,"
     Report 17090 DAN, October 1971.

202. Finstein, M.S. and M. Morris, "Composting," New Jersey Effluents.  Vol. 11, No. 1, April 1978.

203. Gray, K.R., et al.,  "Review of Composting, Part 2 - The Practical Process," Process Biochemistry, p.  22,
     October 1971.

204. B.W. Ryan, E.F. Earth, "Nutrient Control by Plant Modification at El Lago, Texas,"  Wastewater Research Divi-
     sion, MERL, Cincinnati, Ohio.

205. Via telephone, Frank Carlson, Royer Foundry & Machine Co., 158 Pringle Street, Kingston,  PA 18704.

206. Villiers and Farrell, "A Look at Newer Methods for Dewatering Sewage Sludges," Civil  Engineering ASCE, p  66,
     December 1977.

207. Gulp, Wesner and  Gulp, Attached Growth Biological Wastewater Treatment - Construction,  Operating and Main-
     tenance Cost Estimates, Vol.  1, unpublished EPA Document, El Dorado Hills, CA.

208. U.S. EPA, "Lime Use in Wastewater Treatment Design and Cost Data",  U.S.  EPA-600/2-75-038, October 1975.

209. "Compiled Data on Vascular Aquatic Plant Program 1975 - 1977," NASA - NSTL Station, MI  39529.
                                                    A-257
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BIBLIOGRAPHY  (CONTINUED)
210. U.S. EPA, "Evaluation of Dewatering Devices for Producing High Sludge Solids Cake",  Draft Report, Contract
     No. 68-03-2455, MERL 1978.

211. Burant, W., and T.J. Vollstandt, "Full-scale Wastewater Treatment with Powdered Activated Carbon," Water and
     Sewage Works, November 1973.

212. Adams, A.D., "Powdered Carbon:  Is It Really That Good?", Water and Waste Eng., March 1974.

213. Stern, G., "Processing, Economics and Sale of Heat Dried Sludge," Proceedings of the 1975 National Conference
     on Municipal Sludge Management and Disposal, Anaheim, California, August 18-20, 1975.

214. National Academy of Sciences, 1975, "Making Aquatic Weeds Useful:  Some Perspectives for Developing Countries.'
     Commission on International Relations (JH215),  National Academy of Sciences - National Research Council, 2101
     Constitution Ave., Washington, D.C. 20418.

215. Tourbier, J., and R.W. Pierson, Jr. (eds). 1976.  Biological Control of Water Pollution.  University of
     Pennsylvania Press.

216. NASA. "Compiled Data on the Vascular Aquatic Plant Program:  1975 - 1977." National Aeronautics and Space
     Administration, National Space Technology Laboratories, NSTL Station, Mississippi 39529.

217. Tilton, D.L., R.H. Kadlec and C.J. Richardson (eds).  1976.  "Proceedings of a National Symposium on Fresh-
     water Wetlands and Sewage Effluent Disposal."  Wetlands Ecosystem Research Group, The University of Michigan,
     Ann Arbor, MI.

218. Spangler, F.L., W.E. Sloey and C.W. Fetter, Jr. 1976.  "Wastewater Treatment by Natural and Artificial
     Marshes."  EPA 600/2-76-207.

219. Henderson, U.B. and F.S. Wert. 1976.  "Economic Assessment of Wastewater Aquaculture Treatment Systems."  EPA
     600/2-76-293.

220. Duffer, W.R. and J.E. Moyer. 1978.  "Municipal Wastewater Aquaculture."  EPA 600/2-78-110.

221. Von Dreusche and Negra, 1978.  "Pyrolyzer Design Alternatives and Economic Factors for Pyrolyzing Sewage
     Sludge in Multiple Hearth Furnaces," Nichols Engineering & Research Corporation, Belle Meade, NJ.

222. Nichols Engineering & Research Corporation, Belle Meade, NJ, September 1977.  "Pyrolysis of Sewage Sludge -
      The Choice is Yours."

223. Nichols Engineering s Research Corporation, Belle Meade, NJ, 1978.  Excerpt from "Phase I Report of Pyrolysis
     of Sewage Sludges in the N.Y.-N.J. Metropolitan Area."  Interstate Sanitation Commission.

224. Jones and Radding  (eds).  "Solid Wastes  and Residues, Conversion by Advanced Thermal Processes," ACS Sympo-
     sium, Series 76.

225. Letter, Nichols Engineering  to Mr. Leo Pinczuk, Burns and Roe Industrial Services Corp., August 15, 1978.

226. "The Co-Disposal of Sewage Sludge  and Refuse in the Purox System".  EPA 600/2-78-198, December 1978.

 227. Correspondence with Neptune  Microfloc, 1965 Airport  Road, P.O. Box 612, Corvallis, OR 97330.

 228. "Construction Costs for Municipal Wastewater Conveyance  Systems:  1973-1977," 430/9-77-015, MCD-38, U.S.
     EPA,  May 1978.

 229. Telephone communication with L. Moody and D. Triestran,  Clow Corporation.

 230. "Analysis of the Use  of Waste Pickle Liquor  for Phosphorus  Removal"  by Whitman,  Requardt  and  Associates
     Engineers,  Baltimore,  MD, September 1978.

 231.  "Progress in Wastewater Disinfection Technology",  Proceedings of the National  Symposium,  Cincinnati,
     OH,  September 18-20,  1978,  EPA-600/9-79-018, June  1979.

 232.  "Sludge Treatment and Disposal",  Vol. 1, U.S.  EPA  Technology Transfer,  Report  No. 625/4-78-012,  October
      1978.

 233. Via Correspondence -  Ronald L.  Antonie,  Autotrol Corporation, Bio-Systems  Division,  June  13,  1979.

 234. Bowker,  R.P.G.  et al,  "Alternatives for  the Treatment and Disposal of Residuals  from On-Site  Wastewater
      Systems", Technology Transfer Handout for EPA  Seminar -  Wastewater Alternatives  for  Small Communities,
      August 1978.

 235.  Bennett, S. A.,  et al,  "Feasibility of Treating Septic Tank Waste by Activated Sludge," EPA  600/2-77-
      141, August 1977.


                                                    A-258
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BIBLIOGRAPHY  (CONTINUED)
236. Cooper, I. A. et al, "Septage Management".   Draft ORD report,  Contract No.  68-03-2231.

237. Kolega, et al, "Treatment and Disposal of Wastes Pumped from Septic Tanks",  EPA 600/2-77-198,  September 1977.

238. "Maine Guidelines for Septic Tank Sludge Disposal on the Land",  Life Sciences and Agriculture  Experiment
     Station, University of Maine (Orono),  and Maine Soil and Water Conservation Commission,  Miscellaneous
     Report 155, April 1974.

239. "Guidelines for Septage Handling and Disposal", New England Interstate Water Pollution  Control Commission,
     TGM-1, August 1976.

240. Barlow and Cassell, "Septage Management Strategies for Vermont", Vermont Water Resources Research Center,
     University of Vermont, Project Report No. 2, April 1978.

241. Carrol, Robert G. "Planning Guidelines for Sanitary Waste Facilities", CH2M Hill for U.S.D.A.  Forest Service,
     California Region.

242. Segall, B., and C. Ott, "Monitoring Septage Addition to Wastewater Treatment Plants", Vol.  1,  University of
     Lowell, Prepublication Grant No. 805406.

243. Feige, W.  A. et al, "An Alternative Septage Treatment Method:   Lime Stabilization/Sand  Bed  Dewatering",  EPA
     600/2-75-036, September 1975.

244. Noland, R.F. et al, "Full Scale Demonstration of Lime Stabilization", EPA 600/2-78-171,  September 1978.

245. "Septic Tank Sludge Treatment by the Purifax Process of Rapid Chemical Oxidation", BIF,  A Unit of General
     Signal, 1600 Division Road, W.  Warwick, RI 02893.

246. "Evaluation of the Purifax Process for the Treatment of Septic Tank Sludges", U.S. EPA  Lebanon Pilot Plant,
     Unpublished Report, June 1975.

247. "Partial Characterization of Chlorinated Organics in Superchlorinated Septages and Mixed Sludges",  EPA
     600/2-78-20, March 1978.

248. "Operations Manual - Sludge Handling and Conditioning", Chapter VII - Chlorine Treatment, EPA  430/9-78-002,
     February 1978.

249. Epstein, E. et al, "A Forced Aeration System for Composting Wastewater Sludge", JWPCF Vol.  48, No.  4, April
     1976.

250. Colacicco, et al, "Costs of Sludge Composting", ARS-NE-79,  February 1977.

251. Bowker, R.R.G., "Static Pile Composting:  A Potential Septage  Handling Alternative for  Small Communities",
     EPA-MERL,  Draft Report, 1978.

252. Jewell, et al, "Design Guidelines for Septic Tank Sludge Treatment and Disposal", Progress  in  Water
     Technology, T_, 2, 1975.

253. Howley, J.B., "Biological Treatment of Septic Tank Sludge", MS-Thesis, University of Vermont,  October 1973.

254. "The Feasibility of Accepting Privy Vault Wastes at the Bend Waste Treatment Plant", prepared  for City  of
     Bend, Oregon, CSG Engineers, Salem, OR, June 1973.

255. Mignone, N.H., "Aerobic Digestion of Municipal Wastewater Sludges", Envirex, Inc., EPA  Seminar Handout,
     Sludge Treatment and Disposal,  March 1978.

256. Cosulich,  W.F., "Stop Dumping Cesspool Wastes", The American City, Vol. 83,  February 1968,  pp. 78-79.

257. Condren, A.J., "Pilot Scale Evaluations of Septage Treatment Alternatives",  EPA 600/2-78-164,  September 1978.

258. Medbo, F., "Operational Problems at Sewage Treatment Plants",  Nordforsk  (Nordic Research),  Environmental
     Protection Secretariat Publication, No. 9,  1975, pp. 259-274.

259. Benjes, Henry H., Jr. et al, "Capital and O&M Cost Estimates for Biological Wastewater  Treatment Processes",
     unpublished report by Gulp, Wesner and Gulp, El Dorado Hills,  CA for Municipal Environmental Research Lab-
     oratory, U.S. EPA, Cincinnati,  OH.

260. "Oxygen Aeration at Newtown Creek", U.S. EPA 600/2-79-013,  June  1979.

261. Steel, Ernest, W., Water Supply and Sewage,  McGraw Hill.

262. Wang, L.K.,  et al,  "Chemistry of Nitrification-Denitrification Process",  Journal  of  Environmental Science,
     Vol.  21, P.  23-28,  December 1978.


                                                    A-259
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BIBLIOGRAPHY (CONTINUED)
263.  Nash, N.,  et  al, "Oxygen Aeration at Newtown Creek",  EPA-600/2-79-013, Cincinnati, OH,  June 1979.
                                                A-260
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                  APPENDIX B


LEGISLATION, REGULATIONS, AND PROGRAM GUIDANCE
   INFORMATION PERTAINING TO INNOVATIVE AND
    ALTERNATIVE TECHNOLOGY UNDER PL 95-217
                      B-i
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                                 APPENDIX B


Contents                                                             Page

Legislation                                                          B-l
  201(d) 	  B-l
  201(g)(5)	  B-l
  201 (i) 	  B-l
  201(e) 	  B-l
  201 (j) 	  B-2
  202(a)(2) 	  B-2
  202(a)(3) 	  B-2
  202(a)(4) 	  B-2
  304(d)(3) 	  B-3
  205( i) 	  B-3

Regulations
  35.908 	  B-3
  35.915(a)(l) 	  B-5
  35.915(e) 	  B-5
  35.917-1(d)(8)(9) 	  B-6
  35.915-1 (b) 	  B-6
  35.930-5(b) 	  B-6
  35.935.20 	  B-7
  35.936-13 	  B-7

Program Requirements Memoranda
  PRM 79-3, Revision of Agency Guidance for Evaluation of Land  ...  B-10
    Treatment Alternatives Employing Surface Application
  PRM 79-8, Small  Wastewater Systems 	  B-29
                                   B-ii
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LEGISLATION

     The following sections of the Clean Water Act Amendments of 1977
(PL 95-217) contain specific provisions relating to innovative and
alternative technology.  A one sentence synopsis as well as the com-
plete text of the applicable sections of the law has been provided in
this first section of the appendix.  This is followed by all pertinent
agency (EPA) regulations that have been promulgated as required by the
law, along with additional program guidance information.

Section 201(d)  Encourages revenue producing waste management facilities.

Section 201(g)(5)  Requires all applicants to fully study innovative and
alternative treatment options.

          The administrator shall not make grants from funds authorized
     for any fiscal year beginning after September 30, 1978, to any State,
     municipality, or intermunicipal  or interstate agency for the erection,
     building, acquisition, alteration, remodeling, improvement or exten-
     sion of treatment works unless the grant applicant has satisfactorily
     demonstrated to the Administrator that innovative and alternative
     wastewater treatment processes and techniques which provide for the
     reclaiming and reuse of water, otherwise eliminate the discharge of
     pollutants, and utilizing recycling techniques, land treatment, new
     or improved methods of waste treatment management for municipal and
     industrial waste (discharged into municipal systems) and the confined
     disposal of pollutants will not migrate to cause water or other
     environmental pollution, have been fully studied and evaluated by the
     applicant taking into account Section 201(d) of this Act and taking
     into account and allowing to the extent practicable the more efficient
     use of energy and resources.

Section 201(i)  Encourages energy conservation.

          The Administrator shall encourage waste treatment management
     methods, processes, and techniques which will reduce total  energy
     requirements.

Section 201(e)  Requires EPA to encourage treatment techniques which will
reduce total  energy requirements.

          The Administrator shall encourage waste treatment management
     which results in integrating facilities for sewage treatment and
     recycling with facilities to treat, dispose of, or utilize  other
     industrial  and municipal  wastes,  including  but not limited  to solid
     waste and waste heat and thermal  discharges.   Such integrated
     facilities shall  be designed and  operated  to produce revenues in
     excess of capital  and operation  and maintenance costs and such
     revenues shall  be used by the designated regional  management agency
     to aid financing other environmental  improvement programs.
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Section 201(j)  Allows EPA to select the innovative and alternative process
option if costs are as high as 115% of least costly option.

          The Administrator is authorized to make a grant for any treat-
     ment works utilizing processes and techniques meeting the guidelines
     promulgated under Section 304(d)(3) of this Act, if the Administrator
     determines it is in the public interest and if in the cost effectiveness
     study made of the construction grant application for the purpose of
     evaluating alternative treatment works, the life cycle cost of the
     treatment works for which the grant is to be made does not exceed the
     life cycle cost of the most effective alternative by more than 15
     per centum.

Section 202(a)(2)  Increases Federal grant to 85% for treatment works
utilizing innovative or alternative processes.

          The amount of any grant made after September 30, 1978, and
     before October 1, 1981, for any eligible treatment works or sig-
     nificant portion thereof utilizing innovative or alternative
     wastewater treatment processes and techniques referred to in
     section 201(g)(5) shall be 85 per centum of the cost of con-
     struction thereof.  No grant shall be made under this paragraph
     for construction of a treatment works in any State unless the
     proportion of the State contribution to the non-Federal share of
     construction costs for all treatment works in such State receiving
     a grant under this paragraph is the same as or greater than the
     proportion of the State contribution (if any) to the non-Federal
     share of construction costs for all treatment works receiving
     grants in such State under paragraph (1) of this subsection.

Section_202(a)(3)  Authorizes EPA to pay 100% of all costs to replace
innovative or alternative treatment facilities that failed.

          In addition to any grant made pursuant to paragraph (2) of
     subsection 202(a) the Administrator is authorized to make a grant
     to fund all of the costs of the modification or replacement of any
     facilities constructed with a grant made pursuant to paragraph (2)
     if the Administrator finds that such facilities have not met design
     performance specifications unless such failure is attributed to
     negligence on the part of any person and if such failure has sig-
     nificantly increased capital or operating and maintenance expenditures.

Section 202(a)(4)  Limits the treatment works eligible for bonus grant
increases for innovative and alternative processes to treatment plant-
related works only.

          For the purposes of this section, the term "eligible treatment
     works"  means those treatment works in each State which meet the
     requirements of section 201(g)(5) of this Act and which can be
     fully funded from funds available for such purpose in such State in
                                     B-2
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     the fiscal  years ending September 30,  1979,  September 30,  1980,  and
     September 30, 1981.   Such term does not include collector  sewers,
     interceptors, storm or sanitary sewers or the separation thereof,
     or major sewer rehabilitation.

Section 304(d)(3)  Mandates that EPA promulgate guidelines for  identifying
and evaluating innovative and alternative processes during FY 1978.

          The Administrator, after consultation with appropriate Federal
     and State agencies and other interested persons, shall  promulgate
     within one hundred and eighty days after the date of enactment  of
     this subsection guidelines for identifying and evaluating  innovative
     and alternative wastewater treatment processes and techniques referred
     to in section 201(g)(5) of this Act.

Section 205(i)  Authorizes EPA to set aside a reserve of 2% for each
allotment to use only to increase federal share of grants for innovative
and alternative processes to 85%.

          Not less than one-half of one per centum of funds allotted to
     a State for each of the fiscal years ending September 30,  1979.
     September 30, 1980, and September 30, 1981, under subsection (a) of
     this section shall be expended only for increasing the Federal  share
     of grants for construction of treatment works utilizing innovative
     processes and techniques from 75 per centum to 85 per centum pursuant
     to section 202(a)(2) of this Act.  Including the expenditures authorized
     by the preceding sentence, a total of two per centum of the funds  alloted
     to a State for each of the fiscal years ending September 30, 1979, and
     September 30, 1980, and 3 per centum of the funds allotted to a State
     for the fiscal year ending September 30, 1981, under subsection (a)
     of this section shall be expended only for increasing grants for
     construction of treatment works from 75 per centum to 85 per centum
     pursuant to section 202(a)(2) of this Act.


REGULATIONS

     The following regulations describe the Environmental Protection Agency's
requirements for Innovative and Alternative Technolgoy.  The basic Innovative
Alternative Technology regulation is 35.908 and is presented in its  entirety.
Applicable portions of other regulations are presented.

35.908  Describes basic agency requirements and policy for funding,
priority, and replacement costs for innovative and alternative  technology.

          (a)  Policy.  EPA's policy is to encourage, and, where possible,
     to assist in the development of innovative and alternative technologies
     for the construction of wastewater treatment works.  Such  technologies
                                     B-3
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may be used in the construction of wastewater treatment works  under
this subpart as §35.915-1, §35.930-5, Appendix E,  and this section
provide.  New technology or processes may also be  developed or demon-
strated with the assistance of EPA research or demonstration grants
awarded under Title I of the Act (see Part 40 of this subchapter).

     (b)  Funding for innovative and alternative technologies.

          (1)  Projects or portions of projects which meet criteria
          for innovative or alternative technologies in Appendix E
          may receive 85 percent grants (see §35.930-5).

               (i)  Only funds from the reserve in §35.915-1 (b) shall
               be used to increase these grants from 75 to 85 percent.

               (ii)  Funds for the grant increase  shall be distributed
               according to the chronological approval of grants, unless
               the State and the Regional Administrator agree otherwise.

               (iii)  The project must be on the fundable portion of
               the State project priority list.

               (iv)  If the project is an alternative to conventional
               treatment works for a small community (a municipality
               with a population of 3,500 or less  or highly dispersed
               section of a larger municipality, as defined by the
               Regional Administrator), funds from the reserve in
               §35.915(e) may be used for the 75 percent portion of the
               Federal grant.

               (v)  Only if sewer related costs qualify as alternatives
               to conventional treatment works for small communities are
               they entitled to the grant increase from 75 to 85 percent,
               either as part of the entire treatment of works or as
               components.

          (2)  A project or portions of a project  may be designated
          innovative or alternative on the basis of a facilities plan
          or on the basis of plans and specifications.  A project that
          has been designated innovative on the basis of the facilities
          plan may lose that designation if plans  and specifications
          indicate that it does not meet the appropriate criteria stated
          in section 6 of Appendix E.

          (3)  Projects or portions of projects that receive Step 2,
          Step 3, or Step 2+3 grant awards after December 27,  1977,
          from funds allotted or real lotted in fiscal year 1978 may also
          receive the grant increase from funds allotted for fiscal year
          1979 for eligible portions that meet the criteria for alter-
          native technologies in Appendix E, if funds are available for
          such purposes under §35.915-1(b).


                                     B-4
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          (c)   Modification  or replacement of innovative  and  alternative
     projects.

          The  Regional  Administrator may award grant assistance  to  fund
     100 percent of the eligible costs  of the modification or replacement
     of any treatment works  constructed with 85 percent grant assistance  if:

               (1)   He  determines that:

                    (i)  The facilities have not met design performance
                    specifications (unless such failure is due to any
                    person's negligence); and

                    (ii)  Correction of the failure requires  significantly
                    increased capital or operating and maintenance  expenditures;
                    and

                    (iii)  Such failure has occurred within the  two year
                    period following final inspection; and

               (2)   The replacement or modification project is on the fundable
               portion  of the State's priority list.

35.915(a)(1)_.   Part of  the State priority system and project  priority list
that permits raising priority of innovative alternative projects or inno-
vative alternative  100% replacement grants.

          	(iii)  Step 2, Step 3 and Step 2+3 projects utilizing
     processes and  techniques meeting the innovative and  alternative
     guidelines in  Appendix E of this part may receive higher priority.
     Also 100  percent grants for projects that modify or  replace
     malfunctioning treatment works constructed with an 85 percent  grant
     may receive a  higher priority.

          (iv)   Other criteria, consistent with these, may be considered
     (including the special  needs of small and rural communities);  how-
     ever, the State shall not consider the project area's development
     needs not related  to pollution abatement, the geographical  region
     within the State,  or future population growth projections	

35.915(e).  Submission  and review of project priority list.

          The  State shall submit the priority list as part of the annual
     state program  plan under Subpart G of this part.  A  summary of State
     agency response to public comment and hearing testimony  shall  be
     prepared  and submitted with the priority list.  The  Regional Adminis-
     trator will not consider a priority list to be final until  the public
     participation  requirements are met and all information required for
     each project has been received.  The Regional Administrator will review
     the final  priority list within thirty days to ensure compliance with
     the approved State priority system.  No project may  be funded  until
     this review is complete.

                                      B-5
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35.917-1(d)(8)(9).   Energy analysis content of Facilities  plan prepared
after September 30, 1978, for innovative technology.

          (8)  For facilities planning begun after September 30,  1978,
     whether or not prepared under a Step 1 grant, an analysis of inno-
     vative and alternative treatment processes and techniques that
     reclaim and reuse water, productively recycle wastewater constituents,
     eliminate the discharge of pollutants, recover energy or otherwise
     achieve the benefits described in Appendix E	

          (9)  For facilities planning begun after September 30,  1978,
     whether or not prepared under a Step 1 grant, an analysis of the
     primary energy requirements (operational  energy inputs) for  each
     system considered.  The alternative selected shall  propose adoption
     of measures to reduce energy consumption or to increase recovery as
     long as such measures are cost-effective.  Where processes or tech-
     niques are claimed to be innovative technology on the basis  of energy
     reduction criterion contained in paragraph 6e(2) of Appendix E to
     this subpart,  a detailed energy analysis shall  be included  to sub-
     stantiate the claim to the satisfaction of the Regional Administrator.

35.915-1(b).  Reserve funding for innovative alternative technology.

          (b)  Reserve for innovative and alternative technology  project
     grant increase.

          Each State shall set aside from its annual  allotment a  specific
     percentage in order to increase the Federal share of grant awards  from
     75 percent to 85 percent of the eligible cost of construction (under
     §35.908(b)(l)) for construction projects which use innovative or al-
     ternative wastewater treatment processes and techniques.  The set-aside
     amount shall be 2 percent of the State's allotment for each  of the
     fiscal years 1979 and 1980, and 3 percent for fiscal  year 1981.   Of this
     amount not less than one-half of one percent of the State's  allotment
     shall be set aside in order to increase the Federal grant share for
     projects utilizing innovative processes and techniques.  Funds reserved
     under this section may be expended on projects for which facilities
     plans were initiated before fiscal year 1979.  These funds shall  be
     reallotted if not used for this purpose during the allotment period.

35.930-5(b).  Federal  and State funding of Step 2 or 3 grants and Step  2+3
increased (85%) grants.

          (b)  Innovative and alternative technology.

          In accordance with §35.908(b), the amount of any Step 2, Step 3,
     or Step 2+3 grant made from funds allotted for fiscal  years  1979,  1980,
     and  1981 shall be 85 percent of the estimated cost of construction for
     those eligible treatment works or significant portions of them that
     the  Regional Administrator determines meet the criteria for  innovative
     or alternative technology in Appendix E.   These  grants depend on the
     availability of funds from the reserve under § 35.915-1(b).   The

                                     B-6
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     proportional  State contribution to the non-Federal  share  of construction
     costs for 85  percent grants must be the same as or  greater than  the  pro-
     portional State contribution (if any)  to the non-Federal  share of eligible
     construction  costs for all  treatment works which receive  75 percent  grants
     in the State.

          (c)  Modification and replacement of innovative and  alternative
     projects.

          In accordance with §35.908(c) and procedures published by EPA,
     the Regional  Administrator may award grant assistance to  fund 100 percent
     of the eligible costs of the modification or replacement  of any  treatment
     works constructed with grant assistance based upon  a Federal share of 85
     percent under paragraph (b) of this section.

35.935.20.  Post award innovative grant requirements

          If the grantee receives an 85 percent grant for innovative  processes
     and techniques, the following conditions apply during the 5 year period
     following completion of construction:

          (a)  The grantee shall permit EPA personnel and EPA  designated
          contractors to visit and inspect  the treatment works at any
          reasonable time in order to review the operation of  the inno-
          vative processes or techniques.

          (b)  If the Regional Administrator requests, the grantee will
          provide EPA with a brief written  report on the construction,
          operation, and costs of operation of the innovative  processes
          or techniques.

35.936-13.  Application of nonrestrictive specifications to innovative
alternative technology.

          (1)  No specification for bids or statement of work  in connection
     with such work shall be written in such a manner as to contain propri-
     etary, exclusionary, or discriminatory requirements other than those
     based upon performance, unless such requirements are necessary to test
     or demonstrate a specific thing or to  provide for necessary inter-
     changeability of parts and equipment,  or at least two brand names or
     trade names of comparable quality or utility are listed and are  fol-
     lowed by the words "or equal."  The single base bid method of solici-
     tation for equipment and parts for determination of a low, responsive
     bidder may not be utilized.  With regard to materials, if a single
     material is specified, the grantee must be prepared to substantiate
     the basis for the selection of the material.

          (2)  Project specifications shall, to the extent practicable,
     provide for maximum use of structures, machines, products, materials,
     construction  methods, and equipment which are readily available  through
     competitive procurement, or through standard or proven production tech-
     niques, methods, and processes, except to the extent that innovative
     technologies  may be used under §35.908 of this subpart.
                                     B-7
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(b)  Sole source restriction.

     A specification shall not require the use of structures,
materials, equipment, or processes which are known to be available
only from a sole source, unless the grantee's engineer has adequately
justified in writing that the proposed use meets the particular
project's minimum needs.

(c)  Experience clause restriction.

     The general use of experience clauses requiring equipment
manufacturers to have a record of satisfactory operation for a
specified period of time or of bonds or deposits to guarantee
replacement in the event of failure is restricted to special
cases where the grantee's engineer adequately justifies any
such requirement in writing.  Where such justification has been
made, submission of a bond or deposit shall be permitted instead
of a specified experience period.  The period of time for which
the bond or deposit is required should not exceed the experience
period specified.

(d)  Buy American.

     (1)  Definitions.  As used in this subpart, the following
     definitions apply:

          (i)  "Construction material" means any article,
          material, or supply brought to the construction
          site for incorporation in the building or work.

          (ii)  "Component" means any article, material,
          or supply directly incorporated in construction
          material.

          (iii)  "Domestic construction material1^ means an
          unmanufactured construction material which has
          been mined or produced in the United States, or
          a manufactured construction material which has
          been manufactured in the United States if the
          cost of its components which are mined, produced,
          or manufactured in the United States exceeds
          50 percent of the cost of all its components.

          (iv)  "Nondomestic construction material" means
          a construction material other than a domestic
          construction material.

     (2)  Domestic Preference. Domestic construction material
     may be used in preference to nondomestic materials if it
     is priced no more than 6 percent higher than the bid or
                                    B-8
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offered price of the nondomestic materials including
all costs of delivery to the construction site, and
any applicable duty, whether or not assessed.   Compu-
tations will normally be based on costs on the date
of opening of bids or proposals.

(3)  Waiver.  The Regional Administrator may waive
the Buy American provision based upon those factors
that he considers relevant, including:

     (i)  Such use is not in the public interest;

     (ii)  The cost is unreasonable;

     (iii)  The Agency's available resources are not
     sufficient to implement the provision, subject to
     the Deputy Administrator's concurrence;

     (iv)  The articles, materials or supplies of the
     class or kind to be used or the articles, materials,
     or supplies from which they are manufactured are not
     mined, producted, or manufactured in the United
     States in sufficient and reasonably available com-
     mercial quantities or satisfactory quality for the
     particular project; or

     (v)  Application of this provision is contrary to
     multilateral government procurement agreements,
     subject to the Deputy Administrator's concurrence.
                              B-9
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                      WOV 1 5 1373
                                        CONSTRUCTION GRANTS
                                        PROGRAM REQUIREMENTS MEMORANDUM
                                        PRM 79-3
SUBJECT:  Revision of Agency Guidance for Evaluation of Land
          Treatment Alternatives Employing Surface Application
   /An t!>^
JCMottfTng,
FROM:     ThomasJCMottfTng, Assistant Administrator
          Water and Wasp Management  (WH-556)
                      M         I
TO:       Regional Administrators (Regions I thru X)


I.   PURPOSE

     This memorandum consolidates and updates Agency policy and guidance
for evaluation of land treatment alternatives using slow rate,  rapid
infiltration, or overland flow processes in the Construction Grants
Program.  It provides guidance on the extent and nature of material to
be included in facility plans to ensure that these land treatment alter-
natives have been given thorough evaluation.

II.  DISCUSSION

     Evaluation of land treatment in facilities planning has been
mandatory under PL 92-500 (the Act)  since July  1, 1974.   The EPA con-
struction grants regulations as published in the Federal Register
vol. 39, no. 29, February 11, 1974,  provided for coverage of land
application techniques in facility planning [35.917-1 (d)(5)(iii)].
Three land application (land treatment) techniques were included in the
description of alternative techniques for best  practicable treatment
published in October 1975.  Many other technical  information bulletins,
PGM's, and PRM's have been issued as guidance for the  evaluation of land
treatment alternatives in the Construction Grants Program.

     This approach was used to provide the latest information available
to the Regional Offices with a minimum of delay.   While the objective  of
timely distribution of technical information and guidance has been
achieved, this piecemeal  distribution has also  resulted in  some disparities
in the interpretation and implementation of policy.
                                    B-10
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     Distribution of the Process Design Manual  for Lanfl Treatment of
Municipal. Wastewater (EPA 625/1-77-008) consolidates most of the technical
information on surface application approaches into a single reference
source.  This consolidation of technical information provides a sound
basis from which to establish more consistent and effective implementation
of Agency policy on land treatment alternatives using the slow rate,
rapid infiltration, or overland flow processes.

     In the process of coordinating with the Regions on specific projects
involving land treatment, OWPO staff has had the opportunity to review a
number of selected facility plans with respect to their handling of land
treatment alternatives.  In addition to providing information pertinent
to the specific projects being evaluated, this review has been used to
determine what, if any, changes in guidance are needed to achieve more
consistent and complete evaluation of land treatment alternatives.
Areas being considered include technical assistance and staff training
as well as revision of guidance documents.

     The results of this review to date show that land treatment technologies
have had and continue to have inadequate assessment in many instances.
In addition and for substantially more cases, detailed coverage of land
treatment has missed the mark for a variety of reasons.  Three of the
frequently encountered reasons are:  (1) overly conservative and,
consequently, costly design of slow rate (irrigation) systems, (2)
failure to consider rapid infiltration as a proven and implementable
land treatment alternative, and (3) provision for a substantially higher
and more costly level of preapplication treatment than is needed to
protect public health and ensure design performance.

     Such inadequate assessment of land treatment alternatives has led
to rejection of land treatment in cases where it appears that a thorough
assessment would identify less costly alternatives utilizing the recycling
and reclamation advantages of land treatment.  Consistent with the
revised construction grants regulations resulting from enactment of
PL 95-217, award of Step 1 grants and subsequent approval of facility
plans must ensure that the selected alternative is cost-effective and
emphasizes energy conservation and recycling of resources.  This is
important both to meet the statutory requirements of the law and to
provide the maximum pollution control benefits attainable with the funds
allocated to the Construction Grants Program.

     The Administrator's memorandum of October 3, 1977, emphasizes that
the Agency grants program will include thorough consideration of land
treatment as compared to conventional treatment and discharge to surface waters,

     This program requirements memorandum is designed to consolidate the
existing base of guidance into a uniform but still flexible set of
guidelines for slow rate, rapid infiltration, and overland flow systems.
This should improve our capability to effectively and consistently
implement the Agency policy on recycling and reclamation through land
treatment alternatives.

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III. POLICY

     The Administrator's memorandum of October 3,  1977  (Attachment A)
spells out three major points of policy emphasis  on land treatment of
municipal wastewater as follows:

     1.   The Agency will press vigorously for implementation of land
          treatment alternatives to reclaim and recycle municipal
          wastewaters.

     2.   Rejection of land treatment alternatives shall be supported  by
          a complete justification (reason for rejection shall  be well
          documented in the facilities .plan).

     3.   If the Agency deems the level of preapplication treatment to
          be unnecessarily stringent, the costs of achieving the excessive
          level of preapplication treatment will  not be considered as
          eligible for EPA cost sharing when determining the total cost
          of a project.

     These points highlight the Agency's role in implementing the legislative
mandates of PL 92-500 and PL 95-217.  PL 92-500 required EPA to encourage
waste treatment management that recycles nutrients through production  of
agriculture, silviculture, or aquaculture products.  PL 95-217 re-
emphasizes the intent to encourage innovative/alternative systems including
land treatment with many tangible incentives including (1) the "115%"
cost preference, (2) 85% Federal grants with the specific set asides,
(3) the eligibility of land for storage, and (4) 100% grants for modification
or  replacement if project fails to meet design .criteria.  It is imperative
that the Agency moves positively and uniformly to implement land treatment
which is clearly identified as an innovative/alternative technology
which recycles nutrients and conserves energy in conjunction with wastewater
management.

IV.  IMPLEMENTATION

     The guidance detailed in this PRM will apply to all facility
planning grants (Step 1) awarded 30 days after the date of this PRM.  In
addition it should be applied on a case-by-case basis to those unapproved
facility plans for which it appears that further assessment of land
treatment alternatives could result in: (1) the timely and effective
implementation of a reclamation and recycling alternative; and (2)
benefits to the applicant while making better use of EPA construction
grant funds.

     A.   Action Required

     Facility  plans in which land treatment alternatives are eliminated
with only cursory coverage will be rejected as not fulfilling Agency
requirements.  A facility plan  should  not be approved until the coverage
of  these land  treatment  alternatives satisfies the guidance detailed

                                    B-12
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 below.   As a minimum,  the coverage of these  land  treatment  processes
 will  include assessment of at least one slow rate (irrigation)  alternative
 and one rapid infiltration alternative.   Coverage of  an  overland  flow
 alternative will  be optional  (case-by-case)  until  additional  information
 which is presently being developed furnishes design information for
 routine construction grant implementation.   The technical design  basis
 of these land treatment alternatives  will  be in accordance  with the "EPA
 Design  Manual on  Land  Treatment"  (EPA 625/1-77-008),  and "Costs of
 Wastewater Treatment by Land  Application"  (EPA 430/9-75-003).   To be
 adequate,  coverage of  these land  treatment alternatives  shall include
 enough  detail to  support development  of costs, except in those  cases
 where thorough screening for  available sites shows no suitable  sites
 within  economic transport distances.   Designs for slow rate systems and
 rapid infiltration systems will include  preapplication treatment which
 is in accord with  the  discussion  of preapplication in the Design Manual
 (pages  5-26 thru  5-30)  and summarized in Attachment B.

      A  universal  requirement  to reduce biochemical oxygen demand and
 suspended  solids  to  30  mg/1 and to  disinfect to an average  fecal coliform
 count of 200/100 ml  will  be considered as  excessively stringent preappli-
 cation  treatment  if  specified  for all  land treatment  alternatives.
 States  shall  be requested to  reconsider use  of such universal and
 stringent  preapplication  treatment  requirements when  it  is  established
 that  a  lesser level  of  preapplication  treatment will  protect the public
 health,  protect the  quality of surface waters and groundwater,  and will
 ensure  achievement of design  performance for the wastewater management
 system.

      States  should be encouraged  to adopt standards which avoid the use
 of uniform  treatment requirements for  land treatment  systems, including
 a  minimum of  secondary  treatment  prior to application to the land.  The
 EPA guidance  on land treatment systems specifies ranges of values  and
 flexible criteria .for evaluating  factors such as preapplication treatment,
 wastewater application  rates and  buffer zones.  For example, simple
 screening or  comminution  may be appropriate for overland flow systems  in
 isolated areas  with no  public access, while extensive  biochemical  oxygen
 demand and suspended solids control with disinfection  may be called for
 in the case of  slow rate  systems  in public access  areas such as  parks  or
 golf  courses.

      B.   Specific Guidance

     The scope  of work   for preparation of a facility plan will  provide
 for thorough evaluation of land treatment alternatives.  This  evaluation
of land treatment alternatives may be accomplished in  a two-phase  approach.
Such a two-phase approach would provide flexibility for establishing
general  site suitability and cost  competitiveness  before  requiring
extensive on-site investigations.   The first  phase of  the two-phase
approach would include  adequate detail to establish whether  or not sites
are available, wastewater quality  is suitable, and land treatment  is
                                    B-13
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cost competitive.   The second phase would include in-depth  investigation
of sites and the refinement of system design factors  to  complete  all  of
the requirements for preparing a facility plan.   Approval of a  facility
plan will ensure that the following details  for  evaluation  of land
treatment are clearly delineated in the plan.

     1.    Site Selection.   A regional  map shall  be included to show  the
     tracts of land evaluated as probable land treatment sites.   The
     narrative discussion of site evaluation should detail  the  reasons
     for rejection of tracts as well  as the  availability of tracts  used
     in  the preliminary design for land treatment alternatives.
     Table 2-2 of  the Design Manual  (Attachment  C) delineates general
     site characteristics for land treatment alternatives which the
     narrative should cover in detail.

          Categorical  elimination of land treatment for  lack of a
     suitable site (during phase one of a two-phase evaluation) should
     be  documented with support materials showing how the applicant made
     the determination.   For example,  elimination for lack  of suitable
     soils should  be documented with soils information from the area
     Soil Conservation Service representatives or other  soil  scientists
     who may be available.   Any categorical  elimination  of  land treatment
     should demonstrate that additional  engineering necessary to  overcome
     site constraints  would make the .alternative  too  costly to  fund in
     accordance with the cost-effectiveness  requirements of the Taw.

     2.    Loading  Rates and Land Area.    The values for  these parameters
     evaluated in  the  facility plan  should concur with the  technically
     established ranges for application rates and land area needed  for
     a system.   The cost of land treatment is sensitive  to  these  factors
     and overly conservative design  unduly inflates the  cost of technically
     sound alternatives.   Designs in  a  facility  plan  should fall  within
     the general ranges given in Table  2-1 and Figure  3-3 of the  Design
     Manual.   Designs  falling outside  of these ranges  should  do so  only
     because of extenuating circumstances peculiar to  the site.   These
     extenuating circumstances should  be discussed in  detail.   Table  2-1
     (Attachment B)  is recommended as a  quick reference  for determining
     that designs  are  reasonable.

     3.    Estimated  Costs.   The estimated costs of land  treatment
     alternatives  should  be comparable  to those obtained by using
     EPA 430/9-75-003  pages 59-127,  updated  using  local  construction
     cost indices.   Cost  estimates generated by using  this  source are
     being compared  to actual  costs  for  recently  constructed  facilities.
     If  this  comparison shows that the  curves in  EPA 430/9-75-003 need
     adjustment, corrected  curves  will  be made available as  necessary.

          Elimination  of  land treatment  in the cost-effective analysis
     because  of land costs  or transport  costs should be  documented  by
     means of an actual  evaluation for  the cost of land  or  cost of
                                    B-14
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 transport. This evaluation should show clearly that the cost of
 land  or  the cost of  transport does rule out land treatment using
 the approach  shown in "Cost-Effective Comparison of Land Application
 and Advanced  Wastewater Treatment"  (EPA 430/9-75-016).  Examples
 on pages 23-24 (Attachment D) of that source show how to make these
 comparisons.

 4.    Preapplication  Treatment.  The level of preapplication treatment
 prior to storage or  actual application to the land should be in
 accordance with the  guidance given for screening wastewaters to be
 applied  to the land  in the Design Manual.  A universal minimum of
 secondary treatment  for direct surface discharge as published in
 the August 17, 1973  Federal Register and later modified (Federal
 Register July 26, 1976 and October 7, 1977) will not be accepted
 because  it is inconsistent with the basic concepts of land treatment.
 Imposition of a defined discharge criteria at an intermediate point
 in a  treatment train is, in most instances, an unnecessarily
 stringent preapplication treatment requirement as stated in the
 Administrator's memorandum dated October 3, 1977.  Criteria imposed
 at an  intermediate point should be for the purpose of ensuring
 overall system performance in the same context that primary sedi-
 mentation precedes biological secondary treatment by trickling
 filter or activated  sludge processes.

     Assessment of the level  of preapplication treatment proposed
 should be in accord with the discussion in Section 5.2 (pages 5-26
 to 5-30) of the Design Manual.  Guidelines for evaluating the level
 of preapplication for slow-rate, rapid infiltration, and overland
 flow systems in relation to existing state regulations,  criteria
 and guidelines are included in Attachment E.   Preapplication
 treatment criteria more restrictive than the  ranges of treatment
 levels described in Appendix E will  be considered unnecessarily
 stringent unless justified on a case-by-case  basis.   When the more
 stringent preapplication treatment criteria cannot be justified,
 the EPA will consider that portion of the project to meet EPA
 guidance as eligible for Agency funding.   The costs 'Of the additional
 preapplication increment needed to meet more  stringent preapplication
 treatment requirements imposed at the  state or local  level  would be
 ineligible for Agency funding and thus would  be paid for from state
 or local funds.

 5.   Environmental  Effects.  Assessing the environmental  effects of
 land treatment alternatives involves  a somewhat different concept
 than for conventional treatment and  discharge to surface waters.
The assessment for land treatment should include emphasis  on  the
quality and quantity of both  surface  and groundwater resources;  on
energy conservation as well as energy  demands;  on pollutant (resource)
recycling as well  as  chemical  needs,  and  on land use in  the overall
coverage of environmental  effects.
                                    B-15
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          The assessment should determine that the proposed land treatment
     system  is  in accord with Agency policy on groundwater protection.
     The Agency policy for groundwater resulting from land treatment
     systems is set forth in the criteria for Best Practicable Waste
     Treatment Technology (BPWTT).  These criteria specify that the
     groundwater resulting from a land treatment system must meet different
     requirements depending on current use and quality of the existing
     groundwater.  The basic thrust of these criteria is to protect
     groundwater for drinking water purposes by specifying adherence to
     the appropriate National Primary Drinking Water Standards.  The
     BPWTT criteria further require land treament systems which are
     underdrained or otherwise designed to have a surface discharge to
     meet the standards applicable to any treatment and discharge
     alternative.  The criteria are fully described in 41 FR 6190
     (February 11, 1976) which is attached as Appendix F.

          An overall Agency policy statement on groundwater protection
     is scheduled for issuance in the near future.   The draft Agency
     groundwater policy is generally consistent with present criteria
     for land treatment systems.   However, any revisions to the present
     guidance on site evaluation  and system monitoring as a result of
     this statement will have to  be accounted for as they are developed.
     In the meantime, existing guidance should be used to evaluate
     groundwater influences.
Attachments
                                    B-16
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V.   REFERENCES

     Process Design Manual for Land Treatment of Municipal Wastewater
     EPA 625/1-77-008 October, 1977.

     October 3, 1977 memorandum from Administrator:"EPA Policy on
     Land Treatment of Municipal  Wastewater".

     "Cost of Wastewater Treatment by Land Application" Technical Report
     EPA-430/9-75-003 June, 1975.

     "Cost-Effective Comparison of Land Application and Advanced
     Wastewater Treatment" Technical Report EPA-430/9-75-016,
     November, 1975.

     Secondary Treatment Information Federal  Register 38(129),
     August 17,, 1973, pgs 22298-22299.

     Secondary Treatment Information Federal  Register 41(1440,
     July 26, 1976, pp.  30786-30789.

     Suspended Solids Limitations Federal  Register  42(195),
     October 7, 1977, pp.  54664-54666.

     Water Quality Criteria 1972   EPA-R3-73-033,  March 1973, pp.  323-366.

     Quality Criteria for  Water,  USEPA,  July,  1976.

     Alternative Waste Management Techniques  for  Best  Practicable
     Waste Treatment  EPA  430/9-75-013,  October,  1975.

     Final  Construction  Grants  Regulations  Federal Register 39,  No. 29
     February 11,  1974.
VI.  ATTACHMENTS

     Attachment A   Administrator's  Oct.  3,  1977  memo  "EPA  Policy  on
                    Land Treatment of Municipal Wastewater"
     Attachment B   Table 2-1 from Design Manual
     Attachment .C   Table 2-2 from Design Manual
     Attachment D   Pages 23-24 from EPA  430/9-75-016
     Attachment E   Guidance for assessing level  of preapplication
     Attachment F   Alternative Waste Management  Techniques  (BPWTT)
                                    B-17
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                                                            ATTACHMENT A

          UN! 1 ED STATES ENVIRONMENTAL PROTECTION AGENCY

                           WASHINGTON. D C.  JO-l'iO
                                 OCT   3 1977
                                                                 THE ADMINISTRATOR
SUBJECT:


FROM:

TO:
EPA Policy on Lan
Wastewater
The Administr
r   I       /)   ^
earjnent of/lyrmtfpal
Assistant Administrates and
Regional Administrators  (Regions [-X]
     President Carter's recent Environmental  Message to the Congress
emohasized the design and construction of cost-effective publicly owned
wastewater treatment facilities that encourage water conservation as
well as adequately treat wastewater.  This serves to strengthen the
encouragement under the Federal Water Pollution Control Act Amendments
of 1972 (P.L. 92-500} to consider wastewater  reclamation and recycling by
land treatment processes.

     At the time P.L. 92-500 was enacted, it  was the intent of Congress
to encourage to the extent possible the development of wastewater manage-
ment policies that are consistent with the fundamental  ecological principle
that all materials should be returned to'the  cycles from which they were
generated.  Particular attention should be given to wastewater treatment
processes which renovate and reuse wastewatsr as well  as recycle the
organic matter'and nutrients in a beneficial  manner.   Therefore, the
Agency will press vigorously for publicly owned treatment works to
utilize land treatment processes to reclaim and recycle municipal wastewater,

RATIONALE

     Land treatment systems involve the use of plants  and the soil  to
remove previously unwanted contaminants from  wastewaters.  Land treatment
is capable of achieving removal levels comparable to the best available
advanced wastewater treatment technologies while achieving additional
benefits.  The recovery and beneficial reuse  of wastewater and its
nutrient resources through crop production, as well  as  wastewater
treatment and reclamation, allow land treatment systems to accomplish
far more than most conventional treatment and discharge alternatives.
                                   B-18
-------
     The application of wastewater on land is d  practice that  has  been
used for many decades; however, recycling and reclaiming wastewater  that
may involve the planned recovery of nutrient resources  as part of  a
designed wastewater treatment facility is a relatively  new technique.
One of the first such projects was the large scale Muskegon, Michigan,
land treatment demonstration project funded under tne Federal  Water
Pollution Control  Act Amendments of 1966 (P.L.  84-560), whicn  began
operations in May 1974.

     Reliaole wastewater treatment processes that utilize land treatment
concepts to recycle resources through agriculture, silviculture and
aquaculture practices are available.  The technology for planning,
designing, constructing and operating land treatment facilities is
adequate to meet both 1983 and 1985 requirements and goals of  P.L. 92-
500.

     Land treatment is also presently in extensive use  for treatment of
•nany industrial wastewaters, particularly those  .vi th easily degraded
•irqanics such as food processing.  Adoption of suitable in-plant pretreatnent
for the rsnoval of excessive metals and toxic substances would expand
f>e potential for land treatment of industrial  wastewater and  further
enhance the potential for utilization of municipal wastswater  and  sludges
fqr agricultural purposes.

APPROACH

     Because land treatment processes contribute to the reclamation  and
recycling requirements of P.L. 92-500, they should be preferentially-j
considered as an alternative wastewater management technology.  Sucn
consideration is particularly critical for smaller ccmmunities.  While
it is recognized that acceptance, is not universal, the  utilization ofj
land treatment systems has the potential  for saving billions of dollars.
This will benefit not only the nationwide water  pollution control  program,
but will also provide an additional mechanism for the recovery and  ^
recycling of wastewater as a resource.

     EPA currently requires each applicant for construction grant  funds
to make a conscientious analysis of wastewater management alternatives
with the burden upon the applicant to examine all  available alternative
technologies.  Therefore, if a method that encourages water conservation,
wastewater reclamation and reuse is not recommended,  the applicant should
be required to provide complete justification for tne rejection of
land treatment.

     Imposition of stringent wastewater treatment requirements prior to
land application nas quite often nullified the cost-effectiveness  of
land treatment processes in the past.   We must ensure that appropriate
Federal, State and local requirements and regulations are imposed  at the
                                   B-19
-------
 proper point in the  treatment  system  .imj  are  not  'ised  in a manner  that
 may arbitrarily block  land  treatment  projects   VJhi-never States  insist
 upor placing unnecessari1y  strinnent  preapplicat~on  treatment require-
 ments  upon  land treatment,  such  as  requiring  EPA  secondary effluent
 quality in  all  cases  prTpr  to  application on  the  land,  tne unnecessary
 wastewater  treatment  faci1ities  wi11  not  be  funded by  EPA.  This should
 encourage  the  States  to  re-examine -and  revise  their  criteria, and  so
 reduce the  cost burden,  especially  to small  communities, for construction
 and operation  of unnecessary or  too costly facilities.  The reduction of
 potentially  toxic metals  and organics in  industrial  discharges to  municipal
 systems  often  is critical  to the success  of  land  treatment.  The develooment
 and enforcement at  the local level of pretreatment standards that  are
 consistent with nati'onal  pretreatment standards should  be required as an
 integral part  of any consideration or final  selection  of land treatment
 alternatives.   In addition, land treatment alternatives must be  fully
 coordinated  with on-going areawide planning under section 208 of the
 Act.   Section  208 agencies  should be  involved  in  the review and development
 of  land  treatment options.

     Research will be continued  to further improve criteria for preappli-
 cation  treatment and other aspects of land treatment processes.   This
 will add to  our knowledge and  reduce uncertainties .about health and
 environmental  factors.   I am confident,  however, that  land treatment of
 municipal wastewaters can be accomplished without adverse effects on
 human  health if  proper consideration is  given  to design and management
 of  the system.

 INTER-OFFICE COORDINATION

     The implementation of more recent mandates from the Safe Drinking
 Water Act (P.L.  93-532),  the Toxic Substances Control Act (P.L.  94-469),
 and  the Resource Conservation and Recovery Act of 1976 (P.L.  94-580)
 must1be closely  coordinated with the earlier  mandate  to recycle wastes
 and  fully evaluate land treatment in P.L.  92-500.   Agencywide coordination
 is  especially important to the  proper management of section 201  of  P.L.
 92-500, because  the construction and operation of thousands of  POTW's
 involve such a broad spectrum of environmental  issues.   A concerted
 ef-fort must be made to avoid unilateral  actions,  or even the  appearance
 of unilateral actions,  which satisfy a particular  mandate of  one  Act
 while inadvertently conflicting with a major  Agency policy  based  upon
 another Act.   The intention  of  P.L.  92-500, as  it  concerns  land  treatment,
 is compatible with the  pertinent aspects of more  recent environmental
 legislation.

 ACTION REQUIRED

     Each of you must  exert  maximum  effort to  ensure  that  the actions  of
your staffs  reflect  clearly  visible  encouragement  of  wastewater  reclamation
 and recycling of pollutants  through  land treatment processes  in  order to
move toward  the national  goals  of conserving  water and  eliminating  the
discharge of pollutants  in navigable waters by  1985.


                                    B-20
-------
     This policy will  apply to  all  future municipal construction grant
activities,  as well  as all  current  grant applications  in  the Step 1
category that have not been approved  as of  this date.  Detailed information
and guidance for implementation of  this policy  is under preparation and will
be issued in the near  future.
                                   B-21
-------
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B-22
-------
                                                           TABLE 2-2

                         COMPARISON OF SITE CHARACTERISTICS  FOR LAND  TREATMENT  PROCESSES
CO
I
                                                     Principal
                                                                Other processes
            Characteristics
Slow rate
Hap id  infiltration
                                                                             Overland flow  Wetlands
                                                                          Subsurface
            Slope
Less  than 20t un culti-
vated land,.less than
401 on nuiicul I i vated
land
(lot critical; excessive  Finish slopes  Usually less  Hot critical
slopes  renuiie much     2 to UX       than 51
earthwoi k
Soil pcnneabll 1 ty




Depth to
ground. /a ter


Cluiuttc
restrictions


Moderately slow to
moderately rapid



2 to 3 ft (minimum)



Storage often needed
for cold weather and
prec ipl tat ion

Rapid (sands, loau^y
Sands)



10 ft (lesser depths
me acceptable where
underdi ainaye is
provided)
(lone (possibly modify
operation In cold
Weather)

Slow (clays ,
silts, aiid
sol Is with
iiupei unable
bai i lei s)
Not critical



Sturaije often
ni-uded for
cold weather

Slow to
moderate



Not critical



Storage may
be needed
for cold
weather
Slow to rapid




Not critical



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            1 ft " 0.305 m
                                                                                                   o

                                                                                                   fn
                                                                                                                                  o
-------
Example No. 2
                                                     ATTACHMENT D
Requirements.  An existing 20-mgd activated sludge plant is
required to upgrade its effluent quality to meet the following
criteria:
                        BCD -  10 mg/1
                        SS  -  10 mg/1
                        N   -   3 mg/1
                        P   - 0.5 mg/1

Alternatives.  It is evident from a review of Table 2 that
the only methods of treatment capable of providing the neces-
sary degree of treatment are AWT-4 and irrigation.  In this
example, the cost of AWT-4 is compared with that of irrigation
under varying conditions of conveyance distance  (Case A) and
land costs  (Case B).  Sines secondary treatment is existing,
activated sludge or aerated lagoon will not be necessary.
Case A  -  Consider a moderately favorable site for
           irrigation, a distance of S miles away from
           the existing treatment plant site.  How
           much can be paid for land and have the
           irrigation system competitive with the
           AWT-4 system?
             Table 12.  COST COMPARISON FOR CASE A
Troaeatanc •
.retnod Cast component
AhT-4 AWT-'l
Existing activated
sludqe adjustment
Total
Irrigation Irrigation system
Aerated lagoon
adjustment
Land cost
Subtota I
Amount available
Jor land - i28. 0-13.0)
Total icei, .ictus
AllowubL'i Tost/ion.'
20 .Tiqd USC/l.OOO aaL.IUO-1)
Cose
•5/1,000 gal. Source
44.

-(16.
2B.
H.

-(•>.
-(C.
U.

15.
*,300

4 son
0

01
0
0

J)
22.
0

0



Figure 1

Figure 1

Figure 1

Figure 1
Table 7



Table 7


                                B-24
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Conclusions.   Under  the assumed  site  conditions  for the

irrigation system, as  much as $4,500  per acre could be paid

for  land and have  the  irrigation  system competitive with

AWT-4.
Case  B   -  Consider  a  moderately  favorable irrigation site
            at a cost of $2,000 per  acre.  How  far  away from
            the existing treatment plant could  the  site be
            and have  the irrigation  system competitive with
            AWT-4?
              Table  13.   COST COMPARISON FOR CASE  B
Treatment
 nethoc
                    Cost component
  Cost
C/1,OOC gal.  Source
      AWT-4-       From Case A                28.C      Figure 1

      Irrigation   Irrigation system            24.0      Figure 1
                 Aerated lagoon adjustment    -(4.3)     Figure 1
                 Conveyance cost            -(1.7)     Table 7

                  Subtotal                 18.0

                 Anount available for
                 conveyance =  (28.C - 18.0)     10.0

                 Allowable distance, miles     33        Table 4
Conclusions.   Under the  assumed site  conditions for  the

irrigation  system, wastewater could be  conveyed as far  as

33 miles  and  have irrigation be competitive with AWT-4.

Special conditions such  as  river or highway crossings and
easements may add substantial costs and reduce this  distanc
somewhat.
                                B-25
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                                                       ATTACHMENT E


       Guidance for Assessing Level of Preapplication Treatment


I.   Slow-rate Systems (reference sources include Water Quality Criteria
     1972, EPA-R3-73-003, Water Quality Criteria EPA 1976, and various
     state guidelines).

     A.   Primary treatment - acceptable for isolated locations with
          restricted public access and when limited to crops not for
          direct human consumption.

     B.   Biological treatment by lagoons or inplant processes plus
          control of fecal coliform count to less than 1,000 MPN/100 ml
          acceptable for controlled agricultural irrigation except for
          human food crops to be eaten raw.

     C.   Biological treatment by lagoons or inplant processes with
          additional BOD or SS control as needed for aesthetics plus
          disinfection to log mean of 200/100 ml (EPA fecal coliform
          criteria for bathing waters) - acceptable for application in
          public access areas such as parks  and  golf courses.

II.   Rapid-infiltration Systems

     A.   Primary treatment - acceptable for isolated locations with
          restricted public access.

     B.   Biological treatment by lagoons or inplant processes - acceptable
          for urban locations with controlled public access.

III.  Overland-flow Systems

     A.   Screening or comminution -  acceptable  for isolated  sites  with
          no  public access.

     B.   Screening or comminution plus  aeration to control odors during
          storage or application - acceptable for urban  locations with
          no  public access.
                                   B-26
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    ENVIRONMENTAL  PROTECTION
                 AGENCY
                     482-oj

  ALTERNATIVE    WASTE   MANAGEMENT
    TECHNIQUES  FOR 3EST PRACTICABLE
    WASTE  TREATMENT
                Supplement
    Pursuant  to Section 304(cl) (2)  of the
  Federal  Water  Pollution  Control  Act
  Amendments of 1972  (Pub. L. 92-500) ,
  the Environmental Protection  Agency
  (EPA), gave notice on October 23,  1975
  (40 PR 49598)  that  Alternative  Waste
  Management Techniques for Best Prac-
  ticable Waste Treatment has been pub-
  lished in  final form.  The  final  report
  contains the criteria for best practicable
  waste  treatment technology and  infor-
  mation on alternative waste  manage-
  ment techniques.
   The criteria for Best Practicable Waste
  Treatment for Alternatives employing
 land  application techniques  and  land
 utilization practices required  that  the
 ground water resulting from land appli-
 cation of wastewater meet the standards
 for chemical quality  [inorganic chemi-
 cals] and pesticides [organic chemicals}
 specified in the EPA Manual for Evalu-
 ating Public Drinking Water Supplies in
 the case of  groundwater  which  poten-
 tially can  be used  for  drinking water
 supply. In  addition  to the standards  for
 chemical   quality  and  pesticides,  the
 bacteriological  standards [microbiologi-
 cal  contaminants] specified  in  the EPA
 Manual for Evaluating Drinking Water
 Supplies were  required in  the case of
 srroundwater which is presently  being
 used as a drinking water  supply. The
 pertinent section  of  the EPA Manual for
 Evaluating Public Drinking  Water Sup-
 plies was included as Appendix  D of the
 Alternative Waste  Management  Tech-
 niques  for Best Practicable Waste Treat-
 ment report.
   Also  specified in the Criteria  for Best
 Practicable  Waste  Treatment  is  that
 "any chemical, pesticides, or bacterio-
 logical standards for drinking water sup-
 ply sources hereafter issued by EPA shall
 automatically apply in lieu of the stand-
 ards in the EPA Manual for Evaluating
 Public  Drinking  Water Supplies.  The
 National  Interim   Primary  Drinking
 Water  Regulations  were published  in
 final form  on December 24, 1975.
   In consideration  of  the   foregoing,
 Chapter II and Appendix D  of Alterna-
 tive Waste Management Techniques for
 Best Practicable Waste Treatment shall
 read as follows.
   Dated: February 4, 1976.

                RUSSELL E.  TRAIN,
                       Administrator.
              CHAPTER II
   CRITERIA FOR BEST PRACTICABLE WASTE
              TREATMENT
  Applicants for  construction prant  funds
authorized by Section  201 of  the Act must
have evaluated alternative waste treatment
 management techniques and selected  the
technique which will provide for the appli-
  cation  of beat prncUciiblc wnslo  treatment
  technology. Alternatives must bo considered
  lu three brond broiul categories:  treatment
  find discharges into  imvlgnblo waters, Innd
  application mid  utilization practices,  and
  rouso of treated wastev/ater. An alternative
  Is  "best  practicable"  If  it Is determined
  to bo cost-oflectlvo In accordance with the
  procedures  set forth in  40  CFB Part 35
  (Appendix B  to this document)  and if  it
  will meet the criteria set forth below.
    (A)   Alternatives  Employing  Treatment
  and Discharge into Navigable Waters. Pub-
  licly-owned  treatment   works  employing
  treatment and discharge into navigable wa-
  ters shall, as a minimum, achieve the degree
  of  treatment  attainable by the application
  of secondary treatment as defined in 40 CFB
  133  (Appendix C). Requirements  for addi-
  tional treatment, or  alternate  management
  techniques,  will depend on several  factors,
  including availability of cost-effective tech-
  nology,  cost and the specific characteristics
  of the affected receiving water body.
   (B) Alternatives Employing  Land Appli-
  cation"  Techniques and  Land  Utilization
  Practices.  Publicly-owned  treatment works
  employing land application techniques and
  land utilization practices  which result In  a
  discharge to navigable waters shall meet the
  criteria  for treatment and discharge under
  Paragraph (A)  above.
   The ground water resulting from the land
  application of  wastewater, Including  the af-
  fected native ground water, shall meet the
  following criteria:
   Case 1: The  ground water can potentially
 be used  for drinking water supply.
   (1) The maximum  contaminant levels for
 inorganic chemicals and organic chemicals
 specified in  the  National Interim Primary
 Drinking Water Regulations  (40 CFB  141)
  (Appendix D) for drinking water supply sys-
 tems should not be exceeded except as Indi-
 cated below (see Note 1).
   (2) If  the existing concentration of a
 parameter exceeds  the maximum contami-
 nant levels for Inorganic chemicals or organic
 chemicals, there should not be an Increase
 in the concentration of that parameter due
 to land application of  wastewater.
  Case II: The ground water is used for
 drinking water supply.
  (1) The criteria for Case I should be met.
  (2) The maximum microbiological con-
 taminant levels for drinking water  supply
 systems  specified in the National Interim
 Primary  Drinking  Water  Regulations  (40
 CFR 141) (Appendix D) should not  be ex-
 ceeded In cases where the ground water la
 used without disinfection (see Note 1):
  Case III: Uses other than drinking water
 supply.
  (1) Ground water criteria should be  estab-
 lished by the Regional Administrator based
 on the present or potential use of the ground
 water.
  The Regional Administrator In conjunction
 with the appropriate State officials  and the
 grantee  shall  determine on a  slte-by-gite
 basis the nreas in the vicinity of a specific
 land application site where the criteria  In
 Case I, It,  and III  shall apply.  Specifically
 determined shall be the monitoring require-
 ments appropriate for  the project site. This
 determination shall be  made with the objec-
 tive of protecting the  ground water for use
 ns a  drinking  water  supply and/or  other
designated uses as appropriate and prevent-
 ing  irrevocable damage to ground water. Re-
quirements shall include provisions for mon-
itoring the effect on the native ground water.
  (C) Alternatives  Employing Reuse. The
total quantity of any pollutant in the effluent
from a reuse project which 13 directly at-
tributable to the effluent from a publicly-
                                                   B-27
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 owned treatment works shall not exceed that
 which would have been allowed under Par-
 ixpruplis (A)  and (B)  above.
   NOTE 1.—Any amendments of the National
 Interim Primary Drinking Water Regulations
 and any National Revised  Primary Drinking
 Water l(ep;iiliitlons hereafter Irutucd by EPA
 prescribing standards for  public  water sys-
 tem relating to Inorganic chemicals, organic
 chemicals  or microbiological contamination
 shall automatically apply In tho same man-
 ner as the National Interim Primary Drink-
 ing Water Regulations.
                APPENDIX D
        GROUND WATER REQUIREMENTS
   The  following   maximum  contaminant
 levels contained In the National Interim Pri-
 mary Drinking Water Regulations (40 CFR
 141) are reprinted for convenience and clar-
 ity. The National  Interim Primary Drinking
 Water Regulations were published  in final
 form In the  FEDERAL REGISTER on  Decem-
 ber 24,  1975. In accordance with the criteria
 for best practicable waste treatment, 40 CFR
 141 should he consulted in Its entirety when
 applying the standards contained  therein to
 wastewater  treatment systems   employing
 land appplication techniques  and land uti-
 lization practices.
   maximum  contaminant  levels  for  inoi-
 ganic chemicals. The  following are the max-
 imum levels  of Inorganic  chemicals  other
 than fluoride:
                                   Level
                               (milligrams
 Contaminant:                    per liter)
    Arsenic 	   0.05
    Barium	   1.
    Cadmium	    0. 010
    Chromium	   0.05
    Lead	-	   0.05
    Mercury  	    0.002
    Nitrate (as N)	-	   10.
    Selenium	    0. 01
    Silver _	-	    0.05
  The maximum   contaminant  levels .for
fluoride are:
   Temperature
     decrees
   Fahrenheit *
Degrees Celsius
  Level
(milligram*
- per liter)

53 8 to W 3
58.41063.8 	
63.0 to 70.0 	
70 7 to 79 2



121 to 14.0. 	 -.
14.7 to 17.6 	
17.7 to 21.4 	
21.5 to 26.2. 	
28.3 to 32.5 	

2.4
2.2
2.0
1.8
1.6
1.4

  i Annual average of tho maximum dally air tem-
perature.
  Maximum contaminant levels for organic
chemicals. The following are the maximum
contaminant levels for organic chemicals:
                                  Level
                               (•milligram
(a) Chlorinated hydrocarbons:   per liter)
    Endrin  (1,2,3,4,10,10-Hexachloro-
      6,7 - epoxy - l,4,4a,5,6,7,8,8a-oc-
      tahydro-l,4-endo,endo -  6,8-dl-
      methano naphthalene)	0.0002
    Llndane (1,2,3,4,5,8 - Hexachloro-
      cycloh'exane, gamma Isomer)— 0.004
    Methoxychlor  (l,l,l-Trlchloro-2,
      2-bis  [p-methoxyphenyl] eth-
      ane)  		— 0.1
    Toxaphene (OlnH10Cl, - Technical
      chlorinated camphene, 67 to 89
      percent  chlorine)	0.005
(b) Chlorophenoxys:
    2,4-D (2,4-Dlchlorophenoxyacetic
      acid)  		-	— 0.1
    2,4,5-TP Silvex (2,4,5-Trlchloro-
      phenoxyproplonlc acid)	0. 01
  Maximum  microbiological   contaminant
levels. The maximum contaminant levels' for '
coliform bacteria,  applicable to community
water systems  and  non-community water
systems, are as follows:
  (a) When the membrane filter technique
pursuant to § 141.21 (a)  Is used, the number
of coliform bacteria  shall not exceed  any of
the following:
  (1) One per 100 mllllllters as the arith-
metic mean of all  samples  examined  per
month pursuant to § 141.21 (b) or (c);
  (2) Four  per 100 mllllllters In more than
one sample  when less than 20 are examined
per month; or
  (3) Four per 100 mllltllters In more than
five percent of the samples when 20 or more
are examined per month.


  (b)   (1)  When  the  fermentation tube
method and 10  mlllllltbr standard portions
pursuant to § 141.21 (a) are used,  colllorm
bacteria shall not be present in any of  tho
following:
  (1) More than 10 percent of tho portions In
any  month  pursuant to § 141.21 (b) or (c);
  (11) Three- or more portions In more than
one  sample when less  than 20 samples  are
examined per month; or
  (lit) Three or more portions in more than
five percent of the samples when 20 or more
samples are examined per month.
  (2) When the fermentation tube method
and  100 mllllliter standard portions pursuant
to  § 141.21 (a)  are used, coliform  bacteria
shall not be present  In'any of the following:


   (1) Moro than GO percent of the portions
 in  any month pursuant to § 141.21 (b) or
 (o);
  (11) Five portions In more than one sample
when less than flve samples  are examined
per  month; or
   (111) Five portions In  moro than 20 percent
 of the  samples when flve  or  more samples
are examined per month.
   (c)  For  community or non-community
systems that are required to sample at a  rate
of less  than 4 per month, compliance with
Paragraphs (a), (b)  (1), or (2) shall be based
upon, sampling during a 3 month period, ex-
cept that,  at the discretion of the  State,
compliance may  be based  upon  sampling
during  a one-month period.

   [PR Doc.76-3932 Filed 2-10-76;8:45 am]
                                                     B-28
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                                                           OFFICE OF WA I ER AND
                                                           HAZARDOUS MATERIALS
                                              PROGRAM REQUIREMENTS MEMORANDUM
                                              PRM#  79-8

 SUBJECT:  Small Wastewater Systems

 FROM:     John T. Rhett, Deputy Assistant Administrator
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limited conveyance systems serving clusters of households and small
commercial establishments and pressure and vacuum sewers.  These
alternative  sewers are specifically exempted from the collection sewer-
interceptor  designations when planned for small communities and are not
subject to the collection system policy.  These systems also include
other treatment works which employ alternative technologies listed in
Appendix E,  40'CFR 35, and serve communities of 3,500 population or- less
or the sparsely populated areas of larger communities.

     A conventional system is a collection and treatment system consisting of
minimum-size  (6 or 3 inches) or larger gravity collector sewers, normally with
manholes, force mains, pumping and lift stations and interceptors leading to
a central treatment plant employing conventional concepts of treatment as
defined in Section 5, Appendix E, 40 CFR 35.

     Small alternative wastewater systems may be publicly or privately owned.
Privately owned systems (called "individual systems" in the Act and 40 CFR 35)
may serve only one or more principal residences or small commercial establish-
ments.  Publicly owned systems may serve one or more users.  Perpetual or
1ife-of-project easements or other binding convenant running with the land
affording complete access to and control of wastewater treatment works on
private property are tantamount to ownership of such works.

     High wastewater user costs exceeding $200, $300, and even $500 annually
for households in some communities under 10,000 in population have resulted
from debt retirement costs for new collection systems or from high operation
and maintenance costs of new sophisticated plants.  Extremely high cost
projects have culminated in political  upheaval, refusal  to connect into or
to pay after connecting into central sewers, violence at public meetings,
requests for injunctions, and filing suits against several  parties, including
EPA.   In most cases,  all  of the feasible alternatives were not considered in
the cost-effectiveness analysis and some systems were overdesigned by using
inflated population projections and excessive water usage data.  In the past,
it has been difficult during facility plan review to pinpoint those projects
that have severe financial  impacts.

     Previous policy  and facility planning guidance have called for verification
by the grantee that that community is  able to raise the  local  share.   PRM 76-3
requires the estimated operation and maintenance and debt retirement costs to
each user to be presented in clear,  understandable terms at the facility
planning public meeting.   In his letter of December 30,  1976,  the Administrator
asked the Regional  Administrators to pay careful  attention  to facility plans
where average local debt retirement costs per household  exceed 1  percent of
annual median income  and for which local  debt retirement costs plus operation
and maintenance costs exceed 2 percent.

     Guidelines modifying the 1  percent to 2 percent guide  have been  included
below to assist in identification of expensive projects  for further analysis.
We are preparing a format with instructions for municipal  officials and State
and Federal  reviewers to use to determine the size of project the jnunicipality
can afford using readily available local  financial  data.


                                     B-30
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      Loan and grant programs of several  Federal  agencies for construction of
 wastewater treatment works in the past usually have been handled individually
 with little coordination among the agencies.   This has resulted in unnecessary
 paperwork, duplication,  federally imposed administrative burdens, construction
 of inappropriate or too  sophisticated, costly facilities, fostering of
 development on rural land, and poor structuring  of local share debt .financing.

      Under the Interagency Agreement for Rural Water and Sewer Projects,
 Environmental Protection Agency (EPA), Farmers Home Administration (FmHA),
 Economic Development Administration (EDA),  Housing and Urban Development (HUD),
 and Community Services Administration (CSA) will  coordinate their efforts to
 improve the delivery of  Federal  water and sewer  programs to rural and semi-rural
 communities.   Major features include:

      "Emphasis on alternatives that may  have  lower per capita capital and
       operating costs and require less sophisticated technology and skill
       to operate than conventional  collection and treatment facilities;
      o
       A  regular exchange  of information  among  the  agencies  involved  in
       funding  the  project,  including meeting periodically and  using  the
       Federal  Regional  Councils;

      °The  facilitating  of application  and  disbursement  of funds  for  rural
       water  and sewer projects  and  informing communities of the  range of
       funding  and  other assistance  available to  them;

      °The  establishment of  a  universal data base for national  wastewater
       disposal  and treatment  needs;

      "The  more  efficient  use  of the A-95 process of review  by  clearinghouse
       agencies;

      °Use  of the same criteria  to evaluate the financial impact  of the pro-
       posed system upon the community;

      °Coordination of the review of facility plans between  EPA and FmHA and
       use  of the plans  by FmHA  as their feasibility report  to  the extent
       possible;

      °The  demonstration of compliance with Federal requirements  under specific
       statutes  only once when communities are using funds from more  than one
       program with identical  compliance requirements.  Where agency  regulations
       differ in compliance requirements, agencies will work together to ensure
       individual or coordinated review as appropriate.

      Facility planning  in some  small communities with unusual or inconsistent
geologic features or other unusual conditions may require house-to-house
investigations  to provide basic information vital to an accurate cost-effectiveness
analysis for each particular  problem area.   One uniform solution to all
the water pollution problems  in a planning area is not likely and may not be
desirable.   This extensive and  time-consuming engineering work will  normally


                                     B-31
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result in higher planning costs which are expected to be justified by the
considerable construction and operation and maintenance cost savings of small
systems over conventional collection and' treatment works.'

     Though house-to-house visits are necessary in some areas*, sufficient
augmenting information may be available from the local  sanitarian, geologist,
Soil Conservation Service representative or other source to permit .preparation
of the cost-effective analysis.  Other sources include  aerial  photography and
boat-carried leachate-sensing equipment which can be helpful  in locating
failing systems.  Detailed engineering investigation, including soil  profile
examination, percolation tests, etc., on each and every occupied lot should
rarely be necessary during facility planning.

III. Policy

     A.   Funding of Publicly and Privately Owned Small  Alternative  Wastewater
          Systems

          1.    Minimum Standards and Conditions

               The Clean Water Act and the regulations  implementing  the Act
          impose no restrictions on types  of sewage treatment  systems.   These
          alternative systems-are eligible for funding  for  State approved
          certified projects  when the following minimum standards and
          conditions are met:

               a.    For both  publicly and  privately owned systems, the
                    public body must meet  the requirements  of  40 CFR 35.918-1
                    (b), (c), (e) through  (j);  35.918-2  and 35.918-3.

                    A comprehensive program for regulation  and inspection
               of these systems must be  established prior to EPA approval
               of the plans and specifications.   Planning for  this compre-
               hensive program  shall  be  completed  as  part of the facility
               plan.   The program shall  include,  at a minimum,  the
               physical  inspection of all  on-site  systems in the facility
               planning area  every three years  with pumpouts and systems
               renovation or  replacement as required.  The  program shall  also
               include,  at a  minimum,  testing of  selected existing potable
               water wells on an annual  basis.  Where a  substantial  number
               of  on-site systems exist, if necessary, appropriate
               additional  monitoring  of  the aquifer(s) in the  facility
               planning  area  shall  be  provided.

                    For privately owned  systems the applicant must demonstrate
               in  the facility  plan  that the  solution chosen is  cost-effective
               and  selected in  accordance with  the  cost-effectiveness
               guidelines for the Construction  Program,  (Appendix  A,
               40  CFR Part 35).   These systems  are  not eligible  for a
               15  percent cost  preference for the alternative  and  innovative
               processes and  techniques  in  the  cost-effectiveness  analysis.
               Publicly owned systems, however, are eligible for the  15  percent
               cost preference.

                                      B-32
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     b.   In addition to the conditions in paragraph A.I, privately
          owned systems must meet the requirements of 40 CFR 35.918-1(a)
          and (d) and the following:

          (1)  Provide facilities only for principal residences,
               (see 40 CFR 35.918(a)(2)) and small commercial
               establishments (i.e., those with annual or seasonal,
               if not operated throughout the year, dry weather flows
               of less than 25,000 gpd and more than one user
               equivalent per day; e.g. 300 gpd).  Not included
               are second homes, vacation or recreation residences;

          (2)  Require commercial users to pay back the Federal
               share of the cost of construction with no moratorium
               during the industrial cost recovery study.  The
               25,000 gpd exemption does not apply for those
               commercial establishments;

          (3)  Treat nonprofit and non-governmental institutional
               entities such as churches, schools, hospitals and
               charitable organizations, for purposes of this special
               authority, generally the same as small commercial
               establishments.


2.   Other Eligible and Ineligible Costs

     In addition to the costs identified in the Construction Grants
Regulations, 40 CFR 35.918-2, the following costs are also  grant
eligible:

     (a)   Vehicles and associated capital  equipment required for
          servicing of the systems such as septage pumping  trucks
          and/or dewatered residue haul  vehicles.

          (1)  Vehicles  purchased under the grant must have  as
               their sole purpose, the transportation of liquid or
               dewatered  wastes  from the collection point
               (e.g.,  holding tanks, sludge-drying beds)  to  the
               treatment  or  disposal  facility.   (Other mobile
               equipment  is  allowable for  grant participation as
               provided  for  on  pages VII-12 and 13, "Handbook of
               Procedures, Construction  Grants  Program for Municipal
               Uastewater Treatment  Works.")

          (2)  If  vehicles or equipment  are purchased the
               grantee must  maintain property accountability in
               accordance with OMB Circular A-102  and 40  CFR 30.810.
                                      B-33
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      (b)  Septage treatment plants (eligible for 85 percent
          grant funding as part.of an alternative system).

      (c)  Planning for establishment of small alternative
          wastewater systems management districts, including public
          hearings to discuss district formation.  The "mechanics" of
          establishing the districts such as legal and other costs for
          drafting of ordinances and regulations, elections, etc., are
          a normal function of government and are not grant eligible,
          (Construction Grants Program Handbook of Procedures, VII-6).

      (d)  Rehabilitation, repair or replacement of small  alternative
          wastewater systems as provided for by 40 CFR 35.908(c).


3.   Grant Funding of Small Alternative Wastewater Systems

     Small alternative wastewater systems are eligible for 85 percent
grants; 75 percent of the Federal grant may be funded from the
4 percent set-aside.  The 10 percent grant increase must be funded
from  the 2 percent set-aside (3 percent in FY 1981).  The 10 percent
grant increase can also be applied to small alternative wastewater
systems where 4 percent set-aside funds are not available (i.e.,
in States where there is no 4 percent set aside or States where
4 percent set-aside funds have been depleted).

4.   Use of Prefabricated or Preconstructed Treatment Components

     The use of prefabricated or preconstructed treatment components
such as septic tanks, grinder pump/tank units, etc., normally is
more economical than construction in place and should be carefully
considered.   In the case of very small  systems, prefabricated or
preconstructed units should in most instances be the most cost-
effective.  Por somewhat larger systems of standard design,
prefabricated or preconstructed units may also be cost-effective and
should be carefully considered in the facility plan.

5.   Useful  Life of Small  Alternative Hastewater Systems

     Whenever conditions permit, these  alternative treatment works
including soil  absorption systems,  shall  be designed to ensure a
minimum useful  life of twenty years.

6.   Comparison of Small  Alternative Wastewater Systems with
     Collection Systems jn Cost-Effective Analysis

     The present worth of small  alternative wastewater systems for
future development permitted by the cost-effectiveness guidelines,
(40 CFR 35,  Appendix A) may be compared with the costs of alternative
and conventional collection systems for the same planning area.   In
each instance both eligible and ineligible costs shall be considered
including service line costs from residence to collector, connection
fees and service to the on-site units.

                                     B-34
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 IV.   Determination  of  the  Economic  Impact  of  the  Project

      When  total  user charges  for  wastewater treatment  services,  including
 debt  service  and operation and maintenance, for the average  user  in  the
 service  area,  exceed the following  percentages of annual  household
 median incomes:

    •--    1.50 percent when the median  income is  under $6,000;
           2.00 percent when the median  income is  between  $6,000-$10,000;
           2.50 percent when the median  income is over  $10,000.

 the projects  shall  be  considered  expensive and shall receive further  intensive
 review to  determine, at a  minimum:

      1.  the  adequacy  and  accuracy  of the cost-effective  analysis,
         particularly  noting whether all the  feasible  alternatives
         have  been  considered and if the cost estimates are reasonable;

      2.  the  soundness  of  financing of  the local share, and

      3.  whether  the grant  applicant has sought out all the sources of
         supplemental  funding.

 (Costs of an expensive  project can  sometimes  be reduced by additional facility
 planning effort,  including  reduction in scope.)

     A format, instructions and criteria for  determination of the financial
 capability of  the public body to carry  the debt load of a new project are being
 prepared and will be promulgated at an  early  date.  This process will be
 tailored for the use of municipal  authorities and State and EPA reviewing
officials.

V.    Interagency Coordination and Streamlining the Review and Approval of Grants
     or Loans  for Construction of Wastewater Treatment Works in Sparsely Populated
     Communities

     A.    Coordination  with Farmers Home Administration (FmHA)

          Communities should be encouraged  to contact  FmHA during the development
     of their facility  plans to receive informal  comments  before the  plans  are
     finalized and submitted for review.

         Upon receipt  of  State certified facility plans for communities  under
     10,000 population, the Region shall send  a  copy of each plan to  State
    FmHA officials  for their  review concurrently  with  regional  review.   FmHA
    will provide comments  normally  within  30  days to  the  Region on the
    financial  capability of the community  to  carry  the project,  the  structuring
    of the local  share debt,  the  viability of the selected  alternative and
    other  matters in which FmHA is  interested.  The comments are  for  each
    Regional  Administrator's  information and  appropriate  action,  if  received
    within the 30-day  period.  They are not FmHA's  official  comments  to  the
    community on its plan.  Close cooperation between  FmHA  and  regional
    reviewers  is encouraged-.   For States which are delegated final facility
    plan review,  the above coordination shall be  between  the State and State
    FmHA officials.
                                      B-35
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     B.   Exchange of Information Among FmHA, HUD, EDA, CSA and EPA Through
          Joint Meetings

          The agencies shall meet periodically during the year using the Federal
     Regional Councils.  Meetings shall be initiated by any of these organizations
     and one of,.these meetings will take place at least 120 days before the
     beginning'of each new fiscal year.  These meetings may include:

          1.   Review of status of projects being jointly or concurrently
               funded;

          2.   Discussion of future projects in common;

          3.   Exchange of information on current and new administrative
               or substantive procedures or requirements; and

          4.   Review of action items such as:

               a.    One year priority or project lists to identify
                    combined funding possibilities;

               b.    Existing project lists to identify overlapping
                    projects or funding; and

               c.    Construction and inspection schedules to identify
                    areas of coordination.

               Regular meetings between respective state-level  agencies
are encouraged for similar purposes of coordination.

     C.   Encouragement of Alternatives to Conventional  Collection and
          Treatment of Wastewater

          Alternatives to conventional  wastewater collection and treatment
     facilities  that may have lower per capita  capital,  operating and main-
     tenance costs and require less sophisticated technology and skill  to
     operate shall be encouraged.

     D.   Provision of Funding and Other Assistance Information to Small  Communities

          Regional offices  and other sources  will  provide,  on  request,  information
     on the  range  of funding  and other  assistance for rural  sewer projects.
     Technical  information  may be  obtained from the Environmental  Research
     Information Center  (ERIC),  Cincinnati,  Ohio  45268,  telephone number
     (513)  684-7394,  or  the Small  Wastewater  Flows Clearinghouse,  West
     Virginia University, Morgantown, West Virginia 26506,  telephone number
     (800)  624-8301.
                                      B-36
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E.   Establishment of a Universal Data Base for National Wastewater Disposal
     and Treatment Needs

     The EPA biennial Needs Survey will be used as the initial data base for
all agencies involved in funding rural facilities.

F.   More-Efficient Use of the A-95 Process of Review

     Notification of intent to apply for grant funds submitted to A-95
clearinghouses should indicate the intention to apply for joint or combined
funding and identify the prospective assisting agencies.

     The A-95 agency needs to conduct only one review of the actual project
for each plan of study and Step 1 grant (except for special circumstances)
which will meet the requirements for all agencies involved.

     The use of the A-95 process and Water Quality Management Planning
process under section 208 to identify projects that may be eligible for
funding should be promoted.

     Regions should encourage the clearinghouses to use the A-95 process
to evaluate the rural and urban impact of jointly funded projects.

G.   Acceptance of One-Time Demonstration or Assurance of Compliance with
     Federal Requirements for Jointly Funded Projects

     The Regions and States where responsibility has been delegated should
accept evidence of compliance with requirements of the following when they
apply in an identical manner to the programs of each agency:

     1.    Uniform Relocation and Real  Property Acquisition Policies
          Act of 1970;

     2.    Civil  Rights  Act of 1964;  Civil  Rights Act of 1968;
          Executive Order No.  11246;

     3.    Davis-Bacon Fair Labor Standards  Act;

     4.    The Contract  Work Hours Standards Act;

     5.    The Copeland  (Anti-Kickback)  Act;

     6.    The Hatch Act;

     7.    The Coastal Zone  Management  Act of 1972;

     8.    The Archaeological  and  Historic Preservation  Act of  1974;

     9.    The National  Flood  Insurance  Act  of  1968,  as  amended  by  the
          Flood  Disaster  Protection Act of  1973,  and  regulations and
          guidelines  issued thereunder;


                                      B-37
-------
          10.  The Wild and Scenic Rivers Act of 1968;

          11.  The Endangered Species Act of 1973;

          12..  The Clean Air Act;

          13.  Executive Order No. 11988 on floodplains management;

          14.  Executive Order No. 11990 on wetlands protection;

          15.  The National Historic Preservation Act of 1966, and
               Executive Order No. 11593;

          16.  The Safe Drinking Water Act of 1974.

          Further guidance in this area will  be issued after detailed review
     and discussion by all agencies of regulations and requirements imple-
     menting each of the above statutes.

VI.  Implementation

     This policy should be emphasized through Step 1 preapplication conferences,
contacts through municipalities and'the States and reviews of Steps-! and.2
grant applications.  This PRM is effective for facility plans started after
May 31, 1979, except as follows:

     a.   The determination of economic impact is applicable to facility
          plans review commencing 90 days after issuance of this guidance.

     b.   Review of facility plans by FmHA should commence on facility
          plans received for review 60 days after issuance of this guidance.

     c.   Joint meetings to exchange information using the Federal Regional
          Councils should commence prior to May 31,  1979.   At least one of the
          future meetings should take place at least 120 days before the
          beginning of each new fiscal  year that follows.

     d.   The more efficient use of the A-95  review  above  shall  commence
          as soon as practicable, but not later than May 31, 1979.
                                      B-38
-------
                                 APPENDIX C

                                COST INDEXING
C.I  General

Cost data for construction and operation and maintenance (O&M) have origi-
nated from a variety of reference sources and reflect differing time periods
and geographic locations.  Values presented in this manual have been con-
verted to a September, 1976 (constant dollar) base except where noted.

C.2  Indexes

Among the indexes commonly used are the EPA Sewage Treatment Plant Construc-
tion Cost Indexes and the EPA Operation and Maintenance Cost Index.  The
Construction Cost Index for a 1 mgd trickling filter plant (originally
designated the PHS-STP index and later designated as the WPC-STP index for
treatment plant construction costs) was developed through an analysis of
733 contract awards during the period 1956 through 1962.  The econometric
model for a hypothetical 1 mgd trickling filter plant is based on grouping
of input costs and weighted averages of detailed labor and material costs
from each of 20 cities' commercial marketing areas throughout the country.
For construction materials and equipment, area prices for common brick,
concrete, crushed stone, sand, foundry pig iron, structural steel, cast
iron, reinforcing bars, and exterior plyforms are incorporated by weightings
developed for construction conditions of 1957-1962.  The input to labor for
construction includes wage rates for electrical workers, hoisting engineers,
structural workers, bricklayers, carpenters, and common labor.  Table C-l
shows the EPA Sewage Treatment Plant Construction Cost Index for a 1 mgd
plant for the period 1957 through September, 1979.

The EPA Municipal Wastewater Treatment Plant Operation and Maintenance (O&M)
Cost Index was developed to overcome the shortcomings of applying a single
Wholesale Price Index (WPI) to escalate operation and maintenance costs.
The O&M Cost Index was developed through regression analyses of actual 1967
O&M cost data for a composite 5 mgd  conventional activated sludge plant.

The average index is comprised of six sub-indexes which are averaged to form
the single O&M Index.  The six sub-indexes are Labor, Chemicals, Power,
Maintenance, Other Costs, and a "quality-added factor" called Added Input.
Each of these categories is escalated individually on a quarterly basis
(annually before 1974) by using commodity group indexes, productivity data
indexes, chemical prices, and a specialized maintenance index.  Table C-2
gives the parameters that represent each cost category, the weight of each
parameter within the category, and the source of the escalating factors.

Table C-3 summarizes the average O&M Index and the sub-indexes for the
years 1967 through the third quarter of 1979.  A breakdown of the Chemical
Cost sub-index into component chemicals is shown in Table C-4, and details of
the Other Costs sub-index are shown in Table C-5.


                                     C-l
-------
In addition to adjusting to a constant dollar base, cost indexes, such as
those previously described, are used to perform economic analyses, adjust to
current dollars, and make cost comparisons.  However, such indexes, when ap-
plied to the several components of construction or operation and maintenance
costs, will only adjust the data on a national average basis.

In order to arrive at a more accurate cost figure than one which results
from the use of the national average indexes alone, Locality Factors can be
applied to an estimated cost or cost index.  The use of Locality Factors,
which have been calculated from generally available statistics, permit the
localizing of national average cost data for construction labor, construction
materials, total construction cost, operation and maintenance labor costs,
and power costs.  The factors for labor and materials are given in Table C-6
and those for power costs are given in Table C-7.

In order to obtain current cost and price indexes, contact Robert L. Michel,
Priority Needs and Assessment Branch (WH-595), Office of Program Operations,
U.S. Environmental Protection Agency, Washington, D.C.  20460 (202) 426-4443.
                                     C-2
-------
                                                    TABLE C-l

                                EPA SEWAGE TREATMENT PLANT CONSTRUCTION COST INDEX
                                    U.S.  CITY AVERAGE (1957-1959 = 100) (1)(2)

    Year    Jan.    Feb.    March   April    May    June   July    Aug.    Sept.     Oct.    Nov.   Dec.
    1957
    1958
    1959
    1960
    1961
    1962
    1963
    1964
    1965
    1966
    1967
o   1968
c!o   1969
    1970
    1971
    1972
    1973
    1974
    1975
    1976
    1977
    1978
    1979


106.8
109.6
110.8
114.1
117.8
121.1
128.7
137.6
150.6
167.7
176.1
188.1







107.1
109.5
111.0
114.6
118.1
121.2
129.5
137.9
150.9
168.7
177.5
190.2







107.1
109.5
111.1
114.8
118.1
121.2
129.8
138.2
153.3
169.2
180.7
191.0
247.4
256.7
270.9
290.1
322.0


107.1
109.6
111.1
115.1
118.2
121.6
130.0
138.5
155.4
169.9
181.6
196.1







107.2
109.7
111.2
115.3
118.3
121.7
130.0
141.2
157.3
171.4
182.6
197.8







107.8
110.0
111.8
116.1
119.1
122.5
131.1
143.0
158.6
172.2
182.9
208.9
245.9
259.6
273.8
303.1
334.1


108.1
110.2
112.3
116.8
119.6
123.4
132.4
146.3
160.6
172.3
183.7








108.5
110.5
112.6
116.9
120.3
123.7
135.3
146.7
165.1
173.1
183.9







107.2
108.6
110.6
112.7
117.1
120.6
124.5
135.5
147.5
166.3
173.8-
184.5
230.1
251.3
262.5
281.0
311.0
337.8

107.2
109.5
110.7
112.8
117.5
120.9
126.8
135.9
148.1
166.3
174.5
185.0







107.0
109.5
110.7
112.9
117.5
120.9
127.2
136.6
149.3
166.4
175.5
185.8







106.8
109.6
110.7
113.1
117.5
121.0
127.7
136.9
149.6
167.2
175.7
187.5
238.8
255.4
270.3
287.6
314.1

98.0
101.5
103.7
105.0
105.9
107.0
108.5
110.1
112.0
116.1
119.4
123.6
132.7
143.6
159.8
172.0
182.6
217.2
250.0
262.2
278.3
304.6

    (1)  Based on 1.0 MGD high rate trickling filter with aeration.
    (2)  Note:  The input to the two indexes include wage rates (for each of 20 cities) for electrical
         workers, hoisting engineers, structural workers, bricklayers, carpenters, and common labor.  For
         materials and equipment, area prices for common brick, concrete, crushed stone, sand,  foundry pig
         iron, structural steel, cast iron, reinforcing bars, and exterior plyform are incorporated by
         weightings developed for construction conditions of 1957-1962.
-------
                                                                       TABLE C-2
                                          PARAMETERS  USED  TO  ESCALATE  O&M COST CATEGORIES  (1)
o
CATEGORY
Salaries and Wages
Electricity
Chemicals
Maintenance



PARAMETER
Average Hourly Earnings
Water, Steam and Sanitary
Systems
Industrial Power, 500 Kw
Demand, Price Index
Chlorine Liquid
L1me
Methanol
Ferric Chloride
Chemical Freight
Alum
Factory Maintenance
Transformers and
Power Regulators Index
Valves & Fjttlngs
Pumps, Compressors and
Equipment
Centrifugal Blowers
t
Gasoline
Unit Non-Labor Payments
* WEIGHT I/
100
100
70
10
5
5
5
5 '
60
10
10
10
10
7(\
30

SERIES
SIC 4947
PPI 0543
PPI 0613 0101
PPI 0613 0213
$/gal FOB Gulf Coas
$/100 Ib. Sewage Gr
Code 28 - Railroad
$/Bulk Ton
1968 Base Year
PPI 1174
PPI 114901
PPI 1141
PPI 11470101

PPI 0571

SOURCE
y
U
3/
! 1
Freight 3/
4/
I
$
3/
7/
1
5/
                       J7  Percent of Base Year (1967)  Category Cost
                       2/  Employment and Earnings, BLS DOL
                       3/  Producer Price Indexes, BLS  DOL
4/  Chemical Marketing Reporter
5/  Factory Vol. 8, No. 11, November 1975
6/  Monthly Labor Review, May 1976
TJ  EPA Sewage Treatment Plant Cost Index
    with MD Rate Adjustments
                       (1)  Reference:  Development of  a Cost Index for Operation- and Maintenance of Municipal Wastewater Treatment Plants,
                           Robert L. Michel,  July 1976.
-------
                                 TABLE C-3

                EPA MUNICIPAL WASTEWATER  TREATMENT OPERATION
                    AND MAINTENANCE COST  INDEX (1)(2)(3)


Year
1967
1968
1969
1970
1971
1972
1973
1974
1974
1974
1974
1975
1975
1975
1975
1976
1976
1976
1976
1977
1977
1977
1977
1978
1978
1978
1978
1979
1979
1979


Qtr
A
A
A
A
A
A
A
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3

Labor
Index
1.00
1.06
1.14
1.24
1.32
1.41
1.48
1.54
1.57
1.63
1.67
1.70
1.72
1.76
1.79
1.84
1.86
1.91
1.96
1.96
1.97
2.04
2.09
2.13
2.15
2.24
2.24
2.29
2.35
2.37
Chemical
Cost
Index
1.00
1.03
1.08
1.10
1.12
1.13
1.18
1.34
1.54
1.83
2.05
2.37
2.39
2.39
2.39
2.50
2.49
2.55
2.58
2.54
2.56
2.58
2.54
2.54
2.52
2.51
2.58
2.57
2.63
2.75

Power
Index
1.000
1.009
1.022
1.066
1.155
1.239
1.326
1.543
1.741
1.852
1.951
2.080
2.060
2.137
2.152
2.207
2.255
2.341
2.327
2.486
2.562
2.662
2.627
2.797
2.869
2.800
2.830
2.921
3.024
3.144
Main-
tenance
Index
1.000
1.037
1.081
1.133
1.189
1.218
1.321
1.408
1.550
1.660
1.718
1.746
1.767
1.790
1.812
1.835
1.865
1.896
1.919
1.953
1.986
2.041
2.071
2.112
2.182
2.229
2.289
2.334
2.411
2.478
Other
Cost
Index
1.00
1.01
1.03
1.06
1.14
1.19
1.27
1.46
1.60
1.68
1.67
1.73
1.80
1.92
1.93
1.92
1.96
2.03
2.05
2.08
2.13
2.16
2.19
2.19
2.25
2.35
2.41
2.50
2.66
2.91
Added
Input
Index
1.00
1.04
1.11
1.21
1.31
1.40
1.52
1.68
1.80
1.92
1.99
2.08
2.11
2.17
2.19
2.29
2.32
2.39
2.43
2.47
2.53
2.63
2.65
2.73
2.82
2.88
2.91
2.98
3.10
3.23
Average
O&M
Index
1.00
1.03
1.09
1.16
1.23
1.30
1.38
1.50
1.60
1.69
1.76
1.83
1.85
1.90
1.93
1.97
2.00
2.06
2.09
2.12
2.15
2.22
2.24
2.30
2.33
2.38
2.40
2.46
2.54
2.62
 1)   1967 = 1.000
 2)   Based on 5 MGD conventional  activated sludge
(3)   Reference:  EPA Operations and Maintenance Cost Index,
     September 1979, Robert L.  Michel,  EPA,  Washington,  D.C.
                                    C-5
-------
                                  TABLE C-4

                  EPA MUNICIPAL WASTEWATER TREATMENT PLANT
                    OPERATION AND MAINTENANCE COST INDEX
                      CHEMICAL  COST  COMPONENT (1)(2)(3)


Yr
67
68
69
70
71
72
73
74
74
74
74
75
75
75
75
76
76
76
76
77
77
77
77
78
78
78
78
79
79
79
Q
T
R
A
A
A
A
A
A
A
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3

Chlorine
Index
1.000
1.037
1.089
1.111
1.111
1.111
1.111
1.201
1.338
1.645
1.843
2.228
2.265
2.256
2.241
2.347
2.316
2.328
2.370
2.382
2.338
2.334
2.258
2.220
2.201
2.173
2.256
2.214
2.195
2.245

Alum
Index
1.00
1.08
1.08
1.16
1.16
1.26
1.26
1.26
1.60
1.60
1.60
1.98
1.98
2.22
2.22
2.22
2.22
2.42
2.42
2.42
2.59
2.59
E.59
2.75
2.75
2.75
2.75
2.93
2.93
2.95
Ferric
Chloride
Index
1.00
1.00
1.00
1.00
1.14
1.14
1.14
1.28
1.28
1.28
1.42
1.42
1.42
1.42
1.42
1.42
1.42
1.42
1.42
1.42
1.42
1.42
1.57
1.57
1.57
1.57
1.57
1.67
1.69
1.69

Methanol
Index
1.00
1.00
1.11
1.11
1.11
1.11
1.55
2.22
3.00
3.55
4.33
4.33
4.33
4.22
4.22
4.44
4.44
4.77
4.77
4.22
4.66
4.88
4.88
4.88
4.88
4.88
4.88
4.88
5.55
6.22

Lime
Index
1.000
1.000
1.013
1.045
1.113
1.137
1.174
1.482
1.483
1.619
1.705
1.964
1.919
1.932
1.963
2.133
2.207
2.249
2.273
2.313
2.311
2.317
2.371
2.531
2.550
2.604
2.629
2.711
2.762
2.847
R.R. Index
Chemical
Freight
1.000
1.031
1.061
1.146
1.292
1.324
1.350
1.501
1.519
1.656
1.663
1.663
1.763
1.857
1.905
1.907
1.949
1.950
2.003
2.083
2.083
2.085
2.181
2.170
2.163
2.237
2.394
2.397
2.430
2.518
Overall
Chemical
Index
1.00
1.03
1.08
1.10
1.12
1.13
1.18
1.34
1.54
1.83
2.05
2.37
2.39
2.39
2.39
2.50
2.49
2.55
2.58
2.54
2.56
2.58
2.54
2.54
2.52
2.51
2.58
2.57
2.63
2.75
(1)   1967 = 1.000

(2)   Chlorine estimated at 70% of 1967  plant  chemical  cost.
     Lime 10%,  others  5% each.

(3)   Reference:   EPA Operation and Maintenance  Cost  Index,  September 1979,
                 Robert L. Michel, EPA,  Washington,  D.C.
                                    C-6
-------
                                 TABLE C-5

                  EPA MUNICIPAL WASTEWATER TREATMENT PLANT
                    OPERATION AND MAINTENANCE COST INDEX
                      OTHER  COST COMPONENTS  (1)(2)(3)
Year
Quarter
1967
1968
1969
1970
1971
1972
1973
1974
1974
1974
1974
1975
1975
1975
1975
1976
1976
1976
1976
1977
1977
1977
1977
1978
1978
1978
1978
1979
1979
1979
A
A
A
A
A
A
A
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
Insurance
  Index

  1.000
                        .035
                        .111
                       1.202
                       1.338
                       1.440
                       1.529
                       1.599
                       1.749
                       1.927
                         000
                         072
                         059
                         104
                         139
                         151
                         174
                         198
                         263
                         268
                         293
                         353
                         ,408
                         ,429
                         ,538
                         .604
                         .630
                         .696
                         .798
              2.
              2,
              2,
              2.
              2
              2
              2
              2
              2
              2
              2
              2
              2
              2
              2
              2
              2
              2
              2
Administration
    Index	

   1.000
   1.032
   1.040
   1.069
   1.148
   1.190
   1.208
   1.229
   1.269
   1.303
   1.336
   1.384
   1.'427
   1.493
   1.520
   1.550
   1.573
   1.590
   1.629
   1.668
   1.658
   1.697
   1.750
                    769
                    775
                  1.857
                        2.829
                  1.907
                  1.957
                  1.920
                  1.943

Fuel
Index
1.000
.959
.978
.961
1.013
1.040
1.220
1.775
2.059
2.158
2.032
2.094
2.258
2.541
2.499
2.413
2.487
2.658
2.631
2.674
2.821
2.828
2.795
2.759
2.854
3.011
3.103
3.290
3.817
Overall
Other
Index
1.00
1.01
1.03
1.06
1.14
1.19
1.27
1.46
1.60
1.68
1.67
1.73
1.80
1.92
1.93
1.92
1.96
2.03
2.05
2.08
2.13
2.16
2.19
2.19
2.25
2.35
2.41
2.50
2.66
                                              4.598
                                2.91
 (1)   1967  =  1.000
 (2)   Insurance Index  combines rate changes and property valuation increases,
 (3)   Reference:   EPA  Operation and Maintenance Cost Index,  September 1979;
      Robert  L. Michel;  EPA,  Washington,  D.C.
                                     C-7
-------
                                 TABLE C-6

                           COST LOCALITY FACTORS

Atlanta
Baltimore
Birmingham
Boston
Chicago
Cincinnati
Cleveland
Dallas
Denver
Detroit
Kansas City
Los Angeles
Minneapolis
New Orleans
New York
Philadelphia
Pittsburgh
St. Louis
San Francisco
Seattle
NATIONAL INDEX VALUES

Labor
0.66
0.90
0.66
1.12
1.25
1.10
1.19
0.63
0.76
1.17
0.97
1.17
0.93
0.88
1.43
1.23
1.05
1.29
1.23
1.16
1.00
Construction ( | )
Materials
1.03
0.95
1.02
0.90
1.10
1.05
1.01
0.83
1.07
0.98
1.25
1.16
1.03
1.05
0.91
1.00
0.96
0.99
0.96
0.91
1.00

Total
0.79
0.92
0.79
1.04
1.20
1.08
1.13
0.70
0.87
1.10
1.07
1.17
0.97
0.94
1.24
1.15
1.02
1.18
1.13
1.07
1.00
O&M (2)
Labor
0.77
0.79
0.79
0.97
1.02
0.98
1.05
0.92
1.00
1.32
0.88
1.32
1.21
0.66
1.14
1.05
0.87
0.83
1.13
1.21
1.00
(1)   Calculated from EPA Sewage Treatment  Plant  and Sewer Construction Cost
     Index Third Quarter 1979.

(2)   Reference:  U.S.  Department of Commerce  Bureau of Census,  City
     Employment in 1976, GE76 No.  2 July 1977.   Based on average earnings
     by city of non-education employees.
                                    C-8
-------
            TABLE C-7

POWER COST LOCALITY FACTOR (1)(2)


 New  England               1.31

 Mid-Atlantic              1.18

 East North Central        1.10

 West North Central        0.98

 South Atlantic            0.94

 East South Central        0.98

 West South Central        0.87

 Mountain                  0.79

 Pacific                   0.86


 U.S.  Average              1.00
 (1)   Basis:  BLS, September,  1979
      Producers Price  Index

 (2)   Source:  "Construction Cost
      Indexes," EPA, Municipal
      Construction Division;
      R.L. Michel; September,  1979
               C-9
-------
                        APPENDIX  D  -  LIST  OF TABLES

No.                                                                  Page

D-l       Energy Requirements and Transfer Efficiency of Selected    D-15
            Aeration Devices
D-2       Design Criteria for Vacuum Filtration                      D-16
D-3       Design Criteria for Filter Pressing                        D-17
D-4       Energy Conversion and Representative Heat Values           D-18
D-5       Conversion Factors                                         D-19
D-6       Present Worth Factors                                      D-20
                        APPENDIX D - LIST OF FIGURES

D-l       Hydraulic Efficiency of Centrifugal Pumps                  D-29
D-2       Power Requirements for Raw Sewage Pumping                  D-30
D-3       Anaerobic Digester Heating Requirements                    D-31
D-4       Anaerobic Digester Heat Loss                               D-32
D-5       Anaerobic Digester Heat Production                         D-33
D-6       High Rate Anaerobic Digester Mixing Requirements           D-34
D-7       Sludge Pumping Energy for Heat Exchange                    D-35
D-7(a)    Anaerobic Digester Heat Requirements for Primary Sludge    D-36
D-7(b)    Anaerobic Digester Heat Requirements for Primary Plus      D-37
            Waste Activated Sludge
D-8       Fraction of Solids VS Water Content                        D-38
D-9       Flue Gas Temperature Attainable at Different Water Content D-39
D-10      Supplemental Fuel Requirement  at 50% Excess Air           D-40
D-ll      Supplemental Fuel Requirement  at 100% Excess Air          D-41
D-12      Excess Air Requirement                                     D-42
D-13      Heat Recovery from Waste Heat Boiler                       D-43
D-14      Energy Requirements for Vacuum Filtration                  D-44
D-15      Energy Requirements for Filter Pressing                    D-45
D-16      Energy Requirements for Centrifuging                       D-46
                                    D-i
-------
                                 APPENDIX D

              ENERGY UTILIZATION CURVES AND CONVERSION FACTORS
D.I  General

The information in this appendix supplements the energy utilization data
presented in Appendix A for the individual municipal treatment unit pro-
cesses.  Emphasis here is placed on the presentation of energy utilization
curves for the more energy intensive municipal  treatment processes of
pumping and aeration along with the specifically identified alternative
technology processes of anaerobic digestion, incineration, and dewatering.
Also included are commonly used energy conversion tables, conversion fac-
tors, and a table of fuel and energy equivalents.


D.2  Energy Intensive Processes

In conventional municipal wastewater treatment plants, about 60% of the
electrical energy is consumed in aeration, and about 20% in pumping.  Thus,
about 80% of the total electrical energy consumption is associated with
these two processes which offer the greatest potential for electrical
energy conservation.  The major energy requirement for many land treatment
systems is also for aeration (prior to application to the land) and pumping
(when applying the effluent to the land for treatment).  For this reason,
the following principles can be readily applied to those systems.

     D.2.1  Aeration

The two basic methods of aeration of suspended growth systems are mechanical
aeration and air bubble diffusion.   Turbine spargers which are a combination
of the above two devices have also been used.

The oxygen transfer effiencies and energy requirements of selected aeration
devices are shown in Table D-l.  Aeration systems are rated in terms of their
aeration efficiencies as pounds of 0? per horsepower-hour (hp-hr) at
standard conditions.  Standard conditions exist when the temperature is
20°C, pressure is 760mm Hg, the D.O. is 0.0 mg/1 and the test liquid is
clean water.  These ideal efficiencies and transfer rates vary from those
found for wastewater under field conditions.  Efficiency claims should be
accepted only when supported by actual test data for the actual model and
size of aerator under consideration; and for design purposes, the standard
performance data must be adjusted to reflect anticipated field conditions.
This is accomplished by converting Ib 02/hp-hr transferred under standard
conditions to Ib 02/hp-hr transferred under field conditions.  This can be
done by using the following formula:

                                    D-l
-------
           N   =   N    [  ./C*walt  -  CL)e  
-------
                   Elevation (Feet)       Correction Factor, F

                      Sea Level                   1.00
                        2,000                     0.93
                        4,000                     0.87
                        6,000                     0.80
                        8,000                     0.73

Since aeration devices may operate under submerged conditions, and exposure
to more than atmospheric pressure at the point of oxygen transfer, a further
adjustment to C*wait may be needed.  Also, if a value of C*st is given at a
condition of atmospheric pressure, adjustment to this value may also be needed.
These further adjustments are beyond the scope of this manual, but can be ob-
tained from the equipment manufacturer.  As an example, at a ten-foot depth,
these saturation values may increase as much as 9% according to one manufac-
turer.

The value for a can vary widely according to wastewater characteristics, type
of equipment, geometry of the basin, etc.  In fact, the outside range for a
is reported to be from 0.3 to 1.2 whereas a more normal range for a is re-
ported from 0.5 to 1.0.  Since a is part of the numerator, this means that
resultant field 02 transfer efficiencies can be affected as much as two times
(normal range) to four times (outside range).  Therefore, it is critical that
the value for a is selected carefully.  The following example is provided to
demonstrate use of the conversion equation.

Standard test conditions are 20°C, 760mm Hg, 0.0 mg/1 D.O. and the Nr,   is
given as 3.0 Ib 02/hp-hr for a surface aerator,  a is 0.75,  3 is 0.9.  The
field conditions are to be a 30°C average temperature at 2,000 feet elevation
and design D.O. concentration is 2.0 mg/1.

     c*walt  =  9.17 x 0.93  =  8.53 (no change for depth required)
     C*st    =  9.17
     CL      =  2.0 mg/1

     Tc      =  30°C

By applying the aforementioned equation., the conversion factor becomes 0.59,
and the efficiency of the aerator under field conditions (N)   becomes
0.59 x 3.0 = 1.77 or 1.8 Ib 02/hp-hr.

This conversion to actual operating conditions can significantly affect energy
usage in a system.  Therefore, it is important to realize that comparison of
two kinds of aeration devices can be made under standard conditions but when
calculating actual energy use, actual anticipated field conditions must be
used.

The oxygen transfer efficiencies and energy requirements of selected aeration
devices are shown in Table D-l.  The values given are for standard con-
ditions rather than field conditions.  In the fact sheets (Appendix A)
values for efficiencies for aeration devices in terms of Ib 02/hp-hr are
given which do reflect anticipated field conditions.  The energy and power

                                     D-3
-------
cost curves in the fact sheets are based on these field values;and if
another value is to be used,the curves would have to be modified accordingly
by the user.

Example Calculations:

     A 1.0 mgd wastewater flow with a BOD of 200 mg/1 is to be
     treated in an aeration basin equipped with low speed mechanical
     aerators.  Calculate the electrical energy required.
     Assume 1.0 Ib 02/lb BOD required

     1,000,000 Sil  x 200 M  x
                                              Ib
                      ___
                      1,000,000  mg
               day

     = 1,668 Ib 02/day

                x  0.26  KwH  s  433.68 KwH/day
     D.2.2  Pumping

Pumping devices commonly used in municipal wastewater application include
centrifugal, axial-flow, mixed flow, reciprocating, air lift pumps, and
pneumatic ejectors.  The radial, or so-called "non-clog" centrifugal pumps
with specially designed impellers are widely used in raw wastewater pumping.
The axial-flow pumps, such as screw pumps, are applicable to well settled
sewage only, and are used for recirculation or effluent pumping.  The mixed-
flow pumps which are intermediate between centrifugal and axial-flow pumps
are suitable for moderate head pumping.  Reciprocating pumps such as dia-
phragm pumps have their greatest use in pumping sludges.  Air lift pumps
are generally used in smaller treatment plants and are also useful as
sludge pumps.  Pneumatic ejectors are suitable for pumping wastewater of
small flows from an isolated area to a main sewer line or treatment facility.

Since centrifugal pumps are the most widely used pumping equipment, their
hydraulic efficiencies and electrical energy requirements are shown in
Figures D-l and D-2, respectively.  Calculations of energy requirements are
illustrated in the following example.

Example Calculations:

     A 1 mgd flow is to be pumped against a total dynamic head of 30 ft.
     The pump motor is 95% efficient and the efficiency of the pump is
     75%.  Calculate the electrical energy required.
1 mgd6 x 106 x 8.34 Ib/gal
1440 min/day x 60 sec/min
                                        on ...      00_c ,.  1k/
                                      x 30 ft'  = 28% ft 1b/sec
2896ft Ib/sec x
                                                = 5.27 HP
                                    D-4
-------
          5.27 x 0.7457 x 24 hours/day    _  ,„ .
          - 0.95 x o.75 -    -  I3<£'


If the wire to water efficiency is not given, it can be estimated from
Figure D-l.  For the above example, the overall efficiency given in the
figure is approximately 63%.  Using this estimate, the required power in
the above example is:
          5'27 x °;™57 x 24              =  149.7 KwH/day


Estimates of the annual power requirements for raw sewage pumping against
different values of the total dynamic head are provided in Figure D-2.


D.3  Alternative Sludge Handling Processes

The specifically identified energy recovery technology in the Innovative and
Alternative Guidelines includes co-disposal of sludge and refuse, anaerobic
digestion with more than 90% methane recovery, and self-sustaining inciner-
ation.  The energy utilization for anaerobic digestion and incineration is
presented in the following discussion.

     D.3.1  Anaerobic Digestion

Heat energy is required to raise the temperature of the influent sludge
solids and associated water and to compensate for heat losses through the
digester walls, bottom, and cover.  Electrical energy is required for mixed
digesters to operate the mixing equipment and to pump the digester contents
through the heat exchangers.  The digester gas can be collected and burned
to provide needed energy.  The influent heat requirement per ton of sus-
pended solids fed to the digester can be determined from Figure D-3.  The
temperature difference is that between the influent sludge stream and the
digester operating temperature.  Heat losses per ton of solids fed to the
digester are shown in Figure D-4 for varying reactor detention times and
solids feed concentrations.  Figure D-5 shows the heating value of the
digester gas per ton of solids fed to the digester as a function of volatile
solids destruction for different volatile solids percentages in the feed
sludge.  The following example illustrates the use of Figures D-3 thru
D-5 to calculate heat balances around a digester.

Example Calculations:

     Example No. 1

     A sludge stream at 3% solids which are 70% volatile is fed to
     an anaerobic digester in the northern U.S.  The digester detention
     time is 20 days and the volatile solids destruction is 60%.  The
     digester operates at 95°F and the average annual influent sludge
     temperature is 55°F.  The heating equipment has an efficiency of
     75%.

                                    D-5
-------
     From  Figure  D-3    2.67 x  106 BTU/ton required for 3% solids
                       and A Temp of 40°F.

                       Correct for heating equipment efficiency:
                       2.67 x  106/0.75 = 3.56 x  106 BTU/ton  input
                       to heater needed.

     From  Figure  D-4    1.33 x  106 BTU/ton required.
                       Correct for heating equipment efficiency:
                       1.33 x  106/0.75 = 1.77 x  106 BTU/ton  input
                       to heater needed.

     From  Figure  D-5    7.55 x  106 BTU/ton generated.

     Overall  Net  Heat  Generation Potential:

     7.55  x  106  - 3.56 x  106 - 1.77 x  106  =  2.22 x 106  BTU/ton  solids  fed.


     Example  No.  2

     A sludge stream  at 5% solids which  are 75%  volatile  is  fed  to  an
     anaerobic digester in the southern  U.S.  The digester detention
     time  is  15  days  and  the volatile  solids  destruction  is  50%.  The
     digester operates at 95°F and the influent  sludge feed  averages
     70°F.  The  heating equipment has  an efficiency of 75%.

     From  Figure D-3    1.0 x 106 BTU/ton required for  5%  solids  and
                       A Temp  of 25°F.

                       Correct for heating equipment efficiency:
                       1.0 x 106/0.75  =  1.33  x  106 BTU/ton  input to
                       heater  needed.

     From  Figure D-4    0.6 x 106 BTU/ton required  in northern U.S.
                       0.6 x 106 x 0.3 = 0.18 x  106  needed  for southern  U.S.

                       Correct for heating equipment efficiency:
                       0.18  x  106/0.75 = 0.24 x  106  BTU/ton  input to
                       heater  needed.

     From  Figure D-5    6.75  x  106  BTU/ton  generated.

     Overall  Net Heat Generation  Potential:
     6.75  x 106  - 1.33 x 106  - 0.24  x  106  =  5.18 x  106 BTU/ton solids fed.

Electrical Energy

The electrical energy requirement  in  KwH/yr  to mix  the digester(s)  can be
                                    D-6
-------
estimated from Figure D-6.  The required digester total volume in ft3 is
given by the following equation as:

               Sludge Flow, gpd x Digester Detention Time, days
                                 7.48 gal/ft3

The electrical energy required in KwH/yr to pump the sludge through the heat
exchangers can be estimated by finding the sum of the heating requirement
from Figures D-3 and D-4 in million of BTU's per dry ton of solids and
multiplying this value by the tons per day of solids fed to the digester.
This computed value in million BTU/day can be used in Figure D-7 to estimate
the electrical energy requirements for pumping the sludge through the digester.
The total heat requirements of anaerobic digestion can also be estimated by
using Figures D-7(a) and D-7(b).  These heat requirements are based on a
digestion temperature of 95°F.  Typical loading in Ib VS/day/cu ft is 0.05
for standard rate, and 0.15 for high rate digestion.  Typical detention time
is 30 days for standard rate, and 15 to 20 days for high rate digestion.

The amount of sludge produced in a wastewater treatment plant, and the VS
content of the sludge varies with the influent suspended solids concentration,
the BOD, and type and efficiency of the biological treatment process.  The
following sludge quantities are representative of typical primary and
activated sludge plants:

                                           Sludge Solids
                                           (Ib/mil gal)
          Sludge Type                  Total _ Volatile
          Primary                      1,151       690 (60%)
          waste Activated                945       756 (80%)
                              TOTAL    ~Tjm     T7W6"
Generally, about 50% of the volatile solids are destroyed by anaerobic
digestion and the gas produced has a heat value of about 600 BTU/scf.
These criteria give the following estimates for gas and heat available
from anaerobic digestion:

                                                Waste
                                 Primary      Activated
                                 Sludge        Sludge         Total
   Gas Produced,   scf/mil/gal     5,175          5,670      10,845
   Heat Available, BTU/mil/gal 3,105,000      3,402,000   6,507,000

For planning purposes, and in the absence of more specific information, it
may be assumed that about 6.5 mil BTU are available from gas produced by
anaerobic digestion of primary and conventional activated sludge treatment
of one million gallons of wastewater.

     D.3.2  Incineration

Energy requirements for incineration and the potential for energy recovery


                                     D-7
-------
have been described by Smith (1).  When the sludge is 70% volatile, the
minimum solid concentrations needed to operate a self-sustaining incineration
without auxiliary fuel at different flue gas temperatures were calculated to
be 25.9% at 800°F, 30% at 1,000°F, 34.7% at 1,200°F, and 40.4% at 1,400°F.
The attached figures provide a brief summary of some of the design parameters.
Further details are available in the above reference.

Figure D-8:  This figure shows the pounds of water (Ws) per Ib of dry volatile
solids (DVS) as a function of the solids content of the sludge (Fs) for dif-
ferent volatile solids fractions.  For example, a sludge containing 25%
solids which are 70% volatile, has 4.29 Ib of water per Ib of DVS.

Figure D-9:  This figure shows the flue gas temperature (Ts) attained with
50% excess air and 100% excess air for various values of Ws.  For example,
if Ws is 3.0, the flue gas temperature will be 1100°F with 50% excess air
and 920°F with 100% excess air.  If one desires a flue gas temperature of
1000°F, Ws would have to be less than 3.35 to avoid using supplemental fuel.

Figure D-10:  The gallons of fuel oil per ton of DVS (Rf) that must be used
to incinerate sludge with different values of Ws using 50% excess air are
shown in Figure D-10.  For example, to achieve a 1000°F flue gas temperature
with Ws = 6, the supplemental fuel requirement is 77.5 gal/ton DVS.  This
fuel requirement does not include an estimate for start-up requirements.

Figure D-ll:  The gallons of fuel oil per ton of DVS (Rf) that must be used
to incinerate sludge with different values of Ws using 100% excess air are
shown in Figure D-ll.

Figure D-12:  When the sludge is sufficiently dry to sustain combustion,
the excess air requirement varies to hold the desired flue gas temperature.
the excess air requirement (Ex) for different values of Ws is shown as a
function of flue gas temperature in Figure D-12.

Figure D-13:  The heat that can be recovered across a waste heat boiler
operated with an exit temperature of 500°F is shown for different inlet
gas temperatures and values of Ws in Figure D-13.  For a sludge with a
value of Ws of 2.0 and the excess air controlled to provide a flue gas
temperature of 1200°F, the heat recovered across the boiler would be
3920 BTU/lb DVS.

When supplemental fuel is burned in the sludge incineration process, the
total heat that can be recovered from a waste heat boiler is given by:

     BTU/lb DVS   =  (0.505  x  Ws  + 2.55  + 2.09  x Ex  + 0.0152  x  Rf)  x AT

     where  AT  is the temperature drop  across  the waste heat boiler.   For
     Ex =  0.5 or 1.0  the  values  of Rf are presented in  Figures  D-10 and
     D-ll  respectively.   This information can  be used in  conjunction  with
     Figure D-8  to calculate  the recoverable  heat.
                                     D-8
-------
For example, consider a sludge with Ws = 6.0 combusted with 50% excess air at
a flue.gas temperature of 1200°F and a waste heat boiler operating with a
boiler exit temperature of 500°F.  Here Rf = 116 gal/ton DVS (From Figure D-10)
and the heat recovered is:

(0.505 x 6. + 2.55 + 2.09 x 0.5 + 0.0152 x 116) x (1200 - 500) = 5872 BTU/lb DVS


D.4  Dewatering Processes

As previously mentioned, self-sustaining incineration can be achieved if the
sludge is adequately dewatered.  The energy requirements for the three
commonly used sludge dewatering processes, i.e., vacuum filtration, filter
press, and centrifuge, are presented as follows to assist the overall eval-
uations of the energy utilization.

     D.4.1   Vacuum Filtration

The electrical energy requirement in KwH/yr to continuously operate a vacuum
filter of various sizes is given in Figure D-14.

Variables which affect the performance of the vacuum filter include feed
sludge type, feed sludge concentration, feed sludge loading, type and amount
of conditioning chemicals, type and operation of filter, etc.  Alternative
sludge types, typical loading rates, and the corresponding cake solids are
presented in Table D-2.

Example Calculations

     A 100,000 gpd sludge  stream  at  5%'solids  (after  addition  of  conditioning
     chemicals) will  be  fed  at  4  Ib/ft2/hr  for  16  hrs/day.   Solids  capture
     is  96% and cake  solids  are 25%.

         100,000  Ml  x 8.34   1b   x 0.05   =  41,700  lb  solids  fed
                  day        gal                          day

            41,700 Ib/day             ,
         16  hrs x 4  ID/ft?  =  651  ft   ^quired
             day        hr

     From Figure D-14:

         651  ft2:  490,000  KwH/yr

         490,000  x  (16/24)  _
             355 days/yr	  '  895

         895  KwH/day x2000  Ib/ton       ..  7       ....
              41,700 x 0.96	   =   44'7       KwH
                                            ton DS captured
                                     D-9
-------
     Water  Remaining  in  Cake:

         41,700  x  0.96  x  1-0  -  °-25   =  120,096 To
                            0.25

     D.4.2   Filter  Press

The electrical power requirement in KwH/yr to continuously operate a filter
press of various volumes is given in Figure D-15.  Typical conditioning
requirements, cycle times and cake solids for various sludge types are pre-
sented in Table D-3.

Example Calculations:

     A 100,000 gpd  sludge  stream at  5%  solids  (after  addition  of
     conditioning chemicals)  will  be  fed  to a  filter  press with  a
     two  hour cycle time.   Solids  capture is 96% and  cake  solids
     are  45%.  Operation is 16 hrs/day.

         100,000 gal/day                 ,
         - ! - a - r-^    =  13,369  ft3/day
           7.48 gal/ft3

         13,369  ft3/day                ,
           8 cycles/day       =  M70 ft-5 required

     From Attached  Figure  (For 835 ft3  Press)

         2 x 600,000        =  1,200,000 KwH/yr

         100,000 4|1  x  8.34 -lif  x 0.05   =  41,700 lb  solids  fed
                 day          gai
          2,192 KwH/day x 2,000 Ib/ton       _  1no ,       KwH
          - 41,700 x 0.96               '  iuy'b ton DS captured

     Water Remaining in Cake:

          41,700 x 0.96 x 1-00"4°5'45         =  48,928 lb


     D.4.3  Centrifuge

The electrical energy requirement in KwH/yr to continuously operate  a cen-
trifuge at various flow  rates can be estimated from  Figure D-16.

Example Calculations:

     A 100,000 gpd sludge stream at  5% solids (after addition of
     conditioning chemicals) will  be fed to a centrifuge for
     16 hrs/day.  Solids capture is  90% and cake solids are 25%.
                                     D-10
-------
                            =  104 gpm t0 centrifLJ9e
    From Figure D-16:

         104  gpm:  220,000 KwH/yr


                             '  «*
     100,000      x  8.34  -IS-
             day           9al

     402 KwH/day x 2,000 Ib/ton
     - 41,700 x 0.90 -

Water Remaining in Cake:

     41,700 x 0.90 x  1 - °-25
                        .25
x  0.05
                                                  41,700   1b  solids  fed
                                                               day

                                                  91/1 _ ^KwH _ ,
                                                  ^'4 ton  DS captured
                                               =   112,590  15
D.5  Energy Conversion Methods

Whenever various forms of energy are interconverted there will be some loss
due to inefficiencies.  For example, whenever electrical energy is converted
to mechanical energy, some of the energy is lost as heat energy in the motor.
Similarly, if an engine operating on a Carnot cycle has a source temperature
of 1100°F (1560°R) and a receiver temperature of 500°F (960°R) the efficiency
is only (1.0 - 960/1560) or 38.5%.  Since no heat engine can be more efficient
than a Carnot engine, it is clear that this is the maximum possible efficiency
for these source and receiver temperatures.

The efficiency of pumps and blowers is usually in the range of 70-80% so
that mechanical energy can be converted to hydraulic energy with no more
than about 30% loss.  Similarly, mechanical and electrical energy can be
converted from one form to the other with a loss of less than 10%.  On the
other hand, the conversion of heat energy to mechanical energy necessitates
the wasting of roughly 2/3 of the heat energy.  For example, if electrical
energy is converted to heat energy, one KwH will generate about 3,413 BTU
of heat.  However, if heat energy is used to generate electrical energy
in a modern coal fired power plant, about 10,500 BTU of heat energy is
needed to generate one KwH; this is a conversion efficiency of only 32.5%.


D.6  Present-Worth Methodology

The purpose of this methodology is to determine the present-worth cost of
an alternative.  The costs identified include construction cost, constant
and variable operation and maintenance (O&M) costs, existing facility phase
out costs, facility replacement costs, and facility salvage value.  This
procedure converts these costs over the project life into an equivalent cost
                                     D-ll
-------
that represents the current investment that would be required to satisfy all
of the identified project costs for the planning period.   For a more detailed
discussion, the user may consult any standard engineering economy text.

The construction costs incurred by the project represent  single-payment
costs that occur at certain times throughout the planning period.  The
single-payment present-worth factor (sppwf) is used to determine the
present-worth cost, and is determined by the following formula and shown
in the first column of Table D-6:
                             1
               sppwf  =  (i + i)n

     where:  i   is the  interest
            n   is the  number of interest periods

The operation and maintenance  (O&M) cost includes both constant and variable
costs.  The constant O&M cost  is based on the flow rate at the beginning of
the planning period.  The variable O&M cost represents the difference between
the O&M cost at the flow rate  in the final year of the planning period and
the constant O&M cost  identified by the flow rate at the beginning of the
planning period.  The  uniform-series present-worth factor (uspwf) is used
to convert the constant annual O&M cost to a present-worth cost by the
following formula and  shown  in the second column of Table D-6.

          uspwf  =  (1 + i)n -  *
                     i (1 + i)n

     where:  i   is the interest rate
             n is the  number of interest periods

For cases where  the constant payment  is for a period that does not start at
the beginning of the  planning  period  (Phase 2 constant O&M costs), the
uniform-series factor  must  be adjusted by multiplying it by the  single-
payment present-worth  factor for the  number of  years from the beginning
of the planning  period to  the  time that the constant payment begins, as
in the following:

          ( uspwf tl)  x  ( sppwf t2)

     where:  tl is the number of years that the constant  payment will be made
             t2 is the number of years from the beginning of the planning
                period to the time that the constant payment begins

The  variable operation and maintenance  costs  are  assumed to  vary linearly
through the planning  period and  are multiplied  by  the  gradient  series
present-worth  factor  for  the same  number  of years  that the corresponding
constant  operation  and maintenance  is paid.   This  value  is computed  as:

                    (1 + Dn-l   ,     1
          gspwf  =  i  d+  i)n     U+ i)n
                                      D-12
-------
     where:   i   is  the  interest  rate
             n   is  the  number  of interest  periods that the  series  is  in effect

Gradient series present-worth factors are shown in  the third column of
Table D-6.  When using this term for computing the  present worth of a
variable O&M cost,  care must be exercised to insure that the gradient O&M
is used (i.e.,  the  annual average increase in O&M costs  during the phase).

If the gradient series does not start at the beginning of the planning period,
it must be adjusted by multiplying it by the single payment present-worth
factor as follows:

          (gspwftl)   x   (sppwft2)

     where:   tl  is  the period in  which  the  gradient  series  is  in  effect
             t2  is  the number of  years  from the  beginning  of the  planning
                 period to  the time the  variable  payment  is  started

The new cost effectiveness guidelines require that  natural  gas  prices be
escalated at a compound rate of 4% annually over the planning period unless
the regional administrator determines that a lesser or greater rate can be
used based on regional  differentials between historical  natural gas price
escalation and construction cost escalation.  The inflation factor results
in a geometric increase in the value of natural gas and  the geometric series
present-worth factor (gespwf)  can be calculated by the following formula:
          gespwf  -
     where:   i   is  the  interest  rate
             n   is  the  number  of interest  periods  that  the  series
                is  in effect
             a   is  the  appreciation factor

The formula contains three variables.  For an appreciation factor of 4% for
natural gas, the present-worth factor for varying interest rates (6 1/4-8%)
and time periods (1-20 years)  can be found from column four of Table D-6.  The
factor in the table is multiplied by the  initial first-year value of the
natural gas.  For example, to determine the present worth of natural gas
used over 20 years and which is worth $1,000 at the beginning of the first
year, at an interest rate of 6 1/4% per annum; multiply 15.47730 times $1,000
to get $15,477.30.  At this time, the only energy cost which is appreciated
is for natural  gas and any present worth  analysis which does so must break
out the cost of the natural gas from the  rest of the O&M costs.  If the geo-
metric series does not start at the beginning of a planning period, it must
be adjusted by multiplying it by the single payment present-worth factor as
follows:

          (gespwftl)  x  (sppwft^)

                                     D-13
-------
     where:   tl  is the period in which the geometric  series  is  in  effect
             t2  is the number of years from the  beginning  of the planning
                 period to the time  the variable  payment  is started

The facility replacement cost identifies the cost required to extend the
useful life of equipment to the end of the planning period.  This  is com-
puted when a capital item has a service life of less than the remaining
years in the planning period, and is computed by:
Replacement Cost = Planning Period - Remaining Service Life
                                Service Life
       x Capital Value
     where:   Capital  Value represents  the capital  that  would  be  required
             today to completely replace the facility.   This  is  a  single-
             payment  cost, with  present worth computed  using  the factor
             sppwf.

Finally, the salvage value represents the value remaining for all  capital
at the end of the planning period, and  is computed by:
Salvage Value = Service Life - Years to Planning End
                            Service Life
x  Capital
     where:   Capital  (or  Capital  Value)  represents  the  initial  investment
             (or  cost  to  replace  today).   This  is  a negative  cost,  with
             the  present-worth  value  computed using the factor  sppwf.


D.7  References

1.  Smith, R., Total  Energy Consumption for Municipal Wastewater Treatment,
    EPA-600/2-78-149,  August 1978"

2.  Wesner,  G.M.; Gulp, G.L.; Lineck, T.S.; and Hinrichs, D.J.; Energy
    Conservation  in Municipal Wastewater Treatment, EPA 430/9-77-011,
    MCD-32,  March 1978
                                     D-14
-------
                                 TABLE D-l

            COMPARATIVE CLEAN WATER OXYGEN TRANSFER INFORMATION
            FOR AIR AERATION SYSTEMS  UNDER STANDARD CONDITIONS (1)
  Type of Aeration Device
 Range of
Clean Water
 Transfer
    Range  of
  Clean Water
  Efficiencies
#02/wire HP-Hr
  Energy
Requirement
  KwH/#02
Mechanical Aerator

  Low Speed Surface               	
  High Speed Surface              	
  Turbine Sparger (2)            14 -  18

Fine Bubble Aerators (3)

  Fine Bubble Diffuser
    (a) Total Floor Coverage     20 -  32
    (b) Side Wall Mounted        15 -  20

  Jet Aerator (2)                15-26

Coarse Bubble Diffuser (3)

  Static Aerator                 10 -  16
  Coarse Bubble Dual Aeration    10 -  13
  Coarse Bubble Single Side
  Aeration                       8-10
                 2.5 - 3.5
                 2.0 - 3.0
                 2.0 - 3.0
                 5.0 - 7.5
                 3.0 - 5.5

                 2.7 - 3.8
                 2.3 - 3.2
                 2.3 - 2.7

                 2.0 - 2.5
                 0.21 - 0.30
                 0.25 - 0.37
                 0.25 - 0.37
                 0.10 - 0.15
                 0.14 - 0.25

                 0.20 - 0.28
                 0.23 - 0.32
                 0.28 - 0.32

                 0.30 - 0.32
(1)  Compiled using a combination of manufacturers' company bulletins,
     technical reports, and historically accepted data ranges.  See text
     on aeration, Section D.2.1, starting on Page D-l for proper use of
     table
(2)  Includes energy requirements for two prime movers
(3)  Based on clean water test at 15" water depth; submergence varies
     depending on device.
                                    D-15
-------
                                  TABLE  D-2
              DESIGN CRITERIA  FOR VACUUM FILTRATION
Sludge Type

Primary


Primary ^ Fed,
Primary +
 Low Lime
Primary +
 High Lime
Primary + WAS


Primary '+
 (WAS + Fed3)

(Primary + Fed.,)
 + WAS
Design Assumptions

Thickened to 1C3J solids
polymer conditioned

85 mg/1 Fed., dose

Lime conditioning
Thickening to 2.5%  solids

300 mg/1  1ime dose
Polymer conditioned
Thickened to 15% solids

600 mg/1  1ime dose
Polymer conditioned
Thickened to 15% solids

Thickened to 8% solids
Polymer conditioned

Thickened to 8% solids
Fed, & lime conditioned

Thickened primary sludge
to 2.5%
Flotation thickened  WAS
to 5*
Dewater blended sludges
Percent
 Solids
  To VF

   10
    2.5
                                                15
                                                15
    3.5
                                                           Typical
                                                           Loading
                                                            Rates,
                                                          fpsf/hr)

                                                           8-10
                                                          1.0-2.0
               10
Percent
 Solids
VF Cake

 25-38


 15-20



 32-35



 28-32
4-5
3
1.5
16-25
20
15-20
Waste Activated
 Sludge (WAS)

WAS + Fed,
Digested Primary
Digested Primary
 + WAS
Thickened to 5% solids
Polymer conditioned

Thickened to 5% solids
Lime +• Fed. conditioned

Thickened to 8-10% solids
Polymer conditioned

Thickened to 6-8% solids
Polymer conditioned
   (WAS + Fed.

Tertiary Alum
Fed
                           lime conditoned
                   Diatomaceous earth
                   precoat
  8-10
  6-8
Digested Primary    Thickened to 6-8% solids    6-8
                          0.6-0.8
             2.5-3.5
             1.5-2.0
                                                            7-8
                                                          3.5-6
                                      2.5-3
              0.4
    15


    15


 25-38


 14-22


 16-18


 15-20
 Source:  Wesner, G.M., et al,  Energy Conservation in Municipal  Wastewater.
         MCD-32, EPA-430/9-77-011,  March 1978.
                                    D-16
-------
                            TABLE  D-3
             DESIGN CRITERIA FOR  FILTER PRESSING
Sludge Type
Primary
Primary + Fed,
Primary + 2 stage
high lime
Primary +• WAS
Primary + (WAS + FeClJ
(Primary + FeClj) •»- WAS
WAS
WAS + FeCl3
Digested Primary
Digested Primary + WAS
Digested Primary +
(WAS + FeCl3)
Tertiary Alum
Tertiary Low Lime
Percent
Solids Typical Cycle
Conditioning To Pressure Filter Length
5% FeC13, 10% Lime
10% Lime
None
5% FeCl3, 10% Lime
5% FeCK, 10% Lime
10% Lime
7.5% FeCK, 15% Lime
5S FeCl-j. 10% Lime
5% FeCl3, 10% Lime
7.5% FeCl3, 15% Line
5% FeCl3, 10% Lime
10% Lime
None
5
4*
7.5
8*
8*
3.5*
5*
5*
8
6-8*
6-8*
4*
8*
2 hours
4
1.5
2.5
3
4
2.5
3'. 5
2
2.5
3
6
1.5
Percent
Solids
Filter Cake
45
40
50
45
45
40
45
45
45
45
40
35
55
*Thickening used to achieve this solids concentration
Source: Wesner, G.M. , et
al, Energy^ Conservation in
Municipal Wastewater,


MCD-32, EPA-430/9-77-011, March  1978.
                               D-17
-------
                                TABLE D-4

                         ENERGY CONVERSION* AND
                       REPRESENTATIVE HEAT VALUES
ENERGY CONVERSION

   Type of Conversion

   Heat to Mechanical
   Heat to Electrical

   Mechanical to Electrical
   Mechanical to Hydraulic

   Electrical to Mechanical
   Electrical to Heat
   Electric to Hydraulic
Efficiency (%)

  s= 38.5
  ^ 32.5
     70-80

  > 90
  =5100
     65-80
REPRESENTATIVE HEAT VALUES OF COMMON FUELS

   Anthracite Coal                             14,200
   Digester Gas                                  600
   Fuel Oil                                  140,000
   Lignite Coal                                7,400
   Liquified Natural  Gas (LNG)                86,000
   Municipal Refuse (25% Moisture)
   Natural Gas
   Propane Gas
   Waste Paper (10% Moisture)
   Wastewater Sludge                          10,000
4,
1,
2,
7,
200
000
500
600
BTU/# Coal
BTU/ft^
BTU/gal
BTU/# Coal
BTU/gal
BTU/lb
BTU/ft3
BTU/ft3
BTU/lb
BTU/lb dry VS
*Refer to References 1  and 2 for further information on energy conversion
 in municipal  wastewater treatment.
                                   D-18
-------
   Multiply

Acres
Atmospheres
Atmospheres
Atmospheres
BTU
BTU
BTU
BTU
BTU/lb
cu ft
cu ft
cu ft
cu ft/second
cu ft/second
cu yd
°F
ft
gal
gal, water
gpd/sp ft
gpm
gpm/sq ft
hp
hp
hp
hp-hr
in
Ib (mass)
mil gal
mgd
ppm (by weight)
psi
sq ft
tons (short)
                                   TABLE D-5

                              CONVERSION FACTORS
43,560
29.92
33.90
14.70
1.055
777.5
3.927 x ID"4
2.928 x ID'4
2.326
28.32
0.03704
7.481
0.6463
448.8
0.765
0.555 (op - 32)
0.3048
3.785
8.345
0.04074
0.06308
0.06790
0.7457
42.44
33.00
2.685
25.4
0.4536
 ,785
 ,785
 .000
 .895
3
3,
1
6.
0.0929
907.2
                          To Obtain
                           in  of  mercury
                           ft  of  water
                           psi
                           KJ
                           ft-lb
                           hp-hr
                           Kw-hr
                           KJ/kg
                           1
                           cu  yd
                           gal
                           mgd
                           gpm
                           m
                           1
                           Ib,  water
                           m^/m2 •  d
                           1/s
                           1/m2 •  s
                           Kw
                           BTU/min
                           ft-lb/min
                           MJ
                           mm
m
 3/d
KN/m2
m2
kg
Notes: Energy conversion in practice should take into account the efficiences
       shown in Table D-4, e.g. to produce an electrical power of 1  Kwh from
       heat energy, the BTU required is 17(2.928 x 1Q-4)(0.325) = 10,508,
       but not l/(2.928 x 10~4) = 3.415 which does not include the actual
       heat to electrical energy conversion efficiency.
                                     D-19
-------
      TABLE D-6
PRESENT WORTH FACTORS
          D-20
-------
  1/4 PERCENT COMPOUND  INTEREST
P R E S E N T W 0 R T H F A C T 0 R S
N

1
••j
3
4
5
6
7
8
9
.10
11
12
1 3
14
15
16
17
18
19
20
SINGLE
PAYMENT
0,94118
0,88581
0,83371
0*78466
0,73851
0,69507
0,65418
0,61570
0,57948
0,54539
0,51331
0,48312
0,45470
0,42795
0,40278
0,37909
0,35679
0,33580
0, 31605
0,29745
UNIFORM
SERIES
0,94118
1,82699
2,66070
3 , 44536
4,18387
4,87894
5,53312
6,14881
6,72830
7,27369
7,78700
8,27012
8,72482
9,15277
9,55555
9,93463
10,29142
10,62722
10,94327
11,24072
GRADIENT
SERIES
0,00000
0,88581
2,55322
4,90722
7. 86 12ft
11. ,33659
15,26167
19,5715*
24,20741
29,1.1596
34 ,24908
39,5*338
45,01975
50,5831.5
56,22204
ft 1,90830
67,61689
73,32546
79,01430
84 , 66594
GEOMETRIC
SERIES 4%
0,94118
1,86242
2,76416
3,64680
4,51075
5,35640
6.18415
6,99436
7,78743
8,56369
9,32352
10,06725
10,79524
11,50781
12,20529
12,88800
13,55625
14,21035
14,85061
15,47730
6 3/8 PERCENT COMPOUND INTEREST - PRESENT  WORTH  FACTORS
N

1
-.>
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
1.9
20
SINGLE
PAlr'MENT
0,94007
0,88373
0,83077
0,78098
0,73418
0,ft9018
0,64882
0,60993
0.57338
0,53902
0,50672
0,47635
0,44780
0,42096
0,39574
0,37202
0,34973
0, 328/7
0,30906
0,29054
UNIFORM
SERIES
0,94007
1 ,82380
2,65458
3,43556
4,16974
4,85992
5,50874
6,11.867
6,69205
7,23107
7.73779
8,21414
8,66194
9,08290
9,47864
9,85066
.;.
-------
6 1/2 PERCENT COMPOUND INTEREST - PRESENT WORTH FACTORS
N

1
•7
3
4
5
6
7
8
9
10
1 .1.
12
13
14
15
16
17
18
19
20
6 5/8
N

1
•~i
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
SINGLE
PAYMENT
0,93897
0,881 6ft
0,82785
0,77732
0,72988
0,68533
0.64351
0,60423
0,56735
0,53273
0,50021
0 , 46968
0,44102
0,41410
0,38883
0,36510
0,34281
0,32189
0,30224
0,28380
UNIFORM
SERIES
0,93897
1,82063
2,64848
3 , 42580
4,15568
4,84102
5,48452
6,08875
6,65611
7, 18883
7,68905
8,15873
8,59975
9,01385
9,40267
9,76777
10,11058
10,43247
10,73472
11,01851
P E R C E M T C 0 M P 0 U N DIN T E R E S T
SINGLE
PAYMENT
0,93787
0,87959
0,82494
0,77368
0,72561
0,68053
0,63824
0 . 59859
0,56140
0,52651
0,49380
0,46312
0,43434
0,40736
0,38205
0,35831
0,33604
0,31516
0,29558
0,27722
UNIFORM
SERIES
0,93787
1,81746
2,64240
3,41608
4,14170
4,82222
5,46047
6,05905
6,62045
7,14696
7,64076
8.10388
8,53822
8,94558
9,32762
9 . 68593
10,02197
10,33714
10,63272
10,90994
                                  GRADIENT-
                                   SERIES

                                   0,00000
                                   0,88169
                                   2,53741
                                   4,86937
                                   7,78892
                                  11,21560
                                  15,07664
                                  19,30626
                                  23,84509
                                  28,63964
                                  33,64178
                                  38,80829
                                  44,10050
                                  49,48382
                                  54,92739
                                  60,40382
                                  65,88882
                                  71,36095
                                  76.80136
                                  82.19347
GEOMETRIC
SERIES 4X

  0.93897
  1.85589
  2,75129
  3,62568
  4,47953
  5,31335
  6.12759
  6.92271
  7,69917
  8,45741
  9,19784
  9.92090
 10,62698
 11,31649
 11,98981
 12,64732
 13,28940
 13,91641
 14,52870
 15,12662
                                  PRESENT WURTH FACTORS
                                  GRADIENT-
                                   SERIES

                                   0,00000
                                   0,87958
                                   2,52944
                                   4,85051
                                   7,75295
                                  .1.1 , 15557
                                  14,98503
                                  19,17515
                                  23,66630
                                  28,40491
                                  33,34291
                                  38,43719
                                  43,64930
                                  48,94492
                                  54,29354
                                  59,66814
                                  65,04485
                                  70,40265
                                  75,72314
                                  80.99026
GEOMETRIC
SERIES 4%

  0,93787
  1.85264
  2,74490
  3.61519
  4,46405
  5,29202
  6,09960
  6,88730
  7,65561
  8,40500
  9,13594
  9,84889
 10,54429
 11,22257
 11,88414
 12,52944
 13,15884
 13,77275
 14,37.1.54
 14,95560
                           D-22
-------
6 3/4 PERCENT COMPOUND INTEREST
                         P R E S £ N T W 0 R T H F A C T 0 R S
  N
  .1.
  'P
  3
  4
  5
  o
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 .1.8
 19
 20
SINGLE
PAYMENT

0*93677
0,87753
0,82205
0,77007
0.72137
0,67576
0,63303
0,59300
0,55551
0,52038
0,48748
0,45665
0,42778
0,40073
0,37539
0,35165
0,32942
0,30859
0,28907
0,27080
 UNIFORM
 SERIES

 0.93677
 1,81430
 2.63635
 3,40642
 4,12779
 4,80355
 5.43658
 t>,02958
 6,58509
 7,10547
 7,59295
 8,04960
 8,47738
 8,87811
 9,25349
 9,60515
 9,93456
10,24315
10,53223
10,80302
o 7/8 PERCENT COMPOUND INTEREST
  N
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 •~i r.
SINGLE
PAYMENT

0,93567
0,87548
0,81917
0-76647
0,71717
0,67103
Q.&2787
0,58748
0,54969
0,51433
0,48124
0,45028
0,42132
0,39422
0,36886
0,34513
0.32293
0,30215
0,28272
0.26453
 UNIFORM
 SERIES

 0.93567
 1.81116
 2.63032
 3.39679
 4,11396
 4.78499
 5,41286
 6,00033
 6,55002
 7,06434
 7,54559
 7,99587
 8,41719
 8,81140
 9,18026
 9,52539
 9.84832
10,15047
10,4331.9
10,69/?2
GRADIENT
SERIES
0,00000
0,87754
2,52163
4,83184
7,71733
11,09613
14,89432
19,04535
23,48941
28,17282
33, 04758
38,07076
43,20408
48,41355
53,66900
58,94379
64,21445
69,46043
74,66379
79,80891
PRESENT
GRADIENT
SERIES
0,00000
0.87549
2.51381
4.81323
7,68189
11,03704
14,80424
18,91660
23,31408
27.94302
32.75544
37.70856
42.76437
47.88918
53.05318
58,23012
63,39697
08 , 533oO
73,62253
78,64863
GEOMETRIC
SERIES 4%
0,93677
1 .84940
2,73853
3,60475
4,44866
5,27082
6,07181
6,85216
7,01241
8,35307
9.074&5
9.77765
10,46253
11,12977
11,77983
12,41313
13,03013
13,63122
14,21684
14,78736
WORTH FACTORS
GEOMETRIC
SERIES 4%
0,93567
1 ,84617
2.73218
3.59436
4, 43334
5,24975
6,04420
6,81728
7,56957
8,30161
9,01397
9.70716
10.38170
11 .03810
11 .67684
12,29840
12,90323
13,49180
14.0*454
14 ,6218o
                           D-23
-------
7 PERCENT CONFOUND INTEREST

  N
                     PRESENT WORTH FACTORS
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
SINGLE
PAYMENT

0*93458
0*87344
0,81630
0,76290
0,71299
0,66634
0,62275
0,58201
0,54393
0,50835
0,47509
0,44401
0,41496
0,38782
0,36245
0,33873
0,31657
0,29586
0,27651
0,25842
 UNIFORM
 SERIES

 0,93458
 1,80802
 2,62432
 3,38721
 4,10020
 4,76654
 5,38929
 5,97130
 6,51524
 7,02358
 7,49868
 7,94269
 8.35765
 8,74547
 9.10792
 9,44665
 9.76323
10,05909
10,33560
10.59402
7 1/8 PERCENT COMPOUND INTEREST -
  N
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
SINGLE
PATHENT

0,93349
0,87.1.40
0.81344
0,75934
0,70884
0,66169
0,61768
0.57660
0,53825
0,50245
0,46903
0,43783
0,40871
0,38153
0,35615
0,33247
0,31035
0,2897.1
0,27044
0,25245
 UNIFORM
 SERIES

 0,93349
 1.80489
 2,61833
 3.37767
 4,08651
 4.74820
 5,36588
 5.94248
 6,48073
 6,98317
 7,45220
 7.89004
 8,29875
 8.68028
 9,03644
 9,36890
 9,67925
 9,96897
10,23941
10,49186
GRADIENT
SERIES
0 , 00000
0,87345
2.50606
4,79476
7,64671
10,97843
14,7.1494
18,78901
23,14049
27,71562
32 , 46658
37,35071
42.33029
47,37190
52,44617
57,52719
62,59238
67,62207
72.59923
77.50919
PRESENT
GRADIENT
SERIES
0.00000
0,87138
2.49827
4, 77628
7,61161
10,92006
14,62614
18,66232
22,96830
27.49032
32.18063
36.99680
41,90136
46,86125
51.84739
56,83438
61 ,80002
66,72511
71 ,59306
76,38969
GEOMETRIC-
SERIES 4%
0,93458
1,84295
2,72586
3,58401
4,41811
5,22881
6,01679
6.78267
7,52708
8,25062
8,95387
9,63741
10,30178
10,94752
11,57516
12,18520
12,77813
13,35445
13,91460
14,45905
WORTH FACTORS
GEOMETRIC
SERIES 4X
0,93349
1,83975
2.71957
3.57372
4,40296
5,20801
5,98957
6, 74834
7,48497
8,20011
8,89439
9,56841
10,22278
10,85805
11,47480
12,07355
.12,65483
1 3 , 2 1 9 1 6
13,76703
14,29891.
                         D-24
-------
7 1/4 PERCENT COMPOUND INTEREST - PRESENT WORTH FACTORS
N

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
SINGLE
PAYMENT
0,93240
0,86937
0,81060
0,75581
0,70471
0,65708
0, «>1266
0,57124
0.53263
0,49662
0,46305
0,43175
0,40256
0,37535
0,34998
0,32632
0,30426
0,28369
0,26452
0,24663
UNIFORM
SERIES
0,93240
1,80177
2,61238
3,36818
4,07290
4,72997
5,34263
5,91388
6,44651
to. 943 13
7,40618
7,83793
8,24050
8,61585
8,96582
9,29214
9 , 59640
9,88010
10, 14461
10,39125
GRADIENT
SERIES
0,00000
0,86938
2,49058
4, 75800
7,57687
10,86225
14.53820
18,53691
22,79795
27,26755
31 ,89807
3ft. 64732
41,47811
46 , 3576ft
51,25735
56,15215
61 ,02031
65,84309
70,60438
75,29044
GEOMETRIC-
SERIES 4%
0,93240
1 , 83655
2,71330
3.56348
4,38789
5,18733
5.96254
6,71425
7,44319
8,15004
8,83547
9,50013
10, 14465
10,76964
11,37569
11,96337
12,53324
1 3 , 08585
13,62171.
14,14133
7 3/8 PERCENT COMPOUND INTEREST
PRESENT WORTH FACTORS
N

1
•->
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
SINGLE
PAYMENT
0,93132
0.86735
0,80778
0, 75229
0, 7 00 ft 2
0,65250
0,60768
0,56595
0.52707
0,49087
0,45716
0 , 42576
0.39*51
0 , 36928
0,34392
0 , 32029
0 , 29829
0,27781
0,25873
0,24096
UNIFORM
SERIES
0,93132
1 , 79866
2 . 60644
3,35873
4,05936
4,71186
5,31954
5,88549
ft, 4 125ft
6,90343
7,36059
7,78635
8,18286
8,55214
8,89ft06
9,21635
*,51465
9, 792"»5
10, 05 118
.1.0,29213
GRADIENT
SERIES
0 , 00000
0,86735
2,48290
4,73979
7,54229
10,80479
14,45090
18.41252
22,62910
27,04696
31 ,61852
36.30186
41 .06002
45,86065
50.67550
55.47991
60,25264
64,97534
6*, 632 40
74,21057
GEOMETRfC
SERIES 4X
0,93132
1,83336
2,70705
3,55328
4,37290
5 , 1 6 6 7 7
5.93568
ft. ft 804. 3
7,40177
8.10043
8 . 7 7 7 1 3
9.43257
10.06740
10,68228
1 1,27785
11 ,8546ft
1.2,41336
12,95450
13, 4 78 ft 3
13,98ft28
                           D-25
-------
7 1/2 PERCENT COMPOUND INTEREST - PRESENT WORTH FACTORS
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
SINGLE
PAYMENT

0.93023
0,86533
0*80496
0*74880
0,69656
0,64796
0*60275
0*56070
0*52158
0*48519
0.45134
0*41985
0*39056
0*36331
0*33797
0,31439
0,29245
0.27205
0,25307
0,23541
 UNIFORM
 SERIES

 0,93023
 1.79557
 2*60053
 3*34933
 4,04589
 4,69385
 5.29660
 5.85731
 6,37889
 6.86408
 7.31543
 7.73528
 8*12584
 8*48916
 8,82712
 9*14151
 9,43396
 9*70601
 9,95908
10,19449
7 5/8 PERCENT COMPOUND INTEREST
  N
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
SINGLE
PAYMENT

0,92915
0,86332
0*80216
0,74533
0,69252
0,64346
0*59787
0*55551
0,51616
0.47959
0,44561
0,41404
0,38471
0,35745
0,33213
0*30860
0*28673
0,26642
0,24754
0,23000
 UNIFORM
 SERIES

 0,92915
 1,79247
 2,59463
 3,33996
 4.03248
 4.67594
 5.27381
 5,82933
 6,34548
 6,82507
 7.27068
 7,68472
 8,06943
 8*42688
 8*75900
 9*06760
 9.35433
 9.62075
 9,86829
10.09830
GRADIENT
SERIES
0 . 00000
0*86535
2,47528
4,72168
7 , 50792
10,74774
14,36427
18.28918
22,46185
26,82860
31,34205
35.96044
40,64718
45,37028
50*10181
54,81760
59,49685
64, 12168
68,67695
73,14979
PRESENT
GRADIENT
SERIES
0 , 00000
0,86331
2,46763
4. 70360
7,47368
10,69098
14,27821
18,16678
22,29603
26,61232
31.06842
35.62286
40.23932
44,88617
49,53593
54,16485
58,75256
63.28167
67,73743
72,10752
GEOMETRIC
SERIES 4%
0,93023
1,83018
2.70082
3,54312
4 , 35800
5.14634
5,90902
6,64687
7 , 36069
8,05127
8,71937
9,36571
9,99102
10,59596
11 ,18121
11,74740
12,29516
12,82508
13,33775
13,83373
WORTH FACTORS
GEOMETRIC
SERIES 4%
0,92915
1,82701
2,69462
3.53302
4.34317
5,12604
5.88254
6.61355
7.31995
8.00255
8,66217
9,29956
9,91549
10,51067
11 ,08580
11,64157
12,17861
12,69757
13,19904
13,68363
                          D-26
-------
7 3/4 PERCENT COMPOUND INTEREST -- PRESENT WORTH FACTORS
N

1
2
3
4
5
6
7
8
9
.1.0
11
12
13
14
15
16
17
18
19
20
7 7/8
N

1
•"}
A*.
3
4
5
6
7
8
9
10
11
.1.2
13
14
15
16
17
18
19
20
SINGLE
PAYMENT
0,92807
0.86132
0.79937
0.74188
0 , 68852
0.63899
0.59303
0,55038
0.51079
0,47405
0,43996
0,40831
0,37894
0,35169
0,32639
0,30292
0,28113
0,26091
0,24214
0,22473
UNIFORM
SERIES
0.92807
1.78940
2.58877
3,33064
4,01916
4,65815
5,25118
5,80156
6,31235
6,78641
7.22636
7.63468
8.01362
8.36531
8,69170
8,99462
9,27575
9,53666
9,77880
10,00353
PERCENT COMPOUND INTEREST
SINGLE
PAYMENT
0,92700
0,85933
0,79659
0,73844
0,68454
0, 03456
0,58824
0,54530
0,50549
0,46859
0,43438
0,40267
0.37328
0.34603
0,32077
0,29735
0,27564
0,25552
0,23o87
0,21958
UNIFORM
SERIES
0,92700
1 , 78633
2,58292
3,32136
4,00590
4,64046
5,22870
5,77400
6,27949
6.74808
7.18246
7.58513
7.95841
8.30443
8,62520
8,92255
9,19819
9,45371
9,69058
9.91015
                                  GRADIENT
                                   SERIES

                                   0,00000
                                   0,86132
                                   2.46006
                                   4,68568
                                   7,43974
                                  10,63470
                                  14,19290
                                  18,04555
                                  22.13J.88
                                  26,39838
                                  30,79794
                                  35,28938
                                  39,83670
                                  44.40865
                                  48,97816
                                  53,52191
                                  58.01997
                                  62,45543
                                  66.81399
                                  71,08381
GEOMETRIC
SERIES 4%

  0.92807
  1.82385
  2.68845
  3.52296
  4.32842
  5,10586
  5,85623
  6,58049
  7,27955
  7,95427
  8,60552
  9,23410
  9.84080
 10,42638
 10,99159
 11,53713
 12,06368
 12,57190
 13,06244
 13,53591
                                  PRESENT WORTH FACTORS
                                  GRADIENT
                                   SERIES

                                   0.00000
                                   0,85932
                                   2,45252
                                   4.66784
                                   7.40598
                                  10.57879
                                  14,10825
                                  17,92533
                                  21.96925
                                  26.18654
                                  30.53036
                                  34.95974
                                  39.43904
                                  43.93739
                                  48.42811
                                  52,88836
                                  57,29864
                                  61 ,04248
                                  65,90608
                                  70.07800
GEOMETRIC
SERIES 4%

  0,92700
  1.82070
  2,68230
  3.51294
  4.31375
  Si 08580
  5,83011
  0.54768
  7,23948
  7,90643
  8,54942
  9,16931
  9,76694
 10.34309
 10,89855
 11,43406
 11,95034
 12,44806
 1.2,92791
 13,39052
                           D-27
-------
8 PERCENT COMPOUND INTEREST - PRESENT WORTH FACTORS
N

1
7
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
SINGLE
PAYMENT
0*92593
0,85734
0*79383
0*73503
0,68058
0*63017
0*58349
0*54027
0.50025
0*46319
0*42888
0*39711
0,36770
0*34046
0*31524
0*29189
0.27027
0.25025
0.23171
0,21455
UNIFORM
SERIES
0,92593
1 . 78327
2.57710
3.31213
3*99271
4.62288
5.20637
5.74664
6.24689
6.71008
7,13897
7,53608
7.90378
8.24424
8.55948
8.85137
9. 12164
9,37189
9,60360
9,81815
GRADIENT
SERIES
0 . 00000
0.85735
2.44502
4,65011
7,37245
10,52330
14,02425
17,80614
21.80813
25*97688
30,26571
34*63395
39,04t>33
43*47233
47*88572
52,26407
56 , 58838
60,84262
65,01342
69,08986
GEOMETRIC
SERIES 4%
0,92593
1*81756
2.67617
3*50297
4*29916
5*06586
5*80416
6*51512
7,19974
7,85901
8*49386
9*10520
9*69389
10,26078
10*80668
11,33236
11,83857
12,32603
12,79543
13,24745
8 1/8 PERCENT COMPOUND INTEREST - PRESENT WORTH FACTORS
  N
  4
  5
  6
  7
  8
  9
 10
 1.1.
 12
 13
 14
 15
 16
 17
 18
 .1.9
 20
SINGLE
PAYhENT

0,92486
0,85536
0,79108
0.73164
0,67666
0*62581
0.57879
0.53529
0,49507
0,45787
0,42346
0,39164
0,36221
0,33499
0.30982
0.28654
0.26501
0,2450'?
          ,
UNIFORM
SERIES

0.92486
1.78021
2,57129
3.30293
3,97959
4,60540
5,18418
5.71948
6,21455
6,67241
7,09587
7,48751
7,84972
8,18471
8,49453
8,78107
9,0'1-608
9,29117
9,51784
9,72749
GRADIENT
 SERIES

 0,00000
 0,85535
 2.43750
 4,63241
 7.33904
10.46810
13,94079
17,08785
21*64838
25,76918
30.00378
34,31183
38,65834
43*01323
47.35068
51,64877
55.88887
60,05543
64. 1.3557
68,118/6
GEOMETRIC
SERIES 4%

  0,92486
  1,81443
  2,67006
  3,49305
  4,28465
  5,04604
  5,77839
  6,48280
  7,16033
  7,81202
  8.43885
  9.04176
  9,62167
 10,17945
 10,71596
 11,23200
 11,72835
 12,2057o
 .1.2,66497
 13, 1.0665
                          D-28
-------
o
 i
N5
Control Facilities, EPA-600/2-77-214, November 1977
CO
o
c:
-s
O C
n> _ c
0
0
s:
fD
to
3
-5
**
•
3
C
m ^
fD "0
-S
to o
,000
APACITY, gpm
y Requirements for f*'
c
5. o
o "o
-•• o
n o
Q)
T3
O
C
c+
o
3
WIRE TO WATER EFFICIENCY, percent
n S -J o»
5 ° 0 o






















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\
\
\
\
\
\



















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\
\



















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\
\
\
\
\




















^
\
\




















FIGURE D-1
HYDRAULIC EFFICIENCY OF CENTRIFUGAL PUMPS


-------
                             FIGURE D-2

              POWER REQUIREMENTS FOR RAW  SEWAGE  PUMPING
a
7
8
9
4
3
2
1,000,000
8
6
s
4
1
o
\u
tt
a 100,000
w 9
at a
5 I
Ul
X 4
Ul
i
Ul
u 10,000
7
6
9
4
3
2
1 000

— 100 mj
hELECI

















j
^
/

f


jf
/
/
/
A, TDH a ,10
fRICAL















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/
'
/
S




S
t

/















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/


El









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J
4E








~~.
/
0,
RC

|

--I-



-
/




y

y

^



f



>

<
^
—
-,





"~ 'i

i
/

—





tH 	 1— -t-t-r-H-Hi 	 f— -h r-
rr
Y



1

"t
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-^
^

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r i
REQUIRI








S
/ /



jr
r


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/
/
	








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/
/
	







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14,500,000-












/-

A-
T^
V,







t
y


/
^
—
5S
/p
ar









r<-
F
/






/




.

^






_

-H

r

^4 >
~t
^
/


x




-TDH =


y
/V
^ — ./
" .y
y
f y


'/I







'I0r7t
y y
/





y
/
y
/







/





/








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^.

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(
V1


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V
r'
— tX
'

/



^
-?"
r

-
'










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/
/

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x'-TDHa

40 f* r-f
-7 TDH, 30 f. ^J
r
>


/r T
*" ^r 	
f
f













!
f
HS
DH =



	 .










10
: 5















umptions
ical constant speed centrifugal
iable level wet well

--













T_.




















































—


• i

ft
ft
































u



















t
i

























pumps




-






.. .
--

         2   34 9(789     2  34 9(789     2  34 96789     2  34 9(789
    0.1                1.0               10               100               1,000

                                FLOW, mgd
Source:
        RAW SEWAGE PUMPING  (CONSTANT  SPEED)

Wesner, G.M., et al, Energy Conservation in  Municipal Wastewater,
MCD-32, EPA-430/9-77-011, March  1978
                                 D-30
-------
                                     FIGURE  D-3
                    ANAEROBIC DIGESTER HEATING  REQUIREMENTS
    10
-a
0)
a-
ai
(U
3
!fl
       15
           Temp. Difference = Digester Temp.  -  Influent Sludge Temp.
                                                                         ]% Solids Feed
                                                                         4%
                                                                         5%
20         25         30         35

          Temperature Difference, °F
                                                           40
                                                     45
                                         D-31
-------
-a
a;
to
-a
o
GO
c:
o
CQ

c
o
c:
cu

o;

to
CO
o
ro
O)
Q.
^
CL)
4.5




4




3.5




3




2.5




2




1.5



1



0.5




0
                            FIGURE D-4


                   ANAEROBIC DIGESTER HEAT LOSS
          r
             Values  shown are for the Northern  U.S.   For the
r (-    Middle U.S., multiply indicated heat requirements
     f" by 0.5.   For the  Southern U.S.   multiply heat
       requirements by 0.3.
                                                                            soi-
                                                                          2%
                           4%


                           5%

                           6/0
                      10
                             15
20
25
30
                        Reactor Hydraulic  Detention Time, Days
                                D-32
-------
                       FIGURE  D-5

        ANAEROBIC DIGESTER  HEAT  PRODUCTION
10 ,
   30
                                       Feed Volatile
                                       Solids = 50%
                       15  ft  gas produced/1b of VSS  destroyed
                        1  ft  of gas produces 600 BTU
 40         50         60

Volatile Solids Destruction, %
70
                            D-33
-------
10,000,000
                                   FIGURE D-6



              HIGH  RATE ANAEROBIC  DIGESTER MIXING  REQUIREMENTS
9
7
6
5
4
3
2
1,000,000
9
8
7
6
K 9
1 «
3
Q
UJ
5
0
UJ
" 100,000
o 9
S '
z 6
UJ S
i :
U 2
UJ Z
UJ
10,000
1
5
4
3
Z
1,000
10









	





























































-






















































Assumptions:
-Continuous operation
-20' submergence for gas
release
-85-93% motor efficiency





































































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f









s

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**
/
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f
s
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r. k i











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X X
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                               FIGURE  D-7

                          SLUDGE PUMPING  ENERGY
                            FOR HEAT EXCHANGE
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                                    D-35
-------
                       FIGURE  D-7 (a)
           ANAEROBIC DIGESTER HEAT REQUIREMENTS
                     FOR PRIMARY SLUDGE
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              DIGESTION
                        TEMPERATURE:
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        30
                      40           50             60


                      SLUDGE TEMPERATURE  TO  DIGESTER,
                          70
                              D-36
-------
                    FIGURE D-7  (b)
       ANAEROBIC DIGESTER HEAT  REQUIREMENTS  FOR
          PRIMARY PLUS WASTE ACTIVATED SLUDGE
DIGESTER  LOADING'
         0.05  Ib VS/doy/cu ft
         0. 15  	
         40          50          60          70
            SLUDGE  TEMPERATURE  TO  DIGESTER, °F
60
                           D-37
-------
   11.0





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    5.0
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    3.0
                       FIGURE D-8
           FRACTION OF SOLIDS  VS  WATER CONTENT
               0.5 = Volatile Solids Fraction
0.6
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    1.0
        0.1
        0.2
0.3         0.4



  Fraction of Solids
0.5
                           D-.ls
-------
             FIGURE D-9

        FLUE GAS TEMPERATURE
ATTAINABLE AT DIFFERENT WATER CONTENT
                             Excess
             1000        1200        1400

                   Flue Gas Temperature , °F
                 D-39
-------
                          FIGURE  D-10


                SUPPLEMENTAL  FUEL REQUIREMENT
                       AT  50%  EXCESS AIR
                           50% Excess Air
GO
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    250
                                  Water Content
£   200
     150
     100
      50
        600
800
1000
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                                 Flue Gas Temperature, °F
                              D-40
-------
                          FIGURE D-ll


                 SUPPLEMENTAL FUEL REQUIREMENT
                      AT 100% EXCESS AIR
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                               D-41
-------
                   FIGURE D-12
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    3.0
    2.5
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                                    Water Content
                                       W =1.5
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      Flue Gas Temperature, °F
                      D-42
-------
                       FIGURE D-13


          HEAT  RECOVERY FROM WASTE HEAT BOILER
    6000
    5000
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                                    FIGURE D-14


                    ENERGY  REQUIREMENTS FOR VACUUM FILTRATION
9
8
7
6
5
4
3
2
1
9
8
7
6
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See Table D-2 for design assumptions
Operating Parameters:
2 scfm/sq ft
20-22 inches Hg vacuum
Filtrate pump, 50 ft TDH
Curve includes: drum drive, discharge
roller, vat agitator, vacuum pump,
filtrate pump.
1 1 1 1 1 II 1 1 1 I


















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                     3  4
56789

      100
3  4
56789

      1,000
                             5 6 789

                                  10,000
                                VACUUM FILTRATION AREA, sq ft
      Source:   Wesner, G.M.,  et al, Energy Conservation  in Municipal
                Wastewater,  MCD-32, EPA-430/9-77-011, March 1978
                                        D-44
-------
                                    FIGURE  D-15

                     ENERGY  REQUIREMENTS FOR FILTER PRESSING
 10,000,000
•f 1,000,000
*
s
-------
                                   FIGURE D-16


                       ENERGY  REQUIREMENTS FORCENTRIFUGING
  10,
            Operating  Conditions:
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• Dewatering accomplished with low speed centrifuge, G 700'
- Sludge Type Conditions
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                     3  456789
                                            3  4
                                 10
56789

      100
56 789
     1,000
                                         FLOW, gpm
       Source:  Wesner, G.M., et al,  Energy  Conservation in Municipal Wastewater,
                MCD-32, EPA-430/9-77-OH,  March  1978
                                       D-46
-------
                                          APPENDIX  E

               INNOVATIVE  AND ALTERNATIVE TECHNOLOGY  GUIDELINES
  L  Purpaje. These guidelines provide the
criteria for identifying and evaluating Inno-
vative and alternative waste  water treat-
ment processes and techniques. The Admin-
istrator may publish additional information.
  2.  Authority.  These  guidelines axe  pro-
vided under section 304(d)(3) of the Clean
Water Act.
  3. Airplica.lrU.ity. These guidelines apply to:
  a. The analysis oi innovative and alterna-
tive  treatment  processes  and techniques
under § 35.91T-l(dX8>:
  b. Increased, grants for eligible treatment
works  under  §§35.330-6  (b)  and  (c)  and
33J308(bXl);
  c.  The  funding, available for  Innovative
and  alternative processes and techniques
under ?3S.315-Ub):
  d. The funding available for alternatives
to. conventional treatment works for small
communities under § 35.915-Ue);
  e. The cost-effectiveness preference given
Innovative and  alternative processes  and
techniques in section 7 of appendix A to this
subpart;
  f. The treatment works, that may be given
higher priority on  State  project  priority
lists under 5 35.315(IXUi):
  f.  Alternative and innovative  treatment
systems in connection  with Federal facul-
ties:
  h.   Individual  systems , authorized   by
J35.918, as modified in that section to in-
clude unconventional or innovative sewers;
  L The access  and reports conditions in
f 35.935-20.
  +. Alternative processes  and  techniques.
Alternative waste wate%treatment processes
and techniques  are proven methods which
provide  for the- reclaiming  and reuse of
water, productively recycle waste water con-
jtitnents  or  otherwise eliminate the dis-
charge of pollutants, or recover energy.
  «. la Use case of processes and techniques
for the treatment of effluents, these include
land treatment, aquifer recharge, aquacul-
ture, sUvtculture. and: direct nose for indus-
trial, and other nonpotable purposes, horti-
cultore and revegetation oi disturbed- land.
Total containment .ponds and ponds, for the
treatment and storage of waste water pnor
to- land application- and other processes nec-
essary to provide minimum levels of preap-
plirarion  treatment are considered  to  be
pan of  alternative technology systems for
the purpose of this section.
  ts. For sludges, these  include land applica-
tion for norucultural.  sUvtcultural. or agri-
cultural  purposes (including  supplemental
processing by means such as composting or
drying>, and reregetation of disturbed lands.
  c. Energy recovery facilities  Include codls-
posal measures for sludge and refuse which
produce  energy: anaerobic digestion facili-
ties (Provided, That more than 90 percent
of the methane gas is- recovered and used as
fuel): and equipment which provides for the
use of digester gas within the  treatment
works. Self-sustaining Incineration may also
be included provided that the energy recov-
ered and productively used Is greater than
the energy consumed to dewater the sludge
to an autogenous state.
  d. Also Included are individual  and other
onsite treatment systems with subsurface or
other means  of effluent disposal  and facili-
ties constructed for the specific purpose of
septage treatment.
  e. The  term "alternative" as used in these
guidelines includes the  terms "unconven-
tional" and "alternative to conventional" as
used In the Act.
  f. The  term "alternative" does not Include
collector sewers, interceptors, storm or sani-
tary sewers  or the separation thereof;  or
major sewer  rehabilitation, except  insofar
as they   are  alternatives  to  conventional
treatment works  for small  communities
under § 35.915-Ue) or part of individual sys-
tems under §  35.913.
  5.  fnnovative processes  and  tech-nitrites.
Innovative waste water treatment  processes
and   techniques  are  developed  methods
which have not been fully proven under the
circumstances of  their  contemplated  use
and which represent a significant advance-
ment  over the state of the art in terms of
meeting  the  national  goals of cost reduc-
tion, increased energy conservation or recov-
ery, greater  recycling  and conservation  of
water resources (including preventing the
mixing of pollutants with water), reclama-
tion or reuse-of effluents and resources (In-
cluding   increased  productivity   of  arid
lands), improved efficiency and/or reliabil-
ity, che beneficial use of sludges or effluent
constituents,  better  management of toxic
materials or  increased environmental bene-
fits. For  the purpose-of these guidelines, in-
novative  waste water  treatment  processes
and techniques are generally limited to new
and improved applications of those alterna-
tive processes and techniques Identified in
accordance with paragraph 4 of these guide-
lines,  including both  treatment at central-
ized  facilities  and  individual and  other
onsite   treatment.   Treatment   processes
based on the  conventional concept of treat-
ment  (by means of biological or physical/
chemical  unit processes) and discharge  to
surface waters shall not be considered inno-
vative waste  water treatment processes and
techniques except  where it la demonstrated
that these processes  and techniques,  as a
                                             E-l
-------
minimum, meet either the cost-reduction or
energy-reduction criterion described in sec-
tion 8 of these" guidelines. .Treatment and
discharge systems  Include  primary  treat-
ment,  suspended-growth  or  fixed-growth
biological systems for secondary or advance
waste  water treatment, physical/chemical
treatment,  disinfection.  2nd sludge process-
ing. The term "innovative" does not include
collector sewers, interceptors, storm or sani-
tary sewers or  the separation  of  them,  or
major sewer rehabilitation, except insofar
u they meet the criteria in paragraph S of
these guidelines and are alternatives to con-
ventional treatment works for small commu-
nities under § 35.915-l(e) or part of individu-
al systems under § 35.918.
  6.  Cntena for  determining  innovative
processes and techniques, a. The  Regional
Administrator will use the following criteria
in determining, whether a waste water treat-
ment  process or  technique is  innovative.
The criteria should be .read in the context
of paragraph 5. These criteria do not neces-
sarily preclude  a determination by the Re-
gional  Administrator  that a treatment
system is innovative  because of local vari-
ations in geographic  or climatic conditions
which affect treatment plant design and op-
eration or  because  it achieves significant
public benefits through the advancement of
technology  which would otherwise not  be
possible.   The   Regional   Administrator
should  consult  with  EPA headquarters
about determinations made in other EPA re-
gions on similar processes and techniques.
  b. New or improved applications of alter-
native waste water treatment processes and
techniques  may be innovative'  for the pur-
poses of this regulation if they meet one or
more  of the criteria in  paragraphs eU)
through eiSt of this paragraph. Treatment
and discharge systems (i.e.. systems which
are not new or improved applications of  al-
ternative waste water treatment  processes
and techniques in  accordance with para-
graph 4 of these guidelines) must  meet the
criteria, of  either paragraph SeU) or 5e<2),
aa a mjnimiim,  m order to be innovative for
the purposes of these guidelines.
  c. These  six  criteria are essentially  the
same as those used to evaluate any project
proposed for grant assistance. The principal
difference   is  that some newly  developed
processes and techniques may have the po-
tential to provide significant advancements
in the state of the art with respect to one or
more of these criteria. Inherent in the con-
cept of advancement of  technology is  a
degree of risk which Is necessary to initially
demonstrate a method on a full, operational
scale under the circumstances of its contem-
plated use.  This nsfc. while recognized to be
a necessary element in the implementation
of  innovative  technology,  must  be mini-
mized by  limiting  the projects funded to
those which have been fully developed and
shown to be feasible through operation on a
smaller scale. The  risk must also be  com-
mensurate with the potential benefits (i.e.,
greater potential benefits must be possible
in the case of innovative technology pro-
jects where greater risk is involved).
  d.   Increased  Federal   funding  .under
35.908(b)  may  be made only from the re-
serve in § 35.915-Ub). The Regional Admin-
istrator may  fund a  number of projects
using the-same type of innovative technol-
ogy if he  desires to encourage certain inno-
vative processes and techniques because the
potential  benefits are great in comparison
to the risks, or if operation under differing
conditions of climatic, geology, etc.. is desir-
able to demonstrate the technology.
  e.  The  Regional  Administrator will use
the following criteria to determine whether
waste  water treatment processes and  tech-
niques are innovative:
  (1)  The life  cycle cost  of the treatment
worts is at least 15 percent less than that
for the most cost-effective alternative which
does not incorporate innovative waste water
treatment processes and techniques  (I.e..  is
no more than  35 percent of the life  cycle
cost  of the most cost-effective nonmnova-
tive alternative).
  (2) The net primary energy requirements
for the operation of the treatment  works
are at least  20 percent  less than the net
energy requirements of the  least net energy
alternative which does not incorporate inno-
vative waste water  treatment processes and
techniques  (Is.,  the  net  energy require-
ments are no more  than 80 percent of those
for the least net energy noninnovaiive alter-
native). The least net energy noninnovative
alternative must be one of  the alternatives.
selected for analysis under  section S  of ap-
pendix A.
  (3) The operational reliability of the treat-
ment  works  is improved  in terms  of de-
creased susceptibility to upsets or interfer-
ence,  reduced  occurrence  of inadequately
treated discharges  and decreased levels  of
operator attention and skills required.
  (4)  The treatment works provides for
better management of toxic materials which
would otherwise result in  greater environ-
mental hazards.
  (5) The treatment  works results  in  in-
creased  environmental  benefits such   as
water conservation, more  effective land use,
improved  air quality,   improved  ground
water quality, and reduced resource require-
ments for the construction and operation  of
the works.
  (W The treatment works  provide for new
or improved methods of joint treatment and
management  of municipal and industrial
wastes that  are  discharged into- municipal
systems.

  Cm Doc. 78-27241 Filed 9-28-T3; 8:45 am]
           FEDERAL HEG1STW, VOL 43, MO. 1M—WEDNESDAY, SHTEM8E* 27, 1978
                                        E-2
-------
                                      APPENDIX  F

               THE COST  EFFECTIVENESS  ANALYSIS  GUIDELINES
  L Purpose.  These  guidelines  represent
 Agency  policies  and procedures for deter-
 mining the most cost-effective waste treat-
 ment  rrmr-'igemeat system  or component
 part.
  2.-Authority.  These  guidelines  axe  pro-
 vided  under sections 212C2XC) and 217  of
 the Clean Water Act.
  3. Applicability. These guidelines, except
 as  otherwise noted,  apply to all  facilities
 planning under step  1  grant  assistance
 awarded  after  September 30, 1978.  The
 guidelines also apply to State or locally  fi-
 nanced facilities planning on which subse-
 quent step 2 or step 3 Federal grant assist-
 ance is based.
  4. Definitions. Terms-used In these guide-
 lines are defined as follows:
  a. Was is  treatment management system*
 Used svno: .ymously with "complete waste
 treatment system" as defined in {35.905  of
 this subpare.
  b. Cost-effectiveness analysis. An analysis
 performed c,o determine which waste treat-
 ment  management system  or component
 part will r»sult  In the  minimum  total re-
 sources  c- its over time to meet  Federal.
 State, or.  cal requirements.
  c. Planr  no period. The period over which,
 a waste  treatment management system  Is
 evaluated for cost-effectiveness.  The plan-
 ning period begins with  the system's initial
 operation.
  d. Useful life. The  estimated period  of
•time during  which a treatment works  or a
 component  of  » waste treatment  manage-
 ment system will be operated.
  e. Di3a.gyrtga.tion. The process or result  of
 breaking down a sum total of population  or
 economic activity for a State or other juris-
 diction (i.e.,  designated 208 area or SMSA)
 into smaller areas or Jurisdictions.
  5. Identification, selection, and screening
 of alternatives, a. Identification of alterna-
 tives. All -'-asible alternative waste manage-
 ment sysi-ms  snail be  initially  identified.
 These alternatives should Include systems
 discharging to  receiving waters, land appli-
 cation systems, on-site  and other  non-cen-
 tralized systems. Including revenue generat-
 ing applicr .ions, and systems employing the
 reuse of wastewater and reeycyling of  pol-
 lutants. In identifying alternatives, the- ap-
 plicant shall consider-the possibility of no
 action and  staged  development  of  the
 system.
  b. Screening of alternatives. The identi-
 fied alternatives  shall  be  systematically
 screer.ed  to  determine  those capable of
 meeucg  the  applicable Federal, State  and
 local criteria.
  c. 3-elfction of alternatives. The identified
 alternatives shall tw Initially analyzed to de-
 termine  which systems  have cost-effective
potential and which should be fully evaluat-
ed according to the cost-effectiveness analy-
sis procedures established in the guidelines.
  d.  Extent of effort The extent of effort
and  the level  of sophistication  used in the
cost-effectiveness analysis should reflect the
project's size and  Importance. Where proc-
esses or techniques are claimed to be inno-
vative  technology  on the basis  of the cost
reduction criterion contained in paragraph
8eU) of appendix E to this subpart. a suffi-
ciently detailed cost analysis shall be includ-
ed to substantiate the claim to the satisfac-
tion of the Regional Administrator.
  6. Cost-effectiveness analysis procedures.
  a. Method of analysis. The resources costs
shall-be determined by evaluating opportu-
nity costs. For  resources that  can be ex-
pressed in monetary terms, the analysis will
use the-Interest (discount) rate established
in paragraph  6e.  Monetary- costs  shall be
calculated in terms of present worth values
or equivalent  annual values over the plan-
ning period defined in section 8b. The anal-
ysis  shall  descriptively  present nonmone-
tary factors (e.g.. social and environmental)
in order to determine their significance and
Impact. Nonmonetary factors include prima-
ry and secondary environmental effects, im-
plementation  capability, operability. per-
formance  reliability  and  flexibility. Al-
though such factors as use  and recovery of
energy and scarce resources and recycling of
nutrients are to be included in the monetary
cost analysis,  the  non-monetary evaluation
shall also include them. The most cost-effec-
tive alternative .shall be the waste treatment
management system which the  analysis- de-
termines to have the lowest present worth
or equivalent annual value unless nonmone-
tary costs are overriding. The most cost-ef-
fective alternative must also meet the mini-
mum requirements  of  applicable  effluent
limitations,  ground-water  protection,  or
other  applicable  standards-   established
under the Act.
  b.  Planning period. The planning period
for the cost-effectiveness analysis shall be
20 years.
  c. Elements- of monetary costs. The mone-
tary costs to be considered shall include the
total value  of the resources- which are at-
tributable to the waste treatment manage-
ment system  or to one of  its component
parts. To determine these values, all monies
necessary for capital construction costs and
operation and  maintenance  costs  shall  be
identified.
  (1) Capital  construction costs used in a
cost-effective analysis shall Include all con-
tractors'  cost*  of construction  Including
overhead and profit, costs  of land, reloca-
tion, and right-of-way and easement acquisi-
                                             F-l
-------
  tton; costs of design engineering, field explo-
  ration and engineering services during con-
  struction; costs of administrative and. legal
  services including costs of bond «'T star-
  tup costs such as operator training; and in-
  terest during construction. Capital construc-
  tion  costs  shall  also  include  contingency
  allowances consistent  with  the cost  esti-
  mate's level of precision'and detail.
    (2)  The  cost-effectiveness- analysis «h»"
  include  annual  costs for  operation and
  maintenance (including routine replacement
  of equipment and equipment parts). These
  costs  shall be  adequate to ensure effective
  and dependable  operation during the sys-
  tem's planning period. Annual cost* shall be
  divided between fixed annual  costs and costs
  which would depend OQ the *"*"«' quantity
  of- .waste  water-  collected  and. treated.

  Annual  revenues generated  by the waste
  treatment  management   system  through
  energy recovery, crop production, or other
  outputs shall be  deducted from the annual
  costs for  operation and maintenance- In ac-
  cordance  with  guidance Issued  by the Ad-
  ministrator.
   d. Prices. The applicant shall calculate the
  various components  of costs on the basis of
  market prices prevailing at the time of the
 cost-effectiveness  analysis.  The  analysis
 shall not  allow for  inflation  of  wages and
 prices, except those for land, as described in
 paragraph 6h  and for  natural gas. This
 stipulation is based on the implied assump-
 tion that prices, other than the exceptions,
 for resources involved in treatment  worlcs
 construction  and  operation,  will tend  to
 change over time  by  approximately  the
 same  percentage. Changes  in the general
 level of prices will not affect the results of
 the cost-effectiveness analysis. Natural gas
 prices shall be escalated at a compound rate
 of  4 percent annually over  the  planning
 period, unless the Regional Administrator
 determines that the grantee  has Justified
 use of  a greater or lesser  percentage based
 upon regional differentials between histori-
 cal  natural  gas price  escalation and  con-
 struction cost escalation. Land prices shall
 be  appreciated  as provided in  paragraph
 6h(l). Both historical data and future pro-
 jections support the gas and land price esca-
 lations  relative to  those for other goods and
 services related  to waste water  treatment.
 Price escalation  rates may, be updated peri-
 odically in accordance  with Agency guide-
 lines.
  e. Interest (.discount} rate. The rate which
 the Water Resources Council establishes an-
 nually for evaluation  of water resource pro-
 jects shall be used.
  f. Interest during construction.  (1) Where
 capital  expenditures can be expected to be
 fairly  uniform  during  the  construction
period.'interest during construction may be
calculated at I-1/2PC1 where:
 I-the interest accrued during the construc-
    tion period.
 P-the construction period in years,
 C-the total capital expenditures,
 I-the Interest rate (discount rate in section
    Se).
  (2) Where expenditures will  not  be uni-
 form,  or when the construction period will
 be greater than 4 years, interest during con-
 struction shall be calculated on a year-by-
 year basis.
  g.  Useful life. (1) The treatment  works'
 useful life for a cost-effectiveness analysis
 shall be as follows:
 Land—permanent.
 Waste  water  conveyance  structures (in-
    cludes  collection systems, outfall  pipes,
    interceptors,   force  mains,   tunnels,
    etc.)—50 years.
 Other structures  (includes plant building,
    concrete process tankage, basins, lift sta-
    tions structures, etc.)—30-50'years.
 Process equipment—15-20 years.
 Auxiliary equipment—10-15 years.
  (2) Other useful life periods will be accept-
 able when sufficient  justification  can be
 provided. Where a system or a component is
 for  interim service, the anticipated useful
 life shall be reduced to the- penod for inter-
 im service.
  h. Salvage value. (1) Land purchased for
 treatment  works.  Including land  used as.
 pan of the  treatment process  or  for ulti-
 mate disposal of residues, may  be  assumed
 to have a salvage value at the end  of the
 planning period a  least eqoal to its prevail-
 ing market value a  th* time of the analyst*.
 IB ftaJmtating the salvage value of land, the
 land value shall be appreciated at a com-
 pound rate of  3 pern nt annually over the
 planning  period, unles the Regional Ad-
 ministrator determines t hat the grantee has
 justified the use of a gnater or lesser per-
 centage  based upon  historical  differences
 between local land cost escalation and con-
 struction cost escalation. Thi Vt~j cost esca-
 lation  rate say be updated periodically In
 accordance with Agency guidelines. Right-
 of-way  easements  shall be considered to
 hawe a salvage value not greater than t&g
prevailing  market  value- at the ttme of the
 analysis.
  (2) Structures will be assumed to have, *
salvage value U there  is a me for tiiem. at
 the end of  the planning period. In this case,
salvage value  shall  be  estimated  using
straight line depreciation during the useful
life of the treatment works.
 (3) The method  used in paragraph 5h(23
may be used ta estimate salvage value at the
«nd of the  planning period for phased addi-
tions of. process  equipment and auxiliary
equipment.
                                               F-2
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  (4) When the anticipated useful life of a
facility Is less than 20 years (for analysis of
Interim  facilities),  salvage  value  can  be
claimed for  equipment if it can be clearly
demonstrated  that  a specific market  or
reuse opportunity win exist.
  7. Innov&tivt snd  alternative vastmter
tmtfnfnt jmcssszs find tevA"ii(ji*w.
  a. Beginning October I. 1978, the capital
costs ol publicly  owned" treatment -works
which use processes and techniques meeting-
the criteria  of appendix E to-  this snbpart
and which have  only a water pollution con-
trol function, may be eligible tf the present
worth cost  of the treatment works is not
more than 115 percent of the present worth
cost  of the most cost-effective pollution con-
trol  system, exclusive of collection sewers
and  Interceptors common to the two sys-
tems being  compared,   by   US   percent,
except for the following situation.
  b.  Where  mnoratwe or alternative unit
luuce&aes would serve in Hen of csBrentianal
unit processes in a conventional waste water
treatment  plant,  and  the  present worth
costs of the nonconventiooal unit processes
are  less than  50 percent of  the- present
worth costs of the treatment plant, multiply
the present  worth costs of the replaced con-
ventional processes by 115 percent, and add.
ffa^ /.rt.^ gj nonreplaced ""^ processes.
  e. The eligibility of multipurpose project*
which combine a water 'pollution control
function with another function, and wfflcft
•use  processes- and  techniques- meeting the
criteria of appendix S t* this sobpart, shall
be determined ia accordance wrth gaMtnce
issued by the Administrator.
  "a1. The above provisions exclude tadlvWnal
system -under § 38.51*. The regional Admin-
istrator may allow a grantee to apply the 15V
percent preference  authorised by  ttts sec-
tion. to facility plans, prepared under step 1
grast assistance- awarded before Cccobcc 1,
      Cest-cffeettve
                           end  aetn«r  of
   a. PvpuUtitm jwwjeettesa, (1) The dtsag-
 gregatlon of State projections of pntinftTto*
 shall be the baste for the pncnfttfian fare-
 casts presented ta tndftrtdaal Jactttty P*EB.
 except a* noted. Ties* Stsoe projection*
 sisall 1»e those dereloprt in  iSTT 3»y tta
 Bureau of Economic Analysis  The  State  grujeettan totals  aod the
•dfeaggregatioos wdl  be  xubmttbed as  an
ovtput of the statewide vater qvaiity maa>
«iside  & -Hss of  designated.  2S8 areas, 'all
•SiMSA*a. and counties or ^
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IJiovtUe rwhrlr aoCo of toe mrrtlin eonsza
     wtBi pan  2S of. this rfumnr  (See
  rii When, the Stase. mujuOJon totals and

 used thereafter for area-wide water quality
 management planning a* well as for fatality
 pj mining md the needs surveys under sec-
 tion 516(o) of the Act. Within area wide 208
 planning areas,  the designated agencies, tn
 consultation with the States, shall disaggre-
 gate the 208 area projections among the
 STM73A and non-SMSA areas and then disag-
 gregate these SMSA and nooxSMSA projec-
 tions among the facility planning areas and
 the remaining areas. For those SMSA's not
 included  within  designated  208  planning
 areas,  each State, with assistance from ap-
 propriate regional planning  agencies, shall
 disaggregate the S2JSA projection among
 the facility 'planning areas and the remain-
 Ing areas within the SMSA. The State shall
 check the facility planning area .forecasts to
 ensure reasonableness and consistency with
 the SMSA- projections.
  (3) For non-SMSA faefltty  planning areas
 not  Inducted  la designated  areawide  308
 areas,  the State may disaggregate popula-
 tion projections  for  non-SMSA  counties
 among facility planning areas and remain-
 ing areas. Otherwise, the grantee is to fore-
 cast future population growth for the facili-
 ty planning area by linear extrapolation of
 the recent past (I960 to present) population
 trends for the planning area, use of correla-
 tions of planning area growth with popula-
 tion growth for the township, county or
 other larger parent ares population, or an-
 other*  appropriate  method.  A  population
 forecast may be  raised above that indicated
 by the e-vteuMuii of past trends -where likely
 impacts (e.g.. significant new- energy drrel-
          targe new Lutlu&ifiiej* Federal in-
stallations; or institutions) justify  the dif-
ference. The facilities plan must document
the justification. These population fiuecaaia
should be  based  on estimates of new  em-
ployment to  be generated. The State shall
check  individual  population  forecasts  to
Insure consistency with overall projections
for non-SMSA counties and justification for
any difference from past trends.
  (55 Facilities plans prepared tinder step 1
grant  assistance  awarded  later  than  5
months after Agency approval of the State
disaggregaclons shall follow population fore-
casts  developed  in accordance  with  these
guidelines.
  b. Waatewi ttr Jlato estimates^ CD In deter-
mining  total  average  daily  flow  for  the
design of treatment works, the flows to be
considered include  the  average da-fly  base
Sows (ADBF) expected  from  f*****rf\?]
sources;  commercial sources, institutional
sources, and  industries the works will serve
plus allowances  for future Industries and
  aooexcesaive    infiltration/ inflow.    The
  amount of nonexcessive  Lnfiltraiion/ inflow
  not included in the base flow estimates pre-
  aemed herein, a to be determined according
  to the A«eacy guidance far  sewer system
  evaluation <« Agency policy "aa treatment
  and control of combined sewer  overflows
   <2> The estimatioe of
 ADBF. exclusive  of  flow
 combined residentia
                                and future
                            reduction  from
                            eraai and  iasu-
 tatioaal sources. jh»U be based -upon ooe <*
 the following- methods:
   (*> Pi*ffm* attVtod. Sxistin* AOBy is es-
 timated b*aed  upon , a. fuily  documented
 analysis' of water use records adjusted  for
 eoasomptioa and looses or oa records «/
 wastewater Hows for extended dry  periods
 less, estimated  dry  weather  infUtraU«n.
 Future Qowa for the treaocent worts desjga
 stoMid1 b* esciaaated to determiner  to* ex-
 isting  per  capita flows  based  on existing
 sewered resident population and multiply-
 ing this figure by the future projected popu-
 lation to be served. Seasonal population can
 be converted to equivalent full time  resi-
 dents using the following multipliers:
               ————  0.1 to 0.3
               ....                  OJ to O.S
 The preferred method shall be used wherev-
 er water supply records or wastewater flow
 data exist. Allowances for future increases
 of per capita- flow over time will not be ap-
 proved.
   
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less than 70 sped, or the current population
of  the applicant  municipality  ia  under
10,000,  or  the  Regional  Administrator
exempts the-area, for having an effective ex-
isting flow reduction program.. Flow reduc-
tion measures Include public education, pric-
ing and regulatory  approaches or a- combi-
nation of  these. In preparing the facilities
plan and Included .cost  effectiveness analy-
sis, the grantee shall, as a minimum:
  (1). Estimate  the flow reductions Impte-
mentable and cost effective when the treat-
ment works become operational and after 10
and 20 yean of operation. The measures to
be evaluated shall Include a public informa-
tion program;  pricing  and regulatory ap-
proaches;  Installation of, water meters, and
retrofit of toilet dams and  low-flow shower-
heads for existing homes and other habita-
tions:  and specific  changes In local ordin-
ances,  building codes or plumbing codes re-
quiring Installations of water saving devices
such as water meters; water conserving toi-
lets, showerheads. lavatory faucets, and ap-
pliances in new homes, motels, hotels,  insti-
tutions, and other establishments.
  (2) Estimate the costs of  the  proposed
flow reduction measures  over the 20-year
planning period. Including costs of public in-
formation, administration,  retrofit of exist-
ing buildings and the  incremental costs.  If
any, of tn«tjJHng water conserving devices
In new homes and establishments.
  (3) Estimate  the  energy  reductions;  total
cost  savings-   for  wastewater  treatment.
water  supply and energy use;- and the net
 cost savings (total savings minus total costs)
 attributable to the proposed flow reduction
 measures over the planning period. The esti-
 mated cost savings shall reflect reduced
 sizes  of  proposed wastewater treatment
 works plus reduced costs^ of  future  water
 supply facility expansions.
   (4) Develop and provide  for implementing
 a recommended flow  reduction .program.
 This shall Include a public Information pro-
 gram  highlighting effective flow reduction
 measures, their  costs, and the savings  of
 water and costs for a typical household and
 for the community. In addition, the recom-
 mended program shall comprise those flow
 reduction measures which are cost effective,
 supported by the public and within the im-
 plementation  authority of the  grantee  or
 another entity willing to cooperate with the
 grantee.
   (5) Take into account tn the design of the
 treatment works the flow reduction estimat-
 ed for the recommended program.
   d. Industrial /lows.  (1) The  treatment
 works' total design flow  capacity may  in-
 clude  allowances for  Industrial  flows. The
 allowances may include capacity needed for
 Industrial flows which the existing  treat-
ment  works  presently  serves.  However,
these flows shall be carefully reviewed and
means of reducing them shall be considered.
Letters of intent to the grantee are required
to  document  capacity needs  for existing
flows from significant  Industrial users and
for future flows from all Industries Intend-
ing to Increase their flows-or relocate In the
area. Requirements  for  letters of  Intent
from significant  industrial dischargers are
set forth In § 35.925-lKc).
  (2) While many uncertainties accompany
forecasting future industrial, flows, there Is
still a need to allow for some unplanned
future industrial  growth. Thus, the cost-ef-
fective (grant eligible)  design capacity and
flow of the treatment works may Include (in
addition to the existing industrial flows and
future Industrial flows, documented by let-
ters of Intent) a nominal flow allowance for
future nonidentifiable -industries or for un-
planned   industrial   expansions,  provided
that 208 plans, land use plans and zoning
provide for such Industrial growth. This ad-
ditional allowance for future unplanned in-
dustrial flow shall not exceed 5 percent (or
10 percent for towns with less than 10,000
population) of the total design flow of the
treatment  works exclusive of the allowance
or 25 percent of the total Industrial flow
(existing plus documented future), which-
ever Is-greater.
  e. Staffing of treatment plants. (1) The ca-
pacity of treatment plants (Le., new plants,
upgraded plants, or expanded, plants) to be
funded under the construction- grants pro-
gram shall not  exceed- that necessary for
wastewater flows projected during  an initial
staging period determined by one of the fol-
lowing methods:
  (a) First method. The grantee shall ana-
lyze li least three alternative staging peri-
ods (10 years^-45 years, and 20 years). He
shall select-the least  costly (Le., total pres-
ent worth or  average annual cost) staging
period.
  (b) Second  method. The staging period-
shall not exceed the period which  is appro-
priate according to the following table.
  STACZRO Pnioos rox Tmxncnrr PLAJTTS
    Flow growth factors (20 yean)*
Staging
period'
(yeara)
Lea* than 1.3-
1.3 to 1.8.
Greater tnan 1.3.
     20
     15
     10
  •Ratio of wastewater How expected at end of 20
year planning period to initial flow at the time the
plant Is expected to become operational.
  > vr«rimimi initial ata0nc period.
                                                F-5
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  (2) A municipality may stage the construc-
tion of  a treatment  plant lor a  shorter
period than the maximum allowed under
this policy. A shorter  staging period might
be  based upon environmental factors (sec-
ondary Impacts) compliance with other envi-
ronmental laws  under §35.925-14.  energy
conservation,  water supply), an  objective
concerning planned modular construction.
the utilisation  of temporary  treatment
plants, or attainment of consistency with lo-
cally  adopted  plans including  comprehen-
sive and  capital improvement plans.  Howev-
er,  the staging period in no case may be less
than  10  years, because  of associated cost
penalties and the  time  necessary to  plan.
apply for and receive funding, and construct
later stages.
  (3) The  facilities plan  shall  present the
design parameters  for the  proposed treat-
ment plant. Whenever the proposed treat-
ment  plant  components' size  or capacity
would  exceed the  minimum  reliability  re-
quirements suggested in  the EPA technical
bulletin,  "Design Criteria for Mechanical.
Electric,  and Fluid  System and Component
Reliability," a complete justification, includ-
ing supporting data, shall be provided to the
Regional Administrator for his approval.
  f. Staying-of interceptors. Since the loca-
tion and length  of interceptors will influ-
ence growth, interceptor routes and  staging
of construction shall be  planned carefully.
They shall be consistent  with approved 208
plans,  growth management plans and other
environmental laws under  } 35.925-14 and
shall   also  be consistent with Executive
orders  for flood plains and wetlands.
  (1) Interceptors may be allowable for con-
struction grant funding if they eliminate ex-
isting point source discharges and accommo-
date flows from  existing habitations that
violate an  enforceable requirement  of the
Act. Unless necessary  to meet those objec-
tives, interceptors should not be extended
Into environmentally sensitive areas, prune
agricultural lands  and other  undeveloped
areas (density less than one household per 2
acres). Where extension  of  an interceptor
through  such areas would be necessary to
Interconnect two  or more communities, the
grantee shall reassess the need for the inter-
ceptor  by further consideration of alterna-
tive wastewater treatment systems.  If the
reassessment demonstrates  a need for the
interceptor, the grantee  shall evaluate the
Interceptor's primary  and secondary envi-
ronmental impacts, and  provide for appro-
priate  mitigating measures  such as  rerout-
ing the pipe to minimize  adverse impacts or
restricting  future connections  to the  pipe.
Appropriate and  effective grant conditions
(e.g.. restricting sewer hookups) should  be
used where necessary to protect environ-
mentally sensitive areas or prime agricultur-
al lands  from new development.  NFDES
permits  shall  include the  conditions  to
insure  Implementation of  the mitigating
measures  *hen new permits are  issued to
the affected Ueaiuieiit  facilities  in those
eases  where  the measures are required to
protect the treatment facilities against over-
loading.
  (2) Interceptor pipe sizes (diameters for
cylindrical pipes) allowable for construction
grant funding  shall be based on  a  staging
period of  20 years.  A larger pipe size corre-
sponding  to a longer staging period not to
exceed 40  years may be allowed if the grant-
ee can demonstrate, wherever water quality
management plant or other plans developed
for compliance with laws under J"33.925-14
hare been approved, that tt» larger pipe
would be consistent with projected land use
patterns in such plans and that the larger
pipe would reduce overall (primary pica sec-
ondary) environmental Impacts. These envi-
ronmental Impacts include:
  (a) Primary  impact* (1) Short-term  dis-
ruption of traffic, business and  ot&er daily
activities.
  (11) Destruction of flora and fuma. nois*.
erosion, and sedimentation.
  (b)  Secondary impacts,  (i) Pressure  to
rezone or  otherwise facilitate unplanned de-
velopment
  (U)  Pressure  to  accelerate  growth  for
quicker recovery of the non-Federal stare
of the interceptor tnvesoneno.
  (ill) Effects on air  quality  and environ-
mentally   sensitive   areas   by   cultural
changes.
  f3> Th« estimation of peak flows in inter-
ceptors shall be based upon the  following
considerations;
  (a) Daily and seasonal variations  of pipe
flows, the timing of flows from  the various
parts of the tributary area, and pipe storage
effects.
  (b) The feasibility of off-pipe storage to
reduce peak flows.
  (c) The uae of an appropriate peak flow
factor that decreases  as the average daily
flow to be -conveyed increases.
  9. State yuideiinea. If a State has devel-
oped or chooses to develop comprehensive
guidelines on cost-effective sizing  and stag-
ing of treatment works, the Regional  Ad'
ministrator may approve- all or  portion* of
the State  guidance  for application to step 1
faculty plans. Approved State guidance may
be used instead of corresponding portions of
these guidelines, tf  the following conditions
are met:
  a. The State  guidance must be at least as
stringent  as  the provisions  of these guide-
lines.
  S. The State must have heM at least one-
public hearing on proposed State  guidance.
under regulations in part 25 of this chapter.
before submitting tne guidance  for  Agency
approval.
  10. Additional capacity beyond tfie coat-ef-
fective  capacilv. Treatment works which
propose   to  Include  additional  capacity
                                               F-6
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beyond the  cost-effective  capacity  deter-
mined in  accordance with these guidelines
may receive Federal groat assistance if the
following requirements are race
  a. The faculties plan shall determine the
most  cost-effective treatment Tories and its
associated capacity in accordance with these
guidelines. The facilities plan shall also de-
termine the actual characteristics and total.
capacity of the treatment worfcs to be built.
  6. Only a portion of the cost of the entire
proposed treatment Dorics including th« ad-
ditional capacity shall Se eligible for Feder-
al funding. The portion of the cost of con-
struction which snail be eiisibte for Federal
funding under sections 203U) and 30tta> of
the Act shall be equivalent to the estimated
construction costs of the most cost-effective
treatment worts. For the eligibility determi-
nation, the costs of construction  of th«
actual treatment worts and the most cost-
effective treatment works must be estimat-
ed on a consistent basis.  Up-to-date  cost
curves published by ERA'S Office of Water
Program Operations or other cost estimat-
ing guidance shaft be used to determine the
cost  ratios between cost-effective  project
components and those of the actual project.
These cost ratios shall be multiplied by the
step  3  cost and step 3  contract  costs  of
actual components to determine the eligible
step 2 and step 3 costs.
  c. The actual treatment •works-to be built
shall  be assessed. It must  be determined
that the actual treatment worts' meets the
requirements  of the National Envtronmeo-
tal Policy Act and all applicable laws, regu-
lations, sod guidance,  as  required  of  all
treatment  works by H3SJ25-8  and 35.923-
14. Particular attention should be  given  to
assessing the  project's potential secondary
environmental effects and to ensuring that
air quality standards will not be violated.
The actual treatment works' discharge must
not cause violations  of water quality stand-
ards.
  d. The Regional Administrator shall ap-
prove  the plans,  specifications, and esti-
mates for the  actual treatment works under
section 203*3) of the An, even though EPA
will be funding only a  portion of its de-
signed capacity.
  e. The grantee snail satisfactorily assure
the Agency that the funds for the construc-
tion  costs  doe to the addtionxl- capacity
beyond the eost-effective treatment works'
capacity as determined by EPA Ci-e_ the in-
eligible portion of the treatment works), as
well as the local share of the grant eligible
portion of the -construction costs will  be
available.
  f. The grantee  shafl execute appropriate
grant conditions or releases  providing that
the federal Government is protected  from
any further claim by the grantee, the State.
or any other party for any of  the coats of
construction due to the additional capacity.
  g. Industrial cost recovery shall be baaed
upon  the portion of the Federal grant alia-
cable  to the treatment of Industrial wastes.
  h. The  grantee  must  implement a user
charge system which applies to the  entire
service area.of the grantee,  including any
area served by the additional capacity.
                                             F-7
                                                           *U.S. Government Printing Office:  1 980-O-67 7-094/1112
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