UPGRADING WASTEWATER STABILIZATION
PONDS TO MEET NEW DISCHARGE STANDARDS
SYMPOSIUM PROCEEDINGS
Editors:
E. Joe Middlebrooks
Donna H. Falkenborg
Ronald F. Lewis
Donald J. Ehreth
PRWG1S9-1

Utah Water Research Laboratory
College of Engineering
Utah State University
Logan, Utah 84322

November 1974

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UPGRADING WASTEWATER STABILIZATION PONDS TO MEET

                 NEW DISCHARGE STANDARDS
                           Proceedings of a
                Symposium held at Utah State University
                            Logan, Utah
                         August 21-23, 1974
                              Edited by
                         E. Joe Middlebrooks
                         Donna H. Falkenborg
                           Ronald F. Lewis
                           Donald J. Ehreth
                             Sponsored by
                     Utah Water Research Laboratory
                               and the
                   Division of Environmental Engineering
                         College of Engineering
                          Utah State University
                              Logan, Utah

                               and the

                    Office of Research and Development
                    Environmental Protection Agency
                  National Environmental Research Center
                            Cincinnati, Ohio
                               and the
                    Municipal Pollution Control Division
                            Washington, D.C.
                    Utah Water Research Laboratory
                         College of Engineering
                         Utah State University
                          Logan, Utah 84322
                            November 1974                            PRWG1S9-1

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                              ACKNOWLEDGMENTS
     This publication and the Symposium were partially supported by Grant Number R-803294-
01-0 received from the National  Environmental  Research  Center, Environmental Protection
Agency, Cincinnati, Ohio.

     The great expenditure of time and effort made by the Symposium participants and authors
of the papers is  gratefully  acknowledged.  Without such willingness to share knowledge and
experiences, meetings such as this would be impossible.

                                                       E. Joe Middlebrooks
                                                       Dean
                                                       College of Engineering
                                                       Utah State University
                                          iii

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                        TABLE OF CONTENTS


                                                                 Page

INTRODUCTORY REMARKS
    W. A. Rosenkranz	   1

REVIEW OF EPA RESEARCH AND DEVELOPMENT LAGOON UPGRADING PROGRAM
    FOR FISCAL YEARS 1973, 1974, and 1975
    R. F. Lewis	3

STATE OF THE ART OF LAGOON WASTEWATER TREATMENT
    R. E. McKinney	15

CONSTRUCTION PROCEDURES AND REVIEW OF PLANS AND GRANT
    APPLICATIONS
    W.R.Uhte	21

POLISHING LAGOON EFFLUENTS WITH SUBMERGED ROCK FILTERS
    W.J. O'Brien	31

STABILIZATION POND UPGRADING WITH INTERMITTENT SAND FILTERS
    E. J. Middlebrooks and G. R. Marshall	47

INTERMITTENT SAND FILTRATION TO UPGRADE LAGOON EFFLUENTS-
    PRELIMINARY REPORT
    J. H. Reynolds, S. E. Harris, D. Hill, D. S. Filip, and E. J. Middlebrooks	71

PERFORMANCE OF RAW WASTE STABILIZATION LAGOONS IN MICHIGAN
    WITH LONG PERIOD STORAGE BEFORE DISCHARGE
    D. M. Pierce	89

SEPARATION OF ALGAE CELLS FROM WASTEWATER LAGOON EFFLUENTS
    R. A. Gearheart and E. J. Middlebrooks	137

UPGRADING LAGOON TREATMENT WITH LAND APPLICATION
    R. E. Thomas	183

LAGOON EFFLUENT SOLIDS CONTROL BY BIOLOGICAL HARVESTING
    V/.R. Duffer	187

PROGRESS REPORT: BLUE SPRINGS LAGOON STUDY, BLUE SPRINGS,
    MISSOURI
    CM. WalterandS. L. Bugbee	191

COST-EFFECTIVENESS ANALYSIS FOR WATER POLLUTION CONTROL
    R. Smith	199
NOTES
    Research on Cold Climate Wastewater Lagoons
        H. J. Coutts	.227

    Polishing Gravel and Activated Carbon Filter on Aerated Lagoon Effluents
        G. Hartmann	229

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                     TABLE OF CONTENTS (Continued)



                                                             Page




MEMBERS OF THE SYMPOSIUM	231



APPENDIX	233



AUTHOR INDEX	237




SUBJECT INDEX	241
                               VI

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               INTRODUCTORY REMARKS AT THE EPA/ORD INTRA-AGENCY

                      WORKSHOP ON WASTEWATER TREATMENT PONDS

                                            W. A. Rosenkranzl
     In June  of 1973, Region X sent  a letter  to
consulting engineers,  municipal  officials, agencies,
and others concerned  with Water Pollution Control.
That letter contained the following statement:

     "It is generally recognized that neither standard
oxidation lagoons nor  aerated lagoons by themselves
will be able to achieve the required level of treatment.
Therefore, this region will not  be able  to  approve
construction grants for projects proposing lagoons as
the  method  of wastewater  treatment unless  such
lagoons  are part of a system designed to preclude any
discharge or which incorporates supplemental treat-
ment components  capable of improving the effluent
quality to an acceptable level. Meeting our minimum
treatment  requirements  might be achieved by  com-
bining the  lagoon treatment with an irrigation  ef-
fluent disposal system, by adding supplemental treat-
ment components or by constructing a non-overflow
lagoon."

      A report prepared for  the Office of Research
and  Development  by  George Barsom of Ryckman,
Edgerley,  Tomlinson,  and Associates, Inc., entitled
"Lagoon  Performance  and   the  State  of Lagoon
Technology" had an overall negative viewpoint  as to
the suitability of lagoons for secondary treatment and
repeatedly cited the lack of hard performance data on
lagoons. The data contained in the report gave no
assurance  that there  were existing  lagoon  designs
capable  of  meeting  the   secondary  treatment
standards.

      On  behalf  of  the  Office  of  Research and
Development  of   the   Environmental   Protection
Agency (EPA),  I  wish to  welcome  you  to the
Intra-Agency  Workshop  on  Wastewater  Treatment
Pond Upgrading Technology. You  are a select group
of EPA staff and  state officials brought together to
review the  Office  of Research and Development's
program for upgrading wastewater treatment ponds.
Before you leave, we  intend  to pass on to you the
most recent  results of our   on-going research pro-
grams, and program plan for the future. The results of
     *W. A. Rosenkranz is Director, Municipal Pollution
Control  Division,  Office  of  Research and Development,
Environmental Protection Agency, Washington, D.C.
the workshop should provide you with solutions to
the problems posed by Region X and Mr. Barsom.

     The question  as to whether lagoons, as they
now  exist,  meet  the  new secondary  treatment
standards and what methods would work to upgrade
lagoon treatment in cases where they presently  do
not meet the standards is of high priority  for many
Regional Offices of EPA. This is because nearly  90
percent of the  wastewater  lagoons  in  the  United
States  are  located  in small  communities  of 5,000
people or  less.  These communities,  many with an
average daily wastewater flow of only  175,000 to
200,000  gallons, do not have the resources to keep
operators at the treatment sites throughout the day.

      EPA, in my view, has a definite responsibility in
this area. The  agency has  defined secondary treat-
ment,  obviously with the knowledge of the numbers
of  treatment  ponds that exist, and  knowing  that
effluent  quality from the ponds is questionable. I also
clearly recall that, in the early days of the construc-
tion grant  program, the  regions spent considerable
effort  in convincing  state  agencies  that  treatment
ponds were a viable treatment process. If there can be
developed  economical upgrading techniques which
can save the sunk capital costs, we owe that to the
communities with ponds. A high degree of technical
knowledge is  usually lacking in the  operators from
these communities. Often, only periodic inspection or
maintenance is carried out by the community's work
force. Therefore, the development of relatively inex-
pensive methods for upgrading lagoons  that do  not
require sophisticated  and constant operation or ex-
tensive maintenance is urgently needed.

      The  majority of the  research needs identified
this  year  by  our  regional offices  pertaining to
biological treatment are  concerned  with lagoon up-
grading,  particularly algal  removal  from lagoon ef-
fluents.  As  you  may  be  aware,  three  pilot-scale
research contracts are currently in progress to evalu-
ate removal of algae from lagoon effluents.

      The  projects and technology to be discussed
during this seminar were  planned to have a quick
payoff because it is felt  that they can be completed
in time  to impact the July  1, 1977, federal deadline
 for achievement of  secondary  treatment in  all

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         Rosenkranz
 municipal installations. The projects funded at Utah
 State  University,  which  are  the  intermittent sand
 filter  and land application of algae laden effluents,
 and at the University of Kar>,oi, ue submerged rocx
 filter, offer good potential for cost effective upgrac,-
 ing technology.

      We feel  thai  our research program plan will
 identify the inadequacies of facultative  and aerated
 lagoons.  Recommended  practices  for  disinfecting
 lagoon effluents are needed, whether we are consider-
 ing inherent destruction of coliforms (natural die-off
 relative  to  detention  time),  chlorination, or other
 disinfection  processes. Work  is  also  planned  on
 control  of nutrients.  The broad  objective is the
 development and demonstration of technology which
 can  be recommended in  your respective regions  as
 cost effective for upgrading applications.

      Prior  to  today's assembly, there were  at least
 two major symposia held  to disseminate  information
 on  wastewater treatment  pond  technology,  and
 several EPA Technology Transfer  Seminars to dis-
 seminate  upgrading technology to  consulting engi-
 neers. This conference differs from  the  make-up of
 previous seminars  and symposia in that investigators
 engaged  in research  activities  have been  brought
 together with regulatory personnel and those engaged
 in approving treatment plant design to discuss current
 research,  design, and  operational findings of waste-
 water treatment ponds.

      The workshop agenda contains topics including
 the basic biology of the treatment mechanism, algal
 removal process evaluations, disinfection  technology,
 and  cost effective  analysis.  We  look  forward  to
 reviewing  any   special problem confronting  your
 specific region.  While we may not have all the answers
 to these problems, we  must make our R&D program
 responsive to your needs.  An assembly such as this is
 a useful mechanism to that end.

      In  the next  two and  one-half days, we  will
 recap past experience and discuss on-going projects in
 detail. You will be  informed of our R&D  program
 plan, which was prepared to delineate the course of
 action and tentative resource  allocations to  produce
 an array of upgrading technologies. Unfortunately,
 our declining budget situation has precluded alloca-
 ting  resources  as  originally  proposed, but  we will
attempt  to  optimize  our  investment  to  ensure
maximum  utilization  of  resources to  produce the
 results required. Consequently, our demonstration
sites  will not  span all  temperature  zones, waste
compositions,  etc.,  but sites  representative of the
broadest  spectrum  of conditions possible  will be
selected.

      As a result of specific problems  in Region X,
personnel from the  Advanced Waste Treatment Re-
search Laboratory  in  Cincinnati,  Ohio, and R&D
 Headquarters  met with the regional staff to discuss
 specifics  of their policy statement  and the  R&D
 program plan. Based on those conversations, it was
 concluded that the  research program of improving
 effluents  of wastewater treatment ponds would be
 responsive 10  Region X's needs. However, it was also
 concluded that the  output  from the program would
 be available in design-manual form too late. Region X
 staff urged  us to  prepare an  interim  report  on
 whatever  methodology was available. It was readily
 apparent that regional offices need whatever data are
 available as quickly  as  possible so that they can be
 better prepared to  ensure that the requirements of
 the  FWPCA Amendment of 1972 would be satisfied
 with regard  to evaluation of cost effective  alter-
 natives.

      Mr. John Rhett, Deputy Assistant Administra-
 tor  for Water Program  Operations,  repeated the
 regions' request for  interim data from our upgrading
 program.  It became  imperative that an interim report
 on   R&D's  program  be prepared. We  know of no
 better way to provide you  with that interim report
 than to gather together as  we are now doing. Your
 needs were the catalyst that precipitated the events
 leading up to this workshop.

      As a result of  your requests and input, we have
 adjusted our program plan. Due to reduced research
 budget  resources, we are constrained in our participa-
 tion  in the construction phases of demonstration
 projects. We are in a position where we must rely on
 you to assist us in  putting together demonstration
 projects with  joint R&D-construction grant funding.
 Your assistance is  required to  optimize our R&D
 dollars. You will continue to have a direct hand  in
 planning future research in this  field. Either  before
 you leave,  or  when  you  return to your respective
 regions, we want  your recommendations for future
 development and/or  demonstration projects.

      Before  closing I'd like to mention two other
 factors which 'will-or should-impact our R&D. This
 first is recognition  of new technologies that may
 impact pond design  and performance. Such things as
 pressure and vacuum sewer systems may change the
 volume and character of raw wastes. The other factor
 is that, while  we are attempting to upgrade ponds to
 secondary levels, many are or will be located on water
 quality limited streams,  requiring best  practicable
 treatment above secondary.  Let's not repeat our past
 mistakes  and  ignore  future technology  and/or ad-
 ministrative actions  which could further  impact the
 use of treatment ponds.

      We  intend to  be directly  responsive  to your
needs and hope that the information passed on to
you  during the course of the workshop will satisfy
your most immediate requirements.  Perhaps  this
meeting will set  the  stage for  future  meetings of
similar nature. If you have suggestions for improving
the  substance or format we  would like to have them.

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               REVIEW OF EPA RESEARCH AND DEVELOPMENT LAGOON

           UPGRADING PROGRAM FOR FISCAL YEARS 1973,1974, AND 1975

                                            R.F.Lewis1
                 Introduction

     This  paper  will  review  the  Environmental
Protection Agency Research and  Development Pro-
gram for upgrading the performance of lagoon waste-
water treatment systems. Specifically, those lagoon
projects initiated in fiscal years 1973 and 1974 and
those planned for fiscal year 1975 will be discussed.

     In  developing an upgrading program  for any
widely  used wastewater  treatment  process,  it is
important to  consider  the types of communities
served  by that process, the personnel and financial
resources  of those communities, the performance
norm and variability of the process operating in a
conventional non-upgraded  mode, and the degree of
effluent  quality improvement  required to satisfy
pertinent federal and water  quality standards. Before
reviewing the  fiscal year  1973, 1974, and 1975
projects, these  considerations will first be discussed
briefly as related to facultative and aerated  lagoons.
The role these factors had in determining the course
and priorities of the EPA research and development
lagoon upgrading program will be emphasized.

     Approximately 90 percent of the wastewater
lagoons in the United  States are located  in small
communities of 10,000 people or less.  During the
period of  1940-1974, wastewater  lagoons  rapidly
gained popularity as a means of treating wastewaters
from isolated industries, such as meat packing plants,
and from small rural communities. A recent report by
Barsom (1973) shows  that  in 1945  there  were  45
lagoons treating municipal wastes, while by 1960 the
number of lagoons had increased to 4,476. To this
number  must  also be  added  the  many privately
owned  lagoons treating  wastewaters from  motels,
schools, trailer parks, and feed lots that have not been
listed in state or national registers. The proliferation
and acceptance of lagoon treatment  for small com-
munities was especially evident  in the western and
southern portions of the United States.
     1R. F. Lewis is with the National Environmental
Research Center,  Advanced  Waste  Treatment Research
Laboratory, Office of Research and Development, Cincinnati,
Ohio.
     For  these small communities,  lagoons  have
proven to be relatively stable treatment.systems able
to handle fairly wide diurnal or daily fluctuations in
wastewater flow and organic loading with negligible
effect on  effluent quality. The reason lagoons can
handle these variations is that the  long detention
times utilized (10 to 150 days) provide great equaliza-
tion of flow and load. Lagoons  generally cost less
than other biological processes to install, and they do
not  require  around-the-clock surveillance.  Main-
tenance work can be performed by the community
work force.

     The  first lagoons to be used  for secondary
treatment  were   generally  single-cell   facultative
lagoons. Due to the problems of short circuiting and
poor treatment during cold weather with these early
single-cell  systems,  multi-cell  facultative  lagoons,
aerated lagoons, or combinations thereof are specified
by most  design  engineers today. In certain  states,
intermittent-discharge lagoons  have also been widely
used in recent years.

  Summary of Existing Lagoon Performance
      and Characteristic Effluent Quality

     A comprehensive  analysis of the performance
capabilities of existing lagoons is difficult because of
the  lack   of  consistent,  reliable information  and
analytical  data. Since most lagoons  are located in
smaU communities that do not have highly trained
personnel,  very  few   laboratory  analyses  are
performed on  either the  influent or effluent from
these lagoons.  The Barsom (1973) survey reported
that only 28 of 50 states required  routine monitoring
of influent loading parameters. The problems most
often cited by state  engineers  were  offensive odors
(all 50 states), short circuiting (23 states), and algae
carryover problems (21 states).

     One  of the major obstacles in improving the
application of lagoon technology in the past has been
the failure of engineers to relate lagoon performance
to causative factors, and to modify established design
criteria accordingly.  This has created  a lack of
confidence in the treatment technique in general, and
a reluctance  on the part of regulatory authorities to
endorse  new applications  of lagoon treatment sys-
tems.

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        Lewis
      The   state-of-the-art  report  on   lagoon
technology by Barsom (1973) is the most comprehen-
sive study of lagoon performance presently available.
Information  was  assembled during  this study by
questionnaires  and  direct contact  of  state  water
pollution  control  agencies, municipalities,  and in-
dependent  researchers.  The investigation evaluated
data on lagoon performance from all 50  states and
approximately  .3,000 lagoon  installations although
Barsom felt that the data were reliable for only about
200  of the lagoons surveyed. Figure 1, taken from
Barsom's report, shows the  national average median
effluent values for the BOD and suspended solids of
facultative  lagoons,  aerated  lagoons,  oxidation
ditches, and  tertiary lagoons.  The  average median
effluent BOD ranged from  23 to 42 mg/1 and the
average median effluent suspended solids ranged from
37  to 67 mg/1. Figures 2 and  3, also taken from
Barsom's report,  indicate the BOD and  suspended
solids levels in facultative lagoon effluents in different
geographical areas  of the United States, showing the
average median in  each area and  the range of values
found in  that area. For these  areas,  the  average
median effluent BOD and suspended solids  ranged
from-25 to  75 mg/1  and  from 40 to  540 mg/1,
respectively. For aerated lagoons, Figures 4  and 5,
again  taken from  Barsom's report, show that  the
average median effluent BOD by geographic region
varied from 30 to  80 mg/1, and the average median
effluent suspended solids varied from 60 to 210 mg/1.
                                         TERTIARY
                                          LAGOON
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           LEGEND

 I.  Southwest   Region

2.  South Central  Region
3.  Southeast   Region

4.  Ohio   Basin
5.  Great   Lakes  Region

6.  Missouri   Basin
7.  Middle   Atlantic Region
8.  Northeast   Region
9.  Northwest   Region
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Figure 2.  Regional  average median effluent  values
          and ranges of values for BOD in facultative
          lagoons.

                                         LEGEND

                                  Southwest   Region
                              2.  South  Central  Region
                              3.  Southeast   Region
                                         Basin
                                  Great   Lakes  Region
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                              8.  Northeast   Region
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Figure 1. National average median effluent values for
         BOD and suspended solids.
                                                                                       Average  Effluent
                                                                                       Median
        12345678
        TEST    LOCATION

Figure 3.  Regional average median effluent  values
          and ranges of values for suspended solids in
          facultative lagoons.

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                          Review of EPA Research and Development Lagoon Upgrading Program
V.
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                        LEGEND

                 Southwest   Region

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                 Southeast   Region

                 Ohio   Basin

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                 Missouri   Basin

                 Middle  Atlantic  Region
                 Northeast    Region

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                                         Range
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Figure 4. Regional average  median  effluent values
         and ranges of values for BOD in aerated
         lagoons.
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Figure 5. Regional average median effluent values and
         ranges of values  for suspended solids in
         aerated lagoons.
               Previous Lagoon Projects Sponsored by
                  EPA or Predecessor Organizations

                 Over the period of time covering the increased
           utilization  of lagoons,  the EPA and its predecessor
           organizations have  sponsored  several  meetings and
           research projects on the general topic of wastewater
           lagoons and  in  a  few cases  on means  to  upgrade
           lagoons. These  have included the First and Second
           International  Symposium  for  Waste   Treatment
           Lagoons in 1960 and 1970; the treatment of tanning
           wastes  by  an  anaerobic-aerobic  lagoon   system
           (Parker, 1970); a review manual on "Waste Treatment
           Lagoons-State-of-the-Art"  by  McKinney   et  al.
           (1971); a  project  on "Supplementary Aeration of
           Lagoons   in  Rigorous  Climate Areas"  (Champlin,
           1971); studies  on tertiary  treatment  of  lagoon  ef-
           fluents for  phosphorus removal and  reuse  of the
           effluent for a recreational lake (Dryden  and Stern,
           1968); various studies by the EPA staff at the Arctic
           Research Laboratory in  Fairbanks, Alaska, on lagoon
           treatment  in cold  climates,  including a study  on
           coarse-bubble diffusers  for aerated lagoons in cold
           climates  (Christiansen,  1973); and  the  previously
           mentioned review of "Lagoon Performance and the
           State of  Lagoon Technology" by Barsom (1973).
           However, this  previous involvement at the federal
           level lacked overall  planning and had no organized
           strategy to systematically encourage improved lagoon
           design and operation.
                                    Secondary Treatment Standards

                                  The recent promulgation of Secondary Treat-
                            ment Standards for  municipal installations by EPA
                            (Secondary   Treatment  Information,   1973)  has
                            provided the necessary stimulus to develop a vigorous
                            multiple-faceted lagoon upgrading research program.
                            These regulations which will be effective on July 1,
                            1977, state that effluent BOD (5-day) and suspended
                            solids shall not exceed an arithmetic mean value of 30
                            mg/1 each for effluent samples collected in a period of
                            30 consecutive  days nor shall they exceed 15 percent
                            of the  arithmetic mean  of the BOD (5 -day)  and
                            suspended solids values for influent samples collected
                            at approximately the same times during  the same
                            period (85  percent removal).  For effluent samples
                            collected  in a  period of 7 consecutive days,  the
                            arithmetic mean of  the  effluent BOD (5-day)  and
                            suspended solids values shall not exceed 45 mg/1 each.
                            The  geometric  mean of the value for fecal coliform
                            bacteria for  effluent samples shall not exceed 200 per
                            100  milhliters for samples collected in a period of 30
                            consecutive  days nor 400 per 100  milhliters for
                            samples collected hi  a period of 7 consecutive days.
                            The  effluent values  for pH shall remain within the
                            limits of 6.0 to  9.0.

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         Lewis
          Research Needs Identified for
           Lagoon Upgrading Program

      The  major  research  needs  for  wastewater
 lagoons identified over the past several years by EPA
 regional and headquarters personnel and by a variety
 of state, academic, and private groups are summarized
 below:

       1. Develop and demonstrate low  cost suspended
 solids and algal removal processes.

      2. Establish  design guidelines of practice for
 lagoon effluent discharge to the land.

      3. Establish disinfection guidelines and demon-
 strate applicable methods.

      4. Develop  and demonstrate nutrient control
 technology.

      5. Characterize the various alternatives of up-
 grading lagoons so that construction grant funds can
 best be utilized, and that construction grants person-
 nel will have assurance that a given design will at least
 have  the  potential of satisfying applicable effluent
 standards.

      6.  Evaluate the utilization of algae to produce a
 useful produce either as a direct protein supplement
 for animal feed, or as a source  of food for biological
 predators.

      7.  Develop and demonstrate  methods to con-
 trol weeds and other undesirable aquatic  growths in
 lagoons.

           Fiscal Year 1973 Projects

 Removal of algae from
 lagoon effluents

      With the promulgation of the EPA Secondary
 Treatment Standards  and  the  publication of the
 Barsom  (1973)  report,  attention was  suddenly
 focused on lagoon treatment technology. It became
 evident that a careful and comprehensive  reappraisal
 of lagoon capabilities and deficiencies was needed to
 determine the advisability of new lagoon construction
 and potential methods for successfully  upgrading the
 more   than  4,000  existing  lagoons  to  consistent
 secondary  treatment quality.  Methods for solving
many of the operational problems  such as offensive
 odors were known by engineering firms and consul-
 tants who had kept abreast of the continuing evolution
 of lagoon  designs. This information has been  col-
lected and presented at EPA Technology  Transfer
 Design  Seminars  and published in a Technology
Transfer  Design Seminar handout. One major prob-
 lem, however, that seriously affected effluent quality
 at  least in certain periods of the year  in almost all
 lagoon systems was the amount of algae contained in
 the effluent. These algae settle out in the bottom of a
 receiving stream or lake, undergo death and degrada-
 tion,  and exert  a long-term  oxygen  demand and
 oxygen  sag. The  experimental work at Lancaster,
 California (Dryden and Stern, 1968), and research in
 South Africa and  by the firm of Brown and Caldwell,
 Inc., at  Stockton, California,  showed that for larger
 lagoons  with  skilled  operators,  tertiary chemical
 coagulation followed by sedimentation-filtration or
 froth-flotation effectively removed the algae from the
 effluent as well as removing phosphorus to low levels.
 However, it was felt that less costly and less operator
 intensive methods were  needed for the smaller com-
 munities where  personnel are customarily  not  avail-
 able.

      A  Request  for Proposals (RFP) for  simple,
 reliable, low-cost  methods to  remove  algae  and
 suspended solids from lagoon effluents elicited a total
 of  27 responses  proposing a great variety of potential
 algal removal techniques. After evaluation by a panel
 composed of members  of the staff of the Biological
 Treatment Section of the Advanced Waste Treatment
 Research Laboratory  at  the National Environmental
 Research Center in Cincinnati, three  projects were
 chosen for funding as being most likely to meet the
 criteria set forth  in the  RFP. They are  passage of
 lagoon  effluent  through a slow-rock filter being
 studied by Dr.  Walter O'Brien at the University of
 Kansas,  passage  of lagoon-effluent  through inter-
 mittent slow-sand  filters, and crop irrigation and land
 spreading of  lagoon  effluents. These latter  two
 projects  were  combined into a single research con-
 tract to Utah State University. This work is under the
 overall  guidance  of Dr. E. Joe Middlebrooks. The
 University of Kansas study is being conducted at the
 Eudora,  Kansas, lagoon  (three cells hi series), and the
 Utah State projects are being conducted at the Logan,
 Utah, lagoon (seven cells, five in series, the first two
 in  parallel).  Site  plans of these two lagoons are
 illustrated in Figures 6 and 7, respectively. The details
 of these  projects are given in other reports presented
 at this  symposium.

Manual on algae and water pollution

     A sole source contract was awarded  to Dr. C.
M.  Palmer in fiscal  year  1973 for a  revision and
expansion of his manual "Algae in Water Supplies."
The title and emphasis will be changed with inclusion
of  additional  color plates,  an expanded key for
identification of algae,  and new chapters. The new
chapters will discuss Algae and Eutrophication, Algae
and Pollution, Algae as Indicators of Water Quality,
Algae in Streams,  and Algae in Sewage Stabilization
Ponds.

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                    Review of EPA Research and Development Lagoon Upgrading Program
                              ROCK   FILTER   EFFLUENT
                      PUMPED  ROCK  FILTER  INFLUENT
                              o-

                          CELL

                          C
     2nd  CELL

         B
7.8
Ac
                    PRIMARY   I       INFLUENT
                    LAGOON
                          A
                         3.7 Ac
Figure 6. Flow diagram of Eudora, Kansas, .lagoon treatment system.
ROCK

FILTER
39.4 AT
D

1
1
E





28.3 Ac
l_
EFFL

64.4 Ac
C

f
72.3 Ac "*"
1
B.
70.9 Ac

UENT [-J-]




^t-
95.0 Ac
A2
y


Diffusei^X^
^/
A.
95.1 Ac

Intermittent
sand filter




i
z
u
b.
if
]


          Clorination
          test facility
To  spray   irrigation  and  land
spreading   system
Figure 7. Flow diagram of Logan, Utah, lagoon treatment system.

-------
          Lewis
             Fiscal Year 1974 Projects

 Performance evaluation of existing
 facultative lagoons


      As was stated earlier, there is a wide variation in
 the design of lagoon systems and long-term perfor-
 mance  data are  generally  lacking, particularly for
 continuous-discharge facultative and aerated lagoons.
 Typically, there is  no formal test program at  most
 lagoons,  or  at best,  infrequent  grab  sampling and
 analysis. The EPA Task Force Committee assembled
 to prepare a Technical Bulletin on Design Criteria for
 Lagoons   found  little  evidence  of  evaluation  of
 existing lagoon  performance  in  relation  to design.
 What data do exist indicate that multiple-cell lagoons
 (series  or parallel-series  operation)  perform better
 than one large lagoon of equivalent detention  time,
 and that  effluent quality is deteriorated either  by
 large amounts of algae during summer periods or by
 excessive  cold and icing over leading to anaerobic
 conditions during the winter. It was  felt to be of
 utmost importance to determine early in the program
 whether   well-designed,  multiple-cell,  continuous-
 discharge  lagoons can  meet  the  1977  Secondary
 Treatment Standards  on .a year-round basis without
 additional treatment.  To  accomplish this, it was
 decided that  a  performance  evaluation  of several
 lagoons in different climates and geographical  loca-
 tions of the country was an essential first step.

      Qualified contractors were  solicited via an RFP
 to  submit  well-designed  facultative  and aerated
 candidate lagoon systems amenable to rigorous sampl-
 ing and analytical evaluation for a period of one  year.
 Twenty-four hour composite sampling was specified
 on a twice-a-week basis except for four periods during
 the year (once each season) when sampling was  to be
 conducted  for   30   consecutive   days.  It   was
 emphasized that  the candidate lagoons should not be
 presently  over-loaded, and  that   provisions  for
 accurate flow measuring (influent and effluent) had
 to be assured. Lagoons serving  populations greater
 than 5,000 were not considered.

      Sixteen proposals were received comprising a
 total of  39  candidate  lagoons. Due to  funding
 constraints,  it was possible  to  award contacts for
 evaluation  of  only  four  multi-cell,  continuous-
 discharge,  facultative  lagoon systems. The contracts
 were awarded to the University of Kansas, Utah  State
 University, Mississippi State  University,   and  JBF
 Scientific  Corporation for evaluation of  lagoons at
'Eudora,  Kansas;  Corinne,  Utah;  Kilmichael,
 Mississippi;  and  Peterborough,  New Hampshire,
 respectively. All are  three-cell series lagoon systems
 except  Corinne which utilizes seven  cells in series.
The  locations of these four lagoons are spotted on a
map of the United States in Figure 8. The location of
a similar  performance evaluation being conducted by
EPA Region VII personnel at Blue Springs, Missouri,
is also shown in Figure 8. The site plan of the Eudora
lagoon was illustrated previously  in  Figure 6. Site
plans for the Corinne, Kilmichael, and Peterborough
lagoon systems  are given in Figures 9, 10, and 11,
respectively.  Information  on acreage, average flow,
and  organic  loadings for the  four  lagoons  being
surveyed by the research and development program is
presented  in  Table  1. Table  2  summarizes  the
sampling  and  analytical  format  for the  project.
Measurements of daily flow entering and leaving the
lagoon  systems  will  allow  the  determination  of
long-term water balances  (accounts for evaporation
and  percolation losses). The  enumeration  of fecal
coliform  bacteria in  the lagoon effluents will show
whether  or not the long detention time in lagoon
systems is  sufficient  to reduce  the numbers to the
levels specified in the secondary  treatment standards.
The  Peterborough system employs chlorination be-
fore  discharge  of effluent  to  the receiving water.
Soluble BOD and  COD  measurements  before  and
after  chlorination will  provide  information on the
possible solubilization of organic matter due to lysing
of algal cells arising from the application of chlorine.
Lagoon Workshop Symposium

     This symposium is being sponsored with fiscal
year 1974 funds and was planned to accelerate the
exchange of information between the research staffs
conducting experimental work on upgrading lagoon
treatment systems and the EPA and  state officials
charged  with  regulatory  and permit  activity and
decisions on construction grant applications.
Table 1. System  parameters for facultative lagoon
         survey.

Site


Peterborough, N.H.
Corinne, Utah
Eudora, Kansas
Kilmichael, Miss.
Total
Acre-
age

20.7
9.5
19.3
8.1
Average
Flow
mgd)

.150*
.070
.120
.110?
Lagoon Loadings
Ob BOD5/day/
acre)
Primary
Cell
4045
35
34
51
Total
Lagoon
15-20
14
13
33

-------
                                                                                                  H, N.H.
                CORINIS«E,UTAH
                    /    • L
                                                      rKILMICHAEL. MISS
Figure 8. Location of facultative lagoon treatment systems being tested for year-round performance.

-------
 10      Lewis
 EFFLUENT
                                                                     INFLUENT
                                  SAMPLING
                                   STATION

 Figure 9. Flow diagram of Corinne, Utah wastewater    Figure 10. Flow diagram of Kilmichael,  Mississippi,
          lagoon treatment system.                              lagoon treatment system.
Table 2.  Sampling and analytical guide for performance evaluation of existing facultative lagoons.
Parameter
WWFlow
Daily Total
Type of Sample
Continuous
Min. & Peak
pH

WW Temp.
D.O.

Alkalinity
Total
BOD5a _
Soluble BOD5a
Susp.
Fecal
Solids"
Coliforms
Total CODC
Soluble COD0
Total po
TKNC

NH3-NC
N02-NC
N03-NC
Grab, in-situ
Grab, in-situ
Grab, in-situ
Composite
Composite
Composite
Composite
Composite
Composite
Composite
Composite
Composite
Composite
Composite
Composite
Lagoon
Influent
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X


Sample Location
Between
Cells of
Multi-Cell
Lagoons


X
X
X
X
X
X
X
X
X
X





Lagoon
Effluent
X

X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
After
Chlorination


X

X

X
X
X
X
X
X
X
X
X


Algae Cell Count
by Microscope
Composite

X
X
X
     "Nitrification inhibited in BOD bottle.
     ^f LSS and MLVSS analysis (grab) will be performed on the contents of the aerated lagoon.
     cAnalyses to be performed in Cincinnati.

-------
                            Review of EPA Research and Development Lagoon Upgrading Program     11
                           Pond  No. 3
                               6.5 Ac
                            FROM
                    SECONDARY   CELL B
                          OF   LOGAN
                            LAGOON
       Pond  No. I
          8.5  Ac
Pond No. 2
 5.7   Ac
    INFLUENT-*-
   r€FFLUENT
 To  chlorine   contact   tank
                                                                                   FROM  INTERMITTENT
                                                                                   SLOW-SAND   FILTERS
                                k
                                                                                                  -cu
                                                    I.

                                                    2.
                                        D

                                    cone*

(S) (tonotM tomplt locations for chloriM contact tank
infhJtntt a at  attention  tlm«« of 15,30, a 45  min.
                                           BC

                                             different  d.
Figure 11. Flow diagram of Peterborough, New Ham-
          pshire, lagoon treatment system.
                      Figure 12. Process test sequence  for  lagoon chlo-
                                rination study.
            Fiscal Year 1975 Projects
 Disinfection study (planned)
      A scope-of-work has been planned and a con-
 tract is  being prepared for a chlorine disinfection
 study to be  carried out by Utah State University at
 the Logan, Utah, lagoon. The site plan for the Logan
 lagoon  system was shown previously in  Figure  7.
 Effluent to  be disinfected can be  taken  from the
 intermittent  slow-sand   filters,   from   cell  Bj
 (secondary cell), or from cell E (final  effluent). This
 will enable evaluation of a variety of concentrations
 of fecal coliform bacteria, algae, and suspended solids
 in the effluents to be disinfected. Four experimental
 chlorine contact  tanks will  be  constructed with
 baffles  to  control  short   circuiting.  The  flow  of
 effluents  through each  tank will be  precisely con-
 trolled. Samples will be analyzed 2 days per week  on
 tank influents and  at the  15-, 30-, and 45-minute
 detention points. Three of the chlorination systems
 will be operated in parallel with different chlorine
 concentrations using effluent from either cell  Bj  or
 cell E as tank feed. The other experimental system
 will evaluate chlorination of effluent from  the inter-
 mittent slow-sand filters. A diagram of the proposed
 chlorination  experimental layout  is presented  in
 Figure 12. A summary of the sampling and analytical
 program  for this project  is  given in Table 3. The
 objectives of this comprehensive disinfection project
                      are  to  learn  more  precisely  the factors  affecting
                      disinfection  of lagoon effluents and the conditions
                      under  which  chlorine  dosing  will  release soluble
                      organics through lysis of algal cells. As can be seen in
                      the  sampling schedule, the die-off of fecal coliforms
                      from  cell to cell of  the  Lopn lagoon will also be
                      studied.

                      Nitrification of lagoon effluent
                      with a rotating biological
                      contactor (planned)

                            Nitrification does not normally occur in facul-
                      tative lagoon  systems because  the concentration of
                      nitrifying bacteria in the  upper aerobic zone  is not
                      sufficient for significant oxidation of ammonia nitro-
                      gen. The numbers of nitrifying bacteria may be low
                      because  of  inhibition by the algae  or because the
                      nitrifying bacteria tend to adsorb onto soil particles
                      and other aggregates and settle out into the anaerobic
                      zone  where they cannot carry out their  activities.
                      Many lagoon treatment systems, thus, may have high
                      levels of  effluent ammonia nitrogen  (20 to 30 mg
                      NH^-N/l) that can seriously interfere  with chlorine
                      disinfection, can exert an oxygen  demand in the
                      receiving waters if nitrification occurs in those waters,
                      and may be a  major cause  of eutrophication  in
                      receiving waters.

                            A  scope-of-work has been  discussed with the
                      University of Michigan to conduct a lagoon nitrifica-

-------
12
Lewis
Table 3.  Sampling and analytical program for lagoon disinfection project.



Unfiltered-effluent
from Cell B!
FUtered effluent
from Cell Bj before
Chlorination
40! (15 minutes)
4 0, (30 minutes)
4 03 (45 minutes)
Raw Wastewater
Effluent from
Cells Aj & A2
Effluent from
Cells B, & E
Effluent from
Cells C & D
Analyses/day
of sampling


Total
BOD
X

X




X






3



Total
COD
X

X



X
X






7



Sol.
COD
X

X

X
X
X
X






15



Nl^-N
X

X

X
X
X
X






15



Turbidity
X

X

X
X
X







14



Sulfides
X

X

X
X
X







14


TSS
&
vss
X

X

X
X
X
X






15


pH
Temp.
D.O.
X

X



X

X

x

x

12

MPN&
MF
Total
Coliforms
XX

XX

XX
XX
XX
XX
XX

XX

XX

42

MPN&
MF
Fecal
Coliforms
XX

XX

XX
XX
XX
xa
xa

xa

Xs

35



Chlorine
Residual




X
X
X







12

      aMPN not required.
       6 = mean residence time.
tion grant  project at the  Genoa, Ohio, waste water
lagoon system. This is a two-cell facultative lagoon as
shown in the site plan in Figure 13. The project will
investigate if it is possible to nitrify the effluent from
a  continuous-discharge  lagoon  using  a  rotating
biological  contactor  (RBC)  unit  (also  known as
rotating biological  discs  or rotating biological sur-
face), and will attempt to quantify seasonal effects. A
six-stage  RBC pilot plant will be utilized  with 15
4-foot diameter discs in each stage yielding a total of
90 discs. This provides 2,272 sq ft of disc surface area
and  with  a nominal loading of 2.6 gpd/sq ft will
require a throughput of 5,900 gpd. Pumpage will be
variable over a range down to 0.5 gpd/sq ft. Com-
posite samples of the RBC feed (lagoon effluent) and
after each  of the six stages will  be collected  three
times per  week. Analyses to be performed include
organic, ammonia, nitrite and  nitrate nitrogen, BOD,
COD, suspended solids, biomass  on  the discs, pH,
wastewater temperature, and alkalinity. Adjustments
of the flow and organic and ammonia loadings will be
made to optimize the biological response. The effects
of seasonal temperatures on the kinetics of nitrifica-
tion will be observed and the best configuration of
the  six stages  (series, parallel,  or a  combination
thereof) defined. The work plan also calls for loading
the system  to failure of nitrification and then noting
                                                     6.77  Ac
                                                         B

                                                     6.77  Ac
                                                                            INFLUENT
                                                                             EFFLUENT
                                                                                  RBC
                                                                                  PILOT
                                                                                  PLANT
                                           Figure 13. Flow diagram  of Genoa, Ohio, lagoon
                                                     treatment system.

-------
                             Review of EPA Research and Development Lagoon Upgrading Program     13
 the rate of recovery of nitrification upon the resump-
 tion of normal loading.

      Hopefully,  this  project  will generate design
criteria for future full-scale work and will eventually
prove  the  RBC approach  to be a simple, reliable
method for nitrification of lagoon effluents.

Combined phosphorus and nitrogen
control in a lagoon (planned)

     A joint inhouse/extramural  project  is being
planned to  begin  early  in  calendar year  1975 to
remove phosphorus from and nitrify the effluent of
the St. Charles,  Maryland,  lagoon. The  site plan
shown in Figure 14 indicates this is a  six-cell series
lagoon with the first two cells being aerated  followed
by four facultative cells. The average  flow to  this
six-cell system is 0.6 mgd. Equipment installation and
overall project direction will be the responsibility of
the staff of the Joint EPA/District of Columbia Pilot
Plant located several miles  away. A service contract
with the  Charles  County  (Maryland) Community
College is being contemplated  to provide necessary
day-to-day   operation, weekend  surveillance,  and
analytical work.

EFFLUENT
                                     INFLUENT
                                       SURFACE
                                       AERATOR
 Figure 14. Flow diagram of St. Charles lagoon treat-
           ment system-site  of planned  nutrient
           control project.
     Phosphorus removal will  be effected  by the
addition of alum  to different  cells of the lagoon
system. Studies will be conducted to determine which
of  the first  two  or three cells  is  optimal for
phosphorus removal. The rate of sludge buildup at the
bottom of the cells  will  be  followed. The chemical
feed system will  be designed to provide good mixing
with  cell  influent  wastewater.  A most important
observation  will  be  whether  the   precipitated
phosphorus sludge tends to settle out in a "clump" or
 :venly distributes itself across the cell bottom. This
 vill  have  ramifications concerning the frequency at
 vhich  the chemical sludge will have to be removed by
 'clamming" and also  the possible  resuspension of
 >recipitation phosphorus particles by wind action.

     The nitrification studies on the lagoon effluent
will be similar to those planned at Genoa, Ohio, with
the exception that a plastic-media trickling filter pilot
unit will be used instead of an RBC pilot system. The
purpose of the study and parameters to be evaluated
will nearly parallel that work.

      This project  should aid in the development of
guidelines for design and operation to simultaneously
remove phosphorus  and oxidize ammonia nitrogen
for those  lagoons faced with both eutrophication and
excessive  oxygen depletion in their receiving waters.


     Summary  of Lagoon Upgrading Projects

      A summary of fiscal year 1973,1974, and 1975
 research and development sponsored lagoon upgrad-
 ing projects and the  cost of each project are given in
 Tables 4  and 5, respectively. For fiscal year 1975,
 lagoon upgrading  received  the  largest  share  of re-
 search  and  development   funds  of  any  of  the
 biological wastewater treatment processes.

 Table 4.  Ust of EPA lagoon projects FY 73-75.

 1.    Algae Removal (FY'73)
       A.    Intermittent slow-sand filter, Utah State
            University
       B.    Crop irrigation and  land spreading, Utah
            State University
       C.    Slow-rock filter, University of Kansas
 2.    Manual on Algae and Pollution (FY '73), Dr.
       Palmer
 3.    Facultative Lagoon Performance Survey (FY'74)
 4.    Lagoon Symposium (FY '74)
 5.    RBC  Nitrification Following  Lagoon  (FY'75
       Planned)
 6.    Phosphorus  Precipitation in and Plastic Media
       Nitrification Following Lagoon (FY'75 Planned)
 7.    Lagoon Disinfection (FY'75 Planned)
 8.    Aerated  Lagoon Performance  Survey (FY'75
       Tentative)

-------
 14
Lewis
 Table S.  Summary of Ord funding for lagoon upgrad-
          ing projects.
    Description
                        Amount ($ K)
                   FY'73   FY'74   FY'75
 1.  Manual on Algae in          12
    Water Pollution
 2.  Algae Removal Projects     322
 3.  Facultative Lagoon
    Performance Survey
 4.  Lagoon Symposium
 5.  RBC Nitrification Follow-
    ing Lagoon (Planned)
 6.  Phosphorus Removal in
    and Plastic Media Nitri-
    fication Following Lagoon
    (Planned)
 7.  Lagoon Disinfection
    Project (Planned)
 8.  Aerated Lagoon Performance
    Survey (Tentative Based on
    Availability of Funds)
                             148

                              10
         70


         49

        166



        105

       (350)
             TOTALS
                    334
158     390
       (350)
            Future Planned Studies

      Sufficient funds were not available in fiscal year
1974, nor are they as yet available in fiscal year 1975,
to include well-designed aerated lagoons and aerated/
facultative lagoon combinations  in the performance
survey  currently  beginning on  existing facultative
lagoons only. It is hoped  that funds will yet be made
available in fiscal year 1975 for this important survey.
If not, the project will be programmed into the  fiscal
year  1976 budget. It is anticipated that $350,000 -
400,000 will be required to evaluate four to five such
lagoons for 1-year each.

      In future years, it is hoped that studies can be
undertaken  to evaluate  the  use of  algae  as  food
 sources for animals or predators. It is probable that
 unique designs  to limit the predators to certain cells
 of a lagoon system will be needed and that the factors
 affecting the development of the predators will have
 to be understood to develop a successful scheme of
 operation.  Additionally,  to  create  the  necessary
 credibility  and  confidence to convince design engi-
 neers  to  utilize the  upgrading techniques currently
 being researched,  full-scale demonstrations of  the
 more successful methods of removing algae from the
 controlling nutrients  in lagoon effluents are planned.
 The principal objective of the entire lagoon upgrading
 program is to develop design and operating guidelines
 to meet a variety of effluent quality needs, and to do
 so with an array of  upgrading techniques applicable
 to the small community nature of lagoon users. Only
 in this way can the  relative simplicity  of operation
 and  maintenance and  the low cost that have  made
 lagoons such a  popular method of wastewater  treat-
 ment for small  communities in the past be retained.

                   References

 Barsom, G.  1973. Lagoon  performance and the state of
     lagoon technology. EPA Environmental  Protection
     Technology Series EPA-R-2-73-144. June.

Champlin,  R. L. 1971. Supplementary aeration of lagoons in
     rigorous climate areas. EPA  Water Pollution Control
     Research Series 17050 DVO. October.

Christiansen, C. D. 1973. Coarse bubble diffusers for aerated
     lagoons in cold climates. EPA Arctic  Environmental
     Research  Laboratory, College, Alaska,  Working Paper
     No. 17. January.

Dryden, F. D., and G. Stern. 1968. Renovated waste water
     creates recreational lake. Environmental Science  and
     Technology 2:268-278.

McKinney, R. E., J. N.  Dornbush, and J. W.  Vennes. 1971.
     Waste treatment lagoons-state-of-the-art. EPA  Water
     Pollution Control Research Series 17090 EHX. July.

Parker, C.  E. 1970. Anaerobic-aerobic lagoon treatment for
     vegetable tanning wastes. EPA Water Pollution Control
     Research Series 12120 DIK. December.

Secondary  Treatment Information.  1973. Federal Register
     38(159):22,298-22,299. Pt. II. August 17.

-------
                               STATE OF THE ART OF LAGOON

                                  WASTEWATER TREATMENT

                                           R. E. McKinney1
      Oxidation ponds have had extensive use in the
United  States  for the  treatment  of domestic and
industrial wastewaters from small communities and
isolated  industrial plants.  The advantages of  the
oxidation pond systems lie  in their simplicity of
design, construction, and operation. No other waste-
water treatment system is as easy to design, construct,
or  operate.  In spite  of its  simplicity, the oxidation
pond system produces a high degree of  wastewater
stabilization. In recent years with greater emphasis on
wastewater treatment, some concern has  been raised
as to effluent quality produced by oxidation ponds.
With the EPA requirements for secondary treatment
clearly requiring a 30  mg/1  BOD5  and  a  30 mg/1
suspended  solids  for  all  municipal  effluents,  the
oxidation pond has been signaled out for its  potential
failure to meet these standards. Unfortunately, few
people responsible for enforcement of EPA regula-
tions are concerned about wastewater treatment and
the consequences of eliminating oxidation  ponds as
wastewater treatment systems. While oxidation ponds
have been in use for many years, there have  been few
documented  cases of  serious pollution  problems
created  by  the effluent discharged  from oxidation
ponds. The reason for this is that oxidation ponds are
essentially small treatment devices  that produce  a
relatively small discharge. The nature of the  BOD and
the  suspended  solids  from oxidation  ponds  are
different than  the discharges from other treatment
devices;  but this difference has  largely gone  un-
noticed.  It is time that we recognize that the BODS
and the  suspended solids discharged from an oxida-
tion ponds  system are definitely different  than the
BOD5 and the suspended solids  from other treatment
systems.  The  impact on  the receiving waters is
different even though they  are measured  in  the same
units. Unfortunately, there has been a tendency to
lump everything  together into  a  single  simple
standard that can be easily  administered without any
thinking or understanding of either the problem or its
solution.
     1R. E. McKinney is Parker Professor of Civil Engineer-
ing, University of Kansas, Lawrence, Kansas.
           Current Design Concepts

     The design criteria for oxidation ponds develop-
ed empirically by trial and error. Engineers took the
data from  California and  Texas  and applied  it to
other locations throughout the country. They soon
learned that California and Texas were different from
their part of the  country and  that oxidation ponds
worked differently in different parts of the  country.
More was learned from the initial failures than from
the initial successes.  Oxidation ponds were built too
small  as  well  as too large.  Both systems produced
problems which required further  engineering before
solutions were developed. Neither system produced
impossible  solutions. As information was developed
through field experience, it was possible to evolve a
sound set of design criteria that fit different parts of
the country.

     Unfortunately,  little  operational  data  were
generated from oxidation  ponds. Oxidation ponds
were too small to require extensive analytical data.
Simplicity  of  operation eliminated the  need  for
operators and little data were generated. A few tests
were made periodically that showed that oxidation
ponds  performed reasonably well but the data were
limited.  When problems occurred, more extensive
sampling was made to confirm that a problem existed
and to base a case for requiring expanded treatment.
Slowly, a large mass  of data began to be accumulated
on  problem ponds and a question was raised as to
whether or not oxidation ponds should be used for
wastewater treatment.  The  question is a valid one
which  must  be  answered  in  both technical and
nontechnical terms. There is a  need to know exactly
how oxidation ponds function and exactly what kind
of effluent can be produced on a  day in and day out
basis. There is also a need to examine the alternatives
to oxidation ponds and their impact on society if it is
necessary to replace oxidation ponds.

     Oxidation ponds are  simply large flat holes in
the  ground  with adequate capacity  to hold  the
wastewaters for several months.  It was  found that
oxidation ponds should not be too shallow as weeds
would grow up and create a place for mosquitoes to
grow. At the same time the ponds should not be too
                                                                                                  IS

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  16
McKinney
 deep as there has to be adequate surface for algae to
 grow and to produce  sufficient oxygen  to  keep the
 system aerobic at all times. Experience indicated that
 a 4-foot water depth was reasonable for all parts of
 the country  except  the desert southwest  where
 evaporation  required  deeper  ponds.  It was  soon
 learned that flexibility to control the water depth in
 the ponds was also desirable. Often effluent control
 structures permitted operation between 3 and 5 feet.
 The ponds were drawn down  to minimum depth once
 cold weather  set in and were allowed to rise  up to
 maximum  depth by  spring  time.  In this  way the
 sewage was actually retained  during the low tempera-
 ture periods  and discharged when maximum flow
 conditions existed in the receiving stream.

      The size of oxidation ponds was dictated by the
 population  served  with  a  theoretical  volume of
 wastewater per  capita. In the southwestern part of
 the country  the rate of evaporation  during  the
 summer  dictated the  size of the  ponds while the
 length of winter dictated  the  size  of ponds in
 northern  climates.  For the  most  part, the  initial
 ponds were conservatively designed with 120-180 day
 retention  periods. As results indicated  satisfactory
 operation,  engineers slowly reduced the size of the
 ponds down to 90 days and  then to 60 days in some
 instances. With the reduction in retention time came
 an increase in organic load. At 180 days retention the
 theoretical design population  was 72 people/acre with
 a BOD5  load of 12 Ibs/acre/day. The more conveni-
 ent design parameter soon  became population per
 acre since the calculation  was made so easily. At 100
 people/acre the  theoretical  retention time became
 over 120  days  and  the load  was 17  Ibs BOD,/
 acre/day.  At  200 people/acre the  retention period
 was reduced in half and the organic load  doubled. As
 engineers  became more  sophisticated,  the popula-
 tion/acre design criteria was  replaced by the BOD /
 acre/day loading rate.  A 40 Ib BOD5/acre/day loading
 rate  became  popular  as the  basis  of design of
 oxidation ponds.  Even a 65 Ib BOD5/acre/day loading
 rate was employed; but problems began to occur and
 the  loading  rate was reduced. At 65  Ibs BOD,/
 acre/day  there was an increase in operational prob-
 lems and engineers have tended to back off from such
 loads even though the literature indicates that opera-
 tion as high as 100  Ibs  BOD5 /acre/day should be
 possible without  problems. For the most part engi-
 neers have  relied more  on field evaluations than on
 laboratory  scale or even pilot scale  research studies
 over a relatively  short period of time. It should be
 recognized that no one likes to talk about treatment
 systems that fail to operate satisfactorily.  For  this
 reason it has been extremely  difficult to  obtain data
 necessary to develop sound design criteria. Each state
 regulatory agency seems to have arbitrarily developed
 a set of criteria that they felt comfortable  with  and
have proceeded  to use. For  the most part there is
                                            little  scientific or  technical basis for  the  design
                                            criteria.

                                                          Biological Concepts

                                                 In order to  properly design oxidation ponds it
                                            is  essential  to understand  the  biology  and the
                                            biochemistry  occurring within the ponds. Over the
                                            years considerable information has been developed on
                                            various aspects of oxidation ponds but seldom has the
                                            information been  put together in a usable format for
                                            the design engineer. The net effect  has been that the
                                            engineer has simply followed the state health depart-
                                            ment design criteria without any regard to the results
                                            obtained. Too often, if problems  resulted, the engi-
                                            neer was quick to point out that the system followed
                                            state design criteria and  the problem was  not his
                                            responsibility.

                                                 Initially,  the  biochemical   reactions  were
                                            thought to be a  simple set of symbiotic reactions
                                            between the  bacteria  and the  algae. The bacteria
                                            aerobically  stabilized  the organic matter  in the
                                            wastewaters to carbon dioxide and converted it back
                                            to oxygen which the bacteria needed for their aerobic
                                            reaction.  All that  was needed was  time  for the
                                            bacteria to metabolize the organic matter  and ade-
                                            quate  surface for the algae  to obtain enough light for
                                            their metabolic reactions. The simple symbiotic reac-
                                            tion was not  as  simple as it seemed  at  first. The
                                            bacterial reaction  was one  of synthesis, followed by
                                            endogenous  respiration. The synthesis reaction re-
                                            quires  oxygen for  the  metabolism of  the organic
                                            matter to form new cell mass, carbon dioxide, water,
                                            and ammonia. The following reaction is  representa-
                                            tive of the  metabolism   of domestic  sewage by
                                            bacteria in a mixed culture environment. Only the
                                            biodegradable fraction of the domestic sewage is used
                                            in this equation.

                                            Synthesis:

                                            C7.1 H12.6 °3.0N + 3'° °2 -* C5H9°3N + 2A C02
                                                   +  1.8H20


                                            With a normal domestic  sewage  having 200 mg/1
                                            BOD5,  112  mg/1  oxygen  would  be required to
                                            stabilize the organic matter in  the sewage  and 154
                                            mg/1 VSS as microbial solids would be created. These
                                            micfobial  solids  are unstable  organic matter and
                                            continue   to  undergo  aerobic   degradation   via
                                            endogenous respiration as follows:

                                            Endogenous Respiration:
                                                  C5H9O3N + 4 02 — 0.2 C5H903N

                                                       = 4C02+0.8NH3 + 2.4H20

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                                               State of the Art of Lagoon Wastewater Treatment
                                              17
 The endogenous respiration  reaction results in the
 production  of 30 mg/1 inert organic solids as dead
 microbial cells  while  using  150 mg/1  oxygen  and
 releasing  13 mg/1 ammonia  nitrogen and 206 mg/1
 carbon dioxide. The  inert  organic solids  are  still
 suspended solids that  settle  very  slowly since they
 were individual bacteria cells. The empirical formula-
 tion used in the above  equations was C^gC^N
 instead of the more classical CjHyC^N. The reason
 for this is that a number of studies over the past 20
 years  have  indicated  that C5H9O3N  is  the more
 correct value. The most recent study was made at the
 University of  Kansas  this past year and produced
 extensive data on the validity of the C5H^03N value.

      These equations show  the two basic bacterial
 metabolism  reactions  at  completion  but  give  no
 information about the degree of completion and the
 time required to reach the completion of each phase.
 An  oxidation  pond system  is  not a  concentrated
 biological reactor like a trickling  filter or activated
 sludge, but  rather is a dispersed biological reactor like
 the  BOD  bottle.  Under aerobic  conditions  the
 bacteria will complete  the synthesis reaction in 24 to
 48 hours and the endogenous respiration reaction in
 an additional 18 days. From  a practical point of view
 over 99+ percent of the metabolizable organic matter
 in the domestic sewage will have been metabolized at
 the  end  of the synthesis phase. If the bacteria were
 not dispersed, they could be quickly separated with
 the  production of a high quality effluent. In most
 oxidation  ponds  the  bacteria  metabolism will be
 complete with the production of 30 mg/1 VSS and
 about  15 mg/1 inorganic SS, 314 mg/1 carbon dioxide,
 and 13 mg/1 ammonia nitrogen while demanding 262
 mg/1 oxygen.

      The metabolism of the  organic matter dispersed
 in  the domestic sewage results in a relatively clear
 liquid   containing   considerable   carbon   dioxide,
 ammonia nitrogen, and phosphates. In  the  presence
 of light  energy the algae are able to convert these
 elements into new cells by a synthesis reaction similar
 to the bacterial synthesis reaction.
 Synthesis:
                     Algae,
                               >C,Hq(X,
                                  593
Unfortunately,  the  algae reverse the  stabilization
reaction and  take stable  materials and convert them
back to unstable organic compounds in the form of
algal protoplasm. If  the  314 mg/1  carbon dioxide
produced by  the bacterial metabolism reactions were
all  metabolized by  the  algae,  20  mg/1  ammonia
nitrogen  would be required to synthesize  187 mg/1
VSS as algal cells and 229 mg/1 oxygen would be
released. If the  reactions  stopped there, it would be a
standoff with all the organic matter being converted
from  domestic wastewater organics to bacteria and
algal cell mass. The oxygen demand by the bacteria
would exceed the oxygen production by the algae,
262 mg/1 oxygen demand  in  contrast to  229 mg/1
oxygen production. If an additional source of oxygen
were not readily available, the  oxidation pond could
not remain aerobic. There is also another factor that
has to be  considered. The  algae cells are unstable
organic matter the same  as bacteria  cells  and also
undergo endogenous respiration.

Endogenous Respiration:

    C5H903N + 4 02^ 0.2 C5H903N + 4 C02

             + 0.8NH3 + H20

The endogenous respiration reaction of the algae is
exactly  the  same  as  the  endogenous respiration
reaction  of the bacteria. Approximately 37 mg/1 of
dead algal cells will remain as inert VSS with 19 mg/1
inorganic  suspended  solids.  The oxygen  demand
would be 183  mg/1 with  16 mg/1 ammonia nitrogen
released. The  overall  reaction  would  result  in  a
combined  suspended  solids production of 67  mg/1
VSS  and an  oxygen deficit  of 216  mg/1 from  a
wastewater having an initial BODS of 200 mg/1. If the
reactions stopped  here  there would be a  serious
problem. Fortunately the reactions continue.

      Algae  undergo  endogenous respiration  like
bacteria; but with the release of carbon dioxide, new
algal  cells  are  produced as  long as there  is sunlight
available for metabolism. The net effect is  that the
algae  recycle their carbon from active protoplasm to
gas back to active protoplasm  with a small fragment,
approximately 20 percent, being shunted off to inert
volatile organic suspended solids. The two reactions
occur simultaneously  and  pass almost unnoticed.
During the dark  period  algae demand oxygen the
same  as bacteria and synthesis must wait until light is
available.

      The   cycling  between   synthesis-endogenous
respiration and back to synthesis is  not  enough to
keep  the system aerobic nor will it solve the balance
between the bacteria  and the algae. Something more
is needed.  That something more is the alkalinity that
exists in the sewage. The alkalinity forms a source of
carbon for the algae to grow, as shown below.

Alkalinity:
5 Na2CQ3 + 5 62
                                  2 H20
 The production of oxygen requires the conversion of
 inorganic carbon  to organic carbon. If 300, mg/1
 alkalinity as  CaCC>3 were  present in the domestic

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18
McKinney
wastewaters,  the  algae would convert half of it to
the carbonate form and raise  the pH while producing
79 mg/1 VSS  and  96 mg/1 oxygen. Unfortunately the
additional oxygen is produced  at  the expense  of
additional  organic  matter.  The  combination   of
organic  metabolism,  alkalinity, and time permits the
oxidation pond to produce  the oxygen  needed for
waste stabilization. For the oxidation  pond to have a
net gain in oxygen, it is necessary for the algae to
recycle  the carbon through  several cycles to create
inert  organic solids that are not  oxidized  in  the
oxidation pond. With domestic sewage as used in the
previous equations, the minimum balanced retention
period  would  be  160  days.  Fortunately,  sedi-
mentation of both orgafiic solids in the  raw wastes
and algae has resulted in balanced operations at 90 to
100 days retention instead of  160 days.

      The key  to successful production of quality
effluents from oxidation ponds lies in algal removal.
Most  of the efforts  to reduce the algae  in  the
effluents  from oxidation ponds have centered  on
effluent structures drawing  off the  effluent from
below the pond surface. Since light  is critical  for the
algae, the motile  algae tend to predominate over the
nonmotile forms  in  oxidation ponds  and migrate to
the  desired  level  near  the  pond   surface.  The
predominant  nonmotile  algae tend to have  a high
surface  area  to mass ratio so  that they easily  remain
dispersed when agitated slightly. Wind  action over the
surface  of oxidation ponds  tends to  keep the non-
motile algae suspended while  the motile algae have no
difficulty remaining suspended. The nonmotile algae
settle slowly and eventually are removed by  sedi-
mentation where  wind action is  minimal. The use of
multiple  series  ponds  results  in  decreasing  algal
concentrations  where submerged pipes are used be-
tween ponds. In  effect, the  algae retention  time is
increased over   the  liquid   retention  time.   Un-
fortunately,  the effluent quality from multiple cell
oxidation pond systems is not satisfactory unless the
retention period is quite long, 120-180 days, or unless
mixing  action is minimized.  Recent studies on algal
removal from  oxidation  pond  effluents center on
rock  filtration  and sand filtration. It is  hoped that
information will be  forthcoming to demonstrate the
validity of these techniques.

             Coliform Reductions

      In addition  to  BOD and  SS  reductions, EPA
regulations require coliform reductions to 200 fecal
coliforms per 100  ml. The  reduction in fecal coli-
forms follows normal die-off  relationships. There are
no  antibiotics  or toxic  materials produced  in the
oxidation ponds that reduce the fecal coliforms. The
only factors  affecting fecal coliforms are starvation
and predation.  The lack  of sufficient  organic matter
results  in starvation of the fecal  coliforms while
                                            certain protozoa and crustaceans act as predators on
                                            the fecal coliforms the same as on the other bacteria
                                            in oxidation ponds.  Overall, it appears that multicell
                                            ponds will be  needed  with a total retention period
                                            between 60 and  100 days  to meet EPA effluent
                                            requirements without  chlorination. Mixing by wind
                                            action in single cell ponds will permit short circuiting
                                            and make  it  all but  impossible  to meet  effluent
                                            criteria without chlorination.

                                                   Microbiology of Oxidation Ponds

                                                  While an understanding of microbiology is not
                                            essential to the design of oxidation ponds it does help
                                            understand the reactions which occur and the changes
                                            that take place during the different seasons of the
                                            year. The primary bacteria in oxidation ponds appear
                                            to   be   Achromobacter,  Pseudomonas,   and
                                            Flavobacterium  and coliforms.  All  of the bacteria
                                            grow quickly until the organic matter is stabilized and
                                            then die off as a result of simple starvation.

                                                  The  algae which grow  in  oxidation ponds are
                                            related to the chemical quality of the system. For the
                                            most part  the  motile  flagellated  algae  predominate
                                            since they can easily move to the optimum light level.
                                            Chlamydomonas, Euglena, Chlorogonium, Phacus,
                                            Pandorina,  and  Carteria  are  the  major  green
                                            flagellated  algae predominating in oxidation ponds.
                                            The predominant green nonflagellated algae include
                                            Chlorella,  Ankistrodesmus  Microactinium,
                                            Scenedesmus,  Acttnastrum,_ and Closterium. All of
                                            these algae except  Chlorella have sharp projections
                                            that maximize  surface  area per unit mass and are able
                                            to  survive  in the presence of predators. Filamentous
                                            algae are  predominately  blue  green algae such  as
                                            Oscillatoria, Anabaena, and Phormidium, Anacytis is
                                            also a colonial form of blue green algae found  in
                                            oxidation  ponds.  Navicula  is  the  most  common
                                            diatom. The filamentous algae and the colonial algae
                                            survive primarily  because animal predators remove
                                            the flagellated  algae  and  Chlorella,  leaving  these
                                            undesirable forms to predominate.

                                                  The   free  swimming  protozoa  Paramecium,
                                            Glaucoma, Colpidium, and Euplotes have been ob-
                                            served in oxidation ponds.  Vorticella is a  common
                                            stalked ciliated protozoa found occasionally. Rotifers
                                            and the crustaceans, Daphnia,  Moina,  and Cyclops
                                            represent higher animal predators that can quickly
                                            remove the motile green  algae and  Chlorella.  These
                                            large predators metabolize the available  algae and
                                            then starve to death, creating a cyclic  pattern  of
                                            growth,  death,  and regrowth. The undesirable algae
                                            predominate when the predators reach peak popula-
                                            tion  since  the  predators  do not metabolize  these
                                            algae. For this reason some ponds become essentially
                                            clear when the crustaceans  predominate but  other
                                            ponds appear to remain green.

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                                               State of the Art of Lagoon Wastewater Treatment      19
                  Temperature

      Temperature is an important parameter affect-
 ing oxidation ponds. Not only does temperature have
 a normal effect  on the rate  of metabolism of the
 different groups  of microorganisms in the oxidation
 pond but it has a special effect when the temperature
 changes  suddenly.  As the  temperature  changes
 normally, the rate of metabolism changes by a factor
 of 2 with each 10°C temperature change. In the warm
 summer  periods, the  rate  of microbial growth  in-
 creases for the  bacteria, the algae  and  the higher
 animals.  As long  as  the  temperature  change  is
 relatively slow, there is  no  problem.  With a sudden
 change in temperature, either up or down, there are
 short term problems. The reasons for the problems lie
 in the differential growth rates of the various micro-
 organisms.  The bacteria grow the fastest and respond
 more quickly to the temperature changes. This means
 that the rate of oxygen demand increases faster than
 the rate of oxygen supply when the temperature rises.
 The algae are larger organisms and respond slower. If
 the  bacteria respond too rapidly and create excess
 turbidity  or form  black  sulfide precipitates,  the
 growth of the  algae is retarded  even more and the
 adverse impact is extended even further. Recovery
 depends  upon  the  growth  of  the  algae and  the
 production  of oxygen. A sudden drop in temperature
 can  slow the algae down sufficiently that they settle
 out  before reacting as  they  should.  In the  fall a
 sudden frost will result in the algae  dropping  out
 because the low  temperature is accompanied by less
 wind  action and more quiescent conditions. The
 entire  pond becomes quite clear. This is the time that
 regulatory  authorities recommend drawing down the
 pond,  since the water quality is at maximum. While
 many  engineers feel that little action occurs during
 the winter  period, this is not entirely true. Microbial
 reaction continues at a slow rate. The dear oxidation
 pond begins to turn green even under an ice  cover.
 The response is related to light and temperature.  By
 spring there is a reasonable biological activity but the
 melting of  the ice cover is generally accompanied by
 too  rapid  a surface  temperature increase.  The  ac-
 cumulated  organic matter that remained unstabilized
 after the long winter  period  stimulates the  rapid
 bacteria growth and the unpleasant anaerobic condi-
 tions that persist for a few weeks. When the tempera-
 ture  change is  gradual and  the ice  melting  is
 accompanied by a lowering  temperature, the adverse
 conditions  are  minimized.  Like it or not, sudden
 temperature changes always bring major changes for
 oxidation ponds.
                  Evaporation

      The large surface  area of the oxidation ponds
offers  a real  opportunity  for evaporation. In the
eastern part of the United  States the rate of rainfall
exceeds the rate of evaporation and actually dilutes
the effluent. As oxidation ponds move westward, the
rate  of evaporation equals the rate of rainfall; and
then the rate of evaporation exceeds the rainfall. In
the far west the rate of evaporation exceeds rainfall
many times over and  requires a  deep pond system
with minimum surface area.

      It would seem  that a zero discharge system
would be  considered the most desirable. There is no
doubt  that many  small  oxidation ponds  can be
designed as zero discharge systems  with the rate of
evaporation just equal  to  the  rate of inflow. At the
same time, it should be recognized that zero discharge
systems accumulate all the salts and inert solids that
enter  the  oxidation  ponds.  Eventually, the  zero
discharge system must be abandoned as being unsuit-
able for biological life and returned to the environ-
ment. While such eventuality  will be  a considerable
period in  the  future, it must  be  faced. Overall, the
continuously discharging oxidation pond  offers the
best system for  pollution control for small  com-
munities and industries that  require maximum waste-
water treatment with minimum effort.

                 Design Criteria

      Oxidation  pond design is still a retention time
problem.  Most plants  are designed on conventional
concepts but  operate  at much lower loading rates.
The reasons  for this  are simply that we tend  to
overestimate both the wastewater flow and its BOD5
when we apply  a general overall  design factor. It is
easy  to  apply  a  single factor,  and since   it  is
conservative the engineer continues to use it. Oxida-
tion  ponds can play a real role  in  wastewater
treatment for small systems provided they are proper-
ly designed.  It  should be recognized that a  single
pond system is not satisfactory as  it tends to short
circuit both algae and fecal coliforms. A multiceU
oxidation  pond system is the only thing that will
produce the desired results. It is important that we
recognize   that  a three-cell  system  will probably
provide the best system. A 120-day retention period,
three equal cell system with submerged transfer pipes
should  provide  an   effluent  suitable  for   EPA
secondary  treatment requirements. There may be a
few days  in the summer when the suspended solids
and BOD in the effluent exceed the 30-30 standards
but  the impact  on the receiving  stream will not  be
great enough to warrant serious reaction against the
treatment  system. In  the late winter  01 early  spring
the fecal coliform criteria may be exceeded for a few
days, but  once  again there is no real evidence that
deviation  from the fecal coliform criteria represents
any hazard whatsoever. It is important that standards
reflect real conditions and hypothetical conditions.

      Oxidation ponds are  simple devices that are
based on sound scientific principles. Oxidation ponds

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20     McKinney
offer no magic solutions  or  fancy  technological
developments. They are economical to build and to
operate.  No one wants  to  collect  data on  their
operating characteristics.  No  one wants to accept
responsibility  for oxidation ponds. This is  a highly
sophisticated  era  which  is  more  concerned  with
technological  development  than with  solving  real
problems. It should  be recognized that oxidation
ponds can treat wastewaters adequately to meet the
needs of the  environment if  engineers will use the
knowledge they already have.

     The discharge of raw wastewaters to oxidation
ponds results in  the discharge of settleable solids that
will readily settle out  when the velocity drops below
minimum levels. The initial discharge of wastewaters
should be to a deep section 5 to 10 feet deep and
below the normal floor level of the oxidation pond.
The  solids should accumulate around the  influent
pipe and create a special anaerobic zone that removes
most of these solid materials from the oxidation pond
reaction. The extra depth in  a center  section also
results in keeping some of the anaerobic end products
from entering the aerobic zone of reaction. There is
nothing special about shallow oxidation ponds except
where zero discharge ponds are desired or where light
is limiting.

     Evaporation is a major factor in oxidation pond
operation and misinterpretation  of the  operational
data. Evaporation concentrates  the  residuals  and
produces  a greater concentration effect than would
have been produced if evaporation had not occurred.
An effluent standard  based on  concentration alone
fails to consider the influent volume and requires an
effluent  quality that is difficult to obtain even with
the most sophisticated system. It is important that we
develop  criteria  that account for evaporation and
produce  the effluent necessary to prevent significant
environmental pollution.
                   Conclusions

      Oxidation ponds have proved over the years to
be one of the most significant forms of economical
wastewater treatment  for  small  communities and
isolated industries. Unfortunately, a lack of under-
standing of the fundamental biochemistry  has re-
sulted in  considerable criticism of oxidation  ponds.
The  development of a rigid EPA effluent criteria for
domestic  wastewater  treatment  systems has  also
raised a question as to the validity of using oxidation
ponds for wastewater  treatment  systems. When a
total  evaluation is  made of all factors involved, it is
apparent  that  oxidation  ponds  have  a place in
wastewater  treatment.  With proper  design  using
multiple  ponds  and  adequate holding  time  and
properly designed  transfer and  effluent pipe struc-
tures,  oxidation ponds will produce  a satisfactory
effluent when consideration  is made for evaporation
over such a large surface area. In a few instances the
application of rock filters  or slow sand filters may be
necessary  to produce a high quality effluent; but a
high  quality   effluent  can be   produced  on a
continuous basis.  The question is not how  should
oxidation ponds be used, but rather how can engineers
improve  oxidation pond  design  to meet effluent
criteria and still maintain their economical design and
simplicity of operation.

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                      CONSTRUCTION PROCEDURES AND REVIEW OF

                              PLANS AND GRANT APPLICATIONS
                                             W. R. Uhte
                                                       \
       General Problems with Wastewater
               Stabilization Ponds

      Before getting down to the nitty-gritty on the
 design, construction,  and operation considerations
 which are involved in federal and state review  and
 approval of upgrading wastewater stabilization ponds,
 let's first discuss some of the general problems usually
 connected with such facilities. As most pond installa-
 tions are  the equivalent of small plants some of the
 introductory remarks of Professor George Tchobano-
 glous  in  his  paper on "Wastewater Treatment for
 Small  Communities"  given  at the Conference  on
 Rural  Environmental Engineering, Warren, Vermont,
 September  1973,  are directly  applicable  to  this
 discussion.

 Design

      Design  of wastewater  stabilization ponds for
 smaller communities is an area that has not received
 the attention it requires or deserves. Many times large
 consulting  firms will  pass up  the design  of such
 facih'ties  or  assign them to young, inexperienced
 engineers. In other cases,  small firms with little or no
 experience  have  undertaken  the  design  of these
 ponds. Consequently, many of them have now proven
 to be  inadequate to meet original  requirements and
 therefore  have  no chance  of meeting the more
 stringent  discharge  requirements established by vari-
 ous federal and state agencies. Clearly, the design of
 ponds that work, is the responsibility of the engineer
 and not the contractor or  owner.

      It must be pointed out, however, that  design
 fee schedules and allowable  design costs have effec-
 tively  perpetuated  this dilemma.  A small  complete
 wastewater stabilization pond will require just about
 the same engineering  design effort as a large pond.
 Unfortunately most  owners  and  often even  the
 federal and state regulatory agencies do not recognize
 this fact  and  refuse to accept the high engineering
 costs  for the smaller units. Technology  transfer
 information  can be helpful, but full recognition of
 need for  reasonable fees  would also upgrade design.
     !W.  R. Uhte is Project Manager, Brown and CaMwell,
Walnut Creek, California.
Operation and maintenance

     Most wastewater stabilization ponds are built
and  then  practically  forgotten.  If they are visited
more than once or twice a year the owner complains
that  it is a problem installation. Although the more
stringent  discharge requirements  will be a  great
impact  on the need for better operation and main-
tenance an even greater impact on manpower require-
ments  will result  simply from the requirement to
produce continuing operational data. Recently it was
indicated that the  effluent  monitoring requirements
for a small,  less  than  1/2 acre,  pond installation
amounted to 4 man hours  per day. This, of course,
included two men for safety, travel  time and the
necessary waiting time between consecutive coliform
samples but  not  laboratory  time. It is probably
typical for the time which will be necessary to meet
the monitoring requirement at most installations.

     Once the owner has accepted this situation it
will  not be difficult  to see that much of the other
routine maintenance  around the ponds also receives
attention.  Good  pond design should include the
selection of equipment which will reduce the work
associated with such operation and maintenance to a
minimum.  Such equipment should be well proven,
with  adequate service  and parts centers available
within reasonable distances in case of breakdowns.
Budget limitations

      With water pollution such a topical item it has
been  fairly easy  lately to  convince the voters that
capital improvements to the waste treatment system
are worthwhile. This is especially true  with federal
and state participation covering up to 87% percent of
the costs. However, operation and maintenance of the
wastewater stabilization ponds have usually been put
on the welfare side of the budget; i.e., the side which
doesn't produce tangible results such as a library or
city park. Unfortunately this intangible side of the
budget is the first in line when cuts are to be made in
annual expenditures. Often such wastewater facilities
are put on emergency budgeting and only when they
get  into trouble  with the local  pollution  control
agency  does  the owner  seriously  consider  their
budget.
                                                                                                  21

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      Probably the  greatest challenge to  the up-
grading of wastewater stabilization ponds is going to
be in the development of adequate annual  operation
and maintenance budgets. These receive no  federal or
state aids, will be literally hundreds of times the costs
of existing budgets  and will face a long history of
being considered an  intangible budget item. Only by
careful  evaluation  of the  grant  requirements for
proper operation and maintenance, effluent monitor-
ing and fiscal solvency will this challenge be met. The
following discussions of detail  design, construction
and operation considerations must keep in mind the
ever   present  need  to   assure  that  whatever  is
accomplished  under capital improvements be fully
implemented on a continuing basis.

             Design Considerations

      As indicated earlier neither the contractor nor
the owner can do much about  the design  of waste-
water stabilization pond. This task  is  the responsi-
bility of the  design  engineer and involves the deter-
mination of safe loading levels, proper pond recircula-
tion   and  configuration,  good inlet and  outlet
hydraulics, adequate scum  control,  safe dike  con-
struction,  and the  correct location and  sizing of
ancillary facilities.

Loading levels

      Most wastewater stabilization ponds are faculta-
tive ponds having  depths between 3 and 8  feet. The
ponds have two active treatment zones: An aerobic
surface layer and an  anaerobic bottom layer. Oxygen
for aerobic  stabilization  in  the  surface  layer  is
provided by  photosynthesis and surface reaeration,
while the decomposition of the sludge in the bottom
layer  takes place anaerobically.  The carbon dioxide
given  off by the aerobic bacteria degrading organic
wastes in  the  surface zone and  by  the  anaerobic
bacteria degrading the sludge in the bottom zone  is
reused  by the  surface  layer  algae  to form  algal
biomass.  This  algal biomass  produces oxygen to
support  the  aerobic activity and dead cells  which
settle to  the bottom  and support the  anaerobic
activity.  Facultative ponds are  usually loaded be-
tween 15 and 80 pounds of BOD5 per acre per day,
although special seasonal loadings of up to 1 SO to
175  pounds of BOD5 per  acre per  day have been
found practical.

      Other types of ponds are sometimes utilized for
special  purposes.  These  include  high-rate aerobic
ponds, anaerobic ponds, tertiary ponds and aerated
lagoons.  High-rate  aerobic ponds are  usually limited
to applications wishing to produce a maximum algal
biomass, are shallow (12 - 18 inches in depth), and
are usually loaded from  60 to 200 pounds of BOD5
per acre per  day.  Anaerobic ponds are normally so
                                             heavily loaded that no aerobic zone exists. The entire
                                             pond  is  devoid of  oxygen  with loadings usually
                                             ranging from 200 to 1000 pounds per acre per day.

                                                  Tertiary ponds  are similar to facultative ponds,
                                             however  they are  usually very lightly loaded  (less
                                             than  15  pounds of  BOD5  per acre  per day) and
                                             therefore minimize the formation of the  heavy  algal
                                             biomass.  They  are normally  used for polishing ef-
                                             fluents from conventional secondary treatment  pro-
                                             cesses.  Aerated lagoons derive practically all  of the
                                             oxygen  for  aerobic  stabilization from  mechanical
                                             means. No algal biomass is formed so photosynthetic
                                             oxygen generation plays no role in the process. Some
                                             surface  aeration from natural sources  does exist,
                                             however, aerated lagoons cannot  be designed based
                                             on surface  area loadings. They  must be  designed
                                             utilizing activated  sludge  parameters  for detention
                                             and oxygenation capacity.

                                                  So  far  only  surface  loading rates have  been
                                             discussed. While these are probably the  most useful in
                                             determining  pond performance,  detention  time can
                                             also be  effective. Usually with facultative ponds of
                                             reasonable depths (4 to 6 feet) and surface loadings
                                             (50 pounds  BODs  per acre  per  day) sufficient
                                             detention times (90 to 100 days) will be achieved.
                                             However, a  weak  sewage  or  a system  with  large
                                             quantities of infiltration  or inflow  can change  this
                                             situation. An existing pond can be upgraded  by either
                                             increasing  its  detention  time, decreasing  its  areal
                                             BOD5 loading or by doing both.

                                                  If there  is insufficient  area for proper pond
                                             expansion the ponds may be deepened to achieve the
                                             necessary detention  time  and supplemented  with
                                             powered  mixing and aeration to decrease  its  areal
                                             loading rate. This supplementation is usually achieved
                                             by installation of either compressed air diffusers or
                                             mechanical  aerators.  Ponds which require relatively
                                             minor  supplemental  aeration  on  a  uniform  basis
                                             throughout  the  year   usually  find  compressed air
                                             aeration best. The efficiency of oxygen transfer from
                                             air to process BODS demand  is usually  less than  8
                                             percent. If the ponds must operate the  year around in
                                             a  cold climate, then  compressed air aeration will
                                             prevent  surface  freezing and allow  direct surface
                                             oxygen  transfer to  supplement whatever  photo-
                                             synthetic activity is available.

                                                  When  the supplemental requirements are  high
                                             (from 20 to 50 percent  of natural photosynthetic and
                                             surface activity) or  when the requirements are either
                                             seasonal  or  intermittent,  mechanical aerators are
                                             used. Two types of mechanical aerators are available:
                                             Cage  aerators  and the more common  turbine  or
                                             propeller  vertical-shaft  aerators. Mechanical aerators
                                             usually have a BOD5 reduction capacity  of between
                                             1.0 and 1.5  pounds BOD 5 per  horsepower-hour. The

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                             Construction Procedures and Review of Plans and Grant Applications      23
vertical-shaft turbine  or propeller units are  usually
conservatively designed for about 1.15 pounds BOD5
per horsepower-hour and the cage aerators for about
1.3 pounds BOD5 per horsepower-hour.

      Cage aerators may be used in relatively  shallow
pond depths (4 to 6 feet), and are  usually mounted
directly alongside  pond dikes. This mounting assures
easy access for  maintenance and results in  reliable
above  water electric power supply.  Mixing energy
from the cage aerators seems to have a very large zone
of influence. Surface  agitation has been measured on
photographs over  1000 feet from the aerator. When
properly placed near the multiple inlets to a pond the
cage aerators have a tremendous pumping and mixing
capacity.

      Vertical shafted turbine  or propeller  aerators
require  greater  pond  depths  (10  to   15  feet)  or
specially armoured depressed areas under each unit.
Pond depth is directly related to aerator horsepower
capacity. The  units  must  be  mounted  within the
ponds, thereby  requiring  special access walkways  or
boat access and underwater cabling  for power and
control.  Vertical  shafted  aerators  tend to  recycle
much of their  pumped pond volume and therefore
seem to  have less mixing or agitation influence on the
pond surface.

      Although  the vertical-shafted aerators  seem  to
cost  slightly less initially  their maintenance  and
operation costs  are usually more expensive than cage
aerators. Either  type of mechanical aerator may prove
cost effective for  any given pond installation. There-
fore, any comparison  should be  made giving full
consideration of all the facts.

      In addition  to transferring oxygen to the pond
contents, aeration and its resulting  mixing also tends
to   break  up   thermal  stratification  which  often
develops in quiescent ponds. This  allows for deeper
penetration of sunlight and increases the growth  of
algae, thereby  increasing  the  pond's  capacity for
organic loading. Surface agitation from such  aeration
also keeps the thin surface layer of slick or scum from
forming and assures  maximum photosynthetic rates
and surface aeration.

      Wastewater  stabilization  ponds  inherently
provide  a  cost effective means  of  treatment for
excessive summer seasonal organic  loadings and win-
ter  infiltration  and inflow  hydraulic loadings. Pond
loadings  should  be  conservative  to   assure  this
flexibility. Federal grant personnel should be  quick to
recognize these inherent advantages and minimize the
special studies  required  for the tributary  system's
infiltration and inflow  status.  The volume of buffer
built into a stabilization  pond system eliminates the
need  for  any  consideration  of shock or  diurnal
loading variations.
Pond recirculation and configuration

     Upgraded   wastewater  stabilization   ponds
should  include  provisions for  pond  recirculation.
Properly designed  pond  recirculation  will  involve
recycling from four to eight times the average design
flow  into  the system.  It  should be  designed to
thoroughly mix the pond contents with the incoming
flow prior  to its  introduction into the pond(s). This
pre-mixing provides photosynthetic oxygen from the
pond for the immediate satisfaction of the incoming
load, assures a completely mixed environment within
the feed zones of the pond system, helps to  prevent
odors and anaerobic conditions within the feed zones,
assists  in providing pond mixing and simplifies inlet
and interpond transfer hydraulics.

      The transportation of the recycling pond  con-
tents should be via open channels whenever possible.
Channels   should be of  sufficient  size to keep
velocities low (under 10 feet per minute) and total
head loss to a minimum (less  than H inch) when the
system is being operated at maximum recirculation
rates. Low lift, high capacity irrigation type propeller
pumps usually   provide  the  best efficiencies  and
lowest  first costs for this  type of work, although
non-clog,  self-priming centrifugals and  Archimedes
screw  type pumps are also sometimes used.  Regard-
less  of the pumps which are used, however, the pump
station should  be designed to minimize maintenance
and maximize  flexibility.  If  the pump's intake and
discharge  piping is designed to  maintain a siphon
condition, pond operating levels can be varied several
feet  without  affecting  the  pump's  capacity  or
efficiency.

      Good pond configuration will use  all of the
natural and mechanical forces available to achieve full
use  of the  entire wetted area. Inlets, transfer points,
and outlets should be located to eliminate dead spots
and short  circuiting. A proper  design will include a
study of the prevailing wind directions and will locate
outlets in those areas of the pond where surface scum
might accumulate. Pond size need not be a limitation
if adequate recirculation, distribution, and  orienta-
tion is maintained.

       Often the site  or  process  limitations require
multiple pond configurations. This might also result
simply from  the necessity  of  upgrading  existing
facilities. Under  these conditions recirculation be-
comes even more  important. When  the  multiple
ponds  are in a series configuration, the recirculation
reduces the BOD in the  mixture entering  the first
 pond  and this assures that the organic load  is spread
 more  evenly throughout all the ponds. This can be an
immediate  aid in the reduction of odors, especially
 where the first pond has been an anaerobic pond. The
 parallel configuration for multiple ponds is even more
 effective  in reducing pond  loadings because its  in-

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fluent is spread evenly across all ponds. In parallel
operation recirculation makes distribution simpler for
it eliminates the limitations of diurnal flow variations.

      Probably the  most  effective multiple  pond
configuration  with recirculation  involves a parallel-
series arrangement whereby the parallel ponds  are
loaded as facultative ponds with recirculation and the
final series pond is designed as a natural tertiary unit.
This arrangement  allows for the  final series pond to
be  operated  on an intermittent basis for effluent
solids control without affecting the operation of the
recirculation   system.  It  also  provides  a positive
separation  between recirculating  pond contents and
the final effluent outlet.

Inlet and outlet hydraulics

      Without pond  recirculation it is almost impos-
sible to achieve good inlet hydraulics. Such hydraulics
must always be designed for peak wet weather flows
because  this  is the  capacity of the incoming sewer
system. If the influent is pumped into the pond it is
usually  easier to achieve the proper inlet hydraulics,
but often this must  be  at  the sacrifice  of good
pumping station and upstream sewer system design.
Seasonal and diurnal variations will usually mean that
for a major  part  of the  time gravity flows will be
insufficient to achieve the proper distribution  and
mixing  velocities  for good pond feed conditions or
the sewage will be  stored  for increasing lengths of
time  until  sufficient  volume has  accumulated to
operate the influent pumps at their peak flow rate.
This can result in  system septicity and  odor produc-
tion.

      Although most of the literature indicates that
ponds should be fed by a single pipe near the center
of  the  pond, this becomes unnecessary when pond
recirculation  is  employed. A  single inlet  will  not
achieve full utilization of the wetted area of a pond.
Most smaller  ponds can utilize  multiple entry  and
single exit systems and assure full utilization. Large
ponds (over  20 acres) will usually  require multiple
inlets and  outlets. Even a  smaller pond may require
multiple inlets and  outlets if its configuration  and
orientation cannot be made to take advantage of its
natural  flow  pattern. When multiple inlet and outlet
pipes are used with a recirculation system, inlet  and
outlet hydraulic losses should be maintained at least
ten times the  total distribution or collection channel
head loss.

      If a system must operate over a large variation
of  flow it should be  designed to normally provide
good distribution  at average  daily flow rates  and
utilize overflow bypassing weirs for  those periods
when it has to handle peak flows. A good single pipe,
multiple port inlet design will result in a 1 foot head
loss at average design flow (port exit velocity approxi-
                                             mately 8  feet per second).  The ports of this single
                                             pipe should all  be oriented in  same  direction to
                                             induce a mass movement away from the outlet which
                                             is usually  located  nearby.  A second pipe with low
                                             head  overflow  weir inlet  may  be used  to  accom-
                                             modate peak flows.

                                             Scum control

                                                  Probably the  greatest  operational problem en-
                                             countered with  wastewater stabilization  ponds in-
                                             volves  the control of surface accumulations of scum
                                             and the odors which develop when these accumula-
                                             tions  become  septic.  A  good design will eliminate
                                             those  areas in which scum normally accumulates and
                                             will make  it possible for any scum which is formed to
                                             be recirculated within the system until  it is either
                                             degraded aerobically or becomes sufficiently water-
                                             logged to  settle to  the bottom and decomposes
                                             anaerobically.

                                                  Control of scum accumulations is best achieved
                                             by the elimination of all shoreline or aquatic growths,
                                             by proper  pond orientation and by the good location
                                             of adequate numbers  of pond inlets  and  outlets.
                                             Weeds and aquatic growths usually are controlled by
                                             periodic spraying, although cutting, sheep grazing and
                                             actual  physical  removal  may also  be  used. Design
                                             considerations should assure adequate pond depths to
                                             eliminate aquatic growths  (usually 4 feet or more)
                                             and sufficient shoreline access to make weed control
                                             easy.

                                                  Earlier design considerations have covered the
                                             need for proper pond orientation and the location
                                             and number of inlets and outlets. It should be further
                                             pointed out,  however,  that  proper  transfer  pipe
                                             design  must assure the maintenance of water surface
                                             continuity  within  the entire recirculation  system.
                                             This means that the pipes  must be large  enough to
                                             limit peak head loss to about 3 to 5  inches with the
                                             pipes flowing about two-thirds to three-quarters full.
                                             By  operating  these transfer  pipes  less  than  full,
                                             unobstructed water surface is maintained between the
                                             supply and return channels and the ponds.

                                                  Pond transfer pipes are usually best fabricated
                                             of  bitumastic-coated,  corrugated-metal  pipe  with
                                             seepage collars located near the midpoint. This type
                                             of pipe is relatively inexpensive, strong  enough to
                                             withstand  rough  handling  and  rapid  back  filling,
                                             flexible enough  to  allow for the differential settle-
                                             ment  often encountered in pond-dike construction,
                                             and sufficiently corrosion resistant to assure long life
                                             under the proposed wet and dry operating conditions.

                                                  Expensive  isolating control gates are unneces-
                                             sary if each of the transfer pipes are accessible from
                                             the  pond  and channels by boat. Such  gates can be
                                             replaced with  specially made fiberglass plugs which

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                              Construction Procedures and Review of Plans and Grant Applications      25
can be  used to close  the pipes to be taken out of
service.  When  such a system  is  used the  design
engineer can afford to provide  extra transfer inlets
and  outlets to  assure  good  distribution  and then
throttle their  utilization as required. Hydraulic cal-
culations for partially full transfer pipes require quite
a few assumptions,  therefore a few extra pipes for
flexibility  and operation assurance are often well
justified.

Dike construction

      Pond and channel dikes are usually designed
with  side  slopes between 6 horizontal to  1 vertical
and 2 horizontal to 1 vertical. Normally good pond
soil  will support  side slopes of 3 horizontal to  1
vertical. However,  a  proper design will  have the
opinion of a qualified soils and foundation engineer
to back up its final decision. Safety considerations
usually  require dike freeboards  to  be at least 2 and
often 3 feet above the pond's peak operating water
level.

      Dike  slopes  not only depend on the material
available for their construction, but also  must  con-
sider  the  wind and water-erosion  effects and  the
protection  to  be  provided.  All soils,  regardless  of
slope, need protection in zones  subject to turbulence
and agitation.  Such zones  can be created by wind
induced wave  action,  inlet and outlet  increased
hydraulic  activity  and aerator agitation.  Whenever
protection  is  provided around such zones it should
extend  several feet  beyond the areas involved. Wave
protection should extend 1  foot above and below the
extreme operating water levels.

      Erosion protection can  be provided by cobbles,
broken or cast-in-place concrete, wooden bulkheads,
or asphalt strips.  Whatever  is used should recognize
the  need  to control shoreline and aquatic growths.
The steeper the side slope  the  less area there is for
such protective coverings and  aquatic or shoreline
growths. Larger ponds in windy areas require heavier
erosion protection.

      Dike tops should be of sufficient width (10 to
12 feet) to support  a  12-inch thick all-weather gravel
road. Road surfaces  should  be crowned to assure
quick rainwater runoff and minimum  dike erosion.
All pond  and  channel dikes  must be provided  with
such  all-weather  access roads  so  that  operating
personnel  may conveniently maintain necessary pond
surveillance and control of insects, erosion and plant
growth.

Ancillary facilities

      Each pond installation  must be provided with
means for  easily launching trailer mounted boats into
all  water  bodies,  with means of periodically ascer-
taining the quantity of influent entering the system,
with  a  method  of  continuously  measuring  the
quantity of effluent being discharged from the system
and  with  portable  grab and composite  sampling
equipment which can be used to monitor either the
influent or effluent on any required cycle.

     Boat launching ramps should be built  to pro-
vide'all weather access and good vehicle traction and
support for all  parts of the ramp above and at least 3
feet  below operating water  levels. If the level varies
several feet, the ramp should extend to a sufficient
depth  to allow  the boat  to be launched  at the
minimum operating level. Ramps should be construc-
ted of concrete, at least 8 feet in width, and provided
with a 6-inch curb on the outboard edge.

      Influent  flow measurements should be  made
possible by means  of pump calibration or manually
read flumes  designed  to minimize  flow turbulence
and  interference. If sufficient  head  is available  a
calibrated  weir may  be used.  However, this  is  a
potential  odor hazard  if  the incoming sewage  is
septic. Periodic influent flow checks should be made
to assure  that  the ponds are  not  losing flow due to
excess  exfiltration  and to  get  some  estimate of
evaporation losses.

      The continuous effluent flow measuring system
should be designed  to  provide  the  most accurate
measurement possible without excessive operation or
maintenance. Proper design should include the use of
accurate V-notch or Cipolletti weirs  with simple float
actuated electrically timed recorders. Electric timing
action  should  be  backed up with a  spring power
action to assure continuity during power outages. The
flow record must be continuous if effluent quantities,
treatment efficiencies  and  total  receiving  water
loadings are to be reasonably determined.

      Recent  developments  in sampler  technology
have brought  on  to  the  market  several portable
samplers  capable of gathering  both  24-hour com-
posite  or grab  samples.  With or  without electric
power  available these samplers can  provide even the
smallest   pond   installation   with  the   quality
measurement capability necessary to satisfy all local,
state,  and federal water quality  requirements. Some
samplers even  provide for "dry ice"  compartments to
keep the collected samples chilled.

      No write-up on ancillary  facilities for waste-
water stabilization ponds would be complete without
some mention of housing for operation, maintenance,
 and laboratory activities. Certainly the added treat-
ment  and monitoring requirements resulting from the
new federal and state  regulations will warrant some
type of facility capable of supporting these activities.
 Smaller installations  may  attempt to contract for
 these   services and therehv honefullv  share such

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 26
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 facility costs with others. Some may feel that such
 facilities are best located in the owner's corporation
 yard. Wherever they are, however, they must reflect
 the  fact that wastewater stabilization ponds are no
 longer the type of secondary treatment plant which
 can  be built and promptly forgotten. They must now
 be regularily operated, maintained and monitored.

      As a  minimum such facilities should contain
 operator wash  and toilet facilities; proper housing for
 plant growth  control equipment; access  boat and
 portable sampling equipment; and  compact  labora-
 tory capabilities. Minimum laboratory  tests  should
 include  dissolved  oxygen,  BOD5,  total  solids,
 suspended solids, volatile solids, and coliform deter-
 minations.

          Construction Considerations

      Once  engineering design and  local,  state, and
 federal design reviews have been completed a contract
 for  the construction of  the wastewater stabilization
 ponds is put out to  competitive bid. In this manner
 the  owner  selects the lowest  responsible  bidder to
 construct  the  project.   Major  state   and  federal
 monetary participation dictates that this phase of the
 upgrading process receives as much attention  as the
 design. Many an excellent design has been sacrificed
 to loose contract requirements  or  weak inspection
 practices. It is very  important therefore that these
 aspects of construction receive careful consideration.

 Contract requirements

      A good contract begins with a proposal which
 allows the prospective contractors to clearly under-
 stand what they will be  obligated to construct and
 the  rules and regulations which will govern  and limit
 their construction procedures. A clear and concise set
 of drawings and specifications  which  compliment
 each other  are  the keys to  this understanding.
 Additional supporting documents often include soils
 engineering reports,  up-to-date  as-built  drawings  of
 existing facilities and horizontal and vertical  survey-
 ing control data.

      Drawings must provide the  contractor with
 sufficient information to construct all site  and struc-
 ture improvements in the locations selected. Some-
 times on a small contract most of the material quality
 requirements can also be set forth  on  the drawings.
 Most of the time, however, these requirements are
 reserved  for the technical part of the specifications.
 Regardless of  where  they are placed,  it is  always
 important that both documents compliment and not
 contradict each other. Contradictions  can result in
 the contractor  providing an inferior product.

     In addition  to the  technical specifications a
good specification  document will  also  provide the
                                             prospective  contractor  with  bidding information,
                                             copies  of all bidding and contract forms and docu-
                                             ments  and  a  complete  listing  of the  rules  and
                                             regulations governing the project's construction. Bid-
                                             ding information should  indicate the routine  and
                                             special  instructions necessary to the  submission of a
                                             responsible bid.  This should include instructions on
                                             how the contractor should handle  any qualified or
                                             variation  bids,   contingency  allowances  and  major
                                             equipment listings.  Most  sewage treatment facility
                                             contracts  are best bid  as  lump   sum  contracts,
                                             especially when  the owner cannot  afford the extra
                                             supervisory expense of assuring the  accuracy of unit
                                             price quantities.  The lump sum contract also makes it
                                             possible  to  assign the  complete responsibility  of
                                             constructing an operable facility to the contractor. If
                                             he can  prove inadequacy of design to accomplish this,
                                             he of course can relieve  himself of this responsibility.

                                                  Sometimes after reviewing the contract  docu-
                                             ments a contractor will  feel that he can accomplish
                                             the same end result by a somewhat different route. If
                                             the  contract  specification  provides a  perspective
                                             contractor a means of submitting an acceptable bid
                                             under  these  circumstances  the  owner  may save
                                             money. A good qualified and variation bid clause will
                                             do just  that.

                                                  No engineer can anticipate all of the situations
                                             which may develop during construction of a facility.
                                             This is especially true  with the  upgrading of existing
                                             facilities. A  good design will limit these extra work
                                             items to less than 2 to 5 percent of the contract cost,
                                             however, depending on  the contract size. To  assure
                                             the prospective  contractor that such conditions  are
                                             going to be expeditiously and properly handled, a
                                             contigency allowance of these approximate amounts
                                             is included within his bid. If the extra work does not
                                             materialize then the money is never spent.


                                                  Major  equipment  listings  are a means of assur-
                                             ing that the owner receives his major equipment at
                                             the  best  price  available and  that the  successful
                                             contractor will not be able to shop around for lower
                                             prices after he has been  awarded the contract. When
                                             used, such listings must meet the federal regulations
                                             requiring  the  listing  of  two  or more   acceptable
                                             manufacturers with  space  for the  contractor  to
                                             write-in other manufacturer's considered "or equal."

                                                  By including all the necessary bond forms and
                                             other  contract  documents  within the contract
                                             specifications the owner eliminates the risk that some
                                             proposed  contractor  will submit  a  bid with an
                                             unacceptable guarantee  bond or sign a contract and
                                             submit   unacceptable   material  and   performance
                                             bonds.  It also makes the  conditions of bidding and
                                             being allowed to  perform  completely and equally
                                             clear to every interested  contractor.

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                             Construction Procedures and Review of Plans and Grant Applications      27
      The  rules and regulations governing construc-
tion procedures must be mutually equitable if the
contract is to stand up in any court test. This part of
the contract specifications must be written primarily
for the protection of both parties. Neither the owner
nor the contractor  should be required to be deprived
of their basic rights. The owner has a right to expect a
finished product  within  the time  specified which
meets  the quality requirements listed. The contractor
in turn has a right to select  the method of producing
that finished product  within the limits of any listed
restrictions  and to  be paid for his production in this
manner listed.

      Any encroachment by either party into this
basic relationship can weaken its entire premise. The
owner should not have the right to stop work, unless
the contractor is in flagrant breach of contract, and
the contractor must operate within the limits set forth
in the specifications. If the  owner feels he is getting
unacceptable quality or if the work is falling behind
schedule he should withhold contract payments, not
shut down  or  speed up the work  or  in any other
manner encroach upon the  contractor's methods of
operation.

      The contractor must also realize that the limits
set forth cannot be exceeded. Two examples of such
limits are the bypassing of existing treatment facilities
and  the  providing of necessary equipment main-
tenance instruction. Monetary  penalties should  be
spelled out  within the  contract  specifications  for
bypassing  with gradation  for  degrees  and times
involved. These penalties should reflect the effect  on
the owner's reputation  and any possible penalties
imposed by a regulatory  agency. They should  be
sufficiently expensive to  force  him to make  no
bypassing a major  consideration in his methods  of
construction.  Equipment maintenance  instructions
are required prior  to  the placing of the equipment
into  operation and for  the proper preparation  of
operation and maintenance  manuals. To assure their
delivery the contractor should be informed that once
the 75 percent level of completion has been  reached
no further progress payments will be made until  all
such  instructions  have been submitted  and found
acceptable.

Inspection practices

     Often it is assumed by the owner that once the
engineer has  completed  the design  drawings  and
specifications he need no longer take an active role in
the completion of the project. This is most often true
of those  owners who already have  a construction
inspection   department overseeing  other types  of
projects under  their jurisdictions. Unfortunately this
is also sometimes quietly accepted by the engineer,
because he realizes  that under such an arrangement it
will be far more difficult for the owner to make any
charge of legal liability hold up in court.

      To assure  that the design engineer  accepts his
full responsibility for a project it is necessary for him
to  also have the full responsibility  for the resident
engineering and inspection of the construction of that
project.  The review of shop submittal drawings of
process equipment and piping layouts provides  the
design engineer with the final opportunity  to visualize
the system's operation and correct any error which
has heretofore  escaped detection. In addition,  the
continuous involvement of the design engineer assures
that those basic  decisions which are often  inherent in
a design are  also reflected in the quality of the final
construction.

      For  wastewater stabilization ponds the major
responsibility of inspection will  involve  the super-
vision of soil compaction  as part of the construction
of  pond and channel dikes and  the assurance  that
vertical  control (elevation)  tolerances  are  within
contract requirements. Good inspection requires that
an  inspector be present whenever the contractor is
doing any work  on the project.

           Operation Considerations

      As  major  contributors  to  the  cost of  the
construction  of the upgraded wastewater stabiliza-
tion ponds it seems only natural for federal and state
environmental  protection  agencies  to have a great
interest  in their performance. Present  federal  and
some  state  regulations  already  require all  grant
supported plants  to have  an operation and main-
tenance  manual prepared by the  design engineer, to
require its personnel to take part in operation training
programs,  to receive periodic operation performance
evaluations by  agency representatives and to  have
developed a system of user charges (or  equivalent)
sufficient to cover all annual costs,  including capital
cost recovery.

Operation and maintenance (O/M) manuals

      To be  of real value to the operation staff of the
new  or  upgraded  facility  the O/M manual must
provide  them with a complete description of (1) the
treatment processes involved, including  its  idio-
syncrasies,  and  its normal reaction  to  stress  and
seasonal changes; (2) the physical layout, including
hydraulic  flow  pattern,  equipment operation  and
monitoring and control devices; (3) process testing,
including  laboratory analysis  both  for control  and
monitoring  treatment  efficiencies  and  results; (4)
maintenance requirments, including routine preven-
tive and corrective programs; (5) safety  restrictions
and  precautions;  and   (6)  emergency  operation
procedures. The manual must be  presented in words

-------
 28
Uhte
 and pictures which are understandable to lay person-
 nel  and should be prepared as soon as practical so
 that it is available prior to plant set-up. Some parts of
 the  write-up  could  be valuable early in design, but
 unless the engineer is assured of adequate remunera-
 tion there is little incentive to  take the time or make
 the  effort  involved at this stage of the process. Some
 form of up-dating should be made after the plant has
 operated through a complete seasonal cycle.

      Many problems can befall those  unwary  engi-
 neers who assume that this is a simple and relatively
 inexpensive task.  Unfortunately it is similar to the
 design  costs  previously  mentioned, in  that  small
 installations will often require as much or  more time
 and expense than large installations. If 0/M manuals
 are  to become the backbone of successful, efficient
 operation, their true value  and cost  must be recog-
 nized  and accepted  by all owners and federal and
 state personnel.  These  costs can amount to  sums
 which are from  1  to  10  percent  of the facilities
 construction cost depending on whether the plant is a
 major  multimillion   dollar  or  a  minor  hundred
 thousand dollar facility. These costs  may  seem high
 when  compared  to   normal design  fees, but  when
 compared  to  the accumulated  annual cost  savings a
 good manual can accomplish, they become practically
 insignificant. Federal and state insistence for quality
 manuals and their willingness to share in' the costs of
 their preparation is one way they can make it easier
 for the owner to meet the annual budget challenge.

 Operation training programs

      In most  instances owners  of upgraded waste-
 water  stabilization ponds will not be  able to hire
 trained  experienced   personnel   to  perform   their
 plant's necessary operation and maintenance tasks.
 Consequently there is, and will continue to be, a great
 need for operator training  programs.  Federal and
 state   involvement  in  the  development  and
 implementation of these programs is essential.

      On-the-job  training with  mobile  classrooms
 provides the  most effective programs for the smaller
 treatment plants. This is especially true of stabiliza-
 tion pond  operation.  This makes good sense because
 of the need to minimize annual budget impacts. Pond
 owner budgets do  not  have  room  for  travel  or
 away-from-the-job expenses. In  addition,  in many
 cases the  treatment   process  or  configuration for
 individual  plants  varies  so  greatly  that  the  most
 efficient  training  for  unskilled lay  personnel  is  to
 train them for specific tasks and not general concepts.

      Such on-the-job training should incorporate the
use of the plant's 0/M manual as much as possible. In
most instances, if the specific 0/M manual for the
facility  was systematically  studied and thoroughly
explained to the plant's personnel the training would
                                             meet its goals. Such a review would also provide the
                                             owner with an outside opinion of the adequacy of the
                                             manual,  assure its  completeness, and  present  the
                                             federal or  state  supported trainer  with a golden
                                             opportunity for developing favorable  public relations
                                             for the whole  environmental protection effort.

                                             Performance evaluations

                                                  In many areas performance evaluation programs
                                             are just getting started, but already they have raised
                                             questions  regarding  their  ability to  gather  truly
                                             representative and meaningful data.  Certainly  plant
                                             performance,  housekeeping and maintenance can be
                                             observed and  meaningfully recorded. When  it comes
                                             to  the  determinations  of  operator training  and
                                             competency, however, observers must be careful not
                                             to accept at face value  any single  group's viewpoint.
                                             Data collected during these evaluations must reflect a
                                             consensus of the complete staff. This complicates the
                                             data gathering and probably  increases its cost, but
                                             without  such meaningfully  developed data  these
                                             evaluations  could  easily  result in conclusions and
                                             reactions which are completely unverifiable.

                                                  Some type of  public relations program should
                                             be instigated  to assure that all plant personnel are
                                             aware  of the  performance evaluation program and
                                             what it is set-up to accomplish. Its positive aspects of
                                             determining national, state and local needs and the
                                             importance of sharing of meaningful data should be
                                             emphasized.  At no  time  should the  program be
                                            allowed to get the reputation that it's just another
                                            attempt to develop a technique for "big brother to
                                            keep his eye on you."

                                            User charges and self-sufficiency

                                                 Federal,  and in some cases state, grant regula-
                                            tions already require that grant supported treatment
                                            facilities develop and place into action a program of
                                            user charges, including a capital cost recovery system,
                                            which  will assure  each  system's  complete   self-
                                            sufficiency upon completion of the present upgrading
                                            program.  Revenue  program  guidelines   further
                                            illuminating the restrictions  or  objectives of  this
                                            program  have  been  adopted by  several states. If
                                            upgrading of  wastewater  stabilization ponds is to
                                            achieve its twin goals of improving the discharge  from
                                            these ponds and providing the data necessary for the
                                            documentation of these  improvements, then  each
                                            grant eligible project must have enforced upon itself
                                            the necessary user  revenue sharing required for this
                                            self-sufficiency. Complete information on this user
                                            revenue sharing system must  be  presented to the
                                            voters prior to their being asked to accept the capital
                                            obligation for upgrading.

                                                 Although most financial programs  will require
                                            the efforts of experts in the public financing field, the

-------
                             Construction Procedures and Review of Plans and Grant Applications      29
owner and federal  and state  agencies should insist
that the design engineer  also be  actively involved.
Preparation of population growth projections, user
participation  estimates, capital costs and operation
and maintenance costs are all areas where input from
the engineer is essential.

          Summary and Conclusions

      Although in many instances this discussion has
spoken  of  design, construction, and operation con-
siderations  in general  terms most of the  comments
include  specific data, techniques,  parameters,  and
recommendations which when applied  judicially to
review and approval programs should provide guide-
lines for judging a project's acceptability. Although it
may seem to be the result of an in-born prejudiced or
misplaced self-esteem, the one theme throughout the
discussion which cannot be ignored is the need for
the  complete  involvement of the design engineer
throughout  all phases of a project's  development.
Federal and state  regulatory  agencies should insist
that owners assure this continuity of involvement and
take advantage of the responsibility it brings.

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                            POLISHING LAGOON EFFLUENTS WITH

                                  SUBMERGED ROCK FILTERS

                                             W. J. O'Brien^
      Lagoons  have been widely  used  in the United
 States during the  past 20 years for the treatment of
 wastewater  from  small municipalities  and  isolated
 industrial plants.  Their  popularity  has been based
 upon relatively low  first  cost,  low operation  and
 maintenance costs, and a high standard of reliability
 in producing stabilization of the raw wastewater.

      The major flaw with lagoons is the algae which
 are often present in the final effluent. These algae can
 be  removed by a  wide variety  of coagulation, filtra-
 tion, flotation, and oxidation  techniques. (See  Mc-
 Garry,   1970;  Tenny et  al.,  1969;  Shindala  and
 Stewart, 1971; Berry, 1961; Borchardt and  O'Melia,
 1961; Dodd, 1973; Levin  et al.,  1962; Parker et al.,
 1973; Ort, 1972;  Folkman and Wachs, 1973.) How-
 ever, the complexity  and the cost of operating most
 of these processes negate the advantages inherent in
 the  use  of lagoons. Submerged rock filters  have the
 potential for avoiding these problems.

      Preliminary  investigation  on the use of sub-
 merged rock filters for algal removal was  conducted
 with laboratory scale units by Martin (Martin, 1970;
 O'Brien  et al.,  1973). Additional research with pilot
 scale units located outdoors was completed by Martin
 and Weller (1973). The findings of these two studies
 formed  the basis  for the  field scale trials  reported
 herein.

             Experimental Facilities

      The  research  filters  are located at  Eudora,
 Kansas.  The influent for  the research pond  is  ob-
 tained from the effluent  pipe of the three-cell lagoon
 system illustrated  in  Figure 1. This lagoon system is
 very  flexible with regard  to the sequence  of cells
 which may be  used for treatment. Between June 16,
 1973, and   February 19,  1974, the facility  was
 operated with cell 2 as the primary and cell  3 as the
 secondary. From February 20, 1974, to the present
 time, the system has used cell 1 as the primary, cell 2
 as the secondary, and cell 3 for the  tertiary treat-
 ment.
     The sewered population of Eudora is 2,200.
The average daily dry weather sewage flow is approxi-
mately 208 I/capita/day (55 gpcd), however, there is
a  large increase in  flow  during periods of heavy
precipitation.  The  capacity of  the lagoon system,
when operated with a water depth of 1.52 m (5 ft), is
summarized in Table  1. The values given for hydraulic
detention time in Table 1  assume plug flow in each
cell and  no water loss occurs from  evaporation or
seepage.
Table 1. Physical characteristics of the Eudora waste-
        water lagoon system.
  Cell    Surface Area, Water Volume
Number    hectares       106 liters
                                     Time)day&
1
2
3
3.16
1.50
3.17
45.7
21.3
45.9
100
46
100
     1\V,  J.  O'Brien  is Professor  of  Civil  Engineering,
University of Kansas, Lawrence, Kansas.
      The effluent from cell  3 is collected in a wet
well and pumped through a  102 cm (4 in) diameter
plastic pipe to the research facility. A 5.5 m (18 ft)
length of 15.2 cm (6 in)  diameter cast iron pipe is
used  to  go through the berm of the experimental
lagoon into the inlet structure. The inlet structure
divides the flow into two portions  and provides for
the measurement of each portion with a 15° V-notch
weir  plate. The lagoon is divided into two parallel
basins by an  asphalt coated  sheet piling wall. Each
basin contains an influent pond, a rock filter, and an
effluent pond. Flow leaving the experimental facility
is collected in an outlet structure which contains two
parallel  channels  equipped  with  stop  planks to
control the elevation of the  water surface and with
15° V-notch weir plates. Immediately preceding the
stop planks are baffles which protrude 76 cm (30 in)
below the water surface. The purpose of these baffles
is to prevent  ice formation  in the  outlet structure
during the winter and to prevent surface scum from
leaving the ponds during the summer.

      The effluent  from the experimental lagoon is
collected  in a wet well and  is pumped back to the
inlet  structure of the Eudora lagoon  system. Plans of
                                                                                                  31

-------
 32
O'Brien
                                                               *^v  Flow ^ adjustment  valve
                                                                 X              ,i          sampling
  Pump  station   W\Sampling
  for  transferring  ^location   A
  lagoon  effluent
  to  filter.
                                                                Sampling
                                                                location
                                                                       !|_
                                                                                           location  B
                                                                               Experimental  rocK
                                                                               filter   facility

                                                                              	Sampling
                                                                                  location   0
                           Cell   2
                                           Lagoon  influent
                                           structure
                                                                 Pump '  station  to
                                                                 return  filtered
                                                                 effluent  to  lagoon
Figure 1. Physical layout of Eudora, Kansas, municipal sewage oxidation pond system and relative location of
         experimental rock filter facility (for illustrative purposes only-not drawn to scale).
 the experimental lagoon, the inlet structure, and the
 outlet structure are shown in Figures 2,3, and 4.

      A cross  section of the rock filters is given  in
 Figure  5.  The  filters  are  constructed  of crushed
 limestone having the size gradations listed in Table 2.

      Throughout the  remainder of  this paper the
 two filters will be differentiated by designating them
 as large rock or small rock.

      Both  filters are 1.4 m (4.5 ft) high and have 1:3
 side slopes.  The large rock filter is 5.5 m (18 ft) wide
 at the top,  13.7 m  (45 ft) wide at the bottom, and
 12.5 m (41  ft) long at the top. The small rock filter is
 6.1 m (20 ft) wide at the top, 14.3 m (47 ft) wide  at
 the bottom, and 11.9 m (39 ft) long at the top.

      The volume of submerged rock, the volume of
 the influent and effluent ponds, and the surface  area
 of these ponds when the water depth is 1.22 m (4 ft)
 are summarized in Table 3.

      Each  filter also contains three sampling tubes
 spaced  at 2.7 m (9 ft) intervals across the  cross-
 sectional axis. These tubes are constructed from 10.2
 cm (4 in) diameter plastic pipe and contain 1.27 cm
 (.5  in)  diameter holes  spaced  at 7.62  cm  (3  in)
 intervals. There are four holes located 90° apart at
 each interval.
                                             Table 2.  Size gradation of the rock used in the two
                                                      experimental filters.

Sieve Opening
cm
5.08
3.81
2.54
1.91
1.27
0.95
0.67
0.47
% Weight
Large Rock
7.4
28.8
52.0
10.4
1.3
0.1


Retained
Small Rock


13.4
33.1
39.0
10.4
3.2
0.9
                                                Porosity
0.44
0.44
                                             TableS.  Physical  dimensions  of the  experimental
                                                      filter system when the water depth is 1.22
                                                      meters.


Volume of Influent Pond m3
Surface Area of Influent Pond m2
Volume of Submerged Rock m3
Volume of Effluent Pond m3
Surface area of Effluent Pond m2
Large
Rock
126.5
165.7
126.6
84.3
137.1
Small
Rock
119.4
157.6
142.1
86.1
125.0

-------
                                 Polishing Lagoon Effluents with Submerged Rock Filters     33
Pump Station for Transferring

Lagoon Effluent to  Filter

\.        Flow Adjustment Valve

  X
                                            10.2 cm plastic pipe
                                        It

                                        if
                                        u
                                        u
                                        II
                                         cm

                                     CI Pipe
                                        |! Sampling Location
                                         r  Inlet Structure
                                               Vertical
                                              Sampling Tubes
                             Sampling

                             Location

                                 C—<
                                           Outlet Structure  /
                 0
                 i—
                   6
                  -4-
 9
-1
                 Scale  in Meters
n
u
                                  11 15.2cm
                                  i*/   CI Pipe
                                  n
                                  n
             Pump Station to Return     Lj
             Filter Effluent to Lagoon—*
Figure 2. Plan of experimental rode filter field test facility.

-------
34
O'Brien
            Experimental Program

      The experimental lagoon was placed into opera-
tion on January 4, 1974, and completed filling on
January 10.

      Starting January 25 three grab  samples, taken
between 7 and 12 a.m., have been collected per week
from  the  effluent of the  final cell of the  Eudora
lagoon system, the  influent to  the  experimental
lagoon, and the effluent leaving the ponds behind the
large  and the small  rock  filters. These sampling
locations are illustrated in  Figures 1 and 2. Samples
were also collected twice weekly from tubes  1,3,4,
and 6 within the  filters (see Figure 2) from April 8
through June 24. Tubes 2 and 5 were sampled  twice
weekly from May 17 through June 24. All six  tubes
were sampled on July 12, 19, and 29.
                                                 Prior to April 1, in-place temperature measure-
                                           ments were made with a mercury thermometer. No
                                           dissolved oxygen measurements were taken. Begin-
                                           ning April  1, in situ dissolved oxygen measurements
                                           were  made with a portable polarographic membrane
                                           dissolved oxygen probe  and temperature measure-
                                           ments were obtained  with a resistance wire probe.
                                           The pH of the samples was measured with a labora-
                                           tory pH  meter located in the nearby Eudora Water
                                           Treatment Plant.

                                                 The samples obtained from the lagoon effluent,
                                           the influent  to the experimental  lagoon, and  the
                                           effluent leaving the ponds behind the large and the
                                           small rock filters were analyzed for total  suspended
                                           solids  (TSS), volatile  suspended  solids  (VSS), total
                                           and soluble COD,  total  and soluble BOD5,  NH3-
                                           nitrogen, and phosphorus. Chlorophyll analyses were
                            Top
   Stop  Plonk   Grooves
                              Aluminum   Weir
                        Side
  9      j      2

Scale  in  feet
                                                                               Sec. A-A
                                                               Baffle
                                                               Board
                                                              *
Figure 3. Plan of influent structure of the experimental lagoon.

-------
                                         Polishing Lagoon Effluents with Submerged Rock Filters
                                                                                                     35


















1
1
• 1-





1




















• — -






Zl
L|


Stop  Plonk  Grooves
                              Aluminum   Weir
   NBaffle    Board
  Scale  in   feet

                                                                                Sec.  B-B
                                  Side
                                                                               Sec.  A-A
Figure 4. Plan of effluent structure of the experimental lagoon.
    Stop  Plank  for Controlling
    Voter   Level
                          Walkway
                                                                  /10.2 cm  plastic pipe  with
                                                                 / 1.27 cm  dia.  holes   spaced
                                                                 \ at  762cm.  intervals.
                                                                   Four  holes at each   interval.
                                                                         •Lagoon   Bottom
                                                                         El.  246.3m
Figure 5. Cross-section of rock filter.

-------
 36
O'Brien
also conducted starting with the samples collected on
April 12. Samples obtained from sampling tubes 1
through 6 were tested for TSS, VSS, total and soluble
COD,  and  chlorophyll.  A  profile of the in-place
temperature and  concentration of dissolved oxygen
was also made in each sampling tube at 0.3 m (1 ft)
intervals.

     The procedures used to determine TSS, VSS,
COD, BOD,, and pH followed the methods specified
in  the  13th edition of  Standard Methods for the
Examination of  Water and Wastewater (American
Public Health Association, 1971).  However, the mag-
nesium  carbonate precoat specified in this method
was not applied to the filter pads. Total phosphorus
was measured by the procedure specified in Methods
for Analysis of  Water and Wastes (Environmental
Protection  Agency,  1971).  Ammonia nitrogen was
measured with  a  Model  95-10  Orion  Ammonia
Electrode connected to a Model 320 Fisher Accumet
pH Meter.

     The rate of flow  entering and  leaving both
experimental filters was measured  by determining the
head on each weir with a point gage.

             Experimental Results

     The  hydraulic loading  and detention   times
within  the experimental filter system are summarized
in Table 4. These values assume plug flow through the
filters which probably does not occur because of the
increase in cross-sectional  area with depth. Liquid loss
from seepage or evaporation was not considered. The
time periods during which pumping did not  occur,
either due  to pump malfunction or to the loss of
electrical power, were excluded from the calculations.
                                            This  occurred  from February 26  through  March 2,
                                            from  April  22  through April  26, from  June  15
                                            through June 17, and from July 14 through July 15.

                                                 Monthly  summaries of the water quality of the
                                            flow discharged from the Eudora lagoon system, the
                                            flow entering  the experimental  lagoon,  the  flow
                                            leaving the pond behind the large rock filter, and the
                                            flow leaving  the pond behind the small rock filter are
                                            provided in  Tables 5 through 8. In these tables the
                                            water temperature is  expressed in °C; TSS, VSS,
                                            COD, BOD5, and dissolved oxygen are expressed in
                                            mg/1 of the parameter; ammonia is expressed  in mg/1
                                            as nitrogen;  total phosphorus is  expressed in  mg/1 as
                                            phosphorus;  and chlorophyll is expressed  in micro-
                                            grams/I as chlorophyll.

                                                 The magnitude  of the parameters measured in
                                            the samples  obtained from the  tubes located within
                                            the  filters are  summarized in Tables 9 and 10. The
                                            value used in preparing these  tables was the  average
                                            concentration  obtained from  samples obtained at
                                            four  equally spaced depth intervals within each tube.
                                            Changes  in  the  concentration  of TSS, VSS,  total
                                            and soluble COD and chlorophyll at different depths
                                            in the  filters were not significant. The temperature
                                            and the  concentration  of dissolved  oxygen in the
                                            upper 0.3 m (1 ft) of water was usually greater than
                                            that observed in the lower 0.9 m  (3 ft).

                                                              Discussion

                                                 The data presented in Tables 5 and 6 clearly
                                            indicate biological  metabolism  occurred in the wet
                                            well and pipeline used to transfer the lagoon effluent
                                            to the experimental site. However, the  changes which
                                            occurred in  the water quality were not large  enough
Table 4.  Hydraulic loading and detention times within the experimental lagoon system.

                                            Large Rock
Month
February
March
April
May
June
Julv

February
March
April
May
June
July
Influent Pond
Detention
Time, Days
2.7
6.0
2.4
2.0
1.3
3.9

2.7
6.7
2.5
2.1
1.4
4.0

Filter
Hydraulic Loading
1/day/m3
367.4
165.4
418.9
492.9
743.9
257.2
Small
307.8
124.7
339.5
397.6
604.3
210.6
gal/day/ft3
2.7
1.2
3.1
3.7
5.6
1.9
Rock
2.3
0.9
2.5
3.0
4.5
1.6

Detention
Time, Hours
28.7
63.9
25.2
21.4
14.2
41.1

34.3
84.7
31.1
26.6
17.5
50.1
Effluent Pond
Detention
Time, Days
1.8
4.0
1.6
1.4
0.9
2.6

2.0
4.9
1.8
1.5
1.0
2.9

-------
                                        Polishing Lagoon Effluents with Submerged Rock Filters      37
to  significantly influence  the  performance  of the
submerged rock filters.

      The data in  Tables 7 and 8 can be subdivided
into three intervals of time. The first occurred from
the start of operation in January through March 22.
During this period the filters functioned primarily as
sedimentation basins. However, the  capture  of sus-
pended  solids was  relatively low because a biological
slime layer had not become  completely established on
the surfaces of the rock. Algae which settled in the
upper  portions of  the  filters were therefore re-
suspended in the flow moving through lower portions
of  the  filter and  eventually  washed through  the
barrier  formed by  the  rocks.  This situation was
changed by the development of a biological slime
layer on the rock surfaces which trapped the algae
upon contact. Previous investigations with pilot scale
filters indicate approximately 20 days are required to
establish  a  slime  layer when the average  water
temperature  is 32 °C(Martin  and  Weller,  1973).
Approximately four months were required to develop
a  slime layer in  this  investigation  because  the
temperature of the water was much lower.
     The response of the filters during this initial
period was also profoundly influenced by the changes
which  took  place within the  lagoon system. During
December, January,  and the  first half of February,
the lagoons were covered by ice and  the ammonia
concentration  increased  appreciably.  The ammonia
concentration  continued to increase until the water
temperature increased to approximately 7°C.  This
triggered an algal bloom which started February 22
and peaked  on March 6. The bloom was terminated
by  a  rapid  population  increase by Daphnia. Large
numbers of these animals were present in the system
until the end of March. Grazing by Daphnia eventual-
ly lowered the suspended solids concentration in the
kgoon effluent to less than 10 mg/1.

      The second time interval started March 23 and
extended through May  6. During  this  period the
water temperature increased to approximately 20°C
and the biological slime layer became fully developed
on the rock surfaces. The effect of this layer upon the
performance of the filters is vividly  shown by the
suspended solids and the dissolved oxygen observa-
tions  summarized in Tables  9 and 10. Throughout
Table 5. Summary of water quality measurements, effluent from the Eudora wastewater lagoon.
Month
February
Average
Range

March
Average
Range

April
Average
Range

May
Average
Range

June
Average
Range

July
Average
Range

Water
Temp.

5.1
1.0
7.5

10.2
6.0
15.0

15.4
11.0
20.0

22.2
18.9
25.5

23.2
17.8
27.0

29.2
26.2
32.0
Dis-
solved
Oxygen









11.8
5.7
16.4

6.6
1.0
13.9

5.0
2.2
7.8

5.4
2.6
7.9
PH

7.6
7.3
8.2

7.8
7.4
8.5

8.0
7.2
8.6

8.6
8.3
9.3

8.6
8.3
8.8

8.8
8.5
9.1
TSS

73
46
123

66
9
156

47
25
64

54
34
89

52
42
67

57
42
69
VSS

58
45
77

47
8
106

33
13
54

41
29
58

40
27
52

44
32
57
Total
COD

132
76
188

139
88
208

99
64
140

102
68
139

96
82
114

99
77
136
Sol.
COD

41
20
68

56
20
92

65
52
88

52
32
68

45
31
56

49
36
65
Total
BOD5

28
15
39

16
7
30

20
9
30

16
8
25

13
9
18

14
9
17
Sol.
BOD5

7
5
10

5
3
8

5
2
8

3
2
6

3
2
5

4
2
6
Ammo-
nia
N

15.2
11.5
21.0

12.0
9.5
16.0

8.9
5.0
12.0

0.9
0.1
4.4

0.15
0.05
0.21

0.07
0.05
0.17
Phos.
P

8.1
7.0
9.4

6.5
4.7
9.5

6.1
3.4
10.3

2.7
2.0
3.5

2.3
1.9
2.5

1.6
1.3
1.9
Chlo-
rophyll
a + b









355a
176
514

278
142
548

176
131
228

144
86
194
      aData collected fiom April 12 through 29.

-------
38
O'Brien
this period the concentration of ammonia nitrogen in
the system was large enough to support a significant
amount of algal regrowth  in the ponds behind the
filters. Regrowth of algae has continued to occur in
these ponds throughout May, June, and July, but the
magnitude  decreased because of  the  drop in  the
concentration of ammonia in the lagoon effluent.

      The third time period started May 6 and will
continue through the remainder of the  summer and
early fall.  It has  been characterized by a gradual
decrease in suspended solids in the effluent from the
submerged filters  and  by the onset  of anaerobic
conditions  within the filters. The anaerobic environ-
ment was first established in the downstream portions
of the  filters  and has slowly moved  toward  the
influent sampling tubes. The influent  tube in both
filters was anaerobic throughout the  bottom two-
thirds of the water column on July 29. The  con-
centration of dissolved oxygen  in the water moving
through the upstream face  of the filters will continue
to fluctuate throughout the remainder of the summer
and  the  fall. The  major variables which determine
how much of the  filter volume is aerobic are water
                                            temperature and the velocity of water entering the
                                            filter.

                                                 A bright green scum layer consisting primarily
                                            of Chlorella and numerous species of protozoa and
                                            rotifers  developed  upon  the surface  of  the ponds
                                            behind the filters in late April and continued to occur
                                            intermittently throughout May, June,  and July. The
                                            conditions which lead  to the development of this
                                            layer were apparently the release of ammonia by the
                                            anaerobic decomposition  of algae in the  filters and
                                            the relatively thin layer of oxygenated water near the
                                            pond surface. The effect of this scum on the effluent
                                            quality  is not directly reflected in the parameters
                                            summarized in Tables 7 and  8 because the baffles on
                                            the effluent  structure were withdrawing water from
                                            the ponds at approximately the mid-depth.

                                                 The  original objective in providing ponds be-
                                            hind  the filters was to increase the concentration of
                                            dissolved oxygen and to lower the concentration of
                                            ammonia in the final effluent. However, as indicated
                                            in  Tables 7 and 8, the ponds have not been effective
                                            for oxygen transfer  and have produced a significant
Table 6. Summary of water quality measurements, influent to the experimental lagoon.
Month
February
Average
Range

March
Average
Range

April
Average
Range

May
Average
Range

June
Average
Range

July
Average
Range

Water
Temp.

4.9
1.0
7.5

10.0
5.0
17.0

14.4
10.4
19.0

21.5
18.1
25.0

23.8
19.8
26.5

28.2
26.0
30.6
Dis-
solved
Oxygen









5.3
1.0
8.2

3.3
0.5
6.3

3.5
1.8
5.1

0.6
0.2
1.6
pH

7.6
7.3
8.1

7.7
7.4
8.1

7.9
7.3
8.5

8.5
8.1
9.2

8.5
8.3
8.8

8.6
8.4
8.8
TSS

67
45
117

63
11
157

42
20
75

48
30
72

44
38
58

48
33
64
VSS

56
38
87

45
9
109

31
13
51

39
23
55

34
23
44

36
24
53
Total
COD

147
112
172

139
76
220

113
76
160

100
72
141

84
69
96

104
85
144
Sol.
COD

55
28
76

57
32
84

64
52
84

49
36
76

43
27
51

50
38
69
Total
BOD5

27
15
37

17
7
34

19
8
31

19
9
32

12
9
17

11
7
15
Sol.
BOD5

6
5
8

5
3
8

5
1
8

3
2
5

3
1
6

4
2
6
Ammo-
nia
N

15.5
12.5
20.0

11.3
18.0
9.0

8.2
4.7
13.0

0.95
0.05
3.50

0.18
0.05
0.80

0.20
0.05
0.30
Phos.
P

7.9
7.3
8.4

6.4
3.1
8.6

5.8
3.4
7.6

2.8
2.2
3.3

2.3
2.0
2.6

1.7
1.3
1.9
Chlo-
rophyll
a + b









314a
175
382

246
114
443

162
130
200

123
31
168
      Data collected from April 12 through 29.

-------
                                          Polishing Lagoon Effluents with Submerged Rock Filters     39
 deterioration in the net removal of suspended solids
 by  providing an  environment  conducive  to  algal
 multiplication prior to final discharge of the effluent.
 A more effective configuration for the system would
 be to abut the filter to the lagoon berm. The effluent
 would be  removed through a submerged conduit and
 aerated prior to final discharge.

       A filter system based on this concept has been
 designed by Lane-Riddle Engineers,  Inc. of Higgins-
 ville,  Missouri,  to  upgrade an existing lagoon system
 located  at California, Missouri. This  installation con-
 sists of three cells  operated in series.  The surface area
 of each cell at the 1.52  m  (5 ft) water depth are:
 Primary 7.49 ha (18.5 acres); secondary 2.27 ha (5.6
 acres), and tertiary 0.77  ha (1.9 acres). The design
 population  is 3600 based  on an  average flow  of
 378.51/capita/day  (100  BPcd).  The  rock filter is
 placed along one  side of the existing tertiary cell,
 Figure 6. The rock used is  a dolemictric  limestone
 obtained from a quarry near Jefferson City, Missouri.
 The size gradation is summarized in Table 11.

       The   hydraulic  loading   on  the   filter  is
 405.51/day/m3  (3 gal/day/ft3).  This is based  upon
the inflow of 378.51/capita/day (100 gpcd) with no
adjustment  for either evaporation  or seepage. Only
the rock upstream from the effluent collection pipe is
considered  part  of  the filter.  The  rock  located
between the pipe and the existing berm is simply fill
material. The rock filter is placed upon a 15.2 cm (6
in) thick mat of crusher run base rock. The effluent
collection line consists of 48.77 m (160 ft) of double
perforated corrugated metal pipe connected to 54.86
m (180 ft) of single perforated corrugated metal pipe.
Both  pipes  are 16 gage metal and  are 30.48  cm (12
in) in  diameter. The pipes are connected   to  the
existing effluent  structure through a  series  of cor-
rugated metal bends which control the water depth in
the tertiary  cell at either 0.91 m (3 ft) or 1.52 m (5
ft). All metal  parts are coated  with asbestos  bonded
asphalt. The interior and the exterior of the concrete
effluent  structure   is  also  coated  with   asphalt.
Oxygenation of the final effluent  is provided by a
cascade aerator located at the end of the outfall pipe.

      Construction of the filter  at California, Missouri,
was done by city employees under  the supervision of
B. J.  Gilbert, Superintendent  of Utilities. The con-
struction costs are summarized in Table 12. Obviously
Table 7.  Summary of water quality measurements, effluent from the large rock filter.
Month
February
Average
Range

March
Average
Range

April
Average
Range

May
Average
Range

June
Average
Range

July
Average
Range

Water
Temp.

5.1
2.0
7.5

10.2
6.8
17.0

14.8
10.5
18.9

21.6
18.1
25.0

24.3
18.8
26.8

28.4
26.1
31.1
Dis-
solved
Oxygen









7.0
1.5
12.5

0.5
0.0
2.5

0.1
0.0
0.3

0.4
0.0
1.2
pH

7.6
7.0
8.1

7.9
7.5
8.6

8.0
7.4
8.6

8.4
7.9
8.8

8.4
8.0
8.7

8.3
8.0
8.4
TSS

56
41
84

59
10
124

34
14
61

34
17
79

24
17
31

24
19
34
VSS

48
29
70

41
8
94

26
11
51

25
12
35

15
6
24

15
8
25
Total
COD

132
80
180

110
60
176

86
60
124

76
51
97

61
47
76

67
53
90
Sol.
COD

47
24
72

47
32
60

55
40
68

48
32
60

43
35
56

51
37
67
Total
BOD5

21
13
29

13
7
29

19
9
32

13
6
18

9
7
14

9
5
13
Sol.
BOD5

6
5
11

4
1
7

5
2
8

4
3
7

4
2
8

6
3
9
Ammo-
nia
N

14.7
12.5
19.5

7.9
2.3
18.0

5.0
2.0
8.5

1.26
0.90
2.30

1.13
0.60
2.60

1.49
0.69
3.00
Phos.
P

7.4
7.1
8.0

6.2
5.0
7.6

5.7
3.5
6.8

2.7
2.4
3.1

2.1
1.6
2.6

1.6
1.5
1.7
Chlo-
rophyll
a + b









206a
146
305

148
51
313

79
58
105

59
33
83
      aData collected from April 12 through 29.

-------
 40
O'Brien
 the primary factor in the cost of a submerged rock fil-
 ter is  the  filter rock. The  design of the California,
 Missouri, installation is prudently conservative in the
 selection of both the rock size and the hydraulic load-
 ing. When additional information is available to better
 define the long term operating characteristics of sub-
 merged filters, the use of smaller, more heavily loaded
 units will undoubtedly occur.

      A major  question  concerning rock  filters  is
 solids  buildup and  either clogging  or  sloughing  of
 material by the  system. This is a valid concern
 because matter is not  destroyed. The real question
 then is, "How  soon will the system fail?" Obviously
 the answer cannot be  based  upon  field experience
 because filters  have not been in use long enough  to
 provide this information.  However, the problem may
 be  approached by considering a  steady state mass
 balance. The following assumptions are made:
      1.    The hydraulic loading rate on the filter is
           1081.41/day/m3 (8 gal/day/ft3)
     2.    The  average  influent total  suspended
           solids are 60 mg/1 (80 percent VSS)
                                                  3.    The   average  effluent  total  suspended
                                                       solids are 20 mg/1 (80 percent VSS)
                                                  4.    The specific gravity of the fixed SS is 2.0
                                                  5.    The  specific  gravity of the  inert  VSS is
                                                       1.0
                                                  6.    Sixty percent of the influent VSS is non-
                                                       biodegradable
                                                  7.    The final residue from the influent biode-
                                                       gradable VSS is 20 percent  of the initial
                                                       mass and are inert VSS
                                             Buildup Influent FSS (60-20) (0.20) = 8 mg/1
                                                     Influent Inert VSS (60-20) (0.80) (.60)
                                                                      = 19.2 mg/1
                                                     Residual Biodegradable VSS (12.8 mg/1) (.2)
                                                                      = 2.6 mg/1
                                             AVolume/day

                                                8  2.6   19.2
1
                                                           1
gal-
                                             =  (25.8) (8) (231 x ID"6) in3/ft3 = 0.04768 in3/ft3
                                            or  17.40in3/ft3/yr.
Table 8. Summary of water quality measurements, effluent from the small rock filter.
Month
February
Average
Range

March
Average
Range

April
Average
Range

May
Average
Range

June
Average
Range

July
Average
Range

Water
Temp.

5.1
2.0
7.5

9.9
6.8
14.0

14.8
10.5
19.0

21.7
18.5
25.0

24.5
18.9
26.5

28.6
26.2
31.2
Dis-
solved
Oxygen









6.9
1.8
13.2

0.6
0.0
2.0

0.1
0.0
0.3

0.2
0.0
0.5
PH

7.6
7.0
8.2

7.9
7.5
8.7

7.9
7.3
8.4

8.4
8.0
8.7

8.3
8.0
8.7

8.3
8.1
8.5
TSS

52
41
61

46
12
114

25
15
40

34
8
81

22
17
34

23
17
29
VSS

48
39
58

34
10
83

20
9
31

23
8
38

14
9
27

14
9
21
Total
COD

137
104
196

107
60
160

86
56
120

71
48
88

62
53
72

65
51
100
Sol.
COD

49
20
92

52
24
80

52
40
68

49
30
64

44
27
55

51
41
63
Total
BOD5

21
13
32

13
6
25

16
9
27

12
5
19

8
6
12

9
5
14
Sol.
BOD5

6
4
9

5
2
9

6
3
12

4
2
6

4
3
8

5
2
7
Ammo-
nia
N

15.0
12.0
20.0

9.4
5.0
14.5

6.5
4.5
10.0

1.47
0.80
2.80

1.49
0.65
2.70

1.90
0.96
3.40
Phos.
P

7.3
5.9
8.0

6.1
5.2
7.3

5.8
3.1
7.0

2.6
2.2
3.0

2.1
1.7
2.5

1.6
1.4
1.8
Chlo-
rophyll
a + b









140*
111
153

170
56
337

63
39
92

67
28
133
       Data collected from April 12 through 29.

-------
                                        Polishing Lagoon Effluents with Submerged Rock Filters
41
Table 9.  Summary of water-quality measurements obtained from the sampling tubes located in the large rock
         filter.

Month

April
Average
Range

May
Average
Range

June
Average
Range

July
Average
Range


Maya
Average
Range

June
Average
Range

July
Average
Range


April
Average
Range

May
Average
Range

June
Average
Range

July
Average
Range

Water
Temp.


14.5
10.7
18.5

21.5
18.1
24.7

23.5
18.6
25.9

28.9
27.9
29.9


24.7
24.1
25.0

23.5
18.4
26.1

29.4
28.9
30.1


14.6
10.9
18.2

21.2
18.2
24.2

23.7
19.0
25.7

29.4
28.7
30.4
Dissolved
Oxygen
Tube

2.0
0.5
4.8

0.6
0.2
1.0

1.3
0.2
2.4

1.3
0.2
2.3
Tube

0.0
0.0
0.0

0.0
0.0
0.0

0.2
0.1
0.2
Tube

1.5
0.0
8.8

0.0
0.0
0.0

0.0
0.0
0.0

0.3
0.5
0.1
TSS
vss Total
v:>:> COD
Sol.
COD
Chlorophyll
a + b
No. 3 Influent Side of Filter

53
33
79

70
23
122

48
40
50

28
23
35
No. 2 Center

27
23
31

28
24
32

16
13
19

44
25
66

54 106
14 80
78 231

39 91
34 84
42 104

20
12
30
of Filter

16
10
21

20
14
23

11
8
15





54
46
61

48
42
53


















243
166
417

217
84
432

154
124
187






75
71
81

106
89
147




No. 1 Effluent Side of Filter

24
7
39

29
19
49

29
23
35

11
9
14

20
4
35

21 73
13 50
35 98

17 67
10 55
24 84

6
2
9





53
44
68

53
46
68





136
78
175

85
53
146

79
58
89




      Observations cover the period from May 20-31.

-------
 42
O'Brien
Table 10.  Summary of water quality measurements obtained from  the sampling tubes located in the small rock
          filter.

Month
Water
Temp.
Dissolved
Oxygen
TSS
u<::> COD COD
Chlorophyll
a + b
Tube No. 6 Influent Side of Filter
April
Average
Range

May
Average
Range

June
Average
Range

July
Average
Range


May3
Average
Range

June
Average
Range

July
Average
Range


April
Average
Range

May
Average
Range

June
Average
Range

July
Average
Range


14.9
10.6
18.8

21.6
18.1
25.8

23.6
18.9
26.0

29.6
27.9
30.9


25.5
25.2
25.7

24.0
19.0
26.3

29.8
29.0
30.3


14.5
10.8
18.7

22.4
18.8
25.6

24.2
19.9
26.4

29.5
29.2
29.9

1.8
0.4
3.2

0.8
0.1
1.8

3.4
1.8
5.2

2.0
0.1
4.1
Tube

0.0
0.0
0.0

0.0
0.0
0.0

0.2
0.1
0.3
Tube

0.1
0.0
0.3

0.0
0.0
0.0

0.0
0.0
0.0

0.1
0.0
0.2

60
35
90

122
31
242

45
37
49

34
31
40

49
26
78

102 298 46
25 89 39
208 642 56

37 95 46
29 81 41
43 112 50

28
24
36

278
150
389

208
101
386

168
132
180




No. 5 Center of Filter

26
19
32

24
20
28

12
8
14
No. 4 Effluent

16
3
28

27
15
40

20
17
23

12
12
13

17
15
21

18
15
24

9
6
12
Side of Filter

13
2
27

19 84 52
11 57 36
30 138 66

14 71 53
10 63 43
18 80 68

8
5
12

76
56
112

74
55
89






91
63
142

109
45
203

45
31
66




     Observations cover the period from May 20-31.

-------
                                        Polishing Lagoon Effluents with Submerged Rock Filters      43
Table 11.  Size gradation of the rock used in the sub-
          merged filter at California, Missouri.
% Passing Screen
   by Weight
Screen Size
    cm
    85 -100
     0-  15
     0-   5
7.62 - 12.70
6.35-  7.62
below  6.35
Table 12.  Construction  cost of the submerged rock
          filter  installation  at California, Missouri
	(August 1974).	

Filter Rock; 4787.90 tons @ $9.50/ton   $45,485.05
            4342.63 metric tons @
                 $10.47/metric ton
Base Rock; 514.30 tons @ $3.69/ton       1,897.77
           466.47 metric tons @
                 $4.07/metric ton
Filter piping                            3,675.84
Truck Loader and Operator;  106.5 hr @    2,236.50
                 $21.00/hr
City Employees; Salary and Wages         1,327.15
                      Total           $54,622.31
      The porosity of both the large and small rock
 used in this study was 0.44, so the void space is 760
 cubic inches  per cubic foot. On the basis of  the
 preceding example, it would  take approximately 43
 years to fill these voids with solids.

      Obviously, the steady  state assumption used
 above is  an over simplification. During the late fall,
 winter, and early spring the rate of biological  de-
 composition will be  extremely slow because of the
 low  water temperature. There will also be a period
 during the spring when the TSS will be significantly
 greater than 60 mg/1 due  to  the nutrients stored in
 and released from the bottom sediment in the lagoon
 system. The rate of decomposition during the sum-
 mer  months will be greater  than the  rate of solids
 removal  from  the  liquid flowing through the filter
 during this period. The rate  of solids  accumulation
 during part of each year could easily be several times
 that computed  for  the steady state  system. The
 effective  life of a rock filter will, therefore, be shorter
 than the  value computed in the example. However,
 because   of the  extremely low organic loading on
 submerged rock filters, and  the slow  rate of  solids
 accumulation within these filters, the effective  life
 should exceed the 20 to 30 design year life used for
 alternative treatment techniques.
     The void space available  in both  of the rock
filters constructed for this investigation was approxi-
mately the same. However, the size of  the voids is
also important because the many small volume voids
located between small rocks can be plugged by  the
layers of biological  slime  formed  on the rocks. This
type of failure is expected to eventually occur in the
small  rock filter used in this study. On the basis of
the information presently available, a filter  having
voids  which are large enough to  avoid plugging can be
constructed from rock having a minimum size grada-
tion approximately  equal to the large rock filter used
in this investigation and a maximum size gradation
approximately equal to the filter installed  at Califor-
nia, Missouri. As the rock size gradation increases the
maximum allowable hydraulic loading will decrease.
However, additional research will be required before a
precise relationship  between rock size, flow rate, and
suspended solids capture efficiency is available.
      As shown in Tables 9 and 10, during the initial
period of operation  most of the reduction  in  sus-
pended solids occurs  in  the first 2.74 m (9 ft) of
horizontal flow through the rock. The solids capture
efficiency of this portion of the  filter will decrease
with  time because  the  volume  of void  space  will
become  smaller as  inert material builds up and  the
velocity  of flow through this  portion  of the filter
increases. The net  effect is analogous to the sedi-
mentation phenomenon  observed in slightly inclined
tube  settlers.  In these units  the settling zone moves
downstream along the axis of the tube as  the time of
operation increases. Additional research is needed to
quantify this response in submerged rock filters.

      A  second area  of concern is the production of
hydrogen sulfide by  anaerobic decomposition of the
algae. In the  absence of sulfate, algal decomposition
under anaerobic conditions consists of the  production
of volatile acids and their subsequent reduction to
methane. However, if sulfite is present no methane
fermentation  occurs  (Lawrence et  al.,   1966).  A
reasonably accurate prediction of the rate of sulfide
production can  be  made by  considering the COD
change in the system (Force and McCarty,  1969). The
reaction is:
                                               • S=+4H2O
                In other words, 64 g of organic  matter, on a COD
                basis, will reduce one mole of sulfate and produce 32
                g of sulfide ion. The sulfide ion in turn establishes an
                equilibrium with hydrogen ion to form HS"  and/or
                H2S depending upon the pH of the solution.

                      The data for  June for the large rock filter can
                be used to illustrate the magnitude  of the problem.
                The average  total  COD  entering the experimental
                lagoon was 84  mg/1 and the average total COD in the
                sampling pipe on the effluent side of the filter was 67
                mg/1. Therefore:

-------
44     O'Brien
                                                               Effluent   collection
                                                               line   30.48 cm. dia.
                                                               double   perforated
                                                               corrugated   metal
                                                               pipe  48.77m.  long.
                                                               Effluent   collection
                                                               line   30.48 cm.  dia.
                                                               single   perforated
                                                               corrugated    metal
                                                               pipe   54.86 m.  long.
                                                                   Effluent   discharge

                                                             5.03 m
                      11.89 m
                  Section  A-A
Effluent
structure
                                                                          Existing
                                                                          rock
                                                                          rip-rap
Figure 6. Plan of submerged rock filter constructed at California, Missouri.

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                                        Polishing Lagoon Effluents with Submerged Rock Filters      45
ACOD = 17 mg/1 and AS" = (17 mg/1) (fj)= 8.5 mg/1

      The total alkalinity of the lagoon effluent at
Eudora ranges between 260-275 mg/1 as CaCO3. The
minimum pH  observed within the filters is 7.9. The
primary ionization constant of hydrogen sulfide is 1.1
x  10"'  at 25°C. Therefore,  approximately  10.3
percent of the S= will exist as  H2S (0.9 mg/1) and
89.7 percent will be HS-  (7.9 mg/1). At the present
time  the  odor of H,S at Eudora is minimal. The
intensity of the H-S odor will be increased somewhat
by  aerating  the  final effluent.  However, in  most
locations where lagoon systems are already in use this
will not be a significant problem.

      A  third  area  of concern is  the increase in
ammonia nitrogen in effluent from the rock filter. In
the pilot scale units this increase ranged from  2 to 3
mg/1 as nitrogen. The increase observed in the field
scale  filters  has   ranged  from  1 to 2 mg/1. It  is
important  to remember,  however, that  the total
ammonia  concentration in the effluent is between 1
to 4 mg/1  as nitrogen. This is significantly less than
the 6 to 20 mg/1  of ammonia nitrogen present in the
effluent from conventional  secondary   treatment
systems (Earth and Mulbarger,  1966; Fruh, 1967). In
locations where the concentration of ammonia nitro-
gen in  the receiving water is critical  a very  simple
adaptation of the submerged filter could be used to
nitrify the final  effluent  (McHamess  and McCarty,
1973).

                  Conclusions

      The  following conclusions  can be drawn from
the  three  phases of  investigation  that  have been
carried out on the submerged rock filter:

      1.  During the first six months of operation the
field scale installation has responded in the same way
the pilot scale system did during the summer of 1973.
Both units went through an initial phase during which
the biological slime layer was becoming  established
on  the rock surfaces. During this period the capture
of  suspended solids was  relatively  poor.  After the
biological slime layer was established on the rocks the
removal of suspended solids increased  dramatically.

      2. The biological slime layer will function in an
anaerobic environment during part of each year. This
will require providing aeration facilities for the filter
effluent. This unit need not be elaborate and in many
instances a sample cascade aerator will be sufficient.

      3. If sulfate is present in  the carriage water,
hydrogen  sulfide  will be produced.  If the total
alkalinity in  the  lagoon effluent is greater than 260
mg/1 as CaC03 the pH of the  final effluent  wfll be
high  enough
minimum.
to reduce  the odor problem to  a
      4.  The rate of solids accumulation in the filters
will be very slow. As long as the size of the void space
between the  rocks  is  large  enough  the  prevent
plugging the effective life  of the filter  should be
greater than 20 to 30 years.

      5.  Rock sizes greater than 2.54 cm and less
than 12.70 cm will make satisfactory  filters. Most of
the rock used in any one  filter should be within a
range of 5 cm in diameter to insure  a  maximum
amount of void volume. As the rock size increases the
maximum  allowable hydraulic loading will decrease.
More investigation  is needed to  fully define the
relationship between rock size and hydraulic loading.

      6.  Enough information  is now  available to
establish tentative  design guidelines  for  submerged
rock filters. These guidelines can be further refined as
additional data becomes available.

      7.  Submerged rock filters are not going to be a
panacea  for  all lagoon  installations. However, the
results obtained to date  indicate these units will be
applicable  for upgrading the lagoon systems already
in operation in many small municipalities.
                Acknowledgmen ts

      The  major portion of this investigation was
carried out  under  contract  68-0280  between  the
Environmental Protection Agency and the University
of Kansas Center for Research. The  cooperation of
the City of Eudora,  and most especially Mr. John N.
Pinnick, Superintendent  of Utilities,  is  gratefully
acknowledged.

      Laboratory  assistants  on  the  project were:
Christopher  Yu, Hsiang  Huang, Frank B.  Nelson,
Richard  A.  Hirsekorn,  Steven S. Innes, Lynn E.
Osborn, and Rodney J. Hofen
                  Bibliography

American Public Health Association.  1971. Standard meth-
     ods for the examination of water and wastewater, 13th
     Ed. A.P.H.A., New York, N.Y.

Earth, E. F., and M. Mulbarger. 1966. Removal of nitrogen
     by municipal wastewater treatment plants. lout. Water
     Pollution Control Federation, 38:1208.

 Berry,  A. E. 1961. Removal of algae by miciostiainers.
     Journal American Water Works Association 53:1503.

 Borchardt, I. A., and C. E. O'Melia.  1961. Sand filtration of
      algae  suspensions.  Journal American  Water Works
      Association 35:1493.

-------
 46
O'Brien
Dodd, J. C. 1973. Harvesting of algae with a paper precoated
      belt-type filter. Dissertation Abstracts 34:2447-8.

Environmental  Protection  Agency.   1971.   Methods  for
      chemical analysis  of water  and  wastes. Analytical
      Quality Control Laboratory, Cincinnati, Ohio.

Folkman, Y., and A. M. Wachs. 1973. Removal of algae from
      stabilization pond effluents by lime treatment. Water
      Research 7:419.

Force, E. G., and P. L. McCarty. 1969. The rate and extent
      of algal decomposition in anaerobic waters. Proceedings
      of  the  24th  Industrial  Waste  Conference, Purdue
      University, 13.

Ftuh,  E.  G. 1967. The overall picture  of eutrophication.
      Jour. Water Pollution Control Federation, 39:1449.

Lawrence, A. W., P. L. McCarty, and F. J. A. Guerin. 1966.
      The effects of sulfides on anaerobic  treatment. Inter-
      national Journal of Air and Water  Pollution, 10:207.

Levin, G. V., et  al.  1962.  Harvesting of algae by  froth
      Flotation. Applied Microbiology 60:169.

Martin, D. M. 1970.  Several methods of  algae removal in
      municipal oxidation ponds.  M.S.  Thesis, University of
      Kansas.

Martin, J. L.,  and R. Weller. 1973. Removal of algae from
      oxidation pond effluent by upflow rock filtration. M.S.
      Thesis, University of Kansas.
                                                   McGarry, M.  G. 1970.  Algae  flocculation  with aluminum
                                                        sulfate and poly electrolytes.  Journal  Water Pollution
                                                        Control Federation 42:R 191.

                                                   McHamess,  D.  D., and P. L. McCarty. 1973. Field study of
                                                        nitrification with the submerged filter. EPA-R2-73-158
                                                        Environmental Pollution  Technology  Series, Environ-
                                                        mental Protection Agency.

                                                   O'Brien, W. J.  et al. 1973.  Two methods for algae removal
                                                        from  oxidation  pond effluents.  Water  and Sewage
                                                        Works 120:66.

                                                   Ort, J. E. 1972. Lubbock  wraps it up. Water and Wastes
                                                        Engineering 9(9): 6 3.
                                                   Parker, D.  S.  et  al. 1973. Algae removal improves pond
                                                        effluent. Water and Wastes Engineering 10(1):26.
                                                  Shindala, A., and J. W. Stewart. 1971. Chemical coagulation
                                                        of effluents from municipal waste stabilization ponds.
                                                        Water and Sewage Works 118:100.
                                                  Tenny, M. W. et al. 1969. Algal flocculation with synthetic
                                                        polyelectrolytes. Applied Microbiology 18:965.


                                                  U.S. Geological  Survey.  1973. Methods for collection and
                                                        analysis  of aquatic  biological and microbial  samples.
                                                        Book S, Chapter A4, Techniques of Water Resources
                                                        Investigations.

-------
                          STABILIZATION POND UPGRADING WITH

                                INTERMITTENT SAND FILTERS
                                 E. J. Middlebrooks and G, R. Marshall
                                                                    i
                  Introduction

Nature of the problem

      Many rural communities are still fortunate  to
be  surrounded by large areas of open and relatively
inexpensive land.  It was because of this land that
many  of these communities adopted waste stabiliza-
tion lagoons as a means of wastewater treatment. This
treatment  scheme requires large tracts of land, but
the  important  consideration  was  that it  gave  a
satisfactory effluent for minimum cost and  main-
tenance. With the implementation  of  new  water
quality standards, a better quality effluent is neces-
sary. If small cities and towns are  to economically
produce a higher  quality  effluent,  some  form  of
treatment must be utilized  that will continue to take
advantage of the large areas of relatively inexpensive
land surrounding these communities.  One method of
treatment that capitalizes on the availability of large
land areas is intermittent sand filtration.

Objectives

      The objective of this  study was to evaluate the
performance   of  laboratory  and  pilot  field  scale
intermittent sand  filters  as a polishing process that
would  upgrade   existing wastewater  treatment
facilities.  Particular attention  was  directed toward
ascertaining the effectiveness of the intermittent sand
filter as a means  of removing the  highly variable
quantities  of algae present in  stabilization  ponds
during the  warmer months  of the year. These results
were used to develop preliminary design criteria for
intermittent  sand  filters  that  would  consistently
produce  an effluent of a  quality  that  would meet
stringent  water quality  standards.  Details  of this
study  were reported by  Marshall and Middlebrooks
(1974).
     'E. I. Middlebrooks is Dean, College of Engineering,
and G.  R. Marshall is  Research Assistant, Division  of
Environmental  Engineering,  College of  Engineering, Utah
State University, Logan, Utah.
History of intermittent sand filters

     Intermittent sand filtration of sewage began in
this country in  1889 in Massachusetts, and for many
years was centered in the New England area. Approxi-
mately 450 intermittent filter plants were in opera-
tion in this country during 1945. But later reports
showed a  decrease to 398 in use by 1957. Of those
still  in use  by  1957,  94  percent were  serving
communities with populations under 10,000 (ASCE
and FSIWA, 1959).

     Successful research  efforts  at the  Lawrence
Experiment  Station,  Lawrence,  Massachusetts,  re-
sulted  in an  increase in the use of intermittent sand
filters  until land costs forced many communities to
seek other methods of treating wastewaters. Large
numbers of small residential centers such as isolated
tourist courts, motels, trailer parks, drive-in theaters,
consolidated schools,  and  housing developments be-
gan to spring up all over Florida following World War
II. It was soon realized that an economic method of
sewage treatment would be necessary for these small
communities, and  the  study of intermittent sand
filtration was undertaken at the University of Florida
at Gainesville (Calaway et  al., 1952; Furman et al.,
1949;  and  Grantham  et  al.,  1949). Much of the
modern day knowledge on intermittent sand filters
has come  out of the studies carried out at Gainesville.
            Methods and Procedures

Experimental equipment

     The study consisted of both laboratory (Phase
I) and field scale (Phase II) experiments.

Laboratory study

     Nine  laboratory  scale  filter  columns were
erected as shown in Figure 1. Each  individual filter
column was constructed  of 6-inch diameter (15 cm)
plexiglass cylinders  6  feet (1.85 m)  in  length. A
flanged coupling was provided in  the middle of each
column to facilitate the filter cleaning operation.
                                                                                                  47

-------
  I'-,
Middlebrooks and Marshall
               Figure 1. Nine laboratory  scale intermittent sand filters shown during daily
                        loading under laboratory conditions.
      The filter underdrain material for each labora-
tory filter consisted of 3-inch layers of 1/4,  3/4, and
\Vi  inch maximum  diameter rock  supported  on
stainless steel mesh. A depth of 28 inches (71 cm) of
filter sand was then  placed upon  the  quarter inch
diameter rock  (6 mm).  Sands with effective sizes of
0.17, 0.35, and 0.72 mm and uniformity coefficients
of 5.8, 3.8, and 2.6, respectively, were employed.

      The 0.17 mm (.0067 inch) effective size sand
was  the basic sand from which the other two sizes
were produced. The sand was a washed bank run sand
that was primarily used  as fine aggregate in concrete.
The  0.35 mm  (.0137 inch) sand was produced by
sieving the 0.17 mm (.0067 inch) sand through a U.S.
series number  50 sieve, the  0.35 mm (.0137 inch)
sand being the portion  remaining on  the sieve.  The
0.72 mm (.0283 inch) sand was produced through the
use of the U.S. series number 30 sieve.

      Logan  City,  Utah,  wastewater  stabilization
pond effluent was applied once daily  to each of the
laboratory filters. In order to control  the suspended
solids concentration in the lagoon effluent applied to
the filters, the wastewater effluent was diluted, if
necessary, with aerated  tap water. Dilution factors
were determined  on a day to  day basis by  carrying
out a daily suspended  solids  analysis  on the filter
influent. Also, prior to dosing, the water temperature
was  recorded in addition to any  other  observations
                                            noted that day with respect to general filter operation
                                            or lagoon performance.

                                                 Hydraulic  loading rates  of  100,000  gpad
                                            (153.18  m3/hectare-day),  200,000 gpad (306.36
                                            m3 /hectare-day),  and  300,000   gpad  (459.54
                                            m3/hectare-day) were  applied throughout the experi-
                                            ment.  Three  loading periods  of approximately 6
                                            weeks in duration were  employed. A loading period
                                            constituted a  period of operation during which  the
                                            applied algae concentration was held constant. Plug-
                                            ging  is  defined as  the point in  time when all of the
                                            specified quantity of wastewater placed on a filter
                                            does not pass  through the filter in a 24-hour period.
                                            Plugging  did  not  occur during  any of  the  three
                                            loading .periods in the laboratory. At the end of the
                                            Loading Periods I and II, the  filters were dismantled,
                                            the top 10 cm (4 inches) of sand removed from each
                                            and  replaced with new  sand of the same specifica-
                                            tions, and the filters were returned to service  the
                                            same day. At the end of Loading Period III, the  top
                                            of the sand bed was not removed and daily operation
                                            was continued to determine an  estimate of the time
                                            of operation  possible before plugging occurs.

                                                 Suspended  solids  concentrations  of 15 mg/1
                                            (Loading Period II), 30 mg/1 (Loading Period I), and
                                            45   mg/1  (Loading  Period  III) were   maintained
                                            through each of the loading periods. During the first
                                            two  loading periods,  the wastewater used for filter

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                                     Stabilization Pond Upgrading with Intermittent Sand Filters      49
              Figure 2. Nine prototype intermittent sand filters located at the point of dis-
                       charge for the Logan City wastewater stabilization ponds which
                       were used for study under actual field conditions.
loading was obtained directly from the  Logan City
Wastewater  Stabilization Ponds. This water was ob-
tained once  weekly and stored under refrigeration for
use throughout  the remainder of the week. During
the final loading period, the influent to the filters was
obtained from model stabilization ponds operated in
the laboratory.  These  ponds were  enriched with
inorganic nutrients and were illuminated on a fixed
cycle  of 16  hours of light and 8 hours of darkness. In
addition, when water was removed each day for filter
loading, the sample was replaced  with tap water and
once  weekly  the  sample was replaced  with water
obtained from the Logan City wastewater stabiliza-
tion ponds.

Field  study

      Nine prototype field filters  were erected at the
discharge point of the Logan City wastewater stabili-
zation ponds and are shown in Figure 2. These units
were 4 feet  square (1.2 m x 1.2 m) and 6 feet (1.8 m)
in height and were constructed of exterior plywood
lined  with fiberglass and resin. Underdrain construc-
tion was the same  as the laboratory filters with the
exception being  that each of the three layers of gravel
were 4 inches (10 cm) in depth.

      Six  filters each  were filled  with  sands of
effective sizes of 0.17 and 0.72 mm (.0067 and .0283
inch)  to depths of 30 inches (76  cm). The  remaining
three  units were initially filled with  1/4 inch (6 mm)
maximum diameter rock to a depth of 60 inches (152
cm).  Later  in the  study  the  1/4  inch rock  was
replaced with sand of 0.17 mm effective size provid-
ing six filters with the basic sand.

      Lagoon effluent was applied to  the filters with
three  calibrated  pumps  operated for  a  specified
period of time. During the fourth week of operation,
spreading units  were  installed  to   assure  better
distribution  of the raw  water on the filter bed.  A
typical spreading unit is shown in Figure 3.


      During the  first season of operation,  the field
filters were also loaded once daily at rates of 100,000
gpad (153.18 m3/hectare-day), 200,000 gpad (306.36
m3/hectare-day),  and 300,000 gpad (459.54 m3/hec-
tare-day). The  hydraulic loading rates applied in the
second season are summarized in Table  1. The filter
containing 0.17  mm effective size  sand loaded  at
900,000  gpad  (1,378.62   m3/hectare-day)  was
operated at this rate for only 28 days because of the
lack of adequate freeboard to compensate for changes
in percolation rate due  to increased head loss.

      A daily sample of filter influent was taken for
suspended solids  and pH analyses. All other influent
parameters were measured on a weekly basis with the
exception being  the bacteriological  samples which
were taken  immediately  following the  daily dosing
with  stabilization  pond effluent. No attempt was

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50    Middlebrooks and Marshall
made to maintain a  specified  suspended solids con-
tent in the field experiments.

Sampling

      Laboratory  filter effluent samples  were col-
lected  once  weekly and composited  from 2 days of
operation. Filter influent samples were collected for
analysis on  the days corresponding  to  the  effluent
composite sample.

 Figure 3. Typical troughs used on the field prototype
          filters to protect the sand bed and to evenly
          distribute  the applied wastewater over the
          filter bed.
     Raw  or  influent water  samples  for  bacterial
analysis were collected just prior to adding the pond
effluent to  the filters and analyzed for total bacteria
and  total  coliform   bacteria.  The  following  day,
effluent samples were then taken and analyzed for
total bacteria and total coliform bacteria.

     Effluent  samples  from  the  field  filters were
collected once  a week and the samples were  taken
immediately following the application of the pond
effluent. A filter influent sample was taken daily.

Analyses

     Suspended solids, pH, and temperature  mea-
surements were  performed on filter influent samples
on  a daily basis  for both the laboratory and the
prototype  field  filters.  Filter influent and effluent
samples were analyzed once weekly  for biochemical
oxygen demand (BOD),  ammonia,  nitrite, nitrate,
orthophosphate,  total  unfiltered  phosphorus,  sus-
pended solids,  and pH. In addition, flask  bioassays
were performed on the laboratory filter effluent to
determine if viable algae cells were in the effluents.
Approximately 200  ml of each filter effluent were
placed in a 500 ml Erlenmeyer flask and exposed to
the  lighting  pattern  described for the laboratory
ponds.  Growth  was  measured  three to four times
weekly in each flask  by  determining the  optical
density of the suspension.

      Suspended and  volatile suspended solids, reac-
tive  orthophosphate,  and  reactive nitrite and nitrate
were measured by methods outlined in the Practical
Handbook  of  Seawater  Analysis  (Strickland  and
Parsons, 1968). Total phosphorus  and biochemical
oxygen demand analyses  were  performed  in  accor-
dance   with  Standard  Methods (1971).  Ammonia
concentration  was determined by methods  described
in Limnology  and Oceanography (Solorzano,  1969).
 Table 1. Physical characteristics of the filters and the hydraulic loading rates applied to the field filters.
Filter
Unit
Code
A4
A5
A6
A7
A8
A9a
C4
C5
C6
Effective Size

mm
0.17
0.17
0.17
0.17
0.17
0.17
0.72
0.72
0.72
of Sand

inches
0.0067
0.0067
0.0067
0.0067
0.0067
0.0067
0.0283
0.0283
0.0283
Filter
Depth
in
30
30
30
30
(0
JO
K)
!()
30
Hydraulic

gpad
400,000
500,000
600,000
700,000
800,000
900,000a
400,000
500,000
600,000
Loading Rate

m /hectare-day
612.72
765.90
919.08
1,072.26
1,225.44
1,378.62
612.72
765.90
919.08
      aLoaded at this rate for 28 days only.

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                                       Stabilization Pond Upgrading with Intermittent Sand Filters   51
Total plate  counts were made in accordance with
Standard Methods (1971) with the exception being
that all plates were  incubated  at 20 °C for 7 days
(Calaway et al., 1952). Total coliforms were deter-
mined by  the  procedures  described  in  Standard
Methods (1971).

            Results and Discussion

Algae genera

Laboratory filters

      Water  applied  to the laboratory filters were
effluent  from   domestic wastewater  stabilization
ponds and  many different species  of algae were
present.  Chlamydomonas sp.  was predominant in
both the  Logan City  and the laboratory stabilization
ponds. In most cases,  the predominant groups of
organisms in  the filter  effluent were "fusiform
diatoms." They appeared at one time or another in all
effluent  samples studied  and  were  observed quite
regularly  in the applied water.

      There  were cases where  Chlamydomonas sp.,
Scenedesmus sp., and diatoms  were observed separa-
tely and in various  combinations in the  effluents.
There were  a  few effluent samples  in which algae
ZYX5   M^8 usually occurredin *« °17
mm (0067 inch) effective size  sand subjected to the
lowest loading rate. When the  lagoon effluents were
applied to the filters, the alpe, Chlamydomonas sp.,
were  usually found  in a "clumped" or palmelloid
state  and in the effluent were  observed to be single,
motile cells  in  nearly every case. This palemelloid
state  may have contributed   significantly  to the
removal efficiencies obtained with the filters.
Field filters

     Table  2 summarizes the results of the micro-
scopic  analyses for the field filters. As reported for
the laboratory filters, Chlamydomonas sp. were again
predominant in the filter influent during the second
year of the  field study.  A  variety of genera  was
present in the lagoon effluent, but Chlamydomonas
sp.  represented a minimum of 70 percent of the algal
population throughout the study.

Oxidation of nitrogen

Laboratory filters

     Ammonia concentrations  in the influents and
effluents were not measured until Loading Period III.
As  the applied,  effluent  and removal values show
(Table 3), ammonia was present  in large quantities
and was  readily oxidized. This  is in agreement with
earlier results reported at the University of Florida
where  settled primary sewage was applied  to inter-
mittent  sand filters  (Furman  et  al., 1949;  and
Grantham et al., 1949).

     Table   4  shows  the  relationship   between
hydraulic loading rate,  sand size, and  the effluent
nitrate concentration for  the three algal concentra-
tions  applied (Loading Periods I,  II,  III). During
Loading  Period  III,  the  ammonia  concentration,
Table  3,  was found  to be  high in  the artificially
produced wastewater stabilization  pond  effluent
when  compared  with concentrations  that  would be
expected  to exist in a tertiary treated wastewater
stabilization pond effluent. Thus, the large increase in
nitrification  observed during Period HI, when com-
pared  with  that  of Periods I and II, was  probably
 Table 2. Algae genera population estimates for the influent and effluent samples from the field filters.
	 	

Sample
Date
26 July
2 Aug.
9 Aug.
15 Aug.
22 Aug.
28 Aug.
7 Sept.
13 Sept.
19 Sept.
27 Sept.
Genera


Influent
Sample


Chlamydomonas
Anabaena
0%
0%
0%
a
a
5%
10%
15%
20%
10%
Vegetative
25%
25%
25%
20%
5%
5%
10%
10%
5%
a
Palmelloid Daphnia
70%
70%
70%
70%
85%
80%
75%
75%
70%
80%
a
a
a
a
a
a
a
a
a
a
Diatom
5%
5%
5%
5%
5%
5%
5%
a
5%
10%
Euglena
a
a
a
5%
5%
5%
a
a
0%
0%
AS

Anabaena
0%
0%
0%
0%
0%
0%
a
5%
10%
0%
& C5 Effluent Samples

Chlamy.
85% (dead)
85% (dead)
85% (dead)
85% (dead)
85% (dead)
85% (dead)
85% (dead)
80% (dead)
75% (dead)
80% (dead)


Debris Diatom
Mainly
Mainly
Mainly
Mainly
Mainly
Mainly
Mainly
Mainly
Mainly
Mainly
15%
15%
15%
15%
15%
15%
15%
15%
15%
20%
       Occasional.

-------
 52
Middlebrooks and Marshall
Table 3. Mean applied and effluent ammonia nitrogen concentrations obtained during Loading Period III in the
         laboratory study.
Applied
NH4-N
(mg/1)
2.13
Effluent NH4-N Concentration, mg/1
Effective Size of Filter Media
0.17mm
Hydraulic
Loading Rates,
gpadx 10"3
100 200 300
.006 .004 .006
0.35 mm
Hydraulic
Loading Rates,
gpadx la3
100 200 300
.006 .014 .017
0.72 mm
Hydraulic
Loading Rates,
gpadx 10"3
100 200 300
.043 .146 .217
Table 4.  Mean applied and effluent nitrate nitrogen concentrations obtained in the laboratory study.
Loading
Period
I
II
III
Applied
NCyN
(mg7l)
0.034
0.110
0.165
Effluent NO3-N Concentration, mg/1
Effective Size of Filter Media
0.17mm
Hydraulic
Loading Rates,
gpadx 10~3
100 200 300
1.45 1.25 1.20
0.96 0.91 0.91
4.04 3.57 3.89
0.35 mm
Hydraulic
Loading Rates,
gpadx 10'3
100 200 300
0.99 1.12 1.63
0.84 0.81 0.74
3.82 3.44 3.03
0.72 mm
Hydraulic
Loading Rates,
gpad x 10~3
100 200 300
1.06 1.02 1.09
0.82 0.71 0.76
3.97 3.17 2.81
caused by the greater amounts of ammonia nitrogen
present in the artificially enriched wastewater ef-
fluent  produced in the laboratory ponds, and  was
probably not  related to the  increased applied algae
concentrations during Loading Period III.

     Filters constructed of sands with smaller effec-
tive sizes more readily oxidized  ammonia to nitrate
(Table  4). This result  agrees with  the  findings of
Grantham et al. (1949), Furman et al. (1949),  and
Pincince and McKee (1968).

     Table 3 shows the changes in ammonia-nitrogen
concentrations at the  three hydraulic loading rates
and filter sand sizes.  The 0.72 mm (.0283 inch)
effective  size sand filter showed a slight decrease in
ammonia-nitrogen reduction as the hydraulic loading
rate increased. This  decrease was probably caused by
increased  submergence,  decreased  aeration, and  a
reduction in the contact time within the filter bed.

     Field experimental results shown in Tables  5
and 6 were in  agreement with the results observed in
                                           the  laboratory  filters.  The  0.17  mm (.0067  inch)
                                           effective size sand was somewhat more efficient in
                                           the oxidation of ammonia-nitrogen than the 0.72 mm
                                           (.0283 inch) sand. Ammonia-nitrogen oxidation was
                                           not  continued in the second year of the field study;
                                           however, as the  hydraulic  loading is  increased, a
                                           corresponding  decrease in  oxidation would be ex-
                                           pected. The rock filtering media oxidized little of the
                                           ammonia-nitrogen to nitrate. This is probably due to
                                           the short time required for the liquid to pass through
                                           the media.

                                           BOD removal

                                           Laboratory filters

                                                 As shown in Table 7, the concentration of
                                           BOD5  in the lagoon effluent applied to the labora-
                                           tory filters was close to the existing Utah standard of
                                           5 mg/1 even before filtration during Loading Periods I
                                           and  II. This was caused by two factors: The necessity
                                           to dilute the effluent to obtain the desired suspended
                                           solids concentration applied to the filters, and the

-------
                                      Stabilization Pond Upgrading with Intermittent Sand Filters     53
Table 5. Mean applied and effluent ammonia nitro-
        gen  concentrations  obtained  in  the  field
        study during the first year.

Applied
NH4-N
(mg/1)
1.09
Mean Effluent
NH4-N Concentrations, mg/1
.17 mm
0.013
.72mm
0.426
6 mm max.
dia. rock
1.10
Table 6. Mean  applied  and effluent  nitrate  nitro-
        gen  concentrations obtained  in  the  field
        study during the first year.
Applied
NO,-N
(mg/1)
0.078
Mean Effluent
NO3-N Concentrations, mg/1
.17 mm
0.996
.72mm
1.11
6 mm max.
dia. rock
0.479
Table 7. Mean applied and effluent BOD5 concentrations obtained in the laboratory study.
Loading
Period
I
II
III
Applied
BOD5
(mg/1)
6.71
6.34
36.5
Effluent BOD5 Concentration, mg/1
Effective Size of Filter Media
0.17mm
Hydraulic
Loading Rates,
gpadx 10~3
100 200 300
1.15 1.55 2.31
1.17 1.26 1.96
5.81 5.64 7.14
0.35 mm
Hydraulic
Loading Rates,
gpadx 10"3
100 200 300
2.51 2.61 2.97
2.44 2.08 2.41
11.21 10.83 11.53
0.72 mm
Hydraulic
Loading Rates,
gpadx 10"3
100 200 300
2.89 3.09 3.01
2.33 2.50 1.93
12.26 12.72 13.25
high  degree  of BOD5  removal  produced  by the
5-stage Logan lagoon system.

      Results of the laboratory study were in good
agreement with results obtained by Grantham et al.
(1949).  Examination of  Table  8  shows that the
loading rates used had little effect on BOD5 removal.
However, the data show a trend toward an increase in
the concentration  of BOD5  in the effluent  as the
loading rate increased. Higher loadings would probab-
ly show  an even greater increase in effluent BOD5
concentrations for all sand sizes. With respect to sand
size, the  effect of loading rate does slightly decrease
the filter's ability to remove the applied BODS which
agrees with the findings of Grantham et al. (1949).

Field filters

      At  the same  hydraulic loading rates as those
employed in the laboratory  filters, BOD5 removals
obtained during the first  year in the field units in
general agreed with the laboratory findings with the
exception being the lower removal efficiencies ob-
tained with the 0.72 mm (.0283  inch) sand used in
the field (Table 9). The differences in performance
summarized in Table 8 were probably caused by the
10-20°F  greater operating temperature under labora-
tory conditions. In general,  lower air temperatures
produce filter effluents with higher BOD5> This effect
was  even  more pronounced in larger  sized sands
studied by  Grantham et  al. (1949).  Coarser sands
allow  better aeration which  would  allow  the air
temperature to exert a much greater effect on the
biological activity.

      The mean monthly influent and effluent BOD5
concentrations obtained  during  the second  year of
field operation at various hydraulic loading rates for
the two  effective size sands (0.17 and 0.72 mm) are
presented in Table 10. The BOD5 of the influent
remained essentially constant during the second  year
of operation ranging from 10.0 to 24.9 mg/1  with an
average value of 13.7 mg/1 and a median value of 12.5
mg/1.  There appears to be little variation in the
effluent  BOD5 concentration with hydraulic loading
rate  for the 0.72 mm effective size sand; whereas, the
0.17 mm effective size sand shows a definite increase
in effluent BOD5  concentration  as  the hydraulic
loading  rate was  increased. It is likely that the
effluent  BOD5 concentration would also increase for
the 0.72 mm sand sizes if the loadings were increased
to 0.7 and 0.8 mgad.

      The mean effluent BODe concentrations for the
0.17 mm effective size sand filters loaded at 700,000
and   800,000 gpad (1072.3  and  1225.4  m3/hec-

-------
  54    Middlebrooks and Marshall
 Table 8. The comparison of BOD,  removal for the laboratory filters during Loading Period II and the field fil-
         ters containing 0.72 mm (.0283 inch) size sand.
Hydraulic Loading (gpad)
100,000 (153.4 m3/hectare-day)
200,000 (306.4 m3/hectare-day)
300,000 (459.5 m3/hectare-day)
Percent BOD5
Removal
Under Laboratory
Conditions
(70°F Ave. Air)
63.2
59.6
69.6
Percent BOD5
Removal
Under Field
Conditions
(60°F Ave. Air)
24.3
17.8
29.6
 tare-day) was twice as high as the values obtained at a
 hydraulic loading rate of 600,000 gpad (Table 10). A
 higher  effluent  concentration  was  expected, but
 whether such a large increase would have occurred if
 all of the filters had operated for an equal time period
 is unknown. However, based upon the data collected
 in this study it appears that BODs removal efficiency
 reaches a limit in the vicinity of a hydraulic loading
 rate of 600,000 gpad.

      BOD5 reductions with the 0.17 mm effective
 size  sand   filters  ranged between  38.7  and  97.4
 percent with the lower reductions occurring principal-
 ly at the higher hydraulic loading rates (700,000 and
Table 9.  Mean  applied and  effluent BODS  concen-
         trations  obtained in the field study during
         the first year of operation.
Applied
mg/1
6.18
Ave. Effluent BOD^ Concentrations, mg/1
0.17 mm
1.07
0.72 mm
4.70
6 mm max.
dia. rock
4.92
800,000  gpad). BOD5  reductions obtained with the
0.72  mm  effective  size  sand appeared  to  be in-
dependent  of the hydraulic loading rate and  ranged
between 27.0 and 80.7 percent.

      Mean BOD5 reductions for the  second  season
for the 0.17 mm sand ranged from 70.4 percent at a
hydraulic  loading rate of 800,000  gpad to  88.4
percent  for the  400,000  gpad rate.  Mean  BOD5
reductions  for  the 0.72 mm sand were essentially
constant  for all hydraulic loading rates and  ranged
from 59.9 to 63.2 percent.

Phosphorus removal

      Phosphorus was initially removed by the inter-
mittent sand filters, but removal was greatly affected
by the length of time that the units had operated and
the hydraulic loading  rate. Because little biological
growth occurs on or in the filter as the water passes
through, it  is unlikely that any significant phosphorus
removal was obtained through growth needs.  There-
fore, the most  obvious explanation of the relatively
large phosphorus removals obtained at the beginning
of the experiments  was ion  exchange.  The sands
contained some forms  of carbonate which probably
Table 10.  Mean influent and effluent BODs concentrations obtained with each sand size and hydraulic loading
          rate during Phase II under field conditions.
Month
June
July
Aug.
Sept.
Mean
Monthly
Influent
BOD
Concen-
tration
(mg/1)
12.1
12.6
12.9
16.1
Mean Monthly Effluent BOD5 , mg/1
Effective Size, 0.17 mm
Hydraulic Loading Rates, gpad
400,000
ǥȣ
0.75 93.8
1.5 88.1
2.2 82.9
2.0 87.6
500,000
•* £.
1.2 90.1
0.87 93.1
3.1 76.0
1.7 89.4
600,000
•*£.
1.3 89.3
1.1 91.3
3.1 76.0
1.8 88.8
700,000
•* L.
3.5 72.2
4.2 67.4
3.4 78.9
800,000
"* £.
3.3 73.8
4.3 66.7
4.7 70.8
Effective Size, 0.72 mm
Hydraulic Loading Rates, gpad
400,000
-ȣ.
4.5 62.8
5.4 57.1
6.2 51.9
5.9 63.4
500,000
"•» &
3.6 70.2
5.7 54.8
5.8 55.0
5.1 68.3
600,000
-» M.
3.9 67.8
5.9 53.2
6.8 47.3
5.4 66.5

-------
                                      Stabilization Pond Upgrading with Intermittent Sand Filters     55
 served as the exchange medium. Once saturated, there
 would  be  no  phosphorus  removal  of  any  con-
 sequence.  Phosphorus removals in the  field units
 followed the same pattern observed in the laboratory.

 Algal removal

      Algal  concentrations  in  the influent were
 estimated  by the suspended solids  technique which
 measures  a  variety  of organisms,  inert suspended
 matter,  and  a  number of  various  algae  species.
 Effluent algal concentrations  were also estimated as
 volatile  suspended  solids to  overcome  the disad-
 vantages of the silts and clays washed from the filters
 during the early stages of the study.

 Laboratory filters

      Suspended  and  volatile suspended  solids con-
 centrations  applied  and  in  the  effluents  of  the
 laboratory filters are shown in Tables 11 and 12 for
 the  various  hydraulic loading rates and sand  sizes
 employed.  The  suspended and volatile suspended
 solids removals were  independent of the hydraulic
 loading rates employed. However, after the silt and
 clay were  removed, it appeared  that a general trend
 was developing  which indicated an increase in ef-
 fluent solids concentration as the hydraulic loading
was increased,  particularly when greater concentra-
tions of suspended solids were applied.

      Suspended solids removals were directly related
to the effective size of the sands at the higher solids
loading rates.  At  lower  loadings the  removals  ob-
tained  on  the 0.72 mm (.0283  inch)  sand were
approximately  equal  to the removals  obtained with
the 0.35 mm (.0137 inch) filters.

      Some algae  passed through the entire depth of
the filter  bed as verified by microscopic examination
of the effluents.  Borchart and O'Melia (1961), Ives
(1961), and Folkman  and Wachs  (1970) have re-
ported similar results.  Percent removal efficiencies
increased with the application of higher  algal con-
centrations, but more algae passed the filter than at
the  lowest  applied  concentration.  Flask bioassay
results are presented later in an attempt to study the
ability of those algae present in the effluent to grow.

Field filters

       Algal removals by  the  field filters during the
first year of operation are not shown because the silt
and clay  that was washed from the filters made
interpretation  of the results  impossible.  During the
second year of operation, algal concentrations were
Table 11.  Mean applied and effluent suspended solids concentration obtained in the laboratory study.
Loading
Period
I
II
III
Applied
Suspended
Solids
mg/1
31.0
13.7
46.3
Effluent Suspended Solids Concentrations, mg/1
Effective Size of Filter Media
0.17mm
Hydraulic
Loading Rates,
gpadx 10'3
100 200 300
5.53 7.93 11.2
3.96 4.80 6.05
1.86 1.93 5.33
0.35 mm
Hydraulic
Loading Rates,
gpadx 10"3
100 200 300
10.6 10.9 12.8
9.39 8.19 6.50
9.47 11.9 13.7
0.72 mm
Hydraulic
Loading Rates,
gpadx 10'3
100 200 300
13.6 11.9 11.0
11.0 8.15 7.28
16.6 15.9 16.5
Table 12.  Mean applied and effluent volatile suspended solids concentrations obtained in the laboratory study.
Loading
Period
II
III
Applied
Volatile
Suspended
Solids
mg/1
9.16
41.3
Effluent Volatile Suspended Solids Concentration, mg/1
Effective Size of Filter Media
0.17 mm
Hydraulic
Loading Rates,
gpadx 10'3
100 200 300
1.99 2.14 2.30
1.46 1.70 3.48
0.35 mm
Hydraulic
Loading Rates,
gpadx 10"3
100 200 300
3.38 3.33 3.40
7.28 7.14 8.31
0.72 mm
Hydraulic
Loading Rates
gpadx 10'3
100 200 300
3.85 4.00 3.17
10.1 13.1 13.2

-------
 56
Middlebrooks and Marshall
 estimated by measuring fluorescence2 and by deter-
 mining  suspended  and  volatile  suspended  solids.
 Linear   regression  analyses   of  the  solids  and
 fluorescence measurements produced a linear  rela-
 tionship significant at the 1 percent level.

      Influent  and effluent algal  concentrations ex-
 pressed  as  suspended solids produced by the  field
 filters are  summarized in  Table  13.  Volatile sus-
 pended solids concentrations are shown in Table 14.
 Data for the 0.17 mm effective size sand filter loaded
 at  900,000 gpad are  not presented  because of the
 relatively short period of operation. However,  algal
 removals  were  similar to those  obtained with the
 800,000 gpad loading rate.
                                                  Figure  4 shows the relationship  between  the
                                            hydraulic loading rates and the suspended and volatile
                                            suspended solids concentrations in the filter effluents
                                            for the 0.17  and 0.72 mm effective size sands. Algal
                                            removal apparently is independent of hydraulic load-
                                            ing rate  up to a loading of approximately 600,000
                                            gpad.

                                                  Effluent  suspended  solids  concentrations  for
                                            the months of May and June 1973 were much greater
                                            than  the concentrations in the effluents. This was
                                            attributed to the washing of fines and clay from  the
                                            filter  sand. Filter media were produced from pit  run
                                            sands containing large  quantities  of  fines and clays
                                            that were easily washed from the filters. Clean water
Table 13. Mean influent and filter effluent algal concentrations measured as suspended solids for each sand size
          and hydraulic loading rate studied during Phase II under field conditions.
•&
1
May
June
July
Aug.
Sept.
Mean
Monthly
Influent
Algae
Cone, as
Suspended
Solids
(mg/1)
5.0
6.5
29.8
44.2
25.2
Mean Monthly Effluent Suspended Solids Concentrations and Percent Removals
Effective Size Sand, .17 mm

400,000
/i %
mg/1 Red.
25.1 -
15.7 -
14.2 52.3
23.2 47.5
8.7 65.5
Hydraulic Loading Rate, gpad
500,000
/i %
mg/1 Red.
56.0 -
38.9 -
23.9 19.8
18.8 57.5
13.6 46.0
600,000
m^1 Ited.
20.9 -
14.5 -
20.2 32.2
30.0 32.1
8.8 65.1
700,000
mg/1 Red
21.4 28.2
34.5 21.9
20.5 18.7
800,000
/i %
m^ Red.
15.4 48.3
39.1 18.6
16.5 34.5
Effective Size Sand, .72 mm
Hydraulic Loading Rate, gpad
400,000
m^ Red.
31.7 -
11.6 -
17.9 39.9
33.0 25.3
12.4 50.8
500,000
/i *
"^ Red.
7.5 -
9.4 -
14.4 51.7
22.4 49.3
12.4 50.8
600,000
m«/1 Red
15.9 -
12.5 -
16.9 43.3
26.9 39.1
11.4 54.8
Table 14. Mean influent and filter effluent algal concentrations measured as volatile suspended solids for each
          sand size and hydraulic loading rate studied during Phase II under field conditions.
1
o
&
May
June
July
Aug.
Sept.
Mean
Monthly
Influent
Algae
Cone, as
Suspended
Solids
(mg/1)
2.2
3.6
23.6
34.3
22.3
Mean Monthly Effluent Volatile Suspended Solids Concentration and Percent Removals
Effective Size Sand, .17 mm
Hydraulic Loading Rate - gpad
400,000
•* Red.
2.2 -
1.6 55.6
4.5 80.9
5.1 85.1
2.7 87.9
500,000
"* R?d.
4.5 -
2.4 33.3
6.8 71.2
4.3 87.5
5.6 74.9
600,000
•*£
1.6 27.3
1.3 63.9
4.4 81.4
6.2 81.9
2.5 88.8
700,000
•*&
9.8 58.5
17.8 48.1
6.6 70.4
800,000
"* £.
5.6 76.3
13.7 60.1
8:4 62.3
Effective Size Sand, .72 mm
Hydraulic Loading Rate - gpad
400,000
"•"£
3.8 -
1.9 47.2
5.5 76.7
8.9 74.1
4.8 78.5
500,000
•*&.
1.5 31.8
1.7 52.8
4.9 79.2
12.1 64.7
2.1 90.6
600,000
m8fl M.
3.5 -
2.2 38.9
6.5 72.5
9.1 73.5
4.1 81.6
    2G. K. Turner Associates, Palo Alto, California.

-------
                              Stabilization Pond Upgrading with Intermittent Sand Filters     57
was not available to prewash the filters; therefore, it
was necessary  to wash with effluent. Much more
material was washed from the 0.17 mm effective size
sand because much of the fines were removed when
preparing the 0.72 mm sand by screening.

    At the 500,000 gpad hydraulic loading rate,
monthly mean volatile  suspended  removals  were
essentially equal for the 0.17 and 0.72 mm effective
size sands. Efficiencies fluctuated considerably from
one sand to  the other during the study period. But in
                       general the 0.17 mm effective size sand produced a
                       better quality effluent, particularly at the 600,000
                       gpad loading rate. Volatile suspended solids removal
                       efficiencies appeared to be improving with the age of
                       the filters, which is probably related to the washing
                       of debris from the units (Table 14).

                           Examination of  the  effluent suspended solids
                       concentrations  at various hydraulic loading  rates
                       shown in Figure 4 indicates that the 0.72 mm filters
                       were more efficient. However, the volatile suspended
   31
   30
   29
   28
   27
   26
   25
   24
   23
    18
 co!7
 916
 o15
 40 13
 p!2
 lit , |
 o II

 I'9°
 co  8
 to  7
     6
     5
     4
     3
     2
      I
     0
                                 /           N

                                'X—X AVERAGE
                                  EFFLUENT  S.S.
                                  0.17mm  FILTERS

                                 0—0 AVERAGE
                                  EFFLUENT  S.S.
                                  0.72mm FILTERS

                                 X—X AVERAGE
                                  EFFLUENT  VSS. -
                                  0.17mm  FILTERS

                                 0—0 AVERAGE
                                  EFFLUENT  VSS.
                                  0.72mm FILTERS
l
i
                                                                            II
                                                                              m
                                               c
                                             9$
                                               m

                                               m
                                             7o

                                             60
                                               r
                                             5S
                                             4?
                                               (O
                                             33
                                             2
                                             I
                  0.4        0.5        0.6         0.7         0.8
                 HYDRAULIC   LOADING  RATE,    mgpad
Figure 4. The  relationship between the suspended and volatile suspended solids concentrations and the
        hydraulic loading rates for the field filters.

-------
 58
Middlebrooks and Marshall
solids  data  show  just  the  opposite. Again,  this
discrepancy is explained by the washing of silt and
clay into the effluents.

      Laboratory bioassay results indicated that as
greater  concentrations of algae were applied to the
filters more viable cells passed through the 30 inches
of sand. As shown in Table 14, during August when
the algal  concentration  was  at  a  maximum,  more
algae as volatile suspended solids passed the filters.

      Although removal efficiencies  appeared to im-
prove with the age of the project, noticeable increases
in  removal efficiencies  as the  filters approached
plugging  did  not  occur.  This  is   counter  to the
laboratory results and cannot be readily explained
except by the variation normally occurring in solids
analyses.

Bacterial removal

      Stream standards recently adopted by the  State
of Utah include acceptable levels for both total and
fecal coliform organisms. The standards require that a
Class  "C" water have an arithmetic monthly mean
value  of total and fecal coliform that does not exceed
5,000  and 2,000 per  100 ml, respectively (Middle-
brooks etal., 1972).

Laboratory filters

      Total coliform removals  of  better than  86
percent were obtained with all three sand sizes but
due to the high applied counts (610,000 colonies/100
ml) the process was not able to meet the earlier noted
standards  in  this  particular  application. Even at
removals above 95 percent, lesser numbers of applied
coliforms would have to  be applied in order to meet
Class  "C" discharge standards. Calaway et al. (1952)
presented similar results.

     As the effective size of the sand was decreased,
coliform removals increased,  which agrees with the
findings of Calaway et al. (1952). But, at the hydrau-
lic loading rates  employed, total coliform removals
with the 0.72 mm (.0283  inch) sand were equal to
those  obtained  in  the  filters containing  0.35  mm
(.0137 inch) sand.

      Total coliform  removals were independent of
the hydraulic  loading rates employed,  but  it  is
doubted that this would  apply  at  higher loadings.
Calaway et al. (1952) found that at hydraulic loading
rates  approximately twice the rates used in this study
that bacteria penetrated the bed to much greater
depths. Therefore, more bacteria would be expected
to pass the filter at higher loading rates. However, at
the  hydraulic  loading  rates of   100,000  (153.4
m3/hectare-day), 200,000  (306.4  mS/hectare-day),
                                            and 300,000 (459.5 m3/hectare-day) gallons per acre
                                            per day, the coliforms removal was independent of
                                            loading.

                                                  Total plate counts for bacteria showed that the
                                            total  number of  bacteria in the filter influent was
                                            essentially unchanged by any of the three sand sizes
                                            studied. Also, hydraulic loading rate did not affect
                                            the numbers of bacteria present in the effluent.
                                            Field filters

                                                  In an attempt to interpret the bacterial removal
                                            results  obtained with  the laboratory  filters, total
                                            bacterial  counts were  performed  on  influent and
                                            effluent samples collected  from the 0.17 mm and
                                            0.72  mm  effective size sands with both loaded  at
                                            500,000 gpad (765.90  m3 /hectare-day). After the
                                            0.17  mm  filters  plugged and were cleaned, total
                                            bacterial counts were reduced by  99 percent three
                                            days after operation was resumed. But after 18 days
                                            of consecutive  loading,  the  same  filter  effluent
                                            contained  higher  concentrations of  bacteria than
                                            found  in  the influent.  This increase  in  effluent
                                            concentration with time of operation after cleaning is
                                            probably  attributable   to  two factors:  (1)  The
                                            bacterial population in the filter dies off during the
                                            drying period before removing the top few inches  of
                                            sand, and  (2) when operation is resumed, the clean
                                            sand serves as an efficient filter but as more and more
                                            bacteria penetrate  the  bed and  multiply, more are
                                            washed into the effluent.

                                                  The  intermittent  sand  filter  is  as  much a
                                            biological  as  a  physical process and is capable  of
                                            producing  large populations of bacteria within the
                                            filter bed. Treatment provided by  the  intermittent
                                            filter when used as a polishing device is accomplished
                                            throughout the entire  depth of the filter  and not
                                            limited to  the top 12 inches of the bed as implied in
                                            other studies.
                                            Effluent algal bioassays

                                                  As mentioned earlier, microscopic examination
                                            indicated that algae were passing through the filters.
                                            In an attempt to quantify the degree of passage, flask
                                            bioassays were  employed to assess the number  of
                                            viable algae in the effluents.

                                                  Algal growth, measured by an increase in light
                                            absorbancy,  showed a much greater response in the
                                            effluents obtained from the filters when receiving the
                                            highest algal  concentrations. Microscopic examination
                                            also showed higher concentrations of algae in  the
                                            effluents when the highest concentration of algae was
                                            applied.

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                                    Stabilization Pond Upgrading with Intermittent Sand Filters
                                              59
      All of the flask assays exhibited a lag period of
approximately  three  days  before  any significant
growth  occurred.  This lag or  acclimation  period
required for the algae to respond  to a new environ-
ment could be advantageous in that it would allow
the effluent to be transported  considerable distances
before an  effect could develop. This would allow
much of the algae that had passed  the filter to settle
out or be scavenged before growth could develop. If
in the  future it  becomes  necessary to meet more
stringent requirements, disinfection would eliminate
practically any surviving algal cells.

      Microscopic  examinations  of  the  field filter
effluents yielded  similar results, but flask bioassays
were not performed on the field filter effluents.

Filter conditions at plugging

Laboratory filters

      Plugging did not occur during the three original
loading periods  used in  the  laboratory study. To
obtain an estimate of the time required  for plugging
to occur, dosing was continued after Loading Period
III  without removing any  sand  from the beds and
using algal  suspensions from the model  stabilization
ponds. In order to estimate the plugging time under
the most severe conditions evaluated, it  was decided
to continue loading  at the Loading Period  III con-
centrations.

      A comparison of the effluent BOD5 values at
the  time of plugging with those  observed during
normal  operation showed no noticeable differences.
Effluent suspended solids concentrations at the time
of plugging were almost equal and near zero. This
indicates that breakthrough  does not  occur in an
intermittent sand filter. This finding is in agreement
with the work of Ives (1961) which showed that as
the specific deposit  increased, the filter coefficient
increased. Since the  hydraulic head above the sand
was  not  increased  to the  point  that  the filter
coefficient  was forced to decrease, the filters would
plug when the filter coefficient was at a maximum. If
it were practical to increase the head on  intermittent
sand  filters, breakthrough might occur  as in a high
rate or pressurized filter.

      Possibly  the  most  important  polishing
mechanisms in intermittent  sand  filtration is  the
surface mat or "schmutzdecke" which is composed of
suspended matter trapped on the surface  of the filter.
In this study the mat was composed primarily  of
algae that had been deposited upon the sand surface.

      Following Loading Periods I and II, the filters
did not seem  to have a predominant surface skin of
deposited suspended  matter. The top 2 inches (5 cm)
of sand  seemed to  be cemented together  by the
trapped  suspended  matter. Below this,  the  sand
particles, although  moist, were loose and apparently
unaffected by suspended matter. At no time was any
of the applied suspended matter detected  at depths
below  the top 2 -  3 inches (5 - 7.5 cm). Sand 2 - 3
inches (5 - 7.5 cm) below the surface  mat  examined
at the end of Loading Periods I and II  did not appear
to be affected by the applied algal suspensions. Once
this sand had become dry, it was hard to tell it from
new,  clean sand. As the individual filters began to
plug under the continued loadings following Loading
Period III, a more predominant skin was noted on the
sand surface. This  skin was, in  most cases, approxi-
mately one-sixteenth of an inch (1.6 mm)  thick and
covered the  entire  filter. During Loading Period III,
the 0.17 mm (.0067 inch) and the 0.35 mm (.0137
inch)  sands  had  surface  mats  that were  moist,
somewhat porous,  and  flat  or well conformed to the
sand surface. But the surface mat for the 0.72 mm
(.0283 inch) sand, although moist, was curled and
irregular. If a plugged filter is allowed to dry, the
surface mat will curl away from the top surface of the
sand. This indicates why raking or scraping has been
shown to extend the length of filter runs.


 Field filters


      At the higher hydraulic loading  rates employed
 in the field  study, the  surface mats for both the 0.17
 and 0.72 mm sands  followed essentially  the  same
 pattern as that observed in the laboratory. The 0.17
 mm  field  filters  operated approximately  the  same
 period of time  before plugging as reported for the
 laboratory  filters  (Table  15).  At  the loading rates
 employed (400,000 to 600,000 gpad) with the 0.72
 mm filters, plugging did not occur during the entire
 study. Based upon the results of both the laboratory
 and  field   studies,  it  appears  that much  higher
 hydraulic loading rates  can be employed with the
 0.72 mm filters. Higher hydraulic loading rates may
 result in more efficient solids removals with the 0.72
 mm filters because of  an increase in thickness of the
 mat that would accumulate on the surface and serve
 to trap  more of the algae and debris. More detailed
 economic studies of the operation of the filters needs
 to be completed, but it appears that the hydraulic
 loading rate for the 0.17 mm effective  size sand filters
 is limited to approximately 1 mgpad.

      The  0.17 mm filters were  cleaned by  raking
 only which accounts for the relatively  short periods
 of operation between the first and second plugging. If
 a conventional  cleaning by removing the top 2 - 3
 inches of sand had been performed, the second period
 of operation would have matched the initial period.
 However, because raking is an inexpensive method of
 extending  the  period  between  sand  removals,  it

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  60
Middlebrooks and Marshall
 Table 15.  Operational history of the field filters during the second year.


Filter
A4
A5
A6
A7
A8
C4
C5
C6
Date
Began
Loading
14 May
14 May
14 May
9 July
9 July
14 May
14 May
14 May
Date
1st
Plug
10 Aug
10 Aug
7 Aug
10 Aug
10 Aug
27 Septa
27 Septa
27 Septa
Ave.
SSmg/1
Applied
20.75
20.75
18.18
42.12
42.12
25.10
25.10
25.10

Type
Cleaning
Rake
Rake
Rake
Rake
Rake



Date
Loading
Resumed
21 Aug
21 Aug
21 Aug
21 Aug
15 Aug



Date
2nd
Plug
27 Sept3
27 Sept3
12 Sept
27 Sept3
7 Sept



Ave.
SS mg/1
Applied
27.57
27.57
29.58
27.57
34.99



Date
Loading
Resumed


24 Sept

7 Sept



Plug
Type 3r(j
Cleaning Hug


Rake 27 Septa

Rake 27 Septa



Ave.
SSmg/1
Applied


24.57

23.82



       Project ends.
 should be considered part of the  routine operating
 procedure.

 Time of operation

 Laboratory filters

      Figure 5 shows the effect of sand size and run
 time before  plugging occurs.  It is again evident that
 the finer sands produce the lowest effluent suspended
 solids concentrations. But it is  also quite apparent
 that this improved effectiveness  was attained at the
 expense  of  a reduction in operation time  before
 plugging.

      As the operating time increased, an increase in
 the suspended solids removal efficiency  was  noted.
                                            This is the same as noted by Ives (1961); i.e., as the
                                            specific  deposit increases,  the  filter coefficient  in-
                                            creases. Knowledge of this situation could prove to be
                                            valuable when operating a number of filters. Regular
                                            analysis  of the effluent for suspended  solids  would
                                            allow one to predict  when plugging was likely to
                                            occur.

                                                  Continued operation eventually caused plugging
                                            in  all filters. The results  show that the  0.72 mm
                                            (.0283  inch) filter  operated  175 consecutive days
                                            before plugging when loaded at a mean  algal con-
                                            centration of 51 mg/1, the 0.17 mm (.0067 inch) sand
                                            operated  68 consecutive days  at a mean  algal con-
                                            centration of 43 mg/1, and the 0.35 mm (.0137 inch)
                                            sand operated 99 consecutive days at an applied algal
                                            concentration of 45 mg/1.
  s
  Ul
     32
               A  0.1 7 mm
               O  0.35mm
               X  0.72mm
                                   PLUGGED
                                         PLUGGED
                                                                                           PLUGGED
                  _L
-I—I	L
J	1	L
                                                                           J	I	1	L
            15  22 29  36 43  50 51  64 71 78 65 92  99 106 113  120 127 (34 Wl (48 155  162 169  176 183  190
                                             CONSECUTIVE  DAYS
Figure 5. Observed times of operation under approximately 45 mg/I applied algae afforded by each sand size
         under laboratory conditions and the resulting effect  on effluent suspended solids concentration.
         (Loading Period in plus continuation.)

-------
                                      Stabilization Pond Upgrading with Intermittent Sand Filters
                                              61
      Table 16 shows in more detail the operational
results for all the filters during the continuation of
Loading Period  III.  Removing the  top  4  inches (10
cm) of sand from the filters after plugging, replacing
it with  new  sand,  and  putting  the  unit  back in
operation gives second performance periods generally
less than the original period. Longer operating periods
were expected with the lower hydraulic loading rates;
however,  the  0.17 mm (.0067 inch) and 0.35 mm
(.0137 inch) effective size filters at the lowest loading
rate were the first to plug.

      Figure   6  shows  that  the  highest  hydraulic
loading rate studied also allowed greater volumes of
applied water to pass the filter bed before plugging
occurred. As the figure shows, the result  was the same
for all the sand sizes studied.

Field filters

     As reported for the laboratory filters, the finer
sand produced a  superior effluent in all categories
measured,  and again this higher efficiency was at-
tained at the expense of a reduction in operation time
before plugging (Table 15).

     The  increase in suspended solids removal ef-
ficiency with  increasing operating time was observed
for the field filters,  but the effluent concentrations
appeared  to reach a limit and did not continue to
drop until  plugging occurred. The removal efficiency
increase with  time of operation in the field filters
appeared  to  be  more  closely  associated  with the
washing of fines from the filters. However, there is no
reason not to expect similar performances between
the laboratory and field filters, and it may be that the
lack of a  decrease in effluent  solids concentration is
attributable to a continuous washing of fines  from
the  filters  up to  plugging. After more than  one
summer  of operation, it  is likely that  a pattern as
observed in the laboratory would evolve in  the field.
Since the 0.72 mm field  filters did not plug during
the  summer of operation, it  is  possible  that the
laboratory study results would have been duplicated
had  the  project  continued, or had  the suspended
solids concentrations in the influent been increased.

      The 0.72 mm filters operated 137 consecutive
days without plugging when loaded at 0.4, 0.5, and
0.6  mgpad with  a lagoon effluent  containing an
average suspended solids concentration of 25 mg/1. It
was  not  surprising  that  these units  did not plug,
because laboratory  units  with  the same sand and a
hydraulic loading rate of 0.3  mgpad operated  175
days before plugging and  were dosed with a lagoon
effluent containing an average  suspended solids con-
centration of 51 mg/1.

     The consecutive days of operation for the 0.17
mm  filters  appear  to  be  directly  related to the
hydraulic loading rates. Figure  7 shows that up  to a
loading  rate  of  0.6  mgpad  the filters  operated
approximately 100  days before plugging when receiv-
ing a lagoon effluent containing a mean algal con-
centration  of  20 mg/1. During these 100  days, the
filter influent  algae concentration ranged from 4 to
51 mg/1. At loading rates  of 0.7 and 0.8 mgpad, the
0.17 mm filters operated only 32 consecutive days
when receiving a lagoon effluent containing a mean
suspended  solids  concentration of 42  mg/1, and a
range of concentrations varying between 30 and 50
mg/1. Because of the large  difference in the  mean
applied suspended solids concentrations, it is impos-
sible  to   compare  the performances  at  the  two
Table 16.  Results of the continuation of Loading Period III showing approximate period of operation by the
          laboratory filters using two cleaning methods.   Loading Period III began 11/1/72 at which  time
          all filters had the top 4 inches (10 cm) of sand removed and replaced with new sand.
Filter
SF11
SF12
SF13
SF21
SF22
SF23
SF31
SF32
SF33
Date
First
Plugging
4/14
4/27
4/25
12/26/72
12/27/72
3/5/73
12/18/72
1/28/73
1/17/73
Mean
Applied
SSto
Date
51.46
51.08
51.08
44.57
44.57
48.79
46.35
45.19
44.47
Type
Geaning
raking
scraping
scraping
raking
scraping
scraping
scraping
Date
Put
Back
in Use
4/20/73
1/10/73
1/10/73
3/8/73
1/10/73
1/30/73
1/30/73
Date
Second
Plugging
2/6/73
4/2/73
1/20/73
3/14/73
Mean
Applied
SS from
First
Plugging
51.76
53.59
63.56
Type
Geaning
scraping
raking
scraping
raking
Date
Put
Back
in Use
,2/8/73
1/30/73
3/21/73
Date
Third
Plugging
4/3/73

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 62
Middlebrooks and Marshall
hydraulic  loading rates, or to develop relationships
between  consecutive  days of  operation  and the
hydraulic loading rate.

     The  results are useful in estimating the number
of time during an algae growing season that the filters
must be raked and cleaned. During the early spring
and summer it is likely that the units will perform
effectively for the first 3 months, and removing the
top 2 to 4 inches of sand the units should perform a
minimum  of  one  month even  at very high algal
concentrations in the filter influent. It is possible that
the consecutive days of operation at the 0.7 and 0.8
mgpad hydraulic loading rates will match those at the
0.4 to 0.6 mgpad  rates when receiving  equal con-
centrations of influent algae. Length of operation and
the economics of maintenance will be answered in the
continuation of the project which will be conducted
on a prototype scale.

     When the filters plugged, the surface mat and
approximately  the top 2 inches  of sand were raked
and broken  up and  then placed in  service  again.
Figure  7 shows  that  there was  not  a relationship
between hydraulic loading rate and consecutive days
                                          of operation following  the  raking.  The 0.17  mm
                                          filters receiving 0.4,  0.5, and 0.7 mgpad of lagoon
                                          effluent  had loaded  for  38 days  and were  still
                                          operating after the first raking when  the project was
                                          terminated. The  filters receiving 0.6  and 0.8 mgpad
                                          plugged  within  22  days after  the raking. Mean
                                          suspended solids  concentrations  in  the  lagoon ef-
                                          fluent applied to all of the 0.17 mm  filters following
                                          raking were approximately equal, but the two filters
                                          that  plugged the second time did receive the highest
                                          concentrations of algae, 29.6 mg/1 for the 0.6 mgpad
                                          loading rate and 35.0 mg/1 for the 0.8 mgpad loading
                                          rate.

                                               Although direct comparisons of the lengths of
                                          performance at the various hydraulic loading rates are
                                          difficult, it is obvious that the length of runs for all of
                                          the sands and hydraulic loading rates are of adequate
                                          length to make intermittent sand filtration competi-
                                          tive  with all other processes available to upgrade
                                          lagoon effluents to meet new water quality standards.

                                               Figure 8 shows the volume of lagoon effluent
                                          applied  to the field  filters during the 137 days of
                                          operation. As reported for the laboratory filters, the
    1000
                                                                   (II)  -0.72mm, lOO.OOOgpad
                                                                   (12)  -0.72mm,200,000gpad
                                                                   (13)  -0.72mm,300,000gpad

                                                                   (21)  -0.35mm,100,OOOgpad
                                                                   (22)  -0.35mm.200,OOOgpad
                                                                   (23)  -0.35mm,300,OOOgpod

                                                                   (31)  —0.17mm, 100,OOOgpod
                                                                   (32)  —O.I 7 mm,200, OOOgpad
                                                                   (33)  — 0.17 mm,300,OOOgpod
                       50           100           ISO          200

                           DAYS OPERATED  UNTIL   PLUGGING
                                                                    2 SO
Figure 6. The relationship observed between the volume of water applied until plugging occurred under labora-
         tory conditions.                                               1-66-6

-------
                      Stabilization Pond Upgrading with Intermittent Sand Filters   63
    105
  CO
  § 99
  o
  O
  o
  O
  o
  a.
  0
  <
  o
   87

   81

   75

   69

   63

   57



   45
        •
CO

o
o
   33

   27

   81

   15
         X—X CONSECUTIVE DAYS OF OPERATION
        - UNTIL  FIRST PLUGGING

         X---* CONSECUTIVE DAYS OF OPERATION
         AFTER  RAKING FLOWING FIRST PLUGGING
        -^PROJECT TERMINATED BEFORE SECOND PLUGGING
               0.4       0.5       0.6      0.7
             HYDRAULIC   LOADING RATE, mgpod
                                                  0.8
Figure 7. Consecutive days of operation until plugging occurred in the 0.17 mm effective size sand filters at
     various hydraulic loading rates.

-------
 64
   Middlebrooks and Marshall
LU
UJ
13
0.
<
UJ
3
U.
O

2J
=3
 115000

 MOO 00

 105000

 100000

 95000

 90000

 85000

 SO 000

 75000

 70000

 65000

 60000

 550001-

 50000

45000

40000

35000

30000

25000

20000

 15000

 10000

 5000

     0
                      TOTAL VOLUME  OF SEWAGE         /
                   EFFLUENT  IN  LITERS APPLIED TO       /
                  EACH FILTER VS.   TIME  IN  DAYS   /
            10  20  30  40  50  60  70  80 90 100 110 (20 130 140
                     TIME      (DAYS)
Figure 8. Hie relationship observed between the volume of water applied until plugging occurred under field
       conditions. Discontinuity in the lines represents the rest and cleaning period following plugging.

-------
                                     Stabilization Pond Upgrading with Intermittent Sand Filters
                                              65
greatest volume of water was treated in a given time
span  by the filters  receiving  the  highest hydraulic
loading rates even when plugging occurred and it was
necessary to rest the filter and rake the surface before
returning it to operation.

Overall evaluation of the process

Ability to meet present state standards

      Intermittent  sand  filtration  was evaluated  to
assess its capability to produce an effluent that would
meet  the Utah Class "C" stream standards shown in
Table  17 when imposed as discharge standards. In a
system such as the Logan City wastewater stabiliza-
tion ponds, the intermittent sand filter would pro-
duce   an effluent  meeting   Class  "C"  discharge
standards 99  percent  of the time. The  0.17 mm
(.0067  inch)  effective  size laboratory  filters  only
produced an effluent with a mean BOD5 greater than
5 mg/1 (maximum effluent BODs equal 8 mg/1) when
loaded at the highest algal concentration and with an
influent BODs concentration averaging 36 mg/1. The
BODs concentration (36 mg/1) in the influent during
Loading Period  III was much higher  than normally
obtained from a well operated secondary wastewater
treatment plant. The  0.17 mm field filters produced
an effluent with a BOD, concentration of less than 5
mg/1  on all days of  operation when loaded at 0.6
mgpad or less. Effluent BOD5  concentrations for the
filter  loaded at 0.7 mgpad exceeded 5  mg/1 on only 2
days  out of 69 days of operation and the maximum
value  in the effluent was 6.7 mg/1. The average BOD,
in filter A7 effluent was 3.7 mg/1 for the entire period
of 69 days. A loading of 0.8 mgpad produced  an
effluent  of  slightly poorer quality but still  reduced
the BOD5 to a mean value of 4.1 mg/1. Thus,  most
properly operated  secondary treatment plants in the
state  would be able to meet Class  "C" discharge
standards with  the  addition of intermittent  sand
filtration. Even under such heavy  BOD5 loadings as
studied during Loading Period III in the laboratory,
reductions were greater than 80 percent for the 0.17
mm (.0067  inch) sand at all hydraulic loading rates.

      Middlebrooks et al.  (1972) reported  the  ef-
fluent characteristics of 11  existing wastewater treat-
ment plants in the State of Utah, some of which were
heavily  overloaded. Seven were trickling filters and
five  were wastewater stabilization ponds. Assuming
that equivalent' reductions in BOD5, suspended solids,
and coliform organisms would be obtained by inter-
mittent sand  filtration on all  types of  secondary
treatment plant effluents, seven of the eleven plants
would  be able to  meet the BOD5  standards for Class
"C" discharged waters by adding intermittent sand
filters.  If the overloading were  corrected and  the
plants  operated properly, all 11  plants could meet
Class "C" discharge standards by  installing inter-
mittent filters. Several of these plants were  serving
metropolitan areas,  and  it may not be feasible to
utilize  intermittent filters because of land limitations
and economic constraints usually  associated with
metropolitan areas.

     On the  basis of the mean total coliforms per
100 ml reported, five of the eleven Utah wastewater
treatment facilities would be able to meet Class  "C"
discharge standards  by the addition of intermittent
sand filtration. If the plants were not overloaded, in
all probability the coliform  requirements could be
met in  all  11  plants.  Again,  the  addition of a
disinfection step  would  aid materially  in  meeting
coliform  removal  requirements as well as eliminate
the  contributions  to a  downstream algae  bloom
problem.

      Class "C" discharge requirements for pH value
and dissolved oxygen are normally easily met by
secondary treatment, and the intermittent sand filtra-
tion of these effluents further refines effluents. The
pH  values  of the   Logan  lagoon  effluents  were
approximately equal to a value  of 9. When passed
through  the filters, the pH was reduced to values
approximately within the limits imposed. Six to  nine
mg/1 of dissolved oxygen were readily produced by
intermittent  sand filtration which also  meets  Class
"C" water standards.

Cost estimate

      A general approach was taken in the prepara-
tion of the cost estimates for an effluent polishing
intermittent sand  filter process. The estimates shown
 Table 17. Class "C" stream standards for the State of Utah (Middlebrooks et al., 1972).
                 Parameter
                     Concentration or Unit
   pH
   Total Coliform, Monthly Arithmetic Mean
   Fecal Coliform, Monthly Arithmetic Mean
   BOD,, Monthly Arithmetic Mean
   Dissolved Oxygen
   Chemical and Radiological
                   6.5 - 8.5
                   5,000/100 ml
                   2,000/100 ml
                   5 mg/1
                   >  5.5 mg/1
                   PHS Drinking Water Standards

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 66
Middlebrooks and Marshall
 for initial  plant construction outlays are of a higher
 degree  of reliability than the values estimated for
 operation.  Much  better  estimates  of  operational
 expenses  will be  afforded by the future prototype
 study.

      The  in-place total construction  cost  estimates
 were  prepared through the aid of a local consulting
 engineering firm. Thus, they  are representative of the
 outlay necessary to construct a typical  intermittent
 sand  filter process in the intermountain  area during
 1973.

      The  construction  and annual  operation  cost
 estimate shown for the 15 mgd Logan City facility is
 not as general in  nature as the other estimates. This
 estimate was  based upon two assumptions: One, the
 process would be located such that pumping of the
 applied effluent was not necessary; two, additional
 cost for land is not necessary as the final one and a
 half existing tertiary ponds would be drained and the
 polishing   filters  would  be  located  within  these
 boundaries. Also, the  15 mgd Logan  stabilization
 pond system  is presently the largest existing facility
 of this type in Utah. A cost estimate  for  this facility
 will then provide an expense evaluation for the entire
 range of stabilization pond systems in Utah.

      A large difference was found between locally
 available filtering media and specially prepared media,
 so an economic evaluation of the two types of media
 was made. In this case, the 0.17 mm (.0067 inch) size
 media was locally available and the 0.35  mm (.0137
 inch)  and the  0.72 mm (.0283  inch)  sizes  were
 specially prepared. The  specially prepared  media in
 this area was found to be more than five  times more
 costly than the locally available media. Based on the
 assumptions  that  the 0.17 mm (.0067 inch) locally
 available media  was approximately two and one-half
 times more  costly to  operate  than  the 0.72  mm
 (.0283 inch) media, the 0.17 mm (.0067 inch) media
 was found to be the economic choice for a 1 mgd and
 the 15 mgd existing lagoon system.
                                                   The construction costs determined in Estimates
                                             1 through 4, Table 18, reflect a paired bed operation
                                             designed at  300,000 gpad (459.5 m3/hectare-day)
                                             and  800,000 gpad (1225.4 m3/hectare-day) and the
                                             application of the effluent to the filter in less than 90
                                             minutes. It was assumed that in a municipal construc-
                                             tion effort  such  as  this, at least 75  percent  of the
                                             construction cost would be funded  by federal aid.
                                             Also, costs without federal assistance are reported.

                                                   The construction costs  for Estimate  5, Table
                                             18, reflect an optimum design situation for a  1  mgd
                                             facility.  Conditions   considered  optimum  are
                                             minimum bed area  operated  under scheduled rota-
                                             tion, no pumping required for dosing, locally avail-
                                             able media,  and plastic bed liners not required. Under
                                             these conditions with the aid of federal funds, a filter
                                             process designed  at  800,000  gpad  (1225.4 m3/hec-
                                             tare-day)  for a   1  mgd  facility  would  cost the
                                             community $14,500 to construct.

                                                   Sand  or media expense is approximately 25
                                             percent  of  the  total  construction cost. Also, the
                                             plastic liner for the bed is  approximately  25 percent
                                             of the total construction  cost. Whether  or not the
                                             liners are a required  expense in constructing effluent
                                             polishing intermittent sand filters will depend  on the
                                             specific conditions  and  regulations  governing  each
                                             location and installation of this process. As shown in
                                             Estimate 5,  considerable  savings  are made by not
                                             installing the plastic bed liners. In rural  areas,  land
                                             costs for this process are less than 5 percent of the
                                             total construction costs.

                                                   Costs  per million gallons of effluent produced
                                             are  shown in Table 18 with and without federal
                                             assistance. Without federal funds, the costs are greatly
                                             increased.  The  effect  of  an optimum  condition
                                             application is noted by the cost  of $16 per million
                                             gallons (Table 18). Combined effects of larger scale
                                             operation and specific application, which in this case
                                             held conditions near optimum, are noted by the $15
                                             per million gallons cost for the Logan City facility.
Table 18.  Estimated cost per million gallons of filtrate  produced by various designs of an effluent polishing
          intermittent sand filter process.
Application
conditions
General (Estimate 1)
General (Estimate 2)
General (Estimate 3)
Specific (Estimate 4)
Optimum (Estimate 5)
Design
Flow
Rate
1 mgd
1 mgd
1 mgd
15 mgd
1 mgd
Design
Hydraulic
Loading
Rate
0.3 mgad
0.8 mgad
0.8 mgad
0.6 mgad
0.8 mgad
Effective
Sand Size
.17mm
.17mm
.72mm
.17mm
.17mm
Cost With Cost Without
Federal Federal
Assistance Assistance
$/ 1 0 3gallons $/ 1 03 gallons
$47
$33
$46
$15
$16
$115
$ 61
$145
$ 48
$ 26

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                                      Stabilization Pond Upgrading with Intermittent Sand Filters      67
Finally, for the general applications estimates when a
1 mgd plant constructed with 0.17 mm (.0067 inch)
effective size locally available  media is compared to
one constructed of a specially  prepared  media.  The
cost  of  operation  and media  using  the 0.17  mm
(.0067  inch)  effective  size  sand designed  for  a
hydraulic loading rate of 0.3 mgd is essentially equal
to the operation and media costs for the  coarser  0.72
mm (.0283 inch)  effective size specially produced
sand.  If  the  0.72  mm (.0283  inch) effective size
specially  prepared  sand filter were  designed  using
much higher loading rates and optimum conditions,
the  cost  per million gallons for  this  particular  sand
would decrease to  the point where it would become
economically competitive.

      From the present understanding of the opera-
 tion of effluent polishing intermittent sand filters, a
 cost ranging between $15 to $47 per  million gallons
 can be assumed to be  representative of  this process.
 Table 19 lists alternative methods to meet Class "C"
 water standards and their estimated costs as reported
 by Middlebrooks et al. (1972). Based on  these values,
 the   earlier stated  cost  for  an effluent  polishing
 intermittent sand filter process is quite  competitive.
 There  are many avenues of  approach  that may  be
 taken to produce  the same high quality effluent of
 this  process  at even lower expense. Coupling this
 possibility  with the fact  that a majority  of the
 existing wastewater effluents in Utah can be upgraded
 to meet Class "C" water standards by the addition of
 this  process, intermittent  sand filtration of waste-
 water effluents has been found to be an economically
 feasible method of wastewater effluent polishing.


           Summary  and Conclusions

       The  major  objective  of  this  study was  to
 evaluate the  performance of the  intermittent sand
 filter  and to determine if it was capable of upgrading
 existing wastewater treatment plants  in the State of
 Utah to meet Class "C" water quality standards.
Table 19. Cost of alternative methods of polishing
          wastewater effluents (Middlebrooks et al.,
          1972).
 Method
Cost per
106 gal.
 Chemical treatment (solids contact)          $60-130
 Granular or mixed media filtration w/chem      $50
 Dissolved air flotation                        $110
 Electrodialysis                               $200
 Microstraining                                $18
     Hydraulic loading rate was found to have little
effect  on  any  of the parameters  studied  in  the
laboratory  portion of the study. In the field  experi-
ments  at  much higher hydraulic loading rates  and
varying algal concentrations, suspended and volatile
suspended  solids removal appeared to  decrease with
an increase in hydraulic loading. Although significant
quantities  of applied algae  were removed by filtra-
tion, cells  were found to pass the entire bed depth.
Sand size  was found to have a general effect on the
quality of  the effluent produced by filtration. Sand
size was also found to  be related  to the  time of
operation before plugging occurred. It was concluded
that intermittent  sand  filtration  was  capable of
upgrading  a majority of  the  existing wastewater
effluents in Utah to  meet Class "C"  water standards.

     In addition to  the above, the following general
observations and conclusions were made:

       1.  Smaller  effective  size  sands  better oxidize
nitrogen compounds.

       2.  Hydraulic  loading rate has little effect on
ability  of  the sand  filter to oxidize nitrogen at the
loading rates studied in the laboratory.

       3.  The nitrogen form which is being oxidized
is principally that of ammonia.

       4.  After establishing  equilibrium with the
media, intermittent sand  filters do not remove  a
significant quantity of  dissolved phosphorus  com-
pounds.

       5.  Hydraulic loading rate has little effect on
BOD5  removal when secondary wastewater effluent is
applied to  intermittent sand filters with bed depths of
30 inches.

       6.   BOD removal increased as  the effective size
of the sand decreased. The 0.17 mm effective size
sand  filters  produced a project low  mean effluent
BOD5   concentration of 1.6 mg/1 at the 0.4 mgpad
loading rate and  a high value of  4.1  mg/I at 0.8
mgpad. The project mean  effluent BOD5 concentra-
tion for the 0.72 mm effective size sand filters ranged
from 5.0 to 5.5 mg/1 for the 0.4,0.5, and 0.6 mgpad
hydraulic loading rates.

        7.  BOD5   removal   was  independent of the
applied BOD value  at the concentrations studied in
the laboratory.

        8.  Viable algal cells passed the entire depth of
all the filter sands studied.

        9.  Hydraub'c loading rate did not affect the
algae  or suspended solids  removal  efficiency at the

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 68    Middlebrooks and Marshall
 100,000 (153.4  m3/hectare-day), or 200,000 (153.4
 m3/hectare-day), or 300,000 (454.9 m3/hectare-day)
 gallons per acre-day loadings employed in the labora-
 tory study. The effects of hydraulic loading rate on
 SS removals  in  the  field studies were  inconclusive
 because of the large  quantities of fines washed  from
 the filters, but volatile suspended solids removals did
 indicate a reduction in removal efficiency  as the
 hydraulic loading rate was increased.

      10. Smaller effective size sands  produced bet-
 ter algal or suspended and volatile suspended solids
 removals.

      11. Sand  size  was not a significant  factor in
 algal  removal at applied algal concentrations of 15
 and 30 mg/1,  but was significant when  the concentra-
 tion  was  increased   to 45-50  mg/1   in  both  the
 laboratory and field filters.

      12. Intermittent sand filtration produced a 90
 percent reduction in  the total coliform count in the
 laboratory filters.

      13. Coliform removal was  independent of the
 hydraulic loading rates employed in the laboratory
 filters.

      14. Total bacterial counts  as measured by the
 standard plate count  apparently was not reduced by
 any of the sands studied.

      15. Filter  plugging causes no  decline  or im-
 provement in the effluent BOD at or near the time of
 plugging.

      16. Immediately  before plugging occurred in
 the laboratory  filter, the  filter  effluent suspended
 solids  concentrations were  approximately  zero.  As
 the filter operates with time, the  suspended solids
 removal efficiency  increases reaching a maximum
 point at the time of  plugging. This did not occur in
 the field, but if fines were  washed from the  filter
 before placing it in operation, it is likely that a similar
 pattern would occur.

      17. At  hydraulic loading rates  of 0.4  to 0.6
mgpad  the  0.17 mm effective size sand filters will
 operate approximately  100 days before cleaning is
required when receiving a lagoon effluent containing
a mean suspended solids concentration of 20 mg/1.

      18. At loading rates of 0.7 and 0.8 mgpad the
0.17  mm  filters will  operate 32  consecutive  days
before  requiring cleaning when receiving lagoon  ef-
 fluent containing a mean suspended solids concentra-
tion of 42 mg/1.
      19. Laboratory filters containing sands of 0.72
mm  effective  size  operated  175 consecutive  days
before  plugging  when dosed with a lagoon effluent
containing a mean suspended solids concentration of
51 mg/1 at a rate  of 0.3 mgpad.

      20. Field filters containing 0.72 mm effective
size   sand  operated  137  consecutive  days  before
terminating the study without plugging when loaded
at 0.4, 0.5, and 0.6 mgpad with a lagoon effluent
containing a mean suspended solids concentration of
25 mg/1.

      21. If operated and loaded properly, all exist-
ing wastewater treatment plants in the State of Utah
could be upgraded by intermittent sand filtration to
meet Class "C" state standards.

      22. Based  upon current cost figures it appears
that  an effluent polishing  intermittent  sand filter
process can be constructed  and operated for a cost
ranging between  $15  to $47 per million gallons of
filtrate.

                 Literature Cited

American  Society  of Civil Engineers and Federation of
     Sewage and  Industrial Wastes Association.  1959. A
     Joint Conference on Sewage Treatment Plant Design.
     New York.

Borchart, Jack A., and  Charles R. O'Melia. 1961. Sand
     filtration of algal suspensions. Journal of the American
     Water Works Association 53(12):1493-1502.

Calaway, W. T., W.  R. Carroll, and S. K. Long. 1952.
     Hetetotiophic bacteria encountered  in intermittent
     sand filtration of sewage. Sewage and Industrial Wastes
     Journal 24(5):642-653.

Folkman, Yair, and Alberto M. Wachs. 1970. Filtration of
     Chtorella through dune-sand. Journal of the Proceed-
     ings  of the  American  Society  of Civil Engineers,
     Sanitary Engineering Division, 96(SA3):675-690. June.

Furman,  Thomas  De  Saussure, Wilson  T. Calaway, and
     George  R. Grantham. 1949. Intermittent sand filters-
     multiple loadings. Sewage and Industrial Wastes Journal
     27(3):261-276.

Grantham, G. R., D. L. Emerson, and A. K.  Henry. 1949.
     Intermittent sand filter studies. Sewage and Industrial
     Wastes Journal 21(6):1002-1015.

Ives,  Kenneth J, 1961. Filtration of radioactive algae. Journal
     of the  Proceedings of the American  Society  of Civil
     Engineers,  Sanitary  Engineering Division, 87(SA3):
     23-37. May.

Marshall, G. R., and E. Joe Middlebrooks.  1974. Intermittent
     sand filtration to  upgrade existing wastewater treat-
     ment facilities.  PRJEW115-2, Utah  Water  Research
     Laboratory, College of Engineering, Utah State Univer-
     sity, Logan, Utah.

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                                          Stabilization Pond Upgrading with Intermittent Sand Filters      69
Middlebrooks, E. Joe, James H. Reynolds, Gerald L. Shell,
     and Norman  B. Jones. 1972. Modification of existing
     wastewatei treatment plants in Utah to meet Class "C"
     water quality standards. Joint Meeting, Intel-mountain
     Section, American Water Works Association and Utah
     Water Pollution Control Association.  September 23-24,
     Provo, Utah. 32 p. (Mimeographed).

Pincince, Albert B., and Jack E. McKee. 1968.  Oxygen
     relations  in intermittent sand  filtration. Journal  of
     Proceedings of the American Society of Civil Engineers,
     Sanitary  Engineering   Division,  89(SA6):1093-1119.
     December.
Solorzano, L. 1969. Determination of ammonia in natural
      waters by the phenolhypochlorite method. Limnology
      and Oceanography 14:799-800.
Standard Methods for the Examination of Water and Waste
     Water,  Thirteenth  Edition. 1971.  American  Public
     Health Association, New York. 874 p.
Strickland,  J. D. H., and T. R. Parsons. 1968. A practical
     handbook  of seawater  analysis.  Fisheries  Research
     Board of Canada, Ottawa, Bulletin Number 167. 311 p.

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                       INTERMITTENT SAND FILTRATION TO UPGRADE

                         LAGOON EFFLUENTS-PRELIMINARY REPORT
                                   J. H. Reynolds, S. £ Harris. D. Hill,
                                   D. S. Filip, andE. J. Middlebrooks1
                  Introduction
Nature of the problem

      Approximately   90  percent  of  the waste-
water  lagoons  in the  United States are located in
small communities  of 5,000 people or  less. These
communities, many with an average daily wastewater
flow rate of only 175,000-200,000 gallons, do not
have the resources to  keep men  at the lagoon sites
throughout  the day.  A high degree of  technical
knowledge is usually  lacking in these  communities.
Often  only  periodic  inspection  or  maintenance  is
carried out  by the  general  municipal  employees.
Therefore, the  development of a relatively inexpen-
sive, low operation and maintenance method for pol-
ishing  lagoon effluent to meet the requirements of
PL 92-500 is needed.

      There  are many sections of the country that are
still fortunate to be surrounded by large areas of open
and  relatively inexpensive land. It was originally due
to this  reason  that  many  of these  communities
adopted  waste stabilization  lagoons as a means of
wastewater   treatment.  Although   this  treatment
scheme requires large  tracts of land, the important
consideration was that it gave a satisfactory effluent
for minimum cost and maintenance. But now a better
quality effluent is necessary. If small cities and towns
are to economically produce a higher quality effluent,
some form  of treatment must be utilized that will
continue  to  take  advantage  of  the large  areas of
relatively inexpensive  land surrounding  these  com-
munities. One  method of treatment that capitalizes
on the availability of large land areas is intermittent
sand filtration.

      In  most areas of the country where intermittent
sand  filtration  has  been  used,  the  lack  of  large
      J.  H.  Reynolds is Assistant Professor of Civil and
Environmental Engineering, Utah  Water Research Labora-
tory; S. E. Harris and D. Hill are graduate students in Civil
and Environmental  Engineering, D. S. Filip is Research
Biologist,  Utah  Water  Research  Laboratory;  and  E.  J.
Middlcbrooks is Dean of Engineering, Utah State University,
Logan, Utah.
inexpensive tracts of land was a major factor con-
tributing  to  a decline  in use.  Thus, the relatively
inexpensive tracts of rural land available  near many
lagoon sites is a  definite asset. Intermittent sand fil-
tration becomes even more economically attractive if
filter media are available locally.

Objectives

      The objective of this study was to evaluate and
compare the performance of a full-scale intermittent
sand filter with results obtained using laboratory and
pilot field  scale intermittent sand filters as a polishing
process that would upgrade existing wastewater treat-
ment  facilities.   Particular  attention was directed
toward ascertaining the  effectiveness of the inter-
mittent sand filter as a means of removing the highly
variable  quantities of algae  present  in stabilization
ponds during the warmer months of the year.  The
ultimate objective is to develop design criteria  for
intermittent  sand  filters  that  will  consistently
produce an effluent of a quality that would meet
stringent water quality standards.
             Previous Investigations

Historical background

      Use of intermittent sewage filtration began in
this country in the late nineteenth century. The first
intermittent sewage filters were put in use in 1889 in
Massachusetts. For many years their use was centered
in the New  England area. By  1945, approximately
450 intermittent filter plants were in operation in this
country. But later reports showed a  decrease to 398
in use by 1957. It was also noted (ASCE and FSIWA,
1959) that 94  percent of those still in use by  1957
were  serving communities with  populations under
10,000.

      The intermittent sewage  filter has  long  been
known  to have the  ability  to  produce effluents of
relatively high  quality as did the slow sand filter for
culinary waters. The decline of intermittent sewage
filters was related to the same factors that caused the
decline  of slow sand filters-an increase  in quantity of
                                                                                                   71

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72     Reynolds, Harris, Hill, Filip, Middlebrooks
water to be filtered due to a growing population, and
to the rising costs of land.

     Intermittent sand filtration,  as  noted earlier,
began  in the New  England area  of  this  country.
Located  in  Lawrence,  Massachusetts,  was  the
Lawrence Experiment  Station at which many of the
first studies on  intermittent  sand filtration were
accomplished. This region of the country was ideal
for the application of such a process as intermittent
sand infiltration.  Many small  rural communities were
developing to the point that it was necessary to treat
their  wastewater  at  a  central plant  which  was
economical  for the  small town. Land to build the
filters upon was  readily available at reasonable rates
and there was also abundant quantities  of well graded
bank run sand available. These conditions encouraged
efforts  in  research at the  Lawrence  Experiment
Station to improve the intermittent sand filter. As a
result of this experimentation and success, the use of
intermittent sand  filters increased.

     Following World  War II,  many  people found
the mild climate and sparsely populated land of
Florida an ideal  place  to live  following retirement.
Large numbers of small  residential centers  such as
isolated tourist courts,  motels,  trailer parks, drive-in
theaters, consolidated schools,  and  housing develop-
ments began to spring up all over Florida. It was soon
realized  that an  economic method of sewage treat-
ment   would  be  necessary  for these  small  com-
munities. Thus, the study  of  intermittent sand filtra-
tion was undertaken at the University of Florida at
Gainesville, (Calaway  et  al., 1952; Furman et al.,
1949;  and  Grantham  et  al.,  1949).  Much  of the
modern day knowledge on intermittent  sand filters
has come out of the studies carried out at Gainesville.
All of this work was concentrated on treating raw or
primary effluent wastewaters.  A detailed review  of
the  University  of Florida study and  other  in-
vestigations dating back to  1908 has been presented
by Marshall and Middlebrooks (1974).

Laboratory and pilot scale studies

      Marshall  and  Middlebrooks  (1974) evaluated
the performance  of laboratory  and pilot scale inter-
mittent  sand filters to determine if the process was
capable  of upgrading  existing  wastewater treatment
plants in the State of Utah to  meet Class "C" water
quality standards (BOD ^ 5 mg/1, pH = 6.5-8.5, total
coliform  g  5,000/100 ml,  fecal   coliform  ^
2,000/100 ml, and D.O. > 5.5 mg/1). Effective size of
the sand, hydraulic loading rate, and algal concentra-
tions were  the variables  studied. Hydraulic loading
rate was found  to  have  little  effect on any of the
parameters  studied in the laboratory portion of the
study.  In the field experiments  at   much higher
hydraulic loading rates and varying algal concentra-
tions,  suspended  and  volatile  suspended solids re-
moval appeared  to decrease  with an  increase in
hydraulic loading. Although  significant quantities of
applied algae were  removed by filtration, cells were
found to pass  the  entire bed  depth. Sand  size was
found to have  a  general effect on the quality of the
effluent  produced by  filtration. Sand size  was also
found to be related to the time of operation before
plugging occurred.  BOD removal  increased as the
effective size of  the sand decreased. The 0.17 mm
effective size  sand  filters produced a project low
mean effluent BOD5 concentration of 1.6 mg/1 at the
0.14 mgad loading rate and a high value of 4.1 mg/1 at
0.8 mpd.  The project mean  effluent BOD5  con-
centration for the 0.72 mm effective size sand filters
ranged from 5.0 to 5.5 mg/1  for the 0.4, 0.5, and 0.6
mgad hydraulic loading rates. Hydraulic loading rate
did not affect  the algae or suspended solids removal
efficiency at the  100,000 (153.4 m3/hectare-day), or
200,000 (306.8 m3/hectare-day), or 300,000 (454.9
m3/hectare-day)  gallons per acre-day loadings em-
ployed  in  the  laboratory  study.  The effects of
hydraulic loading rate  on SS  removals in  the  field
studies   were   inconclusive   because  of  the  large
quantities  of  fines washed  from  the  filters, but
volatile  suspended  solids  removals did indicate a
reduction in  removal  efficiency  as the hydraulic
loading rate was increased. Immediately before plug-
ging  occurred  in the  laboratory  filter, the filter
effluent  suspended   solids  concentrations  were
approximately  zero. As the filter operated with time,
the suspended solids  removal  efficiency  increased
reaching a maximum point at  the time of plugging.
This  did not occur in the  field,  but if fines were
washed from the  filter before placing it in operation,
it  is  likely  that  a  similar pattern  would occur. At
hydraulic loading rates of 0.4  to 0.6 mgad  the  0.17
mm effective size sand filters were found to operate
approximately  100 days before cleaning is  required
when receiving a  lagoon effluent containing a mean
suspended solids concentration of 20 mg/1. At loading
rates  of  0.7 and  0.8 mgad the  0.17 mm filters will
operate 32 consecutive days before requiring cleaning
when receiving lagoon effluent containing  a mean
suspended  solids  concentration of  42 mg/1. Based
upon  current cost figures it appears that an effluent
polishing  intermittent  sand  filter  process   can be
constructed  and operated for a cost  ranging  between
$15 to  $47 per  million gallons of filtrate. It was
concluded that intermittent sand filtration  was cap-
able of upgrading a majority of the existing waste-
water effluents in  Utah to  meet  Class "C" water
standards.

            Experimental Procedures

Experimental facility

      The experimental facility is located  at the
Logan Municipal  Sewage Lagoons as shown in Figure
1.  The facility consists of six, 25 ft x 36 ft (900 sq ft

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                                       Intermittent Sand Filtration to Upgrade Lagoon Effluents
                                              73
 Figure 1.  Location map.
surface) intermittent sand filters. A cross section of a
typical filter is shown in Figure 2. The soil embank-
ment around each filter is constructed of bank run
granular fill material. Each filter contains 1 foot of
graded gravel (1/4 in max. diameter to 1 1/2 in max.
diameter) and 3 feet of pit run concrete  sand. The
sand  has  an  effective  size  of 0.170  mm  and  a
uniformity coefficient of 9.74. A sieve analysis of the
sand is shown in Table 1.  The filters are lined with a
vinyl liner (10 mm) to prevent infiltration of subsur-
face groundwater or exfiltration  of filter influent.
The filter construction provides 3 feet of freeboard
above the sand surface.
      The filters  are  loaded  once daily  with either
tertiary  or  secondary  effluent  from  the  Logan
Municipal  Sewage  Lagoon  system  (depending  on
Table 1. Sieve analysis of filter sand.3
U.S. Sieve
Designation
Number
3/8"
4
10
40
100
200
ae = 0.170 mm;
Size of
Opening
(mm)
3/8"
4.76
.
0.42
0.149
0.074
; u = 9.74.
Percent
Passing
(%)
100.0
92.1
61.7
27.0
6.2
1.7

which effluent  has  the  highest  suspended  solids
concentration). The hydraulic loading of each filter is
accomplished  in less  than 30 minutes. The loading
rates being studied are 0.2, 0.4, 0.6,0.8,1.0, and 1.2
mgad. When the total amount of applied influent to a
filter  does not drain  through the filter in 24 hours,
the filter is considered to be plugged and is taken out
of service and cleaned.

      Geaning is accomplished  by removing the top
1/2 to 2 inches of filter sand. The sand is stockpiled
and will eventually be washed. The  organic washing
from  the sand will be recycled to the primary lagoon
and the clean  filter sand will be replaced in the filter.

Sampling and analyses

      Samples  of  filter  influent  and effluent are
collected  and  analyzed  for suspended solids  and
'volatile suspended  solids  three times a week, bio-
chemical oxygen demand  (BODc) once a week and
chemical oxygen demand (COD), total phosphorus,
orthophosphorus ammonia, nitrite, pH, temperature,
and dissolved oxygen are monitored  once each week.
The effluent samples  are collected 2 hours after each
filter  is loaded. The procedure employed for each
analysis is shown in Table 2.
                                                                 Results and Discussion
                                                     General
                                                          Data collection  began on July 12, 1974, after
                                                     the filters had been "washed" to remove dirt and fine

-------
 74    Reynolds, Harris, Hill, Filip, Middlebrooks
inorganic  material  generated  by the  filter con-
struction.  Data  collection continued  until  a filter
plugged  and was  taken  out  of service. The data
presented in this report were collected during the first
experiment period (July  12,  1974, to  August 22,
1974) of the project. All data collected during the
report period Jiave been averaged and  these average
values are  reported  in Table 3. The  number of
individual data points averaged depends on the length
  of the particular filter run. However, in no case were
  fewer than three  data  points used  to obtain an
  average value.

  Algae

       The characteristics of the influent algal popula-
  tion are shown in Table 4. The predominant algae are
  small coccoid blue-green, which have been tentatively
                    -LINER
        INFLUENT  
-------
                                      Intermittent Sand Filtration to Upgrade Lagoon Effluents
                                                                  75
Table 2. Procedures for analysis performed.
        Analysis
             Procedure
     Ref. No.
Biochemical Oxygen Demand
Chemical Oxygen Demand
Suspended Solids
Volatile Suspended Solids
Total Phosphorus
Orthophosphorus
Ammonia
Nitrite
Nitrate

Dissolved Oxygen
Temperature
pH
Standard Methods
Standard Methods
Standard Methods
Standard Methods
EPA Methods
Strickland & Parsons (Murphy-Rfley Technique)
Solorzano (Indophenol)
Strickland and Parsons (Diasotization Method)
Strickland & Parsons (Cadmium-Reduction
   Method)
Standard Methods
Standard Methods
Standard Methods
APHAetal., 1971
APHAetal., 1971
APHAetal., 1971
APHAetal., 1971
EPA, 1971
Strickland & Parsons, 1968
Solorzano, 1969
Strickland & Parsons, 1968
Strickland & Parsons,, 1968

APHAetal., 1971
APHAetal., 1971
APHAetal., 1971
Table 3. Average of all samples collected during the experimental period.

Loading
Rate in
mgad
Influent
0.2
0.4
0.6
0.8
1.0
1.2

BOD5
mg/1
8.1
2.4
1.7
2.3
3.5
2.8
4.3

COD
mg/1
69.7
42.1
27.8
27.5
40.6
39.8
49.7

Sus-
pended
Solids
mg/1
26.1
6.8
3.7
5.5
7.2
7.1
4.8
Volatile
Sus-
pended
Solids
mg/1
16.9
0.9
1.0
1.4
0.7
1.0
0.8

Total
Phos-
phorus
mg/1
2.082
1.756
1.595
1.767
1.863
1.980
1.776

Orthcc
Phos-
phate
mg/1'
1.754
1.695
1.458
1.644
1.683
1.717
1.657

NH3-N
mg/1
2.469
0.166
0.197
0.293
0.322
0.486
0.541

N02-N
mg/1
0.025
0.083
0.025
0.055
0.090
0.160
0.154

N03-N
mg/1
0.100
4.670
4.936
4.985
4.372
3.664
3.383

PH
8.8
8.0
8.1
8.0
7.9
8.1
8.1

Temp.
°C
23.2
23.6
24.4
23.7
25.0
25.1
24.0

Dis-
solved
Oxygen
mg/1
4.2
6.2
6.1
5.9
5.7
5.0
4.8

Algal
Mass
Removed
Kg
a
21.988
21.538
26.108
18.783
19.008
12.336
     aNot applicable.
identified as Aphanocapsa sp. The concentration of
this  particular alga  has  increased rapidly in recent
weeks. The unknown unicellular green alga reported
in Table  4  has  been tentatively identified  as the
palmelloid state of Chlamydomonas sp.

      The algal population is  much  different than
that employed in previous laboratory  and field scale
intermittent sand filter  experiments  (Marshall and
Middlebrooks, 1974).  The algal population used in
earlier  experiments  was  predominantly
Chlamydomonas sp.

Length of filter run

      The length of filter run for  each hydraulic
loading  rate is shown in Figure 3. As expected the
length of filter run is directly related to the hydraulic
                      Table 4. Algae present in influent.
Alga
Blue Green Coccoid
Oscillatoria sp.
Mcrocystis sp.
Navicula sp.
Unknown Pennate
Pediastrum sp.
Schoideria sp.
Unknown Unicellular
Green
Unknown Euglenoid
Total
Zooplankton
Cells per ml
Aug. 6
33,920
53
0
8,480
1,272
1,696
53
0

53
45,527
178
Aug. 9
92,928
132
0
5,016
1,696
0
66
0

66
99,904
123
Aug. 14
100,188
858
330
17,688
2,508
0
396
1,254

330
123,552
186

-------
 76     Reynolds, Harris, Hill, Filip, Middlebrooks
 loading rate. The length of filter run varied from 14
 days with a hydraulic loading rate of 1.2 mgad to 42
 days with a hydraulic loading rate of 0.2 mgad.

      These lengths of filter run are somewhat shorter
 than those reported earlier (Figure 4) for laboratory
 and pilot scale filters (Marshall and  Middlebrooks,
 1974).  However,  the  average influent suspended
 solids concentration for previous investigations was
 20.0 mg/1  while for the present study the average
 influent  suspended solids concentration  was 26.1
 mg/1 with a range of 10.9 mg/1 to 72.1 mg/1.

      The time of day at which the filters are loaded
 may  significantly  effect  the  length  of filter  run.
 Filters which are loaded early in the morning and
 have influent standing on them throughout the entire
 daylight period may experience  a tremendous amount
 of algal growth in the liquid above the filter itself. An
 experiment was conducted in which 6-inch diameter
 plexiglass columns were filled with filter influent and
 placed on  the filter surface.  The bottoms of the
 columns were sealed to prevent concentration of the
 algae as the water percolated through the sand  and
                                                   the water level in the column was held at the same
                                                   level  as the water on the filter by removing water
                                                   from the  column every hour.  The experiment was
                                                   conducted with three columns which permitted light
                                                   penetration  and three dark columns which did not
                                                   permit light  penetration to use as  a  control.  The
                                                   suspended solids concentration and the volatile sus-
                                                   pended solids concentration of  the columns were
                                                   monitored with time.  The results are recorded in
                                                   Table 5 and shown graphically in Figure 5. The water
                                                   remained  on the surface of the filter for over 12
                                                   hours after  loading and at the end of the daylight
                                                   period approximately 1 foot of influent water re-
                                                   mained on the filter surface. The suspended solids
                                                   concentration had increased from 77.1 mg/1 at  1 hour
                                                   after loading to 222.4 mg/1 at 12 hours after loading.
                                                   This  indicates that the  average algal concentration
                                                   filtered may have been 45 percent greater than the
                                                   influent measurements indicate. Thus, the filter per-
                                                   formance  data  presented  in  the  report  may be
                                                   extremely conservative.

                                                        As shown by Figure 5 and Table 5, the increase
                                                   in the volatile suspended solids concentration in the
     50
     40
IS  30
Q.
O
O
CO
     20
Q   10
                     42
                                 28
                                              26
                                                          21
                                                                       19
                                                                                   14
                    0.2       0.4       0.6       0.8        1.0
                             LOADING  RATE,    mgad
                                                                                  1.2
 Figure 3. Days of operation before plugging.

-------
                                       Intermittent Sand Filtration to Upgrade Lagoon Effluents      77
  liquid standing on the filter during daylight hours is
  similar to the increase in suspended solids concentra-
  tion.  The volatile  suspended  solids  concentration
  increased from 55.29 mg/1 at 1 hour after loading the
  filter to  109.03 mg/1 at 12 hours after loading the
  filter. This  represents  an  increase in volatile  sus-
  pended  solids  concentration  of 97  percent. This
  further  indicates  the  conservative  nature  of the
  performance  data presented in this report.

       These results indicate that the  length of filter
  run could be substantially increased by either loading
  the filters at night after sundown or by covering the
  filters to prevent photosynthesis.

       An attempt was made to determine the actual
  mass of  suspended matter removal  by  each filter
  before plugging. This was accomplished by multiply-
  ing the  influent  suspended solids concentration by
  the volume  of liquid filtered  by each filter daily.
  Because  influent suspended solids were not moni-
  tored daily, it was necessary to extrapolate values for
  those days without influent suspended solids data by
  averaging the data of the  day  before and following
the day  without  data. The results are reported  in
Table 3  and shown graphically in Figure 6. Ad-
mittedly, this is  only  an approximation,  but it is
superior to not analyzing the data.

     Figure 6 clearly indicates that  the  0.6  mgad
loading  rate  removed a  substantially  greater total
mass than did any  of the other filters. A possible
explanation for this  phenomenon is that these filters
are a biological system, and much of their treatment
capability is related  to aerobic bacteria (see section
on nutrient removal). Thus, like any other biological
system,  there exists  an optimum organic (nutrient)
loading rate. Below this optimum rate, the organisms
receive insufficient nutrients to establish a maximum
population. Above this optimum rate,  the organisms
receive  too  much  organic  matter and  anaerobic
conditions exist which restrict filter performance.

Effluent quality with time

     When the filters were initially placed in opera-
tion, the effluent suspended solids concentration (i.e.,
34.6 mg/1  at 0.4 mgad) far  exceeded the influent
      125
      100
2    75
       50
CO
o    25
                      0.4        0.5       0.6       0.7        0.8
                             LOADING  RATE  IN   mgad
  Figure 4. Days of operation for field scale filters with 0.17 mm sand.
                                0.9

-------
 78   Reynolds, Harris, Hill, Filip, Middlebrooks
 Table 5. Algal growth on filters with time.

Time
in
Hours
1.0
2.3
3.6
5.0
6.0
8.0
10.0
12.0
Average
Algal
Suspended
Solids
(mg/1)
77.1
81.3
92.9
90.0
93.3
102.0
164.0
222.4
111.6
Growth3
Volatile
Suspended
Solids (mg/1)
55.29
56.32
62.33
63.19
66.98
74.94
80.48
109.03
71.07

Suspended
Solids
(mg/1)
75.2
81.4
77.4
73.6
73.1
69.2
68.9
78.9
74.7
Control3
Volatile
Suspended
Solids (mg/1)
49.99
55.44
50.55
49.23
53.24
49.23
48.12
52.19
50.99
     aAverage of three columns.
   250
E  200
CO
9  150

o
CO

g  100
o
LU
Q.
CO

CO
    50
                EXPERIMENTAL SUSPENDED SOLIDS

                CONTROL SUSPENDED SOLIDS

                EXPERIMENTAL VOLATILE SS

                CONTROL VOLATILE  SS
-£r	&-•£*	
                      468
                      TIME   IN  HOURS
                                             10
                                12
14
 Figure 5. Algal growth on filters with time.

-------
                                       Intermittent Sand Filtration to Upgrade Lagoon Effluents      79
suspended  solids (i.e.,  24.9 mg/1). However, the
effluent volatile suspended solids concentration (i.e.,
2.5 mg/1 at 0.4 mgad) was substantially less than the
influent volatile suspended solids concentration (i.e.,
17.8  mg/1).  Essentially,  the  high initial  effluent
suspended  solids concentration  was  composed of
inorganic material  being "washed" from the filters.
This  material had  a fine  sand  texture  and  was
probably very fine sand,  dirt, and grit introduced into
the filter system by the filter construction process.
After several  days  of operation, this  phenomenon
ceased.

     The effluent suspended solids of each filter were
monitored with time after loading on  three separate
occasions to determine if variations existed. A typical
plot is  shown in Figure 7.  It was found  that the
effluent suspended solids concentration peaks be-
tween  20  and  30 minutes  after loading. This  is
probably due to the high velocity through the filter
caused by the maximum head on the filter immedi-
ately  following  loading. However, on  all effluent
samples taken with time the volatile suspended solids
concentration was less than 1.0 mg/1 (influent VSS »
17.0 mg/1). Thus, the variation in effluent suspended
solids is probably caused  by "filter washing."
Because of  this variation in effluent quality with
time,  it was decided to  sample the effluent 2 hours
after loading.

Suspended solids and volatile
suspended solids

      The average effluent suspended solids concen-
tration for each hydraulic loading rate is reported in
Table  3, and  shown  graphically in  Figure  8. The
average influent  suspended solids concentration was
26.1 mg/1 while the average effluent suspended solids
concentration varied from 3.7 mg/1 (0.4 mgad) to 7.2
mg/1  (0.8 mgad).  However, a  maximum  influent
suspended solids concentration of 72.1 mg/1 resulted
in effluent  suspended  solids concentration  of less
than 4.0 mg/1 for the 0.2  mgad and the 0.4 mgad
hydraulic loading rates (all other  filters were plugged
at this time).

      In general, the filtered effluent suspended solids
concentration  increased  slightly  with an increase in
the hydraulic loading rate.

      The  average  effluent  volatile suspended solids
concentration  for each hydraulic  loading  rate  is
    25
 CD
 §20
 o
 o
 5  15
 <  10


 §   5
 <
                                                     i
        0        0.2      0.4      0.6      0.8        1.0
                           LOADING  RATE  IN  mgad

Figure 6. Total mass removed by each filter before plugging.
                       1.2
1.4

-------
 80    Reynolds, Harris, Hill, Filip, Middlebrooks
 reported in Table 3, and shown graphically in Figure
 9. The  average  influent  volatile suspended solids
 concentration was 16.9 mg/1 while effluent  volatile
 suspended solids concentrations were all less than 1.5
 mg/1. A maximum influent volatile suspended solids
 concentration of 63.4  mg/1 resulted in an effluent
 volatile suspended solids concentration of 1.2  mg/1
 for both the 0.2 mgad and the 0.4 mgad loaded filters
 (all other filters were plugged at the time).

      In general,  the  filtered effluent volatile sus-
 pended  solids concentration  appears  to  be in-
 dependent of the hydraulic loading rate. Also, these
 results  indicate that  the  filters  remove over 90
 percent of the applied volatile suspended solids.

 BODS and COD

      The  average  biochemical   oxygen demand
 (BOD5) of  the filtered effluent for each hydraulic
 loading rate is  reported in Table  3, and  shown
 graphically in Figure 10. The average influent BOD5
 was 8.1 mg/1 while the average effluent BOD5  ranged
 from  1.7  mg/1 for a hydraulic loading rate  of 0.4
 mgad to 4.3 mg/1 for a hydraulic loading rate of 1.2
mgad. The maximum influent BOD, applied to the
filters was 14.3 mg/1 with the corresponding effluent
BOD  ranging from 1.3 to 2.8 mg/1.

     In general, the filtered effluent BOD5 increased
with  an increase  in the  hydraulic loading  rate.
However, such increases are relatively slight and may
not be statistically significant.

     The  chemical  oxygen  demand (COD) of the
filtered  effluent  for each hydraulic  loading rate is
reported in Table 3, and shown graphically in Figure
11. The average influent  COD was 69.7 mg/1, while
the effluent COD values changed from 27.5 mg/1 (0.6
mgad) to 49.7 mg/1 (1.2 mgad).

     In general,  the  pattern of COD  removal  was
similar to that for BOD5  removal. The effluent COD
appeared to  increase slightly with increases in the
hydraulic loading rate.

Ammonia, nitrite, nitrate

     The  ammonia, nitrite, and nitrate  concentra-
tions  in  the  filtered effluent  for  each  hydraulic
                SUSPENDED SOLIDS VS.TIME  LOADING RATE  *0.4 mgad

                                         0	JULY  29,  1974
                                         A	JULY 30,  1974
                                                   VSS  <   1.0  mg/1
                                                                      INFLUE_NT_

                                                                      INFLUENT
                                75      100    125      150
                                    TIME     (mln)
                  175     200     225
Figure 7.  Filtered effluent suspended solids concentration with time.

-------
                                      Intermittent Sand Filtration to Upgrade Lagoon Effluents
                                                                                        81
loading  rate  is  reported  in  Table  3  and shown
graphically in Figures 12,  13, and 14. The influent
ammonia-nitrogen concentration averaged 2.469 mg/1
NH,-N while effluent ammonia-nitrogen concentra-
tions were all less than 0.541 mg/lNH3-N. Figure 12
indicates that  the effluent ammonia-nitrogen con-
centration increases  with  an  increase in  hydraulic
loading  rate.  The   influent  ammonia-nitrogen  is
probably converted  to  nitrate-nitrogen by nitrifica-
tion (see  Figure  14) rather than being physically
removed.  Thus,  the  increase  in effluent  ammonia-
nitrogen with hydraulic loading rate  indicates  that
less nitrification occurs at the higher loading rates.

     The  decrease in the nitrification process at the
higher  hydraulic  loading  rate  is  evident  in  the
nitrite-nitrogen and nitrate-nitrogen concentration of
the  filtered  effluents.  Figure  13  indicates  that
effluent nitrite-nitrogen almost doubled between the
0.2 mgad  and the 1.2 mgad hydraulic loading rates.
Figure  14  indicates  a  definite decline in effluent
                                            nitrate-nitrogen   concentration
                                            hydraulic loading rate.
with  increased
                                                  The apparent decrease  in nitrification  with
                                            increasing hydraulic loading rates suggests that the
                                            bacterial population in the higher loaded filters is less
                                            efficient. This could be a result of organic overloading
                                            which may cause anaerobic conditions to exist within
                                            a  portion of  the  sand  filter bed  and restrict the
                                            nitrification process.

                                            Phosphorus

                                                  The values for both influent and  effluent total
                                            phosphorus  and  orthophosphorus  are reported in
                                            Table 3.  Although effluent  phosphorus concentra-
                                            tions are  less  than influent values, previous experi-
                                            ments (Marshall and Middlebrooks, 1974) have in-
                                            dicated  that this is due to ion exchange within the
                                            filter sand bed and that once the ion exchange sites
                                            become  saturated, phosphorus  removal  does not
CO
o
CO
o
tu
o
z
UJ
Q.
CO
o
CO
     20
Q   15
10
             INFLUENT
                   0.2       0.4       0.6       0.8        1.0        1.2
                                     LOADING  RATE  IN  mgad
Figure 8. Suspended solids in filtered effluent.

-------
 82     Reynolds, Harris, Hill, Filip, Middlebrooks
IO.W
16.0
>.
z
to 12-0
Q
8 10.0
£
i 8.0
UJ
Q.
§6.0
UJ
C 4.0
5
_j
5 2.0


16.5
'**
t







f*

••f
.•>-'
.:!














rn
Bl r«3 I'M E^l P^l I3«l
H- TJ T» T» TJ TJ T>
1 1 1 1 1 1 1
J C\J *  - -
Figure 9. Filter volatile suspended solids performance.
                                              occur. Thus, further  operational experience  is re-
                                              quired  before  any  definite  conclusion  on  filter
                                              phosphorus removal performance can be justified.

                                              Filter performance evaluation

                                                   A  crude  attempt   to  select  the  optimum
                                              hydraulic loading rate  based on  the information
                                              presented in this report is presented in Table 6.  Seven
                                              parameters were  selected to  indicate overall filter
                                              performance. Each hydraulic  loading rate  was rated
                                              with a number between one and six. A rating of one
                                              indicates superior performance in a particular para-
                                              meter  while  a  rating of six  indicates poor perfor-
                                              mance. In areas where two filters had equal perfor-
                                              mance the rank order was  averaged.

                                                   The average rating  for  each  filter  was then
                                              determined without giving particular weight to any
                                              one parameter. The results indicated that the  filters
                                              with a hydraulic loading rate of 0.4 mgad or 0.6 mgad
                                              were  superior to  the  other hydraulic loading  rates.
                                              However, such a  selection  must  be viewed with
                                              extreme caution because of the limited data available
                                              for analysis and the selection process employed. The
                                              result could be substantially different if the selection
                                              parameters were weighted according to importance
                                              based  on  design,  construction,  and operational
                                              criteria.
 0»
 E
O
00
10.0

 8.0


 6.0

 4.0

 2.0
             INFLUENT
          '0       0.2      0.4       0.6      0.8       1.0
                           LOADING  RATE  IN  mgad.
                                                                     1.2       1.4
Figure 10. BOD5 in filtered effluent.

-------
                          Intermittent Sand Filtration to Upgrade Lagoon Effluents    83
    120
Q
O
O
    IOO
    80
    60
    40
    20
         INFLUENT
             Q2     0.4    0.6     0.8     1.0
                   LOADING  RATE IN mgad
Figure 11. COD in filtered effluent.
1.2     1.4
 o»
 E
   2.5
    2.0
    1.5
-  1.0
  10
    0.5
         INFLUENT
             0.2     0.4    0.6     0.8      1.0     1.2
                       LOADING  RATE IN  mgad
       1.4
Figure 12. Ammonia nitrogen in filtered effluent.

-------
 84    Reynolds, Harris, Hill, Filip, Middlebrooks
 i
 CVJ
O
    0.25
     0.20
     0.15
     0.10
     0.05
            INFLUENT
        V0     0.2     0.4    0.6     0.8      1.0     1.2

                            LOADING RATE IN mgad

 Figure 13. Nitrite nitrogen in filtered effluent.
     5.0
     4.0
      3.0
 1.4
  i
  to
 O
     2.0
      1.0
        0      (X2    0.4     0.6     0.8     1.0     1.2

                            LOADING RATE IN mgad
1.4
 Figure 14. Nitrate nitrogen in filtered effluent.

-------
                                        Intermittent Sand Filtration to Upgrade Lagoon Effluents
                                              85
Table 6. Overall filter performance evaluation.
Loading
Rate in
mgad
0.2
0.4
0.6
0.8
1.0
1.2
BOD5
3
1
2
5
4
6
COD
5
2
1
4
3
6
SS
4
1
3
6
5
2
vss
3
4.5
6
1
4.5
2
NO3-N
3
2
1
4
5
6
Algal
Mass
Removal
2
3
1
4
5
6
Hydraulic
Loading
Rate
6
5
4
3
2
1
Average
Ranking
3.71
2.64
2.57
3.85
4.07
4.14
       Comparison With Previous Results

      The full-scale filters have basically duplicated
the  performance of the laboratory and  pilot scale
units (Marshall and Middlebrooks, 1974).  In all cases
when the BOD, SS, VSS, and nutrient concentrations
applied to  the  systems were approximately equal,
removals obtained at  various hydraulic loading rates
are practically indistinguishable  between the labora-
tory, pilot, and full-scale filters.

      Fines  were  washed  from  the  full-scale filter
media for a considerable  period  of time  as was the
case with both the laboratory and pilot scale units.
This accounted for the majority of the solids in the
effluents  from the filter  units.  Volatile suspended
solids averaged less than 1 mg/1 in the effluent from
the full-scale filters at all six loading rates employed;
whereas, in the laboratory and pilot units the effluent
VSS  concentrations  frequently  exceeded  4  mg/1.
Whether  this  difference  was  caused   by  the
characteristics of the  genera of  algae being  removed
or is attributable to variations in laboratory technique
cannot  be  determined. However, there were sig-
nificant differences in the genera of algae present.

      During both the  laboratory and pilot  studies,
Chlamydomonas sp. were the predominant genera  in
the lagoon effluent with  only an occasional diatom
(5 percent) or Anabaena sp. (5-20 percent). At no
time were there less than 75 percent Chlamydomonas
sp.   in  the  effluents  applied   to  the filters.  The
full-scale filters received a lagoon effluent containing
mostly   a  blue-green   coccoid  alga,   tentatively
identified as Aphanocapsa sp.  and Chlamydomonas
sp. were present in only small amounts (see Table 4).
Because the performance of the  full-scale filters was
in most  cases superior to the laboratory and pilot
units, it appears that algal genera have little impact on
the intermittent sand filter. The Aphanocapsa sp. are
much smaller than the Chlamydomonas sp.  and do
not agglomerate; therefore, a large percentage of the
Aphanocapsa sp. would be expected to penetrate and
pass the filters. However, this did not occur with the
.170 mm effective  size sands used in the full-scale
filters.

     BOD, removals were essentially the same for all
three size systems, and an effluent containing less
than 5  mg/1 was obtained  at all  hydraulic loading
rates.  The  mean  influent  BOD5  concentrations
applied to  the  laboratory and pilot  filters  were
approximately 50 percent greater  (13 mg/1 versus 8
mg/1)  than  that applied  to  the  large  units, but
approximately equal quality effluents were produced.
Apparently, as in other biological systems, there are
certain  compounds which are difficult to biodegrade
during   the  short residence  time in the filters. Con-
sequently, a minimum effluent  BOD5 concentration
of approximately  2 mg/1 can be obtained with  the
intermittent sand filter.

     The  pH values of  all filter  effluents were
approximately 8.0, but ranged from 7.9 to 8.9. The
value was influenced greatly by  the characteristics of
the lagoon effluents.

     Effluent D.O. measurements were not perfor-
med on  the laboratory  and  pilot  units.  In  the
full-scale unit the D.O. concentration of the effluents
were directly related to the loading rates. Up to a
loading rate of 0.8  mgad  the effluent D.O.  con-
centration was greater than 5.5 mg/1 as required in
the  Utah Class  "C" standard. Above 0.8 mgad the
effluent D.O. concentration dropped below 5.0 mg/1
in several samples.

     Because of  the differences  in applied algal
concentration, a direct comparison of the length of
run  obtained with  the various size units is difficult.
However, at common hydraulic  loading rates and
approximately equal algal concentrations, the units
operated  about equal periods of time before plugging.
Approximately  one month of continuous operation
at the  peak algae  production in the  lagoons  can be
expected with  a  filter  containing  sand  with an
effective  size of 0.17 mm. The larger surface areas
exposed to the sunlight in the large filters introduced

-------
 86    Reynolds, Harris, Hill, Fitip, Middlebrooks
a variable  not  encountered in  the laboratory and
encountered to  a more limited extent in the shaded
pilot units. A significant  increase in algal concentra-
tions due to growth  after  the lagoon effluent was
applied to the  filters probably accounted  for the
slightly shorter  filter  runs obtained in the full-scale
units. The same  asymptotic relationship developed in
all size units when the days of operation were plotted
versus the hydraulic loading rate. A loading rate of
approximately 0.5  mgad  continues to appear to be
the optimum based upon solids and BOD, removals
and period of operation between cleanings.

     The large units have so  far confirmed the
conclusions based upon the laboratory and pilot scale
system.  Intermittent  sand  filtration  treating
secondary lagoon effluent is capable of consistently
producing an effluent with VSS and BODj concentra-
          tions of less than 5 mg/1, and provides operational
          simplicity and economy.

           Series Intermittent Sand Filter Performance

               A  study is  currently underway at the  Utah
          Water Research Laboratory, Utah State University, to
          determine the feasibility of operating intermittent
          sand  filters  with  different effective size sands in
          series. At present  three pilot scale (16 sq ft surface
          area  each) series filter operations are under study.
          Each filter operation consists of three filters in series
          with  the initial filter having an effective size  sand of
          0.72  mm, the intermediate filter sand effective size is
          0.4 mm, and the final polishing filter has an effective
          size  sand of 0.17 mm (see Figure 15).  Hydraulic
          loading  rates for the three systems are 0.5 mgad, 1.0
          mgad, and 1.5 mgad. Preliminary results indicate that
 0.5  mgad
1.0   mgad
  0.72mm
1.5  mgad
 0.72mm
 0.72mm
  0.40mm
 0.40mm
 0.40mm
  0.17mm
 0.17mm
 0.17mm
Figure 15.  Series intermittent sand filtration operation.

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                                        Intermittent Sand Filtration to Upgrade Lagoon Effluents      87
a  high quality  effluent  is  produced  and that the
length of filter run is substantially increased.

           Summary and Conclusions

      Wastewater lagoons provide simple, economical,
and low maintenance waste treatment for many small
communities. However,  the  degree  of treatment
possible with lagoons may be inadequate to meet
future discharge standards. Therefore, a definite need
exists  to develop  a  system which can  simply  and
economically upgrade  lagoon  effluents to a level
which satisfies future discharge requirements.

      A full-scale  experimental intermittent sand fil-
tration system has been constructed at the Logan
Municipal Sewage Lagoons by the Utah Water  Re-
search Laboratory, Utah State  University. The  objec-
tive of the project is  to evaluate the performance of
intermittent  sand  filters in  upgrading the quality of
wastewater lagoon effluent. Data have been collected
and analyzed from July 12,  1974, to  August  22,
1974,  for hydraulic loading rates  ranging from  0.2
mgad to 1.2 mgad.

      Based  on  the information  presented  in  this
article and  previous  studies  (Marshall and  Middle-
brooks, 1974) the following conclusions can be made.

       1.   The  algal genera  present in  the lagoon
           effluent have little impact  on  perfor-
           mance of the intermittent sand filters.
       2.   Length of filter run is directly related to
           influent algal concentration and hydraulic
           loading rate.
       3.   The full-scale filters had a slightly shorter
           length  of filter run than  did previous
           laboratory and pilot scale filters.
       4.   The length of filter run observed in  the
           full-scale filters was substantially affected
           by algal growth in the  liquid above  the
           filter.
       5.   The length of filter run varied from 14
           days with a hydraulic loading rate of 1.2
           mgad to 42 days with a hydraulic loading
           rate of 0.4 mgad.
       6.   The filter with a hydraulic loading rate of
           0.6 mgad  removed over twice as  much
           total  suspended  matter as did the  filter
           with a hydraulic loading rate of 1.2 mgad.
       7.   It is necessary to allow a period of time
           for the filters to "wash" out  fines  intro-
           duced during construction,  before a low
          effluent suspended  solids concentration
           can be achieved.
       8.   With an average influent suspended  solids
          concentration  of  26.1  mg/1, all  filters
           produced  an  effluent suspended solids
          concentration of less than 7.2 mg/1.
       9.   Effluent  suspended solids  concentration
           increased slightly with an increase in the
           hydraulic loading rate.
      10.   With  an   average   influent   volatile
           suspended  solids concentration of  16.9
           mg/1, all filters produced an effluent with
           less  than 1.5  mg/1 of volatile suspended
           solids.
      11.   The  filtered  effluent volatile suspended
           solids  concentration  is  independent  of
           hydraulic loading rate.
      12.   The intermittent sand filter can produce a
           consistent effluent BOD5 of less than 5.0
           mg/1.
      13.   Filtered effluent  BOD5 increases slightly
           with an increase in the hydraulic loading
           rate.
      14.   Filtered effluent COD  increases slightly
           with an increase in the hydraulic loading
           rate.
      15.   Influent  ammonia-nitrogen   concen-
           trations were reduced from 2.469  mg/1
           NH3-N to less than 0.541 mg/1 NH3-N  by
           all hydraulic loading rates.
      16.   The  full-scale intermittent  sand  filters
           essentially  confirm the  previous  labora-
           tory and pilot scale studies.
      17.   Experiments   are  currently   being  con-
           ducted to  evaluate  the performance  of
           series intermittent sand  filter operations.
                   Acknowledgments

      The work upon which this article is based was
performed pursuant to Contract No. 68-03-0281 with
the Environmental Protection Agency.

      Dr.  Ronald  F.  Lewis  has been  the Project
Officer  supervising this contract  for the Environ-
mental Protection Agency.
                    References

 American  Society of Civil  Engineers  and Federation  of
      Sewage  and Industrial Wastes Association.  1959. A
      Joint Conference on Sewage Treatment Plant Design.
      New York.

 APHA,  AWWA,  WPCF.  1971. Standard methods  for the
      examination of water  and  wastewater. 13th Ed.,
      American Public Health Association, Inc., New York,
      New Yoik.

 Calaway,  W.  T., W.  R. Carroll, and  S. K.  Long. 1952.
      Heterotrophic  bacteria  encountered  in intermittent
      sand filtration of sewage. Sewage and Industrial Wastes
      Journal 24(5):642-653.

 EPA. 1971.  Methods for chemical analysis of water and
      wastes.  Environmental Protection Agency.

-------
88
Reynolds, Harris, Hill, Filip, Middlebrooks
Furtnan,  Thomas  De  Saussure,  Wilson  T.  Calaway,  and
     George  R. Grantham. 1949. Intermittent sand filters-
     multiple loadings. Sewage and Industrial Wastes Journal
     27(3):261-276.

Grantham, G. R., D. L. Emerson, and A. K. Henry. 1949.
     Intermittent sand filter studies. Sewage and  Industrial
     Wastes Journal 21(6):1002-1015.

Marshall,  G.  R., and E. Joe Middlebrooks.  1974. Intermittent
     sand filtration  to  upgrade existing wastewater treat-
                                                        ment  facilities.  PRJEW115-2,  Utah  Water Research
                                                        Laboratory, College of Engineering, Utah State Univer-
                                                        sity, Logan, Utah.

                                                  Solorzano,  L. 1969. Determination of ammonia in natural
                                                        waters by the phenolhypochlorite method. Limnology
                                                        and Oceanography 14(5): 799-801.

                                                  Strickland, J.  D. H., and T. R. Parsons. 1968. A  practical
                                                        handbook  of seawater  analysis.  Bulletin No.  167,
                                                        Fisheries Research Board of Canada, Ottawa.

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       PERFORMANCE OF RAW WASTE STABILIZATION LAGOONS IN MICHIGAN

                    WITH LONG PERIOD STORAGE BEFORE DISCHARGE
                                             D. M. Pierce
                                                        1
                  Background
     In recent years the prevalance and popularity of
the waste stabilization lagoon have grown in many
sections of the country. Many additional projects of
this  kind are now  under construction  or  in  the
planning stage, largely in very small communities.
Some, however, are proposed  for flows of up to  one
million  gallons per day.  Although several thousand
municipal projects of this  kind are in operation
today,  and  generally considered  to be performing
quite satisfactorily, very little  factual information has
been assembled on their performance. So today, with
the adoption of regulations calling for a minimum of
secondary  treatment as  specifically defined  and
future requirements for "best  practicable treatment"
there is  an urgent need to assess the capability of this
method of treatment when opeated under a variety of
conditions.

     Information  collected  at  municipally-owned
and operated lagoons in Michigan during the past 5
years indicates  that systems with relatively  low
organic  loadings, long storage periods, and twice-
yearly discharge hold promise  of meeting the require-
ments  for  secondary treatment.  The  special EPA
work group on  waste stabilization  lagoons has ex-
pressed  interest  in exploring the efficacy of  this
method and how it can be managed most effectively
to  achieve   maximum  performance  dependably.
Accordingly a study was undertaken for this purpose.

     The person conducting this study is intimately
familiar with  the Michigan  program,  having been
responsible for state regulatory control of design and
operation of municipal wastewater facilities for many
years until last July. This relationship assured the full
cooperation  and support of both regulatory agency
personnel  and municipal officials and employees in
assembling and interpreting the essential information.
Many conferences  were held with division engineers.
Visits were made to  operating faculties in company
with operation personnel. Many people performing
     1D. M.  Pierce  is special  consultant for the  U.S.
Environmental Protection Agency.
the analyses on the lagoon effluent samples provided
valuable  and  timely  information,  particularly on
samples recently analyzed.

               Faculties Studied

     To obtain maximum available  pertinent infor-
mation it was decided to assemble information on all
municipal raw waste stabilization lagoons discharging
effluents during the past 2 years. Presently there are
about  125   municipal lagoon systems in the state.
Many have  not had their first discharge by reason of
the recency of their completion, or because of soil
conditions  favoring high on-site percolation rates. A
few of the facilities  have some aeration facilities.
Others were designed for percolation into the ground.
Neither of these were included in the study.

     It  was  found  that 49 of the systems are
representative  of the selected pattern of long storage
and twice-annual  discharge. Each of  these  have
sufficient operational data to permit a meaningful
evaluation of performance.

     Although there are quite  a  range  in  design
features  and operational methods, ah1  conform to a
general  pattern adopted  by  the state  regulatory
agency  several years ago as part of  the  overall
pollution control plan related to water quality stan-
dards.

         Essential Features of Michigan
               Lagoon Program

     The  following  information  is provided  to
acquaint the reader with pertinent background  on
concepts relating to loadings, construction features
and management methods used by operating per-
sonnel and the relationship between the operator and
the state regulatory agency. This should be helpful in
the  interpretation  and understanding of the data
collected and analyzed in this study.

Design features

      Generally, the principles of design specified in
Chapter  90 of the  Recommended  Standards for
Sewage  Works adopted by the  Great Lakes-Upper
                                                                                                 89

-------
 90
Pierce
Mississippi Board  of  State Sanitary Engineers (Ten
States'  Standards) have  been incorporated in these
projects.  In  all cases the design loading has been
approximately  100 persons (or PE) and 20 Ibs BOD5
per acre. Inlet, outlet,  and interconnecting  piping
usually  permits control of raw sewage into any cell
and the discharge of treated  wastewaters  from any
cell.  Valving  permits a variety of flow patterns with
capability to  isolate any cell or combination of cells.
Sealing  of the bottom and side slopes is provided in
all of these systems to permit control of water depths
within practical limits. Clay is most commonly used
although bentonite has been mixed with resident soils
at a few locations.

      Apportionment  of surface area  and capacity
among the cells in the system varies  considerably.
Maximum operating water depth usually is about 6
feet plus or minus 1 foot. (See Table 1 for capacity
and discharge data.) Quite commonly cells are equal
in area and volume. Some have equal area in each cell,
but  different  maximum operating water depths.
Usually  the shape, area, and depths depend to some
extent on topography and shape of available pro-
perty, relative elevation of inlet sewer and point of
lagoon discharge, depth to rock or water table, cost of
earth  moving, and related considerations.

      Great care is taken in the earth  work during
construction  to provide  good mixing of the sealing'
materials  with native soils, a level bottom free of
debris or  organic material and a well aligned  shore-
line. Slopes are seeded or sodded  to reduce erosion
and to permit grass mowing and weed control.

      Discharge  control  facilities  are  designed  to
permit  selection  of  any  desired  elevation for dis-
charge,  ranging from  highest  water elevation  (auto-
matic overflow level)  to  within a  foot or  so of the
bottom.

      All  of  these systems were designed for  semi-
annual discharge, with retention of total  flow from
the  sewer system  from late  November until  about
April  15 and  from about May 15 to October 15. It is
expected that the contents will be discharged during a
period of 2  to 4 weeks  depending on the quantity
stored; rates of percolation, precipitation and evapor-
ation; hydraulic capacity limitations of the  piping
system;  and the quality of the effluent in relation to
conditions in the  receiving water  body. This  leaves
some  150-170  days for summer and winter storage
without discharge. Since in Michigan annual precipi-
tation and evaporation are about equal, the volume
accumulated  in 160 days between discharge periods
would increase water depth by about 5 feet, assuming
an average flow of 100 gallons per capita per day and
no percolation. If  the rate of percolation is 1/8 inch
per day, the 5-foot increase in water depth would be
                                            reduced by 20 inches leaving 3 to 3H feet of depth to
                                            be  discharged.  Experience  has shown  that actual
                                            accumulations may range from 1 foot to as much as 8
                                            feet in the  theoretical  160-day period. In some
                                            instances combinations of low per capita flow rates,
                                            high percolation, high evaporation  and low precipi-
                                            tation  rates result in such a  low increase in water
                                            volume that no discharge is needed or desirable in one
                                            of the normal semi-annual discharge periods. There
                                            are several situations of this kind, particularly in the
                                            early years of operation, where no discharge is made
                                            for up to two years.  These are not included in this
                                            study.  In other circumstances where  per capita flow is
                                            high,  usually by reason of high inflow-infiltration
                                            rates,  minimal  percolation  and  high  precipitation-
                                            evaporation  ratios,  the  rate  of accretion  in  the
                                            lagoons is so high that discharge periods in either or
                                            both spring and fall must be extended over a period
                                            of  30  days  or  more  after  accumulation  to  the
                                            maximum safe water elevation.

                                            Operation and maintenance practices

                                                 The  state  regulatory  agency  requires  each
                                            municipality  to delegate full responsibility for lagoon
                                            operation  and  maintenance  to one  person on  its
                                            public  works staff.  Wastewater  Division personnel
                                            work with this person and other  members of the
                                            work force in  a continuing  consultation and sur-
                                            veillance  program,  including  both assembled and
                                            on-the-job  training and advice. A manual on opera-
                                            tion and  maintenance principles is furnished each
                                            local operating agency for  general guidance in addi-
                                            tion to the manual which EPA now requires for each
                                            funded project.

                                                 Regular operation routine involves daily visita-
                                            tion and  maintenance of lift stations.  Usually the
                                            lagoon site is visited each day of the 5-day  working
                                            schedule to observe conditions and perform essential
                                            operations. All lagoon properties are fenced and have
                                            locked gates. On each visit the  operator drives his
                                            pickup truck  on the roadway atop the  dykes making
                                            a  complete tour of  the  lagoons to  observe  their
                                            condition. He looks for signs  of  burrowing rodents,
                                            surface scum, sludge  buildup  near  inlets, emergent
                                            weeds, and evidence  of erosion.  Action is taken as
                                            soon as possible  to correct any adverse conditions.
                                            Grass and weeds on dyke slopes and tops are mowed
                                            when needed to  assure a dense growth for erosion
                                            control. Brush  and weeds at the  shoreline  are  re-
                                            moved or otherwise controlled to prevent spreading
                                            which  would interfere with natural waste treatment
                                            processes. Attention is given to management of flow
                                            into and between cells. In some systems normal flow
                                            patterns consist of the raw  waste  entering Cell No. 1
                                            and flowing  to Cell No. 2 through the  connecting
                                            pipe located near the  bottom. Flow from Cell No. 2
                                            to Cell No.  3  is similar to  this. In other systems

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                                     Performance of Raw Waste Stabilization Lagoons in Michigan     91
differences in elevation require manual regulation of
flow  between the cells by the operation of valves.
Prom time  to time conditions require re-routing of
flow  for water depth adjustment, temporary resting
of a  cell, repair work, etc.  Stop gates, valves, and
control structures  are  examined occasionally  and
maintained or repaired if needed.

Records and reports

      Observations are  recorded routinely on  stan-
dard  monthly  operation  reports  furnished by the
state  regulatory  agency,  Forms D-4.9 and D-4.9a.
Sewage flow quantities  (where measured), power
consumption, and weather data are recorded daily.
Lagoon  liquid  depth, dissolved oxygen,  and ice
conditions are recorded at least one day per  week
during the storage season  and daily during discharge.
Flow  patterns  among the lagoons and effluent dis-
charge are to be recorded regularly on Form D-4.9a.

Discharge control program

      Discharge  of  effluents  follows  a consistent
pattern for  all lagoons.   The  following steps are
usually taken:

       1.  Isolate the lagoon to be discharged, usually
the final one in the series, by valving-off the inlet line
from the preceding lagoon.

      2.  Arrange  with  a  nearby  community  to
analyze samples for chemical analysis including BOD,
suspended solids, volatile  suspended solids,  pH, and
frequently for total phosphorus.

      3.  Plan work  so  as to  spend full  time on
control of the discharge throughout the period.

      4.  Sample contents of lagoon to be discharged
for dissolved oxygen, noting turbidity, color and any
unusual conditions.

       5. Note conditions  in the stream to receive the
effluent.

       6. Notify Basin Engineer of Wastewater Divi-
sion of the  state regulatory agency of results of these
observations and plans for discharge and obtain his
approval.

       7. If  discharge  is approved, proceed as follows:
Commence  discharge and continue so long as weather
is  favorable,  dissolved  oxygen  is near  or  above
saturation  values  and turbidity is  not  excessive
following  the prearranged  discharge  flow pattern
among the  lagoons. Usually this consists of drawing
down the last lagoon in the series, or last two if there
are  three  or  more,  to  about  18-24  inches  after
isolation, interrupting the discharge  for  a  week  or
more to divert raw waste to the last lagoon (or to No.
2 if there are three or more)  and resting the No. 1
lagoon before its discharge. When this lagoon is drawn
down to about 24 inches or so the usual series flow
pattern is resumed.

     During discharge to the receiving waters sam-
ples are taken at least three times each day near the
discharge  pipe  for immediate  dissolved  oxygen
analysis.  Composite samples of the lagoon effluent
are collected, usually  5 days per week, at  points
designated by the Basin Engineer (see 6 above) for
chemical analyses. Each such sample  is composed of
at least three equal volume portions collected morn-
ing, noon, and late afternoon. Samples are refrig-
erated  during  collection  and delivered within  24
hours  (usually  same  day) to the laboratory  con-
ducting the  analyses. The analyst must have demon-
strated capability to perform the analysis. All work is
performed in accordance with Standard Methods  on
unfiltered samples.
      At least one grab sample per day, 5 days per
week, is collected for analysis of  fecal and total
coliforms in  sterilized bottles furnished by the State
Department of Public Health. The standard bacteri-
ological  analysis  form  F216a is used  to  record
pertinent information and is mailed with the bottle to
the department for analysis.


      The  person performing the chemical analyses
furnishes the operator and the regulatory agency a
copy of the test results when all analyses for the
seasonal discharge have been completed, using Form
R4613. Coli  test results are recorded on the Standard
Bacti form and furnished to the Wastewater Division
and the operator.
        The Study and What It Reveals

      The prime objective of this study is to deter-
mine  whether and under what  conditions the secon-
dary treatment requirements can be met by raw waste
stabilization  lagoons  designed  and operated in the
manner  outlined  in   the  foregoing   discussion.
Attention was given to factors which might affect the
level of performance, as reflected in effluent quality.
Factors  considered  were effect of  differences  in
population loadings per acre or unit volume; number
of cells; length  of discharge period; comparison of
spring with fall discharges; effect of ice cover and low
temperatures without ice;  relationship  of BOD5  to
suspended solids under varying conditions; and trends
and levels of coliforms under varying conditions; and
relationship of total coli to fecal coli.

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 92
Pierce
Study methods

      The cooperation and assistance of the Munici-
pal  Wastewater  Division, Department  of Natural
Resources, was solicited  in providing access  to  all
pertinent  records, reports, and design data. This was
provided in full measure in many most helpful ways.
Discussions  with  division staff members assisted
greatly  in identifying the lagoons  which  have dis-
charged effluents during  the  past  2  years and  in
obtaining  desired information  on  design  features,
population loadings,  presence  of industrial wastes,
identification of operating personnel and any unusual
problems  known  to  exist which might affect per-
formance.  All  monthly operation  reports and dis-
charge reports were made  available for review. Many
were discussed  with the responsible basin engineer  for
clarification and analysis.

      Many of the operators were contacted directly,
by  telephone  or visitation,  to obtain additional
information or  to discuss reported  conditions.  In
several instances where chemical data on the effluent
discharges could not be found,  the information was
secured promptly on request  to  the person per-
forming the analyses.

Data reviewed and recorded

      It was  determined that  49 municipal lagoons
met the  selection criteria. All  available  data  on
construction features, loadings and operating reports
were  reviewed.  These consisted of  (1)  monthly
operation  reports for each lagoon  system for the
years 1972 and 1973  and (2) discharge data for the 2
years. These data are recorded on Table 1.

Loadings

      Loadings  shown in  Table  1  for each lagoon
system are expressed  in terms of connected popula-
tion for the  lagoon  capacities listed. Unfortunately
there is insufficient flow data or  raw sewage sampling
for most  lagoons  to  be of much value. It may  be
noted that most loadings are reasonably close to the
design value of 100 persons per acre, although several
are significantly lower than this and a few are well
above. Discussion  with basin  engineers revealed that
no  industrial  wastes  are  tributary  to any of the
systems either in significant volume or characteristics.

Lagoon capacity

      Of the 49 systems studied, 27 have 2 cells,  19
have 3 cells, 2  have  4 and 1 has 5. The number of
cells has no relationship to the total area or volume.
Acreage apportionment between cells is frequently
divided  equally, although  neither this ratio nor the
relative  depths of the cells  follow any consistent
                                            pattern  as  may  be  noted  from Table  1.  Quite
                                            commonly  maximum  operating water  depths range
                                            from 60 to 84 inches with  72  inches found most
                                            frequently.


                                            Discharge patterns and periods

                                                 The  most common pattern of discharge is to
                                            release  the  stored contents  from the last cell in the
                                            series  following a period of several  days,  usually
                                            about a week, with no inflow from preceding cells
                                            and to  reverse  the process  after  this  discharge  is
                                            completed. At some locations no isolation is provided
                                            and inflow  from Cell No. 1  to Cell No. 2 (or to Cells
                                            2 and 3) continues during the total drawdown period.
                                            Many communities do not record the information on
                                            Form  D-4.9a in  a  sufficiently clear  and complete
                                            fashion to show just what flow pattern is used and
                                            how it is changed during the period of discharge. This
                                            information was not required by the department until
                                            a year or so ago. All available information is recorded
                                            in Table 1, as explained in its attached legend.


                                                 Whenever  possible the  spring discharge is de-
                                            layed until after  the  ice on  the lagoon surface has
                                            completely melted. Some locations have found  it
                                            necessary  to  discharge  small quantities during the
                                            early  spring  ice  cover  when  water  levels reach
                                            elevations  which  would either  produce automatic
                                            overflows  or endanger  the  integrity of the dykes.
                                            From the column entitled No. of Days Since Ice-Out
                                            indicates that ice remained in 1972 on  most lagoons
                                            until about April  15,  but was gone by March 15 in
                                            1973. Most systems are predicated on ice free con-
                                            ditions by April  1.


                                                 Periods of discharge shown.under that title in
                                            Table  1 indicate  a substantial variation in calendar
                                            period  and number of days. Some  of the  periods
                                            shown  include  the  intermediate isolation time be-
                                            tween discharges from Cell No. 2 (or 2,3,4) and Cell
                                            No. 1;  others clearly separate the  two periods. The
                                            total length of discharge periods  for  the  186 dis-
                                            charges recorded in Table 1 are as follows:
                                            No. Days Discharged
                                                 0-5
                                                 6-10
                                                11-15
                                                16-20
                                                21-25
                                                26-30
                                                31 or more
No. Discharge Periods
         15
         69
         46
         24
         11
          8
         13

-------
Month
.19
                      Exhibit I
OPERATION  REPORT OF WASTE STABILIZATION  LAGOONS
   	, Michigan
                                                    Operator
                                                                                                                                     MOPH
                                                                                                                                     D- 4.9
DATE
1
2
3
4
5
6
7
8
9
10
11
12
13
U
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
TOTAL
WEATHER
TEMP. -F
Max.































^~>p^
Win.































§^%^ir
a
Ty»e
































b
Wind
































Precip.
inches

































Flaw
MGD
































Power
KWH
































LIQUID DEPTH-Ft.
CELL
1































igpf^
2
































3































T'
D. 0. Mg/l
TIME


































1
































CELL
*
































3
































%
ICE
COVER
































ODORS
































R L MARKS
































              a.  Weather Type - C- Clear     CL - Cloudy     R- Rain
              b.  Wind  - Indicate strength and direction  —    S- Strong
              c.  Odors  - S- Slight    M- Moderate    0- Offentive
                                         W- Windy    CA- Calm
                                         M- Med.     W- Weak
                                        - Complaints

-------
                                                            D-4.9   -  INSTRUCTIONS

 Weother - Report Doily
    Temp.  - Data should be from a reliable source in community. Data must be from a maximum-minimum thermometer.
    Precip. (inches)  -  Data should be from a reliable source in the community, either at the plant or elsewhere.  Do not use general area data.  For
    information regarding official weather stations, write  State Climatologist, Room 202,  Manly Miles Building, 1405 South Harrison, East Lansing,
    Michigan 48823.  If no reliable source is available install a precipitation gage as recommended by the State Climatologist.

 Flow (MGO)  - Report Dolly
    The raw sewage flow should be reported  in million gallons per day (MGD),  for example:    70,000 gallons per day as 0.07 MGD.
                                                                                         375,000 gallons per day as 0.38 MGD.
                                                                                        3,750,000 gallons per day as 3.75 MGD.
    Use no more than three figures.

 Power  —  Report Doily
    Report the power  consumed for pumping  at the major pump station in kilowatt hours (KWH).

 Liquid  Depth - Report ot Leost  Weekly
    The depth to the nearest one-half foot in each of the lagoon cells, for example:   2 foot 2 inches as 2 ft.
                                                                               4 foot 7 inches as 4l/2 ft.
                                                                               5 foot 10 inches as 6 ft.

 Dissolved  Oxygen
    Report time when a dissolved oxygen sample is taken.  The dissolved oxygen concentration should be reported at least once a week in each cell
    during the period when the lagoon is not being discharged and once a day during discharge on the cell being discharged, recording
    the minimum D.O.  value of at least three samples taken during the day (morning, noon and evening).

 Ice Cover  —  Report ot Least Weekly
    Report the percentage of the lagoon system covered with  ice.  If measurements of ice  and snow depths are taken report these results in remarks column.

Odors
    Report odor condition as noted on form.  If odors are not detectable indicate with dashed line in appropriate space.  Discuss any unusual circumstances
    concerning odors in remarks column.

 Remarks
    This space should be reserved for  any observations and information not included in other parts of this form.  Observations on algae concentrations (both
    suspend*-^ and floating) color and turbidity in the lagoon  along with comments on efforts to control rodents, insects and weeds should be reported. Prob-
    lems with industrial waste, storm water or infiltration  should also be  noted. If additional space is necessary, please use Supplemental Remarks Sheet.

 Flow Pottern
    Indicate by brief sketches on Supplemental Remarks Sheet (MDPH -  D-4.9a) the pattern (or route)  of flow through the lagoon system.

-------
                                   Performance of Raw Waste Stabilization Lagoons in Michigan      95
                                               Exhibit 2
                                 WASTE  STABILIZATION  LAGOONS

                                 SUPPLEMENTAL REMARKS SHEET
                                                     ., Michigan
Month 	19 	              Operator .
H.OW I'ATThRN (Sketch flow pattern in space provided below, indicating dates during month.   If more  than
                 one pattern was used  make an additional  sketch for each period.)
       From _ __ _       To
                                                                  (Dale)
        From _________       To
                                                                  (Data)
        From  	       To 	
                      (Dmtt)                                       (Dmle)
REMARKS

-------
 96     Pierce
                                   D-4.9a
                             INSTRUCTIONS
Row PiUtcrn


   Indicate by brief sketches on Supplemental  Remarks Sheet (MDPH- 4.9a) the pattern (or  route) of
   flow  through the lagoon  system.


   Examples:
     From
        Raw
                  October  1, 1968
                    (Dale)
                                                 To
                                          October 4, 1968
                                                               (Date)
     From
                  October 5.  1968
                    (Date)
                                                 To
                                          October 13. 1968
                                                               (Date)
        Raw
                                         Discharge
     From
                  October 14, 1968
                    (Date)
                                   Raw
                                                 To
                                          October 22, 1968
                                             (Date)
    From
October 23, 1968
  (Date)
                                  Raw
                                                To
                                                            October 31. 1968
                                                              (Dale)
                                   Discharge

-------
                                      Performance of Raw Waste Stabilization Lagoons in Michigan      97
                                                Exhibit 3
 Sample
 No.	
        BACTKRim.Or.lCAL  ANALYSIS
SEWAGE, INDUSTRIAL WASTES  AND SURFACE WATERS

      MICHIGAN DEPARTMENT OF  PUBLIC  HEALTH
              BUREAU OF LABORATORIES
      Lansing    Houghton    Powers   Grand Rapids
                                                                                     F21h.,  10M 768
 Received	
Note: Use pencil - Answer all questions and underline words thai apply.

 1.  Source	Sta. No.  	 	County	   _
 2.  Location	
 3.  Date	
 4.  Water temperature.
 , Time.
   .Depth	
 Pt. in cross section	
. Collected by	...
- Width	 Flow	_.
 5.  Turbidity:  turbid,  slightly turbid, clear,  evidence of sewage, septic.
 6.  Color	   _  Odor: offensive, strong, light, none.
 7.  Bottom:  sand,  gravel,  silt,  clay, rocky,  sludge.
 8.  Vegetation:  weeds, algae, fungi.  Amount: abundant, sparse,  none.
 9.  Fish life:  yes,  no.  Species	  .		
10.  Weather:  clear, partly cloudy,  cloudy, rain.
11.  Wind:  strong,  moderate,  calm. Direction	
12.  Nearest source of pollution	
13.  Distance to source of pollution	
14.  Use of frontage and/or water:  water supply, public park,  bathing,  fishing,
    residential, farming, pasture, undeveloped, or	
15.  Report results to	  	  ;	
                                                                              LABORATORY RESULTS
                                                        MEMBRANE  FILTER
                                                             METHOD

                                                         All results reported
                                                        as counts per 100 ml.
                                                                           Coliforms
                                                        DIFFERENTIAL TESTS
                                                     Fecal Coliforms
                                                     Fecal Streptococcal
                                                     Group
                                                     Examiner
            Address.
 Reported-Copies
                                                                            	I
                                                                            (Ij
                                                                               Chief, Bureau ol Lcbo, Horn-:.
Effluent quality—BOD and suspended solids

      Records  were   reviewed  and  recorded  for
analyses of  BOD  and  suspended  solids on 1475
samples from the 49 lagoon systems.  Each of these
samples  was  a daily composite collected by  the
operator.  This information  is recorded under Dis-
charge Data-Chemical in Table  1. Ranges of Values
and arithmetic averages  are shown for each seasonal
discharge period.

      The  BOD and suspended solids data were
analyzed  statistically in  terms  of probability  of
occurrence. All values  were arranged  in  order  of
magnitude and plotted on normal probability paper
with concentration (mg/1) plotted against probability
the value  would   not be  exceeded  under  similar
conditions. Separate plots were made for 2-cell and 3
or more cell systems. These plots (see  Figures 1,2,
and 3) reveal the following quality levels.
% Probability of Occurrence
Mean for Period
Most Probable
90% Probability
2 Cells
BOD SS
17 30
27 46
3 or
More Cells
BOD SS
14 27
27 47
                                    The  distribution of values is reasonably con-
                               sistent  with  normal distribution  showing  a high
                               degree of uniformity for BOD and a reasonably good
                               distribution  for suspended  solids.  No statistically
                               significant difference can be seen between the 2-cell
                               and 3 or more cell systems for the loadings experi-
                               enced.

                                    The  data do not  reveal any detectable  differ-
                               ence in levels  of BOD or suspended  solids between
                               spring and fall discharges, including those from under
                               the ice. Nor is any variation noted with variations in
                               number  of days discharged.  Further,  study  of re-
                               corded water levels during discharge  failed to show
                               any  definite  trend  related  to rate  of  drawdown
                               (inches per day) or  from  initial drawdown to low
                               discharge level. The  exception to this  is  when the
                               water level is reduced below about 18 inches or when
                               the point of drawoff is at or below that level. In these
                               cases BOD and suspended solids concentration in-
                               crease sharply.


                              Effluent quality—coliforms

                                    Analyses for total  coli and fecal coli performed
                              by the  bacteriological laboratories  of the Michigan
                              Department  of  Public   Health were  reported  on

-------
 98
Pierce
standard forms F216a. A total of 1523 such forms
were reviewed and the fecal coli per 100 mis recorded
in Table 1.  This  represents  1523 individual samples
analyzed, one for each day the samples were collected
by the operators.

      The fecal  coli  data were  reviewed for con-
formity with  the secondary treatment requirements
of 200 for  30 consecutive  samples and  400 for 7
consecutive  samples. Where  these standards are met,
this is indicated by an X. When the geometric mean
exceeded these levels the mean is recorded.
     These data clearly indicate that the 200 and
400  levels  were met consistently except: (1) When
the ponds  were  ice covered or a few days following
final thawing of ice, and (2) late in  the fall at some
locations as water  temperatures reach low levels in
the lagoons (Birch  Run, Bridgman, and Plainfield
Township).  This temperature dependency  deserves
further study, but it is clear that low fecal coli levels
cannot  be  achieved  dependably  when  ponds are
ice-covered or a few days afterward.

     Although   analyses for  total  coli  have  been
performed  routinely on lagoon samples  for several
years, the  state regulatory  agency did not  require
fecal coli data until about 2 years ago. Facts on fecal
coli levels are just now emerging. There are still a few
locations  today  where  only  total  coli  data are
available as noted in Table 1.

     An in-depth study of fecal coli data was made
to examine seasonal trends  in coli levels, both total
                                             and  fecal.  Typical  facilities  were selected  and all
                                             available  data  are recorded in  Table  2.  These data
                                             reveal the dramatic  decrease in  fecal coli  levels from
                                             ice covered conditions to warmer weather conditions.


                                                  The lack  of any consistent relationship between
                                             total coli and fecal coli shown in Table 2 is typical of
                                             what generally was found at other installations.


                                                  No  relationship or  indicated trend could be
                                             found between fecal coli concentrations and levels of
                                             BOD or solids in the effluent. There appeared to be
                                             no difference in coli levels for 2 cells compared with
                                             3 or more cell systems.
                                                          General Conclusions

                                                  Study  of operational  data  and related  infor-
                                             mation  from  49  lagoons  for  two years clearly
                                             demonstrates that, with long period storage prior to
                                             fall  and  spring  release,  lagoons can  consistently
                                             produce  effluents meeting  EPA  requirements  for
                                             secondary treatment  for  BOD and  fecal  coli and
                                             generally can meet the suspended solids requirement,
                                             when loadings are in  the 100 person per acre  range.
                                             No data were available to indicate the effect of higher
                                             loadings or short  retention periods. It is recognized
                                             that performance  at this level requires the application
                                             of generally accepted principles of design and con-
                                             struction and that a reasonable amount  of attention
                                             by well trained and interested public works oriented
                                             operators is essential.

-------
      STATE OF MICHIGAN
DEPARTMENT OF NATURAL RESOURCES
                          Exhibit 4
WASTE STABILIZATION LAGOON DISCHARGE REPORT
                                                                                          R 4613  4/74
                           19.
                                                                     Michigan
                                                                                             Sup«rinttnd«nt's Signature
   Plant No.  Mo.  V  Sampling Point Cod*
*
MF
MPN
Facal
31616
31615
Tol»l
31S04
31505
o
A
1 2
PN
ff
O1
02
O3
04
05
06
07
08
09
10
11
12
13
14
IS
16
17
18
19
2O
21
22
23
24

26
27
28
29
30

TI-
ME
WA
FLOW
MGD
50050



































BOD
14
mg/l'
00310



































SS
19
mg/l
00530



































VSS
24
mg/l
00535



































TOTAL-P
29
mg/l
00665



































NH3-N
34
mg/l
00610



































pH
39
su
00400



































F. COLI*
44
*/100ml
31616
31615



































T. COLI*
49
*/ 100ml
315O4
315O5
































'


ICE COVER
ON STREAM
54
\
01 355
































,'•• -


REMARKS OR OTHER PARAMETERS
59





































64





































69





































74 78





































80
C
^
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
3
c
c
c
c
-
;
:
J
c
:
;
;
:
c
j
c
9





































14





































19





































24





































19






































-------
100
Pierce
            WASTE STABILIZATION LAGOON DISCHARGE REPORT INSTRUCTIONS
 Discharge reports are to be submitted by the tenth of the calendar month following
 a month during which a discharge occurred.  They should be mailed to:   Municipal
 Wastewater Division, Department of Natural Resources, Stevens T. Mason Building,
 Lansing, Michigan 48926.

 Enter lagoon identification code number in the six spaces following the letters ID.
 In the next four spaces enter the date with the first two spaces being the month
 and the next two being the year.  The last three spaces should contain the sampling
 point code assigned to your lagoon for final effluent.  For example, ID 740055 10 73 000
 would be the code for Yale's October 1973 discharge data.

 If the results of a test reveal no detectable amount of the substance, then report
 that the amount is less than the least detectable amount.  For example, if the least
 detectable amount of an analysis is 0.1 mg/1 and the analysis indicates less than
 that amount, then report it as L 0.1.  A dash should never be used.  A blank implies
 that no analysis was made.

 If the magnitude of the numbers for a particular parameter exceeds four digits, the
 row marked SF should be used.  A Scaling Factor (SF) of 2 above a column would mean
 that the numbers reported in that column should be multiplied by 100 to equal the
 actual value of that parameter.  Other Scaling Factors are as follows:
Multiplier
Scaling Factor
10
1
fO(T
2
1000
3
10000
4
100000
5
Etc.
IMPORTANT:
      In no instance shall any number be reported in more than four digits
      plus a decimal point or five digits without a decimal point.
FLOW -  Total daily discharge flow should be reported using three figures.
example, 451600 gallons per day should be reported as 0.452 MGD.
                                                                     For
REMARKS OR OTHER PARAMETERS - This space is provided for notes to the basin engineer
or for the record.Other parameters may be reported in these columns by listing the
parameter abbreviation and units in the top two rows, the Parameter Number (PN) in
the third, and the Scaling Factor (SF), if any, in the fourth.  Parameter Numbers
may be obtained from your basin engineer or selected from the abbreviated list on
the Additional Chemical Analyses Sheet (R4612).

TOTAL - Enter column totals 1n the row marked TL, where it is not blacked out.

MEAN -  Enter the Arithmetic Mean (Average) for all parameters except Coliform.
The Geometric Mean should be reported for the Coliform data.

If the discharge is covered by an NPDES permit with a 7 day Average (or Daily
Maximum or Minimum) condition, then, for such parameters, report the required data
in the row marked WA for Weekly Average.  The 7 Day Average should be computed
from what appears to be the worst seven consecutive days.

-------
Table  1.  Capacity  and  discharge  data,  waste  stabilization  lagoons,  Michigan,  1972-73.
                                            CAPACITY AND DISCHARGE DATA - WASTE STABILIZATION LAGOONS - MICHIGAN 1972-73

COMMUNITY
Ashley
Belding
Birch Run
Breckeoridge
POPULATION
DESIGN CONN
600
8000
1200
1250
550
4000
1300
1800
LAGOON CAPACITY

in
u
u
2
4
2
2
CELL 1
< ^ 5 «
U U B. 3!
3.0
20.3
6.0
6.0
108
72
72
72
CELL 2
5? *-• a S
3.0
15. J
6.0
6.0
108
72
96
72
CELL 3
3^N H w
O A. ^
5j ^ § "

*15.0



72






FLOW PATTERN


Al
Bl
Bl
"AI
Bl
Al

w
Crt
5°
og
0
"10

0
0
55
30
30

DISCHARGE DATA - EFFLUENT QUALITY
PERIOD OF
DISCHARGE
DATES
FROM-TO
72-04-14
to 05-15
73-03-23
to 03-30
73-04-23
to 04-27
72-04-11
to 04-27
72-10-02
to 10-25
73-03-16
to 04-09
73-11-05
to 11-13
72-04-12
to 04-28
72-06-06
to 06-19
72-10-28
to 10-30
72-11-08
to 11-16
73-04-12
to 05-07
19-22
72-05-10
to 05-22
72-10-16
to 10-31
I
32
8
1
17
24
24
c
17
14
8
9
25
13
16
CHEMICAL

W t-
8
8

9
11
<
3
16
14
9
18
13
1C
BOD
(mg/1)
RANGE AVG
7-9
~ 9-15

2-15
1-2
1-11
" 3-10
15-28
10-40
12-20
21-32
19-38
14-59
6-26
8
11

5
1
7
6
18
23
15
24
27
37
21
Susp.
Sol.
(ng/1)
RANGE AVG
32-41
11-63

14-60
2-14
27-58
no data
24-68
8-62
10-31
36-140
12-52
10-80
36
24

30
9
35
41
26
16
35
50
26
43
FECAL COLI
«!
<
36
8
5
9
11
ch
ch
17
14
7
9
18
8
N(
RANGE
*C10-36000
i.10-320
<.10-20
*10-1300
*10
.orinated
.orinated
^10-5100
4. 10-4100
*. 10-350
4600-5500
.C10-750
20-1100
) data
EPA SID.
200 400
X
X
X
X
X


X
X
X
4900
X
X

X
X
X
X
X


775
X
X
5000
X
X



NOTES
*Exceeded
stds. before
ice out
*
Cells 3 6, 4
each 7.5
acres
Ice cover
until 4-15-S
2 Coli
samples ^210
No fecal
coli data
for other
periods. Total coli
tests.
                                                                                                                                                                     s
                                                                                                                                                                     >o

                                                                                                                                                                     t
                                                                                                                                                                     s-

-------
Table 1.  Continued.

COMMUNITY
Breckenridge
Continued
Bridgman
Brooklyn
BIT owns town
Township
Wayne County
POPULATION
DESIGN CONN
1250
1250
1200
1050
1800
1308
1107
1360
LAGOON CAPACITY

VI
tl
CJ
%
2
3
J
2
CELL 1
5 tj B, Z
5e ^ w C
6.0
4.5
5.0
7.7
72
72
78
60
CELL 2
«jj *-\
IS
6.0
4.C
3.5
10.8
es
Sjg
Q~
72
72
72
60
CELL 3
x ,-,
S^ H W
u a, a
tf < [4 *H
-< ^- Q ^

4.0
3.5


72


72

DISCHARGE DATA - EFFLUENT QUALITY
FLOW PATTERN
61
Al
Bl
~~A1
A4
Al
A2
Al
Al
A4

A3
Al

1*1
n
5g
Q H
tj

30
0
15


30
40

25


Ib

PERIOD C
DISCHARC
DATES
FROM-TO
72-11-13
to 11-24
73-04-12
to 04-27
73-05-23
to 05-31
73-10-24
to 10-31
72-04-05
to 04-07
72-04-24
to 05-03
72-05-06
to 05-12
72-10-15
to 10-27
72-11-12
to 11-21
73-04-18
to 05-20
72-05-15
b 7 2-05-25
72-10-17
to 10-26
73-04-09
to 04-18
73-10-12
to 10-18
72-10-30
to 12-01
73-04-02
to 04-30

F
,E
VI
3
o
>*
12
16
9
8
3
10
7
13
10
32
11
10
10
7
32
'i
-------
Table I.  Continued.

COMMUNITY
Brownstovn
Township —
Wayne County
Continued
Brown City
Byron Center
Caoden
Capac
POPULATION
DESIGN CONN
1050
1850

600
1400
1360
1142

405
1279
LAGO

to
i
2
3

2
2
CELL 1
25 G o. z
2 -< 3 1-1
7.7
6.5

3.3
7.0
60
72

69
72
DH CAPACIT
CELL 2
5 G g. z
10.8
6.5

2.6
7.0
60
72

60
72

CELL 3
3 O flu SB
&< U M

4.5




72



DISCHARGE DATA - EFFLUENT 0
FLOW PATTERN





Bl
Al
A/
Al


A4
A4
A4
H
%
M
(H

*0
45

55



10
1

14


PERIOD OF
DISCHARGE
DATES
FROM-TO
73-10-29
to 11-15
72-04-10
to 04-24
73-04-25
to 05-03
73-10-19
to 11-02
73-05-08
to 06-01
72-09-06
to 09-15
72-10-30
to 11-07
72-11-17
to 11-21
73-03-22
to 03-30
73-05-01
to 05-09
73-10-31
to 11-07
72-04-21
to 05-15
72-10-27
to 11-11
72-11-20
to 11-30
CO
§
17
15
9
11
6
10
8

9
9
8
25
17
8
CHEMICAL

CO h
13
11
8
8
6
8
4
c
5
6
6
6
22
12
6
Susp.
BOD Sol.
(Bg/1) (mg/1)
RANGE AVG RANGE AVG
9-15
8-55
13-32
5-14
12-40
13-24
23-27
8-19
14-22
31-35
6-10
1-12
4-45
4-6
5-7
11
25
21
8
24
21
25
13
18
33
8
5
16
5
6
31-62
15-62
8-86
5-28
25-64
27-84
41-84
6-21
20-25
47-72
7-26
15-24
13-68
12-43
22-46
49
35
38
15
45
46
60
12
22
54
21
20
32
20
29
UALITY
FECAL COLI
CO t-
10
11
8
7
3
7
8

7
15
8
16
No
No
EPA STD.
RANGE 200 400
4.10-420
4.30-130
4.10-1300
*C 10-340
X100
« 10-1300
410-60

4: 10-50
A 10-90
410-160
£10-8000
data
data
*
«
X
X
*
*
*

X
*
*



*
-
*
X
X
X
*

X
X
X



SHEET
3
NOTES

* Ice out
about 4-15


Total coll
only
Total coll
only
                                                                                                                                                §
                                                                                                                                                !
                                                                                                                                                 f
                                                                                                                                                 J?
                                                                                                                                                 I
                                                                                                                                                 I
                                                                                                                                                 s-

-------
Table  1.  Continued.


COMMUNITY
Capac
Continued
Carleton
Carson City
Coleman
Elkton
POPULATION
DESIGN
1400
2400
1500
2000

CONN
1279
2314
1200
1295



->
2
5
2
3
3
LAGOON CAPACITY
CELL 1
1!
7.0
5.0
8.0
11.0

x ^
72
72
96
72

CELL 2
li
7.0
4.5
Cei:
4.4
8.0
5.5

tl] f)
Q >-'

72
L *4
84
96
72

CELL 3
H o

4.5
Cel
5.8

5.5

|i

72
L 05
84

72


[FLOW PATTERN
A4
A4
A4



Al

Al
Al
Al
Al
Bl
Al
A
Al

u
o
CO
0
15

15


5


15
15

25




PERIOD OF
DISCHARGE
DATES
FROM TO
73-03-05
to 03-14
73-04-01
to 04-30
73-10-17
to 11-09
72-04-26
to 05-05
72-05-10
to 06-01
72-11-23
to 12-12
73-03-19
to 05-16
73-10-17
to 11-14
72-11-06
to 11-16
73-04-01
to 04-12
72-05-01
to 05-05
72-10-18
to 10-31
73-04-11
to 04-30
73-10-16
to 11-02
72 May
72 Oct
73-05-02
to 05-08
VI
1
iU
30
23
10
22
20
48
28
11
12
I
14
20
16


DISCHARGE DATA - EFFLUENT QUALITY
CHEMICAL
E3AYS
ffLING
7
20
17
4
i
6
14
4
11
7
c
11
11
14


BOD
(mg/1)
RANGE AVG
17-20
4-21
2-10
11-34
10
8-25
2-53
5-12
14-52
8-14
32-75
3-23
15-34
1-17

16-21
18
12
5
22
10
15
22
8
25
10
51
15
21
6

18
Susp.
Sol.
(mg/1)
RANGE AVG
14-33
13-90
3-59
32-81
7-41
24-48
10-84
12-18
12-53
12-56
10-50
5-32
16-92
2-19

51-90
24
37
30
62
20
39
46
14
24
26
32
16
49
10
68
FECAL COLJ
'# DAYS
'SAMPLING
6
21
17
7
19
12
35
11
11
7
e
9
8
10
N
RANGE
410-4800
*10-240
AlO-800
X10-140
A. 10-20
10-770
A10-50
AlO-10
* 10-10
.£. 10-400
-10

-------
Table 1.  Continued.
COMMUNITY
Elkton
Continued
Fennvllle
Fowler
Fovlerville
Hemlock
POPULATION
DESIGN CONN

1800
1400
2000
1400

810
1000
1990
1390
LAGOON CAPACITY
Cfl
3
3
3
2
3
2
CELL 1
|G EJB
2 -4 u M
< >- Q ^

10.0
8.0
6.0
5.7

72
78
72
60
CELL 2
3 U S 5!
CA •< bl M

4.0
8.0
6.0
8.7

72
10.2
72
66
CELL 3
$ < U *
+;Z} S^,

4.0

6.0


72

72








DISCHARGE DATA - EFFLUENT QUALITY

FLOW PATTERN
A











A4
A4
Bl
A]
Bl
u
g
t-l
w
sg
a.

0








20

0
20



PERIOD OF
DISCHARGE
DATES
FROM-TO
73-10-15
to 10-2
72-04-05
to 04-11
72-06-13
to 06-22
72-11-14
to 12-01
73-04-06
to 04-15
72-11-13
to 11-17
72-12-07
to 12-14
73-04-0!
72-09-06
to 09-11
72-11-06
to 11-21
73-04-05
to 04-17
73-11-06
to 11-14
72-03-28
to 04-07
72-05-02
to 05-10
72-06-01
to 06-06
72-09-27
to 10-12
72-10-30
to 11-08
W
5

7
10
17
8
5
8

6
16
13
c
10
9
6
16
9
CHEMICAL

9 DAYS
SAKPLING
5
i
8
13
6
i
4

4
4

8
7
7
4
7
3
BOD
(mg/1)
RANGE AVG
1-7
11-16
6-30
7-40
11-16
4-7
8-10

2-6
4

3-8
18-54
16-66
32-44
21-76
32-42
4
13
16
15
13
6
9

3
4

5
44
37
38
40
36
Susp.
Sol.
dug/1)
RANGE AVG
2-7
21-41
17-80
13-59
36-86
10-21
10-22

3-14
2-5

5-11
6-16
36-60
22-34
24-46
24-54
4
34
33
40
55
15
14

10
3

7
10
53
26
40
35
FECAL COL I
V DAYS
SAMPLING
6
i
7
i

c
4



8
6
7
6
4
3
4
RANGE
,£.10-10
^.10-180
* 10-400
X 10-800

^•10-50
^10-40
^10-170


^10
^10-890
2000-10000
30-960
^10-80
90-3900
60-1500
EPA STD.
200 400
X
X
X
X

X
X
X


X
X
4700
315
X
340
240
X
X
X
X

X
X
X


X
X
4700
X
X
X
240


SHEET
5
NOTES







Ice cover
until 4-15
                                                                                                                                                  I
                                                                                                                                                  !
                                                                                                                                                 I
                                                                                                                                                  s
                                                                                                                                                  Cn
                                                                                                                                                  3-


                                                                                                                                                  I

-------
Table 1.  Continued.

COMMUNITY
Hemlock
Continued
Ithaca
Kent City
POPULATION
DESIGN CONN
1400
3500
900
1390
2420
700
I
LAGOON CAPACin
3
u
2
3
3
CELL 1
SG si
is gc
5.7
15.1
4.5
60
72
60
CELL 2
«< x-> H «
3 O B, S!
pi < [d M
^ *"^ Q %«/
8.7
9.8
2.0
66
72
60

CELL 3
S c? o. a
Orf •< b] tH

9.6
2.0

72
84
DISCHARGE DATA EFFLUENT QUALITY
FLOW PATTERN
Al
Bl
El
Al
A2
A3
A3
Al
"A3
A3
Al
Al
' Al
Al
Al
Al
|°
u
20


0
0
24


15

15

10



PERIOD OF
DISCHARGE
DATES
FROM-TO
7 3-04-05
to 04-18
73-04-30
to 05-11
73-10-22
to 10-29
72-03-20
to 03-24
72-04-10
to 04-20
72-05-08
to 05-23
72-09-25
to 10-09
72-11-20
Eo 11-29
73-63-31
to 04-26
73-05-21
to 06-01
Oct 8
72-04-27
to 05-04
72-10-30
to 11-11
73-03-26
to 03-3a
73-04-11
to 04-14
73-05-21
to 05-24
73-11-04
to 11-12
1
14
12
8
5
11
16
15
10
17
12
8
19
5
4
4
9
CHEMICAL
» DAYS
SAMPLING
9
9
5
4
5
6
5
4
6

7
17
4
-
3
7
BOD
(mg/1)
RANGE AVG
18-36
18-32
13-19
11-34
16-40
12-52
4-8
16-19
12-70
20-40
16-37
3-15
27-32
17-23
7-9
7-11
26
23
15
20
22
28
6
17
40
27
14
S
28
19
8
9
Susp.
Sol.
(mg/1)
RADGE AVG
6-32
20-40
21-41
7-30
3-31
22-86
3-14
3-40
25-70
3-31
34-64
16-40^
No dat
— J
No dat
T4-18
No dat
20
25
31
17
20
50
8
16
45
19
43
26
I

17
FECAL COL I
# DAYS
SAMPLING
12
9
5
3
9
11
7
6
14
3
10
16
6
2
3
RANGE
180-4800
^.10-50
-10-10
.* 10-1380
^10-35000
^10-190
46 10-20
^•10
^W. 0—120
-110-350
A10-300
^10-1100
* 10-50
•*io
X.10

EPA STD.
200 400
490
X
X
X
500
X
X
X
X
X
X
*
*
X
*

830
JL
X
X.
1720
JL
X
X
X.
X
X
X
X
X
X



SHEET
6
NOTES


Ice cover
jntil 4-15

                                                                                                                                                      is?
                                                                                                                                                      re

-------
Table  1.  Continued.

COMMUNITY
Laingsburg
'.akeview
Haybee
Memphis
Millington
POPULATION
DESIGN
1300
1150
1050
2000
1800
CONS
1100
1100
485
1120
1500
LAGOON CAPACITY
I
3
3
3
2
2
CELL 1
33 ^
< -^ H in
W U d. 55
•2 ^--
6.5
3.7
2.5
8.0
8.8

96
72
78
72
72
CELL 2
X X-
•rf ^ H W
[u U PT ^
Oj •< Ul l-<

-------
Table  1.  Continued.
                                                                                                                                                            5?


COMMUNITY
Moienci
Mulllken
North Branch
Ovid
POPULATION
DESIGN
2850
750
1300
1600
CONN
2200
450
1100
1870
LAGOON CAPACITY

«j
o
=Sfe
2
3
3


CELL 1
w t?
52
14.8
2.5
8.9


1C *~*
H V3
P-. yz
W M
Q "*~*
84
60
72


CELL 2
W CJ
35
13.9
2.5
4.3


JK *"*
H c/3
E 2
U M
O -^
84
72
72
11
CELL 3
W Q

2.5
4.3
7.0
33 •—
H U5
a. z
U t-l
0 v-



84
72
78
DISCHARGE DATA - EFFLUENT QUALITY
FLOW PATTERN
Al





Al
A3
A2



Al
Al
~A1
ua
j
i-<
w
oB
!i
0



10



1

20

10
15
PERIOD
DISCHAR
DATES
FROM- TO
72-03-27
to 04-08
72-05-02
to 05-16
72-10-02
to 10-13
72-11-03
to 11-10
73-03-22
to 04-06
73-04-23
to 05-04
• 73-10-08
to 11-08
73-04-13
to 05-23
72-04-12
to 04-21
72-10-09
to 10-13
73-04-06
to 04-24
73-11-05
to 11-16
72-04-24
to 05-15
72-11-01
to 11-17
^71-03-28
to 04-08
OF
GE
w
5
Q
=fe
12
li
12
6
Ib
12
30
40
10
c
9
12
22
c
ii
CHEMICAL
# DAYS
SAMPLING
10
10
10
6
12
9

18
7
i
7
8

8
8
BOD
(mg/1)
RANGE AVG
2-36
9-32
1-6
5-9
5-15
7-22

3-9
23-47
2-9
7-36
4-13

6-15
7-18
20
23
4
6
8
13

5
34
6
18
8

8
11
Susp.
Sol.
(mg/1)
RANGE AVG
3-27
10-69
1-9
32-80
2-18
5-73

3-84
36-101
2-15
5-39
7-35

12-57
9-60
12
2!
4
50
12
25

27
61
V
18
19

29
32
FECAL COLI
# DAYS
SAMPLING
10
10
5
6
12
11
15
18
6
5
7
4
9
8
9
RANGE
^S.10-20
-616
^=10-10
-W. 0-800
«10-20
<10-190
«.10-400
<^10-40
^.10-630
AlO-40
4.W
'"
-------
Table  1.  Continued.


COMMUNITY
Ovid
Continued
Pentwater
Pigeon
Plainfield
Township
Port Sanilac
Potterville
POPULATION
DESIGN
1600
1500
1300
370
700
1200
1400
CONN
1870
1385
1175
300
500
900
1360
LAGOON CAPACITY

CELLS

3
4
2
2
3

CELL 1
<: ^ H «
(d CJ O-, 55
< —
4.5
6.9
6.5
2.0
4.7
7.0
0 *"
72
48
72
60
72
60
CELL 2
< ^ H 3
                                                                                                                                                       cT
                                                                                                                                                       C4

                                                                                                                                                       
-------
Table 1. Continued.
                                                                                                                                                         5?


COMMUNITY
Reading
Reese
Saint Charles
Sand Lake
POPULATION
DESIGN CONN
1250
1450
2400
448
1120
1200
1950
365
LAGOON CAPACITY

to
i
2
2
2
2
CELL i
•t ^ f-. CO
td U (L, T&
S5- w £i
7.6
7.2
11.0
2.0
72
72
60
96
CELL 2
•< /-x H to
D£ 
-------
Table 1.  Continued.


COMMUNITY
Scottville
Shepherd
Stantop
Suttons Bay
POPULATION
DESIGN CONN
1900
1500
500
700
1140
1460
400
500
LAGOON CAPACITY
3
a
o
*a
2
2
2
3
CELL 1
s ^
< ^> H to
wo a* ^
53. WC
8.9
10.6
4.0
2.5
120
72
84
54
CELL 2
S G P. z
55- g~
10.1
6.1
3.0
2.5
120
72
96
60
CELL 3
50 *•>
•< /-x H W
bd O &4 55
03 < W w
•3 ~ Q~



2.0



60
DISCHARGE DATA - EFFLUENT QUALITY
FLOW PATTERN
A3
A4
I
to
V) £
3;
Ik 1-
10

Al 15
/
A4
A4
•A4
A4



Al
Al


0
15


15


1



PERIOD OF
DISCHARGE
DATES
FROM-TO
72-04-28
to 05-19
72-11-01
to 11-28
73-04-01
to 06-07
$2-03-28
to 04-19
72-04-29
to 05-25
72-11-01
to 11-30
73-10-15
to 10-31
72-05-01
to 05-08
72-10-23
to 10-27
73-03-2$
to 04-16
72-04-22
to 05-22
72-09-12
to 09-20
72-11-20
to 12-18
10-03
to 11-06
CO
1
^fc
8
28
68
22
36
30
17
8
b
1*
30
9
9

CHEMICAL
z
w t-
n
% 0
(
iy
39
15
23
21
8
E
6
8
15
4
—5

BOD
(mg/D
RANGE AVG
37-60
6-35
11-80
11-29
10-50
5-44
13-30
7-28
7-28
8-23
10-15
5-9
?-io

48
23
37
19
23
18
23
19
18
17
13
7

Susp.
Sol.
(ng/1)
RANGE AVG
17-74
3-38
7-170
12-72
6-68
2-82 '
10-40
11-33
11-23
12-36
12-62
12-20
3-37

54
21
25
44
32
16
19
19
15
30
34
14
12
FECAL COLI
t DAYS
SAMPLING
15
19
6
13
20
21
C
6
9
4
2(
4
(
RANGE
^10-130
^10-3400
* 10
290-31500
^10-1870
.410-760
^.10-40
A10-100
*10-70
^,10-10
^•10-100
^•10-210
^•10-40
EPA STD.
200 400
3.
X
X
2950
X
X
X
y.
x
X
X
X
X
800
X
7200
X
X
X
X
X
X
X
X



SHEET
11
NOTES

Ponds coverd
with ice
nearly all
this period


                                                                                                                                                               i
                                                                                                                                                               OS
                                                                                                                                                               c/j
                                                                                                                                                               a.
                                                                                                                                                               o
                                                                                                                                                              •8
                                                                                                                                                               o

-------
Table 1. Continued.






COMMUNITY
Vernon



Waldron





Wheat land
Township






Wright Township
Ottawa County






COPULATION





DESIGN CONN
900



600





1025















815



525





800















LAGOON CAPACITY



j
-J
4
*
3



2





3















CELL 1



X -^
•< ^ H en
W O pi "^
<: ^ Q *—
2.8



3.1





3.9















72



72





72















CELL 2



P3 "•
•rf --v t-< CO
•3 ^- Q —
3.0



3.1





3.0















72



72





72















CELL 3



•< .-* H co
W U B. Z
< ^ O -^
3.3









3.0















72









96

















M
B
<:
8
t.
A4

A2





A4



















e
CO
in g
gw
!fc M


10







5
















PERIOD OF
DISCHARGE


DATES
FROM-TO
72-10-18
to 10-30
73-03-26
to 04-11
72-05-05
to 05-10
72-09-25
to 10-17
73-10-07
to 11
72-04-24
to 05-11
72-10-31
to 11-27
73-04-01
to 05-04
73-10-08
to 11-01
72-04-10
to 04-28
72-11-08!
to 11-13
72-12-11
to 12-13
73-04-08
to 04-llj


1
<*
13

16

6

23



18

28

34

24

19

6

j

4

DISCHARGE DATA - EFFLUENT QUALITY
CHEMICAL



§3
* &
9

11

4

15



10



24

19

6

5

j

T




BOD
(mg/1)
RANGE AVG
2-10

13-25

6-24

5-37



25-38



9-18

1-4

10-25

4-6

1-5

17-45

4

19

15

20



30



15

2

17

5

3

29



Susp.
Sol.
(mg/1)
RANGE AVG
6-22

22-102

72-88

12-70



72-120



6-50

5-56

37-92

3-30

10-38

42-52

10

49

80

33



101



42

2U

65

15

20

35

FECAL COLI




* a
8

9

4

13



10

19

11

10







3





RANGE
^J.0-20

^.10-220

^10

^10-6300



^ 10-180

^10-10

A10-90

*• 10-680







A10-80




EPA STD.
200 400
X

X

X

X



X

X

X

X







X

X

X

X

X



X

X

X

X







X



SHEET
12


NOTES


























                                                                                                                                            I

-------
Table 1. Continued.






COMMUNITY
Yale









Cooper svllle


POPULATION




DESIGN CONN
1800









3600


1505









2400


LAGOON CAPACITY




,j
a
i_>
2









3


CELL 1



Is 15
11.5









10.0


72









72


CELL 2



II 11
6.5









10.0


72









72


CELL 3



5 G a. 55
2 < W M
< C- o ^










*12.0








' 	 ~~



*96


DISCHARGE DATA - EFFLUENT QUALITY

2
s
<
g
S!






	



Al



•]
w
g
St l-<
5



3i

~






PERIOD OF
DISCHARGE


DATES
FROM- TO
72-04-17
to 04-28
72-05-06
to 05-20
73-04-16
to 04-27
'73-05-07
to 05-18
73-10-22
to 11-02
72-11-01
to 11-15
73-05-08
to 05-15

CO
I
12

IS

12

12

11

16
8

CHEMICAL

P
n M
£ ri
h M
10

1C

10

10

10

11
- 4




BOD
(mg/1)
RANGE AVG
16-53

3-6

5-11

5-12

2-3

2-10
2-7

24

4

7

8

3

4
5



Susp.
Sol.
(mg/D
RANGE AVG
38-109

10-25

14-76

20-46

11-40

4-56
14-30

46

19

33

28

19

28
20

FECAL COLI


i
5 K>
g|
Sfc «
10

9

10

10

10

No
5




RANGE
^.10-1140

^10-720

^.10-30

^.io-io

^10-20

data
^.10




EPA SID.
200 400
X

X

X

X

X


X

X

X

X

X
	
X


X



SHEET
13


NOTES










*Total for
cells 3 & 4


                                                                                                                                                        I
                                                                                                                                                        3

                                                                                                                                                        <£,
                                                                                                                                                        50
                                                                                                                                                        I
                                                                                                                                                        I

                                                                                                                                                        f

-------
114
Pierce
Table  2.  Typical  data  showing  seasonal  trends  in  coli  concentrations,  lagoon  effluents, Michigan.
COMMUNITY
Ashley
(Spring 1972 Discharge)


































Ashley
(Spring 1973 Discharge)












Capac
(Spring 1972 Discharge)










SAMPLE
NO.
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
28
29
30
31
32
33
34
35
36
__
1
2
3
4
5
6
7
8
9
10
11
12
13
1
2
3
4
5
6
7
8
9
10
11
12
DATE
4-10
4-11
4-12
4-13
4-14
4-15
4-16
4-17
4-18
4-19
4-20
4-21
4-22
4-23
4-24
4-25
4-26
4-27
4-28
4-29
4-30
5-1
5-2
5-3
5-4
5-5
5-6
5-7
5-8
5-9
5-10
5-11
5-12
5-13
5-14
5-15
2-28
3-23
3-24
3-25
3-26
3-27
3-28
3-29
3-30
4-23
4-24
4-25
4-26
4-27
3-28
3-29
3-30
3-31
4-3
4-4
4-5
4-6
4-7
4-10
4-11
4-12
TOTAL COLI
120,000
322,000
265,000
355,000
450,000
51,000
23,000,000
290,000
117,000
1,230,000
66,000
83,000
73,000
68,000
78,000
67,000
8,100
31,000
1,600
400
9,000
500,000
11,600
68,000
46,000
55,000
540,000
74,600
300,000
48,000
28,000
10,500
6,900
6,300
10,800
65,000
660,000
1,600
21,000
22,000
23,000
56,000
4,800
47 ,000
31,000
	
	
	
	
	
12,400,000
645,000
150,000
865,000
1,200,000
1,800,000
91,000 000
860,000
1,850,000
496,000
52,300,000
35,000,000
FECAL
2,600
3,010
2,750
3,000
12,100
900
36,000
810
1,160
1,030
490
400
320
570
360
950
90
20
*10
•MO
*10

-------
                             Performance of Raw Waste Stabilization Lagoons in Michigan
115
Table 2.  Continued.
COMMUNITY
Capac Continued
(Spring 1972 Discharge)













Capac
(Spring 1973 Discharge)



















Ovid
(Winter-Spring 1972)











Ovid







Ovid
(Fall 1972 Discharge)



SAMPLE
NO.
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
1
2
3
4
5
6
7
8
9
10
11
12
13
1
2
3
4
5
6
7
8
1
2
3
4
5
DATE
4-13
4-14
4-17
4-18
4-19
4-20
4-21
4-24
4-25
4-26
4-27
4-28
5-01
5-02
5-03
4-02
4-03
4-04
4-05
4-06
4-09
4-10
4-11
4-12
4-13
4-16
4-17
4-18
4-19
4-20
4-23
4-24
4-25
4-26
4-27
4-30
3-14
3-15
3-16
3-17
3-18
3-20
3-21
3-22
3-23
3-24
3-27
3-28
3-29
4-24
4-25
4-26
4-27
4-28
4-29
5-13
5-15
10-03
11-01
11-09
11-10
11-11
TOTAL COLI
3,000,000
9,180,000
630,000
55,000
5,100,000
900,000
620,000
26,000
29,000
52,000
54,000,000
118,000
65,000
39,000
34,000
3,200
17,000
33,000
3,200
30,000
14.200
37,000
11,000
420,000
9,300
6,700
5,600
3,900
7,500
54,000
22,000
4,500
420,000
260,000
18,000
73,000
2,900,000
1,900,000
2,300,000
7,050,000
5,100,000
377,000
595,000
460,000
590,000
37,800
2,300,000
680,000
540,000
12,000
22,000
41,000
30,000
42,000
94.000
720,000
28,000,000
9,300
400
2,900
800
2,000
FECAL
3,000
2,800
790
780
4,000
7,000
1,150
450
400
850
1,900
160
170
80
30
10
10
20
50
240
20
50
30
10
170
10
100
10
50
40
10
10
90
50
140
150
30,000
1,000
50,000
53,200
53,500
2,800
20,500
53,000
42,000
2,160
1,580
2,610
100
400
40
90
40
250
390
-ilO
170
-10
-10
-10
-10
-10
COMMENTS




































Lagqons were full on
March 14 and over-
flowing under iced-
over conditions until
about April 15. Con-
trolled discharge began
under ice-free
conditions on April 24.













Discharged from cell
No. 3 under controlled
conditions following
several months' storage.


-------
116
Pierce
        Table  2.  Continued.
COMMUNITY
Ovid Continued
(Fall 1972 Discharge)




Ovid
(Winter-Spring
1973 Overflow)






















Rose City
(Winter-Spring 1972
Overflow & Discharge)






Rose City
(Fall 1972 Discharge)








Rose City
(Winter 1972-73 Overflow)











SAMPLE
NO.
6
7
8
9
10
11
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
1
2
3
4
5
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
DATE
11-12
11-13
11-14
11-15
11-16
11-17
1-16
1-17
1-18
1-19
1-20
1-21
1-22
3-12
3-13
3-14
3-15
3-28
3-29
3-30
3-31
4-02
4-03
4-04
4-05
4-06
4-23
4-24
4-25
4-26
4-27
3-06
3-07
3-08
3-09
4-08
4-09
4-10
4-11
5-06
9-27
9-28
10-17
10-18
10-19
10-20
10-21
11-08
11-09
11-10
12-19
12-20
12-22
1-25
1-26
1-27
1-28
1-30
1-31
2-01
2-02
3-19
3-20
TOTAL COL I
1,900
1,400
6,700
22,000
4,400
19,000
1,300
1,800
1,900
1,600
5,700
5,000
5,200
330,000
230,000
340,000
43,000
1,000
100
31,000
110,000
4,500
74,000
6,300
76,000
42,000
42,000
45,000
24,000
1,500
2,000
4,100,000
4,900,000
2,100,000
1,300,000
800,000
400,000
1,700,000
LI, 200, 000
1,700,000
59,000
490,000
47,000
2,000
3,000
4,200
1,800
230,000
210,000
48,000
4,300
2,500
1,800
35,000
240,000
600,000
23,000
5,700,000
2,200,000
6,000,000
2,300,000
'8,000,000
380,000
FECAL
*10
-*10
•4.10
30
10
^.10
-tlO
*10
-.10
*. 10
90
110
30
4,100
3,100
4,800
1,600
'10
*10
-C10
-610
10
40
160
70
•*10
<10
10
-tlO
^.10
10
60,000
110,000
10,000
10,000
16,000
12,000
47,000
31,000
3,300
10
290
50
10
10
30
-slO
360
3,700
1,800
«10
*10
-t 10
4,500
2,000
30,000
2,900
9,100
24,000
7,200
33,000
3,400
540
COMMENTS
















Ice cover nearly off
on March 12.




















Ponds still ice-coveret* .
Cell No. 1.







Cell No. 1
Cell No. 1
Cell No. 1



Ponds covered with ice.








Ice about out.

-------
Table  2.  Continued.
                              Performance of Raw Waste Stabilization Lagoons in Michigan     117
COMMUNITY
Rose City
(Spring 1973 Discharge)






Pentwater
(Spring 1972 Discharge)









Pentwater
(Spring 1973 Discharge)























Scottville
(Spring 1972 Discharge)













SAMPLE
NO.
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
9
10
11
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
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
DATE
4-09
4-10
4-11
4-17
4-18
4-19
4-23
4-24
4-24
4-24
4-25
4-26
4-27
4-28
5-01
5-02
5-03
5-04
5-05
4-02
4-03
4-04
4-05
4-06
4-09
4-10
4-11
4-12
4-13
4-16
4-17
4-18
4-19
4-20
4-23
4-24
4-25
4-26
4-27
4-30
5-01
5-02
5-03
5-04
5-01
5-02
5-03
5-04
5-05
5-08
5-09
5-10
5-11
5-12
5-15
5-16
5-17
5-18
5-19
TOTAL COLI
480,000
54,000
790,000
120,000
3,400
8,000
2,000
4,800
6,100
8,000
131,000
97,000
56,000
146,000
86,000
190,000
89,000
310,000
105,000
800
2,000
3,200
1,300
40,000
36,000
2,100
300
26,000
52,000
34,000
17,000
23,000
400
1,900
3,900
29,000
38,000
3,500
5,800
900
2,300
24,000
6,600
5,200
37,000
38,000
52,000
213,000
38,000
32,000
113,000
2,500
780,000
9,300,000
43,000
83,000
42,000
14,200
2,000
FECAL
10
50
150
^10
-.10
20
— 10
-10
10
- 10
^10
— 10
—10
— 10
-10
-elO
10
-10
70
—10
—10
10
•cio
—10
<10
— 10
—10
*10
40
20
10
-10
—10
— 10
20
10
310
— 10
—10
-10
—10
20
*10
20

30
30
10
130
70
70
-.10
-110
—10
-S10

* 10
-£10
— 10
COMMENTS




























































-------
118     Pierce
       Table 2.  Continued.
COMMUNITY
Scottville
(Fal3J1972 Discharge)
















Scottville
(Spring 1973 Discharge)




Shepherd
(Spring 1972 Discharge)






























SAMPLE
NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
1
2
3
4
5
6
1
2
3
4
5
6
7
a
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
DATE
11-01
11-02
11-03
11-06
11-07
11-08
11-09
11-10
11-13
11-14
11-15
11-16
11-17
11-20
11-21
11-22
11-24
11-27
11-28
4-16
4-17
4-18
4-19
4-23
4-24
3-29
3-30
4-04
4-05
4-06
4-10
4-11
4-12
4-13
4-17
4-18
4-19
4-20
4-24
4-25
4-26
4-27
5-01
5-02
5-03
5-04
5-08
5-09
5-10
5-11
5-15
5-16
5-17
5-18
5-22
5-23
5-24
5-25
TOTAL COLI
6,500
9,600
26,000
190,000
22,000
9,000
12,000
140,000
34,000
230,000
230,000
41,000
210,000
21,000
100,000
53,000
90,000
370,000
400,000
25,000
19,000
2,300
25,000
37,000
3,700
1,100,000
1,400,000
730,000
764,000
625,000
490,000
7,300,000
126,000
94,500
77,000
104,000
33,000
31,000
40,000
54,500
20,000
9,000
36,500
250,000
41,000
14,900
65,000
89,000
250,000
8,500
71,000,000
8,000,000
11,600,000
9,800
96,000
98,000
4,700,000
51,000
FECAL
60
20
160
20
200
410
30
580
230
1,100
710
...
3,500
70
2,801
90
650
970
2,700
10
410
440
-6.10
*10
4.10
7,000
10,000
6,000
18,600
31,500
4,200
1,100
390
990
290
2,390
490
870
650
390
150
50
40
1,870
560
130
170
1,190
110
10
440
^10
^10
-610
^.10
10
40
20
COMMENTS

























































-------
Table 2.  Continued.
                            Performance of Raw Waste Stabilization Lagoons in Michigan    119
COMMUNITY
Shepherd
(Fall 1972 Discharge)

















SAMPLE
NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
DATE
10-30
10-31
11-01
11-02
11-06
11-07
11-08
11-09
11-13
11-14
11-15
11-16
11-20
11-21
11-22
11-27
11-28
11-29
11-30
OTAL COL1
23,000
1,600
2,100
1,000
2,100
2,200
3,300
2,300
2,000
1,500
3,000
3,400
300
2,800
32,000
20,000
8,600
15,000
1,900
FECAL
10
410
10
xio
-U.O
40
40
20
30
.410
30
20
10
,610
30
760
370
350
X10
COMMENTS



















-------
   9O--
  80--
  70--
  6O-
  50-
V40--
  30--
   20--
   10-•
                                                  SUSP.  SOLIDS

                                                  3 or  more  CELLS




                                                  SUSP  SOUDS-2 CELLS
                                                                                          BOD-3 or more  CELLS
                                                                                         BO D- 2 CELLS
                                    90
             —r
              O.I
10
                  50
99
99.9
                                     (X)   PROBABILITY   OF   NOT   EXCEEDING   Y
 Figure 1.  Comparison of effluent quality 2-cell systems vs 3 or more with long period storage before discharge, Michigan.

-------
    50- -
— 4O- -
   30--
    20--
    10--
                                                                                                                                    8
                                                                                                                                    •S,
                                                                                                                                     f
                                                                                              I

                                                                                              f
                                                                                              I

                                                                                              I
                                                                                              1
                                                                                              3-
               O.I
    1
   10                 50
(X)  PROBABILITY   OF   NOT  EXCEEDING   Y
                                                                               90
                                                                                                        99.9
  Figure 2. Comparison of effluent quality 2-cell systems vs 3 or more with long period storage before discharge, Nfichigan.

-------
  90--
  8O-
  70--
  60--
> 40--
  SO--
  20- -
   10- •
                                                                                                                                  to
                                         10                 50                90
                                       (X)  PROBABILiTY   OF   NOT   EXCEEDING  Y
                                                                                             99
                                                                                                        99.9
   Figure 1  Effluent quality 49 waste stabilization lagoons with long period storage before discharge, Michigan.

-------
                                      Performance of Raw Waste Stabilization Lagoons in Michigan   123
               SUPPLEMENTARY STUDIES OF LAGOONS OF VARIOUS TYPES
      The preceding report sets forth the  results of
studies, conducted by this investigator during the fall
of  1973, of performance of  49 municipal lagoon
systems in Michigan treating raw wastewater. These
systems were selected for study because, individually
and collectively, they typify features of construction,
loadings, and maintenance and operational practices
which readily accommodate a common mode involv-
ing long  period  storage followed by control  short
period discharge. Monthly  records  of one  to two
years duration, supplemented by chemical and bacter-
iological data on samples collected during discharge
periods,  provide  an excellent indication of the per-
formance capability of the process and  means by
which the adverse effects on the process of prolonged
periods of ice cover common to many northern states
may be overcome.

      Supplementary studies were undertaken during
the summer of  1974 with the following objectives:
To evaluate performance of raw waste  stabilization
lagoons in other northern  states when  managed  in
essentially similar ways; to examine the methods in
use and  results of chlorination for coliform bacteria
destruction both at lagoons so managed  and  those
with  continuous discharge; and  to  collect available
information on  nitrification phenomena. Results  of
these studies led to an examination of performance of
lagoons used as oxidation ponds following trickling
filters at several  typical installations and observations
of  performance  of an aerated lagoon followed by
chemical  precipitation  for phosphorus removal and
by chlorination for coli destruction.
     Supplementary Studies of Raw Waste
       Stabilization Lagoons with Long
       Period Storage and Intermittent
                    Discharge

      Several of the northern states have adopted a
program  with  criteria for  design and operational
control of raw waste stabilization lagoons very similar
to  those in Michigan.  Typical of  these  are  the
Minnesota and North Dakota programs.

Minnesota

      As in Michigan the Minnesota Pollution Control
Agency has  established criteria  for  raw waste  sta-
bilization lagoon loadings in the 100 person per acre
range with provision for long period storage, restric-
ting discharge of effluents to early spring and late fall
with total retention from May 15 to October 31 and
during winter months. Discharge is authorized by the
state  agency  after  testing of  samples  of lagoon
contents at point of discharge show BODj not greater
than 25 mg/1, total suspended  solids not greater than
30  mg/1, and fecal coli concentrations not to exceed
200 MPN/100  mis.  Present  requirements  call for
sampling prior to and during discharge and reporting
of results using the standard state report forms.

      Some elements of the state program essential to
effective performance are  the following, excerpted
from  their Recommended Procedure for Sampling
and Discharging of Wastewater Stabilization Ponds.

           Prior to any impending pond discharge a
      representative pond sample(s) shall be taken to
      determine pond effluent quality. This sample
      shall be  analzyed for 5-day biochemical oxygen
      demand  (BOD,), Total  Suspended  Solids
      (TSS), and fecal coliform bacteria content In
      municipalities  with unusual industrial wastes
      other tests  by  special request  of the Agency
      may be required.

           All pond discharges  shall have a 5-day
      BODj concentration  not to exceed 25 mg/1, a
      TSS concentration not to exceed 30 mg/1, and a
      fecal coliform bacteria count not to exceed 200
      most probable number (MPN/100 ml).2

           Notification of proposed discharge of the
      ponds shall be made  to  either  the  district
      representative  in  your  area or the Section of
      Municipal Works (MPCA). The request can be
      written  or by telephone and must Include  the
      analytical results of  the representative pond
      sample.  Should the results of analysis of  the
      required samples exceed effluent standards, the
      sampling procedures  shall  be repeated until
      effluent standards can be met. Effluent may be
      discharged only when it is in conformance with
      the applicable  regulations  and terms of  the
      permit issued for the disposal system.

           After notification, and  if there is  no
      objection by  the staff, discharge  should be
      accomplished by properly utilizing gate adjust-
      ment in the outfall structure. Utilization of gate
      adjustments should  allow  the  pond to  be
      lowered down to the 18-inch to 1 foot level. At
      no time  should the pond be lowered beyond
      the 1 foot of depth level.
     2If fecal  coliform group  organisms exceed  200
MPN/100 ml, the effluent should be disinfected by use of
chlorine or  other approved  methods to bring it within
standards.

-------
 124     Pierce
            Caution should be used when discharging
       so a minimum of bottom scouring occurs. A
       rapid 01 uncontrolled  discharge  could cause
       bottom scouring, thereby removing the seal.

            Calculation of needed storage capacity
       should be  made by  the  operator.  If more
       storage capacity is required than provided for
       by one release  of a secondary pond, a refilling
       of the secondary pond  and  a repeat of pro-
       cedures  should be undertaken  (NOTIFICA-
       TION FOR SECOND DISCHARGES IS ALSO
       REQUIRED).

            When refilling  the secondary from the
       primary  for a  second discharge,  the operator
       should only utilize gates in the control struc-
       ture. Draw off from  the  primary should be
       conducted  carefully   because  short  circuit
       effects can occur if the refilling is  too rapid or
       bottom discharge valves are utilized. Improper
       draw down of  the primary  could cause poorly
       treated wastes  to fill  the secondary pond,
       thereby lowering the  quality  in the secondary
       pond so that further time would be needed to
       stabilize, thereby causing further  delay before
       tests show  the quality  is  satisfactory for a
       second discharge.

           A  minimum of  two weeks  of actual
      discharging  is  recommended.  This  does not
      include time for  testing between  discharges.
      The discharge should be slow and continuous in
      nature with daily adjustment of the  outfall
      gates.

           During discharge testing ... listing shall be
      undertaken to substantiate effluent quality, i.e.,
      twice a week until the  discharge is complete.
      The results of tests during discharge should be
      submitted on the next regular monthly report
      form.

           Ponds do not operate  themselves; they
      require proper operation and regular mainten-
      ance if extensive and expensive renovations are
      to be eliminated.

      The  state  agency summarized the results  of
laboratory analyses of samples  collected at typical
municipal  raw wastewater  lagoons  during fall 1973
and spring  1974. In the  fall,  BOD5 at 36  of the 39
installations  sampled was  less  than  25  mg/1 and
suspended solids less than 30. Tests for fecal coli were
made  on  samples from 17 installations and for total
coli at 14 other. All  fecal coli  concentrations were
200 or less per 100 mis and 10 of the 14 tested for
total coli were 1000 or less with maximum 3800 for
the other 4. Effluent quality for the spring discharge
as  measured  by these  parameters was  generally
similar. Tests were made at 49 municipal installations.
BOD5   at  5  lagoons  exceeded 25  mg/1 with  3
exceeding 30,  the  high  value  being  39. Suspended
solids values ranged  from 7 to  128 with 16 of the 49
exceeding 30 and 10 greater than 40. Only 3  of the
45 tested for fecal coli exceeded 200 per 100 mis.
 North Dakota

      Design  criteria  and modes of operation  esta-
 blished by the state regulatory  agency (Department
 of Public Health) are similar in most respects to those
 in effect in Michigan and Minnesota. One significant
 difference is the firm requirement, adopted early this
 year, that at least three cells be provided and that the
 area in the primary cell be approximately one-half the
 total surface  area  of all the ponds. Total organic
 loading  on the primary cell may not exceed  30
 pounds  of BOD5  per  acre  per day and the  total
 loading for all ponds may not exceed 20 pounds per
 acre  per day. Further, the total hydraulic loading,
 including  infiltration and inflow,  shall be used to
 determine the volume required to provide a minimum
 storage capacity of 180 days between the 2 and 5
 foot  liquid levels. Although provision must be made
 for series operation "to meet effluent standards and
 provide  for better  nutrient reduction," both series
 and  parallel   operation  is  encouraged to  provide
 desirable flexibility for circumstances when one cell
 must be taken out  of use for repair, enlargement or
 for some other reason.
      The  standards  state that "For winter storage
the  operating level  should be  lowered  before  ice
formation  and gradually increased to 5  feet by  the
retention of winter flows. In the spring, the level in
the  secondary cell can be  lowered to  any desired
depth providing  the  liquid meets effluent standards
and approval to discharge has been obtained."
      Discussions  with responsible  personnel  of the
state  regulatory  agency reveal that lagoon systems
built  and operated in conformity with these  princi-
ples can  consistently  meet EPA requirements  for
BOD, and fecal  coli  and come within  reasonable
range of the requirement  for total suspended solids.
The value of  regular operational control in  accor-
dance with well established principles is recognized.
Upper Peninsula, Michigan

      Several small communities in Michigan's Upper
Peninsula  have constructed raw waste stabilization
lagoons during the last 3 years. Five of these systems
had a spring  discharge  this year following several
months storage during the rigorous  northern winter
with long  periods of ice and snow cover. These
systems  are all approximately  at design  loading of
100 persons per acre.  Operational and maintenance
practices conform to those outlined in this report for
Michigan  communities. None  of the systems have
chlorination.

-------
                                     Performance of Raw Waste Stabilization Lagoons in Michigan     125
 Table 1. Discharge data, Upper Peninsula Lagoons, Spring 1974.

Community
Bessemer Township
(2 cells)





Bergland Township
(3 cells)



Wakefield
(2 cells)



Total Coli
Powers
(2 cells)



Gwinn
(2 cells)



Date BOD5 Suspended
0974) OM» «*
Ice breakup began 4/10
5-7
5-16
5-17
5-18
5-19
5-20
Ice breakup began 4/22
5-1
5-3 o
5-13 Z
5-16
Ice breakup began 4/19
4-24
4-29
5-6
5-13
5-20
; zero ice 4/24
--
10
16
13
19
18
; zero ice 4/26
u
3 2
3*
06
; zero ice 4/23
15
27
21
25
23

-
10
32
13
16
23

72
82
60
30

21
34
35
52
54
Fecal Coli
per 100 mis

<100
<100
<100
<100
<100
<100

<100
<100
<100
<100

100*
2100*
700*
300*
100*
Ice breakup began 4/8; zero ice 4/18
4-25
5-7
5-9
5-10
5-15
6-4
6-5
6-17
6-18
CO
•!_»
M
Q
o
2


3
a
G
o

3
&
o
%


3
rt
<5
I

140
<10

M
< 10


< 10
<10
Belding, Michigan

      Studies conducted by the City of Belding on its
5-cell raw waste stabilization lagoons shed additional
light  on performance  of  facilities  of  this type. Of
particular interest  are the  data on progressive  nitrifi-
cation through the several cells operated in series and
related levels of  BOD5   and suspended  solids. Of
interest also are the data on  coliform reduction by
chlorination of the effluent.

      The project is designed for long period storage
and  seasonal discharge   with provision  for spray
irrigation  of the effluent on nearby lands.  Studies
have been financed by EPA R&D Grant and a wealth
of information has been  collected for a period of
several years.

Facilities

      Raw wastes are collected by  the municipal
sewer  system from  a population  of about  4,000.
Some minor industrial  wastes are  included. At the
lagoon site wastes flow through a small anaerobic cell
followed by four larger cells operated generally in
series. Total surface area is about 55 acres, Cell No. 2
having about 20 acres, Cell No. 3 15 acres, and Cells
No. 4 and No. 5 each about 7.5 acres.

Performance

     Wastes are  generally weak by reason of exten-
sive  infiltration  of  surface  water into  the sewer
system. This is reflected in Table 2 of the Laboratory
Analyses Report  prepared by the  certified resident
operator for samples  collected on July  21, 1972.
These are typical  values for late spring, summer, and
early fall conditions in the several lagoons.  Typical
also  are the values for samples collected from each of
the first four ponds in the series. The quality of the
raw  waste varies widely depending on rate of infil-
tration  and inflow at the time. Quality as measured
by most of the parameters undergoes little change in
the fourth and fifth lagoon.

-------
 126     Pierce
      Quality of the effluent from Pond No. 5 during
 cold  weather  conditions  is indicated  in  Table 3,
 Samples were  collected  during  two periods of dis-
 charge of the chlorinated effluent to the river. Several
 trends may be noted. During the January  discharge
 BOD5 dropped to a very low level. Suspended solids
 concentrations also  were markedly lower, probably
 by reason of reduced algal concentration. Ammonia
 nitrogen was very high compared with warm weather
 levels, continuing  to increase as water temperatures
 became  critically  low in  late January. Phosphorus
 concentrations increased gradually over the period.
 No coli were found in the chlorinated effluent.

      Characteristics of the effluent from Pond No. 5
 discharged  to the  river  are shown  again  in  the
 following analyses (Table 4) conducted by the opera-
 tor for the 1974 spring discharge. All ponds were full
 and overflowing at that time with no ice cover.

      Table 4  indicates  that BOD5 concentrations
 remain low at about the same  level as in the preceding
                                       November and that suspended solids concentrations
                                       are beginning to rise  with increase in algae  popula-
                                       tion.  Significantly, ammonia nitrogen  has dropped
                                       prior  to April  26  and continues to drop, rapidly
                                       reaching mid-summer levels. Lowering in phosphorus
                                       levels is also apparent. Total coli concentrations vary
                                       for no apparent reason.

                                       Nitrification

                                             The seasonal  fluctuation in ammonia concen-
                                       trations, associated with changes in water tempera-
                                       ture  are clearly  indicated in  Table  5 and Figure  1,
                                       data for which were derived from the plant operation
                                       reports. Ammonia concentration (NH3-N) is consis-
                                       tently below 0.5 mg/1 during July-September rising
                                       gradually  through   October-January   with   little
                                       nitrification  during periods of ice cover mid-January
                                       through March,  remaining at the  10-15 mg/1 level
                                       until sometime  in May in 1972 and late March in
                                       1973. The lagoon surface  was ice covered in  1972
                                       until late April and about one month earlier in 1973.
Table 2.  Quality of contents of 5 lagoons operated in series at Belding, Michigan.
Analysis
D.O.
Ammonia Nitrogen
Nitrate Nitrogen
pH
Total Phosphorus
Ortho Phosphorus
Suspended Solids
Influent
Raw Sewage
0.0 mg/1
34.6 mg/1
0.1 6 mg/1
7.1
12.5 mg/1
10 mg/1
121 mg/1
Eff. from
Pond No. 1
0.0 mg/1
27.3 mg/1
0.2 mg/1
7.3
9.9 mg/1
7.8 mg/1
76 mg/1
Eff. from
Pond No. 2
27.8 mg/1
2.7 mg/1
0.44 mg/1
8.6
3.0 mg/1
1.6 mg/1
146 mg/1
Eff. from
Pond No. 3
11. 2 mg/1
0.4 mg/1
0.5 mg/1
8.6
2.5 mg/1
2.0 mg/1
31 mg/1
Eff. from
Pond No. 4
5.0 mg/1
0.6 mg/1
0.1 9 mg/1
8.0
4.4 mg/1
3.4 mg/1
17 mg/1
Eff. from
Pond No. 5
10.8 mg/1
0.5 mg/1
0.08 mg/1
8.6
2.9 mg/1
2.3 mg/1
22 mg/1
Table 3. Effluent quality-Pond No. 5, late fall and winter discharge.
Date
1973
11-5
11-7
11-13
11-20
11-22
D.O.

10.5
10.7
10.8
9.7
10.0
BOD5

3.0
8.9
10.3
9.4
8.7
Suspended
Solids

52
60
102
78
52
NH3-N

2.4
5.58
5.58
5.82
5.22
NO3-N

0.35
0.33
0.41
1.1
0.97
Total
P

2.7
3.9
3.9
3.9
3.5
Total Coli
(MF).

0
0
0
0
0
1974
1-15
1-18
1-22
1-25
1-29
     Total Discharge - 57,559,000 gallons
 9.7
10.9
 8.2
 5.0
10.5
7.2
1.4
5.4
1.2
2.4
 9.5
11
13.5
12.5
30
 5.7
 5.96
 7.4
 9.0
10.8
    Total Discharge - approximately 38 million gallons.
0.82
0.66
0.22
0.16
0.15
3.4
3.6
4.0
4.4
5.1
0
0
0
0
0

-------
                                    Performance of Raw Waste Stabilization Lagoons in Michigan     127
Table 4. Characteristics of the effluent from Pond No. 5.
Date
1974
T26~
4-29
5-1
5-6
5-7
5-8
5-13
D.O.

17.5
12.0
10.7
9.4
10.0
10.3
9.6
BOD5

6.7
10.5
7.8
8.9
9.8
7.0
9.1
Suspended
Solids

53
30
16
23
12
16
27
NH3-N

3.3
3.5
2.6
1.0
0.75
0.8
0.1
NO3-N

1.1
1.0
1.3
1.4
1.5
1.4
1.0
Total
P

2.8
2.9
3.0
3.2
2.8
2.7
2.5
Total Coli
(MF)

—
<100
<100
1800
--
5500
<100
 Note: All chemical results expressed as mg/1.
    14--
                                             0  I  N  I  0   I  J I F
 Figure 1.  Seasonal variation in ammonia nitrogen lagoon effluent, fielding, Michigan, April 1972 - August 1973.

-------
 128    Pierce
 Table 5. Data showing seasonal variation in ammonia nitrogen in lagoon effluent, Belding, Michigan, 1972-1973.

Date
1972
Mar. 20
Mar. 25
Mar. 30
Apr. 4
Apr. 14
Apr. 19
Apr. 29
May 4
May 9
June 16
June 21
June 26
June 30
July 6
July 1 1
July 17
July 21
July 26
July 31
Aug. 5
Aug. 15
Aug. 21
Aug. 25
Aug. 30
Sept. 4
Sept. 9
Sept. 14


Day of
Year

79
84
89
94
104
109
119
124
129
167
172
177
181
187
192
198
202
207
212
217
227
233
237
242
247
252
257


NH3
(mg/1)


17.2
27
19
17
13
13.5
8.0
6.8
2.0
1.1
1.1
1.1
0.6
0.4
0.3
0.5
0.3
0.03
0.05
0.04
0.3
0.3
0.3
0.03
0.2
0.06


Date

Sept. 19
Sept. 25
Sept. 29
Oct. 9
Oct. 14
Oct. 19
Oct. 25
Oct. 30
Nov. 15
Nov. 18
Nov. 27
Nov. 30
Dec. 7
Dec. 11
Dec. 14
Dec. 19
Dec. 21
Dec. 26
Dec. 29
Dec. 31

1973
Jan. 1
Jan. 2
Jan. 5
Jan. 8
Jan. 11
Jan. 15
Jan. 18
Day of
Year

262
267
271
282
287
292
298
303
319
322
331
334
341
345
348
353
355
360
363
365


1
2
5
8
11
15
18
NH3
(mg/1)

0.3
0.3
0.3
0.8
1.8
1.7
3.5
3.6
1.5

0.2
0.4
1.6
0.9
1.6
1.2
2.1
2.1
2.3




2.4
2.8
3.0
3.1
5.7
6.0
Date

Jan. 22
Jan. 25
Jan. 29
Feb. 1
Feb. 5
Feb. 8
Feb. 12
Feb. 15
Feb. 19
Feb. 22
Feb. 26
Feb. 28
Mar. 16
May 24
May 31
June 7
June 14
June 21
June 28
JulyS
July 12
July 19
July 25
Aug. 2
Aug. 16
Aug. 23



Day of
Year

22
25
29
32
36
39
43
46
50
53
57
59
75
144
151
158
165
172
179
186
193
200
206
214
228
235



NHo
(mg/1)

7.4
9.0
10.8
11.1
8.5
10.1
10.6
10.1
9.8
9.6
11.1
10.4
9.6
0.4
0.5
0.1
0.4
0.3
0.3
0.3
0.3
0.2
0.2
0.2
0.2
0.2



Disinfection

      Chlorination of lagoon effluent  both during
discharge to the river and when irrigating is a regular
established practice. Facilities consist of  gas chlori-
nators discharging through diffusers installed at the
entrance to a baffled chlorine contact tank. Control
of chlorine feed is exercised  so as to maintain a
chlorine  residual (total  combined  chlorine by OT
method) of as close to 0.5 mg/1 as possible. Records
indicate that this has been done effectively most of
the time with little difficulty.

      As shown in Tables 3 and 4, these practices
usually have been effective in destruction of  total
coli. Other data at the on-site laboratory indicate that
there are  seldom any  fecal  coli  found  in   these
chlorinated wastes.
     Chlorination at Continuous Discharge
             Stabilization Lagoons

      The July  1,  1974,  printout  of the EPA data
bank (STPOM forms 5 and 12) identify nearly 100
municipal installations with Chlorination facilities at
raw waste stabilization lagoons. The majority of these
use gas type chlorinators with chlorine introduced at
the point where the lagoon effluent enters a chlorine
contact  tank  as it is being  discharged  for  final
disposal. It is discouraging and quite revealing to note
that only seven of these are reported as recording
chlorine  residuals after the contact period and only
four perform bacteriological analysis,  two for fecal
coli and two for total  coli. It is expected, of course,
that most if not all of these municipalities will soon
be performing such  tests to meet EPA regulations and
NPDES requirements.

-------
                                      Performance of Raw Waste Stabilization Lagoons in Michigan   129
      This investigator made a search of the technical
literature and talked with program directors in many
states, attempting to locate and obtain useful, reliable
information on lagoon effluent disinfection practice.
The paucity  of available data of this kind confirms
that only a few municipalities in the nation perform
sufficient laboratory tests of this nature  to provide a
basis either for control  of the process or a reliable
indication of  what  is  actually being  achieved  in
bacterial control.

      In many of  the  states there are  few  if any
installations depending  on  effluent  chlorination for
bacterial  control.  Rather  the  natural  process  of
die-off  during  long period  storage under conditions
prevailing in the  lagoon  are depended upon for this
purpose.  It  is clear, however, that under  many
circumstances  of high loading, short residence time
and unfavorable  climatic  conditions, high concen-
trations of  fecal  coli have been found  and  can  be
expected to be present in the lagoon discharge.
      It is of interest, therefore, to examine the data
 available on effluent disinfection practice and results.


      As indicated herein the City of Belding, Michi-
 gan, has established an effective method of disin-
 fecting, with chlorine,  effluents  discharged  from a
 system  of  five  lagoons  operated  in series after long
 period storage.  No data are available at this location
 for short period storage or continuous discharge.
Chesterfield Township studies

     The  City  of Detroit  operates  a raw waste
stabilization lagoon facility serving limited residential
areas  in Chesterfield  Township,  Macomb  County.
This facility is designed and operated for continuous
discharge with effluent disinfection. There are three
lagoons each of about equal size with a total area of
about 70 acres. Water depth is maintained constantly
at about 6 feet.

     Raw  wastewater is delivered to the lagoon site
by  force  main  from  a  remote  site. Daily flows
fluctuate between 0.5 mgd and 2.0 mgd, influenced
by  infiltration and inflow to the  sewer system. The
wastes are  directed through the three  cells in series,
then flow by gravity through a chlorine contact tank
after initial  mixing with  chlorine  from  two 1-ton
cylinders. Chlorine is usually fed at a constant 90 Ib
per day rate.  Chlorine  residuals  after  5  minutes
contact are  always at least  1.0 mg/1 and usually
higher.

     Alum is fed into the pipe connecting Cells 2
and 3  at a constant rate  of 6& gallons per hour (55
mg/1 A12S04). This is found to assist materially in
clarification of the contents of the final cell.

     Samples  of the  effluent are collected twice
daily for chemical and bacterial analyses and chlorine
residuals are determined  on each sample. The  data
reported by the City of Detroit wastewater treatment
plant operations staff are summarized in Table 6.
Table 6.  Effluent quality 3-cell continuous flow lagoons, Detroit (Chesterfield Twp.), Michigan, January 1973
         May 1974.
Month
1973
Jan.
Feb.
Mar.
Apr.
May
June
July
Aug.
Sept.
Oct.
Nov.
Dec.
1974
Jan.
Feb.
Mar.
Apr.
Mav
PH

6.5-6.8
6.7
6.2-8.4
7.7-8.7
8.1-9.0
7.8-8.6
7.0-8.3
7.4-8.5
7.9-8.6
7.3-7.9
7.6-7.9
7.8-8.2

7.6-8.1
6.8-7.5
7.7-8.5
7.2-8.1
7.5-8.7
BOD5 (n
Range

1-9
3-13
5-14
2-7
2-24
4-26
2-16
1-21
0-19
0-16
0-11
1-4

1-8
5-36
3-29
1-4
1-13
Avg.

4
9
10
4
10
16
11
5
4
4
2
2

2
19
9
2
1
Susp. Solids
Range

11-82
17-124
10-200
18-126
8-50
14-102
1949
5-68
3-83
2-38
4-29
3-47

4-19
9-82
8-36
15-66
13-58
(mg/1)
Avg.

34
35
68
47
31
61
47
31
34
15
11
14

7
39
21
35
41
Total P
mg/1

2.8-6.0
5.2-8.4
5.5-7.2
3.4-6.1
3.0-6.9
3.24.8
1.54.1
1.6-3.0
0.5-2.5
2.2-6.3
1.6-2.9
2.74.5

4.2-6.7
1.9-6.3
3.0-7.6
1.7-3.1
1.6-2.8
Fecal Coli
per 100 mis

<23-230
<23
<23
<23
<23
<23
<23
<23
<23
<23
<23
<23

<23-11000
23-2300
<23-730
<23
<23

-------
  130
Pierce
       No  reliable  data  are available  on fecal coli
 concentrations  of lagoon  effluents prior to  disin-
 fection although spot samples taken  from time  to
 time indicate that  concentration is variable, ranging
 from less than 10 to over 1000 per 100 mis.

       The effluent samples are routinely tested for
 total  phosphorus.  Concentrations  range  generally
 from 1.5  to  6.0 mg/1 as P. No data are available on
 phosphorus levels in the raw waste.

 Illinois studies

       The Illinois Environmental Protection Agency
 assembled information for this report from their data
 printout system on nine municipal waste stabilization
 lagoons with  chlorinated  effluents.   All  of  these
 systems are  of the continuous flow-through  type.
 Present loadings  are  90-105 persons per acre (total
 acreage) except for facility No. 4  which had about
 160 persons per acre when sampled. This facility has
 relatively small volume and surface area in Cells 2 and
 3.

      Samples  are  collected  and  analyzed by the
 agency. Results are summarized in Table 7.

      No information is available at this writing on
 the  type of chlorination facilities, chlorine  feeding,
 and mixing and contact tanks, nor is there  infor-
 mation on chlorine feed control related to chlorine
 residual levels and coliform concentrations. Such data
 are  needed  to determine the capability  of the
 facilities to achieve low fecal  coli levels dependably.

      The  BOD5, suspended solids concentrations are
 generally a bit higher than noted for the long period
 storage  and  controlled discharge lagoons reported
 here but ammonia and nitrate levels are very similar
 to  these.  Here  again  high  ammonia levels  were
 associated  with cold weather  and lowest levels with
 summer temperatures.
                                                     Chlorination of Lagoon Contents


                                                    A  small  residential subdivision known as Red
                                              Oaks of Chemung is served by a wastewater treatment
                                              system consisting of 2-cell lagoons followed by spray
                                              irrigation. The facilities are  operated by the County
                                              Department of Public Works.


                                                   The two cells are operated in  series. All raw
                                              wastewater is delivered to Cell No. 1 and transferred
                                              by pumping  to Cell  No. 2  where  the contents are
                                              isolated for several  weeks before chlorination of the
                                              total liquid surface area prior to release for spray
                                              irrigation.

                                                   The following procedure,  established  by the
                                              consulting engineer who designed  the  facilities, is
                                              utilized by operating personnel  to  assure effective
                                              disinfection.

                                                        Irrigation from the north lagoon shall not
                                                   be carried out until the following chlorination
                                                   procedures have been accomplished. Twenty-
                                                   four hours prior to irrigation an application of
                                                   at least 8 mg/1  of available chlorine shall be
                                                   applied to the lagoon. The application shall be
                                                   as evenly distributed as  possible by  broad-
                                                   casting. Two  hours before irrigation a second
                                                   application of at  least 2  mg/1  of available
                                                   chlorine shall be similarly accomplished. Just
                                                   prior to each chlorine application at least two
                                                   samples shall be  collected  and  a  dissolved
                                                   oxygen test accomplished with the results being
                                                   recorded on the data forms. Before  pumping to
                                                   irrigation   a sample  shall be  collected and
                                                   analzyed for a free chlorine residual-no spray-
                                                   ing shall be accomplished unless a substantial
                                                   chlorine residual is  displayed  and  duly  re-
                                                   corded. These chlorine tests shall be conducted
                                                   at least twice during the period  of pumping to
                                                   determine  that a chlorine residual is being
                                                   maintained. If no residual can be detected,
                                                   spraying shall be halted.

                                                       When a chlorine residual  has been esta-
                                                  blished and maintained, with additional spray-
Table 7.  Summary by  Illinois EPA analysis of results from nine municipal waste stabilization lagoons with
         chlorinated effluents.
Facility
No.
1
2
3
4
5
6
7
8
9
No.
Samples
7
8
2
6
9
7
3
9
3
BOD5I
Range
1-37
4-27
13-27
18-50
1-38
15-45
0-25
12-46
9-33
Avg.
8
19
21
35
9
25
12
23
21
Susp.Sol.(mg/I) NH3-N
Range Avg. Range
4-74
6-80
11-35
70-160
1-19
13-88
1-58
3-66
22-92
26
45
26
105
8
60
25
38
54
0.7-7.0
0.2-1.2
0.4-1.8
0.3-3.1
0.1-5.9
0.2-8.3
0.2-7.1
0.2-3.0
0.3-2.5
(mg/1)
Avg.
2.1
0.5
1.1
1.0
1.0
2.7
2.5
0.9
1.0
NO3-N (mg/1)
Range Avg.
0-0.3
0-0.8
0.1-0.7
0-0.5
0-0.6
0-1.0
0.2-0.3
..
0-1.9
0.1
0.2
0.4
0.2
0.1
0.3
0.2
..
0.6
Fecal Col. (MPN)
p Geom.
Ran8B Mean
100-600
100-1700
0-100
100-3400
10-30000
10-1000
50-100
0-1300
0-140
184
237
10
546
272
116
62
19
5

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                                     Performance of Raw Waste Stabilization Lagoons in Michigan    131
     ing contemplated foi the following day, the 24
     hour prior application of 8 mg/1 wfll not be
     essential. However, the two hour prior 2 mg/1
     application shall be accomplished.

          Chlorine applications shall be in accord
     with the  water level in  the lagoon  and the
     computed quantities tabulated below.
                 Founds Chlorine
                    Required
Pounds Chlorine
   Required
 Liquid  Volume 2 mg/1  40%   70% 8 mg/1 40%  70%
  Depth  in gals.  Appli.  Pow.  Pow. AppU. Pow.  Pow_
  in Feet x 1,000 cation  der   der  cation der   der
1
2
3
4
5
6
7
8
9
255
530
825
1,143
1,485
1,852
2,244
2,662
3,107
4
9
13
18
24
30
36
42
50
10
21
33
46
60
74
90
107
124
6
12
19
26
34
42
51
61
71
16
34
53
73
95
119
144
170
199
41
85
132
183
238
296
359
426
497
23
48
75
105
136
169
205
243
284
     The hypochlorite powder is distributed man-
ually with a rotary-type fertilizer spreader mounted
in a row boat. One man cranks the  spreader while
another rows the boat back and forth  until the entire
surface has been well covered.

     Samples for  bacterial analyses are collected by
the public works staff and sent to the state labora-
tories by sample mailers. Fifty-seven samples were
analyzed for  total and fecal coli, 31  of which were
collected mornings, and  26 during afternoons on 31
days  during  irrigation periods. Total  coli concen-
trations ranged widely from a few thousand to a few
hundred thousand with  a geometric mean of 8984.
On the other hand fecal  coli levels were less than 10
per  100 mis for  SO  of the  57  samples  with a
geometric mean of about 10.

     This appears to be a most effective  method of
disinfection for small installations.
   Lagoons Following Secondary Treatment

      One hundred and  ten lagoons following trick-
 ling filters and activated sludge plants are recorded in
 the July 1 EPA data bank printout of facilities in the
 federal grant program. It is to be expected that many
 more  such  facilities  will be  constructed  to meet
 present and future effluent requirements. It is useful,
 therefore, to examine the great wealth of information
 generated in the study of performance of lagoons
 following  trickling  filters at  the State  Prison  of
 Southern Michigan.
State Prison of Southern Michigan

     The treatment works  serving the prison were
built in the late 1930's and have continued in service
without major modifications until polishing lagoons
were  installed  in  1968  to  meet  more  stringent
requirements for discharge  to a  critically  oxygen-
deficient stream receiving wastes from this and other
sources including the City of Jackson.

Facilities

     Raw wastes  enter  old  Imhoff  Tanks  after
screening arid grit removal, thence to trickling filters
from which  the  effluent is discharged to a 2-cell
lagoon normally operated in series. A yearly manage-
ment pattern of storage in and  discharge from the
lagoons is utilized for controlled release to the Grand
River when flows and dissolved oxygen in  the river
are relatively high and lagoon quality is optimum. In
a typical year storage without discharge begins in May
as  river flow decreases and  continues until about
November when lagoon contents are lowered in series
from about  10-foot depth to about  3 feet. When
water  levels  reach  10 feet  again in December, the
lagoons are discharged in series under ice cover until
some time in April  after ice has  thawed when water
levels  are again lowered to  about 3 feet and  made
ready for summer storage.

      At  the 10-foot operating level  with cells  in
series  residence  time at 1.1  mgd flow  is about 120
days.

      No aeration is provided. Wastes are not chlori-
nated at any point in the process.

Performance

      The following data (Table  8) are taken from
operation reports submitted each month to the state
regulatory  agency   by the certified  plant  super-
intendent. Observations and laboratory testing of a
very thorough  and varied  nature  are made daily
throughout the year by  the operating staff.

      During summer months ammonia nitrogen con-
centrations are typically around 0.5  mg/1 as N, rising
to about 2.0 with coldest water temperatures.

      Analyses are made routinely for total coli in the
lagoon  effluent  or near  the  point   of  discharge.
Generally concentrations are very low. A large per-
centage of tests  were registered  as zero and seldom
exceeded  200 per  100 mis.  During  four  days  in
September  and  five in October  the report indicates
TNTC (too numerous to count).

-------
 132    Pierce
 Table 8. Performance data of lagoons following trickling filters at State Prison of Southern Michigan at Jackson.
     Item
            Period

        December 1971

Daily Range        Mo. Avg.
             Period

           Year 1971

Monthly Range      Ann. Avg.
Raw Flow (mgd)
BOD5 (mg/1)
Raw
T.F. Eff.
Lagoon Eff.
Susp. Sol. (mg/1)
Raw
T.F. Eff.
Lagoon Eff.
PH
Raw
Lagoon Eff.
Total Phosphorus
(mg/1 as P)
Raw
T.F. Eff.
Lagoon
NH3-N (mg/1)
Raw
T. F. Eff.
Lagoon Eff.
0.9-1.2

145-340
13-34
4-11

160-248
24-50
16-42

7.1-7.4



4.5-8.7
4.3-6.0
0.8-2.3

10-19
3.5-7.0
0.6-2.1
1.06

228
22
8

183
34
29

7.2
8.4


6.5
5.4
1.8

13.6
5.3
1.1
1.04-1.22

156-237
13-22
4-22

164-184
34-48
18-93

7.0-7.2
7.9-9.8


4.8-7.2
3.6-5.7
0.1-2.5

9.1-13.7
2.8-5.3
0.2-1.8
1.11

200
17
11

176
38
43

7.1
8.8


5.8
4.6
1.1

10.9
4.1
0.8
 Fargo, North Dakota

      Another example of lagoons installed to supple-
 ment treatment provided by trickling filters are those
 completed by the City of Fargo a year or so  ago to
 meet elevated effluent requirements for discharge to
 the Red River of the North.

 Facilities

      Raw wastewater averaging 5-6 mgd, collected
 by the municipal  sewer  system, passes  through a
 screening  chamber, primary settling tanks, and  two
 trickling filters, one with stationary nozzles, the other
 with  rotary  distributors,  followed  by final settling
 tanks. Sludge digestion facilities complete the mechani-
 cal plant  portion now in  use. Chlorination  facilities
 customarily used in the past have not been used since
 the lagoons were  placed  in operation last fall.  The
 wastes from  the plant are  pumped some  4  miles to
 the lagoon site  which occupies one square mile.
 Lagoons consist of five cells, four of which are used
 as primary and secondary  units on  a selective basis
 and the fifth, deeper than the others is used as the
 final polishing unit prior to discharge.

Performance

      The  final cell normally is filled and  isolated
 with no inflow for several weeks before the contents
                     are released. Storage takes place through the long
                     winter months without discharge. When the quality
                     of the contents of Cell No. 5  are favorable for dis-
                     charge in the spring, the cells are progressively lower-
                     ed. This process continues through summer and fall,
                     drawing all cells down to lowest level consistent with
                     good  effluent  quality  before  the onset  of winter
                     weather.

                           Effluent quality is typically as follows:

                           Trickling filter plant
                             BODJ5   30 • 40 mg/1 - mid-spring to mid-fall
                                     60 • 70 mg/1 - cold weather
                             Suspended solids - A little higher than BOD
                           Lagoons
                             BOD5   10-15 mg/1, sometimes less
                             Suspended solids -10 -  20 mg/1 usually
                             Fecal coli  < 100 per 100 mis consistently
                                     Aerated Lagoons

                           The EPA data bank on facilities constructed or
                     proposed has record of 137 aerated lagoons as of My
                     1, 1974. These  vary widely in construction features
                     and loadings and are designed to achieve a rather wide
                     range of effluent quality, either by themselves or in
                     combination with other treatment units.

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                                     Performance of Raw Waste Stabilization Lagoons in Michigan    133
Reed City, Michigan

     A quite typical  installation of this kind  has
been in operation at Reed City, Michigan, since late
1971. These facilities were selected for study because
they typify the rather  common  circumstance of a
small community with a large but fluctuating organic
loading from industry where the  treated  wastes
discharge to a quite limited stream resource, requiring
a high  quality effluent low in oxygen consuming
substances, nutrients, and coliforms. Industrial wastes
consist of 3040,000 gals/day of rinse water following
withdrawal of strong whey in cottage cheese manu-
facturing plant.  BOD5 of these wastes  ranges from
3000-4000  mg/1.  The  mixed  wastes  have  BOD,
averaging about  350 mg/1  and total suspended solids
averaging about 160 mg/1.

Facilities

     Raw  wastes are  discharged to  three 1-acre
aerated lagoons approximately  10 feet deep (opera-
ting depth) equipped with 45,000 feet of perforated
piping  (Hinde  System). Lagoons are  operated  in
series. Residence time in each cell at present loadings
is about 10 days.

     The lagoon effluent is returned to the old plant
site  for  phosphorus   removal  and   disinfection.
Chemicals (lime  or alum) are added  in  a rapid mix
chamber, thence to a flocculation chamber  where a
polymer is  added  prior  to discharge  to  the  old
sedimentation tanks.  Chlorine  is  applied by semi-
automatic  gas chlorinators  to the settled  effluent
prior to entering the old baffled chlorine  contact tank

Table 9. Performance data  of  aerated lagoons followed by chemical precipitation, sedimentation, and chlo-
         rination at Reed City, Michigan.
10-25 minutes time of passage at present flow rates.
30004000 gallons of chemical sludges are withdrawn
daily from the sedimentation tanks to a small sealed
earthen lagoon  and periodically removed for  land
disposal.

Performance

      The data in Table 9, extracted from the October
1972 and June 1973  monthly  operation reports
submitted  by the  certified  operator to the  state
regulatory  agency, are typical of loadings, chemical
dosages and  effluent quality  during  1972 and the
present time.

      It is  of interest to compare these results with
performance  of the  original  primary plant which
consisted   of  grit  removal,  screening,  plain  sedi-
mentation  tanks, chlorination  and  heated  sludge
digesters. The operation report for September  1971
provides data for these facilities.
Item
Flow (mgd)
BODS
Raw
Eff.
Suspended Solids
Raw
Eff.
Chlorination
C12 feed (Ibs/day)
Residual (mg/1)
Coli, total per 100 mis
Range Mean
0.23-0.31 0.28

250-1120 557
150400 304

150-322 215
72-180 134

88-123 105
16-30
0-1500
   Item
                                          October 1972
                             June 1973
                                     Range
   Mean
Range
Mean
Flow (mgd)
Raw
Eff.
BOD5 (mg/1)
Raw
Eff.
Suspended Solids (mg/1)
Raw
Eff.
Total Phosphorus (P) in mg/1
Raw
Lagoon Eff.
Eff.
Chlorination
C12 feed (Ibs/day)
Residual (mg/1)
Coli, total (per 100 mis)

0.20-0.30
0.18-0.34

160-600
1-6

126-206
6-36

10-21
13.5-15.5
1.3-5.6

5-9
0.4-1.0
0-7.3

0.24
0.26

408
3

163
18

18
14.3
2.4

6.7



0.28-0.37
0.28-0.47

100460
1-13

110-186
7-25

6-17
12-13.5
2.6-12.2

8-17
0.8-1.5
443

0.33
0.35

306
8

159
17

13
13
6.7

13



-------
 134
         Pierce
Operational control

      The treatment facilities and laboratory analyses
are under the control of the same certified operator
who  capably operated  the primary  plant  before,
during and  after construction  of the  modifications
and additions. He has one assistant operator. Between
them they manage the facilities 7 days a week. Some
indication of the continuity of control is the recorded
data for  chlorination. At least 6 readings, usually 8,
between  7 a.m. and 5 p.m. are taken daily on rate of
treated waste flow and chlorine feed rate and chlorine
residuals  are  determined for each reading.  Chemical
analyses are made, usually 4 days per week, and many
physical measurements and observations are recorded
daily. Operators  perform all  maintenance and are
intimately familiar  with all equipment and process
control measures. When questioned about attendance
on  Saturday  and Sunday the certified operator said,
"It's no different than managing a dairy herd. You've
got to milk them twice everyday."

         Observations and Conclusions

      1. Long period storage  and  controlled  dis-
charge. Study of the history of performance of raw
waste stabilization lagoons with an effective discharge
control  program  involving long period storage  and
seasonal  discharge, including over 40 installations in
Minnesota and many in  North  Dakota, confirm the
observation  made last  year on  the  study of 49
Michigan installations of this  kind that:  (1) Such
lagoons can consistently produce  effluents meeting
EPA requirements for secondary treatment for BOD,
and fecal coli and generally can meet the suspended
solids requirement  when loadings  are in the  100
persons per acre range, and (2) fecal coli requirements
of 200 and 400 per 100 mis cannot be met with such
facilities  during  winter ice cover and when water
temperatures approach freezing temperatures. Again
no  data  were available on performance  of these
facilities at loadings above 20-25 pounds of BOD, per
acre  per  day (based on  total  acreage)  or short
retention periods.

      2. Continuous flow systems.  Nine continuous
flow lagoons in Illinois  with system loadings in the
100 person per acre range generally met the EPA sec-
ondary treatment requirements for BOD and  sus-
pended solids.

      3.  Nitrification. Studies of a  5-cell lagoon sys-
tem at Belding demonstrated a high degree of nitri-
fication in the first three cells with ammonia nitrogen
falling from some 20-30 mg/1 in the raw waste to less
than  1 mg/1  in mid-summer but with  practically no
nitrification during winter months. Ammonia levels in
the effluent fell in late spring and rose in early fall in
a cyclic  fashion. Similar results were found at  nine
typical continuous discharge lagoons in Illinois which
were selected for  study by reason of their data on
effluent  disinfection. This temperature relationship
was  found  in  lesser  degree  at  the  State Prison of
Southern Michigan at Jackson where a 2-cell lagoon
system with controlled discharge is used to improve a
trickling filter effluent. Here ammonia concentrations
of around 0.5 mg/1 as N rise to about 2.0 mg/1 during
winter discharge.

     4.  Chlorination for disinfection. Little informa-
tion could  be found  on  fecal coli concentrations
following disinfection of  the lagoon  effluent with
chlorine  although over 100 such installations are
recorded in EPA's O&M file of facilities inspected.
Data  from  the nine  continuous  flow  lagoons in
Illinois indicated fecal  coli  levels  approaching the
required 200  per  100  ml standard but  with a fair
percentage  considerably   higher.   More  study  of
facilities of this kind is needed to determine what can
be achieved  in such installations. Chlorination of the
effluent  from  a  3-cell   continuous  flow  lagoon
operated by the City of Detroit with chlorine residual
levels consistently above  1  mg/1  produced a high
degree of kill.  Fecal coli concentrations were nearly
always less  than 23 per  100 mis. Excellent results
were  obtained also  from  the 5-cell controlled dis-
charge lagoon  at  Belding, Michigan,  with  chlorine
residual concentrations  consistently around 0.5 mg/1
after a 10-25 minute contact period.

     5. Lagoons following trickling filters.  Several
years of good records at the  Southern Prison of
Michigan with two-stage lagoons with up to 4 months
residence time following standard rate trickling filters
document effluents have BODs  usually less than 10
mg/1, total phosphorus under  2 mg/1 most of the year,
a high degree  of nitrification during warm weather
and very low  fecal cob* concentrations. Results at a
similar quite new installation  at Fargo, North Dakota,
indicate promise of similar performance.

     6. Aerated lagoons.  An   aerated lagoon fol-
lowed  by chemical flocculation for phosphorus re-
moval at Reed City, Michigan, routinely produces an
effluent with BOD5 less than 10 mg/1 and suspended
solids under 20 mg/1. Fecal  coli in  the effluent are
consistently under 50 per 100 mis with low chlorine
feed rates and chlorine residuals of 0.5 to 1.5 mg/1.

     7. Number of cells required. In our study of
performance of 49 raw waste  stabilization lagoons
last fall it was observed that little difference could be
detected in  the  quality  of effluent from  2-cell
compared with 3-cell systems. It was noted also that
all of the systems studied were either at or below the
design  loading  of 20 pounds BOD5 per acre per day
or 100 persons per  acre.  Generally, these  facilities
receive  more  attention and are   more effectively

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                                    Performance of Raw Waste Stabilization Lagoons in Michigan     135
operated by specially trained public works personnel
than usually  found elsewhere. Discharge occurs only
after long period storage and usually after a period of
several days or weeks of isolation of the discharging
cell. It  was further noted that nearly all of the 49
systems were relatively young, having been in opera-
tion for 2 to 5 years and some even less.

     Each of these factors provide some increase in
the chance that the effluent from a second cell be of
good quality. It is reasonable to expect, however, that
over a longer period  of time the  greater flexibility
afforded by a third cell will increase the capability of
the system to operate continuously at a  high level of
effectiveness.  The  value  of the third  cell  will  be
greatly increased with provision for parallel or series
operation so that the wastes may  be routed into or
out of any of the three cells. Experience throughout
the country clearly indicates that any one of the cells
may require isolation, drawdown for repairs or special
maintenance, often requiring long periods to correct
the problem.  For these reasons many  of the states
have  adopted standards or guidelines  calling for  a
minimum of three cells for raw waste stabilization
lagoons, a decision well founded on practical  con-
siderations.

      8.  These studies indicate that various types of
lagoon faculties with conservative loadings and effec-
tive operational control are producing effluents which
meet secondary  treatment requirements and  hold
promise  of  a high degree  of nitrification and other
evidences of  a high  quality effluent. It is to be
expected that improved operational controls includ-
ing regular laboratory analyses will greatly improve
the performance of a high percentage of lagoons now
in use,  at the same time providing a firmer base for
design of facilities for the future.

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                    SEPARATION OF ALGAE CELLS FROM WASTEWATER

                    LAGOON EFFLUENTS BY SOIL MANTLE TREATMENT

                                 R. A. Gearheart and E. J. Middlebrooks1
             Soil Mantle Disposal of
                Lagoon Effluent

      A  review of the history  of sewage  treatment
 indicates that  wastewater  irrigation was  originally
 developed in the early nineteenth century as a system
 of both treatment  and  disposal (Rafter,  1897;
 Rudolfs  and Cleary, 1933; Mitchell, 1931). In recent
 years, other forms of waste treatment have become
 popular. The growth of technical knowledge has led
 to a  reexamination of the  possibilities of  treatment
 and disposal of certain industrial, agricultural, and
 domestic wastewaters  through the  application of
 irrigation techniques (Riney, 1928; Mitchell, 1930;
 Goudey, 1931; McQueen, 1934;DeTurk,  1935). Thus
 the cycle has run its course, the earliest form of waste
 treatment is now the subject of research and develop-
 ment  for the  disposal of the water of  our time
 (Skulte,  1956; Dye, 1958; Henry et al.,  1954; Hunt,
 1954;Warrington, 1952; Wells, 1961).

      However, irrigation with  wastewater is not a
 panacea  for the economical treatment and disposal of
 wastes. Sanitary, aesthetic, economic, ecological, and
 other technical and practical considerations must be
 carefully balanced for  a  sound wastewater irrigation
 system.

      The effect of sewage effluent on  the yield of
 agronomic crops has, in most cases, been found to be
 beneficial (Hill  et al.,  1964; Herzik,  1956; Merz,
 1956; Wilcox, 1949). Feinmesser  (1970) obtained a
 significant increase in the yield of reed canary grass.
 Huekelekean (1957) obtained excellent crop yields in
 Israel. Stokes et al. (1930) obtained yield increases in
 Florida amounting to  240 percent for  both Napier
 grass and Japanese cane, when compared with the
 unirrigated  crops,  or  with  the same crops irrigated
 with well water. Day and Tucker (1960a, 1960b) and
 Day  et  al.  (1962) in Arizona, obtained  beneficial
 yield effects on small grains which were  harvested as
 pasture  forage,  as hay or as grain. Parizek et al.
     lR.  A. Gearheart is Associate Professor, Division of
Environmental Engineering, and E. J. Middlebrooks is Dean,
College of Engineering, Utah State University, Logan, Utah.
(1967) at Penn State, have extensively explored the
use of wastewater as a spray irrigant on forestry land.

     More than 100 kinds of viruses are known to be
excreted by man and approximately 70 of these have
been found in sewage (Clark and Chang, 1962). Those
that appear to be transmitted through wastewaters
are the entero-viruses, poliomyelitis (Paul and Trask,
1942a, 1942b; Little, 1954;Kelley, 1957; Bancroft et
al., 1957), coxsachie  (Clark,  1971)  and infectious
hepatitis   (Hayward,  1946;  Dennis,  1959;  Yogt,
1961). There are  a limited number of studies of the
movement of viruses through granular media (Merrell,
1963). These studies showed that rapid sand filtration
preceded  by  coagulation and  sedimentation  only
partially  remove  virus. The removal of virus from
percolating water is largely due to sorption on the soil
particles.  Soils having a higher clay content sorbed
virus more rapidly than those with less clay (Eliassen
etal., 1967).

     The  soil system is composed  of gas, water
microorganisms, minerals, and organic matter which
form the solid matrix. Experience has indicated that
this  dynamic  system  is   constantly   undergoing
physical,  chemical, and biochemical  interactions.
Wastewater applied to the soil mixes with the existing
soil water, becoming a part of the  system, and may
alter the nature and rate of change of the physical,
chemical,  and biochemical  processes  in the  soil
system.

     Many insoluble constituents such as suspended
minerals, participate organics, and inorganic precipita-
tes are  quickly removed from  the  liquid  by  the
surface area of the soil. Some of these substances are
altered,  but some become a permanent  part of the
soil. Irrigation with wastewaters may produce bene-
ficial or detrimental changes in the soil system.

     Physical  clogging of  the soil pores and  the
resulting loss in the infiltration rate have caused many
wastewater soil treatment systems to fail (Avnimelech
and Nevo, 1964; Jones and Taylor,  1965;  Mitchell
and Nevo, 1964; Winneberger et al., 1960; Thomas et
al., 1966; Amramy, 1961). The political hazard of
high sodium rates to the physical properties of certain
soils is of paramount concern. This phenomenon has
                                                                                                137

-------
 138     Gearheart and Middlebrooks
 been  studied extensively  for the improvement  of
 saline and alkali soils by the proper management of
 irrigation practices (U.S. Salinity Laboratory, 1954).
 It is well known that additions  of  organic  matter
 improve the aggregate stability of soils, and waste-
 waters high in organics have been used to improve the
 physical properties of soils (Merz, 1959).

      It has been known for years that organic matter
 serves as  a granulating agent in soils. Bauer (1959)
 showed  that  organic matter  is  conducive to  the
 formation of relatively  large  stable  aggregates and
 that the effect of organic matter is more pronounced
 in  soils  containing small  amounts of  clay. Small
 amounts of added organic matter appear to promote
 large stable aggretages of  clay, silt, and sand.  The
 organic content  of oxidation pond  effluent, both
 dissolved and particulate (algae) may therefore have a
 beneficial effect on the soil permeability. Soil micro-
 organisms  undoubtedly play a major  role  in  pro-
 ducing  organic   cementing  materials.  Martin  and
 Waksman (1940) observed that the growth of micro-
 organisms led to the binding of soil particles, and the
 more  readily  the  substrate  on which  the  micro-
 organisms bred decomposed, the greater the effect on
 aggregation. Plant roots appear to be very effective in
 promoting aggregation by  soils. The  unusual aggre-
gation of soils in the roots of plants probably is the
 consequence of  mechanical  disturbance  by plant
roots and by  wetting and  drying,  together with
cementation by organic compounds (Jenny and Gros-
senbecker, 1963). The efficiency of spray irrigation
of vegetated areas for wastewater disposal is un-
doubtedly  due in part to enhancement of permeable
structures by plant roots.

      Filtration is important  for removing suspended
 particles  from wastewater  effluents penetrating the
 soils  and  for  retaining  the  microorganisms that
 facilitate biological decomposition of dissolved and
 suspended  organic matter.  Even though the removal
 of suspended  particles from water flowing through
 soils  is easily observed, the processes involved are
 difficult to describe in simple cases. Listed below are
three of the simplest mechanisms which might be
combined to describe more complex situations.

      Case  I—Straining at  the  soil  surface.  Under
           these  conditions  the suspended  particles
           accumulate on  the soil surface and be-
           come a part of the filter.

      Case  II—Bridging. Under these conditions sus-
           pended particles penetrate the soil surface
           until they reach a pore opening that stops
           their passage.

      Case  III—Straining  and  sedimentation. This
           includes all of the conditions for Case I
           and Case II except that the suspended
           particles  are   finer  than  half  of  the
           smallest pore openings.

      Irrigation with wastewater  has a marked in-
fluence on the chemical equilibria in the soil. Organic
matter  and clay added in the suspended solids can
increase the  cation exchange  capacity of the soil
(Ramati and  Mor,  1966). Many  of the dissolved
chemicals in wastewater influence  the  suitability of
the  soil for  crop  production.  Nitrogen and  phos-
phorus  compounds have a beneficial fertilizer  value
when retained in the soil and  utilized by the crops.
Pollution of  groundwater by  nitrates which  move
freely in the soil can be a serious problem (Ground-
water Contamination, 1961; Stewart, 1967). Release
of phosphorus from soils to our surface waters can
also contribute to  pollution (Taylor, 1967). Boron
content  has  caused  concern in areas where boron-
sensitive crops are  irrigated  with wastewater (State
Water  Pollution Board of California, 1955). Toxic
concentrations of copper  and  zinc have apparently
accumulated  in the soil  at  sewage farms (Rohde,
1962).

     The  application  of soil  mantle  disposal to
upgrading  lagoon  effluent is  limited by  soil and
groundwater  characteristics. However, most lagoons
are constructed in areas where land is available and
thus capital  investment for land  mantle disposal is
relatively low. Further,  soil mantle  disposal  does not
create  a sludge disposal problem,  has a low  main-
tenance  and  operation  cost, and may provide  addi-
tional irrigation water in arid regions. Therefore, it is
felt that soil mantle disposal may be of practical value
in upgrading lagoon effluent.

              Soil Mantle Disposal
              Experimental Design

     The experimental design  for use of the soil
mantle  as an algal  cell removal  process consists of
several interacting processes. The first rationale for a
process  would be that the soil  mantle system would
essentially be used as a storage compartment for the
effluent. There would be  no  surface  runoff or
groundwater  movement of the  effluent. Evaporation
from the soil, hydraulic  conductivity, and lateral
dispersion would determine the storage capacity of
the  soil.  This process would  have several severe
disadvantages,  such as seasonal  variation  in soil
moisture  storage  potential,  large  volume of soil
necessary, and extensive drainage and surface leveling
to minimize runoff and groundwater implication.

      Another process  design would be to consider
the water requirements of the vegetation being irri-
gated and the  possible  removal of the algal cells by
impaction and impingement of the cells on the plants.

-------
       Oxidation  Pond  Effluent ~
       Water Demand
       Utah Soil Types
       Climatological
       Cons ide ra t i ons
     *• Forage Crops
       Public Health Aspects
Storage
Cons iderat ions
t


                                         ±
                                  Nozzle Configuration
           Soil
           Column
           Pilot

           Chemical
           Physical
           Biological
                                                        Return Flow
                                                        Characteristic
                      Constraints
                      For Waste Treatment
                      Systems
System
Design
Concepts
                                                                           Organic
                                                                           Loading
 Nutrient
 Loading
                           Hydraulic
                           Loading
                                                                           Ion Exchange
                                                                           Capacity
                                                                           Bacteria And
                                                                           Virus Dieoff
Field Test

   With
 Typical
 Crops
                           Validation
Production
    Of
  Forage
   Crops
               Return  Flow
               Characteristic
                                                                           Cost Of Waste
                                                                           Treatment System
Value Of
Forage Crops
                                                                               f
                                                                                                                                I
                                                                               I
                                                                                                                               I
Figure 1. Information flow chart for the research project.
                                                                               <*>
                                                                               SO

-------
140   Gearheart and Middlebrooks
THEORETICAL ASPECTS
                             TREATMENT SYSTEM
                       DESIGN CRITERIA
Single cells
Colony of cells
Auto-flocculation
Other suspended solids
Cell lysing
Release of cellular
   constituents
Cellular deposition
 ALGAL CELL SOURCES
   TRANSPORTATION

IRRIGATION PIPELINES
                                    I
Cell lysing
Release of volatile
   constituents
Evaporation
Reaeration
    SOIL MANTLE

DISTRIBUTION SYSTEM

    SPRAY NOZZLE
Size of algal cells
Concentration of algal cells
Seasonal variation
Temperature
Storage consideration
Pumping consideration
   non-clog pump
Distance to be pumped
Frequency of pumping
Orifice clogging
Spray pattern
Uniformity coefficient
Nozzle pressure
Nozzle flow rate
Physical clogging
Physical degradation
Chemical degradation
Soil storage
Gass transfer
Ion exchange capacity
    SOIL MANTLE

     TREATMENT

       SYSTEM
Infiltration rate
Soil texture
Surface drainage
Soil chemistry
                                SOIL MANTLE

                                RETURN FLOW
Biodegradation by-products
                       Water Quality Standard
                       Flow
                       Storage
                                 RELEASE TO

                                 SURFACE OR

                                 SUBSURFACE
Figure 2. Soil mantle.

-------
                                     Separation of Algae Cells from Wastewater Lagoon Effluents     141
The root zone depth could be the level of intermittent
saturation required to satisfy the plants. This process
design has several limitations also, one being the sea-
sonal productivity and the amount of water necessary
for optimum plant growth.

     A third process design could be envisioned that
would  incorporate the advantages of two previously
mentioned systems. Soil moisture storage as well as
vegetation water requirements could be considered on
a seasonal basis. During the non-productivity period
of the year, the soil mantle system could be loaded to
maximum soil moisture conditions  while  during the
growing season the water requirement of the vegeta-
tion controls  the rate  of application.  A  storage
capacity of 120 days would suffice  for cold weather
operations where ground conditions would not  allow
irrigation.

     The  soil  only  system  would develop infor-
mation typical of spring and  fall spray irrigation of
oxidation pond effluent. Meaningful data concerning
soil  moisture   and  storage  capacity  in terms of
application rates and cell removal could be developed.
The vegetation plot  would allow an analysis of the
transpiration  rates and the effect of  plants on the
filtering  phenomena  of algal  cells,  such  as im-
pingement, impaction, etc.

Soil mantle facility

     The  Utah  State  University reclamation farm
(110 acres) is  located approximately in the center of
Cache  Valley, where the land is essentially  flat. The
slope is actually 0.07  percent to the west. Most any
type  of  irrigation  system  can be  used  without
expensive leveling. Much  of the land in this area
contains humics which  makes efficient farming ex-
tremely difficult. Fortunately only about 3  acres are
classed as humicy on the reclamation farm.

     The top soil over most of the  farm is extremely
thin (1 to 2  feet).  The  texture of this material is
mainly silty clay loam. Below this  top soil is a tight
impermeable clay which may be gleyed or mottled
depending on  the location on the farm. A soil survey
has  been  conducted  on the  reclamation  farm by
drilling 34 test  holes cored to a depth of  11  to 12
feet. The majority of the soil is clay with silty clay,
and silty-clay-loam  within the surface 2 to 3 feet.
Most of the  clay is tight and mottled or gleyed. A
stratified sand,  silty clay layer can be found  under
most of the farm at a depth of from  10 to 12 feet.
This material  may be helpful in removing the water
coming  up from the  aquifer and  down from the
surface.

      An open  drain exists on the reclamation farm
to remove surface  water  and  some  groundwater.
During the winter and spring months the drain carries
off about 3 second feet, helping drain the surface of
about 400 acres on the immediate area of the farm.

Experimental design

     The experimental design will consist of eight 50
x 50 foot test plots irrigated at three different rates
(2,  7,  14  in/week).  The  effluent  from  Logan's
oxidation pond will be pumped approximately  1/2 of
a mile to the reclamation farm. Two  test plots for
each application  rate  consisting of a  forage crop,
alfalfa, and a soil only treatment plot will be irrigated
6 months out of the year for 2 years. One 4 in. drain
pipe will collect the return flow at a depth of 3 feet.
A sample  port  outside  of  the plot  will allow the
collection and subsequent analysis of the return flow.
It  is  anticipated that  only  14  inches/week  will
saturate  the soil to the point of producing a  return
flow on a continuous basis.

      A  slotted  two inch soil corning device will be
used  to obtain  samples on  the various  plots on  a
weekly basis. The slotted corer will allow analysis of
the vertical stratification of the soil and its associated
water quality parameters. The upper most section of
the  soU  mantle  will be most actively involved in
removal of the algal cells. The other water quality
parameters, BOD5,  N-forms, P-forms,and dissolved
organic carbon will be analyzed on a vertical basis to
predict return flow characteristics.

      Ten random samples will be obtained every two
weeks from the nine test plots. The following test will
be performed on the stratified samples over the two
6-month test periods.
                     Forage
                      Crop
            Barren
             Soil
Control
 Organic Content
10/twice   10/twice   10/twice
monthly   monthly   monthly
N-Forms (NH4, 10
N03)
P-Forms (Total, 10
dissolved)
Soil moisture 10
BOD5 (If saturated) -
40
10
10
10
40
10
10
10
lo
      The proposed method of application of oxida-
 tion pond effluent is  through a solid set irrigation
 system. The system will be completely automated,
 controlled by electric  valves which will be varied to
 give irrigation  in blocks of four laterals operating
 simultaneously. The system will be designed such that
 the time of irrigation  of any one block can be  left
 from a few minutes  up to several hours, and  the

-------
142    Gearheart and Middlebrooks
2in./wk.
7 in./wk.
(4 in./wk.
7 in /tub f
control
Holding
pond for
f.
Q
<
t
/f
Q
F(
T
\
J

X
P
fc

f
\
4
it
i

ft
y



3RAGE CROP
REATMENT
i
i
lagoon
TREATMENT ef"uent
100 ft.
1 ^
• f- A
i ~
I
i
r
«. ^
i c
i
i
i
i
From Logan/^
lagoon
i .
50 ft.
~* 1
1
C^50 ft. Drainage ports
I
•i A ^
1 W W
• ^ A

C, 3
• * A
• ft ^

1
1
) ]
.' J


.. cfc


(t

•i
Sprinklers spaced 3<
feet apart on 2" lia
elevated for a 6
1 * foot release.



4" perforated drain 36 in
deep

-------
                                     Separation of Algae Cells from Wastewater Lagoon Effluents     143
Table 1.  Soil analysis for lagoon effluent irrigation study.



Texture
Organic Matter %
PH
ECe mmhos/cm
Phosphorus, ppm
Potassium, ppm
lime
Exchangeable Sodium, me/100 g
Total Sodium, me/ 100 g
Water Soluble Sodium, me/100 g
Cation Exchange Capacity, me/100
Percent Saturation
Drainage
Farm
Soil
clay
5.5
8.1
0.9
7.1
490
++
0.8
1.2
0.3
g 19.7
83
Hyde
Park
Bench
silt loam
1.9
7.6
0.6
4.5
398
-H-
0.2
0.2
<0.1
17.7
42
Brigham
City
Bench
sandy loam
2.3
7.1
1.1
13.0
171
+
0.2
0.2
<0.1
9.9
28
Four Miles
South Main
Logan
silt loam
3.7
7.4
0.5
27.0
490
+
0.3
0.3
< 0.1
23.6
56
system will automatically sequence from one block to
the next.  Any one block can be completely skipped
in an irrigation sequence.

     The  sprinkler  systems  will  be  designed  to
deliver  33 gpm/test plot.  The sprinkler heads will
deliver  .26 in/hour operating at  55 lbs/in2  with a
uniformity  coefficient  of  above  85 percent. To
achieve the desired application rates of 2 in/week, 7
in/week, and 14 in/week at weekly  irrigation periods
of 8, 24, 48 hours respectively would be required.
This would use  a  total  of 115 hours a week which
would allow a simple timing control to operate off of
only one supply  system.

Objective

      To determine the  efficiency of algal cell remov-
al from oxidation pond effluents spray irrigated on
one type  of vegetation and on soil  only control plot
and an effluent with no-algal cell control plot:

1.    Design a  drainage system  for  a  one acre
      experimental plot to monitor the effect of the
      soU mantle system has on algal cell application.

2.    Design a solid set irrigation  system  to deliver
      three flow rates on three different experimental
      plots as well as a control plot.
      Install  the  drainage and irrigation system and
      the sampling and flow measuring devices.

      Spray irrigate the  oxidation pond effluent on
      the experimental plots measuring the following:

      a.    Initial algal cell concentration, BOD, sus-
           pended solids, N-forms, and P-forms.
     b.    Continuous  measurement  of irrigation
           rates, soil moisture, drainage return flow,
           and evaporation rate.

     c.    Analyze drainage  return flow  for  algal
           cells,  suspended solids, BOD,  N-forms,
           and P-forms.

     d.    Measure  the  productivity  of  the  two
           vegetation types at the three application
           rates and  with the no-algal cell effluent
           irrigant.

     e.    Repeat  the  above experiment  after the
           first growing season  in the fall and the
           spring.

     f.    Determine the soil storage  capacity as a
           function of  algal cell removal; determine
           the application rate as a function of algal
           cell removal; determine the vegetation as
           a function of algal cell  removal; deter-
           mine  the seasonal effect  of  algal  cell
           removal  by  the  various  experimental
           plots.

     g.    Determine the system design  based upon
           cost  of equipment, operating cost,  and
           any  economic  benefit  from  increased
           production.
                  Introduction

Nature of the problem

     During the last few years, people have become
increasingly  concerned   about  the  deteriorating
quality of the environment. This concern is beginning

-------
 144    Gearheart and Middlebrooks
to express itself in many ways. Citizen action groups
have formed, laws are  being passed, and more and
more research  is being  conducted in order to solve
these problems.

     Among the  laws being passed in the  State of
Utah is a law  that  will increase the  water quality
standards  of most  of the  receiving waters in Utah
from Class  D to Class  C.  As  a result, the effluent
discharged  into  any of these receiving waters must
meet a more rigid standard of quality. The benefits of
such legislation should  include  more  aesthetically
pleasing water and better environments for wildlife.
Obviously these improvements are extremely desir-
able and in general will be welcomed.

     There  are however,  certain rather important
and  critical considerations  that  arise from such a
course  of action. In many cases wastewater treatment
facilities have already been constructed but were only
designed to  meet Class D standards. When the Class C
standard becomes law, these existing facilities will no
longer  be adequate and therefore will no longer be
allowed to discharge their effluents into any  receiving
water covered by  the law. The implication is clear.
Either  existing  facilities must be  improved to the
point where the effluent can meet the new  receiving
water standard, or a different method of disposing of
the  effluent  must  be  found.  Improving  present
facilities is going to be costly. At the hearings held in
Logan, Utah,  in  August  of  1971, one  industrial
representative asserted that  the cost to his company
to meet the new standard would be in the neighbor-
hood of one million dollars. Sums of this magnitude
represent  severe financial  burdens for large  com-
munities as well as industry. This figure becomes even
more alarming  when initial capital  costs  are con-
sidered. But an even more critical  situation is the
small  community  with  a  population of a  few
thousand  or less. The sums of money required will
probably be less, but still will  be considerable. With
rather  small  tax bases, the large capital investment
required  for treatment  facilities  that  can  meet the
standard  is  for all practical  purposes out of the
question. When  considered on a per capita basis, the
problem  becomes  even more clear.  Given  a tax
burden of one million dollars, a  community of one
thousand  taxpayers  would each be required to pay
one  thousand  dollars.  In a city  of one  hundred
thousand  people,  each taxpayer  would  only  be
required to pay ten dollars. Therefore, the practice of
discharging treated waste effluent into the  receiving
waters is no longer  possible  for these communities.
Obviously the  problem becomes one of finding an
alternative method of disposal.

Purpose and scope of the study

     The objective of this investigation is  to  study
the  wastewater  stabilization  pond  and the possible
use of  the  effluent as an irrigation water.  Typical
pond effluents will be examined for possible toxic
effects of constituents and also for possible beneficial
effects such as fertilizer value.

      Consideration will also be given to the  applica-
tion of land use planning techniques for improving
stabilization pond system appearance and utilization.
Many pond  systems perform rather  well  from an
engineering point of view, but  appear as no more than
well engineered "holes-in-the-ground" visually. Sug-
gestions will be made for improving the appearance of
these ponds such that they improve rather than blight
the  landscape.  These  suggestions  will be  supple-
mented with examples of actual projects to  indicate
just a few of the possibilities available.

      In summary the specific objectives to be dealt
with in this study are as follows:

      1. Investigate the limitations of pond  effluent
for use as irrigation water for crops.

      2. Study the use of land planning techniques to
make ponds more visually pleasing.

      3. From the above  studies, make suggestions
for alternatives to meet the stated problems.

      4. Suggest  possible  research  activities neces-
sary.


         Utah Water Quality Standards

Upgrading from Class D to
Class C standards

      The difference  between Class  D and  Class C
effluent  quality  standards  can  be  compared  by
referring to  Table 2 (Middlebrooks,  1971). The most
significant difference between the two standards is
the 5-day BOD values. The reduction from 25 mg/1 to
5  mg/1 is the  parameter that  causes the  greatest
concern. Middlebrooks et al. (1971) have shown that
present systems including waste stabilization ponds
do not meet Class C standards in this regard.  It is this
aspect of the  Class C water  quality  standards that
necessitates   the   rather  expensive  modifications
alluded to in the Introduction.

      The other parameter of  interest is the specifica-
tion of fecal coliform levels separately in the Class C
standard but  not in  the Class D standard. Middle-
brooks et al. (1971) have commented however, that if
a plant by proper  operation is meeting the  Class D
coliform standard,  in all likelihood  it will also meet
the Class  C  standard. Therefore the revised coliform
standard  should  not in  general  reflect  itself in
increased capital cost improvements.

-------
                                      Separation of Algae Cells from Wastewater Lagoon Effluents     145
 Table 2. Specific standards established for Class "C" and "D" water quality standards pertaining to wastewater
         treatment plant effluents.
                                                              Concentration or Units
      Parameter
                                                  Class "C"
                                Class "D"
PH
Coliform, monthly arithmetical mean
Fecal coliform, monthly arithmetical mean
BOD, , monthly arithmetical mean
Dissolved oxygen
Chemical and radiological

6.5-8.5
5,000/100 ml
2,000/1 00 ml
5mg/l
5.5 mg/1
PHS drinking water
standards
6.5 - 9.0
5 ,000/1 00 ml
.
25 mg/1
-
PHS drinking water
standards
       An  important implication of changing  from
 Class D standards to Class C standards is the improved
 efficiency  required  of the existing plant. If it  is
 operating very  inefficiently,  the new  facility  will
 either be overdesigned  resulting in even larger capital
 costs  for improvements or it will be overloaded and
 will not perform as required. The improved efficiency
 is  again  likely  to   be an expense  that  would be
 difficult for a small community to sustain.
      The standards  discussed above in effect apply
 only  to  plants  actually  discharging  effluents to
 receiving waters. In other words, the change is not a
 change  of effluent standard  but rather a change of
 stream standard. Herein  lies  the possibility of using
 stabilization  pond  effluents  for  irrigation.  If the
 standard was strictly an  effluent  standard, systems
 would not be allowed to discharge their effluents at
 all and  thus total containment would be the only
 alternative.

    Waste Stabilization Pond Considerations

Economics

      One of the most appealing aspects of stabiliza-
tion ponds is the relatively low capital cost required.
In Figure 4, a comparison of construction costs for
stabilization  ponds relative to the construction costs
of several other types of conventional sewage treat-
ment  facilities  is  shown  (Economy  in Sewerage
Design  and  Construction, 1962).  The  data were
compiled by the State of New York, but the  figures
are generally consistent with other geographical areas.
Middlebrooks et al. (1971) performed similar investi-
gations  for several areas  which  are consistent with
those compiled by New  York. Clearly the waste
stabilization  pond is  much less  expensive. Note in
Figure 4  that the cost of the land is not included.
Since pond systems usually require larger parcels of
land, the actual difference would be somewhat less.
      Waste  stabilization ponds  offer another  im-
portant  economic  advantage  associated  with  the
operational aspects of  the system. With trickling
filters  or  activated sludge  one  has a  relatively
sophisticated process which requires constant super-
vision and highly  skilled operators.  On  the  other
hand, a waste stabilization pond from an operations
point of view is not as sophisticated  and so  the
supervision requirement and the level of skill needed
is subsequently lower. Both of these advantages will
manifest themselves as a savings in operation cost.

      To put these cost  figures into proper perspec-
tive, one must think about the situations  for which
this investigation is intended.  If a small town is
considering changing over from a septic tank system
to some type of central municipal system, clearly the
waste stabilization  pond is the answer economically.
But as  was pointed out in  the section concerning
water quality standards,  the Class C standard cannot
be met. Perhaps even more perplexing is the situation
where  the community   already  has gone  to  the
expense  of constructing a  pond system  and  must
spend more money on a more sophisticated system in
order to meet the new standard. Obviously the need
to  meet the standard stands  in conflict  with  the
ability to raise the necessary funds.

      Since the  economics  of the situation  dictate
against  more advanced   treatment  systems,  some
alternative  must  be sought. The alternative which
seems rather appealing is irrigation.


Design

      Since a great number of articles and papers have
been devoted to this subject, only a brief description
will be  given here.  Waste stabilization pond depth,
detention time,  shape, mixing, and  loading  will be
discussed.  These  engineering  aspects will  be  coor-
dinated   with  site  planning considerations  in  the
design of a  waste stabilization pond system.

-------
 146    Gearheart and Middlebrooks
   1000
o

- 500
o
O
   100  -
    50
                                          • Trickling   filter
                                                                                       Activated   sludge
                                              Primary  sedimentation
                           Stabilization  pond
                                      I
                                                            I
      .01                   .05
        E.N.R. Const,  index = 1000
                                     .10                    .5
                                         Design   Flow  (MGD)
                1.0                    5         10


                    Curves   represent  construction
                    costs   only  and  do  not  include
                    land,  engineering,  legal  or   other
                    administrative   costs.
Rgure 4. Sewage treatment plant construction costs.
      The  most  significant effect  of depth on  the
ecology of the stabilization pond is  the decrease in
light intensity with increased depth below the water
surface. Oswald et al. (1964) has shown that in order
for a  pond  to  function  aerobically  throughout its
depth, the pond depth must  be less than 1  foot.
Obviously,  in  general, this would  be  impractical
because the  land requirement  would become enor-
mous. Waste stabilization ponds, as most frequently
employed, range  in  depths between 3  and 7  feet
(Jones et al., 1971). Since light intensity penetrating
to  these  depths in most wastes is  insufficient to
support photosynthetic activity, the lower  regions of
these ponds are usually  devoid of  oxygen. These
ponds are  referred to as facultative ponds. Another
aspect of pond  depth that  is important in   the
operation and performance of the pond is the control
of emergent vegetation such as  cattails and  bulrushes.
This consideration suggests pond depths of at least 3
feet. Control of emergent vegetation is an  important
step  in  controlling   insects   such  as  mosquitoes
(Kitterle  and Enns,  1968). Another factor which
must be  considered in determining the depth of the
pond  is  the  water  table.  The cooling effects of
groundwater and the possibility of contaminating the
groundwater require that the pond bottoms be above
the local water table.
      Pond detention times are important  to allow
sufficient exposure  of  the waste to  the biological
forces necessary to treat the waste. In conventionally
operated overflow type waste stabilization ponds, the
detention time generally ranges between 25  days and
3  months.  Many ponds  are  operated on a  non-
overflow basis so that inflow to the pond is  balanced
by seepage and evaporation. To avoid contamination
of groundwater aquifers by ponds containing toxic
chemicals, it is best  to  minimize seepage. Detention
times  are  affected  by  temperature  effects  on
biological activity and so need to be longer in winter
than in summer.
      Complete  agreement as to the most effective
shape for waste stabilization ponds is not to be found
in the literature. One reason for this lack of definition
is that a  pond is both  a hydraulic  system and  a
biological  system.  A  number of investigators have
argued that hydraulically, ponds are most efficient in
a  two-to-one  rectangular  shape.  Others have stated
that the  optimum shape  is  round or square. Still
others feel that the shape is not nearly so restricted in
terms of overall performance. All agree, however, that
the cells should be regular in shape with no isolated
or partially isolated areas where circulation might be

-------
                                     Separation of Algae Cells from Wastewater Lagoon Effluents    147
impeded, weed growth encouraged, etc. (Jones et al.,
1971).

     Most authorities agree  that multi-cell systems
are more  successful than single cells. The principal
reasons for this are: (1) reduced tendency for short
circuiting,  (2) less  bank erosion caused  by wave
action, and (3) more flexible  operation (Jones et al.,
1971). They  also produce waters of lower coliform
counts. Marais (1972) has done considerable work in
developing multi-cell theory. He found that single
pond systems were  not as  effective as  multi-cell
systems in reducing bacterial  counts. His calculations
show that for  90  percent  removal,  one  pond is
sufficient;  for 99 percent removal, two  ponds are
needed; for  99.9 percent, three ponds;  for 99.99
percent, four ponds, and so on.

     There are two points of view concerning the use
and value of mixing. Pipes (1961) feels that a pond
operates most satisfactorily if it is kept completely
aerobic.  Marais  (1972) has  shown  that bacterial
die-away  is greater in ponds  where gentle mixing
occurs.  He points out that an aerobic environment is
crucial in maintaining a high rate of die-away of the
fecal organisms.  The rate of die-off diminishes sig-
nificantly  when  conditions  become  anaerobic. He
feels that with ponds  in general, wind and tempera-
ture cause a  gentle mixing  and lead to the proper
conditions. In those  cases  where mixing does not
occur,  Marais   suggests some  type  of  stirring
mechanism. The  reason for the mixing is to induce
algal growth  which in turn leads to greater oxygen
production. The other point  of view, held by Oswald
et al. (1964) among others feel that both aerobic and
anaerobic conditions are necessary for best operation.
When   mixing occurs,  oxygen is sent  into  the
anaerobic region. Methane bacteria which perform an
important part  of the  anaerobic  process  are very
sensitive to oxygen and are thus unable to function.

      Another aspect  of mixing is the contribution
from wind.   Initially  wind  was considered useful
because it increased the effective surface area and so
allowed greater aeration. More recent thinking (Jones
et al., 1971)  tends to look upon wind with disfavor
because of several  reasons: (1)  The question of the
value  of mixing,  (2)  the insignificant amount of
aeration that actually occurs,  and (3) the loss of
water  quality because of increased evaporation rates
with associated  increased chemical concentrations.
Wind can also cause increased soil bank  erosion by
wave action and  disperse odors into populated areas.
In view of these disadvantages, sites now are recom-
mended that  have  some sort of screening to reduce
wind effects.

      Pond loading is one of the key technical aspects
of the  design. The total pond area required to treat
the waste of a given community is determined on the
basis  of organic  loading  in  most  cases, usually
reported in terms of pounds of BOD per acre per day.
Oswald et  al.  (1964) give  the  maximum load on
facultative ponds as 60 pounds BOD per acre per day.
However, the  values most frequently recommended
fall in the range of 20 to 50 pounds BOD per acre per
day. It  is obvious  that  when a  pond has  been
overloaded, its operating efficiency is reduced. It may
not be obvious however, that underloading can also
hinder  performance.  Herman  and Gloyna  (1958)
among others  have pointed to low organic loadings as
the cause of unsatisfactory pond performance. Some
recent research (Assenzo and Reid, 1966; Meenaghan
and Alley,  1963) has thrown suspicion on the surface
area loading  criteria. It  indicates  that  a volume
loading criteria would be  more rational,  particularly
in the case of facultative and anaerobic ponds.

       Land Use Planning Considerations

Introduction

      Too  often  in  the  past  designs  for  waste
stabilization  pond systems  have  neglected  an im-
portant  aspect  of the  design,  site  planning.  The
consequences  of such an approach are installations
that, despite their technical performance, are unsight-
ly. Not only is  the appearance  undesirable, but
important natural design elements that could marked-
ly  improve the overall  design  are  not  taken into
consideration. Clearly the best design  can only be
achieved by becoming familiar with  all design tools
available whether  they  come  from  the area  of
engineering or the related fields of site planning and
landscape architecture.

      This chapter will present an inventory of a few
of the  more important tools available from the field
of landscape architecture. Because the process of site
planning has  no best approach, no  attempt will be
made to describe a step by  step process. Such things
as plant materials  and wildlife wUl be shown to offer
great potential in solving certain problems inherent to
waste stabilization pond installations. Only a few of
the potential planning concepts will be  mentioned.
No attempt will be made to list all of these things or
to explore  their usage in great depth. Some of the
considerations in  site selection will  be given when
planning a  pond installation.  Two examples  of
projects that  were  designed with the inclusion  of
planning concepts will conclude the section.

Site selection considerations

       Site  planning  is based on two primary con-
 siderations. First,  the nature of the site, its character
 and its distinguishing and  unique features must be
 considered. Second, consideration must  be  given to

-------
 148     Gearheart and Middlebrooks
 the human purpose for which the site is to be used.
 These two considerations are linked together  in  a
 circular way that is rather interesting (Lynch, 1962).
 The purpose  for which the site is to be used will
 influence  the  interpretation  of   the   inherent
 characteristics  of the site. At  the same  time,  the
 inherent  characteristics  of the  site  determine  the
 purpose  for which  the site may be used. As one can
 see, these two considerations must be merged togeth-
 er in some manner in order to optimize  the use of
 the  site. Failure to successfully merge  these  two
 considerations  will result in  a  system aesthetically
 displeasing and possibly  substandard  in engineering
 performance.

      The primary purpose of the waste stabilization
 pond for this  study, besides  the obvious  treatment
 aspect, is to provide a source of irrigation water. This
 allows effective disposal  of the  effluent and at  the
 same time offers an agricultural  benefit by possibly
 reducing costs.  In  terms of planning, a number of
 implications arise. If agriculturists are going to use the
 water, the pond system site may  need to be centrally
 located in order to  provide the most effective service
 to  the  users. Future  land use  projections  are  im-
 portant in this regard so that today's genius does not
 become tomorrow's folley.

      A  centrally located site may not be the  best
 site. Certain locations may require costly distribution
 systems and added  pumping costs. It may be that by
 using an alternative site  not centrally located, some
 natural terrain feature such as a hill or a deep ravine
 may be avoided with a resultant savings in  cost. This
 saving should  be  compatible with   the  need  for
 efficient  service to the individual user.

      Another important  consideration is the pump-
 ing requirement  dictated by  the site. If  the pond
 system is built in the low point  of a valley, gravity
 flow  can be  used  to transport the  waste  to the
 stabilization pond.  However, with  the ponds at the
 lowest point, effluent distribution  will then require
 extensive pumping  unless the  users are close  to the
 pump (assuming there is  no abrupt change in topo-
 graphy).  One would generally tend to regard such  a
 situation as unlikely because low points in valleys are
 often  swampy  and  are not  usually suitable  for
 agriculture.  Where  exceptions  do  occur,  the alter-
natives for decision making are expanded.

Problems amenable to
planning  techniques

     The problem  of  odors  could  become  rather
significant if the pond system was  near a residential
area. If a pond  system was situated in a low valley
area, the problem would  be still  greater. The odors
would be harder to  diffuse because  of the cool damp
 air which would tend to hang in a depression of this
 type.  In general, the  literature asserts  that  when
 ponds are properly designed, odor problems do not
 occur.  If odors  do  become  a  problem, certain
 chemical treatments such as chlorination,  aeration,
 and additional nutrients are commonly used. Planning
 techniques can also be useful in overcoming any odor
 problems which might occur.

      The concept of pond mixing by wind action
 can also present problems. Bank erosion due  to
 excessive wave action is an important consideration in
 this regard. On the other hand, Marais (1972) felt
 that mixing was  useful and  that sun and wind were
 important contributors to this mixing.

      Mosquitoes  and  other insects are  significant
 problems. This is particularly  so  if some type  of
 recreational area or activity is planned as part of the
 pond system design. Control of emergent vegetation
 in the ponds has  been  cited as the major deterrent to
 these pests. Even  so, chemical treatments (DDT for
 example)  are  still  apparently  necessary.  Planning
 techniques  can offer   some  rather  interesting  ap-
 proaches to this problem.

      Another problem is the type of site commonly
 selected.  Frequently sites are chosen where the soil
 condition is poor and not amenable to most plants.
 This  adds to the  unsightly appearance of the pond
 system since plants and trees  commonly  used  for
 beautification will not survive  in  such unfavorable
 conditions.  Again  by  utilizing  the  talents of the
 landscape architect, this situation can be successfully
 approached.

      The water table  depth must be ascertained. If
the water table is high, precautions must be taken  to
protect the groundwater from contamination and  to
prevent seepage into the pond system and affect the
designed loading  rate.  The depth of the water table
may also influence the type of vegetation  that one
may want to introduce.

      The topography also is an important considera-
tion not  only  for the obvious reason of  reducing
construction costs on smoother land but for potential
advantages of  modifying  the  microclimate.  Steep
slopes are of course undesirable  but flat ground may
not be the best answer either. A careful study of the
individual situation must answer that question.

      The stated considerations do not constitute all
the elements that require the  designer's attention, but
do indicate the importance of this step. It should also
be clear  that the  engineer can reach a better conclu-
sion by collaborating with a landscape architect who
is trained in the field of site analysis.

-------
                                      Separation of Algae Cells from Wastewater Lagoon Effluents     149
Planning techniques

      An existing berm may lend itself to the overall
design. It  may be used for modification of the wind
effects by acting as a screen or wind break. By using
it as a buffer, the wind can be modified so that wave
action in  a  stabilization pond is  reduced  with an
associated reduction in bank erosion. A berm could
be used as a deflector to encourage mixing and so
encourage the  aerobic conditions recommended by
Marais (1972). The berm  could be used  as a visual
screen to  cover objectionable aspects of the installa-
tion.  Berms  might  also assist in the distribution of
sewage  flow  from  pond  to  pond  by providing
different  levels for  series ponds  to  be built and
therefore  allow gravity  flow. The  design of natural
and man-made berms in this distribution can be best
handled with a collaboration of engineer and land-
scape architect to  optimize performance  and  ap-
pearance.

      The  berm  may  lend itself  nicely  if  some
recreational activity is desired. A park's beauty can be
enhanced  by recongizing the  potential and  then
allowing the  landscape architect to use his talents to
maximize  its  effect. Nearby hills may also function as
game preserves and thus attract wildlife. This in turn
can add to the beauty of the surroundings which will
make the  area more attractive if a park is intended.
Obviously a berm may represent a vital parameter and
before simply  bulldozing  it  flat, a competent land-
scape architect should evaluate its potential.

      The use of existing and induced plant materials
can provide a great number  of advantages. By using
existing plant materials in combination with judicious
 induced  planting,  the  general  public  can be dis-
 couraged from entering certain  areas reserved for
 maintenance  personnel  and encouraged to use the
 areas set  aside for the  public. Trees can be used to
 screen  off  areas  from   view  which are unsightly.
 Conversely if certain views are desirable,  trees can be
 used to frame these sights and thus bring emphasis to
 the  sight for the viewer. Trees are effective as wind
 breaks and are even more effective for wind modifica-
 tion than are berms. In  a  study conducted  at the
 Kansas  Agricultural Experiment  Station (Olgyay,
 1963), trees  were shown to reduce wind effects over a
 much greater distance beyond the wind break than
 solid wind breaks.  The solid type was able to provide
 greater close-in reductions but velocities returned to
 original values sooner.

      Correct usage of trees can modify and reduce
 odor problems. Certain trees such as the black locust
 and the tree  of heaven emit aromas that can markedly
 reduce offensive  odors.  The mechanism is dilution
 and  is effective.  Flowers can also be useful in this
 same regard.
     Trees  can also be used  for  space  definition.
People are rather clearly affected emotionally by the
type of space they  find  themselves  in  (Simonds,
1961). If the space is high and majestic, people might
be  affected  with  the  sense  of feeling  small  and
overpowered. If the  space has a low overhead and is
not large, the feeling could be intimate and conducive
to  fellowship and small  social  gatherings such as
family  picnics. If a park is to be a part of the design
these factors become important in terms of human
scale and  desired  response. Frequently one sees an
area that appears pleasing to the eye but no one uses
the area. One possible explanation is that the space
relationship of the area makes people feel uncomfort-
able. Only through the skillful use of these concepts
will such an area really be successful.

     The use of trees and  other plant materials for
attracting specific birds that consume insects can
provide a distinct benefit.  Using birds in  this  way
reduces insecticide requirements,  saves money, and
reduces the hazard of pesticide accumulations in the
ecology. As was mentioned above, mosquitoes are
largely  controlled by preventing emergent growth.
The mosquito  population  and other  insect and fly
problems  can be further controlled by birds.  Purple
martins for  example eat  several times their body
weight each day in insects. And since purple martins
prefer  lots of company, attracting this specie would
provide a large number of birds which could  almost
virtually destroy  any insect  problems inherent  to
stabilization ponds.  Wrens and bats among many
others are also effective against insects. To utilize this
very effective tool requires a knowledge of the kinds
of plant materials or man-made structures (birdhouses
for example) that will attract and keep these forms of
wildlife (Davison, 1967;  Stefferud, 1966). Again  a
competent landscape architect can offer assistance.

Examples of planning applications

     After reviewing the discussion  under Design,
one should note that the use of shape for aesthetic
design  seems rather  plausible. There  are  of  course
some limitations but perhaps something more organic
than an ordinary rectangle is possible, as described by
Oswald et al. (1967). The project was the construc-
tion of a  waste  stabilization  pond  system for  a
subdivision.  The  design  was  the  integration  of
engineering and landscape architecture and resulted in
a product vastly superior to a mere well engineered
"hole-in-the-ground." The  design is shown in Figure
5. Of significance are the pond cells which are not as
stiff and formal as the common rectangle. The  system
also has  been integrated  into  a park allowing for
multiple use of the  land. The designers  have  used
many  trees which meet the new thinking concerning
reduced mixing  for pond systems. The  multi-cell
design also  offers improved treatment potential. The

-------
150    Gearheart and Middlebrooks
most   important  overriding  conclusion  with  this
example is  the obvious compatibility  between the
two   disciplines,  engineering  and  landscape
architecture. The increased cost for aesthetics results
in a  significant  benefit  for the  citizens  of  that
community. At the date  of publication the project
had not been  constructed, but the ideas had been
used in other  projects. The authors call attention  to
one project, the Esparto ponds in California.  They
were  interested  in  determining the possible  odor
problems since the system would be close to habita-
tions  and subsequently found that an odor  nuisance
did not result. They also found that visual and public
health restrictions were also met.

      Another  project illustrating  the  use  of  good
planning is the Santee project (Merrell et al., 1967).
The Santee project is a total  reclamation project
 Figure 5. Pond system in park of subdivision design.

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                                     Separation of Algae Cells from Wastewater Lagoon Effluents     151
which includes several small reservoirs which serve as
tertiary treatment.  The project shows that a design
can successfully  include more than pure engineering.
The  Santee  project  includes  areas  for picnicing,
boating, fishing,  and even swimming. Here is multiple
use of land with great variety resulting in benefits to a
broad spectrum of people.

     Whether one likes or  dislikes the actual designs
of the  aforementioned projects is not as important as
recognizing the feasibility of considering aesthetics in
the overall design. The Santee project clearly shows
the benefits  of such  planning  by the  number of
people using the facilities.  A good many users are
tourists which of course brings an economic benefit
to the community. This to  some degree  answers the
question of greater project cost.

     Based  on   the   above  considerations,  the
approach used by Oswald et al. (1967) in combining
the talents  of the engineer and the landscape architect
seems desirable.  This combination provides the sound
technical basis for site  planning and  construction
available from both disciplines plus the element of
sharpened  sensitivity to aesthetic values which is the
most  important  tool  of   a  competent landscape
architect.  Though  such  a  combination  clearly will
increase  the   design cost,   the long  range  benefits
possible should  be carefully considered before dis-
pensing with planning considerations.
       Effluent Components Considered
                 for Irrigation

Introduction

     Thus far in this discussion, the waste stabiliza-
tion pond has been looked at in terms of economics
and  been found to offer distinct advantages over
other types  of conventional systems. Their operation
and design has been studied and found to offer good
wastewater  treatment capability.  Land use planning
techniques were then discussed showing some  of the
considerations that can integrate the pond system
into a community most effectively. In particular the
land use concept of the pond system as a source of
irrigation water was discussed. All of these considera-
tions have shown the feasibility of the pond system as
an irrigation source. The one remaining question is
the chemical and bacteriological quality of the water.

      Pertinent to the water quality discussion is the
municipal use and  its effect  upon that quality. The
chemical  quality   of   the  wastewater  effluent  is
basically the sum of the original chemical quality and
the   municipal  increment   added.  Conventional
secondary treatment facilities only slightly affect the
chemical  quality.  Their  principal  effect is  in the
biological area. The average municipal increments for
a number of constituents are shown in Table 3 (U.S.
Public  Health  Service,  1963).  Specific  industrial
Table 3.  Average increments added by community use of water.3
                            Overall
        Eastern
Western
Pollutants
BOD
COD
ABS
Na+
K+ .
NH4
Ca++
Mg++
ci-
NO;
NOf
NCOs
C0j=
so4-
Si03=
P04-3 (total)
PO;3 (ortho)
Hardness (CaC03)
Alkalinity (CaCO3)
IDS
Average
22
111
6
69
10
19
17
7
75
9
1
104
-1
28
16
24
22
69
85
323
Range
8- 45
36-218
2- 10
8-115
7- 15
3- 50
1- 44
0- 24
14-200
0- 26
0.1- 2
-44-265
0--10
10- 57
13- 22
2- 50
7- 34
10-185
-35-217
128-541
Average
21
96
5
59
9
21
24
8
53
11
0.8
147
-1
28
15
19
20
95
121
287
Range
8- 33
36-159
2- 10
42- 98
7- 12
9- 29
1- 44
3- 11
14-102
0- 26
0.1- 2
49-265
0- -5
12- 52
15
2- 35
12- 34
15-151
40-217
128-457
Average
23
218
8
74
11
18
13
7
92
7
2
81
•1
29
17
28
25
58
66
352
Range
10- 45
218
6- 9
8-115
7- 15
3- 50
2- 30
0- 24
20-200
0- 15
2
-44-247
0--10
10- 57
13- 22
7- 50
7- 34
10-185
-36-203
194-541
      "Source:  U.S. Public Health Service (1963).

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 152
Gearheart and Middlebrooks
discharges into the community system could totally
distort  the  value  for a  given  component.  Since
generally communities will have a good source water,
problems  that  may  arise  in using  the effluents for
irrigation  are usually  the result of the increments
shown in Table 3.

      The Utah State Division of Health has con-
ducted  extensive chemical  quality  tests on a  great
many waters of the state including several stabiliza-
tion  pond  effluents.  Data from  these  tests are
summarized and presented in Tables 20 to 24 by the
Utah State Division of Health (1968, 1969,  1970) in
the  Appendix. Based  on the water quality factors
tested  by  the  Division  of  Health,  an extensive
literature  review was  performed to  determine the
effects of these constituents on the  water quality for
irrigation use. Beneficial as well as toxic effects are
described.

      In reviewing  the literature it was discovered
that a great many studies have been performed on the
interactions of one component in the  presence of a
second. No  attempt was made to include this infor-
mation, except in a few cases, because of the  great
number of these papers.

Arsenic

      Arsenic can  be  beneficial  or toxic to plants
depending on the  concentration  of arsenic  and the
specie of plant.  Even though some  beneficial results
have been noted, arsenic is not presently considered
an essential nutrient  for plant survival and health. In
toxic concentrations arsenic  can cause rotting  of
roots, arrest seedling germination, and reduce seedling
viability. Arsenic primarily settles in the root system
resulting hi significant plant growth  reduction before
it goes to top-growth. This means that a plant can be
damaged without visible  symptoms occurring. When
physical damage is apparent, the damage  seems to be
the destruction  of  chlorophyll in the foliage. This
condition  is referred to  as chlorosis and  generally
appears as yellowing of the plant leaves.

      Several investigators have performed extensive
investigations regarding the extent of arsenic in soils.
Williams and Whetstone (1940) found in  testing a
wide variety of soils that  natural arsenic occurred in
concentrations  from 0.38 ppm to 38.0 ppm. Moxon
et al. (1944) found in studies of cretacious forma-
tions concentrations of 0.2 ppm to 64.4 ppm.

      In studies  conducted to  determine  toxicity
levels, Vandecaveye et al. (1936) found that the soil
samples from  the  top  6 inches of a  number  of
unproductive fields contained from 4.5 to 12.5 ppm
of  readily  soluble  arsenic  calculated  as  As203.
Marked retardation  of growth of young alfalfa and
                                             barley  plants  was noted.  In  other  experiments,
                                             Lieberg et al. (1959) applied several concentrations of
                                             arsenic and found that at a concentration of 1 mg/1,
                                             either as arsenate or as arsenite, the growth of lemon
                                             trees was stimulated. However, when concentrations
                                             of 5  mg/1  of arsenate  or  10 mg/1 of arsenite  were
                                             applied, these concentrations were found to be toxic
                                             to top growth and root growth.

                                             Bicarbonate and carbonate

                                                  Other than  pH control,  no evidence could  be
                                             found that either carbonate or bicarbonate offers any
                                             beneficial effect at all. Evidence  does exist however,
                                             that excessive amounts of these  ions can be  directly
                                             or indirectly toxic to plant growth.

                                                  Porter and Thorne (1955) found  that sodium
                                             bicarbonate  in  substantial concentrations  was in-
                                             directly responsible for iron  chlorosis  in beans and
                                             tomatoes. They used  10 meq/1  sodium bicarbonate
                                             and observed a decrease in both  chlorophyll  content
                                             and growth compared  to a concentration of only 0.3
                                             meq/1.  Amon  and Johnson (1942)  found that by
                                             using lettuce, tomatoes,  and  bermuda grass, plants
                                             grew satisfactorily  at pH values  of 4 to 8 assuming
                                             plant nutrients were available. At pH values of 3 or
                                             less and 9 or greater, plant growth was reduced.

                                                  Harley and  Lindner  (1945) found that  high
                                             concentrations of bicarbonate ion in irrigation water
                                             over a period of years produced  a detrimental effect
                                             upon peat trees and apple trees. When the concentra-
                                             tion was 3.44 meq/1 to 5.0 meq/1, a marked decline in
                                             vigor was noted. A water with 1.5 meq/1 showed  no
                                             ill effects. Chlorosis was the predominant disorder in
                                             pears, but was  only sporadic in apples. In addition
                                             lime  concretions  formed around roots and  small
                                             carbon nodules formed  on  fibrous  roots. These
                                             effects  were entirely absent from trees irrigated with
                                             low bicarbonate concentrations.

                                                  In  addition  to  chlorosis  other  undersirable
                                             effects  from bicarbonates have been shown to occur.
                                             Steward and  Preston  (1941) found  that large con-
                                             centrations  of potassium bicarbonate and dissolved
                                             carbon  dioxide  reduced  protein-,  synthesis  and
                                             bromide accumulation by potato discs. At 20 meq/1
                                             of potassium  bicarbonate,  protein  synthesis was
                                             almost  totally arrested. Hassan and Overstreet (1952)
                                             found  that  increasing  from  0 to  200 meqA  of
                                             bicarbonate ions  reduced radish elongation. At  50
                                             meq/1,  elongation was reduced by 65 percent and at
                                             200 meq/1, elongation was reduced by 98 percent.

                                                  Bicarbonates may also affect plants indirectly.
                                             One  rather  common  effect   is  the  reaction  with
                                             available calcium ions to form calcium carbonate. The
                                             removal of available  calcium acts to increase the

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                                     Separation of Algae Cells from Wastewater Lagoon Effluents    153
sodium hazard by increasing the SAR value (refer to
the section concerning sodium). Misra and Mishra
(1969) found that carbonates, when added to a soil,
reduce the availability of manganese in black, red, or
alkali soils. Since manganese is an  essential plant
nutrient, this effect  takes on some importance. The
carbonates were shown to reduce  the availability of
manganese regardless of whether the carbonate was
soluble  or insoluble. (Refer  to the section  on  the
characteristics of manganese for more information.)

      Wadleigh  and Brown (1952) found that beans
and  Dallis grass  are very sensitive to bicarbonate
concentrations and that Rhodes grass and  beets are
relatively tolerant.

      Studies have  been  made  in  order to  specify
tolerance  limits for  bicarbonates and carbonates in
irrigation water. One such specification was based on
the amount  of residual sodium carbonate  present.
Residual sodium carbonate is defined as follows:
RSC = (C0= + HC0" ) - (Ca
                                       Mg"1"1")
where the ion concentrations are in meq/1. Wilcox et
al. (1954), in establishing limits for residual sodium
carbonate,  used  Rhodes  grass in  sandy  loam  soil
under greenhouse conditions. Waters containing more
than 2.5  meq/1  of residual sodium carbonate are
unsuitable for irrigation over a long period without
use of amendments, 1.25 to 2.5 meq/1 is  marginal,
and less than 1 .25 meq/1 is probably safe.

Boron

     Boron has for some time been acknowledged as
one of the essential nutrients for plant growth. After
the laying of much groundwork by early  investiga-
tors, this fact was firmly accepted after the work of
Sommer and Lipman (1926). Deficiencies  of  boron
can cause any of several non-parasitic diseases. Some
of these include top sickness of tobacco, heart-rot of
sugar beets,  cork disease  of apple, brown  rot of
cauliflower, and raan of rutabaga.

     Boron  deficiencies will generally not occur if
the water being used has a concentration of 0.10 to
0.20 ppm and is used in quantities of 1 acre-foot or
more. A deficiency may occur under certain  condi-
tions in  the  presence of the calcium ion. Chapman
and Vanselow (1955) showed that water low in boron
but high in calcium will cause plants to exhibit an
increased need for boron.

     Boron  may also be highly toxic to plants in
excessive concentrations.  Some plants, particularly
citrus trees, are very sensitive and can be damaged by
concentrations as low as 0.75 ppm. Table 4 is a table
of plants and their tolerance to boron prepared by
Eaton (1939). Notice that he classifies sensitive crops
Table 4. Relative tolerance of plants to boron.

Tolerant
4mg/l
Athel
Asparagus
Palm
Date palm
Sugar beet
Mangel
Garden beet
Alfalfa
Gladiolus
Broadbean
Onion
Turnip
Cabbage
Lettuce
Carrot
2mg/l





Semitolerant
2mg/l
Sunflower
Potato
Acala cotton
Pima cotton
Tomato
Sweetpea
Radish
Field pea
Ragged robbin rose
Olive
Barley
Wheat
Corn
Milo
Oat
Zinnia
Pumpkin
Bell pepper
Sweet potato
Lima bean
1 mg/1
Sensitive
1 mg/1
Pecan
Black walnut
Persian walnut
Jerusalem artichoke
Navy bean
American elm
Plum
Pear
Apple
Grape
Kadota fig
Persimmon
Cherry
Peach
Apricot
Thornless blackberry
Orange
Avocado
Grapefruit
Lemon
0.5 mg/1
Source: Eaton (1939).
                                             as those that will  show slight to moderate injury at
                                             levels of 0.5 to 1.0 mg/1, semitolerant at levels of 1.0
                                             to 2.0 mg/1, and tolerant crops at levels of 2.0 to 4.0
                                             mg/1. In general past writers have left the impression
                                             that concentrations in excess  of 4  or 5 ppm boron
                                             would cause serious damage to even the very tolerant
                                             plants.  Investigators in the last 10 years  however,
                                             have  found  that  certain  plants  are  much more
                                             tolerant than previously thought.

                                                   Oertli et al. (1961) performed a number of
                                             experiments with several varieties  of turfgrass  and
                                             found  them to be very tolerant  of boron. They
                                             subjected the plants to concentrations up to 10 ppm
                                             without any apparent reduction in growth. At 10
                                             ppm, damage did occur at the leaf tips. This did not
                                             prove  to be significant because the  damage could be
                                             easily removed by  frequent mowing.

                                                   In  another  study,  Oertli  and  Roth  (1969)
                                             studied the effects of boron on sugar beets, cotton,
                                             and soybeans. Their results showed  sugar beets to be
                                             unusually tolerant. Even at concentrations of up to
                                             25 ppm of  boron, yields were  not diminished.
                                             Applications of 40 ppm resulted in some leaf damage
                                             but yields were still  rather good. Cotton showed a
                                             considerable  tolerance for boron although less than
                                             sugar  beets.  Yields  did  not  begin to  drop off
                                             significantly  until  concentrations of  15 ppm  were
                                             applied. Soybeans proved to be the most sensitive.

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 154    Gearheart and Middlebrooks
Yields were significantly affected at concentrations
greater than 5.0 ppm. Notice however, that soybeans
would be considered a tolerant  crop using Eaton's
(1939) criteria, Table 4.

      Boron toxicity can also vary considerably de-
pending  on  the stage of the plant.  Langille and
MaHoney (1959)  conducted studies  on  oats and
found that boron injury was quite dependent on the
stage  of growth. Boron was applied at the rate of 35
pounds  per acre of borax (h^B^jO^lOr^O) to  a
field of oats underseeded to a Ladino clover mixture.
With the first noticeable oat growth, there appeared a
definite chloratic condition of the oat seedlings on
plots  treated with boron. Affected seedlings showed a
distinctly  yellow and  in  some  cases almost  white
appearance. The untreated areas  appeared lush and
green. However, as  the  plants began to mature, the
injury began to decline rapidly.  At the  end of the
season  the  average yields  from the treated and
untreated plots were 61.6 and 61.4 bushels per acre
respectively.  These  yields indicate that  the boron
toxicity noted  earlier in the  season did not cause  a
reduction  in  yield  under  the  conditions of  the
experiment. After examination of the plants and the
soU, the authors suggest a minimum toxic level of
0.84 ppm of boron in the water. Concentrations of
0.84  ppm or less  appeared  to cause no apparent
damage. This seems to disagree slightly from Eaton
(1939) but the difference does not appear significant.

      In  a study using peach  trees, McLarty and
Woodbridge (1950)  studied the effects of boron both
in toxic  and deficient amounts.  When boron levels
were  deficient  the  peach trees showed significant
die-back in the spring of twigs and branches on trees
which had grown normally the previous season when
boron levels  were adequate.  There was no warning
this would occur. Leaf and flower buds appeared to
form  normally  but failed to "break" normally when
growth started in the spring.

      When boron was in excess, small necrotic areas
developed in the leaves along the  midrib eventually
resulting in perforations in  the  leaf. Small cankers
sometimes also  developed on the underside  of the
midrib  and in  the petiole.  In  more  severe  cases,
cankers  developed along the  stems, tips of branches
withered, and gumming occurred. Leaf symptoms like
those described above were  induced on 2-year old
peach trees with the application of 5 ppm boron. The
trees in general seemed to recover the following year
when the excess boron application was discontinued.

      Kelley et  al.  (1952)  found  that with carrots
grown in sand  cultures, boron toxicity  symptoms
occurred at 5 ppm  for carrots grown in the summer
and   10  ppm  for  carrots   grown  in  the winter.
Apparently boron toxicity in certain plants is quite
sensitive  to  climate.  Carotene  content  was  in-
dependent of boron supply for all levels greater than
needed to overcome deficiency.

Cadmium

     Not a great deal has been presented on the
potential toxicity problems related to plants. McKee
and Wolfe (1963) suggest a tollerance limit of 0.005
mg/1 for  irrigation water on a long term basis. They
based this  value  on two assumptions: (1) reported
toxicity levels are correct (Lieber and Welsch, 1954)
and (2) cadmium behaves like zinc relative to plant
uptake and soil reactions.

     In a study Schroeder and Balassa (1963) found
that  when  vegetables normally devoid  of cadmium
were grown in soil heavily fertilized with 20 percent
superphosphate (H2P04~),  the plants absorbed cad-
mium. These plants included potatoes, string beans,
beets, onions, peas, and carrots. They also found that
vegetables  normally containing  cadmium  absorbed
larger quantities than  normal. The plants  were let-
tuce,  turnips,  radishes,  and parsnips.  The  super-
phosphates were found to  contain  7.25  ppm cad-
mium. The authors concluded  that  superphosphate
can  increase  the  cadmium  uptake   of plants and
thereby reduce the plant's tolerance to cadmium.

     In  the same study, the authors applied a large
amount of superphosphate to one of three plots of
vegetables.  Growth of the fertilized plot was far more
lush  than  that  of the two  unfertilized plots. The
plants used were peas, swiss chard, beets, and turnips.
Schroeder  and  Balassa (1963) concluded that  the
plants were not damaged by 7.25 ppm cadmium.

Calcium

     Calcium is  another  of the  16  basic elements
required  for plant growth. It  is the dominant base of
a "normal" soil. In addition to the benefits to plant
growth and soil structure, calcium also offers benefits
for biological  activity. If  soil  conditions  become
either too acid or too alkaline, calcium will become
deficient.

     As pointed out in the section on boron, calcium
can reduce the toxic  effect of boron. Cooper et  al.
(1958) found that concentrations of calcium nitrate
added to a water of 6.9 ppm of boron in amounts
that  increased   the  electrical conductivity of  the
saturation  extract  from  5.5 to 7.2 millimhos/cm
reduced the usual boron effects by one-third. Calcium
is then a useful amendment for reducing problems of
boron toxicity.

     The presence of calcium in the soil can cause
potassium  to  be more readily  available to plants.

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                                      Separation of Algae Cells from Wastewater Lagoon Effluents     155
York et  al. (1954)  showed that when lime  and
potassium fertilizer were used together growth yields
were increased.

      Excessive  concentrations of calcium  can  also
cause  detrimental  effects.  These  effects generally
stem from calcium reacting with  certain  ions in the
soil.  For  example,  if calcium  combines  with
carbonate, a.buffering  effect results.  This  in  turn
produces  a  decrease in nutrient availability. In addi-
tion, with  calcium being  precipitated  as  calcium
carbonate, the sodium hazard increases (see section
on sodium). Lund (1970)  studied calcium and its
effects in relation to magnesium using soybeans for
his crop. He used a ratio of the calcium concentration
divided by  the  sum of the calcium and  magnesium
concentrations  to make evaluations. He  determined
that when the  ratio  of calcium  to magnesium was
small, depressed root  growth occurred  even when
calcium was present  in concentrations of  40 ppm.
Taproot harvest length after 7& days of growth was
299 mm with a calcium to magnesium ratio of 0.05.
With a ratio of 0.20, the length was 485 mm.

Chloride

      Chlorides are another of the essential nutrients
for plant  growth. Though generally not phytotoxic,
in  excessive amounts  chlorides  can cause  leaf tip
burn, premature yellowing, and at times chlorosis in
some plants.

      A number  of investigators have worked in the
area of chloride deficiency  with  interesting results.
Raleigh (1948) studied the effect of chloride addition
to a chloride deficient culture solution on  table beets.
He  found  that  when  several  millequivalents  of
chloride  were  introduced, the  yield  increased  sig-
nificantly. Harward et  al. (1956)  working with  Irish
potatoes  had  similar  results in  increasing  yields.
Corbett and Gausman  (1960) also studied  potatoes
with  significant  yield   increases   when   chloride
deficiencies  were treated with added concentrations
of chloride.

      Table  5 (Eaton, 1966)  shows some common
plants and  their  suggested  tolerance  to  excessive
chloride  concentrations.  Note that fruit  trees are
relatively  sensitive whereas certain vegetables  and
grains are rather tolerant. However, these limits can
be readily modified by leaching. It  is also important
to realize that though these limits are helpful, usually
salinity levels are more important than chloride levels
because salinity will  ordinarily  reduce  crop growth
first.

      A number of studies have investigated the toxic
effects of excessive concentrations  of chloride. Con-
centrations as low as 3 meq/1 of chloride in irrigation
water have caused injury to citrus, stone  fruits, and
almonds  (Bernstein,  1967). Bingham  et  al. (1968)
found that the application of 5 meq/1 of chloride in
irrigation water could constitute a hazard to avacado
trees.

      Foliar absorption of chloride has been found to
be  of importance when using  sprinkler  irrigation
(Eaton  and  Harding, 1959;  Ehlig and  Bernstein,
1959). The difference in evaporation between  day
and night and the amount of evaporation occurring
between revolutions of the sprinkler head can cause
adverse effects.

      Meron  et  al. (1965) in a study performed in
Israel found that  high chloride concentrations may
cause slow but eventually fatal physiological injury to
citrus trees. The authors  also state that as of 1965,
chloride concentrations in the range of 150 to 200
mg/1 (4.15 to 5.55 meq/1, respectively) are accepted
for  irrigation of citrus trees, and chloride  concentra-
tions  of 300 mg/1 (8.3 meq/1) are accepted for other
agricultural crops.
 Table 5. Tolerances to chloride, as measured in sand and water cultures.3
Low Tolerance
GassI
Peach
Avocado
Lemon
Prune
Bean (navy)
Plum
Dallis grass

13
14
15
16
18
18
19

Medium Tolerance
Class II
Strawberry
Apricot
Orange (Valencia)
Rice
Sorghum
Alfalfa
Rhodes grass
Bean (kidney)
20
20
20
23
23
23
24
24
High Tolerance
Class III
Wheat (young)
Tomato
Cotton
Flax
Corn (young)
Barley
Beet

25
39
50
50
70
90
100

      aChloride concentrations in meq/1 producing 80% growth 01 yield.

 Source: Eaton (1966).

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 156    Gearheart and Middlebrooks
Copper

     Evidence was presented by Sommer (1931) and
by Lipman and MacKinney  (1931) that copper was
an  essential  nutrient  for plant growth.  Sommer
(1931) found that when copper was eliminated from
the  diet of  tomatoes,  sunflowers,  and  flax that
growth reductions up to 90 percent occurred. Lipman
and MacKinney (1931) found that barley gave normal
growth when fed one part cooper in ten million parts
of  nutrient  culture  solutions  made  from  highly
refined  chemicals. When  copper was  omitted, the
plant did  not  fruit  properly. Because of  a large
amount of circumstantial evidence built  up  before
these two papers, the evidence of 1931 was accepted.

     In a study done on a  copper deficient  soil in
Manitoba,  Canada,  Campbell  and  Gusta  (1966)
realized  significant  yield increases of carrots and
onions with the application of only 0.5 pounds/acre
of copper. An increase to 2.5 pounds/acre  of copper
gave no further increase but caused no adverse effects
either.  The quality of the  onions was also improved.

     Copper can  act toxically  if in excess quantities.
Anne and Dupuis (1953)  among  others have shown
that toxic amounts of copper can reduce growth and
may depress iron concentrations in leaves causing iron
chlorosis  symptoms.  Forbes  (1917) showed that
excessive copper could also cause root damage. Amon
(1950) found that a 2.0 mg/1 concentration of copper
in a nutrient solution was  toxic to tomato  plants.
Smith  and Specht  (1953) found that  a 0.1 mg/1
concentration  was  toxic  to orange and  mandarin
seedlings. Millikan (1949) found that a concentration
of 0.5 mg/1 in a water culture caused damage to flax.
Hewitt  (1953),  using a  sand  culture, found that
nutrient  solutions containing  6.4 to 31.8 mg/1 of
copper caused damage to sugar beets, tomatoes, and
potatoes but not to oats  and  kale. Tolerance levels
have been  suggested for copper  in irrigation water
which agree in general with the  above findings. Values
of 0.1  mg/1 (McKee and Wolfe,  1963) and 0.2 mg/1
(National Technical Advisory  Committee  on Water
Criteria,  1968)  have  been  suggested. Small dis-
crepancies  may  be accounted for because  irrigation
water  has  an  alkalyzing effect (increase  of  the
exchangeable-sodium  content  of a soil) which may
reduce  copper availability and bring on deficiency.
This is  especially common in sands and high organic
soils.

      Hunter and Vergnano  (1952) found  that when
oats received 2.0 ppm copper  in a nutrient solution,
they were usually normal, though some showed slight
interveinal chlorosis.  Those that  received  10.0 ppm
were very chlorotic. With concentrations of 20.0 ppm
or  greater, the  plants  were  small and the leaves
narrow. A few were chlorotic  but most were orange
colored. Above 2.0 ppm, roots showed a decrease in
size.

Fluorine

     Fluorine is not considered an essential element
for plant growth. It can however, cause toxic effects
in excess amounts. Injury appears as marginal necrosis
(leaf tip burn) and/or interveinal chlorosis.

     The  amount of fluoride uptake by the plant has
been shown conclusively to be independent of soil
concentration by Hurd-Karrer (1950) among others.
The determining factors seem to be soil type, calcium
and phosphorus content, and pH. Hurd-Karrer (1950)
also demonstrated  that excess quantities of soluble
fluorides applied to unlimed acid soils will cause plant
injury.  On  the other hand,  addition of  soluble
fluorides  to  well  limed soils  or the  addition  of
insoluble  fluorides to acid  or limed soils caused  no
apparent  injury. Soils at a pH of 6.5 will almost
completely fix any soluble fluoride compounds in the
soil or added to the soil.

     A number of toxic effects caused by excessive
fluorides have been noted. Leone et al. (1948) found
that when  10 mg/1  of fluorides were applied  to
tomato,  peach,  and  buckwheat  plants, no  injury
occurred.  However, at levels of 100 mg/1, the plants
were severely injured in three days. At levels of 200
mg/1, the  plants were killed in a short time.  In
another study  (Science News  Letter,  1949) using
beans,  levels between  100 to 500 mg/1 inhibited
sprouting  of the beans. At levels of 1000 mg/1 the
growth of the beans were markedly stunted. Prince et
al. (1949) in other studies on buckwheat found that
at levels of 180 mg/1 no injury occurred at pH over
5.5. This  result agrees with the results arrived at by
Hurd-Karrer (1950). However, when the concentra-
tion was  increased  to 360  mg/1 both peach  and
buckwheat were injured even at a pH of 6.5.

     Brewer  et al.  (1959)  used  treatments  of
hydrogen  fluoride at rates of 0, 25, and 100 ppm on
four naval orange trees. All trees were 4 years old. All
four trees receiving 100 ppm wilted within 24 hours
after the  application. Wilting was followed by com-
plete defoliation. Root examination revealed a com-
plete coverage  of  the roots by a slimy, gelatinous
film. The film proved to be mainly calcium, phos-
phate, and  fluoride  ions. The  trees were so badly
damaged they were discarded. The  other two treat-
ments  were continued  for 18 months. During this
time, the  trees treated with 25 ppm became progres-
sively less vigorous than the control trees. Spring leaf
drop was  also more  severe. The foliage also became
increasingly sparse. Tests run on the fruit showed  the
25  ppm trees to be  vastly  inferior both in quantity
and quality.

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                                     Separation of Algae Cells from Wastewater Lagoon Effluents    157
     McNulty and Newman (1961) used concentra-
tions of 1.31 x  10"2M sodium fluoride and found a
definite reduction  in  the amount of chlorophyll in
bush beans. The carotenes of these plants were also
reduced.  Chang  (1968)  found that fluoride in con-
centrations of 5 x lO^M and 1 x 10"3M suppressed
the growth rate  of com seedling roots by about 20
percent and 40  percent  respectively.  Chang  also
pointed out  that fluoride  is known to  act as an
enzyme inhibitor.

Iron

     Iron  was  demonstrated  to  be  an  essential
nutrient  over a century  ago.  Griss (as cited by
Wallihan, 1966) found that foliar application of iron
to  chlorotic grapevines  was very  beneficial.  Iron
toxicity has not occurred to any great degree under
natural conditions.

     The most common symptom of iron deficiency
is  chlorosis  which  is a reduced concentration of
chlorophyll in green plants. The addition of inorganic
iron salts  generally  produces  little  or  no  effect
because such compounds are quickly rendered in-
soluble in alkaline soils. This would also explain why
problems of toxicity have not occurred under natural
conditions.

Lead

     Lead is not considered an essential plant nutri-
ent  although  there  is  evidence   of some  small
beneficial effects. Toxicity results for lead have been
somewhat contradictory. Klintworth  (1952)  stated
that lead is harmful to plants at all concentrations.
On the other hand, Frear (no date) added lead nitrate
to oats and potatoes at concentrations of 1.5 to 25.0
mg/1 and got stimulation effects. When he increased
the dosage to 50.0 mg/1, all plants died within a week.
Hewitt (1953) found that  when sugar  beets were
grown  in  a sand culture, the beets showed a  slight
injury with  a nutrient solution containing 51.8 mg/1
of lead.

     Hooper (1937) found that when dwarf French
beans were grown in a nutrient culture containing 30
ppm lead in the form of lead sulphate, the plants
suffered no apparent  damage. In a  spraying experi-
ment, lead spray again was  found  not to harm the
plants  other than by spraying  heavily  enough to
physically block the stomates.

Magnesium

     Magnesium was  found to be an essential nutri-
ent around  the  turn  of  the century by Pfeffer (as
cited by  Embleton, 1966). A few years later, Meyer
 and Anderson  (1939)  affirmed   this  conclusion.
Studies  during this  period  also indicated  possible
toxicity problems associated with excess magnesium.

     Reports of magnesium toxicity seem to indicate
the problem is one of imbalance with  one  or more
other elements. These problems  could perhaps be
overcome  by  increasing the level  of the particular
element or  elements without  increasing  the  mag-
nesium  level  (Embleton, 1966). This presumes  that
by increasing the other element levels, the problem is
not merely shifted but rather solved. Each case would
require individual analysis.

     Garner  et al. (1930)  showed that soils low  in
calcium which are given applications of magnesium
may produce toxic effects.  Kelley (1948) found that
when a soil had more than 90 percent  of the cation
exchange capacity saturated with magnesium, the soil
was almost totally unproductive. Gauch and Wadleigh
(1944)  found that concentrations  of 3000 to  5000
mg/1 of MgCl2 and MgS04 were toxic to bean plants.

     Magnesium and calcium ions  in irrigation water
tend to keep  soil permeable and in good tilth. (See
Water  for Irrigation  Use,  1951.)  This is expected
because the  SAR is inversely proportional to the
concentrations of these two ions. More  will be said in
the section on sodium concerning this area.

Manganese

     Many early researchers have  shown the neces-
sity  of manganese  as an  essential  plant  nutrient.
Bertrand (as cited by Labanauskas, 1966) was one  of
the first to advance the idea. McHargue (1926) grew
wheat with and without manganese and found that
without manganese the wheat became chlorotic, was
stunted, and produced  no seed. These effects were
absent in the wheat grown with manganese.


      Further research  showed that  manganese  in
excess quantities  could cause toxic effects. Deatrick
(1919)  showed  that  small  concentrations   of
manganese clearly stimulated wheat growth but as the
concentration  became  large,  detrimental effects
appeared.  Bishop (1928)  working with  radishes,
beans, corn, and peas found that concentrations of 5
ppm of applied manganese stimulated growth whereas
concentrations of  10  ppm  or  greater  depressed
growth. He found radishes, however, to be better  at
10 ppm and  declined from that point provided the
pH was neutral rather than acidic.

     Joham  and Amin (1967) determined that  81
ppm of applied manganese  was toxic to cotton. The
optimum  level was found  to  be on the order  of 3
ppm. Good   growth and  fruiting were  obtained,
however, up to levels of 27 ppm.

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 158    Gearheart and Middlebrooks
      It seems that certain soil properties increase the
 probability of excess manganese problems.  Snider
 (1943) has shown  that soils that are strongly acidic
 frequently have excess manganese problems.  This is
 because manganese is rather dependent on pH in its
 availability to plants. In other studies, Fergus (1954)
 showed, using French beans and peanuts, that the
 amount of manganese uptake by the  plants was pH
 dependent. He concluded that where  large amounts
 of manganese were in the soil,  at pH values  greater
 than  5, good growth  could be expected. However, at
 pH values less than 5, symptoms of toxicity would
 probably  appear.  Table 6 is a  portion  of the  data
 taken during this  study. The  proof of  the above
 statements is rather obvious from the table.

      Results  in full  agreement  with Fergus'  (1954)
 work were published by Gupta et al. (1970). They
 found that when manganese  was applied to carrots at
 concentrations of 1000 ppm in a soil with a pH of 5.7
 or higher beneficial results occurred. These included
 reduced bronzing  of leaves and increased  yields.
 Brown  et  al. (1968) showed that sugar  beets  were
 very  tolerant  to manganese.  In one experiment, pots
 of sugar beets were treated with manganese sulfate at
 the rate of 650 ppm manganese with no apparent
 toxic effects.  As the  above studies would suggest, the
 pH was approximately 5.5.
Table 6.  Plant  growth in relation  to soil  pH  and
         manganese content of plant.
Soil pH
4.4
4.5
4.8
4.9
5.0
5.9
Plant Mn (ppm)
3000
2400
1200
800
1100
260
Plant Growth
Very poor
Poor
Fair. Some chlorosis
Good
Fair. Some chlorosis
Good
Nitrogen

      Nitrogen  is an  essential element for  plant
nutrition  and the one most commonly associated
with plant health. To  a large extent  it controls the
growth and fruiting of most plants. One  of the early
milestone pieces  of  work  establishing the need by
plants for nitrogen  was performed  by Kraus and
Kraybill  (1918).  They found that  by using  nitrates
tomato  plants with sufficient nitrogen nutrition did
well whereas those without nitrogen did not  do well
at all. Nitrogen  shortages  are more  likely  to be a
problem than nitrogen excesses because of  the high
mobility of the element and its compounds. Short-
ages result in a reduction of chlorophyll resulting in a
loss of green color.
      Nitrogen excesses can cause several  kinds  of
 problems.  Embleton et al. (1959) using sulfate  of
 ammonia for 3 pounds nitrogen found that plants
 become  highly  vegetative resulting in yield reduc-
 tions. Clements (1958) found that excess  nitrogen
 reduced  sugar production in  sugar  cane.  In  other
 studies (Jones and Embleton,  1959;  Reuther et al.,
 1958) using urea and different nitrates, the quality of
 different fruits was found to be impaired. In excess,
 nitrogen can also add to the salinity of the  soil. This
 has  been confirmed by  Pratt et al. (1959).  Their
 nitrogen sources included urea, manure, dried blood,
 various  nitrates,  and  ammonium  sulfate. Excess
 nitrates  tend to reduce  soil  permeability.  Nitrates
 may  accumulate to toxic levels  but their  effect is
 usually osmotic (Thorne and Peterson, 1949).

      All soils will become deficient in nitrogen  in
 time  if there is no replenishing of the nitrogen using
 some type of fertilization program. Soils especially
 subject to deficiency, however, are sandy soils subject
 to high  rainfall  causing  leaching and  soils low  in
 organic matter.

      Zanoni et al. (1967) performed studies showing
that  if carbohydrate reserves  are  depleted to low
levels in response  to higher soil temperatures and
these levels are further reduced by increased nitrogen
levels, grasses appear to be more susceptible  to injury
from disease.  This happens because at temperatures
greater  than  60 °F, top-growth  is stimulated  thus
drawing on the root reserves. Therefore excess nitro-
gen during warm weather can  indirectly cause injury
by increasing greatly the disease potential.

      Ford et al. (1957) using NH4N03 showed that
 over  fertilization with  nitrogen can reduce  the con-
 centration  of feeder roots in  the principal rooting
 zone of citrus trees on sandy soil. Neither the time of
 application nor the fertilizer ratio was a factor  in the
 shift in root concentration  associated  with  high
 nitrogen. Treatments were initially 0.6, 1.2, and 2.4
 pounds  of  nitrogen per  tree  per year.  This was
 gradually increased to 0.87, 1.75, and 3.5 pounds as
 the trees grew.


 Phosphorus

      Phosphorus  was  established  as  an  essential
 nutrient  in 1839 and 1840 by Liebig in Germany and
 Laws in  England, respectively. (See Bingham, 1966.)
 Along with  nitrogen and  potassium, phosphorus is
 quite commonly supplied to the plant by application
 of commercial fertilizer.  Phosphorus ties up in the
 soil readily and therefore only a small fraction of the
 phosphorus in the  soil is available  for  plant use.
 Acidification of the soil will help to make phosphorus
 more available to the plant.

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                                     Separation of Algae Cells from Wastewater Lagoon Effluents     159
      The soils most likely deficient in phosphorus
 are  highly weathered soils, calcareous soils, and peat
 and muck soils. Highly weathered soils are usually
 acidic and often  deficient in available phosphorus.
 Calcareous soils may have a large total phosphorus
 but the  high pH due  to  the  calcium makes the
 phosphorus mostly unavailable.  Peat and muck soils
 often respond well to phosphorus fertilization.
      Cannell et  al.  (1960) performed studies  on
 tomato plants and found that  phosphorus applica-
 tions of 2,10, 26, and 50 grams of CafHjPO^-HjO
 per  12.5  kg of soil tended to decrease the adverse
 effect of soil  suction. This resulted  in larger  and
 greener plants. These experiments were conducted on
 three  soil  types,  acidic, moderately acidic,  and
 alkaline. The authors suggest that perhaps phosphorus
 in the form used  lowered the pH and made certain
 ions more available to the plants, i.e., became more
 soluble.  They  cited manganese and magnesium as
 examples.
      A   number   of  problems   resulting   from
 phosphorus toxicity studies have been noted. Rossiter
 (1952) found  that the nodulation  of legumes was
 reduced. Bingham and Garber (1960) have  shown a
 phosphorus-copper  antagonism,  and   Loneragan
 (1950) presented  evidence  for  a  phosphorus-zinc
 antagonism.  Phosphorus-iron antagonisms were dis-
 cussed by Brown et al. (1968). In many cases, the bad
 effects of phosphorus  in  view of the  antagonisms
 mentioned above would appear to be indirect. These
 interactions are generally more readily  produced in
 acid soils.
      Bingham  (1966)  found  that with  a  water
soluble concentration of 20 to  100 ppm or more of
phosphorus, copper deficiency was induced in citrus
seedlings by  high  phosphate additions. He suggests
that 40 to 80 pounds of P205 per acre be used on
small grains and 60 to 120 pounds of P205 per acre
on vegetables. Alfalfa requires high rates, from 160 to
320 pounds of P205  per acre. Where needed, citrus
should initially receive 4 to 5 pounds of P2Os  per
tree and a maintenance amount of 1 to 2 pounds per
tree every few years.
      Generally when phosphates occur in irrigation
waters, they offer beneficial fertilizing effects (Joshi,
1945). Blueberry plants grown in nutrient water of
low  phosphate   content  (1  to  5  mg/1) showed
symptoms of phosphate deficiency. When the con-
centration was increased to 60 mg/1, signs of incipient
iron chlorosis appeared. Phosphorus seems  to reduce
the  amount  of available  inorganic  iron thereby
producing the observed chlorosis (Holmes, 1960).
Potassium

      Potassium was established as an essential nutri-
ent  over  one  hundred  years  ago by Birner and
Lucanus (Ulrich and  Ohki, 1966). Using oats, they
found that potassium was essential to flowering and
could  not  be  replaced by  any metal of the same
grouping.  Potassium  problems  generally  occur  as
deficiencies rather than as excesses. The reason is that
both exchangeable  and non-exchangeable potassium
are fixed in  the soils.  There are some indications that
potassium may cause  deficiencies of other nutrients.
Reuther and Smith (1954) for instance suggested that
the absorption of zinc and iron by some plants may
be  adversely  affected  by  excesses of  potassium.
Potassium deficiencies will manifest  themselves  as
interveinal chlorosis near the margins progressing to
what is termed leaf scorch. Table 7 (Ulrich and Ohki,
1966) shows several crops with values of potassium
found to be  minimum levels. These  values were
established by  finding the  point at which potassium
fertilization no longer  provided significant response.

      Potassium, while  essential  for plant  growth,
must be maintained  in  proper  balance  to  other
nutrients such as  phosphorus (Wilcox, 1948).  In
another study (Water for Irrigation Use, 1951), it was
found that potassium in irrigation water can act on
soils somewhat like sodium only it is less harmful.

Table 7. Some exchangeable potassium levels below
        which responses  to potassium fertilization
        have been reported (Ulrich and Ohki, 1966).
                                                     Plant
                       Pounds of Exchangeable
                        Potassium (K) Per Acre
                               of Soil3
Alfalfa


Corn



Cotton

Field crops
Grape

Pineapple
Potato

Sugar cane


Tobacco
80
160
180
155
83
200
150
185
120
200
200
136
156
140-375
220
150
180
200
190
      "Basis: 2,000,000 pounds of soil per acre.

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  160
Gearheart and Middlebrooks
  Salinity

       Increased salinity causes problems by increasing
  the osmotic pressure of the soil for water. As salinity
  increases, the plant  has a more difficult time obtain-
  ing water from the  soil. The relationship expressing
  total soil suction on  a plant is

                   TSS = MS + SS

 where TSS is the total soil suction withholding water
 from the plant, MS is the matric  suction or the
 physical attraction of soil particles for water, and SS
 is  the osmotic pressure due  to  salinity. As water is
 lost  through evapotranspiration, the salt concentra-
 tion builds up rapidly causing the term SS to become
 increasingly important. The  matric suction  increases
 exponentially as water is lost. The combined effect of
 the two factors can cause  critical conditions for soil
 water availability. (See Table 8 for general guidelines
 for salinity in irrigation water.)
       Plants  react  differently to  salinity  problems
  depending on the  growth  stage  at  which salinity
  becomes  a  problem. A study  (Lunin,  1963)  was
  conducted showing the  response of beets to salinity
  at  the seedling  stage  and  at  2  and 4  weeks of
  maturity. Both the roots and  the top growth were
  studied. The  results  indicated  tops  were affected
  about  the   same.   Roots,  however,  were  highly
  dependent on the stage of plant growth.
      Climatic factors such as wind and temperature
 are important in determining evapotranspiration rates
 which relate back to osmotic pressure. Magistad et al.
 (1943)  demonstrated  the effects  of climate  on
 salinity levels. They found using cotton, alfalfa, sugar
 beets, tomatoes, squash,  onions, navy  beans, garden
 beets, and carrots  that at a given  salt  concentration
 these  crops  are  depressed  in relative yield more in
 warm than  in  cool climates.  In  humid regions,
 irrigation water is used to supplement rainfall. There-
 fore a given water will be less likely to cause salinity
 problems. This is true because salt accumulation is a
 function  of the salt concentration of the irrigation
 water, evapotranspiration, drainage and leaching, and
 the  amounts  of  water   applied  and received as
 precipitation.
                                                   Leaching is the best method of controlling the
                                             salinity problem.  Adequate leaching  depends on  a
                                             number  of  factors.  First,  the  drainage must be
                                             sufficient to  wash the  salts below the  root  zone.
                                             Otherwise  root systems will  be subjected to  the
                                             problems of osmotic  pressure  and   not  take  in
                                             sufficient water. Another factor of equal importance
                                             is the proper amount  of  water for  leaching. Not
                                             enough will leave  the salinity problem only partially
                                             solved while too much will clog the pore spaces of the
                                             soil  and displace  the oxygen in  the soil. When  this
                                             condition exists for a prolonged period of time, plant
                                             roots may actually rot away killing the plant. During
                                             a field trip a row of trees was pointed out by the field
                                             trip  leader,  which due to excess  wetness of the root
                                             zone, had nearly died. The problem was determined
                                             and  the  appropriate action executed preventing the
                                             loss  of the trees.

                                                   Saline waters must be used in  greater amounts
                                             than  non-saline waters because more of the  saline
                                             water must pass beyond the root zone than that of
                                             the  non-saline water. When saline water  is  being
                                             considered  for irrigation, the individual making the
                                             decision should only consider well drained soils.

                                                   In  a  study  performed  by Robinson  et al.
                                             (1968), sprinklers  were shown to  be more effective in
                                             the removal of soil salts. The water used was from the
                                             Colorado River with  a salinity of approximately 12
                                             meq/1. They  found that it was necessary to sprinkle
                                             more frequently than usual  to avoid leaf tip burn due
                                             to salt accumulation. They  used clay and sandy clay
                                             loam soils and grew sugar beets, cabbage, carrots,
                                             onions, wheat, barley,  safflower,  and  flax.  Under
                                             these conditions they were  able to successfully grow
                                             these crops.  Peterson (1968) warns  against sprinkler
                                             use  however. He  points out that water applied by
                                             sprinklers may  cause problems  which  would  not
                                             occur  using  surface  application. Salt  buildups  can
                                             occur  causing tip  burn,  marginal leaf burn, or even
                                             defoliation of sensitive plants.

                                                   Bernstein (1965) pointed  out that most fruit
                                             crops are more sensitive to salinity than are field,
                                             forage, or vegetable crops.  He also  pointed out the
                                             difference in  sensitivity  of the  plant to salinity at
                                             different stages of growth. This is in agreement with
                                             Lunin et al. (1963).
Table 8. General guidelines for salinity in irrigation water.
Classification
Water for which no detrimental effects are usually noticed
Water that can have detrimental effects on sensitive crops
Water that can have adverse effects on many crops, requiring careful
management practices
Water that can be used for tolerant plants on permeable soils with careful
management practices
TDS (mg/1)
500
500-1,000
1,000-2,000
2,000-5,000
EC (mmhos/cm)
0.75
0.75-1.50
1.50-3.00
3.00-7.50
Source: National Academy of Science-National Academy of Engineering, Environmental Study Board, ad hoc Committee on
       Water Quality Criteria 1972: Water Quality Criteria 1972, U.S. Government Printing Office  (in press).

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                                      Separation of Algae Cells from Wastewater Lagoon Effluents     161
      Werkhoven et  al. (1966) found that deciduous
trees  were  more  salt tolerant than the coniferous
species. In terms of survival, an ECe value of between
7 and 10 mmhos appeared to be critical for caragana
and elm in  a soil  with a moisture content  of about
midway between the wilting point and field capacity.
The corresponding values for  spruce and pine were
closer  to 4  and 6 mmhos  respectively.  Seedling
survival was markedly improved by maintaining the
soil  moisture  level  at   field  capacity.  Emergence
seemed to  improve  with some salinity, but survival
Was definitely adversely affected by the salinity.

      Table   9 (Eaton,  1939) gives  suggested  salt
tolerances for a number of crops. The table is based
on the criteria of the relative yield of the crop on a
saline soil as compared with its yield on a non-saline
soil  under  similar  growing  conditions. The table
displays the crops in columns with the most tolerant
crop  at the top and the least tolerant crop at the
bottom. The values  of ECe given represent  the levels
of salinity  at which a 50 percent decrease in yield
would  be  expected  compared to  non-saline  soils
under similar growing conditions. Of course climatic
conditions  may  greatly  influence  plant  reactions
compared to these suggested limits.
Table 9.  Relative tolerance of crop plants to salt, list-
         ed in decreasing order of tolerance (Eaton,
         1939).a
Table 9.  Continued.
High Salt
Tolerance
ECeX103 = 12
Garden beets
Kale
Asparagus
Spinach





ECeX103 = 10
High Salt
Tolerance
ECeX103=16
Barley (grain)
Sugar beet
Vegetable Crops
Medium Salt
Tolerance
ECeX103 = 10
Tomato
Broccoli
Cabbage
Bell pepper
Cauliflower
Lettuce
Sweet corn
Potatoes (White
Rose)
Carrot
Onion
Peas
Squash
Cucumber
ECeX103=4
Field Crops
Medium Salt
Tolerance
ECeX103 = 10
Rye (grain)
Wheat (grain)
Low Salt
Tolerance
ECeX103=4
Radish
Celery
Green beans





ECeX103=3
Low Salt
Tolerance
ECeX103=4
Field beans '
Rape
Cotton


ECeX103 = 10
High Salt
Tolerance
EQX103 = 18
Alkali sacaton

Saltgrass
Nuttall alkali-
grass
Bermuda grass
Rhodes grass
Rescue grass
Canada wildrye
Western wheat-
grass
Barley (hay)
Oats (grain)
Rice
Sorghum (grain)
Corn (field)
Flax
Sunflower
Castorbeans
ECeX103=6
Forage Crops
Medium Salt
Tolerance
ECeX103 = 12
White sweet-
clover
Yellow sweet-
clover
Perennial rye-
grass
Mountain brome
Strawberry
clover
Dallis grass
Sudan grass
Hubam clover




Low Salt
Tolerance
ECeX103=4
White Dutch
clover
Meadow fox-
tail
Alsike clover
Red clover
Ladino clover
Burnet
Alfalfa (California
Bridsfoot trefoil
 common)
Tall fescue
Rye (hay)
Wheat (hay)
Oats (hay)
Orchardgrass
Blue grama
Meadow fescue
Reed canary
Big trefoil
Smooth brome
Tall meadow
ECeX103 = 12
High Salt
Tolerance
Date palm
oatgrass
Cicer milkvetch
Sourclover
Sickle milkvetch
ECeX103=4
Fruit Crops
Medium Salt
Tolerance
Pomegranate
Fig
Olive
Grape
Cantaloupe
ECeX103=2
Low Salt
Tolerance
Pear
Apple
Orange
Grapefruit
Peach
Lemon
                                                            ^he numbers following ECeXlO3 are  the electrical
                                                      conductivity values of the saturation extract in millimhos per
                                                      centimeter at 25°C associated with 50 percent decrease in
                                                      yield.

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 162
Gearheart and Middlebrooks
Selenium

     Though some studies have shown a stimulation
of  plant  growth   from  applications  of very  low
concentrations  of selenium (Trelease  and Trelease,
1938), generally selenium is not considered beneficial
to plants.  In fact, problems associated with selenium
are normally those of toxicity due to excess selenium.

     The  literature indicates that the primary prob-
lem of selenium is with forage crops because of the
potential  poisoning of grazing animals. Trelease and
Beath  (1949) have prepared a comprehensive discus-
sion of specific symptoms of selenium poisoning in
animals.

      In   the  continental United  States, selenium
producing seleniferous plants have been found only in
arid or semi-arid areas with mean annual rainfall less
than 20 inches (Trelease and Beath,  1949). Hough et
al. (1941) found 12 to 14 ppm of selenium in some
lava produced soils  in  Hawaii.  This is the  highest
selenium  content encountered  in soils which do not
produce a seleniferous vegetation.

      Bisbjerg  and Gissel-Nielsen (1969) tested  a
variety of  plants  and  found them to  be  Injured
significantly by applications of  2.5 ppm or higher.
The plants included in  their  study  were  clover,
lucerne,   radish,  black  medick,  white mustard,
perennial  rye  grass,  rye, wheat, barley, and  oats.
Hurd-Karrer  (1935)  stated that selenium injury  to
plants can be  reduced or prevented when  the con-
centration of sulfate ion is about twelve times greater
than the  selenium concentration. Table  10 (Miller,
 1954) suggests tentative  limits of selenium in irriga-
 tion water.
 Table 10. Tentative limits of selenium in water for
          irrigation (Miller, 1954).
Irrigation
Class
1. Low
Selenium
(mg/1)
0.00-0.10
Remarks
No plant toxicity
 2. Medium    0.11-0.20
 3. High       0.21-0.50
 4. Very high   over 0.50
                   anticipated
                   Usable, but with possi-
                   ble long-term accumu-
                   lations under particular
                   conditions should be
                   watched
                   Doubtful-probable toxic
                   accumulation in plants
                   except under especially
                   favorable conditions
                   Non-usable under any
                   conditions
Silica

     Up until recently silica was generally considered
of little  importance in irrigation water (Water for
Irrigation Use,  1951).  The  U.S.  Department  of
Agriculture has recommended limits of 10 to 50 mg/1
(McKee and Wolfe, 1963).

      Later studies have increased the importance of
 silica  however.  Eaton  et  al.  (1968)  found  that
 magnesium in the form of silicates can be lost from
 the  soil  by precipitation under  the  following condi-
 tions:  (1)  The concentration of magnesium must be
 on the order of several meq/1, and (2) there must be a
 degree of  alkalinity such  that a part of the  silicon
 dioxide  is ionized  as silicates.  They concluded that
 precipitations  of calcium carbonate by whatever
 mechanism occurred and the associated increases in
 sodium percentages provided the source of alkalinity.
 Thus silica may indirectly  affect the SAR of the  soil
 system.

 Silver

      Silver has not been shown to be an essential
 element  in  the  nutrition  of  plants.  Problems  of
 toxicity  are   unlikely   because  of  the  relative  in-
 solubility of silver and its  common compounds. The
 element  availability to  plants is thus low. Vanselow
 (1966) found that citrus  leaves growing in soil  to
 which  75  ppm of  silver  as nitrate  had been added
 contained only 0.5  ppm. This does not seem to cause
 any injury to the plant at all.

 Sodium

     Except  for two or three  plants, sodium is not
 an essential nutrient for higher plants (the poisonous
 weed  Halogeton  is   one  exception).  However,
 beneficial  results have been reported.  Cope et al.
 (1953)  have  found  that  in  some  soils, sodium
 applications have increased the available potassium
 supply.  Truog et  al.  (1953)  found that sodium
 applications to celery improved the taste and crisp-
 ness markedly. In the  same  study, carrots exhibited
 improved taste (sweeter) with sodium applications.

     Sodium can also produce detrimental effects on
 plants  and in the soil.  The sodium condition in soils
 can  be evaluated using the  sodium-adsorption-ratio
 which is expressed as
                                                                  SAR =
                                                                                  Na+
where  the  ions  are  concentrations  expressed as
milliequivalents  per liter. Another means of defining
the sodium condition is the exchangeable-sodium-

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                                     Separation of Algae Cells from Wastewater Lagoon Effluents     163
percentage, abbreviated ESP. It is related to the SAR
by the following equation:
             _ 100(-0.0126 + 0.01475 SAR)
        ESP = 1 + (-0.0126 + 0.01475 SAR)

When  10  to  20  percent of the  cation-exchange-
capacity of a soil is taken up  by sodium, the  soil
condition exhibits a significant deterioration (Martin
and  Richards,  1959). The soil becomes  very hard
physically. This condition is sometimes referred to as
alkali soil or as chemical compaction.

      Sodium,  in  addition  to  affecting  plants by
damaging the soil,  can  also  affect plants directly.
Harding et al. (1958)  demonstrated  that  certain
plants  can  absorb sodium  through  their leaves  if
irrigated using  sprinkler  irrigation. Ehlig  and Bern-
stein  (1959) showed that leaves can  absorb sodium
rapidly  enough to cause injury to the leaves. Since
citrus trees accumulate sodium readily through their
foliage, these  plants are rather sensitive  to sodium
injury. In fact sufficient sodium has been absorbed by
citrus leaves from a single sprinkling of water contain-
ing 69  to  100  mg/1 of sodium to cause serious leaf
burn and defoliation (Fireman, 1958).

      Sodium  sensitive plants such as woody  plants
may  accumulate  harmful  levels of sodium in  the
leaves when the ESP of the  soil is about 5 percent.
The SAR tolerance limit for water used on fruit crops
is about 4. For nonsensitive crops where  soil effects
predominate, the  SAR value  can be from 8 to 18
(Bernstein,  1967).  Bernstein  and Pearson  (1956)
found  that an ESP of 15  can cause  nutritional
disturbances to green beans, beets, clover, and alfalfa.
Soils  that are permeable  often can be easily leached.
However, soils in an advanced state of sodium excess
are less permeable and consequently more  difficult  to
handle.

      One  exception to  the  above ESP  values  was
described by Werkhoven et al.  (1966). They found
that safflower  showed greatly  increased  growth  as
measured by dry weight of tops when the ESP was
increased  to 20 and 30 percent. ESP levels greater
than 30 percent were detrimental to both growth and
yield.

Sulfate

      Sulfur  has   been  known  to be  an  essential
nutrient for over 100 years. Plants get sulfur from the
sulfates in the soils. Problems with sulfates usually are
more frequently  associated with  deficiencies rather
than  excesses.  Toxic effects  however  have been
noted.

      Many areas in the world are experiencing severe
sulfur  shortages.  Coleman (1966) points out the
reasons for these shortages are: (1) the increasing use
of sulfur-free  fertilizers, (2) the decreasing  use  of
sulfur as a pesticide, and (3) increasing crop yields
which require greater amounts of plant nutrients. He
also  mentions  the  ease of  sulfate  leaching which
contributes to the shortage.

     Deficiencies of sulfur appear visually much like
that  given by nitrogen deficiency  (Ergle,  1953).
However,  Gilbert (1951) found that with plants in
general, the older leaves did not dry  up as did those
with nitrogen  deficiency. Eaton (1942) using a sand
culture  with up to  250 meq/1  of substrate  sulfate
found  reductions in  growth  of several plants. Leaf
damage also was noted in  sorghum and navy beans.
Figure  6  (Eaton,  1966)  shows  more clearly the
results.  Note that concentrations of sulfate  greater
than  about 5 meq/1  begin to cause detrimental
effects. The rate of growth reduction does seem to
slow  down at 100 meq/1 although damage is still
continuing. Scofield (1935) suggested tolerance limits
for sulfates in irrigation waters  which are listed in
Table 11. These values generally agree with  Eaton's
(1942)  work.  Hinman  (1938)  however, was of the
opinion that concentrations  in  excess of 500 mg/1
were  generally hazardous.  This  tolerance  limit  is
somewhat more limiting, of  course,  but not greatly
so.

      For further information regarding sulfur nutri-
tional requirements, see Beaton (1966). He presents a
review of sulfur  needs for a rather  large variety of
plants.


Table 11.  Tolerance  limits for sulfates in irrigation
          water.
    Rating
  Tolerance
  Excellent
  Good
  Permissible
  Doubtful
  Unsuitable
Less than 192 mg/1
192 to 336 mg/1
336 to 576 mg/1
576 to 960 mg/1
Greater than 960 mg/1
Zinc

      Zinc was established in the early 1930's as an
essential nutrient for plant growth. It was widely
accepted as an  essential nutrient after the work of
Sommer and Lipman (1926) and Sommer (1928). In
the former study, sunflowers and barley were shown
to suffer significant injury in the absence of zinc. The
later  work  increased  the  number of  plants under
study including buckwheat, Windsor  beans,  and  red
kidney beans for which zinc was demonstrated to be
essential.

-------
 164     Gearheart and Middlebrooks
          100
            80   _
            60   -
     o


     ..-I
     4-J
      tfl
            40   -
            20  _
              0
                                                                                    Bean
                                                100
                              SO.  -  Culture  Solution, meq/1
                                 4
                            200
Figure 6. Growth depression of seven crops as influenced by varying sulfate concentrations.
     When zinc is deficient, the plant leaves become
mottled. A  rosette-type terminal  growth  also can
occur.  The appearance is an absence of leaves on  a
branch except at the end of the branch where several
leaves appear in a spray arrangement.

     Zinc can also cause toxic  effects. Excess zinc
commonly causes  iron  chlorosis. Excesses  occur in
some  kinds   of acid peats and especially around
mining  operations  where  seepage and dumps can
pollute  the  soil. In one study  (McKee and Wolfe,
1963),  certain  concentrations  of zinc in  nutrient
solutions were found to be toxic to plants. These are
shown in Table 12.

     Zinc deficiencies usually occur in soils that are
acid, leached,  and  sandy; in alkaline soils because of
decreased availability of zinc; organic soils where the
zinc is tied up in  forms not available to plants; and
soils containing clays with low silica to magnesium
ratios which  give  rise  to forms of zinc not readily
available to plants (Elgabaly, 1950).

     Hunter  and Vergnano (1952) found that with
10 ppm zinc in a nutrient solution, oats were normal.
At 25 ppm the plants became slightly chlorotic. At

Table 12.  Some toxic levels of zinc.
 Zinc Cone.
    (mg/1)
      Plant
   25-100
Orange and mandarin seedlings
Flax
Water hyacinths
Oats

-------
                                      Separation of Algae Cells from Wastewater Lagoon Effluents    165
 concentrations of 100 and  150 ppm, the plants were
 stunted and very chlorotic, and many leaf tips were
 yellow-red. Roots were  normal at concentrations of
 75 ppm or less, but were small at concentrations of
 100 and 150 ppm.

 Public health aspects

       In  California  in  1918,  regulations  were  in-
 stituted prohibiting the use of raw sewage, septic or
 Imhoff  tank effluents, or  water polluted by such
 sewages for the irrigation of most garden truck crops
 usually eaten raw by humans.  For those crops that
 were  cooked  first,  these  waters were permissible
 provided irrigation with polluted waters was stopped
 30 days prior to harvest. Exceptions to this rule were
 made, such  as  fruit  and  nut  trees  and  melons,
 provided none  of the fruit or vines made physical
 contact with the sewage. Later, in 1933, these rules
 were  liberalized somewhat provided  adequate  dis-
 infection procedures were used. This allowed the use
 of these effluents on garden truck to be eaten raw.
 However, the effluent quality after treatment had to
 be approximately that of drinking water (Ward and
 Ongerth, 1970).

       In  1967, the Water  Quality  Control Act was
 revised. It  generally differentiated water reuse  and
 allowed standards  to be set based on  the intended
 use. Table  13 (Ward and Ongerth, 1970) shows the
 quality standards instituted for irrigation. As can be
 seen  from  the  table,  the  risk involved to humans
 correlates closely to the severity of the requirement.
 The standard for food eaten raw is that the effluent
 be free  of enteric viruses,  at least those possible to
detect by  existing methods and that the hepatitis
agent not be present.

      Considerable  work  on  this problem  has also
been  done in Israel (Meron et al., 1965). In 1954, the
Israel Ministry of  Health  published  interim regula-
tions for certain restricted crops. These regulations
have  been revised from time to time but include the
following "allowable" uses: (1) industrial crops unfit
for human food, such as sugar beets, cotton, and
fibres; (2) pasture, provided the animals  shall not be
allowed on the field until the grass is entirely dry; (3)
grass  grown for "dry" hay; (4)  vegetables which are
consumed only after cooking,  i.e., eggplant, potatoes,
sweet potatoes,  maize, and  dry  onions; (5) the
following  trees:  citrus,  banana,  nut,  date palms,
avocados,  and all  sapling nursery stock;  (6)  orna-
mental shrubs, plants, and flowers; (7) plants grown
for seed production only; (8) sunflowers and carobs
(St.  John's bread), provided irrigation is in  furrows
only; and  (9) apple, pear, and plum trees, provided
irrigation  is  stopped at  least  one  month before
harvesting.

      Detention  in any oxidation pond for 5 days
under aerobic conditions  is  accepted as minimum
treatment  to  qualify a water for  the irrigation of
restricted crops.  Effluent  from  standard secondary
treatment facilities is similarly accepted for irrigation
of these crops. After 20 days detention time  in an
aerobic pond, the effluent, with  chlorination, may be
used for  any crop. These regulations reflect the water
and  land scarcity  in Israel. The health authorities
recognize they are taking calculated risks and so they
Table 13. Summary of statewide standards for the safe direct use of reclaimed wastewater for irrigation and
          recreational impoundments for California (Ward and Ongerth, 1970).

Use
Irrigation
Fodder crops
Fiber crops
Seed crops
Produce eaten raw, surface irrigated
Produce eaten raw, spray irrigated
Processed produce, surface irrigated
Processed produce, spray irrigated
Landscapes, parks, etc.
Creation of impoundments
Lakes (aesthetic enjoyment only)
Restricted recreational lakes
Nonrestricted recreational lakes
Description
Primary1

X
X
X


X






of Minimum
Secondary
and
Disinfected




X


X
X

X
X

Required Wastewater Characteristics
Secondary
Coagulated,
Filteredb and
Disinfected





X






X
Coliform
MPN/lOOml
Median
(Daily Sampling)

No requirement
No requirement
No requirement
2.2
2.2
No requirement
23
23

23
2.2
2.2
 aEffluent not containing more than 0.1 ml liter hr.
 Affluent not containing more than 10 turbidity units.

-------
 166    Gearheart and Middlebrooks
maintain careful observation of public health condi-
tions.

      In 1953, a study on the bacteriological aspects
of using polluted water on vegetables was conducted
by Norman and  Kabler (1953). They  showed that
coliform counts on vegetables are a consequence of
the soil count and therefore of the  irrigation water.
Coliform counts of leafy vegetables such as lettuce,
celery, and cabbage  tend to be  greater  than smooth
skinned vegetables such as tomatoes and peppers. In
one test, the ratio between leafy to smooth skin was
40 to 1 using  an irrigation water with the same media
coliform count for both vegetable types. Salmonella
was found in  11 of 16 irrigation water samples but in
only 1 of 7 soil samples and in none of 10 vegetable
samples. The  authors pointed out that the length of
time between  the  last irrigation application and the
time of sample collection may be  the reason for the
low Salmonella counts.

      In  an earlier  study,  Rudolfs  et al.  (1951)
investigated the   problem   using  tomatoes. They
showed  that  contamination was independent  of
height of the  tomato above the ground. They also
found the  contamination  to  be independent  of
splashing  from soil due to rain. The study showed
that sunshine   significantly  lowers coliform  counts.
They found that cracked tomatoes had higher coli-
form counts than  the uncracked ones. This was not
surprising in view of the work of Norman and Kabler
(1953)  with leafy vegetables. One  finding of the
study  was  particularly interesting.  When coliform
suspensions were sprayed directly on the fruit, by the
end of 35 days after spraying, the  fruit had levels no
higher than the control fruit. It  was  also shown that
Salmonella levels were down to nearly nil at the end
of  6 days  as also were Shigella. Based  on these
findings, the authors concluded that if sewage irriga-
tion is stopped one month before harvest, the fruit, if
eaten raw, would  not be likely to transmit human
bacterial enteric diseases. They  also concluded that
except  for tomatoes  with  abnormal  stem  ends
(cracks, etc.),   there  was no material difference in
coliform counts per gram of tomato on three dif-
ferently irrigated plots; one plot was irrigated  with
settled sewage concurrently  with  growth, one plot
was irrigated before planting only, and  one was not
irrigated with sewage at all.

     Up to this point one might think the problems
are minor. That in fact is not the case. Wright (1950)
found that there is evidence indicating the consump-
tion of  fresh  vegetables irrigated with  sewage  or
polluted  water has caused  many  disease  outbreaks.
Epidemics of typhoid fever and parasitic infestations
traceable to this cause have occurred in many areas of
the world including the United States. Certainly the
strict   precautions  observed in  California  seem
justified until more research can be done to better
understand  the  problem  and to develop means to
control these problems.

Soil clogging

      The phenomena of clogging is important to soil
and crop systems. Clogging resulting from the applica-
tion of sewage  effluent  can  reduce  the supply of
moisture, air, and nutrients to plants to a point where
severe crop damage can occur.

      Thomas et al. (1966) used  a sewage effluent
from  a  septic tank with a BOD5 of 87 mg/1 to treat a
sand soil. The effluent was applied daily at a rate of 5
gal/day/ft2. The sewage  was applied as nearly as
possible instantaneously and then the  bed allowed to
drain  until the next application. Clogging occurred in
three  phases. The first phase was a gradual reduction
in filtration rate; the second phase was a short period
characterized by a rapid decline in infiltration rate; in
the third phase, the infiltration rate  asymptotically
approached a lower limit. Clogging was shown to be a
surface  phenomena that occurred in the top  1 cm
principally,  but  did occur on down to 6 cm. Total
organic  matter  was shown to  be  a significant con-
tributor to  clogging. The  authors also suggested the
possibility that iron and phosphate may contribute to
the problem.

      Jones and Taylor  (1965)  also found that
clogging  occurred  in  three  phases.  Their  phase
descriptions differ  somewhat from Thomas  et al.
(1966). Jones and Taylor (1965) describe the  three
phases as follows: The first phase is a period in which
the conductivity declines  to nearly  25  percent of its
initial value; during the second phase  the hydraulic
conductivity declines slowly to nearly  10 percent of
the original  value; a rather sharp drop constitutes the
third  phase, and the  conductivity  drops to 1 or  2
percent of the initial  value. Under anaerobic condi-
tions, the second phase of clogging is absent and the
first  and  third phases  are  indistinguishable. The
reason for the discrepancy in the descriptions of the
second phase is not clear, but perhaps has to do with
different soil types.

      In this same  study, Jones and  Taylor (1965)
found that  soil clogging  occurs three  to  10  times
faster under an anaerobic  environment than under an
aerobic  one. They also found that sands of high initial
hydraulic conductivity are clogged at  a much slower
rate than ones of low initial conductivity.

      Rather surprisingly, Avnimelech  and  Nevo
(1964)  claimed  that organic  materials  which de-
compose slowly  do not cause biological clogging of
sands. Included in the list of organic materials that
would not induce clogging because of slow decompos-

-------
                                    Separation of Algae Cells from Wastewater Lagoon Effluents       167
ition  was  sewage  sludge.  This  study  seems  in-
consistent  with  the well known need  for periodic
resting of septic tanks. The need for scraping the tops
off sand filters would also seerrv inconsistent with this
study.
                   Discussion
Introduction
     This  section  consists  of  a summary  of the
discussion  of water quality factors  in  relation to
specific crops. A list of crops that appear suitable for
irrigation by each effluent is also included. The list
includes only those plants specifically mentioned in
this paper.  Following this is a section of case histories
to show successful  utilization of sewage effluent for
irrigation.

     Table 14 summarizes the results of the study of
chemical toxicities. These values represent the most
sensitive levels reported for each component. Specific
cases may be less sensitive depending on climate, soil
type, etc. These values are approximately equivalent
to levels accumulated in  nature  over an extended
period  of time. The blank areas represent those plants
for which effects of the particular constituent were
not found  reported. Table  15 is a summary  of the
average  concentrations  of  constituents  for each
stabilization  pond recorded. Table  16 is a table of
recommended tolerances for trace elements in irriga-
tion water.

Summary of water quality factors

     From Table  14, note that concentrations of
arsenic as  low as  4  ppm  have caused  damage to
certain plants. A value  this low coupled with arsenic's
tendency to  accumulate  suggests close scrutiny. The
largest  average value from  Table 15 is  0.004 ppm
from Logan. Comparing this value to that specified in
Table  16 shows arsenic to be well within  the bounds
of safety.

     Table 14 shows  that citrus is extremely sensi-
tive to boron and that soybeans and fruits are fairly
sensitive. Sugar beets, cotton, and turfgrass are fairly
tolerant. If the effluent is being considered for citrus,
the value from Table  16 would  bar  only that from
Manila. For other crops, the Manila boron level would
be acceptable.

     This  study  did  not  define  toxic levels of
cadmium to  crops. However, comparison of Table 15
and Table 16 show that each of the effluents is within
the specified limit.

     Except for  citrus and perhaps fruits, the plants
mentioned  in this  study seem rather  tolerant of
 chloride. If citrus was the crop, the Manila effluent
 would be the only effluent unsuitable according to
 the  Israeli recommendations (see chloride  section).
 For the other crops mentioned,  chloride could be
 neglected for the effluents under consideration.

      A  number  of  plants  appear  to  be  rather
 sensitive  to  copper  with  citrus  being extremely
 sensitive.  Comparing Table 15  and Table 16 shows
 the  copper  values of the effluents to be well within
 the specified limits.

      This  study  showed  that at  the  pH  levels
 attendant to the pond effluents of Table 15, extreme-
 ly little  if any  fluoride would be taken up by the
 plant and so may be disregarded in this case.

      The levels of lead required for  toxicity  prob-
 lems are rather high. The concentrations from  Table
 15  appear  to be  negligible  for  the plants listed.
 Further comparison with Table 16 shows  the con-
 centrations  in these effluents to be well  within the
 limit.

      The only  magnesium toxicity problem found
 was with beans, and the levels required were in excess
 of 3000  ppm.  Table 15 shows the levels of mag-
 nesium of each  effluent to be at rather low levels hi
 comparison.

      The study showed that at the pH levels associa-
 ted  with these  effluents,  only  extremely limited
 amounts of manganese would  be  available  for plant
 uptake and  therefore  manganese  would be rather
 unlikely to be  toxic. Also comparison of Table 15
 and Table 16 shows  each effluent to  be well within
 the specified limits.

      The only nitrogen toxicity problem occurring
 directly was with citrus trees. Simple calculations
 showed that approximately 210,000 gallons of water
would be necessary  to supply the 2.5  pounds of
nitrogen noted. The calculations used the Huntington
level  of 6.36  ppm for worst case conditions. This
concentration  is   clearly  too  small  to   cause
detrimental  effects. The indirect effect of summer
 fertilization  on  turfgrass  is  not  a problem. The
amount of fertilizer recommended for golf courses is
about  120  pounds/acre/year  and so  3  pounds/
acre/year will have negligible effect.

      The only  case of phosphorus toxicity  found
 was for citrus. The concentration required for injury
 is 20 ppm which is rather  high considering how
 rapidly phosphorus  is  tied  up   in  the  soil and
 particularly  at the pH levels of the effluents.  These
 effluents should therefore cause no toxicity problems
 from phosphorus.

-------
 168     Gearheart and Middlebrooks
       The  data  given  for  salinity  seems  rather   Table  16,  none of  the  levels of selenium  in  the
 contradictory. The most restrictive limits found were   effluents exceeds the specified limit.
 suggested by the  U.S.  Salinity  Laboratory.  (See
 McKee and Wolfe, 1963.) By these limits Huntington        The sodium  concentration  of the Huntington
 and Manila effluents would be unsuitable.              and Manila effluents could not be used for citrus if
                                                     applied by sprinkler  irrigation  due to damage caused
       Levels of only 2.5 ppm of selenium were found   by foliar absorption of the sodium. Their SAR values
 to be toxic to certain plants. Comparing Table 15 and   also  are  too  high  for  fruits.  Other than these

 Table 14.  Summary of chemical toxicities for certain plants.3	

      Component                        Alfalfa     Barley     Beans   Tomatoes   Potatoes    Radish
Arsenic
Bicarbonate & carbonate
Boron
Cadmium
Calcium
Chloride
Copper
Fluoride
Iron
Lead
Magnesium
Manganese
Nitrogen
Phosphorus
Potassium
Salinity (ECexl03)
Selenium
Silica
Silver
Sodium (SAR)
Sulfate
Zinc
4 4
600
3 1.5 3


805 3150 630

100

30
3000
10



16 4
2.5


15 15
480 480


600 1200 3000
1.75 2 1.5


1365
2 6.4
100

50

10



10 10 4
2.5



480

    Component               Turf       Beets      Cotton   Soybeans     Peas       Citrus      Oats
Arsenic
Bicarbonate & carbonate
Boron
Cadmium
Calcium
Chloride
Copper
Fluoride
Iron
Lead
Magnesium
Manganese
Nitrogen


10 25 15
7.25

665 3500 1750
6.4


51.8

650 81

5

5 0.75 1.5
7.25

175
0.1 5
25

50

10
2.5No. N/
                                                                                     tree/year
 Phosphorus                                                                           20
 Potassium
 Salinity (ECexl03)              18         12         16                     6                    10
 Selenium                        2.5                                                               2.5
 Silica
 Silver
 Sodium                                 ESP=15                                       69
 Sulfate                                  480       480                              480
.Zine	3         10
   Values in ppm unless otherwise specified.

-------
                                    Separation of Algae Cells from  Wastewater Lago'on Effluents     169
Table 14. Continued.
    Component
                         Corn     Carrots    Wheat   Safflower   Fruits
 Arsenic
 Bicarbonate & carbonate
 Boron
 Cadmium
 Calcium
 Chloride
 Copper
 Fluoride
 Iron
 Lead
 Magnesium
 Manganese
 Nitrogen
 Phosphorus
 Potassium
 Salinity (ECexl03)
 Selenium
 Silica
 Silver
 Sodium
 Sulfate
 Zinc
                            1.5
                                  1.5
                        2450
                                875
                                  206
                                     5
                                   455

                                   100
                           10      1000
                                                10
                                                 2.5
                                                        ESP=30    SAR=4
 Table IS. Average values for water quality parameters from five stabilization ponds.a
   Component
Blanding
Huntington
Logan
Manila
Roosevelt
Arsenic
Bicarbonate
Boron
Cadmium
Calcium
Carbonate
Chloride
Copper
Fluoride
Iron
Lead
Magnesium
Manganese
Nitrogen
PH
Phosphorus
Potassium
Salinity (micromhos)
Selenium
Silica
Silver
Sodium
Sulfate
Zinc
RSC (meq/1)
SAR
0
236
0.44
0
36.5
0.645
47.5
0
0.305
0.07
0.005
14
0
0.55
7.55
10.7
7.5
600
0.004
16.5
0
58.5
35
0.005
0.88
2.07
0.003
538
0.48
0.003
209
3.23
150
0.024
0.65
0.24
0.007
268
0.089
6.36
7.73
10.9
11.4
4913
0.01 1
11.57
0.01
736
2415
0.04
-23.95
7.9
0.004
342
0.27
0.002
55
8.0
47
0.01
0.27
0.15
0
37
0
2.05
8.46
5.60
9.1
648
0.005
14.1
0
35
17
0.021
-0.10
0.89
0.01
186
1.29
0.02
210
4.53
241
0.01
1.42
0.25
0
241
0.03
2.90
8.50
0.80
28
5118
0.015
3.6
0.01
826
2631
0.01
-27.3
9.16
0
379
0.72
0
45
2.6
80
0
0.49
0.40
0
49
0
0.30
8.10
0.20
14
970
0.01
24.0
0
105
141
0
-0.09
2.57
            than pH and SAR values, units are mg/1 unless otherwise noted.

-------
 170    Gearheart and Middlebrooks
 Table 16.  Trace  element  tolerances  for irrigation
           waters.
  Element
For Waters Used
Continuously On
    All Soil

      mg/1
 For Use Up To
20 Years on Fine
 Textured Soils
of PH 6.0 to 8.5

     mg/1
Aluminum
Arsenic
Beryllium
Boron
Cadmium
Chromium
Cobalt
Copper
Fluoride
Iron
Lead
Lithium
Manganese
Molybdenum
Nickel
Selenium
Vanadium
Zinc
5.0
0.10
0.10
0.75
0.010
0.10
0.050
0.20
1.0
5.0
5.0
2.5b
0.20
0.010
0.20
0.020
0.10
2.0
20.0
2.0
0.50
2.0-10.0
0.050
1.0
5.0
5.0
15.0
20.0
10.0
2.5b
10.0
0.05 Oc
2.0
0.020
1.0
10.0
       These levels will normally not adversely affect plants
 or soils. No data available for Mercury, Silver, Tin, Titanium,
 Tungsten.
       Recommended maximum concentration  for irrigat-
 ing citrus is 0.075 mg/1.
      cFor only acid fine textured soils  or acid soils with
 relatively high iron oxide contents.
 Source:  Above data  based  primarily on  "Water  Quality
 Qiteria  1972," National Academy of  Science-National
 Academy of Engineering, Environmental Study Board, ad hoc
 Committee on Water Quality Criteria, U.S. Government
 Printing Office (in press).
exceptions,  the SAR values are suitable  for  most
crops.

      Table  11 grades generally unsuitable, concentra-
tions of sulfate in excess of 576 ppm. Huntingdon and
Manila  effluents  are  totally  unsuitable   by  this
standard.  The other three effluents rate excellent by
the criteria of Table 11.

      Zinc levels are sensitive for citrus fruits and so
should be checked.  Comparison of  Table 15  and
Table 16 show that each effluent is  easily within the
specified limit.

      Review of Table  15  shows that the criteria of
Wilcox et al. (1954) for residual sodium carbonate is
easily met. Therefore the bicarbonate/carbonate con-
centration does not constitute a problem.

      Iron, potassium, silica, and silver were found to
produce no direct toxic effects. Under certain condi-
tions, however, silica  can act to increase  the  SAR
value.

      Table  17  shows the effluents and their sug-
gested  uses  for  certain  crops.  The   X's  indicate
permissible  usage. These  decisions were based  on
undiluted effluents. If sufficient dilution were used,
those cases  which are rejected could become usable.
Two ponds,  Huntington and Manila, are not recom-
mended for  any crop. Both effluents have conduc-
tivity values and sulfate concentrations that greatly
exceed  the  recommended tolerance  limits. In addi-
tion,  their  SAR  values  are  unsuitable for fruits.
Roosevelt's  effluent  is somewhat questionable for
citrus. This is because  the boron concentration is at a
borderline level.  Further  research is  necessary  to
refine the results  of Table  17 but it does  present a
starting point.

Land requirement  for
effluent discharge

      Another important consideration is the amount
of land required to utilize the total effluent. Since the
irrigation requirements for a given crop vary greatly
because  of  differences  in  soil  type,  management
practices, topography, and climate,  a  more general
approach will be  used to determine this  question.
Table 18 (Overman, 1971) is a computation showing
the required land in  acres  for  a  given total plant
effluent  at  a  number   of  application rates.  For
example, if the effluent discharged was 1 mgd and the
irrigation rate  required  by  a certain  plant was 1
inch/week,  then  250 acres  would  be  required to
utilize  all the effluent.  If  a new crop were  used
requiring 2 inches/week, only  125 acres would be
needed. This is  not a very large area of land and for
small communities would be  rather typical.
                                              Two implications follow from this calculation.
                                         If disposal was the only consideration, a small pasture
                                         or  other such piece of ground would be easier  to
                                         acquire  than large acreage.  If on the  other hand, a
                                         large number of farmers wanted to use the discharge,
                                         only one or two  would be  able to use the effluent.
                                         The solution in this case is obvious—dilution with
                                         their normal source of  irrigation  water. The  cost
                                         savings would not be as great but there would at least
                                         be  some reduction. Another advantage might occur.
                                         If  the effluent had high concentrations of certain
                                         components,  the  dilution  factor  would assist  in
                                         making the water less hazardous. This would reduce
                                         any fertilization benefits but the overall  benefits  of

-------
                                     Separation of Algae Cells from Wastewater Lagoon Effluents     171
Table 17. Suggested crop usage for five stabilization pond effluents.
  Crop
Blanding
Huntingtona
Logan
      Rejected for all crops because of high salinity and sulfate values.

      Questionable because of borderline boron value.

     Rejected for fruits because of high SAR value.
Manila3
Roosevelt
Alfalfa
Barley
Beans
Tomatoes
Potatoes
Radish
Turfgrass
Beets
Cotton
Soybeans
Peas
Citrus
Oats
Corn
Carrots
Wheat
Safflower
Fruits
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X c
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
b
X
X
X
X
X
X
waste disposal, less expensive irrigation water, and
reduced toxicity potential would be well worth the
loss.

Case histories

     Sewage effluent has been used successfully in
many trials. Day and Tucker (1960) reported success-
ful results with small grains. They grew Arivat barley,
Palentine  oats, and Ramona  50 wheat using  flood
irrigation. The water used for irrigation was activated
sludge  effluent and  contained  approximately 65
pounds  nitrogen, 50 pounds P205, and 32 pounds
K20 per acre foot. Four treatments were used: (1)
Pump water with no fertilizer added;(2) pump water
with the recommended fertilizer rates (100 pounds N,
75 pounds P205, and 0 pounds K,O/acre); (3) pump
water with synthetic sewage (200 pounds N, 150
pounds  P205. an^ 100  pounds K20/acre); and (4)
sewage effluent with no  additional fertilizer. Results
of the experiment are shown in Table  19. Note that
the yield for oats and wheat was greater using sewage
effluent than for any other treatment. Barley did not
perform  as well using sewage effluent. The authors
speculated that the greater  salinity and  surfactant
content may have been the reason.

      Another  project using  sewage effluent  was a
golf course in Allamuch, New Jersey (Keshen, 1971).
This course was able to obtain wastewater at no cost
                                  Table 18. Land requirement for sewage effluent dis-
                                           posal as irrigation water in acres (Overman,
                                           1971).
Application
Rate
(inches/week)
J4.
1
2
3J4
7
14
28
Discharge Rate
0.1
50
25
13
7
4
2
1
1
500
250
125
72
36
18
9
, mgd
10
5000
2500 .
1250
720
360
180
90
                                  Table 19.  Results of  four different treatments on
                                            small grains.
                                                                   Tons/acre
                                      Treatment
                                                            Barley   Oats   Wheat
1. Pump water,
added
2. Pump water,
added
3. Pump water,
sewage
4. Sewage effl.,
fert.
no fert.
recom. fert.
synthet.
no added
2.42
5.64
7.15
5.88
2.13
2.73
4.27
6.05
2.76
5.47
5.93
6.43

-------
 172     Gearheart and Middlebrooks
which resulted in a savings of nearly  $21,000 a year.
They  also  felt that because of the nutrients in the
water,  that  money  was  being  saved in  decreased
commercial fertilizer needs. Thus it seems that sewage
effluent  would be  ideal  for golf  courses. If the
nitrogen  concentrations were as high as 30  ppm or
greater as  nitrate, there  are some potential  hazards
that should be considered however.  Studies  (Zanoni
et al., 1967) have indicated that  turf should not be
fertilized during the summer. The primary reason is
that  above  a soil  temperature  of 50°F  or 60°F,
nutrients are utilized  by  plants  to  promote  top
growth.  This  causes  the  grass to become soft  and
succulant and therefore most attractive to disease and
insects. This  problem is further emphasized  because
golf courses  in  general irrigate  at night  resulting in
warm,  moist  areas  ideal  for disease  habitats.  In
contrast,  when fertilization  is performed only in the
early spring and not during the  summer, the grass
tops are not soft and succulant and so are much less
susceptible  to insects and disease.


      In addition, besides running the risk of losing
turf  to  insect  and  disease  damage, the cost for
maintenance  will increase because mowing would be
required  more  frequently  and  larger  amounts of
pesticides would be needed. The  increased usage of
pesticides would of course tend to offset the savings
in commercial fertilizer cost reductions. Then too,
this  increased usage contributes more pesticides to
the ecology which has already become a major area of
concern.
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-------
176     Gearheart and Middlebrooks
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-------
                                         Separation of Algae Cells from Wastewater Lagoon Effluents      177
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-------
 178     Gearheart and Middlebrooks
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                                                   APPENDIX
                               Table 20. Analysis of Blanding and Roosevelt pond
                                          effluents.*
Component
Conductivity
(jumh os/cm)
pH
IDS
Total alkalinity
Arsenic
Barium
Bicarbonate
Boron
Cadmium
Calcium
Carbonate
Chloride
Copper
Fluoride
Total hardness
Total iron
Lead
Magnesium
Manganese
Nitrate
Phosphorus
Potassium
Selenium
Silica
Silver
Sodium
Sulfate
Zinc
Blanding
11/25/69
680

7.85
468
228
0
0
Til
0.38
0
40
1.1
40
0
0.55
148
0
0.01
13
0
1.0
12.6
5
0.008
16
0
37
30
0
8/19/70
520

7.25
364
160
0
0
195
0.50
0
33
0.19
55
0
0.06
144
0.14
0
15
0
0.1
8.8
10
0
17
0
80
40
0.01
Roosevelt
12/15/70
970

8.10
710
314
0
0
379
0.72
0
45
2.6
80
0
0.49
312
0.40
0
49
0
0.3
0.2
14
0.01
24
0
105
141
0
                                     aAll units mg/1 unless otherwise specified.

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                                     Separation of Algae Cells from Wastewater Lagoon Effluents     179
Table 21. Analysis of Huntington pond effluent.3
Date of Reading
Component
Conductivity (jumhos/cm)
pH
IDS
Total alkalinity
Arsenic
Barium
Bicarbonate
Boron
Cadmium
Calcium
Carbonate
Chloride
Copper
Fluoride
Total hardness
Total iron
Lead
Magnesium
Manganese
Nitrate
Phosphorus
Potassium
Selenium
Silica
Silver
Sodium
Sulfate
Zinc
7/10/68
4790
7.55
4510
417
0.01
0
507
0.44
0
240
0.99
140
0.02
0.58
1604
0.90
0
243
0.10
0.20
5.6
15
0.01
11
0
760
2512
0
11/13/68
9800
8.3
9532
690
0
0
824
0.70
0
360
9.1
270
0.08
1.06
3200
0.10
0
559
0.18
1.00
14
14
0.02
20
.0
1700
5520
0.04
3/19/69
10200
8.1
8865
560
0.01
0
674
0.52
0
320
4.7
342
0.05
1.03
3228
0.14
0.05
590
0.09
0.70
3.1
14
0.02
10
0
1600
5680
0.20
7/21/69
850
7.2
478
288
0
0
351
0.60
0
45
0.31
50
0
0.23
244
0.20
0
32
0
35.0
27.6
11
0
11
0
60
64
0.02
11/24/69
2750
7.35
2380
382
0
0
464
0.33
0
144
0.57
80
0.02
0.78
976
0
0
150
0.01
3.3
5.4
7
0.005
9
0
330
422
0
4/14/70
3000
7.2
2532
395
0
0
480
0.28
0.01
151
0.42
80
0
0.30
954
0.20
0
140
0.10
3.5
12.4
8
0.01
8
0.01
375
1319
0.02
8/18/70
3000
8.4
2632
396
0
0
469
0.47
0.01
200
6.50
85
0
0.57
1175
0.16
0
164
0.14
0.80
7.9
11
0.01
12
0
330
1387
0
      aAU units mg/1 unless otherwise specified.

-------
180    Gearheart and Middlebrooks






Table 22. Analysis of Logan pond effluent.3
Component
Conductivity (pmhos/cm)
PH
IDS
Total alkalinity
Arsenic
Barium
Bicarbonate
Boron
Cadmium
Calcium
Carbonate
Chloride
Copper
Fluoride
Total hardness
Total iron
Lead
Magnesium
Manganese
Nitrate
Phosphorus
Potassium
Selenium
Silica
Silver
Sodium
Sulfate
Zinc
Date of Reading
9/11/68
635
8.15
420
301
0
0
361
0.29
0
57
2.8
36
0
0.19
300
0.90
0
38
0
6.9
6.2
10
0
13
0
30
17
0
1/24/69
710
7.9
430
318
0
0
384
0.26
0
59
1.7
44
0.03
0.30
310
0.10
0
40
0
3.7
1.2
10
0.01
18
0
35
21
0.12
5/21/69
710
8.25
402
271
0.02
0
324
0.24
0
57
3.2
58
0.01
0.29
271
0
0
31
0
2.8
4.7
9.0
0
13
0
37
19
0.03
9/24/69
660
8.8
424
324
0
0
369
0.27
0.005
60
12.8
43
0
0.28
320
0
0
41
0
0.7
6.2
10
0
20
0
31
15
0.01
3/11/70
510
8.9
356
262
0
0
294
0.21
0
43
12.9
42
0
0.28
260
0
0
37
0
0.2
5.5
7.0
0.01
2
0
30
17
0
6/3/70
670
7.85
442
310
0
0
375
0.31
0.01
62
1.5
50
0.01
0.29
307
0.20
0
37
0
1.7
10.7
10
0
16
0
36
14
0
11/14/70
565
8.85
396
297
0
0
336
0.26
0
58
13.1
40
0.02
0.23
292
0
0
36
0
0.2
5.3
8.0
0.02
17
0
24
14
0
     aAH units mg/1 unless otherwise specified.

-------
                                        Separation of Algae Cells from Wastewater Lagoon Effluents     181
Table 23.  Analysis of Manila pond effluent.3
Component
Conductivity (fimhos/cm)
pH
IDS
Total alkalinity
Arsenic
Barium
Bicarbonate
Boron
Cadmium
Calcium
Carbonate
Chloride
Copper
Fluoride
Total hardness
Total iron
Lead
Magnesium
Manganese
Mtrate
Phosphorus
Potassium
Selenium
Silica
Silver
Sodium
Sulfate
Zinc
Date of Reading
5/27/68
5350
8.0
5575
178
0
0
215
1.2
0
265
1.2
260
0.02
1.6
1680
0.30
0
247
0
7.6
0.10
30
0.01
1.0
0
1000
3258
0.01
6/12/69
5140
9.25
4688
101
0
0
102
1.0
0
158
10.1
233
0
1.16
1285
0
0
217
0
0.4
0.2
21
0.03
0.8
0
800
2700
0
10/28/69
6760
7.4
6724
100
0.01
0
122
1.7
0
232
0.17
346
0
1.68
1892
0.80
0
319
0
1.7
0
29
0
1.0
0
1150
2450
0
3/31/70
2910
8.85
2440
196
0
0
231
0.85
0
152
4.5
111
0
1.18
905
0.06
0
128
0.20
4.0
3.6
20
0.01
11
0.01
340
1350
0
8/4/70
5050
8.7
5100
222
0
0
259
1.5
0.02
232
7.1
225
0.01
1.4
1620
0.26
0
253
0
3.0
0.8
32
0.02
5.0
0
750
2830
0
12/15/70
5500
8.6
5600
158
0
0
185
1.5
0
221
4.1
270
0.03
1.48
1710
0.10
0
282
0
0.7
0.1
35
0.02
3.0
0
915
3200
0
       All units mg/1 unless otherwise specified.
Table 24. Guidelines to levels of toxic substances in drinking water for livestock.3
Constituent
Aluminum (Al)
Arsenic (As)
Beryllium (Be)
Boron (B)
Cadmium (Cd)
Chromium (Cr)
Cobalt (Co)
Copper (Cu)
Fluoride (F)
Iron (Fe)
Upper Limit
5 mg/1
0.2 mg/1
no data
5.0 mg/1
0.05 mg/1
1.0 mg/1
1.0 mg/1
0.5 mg/1
2.0 mg/1
no data
Constituent
Lead (pb)
Manganese (Mn)
Mercury (Hg)
Molybdenum (Mo)
Nitrate & Nitrite (N03-N+N02-N)
Nitrite (N02-N)
Selenium (Se)
Vanadium (Va)
Zinc(Zn)
Total Dissolved Solids (TDS)
Upper Limit
0.1 mg/lb
no data
0.01 mg/1
0.5 mg/1
100 mg/1
10 mg/1
0.05 mg/1
0.10 mg/1
25 mg/1
10,000 mg/lc
      aBased primarily on "Water Quality Criteria 1972," National Academy of Science-National Academy of Engineering,
Environmental Study Board, ad hoc Committee on Water Quality Criteria, U.S. Government Printing Office (in press).
      bLead is accumulative and problems may begin at threshold value = 0.05 mg/L
      cGuide to the use of saline waters for livestock and poultry.

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              UPGRADING LAGOON TREATMENT WITH LAND APPLICATION

                                            R. E.  Thomas1
                  Introduction

     The enactment  of PL 92-500 and  subsequent
actions  have necessitated  a critical  evaluation  of
processes  which can be  utilized to upgrade lagoon
treatment of wastewaters.  Land application  is  an
approach  which shows promise because it embodies
the principle of water reuse for  conservation and
addresses the "no discharge of pollutants" goal of PL
92-500. The concept of applying lagoon effluents  to
the land is not  new and there are many examples  of
such systems in the  United States. Most  of these
existing systems are located in water-short regions
and the reason  for utilizing this wastewater  manage-
ment technique has been the conservation of a short
water supply and/or the disposal of a pond  effluent
where a surface water discharge was not convenient
or appropriate.  A long history of continued use  at
many locations indicates that  the  land  application
concept has been reasonably successful in achieving
the intended goals of  water conservation  or con-
venient disposal in the absence of access to a suitable
surface  water discharge. The existence of such sys-
tems also provides a ready laboratory for assessing the
performance of several land application  alternatives
for upgrading lagoon treatment in light of the needs
of today and the future.

     Upgrading of lagoons  can also be achieved  by
land application techniques which are not  in common
use at the present time since the options available are
many.  These  options include  addition  of one  of
several  land application  approaches  or complete
replacement of the lagoon system by a land applica-
tion approach.  This wide range in available options
stems from  the fact that there are three basic land
application approaches which have  potential for use
in the  upgrading  of lagoon treatment.  These land
application approaches  are  frequently  designated as
(1) crop  irrigation, (2) infiltration-percolation, and
(3) overland flow. Each of these approaches  has
unique  characteristics  for adaptation to site condi-
tions and treatment needs.

     The purpose of this  presentation will  be  to
describe the use of several of the many ways in which
     IR. E. Thomas is Research Soil Scientist, Water Quality
Control Branch,  Robert S. Kerr  Environmental  Research
Laboratory,   Environmental  Protection   Agency,  Ada,
Oklahoma.
land application approaches are or can be utilized to
upgrade lagoon treatment. The discussion will include
developing technology as well as examples of land
application approaches which have been in use for
many decades.

             Some Practical Options

      The terminology of "soil treatment" or perhaps
more appropriately  "land  application for treatment
and/or reuse" is liberally sprinkled with buzz words
such as  "the living  filter." This situation  behooves
one who  is  discussing  the  topic to  acquaint  his
audience with his own terminology. I am a proponent
of the terminology base which divides  land applica-
tion approaches into three  classes, as  follows:  (1)
Crop irrigation, which  is  characterized  by  com-
paratively low application rates (less than 10 cm per
week) and emphasizes the reuse  of wastewater  for
beneficial growth  of vegetation; (2) overland flow,
which is characterized by intermediate application
rates (7.5 to   15  cm  per  week)  and emphasizes
treatment  with an  effluent discharge to  surface
waters;   and  (3)  infiltration-percolation,  which  is
characterized by high application rates (up to  150 cm
per week)  and  emphasizes  treatment  with un-
derground storage  of the reclaimed wastewater. With
the terminology  base  established, some  practical
options  can  be addressed  for implementing  current
land application approaches to upgrade  lagoon treat-
ment. Crop irrigation as an add-on to existing systems
and infiltration-percolation as an add-on to existing
systems in this category will be discussed.

Crop irrigation following
lagoon treatment

      Crop irrigation  following lagoon treatment or
polishing lagoons has been practiced as  a commonly
accepted  waste  management technique for  many
decades.  There are several hundred of these facilities
currently operating in the southwest and far west. It
is  difficult to find a single  source which identifies
most of  these systems, but there are several sources
which  provide  information  on  the location, age,
design, and  operating schedule for many  of  these
systems.  Deaner (1971) reports on 132 reclamation
operations  in California  including  identification of
the treatment processes  preceding land treatment.
About 70 percent of the systems have  polishing
lagoons following a variety of pretreatment processes,
                                                                                                  183

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 184     Thomas
some 23 percent follow activated sludge or trickling
filters with  direct land application, and  7  percent
have  land  application following primary  treatment.
Crop irrigation is practiced at about 75 percent of the
sites, while landscape irrigation or golf course irriga-
tion is practiced at  25  percent of the sites. Another
source of  information  on crop  irrigation following
lagoon  treatment  is the EPA Municipal  Waste In-
ventory. This source provides information on some
160 facilities with lagoon treatment followed by crop
irrigation. Sullivan, Cohn,  and Baxter (1973) report
detailed information on 26 sites visited during  their
survey of land application facilities. Eighteen of these
systems included oxidation ponds and crop irrigation
as the last two steps in  the overall treatment process.
Three of the systems visited during this survey had
been  in operation for over 50 years and an  additional
11 systems had been in operation for 10 to 50 years.
Myers and Williams  (1970) report on the design of
lagoon systems followed by crop irrigation in Michi-
gan. They indicate that several were in operation in
1970 and  all of the 15 systems which they were
planning for  construction in 1971 would involve
irrigation with the treated effluent. Dean (1974) has
surveyed the use  of land application in the  Rocky
Mountain-Prairie  region  and  reports   10 facilities
where lagoon treatment is followed by land applica-
tion.  One of these systems is 10 years old, while all of
the others have been placed in service since 1972.
This cursory look at  current practices shows that crop
irrigation  following  lagoon  treatment  is a  reality
under widely  differing climatic conditions.  It is
obvious that these  existing  systems are sources of
design information for use in other locales as well as a
ready  laboratory  for assessing  the  performance of
current designs  in relation to the objectives of PL
92-500.
Design of crop irrigation systems

      Myers and Williams (1970) give general applica-
tion rates ranging from 0.3 to  0.8 cm per  hour
programmed to achieve weekly rates of 2.5 to 7.5 cm
and yearly rates of 125 to 250 cm.  They point out
that irrigation system designs are site specific and
make  the following analogy,  "Just as one  does not
hire a butcher when he  needs a surgeon, one should
not  hire  a  plumber when he needs a  professional
irrigation engineer." Pound and Crites (1973) analyze
the data  collected  by  Sullivan,  Cohn, and  Baxter
(1973) as well as  information from site visits which
they conducted during their study on current design
and operating  information.  In  their  chapter on
irrigation with  municipal  effluents, they  present
details on seven facilities with lagoon treatment and
crop  irrigation as  the final  treatment  steps. They
defined crop irrigation to include application rates of
10 cm per  week  or less, and divided the facilities
discussed into high irrigation (7.9 to  10.7 cm per
 week), moderate irrigation (5.6 to 7.6 cm per week),
 and low irrigation (0.8 to 3.8 cm per week).

      Information contained in reports such as those
 by Pound  and  Crites (1973), Myers and  Williams
 (1970),  and Sullivan,  Cohn,  and  Baxter (1973),
 demonstrate that crop irrigation systems have  been
 designed  to adequately  fulfill a wide range of local
 climatic  conditions  and institutional constraints. In
 many  instances,  these existing  systems have evolved
 through  long  periods of  community  growth  and
 associated problems. Long-term experience at these
 existing  systems has not, as yet, generated a ready
 design manual,  but  persons contemplating the up-
 grading of lagoon treatment by addition  of  crop
 irrigation can  glean valuable design, operating, and
 cost information from this  reservoir of information
 on existing systems.

 Infiltration-percolation following
 lagoon treatment

      Infiltration-percolation  following lagoon treat-
 ment  is  another practice  which  has been widely
 accepted  for many decades. There are  many  such
 systems  in the  United  States  but  it is even more
 difficult to identify and locate these  systems than it is
 to  identify and locate crop irrigation systems.  Poor
 definition of terminology in the past has led to the
 inclusion of infiltration-percolation systems  under the
 broad  category of crop irrigation approaches. Regard-
 less of this limitation, there are several sources which
 indicate   the  extent  to  which   the   infiltration-
 percolation approach has been utilized as a final step
 in wastewater management. Deaner  (1971)  identifies
 seven  California systems  as groundwater  recharge
 (infiltration-percolation)  operations, two  of which
 include lagoon treatment prior to the recharge opera-
 tion.  Information from the EPA  Municipal Waste
 Inventory differs from Deaner's (1971) interpretation
 of  the use of infiltration-percolation in California.  A
 1972 listing from the inventory with a  total of 64
 California facilities (less  than 50 percent  of Deaner's
 total) lists 21 facilities as infiltration-percolation type
 systems.   Discrepancies  of  this nature  are readily
 attributable  to  the  lack of  uniform definition for
 terminology. Overall, the listing from the Municipal
 Waste  Inventory  indicated that about 15 percent of
 160 lagoon treatment facilities utilizing land applica-
 tion were entered as infiltration-percolation systems.
 Sullivan, Cohn, and Baxter  (1973)  noted that  they
 did not visit six facilities initially selected for survey
 because the systems  were percolation systems. Pound
 and Crites (1973) noted two cropping systems with
 application  rates greatly  exceeding their defined
 upper limit  of 10 cm per week for crop irrigation and
 classified  these  systems as  infiltration-percolation
systems.   Only  one  of  the  infiltration-percolation
systems which they discuss in depth  involves a lagoon
in the treatment process.

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                                            Upgrading Lagoon Treatment with Land Application     185
Design of infiltration-percolation systems

      It is obvious from the foregoing discussion that
infiltration-percolation  treatment of lagoon effluents
is  less  common  than  crop  irrigation with  pond
effluents. Consequently,  existing systems  do  not
provide  a broad based  reservoir of design, operating,
and  cost information.  Persons contemplating  the
upgrading  of  lagoon   treatment  by  addition  of
infiltration-percolation  treatment will find that infor-
mation  from closely related studies on infiltration-
percolation of activated sludge effluents and trickling
filter effluents may be  the best information available
to them. Thomas and Harlin (1972) describe some
research studies  which provide  quantitative  data
under controlled operating conditions.  Aulenbach et
al. (1973) report the results of intensive studies on a
35 year old facility in a cool, humid climate with an
application rate of about 50 cm per week. Pound and
Crites (1973) evaluate the design and management of
several  operational systems with application  rates
ranging from 20 to 200 cm per week.

      Many reserachers are continuing the assessment
of performance by existing infiltration-percolation
systems; therefore, the  research  community  is an
important source  of recent  information on system
designs and system performance.


    A Developing Land Application Approach

      There is  a newly developing land application
approach which  shows promise as  a  wastewater
management process for utilization on  slowly perme-
able soils. This approach is the overland-flow system
which has been used  with excellent results by the
food processing industry. Current research is directed
to the  development of this  technique for advanced
waste treatment of secondary effluents  and,  alter-
nately,  to the  development  of  this  technique for
complete treatment of raw domestic wastewater.

Overland-flow as an add-on
to secondary treatment

      Hoeppel,  Hunt,  and Delaney  (1973) are  con-
ducting  studies  on the  use  of  the  overland-flow
approach for advanced  treatment of  secondary ef-
fluents.  The results of their short-term greenhouse
studies  show that characteristic total nitrogen remov-
als of  more than 80 percent were achieved  using
secondary effluent amended with sucrose to achieve a
chemical oxygen demand of 200 mg/1 at  an applica-
tion rate of 6.35 cm per week. A second experiment
with sludge amended soil versus a control sou" showed
that  sludge addition neither improved nor hindered
the  removal  of  total nitrogen.  These  preliminary
studies also showed that several heavy metals were
effectively removed from the wastewater as it moved
down slope.
     The encouraging results of  these bench-scale
studies  indicate that  the  overland-flow  technique
shows  promise  as an advanced  waste  treatment
process  with low energy requirements and no addi-
tional  sludge  production.  As  such,  it  may be  a
candidate for  upgrading lagoon  treatment where
additional land is available for use in the treatment
process.

Overland-flow as an alternate
to lagoon treatment

      Thomas et al. (1974) are conducting studies on
the  treatment  of  raw domestic wastewater  by the
overland-flow approach. The results of 18 months of
pilot scale field studies show that the overland-flow
process produces an  effluent substantially better in
quality  than the effluent from an activated sludge
plant.  The capability  of overland-flow to maintain
this level of performance during year-round operation
at  an average  application rate of about  10 cm per
week  indicates that  total land  requirements for
overland-flow treatment would be comparable to land
requirements for multiple cell lagoon systems.

      The pilot-scale  field study is now in its third
year and  the overland-flow  process continues  to
produce an effluent with the following composition:
Suspended solids and biochemical oxygen demand of
less than 10  mg/1; total  nitrogen ranging from 2.5
mg/1 in  summer  to  7 mg/1 in  winter; and total
phosphorus of 4 to 5 mg/1. The total  phosphorus can
be reduced  to less  than  1  mg/1 by addition of a
precipitant such as aluminum sulfate.

      It is obvious that overland-flow is capable  of
achieving advanced treatment of raw domestic sewage
on a year-round basis with favorable climatic condi-
tions. We are  now  initiating a full-scale (0.1 mgd)
development  study  to evaluate performance under
operating conditions  expected for small sewage treat-
ment facilities. The results of this first full-scale study
will be complemented by similar studies under a vari-
ety of climatic conditions in order to ascertain obvi-
ous constraints due  to severe  winter weather and
other site specific factors.

 Design of overland-flow systems

      The  basic  design  of  overland-flow  systems
 which  has  been  developed  for  treatment  of food
 processing wastewaters will apply to  systems treating
 domestic wastewaters. A soil with restricted perme-
 ability  is a prerequisite common to all overland-flow
 systems, as is the  leveling  of the  land to obtain
 uniform and  gentle slopes. Construction  of inter-
 ceptor  terraces  at  about 60  m spacings  and  the
 construction of a distribution system (usually auto-
 mated)  are also integral features of all overland-flow
 facilities. Daily application  and  drying  cycles with

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  186     Thomas
 regular  1-  or 2-day  drying cycles  at  5- or  6-day
 intervals will  also be required to maintain a micro-
 environment which maintains treatment performance
 without promoting the breeding of nuisance insects.

      Major questions  to  be elaborated  regarding
 technical aspects  of  system design  are  the rate  of
 application  and constraints placed on the length  of
 the operational  season by  climatic  conditions. The
 need  for  elaborating  application  rates is readily
 demonstrated  by  comparing  the application rates
 used in the two  research studies which have been
 discussed previously.  Thomas et al. (1974) observed
 successful treatment  of raw  domestic sewage  at  an
 application rate  1.5 times as great as the application
 rate that Hoeppel,  Hunt, and Delaney (1973) used for
 applying amended secondary effluent. The need  to
 ascertain the  constraints imposed  by  subfreezing
 winter  temperatures are complex and many. Resolu-
 tion of these constraints will require evaluation of the
 overland-flow  approach  at  many  field  sites with
 varying climatic conditions.


                    Summary

      Land  application  is  a  viable approach  for
 upgrading lagoon  treatment to meet newly imposed
 standards for secondary treatment. It is also a viable
 approach for satisfying even more stringent require-
 ments which are proposed for future implementation.
 There are several  land application alternatives which
 can be  considered, and the alternative selected will
 depend  largely  upon  local requirements  and site
 characteristics.

      Crop  irrigation is  an alternative which has been
 in use for many decades  under a variety of climatic
 conditions  with a high degree  of success. Existing
 crop  irrigation systems provide  a vast reservoir  of
 information on  design  and  operating  experiences
 which have led to  problems, as well as successes. This
 reservoir of information  from existing systems is a
 valuable resource  which  can be utilized  by  those
 contemplating crop irrigation for upgrading lagoon
 treatment.

      Infiltration-percolation is   another   alternative
 which has limited  but widespread use for advanced
 waste treatment of secondary effluents.  It is  more
typical for infiltration-percolation to follow activated
sludge or trickling filters as the  secondary treatment
 process,  therefore, the reservoir of existing informa-
 tion on design and operating experience  following
 lagoon  treatment  is not  extensive. Information  on
 infiltration-percolation following other conventional
processes  for  achieving secondary treatment does
provide a  valuable resource which can be effectively
utilized  by   those  contemplating  infiltration-
percolation for upgrading lagoon treatment.

      Current  research studies  are exploring  the
utility and practicality of utilizing other land applica-
tion alternatives for management of domestic  waste-
waters. Overland-flow is a land application alternative
which is  being  evaluated  for upgrading  secondary
effluents  and for  complete replacement of conven-
tional secondary  treatment processes.  Development
of both of these approaches is at a rudimentary stage
but they show promise for  successful implementation
in practical situations.

                    References

Aulenbach,  D. B., J. G. Ferris, N. L. Clesceri, and T. J.
     Tofflemire.  1973. Thirty-five years of use of a natural
     sand bed for  polishing a secondary treated effluent.
     Rensselaer Fresh Water Institute at Lake George, FWI
     Report  No.  73-15, Rensselaer Polytechnic Institute,
     Troy,  N.Y. September. 51 p.

Dean, R. J.  1974. Land application of effluents in the rocky
     mountain-prairie  region.  Thesis,  University   of
     Colorado, Boulder. 152 p.

Deaner, D. G. 1971. California water reclamation sites 1971.
     Bur.  Sanit.  Eng., State  of Calif. Dept. Public  Health,
     Berkeley, Calif. June. 64 p.

Hoeppel,  R. E., P.  G.  Hunt, and T. B.  Delaney, Jr. 1973.
     Wastewater  treatment on  soils of low permeability.
     U.S. Army Waterways Experiment Station, Vicksburg,
     Miss. Miscellaneous Paper Y-73-2, December. 85 p.

Myers,  E.A.,  and  T.  C. Williams.  1970.  A  decade  of
     stabilization  lagoons in Michigan  with irrigation  as
     ultimate disposal of effluent. In: 2nd International
     Symposium for Waste Treatment Lagoons,  McKinney,
     R. E.  (ed.). University of Kansas, Lawrence.  June. p.
     89-92.

Pound, C. E.,  and R. W. Crites. 1973. Wastewater treatment
     and reuse  by land application,  Volume II. Environ-
     mental Protection Agency,  Washington, D.C.  Report
     No. EPA-660/2-73-006b, August. 249 p.

Sullivan, R.  H., M. M. Conn, and S. S. Baxter. 1973. Survey
     of facilities  using  land application of Wastewater.
     Environmental  Protection Agency, Washington, D.C.
     Report No. EPA-430/9-73-006, July. 377 p.

Thomas, R. E., and C. C. Harlin, Jr.  1972. Experiences with
     land spreading of municipal effluents.  In: Proc. IF AS
     Waste Water Workshop,  1972,  on  Municipal Sewage
     Effluent. Tampa,  Florida, May 30-June 1. p. 151-164.

Thomas, R. E. et al. 1974. Feasibility of overland flow for
     treatment of raw domestic wastewater. Environmental
     Protection Agency, Washington, D.C. Report No. EPA
     660/2-74-087. July. 30 p.

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                          LAGOON EFFLUENT SOLIDS CONTROL BY

                                   BIOLOGICAL HARVESTING

                                             W. R. Duffer1
                  Introduction

      Stabilization of organic wastes in lagoons has
developed as a wastewater treatment which  favors
establishment and maintenance of specific types of
organisms.  Plantonic  algae  in  combination  with
aerobic bacteria are the organisms responsible for
oxidation of organic materials. Since a large propor-
tion  of the organic  materials  are  converted  to
phytoplankton, suspended solids are usually present
in relatively high  concentrations  in lagoon effluents.
Research effort for this wastewater treatment process
has centered around design and  operation practices
for improving  production  of  algae,  rather  than
developing design criteria for enhancing establishment
of organisms! populations to  consume the excessive
algal production.

      It is the purpose of this paper to (1) review the
accomplishments  of  several studies  oriented toward
removal  of phytoplankton  by  other aquatic or-
ganisms, (2) identify some of the  problems associated
with biological harvesting of phytoplankton, and (3)
suggest research areas which should be developed.

          Suspended Solids Removal

      Studies which  relate to solids  removal have
been  conducted in both marine and  freshwater. It
should be remembered  at this point, however, that
the concept of control of algae by organisms  in the
marine and freshwater food chains is not completely
proven and has  not gained acceptance as a treatment
practice due to the uncertainties involved. Although
most  of the experiments conducted in  the  United
States have been small scale, several have been  highly
successful and will provide a sound basis for develop-
ment   of  applied  pilot scale  research efforts. In-
vestigations  have  centered  around several types of
organisms including  zooplankton, bivalve mollusks,
and fish.
     1\V. R.  Duffer is Research Aquatic Biologist,  Water
Quality  Control  Branch,  Robert  S.  Ken Environmental
Research  Laboratory, Environmental Protection  Agency,
Ada. Oklahoma.
Zooplankton

      Several field and laboratory experiments have
been   conducted  which  utilize  the  cladoceran,
Daphnia,  for  removing excessive  algal growth. A
two-stage  pond system was established at Calabasas,
California, for polishing activated sludge effluent (Las
Virgenes Municipal Water  District, 1973).  The shal-
low first-stage pond developed a high concentration
of phytoplankton. In the  second-stage pond, which
had a water depth of about 3 meters, a population of
Daphnia pulex effectively removed the algae. The
capacity of the  first stage  was about three  times
greater than that of the  second stage and the system
was operated with about  10 days' detention in each
stage.  Daphnia  concentrations  above   500
organisms/liter  were  responsible for  a  suspended
solids  reduction  of about 50  percent. A summer
decline of the Daphnia population and occasional
invasion of Daphnia or rotifers in the first-stage pond
were major problems encountered.

      Aquarium experiments employing Daphnia and
Lemna  cultures  were conducted in Israel (Ehrlich,
1966). In one experiment, sewage stabilization pond
effluent was stored in a feeding container and allowed
to drip into nine basins at varying rates. Each basin
contained Lemna-Daphnia  cultures and the periods of
detention ranged from 8 to 360 hours. Effluent from
the experimental  basins was relatively clear,  while
samples from the feeding container remained turbid.
In another  experiment, stabilization pond effluent
was  fed to four  aquaria, each having a  detention
period of 10 days. This test was designed to deter-
mine the relative roles of Lemna and Daphnia in the
suppression  of a  population of Chlorella.  One unit
contained a Lemna-Daphnia culture, another Lemna
only, another Daphnia  only,  and  the  fourth was
maintained as a blank. Test results indicated that the
Lemna-Daphnia  unit  gave the  best  reduction of
Chlorella,  followed by the Lemna only unit. Numbers
of Chlorella per  cm3 were similar  for the Daphnia
only  unit and  the  blank  following  13  days of
operation.

      Results of  a survey of domestic wastewater
treatment facilities in Texas utilizing ponds indicate
                                                                                                 187

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 188     Duffer
that  occurrence  of Daphnia  is quite  uncommon
(Dinges, 1974a).  Only 29 of the 470 pond systems
support Daphnia populations.  These  systems, how-
ever, are  noted to maintain relatively stable condi-
tions and to have clear effluents. In a discussion of
the  environmental requirements of Daphnia, Dinges
and Rust (1972) conclude that photo-period is the
dominant environmental factor affecting Daphnia in
stabilization ponds. In general, population pulses in
Texas ponds  appear  when the period  of sunlight
approaches about 10 hours per day  and remain until
the period of sunlight approaches 14 hours per day.
Other environmental factors affecting pulses include
hydrogen ion  concentration,  presence  of dissolved
oxygen, free ammonia and hydrogen sulfide.

      An experimental Daphnia culture pond having a
capacity of 10,000 gallons was constructed to treat
effluent  from sewage  oxidation ponds  at Giddings,
Texas (Dinges, 1973).  The site was selected because
the ponds had a past history of producing abundant
algae and had never been known to support Daphnia
populations.  The experimental pond  had a  surface
area  of  .01  acre  and was operated for an  11-day
detention period. The investigation was conducted in
two phases for three  months during the minimum
seasonal photo-period.  The first phase was designated
to  determine  the effectiveness of pH  control by
shading to reduce algal growth, and the second phase
evaluated pH  control through chemical addition and
sulfide reduction by aeration. A continuous  culture
of Daphnia was maintained during  both phases and
suspended solids reductions for the stabilization pond
effluent were 86 percent and 83 percent, respectively.

      Dinges  (1974b)  has proposed several  sewage
stabilization designs for separate facilities which take
into  account  environmental  requirements  of zoo-
plankters. Design  considerations  include pond site
selection, construction  of berms and baffles, inlet and
outlet structures, mixing and depth, substrate and pH
regulation. Culture ponds  requiring rigid control and
extensive  management  are considered,  as well  as
primative  installations requiring minimum regulation.

Bivalve mollusks

      Both marine and freshwater species of mollusks
have been cultured to remove algae  from suspension.
Corbicula,  an  oriental freshwater  clam, has been
reported to filter in  excess of 0.5 liters per day per
organism  (Prokopovich,  1969). Greer  and  Ziebell
(1972), in studies designed  for removal of ortho-
phosphate from water, utilized natural algal popula-
tions and  clam  filtration. Corbicula could  clarify
water  containing high concentrations  of algae and
survive under highly enriched conditions, providing
water  was circulated and temperatures  maintained
below  30°C.  Corbicula has a very high reproductive
capacity and does not  require an obligate parasitic
stage in its life cycle.

      Several laboratory experiments have been per-
formed by  a group at Woods Hole Oceanographic
Institution  using oysters  and other marine  bivalve
mollusks for removal of algae which was grown in a
combination of secondarily treated wastewater and
seawater (Rytler, 1973).  These experiments were
highly  successful from the standpoint of nutrient
removal, and a  prototype process  was  developed
around the food web concept. Several growth systems
involving  marine  phytoplankton, oysters,  deposit
feeders, and seaweed were combined in series and fed
secondarily  treated wastewater diluted with filtered
seawater.  Filter-feeding bivalve  herbivores removed
85 percent of the algae  fed to the system. In order to
determine performance  of the multi-species food web
concept on a large scale,  pilot  plant facilities have
been   designed  and  constructed at  Woods Hole
(Huguenin, 1974).

Fish

      In Asia, fish culture  in highly enriched waters
has  been  practiced  for   centuries  and  the most
commonly  cultured  fish  are  members of the carp
family (Cyprinidoe) (Bardach et  al., 1972). In China,
the most commonly cultured phytoplankton feeder is
the silver carp. The Chinese, however, usually stock
several  types of fish in culture ponds. This  practice
insures the most  efficient use of the variety of fish
food organisms available.

      The Arkansas Game  and Fish Commission has
obtained the silver carp on an experimental basis and
most  of the effort  to date  has centered  around
propogation  studies  (Husley,  1974).  State fish
hatchery personnel have  successfully  spawned  the
silver carp and indicate  that aquarium water contain-
ing high concentrations of algae  could be cleared by
this  plankton  feeding species   within  24  hours.
Hatchery  biologists  expect to  expand their pond
culture studies to include native fish species in  a
polyculture system.

      Fathead minnows were  stocked and  success-
fully  cultured in the sewage  stabilization system at
Belding, Michigan (Trimberger,  1972). The system
consisted of five oxidation ponds operated in  a series.
Minnows were placed in the last three ponds of the
series at stocking rates less  than one pound per acre.
Six months after stocking, the fish were  harvested,
yielding 378 pounds  per  acre. Ponds  stocked with
minnows were noted to be less turbid than the other
oxidation ponds.

     A field study  designed  for removal of algae
from sewage oxidation ponds through the food chain

-------
                                           Lagoon Effluent Solids Control by Biological Harvesting    189
mechnanism was conducted by the Oklahoma State
Department  of Health  (Coleman et al.,  1974). A
six-cell  lagoon system receiving raw domestic waste-
water was operated in series with the first two cells
being aerated. Fingerling channel catfish were stocked
in Cells 3 and 4, while golden  shiner adults were
stocked  in Cells  5 and 6.  Fathead minnows and
Talapia nilotica were  also  placed in the third cell.
Lagoons were contaminated with  the  black bullhead,
green sunfish, and mosquito fish already present in
the system.  Fish  biomass estimates were  based  on
seine  hauls from a closed area of each  cell.  Talapia
biomass  increased  from an  initial 4  to 163  pounds
during a period of about four months. Golden shiner
minnow biomass  increased from  85  to 535  pounds
during a period of about four months. The biomass of
channel catfish increased from an initial 600  to an
estimated 4,400 pounds in  a period  of about eight
weeks. Mean values of weekly analyses for suspended
solids  during  the  4-month  period  of  fish  culture
indicate  a general  decrease  through the pond  series
with an 83 percent solids reduction by comparing  the
effluents of Ponds 2 and 6.

      Problem Areas and  Research Needs

      Based  on the number of successful investiga-
tions utilizing a variety of organisms for removal of
high concentrations of algae, the  food chain concept
appears to be a basically sound approach for develop-
ment of  a mechanism  for  solids control  in sewage
oxidation ponds.  However,  it should be pointed  out
that the  greatest effort to  present has consisted of
either small-scale  laboratory experiments or  descrip-
tive  studies  in  large  systems where  only  limited
control was possible.  Carefully controlled  pilot-scale
experiments are required prior to full-scale  demon-
strations  in  order to  assure research flexibility  for
determining  design  criteria  and  management  ap-
proaches.

      Specific areas which require additional research
effort for development of biological control of lagoon
solids are:

      1.    Extent of selective solids uptake  by vari-
           ous species of herbivores, as well as  the
            mechanisms involved, should  be  estab-
           lished.

      2.   A  greater  number of herbivore species
           should be  examined  to determine  the
           compatibility of their environmental  re-
           quirements with wastewater effluents.

      3.   The science of ecology must be  applied to
           increase the efficiency and stability of
           biological  control systems.  Engineering
           design parameters should  be  couched in
           terms of the multi-species approach and
           polyculture of organisms rather than the
           capability of single species.

     4.    Seasonal  aspects  of  treatment  culture
           units and  life  stage  requirements  of
           organisms must be taken into account.

     5.    Values must be assigned to productivity
           of culture  systems in  terms  of potential
           for use in aquaculture  and  commercial
           markets.

     6.    Potential  for problems  to areas such as
           recreation, agriculture, and aquaculture,
           must be determined for introduction of
           exotic species  such as Corbicula or the
           silver carp.
                    References

Bardach, J. E., J. H. Rytler,  and  W. O. McLarney. 1972.
     Aquaculture, the farming and husbandry of freshwater
     and marine organisms. New York, John Wiley & Sons.
     868 p.

Coleman, M. S., J. P. Henderson, H. G. Chichester, and R. L.
     Carpenter.  1974. Aquacultuie as a means to achieve
     effluent standards. In: Wastewater Use in the Produc-
     tion  of Food and Fiber-Proceedings. Environmental
     Protection Agency, Washington, D.C. Report No. EPA-
     660/2-74-041, p. 199-214.

Dinges, R. 1973. Ecology of Daphnia in stabilization ponds.
     Texas State Department of Health Publication.  155 p.

Dinges, R. 1974a. The availability of Daphnia for water
     quality improvement and as an animal food source. In:
     Wastewater  Use  in  the  Production  of  Food  and
     Fiber-Proceedings. Environmental Protection Agency,
     Washington, D.C. Report No. EPA-660/2-74-041, June.
     p. 142-161.

Dinges, R. 1974b. Biological considerations in stabilization
     pond design. Presented at 56th Texas Water Utilities
     Short School, Texas A&M University. 17 p.

Dinges, R., and A.  Rust.  1972. The role of Daphnia in
     wastewater oxidation  ponds. Public Works, October, p.
     89-91.

Ehrlich, S. 1966. Two experiments in the biological clarifica-
     tion  of  stabilization-pond effluents.  Hydrobiologia
     (Israel), 27:80-90.

Greer, D. E., and C. D. Ziebell. 1972. Biological removal of
     phosphates from water.  J. Water Pollution Control
     Federation  44(12):2342-2348.

Huguenin, J. E. 1974. Development of a marine aquaculture
     research complex. Presented at Annual Meeting, Ameri-
     can Society of Agricultural Engineers, Oklahoma State
     University, Stillwater.  Paper No. 74-5009.

-------
190      Duffer
Hulsey, A.  1974. Personal communication-private conversa-
     tion, Little Rock, Arkansas.

Las Virgenes Municipal Water District, Calabasas, California.
     1973. Tertiary treatment with a controlled ecological
     system. Environmental Protection Agency, Washington,
     D.C.  Report  No. EPA-660/2-73-022, December. 43 p.

Prokopovich, N. P. 1969. Deposition of clastic sediments by
     clams. J.  Sed. Petrol, p. 891.
Rytler, J. H.  1973. The use of flowing biological systems in
     aquaculture. Sewage Treatment, Pollution Assay  and
     Food-Chain Studies. WHOI-73-2. (Unpublished manu-
     script.)

Trimberger,   J.  1972.  Production  of  fathead  minnows
     (Pimephales promelas)  in  a  municipal  waste  water
     stabilization system. Michigan Department of Natural
     Resources, Fisheries Division.  (Mimeographed report.)
     5 p.

-------
                    PROGRESS REPORT: BLUE SPRINGS LAGOON STUDY

                                  BLUE SPRINGS, MISSOURI

                                    C. M. Walter and S. L. Bugbee1
                  Introduction

     Public Law 92-500, the Federal Water Pollution
Control Amendments,  was enacted  by Congress  on
October 18, 1972. These amendments provided the
necessary  regulatory environmental  legislation for
controlling municipal and  industrial waste sources
prior to discharge to receiving waters. The control is
exercised through the implementation of the National
Pollutant Discharge Elimination System (NPDES) as
outlined in Section 402 of the amended act. Simply
stated, the NPDES requires the issuance of permits
for every discharge to navigable waters.

     These permits are written  to include  imple-
mentation schedules for achieving specified levels  of
waste treatment and prescribed  self monitoring re-
quirements. In the case of municipal waste discharge
permits, the permits require secondary  treatment on
all  discharge  by   1977.  For  permit  conditions,
secondary  treatment is  defined  by concentration
limits on 5-day biochemical oxygen demand (BOD5)
and nonfilterable  solids (suspended solids  or NFS)
and fecal coliform densities. The limits are 30 mg/1,
30 mg/1, and 200 organisms/100 ml, respectively.

      The  economic base  of Region  VII  of  the
Environmental Protection Agency is primarily agricul-
tural. As a consequence, approximately 80 percent of
the waste treatment facilities are  located in small
rural communities  which are, for the  most part,
declining  in population with an attendent reduction
in resources to provide  community services. In many
instances, these small towns are not constrained by
land availability and have resorted to lagoon systems
for municipal waste treatment. The towns usually
have  a  locker  plant which does some  custom
slaughtering  and/or a  creamery  which contribute
shock loads to the sewage system. The prime question
is, will a lagoon system furnish the necessary degree
 of treatment to meet the secondary criteria?

      Over the past 3 years we have sampled approxi-
 mately 330  lagoon systems  of  various  sizes  and
      1C. M. Walter is Sanitary Engineer, and S. L. Bugbee is
 Aquatic Biologist, U.S. Environmental Protection Agency,
 Regional Laboratory, Region VII, Kansas City, Kansas.
configurations. This field sampling exercise has been
conducted over all seasons  and is usually comprised
of one  to three 24-hour composite samples of the
influent and a similar number of grab samples from
the effluent. During the same period, we have also
sampled a number of small mechanical and/or pack-
age plants. In March of this year, a summary of our
plant experience was compiled to provide a general
assessment of  plant  performance.  These data  are
shown in Table 1.

      Average  waste  treatment performance  for
BOD5  and  suspended  solids   removal  to  meet
secondary treatment requirements occurred  only in
three-cell  lagoon  systems.  Average  fecal coliform
densities in  effluents from all systems exceeded the
secondary treatment definition limit. Since all  of the
data  presented  were  collected in a more  or  less
random fashion during various seasons,  the resulting
averages should  reflect normal operating conditions.
These  data  then provide  a basis  for developing
practical plans for upgrading waste treatment for the
immediate future.

      There are many economic implications involved
in  selecting  waste treatment systems.  One  of the
prime concerns  is eligibility  for a Federal Construc-
tion  grant   under  the  requirements  of  meeting
secondary treatment.  A special intensive study was
planned to evaluate seasonal performance of a three-
cell lagoon  to provide data on the ability of these
systems to meet secondary treatment criteria.

      The Blue Springs, Missouri, three-cell in a series
lagoon system  was  selected for the  study. This
system, comprised of three cells with an area of 16.8,
5.0,  and  1.7 hectares (41.5,  12.4, and  4.1  acres)
respectively, was  designed  to  serve  a population
equivalent of 11,000 and is now serving an estimated
 12,000 to 13,000 people.

                Study Description

       A study plan was developed with three objec-
 tives in mind:

       1. Determination  of  the  performance of a
 three-cell, series operated, lagoon.
                                                                                                  191

-------
 192     Walter and Bugbee
Table 1.  Treatment plant effluent data, Region VII.
Type of Plant

1 Cell
Lagoons
2 Cell
Lagoons
3 Cell
Lagoons
Activated
Sludge
Trickling
Filter

Primary
No. of Plants


33

28

9

46

178

40
BOD5
mg/1
Ave.
Range
54
17-273
48
3-133
22
9-40
40
8-180
37
20-71
165
84-315
Suspended Solids
mg/1
Ave.
Range
64
8-891
105
8-891
31
7-54
72
5-162
80
44-149
131
32-182
Fecal No./ 100 ml
Coliform
Ave.
Range
2.6 x 104
7x 102 -1.5xl05
1.2 x 10s
2x 102-8.5xl05
2.7 x 104
2x 102-2.7X104
2.2 x 105
5.2X103-2.8X105
7.6 x 105
1.7xl05-1.6xl06
4.4 x 106
5.1xl038.7xl06
      2. Determination  of the  relative performance
of the  first, second, and third cell of a three-cell
lagoon.

      3. Determination  of  the quality  of a  sand
filtered lagoon effluent and the feasibility  of slow
sand filtration.

      In order to meet the study objectives and take
into  account seasonal variations, a minimum  study
period of one year was required. Field sampling was
planned quarterly during  30-day periods in winter,
spring,  summer,  and fall. The first two sampling
periods are  complete and  the  third is currently in
progress. The fourth sampling period is scheduled in
October and November, 1974.

      The sampling scheme selected was based on the
availability of laboratory support and  the minimum
number  of stations that would meet  the  study
objectives. The eight sampling stations used were the
raw waste at the influent wet well, the effluent from
the first, second, and third cells, and effluent  from
four pilot plant sized sand filters, two each, following
the second and  third  cells.

      Automatic  compositors  were  used  at  each
station to collect 24-hour composite samples for all
analyses   except  biological. These  samples   were
analyzed under the scheme shown in Table 2.
     In  addition,  daily  flow measurements  were
taken  from  the influent totalizer and  from the
continuous recording of head measurements on the
Cipolletti Weir in the third cell effluent channel. Two
types of sand filters were used at each location. The
first filter utilized a prepared sand with an effective
size  of 0.3 mm and a uniformity coefficient of 2.5,
while the second filter was filled with river-run sand
with an  effective size and uniformity  coefficient of
0.22  mm  and  3.5, respectively. After the winter
study, all sand filters were converted to prepared sand
because the river-run sand filters plugged throughout
their entire  depth  necessitating  complete  replace-
ment. The sand filters were constructed out of barrels
welded together and had a depth of 1.07 meters (42
in) of sand over 0.30 meters (12  in) of coarse gravel
underdrain. They were considered plugged when the
head loss through the filter exceeded 1.22 meters (4
ft).

                    Results

      Table 3 presents a summary of analytical results
for the winter sampling period. The influent data are
divided in two  sections with significantly different
results. The  reason  for the discrepancy is due to a
change in type of automatic compositor used on the
influent.  Initially a  peristaltic pump  driven  com-
positor was used. Equipment failure  necessitated a
change  and  a  vacuum activated compositor  was
substituted. The vacuum operation results in a collec-

-------
                                             Blue Springs Lagoon Study, Blue Springs, Michigan     193
 tion of a greater proportion of solids and also affects
 the concentration of other parameters which can be
 present  in either dissolved or particulate form. The
 variation between compositors has* been  documented
 by Harris and Keffer (1974). For evaluation between
 cells and overall performance,  the data collected
 between February 3 to 20, 1974, should be utilized.
                       During the winter period 84 percent of the
                  BOD5 removal occurred in Cell 1. The second and
                  third cells provided essentially no additional BOD5
                  removal, but were  effective in reducing concentra-
                  tions of  COD  and NFS  by 32 and 23  percent,
                  respectively. The influent fecal coliform count was
                  decreased from 475,000 to 22,000 organisms/100 ml
Table 2.  Laboratory analyses, Blue Springs Lagoon Study.
Daily 24 Hour Composite
24 Hour Composite Taken 7 of
      the 30 Day Period
        Miscellaneous
5 Day BOD @ 20°C
COD
TOC
Non-filterable Solids
Volatile Solids
Total Phosphorus
Ammonia Nitrogen
Nitrite-Nitrate Nitrogen
Total Kjeldahl Nitrogen
Turbidity
Alkalinity
pH
Specific Conductance
(A) Non-filtered
2,5, 10, 20,35, 56 Day BOD
Nickel
Lead
Cadmium
Zinc
Copper
Chromium
(B) Filtered (0.45 u)
5 Day BOD
COD
TOC
Total Volatile Solids
Total Phosphorus
Ammonia Nitrogen
Total Kjeldahl Nitrogen
(A) Daily
Total Coliform
Fecal Coliform
(B) Weekly
Phytoplankton enumeration and
identification
Chlorophyll a
 Table 3. Summary of operating data, Blue Springs lagoon system, average values, January 22 to February 20,

Sampling
Station

Influent3
Wet Well
1/22-2/2/74
Influent
Wet Well
2/3-2/20/74
Effluent
Celll
Effluent
Cell 2
Effluent
Cell 3

Flow
mgd

3.0

1.48





2.46


Temp.
°C

12.7

11.6

4.5

4.1

3.7


PH

7.57

6.35

7.39

7.34

7.27


BOD,;
mg/I

42.5

176

28.1

27.9

26.8


COD
mg/1

171

900

119

89

81


NFS
mg/1

63

307

17

13

13


TotP
mg/1

3.95

8.75

6.66

6.58

6.93


NH3-N
mg/1

3.53

10.67

10.25

10.63

11.05


NCyNO^N
mg/1

1.71

0.12

0.10

0.10

0.10


TKN
mg/1

6.91

15.94

12.63

12.57

12.86


TotN
mg/1

862

16.06

12.73

12.67

12.96

Fecal
Coliform
Organ/
100ml
420 x 103

475 x 10 3

69.7 x 103

29.9 x 103

22 x 103

      Automatic compositor changed on 2/02/74 from ISCO 1391 to QCEC CVE.
 ISCO operation is by peristaltic pump, CVE by vacuum. Experience to date shows vacuum operation collects more solids.

-------
  194    Walter and Bugbee
 in the  final effluent. The data demonstrates the
 ability of a  three  cell system  to  meet secondary
 treatment limits for  BOD5 and NFS, but shows the
 difficulty in meeting  fecal  coliform  requirements
 without disinfection.

       The April and May,  1974 data are summarized
 in Table 4. With increasing water temperatures, the
 overall system efficiency for  BOD5  removal was 88
 percent.  The final effluent concentration of BOD.
 was 23.2 mg/1, well below the  30 mg/1 secondary
 treatment limit. The  concentration of NFS (Table 4)
 also  met secondary  treatment  criteria. The fecal
 coliform count in the final effluent (Table 4) was still
 in excess of prescribed limits.
      Data from winter and spring sand filter opera-
tion are presented  in  Tables 5  and 6. The  winter
operation was conducted in a heated shelter which
may have affected  the results. Between the  winter
and spring sampling periods, the two filters contain-
ing river-run sand were changed  to  prepared sand.
Until  the summer  and fall data are complete, no
attempt will be  made  to  correlate application rates
and filter efficiency.
     Phytoplankton  and  chlorophyll a  data  for
winter   (January),  Spring  (April),  and   Summer
(August) sampling periods are summarized in Tables 7
through 9.
 Table 4. Summary of operating data, Blue Springs lagoon system, average values, April 22 to May 24, 1974.

Sampling
Station

Influent
Wet Well
Effluent
Celll
Effluent
Cell 2
Effluent
Cell3

Flow
mgd

1.76





1.83


Temp.
°C

13.3

18.2

18.7

20.1



pH

7.14

7.51

7.55

7.62


BOD5
mg/1

196

61.2

30.9

23.2


COD
mg/1

621

208

124

94


NFS
mg/1

557

106

43

26


TotP
mg/1

8.93

8.44

8.59

8.70


NH3-N
mg/1

11.03

6.78

7.30

8.23


N02-NO3-N
mg/1

0.41

0.07

0.06

0.05


TKN
mg/1

19.25

16.77

13.00

12.45


TotN
mg/1

19.66

16.84

13.06

12.50

Fecal
Coliform
Organ/
100ml
534 xlO3

14.1 xlO3

15 x 103

3.8x 103

Table 5. Summary of operating data, Blue Springs lagoon system, Cell 2 and Cell 3 sand filters, average values,
        January 22 to February 20,1974.

Sampling
Station

Prep. Sand
Cell2,Filt.A
River-run Sand
Cell2,Filt.B
Prep. Sand
Cell 3, Filt. C
River-run Sand
Cell 3, Filt. D

Flow
gpma

0.50

0.50

0.50

0.50


Temp.
°C










PH

7.26

7.30

7.29

7.32


BOD5
mg/1

23.2

20.3

25.0

19.8


COD
mg/1

69

61

82

62


NFS
mg/1

10

9

9

10


TotP
mg/1

6.49

6.50

6.69

6.67


NH3-N
mg/1

11.00

10.76

11.05

11.01


N02-N03-N
mg/1

0.10

0.10

0.10

0.10


TKN
mg/1

12.82

12.40

12.90

12.73


TotN
mg/1

12.92

12.50

13.00

12.83

Fecal
Coliform
Organ/
100ml
26xl03

21X103

19xl03

ISxlO3

       How applied at rate of 10 mgad-no plugging.

-------
                                            Blue Springs Lagoon Study, Blue Springs, Michigan      195
     The winter season phytoplankton population
was less than 5,000 cells/ml in each of the three cells.
Correspondingly, the concentration of chlorophyll a
in each of the cells was less than one microgram per
cubic meter (yu g/m3). The predominate  algae forms
during  this period were  Oscillatoria, a  filamentous
blue-green, and Chlamydomonas, a green flagellate.
                               Filtering the effluent from  Cell 2 significantly
                          altered  the  phytoplankton  community  structure.
                          Chlamydomonas, which represented only 28 percent
                          of the total count  from Cell  2, had little trouble
                          passing through the sand filter and represented 56
                          percent  of the total count from  Filter A effluent.
                          Oscillatoria,  the filamentous alga, and a notorious
Table 6.  Summary of operating data, Blue Springs lagoon system, Cell 2 and Cell 3 sand filters, average values,
         April 22 to May 24, 1974.

Sampling
Station

Prep. Sand
Cell 2, Fill. A
Prep. Sand
Cell2,Filt.B
Prep. Sand
Cell3,Filt.C
Prep. Sand
Cell 3, Fill. D

Flow
mgd


a
b

c

d


Temp.
°C










PH

7.45

7.47

7.50

7.56


BOD,
mg/1

20.8

18.5

15.0

14.2


COD
mg/1

75

74

66

66


NFS
mg/1

13

12

11

11


TotP
mg/1

8.38

8.14

8.82

8.28


NH3-N
mg/1

9.41

8.14

9.57

9.01


NO2-N03-N
mg/1

0.09

0.04

0.05

0.04


TKN
mg/1

12.53

12.05

12.46

11.86


TotN
mg/1

12.62

12.09

12.51

11.90

Fecal
Coliform
Organ/
100 ml
670

680

220

210

     a4/21-5/2  10mgad;5/2  -5/14  1.25 mgad;  5/15-5/24  1.25 mgad.
     b4/21-5/4   5 mgad; 5/5  -5/14  2.5 mgad;  5/15-5/24  2.5  mgad.
     c4/21-4/24 10 mgad; 4/24-4/29  10 mgad;  4/30-5/24  1.25 mgad.
     d4/21-4/28  5 mgad; 4/29 - 5/12  5 mgad;  5/13-5/24  2.5  mgad.
 Table 7. Blue Springs Lagoon Study, winter 1974.
     Celll
Cell 2
                                     CellS
Phytoplankton Count
  (cells/ml)
   2,464              2,464
Predominate Algae
  (% of total)
Oscillatoria 59%       Oscillatoria 47%
Chlamydomonas 28%  Chlamydomonas 28%
Chlorophyll a
(micrograms/m3)
   0.576              0.630
                                  3,157
                                  Oscillatpria 63%
                                  Chlamydomonas 24%
                                  0.790
                                         Filter A
                                         1,232
                                         Chlamydomonas 56%
                                         Oscillatoria 37%
                                         0.683
                                                     Filter C
                                                     1,848
                                                     Chlamydomonas 46%
                                                     Oscillatoria 29%
                                                     0.523

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 196    Walter and Bugbee
filter-clogging form, was passed through the filter, but
in broken filaments and in a much smaller quantity.
Similar results were observed in Cell  3 and Filter C
effluent,  even  though the phytoplankton cell counts
were reduced  by as much  as  50 percent. By sand
filtration, the chlorophyll a data did not reflect this
reduction because the concentrations were bordering
on the lower detection limit.

     By  April, warmer water  temperatures and in-
creasing  daylight  hours promoted  heavy  phyto-
plankton   growth.  Phytoplankton  cell  counts ap-

Table 8.  Blue Springs Lagoon Study, spring 1974.
                              preaching or exceeding 100,000 per milliliter were
                              common in  all  three  lagoons through April and
                              continuing  into  the  mid-part of May. The  pre-
                              dominate  algal form  during  this  period  was the
                              coccoid green Micractinium. By filtering the effluent
                              from Cell 2, a 95 percent reduction in phytoplankton
                              cells, and a 42 percent reduction  in chlorophyll a
                              content was accomplished.

                                         The   filtration  fragmented  the
                              Micractinium which allowed some  passage through
                              the filter of broken cells and dislocated setae. A small
    Celll
   Cell 2
   Cell 3
Phytoplankton Count
 (cell/ml)
  68,684
Predominate Algae
 (% of total)
Micractinium 97%
Oscillatoria 1%
Chlorophyll a
(micrograms/m3)
  24.03
116,424
Micractinium 73%
Oscillatoria 21%
24.03
96,096
Micractinium 96%
Euglena 1%
16.02
                                        Filter A
                                        5,852
                                        Micractinium
                                        (fragments) 35%
                                        Euglena 22%

                                        13.35
                                                        Filter C
                                                        7,392
                                                        Euglena 42%

                                                        Micractinium
                                                        (fragments) 16%
                                                        5.07
 Table 9. Blue Springs Lagoon Study, summer 1974.
    Celll
    Cell 2
                                                              Cell 3
 Phytoplankton Count
  (cell/ml)
   225,302
 Predominate Algae
  (% of total)
 Oscillatoria 93%
 Chlamydomonas 2%   Euglena 6%
 Chlorophyll a
 (micrograms/m )
   2,242.80           883.77
 142,758
 Oscillatoria 78%
 108,262
 Oscillatoria 87%
 Euglena 2%
                                      333.75
                                         Filter A
                                         9,086
                                         Oscillatoria 47%
                                         Ankistrodesmus 25%
                                         14.68
                                                        Filter C
                                                        11,858
                                                        Oscillatoria 61%
                                                        Euglena 16%
                                                        12.01

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                                              Blue Springs Lagoon Study, Blue Springs, Michigan     197
flagellate, Euglena,  also  passed through  the filter
without much difficulty.

      Filtering the effluent from Cell 3 also achieved
similar reductions in phytoplankton and chlorophyll
a. The phytoplankton cell counts declined 77 percent
with   a   corresponding  32  percent  decline   in
chlorophyll a concentrations in Filter C effluent.

      In  mid-summer,  all three  lagoons supported a
dense  blue-green  algae  population dominated  by
Oscillatoria, Phytoplankton cell counts were well over
100,000  cells/ml and  chlorophyll a  ranged from
2,242  to 333 //g/m3. As of this  writing, biological
monitoring  has  indicated the  phytoplankton  cell
counts exceeding 500,000 ml and remedial  copper
sulfate treatment will begin  the week of August  19.
Nevertheless,  filtration of Cell 2 and  3  effluents
demonstrates the effectiveness of sand filtration and
the  subsequent  reduction   of  algae  cells,  and
chlorophyll a content.

      Dye studies were conducted  on June 3, 1974,
to measure  flow-through time.  All three cells were
dosed simultaneously with rhodamine WT dye solu-
tion. Break through on Cell 1, 16.8 hectares (41.5
acres), occurred in 5 hours 10 minutes. Cell 2 which
is 5.0 hectares (12.4 acres) had initial break-through
in 4 hours 45 minutes. The first break-through in Cell
3,  1.7 hectares (4.15  acres), occurred  45 minutes
after release.

      Our Blue Springs lagoon  study is about half
finished.  The  summer intensive data which are being
generated presently,  must  be  compiled  and  the
copper sulfate dosing and fall intensive are yet to be
done. The progress to date, as summarized, does not
include consideration  of ail the analytical data but
only  those related to  the major objectives. We are
hopeful that the total  results will provide additional
insight into design and operation of three-cell  sys-
tems.
                    Reference

 Harris,  D.  J., and William J. Keffer. £974.  Wastewater
     sampling methodologies and flow measurement tech-
     niques. EPA 907/9-74-005.

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         COST-EFFECTIVENESS ANALYSIS FOR WATER POLLUTION CONTROL

                                               R. Smith1
      Over  the  past  10 years,  the  direction of the
federal program in water pollution control has shifted
from the purely scientific aspects of the problem to
the  more  practical  considerations  of design  and
cost-effectiveness  (EPA,   1971).  One  of  the  first
indications of this change in attitude appeared in EPA
regulations published in the Federal Register on July
2, 1970.  Subparagraph 601.36  entitled Design reads
as follows:

      No grant shall be made for any project unless
      the Commissioner determines that the proposed
      treatment works  are designed so as to achieve
      economy, efficiency, and effectiveness in the
      prevention  or abatement of pollution or en-
      hancement  of  the  quality of the watei into
      which such treatment works will discharge and
      meet such  requirements as the Commissioner
      may publish  from time to  time concerning
      treatment  works design  so as to  achieve
      efficiency, economy, and effectiveness in waste
      treatment.

The Federal  Water  Pollution  Control Act Amend-
ments of 1972 (PL 92-500) further charged EPA with
a  number of specific tasks relating to development
and publication of information and guidelines.

      Two principal  milestones were mentioned in
the  law. The  first  is achievement  of  secondary
treatment effluent  standards  in all publicly owned
treatment works by July 1, 1977, and the  second is
achievement of best practicable  treatment in  all
publicly owned treatment works by July 1,1983.

      The  definition of  secondary  treatment  was
published in  the Federal  Register on August  17,
1973. Principal provisions of this definition were that
the mean value of effluent samples collected over 30
consecutive  days must not exceed 30 mg/1  for 5-day
BOD, 30  mg/1 for suspended solids, 200/100 ml for
fecal  coliform bacteria, and the pH of the effluent
must fall between 6.0 and 9.0.

      Although   the   formal   definition   of  best
practicable treatment has not, as yet, been published,
     IR. Smith is with the National Environmental Research
Center, Office of Research and Development, U.S. Environ-
mental Protection Agency, Cincinnati, Ohio.
it is expected that the definition will not contain a
minimum effluent quality. The term "best practicable
treatment" seems to be closely related to the concept
of cost-effectiveness. The term best practicable treat-
ment is first mentioned in PL 92-500 in Section 201
(gX2XA) which  provides that the grant  application
must satisfactorily demonstrate to the Administrator
that:

      ...alternative   waste  management  techniques
      have been studied and evaluated and the works
      proposed for grant assistance will provide for
      the application of the best practicable waste
      treatment technology over the life of the works
      consistent with the purposes of this title.

The term "best practicable technology" is defined in
PL 92-500 with reference only to non-publicly owned
facilities but in  Section 304 (b)OXB) the following
statement appears:

      Factors  relating  to the  assessment of best
      practicable control technology ... shall include
      consideration of the total cost of application of
      technology in relation to the effluent reduction
      benefits to be achieved from such application,
      and shall also take  into account the age of
      equipment and facilities involved, the process
      employed,  the  engineering  aspects of the
      application   on  various   types  of control
      techniques,  process changes, non-water quality
      environmental impact  (including  energy re-
      quirements),  and  such other  factors as the
      Administrator deems appropriate.

Thus, it appears that the  term best  practicable
treatment is  used to represent  the ideal situation
where all aspects of each pollution control problem
are  properly  weighted and  taken into  account to
arrive at the ideal solution  which  maximizes  the
common good and minimizes the common cost. The
law (PL 92-500) specifically  states that  social costs
and other  intangible  factors are to  be taken into
account  when the best practicable solution is deter-
mined.
     While the concept of best practicable treatment
is  defined to  include social  and  other  intangible
factors, such as conservation of energy, the concept
of cost-effectiveness  is more easily understood and
more easily  used  in  the solution of any specific
pollution control problem. For example, Appendix A
of 40 CFR, part 35, EPA regulations was published in
                                                                                                     199

-------
 200    Smith
 the  Federal  Register on September 10, 1973. (See
 Cost Effectiveness Analysis.) These cost-effectiveness
 guidelines  require the non-monetary  aspects of the
 problem to be included in descriptive terms only.

      Conceptually,  cost-effectiveness  analysis means
 identifying and enumerating all feasible alternative
 ways of achieving the required level of treatment,
 estimating the  total cost of  each alternative,  and
 finally,  with  proper  consideration  of  the  non-
 monetary factors, selecting the least cost alternative.

      The  most important point made  in  the  cost-
 effectiveness guidelines  is that the  cost  of  each
 alternative must be  the total  cost expressed  as a
 present value or an equivalent continuous cash flow.
 Since the federal government is authorized to pay up
 to 75  percent  of the total cost as a grant-in-aid and
 the  states  often pay another 10 to 15  percent, the
 share of capital cost paid by  the municipality is often
 as little as 10 percent. On the other hand, the munici-
 palities usually pay  the  entire amount for operation
 and  maintenance.
      Therefore,  in  making  a  cost-effectiveness
analysis, the  tendency is often to include only the
monies paid by the municipality which would be the
entire amount for operation and maintenance plus a
small fraction of the capital cost. When this approach
is taken, the least cost alternative selected will always
be capital  intensive. The primary  purpose  of the
cost-effectiveness guidelines is to insist that the  total
cost to federal, state, and municipal sources be used
as the total cost. Other important provisions of the
cost-effectiveness guidelines are listed below:

      1.    Extent of effort used should reflect the
            size and importance of the  project.

      2.    Twenty-year  planning  period  must  be
            used.

      3.    Inflation of wages and prices shall not be
            considered in the analysis.

      4.    Discount  rate  recommended  by Water
            Resources Council must be used.

      It is obvious that an unlimited amount of effort
can be expended in seeking the most cost-effective
solution to any pollution control problem.  This is
recognized  in  the' cost-effectiveness  guidelines by
staling  that the extent of  the effort expended in
making  the analysis  should reflect  the  size  and
importance of the project. This can be expressed in
another way by stating that the cost of  the  cost-
effectiveness analysis should be included as part of
the project cost.
      It is  generally believed  that  design  of waste-
 water treatment facilities tends to be capital intensive
 because of the  relatively small  share of the  capital
 expenditure contributed by the municipality. The
 cost of clean water reports have consistently reported
 statistical data intended to show that, on the average,
 wastewater treatment  plants in  the U.S. are  under-
 loaded, reflecting overestimates  for population and
 industrial   growth   in  the  community.  Recom-
 mendations  for  making more precise  estimates of
 projected  population  growth  are  given  by EPA
 (1972).

      Examples of the  kinds of questions which EPA
 documents  consistently   recommend  for  cost-
 effectiveness consideration are given as follows. First,
 the feasibility of consolidating treatment facilities by
 means  of gravity sewers or  force mains in order to
 realize  the economies of scale. Rough cost estimates
 for plants  and  interconnecting  pipelines  can  often
 settle this question, but in cases where a real potential
 for cost savings exists, a more detailed and precise
 cost study will be necessary.

      Careful consideration  of the  expected  growth
 of  the  residential and industrial  segments  of the
 community served and the corresponding increase in
 load on the treatment facilities should be made. Here
 the potential advantages of staged construction of
 treatment works should be considered.

      The  impact  on   the  treatment  facilities of
 infiltration  and  inflow (Grants for Construction of
 Treatment Works,  1973; and  EPA, 1974) must be
 considered to determine whether  correction of the
 sewerage system  is more or less costly than expansion
 of the treatment facilities.

      The feasibility  of using treated wastewater for
industrial or agricultural purposes should be  explored.
If a  demand for the  treated wastewater exists, a
charge imposed on the  user can be used to offset the
cost of treatment.

      An important  consideration is selection of the
treatment process train which will accomplish the
treatment target at  a minimum cost. Treatment by
land  application2 must  be included  in   the  cost-
effectiveness analysis. Process reliability3 in terms of
the  variability of the effluent stream quality, protec-
     2See  Wastewater Treatment and  Reuse by  Land
Application, Vols. I and II, 1973; Survey of Facilities Using
Land  Application  of Wastewater. 1973; and Recycling
Municipal Sludges and Effluents on Land, 1973.

     3See Design Criterion for Mechanical, Electrical, and
Fluid Systems and Component Reliability, 1973.

-------
                                          Cost-Effectiveness Analysis for Water Pollution Control     201
tion  against  electrical  power  failure,  protection
against flooding, and provision for taking equipment
and structures out of service for periodic cleaning and
maintenance  should be considered.  This kind  of
analysis cannot be made in any precise way because
of the uncertain relationship between process design
parameters and  the effluent quality achieved. For
example, the average effluent quality to be expected
from  an activated  sludge  plant  treating municipal
wastewater can be estimated when the character of
the raw wastewater stream  and the design parameters
are known,  but the  precision  of the  estimate is
limited. Pilot plant results  are more reliable but still
the precision  may  not be fully  adequate for  cost-
effectiveness analysis.

      Engineering  judgment  must play  a part  in
selecting the set of processes needed to achieve any
treatment goal. For example, if the effluent standard
is 10 mg/1 BOD and 15 mg/1 suspended solids this is
achievable  with the  activated  sludge  process but
careful  consideration of factors such as  operating
sludge retention time  (SRT), hydraulic  detention
time, water  temperature, final settler overflow rate,
etc., must be provided.

      If  the  effluent   standards  require  that the
ammonia be  converted to  nitrate, a similar problem
exists. The engineer must carefully consider SRT and
water temperature to determine if nitrification can be
reliably achieved in the activated sludge  process or
whether a separate nitrification process is needed.

      If denitrification is  required by the effluent
standards,   a  decision  between  dispersed  floe
denitrification, columnar denitrification, or the new
cycling  nitrification-denitrification process-must  be
made. The ammonia removal can also be achieved by
ion exchange or by breakpoint chlorination.

      If phosphorus is  to  be removed, the required
level of phosphorus in the  effluent stream is a factor
to  be considered.  Next, the designer must choose
between processes such as alum or iron addition with
the increased amounts of inorganic sludge produced
or  the  Pho-Strip  process which has  been  tried
successfully  at Seneca Falls, New York. Filtration is
sometimes  required for removal of phosphorus to
very low levels  or  to remove additional suspended
solids and BOD.

      Lime  clarification of raw  wastewater  can be
used to remove phosphorus and  to remove sufficient
BOD to assure  good  nitrification in the following
activated sludge process.

      If  a  high  degree of  removal  of organics  is
required, granular carbon adsorption may be needed.
A package of cost and performance estimates, sup-
plied for use with the  1975 Needs Survey, is given in
Appendix A to show how the capital cost can vary
with the level of treatment required.

      The impact  of improved methods of operation
and maintenance on the effluent quality should also
be  given  careful  consideration. Some  forms  of in-
strumentation and automation are believed to  have a
beneficial  impact on  the  average  quality of the
effluent stream as well as the variability of the quality
measures. Certain  kinds of automatic control, such as
dissolved  oxygen  control in the aeration basin, are
known to  result  in  reduced operating  costs.  The
degree  of  automatic control should  be selected to
achieve  the effluent  standards  consistently at a
minimal cost.

      Finally, storm water treatment facilities  should
be  integrated with dry weather treatment facilities so
that  the  maximum use  is made of both types of
facilities in order to minimize the pollutional load on
the receiving stream.

      The cost-effectiveness guidelines specify that no
allowance  should be  made for inflation in  wages,
power cost, or capital cost. The reason for this  is that,
ideally, the analysis should be made on the basis of
real value rather than  dollar value. Dollars are used
only as a measure of real value and, therefore, when
the cost of any structure, equipment item, or  service
is used, it must be referenced  to a specific point in
time.  This  is  done by  means  of various kinds of
indices such as the EPA  sewer and treatment indices,
the average hourly  wages of  water,  steam,  and
sanitary system workers, wholesale price index for
industrial commodities, etc. For example, a plot of
the EPA  indices for construction  of sewers and
treatment  plants is shown in Figure 1. The current
rate of increase for these indices is about 40 percent
per year.

      The justification for omitting inflation, then, is
that it is assumed that the cost of all components of
the facility  are being inflated at the same rate. If the
inflation  rate  for construction  is  known  to be
significantly different than the inflation rate for, say,
electrical  power,  there   is  some justification  for
considering inflation.  Another reason for not  con-
sidering inflation  in cost-effectiveness analysis is the
uncertainty  associated with estimating the rate of
inflation in future years.

      Perhaps the most important concept in making
a cost-effectiveness  analysis is  the  time value of
money. By this, we mean  that one dollar today is
worth more than the promise to pay one  dollar, say,
one year from  now. For  example, one dollar today
will be worth $1.05 in one year if the prevailing rate
of  interest  is  5  percent.  It is also  important in

-------
240
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-------
                                          Cost-Effectiveness Analysis for Water Pollution Control     203
considering  the cost of a service  facility such as a
treatment plant or a sewerage system to consider cost
as distributed over an  endless time continuum. For
truly continuous costs such as  the cost of wages or
chemicals this presents no problem. For other items
such as equipment or structures which have a finite
useful life, provision must be made for replacement at
the end of the useful life period. This can be done by
accumulating money in a  fund (sinking fund) or by
borrowing the money to purchase the needed replace-
ment  item.  The  discarded  equipment or  structure
may have some salvage value but this is not significant
in most cases.

     Thus,  for cost estimation purposes,  the costs
incurred must be visualized as being distributed over
the continuous  and endless time continuum. The
costs can be expressed as a continuous cash flow or as
lump  sums  occurring  at equal intervals. Since  the
expenditures  occur in a  recurring  pattern, it  is
convenient to look at the costs over a finite interval
called  the  planning period. The  cost-effectiveness
guidelines recommend  the use of a 20-year planning
period.

     Compounding of interest is most commonly
done on a yearly  basis, but for illustrative purposes
continuous compounding is more convenient and will
be  used here. The difference  between  continuous
compounding  and yearly  compounding  is  usually
small. The Water Resources Council's (1973) rate was
6  7/8  percent for fiscal  year 1974 and the new
recommended rate for fiscal year 1975 will be 5 7/8
percent.

     When  one or more  equally acceptable alter-
natives are being studied for the purpose  of selecting
the least cost  alternative, the stream of costs which
occur over the planning period must be converted to
an equivalent basis in order that the cost comparison
can be made.

     For example, costs for all alternatives can be
converted to a present  value, a future  worth, or to a
continuous cash flow. By present worth, we mean an
equivalent lump sum expenditure which occurs at the
beginning of the planning period. If we designate time
from the beginning of the planning period as (t) and
the length of the planning period as (T), then the
present value is a lump sum payment made at t = 0.
Similarly, future worth  is defined as a lump sum
expenditure made  at t = T. By continuous cash flow,
we mean a  continuous stream of expenditure at a
fixed  rate with respect  to time  (R) expressed as
dollars per year.

     By means of simple relationships, any stream of
expenditures can be converted to one of these three
equivalent expressions. When the  cost of all alter-
natives are expressed on an equivalent basis, the least
cost alternative can be selected.

     The actual expenditures which occur in connec-
tion with a particular alternative can be lump sums or
continuous expenditures but the rate of the continu-
ous expenditure need not be constant. If we designate
a lump  sum expenditure which occurs at a  time (t)
from the beginning of the planning period as S(t), the
relationships used to convert  S(t) to a present value,
S(0), or to a future worth, S(T), are given below.

    s(o)  =  s(tyrt     	(i)

    S(T)  =  S(t)er(T-t)	(2)

                       r = discount rate, fraction

When the stream of expenditures is continuous, the
expenditure at any time is expressed as Rdt but R can
be  a  function of  time. Any continuous stream of
expenditures can be expressed  as a present value by
the following expression:
    S(0)
     •f
Rert dt	(3)
If R is a constant and the stream of expenditure
covers the entire planning period, the present worth
of the continuous cash flow is expressed as follows:
                 -rT\
    S(0)  = R(l-e'rl)/r
                                          (4)
Similarly,  the  continuous  cash  flow (R) can  be
expressed as a future worth as follows:
S(T) =  R(e
               rT
                                              (5)
If the continuous cash flow covers only a portion of
the planning period, say from tj to t2, the present
value and future worth can be expressed as follows if
R is a constant:
  S(0) =  R(e'rtl - e'rt2Vr

  S(T)=  R(e"rt2-e"rtl)/r
                                          (6)

                                          (7)
If the continuous cash flow R is expressed as a linear
function  such as (a +  bt) and  covers the  entire
planning  period, the present value of the linearly
increasing stream is expressed as follows:
    S(0) = a(l - e'rT)/r + b(l - (1 + rTKrT)/r2 - (8)

If the continuous cash flow R increases exponentially
such  as  R  =  RQe8t, the  present  value of  this
continuous stream can be expressed as follows when
the entire planning period is covered:

-------
  204    Smith
      S(0) =  R(e(a-r)T -
(9)
       Conversions  between  continuous cash  flow,
  present value, and  future  worth  are  shown dia-
  gramatically in Figure 2. Six 20-year planning periods
  are  represented  in Figure 2. In the first  planning
  period, a lump  sum expenditure is  shown at the
  10-year point and the vertical lines on either end of
  the  planning period  represent the present value and
  the future worth of the lump sum expenditure made
  at the 10 year point. In the  second planning period
  the future worth of a constant continuous cash flow
  is represented.  In the  third planning period the
  present value of a constant  continuous  cash flow is
  represented. In the fourth period the present value of
  a continuous cash flow between 10-15 years is shown.
  The cash flow in the fifth period is linearly increasing
  and present value is shown. The sixth period contains
  an   exponentially  increasing  cash  flow with the
  present value shown.

       The  normal method  of financing municipal
  wastewater  treatment  plants  is  to issue municipal
bonds and to pay the interest and principal on the
bonds over a 20-30 year period as a continuous cash
flow. The  rate at which the money is paid can be
expressed as R dollars  per year,  or if continuous
compounding is assumed, the amount paid during the
time period dt is Rdt. Here, time is expressed as years
and dt is an increment of time. If the interest rate (r)
is  known  and  the  time  period  over  which  the
payments are to be made (T) is known, the  required
rate of continuous payback (R) can be calculated.

      If compounding is assumed on a yearly basis,
the value for R can be calculated from the following
simple formula:
                                                 (10)
           R    =     debt service, dollars/yr
           P    =     capital cost of plant, dollars
           I    =     rate of interest, fraction per year
           N    =     time period over which debt service
                      is paid, yrs
   i
Figure 2. Diagramatic illustration  of conversions between  continuous  cash  flow, present value, and future
         worth 20-year planning periods, 7 percent interest.

-------
                                            Cost-Effectiveness Analysis for Water Pollution Control    205
       If  continuous  compounding  of  interest  is
 assumed, R can be calculated if we first notice that R
 is the sum of the interest on the unpaid balance (S)
 over the time period dt plus the nega'tive derivative of
 the unpaid balance with respect to time. This can be
 seen from the diagram shown in Figure 3.

       Figure 3 represents the debt service charge on a
 capital cost of $1,000 amortized over 20 years at an
 interest rate of. 7 percent. The area under the curve
 represents the  interest charges and the area above the
 curve represents the payments on the principal. The
 area above the curve between the ordinate represent-
 ing  zero time  and  any other ordinate representing a
 time (t) equals the initial plant cost minus the unpaid
 balance (S). Thus,  any ordinate  is the sum of the
 interest charges (rS) and the rate of change of (P-S) or
 •dS/dt.

      The  height of the rectangle representing the
 continuous cash flow can be expressed as follows:

     R = rS-dS/dt	(11)

 If we let the length of the rectangle representing the
 planning  period be T years,  Equation  11  can be
 integrated to find the following expression for R:
         The amortization factor, defined  as the fraction of
         the plant cost (?) paid per year,  is calculated from
         Equation  12 as 0.09291.  If  the interest  is  com-
         pounded yearly, the amortization factor is calculated
         from Equation 10 as 0.09439. The difference between
         these two factors is about  1.5 percent. Notice that
         Equation 12 is equivalent to Equation 4.

              In the example  on continuous compounding,
         the  height  of the rectangle is the product of the
         amortization  factor and the  plant  cost  taken as
         $1,000 or $92.91. Initially, the interest charges are
         $1,000 x 0.07 or $70 and the amount for repayment
         of the principal is $ 12.91. By integrating Equation 11
         between any time (t) and T (20 years), the following
         expression for the unpaid balance is found:
            S=
                                            .(13)
        Therefore, the equation of the curve in Figure 3  is
        just  rS.  Also,  by differentiating Equation  13 with
        respect to time, we find
   dS/dt =
                                                     (14)
     R = Pr/(l
•02)
Thus,  it  can be  seen that Equation  13  can  be
multiplied by  (r)  and added to  the negative  of
Equation 14 to equal (R).
                Plant Cost - Unpaid Balance (P-S)
                                                                        14    15    16    17    18    19
   O   1
Figure 3. Distribution of continuous cash flow associated with debt service on $1000 expended at zero time
         amortized at 7 percent interest over 20 years.

-------
 206     Smith
      If Equation 13 is multiplied by r and integrated
between zero and T, the total amount paid in interest
can be found.
                             -rT\
    Interest Paid = RT-R(l-e   )/r
                                        .(15)
In the example cited, the amount of interest paid is
85.82 percent of the plant cost and the total amount
of dollars paid is 1.8582 times the plant cost.

     A more general expression for the total interest
charges divided by the plant cost is given below:
I/p =
                                            .(16)
      An example of the way municipal bonds are
issued to provide for a payback as a continuous cash
flow  is shown by the  notice of  sale  of municipal
bonds for mental hygiene and retardation facilities.
The notice of sale is shown in Figure 4. The expected
rate  of interest  is approximately 6 percent com-
pounded semi-annually.

      If Equation 12 is used to estimate the continu-
ous   cash  flow  (R)  required  to  pay  back  the
$45,000,000 with interest at 6 percent, the amount
which must be repaid each year is $3,475,486. The
division of this amount between interest charges and
principal is  shown in Figure 5, assuming continuous
compounding. The estimated amounts for repayment
of principal from Figure 4 are shown plotted by the
circled points in Figure 5.

      It  can  be seen  that   the  continuous com-
pounding relationship matches the estimates reason-
ably well. In financing the 45 million  dollar facility, a
total  of 86.9 million dollars will be spent, 45 million
for payback of the principal and 42 million in interest
charges.

      For the sake of clarity,  consider the following
simple example.  An  activated sludge  plant with  a
design capacity of 4 mgd is being designed and the
designer plans to use mechanical  aerators with vari-
able effluent weirs to allow the blade submergence to
vary as  the  load on the plant  increases. The popula-
tion of the community served  is expected  to increase
by  1.5  percent per  year over the 20-year planning
period. Thus, the initial flow expected at the plant is
2.96 mgd and this will increase  to 4 mgd at the end of
the 20 year period.

      The amount of oxygen required is estimated at
one  pound  of oxygen per pound  of 5-day BOD
removed. The expected BOD removal in the activated
sludge process is 120 mg/1. Thus, if the field aeration
efficiency is  2.5  Ib  02/hp-hr,  the initial rate  of
electrical power consumption will be 49.37 hp or
36.8  kw. The  power  consumption at  the design
capacity (4 mgd) can be estimated as 66.6 hp or 49.7
kw.

     The  plant  designer  is  faced with  choosing
between two brands of mechanical aerators. Brand A
has an initial cost of $15,000 and an average aeration
efficiency of 2.5 Ib 02/hp-hr  while Brand B has an
initial  cost of $20,000  and  an   average aeration
efficiency of 2.7 Ib 02/hp-hr. In order to satisfy the
oxygen demand at the  end of the  planning period,
both platform mounted  aerators must be rated at 75
hp.

     For  simplicity,  it  will  be assumed  that  the
aeration  efficiency is independent of blade  sub-
mergence. If we take  the cost of electrical power as
1.5 cents/kw-hr, the annual cost for electrical power
to drive the mechanical aerators can be  expressed as
follows:
                                                                   O.OlStj
                                                    $/yr  = $4,836 eu'ulDtfor Brand A
                                            .(17)
                                                    $/yr  = $4,477 e°'015t for Brand B	(18)

                                                      To convert these two  streams of expenditures
                                                 to a present value, we need only substitute them into
                                                 Equation 3 for R. Therefore, the present value of the
                                                 stream of expenditures represented by Equation 17
                                                 can be found by the use of Equation 9 in which the
                                                 value for (r)  is the discount rate (taken as 7 percent)
                                                 minus the rate of growth (1.5 percent) or 5.5 percent.
                                                 The value for (R)  is $4,835.52 for  Brand A and
                                                 $4,477.33 for Brand B. When this is done, the present
                                                 value  of electrical  power  for  Brand  A aerator  is
                                                 computed as  $58,659.  For  Brand  B,  the  cor-
                                                 responding value is $54,304. Since the initial cost is
                                                 already in the form of a present value, these can be
                                                 added to give  a  total present value for Brand A of
                                                 $73,659. The  corresponding value for Brand B  is
                                                 $74,304. Therefore,  over  a 20-year period  the net
                                                 savings in selecting  Brand A is estimated as $645.
                                                 When  the discount rate for municipal bonds is 7
                                                 percent and the growth rate for the community is 1.5
                                                 percent  per year, the  trade-off in aeration efficiency
                                                 with initial cost  can be  seen to be about $2,178 for
                                                 each 0.1 Ib O2/hp-hr increment in aeration efficiency.
                                                 Other  factors,  such as the  difference in maintenance
                                                 and repair cost, can be worked into the analysis.

                                                      If the  life  of any process component  exceeds
                                                 the planning period, the capital expenditure is con-
                                                 verted to a continuous cash flow and that part of the
                                                 continuous cash  flow  which covers  the  planning
                                                 period is then converted to a present value. In making
                                                 cost analysis, the preferred method is to convert all
                                                 expenditures to a continuous cash flow and then sum
                                                 the continuous cash flows for all items to find the
                                                 total  cost expressed as a continuous cash flow. This
                                                 cost is then often converted to a total treatment cost

-------
                            Cost-Effectiveness Analysis for Water Pollution Control   207
                       Notice of Sale of Bonds
                             $45,000,000
                            STATE OF OHIO
      MENTAL HEALTH  FACILITIES BONDS,  SERIES 1974A
      NOTICE IS HEREBY  GIVEN that sealed bids will be received
 at the office of  the Treasurer of State of Ohio in the Capitol
 Building, Columbus, Ohio,  until 11:OO o'clock a.m., Eastern
 Daylight Saving Time,  on
                      Tuesday, July 16, 1974
 at which time and place  said bids will be publicly opened and
 read, for the purchase of  all of the  $45,000,000 State of Ohio
 Mental Health Facilities Bonds, Series 1974A (the "Series 1974A
 Bonds"), to be issued  by the Ohio Public Facilities Commission
 (the "Commission")  to  pay  costs of capital facilities for mental
 hygiene and retardation.

      DATE, DENOMINATIONS,  AND MATURITY:  The Series 1974A Bonds
 in coupon form and  those originally issued in fully registered
 form will be dated  as  of August 1, 1974.  Coupon bonds will be
 in the denomination of $5,000 and fully registered bonds will
 be in the denomination of  $5,000 or any multiple thereof, and
 said bonds will be  exchangeable as between coupon and registered
 form.  The Series 1974A  Bonds will mature serially on June 1 in
 each year as follows:

    Year           Principal          Year           Principal
                   $   820,000          1988          $1,750,000
                      870,000          1989           1,855,000
                      920,000          1990           1,965,000
                      980,000          1991           2,035,000
                   1,035,000          1992           2,210,000
                   1,100,000          1993           2,340,000
                   1,165,000          1994           2,480,000
                   1,235,000          1995           2,630,000
                   1,310,000          1996           2,790,000
                   1,385,000          1997           2,955,000
    -L^O-J           1,470,000          1998           3,135,000
    1986           1,535,000          1999           3,310,000
    1987           1,650,000
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
Figure 4. Notice of sale of municipal bonds appearing in the Cincinnati Enquirer June 24,1974 (in part).

-------
  208    Smith
 w
 u
 a
 H
 H  o
 o  2
 Q
 C
 O
•H
        0
                                            10    12
      14
16     18     20    22
                                                                                                24 25
 Figure 5. Distribution between interest charges and payback of principal for financing a facility with a capital
          cost of $45,000,000 at an interest rate of 6 percent over a 25-year period.
  expressed   as  cents/1000  gallons  of  wastewater
  treated.

       The  1973 Survey of Needs conducted by EPA
  asked each state to identify every plant planned for
  construction by 1990 and to  give estimates for the
  cost and the effluent quality required. An analysis of
  the information submitted by the states produced the
  following results.

       The  survey  showed that about  15,000 new
  plants are planned and about 6,000 of these plan to
  achieve an effluent  quality  in excess  of  the EPA
  definition  of secondary treatment. About  4,000 of
  the 6,000 plants will make no  provision for removal
  of nitrogen  and phosphorus and about 2,000 will
  remove phosphorus, ammonia nitrogen or nitrogen. A
  breakdown of the  1,868 plants which plan to remove
  phosphorus,  ammonia nitrogen or nitrogen is shown
  below.



Number of Plants
Total Flow, mgd
Average Flow/
Plant, mgd
P
Re-
moval
1,868 962
13,923 7,166
7.45 7.44
NH3
Re-
moval
1,141
8,105
7.10
NO3
Re-
moval
182
2,081
11.43
     Most  of  the  plants  which  plan  to  remove
phosphorus estimate the concentration of phosphorus
in the effluent  as 1 mg/1. Most of the plants which
plan to  oxidize the ammonia nitrogen estimate the
concentration of ammonia nitrogen in the effluent as
1-2 mg/1.

      The  group  of  plants  which  planned  no
phosphorus or  nitrogen  removal but  planned to
exceed the EPA secondary standard of 30 mg/1 BOD
and 30 mg/1 SS contained 3,788 plants with effluent
BOD  less  than  30 mg/1  and  3,987  plants with
suspended solids in the effluent less than 30 mg/1. A
breakdown of plants according to BOD level and flow
is shown in Figure 6.  Histograms, according to the
number of plants planning various levels  of BOD and
SS, are shown in Figures 7 and 8. Most of the planned
effluent qualities fell in the 10-15 mg/1 class for BOD
and 15-20 mg/1  for the suspended solids.

      The   Federal   Environmental   Protection
Agency's grant-in-aid  program  for construction of
wastewater treatment represents a significant national
expenditure and careful planning and  design to
minimize cost is easily justified.

      For example, Deputy EPA Administrator John
R.  Quarles reported  in the July  18, 1974, issue of
Engineering News-Record  that  the  total  for con-

-------
Number of Plants
BODmg/1
26-30 303 11
21-25 553 39
16-20 1366 87
11-15 302 34
6-10 464 40
0-5 297 16
0-5 6-10
Figure 6. Distribution
54012102
18 10 8 8 3 3 0 1
35 19 9 6 2 10 1 0
92321420
12 8 5 3 2 1 3 1
58220101
11-15 16-20 21-25 26-30 31-35 3640 41-50 51-60
Flow, mgd
of plants planning to achieve a BOD standard of less than 30 mg/1 from
0 0
0 1
4 1
0 1
2 0
0 1
61-70 71-80
the EPA Needs
Total
1 3 1 0 0 334
0 3 2 1 1 651
0 0 10 2 1 1553
3 1 2 4 2 372
0 1 2 1 0 545
00 0 0 0 333
81-90 91-100 101-200201-300301-400 3788
Survey for 1973.
Cost-Effectiveness Analysis for Water Pollution Control 209

-------
210    Smith
  160O
  1500
  1400
  1300
  1200
  1100
  1000
   900
   7OO
   400
   30O
   200
   10O
       1L.L  J__,.-   _L

g_._ L..1
Q.
         8 . 82r
            17.18f?
                               I   1
                             	,_
                                        -_L_J_I_J	L
                                                                                  •~i
                                                             \   i.
                                                     14.32%
                                                        .L:I	L

                                                          8.79%
J.-J      -5.
   !  i    _1.
                           10
                                                                       30
                                         BOD,  mg/1
                                                 I  i

Figure 7. 1973 survey of needs municipal wastewater treatment facilities.

-------
                                        Cost-Effectiveness Analysis for Water Pollution Control    211
  1600






  1500






  1400






  1300






  1200






  1100






  1000







  900






  800






  700






  600






  500






  400






  300
  200
  100
                              :T~!- T7"t:

5    ,.
c	*•
rt   T"     i
H

*---;-T


^ __L..ii_i
                      t~T
 ' ]

" 1  :
                    13.14?5
                           9.23%

     38.48%
                                         _;;_:ll^iL i)
                                                                                    ___!

                 5

                 !
                     10
.13
                                                     20
                                                                              30
                                              ,  mg/1

Figure 8. 1973 survey of needs municipal wastewater treatment facilities.

-------
 212     Smith
 struction  grant  awards in fiscal  year  1974 totaled
 about 2.6 billion dollars. The actual cash outlays, that
 is,  the  total of checks written in FY 1974 totaled
 about  1.5 billion dollars.  According to Mr. Quarles,
 the cash outlays for other years have been as follows:
                           1974 Capital spending plans
    Year

    1968
    1969
    1970
    1971
    1972
    1973
    1974
  Cash Outlay,
millions of dollars
      120
      130
      180
      480
      410
      680
     1500
Since PL 92-500 authorizes the federal share of the
construction cost of  interceptors, treatment  plants,
and outfalls to  be  as much as 75  percent, the 1.5
billion dollar outlay represents as much as 2.0 billion
dollars in new construction.

      Congress authorized, in Public Law 92-500, the
expenditure of five billion  dollars  in FY 1973, six
billion dollars in FY 1974, and seven billion dollars in
FY 1975. The Administration has released only four
billion of the seven billion authorized for FY 1975,
three billion of  the  six billion authorized  for FY
1974, and two billion of the five billion authorized
for FY 1973.

      The importance  of the construction  program
for water pollution control can be seen  from a recent
estimate  of new  construction planned  for  1974 by
U.S. business. The table shown in Figure 9, showing
spending plan by U.S. business in 1974, appeared in
the November 15, 1973, issue of Engineering News-
Record.

      The Systems and Economic Analysis Section of
AWTRL  at NERC Cincinnati has produced a number
of reports and computer  decks which can be of value
in examining many  of the questions associated with
cost-effectiveness  analyses.   For  example,   the
potential  for consolidation  of  treatment plants by
means of interceptors and  force  mains  and  the
advantages  of  staged  construction are  treated by
Smith and Eilers (1971). A number of reports are
available  on the  cost and  performance of various
processes and process trains.  A cost estimating pro-
gram  (Eilers  and  Smith,  1971)  is   available  for
estimating the cost of complete plants when the size
of  all structures and equipment  are   known. An
Executive Program (Eilers and Smith, 1970) is avail-
able which  will  solve  for all process streams when
performance measures are  known for each process.
This program  is also  capable of sizing all processes
when the performance measures are known and also
                                                    7974
                                                 P/annedf
                                1973-74
ALL MANUFACTURING..
lron& steel	
Nonferrous metals	
Elect, machinery	
Machinery	
Autos, trucks & parts	
Aerospace	
Other transp. equip.
(RR equipment, ships)	
Fabric, metals & instrum..
Stone, clay & glass	
Chemicals	
Pulp& paper	
Rubber	
Petroleum	
Food & Bev	
Textiles	
Misc. manufacturing	
                           NONMANUFACTUniNG ,
                           Mining	
                           Railroads	
                           Airlines	,
                           Other transportation	,
                           Communications	
                           Elect, utilities	
                           Gas utilities	,
                           Commercial (1)	
46.52
2.80
2.35
3.20
4.44
2.58
.59
.37
3.43
2.13
5.51
2.67
1.89
6.59
3.55
.88
3.54
67.33
3.69
2.21
1.78
1.66
13.90
18.56
3.23
22.30
+24
+ 52
+ 45
+ 13
+ 35
+ 20
+ 13
+ 10
+ 19
+ 43
+ 33
+ 45
+ 21
+ 21
+ 17
+ 17
- 5
+ 7
+ 30
+ 10
-24
+ 8
+ 5
+ 14
+ 5
+ 4
                           ALL BUSINESS	  113.05
                                   +14
                           fMcGraw-Hill Dept. of Economics.  'Based
                           on  '73  estimates  by U.S.  Commerce
                           Dept.  (1) Based on largo chain, mail order
                           and  department  stores,  insurance  lirms,
                           banks and other commercial businesses.
                      Figure 9. Estimated  capital  outlays for new plants
                               and equipment for U.S. business Engineer-
                               ing News Record November 15,1973.
                      solving for all recycle streams by means of iterative
                      computation. The cost of water renovation (Smith,
                      1971) for reuse is estimated and compared to the cost
                      of water production by conventional means. Various
                      reports  are available on the potential for improved
                      performance  and cost reduction by  means  of in-
                      strumentation  and  automation.   Recent  reports
                      examine the  cost  of alternative schemes for  sludge
                      handling and disposal (Smith and Eilers,  no date a)
                      alternative  schemes for oxygen  supply (Smith and
                      McMichael, no date), and potential control schemes
                      for the activated sludge process (Smith and Eilers, no
                      date  b). A time  dependent program for the aerated
                      lagoon  was  developed  in  connection   with cost-
                      effectiveness studies of equalization basins (Smith et
                      al., 1973). Cost estimation  programs have recently
                      been developed  for dispsered floe  nitrification and
                      denitrification,   granular  carbon  adsorption,  and
                      aerated  and  facultative lagoons. For example,  the
                      program for lagoons is shown in Appendix B.

-------
                                             Cost-Effectiveness Analysis for Water Pollution Control     113
                    References

Cost Effectiveness Analysis. 1973. EPA Regulations Title 40,
     Chapter I, Subchapter D, Part 35> Appendix A, Federal
     Register 38, No. 174, September 10.

Design Criteria for Mechanical, Electrical, and Fluid System
     and   Component   Reliability.   No   date.
     EPA-430-99-74-001.

Eilers, R. G., and R. Smith. 1970. Executive digital computer
     program.for preliminary design  of wastewater treat-
     ment systems. NTIS, PB 222 765, November.

Eilers,  R. G.,  and R. Smith. 1971. Wastewater  treatment
     plant cost estimating program. NTIS, Rept. No. PB 222
     762, April.

Environmental Protection Agency. 1971. Guidelines, water
     quality management planning. January.

Environmental Protection Agency.  1972. Cost effectiveness
     in water quality programs, a discussion. October.

Environmental Protection Agency. 1974. Guidance for sewer
     system evaluation. March.

Federal Water  Pollution Control  Act Amendments of 1972.
     1972.  Public  Law 92-500,  92nd Congress, S.2770,
     October 18.
Grants for  Construction of Treatment Works. 1973.  EPA
    Regulations, Title 40, Chapter I, Subparagraph D, Part
    35, Federal Register 38, No. 39, February 28.


Recycling Municipal Sludges and Effluents on Land. 1973.
     Proc.  of  Conference  held July  9-13,  Champaign,
     Illinois, Lib. of Congress Cat. No. 73-88570.

Secondary Treatment Information. 1973. EPA Regulations
     Title 40, Chapter  I, Subchapter D, Part 133, Federal
     Register 38, No. 159, August 17.

Smith, R. 1971. Cost of wastewater renovation. NTIS, PB
     213 805/6. November.

Smith, R., and R. G. Eilers. 1971. Economics of consolida-
     ting sewage treatment  plants by means of interceptor
     sewers and force mains. NTIS, PB 213 803/8. April.

Smith, R-, and R. G. Eilers.  No date. Alternative schemes
     for sludge handling and disposal in wastewater treat-
     ment plants. Available in preliminary form.

Smith, R., and R. G. Eilers. 1974. Control schemes for the
     activated sludge  process.  Environmental Protection
     Technology Series  EPA-670/2-74-069. August.

Smith, R.,  R.  G. Eilers, and E. D. Hall. 1973. Design and
     simulation of  equalization basins.   NTIS 222  000.
     February.
Smith, R., and  W. F.  McMichael.  No date. Alternative
     systems for supplying dissolved oxygen in wastewater
     treatment. Available in preliminary form.

Survey of Facilities Using Land Application of Wastewater.
     1973. EPA-430-9-73-006, July.

Wastewater Treatment and Reuse  by Land Application.
     1973. Vols. I &  II, Environmental Research Series,
     EPA-660/2-73-006b&a. August.

Water Resources Council. 1973. Establishment of principles
     and  standards for  planning water and related  land
     resources. Federal Register 38, No. 174, September 10.
                 Appendix A
Table A-l.  Identifying numbers  for individual  pro-
            cesses or process trains.
 Primary Sedimentation I                            1
 Primary Sedimentation II                           2
 Primary Sedimentation I & Iron                    3
 Primary Sedimentation II & Iron                    4
 High Rate Trickling Filter I                         5
 High Rate Trickling Filter II                        6
 Low Rate Trickling Filter I                         7
 Low Rate Trickling Filter II                        8
 Activated Sludge I                                 9
 Activated Sludge II                               10
 Activated Sludge III                              11
 High Rate Trickling Filter I & Alum               12
 High Rate Trickling Filter II & Alum             . 13
 Low Rate Trickling Filter I & Alum               14
 Low Rate Trickling Filter II & Alum              15
 Activated Sludge I & Alum                        16
 Activated Sludge II & Alum                       17
 Activated Sludge HI & Alum                      18
 Separate Nitrification                             19
 Separate Denitrification                           20
  Filtration & Alum                                21

  Note: Activated sludge and  trickling filter groups include
        primary sedimentation.

-------
214    Smith
PRIMARY
SETTLER

                                      SLUDGE HANDLING SCHEME  I,


                                       2
                                                                     ANAEROBIC DIGESTER
                         SLUDGE DRYING BEDS
                                     SLUDGE HANDLING SCHEME II
PRIMARY
SETTLER

 INCINERATOR
                                                                           .ANAEROBIC
                                                                           DIGESTER
Figure A-l. Sludge handling schemes I, II, and III.

-------
                                          Cost-Effectiveness Analysis for Water Pollution Control    215
                                      SLUDGE HANDLING SCHEME III
                                                      AIR FLOTATION
                                                      THICKENER
                                          VACUUM FILTER
                                                                                INCINERATOR
                                                                                     ID
                                                                                    -o
Figure A-l. Continued.
Table A-2. Estimated effluent stream quality (pollutant concentrations in mg/1) achievable with process trains

          identified as PI, P2, P3, and P4. 9/10/11 means activated sludge treatment with sludge handling
          schemes I, II, or III.
BOD
200
130
100
45
25
20
25
15
15
10
10
5
5
SS
200
100
50
60
30
20
30
15
15
20
20
5
5
COD
390
250
185
90
60
45
50
35
35
35
45
25
30
P
10
9
2
8
8
7
2
2
2
8
8
1
1
NH3-N
20
20
20
18
10
17
18
10
17
2
1
20
1
N03-N
0
0
0
0
10
0
0
10
0
18
1
0
1
PI
0
1/2
3/4
5/6
7/8
9/10/11
12/13
14/15
16/17/18
9/10/11
9/10/11
16/17/18
9/10/11
P2
0
0
0
0
0
0
0
0
0
19
19
21
19
P3
0
0
0
0
0
0
0
0
0
0
20
0
20
P4
0
0
0
0
0
0
0
0
0
0
0
0
21
 Note: Expected Range = ± 15 percent for all estimates.

-------
216    Smith
                                                               ' I   : 0_   ...I  _

                                                                         Tmi!
                                                         Trended to June, 1973     , \



1
J i -
I I :
-U
11- . i
I !
L ^
i
, r 1








.











_a
i
i
1
j
i
.aJ—






                                                                                   J
                                                                     J   4  b  6 7 H 9 H.
                           10
                                                        100
                Design Capacity,  millions  of  gallons  per day
Figure A-2.  Capital cost estimates for primary sedimentation plants with sludge handling schemes I (1) and II
          (2) and for activated sludge plants with sludge handling schemes I (9), II (10), and III (11).

-------
                                          Cost-Effectiveness Analysis for Water Pollution Control    217
                                                                        -1-6%-
               __	u.-.-j-  ..I_—	_j^,
               I - I   - 1      ! - 1 - P f :  --   ; -  !-!•-••
                                                             _^!_-i_l Trended to June, 1973
                                                                                           -
                   Design Capacity,  millions  of  gallons  per day
Figure A-3. Capital cost estimates for primary  sedimentation plants equipped with facilities to add iron and
           sludge handling schemes I (3) and II (4). Capital cost estimates for activated sludge plants equipped
           with facilities to add alum and sludge handling schemes I (16), II (17), and III (18).

-------
 218     Smith

                                                                                             H
                                                i    1   !
                                                                   Trended  to June,  1973
! ,
j
"i1
: _ t
i - L;
• i


; ,
i .


LJ

I
1 I



i 1
i
I !
1 1
J_L
i
i.
i - ;
•••In:
'inn
r .
i
;• j"
1 1

•
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i : •
L
j
-|
i-
                 3    -1   [i  6 7 U 9 1U
                                                                                3    4   &  b  7 u 9 i •
                                10
                                                                100
                      Design Capacity,  millions  of gallons per day
Figure A-4. Capital cost estimates for trickling filter plants with sludge handling schemes I (5 & 7) and II (6 & 8)
           and for trickling filter plants with facilities for adding alum ahead of the final settler with sludge
           handling schemes I (12 & 14) and II (13 & 15).

-------
                                     Cost-Effectiveness Analysis for Water Pollution Control    219
                                                                 1OCL

                                                                       rnr	FIT

                                                                         i.       -i
                                                                          -*-1    f     i  '  I
                                                                       _,    ,       ,T,
                                                             Trended  to June, 1973
                                                                    If      •     ! '  :  i ''•
               Design Capacity,  millions of gallons  per day
Figure A-S. Capital cost estimates for separate nitrification (19), separate denitrification (20), and filtration
          with supplementary alum addition (21).

-------
 220     Smith


                                           Appendix B

Table B-l. Input variables to waste stabilization pond cost estimating study.

QD        Average daily volume flow used for design of the system, mgd

RI         Amortization interest rate, fraction

YRS       Amortization period, years

DA        Cost of land, dollars/acre

DHR       Hourly labor rate, dollars/hour

CCI        Sewage treatment plant construction cost index, 1967 = 1.00

WPI        Wholesale price index, 1967 = 1.00

BODIN     5-day BOD concentration of the pond influent stream, mg/1

PLOAD    5-day BOD loading on the system, Ib BOD/day/acre

HP        Total installed capacity of the mechanical aerators, horsepower/million gallons

DCL2      Dose of chlorine, mg/1

TCL2      Chlorine contact time, minutes

FSLAB     Fraction of pond protected by concrete embankment

HEAD     Pumping head of raw wastewater pumps, feet

FORK     Program control: 0  = non-aerated pond, 1  = aerated pond

TEMP     Program control: 0  = non-aerated pond in a cold climate, 1 = non-aerated pond in a warm climate

SLAB      Program control: 0 = no concrete embankment protection, 1 = concrete embankment protection
           included

CL2        Program control: 0 = no chlorination contact basin or feed system,  1 = chlorination contact basin
           and feed system included

DEEP      Program control: 0=10 feet deep aerated pond, 1 = 15 feet deep aerated pond

SAER     Program control: 0  = small impeller floating mechanical aerators, 1 = large impeller stationary
           mechanical aerators

PUMP      Program control: 0 = no raw wastewater pumping, 1 = raw wastewater pumping included

ECFO      Excess capacity factor (raw wastewater pumping)

ECF1       Excess capacity factor (stabilization pond, non-aerated)

ECF2      Excess capacity factor (stabilization pond, aerated)

ECF3      Excess capacity factor (surface aerators)

ECF4      Excess capacity factor (concrete embankment)

ECF5      Excess capacity factor (chlorination contact basin)

ECF6      Excess capacity factor (chlorination feed system)

-------
                                      Cost-Effectiveness Analysis for Water Pollution Control    221
   10
-8
 o
 o
•rl
o

r-t



>rt  ^
CL • JL
  .01
                                                        treatment cost
                                                                                 100,
                                                                                   10.
                                                                              I-1    1.
                                                                                    .1
        .1
                                           1.
10.
                                                                                         (fi
                                                                                         c
                                                                                         o
                                                                                        o
                                                                                        o
                                                                                        o
                                                                                         V)
                                                                                         •p
                                                                                         c
                                                                                         8
                                                                                         c
                                                                                         I
                                                                                         s
                                                                                         H
                 Design Capacity,  million gallons  per  day
   Figure B-l. Estimated cost trended to January 1974 for waste stabilization ponds in warm climates with the

            design criteria of 50 Ibs BOD/day/acre.

-------
 222   Smith
    10.
 0)
* i

-8


-------
                                       Cost-Effectiveness Analysis for Water Pollution Control    223
     10.  CT
H


I
H
H
•p
to

8
•P

•H
      1.
    ,01
           H treatment cost
                                                                                  100.
                                                                                   10,
         .1
                                          1.

                   Design  Capacity,  million gallons per day
                                                                                         in
                                                                                         C
                                                                                         o
                                                                                         H
                                                                                         H
                                                                                         d
                                                                                         o

                                                                                         8
                                                                                         H
                                                                                         \
                                                                                         (0
                                                                                         •p
                                                                                         8
                                                                                         i
                                                                                         •p
                                                                                         Ki
                                                                                         OJ
                                                                                         )-(
                                                                                         H
                                                                                   .1
                                                                             10.
  Figure B-3.  Estimated cost trended to January 1974 for aerated lagoons with the design criteria of 170 Ibs

            BOD/day/acre.

-------
.1 MOD WASTE STABILIZATION POND XARH CLIMATE PUMPING JAN 1974
K>
-b.
COST ESTIMATE 05
FOR 3
HASTE STABILIZATION PONDS S
PROCESS COMPONENTS
RAW KASTEWATER PUMPING
STABILIZATION PONO-NONAERATEO-W
SUBTOTAL
ENGINEERING COST
LAND RECUIREO, 9.78 ACRES
LAND COST
SUBTOTAL
LEGAL, FISCAL, ADMINISTRATIVE
SUBTOTAL
INTEREST CURING CONSTRUCTION
GRA.NO TOTAL
00 RI YRS
0.100 0.060 25.000
BCD IN PLOAD HP
200.000 50.000 0.000
FORK TEMP SLAB
0.000 1.000 0.000
DESIGN CONSTRUCTION
PARAMETER COST, *
0.10 MGD 29602.
3.33 ACRES 45754.
75356.
14766.
14682.
104806.
3524.
108330.
1344.
109675.

OA OHR CC1
1500.000 4.340 1.881
OCL2 TCL2 FSLAB
0.000 0.000 0.000
CL2 DEEP SAER
0.000 0.000 0.000
CAPITAL DEBT COST 0+H COST TOTAL COST
COST, $ CTS/1000 CTS/1000 CTS/1000
43084. 9.233 12.262 21.496
66590. 14.271 4.720 18.992
109675. 23.505 16.903 40.488
HP I
1.405
HEAD
30.000
PUMP
1.000
EXCESS
CAPACITY
1.00
1.00


Figure B-4. Cost estimate for waste stabilization ponds, warm climate.

-------
                     .1 MGO
WASTE  STABILIZATION  POND
                                                                COLD CLIMATE
PUMPING
JAN 1974
                                                        COST  ESTIMATE
                                                              FOR
                                                  WASTE STABILIZATION  PONDS
PROCESS COMPONENTS
RAH HASTEWATER PUMPING
STABILIZATION- PONO-NONAERATEO-C
SUBTOTAL
ENGINEERING COST
LAND REQUIRED, 20.03 ACRES
LAND COST
SUBTOTAL
LEGAL, FISCAL, ADMINISTRATIVE
SUBTOTAL
INTEREST DURING CONSTRUCTION
GRAND TOTAL

QD RI YRS
0.100 0.060 25.000
BODIN PLOAO HP
200.000 17.000 0.000
FORK TEMP SLAB
0.000 0.000 0.000
DESIGN CONSTRUCTION
PARAMETER COST, $
0.10 MGD 29602.
9.80 ACRES 98469.
128072.
20669.
30049.
178791.
4964.
183756.
2876.
186632.

DA DHR CCI
1500.000 4.340 1.881
DCL2 TCL2 FSLAB
0.000 0.000 0.000
CL2 DEEP SAER
0.000 0.000 0.000
CAPITAL DEBT COST
COST, $ CTS/1000
43138. 9.245
143494. 30.753
186632. 39.999




WPI
1.405
HEAD
30. COO
PUMP
1.000
0+M COST TOTAL COST EXCESS
CTS/1000 CTS/1000 CAPACITY
12.262 21.508 1.00
4.644 35.397 I .00
16.906 56.905





Figure R-5.  Cost estimate for waste stabilization ponds, cold dimate.

-------
                    I MOD
                       AERATED LAGOON
                                    PUMPING
                                           JANUARY 1974 DOLLARS
                                                     COST ESTIMATE
                                                          FOR
                                               WASTE STABILIZATION PONDS
     PROCESS COMPONENTS
RAW WASTEWATER PUMPING
STABILIZATION PCND-AERATEO  15FT
SURFACE AERATORS-STATIONARY
CONCRETE SLAB EMBANKMENT
CHLC3INAT1GN CONTACT  BASIN
CHLORI:NATION FEED  SYSTEM

SUBTOTAL
ENGINEERING COST
LAND REQUIRED,  4.84  ACRES
LAND COST

SUBTOTAL
LEGAL,  FISCAL, ADMINISTRATIVE

SUBTOTAL
INTEREST CURING CONSTRUCTION

GRAND TOTAL
                       DESIGN
                      PARAMETER
                         0.10 MGD
                         0.98 AC
                        10.00 HP
     00
    0.100

  80DIN
  200.000

    FORK
    I.000
   RI
  0.060

PLOAO
170.000

 TEMP
  0.000
 YRS        DA
25.000  1500.000
  HP
10.000

SLAB
 1.000
OCL2
15.000

 CL2
 1.000
CONSTRUCTION
COST, S
50 29602.
CRES 41056.
P 33477.
CRES 7401.
U FT 4656.
B/OAY 15330.





DHR
4.340
TCL2
30.000
DEEP
1.000
131524.
21C29.
7265.
159819.
4623.
164442.
2462.
166904.

CCI
1.881
FSLAB
1.000
SAER
1.000
CAPITAL DEBT COST 0+M COST TOTAL COST
COST, $ CTS/1000 CTS/1000 CTS/1000
37566. 8.051 12.262 20.314
52100. 11.166 0.000 11.166
42483. 9.104 18.627 27.732
9392. 2.012 0.000 2.012
5908. 1.266 0.000 1.266
19454. 4.169 6.419 10.589
166904. 35.770 37.310 73.081
HPI
1.405
HEAD
30.000
PUMP
1.000
                                                                                          EXCESS
                                                                                         CAPACITY
                                                                                             1.00
                                                                                             1.00
                                                                                             1.00
                                                                                             1.00
                                                                                             1.00
                                                                                             1.00
  Figure B-6. Cost estimate for waste stabilization ponds, pumping.

-------
                                              NOTE:

                 RESEARCH ON COLD CLIMATE WASTEWATER LAGOONS

                                             H. J. Coutts1
     The waste  treatment research effort  of the
Arctic  Environmental Research Laboratory has been
concentrated on aerated lagoons and extended aera-
tion processes.

     Stabilization (facultative) ponds have not been
extensively  used  in Alaska,  therefore most of the
performance data is from Northern Canadian lagoons.

     Data on facultative lagoons north of 52° north
latitude indicated winter BOD removals of 30 to 73
percent at detentions from 70 to 200 days.2  Summer
BOD removals were generally above 70 percent.

     The Arctic Environmental Research Laboratory
research and monitoring field effort has been con-
centrated on an experimental lagoon at  Eielson Air
Force  Base, Alaska; a  lagoon receiving total sewage
(~ 1/3 mgd) from Ft.  Greely, Alaska; a small lagoon
serving 14 residential  houses at Northway,  Alaska;
and a lagoon serving Eagle River, Alaska (~ 1/7 mgd).
All the above lagoons  were aerated  with submerged
devices.  The  aeration  rates  were high enough to
prevent  thermal  stratification  but  not  sufficient
enough to prevent settleable solids from precipitating.
The detentions varied from 12 to 30 days.

     Experience  with  the Eielson  Air  Force Base
aerated lagoon has shown that first year data is not a
reliable indicator (at least for cold  regions) of long
term  performance.  Due  to  algal blooms  the  first
winter's (startup) performance was better  than  the
following summer. After the first year the summer
performance was consistently better (than winter).
Apparently  it takes a while for the bottom sludge tc
accumulate and digest adding to effluent BOD.

     Performance  data  for  many northern aerated
lagoons are summarized and plotted in Figure 1.
     IH. J.  Coutts is Chemical Engineer, Arctic Environ-
 mental  Research  Laboratory,  Environmental  Protection
 Agency, College, Alaska.
     2"Biok>gical  Waste  Treatment in the Far North,"
 Federal  Water Quality Administration, Northwest Region,
 Alaska,  Water Laboratory  1610, June 1970. Now Arctic
 Environmental Research Laboratory, Environmental Protec-
 tion Agency, College, Alaska 99701.
yj
70
50
m
Sm


J

\ 	
T€R _
c
/
/
/

^

/



, 	 -—
^





^ i




— —
INTER




	 •









 1
                10         20         30
                   DETENTION TIME - DAYS

Figure 1.  Average performance data on  nine cold
          region  aerated  lagoon  systems,  Arctic
          Environmental   Research  Laboratory,
          August 1974.
      It should be recognized that there is consider-
able range in the data and  that many  winter  and
summer points overlap. Figure 1 is preliminary  and
should not be used for design.

      The data are from  the four above-mentioned
Alaska lagoons, three Canadian research lagoons, one
North Dakota,  and three  Minnesota  lagoons. A
comprehensive report  on  Cold  Climate  Aerated
Lagoons is to be  published  by the  Arctic Environ-
mental Research Laboratory this winter.

      Recommendations by the Arctic Environmental
Research Laboratory on aeration devices are applicable
to  all aerated lagoons, independent  of temperature.
The recommendation is  to avoid restricted orifices
when submerged aerators are  used. An  example of
restricted orifice devices are slitted tubing or porous
stones (ceramic  plugs),  which tend  to clog very
readily. The AERL Working Paper No. 17 3 quantifies
the  economical advantages of using coarse bubble
(open)   aerators  versus  fine bubble   (restricted
aerators).

      3"Coarse Bubble Diffusers for Aerated Lagoons in Cold
Climates," by Conrad D. Christiansen, Working Paper No. 17,
U.S. Environmental Protection  Agency, National Environ-
mental Research  Center, Arctic  Environmental Research
Laboratory, College, Alaska 99701.
                                                                                                   227

-------
                                              NOTE:

                  POLISHING GRAVEL AND ACTIVATED CARBON FILTER

                             ON AERATED LAGOON EFFLUENTS
                                            G. Hartmann
      Region VIII has a construction grant project for
the  Boxelder Sanitation  District in  Fort  Collins,
Colorado, under construction that entails the use of a
polishing lagoon with a gravel and activated carbon
filter at the end of an aerated lagoon system. The last
week of August was the first time that the filter was
put  on line and to date no data are available on its
performance.

      The  project  consists  of  expanding  and up-
grading a 4-acre facultative pond with the addition of
two, 2-acre aerated lagoons that can be operated in
series or parallel, followed by the existing facultative
lagoon that will now be used as the polishing cell in
the lagoon system. Built into the discharge end of the
dike of the existing lagoon  is a gravel  and activated
carbon filter. The project was conceived and designed
to meet the State of Colorado effluent standards for
1978 of 20 mg/1 for BOD5, SS, color and turbidity.

      The  State of Colorado was  instrumental in
getting this project underway and hopes to gain data
from it which will enable communities in Colorado to
be able to upgrade their lagoons in an effective and
economical manner. The  total construction cost of
the  filter,  including the  air supply,  was $56,000.
Seventy-five percent of the project costs was paid for
with federal grant funds.

      The filter itself consists of three zones of gravel
followed by a zone  of activated carbon. The gravel
and activated carbon are placed in such a manner that
the flow through each zone is horizontal, with each
zone contiguous to the next.

      The pond effluent first passes through a 30-foot
wide zone of 1^-inch gravel, then through a 13.5-foot
wide zone of 3/4-inch gravel, then through a 4.5-foot
       G. Hartmann is with the Environmental Protection
 Agency, Region 8, Denver, Colorado.
zone of pea gravel, before passing through approxi-
mately 14 feet of coarse activated carbon. Effluent
may be drawn off from the filter after going through
the first two gravel zones or after passing through the
entire  gravel and activated carbon filter. The deten-
tion time for  passage of the pond effluent through
the filter is quite long, being on the order of days.

      The  filter has been constructed with 8-inch
perforated PVC air discharge pipes in the bottom of
the filter. The spacing of the air discharge pipes varies
with the filter medium size, with a closer pipe spacing
for  the  smaller  media. Two  15 HP blowers and
motors have been included to provide for delivery of
air through the filter when required.

      The  Boxelder Sanitation  District and the con-
sultant plan to sample the filter influent and effluent
for  BOD5, SS,  NH3, NO3, turbidity, and  color.
However at this time the owners and consultant have
not yet  decided on  the extent  of the sampling
program. The filter has sampling tubes installed in the
filter  so  that  samples  may  be drawn from several
different  places in the filter  to evaluate  the perfor-
mance of the filter as flow passes through.

      The  district and consultant plan to operate the
filter in  several different modes. With the placement
of air diffusers in the filter, it is hoped that it will be
possible   to  operate  the  filter   in  an  aerobic  or
anaerobic  mode. The water  level  in the  final lagoon
can be regulated so that the filter can be kept flooded
or  left  dry  if  desired. Shortly the  district  and
consultant will be  developing a series of operational
 modes and developing a monitoring program for each
 specific operational mode that is used.

       The  EPA Region VIII Office intends to keep as
 fully informed as possible on the monitoring of the
 filter  and will attempt to  make these monitoring
results available as they are obtained.

       Owner  of  the Project—Boxelder Sanitation
            District, Fort Collins, Colorado
       Consultant-M  &  I Engineers, Fort Collins,
            Colorado
                                                                                                  229

-------
                                  MEMBERS OF THE SYMPOSIUM
         NAME
Donald A. Anderson
J. David Ariail
Charles K. Ashbaker

Richard Bowman
Robert L. Bunch
Stephen L. Bugbee

Robert J. Burm
Robert B. Cameron

Charles H. Campbell
Jack Coutts

Roger Dean
Lloyd Denley
Evan Dildine
Les Dixon
William R. Duffer

Jerry N.  Dunn

Larry E. Eason
Don Ehreth

Fred Evans

Ted Forester

Robert L. Fox
John Gall
William L. Garland
Robert A. Gearheart
Bill J. Gilbert
Terry Hagin
Hugh G. Hannah

Lynn Harrington
Joe L. Haney
          REGION
EPA, Region 9, San Francisco
EPA, Region 4, Atlanta
Oregon Dept. of Environmental
Quality
State of Colorado-Denver
EPA, NERC, Cincinnati, Ohio
EPA/SUAN Region 7, Kansas
City, Kansas
EPA Region 8, Permits
HQS Alaskan Air Command/
DEMV
EPA, Region 9, San Francisco
Arctic Environmental Res.
Lab., U.S. EPA Fairbanks, Alk.
EPA, Region 8, Denver, Colo.
Mayor, California, Mo.
EPA Region 8, Denver
USU, Logan, Utah
EPA, NERC, Corvallis ADA,
Oklahoma
Corps of Engrs., Alaska Dist.
Anchorage, Alk.
Riddle Engineering Inc.
EPA/ORD Process Develop-
ment, Washington, D.C.
Iowa Dept. of Environmental
Quality
Missouri Clean Water
Commission
EPA Region 8, Denver, Colo.
EPA, Region 1, Boston
DEQ, Cheyenne, Wyo.
USU, Logan, Utah
Supt. Utilities, California, Mo.
EPA, Region 8, Denver, Colo.
Ark. Dept.  of Pollution Con.
and Ecology, Little Rock,
Arkansas
EPA/Region 7
Region  6, EPA, Dallas, Texas
     NAME
George Hartmann
Carl F. Heskett
Ronald F. Lewis
Christine  Macko
Stanley Martinson

Robert W. Mason

Ross E. McKinney
E. Joe Middlebrooks
Merritt A. Mitchell

Paul J. Molinari

Willis  H.  Morris

Steve  Moehlmann
Warren Myers
James D. Nelson

Walter J. O'Brien

James Ouchi
Steven Pardieck
Gerry Pidge
Donald M. Pierce
Jay Pitkin
Donald B. Porcella
Roy E. Prior
Jim Reynolds
John T. Riding
William A. Rosenkranz

David Sanders

Paul C. Schwieger
Ray G. Seidelman, Jr.

Bell C. Self
      REGION
EPA, Region 8, O&W
EPA, Region 8, Denver, Colo.
EPA, NERC, Cincinnati, Ohio
USU, Logan, Utah
Calif. Water Resource Con.
Bd., Water Quality Division
EPA, Region 2, New York,
N.Y.
Univ. of Kansas
USU, Logan, Utah
EPA Arctic Lab., Fairbanks,
Alk.
EPA, Region 2, New York,
N.Y.
HQS Alaskan Air Command/
DEMV
Utah State Div. of Health
Montana Dept. of Health
S.D. Dept. of Environ. Prot.
Pierre, S.D.
University of Kansas,
Lawrence
EPA, Region 5, Chicago
EPA, Region 9, San Francisco
USU, Logan, Utah
Special Consultant EPA
Utah State Div. of Health
USU, Logan, Utah
DEQ Cheyenne, Wyo.
USU, Logan, Utah
Va. State Water Control Bd.
Munic. Pollution  Con. Div.,
ORD, EPA, Washington
Missouri  Clean Water
Commission
DEQ Cheyenne, Wyo.
Dept. of Environ. Con.,
Lincoln, Nebraska
USU, Logan, Utah
                                                                                              231

-------
232 Members
         NAME

Norm Sievertson

John C. Taylor

Dick Thomas

Warren R. Uhte

LaRue S. Van Zile
           REGION

EPA, Region 10, Seattle,
Washington
EPA, Region 5, Chicago
Construction Grants
ADA Lab. EPA, ADA,
Oklahoma
Brown and Caldwell, Walnut
Creek, Calif.
Va. State Water Control Bd.
          NAME
           REGION
William A. Whittington EPA Office Water Program
                    Operations
Jack Witherow       IWB-EPA, Corvallis, Oregon

George M. Woolwine   EPA, Region 3, Philadelphia

David Word
Don Zollman
Georgia Water Quality
Control, Atlanta
Montana Dept. of Health-
Helena

-------
                              APPENDIX

                 MONITORING REQUIREMENTS FOR PONDS
    UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                    WASHINGTON, D.C.  20460
Dr. E. J. Middlebrooks
Dean, School of Engineering
Utah State University
Logan, Utah

Dear Dr. Middlebrooks:

   During the recent workshop on Wastewater Treatment Ponds which
your University hosted,  a question was raised regarding the monitoring
requirements for ponds.

   The attached memorandum was obtained from our Permit Policy
Branch.  You will see that their guidance is that "permits should
require sampling of major parameters at least once per month for
small facilities' . It also recognizes that some facilities will need
time to achieve minimum monitoring requirements.

   Also attached is a table of monitoring requirements extracted from
"Permit Program Guidance for Self-monitoring and Reporting Re-
quirements", dated October 1, 1973.

                               Sincerely yours,
                                             tt
                               Sanitary Engineering
                               Municipal Technology Branch(WH-447)
Attachments
                                                                   233

-------
234 Appendix
                                                                                P.G. Permit No. 14
                     UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
SUBJECT: Self-monitoring                                                Date: February 15,1974
FROM: Michael Cook, Acting Branch Chief
        Permit Policy Branch
TO: Regional Permit Branch Chiefs
              and
     Regional Municipal Permit Coordinators
THRU: Kenneth L. Johnson, Director
        Municipal Permits & Operations Division

      Concern and some confusion was expressed at our meetings January 14 and 17 with the Regions in Atlanta
and Seattle about guidance from the headquarters on monitoring frequency. This memo is intended to summarize
briefly our guidance on this subject, and supplement it in the few areas where it needs clarification. The self-
monitoring form to be used is also discussed.

      The document, Permit Program Guidance for Self-monitoring and Reporting Requirements, dated October
1, 1973, states that permits should require sampling of major parameters at least once per month for small
facilities, and more often for larger ones. Where facilities have industrial flows, required sampling frequency
is to be based on industrial monitoring guidance in the same document. The frequencies listed in the document
are considered to be minimums.  Regions should establish more rigid requirements where appropriate.

      Some facilities will need time to achieve minimum requirements. Guidance  for these cases is provided in
Jack Rhett's memo of August 20, 1973 to the Regional Municipal Permit Coordinators, entitled "Use of Draft
Municipal Permits"; and in his memo of November 15,1973 to the Regional Administrator of Region VII,
entitled "Monitoring Periodicity for Small Municipalities."

     Permit Program Guidance for Self-monitoring and Reporting Requirements calls for a self-monitoring
report on a quarterly basis from all municipal  facilities. The quarterly report is to consist of three monthly
summary reports completed on the EPA-designated reporting form, or a State reporting form approved by
EPA for this purpose.

     We have decided after consultation with the Regional Offices to adapt EPA Form 3320-1 (10-72) for use
as the municipal self-monitoring reporting form. A draft of the modifications we propose to make in this form
will be distributed shortly for your comment.

-------
                                    Table III

                     Municipal Wastewater Treatment Facilities
                          Minimum Sampling Frequency
                                                                             Appendix 235
                                                 Effluent











Plant Size (mgd)


Up to 0.99
1 - 4.99
5 - 14.99
15 and greater









|
E

Once
Each
Wkday.2
Daily
Daily
Daily




^
^•i

<§

Q1
03

0
£

•o
o
VJ
•o
•S
c
u
Sf
a











ex,

/.^
^b,
V
H
c
o
1^

•^
^
T3
(S

h
£
^
o
13
.w /^^

'i s
^^ ?s
"8-


*^u
•^
^^
•S
^
C/3

3
«3

*



Once per month
Once per week
Once per weekday
Once per day
1. In smaller plants, we should accept
  total colifoim rather than fecal coli-
  form at this time.
2. Weekday = Monday - Friday.
3. Grab Sample.

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     236 Appendix
                          UTAH   STATE   U N I  V E R  S I  T Y •  L O  G A N .  U TA H  84322
                                                                                      COLLEGEOF ENGINEERING
                                                                                                                UMC 41
OFFICE OF THE DEAN
          801-752-4100
      ext. 7801  or 7802
                                                                                 October 23, 1974
      James D. Nelson
      South Dakota Department of
         Environmental Protection
      Pierre, South Dakota  57501

      Dear Mr. Nelson:

           We are attempting to finalize the proceedings for the symposium on upgrading waste water stabili-
      zation lagoons, and only one written question has been received for inclusion in the appendices.  We are
      still debating as to whether to include a question and answer section  because of the shortage of written
      questions. However, I felt it only appropriate that your question be answered, and because it was
      directed to me, I will attempt to answer the question in the following paragraphs.

           Your question was:  "A two-cell stabilization pond provides 120 day winter storage and the effluent
      from the pond averages 50 mg/1 BOD5 and 70 mg/1 suspended solids. Would you recommend the addition
      of a third cell or another method of treatment such as intermittent sand filtration to comply with the
      secondary treatment standard?"

           I doubt very seriously that the addition  of a third cell to  the present two-cell system will improve the
      effluent  quality significantly.  I would recommend that the intermittent sand filter, rock filter, or some
      other addition  to the present system be considered and carefully evaluated.  This is the only way  that you
      will obtain a consistent quality of effluent and meet the secondary standard.

           I realize that the above answer is rather  general, but to avoid being considered biased in my recom-
      mendation I  feel it only fair that you consider other techniques.  The intermittent sand filter used in series
      with the lagoon effluent passing first through a course sand with an effective size of approximately 0.7 mm,
      to a finer sand (effective size ~ 0.4 mm) and  eventually to a sand similar to the one that we have used in
      our early evaluation  (effective size of .17 millimeters) will provide an excellent effluent. Based upon the
      preliminary data that we have collected the series process will perform an entire season before plugging if
      the unit  is loaded  at a loading rate  of 0.5  million gallons per acre per day.  The optimum loading rate for
      a series type  operation remains to be determined; however, we feel sure that a value greater than 0.5 million
      gallons per acre per day will be selected as the design value.  I would recommend very strongly that a series
      type system be employed. If you have additional questions or wish me to elaborate further  on your above
      question, please let me know.
                                                                         Sincerely yours,
                                                                          &f Joe Middlebrooks
                                                                         Dean
      EJM:js

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                                             AUTHOR INDEX
Alley, F.C., 147, 175
American Public Health Association, 36, 45, 75, 87
American Society of Civil Engineers, 47, 68, 71, 87
Amin.J. V., 157, 174
Amramy, A., 137,172
Anderson, D. B., 157, 175
Anne, P., 156, 172
Ainon, D. I., 152,156, 172
Assenzo, J. R., 147, 172
Attoe.O.J., 177
Aulenbach, D. B., 185, 186
Avnimelech, Y., 137,166,172
AWWA, 87
Ayers, A. D., 175

B

Balassa.J., 154,177
Bancroft, P.M., 137, 172
Bardach, J.E., 188, 189
Barnette, R. M., 177
Barsom, G., 3, 4, 5, 14
Barth, E. F., 45
Batchelder, A. R., 175
Bauer, L. D., 138, 172
Baxter, S. S., 184,186
Bear, F. E., 176
Beath.O.A., 162,177
Beaton, J. D., 163, 172
Bendixen, T. W.,  174,177
Berger, K. C., 177
Bernstein, L., 155, 163, 172,173
Berry, A. E., 31,45
Bingham, F. T., 155,159,  172
Bisbjerg, B., 162, 172
Bishop, W. B. S.,  157, 172
Blair, G. Y., 178
Bott, R. F., 175
Borchardt, J. A., 31, 45, 55, 68
Bower, C. A., 178
Bowling.J. 0., Jr., 174
Bradfield, R., 173,178
Bradford, G. R., 175
Bredell, G. S.,173
Brennan, E. G., 175,176
Brewer, R. F., 156,172
Bronson, J. C, 176
Brown, A. L., 158, 159, 172
Brown, L C.,  172
Brown, J.W., 153,177
Bugbee, S. L., 191
 Calaway, W. T., 47, 51,58, 68,72, 87, 88
 Campbell,!. D., 156,172
 Cannell, G. H., 159,172
 Carpenter, R. L,, 189
 Carroll, W. R., 68, 87
 Champlin, R. L, 5,14
 Chang, C.W., 157.173
 Chang, S. L., 137,173
 Chapman, H. D., 153,172,173,176
Chichester, H. G., 189
Chipman, E. W., 174
Christiansen, C. D., 5,14
Clark, E., 137,  173
Clark, N. A., 137,173
Clark, R., 174
Cleary, E. J., 137,176
Clements, H. F., 158,173
Clesceri, N. L., 186
Cohn.M.M., 184,186
Colby, W. G., 178
Coleman, M. S., 189
Coleman, R., 163,173
Cooper, R. C.,  176
Cooper, W. C.,  154,173
Cope,J.T.,Jr., 162,173
Corbett, E. G., 155, 173
Cram.W. H., 178
Qites, R.W., 184, 185,186

D

Daines, R. H., 175,176
Davis, D. E., 176
Davison, V. E., 149,173
Day, A. D., 137, 171,173
Dean,R.J., 184,186
Deaner, D. G.,  183, 184, 186
Deatrick, E. P., 157,173
Delaney, T. B., Jr.,  185, 186
Dennis, J. M., 137,173
DeTurk,E. E.,  137,173
Dinges, R., 188, 189
Dixon, N., 174
Dodd, J. C., 31, 46
Doner, H. E., 173
Dornbush, J. N., 14
Drake, M., 178
Drewry.W., 173
Druger, P., 173
Dryden, F. D.,  5, 6,14
Duffer, W. R., 187
Dupuis, M., 156,172
Dye.E. O., 137,173
 Eaton, F. M., 153, 154,155,161,162,163,173
 Eaton, S. V., 173
 Ehlig,C. F., 155,163,173
 Ehrlich, S., 187,189
 Eilers, R. G., 212, 213
 Elgabaly.M. M., 164,173
 Eliassen, R., 137,173
 Ellis, G. H., 174
 Embleton, T. W., 157,158,173,174,176
 Emerson, D. L., 88
 Englebert, L. E., 174
 Englehard.W.E., 172
 Enns, W. R., 157, 175
 Environmental Protection Agency, 36,46,75,87,199  200
       213
 Ergle.D. R., 163,173
 Evans, C. A., 172
                                                                                                            237

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238
Author Index
Falk, L. K., 177
Farrell, M. A., 176
Federation of Sewage and Industrial Wastes Association, 47,
      68,71,87
Feinmesser, A., 137,173
Fenn, L. B., 172
Fergus, I. F., 158, 173
Ferris, J. G., 186
Filip, D. S., 71
Fireman, M., 163, 173, 174, 177
Folkman, Y., 31,46, 55,68
Forbes, R. H., 156,  173
Ford, H.W., 158,173
Foree, E. G., 43, 46
Foster, Z. C., 174
Francis, L., 178
Frear, D. E. H., 157, 174
Fruh, E. G., 45, 46
Furman, Thomas De Daussure, 47, 51, 52, 68, 72, 88
                                                Hunt, Henry J., 137,174
                                                Hunt, P. G., 185, 186
                                                Hunter, J.G., 156, 164,174
                                                Hurd-Karrer, Annie M., 162, 174
                                                Husley, A.,188, 190

                                                I

                                                !ves, Kenneth J., 55, 59, 60, 68

                                                J

                                                Jackson, W. A., 174
                                                Jenny, H., 138, 174
                                                Joham, H. E., 157, 174
                                                Johnson, C. M., 152,172
                                                Jones, J. H., 137, 174
                                                Jones, N. B., 69, 146,147, 174, 175
                                                Jones, W. W., 173, 176
                                                Jopling, W. F., 150,158, 174, 175
                                                Joshi, K. G., 159,174
Gallatin, M.H., 175
Garber, M. J., 159,172, 173
Garner, W.W., 157, 174
Gauch, H. G., 157,174, 175
Gausman,H. W., 155, 173
Gearheart, R. A., 137
Gee, H. K.,  176
Gilbert, F. A., 163,174
Gile.P. L., 174
Gissel-Nieken, G., 162, 172
Gloyna, E. F., 147, 174
Golueke,  C. G., 176
Goudey, R.F., 137, 174
Grantham, George R., 47, 51, 52, 53, 68, 72,1
Greer, D. E., 188, 189
Grossenbecker, K., 138, 174
Guerin, F. J. A., 46
Gupta, U. C., 158.174
Gusta, L. V., 156, 172

H

Hall, E. D.,  213
Harding, R. B., 163, 173, 174, 176
Harley, C. P., 152,174
Harlin, C. C.Jr.,  185, 186
Harris, D.J., 193,197
Harris, S. E., 71
Harward, M. E., 155,174
Hassan, M. N., 152,154
Hayward,M. L, 137, 174
Henderson,  J. P.,  189
Henry, A. K., 88
Henry. CO., 137, 174
Herman, E.  R., 147, 174
Herzik, G. R.,Jr., 137,174
Heukelekian, H., 137,174
Hewitt, E.J., 156, 157,174
Hill, D., 71
Hill,R.D., 137,174
Hills, F.J., 172
Hinman, J. J. J., 163,174
Hoeppel,  R. E., 185,  186
Holmes, R. S., 159,172,174
Hooper, Margerat C., 157, 174
Homer, G.M., 177
Hough, G. J., 162, 174
Huguenin, J. E., 188,189
                                                Kabter, P. W., 166, 176
                                                Kardus, L. T., 176
                                                Katko, A., 175
                                                Keaton, C. M., 177
                                                Keffer, William J., 193, 197
                                                Kelley, S. M., 174
                                                Kelley, W. C., 152, 174
                                                Kelley, W. P., 137, 148,175
                                                Keshen, A. S., 171, 175
                                                Kitterle, R. A., 146, 175
                                                Klein, S. A., 178
                                                Klintworth, H., 157, 175
                                                Krantz, B. A., 172
                                                Kraus, E. J., 158,175
                                                KiaybiU, H. R., 158, 175
                                                Eabanauskas, C.K., 157, 175, 176
                                                LangiUe, W. M., 154,175
                                                Larson, G., 174
                                                Las Virgenes Municipal Water District, 187, 190
                                                Lawrence, A. W., 43, 46
                                                Lehman, W. F., 176
                                                Leone, I. A., 156, 175, 176
                                                Leukel, W. A., 177
                                                Levin, G.V.,  31,46
                                                Lewis, R. F.,  3
                                                Ueber, M., 154,175
                                                Lieberg. G. F., 152, 175
                                                Lindner, R. C, 152,174
                                                Lipman, C. B., 153, 156,163,175,177
                                                Uttle,G. M,,  137,175
                                                Loneragan, J. F., 159,175
                                                Long, S. K., 68, 87
                                                Lund, Z. F., 155, 175
                                                Lunin.J., 160,175
                                                Lunt, O. R., 176
                                                Lynch, K., 148, 175

                                                M

                                                MacKay, D. C., 174
                                                MacKinney, G., 156,175
                                                Magjstad, 0. C., 160,175
                                                MaHoney, J. F., 154,175
                                                Marais, G. v. R., 147, 148,149,175
                                                Marshal], G. R., 47, 68, 72, 75, 76, 81, 85, 88

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                              Author
                                                                                                          239
Martin, D.M., 31,46
Martin, J.L., 31, 37, 46
Martin, J. P., 138,163, 175
Mason, D. D., 174
McCarty, P. L., 45, 46
McCoy, 0. D., 176
McCulloch, R. B., 172
McGarry, M. G., 31,46
McGauhey, P. H., 178
McHargue, J. S., 157, 175
McHarness, D. D., 45, 46
McKee, J. E., 52, 69,154,156, 162, 164,168,175
McKinney, R. E.,5, 14, 15
McLarney,W. O., 189
McLaity, H. R., 154,175
McLean, G. W., 173
McMichael, W. F.,212, 213
McMurtrey, J. E.,Jr.,  174
McNulty, I. B., 157,175
McQueen, Frank, 137, 175
Meenaghan, G. F., 147, 175
Meron, A., 155, 165,175
MeneU.J. C, 137, 175
Merz, R.C.,137,138,175
Meyer, B. S., 157,175
Michelson, L. P., 178
Middlebrooks, E. Joe, 47,58, 65, 68, 69, 71, 72, 75, 76, 81,
       85,88, 137,144,145, 175
Miller, M. D., 177
Miller, M. P., 174
Miller, W. M., 162, 175
Millikani C. R., 156,176
Mishra, P. C., 153,176
Misra, S.  G., 153, 176
Mitchell, George A., 137, 176
Mitchell, R., 176
Moldenhauer, R. E., 174
Mor, E., 176
Moss, E. G., 174
Moxon, A. L., 152,176
Myers, E. A., 176, 184,186
Mulbargei, M., 45

N

National Technical Advisory Committee on Water Qualit;
       Criteria, 156, 176
Nesbitt, J. B., 176
Nevo, Z.,137,172,176
Newman, D.W., 157, 175
Norman, N. N., 166, 176

0

O'Brien, W.J., 31,46
Oertli.J.J., 153,172,176
Ohki, K., 159, 177
Olgyay, V., 149,176
Olson, E. 0., 173
Olson, 0. E., 176
O'Melia, C, E., 31,45,55,68
Ongerth, H.J.,165,177
Ort,J. E., 31,46
Oswald, W. J., 146, 147, 149, 151, 176
Overman, A. R., 170, 176
Overstreet, R., 152,174
 Parizek, R. R.,137,176
 Parker, C. E., 5,14
 Parker, D. S., 31, 46
Parsons, T. R., 50, 69, 75, 88
Patwardham, S. D., 174
Paul,J. R., 137, 176
Pearson, G. A., 163,172
Peech, M., 173, 178
Peterson, H. B., 158,  160,176, 177
Peynado, A., 173
Pierce, D. M., 89
Piland, J. E., 174
Pincince, Albert B., 52, 69
Pintler, H. E., 175
Pipes, W.O., Jr., 147, 176
Porter, L. K., 152,176
Pound, C.E., 184,185,186
Pratt, P. F., 158,176
Preston, C., 152,177
Prince, A. L., 176
Prokopovich, N. P., 188,190

R

Rafter, George W., 137, 176
Ragotzkie, R. A., 177
Raleigh, G.J., 155,176
Ramati, B., 176
Rebhun, M., 175
Reid, G. W., 172
Resnicky, J.W., 172
Reuther, W., 158, 159, 173, 176
Reynolds, J. H., 69, 71, 174, 175
 Richards, S. J., 163, 175
 Riney.W. A., 137,176
Robins, W. R., 175
 Robinson, F. E., 160, 176
 Rohde, G., 138, 176
 Rosenkranz, W. A.,  1
 Rossiter, R. C.,159, 176
 Roth, J. A., 176
 Rubeck, G. G., 174
 Rudolfs, Willem, 137, 166,176, 177
 Rust, A., 189
 Ryan, W., 173
 Rytler, J. H., 188, 189, 190
 Salisbury, P. J., 178
 Schroeder, H. A., 154,177
 Schwartz, W. A., 177
 Scofield, C. S., 163, 177
 Searight.W. V., 176
 Shell, Gerald L., 69, 175
 Shindala, A., 31, 46
 Simonds, J. O., 149,177
 Sisson, L. L., 176
 Skulte, Bernard, P., 137, 177
 Sless, B., 175
 Smith,?. F., 173, 176,177
 Smith, R., 199, 212, 213
 Snider, H.J., 158,177
 Soloranzo, L., 50, 69, 75, 88
 Somers, G. F., 174
 Sommer, Anna L., 163,153,177
 Specht, A. W., 172,177
 State Water Pollution Board of California, 138, 177
 Stefferud, A.,  149,177
 Stern, G., 5, 6,14
 Steward, F. C., 152,177
 Stewart, B. A., 138,177
 Stewart, J.W., 31,46
 Stokes, W. E., 137, 177
 Strickland, J. D. H., 50,69, 75,78

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240     Author Index
Sullivan, R. H., 184, 186
Supper, W.E., 176
Sutherland, F. H., 172
Taylor, A. W., 138, 177
Taylor, G, S., 166, 174
Tchobanoglous, G,, 173
Tenny, M. W., 31,46
Thakui, P, S., 174
Thomas, R. E., 137, 166,177, 183,185,186
Thorne, D.W.,  152, 158,176, 177
Tiffin, L  O., 172
Tofflemire, T. J., 186
Trask, J. D., 137, 176
Trelease, Helen M., 162, 177
Tielease, S.  F.,162, 177
Trimberger, J.,  188, 190
Truog, E., 162,174, 177
Tucker, T.C., 137, 171, 173
Tylei, R. W,, 176
U
Uhte,W. R., 21
Ulrich, A., 159, 177
U.S. Geological Survey, 46
U.S. Public Health Service, 151, 177
U.S. Salinity Laboratory, 138, 177
Utah State Division of Health, 152, 177
Vandecaveye, S. C., 151, 177
Vanselow, A. P., 153, 162, 173, 175, 177
Vavich, M. G., 173
Vennes.J. W., 14
Veignano, Ornella, 156, 164,174
W
Wachs, A.M., 31,46,55, 68
Wadleigh, C. H., 153, 157,174, 175,177
Waksman, S. A., 138, 175
Wallihan, E. F., 157,177
Walter, CM., 191
Ward, P. C., 165,177
Warrington, Sam L., 137,177
Water Resources Council, 213
Weller, R., 31, 37, 46
Wells, W.N., 137, 177
Welsch, W.  F., 154, 175
Werkhoven, C. H. E., 161, 163,177, 178
Whetstone, R. R., 152, 178
Wilcox, L.V., 137,159,173, 178
Williams, K.T., 152,178
Williams, T. C, 184, 186
Winkelstein, W., Jr., 174
Winneberger, J. H., 137, 178
Winsser, J., 174
Wolfe, H. W., 154, 156, 162, 164, 168,175
Woodbridge, C. G., 154, !75
Worker, G. F., Jr., 176
WPCF, 87
Wright, C. T., 166, 178
Yogt.J.E.,137, 178
York, E.T., Jr., 137, 155,178
Younger ,V. B., 176
Zanoni, L.J., 158,172, 178
Ziebell, C. D.,188, 189

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                                             SUBJECT INDEX
Aerated lagoons, 132
Aeration, 22
Aerobic zone, 11, 20
Algae, 1,6,8,17,18,51,74
      Actinastrum, 18
      Anabaena, 18
      Anabaena sp., 85
      Ankistrodesmus microactinium, 18
      Aphanocapsa sp., 85
      Blue green coccoid, 75
      Carteria, 18
      Cell count, 10
      Chlamydomonas, 18
      Chlamydomonas sp.,  85
      Chlorella, 18
      Chlorogonium, 18
      Closterium, 18
      Euglena, 18
      Euglenoid, 75
      Food supplement, 6
      Green, unicellular, 75
      Growth, 78
      Miciocystis sp., 75
      Navicula, 18
      Naviculasp., 75
      Oscillatoria, 18
      Oscillatoria sp., 75
      Pandorina, 18
      Pediastrum sp., 75
      Pennate, 75
      Phacus, 18
      Phormidium, 18
      Primary, 18
      Removal, 6, 72, 85
      Scenedesmus, 18
      Schoideria sp., 75
Algae removal
      Biological harvesting, 187
Algal removal, 55, 75
Alkalinity, 10, 17, 45
      Bicarbonate, 152
      Carbonate, 152
Alum
      Phosphorus removal,  13
Aluminum, 170
Ammonia nitrogen, 10,17, 34, 37, 38, 39, 40, 45, 75, 80, 81,
      83,85, 126,127,132
      Increase in effluent, 45
Anabaena, 51
Anaerobic zone, 11
Ancillary facilities
      Boat ramps, 25
      Flow measurement, 25
      Housing, 25
      Samplers, 25
Arsenic, 152,170
Arctic Research Laboratory, 5
Arctic Environmental Research Laboratory, 227
Attendees
      Symposium, 231
                                                         B
Bacteria
      Achromobacter, 18
      Coliform, 18
      Flavobacterium, 18
      Primary, 18
      Pseudomonas, 18
      Removal, 58
Bacteriological analysis
      Form, 97
fielding, Michigan,  125,126,127, 129
Beryllium, 170
Best practicable technology, 199
Bioassays
      Algal, 5 8
Biochemical oxygen demand, 10, 15, 34, 36, 37, 52,53,54,
      59,  73, 75, 80, 82,  85, 97, 98,  120, 126, 127, 129,
      132,133,191,193
      Removal, 4,5
      Soluble, 10, 37, 38, 39, 40
      Total, 10, 37, 38, 39, 40
Biological harvesting, 187
      Algae, 187
      Bivalve mollusks, 188
      Fish, 188
      Research needs, 189
      Zooplankton, 188
Biomass removal
      Algal, 79
Blanding, Utah,  178
Blue Springs, Missouri, 9, 191
Boron, 153, 170
Cadmium, 154,170
Calcium, 154
California, Missouri, 39,43
Capital costs, 216, 217, 218, 219, 221, 223,225
      •Design capacity, 216, 217, 218, 219, 221, 223, 225
Cash flow, 204
Cell count.10
      Algae, 10
Charges
      Engineering fee, 27, 28
      User, 28
Chemical oxygen demand, 10, 34, 36, 73, 75,80, 85,193
      Soluble, 10, 37, 38, 39, 40
      Total, 10, 37, 38, 39, 40
Chlamydomonas, 51
Chlorella, 38
Chloride, 155
Chlorination, 2,11.130, 133,134
Chlorine residual, 12
Chlorophyll, 34, 37, 38, 39,40,194
Chromium, 170
Cincinnati, Ohio, 2, 3
Clogging
      Soil, 166
      Soil pores, 137
                                                                                                           241

-------
 242     Subject Index
Cold climate
      Aerated, 227
      Lagoons, 227
Coliform, 1, 2,12,  18, 133, 194
      Fecal, 5, 10,11,12, 98,129,194
      Reductions,  18
      Removal, 97
Configuration, 23
Construction
      Considerations, 26
      Contract requirements, 26
      Drawings,  26
      Equipment lists, 26
      Procedures, 21
Construction cost index
      Sewers, 202
Continuous cash flow, 204, 205
Contract requirements, 26
Copper, 156
Corinne, Utah, 9, 10
Costs, 3, 43, 65, 66, 67, 199, 200, 202
Cost-effectiveness analysis, 199
Cost estimate
      Lagoons, 224, 225
Crop irrigation, 6,13
      Lagoon effluent, 183
Crop usage
      Lagoon effluent irrigation, 171
Crops
      Effects of  lagoon effluent, 137
D
Daphnia, 37,51
Denitrification, 201
Design
      Ancillary facilities, 25
      Configuration, 23
      Criteria, 19
      Dike construction, 25
      Features, 89
      Housing, 25
      Infiltration-percolation systems, 185
      Inlet, 24
      Intermittent sand filters, 47, 74
      Irrigation, 184
      Lagoon, 89,145
      Liners, 73
      Media, 49
      Operation, 27
      Outlet, 24
      Overland-flow, 185
      Parameters, 90
      Population projections, 29
      Recirculation, 23
      Rock filter, 32, 33, 44
      Scum control, 24
Design capacity, 216, 217, 218, 219, 221, 223
      Capital costs, 216, 217, 218, 219, 221, 223
Detention time, 36
Diatoms, 51
Dike construction, 25
Discharge
      Control, 91
      Controlled, 134
      Patterns, 92
      Report, 99
Disinfection, 1,2, 11, 14
      Chlorination, 130
      Lagoon,12
Dissolved oxygen, 75, 85,126,127
Drawdown, 19
Drinking water
      Livestock, 181
Economics
      Lagoon construction, 21
Effective size, 86
Effluent
      Algal laden, 1, 6
      BOD, 4
      Crop irrigation, 183
      Disinfection, 1,2
      Lagoon, 1, 6, 13, 169
      Land application, 1,13
      Suspended solids, 4
Effluent quality, 77, 97, 125, 132, 177, 178, 179, 180,192
      Seasonal trends, 114
      Variation with time, 80
Endogenous respiration, 16, 17
Environmental Protection Agency, 1, 2, 3, 6, 8, 9, 13, 15, 36,
      87,191, 207, 227, 229, 234
Eudora, Kansas, 7, 9, 31, 32
Euglena, 51
Eutrophication, 6
Evaporation,  19, 20
Fargo, North Dakota, 132
Filters
       Gravel-activated carbon, 229
       Intermittent, 1, 6, 11, 13, 47, 49, 60, 61, 62, 71, 72,
             82, 85, 86
       Rock, 1, 6, 13, 31, 32, 33, 35, 37, 40, 44
Flow rates, 8
Fluorescence, 56
Fluorine, 156, 170
Future worth, 204
Gravel-activated carbon filter, 229
Genoa, Ohio, 12,13

H

Harvesting
      Algae, 187
      Biological, 187
      Bivalve mollusks, 188
      Fish,  188
      Research needs, 189
      Zooplankton, 187
Hydraulic loading rate, 36,48,50.52,54,55, 56, 57, 61, 72,
      73,79,81,82,83,84,85,92
Hydrogen sulfide, 43

I

Illinois, 130
Infiltration-percolation, 184,185
Inlets, 24
Inspection, 27
Interest charges, 208
Intermittent sand filters, 1, 6,11, 47, 71, 72, 74
      Bacterial removal, 57
      Cleaning, 73, 75
      Cost, 65, 66, 67
      Design, 47
      Evaluation, 65
      History, 47, 71

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                                                                                         Subject Index     243
      Hydraulic loading, 48
      Laboratory, 47,72
      Performance, 82, 85
      Period of operation, 60, 61, 62, 63, 75
      Pilot, 47, 72
      Plugging, 59
      Series, 86
      Solids removal, 56,57
      Underdrain, 48
Intermittent sand filtration, 13
Iron, 157,170
Irrigation, 151, 185
      Case history, 171
      Crop usage, 171
      Effluent use, 130
      Lagoon effluent, 137
      Land required, 170, 171
      Public health aspects, 165
      State standards, 165

K

Kilmichael, Mississippi, 9, 10
 Lagoons
      Aerated, 1, 13, 14, 15, 18, 22, 132, 223, 227
      Area, 22
      Cold climate, 227
      Configuration, 23
      Continuous discharge, 8
      Design, 2, 3, 7, 8, 15, 16, 19, 21, 22, 71, 89,145
      Design parameters, 90
      Dike construction, 25
      Disinfection, 11,14
      Drawdown, 19, 89
      Economics, 145,146,191,220,221,222,223,224,225
      Facultative, 3, 4, 7, 8, 10, 12, 14, 22
      Flow rates, 1,8
      Inlets, 24
      Level of treatment, 1, 22
      Maintenance, 1, 3, 21, 27
      Microbiology, 18
      Minimum sampling, 235
      Monitoring requirements, 233, 235
      Multi-cells, 7, 8,10, 22,120,129,134
      Nitrification, 13, 14
      Non-discharge, 1
      Number in use, 3,71
      Operation, 21,22,90
      Operational problems, 6
       Outlets, 24
       Oxidation, 1,15,18
       Parallel, 8, 22
       Performance, 3,4,5,8, 11, 22,89,100, 169,192,194,
              195
       Recirculation, 23
       Series, 8, 22
       Short circuiting, 3
       Size, 1, 3, 8,16,19
       Soil mantle disposal, 137
       Supplemental treatment, 1
       Surface area, 90
       Suspended solids removal, 4,5,10
       Tertiary, 22,49,131,134
       Upgrading, 1, 31, 72, 236
       Wastewater treatment, 15, 71
       Weed control, 6
  Land application, 1, 6,183, 185, 186
  Land disposal, 13
  Land use
        Planning, 147
      Site selection, 147
Lead, 157, 170
Light
      Effect on operation,??
Liners, 73
Lithium, 170
Livestock
      Drinking water quality, 181
Loading
      Hydraulic, 36, 48, 50, 52, 54, 55, 56, 57, 61, 72, 73,
            79,81,82,83,84,85,92
      Organic, 3, 16, 92
Loading rates, 22
      Organic, 8
Logan, Utah, 7, 11,49,73

M

MPN, 12, 123
Magnesium, 157
Manganese, 157, 170
Maps
      USA, 9
Michigan, 100,124
Microbiology, 18
Molybdenum, 170
Monitoring
      Requirements, 233
Municipal bonds, 207
Municipal wastewater treatment
      Needs, 210, 211

N

Nickel, 170
Nitrate nitrogen, 10, 12, 75, 80, 81, 84, 85,126, 127,194
Nitrification, 11, 13, 14, 81, 126, 134
Nitrite nitrogen, 10, 75, 80, 81, 84, 85
Nitrogen, 51,158
      Ammonia,  10, 12, 17, 34, 37, 38, 39,40,52,53,75,
            80, 83, 85, 126,127,128,132
      Nitrate, 10,12, 52, 53, 75, 80, 84, 85,126, 127,194
      Nitrite, 10,12, 75,80, 84, 85
North Dakota, 124
 O&M manuals, 27
 Odors, 3, 6
 Operation, 27
       Discharge, 92
       Intermittent sand filters, 75,76, 77
       Lagoon, 90
       Period of, 60, 61, 62, 63, 72, 77
       Records, 91,93
 Operator training,  28
 Organic loading, 16
 Outlets, 24
 Overland-flow, 185
       Design, 185
 Oxygen, 17,18
 pH, 5,18, 37, 38,49. 75, 85,126,132, 194
 Performance, 3,4,5,8,192
       Evaluation, 8,10, 28
       Intermittent sand filter, 82,85
       Lagoons, 89, 97,100,123,125,127,169
       Multi-cell lagoons, 120
       Seasonal, 127,128,133
       Seasonal trends, 114
       Soil mantle systems, 137

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 244      Subject Index
 Peterborough, New Hampshire, 9, 11
 Phosphorus, 34, 37, 38, 39, 40, 158
       Alum, 13
       Orthophosphate, 75, 81, 126
       Removal, 13
       Sludge, 13
       Total, 75, 81, 126, 129,132
 Photosynthesis, 23
 Phytoplankton, 195
 Planning
       Examples, 149,150
       Lack of, 5
       Techniques, 149,150
 Population projections, 29
 Potassium, 159
 Present value, 204
 Protozoa
       Colpidium, 18
       Euplotes, 18
       Glaucoma, 18
       Paramecium, 18
       Vorticella, 18

 R

 Recirculation, 23
 Reed City, Michigan, 133
 Regions
       Great Lakes Basin, 4
       Middle Atlantic, 4
       Missouri Basin, 4
       Northeast, 4
       Northwest, 4
       Ohio Basin, 4
       South Central, 4
       Southeast, 4
       Southwest, 4
 Reports
       Operating, 93
 Research and development, 2
 Retention period, 19
 Rock filter, 13
       Ammonia nitrogen increase, 45
      Costs, 43
      Design, 44
      Gradation, 43
      Hydrogen sulfide production, 43
      Solids buildup, 40
Roosevelt, Utah, 178
Rotating biological contractor, 12
Rotifers, 18
 Silver, 162
 Sludge
       Buildup, 13
 Sludge handling, 214
 Sodium, 162
 Soil
       Analysis, 143
       Bridging, 138
       Clogging, 166
       Permeability, 138
       Sedimentation, 138
       Straining, 138
 Soil mantle treatment, 137, 183
 Solids buildup, 40
 South Dakota, 236
 St. Charles, Maryland, 13
 Storage
       Long range, 134
 Storm water, 201
 Sulfate, 163, 164
 Surveillance,  3
 Suspended solids, 10
      Removal, 4, 5, .187
      Total, 12, 34, 36,37, 38, 39,40, 48, 50, 55, 56, 57, 75,
             76, 77, 78, 80, 85, 97,120, 126,129,132,133,
             137
      Volatile, 12, 34, 36, 37, 38, 39, 40, 50, 55, 56, 57, 75,
             76,78,80,82,85,120
 Symposium
      Membership, 231
 Synthesis, 16,17
Technology transfer
      EPA, 6
Temperature, 19, 36, 195
Tertiary lagoons, 131
Toxicity
      Plants, 168

U

University of Kansas, 17
Upgrading, 31, 32, 37
      Algae removal, 6
      Wastewater ponds, 1, 2, 5
Utah
      Water quality standards, 144, 145
Utah State University, 2, 11, 48, 72, 86, 141
Salinity, 160.161
Sampling, 8, 7 3
      Minimum frequency, 235
Sand
      Effective size, 49,50, 72, 86
Scum control, 24
Seasonal variation
      Performance, 127
Secondary treatment
      Standards, 1,5,8
Selenium, 162,  170
Settleable solids, 20
Sewers
      Pressure, 2
      Vacuum, 2
Short circuiting, 3
Sieve analysis, 7 3
Silica, 162
Vanodium, 170
Volatile suspended solids, 10

W

Wastewater treatment, 15
      Biological concepts, 16
Water pollution, 6
Water pollution control
      Cost-effectiveness, 199
Water quality
      Factors, 167
Weeds
      Control, 6
Zinc, 163, 170
Zooplankton, 75, 187
      Algae harvesting, 187

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