EPA 815-Z-00-01
                                     Monday,

                                     April 10, 2000
                                     Part H



                                     Environmental

                                     Protection  Agency

                                     40 CFR Parts 141 and 142
                                     National Primary Drinking Water
                                     Regulations: Long Term 1 Enhanced
                                     Surface Water Treatment and Filter
                                     Backwash Rule; Proposed Rule
EPA
815-
7 —
00-01

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 19046
Federal  Register/Vol. 65, No.  69/Monday, April  10,  2000/Proposed Rules
ENVIRONMENTAL PROTECTION
AGENCY

40 CFR Parts 141 and 142
[WH-FRL-6570-5]
RIN 2040-A018

National Primary Drinking Water
Regulations: Long Term 1 Enhanced
Surface Water Treatment and Filter
Backwash Rule
AGENCY: Environmental Protection
Agency (EPA).
ACTION: Proposed rule.

SUMMARY: In this document, EPA is
proposing the Long Term 1 Enhanced
Surface Water Treatment and Filter
Backwash Rule (LTlFBR). The purposes
of the LTlFBR are to: Improve control
of microbial pathogens in drinking
water, including Cryptosporidium. for
public water systems (PWSs) serving
fewer than 10,000 people; prevent
increases in microbial risk while PWSs
serving fewer than 10,000 people
control for disinfection byproducts, and;
require certain PWSs to institute
changes to the return of recycle flows
within the treatment process to reduce
the effects of recycle on compromising
microbial control. Today's proposal
addresses two statutory requirements of
the 1996 Safe Drinking Water Act
(SDWA) Amendments. First, it
addresses the statutory requirement to
establish a Long Term Final Enhanced
Surface Water Treatment Rule
(LTESWTR) for PWSs that serve under
10,000 people. Second, it addresses the
statutory requirement to  promulgate a
regulation which "governs" the recycle
of filter backwash within the treatment
process of public utilities.
  Today's proposed LTlFBR contains 5
key provisions for surface water  and
ground water under the direct influence
of surface water (GWUDI) systems
serving fewer than 10,000 people: A
treatment technique requiring a 2-log
(99  percent) Cryptosporidium removal
requirement; strengthened combined
filter effluent turbidity performance
standards and new individual filter
turbidity provisions; disinfection
benchmark provisions to assure
continued microbial protection is
provided while facilities take the
necessary steps to comply with new
                     disinfection byproduct standards;
                     inclusion of Crvptosporictiuin in the
                     definition of GWL'DI and in the
                     watershed control requirements for
                     unfiltered public water systems; and
                     requirements lor covers on new finished
                     water reservoirs.
                      Today's proposed LTlFBR contains
                     thrue key provisions for all conventional
                     and direct filtration systems which
                     recycle and use surface water or
                     GWUDI:  A provision requiring recycle
                     flows to be introduced prior to the point
                     of primary coagulant addition: a
                     requirement for systems meeting criteria
                     to perform a one-time self assessment of
                     their recycle practice and consult with
                     their primacy agency to address and
                     correct high risk recycle operations; and
                     a requirement for direct filtration
                     systems to provide information to the
                     State on their current recycle practice.
                      The Agency believes implementing
                     the provisions contained in today's
                     proposal will improve public health
                     protection in two fundamental ways.
                     First, the provisions will reduce the
                     level of Cn-ptosporidium in filtered
                     finished drinking water supplies
                     through improvements in filtration and
                     recycle practice resulting in a reduced
                     likelihood of outbreaks of
                     cryptosporidiosis. Second, the filtration
                     provisions aro expected to increase the
                     level of protection from exposure to
                     other pathogens [i.e. Giardia or other
                     waterborne bacterial or viral pathogens).
                     It is also important to note that while
                     today's proposed rule contains new
                     provisions which in some cases
                     strengthen or modify requirements of
                     the 1989  Surface Water Treatment Rule,
                     each public water system must continue
                     to comply with the current rules while
                     new microbial and  disinfectants/
                     disinfection byproducts rules are being
                     developed. In conjunction with the
                     Maximum Contaminant Level Goal
                     (MCLG) established in the Interim
                    Enhanced Surface Water Treatment
                    Rule, the Agency developed a treatment
                    technique in lieu of a Maximum
                    Contaminant Level  (MCL) for
                    Cryptosporidium because it is not
                    economically and technologically
                    feasible to accurately ascertain the level
                    of Cryptosporidium using current
                    analytical methods.
                    DATES: The Agency requests comments
                    on today's proposal. Comments must be
 received or post-marked by midnight
 June 9, 2000. Comments received after
 this date may not be considered in
 decision making on the proposed rule,
 ADDRESSES: Send written comments on
 today's proposed rule to the LTlFBR
 Comment Clerk: Water Docket MC 410,
 W-99-10, Environmental Protection
 Agency 401 M Street. S.W., Washington,
 DC 20460. Please submit an original and
 three copies of comments and
 enclosures (including references).
  Those who comment and want EPA to
 acknowledge receipt of their comments
 must enclose a self-addressed stamped
 envelope. No facsimiles (faxes) will be
 accepted. Comments may also be
 submitted electronically to ow-
 docket@epamail.epa.gov. For additional
 information on submitting electronic
 comments see Supplementary
 Information Section.
  Public comments on today's proposal,
 other major supporting documents, and
 a copy of the  index to the public docket
 for this rulemaking are available for
 review at EPA's Office of Water Docket:
 401 M Street, SW.. Rm. EB57,
 Washington, DC 20460 from 9:00 a.m. to
 4:00 p.m.. Eastern Time. Monday
 through Friday, excluding legal
 holidays. For access to docket materials
 or to schedule an appointment please
 call (202) 260-3027.
 FOR FURTHER INFORMATION CONTACT:
 Technical inquiries on the rule should
 be directed to Jeffery Robichaud at 401
 M Street, SW., MC4607, Washington,
 DC 20460 or (202) 260-2568. For
 general information contact the Safe
 Drinking Water Hotline, Telephone
 (800) 426-4791. The Safe Drinking
 Water Hotline is  open Monday through
 Friday, excluding federal holidays, from
9:00 a.m. to 5:30 p.m. Eastern Time.
SUPPLEMENTARY INFORMATION: Entities
potentially regulated by the LTlFBR are
public water systems (PWSs) that use
surface water or ground water under the
direct influence of surface water
(GWUDI). The recycle control
provisions are applicable to all PWSs
using surface  water or GWUDI,
regardless of the population served. All
other provisions of the LTlFBR are only
applicable to PVVSs serving under
10,000 people. Regulated categories and
entities include:
        Category
                                       Examples of regulated entities
Industry	  Public Water Systems that use surface water or ground water under the direct influence of surface water.
State. Local, Tribal or Fed-    Public Water Systems that use surface water or ground water under the direct influence of surface water.
  eral Governments.

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                               Federal  Register/Vol. 65. No.  69/Monday, April 10, 2000/Proposed Rules
                                                                                                           19047
I
   This table is not intended to be
 exhaustive, but rather provides a guide
 for readers regarding entities likely to be
 regulated by the LTlFBR. This table
 lists the types of entities that EPA is
 now aware could potentially be
 regulated by this rule. Other types of
 entities not listed in this table could
 also be regulated. To determine whether
 your facility is regulated by this action,
 you should carefully examine the
 definition of public water system in
 § 141.3 of the Code of Federal
 Regulations and applicability criteria in
 §§141.76 and 141.501 of today's
 proposal. If you have questions
 regarding the applicability of the
 LTlFBR to a particular entity, consult
 the person listed in the preceding
 section entitled FOR FURTHER
 INFORMATION CONTACT.
 Submitting Comments
   Send an original and three copies of
 your comments and enclosures
 (including references) to VV-99-10
 Comment Clerk, Water Docket
 (MC4101), USEPA, 401 M Street, SW.,
 Washington, D.C. 20460. Comments
 must be received or post-marked by
 midnight June 9, 2000. Note that the
 Agency is not soliciting comment on,
 nor will it respond to, comments on
 previously published regulatory
 language that is included in this
 document to ease the reader's
 understanding of the proposed
 language.
  To ensure that EPA can read,
 understand and therefore properly
 respond to comments, the Agency
 would prefer that commenters cite.
 where possible, the paragraph(s) or
 sections in the proposed rule or
 supporting documents to which each
 comment refers. Commenters should
 use a separate paragraph for each issue
 discussed.

 Electronic Comments
  Comments may also be submitted
 electronically to ow-
 docket@epamail.epa.gov. Electronic
 comments must be submitted as an
 ASCII, WP5.1, WP6.1 or WP8 file
 avoiding the use of special characters
 and form of encryption. Electronic
 comments must be identified by the
 docket number W-99-10. Comments
 and data will also be accepted on disks
 in WP 5.1. 6.1, 8 or ASCII file format.
 Electronic comments on this document
 may be filed online at many Federal
 Depository Libraries.
  The record for this rulemaking has
been established under docket number
W-99-10, and includes supporting
 documentation as well as printed, paper
 versions of electronic comments. The
 record is available for inspection from 9
 a.m. to 4 p.m., Monday through Friday,
 excluding legal holidays at the Water
 Docket, KB 57. US EPA'Headquarters,
 401 M Street. SW.. Washington, D.C. For
 access to docket materials, please call
 (202) 260~:i027 to schedule an
 appointment.

 List of Abbreviations Used in This
 Document
 ASCE  American Society of Civil
    Engineers
 ASDWA  Association of State Drinking
    Water Administrators
 ASTM  American Society for Testing
    Materials
 AWWA  American Water Works
    Association
 AWWARF   American Water Works
    Association Research Foundation
 °C  Degrees Centigrade
 CCP  Composite Correction Program
 CDC  Centers for Disease Control
 CFE  Combined Filter Effluent
 CFR  Code of Federal Regulations
 CO1  Cost of Illness
 CPE  Comprehensive Performance
    Evaluation
 CT  The Residual Concentration of
    Disinfectant (mg/L) Multiplied by
    the Contact Time (in minutes)
 CTA  Comprehensive Technical
    Assistance
 CWSS  Community Water System
    Survey
 DBPs  Disinfection Byproducts
 DBPR  Disinfectants/Disinfection
    Byproducts Rule
 ESWTR  Enhanced Surface Water
    Treatment Rule
 FACA  Federal Advisory Committee
    Act
 GAC  Granular Activated Carbon
 GAO  Government Accounting Office
 GWUDI  Ground Water Under the
    Direct Influence of Surface Water
 HAA5  Haloacetic acids
    (Monochloroacetic, Dichloroacetic,
    Trichloroacetic, Monobromoacetic
    and Dibromoacetic Acids)
 HPC  Heterotropic Plate Count
 hrs  Hours
 ICR   Information Collection Rule
 IESWTR Interim Enhanced Surface
    Water Treatment Rule
 1FA   Immunofluorescence Assay
 Log Inactivation  Logarithm of (N0/NT)
 Log   Logarithm (common, base 10)
 LTESWTR   Long Term Enhanced
    Surface Water Treatment Rule
 LT1FBR  Long Term 1 Enhanced
    Surface Water Treatment and Filter
    Backwash Rule
 MCL  Maximum Contaminant Level
MCLG  Maximum Contaminant Level
    Goal
MGD  Million Gallons per Day
 M-DBP  Microbial and Disinfectants/
    Disinfection Byproducts
MPA  Microscopic Particulate Analysis
NODA  Notice of Data Availability
NPDWR  National Primary Drinking
    Water Regulation
NT  The Concentration of Surviving
    Microorganisms at Time T
NTTAA  National Technology Transfer
    and Advancement Act
NTU  Nephelometric Turbidity Unit
PE  Performance Evaluation
PWS  Public Water System
Reg. Neg.   Regulatory Negotiation
RIA  Regulatory Impact Analysis
RFA  Regulatory Flexibility Act
RSD  Relative Standard Deviation
SAB  Science Advisory Board
SDWA  Safe Drinking Water Act
SWTR  Surface Water Treatment Rule
TC  Total Coliforms
TCR  Total Coliform Rule
TTHM  Total Trihalomethanes
TWG  Technical Work Group
TWS  Transient Non-Community Water
    System
UMRA  Unfunded Mandates Reform
    Act
URCIS  Unregulated Contaminant
    Information System
x log removal  Reduction to 1/10* of
    original concentration

Table of Contents
1. Introduction and Background
A. Statutory Requirements and Legal
    Authority
B, Existing Regulations and Stakeholder
    Involvement
  1. 1979 Total Trihalomethane Rule
  2. Total Coliform Rule
  3. Surface Water Treatment Rule
  4. Information Collection Rule
  5. Interim Enhanced Surface Water
    Treatment Rule
  6. Stage 1 Disinfectants and Disinfection
    Byproduct Rule
  7. Stakeholder Involvement
II. Public Health Risk
A. Introduction
B. Health Effects of Cryptosporidiosis and
    Sourr.es and Transmission of
    Cryptosporidium
C. Waterborne Disease Outbreaks In the
    United States
D. Source Water Occurrence Studies
E. Filter Backwash and Olher Process
    Streams: Occurrence and Impact Studies
F. Summary and Conclusions
111. Baseline Information-Systems Potentially
Affected By Today's Proposed Rule

IV. Discussion of Proposed LTlFBR
Requirements
A. Enhanced Filtration Requirements
  1. Two Log Cryptosporidium Removal
    Requirement
  a. Two Log Removal
  i. Overview and Purpose
  ii. Data
  iii. Proposed Requirements
  iv. Request for Comments
  2. Turbidity Requirements
  a. Combined Filter Effluent

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Federal Register/Vol.  65, No. 69/Monday, April 10, 2000/Proposed Rules
  i. Overview and Purpose
  ii. Data
  iii. Proposed Requirements
  iv. Request for Comments
  b. Individual Filter Turbidity
  i. Overview and Purpose
  ii. Data
  iii. Proposed Requirements
  iv. Request for Comments
B Disinfection Benchmarking Requirements
  1. Applicability Monitoring
  a. Overview and Purpose
  b. Data
  c. 1'ruposed Requirements
  d. Request for Comment
  2, Disinfection  Profiling
  a. Overview and Purpose
  b. Data
  c. Proposed Requirements
  d. Request for Comments
  3. Disinfection  Benchmarking
  a. Overview and Purpose
  b. Data
  c. Proposed Requirements
  d. Request for Comments
C. Additional Requirements
1. Inclusion of Cryptosporidiuin In Definition
    ofGWUDI
  a. Overview and Purpose
  b. Data
  C. Proposed Requirements
  d. Request for Comments
2. Inclusion of (.iryptosporidnim Watershed
    Requirements for Unfiltered Systems
  a. Overview and Purpose
  b. Data
  c. Proposed Requirements
  d. Request for Comments
3. Requirements for Covering New Reservoirs
  a. Overview and Purpose
  b. Data
  c. Proposed  Requirements
  d. Request for Comments
  D. Recycle Provisions for Public Water
    Systems Employing Rapid Granular
    Filtration  Using Surface Water and
    GWLiDl as a Source
  1. Treatment Processes that Commonly
    Kecydo and Recycle Flow Occurrence
    Data
  a. Treatment Processes that Commonly
    Recycle
  i. Conventional Treatment Plants
  ii. Direct Filtration Plants
  iii. Softening Plants
  iv. Contact Clarification Plants
  v. Package Plants
  vi. Summary of Recycle Disposal Options
  b. Recycle Flow Occurrence Data
  i. Untreated Spent Filter Backwash Water
  ii. Gravity Settled Spent Filter Backwash
    Water
  iii. Combined Gravity Thickener
    Supernatant
  iv. Gravity Thickener Supernatant from
    Sedimentation Solids
  v. Mechanical Dewatering Device Liquids
  2. National Recycle Practices
  a. Information Collection Rule
  i.  Recycle Practice
  b. Recycle FAX  Survey
  i.  Recycle practice
  ii. Options to recycle
  iii. Conclusions
  3. Recycle Provisions  for PWSs Employing
   Rapid Granular Filtration Using Surface
                           Water or Ground Water Under the Direct
                           Influence of Surface Water Influence of
                           Surface Water
                         a. Return Select Recycle Streams Prior to
                           the Point of Primary Coagulant Addition
                         i. Overview and Purpose
                         ii. Data
                         iii. Proposed Requirements
                         iv. Request for Comments
                         b. Recycle Requirements for Systems
                           Practicing Direct Recycle and Meeting
                           Specific Criteria
                         i. Overview and Purpose
                         ii. Data
                         iii. Proposed Requirements
                         iv. Request for Comments
                         c. Requirements for Direct Filtration Plants
                           that Recvcle Using Surface Water or
                           GWUDf
                         i. Overview and Purpose
                         ii. Data
                       iii. Proposed Requirements
                       iv. Request for Comments
                       d. Request for Additional Comment
                       V. Slate Implementation and Compliance
                       Schedules
                       A. Special State Primacy Requirements
                       B. Stale Recordkeeping Requirements
                       C. Stale Reporting Requirements
                       U. Interim Primacy
                       E. Compliance Deadlines
                       VI. Economic Analysis
                       A. Overview
                       B. Quantifiable and Non-Quantifiable Costs
                         1. Total Annual Costs
                         2. Annual Costs of Rule Provisions
                        3. Non Quantifiable Costs
                       C. Quantifiable and Non-Quantifiable Health
                           Benefits
                         1. Quantified  Health Benefits
                        2. Non-Quantified Health and Non-Health
                           Related Benefits
                        a. Recycle Provisions
                        b. Issues Associated with Unqualified
                           Benefits
                       D. Incremental Costs and Benefits
                       E. Impacts on Households
                       F. Benefits From the Reduction of Co-
                          Occurring Contaminants
                       G. Risk Increases From Other Contaminants
                       H. Other Factors: Uncertainty in Risk.
                          Benefits, and Cost Estimates
                       I. Benefit Cost Determination
                       J. Request for Comment
                       VII. Other Requirements
                       A. Regulatory Flexibility Act
                        1. Today's Proposed Rule
                        2. Use of Alternative Definition
                        3. Background and Analysis
                        a. Number of Small Entities Affected
                        b. Recordkeeping and Reporting
                        c. Interaction with Other Federal Rules
                        d. Significant Alternatives
                        i. Turbidity Provisions
                        ii. Disinfection Benchmarking
                          Applicability Monitoring Provisions
                        iii. Recycling Provisions
                        e. Other Comments
                       B. Paperwork Reduction Act
                       C. Unfunded Mandates Reform Act
                        1. Summary of UMRA requirements
                        2. Written Statement for Rules With
                          Federal Mandates of $100 Million or
                          More
  a. Authorizing Legislation
  b. Cost Benefit Analysis
  c. Estimates of Future Compliance Costs
    and Disproportionate Budgetary Effects
  d. Macro-economic Effects
  e. Summary of KPA's Consultation with
    Stale, Local, and Tribal Governments
    and Their Concerns
  f. Regulalory Alternatives Considered
  g. Selection of the Least Costly, Most-Cost
    Effective or Least Burdensome
    Alternative That Achieves the Objectives
    of the Rule
  3. Impacts on Small Governments
D. National Technology Transfer and
    Advancement Act
E. Executive Order 12866: Regulatory
    Planning and Review
F. Executive Order 12B98: Environmental
    Justice
G. Executive Order 13045: Protection of
    Children from Environmental Health
    Risks and Safety Risks
H. Consultations with the Science Advisory
    Board, National Drinking Water
    Advisory Council, and the Secretary of
    Health and Human Services
I. Executive Order KS13L': Executive Orders
    on Federalism
J. Executive Order 13084: Consultation and
    Coordination With Indian Tribal
    Governments
K. Likely Effect of Compliance wilh Ihe
    LTlFBRon the Technical, Financial, and
    Managerial Capacity of Public Water
    Systems
L. Plain Language
VIII. Public Comment Procedures
A. Deadlines for Comment
B. Where to Send Comment
C. Guidelines for Commenting
[X.  References

I. Introduction and Background

A. Statutory Requirements and /,«#«/
Authority
  The Safe Drinking Water Act (SDWA
or the Act), as amended in 1986,
requires U.S. Environmental Protection
Agency (EPA) to publish a maximum
contaminant level  goal (MCLC) for each
contaminant which, in the judgement of
the EPA Administrator, "may have any
adverse effect on the health of persons
and which is known or anticipated to
occur in public water systems' (Section
1412(b)(3)(A)). MCLGs are to be set at a
level  at which  "no known or anticipated
adverse effect on the health of persons
occur and which allows an adequate
margin of safety" (Section 1412(b){4}).
  The Act was again amended in
August 1996. resulting in the
renumbering and augmentation of
certain sections with additional
statutory language. New sections were
added establishing new drinking water
requirements. These modifications are
outlined below.
  The Act requires EPA to publish a
National Primary Drinking Water
Regulation (NPDWR) that specifies

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                                                                    19049
either a maximum contaminant level
(MCL) or treatment technique (Sections
1401(1} and 1412(a)(3}) at the same time
it publishes an MCLG, which is a non-
enforceable health goal. EPA is
authorized to promulgate a NPDWR
"that requires the use of a treatment
technique in lieu of establishing an
MCL," if the Agency finds that "it is not
economically or technologically feasible
to ascertain the level of the
contaminant." EPA's general authority
to set MCLGs and NPDWRs applies to
contaminants that may "have an adverse
effect on the health of persons." that are
"known to occur or there is a substantial
likelihood that the contaminant will
occur in public water systems with a
frequency and at levels of public health
concern," and for which "in the sole
judgement of the Administrator,
regulation of such contaminant presents
a meaningful  opportunity for health risk
reduction for persons served by public
water systems" (SDVVA Section
      '
  The 1996 amendments, also require
EPA, when proposing a NPDWR that
includes an MCL or treatment
technique, to publish and seek public
comment on an analysis of health risk
reduction and cost impacts. EPA is
required to take into consideration the
effects of contaminants upon  sensitive
subpopulations (i.e., infants, children,
pregnant women, the elderly, and
individuals with a history of serious
illness), and other relevant factors
(Section 141 2(b)(3)(C)).
  The amendments established a
number of regulatory deadlines,
including schedules for a Stage 1
Disinfection Byproduct Rule (DBPR), an
Interim  Enhanced Surface Water
Treatment Rule (IESWTR), a Long Term
Final Enhanced Surface Water
Treatment Rule (LTESWTR), and a Stage
2 DBPR (Section 1412(b)(2)(C)). To
provide additional time for systems
serving  fewer than 10,000 people to
comply with the IESWTR provisions
and also ensure these systems
implement Stage 1 DBPR and the
IESWTR provisions simultaneously, the
Agency split the IESWTR into two rules:
the IESWR and the LTlESWTR. The Act
as amended also requires EPA to
promulgate regulations to "govern" the
recycle of filter backwash within the
treatment process of public utilities
(Section 1412(b)(l4)).
  Under 1412(b)(4)(E)(ii), EPA must
develop a Small System Technology List
for the LTlFBR. The filtration
technologies listed in the Small System
Compliance Technology  List for the
Surface Water Treatment Rule and Total
Coliform Rule (EPA-815-R-98-001 .
September 1998) are also the
technologies which would achieve
compliance with the provisions of the
LTlFBR. EPA will develop a separate
list for the LTlFBR as new technologies
become available.
  Although the Act permits small
system variances for compliance with a
requirement of a national primary
drinking water regulation which
specifies a maximum contaminant level
or treatment technique, Section
1415(eK6}(B) of SDWA, excludes
variances for any national primary
drinking water regulation for a
microbial contaminant or an indicator
or treatment technique for a microbial
contaminant. LTlFBR requires
treatment techniques to control
Cryptosporidium (a microbial
contaminant), and as such systems
governed by the LTlFBR are ineligible
for variances.
  Finally, as part of the 1996 SDWA
Amendments, recordkeeping
requirements were modified to apply to
every person who is subject to a
requirement of this title or who is a
grantee (Section 1445(a)(l)(A)). Such
persons are required to establish and
maintain such records, make such
reports, conduct such monitoring, and
provide such information as the
Administrator may reasonably require
by regulation.
B. Existing Regulations and Stakeholder
Involvement
1. 1<)79 Total Trihalomethane Rule
  In November 1979 (44 FR 68624)
(EPA, 1979) EPA set an interim MCL for
total  trihalornethanes (TTHM—the sum
of chloroform, bromoform,
bromodichloromethane.
dibromochloromethane) of 0.10 mg/1 as
an annuul average. Compliance is
defined on the basis of a running annual
average of quarterly averages for four
samples taken in the distribution
system. The  value for each sample is the
sum of the measured concentrations of
chloroform .bromodichloromethane,
dibromochloromethane and bromoform.
  The interim TTHM standard applies
to community water systems using
surface water and/or ground water
serving at least 10,000 people that add
a disinfectant to the drinking water
during any part of the treatment process.
At their discretion, States may extend
coverage to smaller PWSs; however,
most States have not exercised this
option. The Stage 1 DBPR (as discussed
later)  contains updated TTHM
requirements.

2. Total Coliform Rule
  The Total Coliform Rule (TCR) (54 FR
27544. June 29, 1989) (E:PA, 1989a)
applies to all public water systems. The
TCR sets compliance with the
Maximum Contaminant Level (MCL) for
total coliforms (TC) as follows. For
systems that collect 40 or more samples
per month, no more than 5 percent of
the samples may be TC-positive; for
those that collect fewer than 40 samples,
no more than one sample may be TC-
positive. If a system has a TC-positive
sample, it must test that sample for the
presence of fecal coliforms or E. coli.
The system must also collect a set of
repeat samples, and analyze for TC (and
fecal coliform or E. coli within 24 hours
of the first TC-positive sample).
  In addition, any fecal coliforrn-
positive repeat sample, E-coli.-posHive
repeat sample, or any total-coliform-
positive repeat sample following a fecal
coliform-positive or E-co/i-positive
routine sample constitutes an acute
violation of the MCL for total coliforms.
If a system exceeds the MCL, it must
notify the public using mandatory
language developed by the EPA. The
required monitoring frequency for a
system depends on the number of
people served and ranges from 480
samples per month for the largest
systems to once annually for the
smallest systems. All systems must have
a written plan identifying where
samples are to be collected.
  The TCR also requires an on-site
inspection (referred to as a sanitary
survey) every 5 years for each system
that collects fewer than five samples per
month. This requirement is extended to
every 10 years for non-community
systems using only protected and
disinfected ground water.
3. Surface Water Treatment Rule
  Under the Surface Water Treatment
Rule (SWTR) (54 FR 27486, June 29.
1989) (EPA, 1989b), EPA set maximum
contaminant level goals of zero for
Giardia lamblia, viruses, and Legionella
and promulgated regulatory
requirements for all PWSs using surface
water sources or ground water  sources
under the direct influence of surface
water. The SWTR includes treatment
technique requirements for filtered and
unfiltered systems that are intended to
protect against the adverse health effects
of exposure to Giardia lamblia, viruses,
and Legionella, as well as many other
pathogenic organisms. Briefly, those
requirements include (1) Requirements
for maintenance of a disinfectant
residual in the distribution system; (2)
removal and/or inactivation of 3 log
(99.9 percent) for Giardia and 4 log
(99.99 percent) for viruses; (3) combined
filter effluent turbidity performance
standard of 5 nephelometric turbidity
units (NTU) as a maximum and 0.5 NTU

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 at the 95th percentile monthly, based on
 4-hour monitoring for treatment plants
 using conventional treatment or direct
 filtration (with separate standards for
 other filtration technologies); and (4)
 watershed protection and other
 requirements for unfiltered systems.
 Systems seeking to avoid filtration were
 required to meet avoidance criteria and
 obtain avoidance determination by
 December 30. 1991, otherwise filtration
 must have been  provided by June 29,
 1993. For systems properly avoiding
 filtration, later failures to meet
 avoidance criteria triggered a
 requirement that filtration be provided
 within 18 months.
 4. Information Collection Rule
   The Information Collection Rule
 (ICR), which was promulgated on May
 14, 1996 (61 FR  24354) (EPA, 1996)
 applied to large  public water systems
 serving populations of 100,000 or more.
 A more limited set of ICR requirements
 pertain to ground water systems serving
 between 50,000  and 100,000 people.
 About 300 PVVSs operating 500
 treatment plants were involved with the
 extensive ICR data collection. Under the
 ICR, these PWSs monitored for water
 quality factors affecting disinfection
 byproduct (DBP) formation and DBFs
 within the treatment plant and in the
 distribution system on a monthly basis
 for 18 months. In addition. PVVSs were
 required to provide treatment train
 schematics, operating data and source
 water occurrence data for bacteria,
 viruses, and protozoa. Finally, a subset
 of PWSs performed treatment studies,
 using either granular activated carbon
 (GAG) or membrane processes, to
 evaluate DBP precursor removal and
 control  of DBFs. Monitoring for
 treatment study  applicability began in
 September 1996. The remaining
 occurrence monitoring began in July
 1997 and concluded in December 1998.
  The purpose of the ICR was to collect
 occurrence and treatment information to
 help evaluate the need for possible
 changes to the current microbial
 requirements and existing microbial
 treatment  practices, and to help evaluate
 the need for future regulation of
 disinfectants and disinfection
 byproducts (DBFs). The ICR will
 provide EPA with additional
 information on the national occurrence
 in drinking water of (1) chemical
 byproducts that  form when disinfectants
 used for microbial control react with
 naturally occurring compounds already
 present  in source water; and (2) disease-
 causing microorganisms, including
 Cryptosporidium, Giardia, and viruses.
Analysis of ICR data is not expected to
be completed in  the time frame
                     necessary for inclusion in the LTlFBR,
                     however if the data is available and has
                     been quality controlled and peer
                     reviewed during the necessary time
                     frame, EPA will consider the datat as it
                     refines its analysis for the final rule.
                       The ICR also required PWSs to
                     provide engineering data on how they
                     currently control for such contaminants.
                     The ICR monthly sampling data will
                     also provide information on the quality
                     of the recycle waters via monthly
                     monitoring (for 18  months) of pH,
                     alkalinity, turbidity, temperature.
                     calcium and total hardness, TOC, UV2M,
                     bromide, ammonia, and disinfectant
                     residual (if disinfectant is used). This
                     data will provide some indication of the
                     treatability of the water, the extent to
                     which contaminant concentration
                     effects may occur, and the potential for
                     contribution to DBP formation.
                     However, sampling to determine the
                     occurrence of pathogens in recycle
                     waters was not performed.

                     5. Interim Enhanced Surface Water
                     Treatment Rule

                       Public water systems serving 10,000
                     or more people that use surface water or
                     ground water under the direct influence
                     of surface water (GWUDI) are required
                     to comply with the IESWTR (63 FR
                     69477. December 16.  1998) (EPA, 1998a)
                     by December of 2001. The purposes of
                     the IESWTR are to  improve control of
                     microbial pathogens,  specifically the
                     protozoan Cryptosporidium, and
                     address risk trade-offs between
                     pathogens and disinfection byproducts.
                     Key provisions established by the rule
                     include: a Maximum Contaminant Level
                     Goal (MCLC) of zero for
                     Cryptosporidium; 2-log (99 percent)
                     Cryptosporidium removal requirements
                     for systems that filter; strengthened
                     combined filter effluent turbidity
                     performance standards of 1.0 NTU as a
                     maximum and 0.3 NTU at the 95th
                     percentile monthly, based on 4-hour
                     monitoring for treatment plants using
                     conventional treatment or direct
                     filtration; requirements for individual
                     filter turbidity  monitoring; disinfection
                     benchmark provisions to assess the level
                     of microbial protection provided as
                     facilities take the necessary steps to
                     comply with new disinfection
                     byproduct standards;  inclusion of
                     Cryplotsporidium in the definition of
                     GWUDI and in the watershed control
                     requirements for unfiltered public water
                     systems; requirements for covers on new
                     finished water  reservoirs; and sanitary
                    surveys for all surface water systems
                    regardless of size.
 6. Stage 1 Disinfectants and Disinfection
 Byproduct Rule
   The Stage 1 DBPR applies to all PWSs
 that are community water systems
 (CWSs) or nontransient noncommunity
 water systems (K'TKCWs) that treat their
 water with a chemical disinfectant for
 either primary or residual treatment. In
 addition, certain requirements for
 chlorine dioxide apply to transient
 noncommunity water systems
 (TNCWSs). The Stage 1 DBPR (EPA,
 1998c) was published at the same time
 as the IESWTR (63 FR 69477, December
 16, 1998) (EPA, 1998a), Surface water
 and GWUDI systems serving at least
 10,000 persons are required to comply
 with the Stage 1 Disinfectants and
 Disinfection Byproducts Rule by
 December 2001. Ground water systems
 and surface water and GWUDI systems
 serving fewer than 10,000 must comply
 with the Stage 1 Disinfectants and
 Disinfection Byproducts Rule by
 December 2003.
  The Stage 1 DBPR finalizes maximum
 residual disinfectant level goals
 (MRDLGs) for chlorine, chloramines,
 and chlorine dioxide; MCLGs for four
 trihalomethanes (chloroform,
 bromodichloromethane.
 dibromochloromethane, and
 bromoform), two haloacetic acids
 (dichloroacetic acid and trichloroacetic
 acid), bromate. and chlorite; and
 NPDWRs for three disinfectants
 (chlorine, chloramines. and chlorine
 dioxide), two groups of organic
 disinfection byproducts TTHMs and
 HAAS and two inorganic disinfection
 byproducts, chlorite and bromate. The
 NPDWRs consist of maximum residual
 disinfectant levels (MRDLs) or
 maximum contaminant levels (MCLs) or
treatment techniques  for these
disinfectants and their byproducts. The
NPDWRs also include monitoring,
reporting, and public notification
requirements for these compounds. The
Stage 1 DBPR includes the best available
technologies (BATs) upon which the
MRDLs and MCLs are based. EPA
believes the implementation of the Stage
1 DBPR will reduce the levels of
disinfectants and disinfection
byproducts in drinking water supplies.
The Agency believes the rule will
provide public health protection for an
additional 20 million  households that
were not previously covered by drinking
water rules for disinfection byproducts.
7. Stakeholder Involvement
  EE]A conducted two stakeholder
meetings to solicit feedback and
information from the regulated
community and other concerned
stakeholders on issues relating to

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                   Federal Register/Vol. 65, No.  69/Monday. April  10,  2000/Proposed Rules
                                                                     19051
 today's proposed rule. The first meeting
 was held July 22 and 23. 1998 in
 Lakewood, Colorado.  EF'A presented
 potential regulatory components for the
 LT1FBR. Breakout sessions with
 stakeholders were held to generate
 feedback on the regulatory provisions
 being considered and  to solicit feedback
 on next steps for rule development and
 stakeholder involvement. Additionally,
 information was presented summarizing
 ongoing research and data gathering
 activities regarding the recycle of filter
 backwash. The  presentations generated
 useful discussion and provided
 substantial feedback to E:PA regarding
 technical issues, stakeholder concerns,
 and possible regulatory options (EPA
 1999k). The second stakeholder meeting
 was held in Dallas, Texas on March 3
 and 4,1999. EPA presented new
 analyses, summaries of current research,
 and revised regulatory options and data
 collected since  the July stakeholder
 meeting. Regional perspectives on
 turbidity and disinfection benchmarking
 components were also discussed with
 presentations from EPA Region VI and
 the Texas Natural Resources
 Conservation Commission. Four break-
 out sessions were extremely useful and
 generated a wide range of information,
 issues, and technical input from a
 diverse group of stakeholders (EPA
 1999J).
  The Agency utilized the feedback
 received during these two stakeholder
 meetings in developing today's
 proposed rule. EPA also mailed a draft
 version of the preamble for today's
 proposed rule to the attendees of these
 meetings. Several of the options which
 are presented today represent
 modifications suggested by
 stakeholders.

 II. Public Health Risk

  The purpose of this  section is to
 discuss the health risk associated with
 pathogens, particularly
 Cryptosporidium, in surface waters and
GWUDI. More detailed information
 about such pathogens and other
 contaminants of concern may be found
 in an EPA criteria document for Giardia
 (EPA 1998d), three EPA criteria
documents for viruses (EPA, 1985;
 1999a; I999b), the Cryptosporidium and
 Giardia Occurrence Assessment for the
Interim Enhanced Surface Water
Treatment Rule (EPA,  1998b) and the
 LTlFBR Occurrence and Assessment
Document (EPA 1999c). EPA requests
comment on today's proposed rule, the
 information supporting the proposal,
and the potential impact of proposed
regulatory provisions on public health
risk.
 A. Introduction

  In 1991), EPA's Science Advisory
 Board (SAB), an independent panel of
 experts established by Congress, cited
 drinking water contamination as one of
 the most important environment;)! risks
 and indicated that disease-causing
 microbial contaminants (i.e., bacteria,
 protozoa and viruses) are probably the
 greatest remaining health risk
 management challenge for drinking
 water suppliers (EPA/SAB. 1990).
 Information on the number of
 waterborne disease outbreaks from the
 U.S. Centers for Disease Control and
 Prevention (CDC) underscores this
 concern. CDC  indicates that, between
 1980 and 1996, 401 waterborne disease
 outbreaks were reported, with over
 750,000 associated cases of disease.
 During this period, a number of agents
 were implicated as the cause, including
 protozoa, viruses and bacteria.
  Waterborne  disease caused by
 Cryptosporidium is of particular
 concern, as it is difficult to inactivate
 Crvptosporidiam oocysts with standard
 disinfection practices (unlike pathogens
 such as viruses and bacteria), and there
 is currently no therapeutic treatment for
 cryptosporidiosis (unlike giardiasis).
 Because Cryptosporidium is not
 generally inactivated in systems using
 standard disinfection practices, the
 control of Cryptosporidium is
 dependent on  physical removal
 processes (e.g.. filtration).
  The filter effluent turbidity limits
 specified under the SWTR were created
 to remove large parasite cysts such as
 Giardia and did not specifically control
 for smaller Cryptosporidium oocysts. In
 addition, filter backwash water
 recycling practices such as adding
 recycled water to the treatment train
 after primary coagulant addition may
 overwhelm the plant and harm efforts to
 control Giardia lamblia,
 Cryptosporidium, and emerging
 pathogens. Despite filtration and
 disinfection, Cryptosporidium oocysts
 have been found in filtered drinking
 water (LeChevallier, et al.,  1991a; EPA,
 I999c), and many of the individuals
 affected by waterborne disease
 outbreaks caused by Cryptosporidium
 were served by filtered surface water
 supplies (Solo-tjabriele and Neumeister,
 1996)' Surface water systems that filter
 and disinfect may still be vulnerable to
 Crvptosporidium. depending on the
source water quality and treatment
effectiveness. EPA believes that today's
proposal, however, will ensure that
drinking water treatment is operating
efficiently to control Cryptosporidium
 (see Sections IV.A and IV.D) and other
microbiological contaminants of
concern [e.g., Giardia).
  In order to assess the public health
risk associated with consumption of
surface water or GWUDI from PWSs,
EPA has evaluated information and
conducted analysis in four important
areas discussed in the following
paragraphs.  These areas are: (1) The
health effects of cryptosporidiosis; (2)
cryptosporidiosis waterborne disease
outbreak data; (3) Cryptosporidium
occurrence data from raw surface water,
raw GWUDI, finished water, and recycle
stream studies; and (4) an assessment of
the current baseline surface water
treatment required by existing
regulations.
B. Health  Effects of Cryptosporidiosis
and Sources and Transmission of
Cryp tosporidi u m
  Waterborne diseases are usually acute
(i.e., sudden onset and typically lasting
a short time in healthy people), and
most  waterborne pathogens cause
gastrointestinal illness, with diarrhea,
abdominal discomfort, nausea,
vomiting, and/or other symptoms. Some
waterborne pathogens cause or are
associated with more serious disorders
such as hepatitis,  gastric cancer, peptic
ulcers, myocarditis, swollen lymph
glands, meningitis, encephalitis, and
many other diseases. Cryptosporidiosis
is a protozoal infection that usually
causes 7-14 days  of diarrhea with
possibly a low-grade fever, nausea, and
abdominal cramps in healthy
individuals (Juranek, 1995). Unlike
giardiasis  for which effective antibiotic
therapy is available, an antibiotic
treatment  for cryptosporidiosis does not
exist (Framm and Soave, 1997).
  There are several species of
Cryptosporidium which have been
identified, including C. baileyi and C.
meleagridis (bird host); C. muris (mouse
host); C. nasorum (fish host), C. parvum
(mammalian host), and C. serpentis
(snake host). Cryptosporidium parvum
was first recognized as a human
pathogen in  1976  (Juranek, 1995).
Recently,  both the human and cattle
types of C. parvum have been found in
healthy individuals, and these types, C.
felis, and a dog type have been found in
immunocompromised individuals
(Pieniazek et al., 1999). Transmission of
cryptosporidiosis  often occurs through
the ingestion of infective
Cryptosporidium oocysts from feces-
contaminated food or water, but may
also result from direct or indirect
contact with infected persons or
mammals  (Casemore, 1990; Cordell and
Addiss, 1994). Dupont, et. al., 1995,
found through a human feeding study
that a low dose of C. parvum is

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19052
Federal  Register/Vol. 65, No. 69/Monday,  April 10, 2000/Proposed Rules
sufficient to cause infection in healthy
adults (Dupont et. al., 1995). Animal
agriculture as a nonpoint source of C.
parvum has been implicated as the
source of contamination tor the 1993
outbreak in Milwaukee, Wisconsin, the
largest outbreak of waterborne disease
in the history of the United States
(Walker et al., 1998). Other sources of C.
parvum include discharges from
municipal wastewater treatment
facilities and drainage from
slaughterhouses. In addition, rainfall
appears to increase the concentration of
Cryptosporidium in surface water,
documented in a study by  Atherholt, et
al. (1998).
  There is evidence that an immune
response to Cryptosporidium exists, but
the degree and duration of this
immunity is not well characterized
(Payer and Ungar, 1986). Recent work
conducted by Chappell, et al. (1999)
indicates that individuals with evidence
of prior exposure to Cryptosporidium
parvum have demonstrated immunity to
low doses of oocysts (approximately 500
oocysts). The investigators found the 50
percent infectious dose for previously
exposed individuals  (possessing a pre-
existing blood serum antibody) to be
1,880 oocysts compared to 132 oocysts
for individuals without prior exposure,
and individuals with prior exposure
who became infected shed fewer
oocysts. Because of this type of immune
response, symptomatic infection in
communities exposed to chronic low
levels of oocysts will primarily be
observed in newcomers [e.g., visitors,
young children) (Frost et al., 1997;
Okhuysen et al., 1998).
  Sensitive populations are more likely
to become infected and ill, and
gastrointestinal illness among this
population may be chronic. These
sensitive populations include children.
especially the very young; the elderly;
pregnant women; and the
immunocompromised (Gerba et al.,
1996; Payer and Ungar, 1986; EPA
1998e). This sensitive segment
represents almost 20 percent of the
population in the U.S. (Gerba et al.,
                     1996). EPA is particularly concerned
                     about the exposure of severely
                     immunocornpromised persons to
                     Crvptosporidium in drinking water,
                     because the severity and duration of
                     illness is often greater in
                     immunocompromised persons than in
                     healthy individuals, and it may be fatal
                     among this population. For instance, a
                     follow-up study of the 1993 Milwaukee,
                     Wisconsin, waterborno disease outbreak
                     reported that at least 50
                     Cryptospor/rf/um-associated deaths
                     occurred among the severely
                     immunocompromised (Hoxie et al.,
                     1997).
                       Cases of illness from
                     cryptosporidiosis were rarely reported
                     until 1982, when the disease became
                     prevalent due to the AIDS epidemic
                     (Current, 1983). As laboratory diagnostic
                     techniques improved during subsequent
                     years, outbreaks among
                     immunocompetent persons were
                     recognized as well. Over the last several
                     years there have been a number of
                     documented waterborne
                     cryptosporidiosis outbreaks in the U.S.,
                     United Kingdom, Canada and other
                     countries (Rose,  1997. Craun t:t al.,
                     1998).

                     C. Waterborne Disease Outbreaks in the
                     United States

                       The occurrence of outbreaks of
                     waterborne gastrointestinal infections,
                     including cryptosporidiosis, may be
                     much greater than suggested by reported
                     surveillance data (Craun and Calderon
                     1996). The CDC-EPA, and the Council
                     of Slate and Territorial Epidemiologists
                     have maintained a collaborative
                     surveillance program for collection and
                     periodic reporting of data on waterborne
                     disease outbreaks since 1971. The CDC
                     database and biennial CDC-EPA
                     surveillance summaries include data
                     reported voluntarily by the States on the
                     incidence and prevalence of waterborne
                     illnesses. However, the following
                     information demonstrates why the
                     reported surveillance data may under-
                     report actual outbreaks.
  The U.S. National Research Council
strongly suggests that the number of
identified and reported outbreaks in the
CDC database (both for surface and
ground  waters) represents a small
percentage of actual waterborne disease
outbreaks National Research Council,
1997; Bennett et al., 1987). In practice,
most waterborne outbreaks in
community water systems are not
recognized until a sizable proportion of
the population is ill (Perz et al.}
  Healthy adults with cryptosporidiosis
may not suffer severe symptoms from
the disease; therefore, infected
individuals may not seek medical
assistance, and their cases are
subsequently not reported. Even if
infected individuals consult a
physician, Cryptosporidium may not be
identified by  routine  diagnostic tests for
gastroenteritis and, therefore, tends to
be under-reported in  the general
population (Juranek 1995). Such
obstacles to outbreak reporting indicate
that the incidence of  disease and
outbreaks of cryptosporidiosis may be
much higher  than officially reported by
the CDC.
  The CDC database is based upon
responses to a voluntary and
confidential survey that is completed by
State and local public health officials.
CDC defines a wiiterborne disease
outbreak as occurring when at least two
persons experience a  similar illness
after ingesting water (Kramer et al.,
1996). Cryptosporidiosis water system
outbreak data from the CDC database
appear in Table H.I and Table II.2.
  Table  II. 1 illustrates the reported
number of waterborne disease outbreaks
in U.S. community, noncommunity, and
individual drinking water systems
between 1971 and 1996. According to
the CDC-EPA database, a total of 652
outbreaks and 572.829 cases of illnesses
were reported between 1971 and 1996
(see Table H-l). The total number of
outbreaks reported includes outbreaks
resulting from protozoan contamination,
virus contamination,  bacterial
contamination, chemical contamination,
and unknown factors.
  TABLE H.1.—COMPARISON OF OUTBREAKS AND OUTBREAK-RELATED ILLNESSES FROM GROUND WATER AND SURFACE
                                       WATER FOR THE PERIOD 1971-19961
                         Water source
                                          !  Total out-  : Cases of2 .   Outbreaks in    i   Outbreaks in
                                          :  breaks2   :  illnesses        CWSs           NCWSs
Ground 	 : 371 (57%)  i 90,815
                                                                       !   (16%).
Surface	  223(34%)   471.375
                                                                          (82%).
Other 	  58(9%) ....  10,639
                                                                       •   (2%).
                                                                            113 i

                                                                            148

                                                                             30 i
                                  258

                                  43

                                  19

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                  Federal Register/Vol.  65, No. 69/Monday, April  10,  2000/Proposed Rules
                                                                   19053
  TABLE ILL—COMPARISON OF OUTBREAKS AND OUTBREAK-RELATED ILLNESSES FROM GROUND WATER AND SURFACE
                                WATER FOR THE PERIOD 1971-19961—Continued
Water source
All Systems3

Total out-
breaks2
652
(100%).
Cases of2
illnesses
572 829
(100%).
Outbreaks in
CWSs
291

Outbreaks in
NCWSs
320

  'Craun and Calderon, 1994. CDC, 1998.
  2 Includes outbreaks in CWSs + NCWSs + Private wells.
  Epidemiological investigations of
outbreaks in populations served by
filtered systems have shown that
treatment deficiencies have resulted in
the plants' failure to remove
contamination from the water.
Sometimes operational deficiencies
have been discovered only during post-
outbreak investigations. Rose (1997)
identified the following types of
environmental and operating conditions
commonly present in filtered surface
water systems at the time
cryptosporidiosis outbreaks have
occurred:
  • Improperly-installed, -operated,
-maintained, or -interpreted monitoring
  • Equipment [e.g., turbidimeters);
  • Inoperable flocculators, chemical
injectors, or filters;
  • Inadequate personnel response to
failures of primary monitoring
equipment;
  • Filter backwash recycle;
  • High concentrations of oocysts in
source water with no mitigative barrier;
  • Flushing of oocysts (by heavy rain
or snow melt) from land surfaces
upstream of the plant intakes; and
  • Altered or suboptimal filtration
during periods of high turbidity, with
turbidity spikes detected in finished
water.
  From 1984 to 1994, there have been
19 reported outbreaks of
cryptosporidiosis in the U.S. (Craun et
al, 1998). As mentioned previously, C.
parvum was not identified as a human
pathogen until 1976. Furthermore,
cryptosporidiosis outbreaks were not
reported in the U.S. prior to 1984. Ten
of these cryptosporidiosis outbreaks
have been documented in CWSs,
NCWSs, and a private water system
(Moore et al,  1993; Kramer et al., 1996;
Levy et al.,  1998;; Craun et al., 1998).
The remaining nine outbreaks were
associated with recreational activities
(Craun et al., 1998). The
cryptosporidiosis outbreaks in U.S.
drinking water systems are presented  in
Table II.2.
                  TABLE 11.2.—CRYPTOSPORIDIOSIS OUTBREAKS IN U.S. DRINKING WATER SYSTEMS
Year
1984
1987
1991
1992
1992 	
1993
1993
1993
1994
1994

Location and CWS.
NCWS, or private
Braun Station TX
CWS.
Carroltton GA CWS
Berks County PA
NCWS.
Medford (Jackson
County), OR, CWS.
Talent, OR, CWS 	
Milwaukee Wl CWS
Yakima WA private
Cook County MN
NCWS.
Clark County, NV
CWS.
Walla Walla WA
CWS.
Cases of
illness
(estimated)
1 1 7 (2 000)
(13000)
(551) 	
(3 000; combined
total for Jackson
County and Talent,
below).
see Medford, OR 	
(403,000) 	
7
	
27 	
103; many confirmed
for
cryptosporidiosis
were HIV positive.
134 	

Source water
Well
River
Welt 	
Spring/River 	
Spring/River 	
Lake 	
Well
Lake 	
River/Lake 	
Well 	

Treatment
Chlorination 	
Conventional filtra-
tion/chlorination; in-
adequate
backwashing of
some filters.
Chlorination 	
Chlori nation/package
filtration plant.
Chlorination/package
filtration plant.
Conventional filtration
N/A 	
Filtered, chlorinated ..
Prechlorination. filtra-
tion and post-filtra-
tion Chlorination.
None reported 	

Suspected cause
Sewage-contami-
nated well.
Treatment defi-
ciencies.
Ground water under
the influence of
surface water.
Source not identified.
Treatment defi-
ciencies.
High source water
contamination and
treatment defi-
ciencies.
Ground water under
the influence of
surface water.
Possible sewage
backflow from toi-
let/septic tank.
Source not identified.
Sewage contamina-
tion.
  Craun, et at., 1998.

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19054
Federal  Register/Vol.  65,  No. 69/Monday, April 10, 2000/Proposed Rules
  Six of the ten cryptosporidiosis
outbreaks reported in Table II.2
originated from surface water or
possibly GWUDI supplied by public
drinking water systems serving fewer
than 10,000 persons. The first outbreak
(117 known cases, 2,000 estimated cases
of illness), in Braun Station, Texas in
1984, was caused by sewage leaking into
a ground water well suspected to be
under the influence of surface water. A
second outbreak in Pennsylvania in
1991 (551 estimated cases of illness),
occurred at a well also under the
influence of surface water. The third
and fourth (multi-episodic)  outbreaks
took place in Jackson County, Oregon in
1992 (3,000 estimated cases of illness)
and were linked to treatment
deficiencies in the Talent, OR surface
water system. A fifth outbreak (27 cases
of illness) in Minnesota, in 1993,
occurred at a resort supplied by lake
water. Finally, a sixth outbreak (134
cases of illness) in Washington in 1994,
occurred due to sewage-contaminated
wells at a CWS.
  Three of the ten outbreaks (Carollton,
GA (1987);  Talent, OR (1992);
Milwaukee, WI (1993)) were caused by
water supplied by water treatment
plants where the recycle of filter
backwash was implicated as a possible
cause of the outbreak. In total, the nine
outbreaks which have taken place in
PWSs have caused an estimated 419,939
cases of illness. These outbreaks
illustrate that when treatment in place
is not operating optimally or when
source water is highly contaminated,
Cryptosporidium may enter the finished
drinking water and infect drinking
water consumers, ultimately resulting in
waterborne disease outbreaks.
D. Source Water Occurrence Studies
  Cryptosporidium is common  in the
environment (Rose, 1988; LeChevallier
                     et al., 1991b). Runoff from unprotected
                     watersheds allows the transport of these
                     microorganisms from sources of oocysts
                     (e.g., untreated wastewater, agricultural
                     runoff) to water bodies used as intake
                     sites for drinking water treatment
                     plants. If treatment operates
                     inefficiently, oocysts may enter the
                     finished water at levels of public health
                     concern. A particular public health
                     challenge is that simply increasing
                     existing disinfection levels above those
                     most commonly practiced for standard
                     disinfectants (i.e., chlorine or
                     chloramines) in the U.S. today does not
                     appear to be an effective strategy for
                     controlling Cryptosporidium.
                       Cryptosporidium oocysts have been
                     detected in wastewater, pristine surface
                     water, surface water receiving
                     agricultural runoff or contaminated by
                     sewage, ground water under the direct
                     influence of surface water (GWUDI),
                     water for recreational use, and drinking
                     water (Rose 1997, Soave 1995). Over 25
                     environmental surveys have reported
                     Crvptosporidium source water
                     occurrence data from surface water or
                     GWUDI (presented in Tables II.3 and
                     II.4), which typically involved the
                     collection of a few water samples from
                     a number of sampling locations having
                     different characteristics (e.g., polluted
                     vs. pristine; lakes or reservoirs vs.
                     rivers). Results are presented as oocysts
                     per 100 liters, unless otherwise marked.
                       Each of the studies cited in Tables 11.3
                     and II.4 presents Cryptosporidium
                     source water occurrence information,
                     including (where possible): (1) The
                     number of samples collected; (2) the
                     number of samples positive; and (3)
                     both the means and ranges for the
                     concentrations of Cryptosporidium
                     detected (where available). However,
                     the immunofluorescence assay (IFA)
                     method and other Cryptosporidium
detection methods are inaccurate and
lack adequate precision. Current
methods do not indicate the species of
Cryptosporidium identified or whether
the oocysts detected are viable or
infectious (Frey et al., 1997). The
methods for detecting Cryptosporidium
were modeled from Giardia methods,
therefore recovery of Cryptosporidium is
deficient primarily because
Cryptosporidium oocysts are more
difficult to capture due to their size
(Cryptosporidium oocysts are 4-6U.92 m;
Giardia cysts are 8-12ji9£m).  In
addition, it is a challenge to recover
Cryptosporidium oocysts from the filters
when they are concentrated, due to the
adhesive character of the organisms.
Other potential limitations to the
protozoan detection methods include:
(1) Filters  used to concentrate the water
samples are easily clogged by debris
from the water sample; (2) interference
occurs between debris or particulates
that fluoresce due to cross reactivity of
antibodies, which results in false
positive identifications; (3) it is difficult
to view the structure of oocysts on the
membrane filter or slide, resulting in
false negative determinations: and (4)
most methods require an advanced level
of skill to be performed accurately.
  Despite  these limitations, the
occurrence information generated from
these studies demonstrates that
Cryptosporidium occurs in source
waters. The source waters for which
EPA has compiled information include
rivers, reservoirs, lakes, streams, raw
water intakes, springs, wells under the
influence of surface water and
infiltration galleries. The most
comprehensive study in scope and
national representation (LeChevallier
and Norton, 1995) will be described in
further detail following Tables 11.3 and
II.4.
     TABLE H.3.—SUMMARY OF SURFACE WATER SURVEY AND MONITORING DATA FOR CRYPTOSPORIDIUM OOCYSTS

Sample source
Number of
samples (n)

Rivers ?5
River 	

6
Reservoirs/rivers (polluted) 6
Reservoir (pristine) 	 ' 6
Impacted river 	 11
Lake 20
Stream 	 19
Raw water 	
85

River (pristine) 59
River (polluted) 	 38
Lake/reservoir (pristine) 34
Lake/reservoir (Dolluted) 	
24
Samples
positive
for
Cryptosporidium
(percent)"
Range of oocysl
cone.
(oocysts/100L)

Mean
(oocysts/100L)

100 200-11 200 ' 251 n
100 i 200-580.000 ....
100
83
100
19-300
1-13
200-11,200" 	
192,000(a) 	
99(a)
2(a)
2.500(g) 	
71 0-2200 58(g)
74 0-24000 10Qfnl
87
7-48,400 	

270(g) detect-
able.
32 NR 29(g)
74 <0l-4400b fififnl
53
58
NR
<0.1-380" 	
93(g)
103(al 	

Reference

Ongerth and Stibbs 1987
Madoreet al. 1987.
Rose 1988
Rose 1988
Rose et al. I988a".
Rose et a I 1988b"
Rose et al 1 988bb
LeChevallier et al. 1991c.

Rose et at 1991
Rose et al 1991
Rose et ai 1991
Rose et al. 1991.

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                  Federal  Register/Vol. 65, No. 69/Monday. April  10, 2000/Proposed  Rules
19055
TABLE it.3. — SUMMARY OF SURFACE WATER SURVEY AND MONITORING DATA FOR CRYPTOSPORIDIUM OOCYSTS—
Continued
i Samples
Number of positive Range of oocyst
Sample source samples (n) ^ for conc-
samples (nj Cryptosporidium (oocysts/100L)
(percent)"
River (all samples)
Protected drinking water supply
(subset of all).
Pristine river, forestry area {subset
of all).
River below rural community in for-
ested area (subset of all).
River below dairy farming agricul-
tural activities (subset of all).
Reservoirs 	
Streams
Rivers
Site 1 — River source (high turbidity)
Site 2 — River source (moderate tur-
bidity).
Site 3 — Reservoir source (low tur-
bidity)
Lakes 	
Streams
Finished water 	
River/lake
River/lake
River 1
River 2
Dairy farm str63m
Reservoir inlets 	
Reservoir outlets •-
River (polluted)
Source water . .

Grab (non-storm event)
River 1
Stream by dairy farm
River 2 (at plant intake)
Reservoirs (unfiltered system) 	
Raw water intakes (rural) 	
Raw Water
DE River, Winter 	

DE River Summer
DE River, Fall 	
36 97 15-45 (pristine)
1000-6,350
(agricultural).
6 81 15-42
6 100 46-697 	
6 100 54-360 	
6 100 330-6,350 	
56 45 NR 	
33 48 NR 	
37 51 NR 	
10 100 82-7,190 	
10 70 42-510 	
10 70 77-870 	
179 6 0-2,240 	
210 6 0-2.000 	
262 13 0.29-57 	
262 52 6.5-6,510 	
147 20 30-980 	
15 73 0-2230 .. ..
15 80 0-1,470 	
13 77 0-1,110
60 5 ' 0.7-24 	
60 12 1.2-107 	
72 40 20-280
NR 24 1-5,390' 	
20 35 0-41,700 	
21 19 0-650 	
24 63 0-1 470
22 82 0-2,300 	
24 63 0-2,200 	
NR 37-52" 15-43 (maxi-
ma)*1.
148 25 004-18
NR NR •' 40-400
100 plants 77 0.5-117 	
18 NR NR 	
18 NR NR 	
18 NR •• NR 	
18 NR NR 	
(oocysts/100L) Reference
20 (pristine) Hansen and Ongerth 1991.
1 ,830 (agricul-
tural).
24(g) . . . . Hansen and Ongerth 1991
!62{g) 	 Hansen and Ongerth 1991.
107(g) Hansen and Ongerth 1991
1 072(g) . Hansen and Ongerth 1991
NR 	 ! Consonery et al. 1992.
NR 	 Consonery et al. 1992.
NR 	 Consonery et al. 1992.
480 	 '• LeChevallier and Norton 1992
250 LeChevaliier and Norton 1992
250 	 LeChevallier and Norton 1992.
3.3 (median) 	 ! Archer et al. 1995.
7 (median) Archer et al 1995
33 (detectable) LeChevallier and Norton 1995.
240 (detectable) LeChevallier and Norton 1995.
200 	 LeChevallier et al. 1995.
188 (a) all sam- States et al. 1995.
pies 43 (g)
detected.
147 (a) all sam- States et al. 1995.
pies 61 (g)
detected.
126 (a) all sam- ; States et al. 1995.
pies 55 (g)
detected.
1 .9(g) 1 .6 (me- LeChevallier et al. 1997b.
dian). .
6.1(g) 60 (me- -, LeChevallier et al. 1997b.
dian).
24(g) 	 LeChevallier et al. 1997a.
740(a)c 71(g)= ... Swertfeger et al. 1997.
NR Stewart et al. 1997.
NR 	 Stewart et al. 1997.
58(g) 	 States et al. 1997.
42(g) 	 States et al. 1997.
31(g) 	 States etal. 1997.
0 8-1 4d ; Okun et al 1997.
03 	 Consonery et al. 1997.
NR Swigeret al. 1999.
3(g) 	 McTigue. etal. 1998.
70 per 500L(g) .. Atherholt, et al. 1998.
100 per 500L(g) Atherholt, et al. 1998.
30 per 500L(g) .. } Atherholt, et al. 1998.
20 per 500L(g) .. ! Atherholt, et al. 1998.
' Rounded to nearest percent
hAs cited in Lisle and Rose 1995.
<• Based on presumptive oocyst count
''Combined monitoring results for multiple sites in large urban water supply.
'As cited in States et al. 1997.
(a) = arithmetic average.
(g) = geometric average.
NR = not reported, NA = not applicable

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 19056
Federal  Register/Vol. 65, No. 69/Monday,  April 10, 2000/Proposed  Rules
             TABLE 11.4.—SUMMARY OF U.S. GWUDI MONITORING DATA FOR CRYPTOSPORIDIUM OOCYSTS
                                                              Range of
                                                            positive val-
                                                            ues (oocysts/
                                                               100L)
                                                            085L
                                                           0002-0.45d
                                                           NR

                                                           NR

                                                           NR

                                                           NR

                                                           NR
                                                            13
                                                           0.25-10
                                                           0.26-3
                                                           NR
Sample source
Well
Ground water sources (all categories)
Vertical wells (subcategory of above
ground water sources).
Springs (subcategory of above
ground water sources).
Infiltration galleries (subcategory of
above ground water sources).
Horizontal wells (subcategory of
above ground water sources).
Ground water
Ground water
Springs 	
Wells 	
Vertical well Lemont Well #4 (Center
Co., PA, Aug. 1992)
Number of
samples (n)
17 (6 wells)
199 sites" 	
149 sites" ...
35 sites" 	
4 sites'- 	
11 sites" 	
17
18
7 (4 springs)
5 sites 	
6 	
Samples posi-
tive for
Cryptosporidium
oocysts (per-
cent)
(1 sample)
11" 	
5" 	
20" 	
50" 	
45" 	
41 2
5 6
57" 	
100 	
66.7 	
Mean
j (oocysts/
j 100L)-
NA
. NR
NR
• NR
NR
NR
NR
.13
A
0.9
NR

Reference

Archer et al. 1995
Hancock et al. 1998.
Hancock et al. 1998.
Hancock et al 1998.
Hancock et al 1998.
Hancock et al. 1998.
Rosen et al., 1996
Rose et al. 1991
Roseet al. 1991.
SAIC, 1997'
Lee, 1993.
  a Geometric mean reported unless otherwise indicated.
  "Data are presented as the percentage of positive sites.
  cData included are confirmed positive samples not reported in Hancock,
  NA = not applicable
  NR = not reported.
                                         1998.
   The LeChevallier and Norton (1995)
 study collected the most samples and
 repeat samples from the largest number
 of surface water plants nationally.
 LeChevallier and Norton conducted the
 study to determine the level of
 Cryptosporidium in surface water
 supplies and plant effluent water. In
 total, surface water sources for 72
 treatment  plants in 15 States and 2
 Canadian  provinces were sampled.
 Sixty-seven surface water locations were
 examined. The generated  data set
 covered a  two-year monitoring period
 (March, 1991 to January, 1993) which
 was combined with a previous set of
 data (October,  1988 to June, 1990)
 collected from most of the same set of
 systems to create a database containing
 five samples (IFA)  per site or more for
 94 percent of the 67 systems sampled.
 Cryptosporidium oocysts were detected
 in 135  (51.5 percent) of the 262 raw
 water samples collected between March
 1991 and January 1993, while 87
 percent of the 85 samples were positive
 during the survey period from October.
 1988 to June, 1990. The geometric mean
 of detectable Cryp/osporidium was 240
 oocysts/lOOL. with a range from 6.5 to
 6510 oocysts/lOOL. When the 1991-
 1993 results (n=262) were combined
 with the previous results (n=85).
 Cryptosporidium was detected in 60.2
 percent of the samples. The authors
 hypothesize the origin of the decrease in
detections in the second round of
sampling to be most probably linked to
fluctuating or declining source water
concentrations of Crvptosporidium
                     oocysts from the first reporting period to
                     the second.
                      LeChevallier and Norton (1995) also
                     detected Cryptosporidium oocysts in 35
                     of 262 plant effhient samples (13.4
                     percent) analyzed between 1991 and
                     1993. \Vh«n detected, the oocyst levels
                     averaged 3.3 oocysts/100 L (range = 0.29
                     to 57 oocysts/100 L).  A summary of
                     occurrence data for all samples in
                     filtered  effluents for the years 1988 to
                     1993 showed that 32  of the water
                     treatment plants (45 percent) were
                     consistently negative for
                     Cryptosporidium; 24  plants (34 percent)
                     were positive once; and 15 plants (21
                     percent) were positive for
                     Cryptosporidium two or more times
                     between 1988 to 1993. Forty-four of the
                     plants (62 percent) wore positive for
                     Ciardia. Crvptosporidium, or both at
                     one time or another (LeChevallier and
                     Norton  1995).
                      The oocyst recoveries and densities
                     reported by LuChevallier and Norton
                     (1995) are comparable to the results of
                     another survey of treated, untreated,
                     protected (pristine) and feces-
                     contaminated (polluted) water supplies
                     (Rose et al. 1991). Six of thirty-six
                     samples (17 percent) taken from potable
                     drinking water were positive for
                     Cryptosporidium, and concentrations in
                     these waters ranged from .5 to 1.7
                     oocysts/100L. In addition, a total of 188
                     surface water samples were analyzed
                     from rivers, lakes, or springs in 17
                     States. The majority of surface water
                     samples were obtained from Arizona.
                     California, and Utah (12G samples in
all), with others from eastern States (28
samples), northwestern States (14
samples), southern States (13 samples).
midwestern States (6 samples), and
Hawaii (1 sample). Arithmetic average
oocyst concentrations ranged from l«;ss
than 1 to 4.400 oocysts/100 L.
depending on the type of water
analyzed. Cryptosporidium oocysts were
found in 55  percent of this surface water
samples at an average concentration of
43 oocysts/100 L.
  The LeChevallier and Norton (1995)
study collected the most samples and
repeat samples from the most surface
water plants on a national level.
Therefore, the data from this study were
analyzed by EPA (EPA, 1998n) to"
generate a distribution of source water
occurrence, presented in Table II.5.

TABLE U.S.—BASELINE  EXPECTED NA-
  TIONAL       SOURCE       WATER
  CRYPTOSPORIDIUM DISTRIBUTIONS
       Percentile
   Source
   water
concentration
(oocysts/100L)
25
50
75
90
95
    Mean	
    Standard Deviation
          103
          231
          516
         1064
         1641
          470
          841
  Although limited by the small number
of samples per site (one to sixteen
samples; most sites were sampled five
times), the mean concentration at the 69

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                  Federal Register/Vol. 65, No.  69/Monday. April  10, 2000/Proposed  Rules
                                                                                      19057
sites from the eastern and central U.S.
seems to be represented by a lognorinal
distribution.
                   In addition to the source water data,
                 several studies have detected
                 Crvptosporidium oocysts in finished
                                        water. The results of these studies have
                                        been compiled in Table H.6.
         TABLE H.6.—SUMMARY OF U.S. FINISHED WATER MONITORING DATA FOR CRYPTOSPORIDIUM OOCYSTS
         Sample source
           Number of
           samples (n)
Filtered water	
Finished water (unfiltered)
Finished water 	
Finished water (clearwell) 	
Finished water (filter effluents)
Site 1—Filler effluent	
Site 2—Filter effluent	
Site 3—Filter effluent	
Finished water	
Filtered (non-storm event) 	
Finished water	
Finished water
Finished water
  •Plants
  "Confirmed
  •"Presumed
                    82
                     6
                   262

                    14 I
                   118 '
                    10
                    10
                    10
                 1,237
                    87
                    24
Samples posi-
tive for
Cryptosporidium
(percent)
27
33
13
14
26
70
10
10
•J
10
"8
"*13
25
15
Range of
oocyst cone
(oocysts'
100L)
0.1^t8 	
0 1--1 7
0.29-57 	
NR
NR
1-4
05 	
2
NR 	
0-420 	
0-0.6 	
0 02-0 8
0.04-0.08 ....
Mean
(oocysts/
100L)
1 5 	
02
33 (detect-
able).
NR
NR
NR
NA 	
NA
NR 	
NR 	
0.5 (g) 	
0.2 	
0.08 (g) 	
Reference
LeChevallier et al. 1991 a.
LeChevallier et al 1992
LeChevallier and Norton 1995.
Consonery et al 1992
Consonery et al. 1992
LeChevallier and Norton 1992.
LeChevallier and Norton 1992.
LeChevallier and Norton 1992.
Rosen etal. 1996.
Stewart el al. 1997a.
States etal. 1997.
Consonery et al. 1997
McTigue, et al. 1998.
  These studies show that despite some
treatment in place, Cryptosporidiiim
may still pass through the treatment
plant and into finished water.
  In general, oocysts are detected more
frequently and in higher concentrations
in rivers and streams than in lakes and
reservoirs (LeChevallier et al., 1991b:
Rose et al.,  1988a,b). Madore et al.
(1987) found high concentrations of
oocysts in a river affected by
agricultural runoff (5800 oocysts/L).
Such concentrations are especially
significant  if the contaminant removal
process (e.g., sedimentation, filtration)
of the treatment plant is not operating
effectively. Oocysts may pass through to
the finished water, as LeChevallier and
Norton (1995) and  several other
researchers also found, and infect
drinking water consumers.
E. Filter Backwash and Other Process
Streams: Occurrence and Impact
Studies
  Pathogenic microorganisms are
removed during the sedimentation and/
                 or filtration processes in a water
                 treatment plant. Recycle streams
                 generated during treatment, such as
                 spent filter backwash water,
                 sedimentation basin sludgo, or thickener
                 supernatant are often returned to Ihe
                 treatment train. These recycle streams,
                 therefore, may contain high
                 concentrations of pathogens, including
                 chlorine-resistant Cryptosporidium
                 oocysts. Recycle can degrade the
                 treatment process, especially when
                 entering the treatment train after the
                 rapid mix stage, by causing a chemical
                 imbalance, hydraulic surge and
                 potentially overwhelming the plant's
                 filtration capacity with a large
                 concentration of pathogens. High oocyst
                 concentrations found in recycle waters
                 can increase the risk of pathogens
                 passing through the treatment plant into
                 finished water.
                   AWWA has compiled issue papers on
                 eai:h of the following recycle streams:
                 Spent filter backwash water,
                 sedimentation basin solids, combined
                                        thickener supernatant, ion-exchange
                                        regenerate, membrane concentrate,
                                        lagoon decant, mechanical dewatering
                                        device concentrate, monofill leachate,
                                        sludge drying bed leachate, and small-
                                        volume streams (e.g., floor, roof, lab
                                        drains) (Environmental Engineering &
                                        Technology, 1999). In addition, EPA
                                        compiled existing occurrence data on
                                        Cryptosporidium in recycle streams.
                                        Through these efforts, Cryptosporidium
                                        occurrence data has been found for
                                        three types of recycle streams: Spent
                                        filter backwash water, sedimentation
                                        basin solids, and thickener supernatant.
                                          Nine studies have reported the
                                        occurrence of Cryptosporidium for these
                                        process streams. Each study's scope and
                                        results are presented in Table II.7, and
                                        brief narratives on each major study
                                        follow the table. Note that the results  of
                                        the studies, if not presented in  the
                                        published report as oocysts/lOOL, have
                                        been converted into oocysts/lOOL.
          TABLE 11.7.—CRYPTOSPORIDIUM OCCURRENCE IN FILTER BACKWASH AND OTHER RECYCLE STREAMS
Name/location of study
Number of
samples (n)
Type of sample
Cyst/oocyst concentration
Drinking water treat-
  ment facilities.
             backflush waters from
               rapid sand filters.
                   (calc.  as  686,900  oocysts/
                   100L).
                 sample 2:  92,000 oocysts/gal
                   (calc as  2,430,600  oocysts/
                   100L)
ration
cvsts/aal
Number of
treatment
plants sampled
2 	
Reference
Rose etal. 1986.

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19058
Federal Register/Vol.  65, No.  69/Monday,  April 10, 2000/Proposed Rules
    TABLE 11.7.—CRYPTOSPORIDIUM OCCURRENCE IN FILTER BACKWASH AND OTHER RECYCLE STREAMS—Continued
 Name/location of sludy
     Number of
    samples (n)
   Type of sample
  Cysl/oocyst concentration
  Number of
  treatment
plants sampled
                                                                                                       Reference
Thames, U.K.,
   not reported
 Potable water supplies
  in 17 States.
   not reported ....
backwash water from
  rapid sand filter.
filter backwash from
  rapid sand filters (10
  to 40 L sample vol.).
Over 1,000,000 oocysts/100L
  in backwash water on 2/19/
  89.
100,000  occysts/100L  in su-
  pernatant  from   settlement
  tanks during  the next few
  days
217 oocysts/ 100 L (geometric
  mean).
                                                                                    1
                                                                                                  Colbourne 1989
not reported
                                                                                                  Rose et al. 1991.
Name/location not re-
ported.
Bangor Water Treat-
ment Ptant (PA).
Round 2: 1 (8-hour
composite).
Moshannon Valley
Water Treatment
Plant.
Plant "C" 	
Pittsburgh Drinking
Water Treatment
Plant.
"Plant Number 3" 	
"Plant C" (see Karanis,
etal., 1996).
"Plant A" 	

not reported ....
I Round 1: 1 (8-
! hour com-
posite).
raw water 	
filter backwash
supernatant re-
cycle
Round 1: 1 (8-
hour com-
posite).
Round 2: 1 (8-
hour com-
posite).
11 samples
using contin-
uous flow
centrifuga-
tion;.
24 (two years
of monthly
samples).
not reported ....
12 	
50
1 	

raw water 	
initial backwash water
raw water 	
filter backwash 	
supernatant recycle 6
oocysts/100L.
140 oocysts/IOOL 	
raw water 	
spent backwash 	
supernatant recycle 	
sludge 13 oocysts/
100L.
raw water
supernatant recycle 	
39 samples using car-
tridge filters.
filter backwash 	
raw water
spent backwash 	
raw water 	
backwash water from
rapid sand filters.
rapid sand filter (sam-
ple taken 10 min.
after start of
backwashing).
7 to 108 oocysts/ 100L 	
detected at levels 57 to 61
times higher than in the raw
water.
902oocysts/100L.
850 oocysts/100L.
16,613 oocysts/IOOL.
20 oocysts/100L
backwash water from rapid
sand filters; samples col-
lected from sedimentation
basins during sedimentation
phase of backwash water at
depths of 1, 2, 3, and 3.3 m.
328 oocysts/ 100 L (geometric
mean); (38 percent occur-
rence rate).
140 oocysts/100L
avg. 23.2 oocysts/100L (max.
109 oocysts/100L) in 8 of 12
samples,
150 oocysts/100L
not reported ....
not reported
141 oocysts/
100L. 1
750 oocysts/
i 100L. 1
82 oocysts/
. 100L.
1 420 oocysts/
100L. 1
continuous
flow: range 1
\ to 69
oocysts/100
L; 8 of 11
samples
positive.
rton-detect-
13.158
oocysts/
100L. 1
850 oocysts/
100L.
avg. 22.1
oocysts/100L
(max. 257
oocysts/
100L) in 41
of 50 sam-
ples :
LeChevallier et al.
1991c.
Cornwell and Lee
1993.
Cornwell and Lee
1993.
2.642 oocysts/100L. 1
Cornwell and Lee
1993
Cornwell and Lee
1993
cartridge filters: ranges
0.810252/100 L; 33
of 39 samples posi-
tive 1 Karanis et al.
1996.
States e! al. 1997.
not reported Cornwell
1997.
1 Karanis et al 1998.
  The occurrence data available and
reported are primarily for raw and
recycle stream water.  If filter backwash
enters the treatment train as a slug load
and disrupts the treatment process, it is
possible its effects would not be readily
seen in  the finished water until several
minutes or hours after returning the
filter to service. In addition, the poor
recovery efficiencies of the  IFA
Cryptosporidsum detection  method
                     complicate measurements in dilute
                     finished effluent waters.
                       As shown in Table II.7, the
                     concentrations of oocysts in backwash
                     water and other recycle streams are
                     greater than the concentrations
                     generally found in raw water. For
                     example, four studies (Cornwell and
                     Lee, 1993; States et al., 1997: Rose et lit..
                     1986: and Colbourne. 1989) have
                     reported Crvptosporidium oocyst
                     concentrations in filter backwash water
                                           exceeding 10,000 oocysts/IOOL. Such
                                           concentrations illustrate that the
                                           treatment plant has been removing
                                           oocysts from the influent water during
                                           the sedimentation and/or filtration
                                           processes. As expected, the oocysts have
                                           concentrated on the filters  and/or in the
                                           sedimentation basin sludge. Therefore.
                                           the recycling of such process streams
                                           [e.g., filter backwash, thickener
                                           supernatant, sedimentation basin

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                  Federal Register/Vol.  65, No. 69/Monday,  April 10. 2000/Proposed  Rules
                                                                     19059
sludge) re-introduces high
concentrations of oocysts to the
drinking water treatment train.
  Recycle can potentially return a
significant number of oocysts to the
treatment plant in a short amount of
time, particularly if the recycle is
returned to the treatment process
without prior treatment, equalization, or
some other type of hydraulic detention.
In addition, Di Giovanni, at at. (1999)
presented data indicating that viable
oocysts have been detected in filler
backwash samples using a cell culture/
polymerase chain reaction (PCR)
method. Cell culture is a test of the
viability/infectivity  of the oocysts, while
PCR identified the cells infected by C.
parvum. Although recovery by IFA was
poor (6 to 8 percent  for backwash
samples), 9 filter backwash recycle
samples were found to contain viable
and infectious oocysts, and the
infectious agent was determined to be
more than 98 percent similar in
structure to C. parvum. Should filter
backwash recycle disrupt normal
treatment operations or should
treatment not function efficiently due to
other deficiencies, high concentrations
of potentially viable, infectious oocysts
may pass through the plant into finished
drinking water. The recycle stream
occurrence studies presented in Table
II.7 are described in further detail in the
following sections.
Thames, U.K. Water Utilities Experience
with Cryptosporidium, Colbounit: (1989)
  In response to a cryptosporidiosis
outbreak reported in February of 1989.
Thames Water undertook an
investigation of pathogen concentrations
within the Farmoor  conventional
treatment plant's treatment train,
finished and raw waters. The
investigation occurred over a two month
period, from February to April 1989 and
included sampling of settled  filter
backwash, the supernatant from spent
filter backwash, raw water, and water
sampled at the end of various Thames
distribution points.
  On February 19, 1989 at the start of
the outbreak investigation, a
concentration of approximately
1,000,000 oocysts/lOOL was detected in
the filter backwash water. During the
first few days of the  following
investigation, the  supernatant of the
settled backwash water contained
approximately 100,000 oocysts/100L. At
the peak of the outbreak, thirty percent
of Thames' distribution system samples
were positive for oocysts, and ranged in
concentration from 0.2 to 7700 oocysts/
100L. Raw reservoir water contained
oocyst concentrations ranging from .2 to
1400 oocysts/lOOL. After washing the
filters twice in 24 hours, no oocysts
were found in the settled backwash
waters. Thames, U.K. Water Utilities
determined that a storm causing intense
precipitation and runoff resulted in
elevated levels of oocysts in the source
water which led to the high
concentrations of oocysts entering the
plant and subsequently deposited on the
filters and recycled as filter backwash.
Survey of Potable Water Supplies for
Cryptosporidium and Giardia. Rose, et
ai, 1991
  In this survey. Rose, et al, collected
257 samples from 17 States from 1985
to 1988. The samples were collected on
cartridge filters and analyzed using
variations of the IFA method. The
reported percent recovery for the
method was 29 to 58 percent. Filter
backwash samples were a subset of the
257, 10 to 40 L samples were collected
from rapid sand filters.
  Rose,  et al. reported the geometric
mean of the backwash samples at 217
Cryptosporidium oocysts/lOOL. This
was the highest reported average
Cryptosporidium concentration of any
of the water  types tested, which
included polluted and pristine surface
and ground water sources,  drinking
water sources in addition to filter
backwash recycle water.

Giardia  and Cryptosporidium in IVafer
Supplies,  LeChevallier,  et al. (1991c)
  LeChevallier et al. conducted a study
to determine "whether compliance with
the SWTR would ensure control of
Giardia  in potable water supplies." Raw
water and plant effluent samples were
collected from 66 surface water
treatment  plants in 14 States and one
Canadian  province, although only
selected sites were tested for
Cryptosporidium oocysts in filter
backwash and settled backwash water.
  In the analysis of pathogen
concentrations in the raw water and
filter backwash water of the water
treatment  process, LeChevallier et al.
(I991c) found very high oocyst levels in
backwash water of utilities that had low
raw water parasite concentrations. The
pathogens were detected using a
combined IFA method that the authors
developed. Cryptosporidium levels in
the initial backwash water  were 57 to 61
times higher than in the raw water
supplies. Raw water samples were
found to contain from 7 to  108 oocysts/
100L. LeChevallier et al. (1991c) also
noted that when Cryptosporidium were
detected in plant effluent samples (12 of
13 times), the organisms were also
observed in the backwash samples. The
study concluded that the consistency of
these results shows that accumulation of
parasites in the treatment filters (and
subsequent release in the filter
backwash recycle water) could be
related to subsequent passage through
treatment barriers.

Recycle Stream Effects on Water
Treatment, Cormvell and Lee (1993,
1994)

  The results described in Cornwall and
Lee's 1993 American Water Works
Association Research Foundation
Report and 1994  Journal of the
American Water  Works Association
article on the Bangor and Moshannon
Valley, PA water treatment plants are
consistent with the results of States ef
al. (1997). In total, Cornwell and Lee
investigated eight water treatment
plants, examining treatment efficiencies
including several recycle streams and
their impacts, and reporting a range of
pathogen and other water quality data.
All of the pathogen testing was
conducted using the EPA IFA method
refined by LeChevallier, et al. (1991c).
  Cornwell and Lee (1993) conducted
two rounds of sampling at both the
Bangor and Moshannon plants,
sampling the  different recycle and
treatment streams as eight-hour
composites. They detected
Cryptosporidium concentrations of over
16,500 Cryptosporidium oocysts/lOOL
in the backwash  water at an adsorption
clarifier plant (Moshannon Valley) and
over 850 Cryptosporidium oocysts/lOOL
in backwash water from a direct
filtration plant (Banger). The parasite
levels in the backwash samples were
significantly higher than concentrations
found in the raw source water, which
contained Cryptosporidium oocyst
concentrations of 13-20 oocysts/lOOL at
the Moshannon Valley plant and 6-140
oocysts/100L at the Bangor plant.
  In addition, Cornwell and Lee
determined oocyst concentrations for
two other recycle streams, combined
thickener supernatant and
sedimentation basin solids. The
supernatant pathogen concentrations
were reported at  141 Cryptosporidium
oocysts/lOOL at the Bangor plant, and
levels were reported at 82 to 420
oocysts/lOOL for the Moshannon plant
in Rounds 1 and  2 of sampling,
respectively. The sedimentation basin
sludge was reported at 2,642
Cryptosporidium oocysts/ 100L in the
clarifier sludge from the Moshannon
Valley plant.

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Federal  Register/Vol.  65,  No. 69/Monday, April 10, 2000/Proposed  Rules
Giardia and Cryptosporidium in
Backwash Water from Rapid Sand
Filters Used for Drinking Water, Karanis
et al. (1996) and Distribution and
Removal of Giardia and
Crvptosporidium in Water Supplies in
Germany Karanis, et al, (JS98)

   Karanis et al. (1996 and 1998)
conducted a four-year research study
(samples collected from July. 1993-
December, 1995) on the efficiency of
Cryptosporiciiimi removal by six
different surface water treatment plants
from Germany, all of which treat by
conventional filtration. The method
used was an IF A method dubbed the
"EPA method", developed by
Jakubowski and Ericksen, 1979.
   Karanis et a). (1996) detected
Cryptosporidium in 82 percent of the
samples of backwash water from  rapid
sand filters of a water treatment plant
("Plant C") supplied by small rivers.
Eight out of 12 raw water samples tested
were positive for Cryptosporidium
(range of 0.8 to 109 bocysts/lOOL).
Backwash water samples collected by
continuous flow centrifugation were
positive for Cryptosporidium in 8 of 11
samples (range of 1 to  69/100L). Of 39
samples collected using cartridge filters,
33 were positive for Cryptosporidium
(range of 0.8 to 252/1 OOL). The authors
called  attention to the high detection
rate of Cryptosporidium in the
backwash waters (82 percent) of Plant C
and to the fact that the supernatant
following sedimentation was not free
from cysts and oocysts  (Karanis et al.
1996)."
   In the 1998 publication, Karanis et al.
compiled the data from the 1996  study
with more backwash occurrence data
collected from another treatment plant
("Plant A"). The filter backwash of Plant
A was  sampled 10 minutes after the
start of backwashing, and the backwash
water was found to contain 150
Cryptosporiilium oocysts/1 OOL.

Protozoa in River Water: Sources,
Occurrence, and Treatment, States, et
al. (1997)

   Over a two year period (July. 1994-
June. 1996), States et al, sampled
monthly for Crvptosporidium in the
raw, settled, filtered and filter backwash
water at the Pittsburgh  Drinking Water
Treatment Plant, in order to gauge the
efficiency of pathogen removal at the
plant. States et al. identified several
sources contributing oocysts to the
influent water, including sewage plant
effluent, combined sewer overflows,
dairy farm streams, and recycling of
backwash water. All pathogen sampling
was conducted with the IFA method.
                       Cryptosporidium occurred in the raw
                     Allegheny river water supplying the
                     plant with a geometric mean of 31
                     oocysts/lOOL in 63 percent of samples
                     collected, and ranged from non-detect to
                     2,333 oocysts/1 OOL (see Table 11.3 for
                     source water information). Of the filter
                     backwash samples, a geometric mean of
                     328 oocysts/lOOL was found at an
                     occurrence rate of 38 percent of
                     samples, with a range from non-detect
                     to 13,158 oocysts/lOOL. The fact that the
                     mean concentration of Cryptosporidium
                     oocysts in backwash water can be
                     substantially higher than the oocyst
                     concentration in untreated river water
                     suggests that recycling untreated filter
                     backwash water can be a significant
                     source of this parasite to water within
                     the treatment process.
                     F. Summary and Conclusions
                       Cryptosporidiosis is a disease without
                     a therapeutic cure, and its causative
                     agent. Cryptosporidium. is resistant to
                     chlorine disinfection. Crvptosporidium
                     has been known to cause severe illness,
                     especially in immunocompromised
                     individuals, and can be fatal. Several
                     waterborne Cryptosporidiosis outbreaks
                     have been reported, and it is likely that
                     others have occurred but have gone
                     unreported. Cryptosporidium has been
                     detected in a wide range of source
                     waters, documented in over 30 studies
                     from the literature, and it has been
                     found at levels of concern in filter
                     backwash water and other recycle
                     streams.
                       One of the key regulations EPA has
                     developed and implemented to counter
                     pathogens  in drinking water is the
                     SVVTR (54 FR 27486, June 19, 1989).
                     The SVVTR requires that surface water
                     systems have sufficient treatment to
                     reduce the source water concentration
                     of Giardia and viruses by at least 99.9
                     percent (3 log) and 09.99 percent (4 log),
                     respectively. A shortcoming of the
                     SWTR,  however, is that the rule does
                     not specifically control for
                     Cryptosporidium. The first report of a
                     recognized waterborne outbreak caused
                     by Cryptosporidium was published
                     during the development of the SVVTR
                     (D'Antonio et al. 1985).
                      In 1998, the Agency finalized the
                     1ESWTR that enhances the microbial
                     pathogen protection provided by the
                     SVVTR for systems serving 10,000 or
                     more persons. The IESWTR includes an
                     MCLG of zero for Cryptosporidium and
                     requires a minimum 2-log (99 percent)
                     removal of Cryptosporidium, linked to
                     enhanced combined filter effluent and
                     individual filter turbidity control
                     provisions.
                      Several provisions of today's
                     proposed rule, the LTlFBR, are
designed to address the concerns
covered by the IESWTR, improving
control of Cryptosporidium and other
microbial contaminants, for the portion
of the public served by small PWSs (i.e..
serving less than 10.000  persons). The
LT1FBR also addresses the concern that
for all PWSs that practice recycling.
Cryptosporidium (and other emerging
pathogens resistant to standard
disinfection practice) are reintroduced
to the treatment process  of PWSs by the
recycle of spent filter backwash water,
solids treatment residuals, and other
process streams.
  Insufficient treatment  practices have
been cited as the cause of several
reported waterborne disease outbreaks
(Rose, 1997). Rose (1997) also found that
a reduction in turbidity is indicative of
a more efficient filtration process.
Therefore, the turbidity and filter
monitoring requirements of today's
proposed LTlFBR will ensure that the
removal process necessary to protect the
public from Cryptosporidiosis is
operating properly, and the recycle
stream provisions will ensure that the
treatment process is not disrupted or
operating inefficiently. The LTlFBR
requirements that address the potential
for Cryptosporidium to enter the
finished drinking water supply will be
described in more detail  in tin;
following sections.
III. Baseline Information-Systems
Potentially Affected By Today's
Proposed Rule

  EPA utilized the 1997  state-verified
version of the Sale Drinking Water
Information System (SDVV'IS) to develop
the total universe of systems which
utilize surface water or groundwater
under the direct influence (CWLID1) as
sources. This universe consists of
11,593 systems serving fewer than
10,000 persons, and 2.096 systems
serving 10,000 or more persons. Given
this initial baseline, the Agency
developed estimates of the number of
systems which would be affected by
components of today's proposed rule by
utilizing three primary sources: Safe
Drinking Water Information Systems;
Community Water Supply Survey; and
Water: Stats. A brief overview of each of
the data sources is described in the
following paragraphs.

Safe Drinking Water Information System
(SDWIS)
  SUWIS contains information about
PVVSs including violations of KPA's
regulations for safe drinking water.
Pertinent information in  this database
includes system name and ID.
population served, geographic location.

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                  Federal  Register/Vol. fi5, No.  (><)/Monday, April  10,  2000/Proposed  Rules
                                                                    19061
type of source water, and type of
treatment (if provided).
Community Water System Survey
(CWSS)
  EPA conducted the 1995 CWSS to
obtain data to support its development
and evaluation of drinking water
regulations. The survey consisted of a
stratified random  sample of 3.700 water
systems nationwide (surface water and
groundwater). The survey asked 24
operational and 13 financial questions.
Water/Stats {WaterStats)
  WaterStats is an in-depth database of
water utility information compiled by
the American Water Works Association.
The database consists of 898 utilities of
all sizes and provides a variety of data
including treatment information.
  Information regarding estimates of the
number of systems which may
potentially be affected by specific
components of today's proposed rule
can be found in the discussion of each
proposed rule component in Section  IV,
IV. Discussion of Proposed LTlFBR
Requirements
A. Enhanced Filtration Requirements
  As discussed earlier in this preamble,
one of the key objectives of today's
proposed rule is ensuring that an
adequate level of public health
protection is maintained in order to
minimize the risk associated with
Cryptosporidium.  While the current
SWTR provides protection from viruses
and Giardia, it does  not specifically
address Cryptosporidium, which has
been linked to outbreaks resulting in
over 420,000 cases of gastrointestinal
illness in the 1990s (403,000 associated
with the Milwaukee outbreak). Because
of Cryptosporidium's resistance to
disinfection practices currently in place
at small systems throughout the
country, the Agency believes enhanced
filtration requirements are necessary to
improve control of this microbial
pathogen.
  In the IESWTR, the Agency utilized
an approach consisting of three major
components to address Crvptosporidium
at plants serving populations of 10,000
or more. The first component required
systems to achieve a 2 log removal of
Cryptosporidium. The second
component consisted of strengthened
turbidity requirements for combined
filter effluent. The third component
required individual filter turbidity
monitoring.
  In today's proposed rule addressing
systems serving fewer than 10,000
persons, the Agency is utilizing the
same framework. Where appropriate.
EPA has evaluated additional options in
an effort to alleviate burden on small
systems while still maintaining a
comparable level of public health
protection.
  The following sections describe the
overview and purpose of each of the
rule components, relevant data utilized
during development, tht: requirements
of today's proposed rule (including
consideration of additional options
where appropriate), and a request for
comment regarding each  component.

1. Two Log Cryptosporidium Removal
Requirement

a. Two Log R«moval
i. Overview and Purpose
  The 1998 IESWTR (63 FR 69477,
December  IB. 1998) establishes an
MCLG of zero for Cryptosporidium in
order to adequately protect  public
health. In conjunction with the MCLG,
the  IESWTR also established a treatment
technique  requiring 2 log
              Cryptosporidium removal for all surface
              water and GWUDI systems which filter
              and serve populations of 10,000 or more
              people, because it was not economically
              and technologically feasible to
              accurately ascertain the level of
              Cryptosporidium using current
              analytical methods. The Agency
              believes it is appropriate and necessary
              to extend this treatment  technique of 2
              log Crvptosporidium removal
              requirement to systems serving fewer
              than 10.000 people.

              ii. Data

               As detailed later in this section, EPA
              believes that the data and principles
              supporting requirements established for
              systems serving populations of 10,000
              or more are also applicable to systems
              serving populations fewer than 10,000.
              The following section provides
              information and data regarding: (1) the
              estimated number of small systems
              subject to the proposed 2 log
              Cryptosporidium removal requirement;
              and (2) Cryptosporidium removal using
              various filtration technologies.

              Estimate of the  Number  of Systems
              Subject to 2 log Cryptosporidium
              Removal Requirement

               Using the baseline described in
              Section III of today's proposed rule, the
              Agency applied percentages of surface
              water and GWUDI systems which filter
              (taken from the 1995 CWSS) in order to
              develop an estimate of the number of
              systems which filter and serve fewer
              than 10,000 persons. This resulted in an
              estimated 9,133 surface water and
              GWUDI systems that filter which may
              be subject to the proposed removal
              requirement. Table IV.1 provides this
              estimate broken down by system size
              and type.
         TABLE IV.1 .—ESTIMATE OF SYSTEMS SUBJECT TO 2 LOG CRYPTOSPORIDIUM REMOVAL REQUIREMENT*
                 System type
                                                 <100
                                                           101-500
                                 Population served

                                501-1K"     1K-3.3K"
                                                      3.3K-10K*   Total #Sys.
Community 	
Non Community ...
NTNC 	
     Total
              888
             1099
              214

             2201
1453
 374
 204

2031
950
78
82
2022
64
64
1591
35
17
6903
1649
581
                                                                           1110
                                                                                      2150
                                                                                                  1643
                                                                                                           b9134b
  'Numbers may not add due to rounding
  bK = thousands

                          Crvptosporidium Removal Using Conventional and Direct Filtration

    During development of the LTlFBR, the Agency  reviewed thu results of several studies that demonstrated the ability
of conventional and direct filtration systems to achieve 2 log removal of Cryptosporidium at well operated plants achieving
low turbidity levels. Table IV.2  provides key  information from these studies. A brief  description  of each study follows
the  table.

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 19062
 Federal  Register/Vol. 65, No. 69/Monday, April  10, 2000/Proposed Rules
                        TABLE IV.2.—CONVENTIONAL AND DIRECT FILTRATION REMOVAL STUDIES
  Type of treatment
            Log removal
        Experimental design
                                                                                                   Researcher
 Conventional
 Direct filtration
 Rapid Granular Fil-
  tration (alone).
 Cryptosporidium 4.2-5.2 .
 G(ard/a4.1-5.i 	
 Cryptosporidium 1.9-4.0 .
 Giardia 2.2-3.9	
 Cryptosporidium 1.9-2.8 .
 Giardia 2.8-3.7	
 Cryptosporidium 2.3-2.5 .
I Giardia 2.2-2.8 	
! Cryptosporidium 2-3 	
| Giardia and Crypto 1.5-2

 Cryptosporidium 4.1-5.2 .
 Cryptosporidum .2-1.7 ....
Pilot plants	
Pilot plants	
Pilot-scale plants 	
Pilot-scale plants 	
Full-scale plants 	
Full-scale plants 	
Fult-scale plants 	
Full-scale plants 	
Pilot plants	
Full-scale  plant  (operation considered
  not optimized).
Pilot Plant (optimal treatment) 	
Pilot Plant (suboptimal treatment) 	
 Cryptosporidium 2.7-3.1 	, Pilot plants
 Giardia 3.1-3.5	 | Pilot plants
 Cryptosporidium 2.7-5.9 	  Pilot plants
 Giardia 3.4-5.0	  Pilot plants
 Cryptosporidium 1.3-3.8 	  Pilot plants
 Giardia 2.9-4.0	  Pilol plants .
 Cryptosporidium 2-3 	 | Pilot plants
 Cryptosporidium 2 3-4.9 	  Pilot plant .

 Giardia 2.7-5 4	
 Patania et at. 1995
 Patania etal. 1995
 Nieminski/Ongerth 1995
 Nieminski/Ongerth 1995
 Nieminski/Ongerth 1995
 Nieminski/Ongerth 1995
I LeChevallier and Norton 1992

! LeChevallier and Norton 1992
 Foundation for Water Research, Britain
i   1994
| Keltey etal. 1995
: Dugan etal. 1999
 Dugan et al. 1999
 Ongerth/Pecaroro 1995
 Ongerth/Pecaroro 1995
 Patania etal. 1995
 Patania et al. 1995
 Nieminski/Ongerth 1995
 Nieminski/Ongerth 1995
 West etal.  1994
 Swertfegereia/., 1998
                                                   _L
                                                                                     _L
 Patania, Nancy L, et al. 1995
   This study consisted of four pilot
 studies which evaluated treatment
 variables for their impact on
 Cryptosporidium and Giardia removal
 efficiencies. Raw water turbidities in the
 study ranged between 0.2 and 13 NTU.
 When treatment conditions were
 optimized for turbidity and particle
 removal at four different sites,
 Cryptosporidium removal ranged from
 2.7 to 5.9 log and Giardia removal
 ranged from 3.4 to 5.1  log during stable
 filter operation. The median turbidity
 removal was 1.4 log, whereas the
 median particle removal was 2 log.
 Median oocyst and cyst removal was 4.2
 log. A filter effluent turbidity of 0.1
 NTU or less resulted in the most
 effective cyst removal, up to 1 log
 greater than when filter effluent
 turbidities were greater than 0.1 NTU
 (within the 0,1 to 0.3 NTU range).
 Cryptosporidium removal rates of less
 than 2.0 log occurred at the end of the
 filtration cycle.
 Nieminski, Eva  C. and Ongerth, ferry E.
 1995

   This 2-year study evaluated Giardia
 and Cryptosporidium cyst removal
 through direct and conventional
 filtration. The source water of the full
 scale plant had turbidities typicaily
 between 2.5 and 11 NTU with a
 maximum of 28 NTU. The source water
 of the pilot plant typically had
turbidities of 4 NTU with a maximum
of 23 NTU. For the pilot plant achieving
filtered water turbidities between 0.1-
                      0.2 NTU, Cryptosporidium removals
                      averaged 3.0 log for conventional
                      treatment and 3.0 log for direct
                      filtration, while the respective Giardia
                      removals averaged 3.4 log and 3.3 log.
                      For the full scale plant achieving similar
                      filtered water turbidities,
                      Cryptosporidium removal averaged 2.25
                      log for conventional treatment and 2.8
                      log for direct filtration, while the
                      respective Giardia removals averaged
                      3.3 log for conventional treatment and
                      3.9 log for direct filtration. Differences
                      in performance between direct filtration
                      and conventional treatment by the full
                      scale plant were attributed to
                      differences in source water quality
                      during the filter runs.

                      Ongerth, Jerry E. and Pecaroro, J.P.  1995
                        A 1 gallon per minute (gpm) pilot
                      scale water filtration plant was used to
                      measure removal efficiencies of
                      Cryptosporidium and Giardia using very
                      low turbidity source waters (0.35 to 0.58
                      NTU). With optimal coagulation, 3 log
                      removal lor both pathogens were
                      obtained. In one test run, where
                      coagulation was intentionally sub-
                      optimal, the removals were only 1.5 log
                      for Cryptosporidium and 1.3 log  for
                      Giardia. This demonstrates the
                      importance of proper coagulation for
                      cyst removal even though the effluent
                      turbidity was less than 0.5 NTU.
                      LeChevallier, Mark W. and Norton,
                      William D. 1992
                        The purpose of this study was to
                      evaluate the relationships among
                      Giardia, Cryptosporidium, turbidity,
                           and particle counts in raw water and
                           filtered water effluent samples at three
                           different systems. Source water
                           turbidities ranged from less than 1 to
                           120 NTU. Removals of Giardia and
                           Cryptosporidium (2.2 to 2.8 log) were
                           slightly less than those reported by
                           other researchers, possibly because full
                           scale plants were studied under less
                           ideal conditions than the pilot plants.
                           The participating treatment plants
                           operated within varying stages of
                           treatment optimization. The median
                           removal achieved was 2.5 log for
                           Cryptosporidium and Giardia.
                           LeChevallier: Mark W.; Morton. William
                           D.; and Lee, Raymond G.  199lb
                             This study evaluated removal
                           efficiencies for Giardia and
                           Cryptosporidium in 66 surface water
                           treatment plants in 14 States  and 1
                           Canadian province. Most of the utilities
                           achieved between 2 and 2.5 log
                           removals for both Giardia and
                           Cryptosporidium. When no oocysts
                           were detected in the finished water.
                           occurrence levels were assumed at the
                           detection limit for calculating removal
                           efficiencies.
                           Foundation for Water Research 1994
                             This study evaluated
                           Cryptosporidium removal efficiencies
                           for several treatment processes
                           (including conventional filtration) using
                           a pilot plant and bench-scale testing.
                           Raw water turbidity ranged from 1 to 30
                           NTU. Cryptosporidium oocyst removal
                           was between 2 and 3 log using
                           conventional filtration. Investigators

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                   Federal Register /Vol. 65, No.  (59/Monday, April  10,  2000/Proposed Rules
                                                                     19063
concluded that any measure which
reduced filter effluent turbidity should
reduce risk from Cryptosporidium, and
also showed the importance of selecting
proper coagulants, dosages, and
treatment pH, In addition to turbidity,
increased color and dissolved metal ion
coagulant concentration in the effluent
are indicators of reduced efficiency of
coagulation/flocculation and possible
reduced oocysts removal efficiency.
Kelley, M.S. et al. 1995
  This study evaluated two U.S. Army
installation drinking water treatment
systems for the removal of Giardia and
Cryptosporidium. Protozoa removal was
between 1.5 and 2 log. The authors
speculated that this low
Cryptosporidium removal efficiency-
occurred because the coagulation
process was not optimized, although the
finished water turbidity was less than
0.5 NTU.
West, Thomas;eta!. 1994
  This study evaluated the removal
efficiency of Cryptosporidium through
direct  filtration using anthracite mono-
media at filtration rates of 6 and 14
gpm/sq.ft. Raw water turbidity rangnd
from 0.3 to 0.7 NTU. Removal
efficiencies for Cryptosporidium al both
filtration rates were 2 log during filter
ripening (despite turbidity exceeding
0.2 NTU}, and 2 to 3 log for the stable
filter run, Log removal declined
significantly during particle
breakthrough. When effluent turbidity
was less than 0.1 NTU, removal
typically exceeded 2 log, Log removals
of Cryptosporidium generally exceeded
that for particle removal.
Swertfegeretal., 1998
  The  Cincinnati Water Works
conducted a 13 month pilot study to
determine the optimum filtration media
and depth of the media to replace media
at its surface water treatment plant. The
study investigated cyst and oocyst
removal through filtration alone
(excluding chemical addition, mixing,
or sedimentation) and examined sand
media, dual media, and deep dual
media. Cyst and oocyst removal by each
of the media designs was > 2.5 log by
filtration alone.

Dugan et ul, 1999
  EPA conducted pilot scale
t:xp«rimeiit.s to assess the ability of
conventional treatment to control
Cryptosporidium oocysts under steady
state conditions. The work was
performed with a pilot plant designed to
minimize flow rates and the number of
oocysts required for spiking. With
proper coagulation control, the
conventional treatment process
achieved at  least 2 log removal of
Crvptosporidium. In all cases where  2
log removal was not achieved, the plant
also did not comply with the IESWTR
filter effluent turbidity requirements.
  All of the studies described above
indicate that rapid granular filtration,
when operated under appropriate
coagulation conditions and optimized to
achieve a filtered water turbidity level
of less than  0.3 NTU, should achieve at
least 2  log of Cryptosporidium removal.
Removal rates  vary widely, up to almost
6 log. depending upon water matrix
conditions, filtered water turbidity
effluent levels, and where and when
removal efficiencies are measured
within the filtration cycle. The highest
log pathogen removal rates occurred  in
those pilot plants and systems which
achieved very  low finished water
turbidities (less than 0.1 NTU). Other
key points related to the studies
include:
  • As turbidity performance improves
for treatment of a particular water, there
tends to be greater removal of
Cryptosporidium.
  • Pilot plant  study data in particular
indicate high likelihood of achieving at
least 2 log removal when plant
operation is optimized to achieve low
turbidity levels. Moreover, pilot studies
represented  in Table IV.2.a tend to be
for low-turbidity waters, which are
considered to be the most difficult to
treat regarding particulate removal and
associated protozoan removal.
  • Because  high removal rates were
demonstrated in pilot studies using
lower-turbidity source waters, it is
likely that similar or higher removal
rates can be achieved for higher-
turbidity source waters.
  • Determining Cryptosporidium
removal in full-scale plants can be
difficult due to the fact that data
includes many non-detects in the
finished water. In these cases, finished
water concentration levels are assigned
at the detection limit and are likely to
result in over-estimation of oocysts in
the finished water. This  tends to under-
estimate removal levels.
  • Another factor that contributes to
differences among the data is that some
of the full-scale plant data comes from
plants that are not optimized, but meet
existing SWTR requirements. In such
cases, oocyst removal may be less than
2 log. In those studies that indicate that
full-scale plants are achieving greater
than 2 log removal {LeChevallier studies
in particular), the following
characteristics pertain:
—Substantial numbers of filtered water
    measurements resulted in oocyst
    detections;
—Source water turbidity tended to be
    relatively high compared to some of
    the other studies; and
—A significant percentage of these
    systems were also achieving low
    filtered water turbidities,
    substantially less than 0.5 NTU.
  •Removal of Cryptosporidium can
vary significantly in the  course of the
filtration cycle (i.e., at the start-up and
end of filter operations versus the stable
period of operation).
Cryptosporidium Removal Using Slow
Sand and Diatomaceous Earth Filtration

  During development of the IESWTR,
the Agency also evaluated several
studies which demonstrated that  slow
sand and diatomaceous earth filtration
were capable of achieving at least 2 log
removal of Cryptosporidium. Table IV.3
provides key information from these
studies. A brief description of each
study follows the table.
                 TABLE iv.3.—SLOW SAND AND DIATOMACEOUS EARTH FILTRATION REMOVAL STUDIES
Type of treatment
Slow~sand filtration

Diatomaceous earth
filtration

Log removal
Giardia & Cryptosporidium > 3

Giardia & Cryptosporidium > 3
Cryptosporidium 3 3—6 68

Experimental design
Pilot plant at 4 5 to 16 5°C 	
Full-scale plant
Pilot plant
Bench scale

Researcher
Shuler and Ghosh 1991.
imms et at 1995
Shuler et al 1990
Ongerth & Mutton 1997

Shuler and Ghosh 1991

  This pilot study was conducted to
evaluate the ability of slow sand filters
to remove Giardia. Cryptosporidium,
coliforms. and turbidity. The pilot study
was conducted at Pennsylvania State
University using a raw water source
with a turbidity ranging from 0.2-0.4
NTU. Influent concentration of

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Crvptosporidium oocysts during the
pilot study ranged from 1.300 to 13.000
oocysts/gallon. Oo<:yst removal was
shown to be greater than 4 log.
Timms et al 1995
  This pilot study was conducted to
evaluate the efficiency of slow sand
filters at removing C'ryplosporidium. A
pilot plant was constructed of 1.13 ru-
in area and 0.5 m in depth with a
filtration rate of ().3m/h. The filter was
run for 4-5 weeks before the experiment
to ensure proper operation.
Cn'ptoxpfiridium oocysts were spiked to
a concentration of 4,000/L. Results of
the study indicated a 4.5 log removal of
Crvptosporidium oocysts.

Shuleretal 1990
  In this study, diatomaceous earth (DE)
filtration was evaluated for removal of
Giardia. Cryptosporidium. turbidity and
culifonn bacteria. The study used a
O.lm2 pilot scale UK filter with three
grades of"diatonuiccous earth (A, B, and
C). The raw water turbidity varied
between 0.1 and 1 NTU. Filter runs
ranged from 2 days to 34 days. A greater
than 3 log removal of Cryptosporidium
was demonstrated in the 9 filter runs
which made up the study.

Ongerth and Mutton. 1997
  Bench scale studies were used to
define basic characteristics of DE
filtration as a function of DE grade and
filtration rate.  Three grades of DE were
used in the tests, (.'ryptosporidium
removal was measured by applying river
water seeded with Cryptosporidium to
Walton test filters. Tests were run for
filtration rates of 1 and 2 gpm/sq ft.
                     Each run was replicated 3 times.
                     Approximately 6 logs reduction in the
                     concentration of Cryptosporidium
                     oocysts was expected under normal
                     operating conditions.

                     Cn'ptosporidium Removal Using
                     Alternative Fi It nit ion Technologies

                       EPA recognizes that systems serving
                     fewer than 10.000 individuals employ a
                     variety of filtration  technologies other
                     than those previously discussed. EPA
                     collected information regarding several
                     other popular treatment techniques in
                     an effort to verify that these treatments
                     were also technically capable of
                     achieving a 2 log removal of
                     Cryptosporidium. A brief discussion of
                     these alternative technologies  follows
                     along with studies demonstrating
                     effective Cryptosporidium removals.

                     Membrane Filtration

                       Membrane filtration (Reverse
                     Osmosis, Nanofiltration. Ultrafiltration.
                     and Microfiltration) relies upon pore
                     size in order to remove particles from
                     water, Membranes possess a pore size
                     smaller than  that of a Cryptosporidium
                     oocyst. enabling them to achieve
                     effective log removals. The smaller the
                     pore size, the more  effective the rate of
                     removal. Typical pure sizes for each of
                     the four types of membrane filtration are
                     shown below:
                       • Microfiltration — 1-0.1 microns
                       • Ultrafiltration— 0.1-.01 (urn)
                       • Nanofiltration--.01-.001 (urn)
                       • Resvorse Osmosis— <.001
                                                             Bag Filtration
                                                               Bag filters are non-rigid, disposable.
                                                             fabric filters where water flows from
                                                             inside of the bag to the outside of the
                                                             bag. One or more filter bags are
                                                             contained within a pressure vessel
                                                             designed to facilitate rapid change of the
                                                             filter bags when the filtration capacity
                                                             has been used up. Bag filters do not
                                                             generally employ any chemical
                                                             coagulation. The pore sizes in the filter
                                                             bags designed for protozoa removal
                                                             generally are small enough to remove
                                                             protozoan cysts and oocysts but large
                                                             enough that bacteria, viruses and fine
                                                             colloidal clays would pass through. Bag
                                                             filter studies have shown a significant
                                                             range of results in the removal of
                                                             Cryptosporidium oocysts (0.33-3.2 log).
                                                             (Goodrich, 1995}

                                                             Cartridge Filtration
                                                               Cartridge filtration also relies on
                                                             physical screening to remove particles
                                                             from water. Typical cartridge filters are
                                                             pressure filters with glass, fiber or
                                                             ceramic membranes, or strings wrapped
                                                             around  a filter element housed in a
                                                             pressure vessel (USEPA, 1997a).
                                                               The Agency evaluated several studies
                                                             which demonstrate the ability of various
                                                             alternative filtration technologies to
                                                             achieve 2 log removal of
                                                             Cryptosporidium ( in several studies 2
                                                             log removal of 4-5 (urn) microspheres
                                                             were used as a  surrogate for
                                                             Cryptosporidium). These studies
                                                             demonstrate that 2 log removal was
                                                             consistently achievable in all but bag
                                                             filters. Table IV.4 provides key
                                                             information from these studies. A brief
                                                             description of each study follows:
                               TABLE IV.4.—ALTERNATIVE FILTRATION REMOVAL STUDIES
 Type of treatment

Microfiltration 	
Ultrafiltration 	
           Log removal
                                         Experimental design
                                                                                                 Researcher
                                                     Bench Scale
                                                                                      Jacangelo et al. 1997.
                                                                   Drozd & Schartzbrod, 1997.
                                                                   Hirata & Hashimoto.  1998.
                                                                   Goodrich et al. 1995.
                                                                   Jacangelo ef al. 1997.
                                                     Bench Scale  	 ! Collins et al. 1996.
Reverse Osmosis

Hybrid Membrane
Bag Filtration  	
Cartridge filtration .
Cryptosporidium 4.2-4.9 log 	
Giardia 4 6-5.2 log 	
Cryptosporidium 6.0—7.0 log 	  Pilot Plant ...
Cryptosporidium A.3—5.0 log 	 \ Pilot Plant ...
Cryptosporidium 7.0-7.7 log 	  Bench Scale
Microspheres 3.57-3 71 log	  Full Scale ...
Cryptosporidium 4 4—4.9 log 	  Bench Scale
Giardia 4.7-5.2 log 	
Cryptosporidium 5.73-5.89  log 	
Giardia 5.75-5.85 log 	
Cryptosporidium 7.1-7.4 log 	
Cryptosporidium 35 log 	
Microspheres 3-4 log	
Cryptosporidium > 5.7 log 	 ] Pilot Scale
Giardia > 5.7 log
Microspheres 4.18 log 	  Bench Scale 	  Goodrich et al  1995
Microspheres 33-3 2 log 	  Pilot Plant 	  Goodrich et al  1995
Microspheres 3.52-3 68 log	  Pilot Plant 	  Goodrich et al. 1995
Particles (5-15 um) > 2 log  	 ' Bench Scale 	 I Land, 1998.
                                                     Bench Scale
                                                     pilot Plant  ....
                                                                   Hirata & Hashimoto, 1998.
                                                                   Lykins et al. 1994.

                                                                   Adham et at. 1998

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                                                                     19065
Jacangelo et a!., 1997

  Bench scale and pilot plant tests were
conducted with microfiltration and
ultrafiltration filters (using six different
membranes) in order to evaluate
microorganism removal.  Bench scale
studies were conducted under worst
case operating conditions (direct flow
filtration at the maximum recommended
transmembrane pressure using
deionized water slightly buffered at pH
7). Log removal ranged from 4.7 to 5.2
log removal. Pilot plant results ranged
from 6.0-7.0 log removal during worst-
case operating conditions (i.e., direct
filtration immediately after backwashing
at the maximum recommended
operating transmembrane pressure).

Drozd and Schartzbrod, 1997

  A pilot plant system was established
to evaluate the removal of
Cryptosporidium using crossflow
microfiltration (.2 nm porosity). Results
demonstrated Cryptosporidium log
removals of 4.3 to greater than 5.5 with
a corresponding mean filtrate turbidity
of0.25NTU.

Collins et. al, 1996

  This study consisted of bench scale
testing of Cryptosporidium and Giardia
log removals using an ultrafiltration
system. Log removal of Cryptosporidium
ranged from 5.73 to 5.89  log.  while
removal of Giardia ranged from 5.75 to
5.85 log.

Hirata & Hashimoto, 1998

  Pilot scale testing using
microfiltration (nominal pore size of .25
(im) and ultrafiltration (nominal cut-off
molecular weight (MW) 13,000 daltons)
was conducted to determine
Cryptosporidium oocyst removal.
Results conducted on the ultrafiltration
units ranged from 7.1 to 7.5 logs of
Cryptosporidium removal. Results of the
microfiltration studies yielded log
removals from 7.0 to 7.7 log.

Lykins et al., [J994]

  An ultrafiltration system was
evaluated for the removal of
Cryptosporidium oocysts at the USEPA
Test and Evaluation Facility in
Cincinnati, Ohio. The filter run was just
over 48 hours. A  3.5 log removal of
Cryptosporidium oocysts was observed.
Additionally, twenty-four experiments
were performed using 4.5 um
polystyrene microspheres as a surrogate
for Cryptosporidium because of a
similar particle distribution. Log
removal of microspheres ranged from 3
to 4 log.
Adham et al., 1998
  This study was conducted to evaluate
monitoring methods for membrane
integrity. In addition to other activities,
microbia! challenge tests were
conducted on reverse osmosis (RO)
membranes to both determine log
removals and evaluate system integrity.
Log removal of Cryptosporidium and
Giardia was >5.7 log in uncompromised
conditions, and > 4.5 log in
compromised conditions.
Goodrich et al.,  J995
  This study was conducted to evaluate
removal efficiencies of three different
bag filtration systems. Average filter
pore size of the filters was 1 um while
surface area ranged from 35 to 47 sq ft.
Bags were operated at 25. 50 and 100
percent of their maximum flow rate
while spiked with 4.5 u,m polystyrene
microspheres (beads) as a surrogate for
Cryptosporidium. Bead removal ranged
from .33 to 3.2 log removal.

Goodrich et al 1995.
  This study evaluated a cartridge filter
with a 2 um rating and 200 square feet
of surface area for removal  efficiency of
Cryptosporidium sized particles. The
filter was challenge tested with 4.5 um
polystyrene microspheres as a surrogate
for Cryptosporidium. Flow was set at 25
gpm with 50 psi at the inlet. Results
from two runs under the same
conditions exhibited log removals of
3.52 and 3.68.
land, 1998
  An alternative technology
demonstration test was conducted to
evaluate the ability of a cartridge filter
to achieve 2 log removal  of particles in
the 5 to 15 um range. The cartridge
achieved at least 2 log removal of the 5
to 25 um particles 95 percent of the time
up to a 20 psi pressure differential. The
filter achieved at least 2 log removal of
5 to 15 um particles up to 30-psi
pressure differential.
  While the studies above note that
alternative filtration technologies have
demonstrated in the lab the capability to
achieve a 2 log removal of
Cryptosporidium, the Agency believes
that the proprietary nature  of these
technologies necessitates a more
rigorous technology-specific
determination be made. Given this
issue, the Agency believes that its
Environmental Technology Verification
(ETV) Program can be utilized to verify
the performance of innovative
technologies. Managed by EPA's Office
of Research and Development, ETV was
created to substantially accelerate the
entrance of new environmental
technologies into the domestic and
international marketplace. ETV consists
of 12 pilot programs, one of which
focuses on drinking water. The program
contains a protocol for physical removal
of microbiological and particulate
contaminants, including test plans for
bag and cartridge filters and membrane
filters (NSF, 1999). These protocols can
be utilized to determine whether a
specific alternative technology can
effectively achieve a 2 log removal of
Cryptosporidium, and under what
parameters that technology must be
operated to ensure consistent levels of
removal. Additional information on the
ETV program can be found on the
Agency's website at http://
www. epa.gov/etv.

iii. Proposed Requirements
  Today's proposed rule establishes a
requirement for 2 log removal of
Cryptosporidium for surface water and
GWUDI systems serving fewer than
10,000 people that are required to filter
under the SWTR. Compliance with the
combined filter effluent turbidity
requirements, as described later, ensures
compliance with the 2 log removal
requirement. The requirement for a 2 log
removal of Cryptosporidium applies
between a point where the raw water is
not subject to recontamination by
surface water runoff and a point
downstream before or at the first
customer.
iv. Request for Comments
  EPA requests comment on the 2 log
removal requirement as discussed. The
Agency is also soliciting public
comment and data on the ability of
alternative filtration technologies to
achieve 2 log Cryptosporidium removal.

2, Turbidity Requirements
a. Combined Filter Effluent
i. Overview and Purpose
  In order to address concern with
Cryptosporidium, EPA has analyzed log
removal performance by well operated
plants (as described in the previous
section) as well as filter performance
among small systems to develop an
appropriate treatment technique
requirement that assures an increased
level of Cryptosporidium removal. In
evaluating combined filter performance
requirements, EPA considered the
strengthened turbidity provisions
within the IESWTR and evaluated
whether these were appropriate for
small systems as well.
ii. Data
  In an effort to evaluate combined filter
effluent (CFE) requirements, EPA
collected data in several areas to

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supplement existing data, and address
situations unique to smaller systems.
This data includes:
  • An estimate of the number of
systems subject to the proposed
strengthened turbidity requirements;
  • Current turbidity levels at systems
throughout the U.S. serving populations
fewer than 10,000;
  • The ability of package plants to
meet strengthened turbidity standards:
and
  • The correlation between meeting
CFE requirements and achieving 2 log
removal of Cryptosporidium.

Estimate of the  Number of Systems
Subject to Strengthened CFE Turbidity
Standards
  Using the estimate  of 9,134 systems
which filter and serve fewer than 10,000
persons (as described in Section IV.A.I
of today's proposal), the Agency used
the information contained within the
CWSS database to estimate the number
of systems which utilized specific  types
of filtration. The data was segregated
based on the type of filtration utilized
and the population size of the system.
Percentages were derived for each  of the
following types of filtration:
  • Conventional and Direct Filtration;
  • Slow Sand  Filtration;
  • Diatomaceous Earth Filtration; and
  • Alternative Filtration Technologies.
  The percentages were applied to the
estimate discussed in Section IV.A.I of
today's proposal for each of the
respective population categories. Based
on this analysis, the Agency estimates
5,896 conventional and direct filtration
systems will be subject to the
strengthened combined filter effluent
turbidity standards. EPA estimates 1,756
systems utilize slow sand or
diatomaceous earth filtration, and  must
continue to meet turbidity standards set
forth in the SWTR. The remaining  1,482
systems are estimated to use alternative
filtration technologies and will be
required to meet turbidity standards as
                     set forth by the State upon analysis of
                     a 2 log Cryptosporidium demonstration
                     conducted by the system.
                     Current Turbidity Levels
                       EPA has developed a data set which
                     summarizes the historical turbidity
                     performance of various filtration plants
                     serving populations fewer than 10,000
                     (EPA, 1999d). The data set represents
                     those systems that were in compliance
                     with the turbidity requirements of the
                     SWTR during all months being
                     analyzed. The data set consists of 167
                     plants from 15 States. Table IV.5
                     provides information regarding the
                     number of plants from each State. The
                     data set includes plants representing
                     each of the five population groups
                     utilized in the CWSS (25-100, 101-500,
                     501-1,000. 1.001-3,300. and 3.301-
                     10,000). The Agency has also received
                     an additional data set from the State of
                     California (EPA, 2000). This data has
                     not been included in the assessments
                     described below. The California data
                     demonstrates similar results to the
                     larger data set discussed below.

                      TABLE IV.5.—SUMMARY OF  LT1FBR
                             TURBIDITY DATA SET
                               State
                     Alabama	
                     California	
                     Colorado 	
                     Illinois 	
                     Kansas  	
                     Louisiana 	
                     Minnesota 	
                     Montana 	
                     North Carolina
                     Ohio  	
                     Pennsylvania ..
                     South Carolina
                     Texas 	
                     Washington 	
                     West  Virginia .

                        Total	
Number of
  Plants

        1
        1
       16
       13
       20
        6
        3
        2
       16
        4
       27
       16
       23
       17
        2
  This data was evaluated to assess the
national impact of modifying existing
turbidity requirements. The current
performance of plants was assessed with
respect to the number of months in
which selected 95th percentile and
maximum turbidity levels were met.
The data show that approximately 88
percent of systems art; also currently
meeting the new requirements of a
maximum turbidity limit of 1 NTli
(Figure IV.l).  With" respect to the 95th
percentilo turbidity limit, roughly 46
percent of these systems are currently
meeting the new requirement of 0.3
NTU (Figure IV.2) while approximately
70 percent meet this requirement (J
months out of the year. Estimates for
systems needing to make changes to
meet a turbidity performance limit of
0.3 NTU were based on the ability of
systems currently to meet a 0.2 NTU.
This assumption was intended to take
into account a utility's concern with
possible turbidity measurement error
and to reflect  the expectation that a
number of utilities will attempt to
achieve finished  water turbidity levels
below the regulatory performance level
to assure compliance.
  As depicted in Figure IV.l  and IV.2.
the tighter turbidity performance
standards lor  combined filter effluent in
today's proposed rulo reflect the actual,
current performance many systems
already achieve nationally. Revising the
turbidity criteria  effectively ensures that
these systems continue to perform at
their current level while also improving
performance of a substantial  number of
systems that currently meet existing
SWTR criteria, but operate at turbidity
levels higher than proposed in today's
rule.
BILLING CODE C5CO-50-P
                                                       167
                      (EPA, 1999d)

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                                                                19067
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                  Federal Register/Vol. 65, No.  69 / Monday, April 10, 2000/Proposed  Rules
                                                                     19069
Package Plants
  During development of today's
proposed rule, some stakeholders
expressed concern regarding the ability
of "package plants" to meet the
proposed requirements. EPA evaluated
these systems by gathering data from
around the country. The information
affirms the Agency's belief that package
plants can and currently do meet the
turbidity limits in today's proposed
rule.
  Package plants combine the processes
of rapid mixing, flocculation.
sedimentation and filtration (rapid sand,
mixed or dual media filters) into a
single package system. Package
Filtration Plants are preconstructed,
skid mounted and transported virtually
assembled to the site. The use of tube
settlers, plate settlers, or adsorption
clarifiers in some Package Filtration
Plants results in a compact size and
more treatment capacity.
  Package Filtration Plants are
appropriate for treating water of a fairly
consistent quality with low to moderate
turbidity. Effective treatment of source
waters containing high levels of or
extreme variability in turbidity levels
requires skilled operators and close
operational attention. High turbidity or
excessive color in the source water
could require chemical dosages above
the manufacturer's recommendations for
the particular plant. Excessive turbidity
levels may require presedimentation or
a larger capacity plant. Specific design
criteria of a typical package plant and
operating and maintenance
requirements can vary, but an example
schematic is depicted in Figure IV.3.

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 19070
Federal Register/Vol. 65, No. 69/Monday, April 10, 2000/Proposed Rules
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                  Federal  Register/Vol. 65. No.  69/Monday. April  10,  2000/Proposed Rules
                                                                       19071
  The Agency believes that historic data
show that package plants have a
comparable ability to meet turbidity
requirements as conventional or direct
filtration systems.
  A 1987 report of pilot testing using a
trailer-mounted package plant system  to
treat raw water from Clear Lake in
Lakeport, California demonstrates the
ability of such systems to achieve low
turbidity requirements. The raw water
contained moderate to high turbidity (1H
to 103 NTU). Finished water turbidities
ranged from 0.07 to 0.11 NTU (EPA,
1987). Two previous studies (USEPA.
1980a,b and Cambell et al.. 1995) also
illustrate the ability of package systems
throughout the country to meet historic
turbidity performance criteria. These
studies are described briefly:

Package Water Treatment Plant
Performance Evaluation (USEPA,
2980a,b)
  The Agency conducted a study of
package water treatment systems which
encompassed 36 plants in Kentucky.
West Virginia, and Tennessee. Results
from that study showed that the  plants
could provide water that met the
existing turbidity limits established
under the National Interim Primary
Drinking Water Standards. Of the 31
plants at which turbidity measurements
were made, 23 (75 percent) were found
to be meeting existing standards. Of the
8 which did not meet requirements, one
did not use chemical coagulants, and 6
operated less than four hours per day.
(USEPA, 1980a, b)

Package Plants for Small Systems: A
Field Study (Cambell et a!,'1995)
  This 1992 project evaluated the
application of package plant technology
to small communities across the U.S.
The project team visited  48 facilities
across the U.S. Of the 29 surface water
and GWUDI systems, 21  (72 percent)
   li.td grab turbidity samples less than 0.5
   NTU, the 95 percent limit which
   became effective in June of 1993.
   Twelve systems (41 percent) had values
   less than today's proposed 0.3 NTU 95
   percent turbidity limit, (Cambell et al.,
   1(195) It should be noted that today's
   rule requires compliance with turbidity
   limits based on 4 hour measurments.
     The Agency recently evaluated Filter
   Plant Performance Evaluations (FPPEs)
   conducted by the State of Pennsylvania,
   in an effort to quantify the comparative
   abilities of package plants and
   conventional filtration systems to meet
   the required turbidity limits. The data
   set consisted of 100 FPPEs conducted at
   systems serving populations fewer than
   10,000 (PADEP, 1999). Thirty-seven
   FPPEs were conducted at traditional
   conventional filtration systems while 37
   were conducted at package plants or
   "pre-engineered" systems. The
   remaining 26 systems utilized other
   filtration technologies.
     The FPPEs provided a rating of either
   acceptable or unacceptable as
   determined by the evaluation team. This
   rating was based on an assessment of
   the capability of individual unit
   processes to continuously provide an
   effective barrier to the passage of
   microorganisms. Specific performance
   goals were utilized to evaluate the
   performance of the system including the
   consistent ability to produce a finished
   water turbidity of less than 0.1 NTU,
   which is lower than the combined filter
   effluent turbidity requirement in today's
   proposed rule. Seventy-three percent of
   the traditional conventional filtration
   systems were rated acceptable and 89
   percent of the package plants were rated
   acceptable.
     The Agency also evaluated historic
   turbidity data graphs contained within
   each FPPE to provide a comparison of
   the ability of package plants and
   conventional systems to meet the 1 NTU
        max and 0.3 NTU 95 percent
        requirements that are contained in
        today's proposed rule. Sixty-seven
        percent of the conventional systems
        would meet today's proposed
        requirements while 74 percent of
        package systems in the data set would
        meet today's proposed requirements.
        The Agency believes that, when viewed
        alongside the aforementioned studies
        (USEPA, 1980a,b and Cambell et al.,
        1995), it is apparent that package
        systems have the ability to achieve more
        stringent turbidity limits.
        Correlation Between CFE Requirements
        and 2-log Cryptosporidium Removal

          Recent pilot scale experiments
        performed by the Agency assessed the
        ability of conventional treatment to
        control Cryptosporidium under steady
        state conditions. The work was
        performed with a pilot plant that was
        designed to minimize flow rates and as
        a result the number of oocyst required
        for continuous spiking. (Dugan et al.
        1999)
          Viable oocysts were fed into the plant
        influent at a concentration of 106/L for
        36 to 60 hours. The removals of oocysts
        and the surrogate parameters turbidity,
        total particle counts and aerobic
        endospores were measured through
        sedimentation and filtration. There was
        a positive correlation between the log
        removals of oocysts and all surrogate
        parameters through the coagulation and
        settling process. With proper
        coagulation  control, the conventional
        treatment process achieved the 2 log
        total Cryptosporidium removal required
        by the IESWTR. In all cases where 2 log
        total removal was not achieved, the
        plant also did not comply with the
        lESWTR's CFE turbidity requirements.
        Table IV. 6 provides information on
        Cryptosporidium removals from this
        study.
                           TABLE Iv.6.—LOG REMOVAL OF OOCYSTS (DUGAN ET AL. 1999)
               Run
Log removal
  crypto
Exceeds CFE requirements
1 ..
2 ..
3 ..
4 ..
5 ..
6 ..
7 ..
8 ..
9 ..
10
       4.5 j No.
       5.2 ! No.
       1.6 ! Yes. average CFE 2.1 NTU.
       1.7 : Yes, only 88% CFE under 0.3 NTU.
       4.1 No.
       5.1 No.
       02 Yes, average CFE 0.5 NTU.
       0.5 . Yes, only 83% CFE under 0.3 NTU.
       5.1 No.
       4.8 i No.

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 19072
Federal  Register/Vol.  65,  No. 69/Monday,  April 10, 2000/Proposed Rules
 iii. Proposed Requirements
   Today's proposed rule establishes
 combined filter effluent turbidity
 requirements which apply to all surface
 water and GWUDI systems which filter
 and serve populations fewer than
 10,000. For conventional and direct
 filtration systems, the turbidity level of
 representative samples of a system's
 combined filter effluent water must be
 less than or equal to 0.3 NTU in at least
 95 percent of the measurements taken
 each month. The turbidity level of
 representative samples of a system's
 filtered water must not exceed 1 NTU at
 any time.
   For membrane filtration,
 (microfiltration. ultrafiltration,
 nanofiltration,  and  reverse osmosis) the
 Agency is proposing to require that the
 turbidity level of representative samples
 of a system's combined filter effluent
 water must be less than or equal to 0.3
 NTU in at least 95 percent of the
 measurements taken each month. The
 turbidity level of representative samples
 of a system's filtered water must not
 exceed 1  NTU at any time. EPA
 included turbidity limits for membrane
 systems to allow such systems the
 ability to opt out of a possible costly
 demonstration  of the ability to remove
 Cryptosporidium. The studies displayed
 previously in Table IV.4. demonstrate
 the ability of these technologies to
 achieve log-removals in excess of 2 log.
 In lieu of these turbidity limits, a public
 water system which utilizes membrane
 filtration  may demonstrate to the State
 for purposes of membrane approval
 (using pilot plant studies or other
 means) that membrane filtration in
 combination with disinfection treatment
 consistently achieves 3 log removal and/
 or inactivation  of Giardia lamblia cysts,
 4  log removal and/or inactivation of
 viruses, and 2 log removal of
 Cryptosporidium oocysts. For each
 approval, the State will set turbidity
 performance requirements that the
 system must meet at least 95 percent of
 the time and that the system may not
 exceed at any time at a level that
 consistently achieves 3 log removal and/
 or inactivation of Giardia lamblia cysts,
 4 log removal and/or inactivation of
 viruses, and 2 log removal of
 Cryptosporidium oocvsts.
   Systems utilizing slow sand or
 diatomaceous earth filtration must
 continue to  meet the combined filter
 effluent limits established for these
 technologies under  the SWTR (found in
 § 141.73 (b)  and (c)). Namely, the
 turbidity levei of representative samples
of a system's filtered water must be less
than or equal to 1 NTU in at least 95
percent of the measurements taken each
                     month and the turbidity level of
                     representative samples of a system's
                     filtered water must at no time exceed 5
                     NTU.
                       For all other alternative filtration
                     technologies (those other than
                     conventional, direct, slow sand.
                     diatomaceous earth, or membrane),
                     public water systems  must demonstrate
                     to the State for purposes of approval
                     (using pilot plant studies or other
                     means), that the alternative filtration
                     technology in combination with
                     disinfection treatment, consistently
                     achieves 3 log removal and/or
                     inactivation of Giardia lamblia cysts,  4
                     log removal and/or inactivation of
                     viruses, and 2 log removal of
                     Cryptosporidium oocysts. For each
                     approval, the State will set turbidity
                     performance requirements that the
                     system must meet  at least 95 percent of
                     the time and that the system may not
                     exceed at any time at a level that
                     consistently achieves  3 log removal and/
                     or inactivation  of Giardia lamblia cysts,
                     4 log removal and/or inactivation of
                     viruses, and 2 log removal of
                     CryptosporiiHuni oocyst s.

                     iv. Request for Comments
                       EPA solicits comment on the proposal
                     to require systems to meet the proposed
                     combined filter effluent turbidity
                     requirements. Additionally, EPA solicits
                     comment on the following:
                      • The ability of  package plants and/
                     or other unique conventional and/or
                     direct systems to meet the combined
                     filter effluent requirements;
                      • Microbial attachment to particulate
                     material or inert substances in water
                     systems may have  the effect of
                     providing "shelter" to microbes by
                     reducing their exposure to disinfectants
                     (USEPA, 1999e). While inactivation of
                     Cryptosporidium is not a consideration
                     of this rule, should maximum combined
                     filter  effluent limits for slow sand and
                     diatomaceous earth filtration systems  be
                     lowered to 1 or 2 NTU and/or 95th
                     percentile requirements lowered to 0.3
                     NTU  to minimize the ability of turbidity
                     particles to "shelter" Cryptosporidium
                     oocysts?
                      • Systems which practice enhanced
                     coagulation may produce higher
                     turbidity effluent because of the process.
                     Should such systems be allowed to
                     apply to the State for alternative
                     exceedance levels similar to the
                     provisions contained in the rule for
                     systems which practice lime softening'?
                      • Issues specific to small systems
                     regarding the proposed combined filter
                     effluent requirements;
                      • Establishment  of turbidity limits for
                    alternative filtration technologies;
   •  Allowance of a demonstration to
 establish site specific limits in lieu of
 generic turbidity limits, including
 components of such demonstration: and
   •  The number of small membrane
 systems employed throughout the
 country.        :
   The Agency also requests comment on
 establishment of turbidity limits for
 membrane systems. While integrity of
 membranes provides the clearest
 understanding of the effectiveness of
 membranes, turbidity has been utilized
 as an indicator of performance (and
 corresponding Crvptosporidium log
 removal) for all filtration technologies.
 EPA solicits comment on modifying the
 requirements for membrane filters to
 meet integrity testing, as approved by
 the State and with a frequency approved
 by the State.

 b. Individual Filter Turbidity
 i. Overview and  Purpose
   During development of the 1ESVVTR,
 it was recognized that performance of
 individual filters within a plant were of
 paramount importance to producing
 low-turbidity water. Two important
 concepts regarding individual filters
 were discussed.  First, it was recognized
 that poor performance (and potential
 pathogen breakthrough) of one filter
 could be masked by optimal
 performance in other filters, with no
 discernable rise in combined filter
 effluent turbidity. Second, it was noted
 that individual filters are susceptible to
 turbidity spikes (of short duration)
 which would not be captured by four-
 hour combined filter effluent
 measurements. To address the
 shortcomings associated with individual
 filters, EPA established individual filter
 monitoring requirements in the
 IESWTR. For the reasons discussed
 below, the Agency believes it
 appropriate and necessary to extend
 individual filter monitoring
 requirements to systems serving
 populations fewer than 10,000  in the
 LT1FBR.
 ii.  Data
  EPA believes that the support and
 underlying principles regarding the
 IESWTR individual filter monitoring
 requirements are also applicable for the
 LTlFBR. The Agency has estimated that
 5,897 conventional and direct filtration
systems will be subject to today's
proposed individual filter turbidity
requirements. Information regarding this
estimate is found in Section IV.A.2.a of
today's proposal. The Agency has
analyzed information regarding
turbidity spikes and filter masking
which are presented next.

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                  Federal Register/Vol.  05, No. 69/Monday, April  10,  2000/Proposed Rules
                                                                     19073
Turbidity Spikes

  During a turbidity spike, significant
amounts of paniculate matter (including
Cryptosporidium oocysts, if present)
may pass through the filter. Various
factors affect the duration and
amplitude oI filter spikes, including
sudden changes to the flow rate through
tho filter, treatment of the filter
backwash water, filter-to-waste
capability, and site-specific water
quality conditions. Recent experiments
have suggest that surging has a
significant effect on rapid sand filtration
performance (Glasgow and Wheatley,
1998). An example filter profile
depicting turbidity spikes is shown in
Figure IV.4.
BILLING CODE 6560-50-P

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 19074
Federal Register/Vol. 65, No. 69/Monday, April 10, 2000/Proposed Rules
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                  Federal Register/Vol.  65,  No. 69/Monday, April 10,  2000/Proposed Rules
                                                                     19075
  Studies considered by both EPA and
the M-DBP Advisory Committee noted
that the greatest potential for a peak in
turbidity (and thus, pathogen
breakthrough) is near the beginning of
the filter run after filler backwash or
start up of operation (Amirtharajah,
1988; Bucklin. et al. 1988; Cleasby.
1990; and Hall and Croll, 1996). this
phenomenon is depicted in Figure IV.4.
Turbidity spikes also may occur for a
variety of other reasons. These include;
  • Outages or maintenance activities at
processes within the treatment train;
  • Coagulant feed pump or equipment
failure;
  • Filters being run at significantly
higher loading rates than approved;
  • Disruption in filter media:
  • Excessive or insufficient coagulant
dosage: and
  • Hydraulic surges due to pump
changes or other filters being brought
on/off-line.
  A recent study was completed which
evaluated particle removal by filtration
throughout the country. While the
emphasis of this study was particle
counting and removal, fifty-two of the
100 plants surveyed were also surveyed
for turbidity with on-line turbidimeters.
While all of the plants were able to meet
0.5 NTU 95 percent of the time, it was
noted that there was a significant
occurrence of spikes during the filter
runs. These were determined to be a
major source of raising the 95th
percentile value for most of the filter
runs. (McTigue et al. 1998)
BILLING CODE 6560-SO-P

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19076
Federal Register/Vol. 65,  No. 69/Monday, April 10, 2000/Proposed Rules
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       Federal  Register /Vol.  65.  No.  69/Monday, April 10,  2000/Proposed Rules
                                                                                    19077
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      Federal  Register/Vol.  65, No. 69/Monday. April  10, 2000/Proposed  Rules
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      Federal Register/Vol. 65, No. 69/Monday, April 10, 2000/Proposed Rules
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Federal Register/Vol.  65, No. 69/Monday, April 10, 2000/Proposed Rules
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                Federal Register/Vol. 65, No. 69/Monclay, April 10, 2000/Proposed Rules
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19082
Federal  Register/Vol. 65, No.  69/Monday, April  10,  2000/Proposed Rules
Masking of Filter Performance

  Combined Filter Effluent monitoring
can mask poor performance of
individual filters which may allow
passage of participates (including
Cryptosporidium oocysts). One poorly
performing filter, can be effectively
                     "masked" by other well operated filters
                     because water from each of the filters is
                     combined before an effluent turbidity
                     measurement is taken. The following
                     example illustrates this phenomenon.
                      The fictitious City of "Smithville"
                     (depicted in Figure IV.6) operates a
                     conventional filtration plant with lour
rapid granular filters as shown below.
Filter number 1 has significant problems
because the depth and placement of the
media are contributing to elevated
turbidities. Filters 2, 3, and 4 do not
have these problems and are operating
properly.
BILLING CODE 6560-50-P

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                Federal Register/Vol. 65,  No.  69/Monday, April 10,  2000/Proposed  Rules
19083
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 19084
Federal  Register/Vol.  65,  No. 69/Monday, April 10, 2000/Proposed Rules
  Turbidity measurements taken at the
clearwell indicate 0.3 NTU. Filter 4
produces water with a turbidity of 0.08
NTU, Filter 3 a turbidity of 0.2 NTU,
Filter 2 a turbidity of 0.1 NTU, and
Filter 1 a turbidity of 0.9 NTU. Each
filter contributes an equal proportion of
water, but each is operating at different
turbidity levels which contributes to the
combined filter effluent of 0.32 NTU.
([0.08-t-0.2+0.1+0.9M = 0.32 NTU)
  As discussed previously in Section
IV.2.a, the Agency believes that a system
must meet 0.3 NTU 95 percent of the
time an appropriate treatment technique
requirement that assures an increased
level of Cryptosporidium removal.
While the fictitious system described
above  would barely meet the required
CFE turbidity, it is entirely possible that
they would  not be achieving an overall
2 log removal of Cryptosporidium with
one filter achieving considerably less
than 2-log removal. This issue
highlights the importance of
understanding the performance of
individual filters relative to overall
plant performance.

iii. Proposed Requirements

  Today's proposed rule establishes an
individual filter turbidity requirement
which applies to all surface water and
GWUDI systems using filtration and
which serve populations fewer than
10.000 and utilize direct or
conventional filtration. In developing
this requirement, the Agency evaluated
several alternatives (A. B and C) in an
attempt to reduce the burden faced by
small systems while still providing:  (1)
A comparable level of public health
protection as that afforded to systems
serving 10,000 or more people and (2)
an early-warning tool systems can use to
detect  and correct problems with filters.

Alternative A

  The  first alternative considered by trm
Agency was requiring direct  and
conventional filtration systems serving
populations fewer than 10,000 to meet
the same requirements as established for
systems serving 10,000 or more people.
This alternative would require that all
conventional and direct  filtration
systems must conduct continuous
monitoring of turbidity (one turbidity
measurement every 15 minutes) for each
individual filter. Systems must provide
an exceptions report to the State as part
of the existing combined filter effluent
reporting process for any of the
following circumstances:
  (l) Any individual filter with a
turbidity level greater than 1.0 NTU
based on two consecutive measurements
fifteen  minutes apart;
                       (2) Any individual filter with a
                     turbidity greater than 0.5 NTU at the
                     end of the first four hours of filter
                     operation based on two consecutive
                     measurements fifteen minutes apart;
                       (3) Any individual filter with
                     turbidity levels greater than 1.0 NTU
                     based on two consecutive measurements
                     fifteen minutes apart at any time in each
                     of three consecutive months (the system
                     must, in addition to filing an exceptions
                     report, conduct a self-assessment of the
                     filter); and
                       (4) Any individual filter with
                     turbidity levels greater than 2.0 NTU
                     based on two consecutive measurements
                     fifteen minutes apart at any time in each
                     of two consecutive months (the system
                     must file an exceptions report and must
                     arrange for a comprehensive
                     performance evaluation (CPE) to be
                     conducted by the State or a third party
                     approved by the State).
                       Under the first two circumstances
                     identified, a  system must produce a
                     filter profile if no obvious reason for the
                     abnormal filter performance can be
                     identified.

                     Alternative B
                       The second alternative considered by
                     the Agency represents a slight
                     modification from the individual filter
                     monitoring requirements of large
                     systems. The 0.5 NTU exceptions report
                     trigger would be omitted in an effort to
                     reduce the burden associated with daily
                     data evaluation. Additionally, the filter
                     profile requirement would be removed.
                     Requirement language was  slightly
                     modified in an effort to simplify the
                     requirement  for small system operators.
                     This alternative would  still require that
                     all conventional and direct  filtration
                     systems conduct continuous monitoring
                     (one turbidity measurement every 15
                     minutes)  for each individual filter, but
                     includes the  following three
                     requirements:
                       (1) A system must provide an
                     exceptions report to the State as part of
                     the existing combined effluent reporting
                     process if any individual filter turbidity
                     measurement exceeds 1.0 NTU (unless
                     the system can show that the next
                     reading is less than 1.0  NTU):
                       (2) If a system is required to submit
                     an exceptions report for the same filter
                     in three consecutive months, the system
                     must conduct a self-assessment of the
                     filter.
                       (3) If a system is required to submit
                     an exceptions report for the same filter
                     in two consecutive months  which
                     contains an exceedance of 2.0 NTU by
                     the same filter, the system must arrange
                     for a CPE  to be  conducted by the State
                     or a third party approved by the State.
Alternative C
  The third alternative considered by
the Agency would include new triggers
for reporting  and follow-up action in an
effort to reduce the daily burden
associated with data review. This
alternative would still require that all
conventional and direct filtration
systems must conduct continuous
monitoring (one turbidity measurement
every 15 minutes) for each individual
filter, but would include the following
three requirements:
  (1) A system must provide an
exceptions report to the State as part of
the existing combined effluent reporting
process if filter samples exceed 0.5 NTU
in at least 5 percent of the
measurements taken each month and/or
any individual filter measurement
exceeds 2.0 NTU (unless the system can
show that the following reading was  <
2.0 NTU).
  (2) If a system is required to submit
an exceptions report for the same filter
in three consecutive months the system
must conduct a self-assessment of the
filter.
  (3) If a system is required to submit
an exceptions report for the same filter
in two consecutive months which
contains an exceedance of 2.0 NTU by
the same filter, the system must arrange
for a CPE to be conducted by the State
or a third party approved by the State.
  For all three alternatives the
requirements regarding self assessments
and CPEs are the same. If a CPE is
required, the  system must arrange for
the State or a  third party approved by
the State to conduct the CPE no later
than 30 days  following the exceedance.
The CPE must be completed and
submitted to the State no later than 90
days following the exceedance which
triggered the CPE. If a self-assessment is
required  it must  take place within 14
days of the exceedance and  the system
must report to the State that the self-
assessment was conducted.  The self
assessment must consist of at least the
following components:
  • assessment of filter performance;
  • development of a filter profile;
  • identification and prioritization of
factors limiting filter performance;
  • assessment of the applicability of
corrections; and
  • preparation of a filter self
assessment report.
  In  considering each of the above
alternatives, the Agency attempted to
reduce the burden faced by small
systems. Each of the three alternatives
was judged to provide levels of public
health protection comparable to those in
the IESWTR for large systems.
Alternative A, because it contains the

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                  Federal Register/Vol. Ii5, No. 69/Monday, April 10, 2000/Proposed Rules
                                                                     19085
same requirements as IESWTR, was
expected to afford the same level of
 Rublic health protection. Alternative B,
 vhich removes the four-hour 0.5 NTU
trigger and the filter profile
requirement) was expected to afford
comparable health protection because
the core components which provide the
overwhelming majority of the public
health protection (monitoring
frequency, trigger which requires
follow-up action, and the follow-up
actions) are the same as the IESWTR.
Alternative C was expected to provide
comparable health protection because
follow-up action is the same as under
the IESWTR and a 0.5 NTU 95percent
percentile trigger was expected to
identify the same systems which the
triggers established under the IESWTR
would identify. All three were also
considered useful diagnostic tools for
small systems to evaluate the
performance of filters and correct
problems before follow-up action was
necessary. The first alternative was
viewed as significantly more
challenging to implement and
burdensome for smaller systems due to
the amount of required daily data
review. This evaluation was also echoed
by small entity representatives during
the Agency's SBREFA process as well as
stakeholders at each of the public
meetings held to discuss issues related
to today's proposed rule. While
Alternative C reduced burden associated
with daily data review, it would
institute a very  different trigger for small
systems than established by the IESWTR
for  large systems, This was viewed as
problematic by  several stakeholders
who stressed die importance of
maintaining similar requirements in
order to limit transactional costs and
additional State burden. Therefore, the
Agency is proposing Alternative B as
described above, which allows operators
to expend less time to evaluate their
turbidity data. Alternative B maintains a
comparable level of public health
protection as those afforded large
systems, reduces much of the burden
associated with daily data collection
and review (removing the requirement
to conduct a filter profile allows systems
to review data once a week instead of
daily if they so choose), yet still serves
as a self-diagnostic tool for operators
and provides the mechanism for State
follow-up when significant performance
problems exist.
iv. Request for Comments
  The  individual filter monitoring
provisions represent a challenging
opportunity to provide systems with a
useful  tool for assessing  filters and
correcting problems before State
intervention is necessary or combined
filter turbidity is affected and treatment
technique violations occur. The Agency
is actively seeking comment on this
provision. Because of the complexity of
this provision, specific requests for
comment have been broken down into
five distinct areas.

Comments on the Alternatives
  EPA requests comment on today's
proposed individual filter requirement
and each of the alternatives as well as
additional alternatives for this provision
such as establishing a different
frequency for individual filter
monitoring (e.g., 60 minute or 30 minute
increments). The Agency also seeks
comment or information on:
  • Tools and or guidance which would
be useful and necessary in order to
educate operators on how to comply
with individual filter provisions and
perform any necessary calculations;
  • Data correlating individual filter
performance relative to combined filter
effluent;
  • Contributing factors to turbidity
spikes associated with reduced filter
performance;
  • Practices which contribute to poor
individual filter performance and filter
spikes; and
  • Any additional concerns with
individual filter performance.

Mollifications to the Alternatives
  The Agency also seeks comment on a
variety of proposed modifications to the
individual filter monitoring alternatives
discussed which could be incorporated
in order to better address the concerns
and realities of small surface  water
systems. These modifications include:
 " • Modification of the alternatives to
include a provision which would
require systems which do not staff the
plant during all hours  of operation, to
utilize an alarm/phone system to alert
off-site operators of significantly
elevated turbidity levels and  poor
individual filter performance;
  • A modification to allow
conventional and direct filtration
systems with either 2-3 or less filters to
sample combined filter effluent
continuously (every 15 minutes) in lieu
of monitoring individual filter turbidity.
This modification would reduce the
data collection/analysis burden for the
smallest systems while not
compromising the level of public health
protection;
  • A modification to lengthen the
period of time (120 days or a  period of
time established by the State  but not to
exceed 120 days) for completion of the
CPE and/or a modification to lengthen
the requirement that a CPE must be
conducted no later than 60 or 90 days
following the exceedance; and
  • A modification to require systems
to notify the State within 24 hours of
triggering the CPE or IFA. This would
inform States sooner so they can begin
to work with systems to address
performance of filters and conduct CPEs
and IFAs as necessary.
Establishment of Subcategories
  The Agency is also evaluating the
need to establish subcategories in the
final rule for individual filter
monitoring/reporting. EPA is currently
considering these three categories:
  1. Systems serving populations of
3,300 or more persons;
  2. Systems with more than 2 filters,
but less than 3,300 persons; and
  3. Systems with 2 or fewer filters
serving populations fewer than 3,300
persons.
  Individual filter monitoring
requirements would also be based on
these subcategories. Systems serving
3.300 or greater would be required to
meet the same individual turbidity
requirements as the IESWTR
(Alternative A as described above).
Systems serving fewer than 3,300 but
using more than 2 filters would be
required to meet a modified version of
the IESWTR individual filter
requirements (Alternative B as
described above). Systems serving fewer
than 3,300 and using 2 or fewer filters
would  continue to monitor and report
only combined filter effluent turbidity at
an increased frequency (once every 15
minutes, 30 minutes, or one hour).
  Input and or comment on cut-offs for
subcategories and how to apply
subcategories to Alternatives is
requested. The Agency would also like
to take comment on additional strategies
to tailor individual filter monitoring for
the smallest systems while continuing
to maintain an adequate level of public
health  protection. Such possible
strategies include:
  • Since small systems are  often
understaffed one approach would
require those systems utilizing only two
or fewer filters to utilize, maintain, and
continually operate an alarm/phone
system during all hours of operation,
which  alert off-site operators of
significantly elevated turbidity levels
and poor individual filter performance
and/or automatically shuts the system
down if turbidity levels exceed a
specified performance level.  This
modification would be in addition to
the proposed requirements.
  • Establishing a more general
modification which would require
systems which do not staff the plant
during all hours of operation to utilize

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Federal  Register/Vol. 65,  No, 69/Monday, April 10, 2000/Proposed Rules
an alarm/phone system to alert off-site
operators of significantly elevated
turbidity levels and poor individual
filter performance, and/or to
automatically shut the system down if
turbidity levels exceed a specified
performance level.
  •  If systems with 2 or fewer filters is
allowed to sample combined filter
effluent in lieu  of individual filter
effluent with a frequency of a reading
every hour and combined filter effluent
turbidity exceeds 0.5 NTU,  should the
system be required to take grab samples
of individual filter turbidity for all
filters every 15  minutes until the results
of those samples are lower than 0.5
NTU?

Reliability
  Maintaining reliable performance at
systems using filtration requires that the
filters be examined at intervals to
determine if problems are developing.
This can mean that a filter must go off-
line for replacement or upgrades  of
media, underdrains, backwash lines etc.
In order to provide adequate public
health protection at small systems, the
lack of duplicate units can be a problem.
EPA is considering requiring any system
with only one fiher to install an
additional filter. The schedule would be
set by the primacy agency, but the filter
would have  to be installed no later than
6 years after promulgation.  Ef'A is
requesting comment on this potential
requirement.

Data Gathering Recordkeeping and
Reporting
  The Agency is evaluating data
gathering/reporting requirements for
systems.  A system collecting data at a
frequency of once every 15  minutes,
(and operating) 24 hours a day, would
record approximately 2800  data points
for each filter throughout the course of
the month. Although the smallest
systems in operation today  routinely
operate on the average of 4 to 12 hours
a day (resulting in 480 to 1400 data
points per filter}, these systems do not
typically use sophisticated data
recording systems such as SCADAs. The
lack of modern equipment at small
systems may result in difficulty with
retrieving and analyzing data for
reporting purposes.  While the Agency
intends to issue guidance targeted at
aiding these systems with the data
gathering requirements, EPA is also
seeking feedback on a modification to
the frequency of data gathering required
under each of the aforementioned
options. Specifically, the  Agency would
like to request comment on  modifying
the frequency for systems serving fewer
than 3,300 to continuous monitoring on
                     a 30 or 60 minute basis. EPA also
                     requests comment on the availability
                     and practicality of data systems that
                     would allow small systems. State
                     inspectors, and technical assistance
                     providers to use individual filter
                     turbidity data to improve performance,
                     perform filter analysis, conduct
                     individual filter soil'assessments, etc.
                     The Agency is interested in specific
                     practical combinations of data
                     recorders, charts, hand written
                     recordings from turbidimeters, that
                     would accomplish this.

                     Failure of Continuous Turbidity
                     Monitoring
                       Under today's proposed rule, the
                     Agency requires that if there is a  failure
                     in the continuous turbidity monitoring
                     equipment, the system must conduct
                     grab sampling every four hours in lieu
                     of continuous monitoring until the
                     turbidimeter is back on-line. A system
                     has live working days to resume
                     continuous monitoring before a
                     violation is incurred. EPA would like to
                     solicit comment on modifying this
                     component to require systems to take
                     grab samples at an increased frequency,
                     specifically every 30 minutes. 1 hour, or
                     2 hours.
                     B. Disinfection Benchmarking
                     Requirements
                      Small systems will be required to
                     comply with the Stage 1 Disinfection
                     Byproduct Rule (Stage 1 DBPR) in the
                     first calendar quarter of 2004. The Stage
                     1 DBPR set Maximum Contaminant
                     Levels (MCLs) for Total
                     Trihalomethanes (chloroform,
                     bromodichlorometlKine,
                     chlorodibromomethane, and
                     bromoform),  and five Haloacetic Acids
                     (i.e.. the sum of the concentrations of
                     mono-, di-. and trichloroacetic acids and
                     mono- and dibrornoacetic acids.) The
                     I/I'1FBR follows the principles set forth
                     in earlier FACA negotiations, i.e., that
                     existing microbial protection must not
                     be significantly reduced or undercut as
                     a result of systems taking the necessary
                     steps to comply with the MCL's for
                     TTHM and HAAS set forth in Stage 1
                     DBPR. The disinfection benchmarking
                     requirements are designed to ensure that
                     risk from one contaminant is not
                     increased while risk from another
                     contaminant is decreased.
                      The Stage 1 DBPR was promulgated
                     because disinfectants such as chlorine
                     can react with natural organic and
                     inorganic matter in  source water and
                     distribution systems to form
                     disinfection byproducts (DBFs). Results
                     from toxicology studies have shown
                     several DBPs (e.g..
                     bromodichloromethane, bromoform.
chloroform, dichloroacetic acid, and
bromate) to potentially cause cancer in
laboratory animals. Other DBl's (e.g..
certain haloacetic acids) have been
shown to cause adverse reproductive or
developmental effects in laboratory
animals. Concern about these health
effects may cause public water utilities
to consider altering their disinfection
practices to minimize health risks to
consumers.
  A fundamental principle, therefore, of
the 1992-1993 regulatory negotiation
reflected in the 1994 proposal for the
1ESVVTR was that new standards for
control of DBPs must not result in
significant  increases in microbial risk.
This principle was also one of the
underlying premises of the 1997 M-DBP
Advisory Committee's deliberations,
i.e., that existing microbial protection
must not be significantly reduced or
undercut as a result  of systems taking
the necessary steps to comply with the
MCL's for TTHM and HAA5 set forth in
Stage 1 DBPR. The Advisory Committee
reached agreement on the use of
microbial profiling and benchmarking
as a process by which a PWS and the
State, working together, could assure
that there would be no significant
reduction in microbial protection as the
result of modifying disinfection
practices in order to comply with Stage
1 DBPR.
  The process established under the
IESWTR has three components: (1)
Applicability Monitoring; (2)
Disinfection Profiling; and (3)
Disinfection Benchmarking. These
components have the following three
goals respectively; (1) determine which
systems have annual average TTHM and
HAAS levels close enough to the MCL
(e.g., 80 percent of the MCL) that they
may need to consider altering their
disinfection practices to comply with
Stage 1 DBPR; (2) those systems that
have TTHM and HAAS levels of at least
80 percent  of the MCLs must develop a
baseline of current microbial
inactivation over the period of  1 year;
and (3) determine the benchmark, or the
month with the lowest average  level of
microbial inactivation, which becomes
the critical  period for that year.
  The aforementioned components were
applied to systems serving 10,000 or
more people in the IESWTR and were
carried out sequentially. In response to
concerns about early implementation
(any requirement which would require
action prior to 2 years after the
promulgation date oi the rule),  the
Agency is considering modifying the
IESWTR approach for small systems, as
described in the following section.
Additionally, the specific provisions
have been modified  to take into account

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                                                                    19087
specific needs of small systems. EPA's
goal in developing these requirements is
to recognize the specific needs of small
system and States, while providing
small systems with a useful means of
ensuring that existing microbial
protection must not be significantly
reduced or undercut as a result of
systems taking the necessary steps to
comply with the MCL's for TTHM and
HAAS set forth in Stage 1 DBPR.
  The description of me disinfection
benchmarking components of today's
proposed rule will be broken into the
three segments: (1) Applicability
Monitoring;  (2) Disinfection Profiling;
and (3) Disinfection Benchmarking.
Each section will provide an overview
and purpose, data, a description of the
proposed requirements, and request for
comment.
1. Applicability Monitoring
a. Overview  and Purpose
  The purpose of the TTHM and HAAS
applicability monitoring is to serve as
an indicator  for systems that are likely
to consider making changes to their
disinfection  practices in order to
comply with the Stage  1 DBPR. TTHM
samples which equal or exceed 0.064
mg/L and/or HAAS samples equal or
exceed 0.048 mg/L (80 percent of their
respective MCLs) represent DBP levels
of concern. Systems with TTHM or
HAAS levels exceeding 80 percent of
the respective MCLs may consider
changing their disinfection practice in
order to comply with the Stage 1 DBPR.

b. Data

   In 1987, EPA established monitoring
requirements for 51 unregulated
synthetic organic chemicals.
Subsequently, an additional 113
unregulated contaminants were added
to the monitoring requirements.
Information on TTHMs has become
available from the first round of
monitoring conducted by systems
serving fewer than 10.000 people.
  Preliminary analysis of the data from
the Unregulated Contaminant
Information System (URCIS, Data]
suggest that roughly 12 percent of
systems serving fewer than 10,000
would exceed 64 pi/L or 80 percent of
the MCL for TTHM (Table 1V.7). This
number is presented only as an
indicator, as it  represents samples taken
at the entrance to distribution systems.
In general, TTHMs and HAASs tend to
increase with time as water travels
through the distribution system. The
Stage 1 Disinfection Byproducts Rule
estimated 20 percent of systems serving
fewer than 10,000 would exceed 80
percent of the MCLs for either TTHMs
or HAASs or both. EPA is working to
improve the knowledge of TTHM and
HAAS formation kinetics in the
distribution systems for systems serving
fewer than 10,000 people. EPA is
currently developing a model to predict
the formation of TTHM and HAAS in
the distribution system based on
operational measurements. This model
is not yet available. In order to develop
a better estimate of the percent of small
systems that would be triggered  into the
profiling requirements (i.e., develop a
profile of microbial inactivation over a
period of 1 year) EPA is considering the
following method:
  • Use URCIS data to show how many
systems serving 10,000 or more people
have TTHM levels at or above  0.064 mg/
L;
  • Compare those values to the data
received from the Information
Collection Rule for TTHM average
values taken at representative points in
the distribution system;
  • Determine the mathematical factor
by which the two values differ; and
  • Apply that factor to the URCIS data
for systems serving fewer than 10,000
people to estimate the percent of those
systems that would have TTHM values
at or above 0.064mg/L as an average of
values taken at representative points in
the distribution system.
                             TABLE iv,7.—TTHM LEVELS AT SMALL SURFACE SYSTEMS
                                  [Data from Unregulated Contaminant Database. 1987-92']
System size (population served)
<500 . .. 	
501 1 000 . 	
1001 3300 ... 	
3301-10000 	

Total 	
Total num-
ber of sys-
tems
74
44
114
116

348
Number of
systems w/
ave. TTHM
> 64 ug/L
(80 % of
MCL)
0 (0%)
6 (136%)
12(10.5%)
25(21.6%)

43(12.4%)
Maximum
level of ave.
TTHM
(M9/1-)
56
222
172
279

279
  1ln Unregulated Contaminant Database (1987-1992). (here are ten States (i.e., CA. DE. IN, MO, Ml, MO. NC, NY, PR, WV). However, only
eight of them can be identified with the data of both population and TTHM for systems serving fewer than 10.000 people (See next page).
  The Agency requests comment on this
approach to estimating TTHM levels in
the distribution system based on TTHM
levels at the entry point to the
distribution system. The Agency also
requests comment on the relationship of
HAAS formation relative to TTHM
formation in the distribution system.
Specifically, is there data to support the
hypothesis that HAA5S do not peak at
the same point in the distribution
system as TTHMs?
  The Agency also received two full
years of TTHM data for seventy-four
systems in the State of Missouri
(Missouri, 1998). This data consisted of
quarterly TTHM data, which was
converted into  an annual average. The
data (presented in Table IV.8)
demonstrates a very different picture
than that displayed by the URCIS data
described above. In 1996, 88 percent of
the systems exceeded 64 Mg/L, while in
1997, 85 percent exceeded 64 u.g/L.
Figure IV. 7 graphically displays this
data set.

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Federal Register/Vol. 65, No. 69/Monday, April 10, 2000/Proposed Rules
               TABLE IV.8. — TTHM LEVELS AT SMALL SURFACE SYSTEMS IN THE STATE OF MISSOURI
                                          [State of Missouri, 1996, 1997]
                                   Year
                                                            Total num-
                                                            ber of sys-
                                                              tems
Number of  •
systems w/  j  Maximum
ave. TTHM  \  Level of
> 64 ng/L  | Ave. TTHM
(80 percent  \

1996 	 	
1997 	 	
All years 	


74
75
149

OI WOLJ
65 (88%)
64 (85%)
129 (87%)


276
251
276

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                  Federal Register/Vol.  65,  No. 69/Monday,  April  10,  2000/Proposed Rules
                                                                 19089
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  There are several potential reasons for
the differences between the datn shown
in Tables IV.7 and IV.8. Data in Table
IV.7 contains zero values which may be
indicative of no sample being taken
rather than a sample with a value of
zero. Additionally, data shown in IV.8
was collected within the distribution
system, while data in Table IV.7 was
taken at the entry point to the
distribution system. The data collection
method used in collecting the data

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Federal  Register/Vol. 65, No.  69/Monday, April  10,  2000/Proposed Rules
 shown in Table IV.8 is similar to the
 methodology required under the Stage 1
 DBPR.

 c. Proposed Requirements
   EPA considered four alternatives for
 systems to use TTHM and HAAS data to
 determine  which systems whether they
 would be required to develop a
 disinfection profile. In today's proposed
 rule, EPA is proposing Alternative 4.

 Alternative 1
   The IESWTR required that systems
 monitor for TTHMs at four points in the
 distribution system each quarter. At
 least one of those samples must  be taken
 at a point which represents the
 maximum  residence time of the  water in
 the system. The remaining three must be
 taken at representative locations in the
 distribution system, taking into account
 number of persons served, different
 sources of water and  different treatment
 methods employed. The results  of all
 analyses per quarter are averaged and
 reported to the State.
   EPA considered applying this
 alternative to systems serving fewer
 than 10,000 people and requested input
 from small system operators and other
 interested parties, including the  public.
 Based on the feedback EPA received.
 two other alternatives were developed
 for consideration (listed as Alternatives
 2 and 3).

 Alternative 2
   EPA considered requiring systems
 serving fewer than 10,000 people to
 monitor for TTHM and HAAS at the
 point of maximum residence time
 according to the following schedule:
   • No less than once per quarter per
 treatment plant operated for systems
 serving populations between 500 and
 10,000 persons; and no less than once
 per year per treatment plant during the
 month of warmest water temperature for
 systems serving populations less than
 500. If systems wish to take additional
 samples, however, they would be
 permitted to do so.
   • Systems may consult with States
 and elect not to perform TTHM and
 HAAS monitoring and proceed directly
 with the development of a disinfection
 profile.
   This alternative provides an
 applicability monitoring frequency
 identical to the DBF monitoring
 frequency under the Stage 1 DBPR that
 systems will have to comply with in
 2004. In addition, it allows systems the
 flexibility to skip TTHM and'HAAS
 monitoring completely, pending State
approval, and begin profiling
 immediately.
                    Alternative 3
                      EPA considered requiring all systems
                    serving fewer than 10,000 people to
                    monitor once per year per system during
                    the month of warmest water
                    temperature of 2002 and at the point of
                    maximum residence time.
                      During the SBREFA process and
                    during stakeholder meetings, EPA
                    received some positive comments
                    regarding Alternative 3 as the least
                    burdensome approach. Other
                    stakeholders, however, pointed out that
                    Alternative 3 does not allow systems to
                    measure seasonal variation as is done in
                    Alternative 2 for systems serving
                    populations between 500 and 10,000.
                    Several stakeholders agreed that despite
                    the costs,  the information obtained from
                    applicability monitoring will be useful.
                    EPA agrees that it is valuable to systems
                    to monitor and understand the seasonal
                    variation in TTHM and HAAS values,
                    however, EPA has determined that
                    requiring a full year of monitoring may
                    place an excessive burden on both
                    States and systems. In order to complete
                    a full year of monitoring and another
                    full year of disinfection data gathering,
                    systems would have to start TTHM and
                    HAAS monitoring January of 2002.
                      Under SDVVA, States have two years
                    to develop their own regulations as part
                    of their primacy requirements, EPA
                    recognized that requiring Applicability
                    Monitoring during this period would
                    pose a burden on States.  In response to
                    these concerns, the Agency developed a
                    new alternative, described in the
                    following paragraph.

                    Alternative 4
                      Applicability Monitoring is optional
                    and not a requirement under today's
                    proposed rule. If a system has TTHM
                    and HAAS data taken during the month
                    of warmest water temperature (from
                    1998-2002) and taken at the point of
                    maximum residence time, they may
                    submit this data to the State prior to
                    [DATE 2 YEARS AFTER PUBLICATION
                    OF FINAL RULE]. If the data shows
                    TTHM and HAAS levels  less than 80
                    percent of the MCLs, the system does
                    not have to develop a disinfection
                    profile. If the data shows TTHM and
                    HAAS levels at or above 80 percent of
                    the MCLs, the system would be required
                    to develop a disinfection profile in 2003
                    as described later in section IV.B.2. If
                    the system does not have, or does not
                    gather TTHM and HAAS data during the
                    month of warmest water temperature
                    and at the point of maximum residence
                    time in the distribution system as
                    described, then the system would
                    automatically be  required to develop a
                    disinfection profile starting January 1 of
 2003. This option still provides systems
 with the necessary tools for assessing
 potential changes to their disinfection
 practice, (i.e. the generation of the
 profile), while not forcing States to pass
 their primacy regulations, contact all
 small systems within their jurisdiction,
 and set up TTHM and HAAS monitoring
 all within the first year after
 promulgation of this rule. Systems will
 still be able to ensure public health
 protection by having the disinfection
 profile when monitoring under Stage 1
 DBPR takes effect. It should be noted
 that EPA estimates the cost for
 applicability monitoring (as described
 in Alternative 4) and disinfection
 profiling (as described in Alternative 3
 in Section IV.B.2.C of this preamble) are
 roughly equivalent. EPA anticipates that
 systems with known low levels of TOG
 may opt to conduct the applicability
 monitoring while the remaining systems
 will develop a disinfection profile.
 d. Request for Comment
  EPA requests comment on the
 proposed  requirement, other
 alternatives listed, or other alternatives
 that have not yet been raised for
 consideration. The Agency also requests
 comment on approaches for determining
 the percent of systems that would be
 affected by this requirement.
 Specifically:
  • With  respect to Alternative 4, the
 Agency requests comment on
 approaches for determining the percent
 of systems that might demonstrate
 TTHM and HAAS levels less than 80
 percent of their respective MCLs and
 would therefore not develop a
 disinfection profile.
  • The Agency requests additional
 information  (similar to the State of
 Missouri data discussed previously) on
 the current levels of TTHM and HAASs
 in the distribution systems of systems
 serving fewer than 10,000 people.
  • The Agency requests comment on
 developing a TTHM and HAAS
 monitoring scheme during the winter
 months as opposed to the current
 monitoring scheme based on the highest
TTHM/HAA5 formation potential
 during the month of warmest water
 temperature. If a relationship can be
 established, and shown to be consistent
 through geographical variations, EPA
 would consider modifying an
alternative so that applicability
 monitoring would occur during the 1st
quarter of  2003.
  •  The Agency requests comment on
modifying Alternative 3, to require
systems to begin monitor for TTHMs
and HAASs during the warmest water
temperature month of 2003, The results
of this monitoring would be used to

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                  Federal Register/Vol.  65,  No. 69/Monday, April 10, 2000/Proposed  Rules
                                                                     19091
determine whether a system would need
to develop a disinfection profile during
2004. This option is closer in structure
and timing to the 1ESWTR and has been
included for comment. It should be
noted, however, that postponing the
disinfection profile until 2004 would
prevent systems from having
inactivation data prior to their
compliance date with the Stage 1 DBPR,
possibly compromising simultaneous
compliance.

2. Disinfection Profiling
a. Overview and Purpose

  The disinfection profile is a graphical
representation showing how
disinfection varies at a given plant over
time. The profile gives the plant
operator an idea of how seasonal
changes in water quality and water
demand can have a direct effect on the
level of disinfection the plant  is
achieving.
  The strategy of disinfection  profiling
and benchmarking stemmed from data
provided to the EPA and M-DBP
Advisory Committee by PWSs and
reviewed by stakeholders. The microbial
inactivation data (expressed as logs of
Giardia lamblia inactivation) used bv
the M-DBP Advisory Committee
demonstrated high variability.
Inactivation varied by several log on a
day-to-day basis at any particular
treatment  plant and by as much as tens
of logs over a year due to changes in
water temperature, flow rate [and,
consequently, contact lime), seasonal
changes in residual disinfectant, pH,
and disinfectant demand and,
consequently, disinfectant residual.
There were also differences between
years at individual plants. To address
these variations, M-DBP stakeholders
developed the procedure of profiling
inactivation levels at an individual
plant over a period of at least one year,
and then establishing a benchmark of
minimum inactivation as a way to
characterize disinfection practice. This
approach makes it possible for a plant
that may need to change its disinfection
practice in order to meet DBP MCLs to
determine the impact the change would
have on its current level of disinfection
or inactivation and, thereby, to assure
that there  is no significant increase in
microbial  risk. In order to develop the
profile, a system must measure four
parameters (EPA is assuming most small
systems use chlorine as their
disinfection agent, and these
requirements are based on this
assumption):
  (1) Disinfectant residual concentration
(C, in mg/L) before or at the first
customer and just prior to each
additional point of disinfectant
addition;
  (2) Contact time (T, in minutes)
during peak flow conditions;
  (3) Water temperature (°C); and
  (4) PH.
  Systems convert  this operational data
to a number representing  log
inactivation values for Giardia by using
tables provided by  EPA. Systems graph
this information over time to develop a
profile of their microbial inactivation.
EPA will prepare guidance specifically
developed for small systems to assist in
the development of the disinfection
profile. Several spreadsheets and simple
programs are currently available to aid
in calculating microbial inactivation
and the Agency intends to make such
spreadsheets available in  guidance.

b. Data

  Figure IV.8a depicts a hypothetical
disinfection profile showing seasonal
variation in microbial inactivation.
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Federal Register/Vol. 65, No. 69/Monday. April 10, 2000/Proposed Rules
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                  Federal Register/Vol.  65, No. 69/Monday, April 10, 2000/Proposed Rules
                                                                     19093
c. Proposed Requirements
  EPA considered four alternatives for
requiring systems to develop the
disinfection profile.

Alternative 1
  The IESWTR requires systems serving
10,000 or more persons to measure the
four parameters described above and
develop a profile of microbial
inactivation on a daily basis. EPA
considered extending this requirement
to systems serving fewer than 10,000
persons and requested input from small
system operators and other interested
stakeholders including the public. EPA
received feedback that this requirement
would place too heavy of a burden on
the small system operator for at least
two reasons:
  • Small system operators are not
present at the plant every day; and
  • Small systems often have only one
operator at a plant who is responsible
for all aspects of maintenance,
monitoring and operation.

Alternative 2
  EPA also considered not requiring the
disinfection profile at all. After
consideration of the feedback of small
system operators and other interested
stakeholders, however, EPA believes
that there is a strong benefit in the plant
operator knowing the level of microbial
inactivation, and that the principles
developed during the regulation
negotiation and Federal Advisory
Committee prior to promulgation of the
IESWTR could be applied to small
systems for the purpose of public health
protection. Recognizing the potential
burdens the profiling procedures placed
on small systems, EPA considered two
additional alternatives.

Alternative 3
  EPA considered requiring all systems
serving fewer than 10,000 persons, to
develop a disinfection profile based on
weekly measurements for one year
during or prior to 2003. A system with
TTHM and HAAS levels less than 80
percent of the MCLs (based on either
required or optional monitoring as
described in section IV.B.I) would not
be required to conduct disinfection
profiling. EPA believes this alternative
would save the operator time [in
comparison to Alternative 1). and still
provide information on seasonal
variation over the period of one year.
Alternative 4
  Finally, EPA considered a monitoring
requirement only during a one month
critical monitoring period to be
determined by the State. In general,
colder temperatures reduce disinfection
efficiency. For systems in warmer
climates, or climates that do not change
very much during the course of the year,
the State would identify other critical
periods or conditions. This alternative
reduces the number of times the
operator has to calculate the microbial
inactivation.
  EPA considered all of the above
alternatives, and in today's proposed
rule, EPA is proposing Alternative 3.
First, this alternative does not require
systems to begin monitoring before
States have two years to develop their
regulations as part of primacy
requirements. Given early
implementation concerns, the timing of
this alternative appears to be the most
appropriate in balancing early
implementation issues with the need for
systems to prepare for implementation
of the Stage 1 DBPR and ensuring
adequate and effective microbial
protection. Second, it allows  systems
and States which have been proactive in
conducting applicability monitoring to
reduce costs for those systems which
can demonstrate low TTHM and HAA5
levels. Third, this alternative allows
systems and States the opportunity to
understand seasonal variability in
microbial disinfection. Finally, this
alternative takes into account the
flexibility needed by the smallest
systems while maintaining comparable
levels of public health protection with
the larger systems.
Request for Comments
  EPA requests comment on this
proposed requirement as well as
Alternatives 1,2, and 4.  The Agency also
requests comment on a possible
modification to Alternatives 1, 3 and 4.
Under this modification, systems
serving populations fewer than 500
would have the opportunity to apply to
the State to perform the weekly
inactivation calculation (although data
weekly data collection would  still be
required). If the system decided to make
a change in disinfection practice, then
the State would assist the system with
the development of the disinfection
profile.
  The Agency also requests comment on
a modification to Alternative 3 which
would require systems to develop a
disinfection profile in 2004 only if
Applicability Monitoring conducted in
2003 indicated TTHM and HAAS levels
of 80 percent  or greater of the MCL. This
modification would be coupled with the
applicability monitoring modification
discussed in the previous section.
3. Disinfection Benchmarking
a. Overview and Purpose

  The DBPR requires systems to meet
lower MCLs for a number of disinfection
byproducts. In order to meet these
requirements, many systems will
require changes to their current
disinfection practices. In order to ensure
that current microbial inactivation does
not fall below those levels required for
adequate Giardia and virus inactivation
as required by the SWTR, a disinfection
benchmark is necessary. A disinfection
benchmark represents the lowest
average monthly Giardia inactivation
level achieved by a system. Using this
benchmark States and systems can begin
to understand the current inactivation
achieved at the system, and estimate
how changes to disinfection practices
will affect inactivation.

b. Data

  Based on the hypothetical
disinfection profile depicted in Figure
IV.8a, the benchmark, or critical period,
is the lowest level of inactivation
achieved by the system over the course
of the year. Figure IV.Sb shows that this
benchmark (denoted by the dotted line)
takes place in December for the
hypothetical system.
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19094
Federal Register/Vol. 65, No. 69/Monday, April 10,  2000/Proposed Rules
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                  Federal Register/Vol.  65.  No. 09/Monday,  April 10. 2000/Proposed  Rules
                                                                     19095
c. Proposed Requirements

  If a system that is required to produce
a disinfection profile decides to make a
significant change in disinfection
practice after the profile is developed, it
must consult with the State and receive
approval before implementing such a
change. Significant changes in
disinfection practice are defined as: (1)
moving the point of disinfection (other
than routine seasonal changes already
approved by the State): (2) changing the
type of disinfectant; (3) changing the
disinfection process; or (4) making other
modifications designated as significant
by the State. Supporting materials for
such consultation with the State must
include a description of the proposed
change, the disinfection profile
developed under today's proposed rule
for Giardia lamblia (and, if necessary,
viruses for systems using ozone or
ehloramines), and an analysis of how
the proposed change might affect the
current level of Giardia inactivation. In
addition, the State is required to review
disinfection profiles as part of its
periodic sanitary survey,
  A log inactivation benchmark is
calculated as follows:
  (1) Calculate the average log
inactivation for either each calendar
month, or critical  monitoring period
(depending on final rule requirement for
the profiling provisions).
  (2) Determine the calendar month
with the lowest average log inactivntkm;
or lowest inactivation level within the
critical monitoring period.
  (3) The lowest average month, or
lowest level during the critical
monitoring period becomes the critical
measurement for that year.
  (4) if acceptable data from multiple
years are available, the average of
critical periods for each year becomes
the benchmark.
  (5) If only one year of data is
available, the critical period (lowest
monthly average inactivation level) for
that year is the benchmark.

d. Request for Comments

  EPA has included a requirement that
State approval be obtained prior to
making a significant change to
disinfection practice. EPA requests
comment on whether the rule should
require State approval or whether only
state consultation  is necessary.
  EPA also requests comment on
providing systems serving fewer than
500 the option  to provide raw data to
the State, and allowing the State to
determine the benchmark.
C. Additional Requirements

1, Inclusion of Cryptosporidium in
del mil ion of GWUDI
a. Overview and Purpose
   Croundwater sources are found to be
under the direct influence of surface
water (GWUDI) if they exhibit specific
traits. The SWTR defined ground waters
containing Giardia lamblia as GWUDI.
Onti such trait is the presence of
protozoa such as Giardia which migrate
from surface water to groundwater. The
IESVVTR expanded the SWTR's
definition of GWUDI to include the
presence of Cryptosporidium. The
Agency believes it appropriate and
necessary to extend this  modification of
the definition of GWUDI to systems
serving  fewer than  10,000 persons.

b. Data
  The Agency issued guidance on the
Microscopic Particulate Analysis (MPA)
in October 1&92 as the Consensus
Method for Determining Groundwater
Under the Direct Influence of Surface
Water Using Microscopic Particulate
Analysis (EPA,  1992). Additional
guidance for making GWUDI
determinations is also available
(USEPA, 1994a,b). Since 1990. States
have acquired substantial experience in
making  GWUDI determinations and
have documented their approaches
(Massachusetts Department of
Environmental Protection, 1993;
Maryland. 1993; Sonoma County Water
Agency, 1991). Guidance on existing
practices undertaken by States in
response to the SWTR may also be
found in the State Sanitary Survey
Resource Directory, jointly published in
December 1995 by EPA and the
Association of State Drinking Water
Administrators (EPA/ASDWA).
AWWARF has also published guidance
(Wilson et al., 1996).
  Most recently. Hancock et al. (1997)
used the MPA test to study the
occurrence of Giardia and
Cryptosporidium in the subsurface.
They found that, in a study of 383
ground water samples, the presence of
Giardia  correlated with the presence of
Cryptosporidium. The presence of both
pathogens correlated with the amount of
sample examined, but not with the
month of sampling. There was a
correlation between source depth and
occurrence of Giardia but not
Cr\rptosporidium. The investigators also
found no correlation between the
distance of the ground water  source
from adjacent surface water and the
occurrence of either Giardia or
Cn'ptosporidium. However, they did
find a correlation between distance from
a surface water source and generalized
MPA risk ratings of high (high
represents an MPA score of 20 or
greater), medium or low, but no
correlation was found with the specific
numerical values that are calculated by
the MPA scoring system. An additional
two reports (SAIC 1997a and 1997b)
provide data on wells with Giardia cyst
and Cryptosporidium oocyst recovery
and concurrent MPA analysis.

c. Proposed Requirements
  In today's proposed rule, EPA is
modifying the definition of GWUDI to
include Cryptosporidium for systems
serving fewer than 10,000 persons.
  Under the SWTR. States were
required to determine whether systems
using ground  water were using ground
water under the direct influence of
surface water (GWUDI). State
determinations were required to be
completed by June 29,1994 for CWSs
and by June 29,1999 for NCWSs. EPA
does not believe that  it is necessary to
make a new determination of GWUDI
for this rule based on the  addition of
Cryptosporidium to the definition of
"ground water under the direct
influence of surface water". While a
new determination is not required,
States may elect to conduct a new
analysis based on such factors as a new
land use pattern (conversion to dairy
farming, addition of septic tanks).
  EPA does not believe that a new
determination is necessary because the
current screening methods appear to
adequately address the possibility of
Cryptosporidium in the ground water.
d. Request for Comments
  The Agency requests comment on the
proposal to modify the definition of
GWUDI to include Cryptosporidium for
systems serving fewer than 10,000
persons.
2. Inclusion of Cryptosporidium
Watershed Requirements  for Unfiltered
Systems
a. Overview and Purpose
  Existing SWTR requirements for
unfiltered surface water and GWUDI
systems require these systems to
minimize the  potential for source water
contamination by Giardia lamblia and
viruses. Because Cryptosporidium has
proven resistant to levels  of disinfection
currently practiced at systems
throughout the country, the Agency felt
it imperative to include
Cryptosporidium in the watershed
control provisions wherever Giardia
lamblia is mentioned. The lESWTR
therefore, modified existing watershed
regulatory requirements for unfiltered
svstems to include the control of

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Federal  Register/Vol.  65,  No. 69/Monday,  April 10, 2000/Proposed  Rules
Cryptosporidhim. The Agency believes
it appropriate and necessary to extend
this requirement to systems serving
fewer than 10,000 persons.
  It should be noted that today's
proposed requirements do not replace
requirements established for unfiltered
systems under the SVVTR. Systems must
continue to maintain compliance with
the requirements of the SVVTR for
avoidance of filtration. If an unfiltered
system fails any of the avoidance
criteria, that system must install
filtration within  18 months, regardless
of future compliance with avoidance
criteria.
  EPA anticipates that in the planned
Long Term 2 Enhanced Surface Water
Treatment rule, the Agency will
reevaluate treatment requirements
necessary to manage risks posed by
Cryptosporidium and other microbial
pathogens in hoth filtered and unfiltered
surface water systems. In conducting
this revaluation, EPA will utilize the
results of several large surveys,
including the Information Collection
Rule (ICR) and ICR Supplemental
Surveys, to more fully characterize the
occurrence of waterborne pathogens, as
well as watershed and water quality
parameters which might  serve as
indicators of pathogen risk level.  The
LT2ESWTR will also incorporate the
results of ongoing research on removal
and inactivation efficiencies of
treatment processes, as well as studies
of pathogen health effects and disease
transmission. Promulgation of the
LT2ESWTR is currently scheduled for
May, 2002.
b. Data
  Watershed control requirements were
initially established in 1989 (54 FR
27496, June 29, 1989) (EPA, 1989b), as
one of a number of preconditions that a
public water system using surface water
must meet to avoid filtration. The SWTR
specifies the conditions under which a
system can avoid filtration (40 CFR
141.71). These conditions include good
source water quality, as measured by
concentrations of coliforms and
turbidity; disinfection requirements;
watershed control; periodic on-site
inspections; the absence  of waterborne
disease outbreaks; and compliance with
the Total CoHform Rule and the MCL for
TTHMs. The watershed control program
under the SWTR must include a
characterization of the watershed
hydrology characteristics, land
ownership, and activities which may
have an adverse effect on source water
quality, and  must minimize the
potential for source water
contamination by Giardia iamblia and
viruses.
                       The SWTK Guidance Manual (EPA,
                     1991a) identifies both natural and
                     human-caused sources of contamination
                     to be controlled. These sources include
                     wild animal populations, wastewater
                     treatment plants, grazing animals,
                     feedlots, and recreational activities. The
                     SWTR Guidance Manual recommends
                     that grazing and so wage discharges not
                     be permitted within the watershed of
                     unfiltered systems, but indicates that
                     these activities may be permissible on a
                     case-by-case basis where there is a long
                     detention time and a high degree of
                     dilution between the point of activity
                     and the water intake. Although there are
                     no specific monitoring requirements in
                     the watershed protection program, the
                     non-filtering utility is required to
                     develop State-approved techniques to
                     eliminate or minimize the impact of
                     identified point and non-point sources
                     of pathogenic contamination. The
                     guidance already suggests identifying
                     sources of microbial contamination,
                     other than Giardia, transmitted by
                     animals, and points out specifically that
                     Cryptosporidium may be present if there
                     is grazing in the watershed.
                     c. Proposed Requirements
                       In today's proposed rule,  EPA is
                     extending the existing watershed
                     control regulatory requirements for
                     unfiltered systems serving fewer than
                     10,000 people to include the control of
                     Crvptosporidium. Crvptosporidium will
                     be included in the watershed control
                     provisions for these systems wherever
                     Giardia hmbiia is mentioned,
                       Specifically, the public water system
                     must maintain a watershed  control
                     program which minimizes the potential
                     for contamination by Giardia Iamblia,
                     and Cryptosporidium oocysts and
                     viruses in the water. The State must
                     determine whether the watershed
                     control program is adequate to meet this
                     goal. The adequacy of a  program to limit
                     potential contamination by Giardia
                     Iamblia cysts, Cryptosporidium oocysts
                     and viruses  must be based on: The
                     comprehensiveness of the watershed
                     review; the effectiveness of the system's
                     program to monitor and control
                     detrimental activities occurring in the
                     watershed; and the extent to which the
                     water system has maximized land
                     ownership and/or controlled land use
                     within tho watershed.
                       It should be noted that unfiltered
                     systems must continue to maintain
                     compliance with the requirements of the
                     SVVTR for avoidance of filtration. If an
                     unfiltered system fails any of the
                     avoidance criteria, that system must
                     install filtration within 18 months,
                     regardless of future compliance with
                     avoidance criteria.
d, Request for Comments
  EPA requests comment on the
inclusion of these requirements for
unfiltered systems serving fewer than
10,000 people.
3. Requirements for Covering New
Reservoirs
a. Overview and Purpose
  Open finished water reservoirs.
holding tanks, and storage tanks are
utilized by public water systems
throughout the country. Because these
reservoirs are open to the environment
and outside influences, they can be
subject to the reintroduction of
contaminants which the treatment plant
was designed to remove. The 1ESWTR
contains a requirement that all newly
constructed finished water reservoirs,
holding tanks, and storage tanks be
covered. The Agency believes it
appropriate and necessary to extend this
requirement to systems serving fewer
than 10,000 people.

b. Data

  Existing EPA guidelines recommend
that all finished water reservoirs and
storage tanks be covered (EPA. 199lb).
The American Water Works Association
(AWVVA) also has issued a policy
statement strongly supporting the
covering of reservoirs that store potable
water (AWWA. 1993).  In addition, a
survey of nine States was conducted  in
the summer of 1996 (Montgomery
Watson, 1996). The States which were
surveyed included several in the West
(Oregon, Washington,  California, Idaho,
Arizona, and Utah), two States in the
East known to have water systems  with
open reservoirs (New York and New
Jersey), and one midwestern State
(Wisconsin). Seven of  the nine States
which were surveyed require by direct
rule that all new finished water
reservoirs and tanks be covered.
  Under the IESWTR,  systems serving
populations of 10,000  or greater were
prohibited from constructing uncovered
finished water reservoirs after February
16, 1999. The Agency developed an
Uncovered Finished Water Reservoirs
Guidance Manual [USEPA. 1999f)
which provides a basic understanding of
the potential sources of external
contamination in uncovered finished
water reservoirs. It also provides
guidance to water treatment operators
for evaluating and maintaining water
quality in reservoirs. The document
discusses:
  • Existing regulations and policies
pertaining to uncovered reservoirs;
  • Development of a reservoir
management plan;

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                  Federal Register/Vol. 65, No.  f>9/Mondiiy, April 10,  2000/Proposed Rules
                                                                     19097
  » Potential sources of water quality
degradation and contamination;
  • Operation and maintenance of
reservoirs to maintain water quality; and
  • Mitigating potential water quality
degradation.
  As discussed in the 1997 IESWTR
NODA (EPA, 1997b), when a finished
water reservoir is open to the
atmosphere it may be subject to some of
the environmental factors that surface
water is subject to, depending upon site-
specific characteristics and the extent of
protection provided. Potential sources
of contamination to uncovered
reservoirs and tanks include airborne
chemicals, surface water runoff, animal
carcasses, anima! or bird droppings and
growth of algae and other aquatic
organisms due to sunlight that results in
biomass (Bailey and Lippy, 1978). In
addition, uncovered reservoirs may he
subject to contamituition by persons
tossing items into the reservoir or illegal
swimming (Pluntzu 1974; Erb, 1989).
Increases in algal cells, heterotrophic
plate count (UPC) bacteria, turbidity.
color, particlo counts, biomass and
decreases in chlorine residuals have
been reported (Pluntze, 1974. AVVWA
Committee Report, 1983, Silverman i;t
al., 1983, LeChevallier et al. 1997a).
  Small mammals, birds, fish, and the
growth of algae may contribute to the
microbial degradation ot an open
finished water reservoir [Graczyk et al..
1996a; Geldreich, 1990; Fayer and
Ungar, 1986;). In one study, sea gulls
contaminated a 10 million gallon
reservoir and increased bacteriological
growth, and in another study waterfowl
were found to elevate coliform levels in
small recreational lakes by twenty times
their normal levels (Morra, 1979). Algal
growth increases the biomass in the
reservoir, which reduces dissolved
oxygen and thereby increases the release
of iron, manganese, and nutrients from
the sediments. This, in turn, supports
more growth (Cooke and Carlson, 1989).
In addition, algae can cause drinking
water taste and odor problems as well
as impact water treatment processes. A
1997 study conducted by the City of
Seattle (Seattle Public Utilities. 1997)
evaluated nutrient  loadings by three
groups of birds at Seattle's open
reservoirs. Table IV.9 indicated the
amount of soluble nutrient loadings
estimated over the  course of the year. It
shows that bird feces may contribute
nutrient loadings that can enhance algal
growth in the reservoir.
              TABLE IV.9.—1997 NUTRIENT LOADINGS BY BIRD GROUPS IN SEATTLE'S OPEN RESERVOIRS
                                             Geese
                                                                 Gulls
                                                                                    Ducks
                                                                                                      Overall
               Reservoir
Beacon Hill*
Bitter Lake  ....
Green Lake .
Lake Forest .
Lincoln 	
Maple Leaf ...
Myrtle 	
Volunteer	
West Seattle .
Nitr. I
kg/yr |
0.00
0.82
1.78
2.23
0.00
2.16
0.00
0.00
0.40
Phos. ;
kg/yr :
0.00
0.24
0.52
0.65 ,
0.00 .
0 63 ;
0.00 :
0.00
0.12
Nitr. Phos.
kg/yr kg/yr
0.00 000
0.01 000
0.03 0.01
0.36 0.11
0.24 0.07
0.13
0.08
0.01
0.38
0.04
002
0.00
0.11
Nitr.
kg/yr ,
0.00 :
0.06
0.53
0.07
0.01
0.35
0.01
0.01
0.02
Phos.
kg/yr
0.00
Total
kg/yr
0.00
0.02 > 1.15
Cone.
(mg/L)
0.00
14.09
0.16 3.04 ! 16.05
0.02 3.43 | 15.09
0.00 0.31 3.96
0.10 : 3.42
0.00 0.12
0.00
0.01
0.03
1.03
15.43
4.35
0.42
4
c. Proposed Requirements
  In today's proposed rule EPA is
requiring surface water and GVVUDI
systems that serve fewer than 10,000
people to cover all new reservoirs,
holding tanks or other storage facilities
for finished water for which
construction begins 60 days after the
publication of the final rule in the
Federal Register. Today's proposed rule
does not apply these requirements to
existing uncovered finished water
reservoirs.
d. Request for Comments
  EPA solicits comments regarding the
requirement to require that all new
reservoirs, holding tanks and storage
facilities for finished water be covered.
D. Recycle Provisions for Public  Wafer
Systems Employing Rapid Granular
Filtration Using Surface Water and
GWUDI as a Source
  Section 1412(b)(14) of the 1996
SDWA Amendments requires EPA to
promulgate a regulation to govern the
recycle of filter  backwash within the
treatment process of public water
systems. The Agency is concerned that
the recycle of spent filter backwash and
other recycle streams may introduce
additional Cryptosporidium oocysls to
the treatment process. Adding oocysts to
the treatment process may increase the
risk oocysts will occur in finished water
supplies and threaten public health. The
Agency is further concerned because
Crvptosporidium is not inactivated by
standard disinfection practice, an
important treatment barrier employed to
control microbial pathogens. Oocysts
returned to the plant by recycle flow
therefore remain a threat to pass through
filters into the finished water.
  The Agency engaged in three primary
information gathering activities to
investigate  the potential risk posed by
returning recycle flows that may contain
Crvptosporidium to the treatment
process. First, the Agency performed a
broad literature search to gather
research papers and information on the
occurrence of Cryptosporidium and
organic and inorganic materials in
recycle flows. The literature search  also
sought information regarding the
potential impact recycle may have on
plant treatment efficiency. Second,  the
Agency worked with AWWA.
AVVWSCo., and Cincinnati Water Works
to develop twelve issue papers on
commonly generated recycle flows
(Environmental Engineering and
Technology, Inc.,1999). These papers
are summarized in the next section.
Information from EPA's literature search
was incorporated into the issue papers.
Third, the Agency presented
preliminary data and potential
regulatory components to stakeholders,
and solicited feedback, at public
meetings in Denver, Colorado, and
Dallas, Texas. EPA also received
valuable input from representatives of
small water systems through the
SBREFA process.
  Through the above activities, the
Agency has identified four primary
concerns regarding the recycle of spent
filter backwash and other recycle
streams within the treatment process of
PWSs. The first concern is that some
recycle flows contain Cryptosporidium
oocysts, frequently at higher
concentrations than plant source waters.
Recycling these flows may increase the
number of oocysts entering the plant
and the number of oocysts reaching the
filters. Loading more oocysts to the

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filters could increase finished water
oocyst concentrations. The second
concern regards the location in the
treatment process recycle flow is
returned. The return of recycle at the
point of primary coagulant addition or
downstream of it may disrupt treatment
chemistry by introducing residual
coagulant or other treatment chemicals
to the process stream and thereby lower
plant treatment efficiency. Also, recycle
flow returned to the clarification
process may not achieve sufficient
residence time  for oocysts in the recycle
flow to be removed, or it may create
hydraulic currents that lower the unit's
overall oocyst removal efficiency. The
third concern regards direct filtration
plants. Direct filtration plants do not
employ clarification in their primary
treatment process to remove suspended
solids and oocysts; all oocyst removal is
achieved by the filters. If the recycle
flow is not treated before being returned
to the plant, all of the oocysts captured
by a filter during a filter run \vill be
returned to the plant and again loaded
to the filters. This may lead to ever
increasing levels of oocysts being
applied to the filters and could increase
the concentration of oocysts in finished
water. Therefore, it  is important for
direct filtration plants to provide
adequate recycle flow treatment to
remove oocysts and protect the integrity
of the filters and finished water quality.
Finally, the fourth concern is that the
direct recycle of spent filter backwash
without first providing treatment.
equalization, or some form of hydraulic
detention for the recycle flow, may
cause plants to  exceed State-approved
operating capacity during recycle
events. This can cause clarification and
filter loading rates to be exceeded,
which may loxver overall oocyst removal
provided by the plant and increase
finished water oocyst concentrations.
   EPA has particular concerns regarding
the direct recycle of spent filter
backwash water as it is produced (i.e..
recycle flow is not retained in an
equalization basin, treatment unit, or
other hydraulic detention unit prior to
reintroduction to the main treatment
process) for the following reasons:
   (1) Direct recycle  may cause operating
rates for clarification and filtration to be
exceeded, which may lower overall
Cryptosporidium removal;
   (2) Direct recycle  may hydraulically
upset some plants, lowering overall
plant treatment performance, and;
  (3) Clarification and filtration
operating rates may he exceeded at
precisely the time recycle flow may be
returning large numbers of oocysts to
the treatment process.
                       The impact of direct recycle practice
                     to smaller plants with few filters is of
                     greatest concern because return  of
                     recycle How can double or triple plant
                     influent flow, which may hydraulically
                     overload the plant and reduce oocyst
                     removal.
                       Since standard disinfection practice
                     does not inactivate (Irvptosporidiiim, its
                     control is entirely dependent on
                     physical removal processes. The Agency
                     is concerned that direct  recycle  may
                     cause some plants to exceed  operating
                     capacity and thus lower their physical
                     removal capabilities. This can increase
                     the risk of oocysts entering the finished
                     water and lead to an increased risk to
                     public health.
                       The limited data (Cornwell and Lee,
                     1993) EPA has identified regarding
                     plants with existing equalization and/or
                     treatment indicates they may be at no
                     greater risk of hydraulic upset or
                     degradation of oocyst removal
                     performance than non-recycle plants.
                     Given current data limitations, it is
                     reasonable to assume the presence and
                     utilization of adequate recycle flow
                     equalization and/or treatment processes
                     will alleviate the potential for hydraulic
                     disruptions and the impairment of
                     treatment performance. Data suggesting
                     otherwise is currently unavailable.
                       The potential for recycle to return
                     significant numbers of oocysts to the
                     treatment train does provide a general
                     basis for concern regarding the impact
                     of recycle practice to finished water
                     quality.  However, the Agency does  not
                     currently believe data warrants a
                     national regulation requiring all recycle
                     plants to provide recycle flow
                     equalization or treatment for the
                     following reasons:
                       (1) Data correlating oocyst  occurrence
                     in recycle streams to increased oocyst
                     occurrence in finished water is
                     unavailable;
                       (2) Data regarding the  response of full-
                     scale plants to recycle events is limited;
                       (3) Data is not available to  determine
                     the level of recycle flow equalization or
                     treatment lull-scale systems may need.
                     if any, to control the risk of oocysts
                     entering finished water,  and;
                       (4) Whether and the extent to which
                     oocyst occurrence in source water
                     influences the necessary level of recycle
                     treatment and equalization is unknown.
                       The Agency believes requiring plants
                     that may be at greater risk due to
                     recycle, such as direct recycle plants
                     and direct filtration  plants, to
                     characterize their recycle practice and
                     provide data to the State for its review
                     provides a cost effective opportunity to
                     increase public health protection and
                     supply a measure of safety to finished
                     drinking water supplies. EPA believes
that today's proposal will address
potentially higher risk recycle situations
that may threaten the performance of
some systems, and will do so by
allowing State drinking water programs
to consider site-specific treatment
conditions and needs. The Agency
believes these recycle provisions are
needed to protect plant performance,
the quality of finished water supplies,
and to provide an additional measure of
public health protection.

1.  Treatment Processes That Commonly
Recycle and Recycle Flow Occurrence
Data
a.  Treatment Processes That Commonly
Recycle
  The purpose of this section is to
provide general background on common
treatment plant processes, fundamental
plant operations, and the origin of plant
recycle streams. Detailed information on
the specific recycle flows these
processes generate are presented after
this background discussion. Four
general types of water treatment
processes, conventional filtration, direct
filtration, softening, and contact
clarification, are discussed. Although
there  are numerous variations of these
four treatment processes, only the most
basic  configurations are discussed here.
The operation of package plants and
options to returning recycle to the
treatment process are also summarized.

i. Conventional Treatment Plants
  Conventional water filtration plants
are defined by the use of four essential
unit processes: Rapid mix, coagulation/
flocculation. sedimentation, and
filtration. Sedimentation employs
gravity settling to remove floe and
particles. Particles not removed  by
sedimentation may be removed by the
filters. Periodically, accumulated solids
must be removed from the
sedimentation unit. These solids,
termed "residuals." are currently
disposed to sanitary sewer, treated with
gravity thickening, or some other
process prior to returning them to plant
headworks or other locations  in the
treatment train. Clarification processes
other  than sedimentation may also be
used,  and they also produce process
residuals.
  Clarification sludge may be processed
on-site if the plant is equipped with
solids treatment facilities. Commonly
employed treatment processes include
thickeners, dewatering equipment (e.g.,
plate and frame presses, belt filter
presses, or centrifuges), and lagoons.
Each of these processes produces
residual water streams that  are currently
returned to the treatment process at the

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                                                                     19099
headworks or other locations prior to
filtration. The volume of residuals
produced by clarification depends upon
the amount of solids present in the raw
water, the dose and type of coagulant
applied, and the concentration of solids
in the treated water stream.
  The one residual stream associated
with filtration, spent filter backwash
water, is produced during periodic
backwashing events performed to
remove accumulated solids from the
filter. Spent filter backwash is
frequently returned to the treatment
process at the head of the plant, other
locations prior to the filters, or disposed
of to sanitary sewer or surface water.
Some plants have the capability to send
the filtrate produced during the  filter
ripening period to plant headworks,  a
raw water reservoir, or to a sanitary
sewer or surface water rather than to the
clear well as finished water. This
practice, referred to as "filter-to-waste"
is used to prevent solids, which pass
through the filter more easily during the
ripening period, from entering the
finished water.
  Filter backwash operations can differ
significantly from plant to plant. The
main variables are the time between
backwashes (length of filter run), the
rate of backwash flow, the duration of
the backwash cycle, and the
backwashing method. The time between
filter backwashes is generally a function
of either run time, headloss, or solids
breakthrough. Both headloss and solids
breakthrough can be dependent  upon
the quality of the sedimentation
effluent. Regardless of the variable
driving backwash frequency, the
interval between backwashes typically
vary from 24 to 72 hours. Recommended
backwash frequency is every 24-48
hours (ASCE/AWWA, 1998),
  There are a number of different
methods that can be used 1o backwash
a filter. These include: Upflow water
only, upflow water with surface wash,
and air/water backwash. Air/water
backwash systems typically use 30-50
percent less water than the other two
methods. The filter backwash flow rate
can vary, depending on media type,
water temperature, and backwash
method, but generally has a maximum
of 15-23 gpm/ft2 (air/water backwash
may have a lower maximum rate of 6-
7 gpm/ft2).  A number of different
backwash sequences are employed, but
a typical backwash consists of a low  rate
wash (6—7 gpm/ft2 for several minutes),
followed by a high rate wash (15-23
gpm/ft2 for 5—15 minutes), which is
then followed by a final  low rate wash
(6-7 gpm/ft2 for several additional
minutes). Some treatment plants only
use a high rate wash for 15 to 30
minutes. Backwash rates are
significantly higher than filtration rates.
which vary from 1 to 8 gpm/ft-.

ii. Direct Filtration Plants
  The direct filtration process is similar
to conventional treatment, except the
clarification process is not present.
Direct filtration plants produce th« same
filter residual as conventional filtration
plants, namely filter backwash, and may
also generate a filter-to-waste flow.
Direct filtration plants do not produce
clarification residuals because
clarification is not employed. Filter
backwash may be either recycled to the
head of the plant or discharged to
surface waters or a sanitary sewer.
Although direct filtration plants
generally treat source waiters that have
low concentrations of suspended
material, the solids loading to the filters
may be higher than at conventional
plants because solids are not removed in
a clarification process prior to filtration.
If spent filter backwash is not treated to
remove solids prior to recycle, solids
loading onto the filters will continue to
increase over time, as an exit from the
treatment process is unavailable. Filter
run length may be shorter in some direct
filtration plants relative to conventional
plants because the solids loading to the
filters may be higher due to the lack  of
a clarification process. The
concentration of solids in the source
water is a key variable in filter run
length.
iii. Softening Plants
  Softening plants utilize the same basic
treatment processes as conventional
treatment plants. Softening plants
remove hardness (calcium and
magnesium ions) through precipitation,
followed by solids removal. Many
softening piants employ a two-stage
process, which consists of a rapid mix-
flocculation-sedimentation sequence, in
series, followed by filtration. Others  use
a single stage process, resembling
conventional treatment plants.
Precipitation of the calcium and
magnesium ions is accomplished
through the addition of lime (calcium
hydroxide), with or without soda ash
(sodium carbonate), which reacts with
the calcium and magnesium ions in the
raw water to form calcium carbonate
and magnesium hydroxide. The
precipitation of the calcium carbonate
can be improved by recirculating some
of the calcium carbonate sludge into the
rapid  mix unit because the additional
solids provide nucleation points for the
precipitation of calcium and
magnesium. Without this recirculation,
additional hydraulic detention time  in
the! flocculation and sedimentation
basins may be required to prevent
excessive scale deposits in the plant
clearwell or in the distribution system.
  A softening plant generally has the
same residual streams as a conventional
plant: Filter backwash, sedimentation
solids, and thickener supernatant and
dewatering liquids. A filter-to-waste
flow may also be generated. These
residual streams are either disposed or
recycled within the plant. A portion of
the sedimentation basin solids are
commonly recycled as the
sedimentation basin solids contain
significant quantities of precipitated
calcium carbonate, recycle of these
solids reduces the required chemical
dose. Solids are generally recycled into
the rapid mix chamber to maximize
their effectiveness.
iv. Contact Clarification Plants
  In the contact clarification process,
the flocculation and clarification (and
often the rapid mix) processes are
combined in  one unit, an upflow solids
contactor or contact clarifier. Contact
clarifiers are employed in both softening
and non-softening processes. Raw water
flows into the contact clarifier at the top
of the central compartment, where
chemical addition and  rapid mix occurs.
The water then flows underneath a skirt
and into the outer sedimentation zone
where solid separation occurs. A large
portion of previously settled solids from
the sedimentation zone is circulated to
the mixing zone to enhance
flocculation. The remainder of the
solids are disposed to prevent their
accumulation. Circulation and disposal
of accumulated solids allows clarifier
loading rates  to be 10 to 20 times greater
than loading rates for conventional
sedimentation basins. Solids
recirculation  rates are generally
different for softening and turbidity
removal applications, with rates of up to
12 times the raw water flow for
softening processes and up to 8 times
the raw water flow for non-softening
processes  (ASCE/AWWA, 1998).
Following clarification, treated water
from the contactor is then filtered.
  The residual streams from contact
clarification plants are  similar to those
for conventional filtration plants. They
include filter  backwash, clarification
solids, thickener supernatant, and
dewatering liquids. The key operational
consideration for these types of systems
is the maintenance of a high
concentration of solids within the skirt
to allow high loading rates while
maintaining adequate solids removal.
Solids recirculation (e.g., recycle) helps
contact clarification processes maintain
the necessarv solids concentration.

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Federal Register/Vol.  65,  No. 63/Monday, April  10.  2000/Proposed Rules
Softening plants may also generate filter
to waste flow.

v. Package Plants
   Package plants are typically used to
produce between a few thousand to 1
million gallons of water per day.
Package plants can employ a
conventional treatment train, as welt  as
proprietary unit processes.  Package
plants typically include the same
processes found in large plants.
including coagulation, flocculation,
clarification and filtration. The potential
recycle streams are also comparable.
The recycle of filter backwash may
occur, however, the typical package
plant may not be designed to convey
process streams back into the plant as
recycle.
vi. Summary of Recycle Disposal
Options
   Two recycle disposal options
available to some plants are direct
discharge to sanitary sewers or
discharge to surface waters. Discharge of
recycle waters to the municipal sewer
system may occur when the treatment
plant and Publicly Owned Treatment
Works (POTVV) are under the same
authority or when the plant has access
to a sanitary sewer and a POTW agrees
to accept its discharge,
   There may  be a fee associated with
discharge to a sanitary sewer system.
and the total  fee may vary with the
volume of backwash effluent discharged
as well as the amount  of solids in the
effluent (Cornwell and Lee, 1994). In
addition to the fee requirement,
discharging into the sewer system may
require the plant to equalize the effluent
prior to discharging to the POTW. The
equalization process requires holding
the effluent in tanks and gradually
releasing it into the sanitary sower
system. The fee associated with sanitary
sewer discharge may influence whether
a plant recycles to the treatment process
or discharges to a sanitary sewer.
   Another option to recycle within the
treatment process is the direct discharge
of recycle flow to surface waters, such
as creeks, streams, rivers, and reservoirs.
Direct discharge is a relatively common
method of disposal for water treatment
plant flows. A National Pollutant
Discharge Elimination System (NPDES)
permit requires that certain water
quality conditions be met prior to the
discharge of effluent into surface waters.
Treatment of  the effluent prior to
discharge may be required.  The cost of
effluent treatment may influence
whether plants recycle within the
treatment process or discharge to
surface water.
                     b. Recycle Flow Occurrence Data
                       EPA has not regulated recycle flows
                     in previous rulemakings. The 1996
                     SDWA Amendments have lead the
                     Agency to perform an examination of
                     recycle flow occurrence data for the first
                     time. EPA discovered through its
                     literature search and its work with
                     AWWA. AWU'SCo., and Cincinnati
                     Water Works to develop the issue
                     papers, that the amount of recycle
                     stream occurrence data available is very
                     limited, particularly for
                     Cryptosporidium. the primary focus of
                     this regulation. This may be because
                     Crvptosporiclium was identified as a
                     contaminant of concern relatively
                     recently and because currently available
                     oocyst detection methods have
                     limitations.
                       Twelve issue papers were developed
                     to compile information on several
                     commonly produced recycle streams.
                     Each individual paper summarizes how
                     the recycle stream is generated, the
                     typical volume generated, characterizes
                     the occurrence of various recycle stream
                     constituents to the extent data allows,
                     (/.
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                  Federal Register/Vol. 65, No.  69/Monday, April  10,  2000/Proposed Rules
                                                                     19101
supernatant (a combination of spent
filter backwash and clarification process
solids), gravity thickener supernatant
from clarification process solids, and
mechanical dewatering device liquids.
These five recycle streams are discussed
in detail because they are most likely to
present a threat to treatment plant
performance or finished water quality
when recycled. For example, treated
and untreated spent filter backwash
water and thickener supernatant are the
only two recycle streams of sufficient
volume to cause plants to exceed their
operating capacity during recycle
events. The five recycle streams
discussed below are also most likely to
contain Cryptosporidium.
  Copies of all the issue papers are
available for public review in the Office
of Water docket for this rulemaking.
Portions of the following recycle stream
descriptions use excerpts from the issue
papers.
/. Untreated Spent Filter Backwash
Water
  Water treatment plants that employ
rapid granular filtration (e.g.,
conventional, softening, direct filtration,
contact clarification) generate spent
filter backwash water. The backwash
water is generated when water is forced
through the filter, counter-current to the
flow direction during treatment
operations, to dislodge and remove
accumulated particles and pathogens
residing in the filter media. Backwash
rates are typically five to eight times the
process rate, and are used to clean the
filter at the end of a filter run, which is
generally 24 to 72 hours in length.
Backwash operations usually last from
10 to 25 minutes. The flow rate and
duration of backwashing are the primary
factors that determine the volume of
backwash water produced. Once the
backwashing process is complete, the
backwash water and entrained solids are
either disposed of to a sanitary sewer,
discharged to a surface water, or
returned to the treatment process. Plants
currently return spent filter backwash to
the treatment process at a variety of
locations, usually between plant
headworks and clarification. Data
regarding common recycle return
locations is discussed in the next
section of this preamble.
  Spent filter backwash can be returned
to the treatment process directly as it is
produced, be detained in an
equalization basin, or passed through a
treatment process, such as clarification,
prior to being returned to the plant. On
a daily basis, spent filter backwash can
range from 2 to 10 percent of plant
production. Spent filter backwash is
usually produced on an intermittent
basis, but large plants with numerous
filters may produce it continuously. At
small and mid-size plants, large volume,
short duration flows of spent filter
backwash are usually produced. This
may cause some plants, particularly
smaller plants that recycle directly
without flow equalization or treatment,
to exceed their operating capacity or to
experience hydraulic disruptions, both
of which may negatively impact
treatment efficiency and oocyst removal.
  The concentrations of
Cryptosporidium reported in the
untreated spent filter backwash issue
paper ranges from non-detect to a
concentration of 18,421 oocysts per 100
L. This range is not amenable to formal
statistical analysis, but rather provides a
summary of minimum and maximum
oocyst concentrations reported in
available literature. Although a few
studies report isolated data points of
greater than  10,000 oocysts/lOOL for
filter backwash  water (Rose et al, 1989;
Cornwell and Lee. 1993; Colbourne,
1989), occurrence studies that collected
the largest number of samples reported
mean filter backwash oocyst occurrence
concentrations of a few hundred oocysts
per TOOL (States et al., 1997; Karanis et
al.. 1996). The high concentration of
oocysts found in some spent  filter
backwash samples is cause for concern,
because oocysts are not inactivated by
standard disinfection practice. They
remain a threat to  pass through the plant
into the finished water if they are
returned to the treatment process.
However, current oocyst detection
methods do  not allow the occurrence of
oocysts in spent filter backwash water to
be correlated to finished water oocyst
concentrations for a range of plant
types, source water qualities, and
recycle practices. Today's proposal does
not require the installation of recycle
equalization or treatment for spent filter
backwash water on a national basis due
to these data limitations.
  The Agency is concerned that certain
recycle practices, such as returning
spent filter backwash to locations other
than prior to the point of primary
coagulant addition, or hydraulically
overloading  the plant with recycle flow
so it exceeds its State approved
operating capacity, may present risk to
finished  water quality  and public
health. Exceeding plant operating
capacity  during recycle events may
cause greater risk to finished water
quality, because plant  performance is
potentially being lowered at precisely
the time oocysts are returned to the
plant in the recycle flow. To address
this concern, today's proposal requires
that certain direct recycle plants that
recycle spent filter backwash water and/
or thickener supernatant to perform a
self assessment of their recycle practice
and report the results to the State. The
self assessment requirements are
discussed in detail later in this
preamble.

ii. Gravity Settled Spent Filter Backwash
Water
  Gravity settled spent filter backwash
water is generated by the same filter
backwash process and is produced in
the same volume as untreated spent
filter backwash water. The difference
between the two streams is that the
former is treated by gravity settling prior
to its return to the primary treatment
process. Sedimentation treatment is
usually accomplished by retaining the
spent filter backwash water in a
treatment unit for a period of time to
allow suspended solids (including
oocysts) to  settle to the bottom of the
basin. Polymer may be used to improve
process efficiency. The water that leaves
the basin is gravity settled spent filter
backwash water. Removing solids from
the spent filter backwash causes only a
minor reduction in volume as the solids
content of the untreated stream is low,
usually below 1 percent.
  Providing gravity settling for spent
filter backwash is advantageous for two
reasons. First, the sedimentation process
detains the spent filter backwash in
treatment basins for a period of hours,
which lowers the possibility a large
recycle volume will be returned to the
plant in a short amount of time and
cause the plant operating capacity to be
exceeded. Second, treating the spent
filter backwash flow can remove
Cryptosporidium oocysts from the flow,
which will  reduce the number of
oocysts returned to the plant.
  Limited data show that sedimentation
can effectively remove oocysts.
Cornwell and Lee (1993) conducted
limited sampling of spent filter
backwash water at two plants prior to
and after sedimentation treatment. The
first facility practiced direct filtration
and was sampled twice. The
Cryptosporidium concentrations into
and out of the sedimentation basin
treating spent filter backwash were 900/
100L and 140/100L, respectively, for the
first sampling and 850/1OOL in the
influent and 750/1 OOL in the effluent for
the second  sampling. At the second
plant a sludge settling pond received
both sedimentation basin sludge and
spent filter backwash, and the spent
filter backwash oocyst concentration
was 16,500/lOOL, and the treated
recycle water concentration was 420/
100L. In a study by Karanis (1996),
Cryptosporidium was regularly detected
in settled backwash waters. Of the 50

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Federal  Register/Vol. 65,  No. 69/Monday, April 10, 2000/Proposed Rules
samples collected, 82 percent tested
positive for Cryptosporidium. The mean
value for Cryptosporidium was 22
oocysts/lOOL.
  Sedimentation treatment can remove
oocysts from spent filter backwash, but
data indicate oocysts remain in gravity
settled spent filter backwash water even
after treatment. The Agency believes
that sedimentation treatment for spent
filter backwash waters is capable of
removing oocysts and improving the
quality of the water  prior to recycle.
However, given current data limitations,
the Agency does not believe it is
possible to specify, in a national
regulation, the conditions (e.g., source
water oocyst concentrations, primary
treatment train performance,
concentration of oocysts in spent filter
backwash, ability of sedimentation to
remove oocysts under a range of
conditions) under which sedimentation
treatment of spent filter backwash water
may be appropriate. This decision is
best made by State programs to allow
consideration of site-specific conditions
and treatment needs.

ill.  Combined Gravity Thickener
Supernatant
  Combined gravity thickener
supernatant is derived from the
treatment of filter backwash water and
sedimentation basin solids in gravity
thickener units. These two flows may
not reside in the thickener at the same
time or in equal volumes, depending on
plant operations. The volume of
thickener supernatant generated at a
water treatment plant is  a function of
the type of flows it treats, the solids
content of the influent stream, and the
method of thickener operation.
Regardless of whether a continuous or a
batch process is used, a number of
factors, including residuals production
(a function of plant production, raw
water suspended solids,  and coagulant
dose), volume of spent filter backwash
water produced, and the level of
treatment provided to thickener influent
streams, directly affect the quantity of
thickener supernatant produced.
  The flow entering the thickener is
primarily spent filter backwash water.
Sedimentation basin solids is the
second largest flow. Flow from
dewatering devices, which is generated
by the dewatering of residuals, may
comprise a minor volume entering the
thickener. Combined thickeners will
have an influent that may be eighty-
percent spent filter backwash or more
by volume. About eighty-percent of the
solids entering the thickener will be
from the sedimentation basin sludge, as
spent filter backwash water has a
comparatively low solids concentration.
                       A recent FAX survey (AWWA, 1998)
                     identified more than 300 water
                     treatment plants in the United States
                     with production capacities ranging from
                     less than 2 mgd to greater than 50 mgd
                     that recycle spent filter backwash water.
                     Many of the survey respondents
                     indicated that they recycle more than
                     just spent filter backwash water. Based
                     on the survey and  published literature,
                     thickener supernatant is probably the
                     second largest and second most
                     frequently recycled stream at water
                     treatment facilities after spent filter
                     backwash.
                       Data summarized in the issue paper
                     showed that thickener supernatant
                     quality varies widely, due in large part
                     because the type and quality of recycle
                     streams entering thickeners varies over
                     time and from plant to plant. The
                     turbidity, total suspended solids, and
                     particle counts of thickener effluent are
                     directly impacted by the quality of
                     water loaded onto the thickener,
                     thickener design, and thickener
                     operation (e.g., residence time, use of
                     polymer).
                       Data on the occurrence of
                     Cryptosporidium was limited to two
                     samples, with oocyst occurrence ranging
                     from 82 to 420 oocysts per 100 L. Data
                     is too limited, and practice varies too
                     widely, to draw conclusions on the
                     impact recycle of this flow may have on
                     plant performance. However, given that
                     the contents of the thickener have been
                     treated and the amount of flow
                     produced by gravity thickeners is
                     relatively modest,  it may be feasible to
                     recycle the flow in a manner that
                     minimizes adverse impact.
                     Additionally,  treatment plant personnel
                     have a vested  interest in optimizing
                     thickener operation to minimize sludge
                     dewatering and handling costs;
                     optimization ot thickener operation  is
                     likely to assist oocyst removal.
                     However, additional data is needed  to
                     characterize the occurrence of
                     Cryptosporidium and the potential
                     impact recycle of combined thickener
                     supernatant may have on finished water
                     quality.

                     iv. Gravity Thickener Supernatant from
                     Sedimentation Solids
                       Gravity settled sedimentation basin
                     solids are sedimentation basin  solids
                     that have undergone settling to allow
                     solid sludge components to settle to the
                     bottom of a gravity thickener. The
                     supernatant from the thickener is a
                     potential recycle flow. The tank bottom
                     is sloped to enhance solids thickening
                     and collection and removal of settled
                     solids is accomplished with a bottom
                     scraper mechanism. If the supernatant is
                     recycled, it can be returned to the plant
continuously or intermittently.
depending on whether the thickener is
operated in batch mode. Thickeners
may receive and treat both spent filter
backwash water and sedimentation
basin solids. For purposes of this
discussion, and the data presented in
the issue paper, the gravity thickener is
only receiving sedimentation basin
solids.
  The volume of treated sedimentation
basin solids supernatant generated is
dependent on the amount of sludge
produced in the sedimentation basin,
the solids content of the sludge, and
method of thickener operation. Sludge
production is a function of plant
production, raw water suspended
solids, coagulant type, and coagulant
dose.  The quantity of sedimentation
basin sludge supernatant is
approximately 75 to 90 percent of the
original volume of sedimentation basin
sludge produced.
  There is a very limited amount of data
on the quality of thickener supernatant
produced by gravity settling of only
sedimentation basin solids (i.e., spent
filter backwash and other flows are not
added to the thickener), and no data was
identified regarding the concentration of
Cryptosporidium that occur in the
supernatant. As is the case with
combined gravity  thickener supernatant,
it is difficult to determine what impact,
if any, the return of the supernatant may
have on plant operations and finished
water quality due to limited data.
Additional data is necessary to
determine the concentration of oocysts
in this recycle stream, and to
characterize the impact its recycle  may
have to plant performance.
v. Mechanical Dewatering Device
Liquids
  Water treatment plant residuals
(usually thickened sludge) are usually
dewatered prior to disposal to remove
water and reduce volume. Two common
mechanical dewatering devices usud to
separate solids from water are the belt
filter press, which compresses the
residuals between two continuous
porous belts stretched over a series of
rollers, and the centrifuge, which
applies a strong centrifugal force to
separate solids from water. The plate
and frame press is another dewatering
device that contains a series of filter
plates, supported and contained  in a
structured frame, which separate sludge
solids from water using a positive
pressure differential as the driving force.
Water removed from the solids with a
belt filter press is called  filtrate, from a
filter press it is called pressate, and the
water separated from the residuals with
a centrifuge is referred to as centrate.

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                                                                     19103
These streams will be collectively
referred to as "dewatering liquid" for
the following discussion.
  The volume of dewatering liquid
produced depends primarily on the
volume and solids content of the
thickened residuals fed to the
mechanical dewatering device. Plants
that produce small sludge volumes, and
hence a low volume of thickener
residuals, will process fewer residuals
in the mechanical dewatering device
and hence produce a smaller volume of
dewatering liquid than a plant
producing a large volume of solids, all
else being equal. Since residuals are
often  thickened (typically to about 2 -
percent solids) prior to dewatering, the
volume of the dewatering device feed
stream is significantly lower than the
volume of sedimentation basin residuals
generated. If the sedimentation basin
sludge flow is assumed to be 0.6 percent
of plant production, then dewatering
device flow may be approximately 0.1 to
0.2  percent of plant flow. Generally
these  streams are mixed in with other
recycle streams prior to being returned
to the plant. Mechanical dewatering
devices may be operated intermittently.
after a suitable volume of residuals have
been produced for dewatering. The
production of dewatering liquid and its
recycle may not be a continuous
process.
  Data on the constituents in
dewatering liquid were found in three
references, one on belt filter press
liquids, one on plate and  frame pressate,
and one on centrifuge centrate. Data on
the  occurrence of Cryptosporidium was
not  identified. Given the small,
intermittent flow produced by
mechanical dewatering devices, recycle
flows from them are unlikely to cause
plants to exceed operating capacity.
However, it is possible that dewatering
device liquid contains Cryptosporidium
because it derived from solids likely to
hold a large numbers of oocysts.
Additional data is necessary to
determine the concentration of oocysts
in this recycle stream, and to
characterize any impact its recycle may
have to plant performance.

2. National Recycle Practices
a. Information Collection Rule

   Public water systems affected by the
ICR werei required to report whether
recycle is practiced and sample
washwater (i.e., recycle flow) between
the washwater treatment plant (if one
existed) and the point at which recycle
is added to the process train. Sampling
of plant recycle flow was required prior
to blending with the process train.
Monthly samples were required for pH,
alkalinity, turbidity, temperature,
calcium and total hardness, TOC. UV^sj.
bromide, ammonia, and disinfectant
residual if disinfectant was used.
Systems were also required to measure
recycle flow at the time of sampling, the
twenty four hour average flow prior to
sampling, and report whether treatment
of the recycle was provided and, if so,
the type of treatment. Reportable
treatment types were plain
sedimentation, coagulation and
sedimentation, filtration,  disinfection,
or a description of an alternative
treatment type. Plants were also
required to submit a plant schematic to
identify sampling locations. EPA used
the sampling schematics and other
reported information to compile a
database of national recycle practice.

;'. Recycle Practice

  The Agency developed a database
from the ICR sampling schematics and
other reported information. Table IV,10
summarizes the plants in the database.
Of the 502 plants in the database at the
time the analysis was performed, 362
used rapid granular filtration.

TABLE IV. 10.—RECYCLE PRACTICE AT
             ICR PLANTS
       Plant classification
Num-
 ber
All ICR plants	
Filtration plants3 	
Filtration plants recycling"	
Filtration plants treating recycle ..
Recycle plants serving 2100.000
Recycle plants serving <100,OQO
  502
  362
  226
  148
  168
   58
  "Defined as conventional, lime  softening,
other softening, and direct filtration plants.
  "Plants  report  existence of  a  recycle
stream, not its origin.

  These plants are classified as
conventional, lime softening, other
softening, and direct filtration. The
remaining 140 plants in the database do
not employ rapid granular filtration
capability and generally provide
disinfection for ground water. Of the
362 filtration plants in the database, 226
(62.4 percent) reported recycling to the
treatment process. Seventy-four percent
of the plants that recycle serve
populations greater than 100,000 and 26
percent serve populations below
100,000. Figure IV.9 shows the
distribution of plants by treatment type
and Figure IV.10 shows the distribution
of plants by population served. Table
IV. 11 shows that 88 percent of ICR
recycle plants use surface water. An
additional one percent use GWUDI and
another one percent use a combination
of ground water and surface water.
Therefore, 90 percent of ICR recycle
plants use a source water that could
contain Cryptosporidium.
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Federal Register/Vol. 65, No. 69/Monday, April 10,  2000/Proposed Rules

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Federal  Register/Vol.  65, No.  69/Monday, April  10,  2000/Proposed  Rules
                            TABLE IV.11.—SOURCE WATER USE BY ICR RECYCLE PLANTS
                                       Source water type
                                                                                               Number of
Total nu
Surface
Ground
Ground
Ground
mber of recycle plants 	 	 	
Water 	 	
water under the influence 	 	
water and surface water ... 	
water only 	 	 	

226
199
3
2
22
                                                                                                           "**<*
                                                                                                                 100
                                                                                                                  88
                                                                                                                   1
                                                                                                                   1
                                                                                                                  10
  Table IV. 12 shows that 65 percent of
ICR recycle plants report providing
treatment for the recycle flow. The
percentage of plants providing treatment
is the same for the subsets of plants
                     serving greater than and less than
                     100,000 people. Sedimentation is the
                     most widely reported treatment method,
                     as 77 percent of plants providing
                     treatment employ it. The database does
not provide information on the solids
removal efficiency of the sedimentation
units. All direct filtration plants
practicing recycle reported providing
treatment for the recycle flow.
                               TABLE IV.12.—TREATMENT OF RECYCLE AT ICR PLANTS 1
                                    ICR recycling plants
                                                                         Number of
                                                                           plants
                          Percentage of
                          recycle plants
Number of recycle plants	
Practice recycle treatment 	
Use sedimentation 	
Use sedimentation/coagulation
Use two or more treatments ....
Other treatment	
  1 Disinfection not counted as treatment because it does not inactivate Cryptospondium.
                                                                                226
                                                                                147
                                                                                114
                                                                                 14 :
                                                                                 14
                                                                                  5
                                   100
                                   65
                                   77
                                   10
                                   10
                                    3
  Table IV. 13 indicates that 75 percent
of ICR recycle plants return recycle
prior to rapid mix. Fifteen percent
return it prior to sedimentation, and ten
percent of plants return it prior to
filtration. These percentages hold for the
                     subsets of plants serving greater than
                     and less than 100.000 people. The data
                     indicate that introducing recycle prior
                     to rapid mix may be a common practice.
                     EPA believes that introducing recycle
                     flow prior to the point of primary
coagulant addition, is the best recycli;
return location because it limits the
possibility residua! treatment chemicals
in the recycle flow will disrupt
treatment chemistry.
TABLE IV. 13.— RECYCLE RETURN POINT
Point of recycle return
Number of recycle plants 	 	
Prior to point of primary coagulant addition 	
Prior to sedimentation 	
Priorto filtration 	 	


Number of percent of
plants i plants
1224 100
169 75
34 15
21 10

  1 Recycle return point could not be determined for two plants.
  The data provides the following
conclusions regarding the recycle
practice of ICR plants: (1) The recycle of
spent filter backwash and other process
streams is a common practice; (2) the
great majority of recycle plants in the
database use filtration and surface water
sources; (3) a majority of plants in the
database that recycle provide treatment
for recycle flow, and; (4) a  large majority
of plants in the  database that recycle
(approximately  3 out of 4) recycle prior
to the point of primary coagulant
addition.
                     b. Recycle FAX Survey
                       The AWWA sent a FAX survey
                     {AWWA, 1998) to its membership in
                     June 1998 to gather information on
                     recycle practices. Plants were not
                     targeted based on source water type, the
                     type of treatment process employed, or
                     any other factor. The survey was sent to
                     the broad membership to increase the
                     number of responses. Responses
                     indicating a plant recycled spent filter
                     backwash or other flows were compiled
                     to create a database. The resulting
                     database included 335 plants. The
                     database does not contain information
                     from respondents who reported recycle
was not practiced. Data from some of
the FAX survey respondents also
populates the ICR database. Plants in
the database are well distributed
geographically and represent a broad
range of plant sizes as measured by
capacity. Figure IV.11 shows plant
distribution by capacity and Figure
IV.12 by geographic location. The
following discussion of FAX survey  data
is divided into two sections. The first
discusses  national recycle practice and
the second discusses options for recycle
disposal in lieu of returning recycle to
the treatment process.
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      Federal Register/Vol. 65, No. 69/Monday, April 10,  2000/Proposed Rules
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19108
Federal Register/Vol. 65, No. 69/Monday, April 10, 2000/Proposed Rules
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                   Federal Register/Vol. 65, No. 69/Monday, April 10, 2000/Proposed Rules
                                                                              19109
i. Recycle practice

  Data summarized in Table IV. 14 show
that 78 percent of plants in the database
rely on a surface water as their source.
The percentage of plants using source
water influenced by a surface water
(which may contain Cryptosparidium)
could be higher because the data do not
report whether wells were pure ground
water or GWUDl.

 TABLE IV.14.—SOURCE WATER USED
       BY FAX SURVEY PLANTS
       Source water type
Surface Water.
River 	
Reservoir 	
Lake 	
Other	
Well1 	
Percent
of plants
     78
     27
     28
     16
      7
     22
  1 Wells sources not defined as either ground
water or ground water under the direct influ-
ence of surface water.

  Table IV. 15 shows that a wide variety
of treatment process types are included
in the data, with conventional filtration
(rapid mix, coagulation, sedimentation,
filtration) representing over half of the
plants submitting data. Upflow
clarification is the second most common
treatment process reported. Ten percent
of plants in the database use direct
filtration. Only four percent of plants do
not use rapid granular filtration.
         TABLE IV.15.—TREATMENT TRAINS OF
                 FAX SURVEY PLANTS
              Treatment process type
                             :  Percent
                             :    of
                               plants1
         Rapid mix, coagulation, filtration
         Upflow clarifier 	
         Softening	
         Direct filtration	
         Other	
                                   51
                                   21
                                   14
                                   10
                                    4
  196 percent of plant in the database provide
filtration.
  Table IV. 16 indicates that a vast
majority of plants recycle prior to the
point of primary coagulant addition.
Only six percent of plants returned
recycle in the sedimentation basin or
just prior to filtration.

   TABLE IV.16.—RECYCLE RETURN
   POINT OF FAX SURVEY PLANTS
                                                 Return point
                                        Percent
                                       of plants
         Prior to point of primary coagulant
           addition	       83
         Pre-sedimentation (e.g.. rapid mix)        11
         Sedimentation basin 	        4
         Before filtration 	        2

           Table IV.17 shows that the majority of
         plants in the database provide some
         type of treatment for the recycle flow
         prior to its reintroduction to the
         treatment process. Approximately 70
         percent of plants reported providing
         treatment, with sedimentation being
         employed by over half of these plants.
         Equalization, defined as a treatment
technology by the survey, is practiced
by 20 percent of plants in the database.
Fourteen percent of plants reported
using both sedimentation and
equalization.

 TABLE IV.17.—RECYCLE TREATMENT
       AT FAX SURVEY PLANTS
        Treatment type
Percent
of plants
No treatment	
Treatment 	
Sedimentation	
Equalization 	
Sedimentation and equalization
Lagoon	
Others 	
     30
     70
     54
     20
     14
      5
      7
  Table IV. 18 summarizes recycle
treatment practice and frequency of
direct recycle based on population
served. The table illustrates that, for
plants supplying data, treatment of
recycle with sedimentation is provided
more frequently as plant service
population deceases. Plants serving
populations of less than 10,000 recycle
directly (27.5 percent) less frequently
than plants serving populations greater
than 100,000 (50 percent). The data
indicate that a majority of small plants
in the database may have installed
equalization or sedimentation treatment
to protect treatment process integrity
from recycle induced hydraulic
disruption. All direct filtration plants in
the FAX survey provide recycle
treatment or equalization.
                         TABLE IV. 18.—RECYCLE PRACTICE BASED ON POPULATION SERVED1
                        Population served
                                                                                   Recycle practice
                                                                 #Plants    Equalization    Sedimentation     Direct recycle
<10000 	
10000-50000 	
50000-100000 	
100.000 	
43
79
35
65
9% (n=4)
10% (n=8)
17% (n=6)
35% (n=23)
67% (n=29)
57% (n=45)
54% (n=19)
23% (n=15)
23% (n=10)
33% (n=26)
29% (n=10)
42% (n=27)
  1 Based on 222 surface water plants suppling all necessary data to make determination.
  FAX survey data support the
following conclusions regarding the
recycle practice of plants supplying
data: (1) The recycle of spent filter
backwash and other process streams is
a common practice; (2) the majority of
recycle plants use surface water as their
source and are thereby at risk from
Cryptosporidium; (3) a large majority of
plants providing data recycle prior  to
the point of primary coagulant addition.
and: (4) a majority of plants supplying
data provide treatment for recycle
waters prior to reintroducing them to
         the treatment plant. The FAX survey
         provides an informative snapshot of
         national recycle practices due to the
         number of recycle plants it includes, the
         geographic distribution of respondents,
         and the good representation of plants
         serving populations of less than 10,000
         people.

         ii. Options to recycle.

           The FAX survey asked whether
         feasible alternatives to recycle are
         available (i.e., NPDES surface water
         discharge permit, pretreatment permit
                                       for discharge to POTW) and the
                                       importance of recycle to optimizing
                                       treatment performance and meeting
                                       production requirements. Responses to
                                       these questions is summarized in Table
                                       1V.19.
                                         Table IV.19 shows that approximately
                                       20 percent of respondents could not
                                       obtain either an NPDES surface water
                                       discharge permit or a pretreatment
                                       permit for discharge to a POTW.
                                       Approximately 90 percent of
                                       respondents stated that recycle flow is
                                       not important to meet typical demand.

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Federal  Register/Vol.  65,  No, 69/Monday, April  10,  2000/Proposed Rules
Twenty-four percent of all respondents    respondents may have considered not
stated that returning recycle to the        changing current plant operation (e.g.,
treatment process is important for         not changing current recycle practice)
optimal operation. "Optimal operation"   an aspect of optimal treatment, rather
was not defined by the survey and        than addressing whether recycle
                                                            practice is important for the plant to
                                                            produce the highest quality finished
                                                            water.
                     TABLE IV.19.—OPTIONS TO RECYCLE AS REPORTED BY FAX SURVEY PLANTS'
Question
Able to obtain NPDES surface discharge permit"*1 	
Able to obtain pretreatment permit for POTW discharge?
Can obtain either an NPDES or a POTW discharge permit? 	
Is recycle important to meet peak demand? 	 	
Is recycle important to meet typical demand9 	
Is recycle important to optimal operation*^ {All plants in survey)
Is recycle important to optimal operation^2 (softening plants only)

Percent
Yes
	 41%
(n=131)
43%
1 (n=137) '
60%
(n=i92)
	 : 14% ,
i (n=44) ;
	 9%
(n=28)
24% ,
: (rt=75) '
13%
(n=3)
Percent
No L
37%
(n=120)
42%
(n=136) '
19.5%
(n=63)
80%
(n=257) :
85%
=48)
20.5%
(n=66)
6%
(n=20)
6%
(n=21)
6%
(n=21)
4%
(n=1)
  1 Number of plants varies from question to question due to different response rates.
  2 Optimal operation not defined by survey. May include overall plant operation rather than importance of recycle to producing highest possible
 quality finished water.
 iii. Conclusions
   The ICR and FAX survey data are
 complimentary, as the ICR data supplies
 a wealth of data regarding recycle
 practices at large capacity plants, while
 the FAX Survey provides data on
 recycle practices over a range of plant
 capacities. Taken together, the two data
 sets provide a good picture of current
 recycle practice. The data indicate that
 recycle is a common practice for plants
 sampled. Approximately half of the
 respondents providing data return
 recycle flow to the treatment process
 and 70 percent provide some type of
 recycle treatment. Sedimentation and
 equalization are the two most
 commonly employed treatment
 technologies for plants supplying data.
 Approximately 80 percent of plants
 sampled return recycle prior to the
 point of primary coagulant addition.
 Examining the recycle practices of
 plants in the ICR and FAX survey data
 show that small plants (i.e., fewer than
 10,000 people served) are more than
 twice as likely as large plants (i.e.,
 greater than 100.000 people served) to
 provide sedimentation lor recycle
 treatment (58 versus 20 percent).
  The FAX survey responses show that
 approximately half of plants providing
 data have an option to recycle return,
 whether it be an NPDES surface water
 discharge permit or discharge to a
 POTW. Eighty-five percent of
 respondents stated that recycle flow is
 not important  to meet peak demand.
Less than a quarter of respondents have
monitored pathogen concentrations in
                     backwash water and fewer than half
                     have any monitoring data to
                     characterize the quality of the backwash
                     water.

                     3. Recycle Provisions for PVVSs
                     Employing Rapid Granular F'iltration
                     Using Surface Water or Ground Water
                     Under the Direct Influence of Surface
                     Water
                     a. Return Select Recycle Streams Prior
                     to the Point of Primary Coagulant
                     Addition
                     i. Overview and Purpose
                       Today's proposal requires that
                     systems employing rapid granular
                     filtration and using surface water or
                     GWUDI as a source return filter
                     backwash, thickener supernatant, and
                     liquids from dewatering processes to the
                     primary treatment process prior to the
                     point of primary coagulant addition.
                     The goal of this provision is to protect
                     the integrity of chemical treatment and
                     ensure these recycle streams are passed
                     through as many physical removal
                     processes as possible to provide
                     maximum opportunity for removal of
                     Cryptosporidium oocysts from the
                     recycle flow. Since Crvptosporidium is
                     resistant to standard disinfection
                     practice, it is important that chemical
                     treatment be optimized to protect
                     treatment plant efficiency and that all
                     available physical removal processes be
                     employed to remove it.
                      Today's proposal requires these flows
                     be returned prior to the point of primary
                     coagulant addition because these
                     streams are either of sufficient volume
to cause hydraulic disruption within the
treatment process when recycled and/or
are likely to contain Crvptosporiilium
oocysts. Minor recycle streams, such as
lab sample lines, pump packing water.
and infroquent process overflows are
nut likely to threaten plants' hydraulic
stability or contain appreciable numbers
of oocysts.
  Treatment plant types that need to
return recycle to a location other than
prior to the point of primary coagulant
addition to maintain optima! treatment
performance (optimal performance as
indicated by finished water or intra-
plant  turbidity levels), plants that are
designed to employ recycle flow as an
intrinsic component of their operations.
plants with very low influent turbidity
levels that may need alternative recycle
locations to obtain satisfactory
suspended solids removal, or other
types  of plants constrained by unique
treatment considerations, may apply to
the State to recycle at an alternative
location under today's proposal. Once
approved by the State, plants may
recycle to the specified location.

ii. Data
  Data from the ICR and FAX Survey
indicate that 75 and 78 percent of
plants, respectively, return recycle prior
to the point of primary coagulant
addition. The "point of primary
coagulant addition" was defined in both
analyses as the return of recycle prior to
the rapid mix unit. The FAX Survey
data indicate that 77 percent of plants
serving under  10.000 people recycle
prior to the point of primary coagulant

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                  Federal Register/Vol. 65. No.  69/Monday, April 10, 2000/Proposed  Rules
                                                                     19111
addition. It also showed that 78 percent
percent of all plants in the database
return recycle there, which suggests that
plants serving smaller populations may
return recycle prior to the point of
primary coagulant addition as
frequently as plants serving larger
populations. Other common recycle
return locations are the rapid mix unit,
between rapid mix and clarification, or
into the clarification unit itself.
  The Agency does not believe filter
backwash, thickeners supernatant, or
liquids from dewatering processes
should be recycled at the point of
primary coagulant addition or after it for
three reasons:
  (1) Addition of these recycle streams,
which can contain residual coagulant
and other treatment chemicals, after the
location of primary coagulant addition,
may render the chemical dose applied
less effective, potentially harming the
efficiency of subsequent treatment
processes;
  (2) Introduction of recycle into the
flocculation unit or clarification unit
may create hydraulic currents that
exacerbate or create short circuiting,
and;
  (3) Recycle introduced into the
clarification process may not experience
sufficient residence time for adequate
solids removal to occur.
  The Agency is concerned that plants
may not adjust chemical dosage during
recycle events to account for: (1) The
presence of a potentially significant
amount of residual treatment chemical
in recycle flow and changes in recycle
flow quality, and; (2) potentially large
fluctuations in plant influent flow
during recycle events. EPA is concerned
that changes in influent water quality
and flow are not monitored on an
instantaneous basis during recycle
events. Since the chemistry of the
recycle flow and source water may
differ significantly, it is important
plants mix source and recycle water to
establish a uniform chemistry prior to
applying treatment chemical so the dose
is appropriate for the mixture.
Additionally, wide fluctuation in plant
influent flow during recycle events may
cause chemical over-or under-dosing,
which can lower overall oocyst removal
efficiency. In an article concerning
optimization of filtration performance,
Lytle and Fox (1996) state, "The
capability to instantaneously monitor
treatment processes and rapidly and
effectively respond to raw and filter
effluent quality changes are important
factors in consistently producing low
turbidity water." Logdson (1987) further
states, "For a plant to be operated
properly, the total flow rate has to be
known on an instantaneous basis or by
volumetric measurement." EPA believes
it is important plants diligently monitor
the appropriateness of chemical dosing
at all times, but particularly during
recycle events, and strive for real-time
chemical dose and influent flow
management to optimize plant oocyst
removal.
  Pilot-scale research conducted by
Patania fit al. (1995) to examine the
optimization of filtration found that
chemical pretreatment was the most
important variable determining oocyst
removal by filtration. Edzwald and
Kelley (1998) performed pilot-scale
work to determine the ability of
sedimentation, DAF, and filtration to
remove Crvptosporidium and found that
coagulation is  critical to effective
Cryptosporidium control by clarification
and filtration. Bellamy et al. (1993)
stated that the most important factor in
plant performance is the use of optimal
chemical dosages. Coagulation was
recognized as the single most important
step in the process of water clarification
by Conley (1965). Ten pilot scale runs
performed by Dugan et al. (1999)
showed that coagulation has a large
influence on the log removal of
Crvptosporidium achieved by
sedimentation. The importance of
proper coagulation to filter performance
was noted by Robeck et al. (1964) in
pilot and full-scale work that showed
proper coagulation is more important to
the production of safe water than the
filtration rate used. Results of direct
filtration pilot studies, summarized by
Trussell et al. (1980), showed that
"effective  coagulant is absolutely
necessary  if good effluent qualities are
to be consistently produced."
  Given the critical role proper
chemical dosing plays in maintaining
effective clarification and filtration
processes, the  Agency believes it is
prudent and necessary to minimize the
possibility recycle of spent filter
backwash, thickener supernatant, and
dewatering liquids will render chemical
dosages applied  during recycle events
inaccurate, due to the presence of
residual chemical or variations in
influent flow, by requiring they be
returned prior to the point of primary
coagulant  addition.
  Finally, a fundamental tenet of water
treatment  is multiple treatment barriers
should be provided to prevent microbial
pathogens from entering finished water.
To achieve this, conventional plants
rely on coagulation, flocculation,
clarification, and filtration as preventive
microbial barriers. The Agency believes
it is important that recycle waters be
passed through each of these treatment
processes to maximize the probability
disinfection resistant oocysts will be
removed in the plant and not enter the
finished water supply.
iii. Proposed Requirements
  Today's proposal requires that rapid
granular filtration plants using surface
water or GWUDI as a source return filter
backwash, thickener supernatant, and
liquids from dewatering processes prior
to the point of primary coagulant
addition. Plants that require an
alternative recycle return location to
maintain optimal finished water quality
(as indicated by finished water or intra-
plant turbidity levels), plants that are
designed to employ recycle flow as an
intrinsic component of the treatment
process, or plants with unique treatment
requirements or processes may apply to
the State to return recycle flows to an
alternative location. Plants may utilize
this alternative location once granted by
the State. EPA will develop detailed
guidance and make it available to States
and PWSs.
  Softening systems may recycle
process solids, but not spent filter
backwash, thickener supernatant, or
liquids from dewatering processes, at
the point of lime addition immediately
preceding the softening process to
improve treatment efficiency. Literature
establishes that return of process solids
to point of lime addition decreases
production of nuclei, increases the rate
of crystallization, and increases crystal
size, all of which enhance settling and
process integrity (Randtke, 1999;
Snoeyink and Jenkins, 1980). Contact
clarification systems may recycle
process solids, but not spent filter
backwash, thickener supernatant, or
liquids from dewatering processes,
directly into the contactor to improve
treatment efficiency.
iv. Request for Comments
  EPA requests comment on the
proposed requirements. The Agency
also requests comment on the following
aspects of this provision:
  (1) What regulatory options are
available to ensure direct recycle plants
practice real-time chemical dose and
influent flow management? Should
flow-paced coagulant feed be required at
direct recycle plants to minimize
potential harmful impacts of recycle?
What regulatory requirements may be
applicable to ensure the integrity of the
coagulation process?
  (2) What treatment processes or
treatment configurations may need an
alternative recycle location to maintain
optimal treatment?
  (3) What alternative recycle locations
are appropriate for such treatment
configurations and what location may
be inappropriate?

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19112
Federal Register/Vol.  65, No.  69/Monday,  April 10, 2000/Proposed Rules
  (4) Are there other reasons, beyond
maintaining optimal treatment
efficiency, to justify granting alternate
recycle locations to plants? What are
they?
  (5) What criteria, operating practices,
or other parameters should be evaluated
to determine whether an alternative
recycle return location should be
granted?
  (6) Does recycling at the point of
primary coagulant addition, instead of
prior to it, provide assurance that an
appropriate  dose of treatment chemicals
will be consistently applied during
recycle events? Is it necessary to mix the
recycle and  raw water prior to chemical
addition to ensure a consistent water
chemistry for chemical dosing?
  (7) Are  there circumstances where it
would be  appropriate to allow systems
to recycle at the point of primary
coagulant addition?

b. Recycle Requirements for Systems
Practicing Direct Recycle and Meeting
Specific Criteria
i. Overview  and Purpose

  Today's proposal requires that self
assessments be performed at
conventional filtration plants meeting
all of the following criteria and the
results of  the self assessment reported to
the State.  The criteria are:
  (1) Use  of surface water or GWUDI as
a source;
  [2) Employ of 20 or fewer filters to
meet production requirements during
the highest production month in the 12
month period  prior to LTlFBR's
compliance date, and;
  (3) Recycle spent filter backwash or
thickener  supernatant directly to the
treatment  process (i.e., recycle flow is
returned within the treatment process of
a PWS without first passing the recycle
flow through a treatment process
designed to remove solids, a raw water
storage reservoir, or some other
structure with a volume equal to or
greater than  the volume of spent filter
                     backwash water produced by one filter
                     backwash event.)
                       The goal of the self assessment is to
                     identify those direct recycle plants that
                     exceed their State approved operating
                     capacity, on an instantaneous basis,
                     during recycle events. Plants are
                     required to submit a monitoring plan to
                     the State prior to conducting the month
                     long self assessment monitoring. Results
                     of self assessment monitoring must be
                     reported to the State. The State is
                     required to determine, by reviewing the
                     self assessment, whether the plant's
                     current recycle practice should be
                     modified to protect plant performance
                     and provide an additional measure of
                     public health protection. The State is
                     required to report its determination for
                     each plant performing a self assessment
                     to EPA and briefly summarize the
                     reason(s) supporting each
                     determination.
                       EPA selected the three
                     aforementioned criteria to identify
                     plants required to perform a self
                     assessment for the following reasons.
                     First, surface or GWUDI source waters
                     may contain Cryptosporidium. Second,
                     the hydraulic impact of recycle to plants
                     typically employing more than 20 filters
                     to meet production requirements should
                     be dampened because plant influont
                     flow is of significantly greater
                     magnitude than the flow produced by a
                     backwash event. Third, plants that
                     practice direct recycle of filter backwash
                     and/or thickener supernatant may
                     exceed their operating capacity during
                     recycle events due to the large volume
                     of these streams.

                     ii. Data
                       Plants that recycle filter backwash
                     and thickener supernatant, directly,
                     without recycle flow equalization or
                     treatment, may exceed their operating
                     capacity during recycle events. Table
                     IV.20 illustrates the magnitude by
                     which direct recycle plants may exceed
                     their operating capacity during recycle
                     events. For purposes of the table.
operating capacity is assumed to be
either plant design flow or average flow
(see example below). The values in the
table  are conservative, as they are likely
to over predict the factor by which
direct recycle plants will exceed
operating capacity during recycle
events. This conservatism is due to the
assumed filter backwash rate of 15 gpm/
ft2 and the assumed backwash duration
of 15  minutes, the minimum backwash
rate and duration recommended by the
Great Lakes-Upper Mississippi River
Board of State and Provincial Public
Health and Environmental Managers
(1997). Design and average flow values
assumed for plant operating capacity
were developed from equations
presented in EPA's baseline handbook
(1999g). For purposes of this example,
plant  design and average flow are
assumed to equal State approved
operating capacity to illustrate the
potential for plants to exceed operating
capacity during recycle events. Relevant
equations and example calculations are
shown below,

Example
  (l) Design to average ratios:
design flow < .25 mgd; ratio design flow :
    average flow = 3.2:1
design flow > .25 mgd to 1 mgd; ratio design
    flow : average flow = 2.8:1
design flow > 1 mgd to 10 mgd; ration design
    flow : average flow = 2.4:1
design flow > 10 mgd; ratio design flow :
    average flow = 2.0:1
  (2) Maximum filter size: 700 sq./ft^ (EPA,
1998a)
  (3) Backwash volume calculation:
Kilter area [ft2] x 15  gpm/ft^ x 15 minutes =
    volume of one backwash
  (4) Design and average capacity exceedence
factors:
(Backwash flow + design (or average) flow)
* design flow = exceedence factor
  (5) Percent Influent that is recycle:
Backwash flow -s- (Backwash flow + design
(or average flow)) =  percent of influent that
is backwash
  (6) Design flow = State approved operating
How
                                     TABLE IV.20— IMPACT OF DIRECT RECYCLE
°Gsr '•"*
(MGD)
.033
.669
2.02
8.8
14.5
42.44 1
56.23
1
fi& *'£"«£
"lters (sq. ft)
i
2 i 5
4 50
6 i 100
8 320
10 425
18 700
24 700
Volume of
one back-
wash
(gallons)
1,125
Backwash
return flow
(15 minute
return;
gpm)
75
11,250. 750
22,500
72,000
1,500
4,800
95,625 6.375
157.500
10,500
157.500 10.500
Design
flow
(gpm)
23
465
1.403
6.111
10.069
29.472
39.048
Average
flow
(gpm)
7
166
584
2,546
5,135
14,736
19.524
Factor de-
sign flow
is exceed-
ed by dur-
ing recycle
(at design
flow)
4.3
2.6
2.1
1.8
1.6
1.4
1.3
Percent in-
fluent that
is recycle
(at design
flow)
(percent)
77
62
52
44
39
26
21
Fj£n°fl±~ ' Percent in-
islxceed fluentthat
e^bTdut ; «
'(is16 £,*:>
ag'ellow) ' 
3.6 j 91
2.0 82
1.5 : 72
12 I 65
11 55
.86 , 42
.77 ' 35

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                   Federal Register/Vol. 65. No.  69/Monday,  April 10, 2000/Proposed  Rules
                                                                      19113
  The purpose of Table IV.20 is to
illustrate the impact direct recycle can
have on plant hydraulic loading and the
factor by which plant operating capacity
can be exceeded during recycle events.
As shown in Table IV.20. a plant with
two filters would process influent at
over three times its operating capacity
during a recycle event.  Even if the plant
reduced or eliminated its raw water
influent flow for the duration of the
event, the remaining filter would be
subject to a loading rate that exceeds its
operating capacity, which could harm
finished water quality.
  The amount of sedimentation basin or
clarification process storage available
during recycle events will have an
impact on the hydraulic loading to the
filters and the performance of the
sedimentation or clarification process.
The actual increase to filter loading
rates may be less than predicted in
Table IV'20 due to site-specific
conditions. However, the potential for
direct recycle plants to exceed operating
capacity is cause for concern because
oocyst removal can be compromised.
The Agency believes 20 filters  is an
appropriate number for specifying
which plants are required to perform a
self assessment due  to the results in
Table IV.20 and the  above
considerations.
  The importance of maintaining proper
plant hydraulics has been
acknowledged, notably by Logdson
(1987) who wrote, "Both the quantity
and quality of filtered water can be
affected by plant hydraulics. Maximum
hydraulic capacity is an obvious
limitation. The adverse influences of
rate of flow and flow patterns on water
quality may  not be so obvious, but they
can be important." Fulton (1987)
recognized that short circuiting can
diminish the performance of settling
basins, cause overloading of filters, and
increase breakthrough of turbidity.
Other publications (Cleasby, 1990)
recognize that settled water quality
deteriorates  when the surface loading
rate of sedimeijtation basins is
increased. Direct recycle practice can
give rise to short circuiting, cause plant
operating capacity to be exceeded, and
increase surface  loading rates, all of
which can be detrimental to
Cryptosporidium removal.
  Direct recycle  practice can abruptly
increase filter loading rates, which has
been shown to lower filter performance.
Cleasby et al. (1963) performed
experimental runs with three pilot plant
filters by increasing the filtration rate
ten, twenty-five, and fifty-percent over
various time periods and monitoring the
passage of a  target material during the
rate increase. Conclusions drawn from
the experiments wens:
  (1) Disturbance in filtration rate can
cause filters to pass previously
deposited material and the amount of
material passed is dependent on the
magnitude of the rat<; disturbance;
  (2) Morti rapid disturbances cause
more material to be (lushed through the
filter;
  (3) The amount of material flushed
through the filter is independent, or
very nearly independent of
disturbance's duration, and;
  (4) The amount of material flushed
through the filter following a
disturbance is dependent on the; type of
material being filtered.
  Pilot scale work was recently
performed by Glasgow and Wheatley
(1998) to investigate whether surges
affect filtrate quality. Effluent turbidity
and headloss within the filter media
were monitored for two pilot filter
columns that were surged  at different
magnitudes. The results were compared
to control runs through the same pilot
columns to determine the effect of the
surge. Results indicated that surging
may significantly affect full scale filter
performance. Additional work is needed
to confirm these results.
  Recent pilot scale work by McTigue et
«/. (1998) examined the impact of
doubling the filter loading
instantaneously and gradually (over an
80 minute period) on pilot filters that
had been in operation for a period of
time or were "dirty." The experiments
showed that Cryptosporidium removal
achieved by the filters was lowered by
changes in filtration rate n;gardless of
whether loading rate was increased
instantaneously or gradually. In the
experiment, filter loading rates of 2
gpm/fl- and 4 gpm/ft* were doubled in
six separate test runs to determine
whether oocysts removal was affected.
Results showed that log removal of
oocysts was reduced by approximately
1.5 to 2.0 logs for when filter loading
rates of 2 gpm/'ft* and  4 gpin/ft2 were
either instantaneously and gradually
doubled. The report states, "These data
clearly demonstrate that any change in
filter loading rate on a filter that is dirly
presents a risk for breakthrough of
Giardia and  Cryptosporidium to the
finished water, should these organisms
be present in the filter." Effluent
turbidity values remained  low during
increases in filter loading rates but
particle count concentrations
immediately increased with increases in
loading rate. This may indicate that
turbidity is not a good indicator of
oocyst passage by dirty filters during
filtration rate increases.
  Results of three other pilot runs from
the study showed that log removal of
oocysts did not change when the
influent oocyst concentration varied and
all other treatment conditions were held
constant. A four log removal of oocysts
was obtained for all three runs despite
influent oocyst concentrations of 4,610/
L, 688/L, and 26/L. The report states,
"This finding indicates that the risk for
passage of large numbers of cysts to the
finished water is greater  when a water
treatment plant receives  a highly
concentrated slug of cysts at its intake."
The Agency believes this is an
interesting conclusion, even though it  is
based on a limited number of pilot runs.
If further pilot and full-scale work
verifies this finding, it indicates that log
removal of oocysts does  not increase as
more oocysts are loaded  to plant.
Recycle of flows containing oocysts
would therefore increase the number of
oocysts present in finished water,
relative to the number of oocysts that
would occur were recycle not practiced,
because plant treatment  efficiency
would not increase to remove the
additional oocysts returned by recycle.
  In summary, the Agency is concerned
that direct recycle of spent filter
backwash, thickener supernatant, and
liquids from dewatering process may
increase the risk of oocyst occurrence in
finished water for the following reasons:
  (1) Sampling has established that
oocysts occur in finished water supplies
(see Table II.6 of this preamble):
  (2) Data show that oocysts occur in
recycle streams;
  (3) Literature indicates that
hydraulically overloading the
sedimentation process, as may happen
during direct recycle events, can harm
sedimentation performance;
  (4) Literature indicates increasing or
abruptly changing filtration rates can
lead to more material passing through
filters, and;
  (5) Recent pilot scale work by
McTigue et al, (1998) and Glasgow and
Wheatley (1998) indicates that filter
performance can be harmed by surges
and changes to filtration rate.
  The  Agency encourages the States to
closely examine recycle  self assessments
performed by direct recycle plants to
determine whether direct recycle poses
an unacceptable risk to finished water
quality and public health and needs to
be modified due to the considerations
cited above.
  Finally, EPA realizes that State
programs may use different
methodologies to set plant operating
capacity. States may also apply safety
factors of different magnitudes when
determining operating capacity. The
Agency does not believe it is

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Federal  Register/Vol.  65,  No. 69/Monday, April 10, 2000/Proposed Rules
appropriate to erode any safety factor or
margin of safety States provide when
setting operating capacity. Safety factors
are provided for a reason: to provide a
margin of safety to public health
protection efforts. The integrity and
magnitude of a safety factor should be
maintained, as it is in and of itself
integral to adequate public health
protection. The fact a safety factor is
applied when plant operating capacity
is set is not  a justification, a priori, for
allowing plants to operate above said
operating capacity during recycle
events.
   EPA also  acknowledges that States
may use different methodologies to set
plant operating capacity. The Agency is
confident that the State programs, its
partners in public health protection, set
plant capacity to provide necessary
level of public health protection. The
fact that some State programs may set
plant operating capacities with different
methodologies likely reflects
geographical conditions and public
expectations unique to certain States
and sections of the country. EPA
believes methodologies employed by the
States results in establishment of
operating capacities  necessary to protect
public health, meet regulatory
requirements, and satisfy unique
treatment needs and considerations
where they exist.
iii. Proposed Requirements
   Self assessments must be performed at
plants meeting all of the following
criteria and the results of the self
assessment reported  to the State:
   (1) Use surface water or GWUDI as a
source and employ conventional rapid
granular filtration treatment;
   (2) Employ of 20 or fewer filters to
meet production requirements during
the highest production month in the 12
month period prior to LT1 FBR's
compliance date, and;
   (3J Recycle spent filter backwash or
thickener supernatant directly to the
treatment process (i.e., recycle flow is
returned within the treatment process of
a PWS without first passing the recycle
How through a treatment process
designed to remove solids, a raw water
storage reservoir, or some other
structure with a volume equal to or
greater than the volume of spent filter
backwash water produced by one filter
backwash event).
  Systems are required to develop and
submit a recycle self assessment
monitoring plan to the State no later
than three months after the  rule's
compliance date for each plant the
requirements are applicable to. At a
minimum, the monitoring plan must
identify the month during which
                     monitoring will be conducted, contain a
                     schematic identifying the location of
                     raw and recycle flow monitoring
                     devices, describe the type of flow
                     monitoring devices to be used, and
                     describe how data from the raw and
                     recycle flow monitoring devices will be
                     simultaneously retrieved and recorded.
                       The self assessment of recycle
                     practices shall  consist of the following
                     five steps:
                       (1) From historical records, identify
                     the month in the calendar year
                     preceding LTlFBR's effective date with
                     the highest water production.
                       (2) Perform the monitoring described
                     below in the twelve month period
                     following submission ot the  monitoring
                     plan to the State.
                       (3) For each day of the month
                     identified in (1). separately monitor
                     source water influent flow and recycle
                     flow before their confluence during one
                     filter backwash recycle event per day, at
                     three minute intervals during the
                     duration of the event. Monitoring must
                     be performed between 7:00 a.m. and
                     8:00 p.m. Systems that do not have a
                     filter backwash recycle event every day
                     between 7:00 am and 8:00 p.m. must
                     monitor one filter backwash recycle
                     event per day, any three days of the
                     week, for each  week during the month
                     of monitoring,  between  7:00 a.m. and
                     8:00 p.m. Record the time filter
                     backwash was  initiated, the  influent and
                     recycle flow at  three minute  intervals
                     during the duration of the event, and the
                     time the filter backwash recycle event
                     ended. Record  the number of filters in
                     use when the filter backwash recycle
                     event is monitored.
                       (4) Calculate  the arithmetic average of
                     all influent and recycle flow values
                     taken at three minute intervals in  (3).
                     Sum the arithmetic average calculated
                     for raw water influent and recycle flows.
                     Record this value and the date the
                     monitoring was performed. This value is
                     referred to as event flow.
                       (5) After monitoring is complete,
                     order the event flow values in
                     increasing order, from lowest to highest,
                     and identify the monitoring events in
                     which plant operating capacity is
                     exceeded.
                       Systems are required to submit a self
                     assessment report to the State within
                     one month of completing the self
                     assessment monitoring. At a  minimum,
                     the report must provide  the following
                     information:
                       (l) All source and recycle flow
                     measurements taken and the dates they
                     were taken. For all events monitored,
                     report the times the filter backwash
                     recycle event was initiated, the flow
                     measurements taken at three minute
                     intervals, and the time the filter
backwash recycle event ended. Report
the number of filters in use when the
backwash recycle event is monitored.
   (2) All data and calculations
performed to determine whether the
plant exceeded its operating capacity.
Report the number of event flows that
exceed State approved operating
capacity.
   (3) A plant schematic showing the
origin of all recycle flows, the hydraulic
conveyance used to transport them, and
their final destination in the plant.
   (4) A list of all the recycle flows and
the frequency at which they are
returned to the plant.
   (5) Average and maximum backwash
flow through the filters and the average
and maximum duration of backwash
events in minutes, for each monitoring
event, and;
   (6] Typical filter run length, number
of filters typically employed, and a
written summary of how filter run
length is determined (preset run time,
headloss. turbidity level).
  EPA is proposing that the State review
all self assessments submitted by PWSs
and report  to the Agency the below
information as it applies to individual
plants:
   (1) A finding that  modifications to
recycle practice are necessary, followed
by a brief description of the required
change and a summary of the reason(s)
the change is required, or;
  (2) A finding that changes to recycle
practice are not necessary and a brief
description of the reason(s) this
determination vvas made.
  The Agency also considered requiring
all recycle plants without existing
recycle flow equalization or treatment to
install recycle flow equalization.  As
summarized in Table IV.21, several
recommendations for recycle
equalization and treatment have been
provided. However, these
recommendations are based on
theoretical  calculations and/or limited
pilot-scale data that  has not been
verified by  full-scale plant performance
data. The Agency currently believes
insufficient data is available to
determine whether recycle flow
equalization is necessary to protect
finished water quality, and, if it is, the
level of equalization required to provide
protection to finished water supplies for
a wide variety of source water qualities,
treatment process types, and levels  of
treatment effectiveness. The Agency
does not believe it is  appropriate  at  this
time to propose a national recycle flow
equalization requirement for the
following reasons:
  (1) Data on the occurrence of oocysts
in recycle streams, and their impact to

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                   Federal  Register/Vol. 65,  No. 69/Monday. April  10,  2000/Proposed Rules
                                                                       19115
finished water quality upon recycle, is
very limited;
  (2) Data that establishes the
magnitude of hydraulic disruption
caused by direct recycle events for a
variety of plant types, designs, and
operational practices has not been
identified:  without this data, it is not
possible to quantify how much
treatment efficiency is reduced by the
hydraulic disruption and the number of
oocysts in the recycle flow that will
enter the finished water due to the
disruption. Without this information, it
is not possible to specify the level of
equalization necessary to control
hydraulic disruption for a variety of
plant configurations and operational
practices with any degree of certainty
and cost effectiveness, and:
   (3) A uniform, national equalization
  standard may not be appropriate
  because it would not allow
  consideration of site-specific factors
  such as plant treatment efficiency,
  loading capacity of clarification and
  filtration units, source water quality,
  and other site-specific factors that
  influence the level of equalization a
  plant may need to control recycle event
  induced hydraulic disruption.
   EPA believes some  plants can realize
  substantial benefit by installing recycle
  flow equalization and will review data
  to determine the need for an
  equalization requirement when it
  becomes available. The Agency requests
  that co mm enters submit the following
  pilot or full-scale data to assist its effort
  to conduct a thorough analysis of
            equalization based upon the best
            available science:
              (1) Data on the magnitude of
            hydraulic disruption caused by recycle
            events and its affect on finished water
            turbidity and particle count levels;
              (2) Data that correlate hydraulic
            disruption to increased oocyst
            concentration in finished water, and;
              (3) Any other data commenters
            believe that may be appropriate to
            analyze the need for equalization, and;
              (4) Whether the regulation should
            require States to specify modifications
            to recycle practice, for all plants that
            exceed operating capacity during
            monitoring, to ensure said plants'
            remain below their State approved
            operating capacity during recycle
            events.
                              TABLE IV.21— RECOMMENDED EQUALIZATION PERCENTAGES
                     Source of recommendation-1
                                Equalization
                                Percentage
                   Is recycle treatment recommended?
Recommended Standards  for Water  Works. Great Lakes—Upper  Mississippi
  River Board of State and Provincial Public Health and Environmental Man-
  agers. 1997. Albany: Health Education Services.
Removal of GrypfosporidYurn Oocysts by Water Treatment Process. Foundation
  for Water Research Limited, United Kingdom (1994).
                                                                   10%
                             10%
Recycle Stream Effects on Water Treatment
  Denver: AWWARF
Comwelt, D.,  and R. Lee. 1993.
Use equalized.
  continuous recy-
  cle.
                                                                                     No.
Yes. Turbidity less than 5.0 NTU or re-
  sidual of IQmg/L suspended solids in
  treated recycle flow.
Use  proper waste  stream treatment
  prior to recycle.
  "See the reference list at the end of the preamble for complete citations.
  Finally, the Agency considered
requiring conventional filtration plants
that recycle within the treatment
process to provide sedimentation or
more advanced recycle treatment and
concluded a national treatment
requirement is inappropriate at this time
due data deficiencies. The Agency
believes the following data is necessary
to determine whether recycle flow
treatment is necessary to protect public
health and the requisite level of
treatment:
  (l) Significant amounts of additional
data on the occurrence of oocysts for a
complete range of recycle streams
generated by a wide variety of source
water qualities, treatment plant types,
plant operational and recycle practices,
and plant treatment efficiencies;
  (2) Data that correlates recycle stream
oocyst occurrence to finished water
occurrence;
  (3) Additional data on the ability of
full-scale sedimentation basins to
remove oocysts during normal operation
and during recycle events. The Agency
has identified only three full-scale
studies, States et al. (1995), Baudin and
Lame (1998), and Kelly ef al. (1995),
that allow quantification of oocyst
removal by sedimentation basins. Pilot
 scale work, such as Edzwald and Kelley
 11998) and Dugan et al. (1999) is also
 available, but the number of studies is
 not extensive. The removal achieved by
 sedimentation and other clarification
 processes is critical for determining the
 number of oocysts loaded to the filters,
 the likely concentration of oocysts in
 various recycle streams, and the impact
 recycle may have on intra-plant oocyst
 concentrations. Good oocyst removal in
 the clarification process will remove a
 large percentage of oocysts  from recycle
 and source water flows before they
 reach the filters. The amount  of removal
 provided by primary clarification
 therefore has a large influence on the
 level of recycle flow treatment that may
 be needed to mitigate risk to finished
 water quality. Given that data on oocyst
 removal by sedimentation and other
 clarification processes is very limited,
 the Agency does not believe it is
 possible to assess the need for recycle
 tr«atment and specify a minimum
 treatment level that is meaningful for a
 wide variety  of plant types  and recycle
 practices;
   (4) Data regarding the ability of DAF
 and other clarification processes to
 remove oocysts from recycle flow is
            very limited. This data is important,
            because the Agency anticipates plants
            may respond to any recycle treatment
            requirement by using DAF to treat
            recycle flow because of the advantages
            it provides relative to sedimentation.
            However, EPA has only identified four
            studies. Hall et al. (1995), Plummer et
            al. (1995), Edzwald and Kelley (1998),
            and Alvarez et al. (1999), that
            determined the ability of DAF to remove
            oocysts from source water. One study,
            by Grubb et al. (1997), addresses the
            ability of DAF to treat filter backwash
            waters has been identified, but sampling
            for oocyst removal was not performed,
            although turbidity and color removal
            were monitored and good results
            obtained. Additional data is needed to
            characterize the ability of DAF to
            remove oocysts from recycle flow before
            it can be used to meet any recycle
            treatment requirement;
              (5) Full-scale data on the ability of
            sedimentation and other clarification
            processes to remove oocysts from
            recycle streams before they are returned
            to the plant is very limited. EPA has
            identified two studies, one by Cornwell
            and Lee (1993) and a study by Karanis
            ef al. (1998) that provide data regarding

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 19116
Federal  Register/Vol.  65,  No. 69/Monday, April  10,  2000/Proposed Rules
 sedimentation's ability to remove
 oocysts from recycle flows. Additional
 information is needed to establish lower
 and upper bounds on the oocyst
 removal sedimentation can achieve;
 without this data, it is difficult to
 specify a feasible level of oocyst
 removal in a recycle flow treatment
 requirement;
   (6) Microfiltration and ultrafiltration
 membranes appear to be very reliable at
 removing Cryptosporidium from source
 waters (Jacangelo era/.,  1995). However,
 the Agency has identified limited data
 regarding the ability of membranes to
 effectively treat recycle flow, and
 treatment of backwash with membranes
 may not be appropriate at all locations
 (Thompson eta!,, 1995) due to
 incompatibility between membrane
 filter material and residual  treatment
 chemical(s) in the backwash water.
 Additional information regarding the
 ability of microfiltration and
 ultrafiltration membranes to treat
 recycle flow is necessary to
 comprehensively evaluate their
 applicability, and;
   f7) EPA is not aware of a  surrogate,
 including turbidity, particle counts, or
 any other common and easy to measure
 parameter, that can serve as an indicator
 of the log removal of Cryptosporidium
 recycle flow treatment units achieve.
 The Agency does not believe it is
 economically or technically feasible to
 directly monitor oocysl removal by
 treatment units. Without an accurate,
 easy to measure surrogate for
 Cryptosporidium removal, the Agency
 does not believe it is possible to
 ascertain the level of treatment recycle
 flow treatment units achieve during
 routine operations.
   Given the above limiting  factors, the
 Agency does not believe it is prudent to
 establish a national recycle flow
 treatment requirement until additional
 data becomes available. EPA requests
 the following data be submitted:
   (1) Data regarding intra-plant and
 recycle stream occurrence of oocysts;
   (2) Information on  the ability of
 individual treatment units of the
 primary treatment train to remove
 oocysts during normal, hydraulically
 challenged, and suboptimal chemical
 dose operations;
   (3) Data on the ability of
 sedimentation and other clarification
 processes to remove oocysts from a wide
 range of recycle streams;
   (4) Data on the compatibility of
 specific ultrafiltration and
 microfiltration membrane materials
 with residual chemicals that occur in
recycle streams and data regarding the
performance of these membrane
materials at ful! and pilot scale, and;
                       [5] Information on potential
                     surrogates that can be easily measured
                     and can accurately establish the log
                     removal of oocysts removed by recycle
                     flow treatment processes.

                     iv. Request for Comments
                       EPA requests comment on the
                     proposed requirements. The Agency
                     also requests comment on the following:
                       (1) What other parameters could be
                     monitored or what other overall
                     monitoring schemes could be employed
                     to assess whether a plant is exceeding
                     its operating capacity?
                       (2) What data should the plant report
                     to the State as part of its self assessment,
                     beyond the monitoring data and other
                     information listed above?
                       (3) Is monitoring during the highest
                     flow month appropriate? Is monitoring
                     during additional months necessary? Is
                     daily monitoring necessary or would
                     less frequent monitoring during the
                     month be sufficient?
                       (4) Should systems be required to
                     monitor and report turbidity
                     measurements from a representative
                     filter taken immediately preceding and
                     after recycle events monitored during
                     the self assessment to help characterize
                     the impact of recycle on plant
                     performance?
                       (5) Is limiting the self assessment to
                     plants with 20 or less filters
                     appropriate? Should the number of
                     filters be less or greater than 20? What
                     is the appropriate number of filters?
                       (6) Should systems be required to
                     monitor sedimentation overflow rates or
                     clarification loading rates while the
                     recycle flow monitoring is performed?
                       (7) EPA requests comment on criteria
                     that may identify recycle plants that
                     could receive substantial benefit from
                     implementing recycle equalization or
                     treatment as a standard practice.
                       (8) What type and amount of data is
                     required to determine whether recycle
                     flow equalization would provide a
                     benefit to finished water quality? What
                     methodology could be used to
                     determine an appropriate recycle flow
                     equalization percentage, and how
                     relevant are turbidity and particle
                     counts, at various locations in a plant,
                     to assessing an appropriate equalization
                     percentage for a single plant or a plant
                     type?
                     d. Requirements for Direct Filtration
                     Plants that Recycle Using Surface Water
                     or GWUDI

                     i. Overview and Purpose
                      Today's proposal requires direct
                     filtration plants that recycle to report to
                     the State whether flow equalization or
                     treatment is provided for recycle flow
 prior to its return to the treatment
 process. The purpose of today's
 proposed requirement is to assess
 whether the existing recycle practice of
 direct filtration plants addresses
 potential risks. The Agency bolievos that
 direct filtration plants need to remove
 oocysts from recycle flow prior to
 reintroducing it to the treatment
 process.

 ii. Data
  Twenty-three direct filtration plants
 that used surface water responded to the
 FAX Survey (AWWA, 1998). In the FAX
 survey, plants could report whether
 they provide recycle flow equalization.
 sedimentation, or some other type of
 treatment. Of the respondents, 21
 reported providing treatment for the
 recycle flow and two plants reported
 providing only equalization. In the ICR
 database, there were 23 direct filtration
 plants and fourteen of them recycled to
 the treatment process. All fourteen
 plants provide recycle treatment. It is
 not possible to determine the level of
 oocyst removal FAX survey and ICR
 plants achieve with available data.
  The treatment train of a direct
 filtration plant does not have a
 clarification process to remove
 Cryptosporidium before they reach the
 filters; all oocyst removal is achieved by
 the filters. If recycle flow treatment is
 not provided, all of the oocysts captured
 in the filters will be returned to the
 treatment process in the recycle flow.
 Because a primary clarification process
 is not present to remove recycled
 oocysts, they are caught in a closed
 "loop" from which the only exit is
 passage through the filters into the
 distribution system. The Agency
 believes direct filtration plants should
 provide solids removal treatment for
 recycle flows to limit the number of
 oocysts returned to the treatment plant.
 iii. Proposed Requirements
  EPA is proposing that PWSs using
 direct filtration that recycle to the
 treatment process and utilize surface
 water or GWUDI as a source report data
 to the State that describes their current
 recycle practice. Plants should report
 the following information to the State:
  (1) Whether recycle flow treatment  or
 equalization is in place:
  (2) The type of treatment provided lor
 the recycle flow;
  (3) If equalization, sedimentation, or
 some type of clarification process is
 used, the following information should
be provided; a) physical dimensions of
 the unit (length, width, (or
 circumference) depth,) sufficient to
 allow calculation of volume and the

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                                                                     19117
type, typical dose, and frequency with
which treatment chemicals are used;
  (4) The minimum and maximum
hydraulic loading the treatment unit
experiences, and;
  (5) Maximum backwash rate,
duration, typical filter run length, and
the number of filters at the plant.
  The State should use the above
information to determine which plants
need to modify recycle practice to
provide additional public health
protection. States are required to report
to EPA whether they required
individual direct filtration plants tt)
modify recycle practice and provide a
brief explanation of the reason(s) for the
decision.
  The Agency also considered requiring
that all direct filtration plants provide a
specific level of treatment for the
recycle flow. However, data necessary to
determine the appropriate level of
treatment is unavailable. Specifically.
the following data is needed:
  (I) Data on  the on the occurrence of
oocysts in the spent filter backwash of
direct filtration plants. Direct filtration
plants generally use higher quality
source water than conventional plants
(AWVVA. 1990) and  it would be
inaccurate to  use spent filter backwash
occurrence data from conventional
plants to  assess the level of treatment
direct recycle plants may need:
  (2) Data regarding the ability of
sedimentation and other clarification
processes to remove oocysts from
recycle flows is needed to determine
what may be a feasible level of
treatment. This data need was treated to
a detailed discussion in the previous
section of the preamble;
  (3) An easy to measure and accurate
surrogate for oocyst  removal is  currently
unavailable; without such a surrogate, it
is not feasible to monitor the
performance of recycle treatment units,
and;
  (4) Data on  the applicability of
niicrofiltration and ultrafiltralion for
treating spent filter backwash produced
by direct  filtration plants. This data
nuftd was discussed  in detail in the
previous  section.
  Given the lack of oocyst occurrence
data for direct filtration recycle streams.
and limited knowledge of the level of
treatment clarification processes can
achieve, the Agency does not currently
believe it is possible to identity a
treatment standard for direct filtration
plants.

iv. Request for Comments
  EPA requests comment on the
proposed requirements. The Agency
also requests comment on the following:
  il) Whether direct filtration plants
should be required to provide treatment
for recycle flows;
  [2) The level of treatment direct
filtration plants should achieve;
  !3) Data that establishes turbidity,
particle counting, or some other
surrogate as an appropriate indicator of
oocyst removal achieved by recycle
treatment units, and;
  f4) Data on the ability of clarification
processes to remove oocysts and criteria
that can be used to determine the
applicability of specific membrane
materials for treatment of spent filter
backwash produced by direct filtration
plants.

d. Request for Additional Comment
  EPA requests comment on the
following:
  (1) Should the recycle of untreated
clarification sludges be allowed to
continue, or should the Agency ban this
practice? What affect would a ban have
on the operation of specific plant types,
such as softening plants?
  (2) Is it appropriate to apply
regulatory requirements to the
combined recycle flow rather than
stipulating requirements for individual
recycle flows? Which flows should be
regulated individually and why?

V. State Implementation and
Compliance Schedules
  This section describes the regulations
and other procedures and policies States
have to adopt, or have in place, to
implement today's proposed rule. States
must continue to meet all other
conditions of primacy in 40 CFR part
142.
  Section 1413 of the SDWA establishes
requirements that a State or eligible
Indian tribe must meet to maintain
primary enforcement responsibility
(primacy) for its public water systems.
These include: (1) Adopting drinking
water regulations that are no less
stringent than Federal  NPDWRs in effect
under sections 1412(a) and 1412(b) of
the Act, (2) adopting and implementing
adequate procedures for enforcement,
(3) keeping records and making reports
available on activities that EPA requires
by regulation, (4) issuing variances and
exemptions (if allowed by the State)
under conditions no less stringent than
allowed by sections 1415 and 1416. and
(5) adopting and being capable of
implementing an adequate plan for the
provision of safe drinking water under
emergency situations.
  40 CFR part 142  sets out the specific
program implementation requirements
for States to obtain primacy for the
public water supply supervision
program, as authorized under section
1413 of the Act. In addition to adopting
the basic primacy requirements, States
may be required to adopt special
primacy provisions pertaining to a
specific regulation. These regulation-
specific provisions may be necessary
where implementation of the NPDWR
involves activities beyond those in the
generic rule. States are required by 40
CFR 142.12 to include these regulation-
specific provisions in an application for
approval of their program revisions.
These State primacy requirements apply
to today's proposed rule, along with the
special primacy requirements discussed
below.
  To implement today's proposed rule.
States are required to adopt revisions to
§ 141.2—definitions; § 141.32—public
notification; § 141.70—general
requirements; § 141.73—filtration;
§ 141.76—recycle; § 141.153—content of
the reports; § 141.170—general
requirements; § 142.14—records kept by
States; § 142.16—special primacy
requirements; and a new subpart T,
consisting of § 141.500 to § 141.571.
A. Special State Primacy Requirements
  In addition to adopting drinking water
regulations at least as stringent as the
Federal regulations listed above, EPA
requires that States adopt certain
additional provisions related to this
regulation to have their program
revision application approved by EPA.
This information advises the regulated
community of State requirements and
helps  EPA in its oversight of State
programs. States which require without
exception subpart H systems (all public
water systems using a surface water
source or a ground water source under
the direct influence of surface water) to
provide filtration, need not demonstrate
that the State program has provisions
that apply to systems which do not
provide filtration  treatment. However,
such States must provide the text of the
State statutes or regulations which
specifies that public water systems
using a source water must provide
filtration.
  EPA is currently developing, with
stakeholders input, several guidance
documents to aid  the States and water
systems in implementing today's
proposed rule. This  includes guidance
for the following topics: Disinfection
benchmarking and profiling, Turbidity,
and Filter Backwash and Recycling.
EPA will also work with States to
develop a State implementation
guidance manual.
  To ensure that the State program
includes all the elements necessary for
a complete enforcement program, the
State's application must include the

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 following in order to obtain EPA's
 approval for implementing this rule:
   fl) Adoption of the promulgated
 LT1FBR.
   (2) Description of the procedures the
 State will use to determine the adequacy
 of changes in  disinfection process by
 systems required to profile and
 benchmark under § 142.1G(h)[2)(ii) and
 how the State will consult with PVVSs
 to approve modifications to disinfection
 practice.
   (3) Description of existing or adoption
 of appropriate rules or other authority
 under § 142.16(h)(l) to require systems
 to participate  in a Comprehensive
 Technical Assistance (CTA) activity,
 and the performance improvement
 phase of the Composite Correction
 Program (CCP).
   (4) Description of how the State will
 approve a method to calculate the logs
 of inactivation for viruses for a system
 that uses either chloramines or ozone
 for primary disinfection.
   (5) For filtration technologies other
 than conventional filtration treatment,
 direct filtration, slow* sand filtration or
 diatomaceous earth filtration, a
 description of how the State will
 determine under § 142.10(h)(2)(iii), that
 a  public water system may use a
 filtration technology if the PWS
 demonstrates  to the State, using pilot
 plant studies or other means, that the
 alternative filtration technology, in
 combination with the disinfection
 treatment that meets the requirements of
 Subpart T of this title, consistently
 achieves 99.9  percent removal and/or
 inactivation of Giardia lamblia cysts and
 99.99 percent  removal and/or
 inactivation of viruses, and 99 percent
 removal of Crvptosporidium oocysts;
 and a description of how,  for  the system
 that makes this demonstration, the State
 will set turbidity performance
 requirements that the system  must meet
 95 percent of the time and that the
 system may not exceed at any time a
 level that consistently achieves 99.9
 percent removal and/or inactivation of
 Giardia iamblia cysts, 99.99 percent
 removal and/or jnactivation of viruses.
 and 99 percent removal of
 Cryptosporidium oocvsts.
   (6) Description of the criteria the State
 will use under §142.16(b)(2)(vi) to
 determine whether public water systems
 completing self assessments under
 § 141.76 (c) are required to modify
 recycle practice and the criteria that will
 be used to specify modifications to
 recycle practice.
   (7) Description of the criteria the State
 will use under § 142.16(b)(2)(vii) to
 determine whether direct filtration
systems reporting data under § 141.76
 (d) are required to change recycle
                     practice and the criteria that will be
                     used to specify changes to recycle
                     practice.
                       (8) The application must describe the
                     criteria the State will use under
                     § 142.16(b)(2)(viii) to determine whether
                     public water systems applying for a
                     waiver to return recycle to a location
                     other than prior to the point of primary
                     coagulant addition, will be granted the
                     waiver for an alternative recycle
                     location.

                     B. State ftecordkeeping Requirements
                       Today's rule includes changes to the
                     existing record-keeping provisions to
                     implement the requirements in today's
                     proposed rule. States must maintain
                     records of the following: (1J Turbidity
                     measurements must be kept for not less
                     than one year;
                       (2) disinfectant residual
                     measurements and other parameters
                     necessary to document disinfection
                     effectiveness must be kept for  not less
                     than one year: (3) decisions made on a
                     system-by-system basis and case-by-case
                     basis under provisions of part  141,
                     subpart H or subpart P or subpart T; (4)
                     records of systems consulting with the
                     State concerning a modification of
                     disinfection practice (including the
                     status of the consultation);
                       (5) records of decisions that  a system
                     using alternative filtration technologies
                     can consistently achieve a 99 percent
                     removal of Cryptosporidium oocysts as
                     well as the required levels of removal
                     and/or inactivation of Giardia  and
                     viruses for systems using alternative
                     filtration technologies, including State-
                     set enforceable turbidity limits for each
                     system. A copy of the decision must be
                     kept until the decision is reversed or
                     revised and the State must provide a
                     copy of the decision to the system, and;
                     (6) records of systems required to do
                     filter self-assessments. CPE or CCP.
                     These decision records must be kept for
                     40 years (as currently required by
                     § 142.14 for other State decision
                     records)  or until a subsequent
                     determination is made, whichever is
                     shorter.

                     C. State Reporting Requirements
                       Currently States must report to EPA
                     information under 40 CFR 142.15
                     regarding violations, variances and
                     exemptions, enforcement actions and
                     general operations of State public water
                     supply programs. Today's proposal
                     requires States to report a list of direct
                     recycle plants performing self
                     assessments, whether the State required
                     these systems to modify recycle
                     practice, and the reason(s)modifications
                     were or were not required and a list of
                     direct filtration plants performing self
 assessments, whether the State required
 these systems to modify recycle
 practice, and the reason(s) modifications
 were or were not required

 D. Interim Primacy
   On April 28, 1998, EPA amended its
 State primacy regulations at 40 CFR
 142.12 (63 FR 23362) (EPA 1998i) to
 incorporate the new process identified
 in the 1996 SOW A amendments for
 granting primary enforcement authority
 to States while their applications to
 modify their primacy programs are
 under review. The new process grants
 interim primary enforcement authority
 for a new or revised  regulation during
 the period in which  EPA is making a
 determination with regard to primacy
 for that new or revised regulation. This
 interim enforcement authority begins on
 the date of the primacy application
 submission or the effective date of the
 new or revised State regulation,
 whichever is later, and ends when EPA
 makes a proposed determination.
 However, this interim primacy authority
 is only available to a State that has
 primacy for every existing national
 primary drinking water regulation in
 effect when the new regulation is
 promulgated.
   As a result, States that have primacy
 for every existing NPDWR already in
 effect may obtain interim primacy for
 this rule, beginning on the date that the
 State submits its final application  for
 primacy for this rule to EPA, or the
 effective date of its revised regulations,
 whichever is later. Interim primacy is
 available for the following rules:
   • Stage 1 Disinfectants and
 Disinfection Byproducts Rule
 (December 16,1998)(EPA,1998c)
   • Interim Enhanced Surface Water
 Treatment Rule (EPA,1998a)
   • Consumer Confidence Report  Rule
 (EPA, 1998f)
   • Variances and Exemptions Rule
 (EPA, 1998g)
   • Drinking Water Contaminant
 Candidate List (EPA, 1998h)
   • Revisions to State Primacy
 Requirements (EPA,1998i)
   • Public Notification Rule (EPA,
 1999i)
   In addition, a State which wishes to
 obtain interim primacy for future
 NPDVVRs must obtain primacy for this
 rule. After the effective date of the final
 rule, any State that does not have
 primacy for this rule  cannot obtain
 interim primacy for future rules.

E. Compliance Deadlines
  Section 1412(b)(10) of SOW A
 provides that drinking water rules
become effective 36 months after
promulgation unless  the Administrator

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                                                                     19119
 determines that an earlier time is
 practicable. The Administrator may also
 extend the effective date by an
 additional 24 months if capital
 improvements are necessary. The
 Agency believes the three year effective
 date is appropriate for all of the
 provisions in today's notice except for
 those provisions that address the return
 of recycle flows. The Agency believes
 providing a five year compliance period
 for systems making modifications to
 recycle practice is appropriate and
 warranted under 1412(b)(10). To
 effectively modify recycle practice,
 capital improvements, such as installing
 additional equipment and/or
 constructing new facilities, will likely
 be required. Specific examples of
 potential capital improvements are
 installing new piping and pumps to
 convey recycle flow prior to the point of
 primary coagulant addition and
 constructing equalization basins or
 recycle flow treatment facilities. A
 limited number of systems may be able
 to make operational modifications,  per
 the State's determination, that will
 effectively address potential risks.
 However, the Agency believes the great
 majority of systems required to either
 relocate their recycle return location or
 modify recycle practice as directed by
 the State will need to perform capital
 improvements. The capital
 improvement process is lengthy;
 systems will need to engage in
 preliminary planning activities, consult
 with State and local officials, develop
 engineering and construction designs,
 obtain financing, and construct the
 facilities. The Agency believes the
 widespread need that systems making
 modifications to recycle practice will
 have for capital improvements warrants
 the additional 24 months  for
compliance purposes. The Agency
 solicits comment on the appropriateness
 of providing an additional two years for
 compliance with the recycle provisions.
 EPA seeks comment on extending the
 compliance deadline an extra two years
because systems are expected to make
capital improvements to address recycle
 practice. EPA also seeks comment on a
similar two year extension to comply
with the turbidity provisions of today's
 proposed rule.
 II. Economic Analysis
  This section summarizes the Health
Risk Reduction and Cost Analysis in
 support of the Long Term 1 Enhanced
Surface Water Treatment and Filter
 Backwash Rule (LTlFBR) as required by
Section  1412(b)(3)(C) of the 1996
Amendments to the SDWA. In addition,
under Executive Order 12866.
Regulatory Planning and Review, EPA
must estimate the costs and benefits of
LTlFBR in a Regulatory Impact
Analysis (R1A) and submit the analysis
to the Office of Management and Budget
(OMB) in conjunction with publication
of the proposed rule. EPA has prepared
an RIA to comply with the requirements
of this Order and the SDWA Health Risk
Reduction and Cost Analysis [EPA,
1999h). The RIA has been published on
the Agency's web site, and can be found
at http://www.epa.gov/safewater. The
RIA can also be found in the docket for
this rulemaking.
  The goal of the following section is to
provide an analysis  of the costs,
benefits, and other impacts of the
proposed rule to support future
decisions regarding  the development of
the LTlFBR.
A. Overview

  The analysis for this rule examines
the costs and benefits for five rule
provisions: filter effluent turbidity,
applicability monitoring, disinfection
benchmark profiling, uncovered finish
water reservoirs, and recycle. Several
options were considered for each
provision. Costs were estimated for
three individual turbidity options, three
profiling options, and three
applicability monitoring options. In
addition, costs were estimated for four
different recycle options. All four
recycle options require spent filter
backwash, thickener supernatant, and
liquids from dewatering be returned to
the treatment process prior to the point
of primary coagulant addition. The
extent of modifications to recycle
practice varies among the rule options.
  The value of health benefits from the
turbidity provision was estimated for
the preferred option. The benefits from
the other rule provisions are described
qualitatively. Several non-health
benefits from this rule were also
considered by  EPA but were not
monetized. The non-health benefits of
this rule include: avoided outbreak
response costs and possibly reduced
uncertainty and averting behavior costs.
By adding the  non-monetized benefits
with those that are monetized, the
overall benefits of theso rule options
increase beyond the dollar values
reported
  Additional analysis was conducted by
EPA to look at the incremental impacts
of the various rule options, impacts on
households, benefits from reductions in
co-occurring contaminants, and possible
increases in risk from other
contaminants.  Finally, the Agency
evaluated the uncertainty regarding the
risk, benefits, and cost estimates.
B, Quantifiable, and Non-Quantifiable
Costs
  In estimating the costs of each rule
option, the Agency considered impacts
on public water systems and on States
(including territories and EPA
implementation in non-primacy States),
The LTlFBR will result in  increased
costs to public water systems for
improved turbidity treatment,
applicability monitoring, disinfection
benchmarking, covering new finished
water reservoirs and modification to
recycle practice. States will also face
implementation costs. Most of the
provisions of this rule, except the
recycle provision, apply to systems
using surface water or ground water
under the direct influence  of surface
water that serve less than 10,000 people.
The recycle provisions, however, apply
to all surface water systems that recycle
filter backwash, thickener supernatant,
or liquids from dewatering.

1. Total Annual Costs
  EPA estimates that the annualized
cost of the preferred alternatives for the
proposed rule will be $97.5 million.
This estimate includes capital costs for
treatment changes and start-up labor
costs for  monitoring and reporting
activities that have been annualized
assuming a 7% discount rate and a 20-
year amortization period. Other cost
estimates reported in this section also
use these same amortization
assumptions. The estimated cost of the
preferred alternatives also  includes
annual operating and maintenance costs
for treatment changes and annual labor
for turbidity monitoring activities.
  The turbidity provisions (including
treatment changes, monitoring, and
exceptions  reporting) account for 70%
($68.6million annually) of total costs
and the recycling provisions (i.e.,
recycle to headworks, self assessment,
and direct filtration) account for 25%
($24.5 million annually) of total costs.
Utility expenditures for all provisions
equal almost 93% ($90.2 million
annually) of total costs; State
expenditures make up the other 7%
($6.7 million annually).
  To reduce the potential cost to small
systems.  EPA developed and evaluated
the cost implications of several
regulatory alternatives for four of the
proposed LTlFBR provisions:
individual filter turbidity monitoring,
applicability monitoring, disinfection
benchmark profiling, and recycle. Many
of these alternatives reduce the labor
burden on small systems relative to
what it would be if the proposed rule
used the  same requirements as IESWTR.
The total national costs previously

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 discussed only included the costs of the
 preferred alternatives. The following
 section will describe the cost estimates
 for each provision and discuss the cost
 of other alternatives that were
 considered.
 2. Annual Costs of Rule Provisions
  The national estimate of annual utility
 costs for the proposed turbidity
 provisions is based on estimates of
 system-level costs for the various
 provisions of the rule and estimates of
 the number of systems expected to incur
 each type of cost. The following
 paragraphs describe the cost estimates
 for each of the rule provisions.

 Turbidity Provision Costs
  The turbidity provisions are estimated
 to cost $69.0 million annually. This cost
 is associated with three primary
 activities that result from this provision:
 treatment changes, monitoring, and
 exceptions reporting.
  The treatment costs associated with
 meeting the revised turbidity standard
 of 0.3 NTU or less are the main costs
 associated with the turbidity provision.
 EPA estimates that 2.406 systems will
 modify their turbidity treatment in
 response to this rule. These costs are
 estimated to be $52.2 million annually.
 O&M expenditures account for 59% of
 annual costs and the remain 41%
 percent is annualized capital costs.
  In addition to the turbidity treatment
 costs, turbidity monitoring costs apply
 to all small surface water or GWUDI
 systems using conventional or direct
 filtration methods. There are an
 estimated 5,896 systems that fall under
 this criteria. EPA estimated the costs to
 utilities for three turbidity monitoring
 alternatives. Alternative B, the preferred
 alternative, excludes the exceptions
 report for an individual filter exceeding
 0.5 NTU in two consecutive
 measurements, enabling systems to shift
 from daily to weekly analysis and
 review of the monitoring data. The
 annualized individual filter turbidity
 cost to public water systems for this
 preferred option is approximately $10.1
 million. In contrast, under the IESWTR
 monitoring requirements of Alternative
 A, small systems would expend $63.3
 million annually for turbidity
 monitoring. Alternative C, which only
 requires monthly analysis is estimated
 to cost $5.6 million annually. The total
 state turbidity start-up and monitoring
 annual costs are $4.98 million annually
 and is assumed to be the same for all of
 the three alternatives.
  In addition to the turbidity treatment
 and monitoring costs, individual filter
turbidity exceptions are estimated to
cost utilities $120 thousand annually for
                     the preferred option. State costs will be
                     approximately $1.17 million. This cost
                     includes the annual exception reports
                     and annual individual filter self
                     assessment costs. Costs are slightly
                     higher for the other two alternative
                     individual filter turbidity monitoring
                     options because they result in increased
                     number of exception reports.

                     Disinfection Benchmarking Costs
                       Disinfection benchmarking involves
                     three components: profiling,
                     applicability monitoring, and
                     benchmarking.  Four options were
                     costed for applicability monitoring.
                     Alternative 3, which uses the critical
                     monitoring period, is estimated to cost
                     less than $0.4 million annually. This  is
                     substantially lower than the $6.0
                     million estimated for Alternative 1,
                     which has the same requirements as
                     IESWTR. Alternative 2 requires
                     sampling once per quarter for 4 quarters
                     for systems serving 501-10,000, but
                     allows systems  under 500 to sample
                     once during the critical monitoring
                     period. This option has an annualized
                     cost of $1.1 million. The preferred
                     option, Alternative 4, makes it optional
                     to sample during the critical monitoring
                     period and is estimated to  cost $0.04
                     million annualized.
                       Three options were considered for
                     disinfection profiling and
                     benchmarking. They differed in the
                     frequency and duration of data
                     collection. The  preferred alternative,
                     Alternative 2, requires weekly
                     monitoring for one year and is estimated
                     to have an annualized cost of $0.8
                     million. In comparison, Alternative 1
                     which  requires  daily data collection for
                     one year, has an annualized cost of
                     approximately $1.3 million. The final
                     option, Alternative 3, requires daily
                     monitoring for 1 month and has an
                     estimated annualized cost of $0.5
                     million.
                       State disinfection benchmarking
                     annualized costs are estimated to be
                     $0.4 million. This estimate includes
                     start-up, compliance tracking/
                     recordkeeping, and benchmark related
                     costs.

                     Covered Finished Water Reservoir
                     Provision Costs
                       The proposed LTlFBR requires that
                     new systems cover all finished water
                     reservoirs, holding tanks, or other
                     storage facilities for finished water.
                     Historical construction rates suggest that
                     new reservoirs over the next 20 years
                     will roughly  equal to  five percent of the
                     existing number of systems. Assuming
                     then that 580 new uncovered finished
                     water reservoirs would be built in the
                     next 20 years, total annual costs,
 including annualized capital costs and
 one year of O&M costs are expected to
 be $2.6 million for this provision using
 a  7% discount rate. This estimate is
 calculated from a projected construction
 rate of new reservoirs and unit cost
 assumptions for covering new finished
 water reservoirs.
 Recycle Provision Cost
   EPA considered four different
 regulatory options for recycle. Each of
 the four options requires spent filter
 backwash, thickener supernatant, and
 liquids from dewatering be returned
 prior to the point of primary coagulant
 addition. Alternative 1, is estimated to
 result in an annualized cost of $16.7
 million. Of the total costs of this
 alternative, State  start-up and review
 costs for this alternative are only $20 to
 $30 thousand annually.
   Alternative 2, the preferred option,
 further requires that conventional rapid
 granular filtration plants using surface
 water or GWUDI perform a self
 assessment if they recycle spent filter
 backwash and thickener supernatant,
 employ 20 or less filters, and  practice
 direct recycle (treatment  for the recycle
 flow or equalization in a  basin that has
 a volume equal to the volume of spent
 filter backwash produced by a single
 filter backwash event is not provided).
 The results of the self assessment are
 reported to the State, and it specifies
 whether modifications to recycle
 practice are necessary. PWSs  are
 required to implement the modification
 specified by the State. Under
 Alternative 2, direct filtration plants are
 required to submit data to the State on
 current recycle practice, and the State
 specifies whether changes to recycle
 practice are required. The total
 annualized cost of Alternative 2 is $17.4
 to $24.5 million. $0.4 to $5.9 million of
 the total annualized cost  is for the direct
 recycle component, $0.1 to $1.7 million
 is  for the direct filtration  component,
 and the remaining cost is for the
requirement to return recycle prior to
the point of primary coagulant addition.
Of the total costs of this alternative.
 State start-up, review, and self
assessment costs for this alternative is
only $115 thousand annually.
  Alternative 3 contain the same
requirements for direct filtration plants
and also requires the three recycle flows
mentioned above be returned  prior to
the point of primary coagulant addition.
Direct recycle  plants are required to
install equalization basins with a
volume equal to or greater than the
volume produced by two filter
backwash events.  The annualized cost
of Alternative 3 is $55.0 to $56.7
million. Of this range, $38.1 million of

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                  Federal Register/Vol.  65,  No. 69/Monday,  April 10, 2000/Proposed Rules
                                                                     19121
the annualized cost is directly
associated with requiring direct recycle
plants to install equalization, and $0.1
to $1.7 million is associated with the
direct filtration component. State start-
up and self assessment costs for this
alternative is $95 thousand annually.
  Alternative 4 requires the three
recycle flows mentioned above be
returned prior to the point of primary
coagulant addition and also requires
that all systems that recycle
(conventional and direct systems) install
sedimentation basins for recycle flow
treatment. Systems may also install
recycle flow treatment technologies that
provide treatment capability equivalent
or superior to sedimentation. For cost
estimation purposes, sedimentation
basins with tube settlers and polymer
addition where used. The Agency
approximated the annualized costs of
this option to be $151.8 million. The
sedimentation basin treatment
requirement for conventional and direct
filtration plants is 88% ($133.3 million)
of the total annualized cost of
Alternative 4. State start-up and self
assessment costs for this alternative is
$100 thousand annually.

3. Non-Quantifiable Costs
  Although EPA has estimated the cost
of all the rule's components on drinking
water systems and States, there are some
costs that the Agency did  not quantify.
These non-quantifiable costs result from
uncertainties surrounding rule
assumptions and from modeling
assumptions. For example, EPA did not
estimate a cost for systems to acquire
land if they needed to build a treatment
facility or significantly expand their
current facility. This was not costed
because many systems will be able to
construct new treatment facilities on
land already owned by the utility. In
addition, if the cost of land was
prohibitive, a system may choose
another lower cost alternative such as
connecting to another source. A cost for
systems choosing this alternative is
unquantified in our analysis.
C. Quantifiable and Non-Quantifiable
Health Benefits
  The primary benefits of today's
proposed rule come from reductions in
the risks of microbial illness from
drinking water. In particular, LT1FBR
focuses on reducing the risk associated
with disinfection resistant pathogens,
such as Cryptosporidium. Exposure to
other pathogenic protozoa, such as
Giardia, or other waterborne bacteria,
viral pathogens, and other emerging
pathogens are likely to be reduced by
the provisions of this rule as well but
are not quantified. In addition, LTlFBR
produces nonquantifiable benefits
associated with the risk reductions that
result from the recycle provision,
uncovered reservoirs provision,
including Cryptosporidium in GWUDI
definition, and including
Cryptosporidium in watershed
requirements for unfiltered systems.

1. Quantified Health Benefits
a. Turbidity Provisions
  The quantification of benefits from
this rule is focused solely on reductions
in the risk of cryptosporidiosis.
Cryptosporidiosis is an infection caused
by Cryptosporidium which is an acute,
self-limiting illness lasting 7 to 14 days
with symptoms that include diarrhea,
abdominal cramping, nausea, vomiting
and fever (Juranek, 1995). The cost of
illness avoided of cryptosporidiosis is
estimated to have a mean of $2,016
(Harrington et  al., 1985; USEPA 1999h)
  The benefits of the turbidity
provisions of LTlFBR come from
improvements in filtration performance
at water systems. The benefits analysis
attempts to take into account some of
the uncertainties in the analysis by
estimating benefits under two  different
current treatment and three improved
removal assumptions. The benefits
analysis also used Monte Carlo
simulations to derive a distribution of
estimates, rather than a single  point
estimate.
  The benefits analysis focused on
estimating changes in incidence of
cryptosporidiosis that would result from
the rule. The analysis included
estimating the  baseline (pre-LTlFBR)
level of exposure from Cryptosporidium
in drinking water, reductions in such
exposure resulting from treatment
changes to comply with the LTlFBR,
and resultant reductions of risk.
  Baseline levels of Cryptosporidium in
finished water were estimated by
assuming national source water
occurrence distribution (based on data
by LeChevallier and Norton, 1995) and
a national distribution of
Cryptosporidium removal by treatment.
  In the LTlFBR RIA, the following two
assumptions were made regarding the
current Cryptosporidium oocyst
performance to estimate finished water
Cryptosporidium concentrations. First,
based on treatment removal efficiency
data presented in the 1997 IEWSTR.
EPA assumed a national distribution of
physical removal efficiencies with a
mean of 2.0 logs and a standard
deviation oft 0.63 logs. Because the
finished water concentrations of oocysts
represent the baseline against which
improved removal from the LTlFBR is
compared, variations in the log removal
assumption could have considerable
impact on the risk assessment. Second.
to evaluate the impact of the removal
assumptions on the baseline and
resulting improvements, an alternative
mean log removal/inactivation
assumption of 2.5 logs and a standard
deviation of ± 0.63 logs was also used
to calculate finished water
concentrations of Cryptosporidium.
  For each of the two baseline
assumptions, EPA assumed that a
certain number of plants would show
low, mid or high improved removal,
depending upon factors such as water
matrix conditions, filtered water
turbidity effluent levels, and  coagulant
treatment conditions. As a result, the
RIA considers six scenarios that
encompass the range of endemic health
damages avoided based on the rule.
  The finished water Cryptosporidium
distributions that would result from
additional log removal with the
turbidity provisions, were derived
assuming that additional log removal
was dependent on current removal, i.e.,
that sites currently operating at the
highest filtered water turbidity levels
would show the largest improvements
or high improved removal assumption
(e.g., plants now failing to meet a 0.4
NTU limit would show greater removal
improvements than plants now meeting
a 0.3 NTU limit).
  Table VI.1 indicates estimated annual
benefits associated with implementing
the LTlFBR. The benefits analysis
quantitatively examines endemic health
damages avoided based on the LTlFBR
for each of the six scenarios mentioned
above. For each of these scenarios, EPA
calculated the mean of the distribution
of the number of illnesses avoided. The
10th and 90th percentiles imply that
there is a 10 percent chance that the
estimated value could be as low as the
10th percentile and there  is a 10 percent
chance that the estimated value could
be as high as the 90th percentile. EPA's
Office of Water has evaluated drinking
water consumption data from USDA's
1994-1996 Continuing Survey of Food
Intakes by Individuals (CSFII) Study.
EPA's analysis of the CSFII Study
resulted in a daily water ingestion
lognormally distributed with a mean of
1.2 liters per person (EPA, 2000a). The
risk and benefit analysis contained
within the RIA reflects this distribution.

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Federal  Register/Vol.  65,  No. 69/Monday, April 10,  2000/Proposed Rules
          TABLE VI. 1.—NUMBER AND VALUE OF ILLNESSES AVOIDED ANNUALLY FROM TURBIDITY PROVISIONSa
                                               [Dollar amounts in billions]
                             Improved Log-Removal Assumption
                                                                       Daily Drinking Water Ingestion
                                                                       and Baseline Cryptosporidium
                                                                        Log-Removal Assumptions
                                                                       (Mean = 1.2 Liters per person)
                                                                                           2.0 log
                                                                                       2.5 log
Illnesses Avoided with Low Improved Cryptosporidium Removal Assumption:
Mean 	 	 	 	
10th Percentile 	
90th Percentile 	
COI Avoided with Low Improved Cryptosporidium Removal Assumption:
Mean
10th Percentile
90th Percentile
Illnesses Avoided with Mid Improved Cryptosporidium Removal Assumption:
Mean
10th Percentile
90th Percentile . . 	
COI Avoided with Mid Improved Cryptosporidium Removal Assumption:
Mean 	 .... 	
10th Percentile 	
90th Percentile
Illnesses Avoided with High Improved Cryptosporidium Removal Assumption:
Mean . . . 	
10th Percentite 	
90th Percentile 	
COI Avoided with High Improved Cryptosporidium Removal Assumption:
Mean 	
10th Percentile .
90th Percentile 	
62 800 0
00
1520000
$1503
$00
$2882
77 500 0
00
184 000 0
$185.3
$00
$3509
83 600 0
00
1960000
$199.5
$00
$376.7
22 800 0
00
43 900 0
$539
$00
$81 4
27 900 0
00
52 900 0
$66.2
$00
$988
30 000 0
0 0
56 500 0
$71 1
$00
$105.8
  "All values presented are in January 1999 dollars.
  According to the RIA performed for
the LTlFBR published today, the rule is
estimated to reduce the mean annual
number of illnesses caused by
Cryptosporidium in water systems with
improved filtration performance by
22,800 to 83,600 cases depending upon
which of the six baseline and improved
Cryptosporidium removal assumptions
was used, and assuming the 1.2 liter
drinking water consumption
distribution. Based on these values, the
mean estimated annual benefits of
reducing the illnesses ranges from $54
million to $200 million per year. The
RIA also indicated that the rule could
result in  a mean reduction of 3 to 10
fatalities each year, depending upon the
varied baseline and  improved removal
assumptions. Using a mean value of
$5.7 million per statistical life saved,
reducing these fatalities could produce
benefits in the range of $16.0 million to
$60 million.
  Combining the value of illnesses and
mortalities avoided, the total benefits
range from $70 million to $260 million
assuming a 1.2 liter  drinking water
consumption distribution.
b. Sensitivity Analysis for Recycle
Provisions
  Available literature research
demonstrates that increased hydraulic
                     loading or disruptive hydraulic
                     currents, such as may be experienced
                     when plants exceed State-approved
                     operating capacity or when recycle is
                     returned directly into the sedimentation
                     basin, can disrupt filter (Cleasby, 1963;
                     Glasgow and Wheatley, 1998; McTigue
                     et al, 1998) and sedimentation (Fulton,
                     1987; Logsdon, 1987; Cleasby, 1990)
                     performance. However, the literature
                     does not quantify the extent to which
                     performance can be lowered and, more
                     specifically, does not quantify the log
                     reduction in Cryptosporidium removal
                     that may be experienced during direct
                     recycle events.
                       In the absence of quantified log
                     reduction data, the Agency performed a
                     sensitivity analysis to estimate a range
                     of potential benefit provided by the
                     recycle provisions. The analysis
                     assumes a baseline Cryptosporidium log
                     removal value of 2.0. The analysis
                     estimates the effect of recycle by
                     reducing the average baseline log
                     removal by a range of values (reduction
                     ranged from 0.05 to 0.50 log) to account
                     for the reduction in removal
                     performance plants may experience if
                     they exceed State-approved operating
                     capacity or return recycle to the
                     sedimentation basin. The installation of
                     equalization to eliminate exceedence of
State-approved operating capacity or
moving the recycle return location from
the sedimentation basin to prior to the
point of primary coagulant addition will
result in the health benefit. The benefit
estimate is conservative, because it does
not account for the fact that recycle
returns additional oocysts to the plant.
  Benefits are estimated by assuming
that the installation of equalization or
moving the recycle return point prior to
the point of primary coagulant addition
will return the plant to the baseline
Cryptosporidium removal of 2.0 log. The
difference between the number of
illnesses that result from the baseline
situation and the reduced performance
is used to calculate the monetary
benefit.  The benefit is compared to the
cost of returning recycle prior to the
point of primary coagulant additional
and the cost of installing equalization
for  two service populations. Service
populations of 1,900 persons,  which
represents a plant serving fewer than
10,000 people, and a service population
of 25,108, which represents a plant
serving greater than 10,000 people, are
used. Results are summarized in Tables
1V.2 and IV.3 below.

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                   Federal Register/Vol. 65, No. 69/Monday,  April 10, 2000/Proposed Rules
                                                                     19123
                              TABLE IV.2.—BENEFIT FOR SERVICE POPULATION OF 1,900
                           Log removal reduction
                                                                              1 900
                                                ; Cost* °f moving   Cost' of install-
                                                  recyde return  '  ina
0.05 	
0.50 	
.... ! $1,400 '
30.700
$5,200
5,200
$25,200
25,200
  aCost and benefit are annualized with a 7% capital cost over 20 years.

                         TABLE IV.3.—BENEFIT  RANGE FOR SERVICE POPULATION OF 25,108

005
0.50 	
i
! Benefit" for
Log removal reduction ' population of
25.108
	 $18,700
	 405,800
Cost3 of moving Cost" of install-
recycle return ing rqualization
$18,700 $57,200
18,700 j 57,200
  »Cost and benefit are annualized with a 7% capital cost over 20 years.
  Although literature research does not
quantify the log reduction caused by
specific recycle practices, the results of
the sensitivity analysis show that the
benefit a plant serving 25,108 people
would realize by improving its baseline
performance to 2.0 logs would range
from $18,700 to $405,800. $27,256
Benefits would range from $1,400 to
$30,700 for a plant serving 1,900. This
benefit range supports the Agency's
determination that unqualified benefits
will justify costs. The determination is
discussed in the Benefit Cost
Determination section.

2. Non-Quantified Health and Non-
Health Related Benefits
a. Recycle Provisions
  The benefits associated with the filter
backwash provision are unquantified
because of data limitations. Specifically.
there is a lack of treatment performance
data to accurately model the oocysts
removal achieved by individual full-
scale treatment processes and the
impact recycle may have on treatment
unit performance and finished water
quality. Additional data on the ability of
unit processes (sedimentation. DAF,
contact clarification, filtration) to
remove oocysts from source and recycle
flows, the extent to which recycle may
generate hydraulic surge within plants
and lower the performance of individual
treatment processes,  data on the
potential for recycle to  threaten the
integrity of chemical treatment, and
additional  information on the
occurrence of oocysts in recycle streams
are all needed before an impact model
can be calibrated and used as a
predictive tool.
  However, available data demonstrate
that oocysts occur in recycle streams,
often at concentrations higher than
found in source water,  and returning
recycle streams to the plant will
increase intra-plant oocyst
concentrations. Data also shows that
oocysts frequently occur in the finished
water of treatment plants that are not
operating under stressed conditions.
Engineering literature also shows that
proper coagulation and the maintenance
of balanced hydraulic conditions within
the plant (i.e., not exceeding State
approved sedimentation/clarification
and filtration operating rates) are
important to protect the integrity of the
en I ire treatment process. Some recycle
practices, such as direct recycle, can
potentially upset coagulation and the
proper hydraulic operation of
sedimentation/clarification and
filtration processes. The benefits of the
recycle provisions are derived from
protecting the coagulation process and
the hydraulic performance of
sedimentation/clarification and
filtration processes. Today's recycle
provisions reduce the risk posed by
recycle and provided additional public
health protection in the following ways:
  (1) Returning spent filter backwash.
thickener supernatant, and liquids from
dewatering into, or downstream of, the
point of primary coagulant addition may
disrupt treatment chemistry by
introducing residual coagulant or other
treatment chemicals to the process
stream. The wide variation in plant
influent flow can also result in chemical
over-or under-dosing if chemical dosage
is not adjusted to account for flow
variation. Returning the above flows
prior to the point of primary  coagulant
addition will help protect the integrity
of coagulation and protect the
performance of downstream unit
processes, such as clarification and
filtration, that require proper
coagulation be conducted to maintain
proper performance. This will provide
an additional measure of public health
protection.
  (2) The direct recycle of spent filter
backwash without first providing
treatment, equalization, or some form of
hydraulic detention for the flow, may
cause plants to exceed State-approved
operating capacity during recycle
events. This may lead to lower overall
oocyst removal performance due to the
hydraulic overload unit processes (i.e..
clarification and filtration) experience
and increase finished water oocyst
concentrations. The self assessment
provision  in today's rule will help the
States identify direct recycle systems
that may experience this problem  so
modifications to recycle practice can be
made to protect public health.
  (3) Direct filtration plants do not
employ a sedimentation basin in their
primary treatment process to remove
solids and oocysts; all oocyst removal is
achieved by the filters. If treatment for
the recycle flow is not provided prior to
its return to the plant, all  of the oocysts
captured by  a filter during a filter run
will be returned to the plant and again
loaded to the filters. This may lead to
ever increasing levels of oocysts being
applied to the filters and could increase
the concentration of oocysts in finished
water. Today's provision for direct
recycle systems will help States identify
those systems that are not obtaining
sufficient oocyst removal from the
recycle flow. Public health protection
will be increased when systems
implement modifications to recycle
practice specified by the State.
  The goal of the recycle provisions is
to reduce the potential for oocysts
getting into the finished water and
causing cases of cryptosporidiosis.
Other disinfection resistant pathogens
may also be removed more efficiently
due to implementation of these
provisions.

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b. Issues Associated With Unqualified
Benefits
   The monetized benefits from filter
performance improvements are likely
not to fully capture all the benefits of
the turbidity provisions. EPA monetized
the benefits from reductions in
cryptosporidiosis by using cost-of-
illness (COI) estimates. This may
underestimate the actual benefits of
these reductions because COI estimates
do not include pain and suffering. In
general, the COI approach is considered
a lower bound estimate of willingness-
to-pay (WTP) to avoid illnesses. EPA
requests comment on the use of an
appropriate WTP study to calculate the
benefits of this rule.
   Several non-health benefits from this
rule were also considered by EPA but
were not monetized. The non-health
benefits of this rule include avoided
outbreak response costs and possibly
reduced uncertainty  and averting
behavior costs.  By adding the non-
monetized benefits with those that are
monetized, the overall benefits of this
rule would increase beyond the dollar
values reported.

D. Incremental Costs and Benefits
   EPA evaluated the incremental or
marginal costs of today's proposed
turbidity option by analyzing various
turbidity limits, 0.3 NTU, 0.2 NTU, and
0.1 NTU. For each turbidity limit, EPA
developed assumptions about which
process changes systems might
implement to meet the turbidity level
and how many systems would adopt
each change. The comparison of total
compliance cost estimates show that
costs are expected to increase
significantly across turbidity limits. The
total cost of a 0.1 NTU limit, $404.6
million, is almost eight times higher
than the cost of the 0.3 NTU limit,
which is $52.2 million. Similarly, the
total cost of the 0.2 NTU limit, $134.1
million, is more than twice as great as
the 0.3 NTU cost.
  Analytical limitations in the
estimation of the benefits of LTlFBR
prevent the Agency from quantitatively
describing the incremental benefits of
alternatives. The Agency requests
comment on how to analyze and the
appropriateness of analyzing
incremental benefits  and costs for
treatment techniques that address
microbial contaminants.

E. Impacts on Households
  The cost impact of LTlFBR at the
household level was also assessed.
Household costs are a way to represent
water system treatment costs as costs to
the system's customers. As expected.
                     costs per household increase as system
                     size decreases. Costs to households are
                     higher for households served by smaller
                     systems than larger systems for two
                     reasons. First, smaller systems serve far
                     fewer households than larger systems,
                     and consequently, each household must
                     bear a greater percentage share of capital
                     and O&M costs. Second, filter backwash
                     recycling may pose a greater risk
                     because the flow of water from filter
                     backwash recycling is a larger portion of
                     the total water flow in smaller systems.
                     This greater risk potential in small
                     systems makes it more likely that some
                     form of recycle treatment might be
                     needed.
                       The average (mean) annual cost for
                     the turbidity, benchmarking, and
                     covered finished water provision per
                     household is $8.66. For almost 86
                     percent of the 6.6 million households
                     affected by these provisions, the per-
                     household costs are $10 per year or less,
                     and costs of $120 per year (i.e., $10 per
                     month) or less for approximately 99
                     percent of the households. Costs
                     exceeding $500 per household occur
                     only for the smallest size category, and
                     the number of affected households
                     represent about 34 of the smallest
                     systems. The highest per-household cost
                     estimate is $2,177. This extreme
                     estimate, however, is an artifact of the
                     way the system cost distribution was
                     generated. It is unlikely that any small
                     system will incur annual costs of this
                     magnitude because less costly options
                     are available.
                       The average household cost for the
                     recycle  provisions is $1.80 per year for
                     households that are served by systems
                     that recycle. The cost per household is
                     less than $10 per year for almost 99%
                     of 12.9 million households potentially
                     affected by the proposed rule. The cost
                     per household exceeds $120  per year for
                     less than 1800 households and it
                     exceeds $500 per year for approximately
                     100  households. The maximum cost of
                     $1,238 per year would only be incurred
                     if a direct filtration system that serves
                     less  than 100 customers installed a
                     sedimentation basin for backwash
                     treatment.
                      There are approximately 1.5 million
                     households served by small drinking
                     water systems that may be affected by
                     the recycling provisions in addition to
                     the turbidity, benchmarking, and
                     covered finished water provisions. The
                     expected aggregate annual cost to these
                     households can be approximated by the
                     sum of the expected cost for each
                     distribution, which is $10.45 per year.
                      The assumptions and structure of this
                     analysis tend to overestimate the highest
                     costs. To face the highest household
                     costs, a system would have to
implement all, or almost all, of the
treatment activities. These systems.
however, might seek less costly
alternatives, such as connecting into a
larger regional water system.
F. Benefits From the Reduction of Co-
Occurring Contaminants
   If a system chooses to install
treatment, it may choose a technology
that would also address other drinking
water contaminants. For example, some
membrane technologies installed to
remove bacteria or viruses can reduce or
eliminate many other drinking water
contaminants including arsenic.
   The technologies used to reduce
individual filter turbidities have the
potential to reduce concentrations of
other pollutants as well. Reduction in
turbidity that result from today's
proposed rule are aimed at reducing
Cryptosporidium by physical removal. It
is reasonable to assume that similar
microbial contaminants will also be
reduced as a result of improvements in
turbidity removal. Health risks from
Giardia lamblia and emerging
disinfection resistant pathogens, such as
microsporidia, Toxoplasma, and
Cyclospora, are also likely to be reduced
as a result of improvements in turbidity
removal and recycle practices. The
frequency and extent that LTlFBR
would reduce risk from other
contaminants has not been
quantitatively evaluated because of the
Agency's lack of data on the removal
efficiencies of various technologies for
emerging pathogens and the lack of co-
occurrence data for microbial pathogens
and other contaminants from drink
water systems.
G. Risk Increases From  Other
Contaminants
  It is unlikely that LTlFBR will result
in any increased  risk from other
contaminants. Improvements in plant
turbidity performance will not result in
any increases in risk. In addition, the
benchmarking and profiling provisions
were designed to minimize the potential
reductions in microbial disinfection in
order to lower disinfection byproduct
levels to comply with the Stage 1
Disinfection Byproducts Rule.
Furthermore, the filter backwash
provision does not potentially increase
the risk  from other contaminants.
H. Other Factors: Uncertainty in Risk,
Benefits, and Cost Estimates
  There is uncertainty in the baseline
number of systems, the  risk calculation,
and the  cost estimates. Many of these
uncertainties are discussed in more
detail in previous sections of today's
proposal.

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                  Federal Register/Vol.  65,  No. 69/Monday, April 10. 2000/Proposed  Rules
                                                                     19125
  First, the baseline number of systems
is uncertain because of data limitation
problems in SDWIS, For example, some
systems use both ground and surface
water but because of other regulatory
requirements are labeled in  SDWIS as
surface water. Therefore. EPA does not
have a reliable estimate of how many of
these mixed systems exist. The SDWIS
data on non-community water systems
does not have a consistent reporting
convention for population served. Some
states may report the population served
over the course of a year, while others
may report the population served on an
average day. Also, SDWIS does not
require states to provide information on
current filtration practices and. in some
cases, it may overestimate the daily
population served. For example, a park
may report the population served yearly
instead of daily. EPA is looking at new
approaches to address these issues and
both are discussed below in request for
comment.
  Second, there are several important
sources of uncertainty that enter the
benefits assessment, they include the
following:
  • Occurrence of Cryptosporidium
oocysts in source waters
  • Baseline occurrence of
Cryptosporidium oocysts in finished
waters
  • Reduction of Cryptosporidium
oocysts due to improved treatment.
including filtration and disinfection
  • Viability of Cryptosporidium
oocysts after treatment
  • Infectivity of Cryptosporidium
  • Incidence of infections  {including
impact of under reporting)
  • Characterization of the risk
Willingness-to-pay to reduce risk and
avoid costs.
  • The baseline water system
treatment efficiency for the removal of
Cryptosporidium is uncertain. Turbidity
measurements have been used as a
means of estimating removal treatment
efficiency {i.e. log removal). In addition
to the baseline treatment efficiency
estimates, improvements in treatment
efficiency for Cryptosporidium removal
that result from this rule are uncertain.
  The benefit analysis incorporates all
of the uncertainties associated with the
benefits assessment in either the Monte
Carlo simulations or the assumption of
two baselines—2.0 log removal and 2.5
log removal. The results in table VI. 1
show that benefits are  more sensitive to
the baseline log removal assumptions
than the range of low to high improved
removal assumptions.  Third, some costs
of today's proposed rule are uncertain
because of the diverse  nature of the
modifications that may be made to
address turbidity limits. Cost analysis
uncertainties are primarily caused by
assumptions made about how many
systems will be affected by various
provisions and how they will likely
respond. Capital and O&M expenditures
account for a majority of total costs. EPA
derived these costs for a "model"
system in each size category using
engineering models, best professional
judgement, and existing cost  and
technology documents. Costs for
systems affected by the proposed rule
could be higher or lower, which would
affect total costs. Also, the filter
backwash provision's flexibility for
States to assess plants' need to modify
recycle practices leads to some
uncertainty in the estimates of how
many plants will have to potentially
install some form of recycle equalization
or treatment. These uncertainties could
either under or overestimate the costs of
the rule.
I. Benefit Cost Determination
  The Agency has determined that the
benefits of the LTlFBR justify the costs.
EPA made this determination for both
the LTl and the FBR portions of the rule
separately as described below.
  The Agency has determined that the
benefits of the LTl provisions justify
their costs on a quantitative basis. The
LTl provisions include enhanced
filtration, disinfection  benchmarking
and other non-recycle  related
provisions. The quantified benefits of
$70 million to $259.4 million annually
exceed the costs of $73 million at the
seven percent cost of capital over a
substantial  portion of the range of
benefits. In addition, the non-quantified
benefits include avoided outbreak
responsE! costs and possibly reduced
uncertainty and averting behavior costs.
  The Agency has determined that the
benefits of the recycle  provisions (FBR)
justify their cost on a qualitative basis.
The recycle provisions will reduce the
potential for certain recycle practices to
lower or upset treatment plant
performance during recycle events; the
provisions will therefore help prevent
Cryptosporidium oocysts from entering
finished drinking water supplies and
will increase public health protection.
  The Agency strongly believes that
reluming Cryptosporidium to the
treatment process in recycle flows, if
performed improperly, can create
additional public health  risk. The
Agency holds this belief for three
reasons. First, returning recycle flow
directly to the plant, without
equalization or treatment, can cause
large variations in the influent flow
magnitude and influent water quality. If
chemical dosing is not adjusted to
reflect this, less than optimal chemical
dosing can occur, which may lower the
performance of sedimentation and
filtration. Returning recycle flows prior
to the point of primary coagulant
addition will help diminish the risk of
less than optimal chemical dosing and
diminished sedimentation and filtration
performance. Second, exceeding State-
approved operating capacity, which is
likely to occur if recycle equalization or
treatment is not in place, can
hydraulically overload plants and
diminish the ability of individual unit
processes to remove Cryptosporidium.
Exceeding approved operating capacity
violates fundamental engineering
principles and water treatment
objectives. States set limits on plant
operating capacity and loading rates for
individual unit processes to ensure
treatment plants and individual
treatment processes are operated to
within their capabilities so that
necessary levels  of public health
protection are  provided. Third,
returning recycle flows directly into
flocculation or sedimentation basins,
which can generate disruptive hydraulic
currents, may lower the performance of
these units and increase the risk of
Cryptosporidium in finished water
supplies.
  The recycle  provisions in today's
proposal are designed to address those
recycle practices that are inconsistent
with fundamental engineering and
water treatment principles. The
objective of the provisions is to
eliminate practices that are counter to
common sense, sound engineering
judgement, and that create additional
and preventable  risk to public health.
EPA believes the public health
protection benefit provided by the
recycle provisions justifies their cost
because they are based upon sound
engineering principles and are designed
to eliminate recycle practices that are
very likely to create additional public
health risk,
/. Request for Comment
  Pursuant to Section 3142(b)(3)(C), the
Agency requests comment on all aspects
of the rule's economic impact analysis.
Specifically, EPA seeks input into the
following two  issues.
NTNC and TNC Flow Estimates
  As part of the total cost estimates for
LTlFBR, EPA  estimated the cost of the
rule  on NTNC and TNC water systems
by using flow models. However, these
flow models were developed to estimate
flows only for  CWS and they may not
accurately represent the much smaller
flows generally found in NTNC and
TNC systems. The effect of the
overestimate in flow would be to inflate

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the cost of the rule for these systems.
The Agency requests comment on an
alternative flow analysis for NTNC and
TNC water systems described below.
  Instead of using the population served
to determine the average flow for use in
the rule's cost calculations, this
alternative approach would re-
categorize NTNC and TNC water
systems based on service type (e.g.,
restaurants or parks). Service type
would be obtained from SDWIS data.
However, service type data is not always
available because it is a voluntary
SDWIS data field. Where unavailable,
the service type would be assigned
based on statistical analysis. Estimates
of service type design flows would be
obtained from engineering design
manuals and best professional
judgement if no design manual
specifications exist.
  In addition, each service type category
would also have corresponding rates for
average population served and average
water consumption. These would be
used to determine contaminant
exposure which  is  used in the benefit
determination. For example, schools
and churches would be two separate
service type categories. They each
would have their own corresponding
average design flow, average population
served (rather than the population as
reported in SDWIS), and average water
consumption rates. These elements
could be used to estimate a rule's
benefits and costs for the average church
and the average school.

Mixed Systems
  Current regulations require that all
systems that use any amount of surface
water as a source be categorized as
surface water systems. This
classification applies even if the
majority of water in a system is from a
ground water source. Therefore, SDWIS
does not provide the Agency with
information to identify how many
mixed systems exist. This information
would help the Agency to better
understand regulatory impacts.
  EPA is investigating ways to identify
how many mixed systems exist and how
many mix their ground and surface
water sources at the same entry point or
at separate entry points within the same
distribution  systems. For example, a
system may have several plants/entry
points that feed the same distribution
system. One of these entry points may
mix and treat surface water with ground
water prior to its entry into the
distribution  system. Another entry point
might use ground water exclusively for
its source while a different entry point
would exclusively use surface water.
However, all three entry points would
                     supply the same system classified in
                     SDWIS as surface water.
                       One method EPA could use to address
                     this issue would be to analyze CWSS
                     data then extrapolate this information to
                     SDWIS to obtain a national estimate of
                     mixed systems. CWSS data, from
                     approximately 1.900 systems, details
                     sources of supply at the level of the
                     entry point to the distribution system
                     and further subdivides flow by source
                     type. The Agency is considering this
                     national estimate of mixed systems to
                     regroup surface water systems for
                     certain impact analyses when
                     regulations only impact one type of
                     source. For example, surface water
                     systems that get more than fifty percent
                     of their flow from ground water would
                     be counted as a ground water system in
                     the regulatory impact analysis for this
                     rule. The Agency requests comment on
                     this methodology and its applicability
                     for use in regulatory impact analysis.

                     VII. OtKer Requirements

                     A. Regulatory Flexibility Act (BFA), as
                     amended by the. Small Business
                     Regulatory Enforcement Fairness Act of
                     1996 (SBREh'A). 5 USC 601  et seq.

                     1. Background
                       The RFA, generally requires an
                     agency to prepare a regulatory flexibility
                     analysis of any rule subject to notice
                     and comment rulemaking requirements
                     under the Administrative Procedure Act
                     or any other statute unless the agency
                     certifies that the rule will not have a
                     significant economic impact on a
                     substantial number of small entities.
                     Small entities include small businesses,
                     small organizations, and small
                     governmental jurisdictions.

                     2. Use of Alternative Definition
                       The RFA provides default definitions
                     for each type of small entity. It also
                     authorizes an agency to use alternative
                     definitions for each category of small
                     entity, "which are appropriate to the
                     activities of the agency" after proposing
                     the alternative definition(s) in the
                     Federal Register and taking comment. 5
                     U.S.C. sees. 601(3)-(5). In addition to
                     the above, to establish an alternative
                     small business definition, agencies must
                     consult with SBA's Chief Counsel for
                     Advocacy.
                       EPA is"proposing the LTlFBR which
                     contains provisions which apply to
                     small PWSs serving fewer than 10,000
                     persons. This is the cut-off level
                     specified by Congress in the 1996
                     Amendments to the Safe Drinking Water
                     Act for small system flexibility
                     provisions. Because this definition does
                     not correspond to the definitions of
                     "small" for small businesses.
governments, and non-profit
organizations, EPA requested comment
on an alternative definition of "small
entity" in the preamble to the proposed
Consumer Confidence Report (CCR)
regulation (63 FK 7620, February 13,
1998). Comments showed that
stakeholders support the proposed
alternative definition. EPA also
consulted with the SBA Office of
Advocacy on the definition as it relates
to small business analysis. In the
preamble to the final CCR regulation (63
FR 4511, August 19, 1998). EPA stated
its intent to establish this alternative
definition for regulatory flexibility
assessments under the RFA for all
drinking water regulations and has thus
used it in this proposed rulemaking.
  In accordance with Section 603 of the
RFA,  EPA prepared an initial regulatory
flexibility analysis (IRFA) that examines
the impact of the proposed rule on small
entities along with regulatory
alternatives that could reduce that
impact. The IRFA is available for review
in the docket and is summarized below,
3. Initial  Regulatory Flexibility Analysis
  As part of the 1996 amendments to
the Safe Drinking Water Act (SDWA),
Congress required the U.S.
Environmental Protection Agency (EPA)
to develop a Long Term Stage 1
Enhanced Surface Water Treatment Rule
(LT1ESWTR) under Section
1412(b)(2)(C) which focuses on surface
water drinking water systems that serve
fewer than 10,000 persons. Congress
also required EPA to develop a
companion Filter Backwash Recycle
Rule (FBRR) under Section 1412(b)(l4)
which will require that all surface water
public water systems, regardless of size,
meet new requirements governing the
recycle of filter backwash within the
drinking  water treatment process. The
goal of both the LTlESWTR and the
related FBRR is to provide additional
protection from disease-causing
microbial pathogens for community and
non-community public water systems
(PWSs) utilizing surface water.
  For purposes  of assessing the impacts
of today's rule on small entities, small
entity is defined by systems serving
fewer than 10.000 people. The small
entities directly regulated by this
proposed rule are surface water and
systems using ground water under the
direct influence of surface water
(GWUDI), using filtration and serving
fewer than 10,000 people. We have
determined that the final rule would
result in approximately 2,400 systems
needing capita!  improvement to  meet
the turbidity requirements,
approximately 3,360 systems would
need to significantly change their

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disinfection practices, and
approximately 790 systems would need
to make capital improvements to change
the location of return of their filter
backwash recycle stream. A discussion
of the impacts on small entities is
described in more detail in chapters six
and seven of the Regulatory Impact
Analysis of the LT1FBR (EPA, 1999).
  The following recordkeeping and
reporting burdens were projected in the
IRFA:
Turbidity Monitoring and Reporting
Costs
  Utility monitoring activities at the
plant level include data collection, data
review, data reporting and monthly
reporting to the State. The labor burden
hours for data collection and review
were calculated under the assumption
that plants are using on-line monitoring,
in the form of a SCADA or other
automated data collection system. The
data collection process requires that a
plant engineer gather and organize
turbidimeter readings from the SCADA
output and enter them into either a
spreadsheet or a log once per 8-hour
shift (three times per day).
  After data retrieval, the turbidity data
from each turbidimeter will be reviewed
by a plant engineer once per 8-hour shift
(three times per day) to ensure that the
filters are functioning properly and are
not displaying erratic or exceptional
patterns, A monthly summary data
report would be prepared. This task
involves the review of daily
spreadsheets and the compilation of a
summary report. It is assumed to take
one employee 8 hours per month to
prepare. Recordkeeping is expected to
take 5 hours per month. Recordkeeping
entails organizing daily monitoring
spreadsheets and monthly  summary
reports.
  Plant-level data will also be reviewed
monthly at the system level to ensure
that each plant in a system is in
compliance with the rule. A system-
level manager or technical worker will
review the daily monitoring
spreadsheets and monthly summary
reports that are generated at the plant
level. This task is estimated to take
about 4 hours per month. Once the
plant-level data have been reviewed, the
system manager or technical worker will
also compile a monthly system
summary report. These reports are
estimated to take 4 hours each month to
prepare.
Disinfection Benchmarking Monitoring
and Reporting Costs
  It is assumed that all Subpart H
systems currently collect the daily
inactivation data required to generate a
disinfection profile, in tiither an
electronic or paper format, and therefore
would not incur additional data
collection expenses due to rnicrobial
profiling. Costs per plant are divided
into costs per plant using paper data,
costs per plant using mainframe data
and costs pur plant using PC data. Plants
with paper data were assumed to
represent half of the number of plants
needing benchmarking, while plants
with mainframe and plants with PC data
each represent a quarter.

Filter Backwash Monitoring and
Reporting Costs
  The proposed requirements are as
follows: All subpart H systems,
regardless of size, that use conventional
rapid  granular filtration, and that return
spent filter backwash, thickener
supernatant, or liquids from dewatering
process to submit a schematic diagram
to the State showing their intended
changes to move the return location
above the point of primary coagulant
addition.
  All  subpart H systems, regardless of
size, that use conventional rapid
granular filtration and employ 20 or
fewer filters during the highest
production month and that use direct
recycling, to perform a self assessment
of their recycle practice and report the
results to the State.
  All  subpart H systems, regardless of
system size that use direct filtration
must submit a report of their recycling
practices to the State. The State would
then determine whether changes in
       ij> practices were warranted.
  EPA believes that the skill level
required for compliance with all of the
above recordkeeping. reporting and
other compliance activities are similar
or equivalent to the skill level required
to pass the first level of operator
certification required by most States.
Relevant Federal Rules
  EPA has issued a Stage 1
Disinfectants/Disinfection Byproducts
Rule (DBPR) along with an Interim
Enhanced Surface Water Treatment Rule
(IESWTR) in December 1998, as
required by the Safe Drinking Water Act
Amendments of 1996. EPA proposed
these rules in July 1994. The Stage 1
DBPR includes a THM MCL of 0.080
mg/L (reduced from the existing THM
MCL of 0 10 mg/L established in 1979)
and an MCL of 0.060 mg/L for five
haloacetic acids (another group of
chlorination) as well as MCLs for
chlorite (1.0 mg/L) and bromate (0,010
mg/L) byproducts. The Stage  1 DBPR
also finalized MRDLs for chlorine (4
mg/L as Cb). chloramine (4 mg/L as Cl
and chlorine dioxide (0.8 mg/L as
  In addition, the Stage 1 DBPR
includes requirements for enhanced
coagulation to reduce the concentration
of TOC in the water and thereby reduce
DBF formation potential.  The IESWTR
was proposed to improve control of
rnicrobial pathogens and to control
potential risk trade-offs related to the
need to meet lower DBP levels under
the Stage 1 DBPR.
  None of these regulations duplicate,
overlap or conflict with this proposed
rule.

Significant Alternatives
  As a result of consultations during the
SBREFA process, and public meetings
held subsequently, EPA has developed
several alternative options to those
presented in the IRFA. and has selected
preferred alternatives for each of the
turbidity, disinfection benchmarking
and filter backwash recycle provisions.
These alternatives were developed
based on feedback from small system
operators and trade associations and are
designed to protect public health, while
minimizing the burden to small
systems. In summary, the proposed
turbidity requirements are structured to
require recordkeeping once a week as
opposed to daily which was written in
the IRFA; the proposed disinfection
profile requirements are structured to be
taken once per week, as opposed to
daily which was written in the IRFA;
and the filter backwash requirements
have been scaled back significantly from
those included in the IRFA, i.e. a ban on
recycle is no longer being considered,
nor are several treatment techniques
now being considered that were in the
IRFA prior to discussions with
stakeholders. The provisions being
proposed are: systems that recycle will
be required to return recycle flows prior
to the rapid mix unit; direct recycle
systems will need to perform a self
assessment to determine whether
capacity is exceeded during recycle
events, and States will determine
whether recycle practices need to be
changed based on the self-assessment:
and direct filtration systems will need to
report their recycle practices to the
State, which will determine whether
changes to recycle practices are
required.

4. Small Entity Outreach and Small
Business Advocacy Review Panel
  As required by section 609(b) of the
RFA, as amended by SBREFA, EPA also
conducted outreach to small entities
and convened a Small Business
Advocacy Review Panel to obtain advice
and recommendations of representatives
of the small entities that potentially
would  be subject to the rule's

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requirements. The SBAR Panel
produced two final reports; one tor the
LTl provisions and the other for the
filter backwash provisions. Although
the LTl and filter backwash provisions
have since been combined into tho same
rule, the projected economic impact of
the provisions have not significantly
changed, and the relevance of SERs'
comments has not been affected.
  The Agency invited 24 SKRs to
participate in the SBREFA process, and
16 agreed to participate. The SERs were
provided with background information
on the Safe Drinking Water Act and the
LTlFBR in preparation for a
teleconference on April 28. 1998. This
information package included data on
options as well as preliminary unit costs
for treatment enhancements under
consideration. Eight SERs provided
comments on these materials.
  On August 25.1998, EPA's Small
Business Advocacy Chair person
convened the Panel under section
609[b) of the Regulatory Flexibility Act
as amended by the Small Business
Regulatory Enforcement Fairness Act
(SBREFA).  In addition to its
chairperson, the Panel consisted of the
Director of the Standards and Risk
Management Division of the Office of
Ground Water and Drinking Water
within EPA's Office of Water, the
Administrator of the Office of
Information and Regulatory  Affairs
within the Office of Management and
Budget, and the Chief Counsel for
Advocacy of the Small Business
Administration. The SBAR Panels
reports, Final Report of the SBREFA
Small Business Advocacy Review Panel
on EPA's Planned Proposed Rule: Long
Term 1 Enhanced Surface Water
Treatment (EPA. 1998k) and the  Final
Report of the SBREFA Small Business
Advocacy Review Panel on EPA's
Planned Proposed Rule: Filter Backwash
Recycling (EPA, 19981), contain the
SERs comments on the components of
the LTlFBR.
  The SERs were provided with
additional information on potential
costs related to LTlFBR regulatory
options during teleconferences on
September  22 and 25. 1998.  Nine SERs
provided additional comments during
the September 22 teleconference, four
SERs provided additional comments
during the September 25 teleconference,
and three SERs provided written
comment on these materials.
  In general, the SERs that were
consulted on the LTlFBR were
concerned about the impact of the
proposed rule on small water systems
(because of their small staff and limited
budgets), small systems' ability to
acquire the technical and financial
                    capability to implement requirements,
                    and maintaining flexibility to tailor
                    requirements to the needs and
                    limitations of small systems. Consistent
                    with the RFA/SBREFA requirements,
                    the Panel evaluated the assembled
                    materials and small-entity comments on
                    issues related to the elements of the
                    IRFA. The background information
                    provided to the SBAR Panel and the
                    SERs are available lor review in the
                    water docket. A copy of the Panel report
                    is also included in the docket for this
                    proposed rule. The Panel's
                    recommendations to address the SERs
                    concerns are described next.

                    a. Number of Small Entities Affected
                      When the IRFA was prepared, EPA
                    initially estimated that there were 5,165
                    small public water systems that use
                    surface  water or GWUDI. A more
                    detailed discussion of the impact of the
                    proposed rule and the number of
                    entities  affected is found in Section VI.
                    None of the commenters  questioned the
                    information provided by  EPA on the
                    number and typos of small entities
                    which may be impacted by the LTlFBR.
                    This information is based upon the
                    national Safe Drinking Water
                    Information System (SDWIS) database.
                    which contains data on all public water
                    svstems in the country. The Panel
                    believed this was a reasonable data
                    source to characterize the number and
                    types of systems impacted by the
                    proposed rule.
                    b. Recordkeeping and Reporting
                      The Panel noted that some small
                    systems are operated by a sole, part time
                    operator with many duties beyond
                    operating and maintaining the drinking
                    water treatment system and that several
                    components of the proposed rule may
                    require  significant additional operator
                    time to  implement. These included
                    disinfection profiling, individual filter
                    monitoring, and ensuring that short-
                    term turbidity spikes are  corrected
                    quickly.
                      One SER stated that assumptions can
                    be made that small systems will have to
                    add an additional person to comply
                    with the monitoring and recordkeeping
                    portions of the rule. Another SER
                    commented th;tt the most viable and
                    economical option would be to use
                    circuit riders (a trained operator who
                    travels between plants) to fill staffing
                    needs, but the LTlFBR would increase
                    the amount of time that a circuit rider
                    would be required to spend at each
                    plant. An additional option
                    recommended by several SERs to reduce
                    monitoring burden and cost was to
                    allow the use of one on-line
                    turbidimeter to measure several filters.
This would entail less frequent
monitoring of each filter but might still
be adequate to ensure that individual
filter performance is maintained.
  The proposed LTlFBR takes into
consideration the recordkeeping and
reporting concerns identified by the
Panel and the SERs. For example,
initially the Agency considered
requiring systems to develop a profile of
individual filter performance. Based on
concerns from the SERs this
requirement was eliminated. In
addition, the Agency initially
considered requiring operators to record
pH, temperature, residual chlorine and
peak hourly flow every day. This
requirement has been scaled back to
once per week to meet difficulties faced
by small system operators. Finally, in
today's proposed rule the Agency is
requesting comment on a modification
to allow one on-line turbidimeter
instead of several to be used at the
smallest size systems (systems serving
fewer than 100 people).

c. Interaction With Other Federal Rules
  The Panel noted that the LTlFBR and
Stage 1 DBP rules will affect small
systems virtually simultaneously and
that the Agency  should analyze  the net
impact of these rules and consider
regulatory options that would minimize
the impact on small systems.
  One SER commented that any added
responsibility or workload due to
regulations will  have to be absorbed by
him and his staff. He noted that  many
systems, including his own, are  losing
staff through attrition and are unable to
hire replacements. The SER stated that
he hoped the Panel was aware of the
volume of rules and regulations  to
which small systems are currently
subject. As an example, the SER stated
that he had spent a week's time
collecting samples for the mandated
tests of the Lead and Copper rule. He
noted that the sampling had delayed
important maintenance to his system by
over a month.
  The Agency considered these
comments when developing the
requirements of today's proposed rule,
and developed the alternatives with the
realization that small systems will be
required to implement several rules in
a short time frame. In today's proposed
rule, the preferred options attempt to
minimize the impact on small systems
by reducing the amount of monitoring
and the amount of operator's time
necessary to collect and analyze data.
For example, under the 1ESWTR, large
systems are required to monitor
disinfection byproducts for 1 year to
determine whether or not they must
develop a disinfection profile (based on

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                                                                    19129
daily measurements of operating
conditions). In response to SERs
concerns, the Agency is proposing to
eliminate the requirement for
disinfection byproduct monitoring all
together. Under the proposed
requirements, all systems would
develop a disinfection profile based on
weekly measurements of operating
parameters for 1 year. Overall, this will
save small system operators both time
and money. The proposed rule also
requests comment on several additional
strategies for reducing impacts.
d. Significant Alternatives
  During the SBAR panel several
alternatives were discussed with the
Panel and SERs. These alternatives and
the Panel's recommendations are
discussed next.
i. Turbidity Provisions
  During the SBAR Panel, the Agency
presented the IESWTR turbidity
provisions as appropriate components
for the LTlFBR. The Panel  noted that
one SER commented that it was a fair
assumption that turbidity up to 1 NTU
maximum and 0.3 NTU in 95% of all
monthly  samples is a good  indicator of
two log removal of Cryptosporidium,
but stressed the need to allow operators
adequate time to respond to
exceedances in automated systems.
They were referring to the fact the small
system operators are often away from
the plant performing other  duties, and
cannot respond immediately if the
turbidity levels exceed a predetermined
level. The Panel recommended that EPA
consider  this limitation when
developing reporting and recordkeeping
requirements.
  The Panel also noted that another SER
agreed that lowered turbidity level is a
good indicator of overall plant
performance but thought the 0.3 NTU
limit for the 95th percentile reading was
too low in light of studies which appear
to show variability and inaccuracies in
low level turbidity measurements. This
SER referenced specific data suggesting
that current equipment used to measure
turbidity levels below the 0.3 NTU may
nonetheless give readings above 0.3
which would put the system out of
compliance. EPA has evaluated this
issue in the context of the 1997 IESWTR
FACA negotiations and believes that
readings below the 0.3 NTU are reliable.
Moreover, EPA notes that the SERs'
concern was based on raw performance
evaluation data that had not been fully
analyzed.
  Finally, the Panel recognized that
several SERs supported individual filter
monitoring, provided there was
flexibility for short duration turbidity
spikes. Other SERs, however, noted that
the assumption thai individual filter
monitoring was necessary was
unreasonable. The Panel recommended
that EPA consider the likelihood and
significance of short duration spikes
(i.e., during the first 15-30 minutes of
filter operation) when evaluating the
frequency of individual filter
monitoring and reporting requirements
and the number and types of
exceedances that will trigger
requirements for Comprehensive
Performance Evaluations (CPEs). The
Panel also noted the concern expressed
by several SERs that individual filter
monitoring may not be practical or
feasible in all situations.
  The Agency has structured today's
proposed rule with an emphasis on
providing flexibility for small systems.
The individual filter provisions have
been tailored to be easier to understand
and implement and require less data
analysis, For example, the operator can
look at monitoring data once per week
under this rule, as opposed to having to
review turbidity data every day as the
larger systems are required to do. The
proposed rule also requests comment on
several modifications to provide
additional flexibility to small systems.

ii. Disinfection Benchmarking:
Applicability Monitoring Provisions
  None of the SERs commented
specifically on the applicability
monitoring provisions which are
designed to identify systems that may
consider cutting back on their
disinfection doses in order to avoid
problems with disinfection byproducts
formation. The Panel noted, however,
that burden on small systems might be
reduced if alternative applicability
monitoring provisions were adopted. In
consideration of the Panel's suggestions,
the Agency first considered limiting the
applicability monitoring, and has now
eliminated this requirement from the
proposal. It is optional, however, for
systems who believe their disinfection
byproduct levels are below 80% of the
MCL—as required under the Stage  1
DBPR.
  The Panel noted SER comments that
monitoring and computing Giardia
lamblia inactivation on a daily basis for
a year would  place a heavy burden on
operators that may only staff the plant
for a few hours per day. The Panel
therefore recommended that EPA
consider alternative profiling strategies
which ensure adequate public health
protection, but will minimize
monitoring and recordkeeping
requirements for small system operators.
  The Agency considered several
alternatives to the profile development
strategies, and decided to propose that
systems perform the necessary
monitoring and record the results once
per week, instead of every day as the
larger systems are required to do. This
will significantly reduce burden and
costs for small systems.
iii. Recycling Provisions
  During the SBAR Panel, the Agency
proposed several alternatives for
consideration in the LTlFBR including
a ban on recycle, a requirement to return
recycle flow to the head of the plant,
recycle flow equalization, and recycle
flow treatment. The Panel noted the
concern of the SERs regarding a ban on
the recycle of filter backwash water.
These concerns included the expense of
filter backwash disposal and the
economic and operational concerns of
western and southwestern drinking
water systems which depend on
recycled flow to maintain adequate
supply. The Panel strongly
recommended that EPA explore
alternatives to an outright ban on the
recycle of filter backwash and other
recycle flows.
  The Panel noted that SERs supported
a requirement that all recycled water be
reintroduced at the head of the plant.
This was considered an element of
sound engineering practice. The Panel
recommended that EPA consider
including such a requirement in the
proposed rule, and investigate whether
there are small systems for which such
a requirement would present a
significant financial and operational
burden.
  The Panel noted that SERs agreed
with the appropriateness of flow
equalization for filter backwash. The
Panel supported the concept of flow
equalization as a means to minimize
hydraulic surges that may be caused by
recycle and the reintroduction of a large
number of Cryptosporidium oocysts or
other pathogenic contaminants to the
plant in a brief period of time. The
Panel noted that there are various ways
of achieving flow equalization and
suggested that specific requirements
remain flexible.
  The Panel noted the concerns of SERs
regarding installation of treatment,
solely for the purpose of treating filter
backwash water and/or recycle streams
may be costly and potentially
prohibitive for small systems. The
Agency addressed this concern by
allowing the States to determine
whether recycle flow equalization or
treatment  is necessary based on the
results of the self assessment prepared
by the system rather than requiring
universal flow equalization or
treatment. This will allow site-specific

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factors to be considered and help
minimize cost and burden.

e. Other Comments
  The Panel also noted the concern of
several SERs that flexibility be provided
in the compliance schedule of the rule.
SERs noted the technical and financial
limitations that some small systems will
have to address, the significant learning
curve for operators with limited
experience, and the need to continue
providing uninterrupted service as
reasons why additional compliance time
may be needed for small systems. The
panel encouraged EPA to keep these
limitations in mind in developing the
proposed rule and provide as much
compliance  flexibility to small systems
as is allowable under the SDWA. We
invite comments on all aspects of the
proposal and its impacts on small
entities.
  The Agency structured the timing of
the LTlESVVTR provisions specifically
to follow the promulgation of the
IESWTR. Since the IESWTR served as a
template for the establishment of the
LT1ESWTR provisions, the Agency
decided that small systems would have
an advantage by giving them an
opportunity to see what was in the rule,
and how it was implemented by larger
systems.
  Under SDWA, systems have 3 years to
comply with the requirements of the
final rule. If capital improvements are
necessary for a particular PWS, a State
may allow the system up to an
additional 2 years to comply with the
regulation. The Agency is developing
guidance manuals to assist the
compliance  efforts of small entities.

B. Paperwork Reduction Act
  The information collection
requirements in this proposed rule have
been submitted for approval to the
Office of Management and Budget
(OMB) under the Paperwork Reduction
Act, 44 U.S.C. 3501  et seq. An
Information  Collection Request (1CR)
document has been prepared by EPA
(ICR No.  1928.01) and a copy may be
obtained from Sandy Farmer by mail at
OP Regulatory Information Division;
U.S. Environmental Protection Agency
(2137); 401 M St., S.W.; Washington, DC
20460, by email at
farmer.sandy@epamail.epa.gov, or by
calling (202) 260-2740. A copy may also
be downloaded off the Internet at http:/
/www.epa.gov/icr. For technical
information about the collection contact
Jini Mohanty by calling (202) 260-6415.
  The information collected as a result
of this rule will allow the States and
EPA to determine appropriate
requirements for specific systems, in
                    some cases, and to evaluate compliance
                    with the rule. For the first three years
                    after the effective date (six years after
                    promulgation) of the LTlFBR. the major
                    information requirements are (1)
                    monitor filter performance and submit
                    any exceedances of turbidity
                    requirements (i.e. Rxceptions reports) to
                    the State; (2) develop a 1 month recycle
                    monitoring plan and submit both plan
                    and results to the State; (3) submit flow
                    monitoring plan and results to the State;
                    and (4) report data on current recycle
                    treatment (self assessment) to the State.
                    The in formation collect ion requirements
                    in Part 141, for systems, and Part 142,
                    for States are mandatory. The
                    information collected is not
                    confidential.
                      Burden means the total time, effort, or
                    financial resources expended by persons
                    to generate, maintain, retain, or disclose
                    or provide  information to or for a
                    Federal Agency. This includes the time
                    needed to review  instructions; develop,
                    acquire, install, and utilize technology
                    and systems for tho purposes of
                    collecting,  validating, and verifying
                    information, processing and
                    maintaining information, and disclosing
                    and providing information; adjust the
                    existing ways to comply with any
                    previously applicable instructions and
                    requirements; train personnel to be able
                    to respond  to a  collection of
                    information; search data sources;
                    complete and review the collection of
                    information; and transmit or otherwise
                    disclose the information.
                      The preliminary estimate of aggregate
                    annual average burden hours for
                    LTlFBR is  311.486. Annual average
                    aggregate cost estimate is $10.826,919
                    for labor, $2,713,815 for capital, and
                    $1,898,595 for operation and
                    maintenance including lab costs which
                    is a purchase of service. The burden
                    hours per response is 18.9. The
                    frequency of response (average
                    responses per respondent) is 2.7
                    annually. The estimated number of
                    likely respondents is 6,019 (the product
                    of burden hours per response.
                    frequency,  and  respondents does not
                    total the annual average burden hours
                    due to rounding).  Most of the regulatory
                    provisions  discussed in this notice
                    entail new  reporting and record keeping
                    requirements for States, Tribes, and
                    members of the regulated public.  An
                    Agency may not conduct or sponsor,
                    and a person is not required to respond
                    to a collection of information unless it
                    displays a currently valid OMB control
                    number The OMB control numbers for
                    EPA's regulations are listed in 40 CFR
                    Part 9 and 48 CFR Chapter 15.
                      Comments are requested on the
                    Agency's need for this information, the
accuracy of the provided burden
estimates, and any suggested methods
for minimizing respondent burden,
including through the use of automated
collection techniques. Send comments
on the ICR to the Director, OP
Regulatory Information Division; U.S.
Environmental Protection Agency
(2137); 401 M St., S.W.; Washington, DC
20460; and to the Office of Information
and Regulatory Affairs, Office of
Management and Budget, 725 17th St.,
N.W., Washington, DC 20503, marked
"Attention; Desk Officer for EPA."
Include the ICR number in any
correspondence. Since OMB is required
to make a decision concerning the ICR
between 30 and 60 days after April 10,
2000, a comment to OMB is best assured
of having its full effect if OMB receives
it by May  10, 2000. The final rule will
respond to any OMB or public
comments on the information collection
requirements contained in this proposal.
C. Unfunded Mandates Reform Act
1. Summary of UMRA requirements
  Title II of the Unfunded Mandates
Reform Act of 1995 (UMRA), Public
Law 104-4, establishes requirements for
Federal agencies to assess the effects  of
their regulatory actions on State, local,
and tribal governments and  the private
sector. Under UMRA section 202, EPA
generally must prepare a written
statement, including a cost-benefit
analysis, for proposed and final rules
with "Federal mandates" that may
result in expenditures by State, local,
and tribal governments, in the aggregate,
or to the private sector, of $100 million
or more in any one year.  Before
promulgating an EPA rule, for which a
written statement is needed, section 205
of the UMRA generally requires EPA to
identify and consider a reasonable
number of regulatory alternatives and
adopt the  least costly, most cost-
effective or least burdensome alternative
that achieves the objectives of the rule.
The provisions of section 205 do not
apply when they are inconsistent with
applicable law. Moreover, section 205
allows EPA to adopt an alternative other
than the least costly, most cost effective
or least burdensome alternative if the
Administrator publishes with the final
rule an explanation why  that alternative
was not adopted.
  Before EPA establishes any regulatory
requirements that may significantly or
uniquely affect small governments,
including tribal governments, it must
have developed, under section 203 of
the UMRA, a small government agency
plan. The plan must provide for
notification to potentially affected small
governments, enabling officials of

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affected small governments to havt;
meaningful and timely input in the
development of EPA regulatory
proposals with significant Federal
intergovernmental mandates and
informing, educating, and advising
small governments on compliance with
the regulatory requirements.
2, Written Statement for Rules With
Federal Mandates of $100 Million or
More
  EPA has determined that this rule
does not contain a Federal mandate that
may result in expenditures of $100
million or more for the State, local and
Tribal governments, in the aggregate, or
the private sector in any one year. Thus
today's rule is not subject to (the
requirements of sections 202 and 205 of
the UMRA. Nevertheless, since the
estimate of annual impact is close to
$100 million under certain assumptions
EPA has prepared a written statement,
which is summarized below, even
though one is not required. A more
detailed description of this analysis is
presented in EPA's Regulatory Impact
Analysis of the LTlFBR (EPA', 1999h)
which is available for public review in
the Office of Water docket under docket
number W-99-10. The document is
available for inspection from 9 a.m. to
4 p.m., Monday through Friday.
excluding legal holidays. The docket is
located in room EB 57, LJSEPA
Headquarters, 401 M St.  SW,
Washington, D.C. 20460. For access to
docket materials, please call (202) 260-
3027 to schedule an appointment.
a. Authorizing Legislation
  Today's rule is proposed pursuant to
Section 1412 (b)(2)(C) and 1412(b)(14) of
the SDWA. Section 1412 (b)(2)(C)
directs EPA to establish a series of
regulations including an interim and
final enhanced surface water treatment
rule. Section 1412(b)(14) directs EPA to
promulgate a regulation to govern the
recycling of filter backwash water. EPA
intends to finalize the  LTlFBR  in the
year 2000  to allow systems to consider
the dual impact of this rule and the
Stage 1 DBF rule on their capital
investment decisions.
b. Cost Benefit Analysis
  Section  VI of this preamble discusses
the cost and benefits associated with the
LTlFBR. Also, the EPA's Regulatory
Impact Analysis of the LTlFBR (EPA,
1999h) contains a detailed cost benefit
analysis. Today's proposal is expected
to have a total annualized cost of
approximately $ 97.5 million using a 7
percent discount rate. At a 3 percent
discount rate the annualized costs drop
to $87.6 million. The national cost
estimate includes cost tor all of the
rule's major provisions including
turbidity monitoring, disinfection
benchmarking monitoring, disinfection
profiling covered finished storage, and
recycling. The majority of the costs for
this rule will be incurred by the public
sector. A more detailed discussion nf
these costs  is located in Section VI of
this preamble,
  In addition, the regulatory impact
analysis includes both monetized
benefits and descriptions of
unqualified benefits for improvements
to public health and safety the ruin will
achieve. Because of scientific
uncertainty regarding LTlFBR's
exposure and risk assessment, the
Agency has used Monte Carlo methods
and sensitivity analysis to assess the
quantified benefits of today's rule. The
monetary analysis was based upon
quantification of the number of
cryptosporidiosis illnesses avoided due
to improved particulate removal that
results from the turbidity provisions.
The Agency was not able to monetize
the benefits from the other rule
provisions  such as disinfection
benchmarking and covered finished
storage. The monetized annual benefits
of today's rule range from $70.1 million
to $259.4 million depending on the
baseline and removal assumptions.
Better management of recycle streams
required by the proposal also result  in
nonquantifiable health risk reductions
from disinfection resistant pathogens.
The rule may also decrease illness
caused by Giardia and other emerging
disinfection resistant pathogens, further
increasing the benefits.
  Several non-health benefits from this
rule were also identified by EPA but
were not monetized. The non-health
benefits of this rule include outbreak
response costs avoided, and possibly
reduced uncertainty and averting
behavior costs. By adding the non-
monetized benefits with those that are
monetized, the overall benefits of this
rule increase beyond the dollar values
reported.
  Various Federal programs exist to
provide financial assistance to State,
local, and Tribal governments in
complying  with this rule. The Fedtsral
government provides funding to States
that have primary enforcement
responsibility for their drinking water
programs through the Public Water
Systems Supervision Grants program.
Additional  funding is available from
other programs administered either by
EPA. or other Federal Agencies. These
include EPA's Drinking Water State
Revolving Fund (DWSRF), U.S.
Department of Agriculture's Rural
Utilities' Loan and Grant Program, and
Housing and Urban Development's
Community Development Block Grant
Program.
  For example, SDWA authorizes the
Administrator of the EPA to award
capitalization grants to States, which in
turn can provide low cost loans and
other types of assistance to eligible
public water systems. The DWSRF helps
public water systems finance the cost of
infrastructure necessary to achieve or
maintain compliance with SDWA
requirements. Each State has
considerable flexibility to design its
program and to direct funding toward
the most  pressing compliance and
public health protection needs. States
may also, on a matching basis, use up
to ten percent of their DWSRF
allotments each fiscal year to run the
State drinking water program.
  Furthermore, a State can use the
financial resources of the DWSRF to
assist small systems. !n fact, a minimum
of 15% of a State's DWSRF grant must
be used to provide infrastructure loans
to small systems. Two percent of the
State's grant may be used to provide
technical assistance to small systems.
For small systems that are   ,
disadvantaged, up to 30% of a State's
DWSRF may be used for increased loan
subsidies. Under the DWSRF, Tribes
have a separate set-aside which they can
use. In addition to the DWSRF, money
is available from the Department of
Agriculture's Rural Utility Service
(RUS) and Housing and Urban
Development's Community Block Grant
(CDBG) program. RUS provides loans,
guaranteed loans, and grants to improve,
repair, or construct water supply and
distribution systems in rural areas and
towns up to 10,000 people. In fiscal year
1997, the RUS had over $1.3 billion in
available funds. Also, three sources of
funding exist under the CDBG program
to finance building and improvements
of public faculties such as water
systems. The three sources of funding
include: (1) Direct grants to
communities with populations over
200,000; (2) direct grants to States,
which they in turn award to smaller
communities, rural areas, and colonias
in Arizona, California, New Mexico, and
Texas; and (3) direct grants to US.
Territories and Trusts. The CDBG
budget for fiscal year 1997 totaled over
$4 billion dollars.

c. Estimates of Future Compliance Costs
and Disproportionate Budgetary Effects
  To meet the UMRA requirement in
section 202, EPA analyzed future
compliance costs and possible
disproportionate budgetary effects. The
Agency believes that the cost estimates,
indicated previously and discussed in

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more detail in Section VI of this
preamble, accurately characterize future
compliance costs.
  In analyzing the disproportionate
impacts, EPA considered four measures:
  (l) The impacts of small versus large
systems and the impacts within the five
small svstem size categories;
  (2) The costs to public versus private
water systems;
  (3) The costs to households, and;
  (4) The distribution  of costs across
States.
  First, small systems  will experience a
greater impact than large systems under
LTlFBR because large systems are
subject only to the recycle provisions.
The Interim Enhanced Surface Water
Treatment Rule (IESVVTR) promulgated
turbidity, benchmarking, and covered
finished storage provisions for large
systems in December,  1998. However,
smalt systems have realized cost savings
over time due to their  exclusion from
the IESWTR. Also, some provisions in
the LTlFBR have been modified so they
would not be as burdensome for small
systems. Further information on these
changes can be  found  in section
VII. A.3.of this proposal.
  The second measure of impact is the
relative total cost  to privately owned
water systems compared to the incurred
by publicly owned water systems. A
majority of the systems are publicly
owned (60 percent of the total). As a
result, publicly owned systems will
incur a larger share of  the total costs of
the rule.
  The third measure, household costs,
is described in further detail in VI.E of
this preamble. The fourth measure,
distribution of costs across States,  is
described  in greater detail in the RIA for
today's proposed rule  (EPA, 1999h).
There is nothing to suggest that costs to
individual systems would vary
significantly from State to State, but as
expected, the States with the greatest
number of systems experience the
greatest costs.

d. Macro-Economic Effects
  As required under UMRA Section
202, EPA is required to estimate the
potential macro-economic effects of the
regulation. These  types of effects
include those on productivity, economic
growth, full employment, creation of
productive jobs, and international
competitiveness. Macro-economic
effects tend to be measurable in
nationwide econometric models only if
the economic impact of the regulation
reaches 0.25 percent to 0.5 percent of
Gross Domestic Product (GDP). In 1998.
real GDP was $7,552 billion. This
proposal would have to cost at least $18
billion to have a measurable effect. A
                     regulation of less cost is unlikely to
                     have any measurable effect unless it is
                     highly focused on a particular
                     geographic region or economic sector.
                     The macro-economic effects on the
                     national economy from LTlFBR should
                     not have a measurable effect because the
                     total annual cost of the preferred option
                     is approximately $ 97.5 million per year
                     (at a seven percent discount rate). The
                     costs are not expected to be highly
                     focused on a particular geographic
                     region or sector.
                     e. Summary of EPA's Consultation  with
                     State, Local, and Tribal Governments
                     and Their Concerns
                       Consistent with the intergovernmental
                     consultation provisions of section 204 of
                     UMRA EPA has already initiated
                     consultation with the governmental
                     entities affected by this rule.
                       EPA began outreach efforts to develop
                     the LTlFBR in the summer of 1998.
                     Two public stakeholder meetings,
                     which were announced in the Federal
                     Register, were held on July 22-23,  1998,
                     in  Lakewood, Colorado, and on March
                     3-4,  1999. in Dallas, Texas. In addition
                     to these meetings. EPA has held several
                     formal and informal meetings with
                     stakeholders including the Association
                     of State Drinking Water Administrators.
                     A summary of each meeting and
                     attendees is available in the public
                     docket for this rule. EPA also convened
                     a Small Business Advocacy Review
                     (SBAR) Panel in accordance with the
                     Regulatory Flexibility Act (RFA). as
                     amended by the Small Business
                     Regulatory Enforcement Fairness Act
                     (SBREFAjto address small entity
                     concerns including those of small local
                     governments.  The SBAR Panel allows
                     small regulated entities to provide input
                     to EPA early in the regulatory
                     development process. In early June.
                     1999. EPA mailed an informal draft of
                     the LTlFBR preamble to the
                     approximately 100 stakeholders who
                     attended one of the public stakeholder
                     meetings. Members of trade associations
                     and the SBREFA Panel also received the
                     draft preamble. EPA received valuable
                     comments and stakeholder input from
                     15  State representatives, trade
                     associations, environmental interest
                     groups, and individual stakeholders.
                     The majority of concerns dealt with
                     reducing burden on small systems and
                     maintaining flexibility. After receipt of
                     comments, EPA made every effort to
                     make modifications to address these
                     concerns.
                      To inform and involve Tribal
                     governments in the rulemaking process,
                     EPA presented the LTlFBR at three
                     venues: the 16th Annual Consumer
                     Conference of the National Indian
Health Board, the annual conference of
the National Tribal Environmental
Council, and the OGWDW/Inter Tribal
Council of Arizona. Inc. tribal
consultation meeting. Over 900
attendees representing tribes from
across the country attended the National
Indian Health Board's Consumer
Conference and over 100 tribes were
represented at the annual conference of
the National Tribal Environmental
Council. At both conferences, an
OCWDW representative conducted two
workshops on EPA's drinking water
program and upcoming regulations,
including the LTlFBR.
  At the OGWDW/Inter Tribal Council
of Arizona meeting, representatives
from 15 tribes participated. The
presentation materials and meeting
summary were sent to over 500 tribes
and tribal organizations.  Additionally,
EPA contacted each of our 12 Native
American Drinking Water State
Revolving Fund Advisors to invite
them, and representatives of their
organizations to the stakeholder
meetings described previously. A list of
tribal representatives contacted can be
found in the docket for this rule.
  The primary concern expressed by
State, local and Tribal governments is
the difficulty the smallest systems will
encounter in adequately staffing
drinking water treatment facilities to
perform the monitoring and reporting
associated with the new requirements.
Today's proposal attempts to minimize
the monitoring and reporting burden to
the greatest extent feasible and still
accomplish the rule's objective of
protecting public health. The Agency
believes the monitoring and reporting
requirements are necessary to ensure
consumers served by small systems
receive the same level of public health
protection as consumers served by large
systems. Summaries of the meetings
have been included in the public docket
for this rulemaking.

f. Regulatory Alternatives Considered

  As required under Section 205 of the
UMRA, EPA considered several
regulatory alternatives for individual
filter monitoring and disinfection
benchmarking, as well as several
alternative strategies for addressing
recycle practices. A detailed discussion
of these alternatives can be found in
Section IV and also in the RIA for
today's proposed rule (EPA, I999h).
Today's proposal also seeks comment
on several regulatory alternatives  that
EPA will consider for the final rule.

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                                                                    19133
 g. Selection of the Least Costly, Most-
 Cost Effective or Least Burdensome
 Alternative That Achieves the
 Objectives of the Rule
   As discussed previously, EPA has
 considered and requested comment on
 various regulatory options that would
 reduce Cryptosporidium occurrence in
 the finished water of surface water
 systems. The Agency believes that the
 preferred option for turbidity
 performance, disinfection
 benchmarking, and recycle management
 are the most cost effective combination
 of options to achieve the rule's
 objective; the reduction of illness and
 death from Crvptosporidium occurrence
 in the finished water of PVVSs using
 surface water. The Agency will carefully
 review comments on the proposal and
 assess suggested changes to the
 requirements.

 3, Impacts on Small Governments
  In developing this proposal, EPA
 consulted with small governments to
 address impacts of regulatory
 requirements in the rule that might
 significantly or uniquely affect small
 governments. As discussed previously, a
 variety of stakeholders, including small
 governments, were provided the
 opportunity for timely and meaningful
 participation in the regulatory
 development process through the
 SBREFA panel, public stakeholder and
 Tribal meetings. EPA used these
 processes to notify potentially affected
 small governments of regulatory
 requirements being considered and
 provided officials of affected small
 governments with an opportunity to
 have meaningful and timely input to the
 regulatory development process.
  In addition, EPA will educate, inform,
 and advise  small systems, including
 those run by small governments, about
 LTlFBR requirements. One of the most
 important components of this outreach
 effort will be the Small  Entity
 Compliance Guide, required by the
 Small Business Regulatory Enforcement
 Fairness Act of 1996. This plain-Knglish
guide will explain what actions a small
 entity must take to comply with the
 rule. Also, the Agency is developing fact
 sheets that concisely describe various
 aspects and requirements of the LTlFBR
 and detailed guidance manuals to assist
the compliance effort of PWSs and small
government entities.

D. National Technology Transfer and
 Advancement Act
  Section 12(d) of the National
Technology Transfer and Advancement
Act of 1995 (NTAA), Public Law No.
104-113, section 12(d) (15 U.S.C. 272
 iv.jle). directs EPA to use voluntary
 consensus standards in its regulatory
 activities unless to do so would be
 inconsistent with applicable law or
 otherwise impractical. Voluntary
 consensus standards are technical
 standards (e.g.. materials .specifications,
 test methods, sampling procedures,
 business, practices) that are developed or
 adopted by voluntary consensus
 standards bodies. The NTAA directs
 EPA to provide Congress, through the
 Office of Management and Budget.
 explanations when the Agency decides
 not to use available and applicable
 voluntary consensus standards.
  Today's rule requires the use of
 previously approved technical
 standards for the measurement of
 turbidity. In previous rulemakings, EPA
 approved three methods for measuring
 turbidity in drinking water. These can
 bo found in 40 CFR, Part 141.74 (a).
 Turbidity is a method-defined
 parameter and therefore modifications
 to any of the three approved methods
 requires prior EPA approval. One of the
 approved methods was published by the
 Standard Methods Committee of
 American Public Health Association.
 the American Water Works Association,
 and the Water Environment Federation,
 the latter being a voluntary consensus
 standard body- That method, Method
 2130B (APHA, 1995), is published  in
 Standard Methods for the Examination
 of Water and Wastewaler (19th ed.).
 Standard Methods is a widely used
 reference which has been  peer-reviewed
 by the scientific community. In addition
 to this voluntary consensus standard.
 EJ'A approved two additional methods
 for the measurement of turbidity. One is
 the Great Lakes Instrument Method 2,
 which can be used as an alternate test
 procedure for the measurement of
 turbidity (Great Lakes Instruments,
 1992). Second, the Agency approved
 revised EPA Method 180.1 for turbidity
 measurement in August 1993 in
 Methods for the Determination of
 Inorganic Substances in Environmental
 Samples (EPA-600/R-93-100) (EPA.
 1993).
  In 1994. EPA reviewed and rejected
 an additional technical standard, a
 voluntary consensus standard, tor the
 measurement of turbidity, the ISO 7027
 standard, an analytical method which
 measure!; turbidity at a higher
 wavelength than the approved test
 measurement standards. ISO 7027
 measures turbidity using either 90s
 scattered or transmitted light depending
 on the turbidity concentration
evaluated. Although instruments
conforming to ISO 7027 specifications
an: similar to the GLI instrument, only
the GLI instrument  uses pulsed,
 multiple detectors to simultaneously
 read both 90° scattered and transmitted
 light. EPA has no data upon which to
 evaluate whether the separate 90"
 scattered or transmitted light
 measurement evaluations, according to
 the ISO 7027 method,  would produce
 results that are equivalent to results
 produced using GLI Method 2, Standard
 Method 2130B (APHA, 1995), or EPA
 Method 180.1  (EPA, 1993).
  Today's proposed rule also requires
 continuous individual filter monitoring
 for turbidity and requires PWSs to
 calibrate the individual turbidimeter
 according to the turbidimeter
 manufacturer's instructions. These
 calibration instructions may constitute
 technical standards as that term is
 defined in the NTTAA. EPA has looked
 for voluntary consensus standards with
 regard to calibration of turbidimeters.
 The American Society for Testing and
 Materials (ASTM) is developing such
 voluntary consensus standards.
 however, there do not  appear to be any
 voluntary consensus standards available
 at this time. EPA welcomes comments
 on this aspect  of the proposed
 rulemaking and, specifically invites the
 public to identify potentially applicable
 voluntary consensus standards and to
 explain why such standards should be
 used in  this regulation.
  EPA plans to implement in the future
 a performance-based measurement
 system (PBMS) that would allow the
 option of using either performance
 criteria or reference methods in its
 drinking water regulatory programs. The
 Agency  is currently determining the
 specific steps necessary to implement
 PBMS in its programs and preparing an
 implementation plan. Final decisions
 have not yet been made concerning the
 implementation of PBMS in water
 programs. However, EPA is currently
 evaluating what relevant performance
 characteristics should be specified for
 monitoring methods used in the water
 programs under a PBMS approach to
 ensure adequate data quality. EPA
 would then specify performance
 requirements in its regulations to ensure
that any method used for determination
 of a regulated analyte is at least
equivalent to the performance achieved
by other currently approved methods.
  Once EPA has made its final
determinations regarding
implementation of PBMS in programs
under the Safe Drinking Water Act, EPA
would incorporate specific provisions of
PBMS into its regulations, which may
include specification of the performance
characteristics for measurement of
regulated contaminants in the drinking
water program regulations.

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E. Executive Order 12866: Regulatory
Planning and Review
  Under Executive Order 12866, (58 FR
51735 (October 4, 1993) the Agency
must determine whether the regulatory
action is "significant" and  therefore
subject to OMB review and the
requirements of the Executive Order.
The Order defines "significant
regulatory action" as one that is likely
to result in a rule that  may:
  1. Have an annual effect  on the
economy of $100 million or more or
adversely affect in a material way the
economy, a sector of the economy,
productivity, competition,  jobs, the
environment, public health or safety, or
State, local, tribal governments or
communities;
  2. Create a serious inconsistency or
otherwise interfere with an action taken
or planned by another agency;
  3. Materially alter the budgetary
impact of entitlement, grants, user fees,
or loan programs or the rights and
obligations of recipients thereof, or;
  4. Raise novel  legal or policy issues
arising out of legal mandates,  the
President's priorities, or the principles
set forth in the Executive Order.
  Pursuant to the terms of  Executive
Order 12866, it has been determined
that this rule is a "significant  regulatory
action." As such, this action was
submitted to OMB  for review. Changes
made in response to OMB suggestions or
recommendations will be documented
in the public record.

F. Executive Order 1289V:
Environmental Justice
  Executive Order 12H98 establishes a
Federal policy for incorporating
environmental justice into  Federal
agency missions by directing agencies to
identify and address disproportionately
high and adverse human health or
environmental effects  of its programs.
policies, and activities on minority and
low-income populations. The Agency
has considered environmental justice
related issues concerning the  potential
impacts of this action and consulted
with minority and low-income
stakeholders.
  This preamble has discussed many
times how the IKSWTR served as a
template for the development of the
LT1FBR. As such, the  Agency also built
on the efforts conducted during the
lESWTRs development to comply with
E.O.  12898. On March 12. 1998. the
Agency held a stakeholder meeting to
address various components of pending
drinking water regulations  and how
they may impact sensitive sub-
populations, minority  populations, and
low-income populations. Topics
                     discussed included treatment
                     techniques, costs and benefits, data
                     quality, health effects, and the
                     regulatory process. Participants
                     included national, State, tribal,
                     municipal, and individual stakeholders.
                     EPA conducted the meetings by video
                     conference call between eleven cities.
                     This meeting was a continuation of
                     stakeholder meetings that started in
                     1995 to obtain input on the Agency's
                     Drinking Water Programs. The major
                     objectives for the March  12. 1998
                     meeting were:
                       (1) Solicit ideas from stakeholders on
                     known issues concerning current
                     drinking water regulatory efforts;
                       (2) Identify key issues "of concern to
                     stakeholders, and:
                       (3) Receive  suggestions from
                     stakeholders concerning  ways to
                     increase representation of communities
                     in OGWDW regulatory efforts.
                       In addition. EPA developed a plain-
                     English guide specifically for this
                     meeting to assist  stakeholders in
                     understanding the multiple and
                     sometimes complex issues surrounding
                     drinking water regulation.
                       The LT1FBR applies to community
                     water systems, non-transient non-
                     community water systems, and transient
                     non-community water systems that use
                     surface Wiitor or ground water under the
                     direct influence (GVVUDI) as their
                     source water for PVVSs serving less than
                     10,000 people. The recycle provisions
                     apply to all conventional and direct
                     surface water or CWUDI  systems
                     regardless of size.
                       EPA believes this rule  will provide
                     equal health protection for all minority
                     and low-income populations served by
                     systems regulated under  this rule from
                     exposure to microbial contamination.
                     These requirements will  also be
                     consistent with the protection already
                     afforded to pt;oplt; being  served by
                     systems with larg*;r population bases.

                     G, Executive Order 23045: Protection of
                     Children from Environmental Health
                     Risks and Safety  Risks
                       Executive Order 13045: "Protection of
                     Children from Environmental Health
                     Risks and Safety  Risks" (62 FR 19885,
                     April 23. 19SI7) applies to any rule that;
                     1) is determined to be economically
                     significant as defined under E.O. 12866,
                     and; 2) concerns  an environmental
                     health or safety risk that  EPA has reason
                     to believe may have a disproportionate
                     effuct on children. If the regulatory
                     action meets both criteria, the Agency
                     must evaluate the environmental health
                     or safely effects of the planned rule on
                     children and explain why the planned
                     regulation is preferable to other
                     potentially effective and  reasonably
feasible alternatives considered by the
Agency.
  While this proposed rule is not
subject to the Executive Order because
it is not economically significant as
defined by E.O. 12866, we nonetheless
have reason to believe that the
environmental health or safety  risk
addressed by this action may have a
disproportionate effect on children.
Accordingly, EPA evaluated available
data on the health effect of
Cryptosporidium on children. The
results of this evaluation are contained
in Section II.B of this preamble and in
the LTlFBR R1A (EPA, 1999h).  A copy
of the RIA and supporting documents is
available for public review in the Office
of Water docket at 401 M St. SW,
Washington, D.C.
  The risk of illness and death  due to
cryptosporidiosis depends on several
factors, including the age, nutrition,
exposure, and the immune status of the
individual. Information on mortality
from diarrhea shows the greatest risk of
mortality occurring among the very
young and elderly (Gerba et al., 1996).
Specifically, young children are a
vulnerable population subject to
infectious diarrhea caused by
Cryptosporidium (CDC 1994).
Cryptosporidiosis is prevalent
worldwide, and its occurrence  is higher
in children than in adults (Payer and
Ungar. 1986).
  Cryptosporidiosis appears to be more
prevalent in populations that may  not
have established immunity against the
disease and may be in greater contact
with environmentally contaminated
surfaces, such as infants (DuPont, et al.,
1995). Once a child is infected  it may
spread the disease to other children or
family members. Evidence of such
secondary transmission of
cryptosporidiosis from children to
household and other close contacts has
been found in many outbreak
investigations (Casemore, 1990; Cordell
et al., 1997; Frost et al., 1997). Chapell
et al., 1999, found that prior exposure to
Crvptosporidium through the ingestion
of a low oocyst dose provides protection
from infection and illness. However, it
is not known whether this immunity is
life-long or temporary. Data also
indicate that either mothers confer short
term immunity to their children or that
babies have reduced exposure to
Crvptosporidium. resulting in a
decreased incidence of infection during
the first year of life. For example, in a
survey of over 30.000 stool sample
analyses from different UK patients, the
1-5 year age group suffered a much
higher infection rate than individuals
less than one year of age. For children
under one year of age, those older than

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                                                                     19135
 six months of age showed a higher rate
 of infection than individuals aged fewer
 than six months (Casemore, 1990).
  EPA has not been able to quantify the
 differential health effects for children as
 a result of Crvptosporidium-
 contaminated drinking water. However,
 the result of the LTlFBR will be a
 reduction in the risk of illness for the
 entire population, including children.
 Furthermore, the available anecdotal
 evidence indicates that children may be
 more vulnerable to cryptosporidiosis
 than the rest of the population. The
 LTlFBR would, therefore, result in
 greater risk reduction for children than
 for the general population.
  The public is invited to submit or
 identify peer-reviewed studies and data,
 of which EPA may not be aware, that
 assessed results of early life exposure to
 Cryptosporidium.

 H. Consultations with the Science
 Advisory Board, National Drinking
 Water Advisory Council, and the
 Secretary of Health and Human Sen-ices
  In accordance with section 1412 (d)
 and (e) of the SDWA, the Agency will
 consult with the National Drinking
 Water Advisory Council (NDWAC) and
 the Secretary of Health and Human
 Services and request comment from the
 Science Advisory Board on the
 proposed LTlFBR.
 /. Executive Order 13132: Executive
 Orders on Federalism
  Executive Order 13132, entitled
 "Federalism" (64  FR 43255, August 10,
 1999), requires EPA to develop an
 accountable process to ensure
 "meaningful and timely input by State
 and local officials in the development of
 regulatory policies that have federalism
 implications." "Policies that have
 federalism implications" is defined in
 the Executive Order to include
regulations that have "substantial direct
 effects on the States, on the relationship
between the national government and
the States, or on the distribution of
 power and responsibilities among the
 various levels of government."
  Under section 6 of Executive Order
 13132, EPA may not issue a regulation
that has federalism implications, that
 imposes substantial direct compliance
costs, and that is not required by statute.
unless the Federal government provides
the funds necessary to pay the direct
compliance costs incurred by State and
 local governments, or EPA consults  with
State and local officials early in the
process of developing the proposed
regulation. EPA also may not issue a
regulation that has federalism
implications and that preempts State
law, unless the Agency consults with
State and local officials early in the
process of developing the proposed
regulation.
  If EPA complies by consulting.
Executive Order 13132 requires EPA to
provide to the Office of Management
and Budget (OMB), in a separately
identified section of the preamble to the
final rule, a federalism summary impact
statement (FSIS). The  FSIS must include
a description of the extent of EPA's
prior consultation with State and local
officials, a summary of the nature of
their concerns and the agency's position
supporting the need to issue the
regulation, and a statement of the extent
to which the concerns of State and local
officials have been met. Also, when EPA
transmits a draft final  rule with
federalism implications to OMB for
review pursuant to Executive Order
12H66, EPA must include a certification
from the agency's Federalism Official
stating that EPA  has met the
requirements of Executive Order 13132
in a meaningful and timely manner.
  EPA has concluded  that this proposed
rule may have federalism  implications
since it may impose substantial direct
compliance costs on local governments,
and the Federal government will not
provide the funds necessary to pay
those cost. Accordingly, EPA provides
the following FSIS as required by
section 6(b) of Executive Order 13132.
  As discussed further in section
VII.C.2.e, EPA met with a  variety of
State and local representatives, who
provided meaningful and  timely input
in the development of the proposed
rule. Summaries of the meetings have
been included in the public record for
this proposed rulemaking. EPA
consulted extensively  with State, local,
and tribal governments. For example,
two public stakeholder meetings were
held on July 22-23, 1998, in Lakewood,
Colorado, and on March 3-4,1999, in
Dallas, Texas. Several  key issues were
raised by stakeholders regarding the LTl
provisions, many of which were related
to reducing burden and maintaining
flexibility. The Office of Water was able
to significantly reduce burden and
increase flexibility by tailoring
requirements to reduce monitoring.
reporting, and recordkeeping
requirements faced by small systems.
These modifications and others aided in
lowering the cost of the LTlFBR by $87
million (from $184.5 million to $97.5
million).  It should be noted that this
rule is important because it will reduce
the  level of Cryptosporidium in filtered
finished drinking water supplies
through improvements in  filtration and
recycle practices resulting in a reduced
likelihood of outbreaks of
cryptosporidiosis. The rule is also
expected to increase the level of
protection from exposure to other
pathogens (i.e., Giardia and other
waterborne bacterial or viral pathogens).
Because consultation on this proposed
rule occurred before the November 2,
1999 effective date of Executive Order
13132, EPA will initiate discussions
with State and local elected officials
regarding the implications of this rule
during the public comment period.

/. Executive Order 13084: Consultation
and Coordination With Indian Tribal
Governments
  Under Executive Order 13084,  EPA
may not issue a regulation that is not
required by statute, that significantly or
uniquely affects the communities of
Indian tribal governments, and that
imposes substantial direct compliance
costs on those communities, unless the
Federal government provides the funds
necessary to pay the direct compliance
costs incurred by the tribal governments
or EPA consults with those
governments. If EPA complies by
consulting, Executive Order 13084
requires EPA to provide to the Office of
Management and Budget, in a separately
identified section of the preamble to the
rule, a description of the extent of EPA's
prior consultation with representatives
of affected tribal governments, a
summary of the nature of their concerns,
and a statement supporting the need to
issue the regulation. In addition,
Executive Order 13084 requires EPA to
develop an effective process permitting
elected officials and other
representatives of Indian tribal
governments "to provide meaningful
and timely input in the development of
regulatory policies on matters that
significantly or uniquely affect their
communities."
  EPA has concluded that this rule may
significantly or unique affect the
communities of Indian tribal
governments. It may also impose
substantial direct compliance costs on
such communities. The Federal
government will not provide the funds
necessary to pay all the direct costs
incurred by the Tribal governments in
complying with the rule. In developing
this rule, EPA consulted with
representatives of Tribal governments
pursuant to UMRA and Executive Order
13084. EPA held extensive meetings
that provided Indian Tribal
governments the opportunity for
meaningful and timely input in the
development of the proposed rule.
Summaries of the meetings have been
included in the public docket for  this
rulemaking. EPA's consultation, the
nature of the government's concerns,
and the position supporting the need for

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this rule are discussed in Section
VII.C.2.e, which addresses compliance
with UMRA.

K. Likely Effect of Compliance with the
LTlFBR on the Technical, Financial,
and Managerial Capacity of Public
Water Systems
  Section 1420(d)(3) of the SDVVA as
amended requires that, in promulgating
a NPDWR, the Administrator shall
include an analysis of the likely effect
of compliance with the regulation on
the technical, financial, and managerial
capacity of public water systems. This
analysis can be found in the LTlFBR
R1A"(EPA, 1999h).
  Overall water system capacity is
defined in EPA guidance (EPA, 1998J) as
the ability to plan for, achieve, and
maintain compliance with applicable
drinking water standards. Capacity has
three components: technical,
managerial, and financial.
  Technical capacity is the physical and
operational ability of a water system to
meet SDWA requirements. Technical
capacity refers to the physical
infrastructure of the water system,
including the adequacy of source water
and the adequacy of treatment, storage,
and distribution infrastructure. It also
refers to the ability of system personnel
to adequately operate and maintain the
system and to otherwise  implement
requisite technical knowledge. A water
system's technical capacity can be
determined by examining key issues
and questions, including:
  • Sourer water adequacy. Does the
system have a reliable source of
drinking water? Is the source of
generally good quality and adequately
protected?
  • Infrastructure adet{wicy. Can the
system provide water that meets SDVVA
standards? What is the condition of its
infrastructure, including well(s) or
source water intakes, treatment,  storage,
arid distribution? What is the
infrastructure's life expectancy? Does
the system have a capital improvement
plan?
  • Technical knowledge and
implementation. Is the system's  operator
certified? Does the operator have
sufficient technical knowledge of
applicable standards? Can the operator
effectively implement this technical
knowledge? Does the operator
understand the system's technical and
operational characteristics? Does the
system have an effective operation and
maintenance program?
  Managerial capacity is the ability of a
water system to  conduct  its affairs to
achieve and maintain compliance with
SDWA requirements. Managerial
capacity refers to the system's
                     institutional and administrative
                     capabilities. Managerial capacity can be
                     assessed through key issues and
                     questions, including:
                       •  Ownership accountability. Are the
                     system owner(s) clearly identified? Can
                     they be held accountable for the system?
                       •  Staffing and organization. Are the
                     system operator(s) and manager(s)
                     clearly identified? Is the system
                     properly organized and staffed? Do
                     personnel understand the management
                     aspects of regulatory requirements and
                     system operations? Do they have
                     adequate expertise to manage water
                     system operations? Do personnel have
                     the necessary licenses and
                     certifications?
                       •  Effective external linkages. Does the
                     system interact well with customers,
                     regulators, and other entities? Is the
                     system aware of available external
                     resources, such as technical and
                     financial assistance?
                       Financial capacity is a water system's
                     ability to acquire and manage sufficient
                     financial resources to allow the system
                     to achieve and maintain compliance
                     with SDVVA requirements. Financial
                     capacity can be assessed through key
                     issues and questions, including:
                       •  Revenue sufficiency. Do revenues
                     cover costs? Are water rates and charges
                     adequate to covor the cost of water?
                       •  Credit worthiness. Is the system
                     financially healthy? Does it have access
                     to capital through public or private
                     sources?
                       •  Fiscal management and controls.
                     Are adequate books and records
                     maintained? Are appropriate budgeting.
                     accounting, and financial planning
                     methods used? Does the system manage
                     its revenues effectively?
                       Systems not making significant
                     modifications to the treatment process
                     to meet LTlFBR requirements are not
                     expected to require significantly
                     increased technical, financial, or
                     managerial capacity.

                     L. Plain Language
                       Executive Order 12866 and the
                     President's memorandum of June 1,
                     1998, require each agency to write its
                     rules in plain language. We invite your
                     comments on how to make this
                     proposed rule easier to understand. For
                     example: Have we organized the
                     material  to suit your needs? Are the
                     requirements in the rule clearly stated?
                     Does the rule contain technical language
                     or jargon that is not clear? Would a
                     different format (grouping and order of
                     sections, use of headings, paragraphing)
                     make the rule easier to understand?
                     Would shorter sections make the final
                     rule easier to understand? Could we
                     improve clarity by adding tables, lists,
or diagrams? What else could we do to
make the rule easier to understand?
VIII. Public Comment Procedures
  EPA invites you to provide your
views on this proposal, approaches we
have not considered, the potential
impacts of the various options
(including possible unintended
consequences), and any data or
information that you would like the
Agency to consider.  Many of the
sections within today's proposed rule
contain "Request for Comment"
portions which the Agency is also
interested in receiving comment on.
A. Deadlines for Comment
  Send your comments on or before
June 9, 2000. Comments received after
this date may not be considered in
decision  making on the proposed rule.
Again, comments must be received or
post-marked by midnight June 9, 2000.

B. Where To Send Comment
  Send an original and 3 copies of your
comments and enclosures (including
references) to W-99-10 Comment Clerk,
Water Docket (MC4101),  USEPA, 401 M,
Washington, D.C. 20460. Comments
may also be submitted electronically to
ow-docket@epamai!.epa.gov. Electronic
comments must be submitted as an
ASCII, WP5.1, WP6.1 or WP8 file
avoiding the use of special characters
and form of encryption. Electronic
comments must be identified by the
docket number W-99-10. Comments
and data  will also be accepted on disks
in WP 5.1, 6.1, 8 or ASCII file format.
Electronic comments on this notice may
be filed online at many Federal
Depository Libraries. Those who
comment and want EPA to acknowledge
receipt of their comments must enclose
a self-addressed stamped envelope. No
facsimiles (faxes) will be accepted.
Comments may also be submitted
electronically to ow-
docket@epamail.epa.gov.

C. Guidelines for Commenting
  To ensure that EPA can read,
understand and therefore properly
respond to comments, the Agency
would prefer that commenters cite,
where possible, the paragraph(s) or
sections in the notice or supporting
documents to which each comment
refers. Commenters should use a
separate paragraph for each  issue
discussed. Note that the Agency is not
soliciting comment on, nor will it
respond to, comments on previously
published regulatory language that is
included in this notice to ease the
reader's understanding of proposed
language. You may find the following

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                    Federal  Register/Vol.  65, No. 69/Monday, April  10,  2000/Proposed Rules
                                                                           19137
suggestions helpful for preparing your
comments:
   1. Explain your views as clearly as
possible.
   2. Describe any assumptions that you
used.
   3. Provide solid technical information
and/or data to support your views.
   4. If you estimate potential burden or
costs, explain how you arrived at the
estimate.
   5. Indicate what you support, as well
as what you disagree with.
   6. Provide specific examples to
illustrate your concerns.
   7. Make sure to submit your
comments by the deadline in this
proposed rule.
   8. At the beginning of your comments
(e.g., as part of the "Subject" heading),
be sure to properly identify the
document you are commenting on. You
can do  this by providing the docket
control number assigned to the
proposed rule, along with  the name,
date, and Federal Register citation.
DC, References
Adham, S., Gagliado, P., Smith, D., Ross. D .
    Gramith, K., and Trussell, R. 1998.
    Monitoring of Reverse Osmosis for Virus
    Rejection, Proceedings Water Quality
    and Technology Conference. 9pp.
Alvarez, M., Bellamy, B., Rose, J., Gibson, C,
    and Mitskevich, G. 1999.
    Ctyptosporidium Removal Using a
    Pulsating Blanket Clarifier, Microsand
    Ballated Clarifier, and Dissolved Air
    Floatation in Treatment of a Highly
    Colored Florida Surface Water: A Pilot
    Study. Proceedings Water Quality and
    Technology Conference, 7pp.
American Society of Civil Engineers (ASCE)
    and American Water Works Association
    (AWVVA). 1998. Chapter 8, High-Rate
    Granular Media Filtration Water
    Treatment Plant Design. McGraw Hill,
    New York, 23pp.
American Water Works Association
    Committee Report. 1983.  Deterioration of
    water quality in large distribution
    reservoirs (open reservoirs). AWWA
    Committee on Control of  Water Quality
    in Transmission and Distribution
    Systems. J. AWWA. June  1983, 313-318.
American Water Works Association.  1991.
    Guidance Manual for Compliance With
    the  Filtration and Disinfection
    Requirements for Public Water Systems
    Using Surface Water Sources.  AWWA.
    Denver, 73pp.
American Water Works Association.  1998.
    Spent Filter Backwash Water Survey.
Amirtharajah, A.  1988. Some  theoretical and
    conceptual views of filtration. J. AWWA.
    (80:12: 36-46)
APHA. 1995. 19th Edition of Standard
    Methods for the Examination of Water
    and Wastewater, 1995. American Public
    Health Association. 1015  15th Street
    NW, Washington DC 20005. (Includes
    method 2130A, B).
Archer, J., Ball, J., Standridge,)., Greb, S.,
    Rasmussen, P., Masterson, J., and
    Boiishon, L. 1095. Cryptosporidium spp.
    oocyats and Giardia spp. cyst
    occurrence, concentrations, and
    distribution in Wisconsin waters.
    Wisconsin Department of Natural
    Resources (PUBL-WR420-95:August),
    96pp.
Atherhott, T., LeChevallier, M., Norton, W.,
    and Rosen. J. 1998. Effect of rainfall on
    Giardia and crypto. J.AWWA (90:9:66-
    80).
Bailey, S., and Lippy, E. 1978. Should all
    finished water reservoirs be covered.
    Public Works. April 1978, 66-70.
Baudin. I., and Lame, J, 1998. Assessment
    and Optimization of Clarification Process
    for Cryptosporidium Removal.
    Proceedings of AWWA Water Quality
    and Technology Conference, Spp.
Bellamy, W., Cleasby,)., Logsdon, G., and
    Allen, M. 1993. Assessing Treatment
    Plant Performance. J. AWWA (85:12:34-
    38).
Bennett, J., Holmberg. S., Rogers. M., and
    Solomon, S. 1987. Infectious and
    parasitic diseases. Am. J. Prev. Med.
    3:102-114. In: R.W. Amler and H.B. Dull
    (Eds.), closing the gap: the burden of
    unnecessary illness. Oxford University
    Press (112-114).
Bucklin. K.. Amirtharajah, A., and Cranston,
    K. 1988. The characteristics of initial
    effluent quality and its implications for
    the filter-to-waste procedure. AWWARF.
    Denver, ISflpp.
Campbell, S.. Lykins. B., Goodrich. J., Post.
    D., and Lay", T. 1995. "Package Plants for
    Small Systems: A Field Study," J.
    AWWA. (82:11:39-47).
Casemore, D. 1990. Epidemiological aspects
    of human cryptosporidiosis. Epidemic].
    Infect. (104:1-28).
CDC 1998. CDC Morbidity and Mortality
    Weekly Report. Surveillance for
    Waterbome-Disease Outbreaks—United
    States, 1995-1996. December 11. 1998
    Vol: 47. No. SS-5. US Department of
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                       Perz, J., Ennever, K., and Le  Blancq, S. 1998.
                           "Cryptosporidium in tap water;
                           Comparison of predicted risks with
                           observed levels of disease." Amer. ).
                           Epidem. (147:289-301).
                       Petersen, C. 1992. Cryptosporidiosis in
                           patients infected with the human
                           immunodeficiency virus. Clin. Infect.
                           Dis. (15:903-909).'
                       Pieniazek, N., Bornag-Uinaes, F., Slemenda.
                           S., daSilva, A., Moura, I., Arrowood, M.,
                           Ditrich, O. and Addiss.  D. New
                           Cryplosporidium Genotypes in HIV-
                           Infected Persons. 1999.  Emerging
                           Infectious Diseases. May-June 5:3: 444-
                           449.
                       Plummer, J., Edzwald, J., and Kelley, M.
                           1995. Removing Cryptosporidium by
                           dissolved-air floatation. J. AWWA
                           (87:9:85-95).
                       Pluntze. J. 1974. Health aspects of uncovered
                           reservoirs. Journal AWWA. August 1974,
                           pgs 432-437.
                       Randtke, S. 1999. Letter to Sarah Clark. City
                           of Austin Water and Wastewater Utility,
                           dated |une 28, 1999. Provided as
                           informal comment to EPA by AWWA.
                       Robeck, G., Dostal, K., and Woodward, R.
                           1964. Studies of Modification in Water
                           Filtration. J. AWWA (56:2:198-213).
                       Rose, J., Cifrino, A., Madore, M., Gerba. C.,
                           Sterling, C., and Arrowood, M. 1986.
                           Detection of Cryptosporidium from
                           Wastewater and Freshwater
                           Environments.  Wat. Sci. Tec. (18:10:233-
                           239).
                       Rose. J. 1988. Occurrence and significance of
                           Cryptosporidium in water. J. AWWA
                           (80:2:53-58).
                       Rose, J., Darbin, H., and Gerba, C. 1988a.
                           Correlations of the protozoa
                           Cryptosporidium and Giardia with water
                           quality variables in a watershed. Proc.
                           Int. Conf. Water Wastewater Microbial.
                           Newport Beach, CA.
                       Rose. J.. Kayed. D.. Madore,  M., Gerba, C,
                           Arrowood, M., and Sterling. C. 1988b.
                           Methods for the recovery of Giardia and
                           Cryptosporidium from environmental
                           waters and their comparative occurrence.
                           In: P.Wallis and B. Hammond, eds.
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                           Canada:  University of Calgary Press.
                       Rose. J., Gerba, C., and Jakubowski. W. 1991.
                           Survey of potable water supplies for
                           Cryptosporidium and Giardia. Environ.
                           Sci. and Technol. (25:8:1393-1400).
                       Rose, J. 1997. Environmental ecology of
                           Cryptosporidium and public health
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                           (18:135-161).
                       Rosen.).. LeChevallier, M., and Roberson, A.
                           1996. Development and Analysis of a
                           National Protozoa Database, 15pp.
                       SA1C. 1997a. Microscopic Particulate
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    Giardia and Cryplnsporidiuui
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Schuler, P., and Gosh, M. 1991. Slow Sand
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Solo-Gabriele, H., and Neumeister. S. 1996.
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    Jacangelo, J., and Braghetia, A. 1998.

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                   Federal  Register/Vol.  65, No.  69/Monday,  April 10, 2000/Proposed Rules
                                                                       19141
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    184pp.

List of Subjects

40 CFR Part 141

  Environmental protection, Chemicals,
Indians-lands, Intergovernmental
relations, Radiation protection,
Reporting and recordkeeping
requirements, Water supply.

40 CFR Part 142

  Environmental protection,
Administrative practice and procedure,
Chemicals, Indians-lands, Radiation
protection, Reporting  and recordkeeping
requirements, Water supply.
  Dated: March 27, 2000.
Carol M. Browner,
Administrator.

  For the reasons set forth in the
preamble, title 40 chapter I of the Code
of Federal Regulations is proposed to be
amended as follows:
PART 141—NATIONAL PRIMARY
DRINKING WATER REGULATIONS

  3. The authority citation for part 141
continues to read as follows:
  Authority: 42 U.S.C. 300f, :(00g-l. :iOOg-2.
300g-3. 300|j>-4, 30Ug-5, 300g-6, 30UJ-4,
30UJ-9, and 300J-11.
  4. Section 141.2 is amended by
revising the definition of "Ground water
under the direct influence of surface
water" and "Disinfection profile" and
adding the following definitions in
alphabetical order to read as follows:

§141.2  Definitions.
*****
  Direct recycle is the return of recycle
flow within the treatment process of a
public water system without first
passing the recycle flow through a
treatment process designed to remove
solids, a raw water storage reservoir, or
some other structure with a volume
equal to or greater than the volume of
spent filter backwash water produced by
one filter backwash event.
*****
  Disinfection profile is a summary of
Ciardia lamblia mactivation through the
treatment plant, from the point  of
disinfectant application to the first
customer. The procedure for developing
a disinfection profile is contained in
§ 141,172 (Disinfection profiling and
benchmarking) in subpart P and
§S 141.530-141.536 (Disinfection
profile) in subpart T of this part.
*****
  Equalization is the detention  of
recycle flow in a structure with a
volume equal to or greater than  the
volume of spent filter back wash
produced by one filter backwash event.
*****
  Ground water under the direct
influence of surface water (GWUDI)
means any water beneath the surface of
the ground with significant occurrence
of insects or other macroorganisms,
algae, or large-diameter pathogens such
as Giardia lamblia or Cryptosporidium,
or significant and relatively rapid shifts
in water characteristics such as
turbidity, temperature, conductivity, or
pH  which closely correlate to
chmatological or surface water
conditions. Direct influence must be
determined for individual sources in
accordance with criteria established by
the State. The  State determination of
direct influence may be based on site-
specific measurements of water quality
and/or documentation of well
construction characteristics and geology
with field evaluation.
  Membrane Filtration means any
filtration process using tubular or spiral
wound elements that exhibits the ability
to mechanically separate water from
other ions and solids by creating a
pressure differential and flow across a
membrane with an absolute pore size <1
micron.
*****
  Operating capacity is the maximum
finished water production rate approved
by the State drinking water program.
*****
  Recycle is the return of any water,
solid, or semisolid generated by plant
treatment processes, operational
processes, maintenance processes, and
residuals treatment processes into a
PWS's primary treatment processes.
*****
  5. Section 141.32 is amended by
revising paragraph (e)(10) to read as
follows:

§ 141.32  Public notification.
*****
  (e) *   *  *
  (10) Microbiological contaminants (for
use when there is a violation of the
treatment technique requirements for
filtration and disinfection in subpart  H,
subpart P, or subpart T of this part). The
United States Environmental Protection
Agency (EPA) sets drinking water
standards and has determined that the
presence of microbiological
contaminants are a health concern at
certain levels of exposure, if water is
inadequately treated, microbiological
contaminants in that water may cause
disease. Disease symptoms may include
diarrhea, cramps, nausea, and possibly
jaundice, and any associated headaches
and fatigue. These symptoms, however,
are not just associated with disease-
causing organisms in drinking water,
but also may be caused by a number of
factors other than your drinking water.
EPA has set enforceable requirements
for treating drinking water to reduce the
risk of these adverse health effects.
Treatment such as filtering and
disinfecting the water removes or
destroys microbiological contaminants.
Drinking water which is treated to meet
EPA requirements is associated with
little to  none of this risk and should be
considered safe.
*****
  6. Section 141.70 is amended by
revising paragraph (b)(2) and adding
paragraph (e) to read as  follows:

§141.70   General requirements.
*****
  (b) ,   *  *
  (2) It meets the  filtration requirements
in § 141.73, the disinfection

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19142
Federal  Register/Vol.  65.  No. 69 /Monday. April 10,  2000/Proposed Rules
requirements in § 141.72(b) and the
recycle requirements in § 141.7C.
*    *    *    *    *
  (e) Additional requirements for
systems serving fewer than "10,000
people. In addition to complying with
requirements in this subpart. systems
serving fewer than 10,000 people must
also comply with  the requirements in
subpart T of this part.
  7. Section 141.73 is amended by
adding paragraph (a)(4) and revising
paragraph (d) to re;id as follows:

§141.73   Filtration.
*    *    *    *    *
  (a) • *  *
  (4) Beginning (DATE 36 MONTHS
AFTER DATE OF PUBLICATION OF
FINAL RULE IN THE FEDERAL
REGISTER], systems  serving fewer than
10.000 people must meet the turbidity
                     requirements in §§ 141.550 through
                     141.553.
                     *****
                       (d) Other filtration technologies. A
                     public water system may use a filtration
                     technology not listed in paragraphs (a)
                     through (c) of this section if it
                     demonstrates to the State, using pilot
                     plant studies or other means, that the
                     alternative filtration technology, in
                     combination with disinfection treatment
                     that meets the requirements of
                     § 141.72{b), consistently achieves 99.9
                     percent removal and/or inactivation of
                     Ciardia Iambiiu cysts and 99.9G percent
                     removal and/or inactivation of viruses.
                     For a system that makes this
                     demonstration, the requirements of
                     paragraph (b) of this section apply.
                     Beginning December 17, 2001, systems
                     serving at least 10,000 people must meet
                     the requirements for other filtration
technologies in paragraph (b) of this
section. Beginning [DATE 36 MONTHS
AFTER DATE OF PUBLICATION OF
FINAL RULE IN THE FEDERAL
REGISTER], systems serving fewer than
10.000 people must meet the
requirements for treatment technologies
in §§ 141.550 throughl41.553.
  8. Subpart H is amended by adding a
new § 141.76 to subpart H to read as
follows:

§141.76  Recycle Provisions.
  (a) Public water systems employing
conventional filtration or direct
filtration that use surface water or
ground water under the direct influence
of surface water and recycle within the
treatment process must meet all
applicable requirements of this section.
Requirements are summarized in the
following table.
                                   RECYCLE PROVISIONS FOR SUBPART H SYSTEMS
                          If you are a
                                                     You are required to meet the requirements in .
(1) subpart H public water system employing conventional or direct filtration re-  §141.76 (b).
  turning spent filter backwash, thickener supernatant, or liquids from dewatering
  processes concurrent with or downstream of the point of primary coagulant ad-
  dition.
(2) Plant that is part of a subpart H public water system, employ conventional fil-  § 141.76 (c).
  tration treatment, practice direct recycle, employ 20 or fewer filters to meet pro-
  duction requirements during the highest production month in the 12 month pe-
  riod [date 60  months  after publication of final rule], and recycle spent filer
  backwash or thickener supernatant to the treatment process.
(3) subpart H public water system practicing direct filtration and recycling to the  § 141.76 (d)
  treatment process.                                                  |
  (b) Recycle return location. All
subpart H systems employing
conventional filtration or direct
filtration and returning spent filter
backwash, thickener supernatant, or
liquids from dewatering processes at or
after the point of primary coagulant
addition must return these recycle flows
prior to the point of primary coagulant
addition by [DATE 60 MONTHS AFTER
DATE OF PUBLICATION OF FINAL
RULE IN THE FEDERAL REGISTER],
The system must apply to the State for
approval of the change in recycle
location before the system implements
it.
  (1) All subpart H systems employing
conventional filtration or direct
filtration,  returning spent filter
backwash, thickener supernatant, or
liquids from dewatering processes at or
after the point of primary coagulant
addition must submit  a plant schematic
to the State by [DATE  42 MONTHS
AFTER DATE OF PUBLICATION OF
FINAL RULE IN THE FEDERAL
REGISTER] showing the current recycle
return location(s) for the recycle
stream(s) and the new return location
                     that will be used to establish
                     compliance. The system must keep the
                     plant schematic on file for review
                     during sanitary surveys.
                       (2) Softening systems may recycle
                     process solids at the point of lirne
                     addition preceding the softening process
                     to improve treatment efficiency. Process
                     solids may not be returned prior to the
                     point of lime addition. Softening
                     systems shall not return spent filter
                     backwash, thickener supernatant, or
                     liquids from dewatering processes to a
                     location other than prior to the point of
                     primary coagulant addition  unless an
                     alternate location is granted by the
                     State.
                       (3) Contact clarification systems may
                     recycle process solids directly into the
                     contactor. Contact clarification systems
                     shall not return spent filter backwash,
                     thickener supernatant, or  liquids from
                     duwatering processes to a  location other
                     than prior to the  point of primary
                     coagulant addition unless an alternate
                     location is granted by the  State.
                       [4) Systems may apply to  the  State to
                     return spent filter backwash, thickener
                     supernatant, or liquids from dewatering
processes to an alternate location other
than prior to the point of primary
coagulant addition.
  (c) Plants that are part of subpart H
public water systems that employ
conventional rapid granular filtration,
practice direct recycle, employ 20 or
fewer fitters to meet production
requirements during the highest
production month in the 12 month
period prior to [DATE 60 MONTHS
AFTER PUBLICATION OF FINAL RULE
IN THE Federal Register), and recycle
spent filter backwash or  thickener
supernatant  to the primary treatment
process shall complete a recycle self
assessment,  as stipulated in
paragraphs(c)(l) and (c)(2) by [Date 51
Months After Date of Publication of
Final Rule in the Federal Register].
Systems required to perform the self
assessment shall:
  (1) Submit a recycle self assessment
monitoring plan to the State no later
than [Date 39 Months After Date of
Publication of Final Rule in the Federal
Register). At a minimum, the
monitoring plan must identify the
highest water production month during

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                  Federal  Register/Vol, 65, No.  69/Monday, April 10, 2000/Proposed Rules
                                                                    19143
which monitoring will be conducted.
contain a schematic identifying the
location of raw and recycle flow
monitoring devices, describe the type of
flow monitoring devices to be used.
identify the system's State approved
operating capacity, and describe how
data from the raw and recycle flow
monitoring devices will be
simultaneously retrieved and recorded.
  (2) Implement the following recycle
self assessment monitoring and analysis
steps:
  (i) Steps for Implementation of
Recycle Self Assessment:
  (A) Identify the highest water
production month during the 12 month
period preceding [Date 36 Months After
Date of Publication of Final Rule in the
Federal Register],
  (B) Perform the monitoring described
in paragraph (c)(2)(i)(C) of this section
during the 12 month period after
submission of the monitoring plan  to
the State. The twelve month period
must begin no later than [Date 39
Months After Date of Publication of
Final Rule in  the Federal Register].
  (C) For each day of the month
identified in paragraph (c)(2)(i)(A) of
this section, separately monitor sovirce
water influent flow and recycle flow
before their confluence during one  filter
backwash recycle event per day, at  three
minute intervals during the duration of
the event. Monitoring must be
performed between 7:00 a.m. and 8:00
p.m. Systems that do not have a filter
backwash recycle event every day
between 7:00 am and 8:00 p.m. must
monitor one filter backwash recycle
event per day, any three days of the
week, for each week during the month
of monitoring, between 7:00 a.m. and
8:00 p.m. Record the time filter
backwash was initiated, the influent and
recycle flow at three minute intervals
during the duration of the event, and the
time the filter backwash recycle event
ended. Record the number of filters in
use when the filter backwash recycle
event is monitored.
  (D) Calculate the arithmetic average of
all influent and recycle flow values
taken at three minute intervals in
paragraph (c)(2)(i)(c) of this section.
Sum the arithmetic average calculated
for raw water influent and recycle flows.
Record this value and the  date the
monitoring was performed. This value is
referred to as event flow.
  (E) After the month of monitoring is
complete, order the event flows in a list
of increasing order, from lowest to
highest. Highlight the event flows that
exceed State approved operating
capacity and then sum the number  of
event flows highlighted.
  (ii) [Reserved]
  (3) Subpart H systems performing
recycle self assessments are required to
report  the results of the self assessment
and supporting documentation to the
State within one month of completing
raw water influent and recycle flow
monitoring. The report must be
submitted no later than [DATE 52
MONTHS AFTER DATE OF
PUBLICATION OF FINAL, RULE IN
THE FEDERAL REGISTER]. If the State
determines the self assessment is
incomplete or inaccurate, it may require
the system to correct deficiencies or
perform an additional self assessment.
At a minimum, the report must contain
the following information:
  (i) Minimum Information Included in
Recycle Assessment Report to State:
  (A) All source and recycle flow
measurements taken and the dates they
were taken. For all events monitored,
report the times the filter backwash
recycle event was initiated, the flow
measurements taken at three minute
intervals, and the time the filter
backwash recycle event ended. Report
the number of fillers in use when the
backwash recycle event is monitored.
  (B) All data used and calculations
performed to determine whether the
system exceeded operating capacity
during monitored recycle events and the
number of event flow values that
exceeded State approved operating
capacity.
  (C) A plant schematic showing the
origin of all recycle flows, the hydraulic
conveyance used to transport them, and
their final destination in the plant.
  (D) A list of all the recycle flows and
the frequency at which they are
returned to the plant's primary
treatment process.
  (E) Average and maximum backwash
flow rate through the filters and the
average and maximum duration of the
filter backwash process, in minutes.
  (F) Typical filter run length and a
written summary of how filter run
length  is determined (preset run time,
headless, turbidity breakthrough, etc.).
  (ii) [Reserved]
  (4) All subpart H systems performing
self assessments are required to modify
their recycle practice in accordance
with the State determination by [DATE
60 MONTHS AFTER DATE OF
PUBLICATION OF FINAL RULE IN
THE FEDERAL REGISTER] and keep a
copy of the self assessment report
submitted to the State on file for review
during sanitary surveys.
  (d) Subpart H public water systems
practicing direct filtration and recycling
to the primary treatment process are
required to submit data to the State on
their current recycle treatment no later
than [DATE 42 MONTHS AFTER DATE
OF PUBLICATION OF FINAL RULE IN
THE FEDERAL REGISTER.]
  (1) Direct filtration systems
submitting data to the State shall report
the following information, at a
minimum:
  (i) Data Submitted to States by Direct
Filtration Systems:
  (A) A plant schematic showing the
origin of all recycle flows, the hydraulic
conveyance used to transport them, and
their final destination in the plant.
  (B) The number of filters used at the
plant to meet average daily production
requirements and average and
maximum backwash flow rate through
the filter and the average and maximum
duration of the filter backwash process,
in minutes.
  (C) Whether recycle flow treatment or
equalization is in place.
  (D) The type of treatment provided for
the recycle flow.
  (E) For recycle equalization and
treatment units: data on the physical
dimensions of the unit (length, width
(or circumference), depth,) sufficient to
allow calculation of volume; typical and
maximum hydraulic loading rate; type
of treatment  chemicals used and average
dose and frequency of use, and
frequency at which solids are removed
from the unit, if applicable.
  (ii) [Reserved]
  (2) All direct filtration systems
submitting data to the State are required
to modify their recycle practice in
accordance with the State determination
no later than [DATE 60 MONTHS
AFTER DATE OF PUBLICATION OF
FINAL RULE IN THE FEDERAL
REGISTER] and keep a copy of the
report submitted  to the State on file for
review during sanitary surveys.
  9. Section  141.153 is amended by
revising the first sentence of paragraph
(d)(4)(v)(C) to read as follows:

§ 1 41 .1 53 Content of the reports.
  M* * *
  (C) When it is reported pursuant to
§141.73 or §141.173 or §141. 551: the
highest single measurement and the
lowest monthly percentage of samples
meeting the turbidity limits specified in
§ 141.73 or § 141.173, or § 141.551 for
the filtration technology being used.
  10. The heading to Subpart P is
revised as follows:

Subpart P—Enhanced Filtration and
Disinfection-Systems Serving 10,000
or More People
                                                                                                                             I

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19144
Federal Register/Vol. 65,  No. 69/Monday,  April 10,  2000/Proposed  Rules
  11. Section 141.170 is amended by
adding paragraph (d) to read as follows:

§141.170  General requirements.
*     *     *     *     *
  (d) Subpart H systems that did not
conduct applicability monitoring under
§ 141.172 because they served fewer
than 10,000 persons when such
monitoring was required but serve more
than 10,000 persons prior to [DATE 36
MONTHS AFTER DATE OF
PUBLICATION OF FINAL RULE IN
THE FEDERAL REGISTER] must
comply with §§141.170, 141.171.
141.173, 141.174, and 141.175. These
systems must also consult with the State
to establish a disinfection benchmark. A
system that decides to make a
significant change to its disinfection
practice, as described in
§141.172(c)(l)(i) through (iv) must
consult with the State prior to making
such change.
*     *     *     *     *
  12. Part 141 is amended by adding a
new subpart T to read as follows:

Subpart T—Enhanced Filtration and
Disinfection—Systems Serving  Fewer
than 10,000 People

Sec.
General Requirements
141.500  General requirements.
141.501  Who is subject tti the requirements
    of subpart T?
141.502  When must my system comply
    with these requirements?
141.503  What does subpart T require?
Finished Water Reservoirs
141.510  Is my system subject to the new
    finished water reservoir requirements?
141.511  What is required of new finished
    water reservoirs?
Additional Watershed Control Requirements
141.520  Is my system subject to the updated
    watershed control requirements?
141.521  What updated watershed control
    requirements must my system comply
    with?
141.522  How does the State  determine
    whether my system's watershed control
    requirements are  adequate?
Disinfection Profile
141.Sao  Who must develop a Disinfection
    Profile and what is a Disinfection
    Profile?
141.531  How does my system demonstrate
    TTHM and HAAS "levels below 0.064
    rm>/l and G.O48 mg/1 respectively?
141.532  How does my system develop a
    Disinfection Profile tint! when must it
    bejjin?
I41.5:i:i  What measurements must my
   system collect to calculate a Disinfection
    Profile?
141.534  How doi.'S my system use these
   measurements to  calculate an
   inactivation ratio?
                      141.5:15  How does my system develop a
                         Disinfection Profile if we use
                         chloramines. ozone, or chlorine dioxide
                         for primary disinfection?
                      141.5315  If my system has developed an
                         inactivation ratio; what must we do
                         now?
                      Disinfection Benchmark
                      141.540  Who has to develop a Disinfection
                         Benchmark?
                      141.541  What are significant changes to
                         disinfection practice?
                      141.542  How is the Disinfection Benchmark
                         calculated?
                      141.543  What if my system uses
                         chloramines or ozone for primary
                         disinfection?
                      141.544  What must my system do if
                         considering a significant  change to
                         disinfection practices?
                      Combined Filter Effluent Requirements
                      141.550  Is rny system required to meet
                         subpart T combined filter effluent
                         turbidity limits?
                      141.551  What strengthened combined filter
                         effluent turbidity limits must my system
                         meet?
                      141.552  If my system consists of
                         "alternative filtration" and is required to
                         conduct a demonstration, what is
                         required uf my system and how does the
                         State establish my turbidity limits?
                      141.553  If my system practices lime
                         softening, is there anv special provision
                         regarding my combined filter effluent?
                      Individual Filter Turbidity Requirements
                      141.500  Is my system subject to individual
                         filler turbidity requirements?
                      141.5!il  What happens if my turbidity
                         monitoring equipment fails?
                      141.5B2  What follow-up action is my
                         system required to take based on
                         turbidity monitoring of individual
                         filters?
                      141.503  My system practices lime
                         softening. Is there any special provision
                         regarding my individual filter turbidity
                         monitoring?
                      Reporting and Recordkeeping Requirements
                      142.570  What does subpart T require that
                         my system report to the State?
                      142.571   What records does suhp.irt T
                         require my system to keep?

                      Subpart T—Enhanced Filtration and
                      Disinfection—Systems Serving Fewer Than
                      10,000 People

                      General Requirements

                      §141.500  General requirements.
                       The requirements of subpart T
                      constitute national primary drinking
                      water regulations. These regulations
                      establish requirements for  filtration and
                      disinfection that are in addition to
                      criteria under which filtration nnd
                      disinfection are required under subpart
                      H of this part. The regulations in this
                      subpart establish or extend treatment
                      technique requirements in lieu of
                      maximum contaminant levels for the
                      following contaminants: Giardia
lamblia, viruses, heterotrophic plate
count bacteria, Legionella,
Cryptasporidium and turbidity. The
treatment technique requirements
consist of installing and properly
operating water treatment processes
which reliably achieve:
  (a) At least 99 percent (2 log) removal
of Cryptosporidium between a point
where the raw water is not subject to
recontamination by surface water runoff
and a point downstream before or at the
first customer for filtered systems, or
Crvptosporidium control under the
watershed control plan for unfiltered
systems.
  (b) Compliance with the profiling and
benchmark requirements in §§ 141.530
through 141.544.

§ 141.501  Who is subject to the
requirements of subpart T?
  You are subject to these requirements
if your system:
  (a) Is a public water system;
  (b) Uses  surface water or GWUDI as a
source; and
  (c) LServes fewer than 10.000 persons
annually.

§ 141.502  When must my system comply
with these requirements?
  You must comply with these
requirements beginning |DATE 36
MONTHS AFTER DATE OF
PUBLICATION OF FINAL RULE IN
THE FEDERAL REGISTER] except
where otherwise noted.

§141.503  What does subpart T require?
  There are six requirements of this
subpart which your system may need to
comply with. These requirements are
discussed in detail  later in this subpart.
They are;
  (a) Any finished water reservoir for
which construction begins on or after
[DATE 60 DAYS AFTER DATE OF
PUBLICATION OF  FINAL RULE IN
THE FEDERAL REGISTER] must be
covered;
  (b) Unfiltered systems must comply
with updated watershed control
requirements;
  (c) All systems subject to the
requirements of this subpart must
develop a disinfection profile;
  (d) All systems subject to the
requirements of this subpart that are
considering a significant change to their
disinfection practice must develop a
disinfection benchmark and receive
State approval before changing their
disinfection practice;
  (c) Filtered systems must comply with
specific combined filter effluent
turbidity limits and monitoring and
reporting requirements; ami
  (f) Filtered systems using
conventional or direct filtration must

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                                                                     19145
comply with individual filter turbidity
limits and monitoring and reporting
requirements.
Finished Water Reservoirs

§ 141.510 Is my system subject to the new
finished water reservoir requirements?
  All subpart H systems which serve
populations fewer than 10,000 are
subject to this requirement.

§141.511 What is requi red for new
finished water reservoirs?
  If your system  initiates construction
of a finished water reservoir after [DATE
60 DAYS AFTER DATE OF
PUBLICATION OF FINAL RULE IN
THE FEDERAL REGISTER the reservoir
must be covered. Finished water
reservoirs constructed prior to (DATE 60
DAYS AFTER DATE OF PUBLICATION
OF FINAL RULE IN THE FEDERAL
REGISTER are not subject to this
requirement.
Additional Watershed Control
Requirements

§ 141.520 Is my system subject to the
updated watershed control requirements?
  If you are a subpart H system serving
fewer than 10,000 persons which does
not provide filtration,  you must
continue to comply with all of the
watershed control requirements  in
§ 141.71, as well  as the additional
watershed control requirements  in
§141.521.

§ 141.521 What additional watershed
control requirements must my system
comply with?
  Your system must also maintain the
existing watershed control program to
minimize the potential for
contamination by Cryptosporidium
oocysts  in the source water. Your
system's watershed control program
must, for Cryptosporidium:
  (a) Identify watershed characteristics
and activities which may have an
adverse effect on source water quality;
and
  (b) Monitor the occurrence of
activities which may have an adverse
effect on source water  quality.

§ 141.522 How does the State determine
whether my system's watershed control
requirements are adequate?
  During an onsite inspection
conducted under the provisions  of
§ I41.71(b)(3), the State must determine
whether your watershed control
program is adequate to limit potential
contamination by Cryptosporidium
oocysts. The adequacy of the program
must be based on the
comprehensiveness of the watershed
review; the effectiveness of your
program to monitor and control
detrimental activities occurring in the
watershed; and the extent to which your
system has maximized land ownership
and/or controlled land use within the
watershed.

Disinfection Profile

§ 141.530  Who must develop a
Disinfection Profile and what is a
Disinfection Profile?
  All subpart H community and non-
transient non-community water systems
which serve fewer than 10,000  persons
must develop a disinfection profile. A
disinfec'ion profile is a graphical
representation of your system's level of
Giardia lamblia or virus inactivation
measured  during the course of a year.
Your system must develop a
disinfection profile unless you  can
demonstrate to the Stale that your
TTHM and HAA5 levels are less than
0.064 mg/1 and 0.048 mg/1 respectively.
prior to January 7, 2003.

§ 141.531  How does my system
demonstrate TTHM and HAAS levels below
0.064 mg/l and 0.048 mg/1 respectively?
  In order to demonstrate that your
TTHM and HAAS levels are below 0.064
mg/L and 0.048 mg/L,  respectively your
system must have collected one TTHM
and one HAAS sample taken between
1998-2002. Samples must have been
collected during the month with the
warmest water temperature, at the point
of maximum residence time in  your
distribution system which indicate
TTHM levels below 0.064 mg/1 and
HAAS levels below 0.048 mg/L. By
January 7, 2003, you must submit a copy
of the results to the State along  with a
letter indicating your intention to forgo
development of a disinfection profile
because of the  results of the sampling.
This letter, along with  a copy of your
TTHM and HAAS sample lab results
must be kept on file for review by the
State during a sanitary survey. If the
data you have collected is either equal
to or exceeds either 0.064 mg/1  for
TTHM and/or 0.048 mg/1 for HAA5s,
you must develop a disinfection profile.

§141.532 How does my system develop a
Disinfection Profile and when must it
begin?
  A disinfection profile consists of three
steps:
  (a) First, your system must collect
measurements for several treatment
parameters from the plant as discussed
in § 141.533. Your system must begin
this monitoring no later than January 7,
2003.
  (b) Second, your system must use
these measurements to calculate
inactivation ratios as discussed in
§§141.534 and 141.535;  and
  (c) Third, your system must use these
inactivation ratios to develop a
disinfection profile as discussed in
§141.536.

§ 141.533 What measurements must my
system collect to calculate a Disinfection
Profile?
  Your system must monitor the
parameters necessary to determine the
total inactivation ratio using analytical
methods in § 141.74 (a), once per week
on the same calendar day each week as
follows:
  (a) The temperature of the disinfected
water must be measured at each residual
disinfectant concentration sampling
point during peak hourly flow;
  (b) If the system uses chlorine, the pH
of the disinfected water must be
measured at each chlorine residual
disinfectant concentration sampling
point during peak hourly flow;
  (c) The disinfectant contact time(s)
("T") must be determined during peak
hourly flow; and
  (d) The residual disinfectant
concentration(s)  ("C") of the water
before or at the first customer and prior
to each additional point of disinfection
must be measured during peak hourly
flow.

§ 141.534 How does my system use these
measurements to calculate an inactivation
ratio?
  Calculate the total inactivation  ratio
as follows, and multiply the value by
3.0 to determine log inactivation of
Giardia lamblia:

                       If a system...
                                    The system must determine...
(a) Uses only one point of disinfectant application 	
                   (1) One inactivation ratio (CTcalc/CTV,») before or at the first customer
                     during peak hourly flow, or
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Federal Register/Vol. 65,  No. 69/Monday, April 10, 2000/Proposed Rules
                         If a system...
                                                           The system must determine...
 (b) Uses more than one point of disinfectant application before the first
   customer.
                                          (2) Successive CTcalc/CTV>» values, representing sequential inactiva-
                                            tion ratios, between the point of disinfectant application and a point
                                            before or at the first customer during peak hourly flow. Under this al-
                                            ternative, the system must calculate the total inactivation ratio by de-
                                            termining (CTcalc/CT,«,,) for each sequence and then adding !he
                                            (CTcalc/CTw.») values together to determine (I (CTcalc/CTw«)}. You
                                            may use a spreadsheet that  calculates  CT and/or contains the nec-
                                            essary inactivation tables.
                                          (1) The CTcalc/CT.wg value of  each disinfection segment immediately
                                            prior to the next point of disinfectant application, or for the final seg-
                                            ment, before or at the first customer, during peak hourly flow using
                                            the procedure described in the above paragraph.
 §141.535  How does my system develop a
 Disinfection Profile if we use chloramines,
 ozone, or chlorine dioxide for primary
 disinfection?
   If your system uses either
 chloramines, ozone or chlorine dioxide
 for primary disinfection, you must also
 calculate the logs of inactivation for
 viruses. You must develop an additional
 disinfection profile for viruses using a
 method approved by the State.

 § 141.536  If my system has developed an
 inactivation ratio, what must we do now?
   Each inactivation ratio serves as a
 data point in your disinfection profile.
 Your system will have obtained 52
 measurements (one for every week of
 the year). This will allow  your system
 and the State the opportunity to
 evaluate how microbial inactivation
 varied over the course of the year by
 looking at all 52 measurements (your
 Disinfection Profile). Your system must
 retain the Disinfection Profile data in
 graphic form, as a spreadsheet, or  in
 some other  format acceptable to the
 State for review as part of sanitary
 surveys conducted by the State. Your
 system will need to use this data to
 calculate a benchmark if considering
 changes to disinfection practices.

 Disinfection Benchmark

 § 141.540  Who has to develop a
 Disinfection Benchmark?
   If you are a subpart H system required
 to develop a disinfection profile under
 §§ 141.530 through 141.536, your
 system  must develop a Disinfection
 Benchmark  if you decide to make a
 significant change to disinfection
 practice. State approval must be
 obtained before you can implement a
 significant disinfection practice change.

 § 141.541  What are significant changes to
 disinfection practice?
   Significant changes to disinfection
 practice are:
   (a) Changes to the point of
disinfection;
                        (b) Changes to the disinfectant(s) used
                      in the treatment plant:
                        (c) Changes to the disinfection
                      process; or
                        (d) Any other modification identified
                      by the State.

                      § 141.542   How is the Disinfection
                      Benchmark Calculated?
                        If your system is making a significant
                      change to its disinfection practice, it
                      must calculate a disinfection benchmark
                      using the following procedure:
                        (a) To calculate a disinfection
                      benchmark a system must perform the
                      following steps:
                        Step  1: Using  the data your system
                      collected to develop the Disinfection
                      Profile, determine the average Giardia
                      lamblia inactivation for each calender
                      month by dividing the sum of all
                      Giardia larnblia inactivations for that
                      month by the number of values
                      calculated for that month.
                       Step 2: Determine the lowest monthly
                      average value out of the twelve values.
                      This value becomes the disinfection
                      benchmark.
                       (b) [Reserved]

                      § 141.543  What if my system uses
                      chloramines or ozone for primary
                      disinfection?
                       If your system uses chloramines,
                      ozone or chlorinated dioxide for
                      primary disinfection your system must
                     calculate the disinfection benchmark
                      from the data your system collected for
                     viruses  to develop the disinfection
                     profile in addition to the Giardia
                     lamblia disinfection benchmark
                     calculated under § 141.542. The
                     disinfection benchmark must be
                     calculated as described in § 141.542.

                     § 141.544  What must my system do if
                     considering a significant change to
                     disinfection practices?
                       If your system is considering a
                     significant change to the disinfection
                     practice, it must complete a disinfection
                     benchmark(s) as described in §§ 141.542
                     and 141.543 and provide the
benchmark(s) to your State. Your system
may only make a significant disinfection
practice change after receiving State
approval. The following information
must be submitted to the State as part
of their review and approval process:
  (a) A description of the proposed
change;
  (b) The disinfection profile for Giardia
lamblia (and, if necessary, viruses) and
disinfection benchmark;
  (c) An analysis of how the proposed
change will affect the current levels of
disinfection; and
  (d) Additional  information requested
by the State.

Combined Filter Effluent Requirements

§141.550  Is my system required to meet
subpart T combined filter effluent turbidity
limits?
  All subpart H systems %vhich serve
populations fewer than 10,000. and are
required to filter, must meet combinfid
filter effluent requirements. Unless your
system consists of slow sand or
diatomaceous earth filtration, you are
required to meet the combined filter
effluent turbidity limits in § 141.551. If
your system uses slow sand or
diatomaceous earth filtration you must
continue to meet  the combined filter
effluent turbidity limits in §141.73.

§ 141.551  What strengthened combined
filter effluent turbidity limits must my
system meet?
  Your system must meet two
strengthened combined filter effluent
turbidity limits.
  (a) The first combined filter effluent
turbidity limit is a "95th percentile"
turbidity limit which your system must
meet in at least 95 percent of the
turbidity measurements taken  each
month. Measurements must continue to
be taken as described in § 141.74(a) and
(c). The following table describes the
required limits for specific filtration
technologies.

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                                                                                                                 19147
                  If your system consists of
                                                                         Your 95th percentile turbidity value is
(1) Conventional filtration or direct filtration
(2) Membrane filtration 	
                                                             0.3 NTU.
                                                             0.3 NTU or a value determined by the  State (not to exceed 1 NTU)
                                                               based on a demonstration conducted by the system as described in
                                                            I   §141.552.
(3) All other "alternative" filtration 	 I A value determined by the State (not to exceed 1 NTU) based on the
                                                               demonstration described in §141.552.
  (b) The second combined filter
effluent turbidity limit is a "maximum"
turbidity limit which your system may

                 If your system consists of.

(1) Conventional filtration or direct filtration  	
(2) Membrane filtration 	
                                         at no time exceed during the month.
                                         Measurements must continue to be
                                         taken as described in § 14l.74[a) and (c).
                    The following table describes the
                    required limits for specific filtration
                    technologies.
                                                                           Your maximum turbidity value is .
(3) All other "alternative" filtration
                                                             1 NTU
                                                             1 NTU  or  a  value determined by the State (not to exceed 5 NTU)
                                                               based on a demonstration conducted by the system as described in
                                                               §141.552
                                                             A value determined by the State (not to exceed 5 NTU) based on the
                                                               demonstration as described in §141.552.
§141.552  If my system consists of
"alternative filtration" and is required to
conduct a demonstration, What is required
of my system and how does the State
establish my turbidity limits?
  (a) If your system is required to
conduct a demonstration (see tables in
§141.551), your system must
demonstrate to the State, using pilot
plant studies or other means, that your
system's filtration, in combination with
disinfection treatment, consistently
achieves:
  (1) 99.9 percent removal and/or
inactivation of Giardia iamblia cysts;
  (2) 99.99 percent removal and/or
inactivation of viruses: and
  (3) 99 percent removal of
Cryptosporidium oocysts.
  (b) If the State approves your
demonstration, it will set turbidity
performance requirements that your
system must meet:
 ' (1) At least 95 percent of the time (not
to exceed 1  NTU); and
  (2) That your system must not exceed
at any time  (not to exceed 5 NTU).
                                         § 141.553  If my system practices lime
                                         softening, is there any special provision
                                         regarding my combined filter effluent?

                                           If your system practices lime
                                         softening, you may acidify
                                         representative combined filter effluent
                                         turbidity samples prior to analysis using
                                         a protocol approved by the State.

                                         Individual Filter Turbidity
                                         Requirements

                                         § 141.560  Is my system subject to
                                         individual filter turbidity requirements?

                                           If your system is a subpart H  system
                                         serving fewer than 10.000 people and
                                         utilizing conventional filtration or direct
                                         filtration, you must conduct continuous
                                         monitoring of turbidity for each
                                         individual filter at your system. The
                                         following requirements apply to
                                         individual filter turbidity monitoring:
                                           (a) Monitoring must be conducted
                                         using an approved method in
                                         §141.74(a):
           If the turbidity of an individual filter exceeds...
                       (b) Calibration of turbidimeters must
                    be conducted using procedures
                    specified by the manufacturer;
                       (c) Results of individual filter
                    turbidity monitoring must be recorded
                    every 15 minutes;
                       (d) Monthly reporting must be
                    completed according § 141.570; and
                       (e) Records must be maintained
                    according to §141.571.

                    §141.561  What happens if my system's
                    turbidity monitoring equipment fails?
                       If there is a failure in the continuous
                    turbidity monitoring equipment, the
                    system must conduct grab sampling
                    every four hours in lieu of continuous
                    monitoring until the  turbidimeter is
                    back on-line. A system has five working
                    days to resume continuous monitoring
                    before a violation is incurred.

                    § 141.562  What follow-up action is my
                    system required to take based on turbidity
                    monitoring of individual filters?
                       Follow-up action is required
                    according to the following tables:

                      The system must...
(a) If the turbidity of an individual filter exceeds
  secutive recordings).
                                          .0 NTU (in two con-
Submit an exceptions  report to the  State by the  10th of the month
  which includes the filter number(s), corresponding date(s), and the
  turbidity value(s) which exceeded 1.0 NTU.
       If an exceptions report is submitted for the same filter...
                                                                                   The system must...
(b) If an exceptions report is submitted for the same filter three months
  in a row.
                                                             Conduct a self-assessment of the filter within 14 days of the exceed-
                                                               ance and report that the self assessment was conducted by the 10th
                                                               of the following month. The self assessment must consist of at least
                                                               the following components: Assessment of filter performance; devel-
                                                               opment of a filter profile; identification and prioritization of factors lim-
                                                               iting filter performance; assessment of the applicability of corrections;
                                                               and preparation of a filter self-assessment report.
                                                                                                                                      !

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 19148
Federal  Register/Vol. 65,  No.  69/Monday,  April 10,  2000/Proposed  Rules
        If an exceptions report is submitted for the same filter..
                                                                   The system must..
 (c) If an exceptions report is submitted for the same filter two months in  (1) Arrange to have a comprehensive  performance evaluation (CPE)
   a row and both months contain exceedances of 20 NTU  {in 2 con- j   conducted by the State or a third party approved by the State no
   secutive recordings)                                               later than 30 days following the exceedance and have the evaluation
                                                                   completed and submitted to the State no later than 90 days following
                                                                   the exceedance, Unless—
                                                                 (2) A CPE has been completed by (he State  or a third  party approved
                                                                   by the State within the 12 prior months or the system and State are
                                                                   jointly participating in an ongoing Comprehensive Technical Assist-
                                                                !   ance (CTA) project at the system.
 § 141.563  My system practices lime
 softening. Is there any special provision
 regarding my  individual filter turbidity
 monitoring?

   If your system utilizes lime softening.
 you may apply to the State for
 alternative turbidity exceedance levels
 for the levels specified in the table in
 § 141.562. You must be able to
 demonstrate  to the State that higher
                       turbidity levels in individual filters are
                       due to lime carryover only, and not due
                       to degraded filter performance.

                       Reporting and Recordkeeping
                       Requirements

                       § 141.570  What does subpart T require that
                       my system report to the State?
                         This subpart T requires your system
                       to report several items to the  State. The
following table describes the items
which must be reported and the
frequency of reporting. Your  system is
required to report the information
described below, if it is subject to the
specific requirement shown in the first
column.
    Corresponding requirement
                             Description of information to report
                     Frequency
 (a) Combined  Filter  Effluent  Re-  (1)The total  number of filtered  water turbidity measurements taken  By  the  10th  of  the  following
   quirements.                        during the  month.                                             :   month.

                                  (2) The number and percentage of filtered water turbidity measure-  By  the  10th  of  the  following
                                    ments taken during  the month which  are greater than  your sys-    month.
                                 j   tern's required 95th percentile limit.
                                  (3)  The date and value of any turbidity measurements taken during  (i) Within 24 hours of exceedance
                                    the month which exceed the maximum turbidity value for your fil- |   and
                                    tratiort system.                                               j
                                                                                                 (ii) By  the  10th  of  the  following
                                                                                                ,   month.
(b) Individual  Filter  Turbidity  Re-  (1) That your system conducted individual filter turbidity monitoring !  By  the  10th  of  the   following
   quirements.                     j   during the month.                                            '    month.
                                 1 (2)  The filter number(s).  corresponding  date(s), and  the  turbidity '  By the 10th of the following month
                                    value(s) which exceeded 1.0 NTU during the month .                 only if—
                                 i                                                              ,  (ii) 2 consecutive  values exceeded
                                 1                                                              '    1.0 NTU.
                                  (3) That a self assessment was conducted within 14 days of the date   (i)  By the 10th of the following
                                    it was triggered.                                                 month (or 14 days after the self
                                                                                                  assessment was  triggered only
                                                                                                  if the self assessment was trig-
                                                                                               |   gered during the  last four days
                                                                                                  of the month) only if—
                                                                                                 (ii)  A self-assessment is required.

                                  (4) That a CPE is required and the date that it was triggered 	 !  (i)  By the 10th of the following
                                                                                                  month only if—
                                                                                                 (ii)  A CPE is required.
                                  (5) Copy of completed CPE report
                                                                            Within 90 days after the CPE was
                                                                              triggered.
(c) Disinfection Profiling  	
(d) Disinfection Benchmarking
             (1)  Results  of  applicability monitoring  which show  TTHM  levels  No later than January 7, 2003.
               <0.064 mg/l and HAAS levels <0.048 mg/l. (Only if your system \
               wishes to forgo profiling) or that your system has begun disinfec- I
               lion profiling                                                 ,
             (1) A description of the proposed change in disinfection, your sys-
               tem's disinfection profile for Giardia lamblia (and, if necessary, vi-
               ruses) and disinfection  benchmark, and an  analysis  of how the
               proposed change will affect the current levels  of disinfection.
          Anytime your  system is  consid-
            ering a significant change to its
            disinfection practice.

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                                                                             19149
§141.571  What records does subpart T
require my system to keep?
  Your system must keep several types
of records based on the requirements of
subpart T. The following table describes

    Corresponding requirement
        the necessary records, the length of time  subject to the specific requirement
        ihf.se records must be kept, and for       shown in the first column. For example,
        which requirement the records pertain.   if your system uses slow sand filtration,
        Your system is required to maintain      you would not be required to keep
        records described in this table, if it is     individual filter turbidity records:
               Description of necessary records
          Duration of time records musl be
                      kept
(a)  Individual  Filter  Turbidity Re- ! Results of individual filter monitoring
  quirements.
                                                         At least 3 years.
(b) Disinfection Profiling 	 \ Results of Profile (including raw data and analysis)	|  Indefinitely.

(c) Disinfection Benchmarking ...
Benchmark (including raw data and analysis) 	i Indefinitely.
(d) Covered Reservoirs 	  Date of construction for all uncovered finished water reservoirs uti- |  Indefinitely.
                                 lized by your system
PART 142—NATIONAL PRIMARY
DRINKING WATER REGULATIONS
IMPLEMENTATION
  13. The authority citation for Part 142
continues to read as follows:
  Authority: 42 U.S.C. 300f, 300g-l. 300g-2.
300g-3, 300g-4, 300g-5, 30Qg-6, 300J-4,
300)-9,and300j-ll.
  14. Section 142.14 is amended by
revising paragraphs (a)(3), (a)(4)(i),
(a)(4)(ii) introductory text, and (a)(7) to
read as follows:

§ 142.14  Records kept by States.
  (a)*  *  *
  (3) Records of turbidity measurements
must be kept for not less than one year.
The information retained must be set
forth in a form which makes possible
comparison with the limits specified in
§§141.71, 141.73, 141.173 and 141.175.
141.550-141.553 and 141.560-141.563
of this chapter. Until June 29, 1993, for
any public water system which is
providing filtration treatment and until
December 30,1991, for any public water
system not providing filtration
treatment and not required by the State
to provide filtration treatment, records
kept must be set forth in a form which
makes possible comparison  with the
limits contained in §141.13 of this
chapter.
*****
  (4)(i) Records of disinfectant residual
measurements and other parameters
necessary to document disinfection
effectiveness in accordance with
§§ 141.72 and 141.74 of this chapter and
the  reporting requirements of §§ 141.75,
141.175, and 141.570, of this chapter
must be kept for not less than one year.
  (ii) Records of decisions made on a
system-by-system and case-by-case basis
under provisions of part 141, subpart H,
subpart P, or subpart T of this chapter,
must be made in writing and kept at the
State.
          (7) Any decisions made pursuant to
        the provisions of part 141, subpart P or
        subpart T of this chapter.
          (i) Records of systems consulting with
        the State concerning a modification to
        disinfection practice under
        §§141.172(c), 141.170(6), and 141.544
        of this chapter, including the status of
        the consultation or approval.
          (ii) Records of decisions that a system
        using alternative filtration technologies,
        as allowed under §§ 141.173(b) and
        § 141.552 of this chapter, can
        consistently achieve a 99.9 percent
        removal and/or inactivation of Giardia
        lasnbiia cysts, 99.99 percent removal
        and/or inactivation of viruses, and 99
        percent removal of Cn'ptosporidium
        oocysts. The decisions must include
        State-set enforceable turbidity limits for
        each system. A copy of the decision
        must be kept until the decision is
        reversed or revised. The State must
        provide a copy of the decision to the
        system.
          (iii) Records of systems required to do
        filter self-assessment, CPE, or CCP
        under the requirements of § 141.175 and
        § 141.562 of this chapter.
        *    *     *    *     *
          15. Section 142.15 is amended by
        adding paragraphs (c)(6) and (c)(7) and
        § 142.1 5  Reports by States.
        *****
          (c) * *  *
          (6) Recycle return location. A list of
        all systems moving the recycle return
        location prior to the point of primary
        coagulant addition. The list must also
        contain all the systems the State granted
        alternate recycle locations, describe the
        alternative recycle return location, and
        briefly discuss the reason(s) the
        al [ornate recycle location was granted
        and is due |DATE 60 MONTHS AFTER
        DATE OF PUBLICATION OF FINAL
        RULE IN THE FEDERAL REGISTER].
  (7) Self assessment determination. A
list of all systems performing self
assessments must be reported to EPA.
The list must state whether individual
plants exceeded State approved
operating capacity during self
assessment monitoring and whether the
State required modification to recycle
practice. A brief description of the
modification to recycle practice
required at each plant must be provided.
If a plant exceeded State approved
operating capacity, and the State did not
require modification of recycle practice,
the State must provide a brief
explanation for this decision. Self
assessment results must be reported no
later than [DATE 54 MONTHS AFTER
DATE OF PUBLICATION OF FINAL
RULE IN THE FEDERAL REGISTER].
  (8) Direct filtration determination. A
list of all direct filtration systems
recycling within  the treatment process
must be submitted to EPA. The list must
state which systems were required to
modify recycle practice and briefly
describe the modification and the
reason it was required. It must also
identify systems  not required to modify
recycle practice and provide a brief
description of the reason modification
to recycle practice was not required.
The list must be submitted no later than
(DATE 54 MONTHS AFTER DATE OF
PUBLICATION OF FINAL RULE IN
THE FEDERAL REGISTER].
*****
  16. Section 142.16 is amended by
adding paragraph (b)(2)(v), (b)(2)(vi),
and (b)(2)(vii) and (i) to read as follows:

§ 142.16  Special primacy requirements.
*****
  (b)*  * *
  (2),  . *
  (v) The application must describe the
criteria the State  will use to determine
alternate recycle  locations for public
water systems applying to return spent
filter backwash, thickener supernatant.

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Federal Register/Vol.  65, No. 69/Monday, April  10,  2000/Proposed Rules
or liquids from dewatering to an
alternate location other than prior to the
point of primary coagulant addition.
  (vi) The application must describe the
criteria the State will use to determine
whether public water systems
completing self assessments are
required to modify recycle practice and
the criteria that will be used to specify
modifications to recycle practice.
  (vit) The application must describe
the criteria the State will use to
determine whether direct filtration
systems are required to change recycle
practice and the  criteria that will be
used to specify changes  to recycle
practice.
*    *    it     *     *
  (i) Requirements for States to adopt
40 CFR part 141, subpart T Enhanced
Filtration and Disinfection, In addition
to the general primacy requirements
enumerated elsewhere in this part,
including the requirement that State
provisions are no less stringent than the
federal requirements, an application for
approval of a State program revision
that adopts 40 CFR part  141, subpart T
Enhanced Filtration and Disinfection,
must contain the information specified
in this paragraph:
  (l) Enforceable requirements. States
must have rules or other authority to
require systems to participate in a
Comprehensive Technical Assistance
                     (CTA) activity, the performance
                     improvement phase of the Composite
                     Correction Program  (CCP). The State
                     shall determine whether a CTA must be
                     conducted based on results of a CPE
                     which indicate the potential for
                     improved performance, and a finding by
                     the State thai the system is able to
                     receive and implement technical
                     assistance provided  through the CTA. A
                     CPE is a thorough review and analysis
                     of a system's performance-based
                     capabilities and associated
                     administrative, operation and
                     maintenance practices. It is conducted
                     to identify factors that may be adversely
                     impacting a plant's capability to achieve
                     compliance. During  the CTA phase, the
                     system must identify and systematically
                     address factors limiting performance.
                     The CTA is a combination of utilizing
                     CPE results as a basis for follow-up,
                     implementing process control priority-
                     setting techniques and maintaining
                     long-term involvement to systematically
                     train staff and administrators.
                       (2) State practices or procedures, (i)
                     Section 141.536 of this chapter—How
                     the State will approve a method to
                     calculate the logs of  inactivation for
                     viruses for a system  that uses either
                     chloramines or ozone for primary
                     disinfection.
                       (ii) Section  141.544 of this chapter—
                     How the State will approve
                     modifications to disinfection practice.
  (iii) Section 141.552 of this chapter—
For filtration technologies other than
conventional filtration treatment, direct
filtration, slow sand filtration.
diatomaceous earth filtration, or
membrane filtration, how the State will
determine that a public water system
may use a filtration technology if the
PWS demonstrates to the State, using
pilot plant studies or other means, that
the alternative filtration technology (or
membrane filtration), in combination
with disinfection treatment that meets
the requirements of § 141.72(b) of this
chapter, consistently achieves 99.9
percent removal and/or inactivation of
Giardia lamblia cysts and 99.99 percent
removal and/or inactivation of viruses,
and 99 percent removal of
Cryptosporidium oocysts. For a system
that makes this demonstration, how the
State will set turbidity performance
requirements that the system must meet
95 percent of the time  and that the
system may not exceed at any time at a
level that consistently achieves 99.9
percent removal and/or inactivation of
Giardia lamblia cysts,  99.99 percent
removal and/or inactivation of viruses,
and 99 percent removal of
Cryptosporidium oocysts.
[FR Doc. 00-8155 Filed 4-7-00; 8:45 am)
BILLING CODE 656»-50-P

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