EPA 815-Z-03-004
Monday,

August 11, 2003
Part II



Environmental

Protection  Agency

40 CFR Parts 141 and 142
National Primary Drinking Water
Regulations: Long Term 2 Enhanced
Surface Water Treatment Rule; Proposed
Rule

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47640
Federal  Register/Vol. 68, No.  154/Monday, August 11, 2003/Proposed  Rules
ENVIRONMENTAL PROTECTION
AGENCY

40 CFR Parts 141 and 142
IFRL-7530-5]
RIN 2040—AD37

National Primary Drinking Water
Regulations: Long Term 2 Enhanced
Surface Water Treatment Rule

AGENCY: Environmental Protection
Agency.
ACTION: Proposed rule.	

SUMMARY: In this document, the
Environmental Protection Agency (EPA)
is proposing National Primary Drinking
Water Regulations that require the use
of treatment techniques, along with
monitoring, reporting, and public
notification requirements, for all public
water systems (PWSs) that use surface
water sources. The purposes of the Long
Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR) are to
improve control of microbial pathogens,
including specifically the protozoan
Cryptosporidium, in drinking water and
to address risk-risk trade-offs with the
control of disinfection byproducts. Key
provisions  in today's proposed
LT2ESWTR include the following:
source water monitoring for
Cryptosporidium, with reduced
monitoring requirements for small
systems; additional Cryptosporidium
treatment for filtered systems based on
source water Cryptosporidium
concentrations; inactivation  of
Cryptosporidium by all unfiltered
systems; disinfection profiling and
benchmarking to ensure continued
levels of microbial protection while
PWSs take the necessary steps to
comply with new disinfection
byproduct  standards; covering, treating,
or implementing a risk management
plan for uncovered finished water
storage facilities; and criteria for a
 number of treatment and management
 options (i.e., the microbial toolbox) that
PWSs may implement to meet
 additional  Cryptosporidium treatment
 requirements. The LT2ESWTR will
 build upon the treatment technique
 requirements of the Interim Enhanced
 Surface Water Treatment Rule and the
 Long Term 1 Enhanced Surface Water
 Treatment Rule.
   EPA believes that implementation of
 the LT2ESWTR will significantly reduce
 levels of Cryptosporidium in finished
 drinking water. This will substantially
 lower rates of endemic
 cryptosporidiosis, the illness caused by
 Cryptosporidium, which can be severe
 and sometimes fatal in sensitive
                      subpopulations (e.g., AIDS patients, the
                      elderly). In addition, the treatment
                      technique requirements of this proposal
                      are expected to increase the level of
                      protection from exposure to other
                      microbial pathogens (e.g., Giardia
                      lamblia}.
                      DATES: EPA must receive public
                      comment on the proposal by November
                      10,2003.
                      ADDRESSES: Comments may be
                      submitted by mail to: Water Docket,
                      Environmental Protection Agency, Mail
                      Code 4101T, 1200 Pennsylvania Ave.,
                      NW., Washington, DC 20460, Attention
                      Docket ID No. OW-2002-0039.
                      Comments may also be submitted
                      electronically or through hand delivery/
                      courier by following the detailed
                      instructions as provided in section I.C.
                      of the SUPPLEMENTARY INFORMATION
                      section.
                      FOR FURTHER INFORMATION CONTACT: For
                      technical inquiries, contact Daniel
                      Schmelling, Office of Ground Water and
                      Drinking Water (MC 4607M), U.S.
                      Environmental Protection Agency, 1200
                      Pennsylvania Ave., NW., Washington,
                      DC 20460; telephone (202) 564-5281.
                      For regulatory inquiries, contact Jennifer
                      McLain at the same address; telephone
                      (202) 564-5248. For general information
                      contact the Safe Drinking Water Hotline,
                      Telephone (800) 426^791. The Safe
                      Drinking Water Hotline is open Monday
                      through Friday, excluding legal
                      holidays, from 9 a.m. to 5:30 p.m.
                      Eastern Time.
                      SUPPLEMENTARY INFORMATION:

                      1. General Information
                      A. Who Is Regulated by This Action?
                         Entities potentially regulated by the
                      LT2ESWTR are public water systems
                      (PWSs) that use surface water or ground
                      water under the direct influence of
                      surface water (GWUDI). Regulated
                      categories and entities are identified in
                      the following chart.
                         Category
                       Industry
                       State, Local,
                        Tribal or
                        Federal
                        Govern-
                        ments.
 Examples of regulated enti-
          ties
Public Water Systems that
  use surface water or
  ground water under the di-
  rect influence of surface
  water.
Public Water Systems that
  use surface water or
  ground water under the di-
  rect influence of surface
  water.
                         This table is not intended to be
                       exhaustive, but rather provides a guide
                       for readers regarding entities likely to be
                       regulated by this action. This table lists
                       the types of entities that EPA is now
aware could potentially be regulated by
this action. 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
Title 40 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
LT2ESWTR to a particular entity,
consult one of the persons listed in the
preceding section entitled FOR FURTHER
INFORMATION CONTACT
B. How Can I Get Copies of This
Document and Other Related
Information?
  1. Docket. EPA has established an
official public docket for this action
under Docket ID No.  OW-2002-0039.
The official public docket consists of the
documents specifically referenced in
this action, any public comments
received, and other information related
to this action.  Although a part of the
official docket, the public docket does
not include Confidential Business
Information (CBI) or  other information
whose disclosure is restricted by statute.
The official public docket is the
collection of materials that is available
for public viewing at the Water Docket
in the EPA Docket Center, (EPA/DC)
EPA West, Room B102,1301
Constitution Ave., NW., Washington,
DC. The EPA Docket Center Public
Reading Room is open from 8:30 a.m. to
 4:30 p.m., Monday through Friday,
 excluding legal holidays. The telephone
 number for the Public Reading Room is
 (202) 566-1744, and the telephone
 number for the Water Docket is (202)
 566-2426. For access to docket material,
 please call (202) 566-2426 to schedule
 an appointment.
   2. Electronic Access. You may access
 this Federal Register document
 electronically through the EPA Internet
 under the "Federal Register" listings at
 h Up -.//www.epa .gov/fedrgstr/.
   An electronic version of the public
 docket is available through EPA's
 electronic public docket and comment
 system, EPA Dockets. You may use EPA
 Dockets at http://www.epa.gov/edocket/
 to submit or view public comments,
 access the index listing of the contents
 of the official public docket, and to
 access those documents in the public
 docket that are available electronically.
 Once in the system,  select "search,"
 then key in the appropriate docket
 identification number.
   Certain types of information will not
 be placed in the EPA Dockets.
 Information claimed as CBI and other

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                 Federal Register/Vol. 68, No.  154/Monday, August 11, 2003/Proposed Rules
                                                                     47641
 information whose disclosure is
 restricted by statute, which is not
 included in the official public docket,
 will not be available for public viewing
 in EPA's electronic public docket. EPA's
 policy is that copyrighted material will
 not be placed in EPA's electronic public
 docket but will be available only in
 printed, paper form in the official public
 docket. Although not all docket
 materials may be available
 electronically, you may  still access any
 of the publicly available docket
 materials through the docket facility
 identified in section I.B.I.
   For public commenters, it is
 important to note that EPA's policy is
 that public comments, whether
 submitted electronically or in paper,
 will be made available for public
 viewing in EPA's electronic public
 docket as EPA receives them and
 without change, unless the comment
 contains copyrighted material, CBI, or
 other information whose disclosure is
 restricted by statute. When EPA
 identifies a comment containing
 copyrighted material, EPA will provide
 a reference to that material in the
 version of the comment that is placed in
 EPA's electronic public docket. The
 entire printed comment, including the
 copyrighted material, will be available
 in the public docket.
   Public comments submitted on
 computer disks that are mailed or
 delivered to the docket will be
 transferred to EPA's electronic public
 docket. Public comments that are
 mailed or delivered to the Docket will
 be scanned and placed in EPA's
 electronic public docket. Where
 practical, physical  objects will be
 photographed, and the photograph will
 be placed in EPA's electronic public
 docket along with a brief description
 written by the docket staff.
 C. How and to Whom Do I Submit
 Comments;'
  You may submit comments
 electronically, by mail, or through hand
 deli very/courier. To ensure proper
 receipt by EPA, identify the appropriate
 docket identification number in the
 subject line on the first page of your
 comment. Please ensure that your
 comments are submitted  within the
 specified comment period. Comments
 received after the close of the comment
 period will be marked "late." EPA is not
required  to consider these late
comments.
  1. Electronically.  If you submit an
 electronic comment as prescribed
below, EPA recommends that you
include your name, mailing address,
and an e-mail address or other contact
information in the body of your
 comment. Also include this contact
 information on the outside of any disk
 or CD ROM you submit, and in any
 cover letter accompanying the disk or
 CD ROM. This ensures that you can be
 identified as the submitter of the
 comment and allows EPA to contact you
 in case EPA cannot read your comment
 due to technical difficulties or needs
 further information on the substance of
 your comment. EPA's policy is that EPA
 will not edit your comment, and any
 identifying or contact information
 provided in the body of a comment will
 be included as part of the comment that
 is placed in the official public docket,
 and made available in EPA's electronic
 public docket. If EPA cannot read your
 comment due to technical difficulties
 and cannot contact you for clarification,
 EPA may not be able to consider your
 comment.
   a. EPA Dockets. Your use of EPA's
 electronic public docket to submit
 comments to EPA electronically is
 EPA's preferred method for receiving
 comments. Go directly to EPA Dockets
 at http://www.epa.gov/edocket, and
 follow the online instructions for
 submitting comments. Once in the
 system, select "search," and then key in
 Docket ID No. OW-2002-0039. The
 system is an "anonymous access"
 system, which means EPA will not
 know your identity, e-mail address, or
 other contact information unless you
 provide it in the body of your comment.
  b. E-mail. Comments may be sent by
 electronic mail (e-mail) to  OW-
 Docket@epa.gov, Attention Docket ID
 No. OW-2002-0039. In contrast to
 EPA's electronic public docket, EPA's e-
 mail system is not an "anonymous
 access" system. If you send an e-mail
 comment directly to the Docket without
 going through EPA's electronic public
 docket, EPA's  e-mail system
 automatically captures your e-mail
 address. E-mail addresses that are
 automatically captured by  EPA's e-mail
 system are included as part of the
 comment that is placed in the official
 public docket, and made available in
 EPA's electronic public docket.
  c. Disk or CD ROM. You  may submit
 comments on a disk or CD  ROM that
 you mail to the mailing address
 identified in section I.C.2. These
 electronic submissions will be accepted
 in WordPerfect or ASCII file format.
 Avoid the use of special characters and
 any form of encryption.
  2. By Mail. Send three copies of your
 comments and any enclosures to: Water
 Docket, Environmental Protection
Agency, Mail Code 4101T,  1200
Pennsylvania Ave., NW., Washington,
DC, 20460, Attention Docket ID No,
OW-2002-0039.
   3. By Hand Delivery or Courier.
 Deliver your comments to: Water
 Docket, EPA Docket Center,
 Environmental Protection Agency,
 Room B102,1301 Constitution Ave.,
 NW, Washington, DC, Attention Docket
 ID No. OW-2002-0039. Such deliveries
 are only accepted during the Docket's
 normal hours of operation as identified
 in section I.B.I.

 D. What Should I Consider as I Prepare
 My Comments for EPA?
   You may find the following
 suggestions helpful for preparing your
 comments:
   1. Explain your views as clearly as
 possible.
   2. Describe any assumptions that you
 used.
   3. Provide any technical information
 and/or data you used that support your
 views.
   4. If you estimate potential burden or
 costs, explain how you arrived at your
 estimate.
   5. Provide specific examples to
 illustrate your concerns.
   6. Offer alternatives.
   7. Make sure to submit your
 comments by the comment period
 deadline identified.
   8. To ensure proper receipt by EPA,
 identify the appropriate docket
 identification number in the subject line
 on the first page of your response. It
 would also be helpful if you provided
 the name, date, and Federal Register
 citation related to your comments.

 Abbreviations Used in This Document
 AIPC  All Indian Pueblo Council
 ASDWA  Association of State Drinking
   Water Administrators
 ASTM  American  Society for Testing
   and 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 and
   Prevention
 CFE  Combined Filter Effluent
 CFR  Code of Federal Regulations
 COI Cost-of-Illness
 CT  The Residual Concentration of
   Disinfectant (mg/L) Multiplied by the
   Contact Time (in minutes)
 CWS Community Water Systems
 DAPI  4',6-Diamindino-2-phenylindole
DBFs  Disinfection Byproducts
DBPR  Disinfectants/Disinfection
  Byproducts Rule
DE  Diatomaceous Earth
DIG Differential Interference Contrast
  (microscopy)
EA  Economic Analysis

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                 Federal Register/Vol.  68. No.  154/Monday, August  11, 2003/Proposed Rules
EPA  United States Environmental
  Protection Agency
GAG   Granular Activated Carbon
GWUDI   Ground Water Under the
  Direct Influence of Surface Water
HAAS  Haloacetic acids
  (Monochloroacetic, Dichloroacetic,
  Trichloroacetic, Monobromoacetic
  and Dibromoacetic Acids)
HPC   Heterotrophic Plate Count
ICR  Information Collection Request
ICRSS  Information Collection Rule
  Supplemental Surveys
ICRSSM   Information Collection Rule
  Supplemental Survey of Medium
  Systems
ICRSSL  Information Collection Rule
  Supplemental Survey of Large
   Systems
IESWTR  Interim Enhanced Surface
   Water Treatment Rule
IFA   Immunofluorescence Assay
Log  Logarithm (common, base 10)
 LRAA  Locational Running Annual
   Average
 LRV  Log Removal Value
 LTlESWTR  Long Term 1 Enhanced
   Surface Water Treatment Rule
 LT2ESWTR  Long Term 2 Enhanced
   Surface Water Treatment Rule
 MCL  Maximum Contaminant Level
 MCLG  Maximum Contaminant  Level
   Goal
 MGD  Million Gallons per Day
 M-DBP   Microbial and  Disinfectants/
   Disinfection Byproducts
 MF   MicrofiUration
 NCWS   Non-community water systems
 NF  Nanofiltration
 NODA   Notice of Data Availability
 NPDWR  National Primary Drinking
    Water Regulation
 NTNCWS  Non-transient Non-
    community Water System
 NTTAA  National Technology Transfer
    and Advancement Act
 NTU  Nephelometric Turbidity Unit
 OMB  Office of Management and
    Budget
 PE   Performance Evaluation
 PWS  Public Water System
  QC  Quality Control
  QCRV   Quality Control Release Value
  RAA Running Annual Average
  RFA  Regulatory Flexibility Act
  RO  Reverse Osmosis
  RSD  Relative Standard Deviation
  SAB  Science Advisory Board
  SBAR   Small Business  Advocacy
    Review
  SERs  Small Entity Representatives
  SDWA   Safe Drinking Water Act
  SWTR   Surface Water Treatment Rule
  TCR  Total Coliform Rule
  TTHM   Total Tribal omethanes
  TNCWS  Transient Non-community
    Water Systems
  UF  Ultrafiltration
  UMRA  Unfunded Mandates Reform
    Act
Table of Contents
  1. Summary
  A. Why Is EPA Proposing the LT2ESWTR?
  B, What Does the LT2ESWTR Proposal
    Require?
  1. Treatment Requirements for
    Cryptosporidium
  2. Disinfection Profiling and Benchmarking
  3, Uncovered Finished Water Storage
    Facilities
  C. Will This Proposed Regulation Apply to
    My Water System?
 H. Background
  A. What Is the Statutory Authority for the
    LT2ESWTR?
  B. What Current Regulations Address
    Microbial Pathogens in Drinking Water?
  1. Surface Water Treatment Rule
  2. Total Coliform Rule
  3. Interim Enhanced Surface Water
     Treatment Rule
  4. Long Term 1 Enhanced Surface Water
     Treatment Rule
   5. Filter Backwash Recycle Rule
   C. What Public Health Concerns Does This
     Proposal Address?
   1. Introduction
   2. Cryptosporidium Health Effects and
     Outbreaks
   a. Health Effects
   b. Waterborne Cryptosporidiosis
     Outbreaks.
   3. Remaining Public Health Concerns
     Following the IESWTR and LTlESWTR
   a. Adequacy of Physical Removal To
     Control Cryptosporidium and the Need
     for Risk Based Treatment Requirements.
   b. Control of Cryptosporidium in
     Unnhered Systems
   c. Uncovered Finished Water Storage
     Facilities
   D. Federal Advisory Committee Process
 III. New Information on Cryptosporidium
     Health Risks and Treatment
   A. Overview of Critical Factors for
     Evaluating Regulation of Microbial
     Pathogens
    B. Cryptosporidium Infectivity
    1, Cryptosporidium Infectivity Data
     Evaluated for IESWTR
    2. New Data on Cryptosporidium
     Infectivity
    3. Significance of New Infectivity Data
    C. Cryptosporidium Occurrence
    1. Occurrence Data Evaluated for IESWTR
    a. Filtered Systems.
    b. Unfiltered Systems
    2. Overview of the Information Collection
     Rule and Information Collection Rule
     Supplemental Surveys (ICRSS)
    a. Scope of the Information Collection Rule
    b. Scope of the ICRSS
    3. Analytical Methods for Protozoa in the
     Information Collection Rule and ICRSS
    a. Information Collection Rule Protozoan
      Method
    b. Method 1622 and Method 1623
    4. Cryptosporidium Occurrence Results
      from the Information Collection Rule and
      ICRSS
    a. Information Collection Rule Results
    b. ICRSS Results
    5. Significance of New Cryptosporidium
      Occurrence Data
    6. Request for Comment on Information
      Collection Rule and ICRSS Data Sets
 D. Treatment
 1. Overview
 2. Treatment Information Considered for
   the IESWTR and LTlESWTR
 a. Physical Removal
 b. Inactivation
 3. New Information on Treatment for
   Control of Cryptosporidium
 a. Conventional Filtration Treatment and
   Direct Filtration
 i. Dissolved Air Flotation.
 b. Slow Sand Filtration
 c. Diatomaceous Earth Filtration
 d. Other Filtration Technologies
 e. Inactivation
 i. Ozone and Chlorine Dioxide
 H. Ultraviolet Light
 iii. Significance of New Information on
   Inactivation
IV. Discussion of Proposed LT2ESWTR
   Requirements
  A.  Additional Cryptosporidium Treatment
   Technique Requirements for Filtered
    Systems
  1. What Is EPA Proposing Today?
  a. Overview of Framework Approach
  b. Monitoring Requirements
  c. Treatment Requirements
  i. Bin Classification
  ii.  Credit for Treatment in Place
  iii. Treatment Requirements Associated
    With LT2ESWTR Bins
   o.  Use of Previously Collected Data
   2.  How Was This Proposal Developed?
   a. Basis for Targeted Treatment
    Requirements
   b.  Basis for Bin Concentration Ranges and
    Treatment Requirements
   i. What Is the Risk Associated With a Given
     Level of Cryptosporidium in a Drinking
     Water Source?
   ii. What Degree of Additional Treatment
     Should Be Required for a Given Source
     Water Cryptosporidium Level?
   c. Basis for Source Water Monitoring
     Requirements
   i.  Systems Serving at Least 10,000 People
   ii. Systems Serving Fewer Than 10,000
     People
   iii. Future Monitoring and Reassessment
   d. Basis for Accepting Previously Collected
     Data
   3. Request for Comment
   B. Unfiltered System Treatment Technique
     Requirements for Cryptosporidium
   1. What Is EPA Proposing Today?
   a. Overview
   b. Monitoring Requirements
   c. Treatment Requirements
   2. How Was This Proposal Developed?
   a. Basis for Cryptosporidium Treatment
     Requirements
   b. Basis for Requiring the Use of Two
     Disinfectants
   c. Basis for Source Water Monitoring
     Requirements
   3. Request for Comment
   C. Options for Systems to Meet
     Cryptosporidium Treatment
     Requirements
   1. Microbial Toolbox Overview
   2. Watershed Control Program
   a. What Is EPA Proposing Today?
   b. How Was This Proposal Developed?
   c. Request for Comment
   3. Alternative Source

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                 Federal  Register/Vol.  68, No. 154/Monday, August 11,  2003/Proposed  Rules
                                                                            47643
 a. What Is EPA Proposing Today?
 b. How Was This Proposal Developed?
 c. Request for Comment
 4. Off-stream Raw Water Storage
 a. What Is EPA Proposing Today?
 b. How Was This Proposal Developed?
 c. Request for Comment
 5. Pre-sedimentation With Coagulant
 a. What Is EPA Proposing Today?
 b. How Was This Proposal Developed?
 i. Published Studies of Cryptosporidium
   Removal by Conventional Sedimentation
   Basins
 ii. Data Supplied by Utilities on the
   Removal of Spores by Presedimentation
 c. Request for Comment
 6. Bank Filtration
 a. What Is EPA  Proposing Today?
 b. How Was This Proposal Developed?
 c. Request for Comment
 7. Lime Softening
 a. What Is EPA  Proposing Today?
 b. How Was This Proposal Developed?
 c. Request for Comment
 8. Combined Filter Performance
 a. What Is EPA  Proposing Today?
 b. How Was This Proposal Developed?
 c. Request for Comment
 9. Roughing Filter
 a. What Is EPA  Proposing Today?
 b. How Was This Proposal Developed?
 c. Request for Comment
 10. Slow Sand Filtration
 a. What Is EPA Proposing Today?
 b. How Was This Proposal Developed?
 c. Request for Comment
 11. Membrane Filtration
 a. What Is EPA Proposing Today?
 b. How Was This Proposal Developed?
 c. Request for Comment
 12. Bag and Cartridge Filtration
 a. What Is EPA Proposing Today?
 b. How Was This Proposal Developed?
 c. Request for Comment
 13. Secondary Filtration
 a. What Is EPA Proposing Today?
 b. How Was This Proposal Developed?
 c. Request for Comment
 14. Ozone and Chlorine Dioxide
 a. What Is EPA Proposing Today?
 b. How Was This Proposal Developed?
 c. Request for Comments
 15. Ultraviolet Light
 a. What Is EPA Proposing Today?
 b. How Was This Proposal Developed?
 c. Request for Comment
 16. Individual Filter Performance
 a. What Is EPA Proposing Today?
 b. How Was This Proposal Developed?
 c. Request for Comment
 17. Other Demonstration of Performance
 a. What Is EPA Proposing Today?
b. How Was This Proposal Developed?
 c. Request for Comment
 D. Disinfection Benchmarks for Giardia
  lambHa  and Viruses
 1. What Is EPA Proposing Today?
 a. Applicability  and Schedule
b. Developing the Disinfection Profile and
  Benchmark
c. State Review
2. How Was This Proposal Developed?
3. Request for Comments
E. Additional Treatment Technique
  Requirements  for Systems with
  Uncovered Finished Water Storage
  Facilities
   1. What Is EPA Proposing Today?
   2. How Was This Proposal Developed?
   3. Request for Comments
   F. Compliance Schedules
   1. What Is EPA Proposing Today?
   a. Source Water Monitoring
   i. Filtered Systems
   ii. Unfiltered Systems
   b. Treatment Requirements
   c. Disinfection Benchmarks for Giardia
    lamblia and Viruses
   2. How Was This Proposal Developed?
   3. Request for Comments
   G. Public Notice Requirements
   1. What Is EPA  Proposing Today?
   2. How Was This Proposal Developed?
   3. Request for Comment
   H, Variances and Exemptions
   1. Variances
   2. Exemptions
   3. Request for Comment
   a. Variances
   b. Exemptions
   I. Requirements for Systems To Use
    Qualified Operators
   J. System  Reporting and Recordkeeping
    Requirements
   1. Overview
   2. Reporting Requirements for Source
    Water Monitoring  -
   a. Data Elements To Be Reported
   b. Data System
   c. Previously Collected Monitoring Data
   3. Compliance With Additional Treatment
    Requirements
   4. Request for Comment
   K. Analytical Methods
   1. Cryptosporidium
   a. What Is EPA Proposing Today?
   b. How Was This Proposal Developed?
   c. Request for Comment
   2. E. coif
   a. What Is EPA Proposing Today?
   b. How Was This Proposal Developed?
   c. Request for Comment
   3. Turbidity
   a. What Is EPA Proposing Today?
   b. How Was This Proposal Developed?
   c. Request for Comment
   L. Laboratory Approval
   1. Cryptosporidium Laboratory Approval
   2. E. coli Laboratory Approval
   3. Turbidity Analyst Approval
   4. Request for Comment
   M. Requirements for Sanitary Surveys
    Conducted by EPA
   1. Overview
   2. Background
   3. Request for Comment
V. State Implementation
  A. Special State  Primacy Requirements
  B. State Recordkeeping Requirements
  C. State Reporting Requirements
  D. Interim Primacy
VI. Economic Analysis
  A. What Regulatory Alternatives Did the
    Agency Consider?
  B. What Analyses Support Selecting the
    Proposed Rule Option?
  C. What Are the  Benefits of the Proposed
    LT2ESWTR?
  1. Non-quantifiable Health and Non-health
    Related Benefits
  2. Quantifiable Health Benefits
  a. Filtered  Systems
  b. Unfiltered Systems
  3, Timing of Benefits Accrual (latency)
  D. What Are the Costs of the Proposed
    LT2ESWTR?
  1. Total Annualized Present Value Costs
  2. Water System Costs
  a. Source Water Monitoring Costs
  b. Filtered Systems Treatment Costs
  c. Unfiltered Systems Treatment Costs
  d. Uncovered Finished Water Storage
    Facilities
  e. Future Monitoring Costs
  f. Sensitivity Analysis-influent Bromide
    Levels on Technology Selection for
    Filtered Plants
  3. State/Primacy Agency Costs
  4. Non-quantified Costs
  E. What Are the Household Costs of the
    Proposed Rule?
  F. What Are the Incremental Costs and
    Benefits of the Proposed LT2ESWTR?
  G. Are There Benefits From the Reduction
    of Co-occurring Contaminants?
  H. Are There Increased Risks From Other
    Contaminants?
  I. What Are the Effects of the Contaminant
    on the General Population and Groups
    Within the General Populations That Are
    Identified as Likely to be at Greater Risk
    of Adverse Health Effects?
  J. What Are the Uncertainties in the
    Baseline, Risk, Benefit, and Cost
    Estimates for the Proposed LT2ESWTR
    as well as the Quality and Extent of the
    Information?
  K. What Is the Benefit/Cost Determination
    for the Proposed LT2ESWTR?
  L. Request for Comment
VII. Statutory and Executive Order Reviews
  A. Executive Order 12866: Regulatory
    Planning and Review
  B. Paperwork Reduction Act
  C. Regulatory Flexibility Act
  D. 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 EPA Consultation With
    State, local, and Tribal Governments and
    Their Concerns
  f. Regulatory 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
  E. Executive Order 13132: Federalism
  F. Executive Order 13175: Consultation
    and Coordination With Indian Tribal
    Governments
  G. Executive Order 13045: Protection of
   Children from Environmental Health and
   Safety Risks
  H. Executive Order 13211: Actions that
   Significantly Affect Energy Supply,
   Distribution, or Use
  I. National Technology Transfer and
   Advancement Act
  J. Executive Order 12898: Federal Actions
   to Address Environmental Justice in
   Minority Populations or Low-Income
   Populations

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  K. Consultations With the Science
   Advisory Board, National Drinking
   Water Advisory Council, and the
   Secretary of Health and Human Services
  L. Plain Language
Vlll. References

I. Summary
A. Why Is EPA Proposing the
LT2ESWTR?
  EPA is proposing the Long Term 2
Enhanced Surface Water Treatment Rule
(LT2ESWTR) to provide for increased
protection against microbial pathogens
in public water systems that use surface
water sources. The proposed
LT2ESWTR focuses on
Cryptosporidium, which is a protozoan
pathogen that is widespread in surface
water. EPA is particularly concerned
about Cryptosporidium because it is
highly resistant to inactivation by
standard disinfection practices like
chlorination. Ingestion of
Cryptosporidium oocysts can cause
acute gastrointestinal illness, and health
effects in sensitive subpopulations may
be severe, including risk of mortality.
 Cryptosporidium has been identified as
the pathogenic agent in a number of
waterborne disease outbreaks across the
U.S. and in Canada (details in section
II).
   The intent of the LT2ESWTR is to
 supplement existing microbial treatment
 requirements for systems where
 additional public health protection is
 needed. Currently,  the Interim
 Enhanced Surface Water Treatment Rule
 (IESWTR) requires  large systems that
 filter to remove at least 99% (2 log) of
 Cryptosporidium (63 FR 69478,
 December 16,1998) (USEPA 1998a).
 The Long Term 1 Enhanced Surface
 Water Treatment Rule (LT1ESWTR)
 extends this requirement to small
 systems (67 FR 1812, January 14, 2002)
 (USEPA 2002a). Subsequent to
 promulgating these regulations, EPA has
 evaluated significant new data on
 Cryptosporidium infectivity,
 occurrence, and treatment (details in
 section HI). These data  indicate that
 current treatment requirements achieve
 adequate protection for the  majority of
 systems, but there is a subset of systems
 with higher vulnerability to
 Cryptosporidium where additional
 treatment is necessary.
   Specifically, national survey data
 show that average Cryptosporidium
 occurrence in filtered systems is lower
 than previously estimated. However,
 these data also demonstrate that
  Cryptosporidium concentrations vary
 widely among systems, and that a
  fraction of filtered  systems have
 relatively high levels of source water
                      Cryptosporidium contamination. Based
                      on this finding, along with new data
                      suggesting that the infectivity (i.e.,
                      virulence) of Cryptosporidium may be
                      substantially higher than previously
                      understood, EPA has concluded that the
                      current 2 log removal requirement does
                      not provide an adequate degree of
                      treatment in filtered systems with the
                      highest source water Cryptosporidium
                      levels. Consequently, EPA is proposing
                      targeted additional treatment
                      requirements under the LT2ESWTR for
                      filtered systems with the highest
                      Cryptosporidium risk.
                        Under current regulations, unfiltered
                      systems are not required to provide any
                      treatment for Cryptosporidium. New
                      occurrence data suggest that typical
                      Cryptosporidium levels in the treated
                      water of unfiltered systems are
                      substantially higher than in the treated
                      water of filtered systems. Hence,
                      Cryptosporidium treatment by
                      unfiltered systems is needed to achieve
                      equivalent public  health protection.
                      Recent treatment studies have allowed
                      EPA to develop criteria for systems to
                      inactivate Cryptosporidium with ozone,
                      ultraviolet (UV) light, and chlorine
                      dioxide. As a result, EPA has concluded
                      that it is feasible and appropriate to
                      propose under the LT2ESWTR that all
                      unfiltered systems treat for
                       Cryptosporidium.
                         In addition to concern with
                       Cryptosporidium,  the LT2ESWTR
                      proposal is intended to ensure that
                      systems maintain  adequate protection
                       against microbial pathogens as they take
                       steps to reduce formation of disinfection
                      byproducts (DBFs). Along with the
                       LT2ESWTR, EPA  is also developing a
                       Stage 2 Disinfection Byproducts  Rule
                       (DBPR), which will further limit
                       allowable levels of trihalomethanes and
                       haloacetic acids. The proposed
                       LT2ESWTR contains disinfection
                       profiling and benchmarking
                       requirements to ensure that  microbial
                       protection is maintained as systems
                       comply with the Stage 2 DBPR. Also in
                       the proposed LT2ESWTR are
                       requirements to limit risk associated
                       with existing uncovered finished water
                       storage facilities. Uncovered storage
                       facilities are subject to contamination if
                       not properly managed or treated.
                         Today's proposed LT2ESWTR reflects
                       consensus recommendations from the
                       Stage 2 Microbial and Disinfection
                       Byproducts (M-DBP) Federal Advisory
                       Committee. These recommendations are
                       set forth in the Stage 2 M-DBP
                       Agreement in Principle (65 FR 83015,
                       December 29, 2000} (USEPA 2000a).
B. What Does the LT2ESWTH Proposal
Require?
1. Treatment Requirements for
Cryptosporidium
  EPA is proposing risk-targeted
treatment technique requirements for
Cryptosporidium control in filtered
systems that are based on a microbial
framework approach. Under this
approach, systems that use a surface
water or ground water under the direct
influence of surface water (referred to
collectively as surface water systems)
will conduct source water monitoring to
determine an average Cryptosporidium
concentration. Based on monitoring
results, filtered systems will be
classified in one of four possible risk
categories (bins). A filtered system's bin
classification determines  the extent of
any additional Cryptosporidium
treatment requirements beyond the
requirements of current regulations.
   EPA expects that the majority of
filtered systems will be classified in the
Bin 1, which carries no additional
treatment requirements. Those systems
classified Bins 2-4 will be required to
provide from 1.0 to 2.5 log of treatment
(i.e., 90 to 99.7 percent reduction) for
Cryptosporidium in addition to
conventional treatment that complies
with the 1ESWTR or LT1ESWTR (details
in section IV.A). Filtered systems will
meet additional Cryptosporidium
treatment requirements by using one or
more treatment or control steps from a
"microbial toolbox" of options (details
in section IV.C). Rather than monitoring,
filtered systems may elect to comply
with  the treatment requirements of Bin
4 directly.
   Under the proposed LT2ESWTR, all
surface water systems that are not
required to filter (i.e., unfiltered
systems) must provide at least 2 log (i.e.,
 99 percent) inactivation of
 Cryptosporidium. In addition, unfiltered
 systems will monitor for
 Cryptosporidium in their source water
 and must achieve at least 3 log (i.e., 99.9
 percent) inactivation of
 Cryptosporidium if the mean level
 exceeds 0.01 oocysts/L. Alternatively,
 unfiltered systems may elect to provide
 3 log Cryptosporidium inactivation
 directly, instead of moriitoring. All
 requirements established under the
 Surface Water Treatment Rule (SWTR)
 (54 FR 27486, June 29, 1989) (USEPA
 1989a) for unfiltered systems will
 remain in effect, including 3 log
 inactivation of Giardia lamblia and 4 log
 inactivation of viruses. However, the
 LT2ESWTR proposal requires that
 unfiltered systems achieve their overall
 inactivation requirements using a

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                                                                     47645
 minimum of two disinfectants (details
 in section IV.B).
 2. Disinfection Profiling and
 Benchmarking
  The purpose of disinfection profiling
 and benchmarking is to ensure that
 when a system makes a significant
 change to its disinfection practice, it
 does not compromise the adequacy of
 existing microbial protection. EPA
 established the disinfection benchmark
 under the IESWTR and LTlESWTR for
 the Stage 1 M-DBP rules, and the
 LT2ESWTR proposal extends
 disinfection benchmark requirements to
 apply to the Stage 2 M-DBP rules.
  The proposed profiling and
 benchmarking requirements are similar
 to those promulgated under IESWTR
 and LTlESWTR. Systems that meet
 specified criteria must prepare
 disinfection profiles that characterize
 current levels of virus and Giardia
 lamblia inactivation over the course of
 one year. Systems with valid
 operational data from profiling
 conducted under the IESWTR or
 LTlESWTR  are not required to collect
 additional data. If a  system that is
 required to prepare a profile proposes to
 make a significant change to its
 disinfection practice, the system must
 calculate a disinfection benchmark and
 must consult with the State regarding
 how the proposed change will affect the
 current benchmark (details in section
 IV.D).
 3. Uncovered Finished Water Storage
 Facilities
  The proposed LT2ESWTR also
 includes requirements for systems with
 uncovered finished water storage
 facilities. The IESWTR and LTlESWTR
 require systems to cover all new storage
 facilities for  finished water, but these
 rules do not  address existing uncovered
 finished water storage facilities. Under
 the LT2ESWTR proposal, systems with
 uncovered finished water storage
 facilities must cover the storage facility
 or treat the storage facility discharge to
 achieve 4 log virus inactivation unless
the State determines that existing risk
 mitigation is adequate. Where the State
 makes such a determination, systems
 must develop and implement a risk
 mitigation plan that addresses physical
 access, surface water run-off, animal
 and bird wastes, and on-going water
quality assessment (details in section
IV.E).
 C. Will This Proposed Regulation Apply
 to My Water  System?
  All community and non-community
water systems that use surface water or
ground water under the direct influence
 of surface water are affected by the
 proposed LT2ESWTR.

 II. Background

 A. What Is the Statutory Authority for
 the LT2ESWTR?
   This section discusses the Safe
 Drinking Water Act (SDWA or the Act)
 sections that direct the development of
 the LT2ESWTR.
   The Act, as amended in 1996, requires'
 EPA to publish a maximum
 contaminant level  goal (MCLG) and   ,
 promulgate a national primary drinking
 water regulation (NPDWR) with
 enforceable requirements for any
 contaminant that the Administrator
 determines may have an adverse effect
 on the health of persons, is known to
 occur or there is a  substantial likelihood
 that the contaminant will occur in
 public water systems (PWSs) 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 PWSs
 (section 1412 (b)(l)(A)).
   MCLGs are non-enforceable health
 goals, and 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 (sections 1412(b)(4) and
 1412(a)(3)). EPA established an MCLG
 of zero for Cryptosporidium under the
 IESWTR (63 FR 69478, December 16,
 1998) (USEPA 1998a). The Agency is
 not proposing any  changes to the
 current MCLG for Cryptosporidium.
   The Act also requires that at the same
 time EPA publishes an NPDWR and
 MCLG, it must specify in the NPDWR a
 maximum contaminant level (MCL)
 which is as close to the MCLG as is
 feasible (sections 1412(b)(4) and
 1401(l)(c)). The Agency is authorized to
 promulgate an 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 (sections
 1412(b)(7)(A) and 1401(1)(Q). The Act
 specifies that in such cases, the Agency
 shall identify those treatment
 techniques that would prevent known
 or anticipated adverse effects on the
 health of persons to the extent feasible
 (section 1412(b)(7)(A)).
  The Agency has concluded that it is
not currently economically or
technologically feasible for PWSs to
determine the level of Cryptosporidium
in finished drinking water for the
purpose of compliance with a finished
water standard (the performance of
 available analytical methods for
 Cryptosporidium is described in section
 III.C; the treated water Cryptosporidium
 levels that the LT2ESWTR will achieve
 are described in section IV.A).
 Consequently, today's proposal for the
 LT2ESWTR relies on treatment
 technique requirements to reduce health
 risks from Cryptosporidium in PWSs.
  When proposing a NPDWR that
 includes an MCL or treatment
 technique, the Act requires EPA to
 publish and seek public comment on an
 analysis of health risk reduction and
 cost impacts. This includes an analysis
 of quantifiable and non quantifiable
 costs and health risk reduction benefits,
 incremental costs and benefits of each
 alternative considered, the effects of the
 contaminant upon sensitive
 subpopulations (e.g., infants, children,
 pregnant women, the elderly, and
 individuals with a history of serious
 illness), any increased risk that may
 occur as the result of compliance, and
 other relevant factors (section 1412
 (b)(3)(C)). EPA's analysis of health
 benefits and costs associated with the
 proposed LT2ESWTR is presented in
 "Economic Analysis of the LT2ESWTR"
 (USEPA 2003a) and is summarized in
 section VI of this preamble. However,
 the Act does not authorize the
 Administrator to use additional health
 risk reduction and cost considerations
 to establish MCL or treatment technique
 requirements for the control of
 Cryptosporidium (section 1412
  Finally, section 1412 (b)(2)(C) of
SDWA requires EPA to promulgate a
Stage 2 Disinfectants and Disinfection
Byproducts Rule within 18 months after
promulgation of the LTlESWTR, which
occurred on January 14, 2002.
Consistent with statutory requirements
for risk balancing (section
1412(b)(5)(B)), EPA will finalize the
LT2ESWTR with the Stage 2 DBPR to
ensure parallel protection from
microbial and DBF risks.

B. What Current Regulations Address
Microbial Pathogens in Drinking Water?
  This section summarizes the existing
regulations that apply to control of
pathogenic microorganisms in surface
water systems. These rules form the
baseline of regulatory protection that
will be supplemented by the
LT2ESWTR.
1. Surface Water Treatment Rule
  The SWTR (54 FR 27486, June 29,
1989) (USEPA 1989a) applies to all
PWSs using surface water or ground
water under the direct influence
(GWUDI) of surface water as sources
(Subpart H systems). It established

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MCLGs of zero for Giardia lamblia,
viruses, and Legionella, and includes
treatment technique requirements to
reduce exposure to pathogenic
microorganisms, including: (1)
Filtration, unless specified avoidance
criteria are met; (2) maintenance of a
disinfectant residual in the distribution
system; (3) removal and/or inactivation
of 3 log (99.9%) of Giardia lamblia and
4 log (99.99%) of viruses; (4) combined
filter effluent turbidity of 5
nephelometric turbidity units (NTU) as
a maximum and 0,5 NTU at 95th
percentile monthly for treatment plants
using conventional treatment or direct
filtration (with separate standards for
other filtration technologies); and (5)
watershed protection and source water
quality requirements for unfiltered
systems.
2. Total Coliform Rule
   The Total Coliform Rule (TCR) (54 FR
27544, June 29, 1989) (USEPA 1989b)
applies to all PWSs. It established an
MCLG of zero for total and fecal
coliform bacteria, and an MCL based on
the percentage of positive samples
 collected during a compliance period.
 Coliforms are used as a screen for fecal
 contamination and to determine the
 integrity of the water treatment process
 and distribution system.  Under the TCR,
 no more than 5 percent of distribution
 system samples collected in any month
 may contain coliform bacteria (no more
 than 1 sample per month may be
 coliform positive in those systems that
 collect fewer than 40 samples per
 month). The number of samples to be
 collected in a month is based on the
 number of people served by the system,

 3. Interim Enhanced Surface Water
 Treatment Rule
   The IESWTR  (63 FR 69477, December
 16, 1998) (USEPA 1998a) applies to
 PWSs serving at least 10,000 people and
 using surface water or GWUDI sources.
 Key provisions established by the
 IESWTR include the following: (1) An
 MCLG of zero for Cryptosporidium; (2)
 Cryptosporidium removal requirements
 of 2 log (99 percent) for systems that
 filter; (3) strengthened combined filter
 effluent turbidity performance standards
 of 1.0 NTU as a maximum and 0.3  NTU
 at the 95th percentile monthly for
 treatment plants using conventional
 treatment or direct filtration; (4)
 requirements for individual filter
 turbidity monitoring; (5) disinfection
 benchmark provisions to assess the level
 of microbial protection provided as
 facilities take steps to comply with new
 DBF standards; (6) inclusion of
  Cryptosporidium in the  definition of
 GWUDI and in  the watershed control
                      requirements for unfiltered public water
                      systems; (7) requirements for covers on
                      new finished water storage facilities;
                      and (8) sanitary surveys for all surface
                      water systems regardless of size.
                        The IESWTR was developed in
                      conjunction with the Stage 1
                      Disinfectants and Disinfection
                      Byproducts Rule (Stage 1 DBPR) (63 FR
                      69389; December 16,1998) (USEPA
                      1998b), which reduced allowable levels
                      of certain DBFs, including
                      trihalomethanes, haloacetic acids,
                      chlorite, and bromate.

                      4. Long Term 1 Enhanced Surface Water
                      Treatment Rule

                        The LT1ESWTR (67 FR 1812, January
                      14, 2002) (USEPA 2002a) builds upon
                      the microbial control provisions
                      established by the IESWTR for large
                      systems, through extending similar
                      requirements to small systems. The
                      LT1ESWTR applies to PWSs using
                      surface water or GWUDI as sources that
                      serve fewer than 10,000 people. Like the
                      IESWTR, the LTlESWTR established
                      the following: 2 log (99 percent)
                      Cryptosporidium removal requirements
                      for systems that filter; individual filter
                      turbidity monitoring and more stringent
                      combined filter effluent turbidity
                      standards for conventional and direct
                      filtration plants; disinfection profiling
                      and benchmarking; inclusion of
                      Cryptosporidium in the definition of
                      GWUDI and in the watershed control
                      requirements for unfiltered systems; and
                      the requirement that new finished water
                       storage facilities be covered.

                       5. Filter Backwash Recycle Rule

                         EPA promulgated the Filter Backwash
                       Recycling Rule (FBRR) (66 FR 31085,
                      June 8, 2001} (USEPA 2001a) to increase
                       protection of finished drinking water
                       supplies from contamination by
                       Cryptosporidium and other microbial
                       pathogens.  The FBRR requirements will
                       reduce the potential risks associated
                       with recycling contaminants removed
                       during the filtration process. The FBRR
                       provisions apply to all systems that
                       recycle, regardless of population served.
                       In general, the provisions include the
                       following: (1) Recycling systems must
                       return certain recycle streams prior to
                       the point of primary coagulant addition
                       unless the State specifies an alternative
                       location; (2) direct filtration systems
                       recycling to the treatment process must
                       provide detailed recycle treatment
                       information to the State; and (3) certain
                       conventional systems that practice
                       direct recycling must perform a one-
                       month, one-time recycling self
                       assessment.
C. What Public Health Concerns Does
This Proposal Address?
  This section presents the basis for the
public health concern associated with
Cryptosporidium in drinking water by
summarizing information on
Cryptosporidium health effects and
outbreaks. This is followed by a
description of the specific areas of
public health concern that remain after
implementation of the IESWTR and
LTlESWTR and that are addressed in
the LT2ESWTR proposal. More detailed
information about Cryptosporidium
health effects may be found in the
following criteria documents:
Cryptosporidium: Human Health
Criteria Document (USEPA 2001b),
Cryptosporidium: Drinking Water
Advisory (USEPA 2001c), and
Cryptospondium: Risks for Infants and
Children (USEPA 2001 d).

1. Introduction
  While  modern water treatment
systems have substantially reduced
waterborne disease incidence, drinking
water contamination remains  a
significant health risk management
challenge. EPA's Science Advisory
Board in 1990 cited drinking water
contamination, particularly
contamination by pathogenic
microorganisms, as one of the most
important environmental risks (USEPA
1990). This risk is underscored by
information from the Centers  for Disease
Control and Prevention (CDC) which
indicates that between  1980 and 1998 a
total  of 419 outbreaks associated with
 drinking water were reported, with
greater than 511,000 estimated cases of
 disease.  A number of agents were
 implicated in these outbreaks, including
 viruses,  bacteria, and protozoa, as well
 as  several chemicals (Craun and
 Calderon 1996, Levy et al 1998,
 Barwick et al, 2000). The majority of
 cases were associated with surface
 water, and specifically with the 1993
 Cryptosporidium outbreak in
 Milwaukee, WI with an estimated
 403,000 cases (Mac Kenzie et al. 1994).
 A  recent study by McDonald  et al
 (2001), which used blood  samples from
 Milwaukee children collected during
 and after the 1993 outbreak, suggests
 that  Cryptosporidium infection,
 including asymptomatic infection, was
 more widespread than might be inferred
 from the illness estimates by  Mac
 Kenzie etal. (1994).
    It is important to note that  the number
 of identified and reported outbreaks in
 the CDC database is believed to
 substantially understate the actual
 incidence of waterborne disease
 outbreaks and cases (Craun and

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                                                                     47647
Calderon 1996, National Research
Council 1997). This under reporting is
due to a number of factors. Many people
experiencing gastrointestinal illness do
not seek medical attention. Where
medical attention is provided, the
pathogenic agent may not be identified
through routine testing. Physicians often
lack sufficient information to attribute
gastrointestinal illness to any specific
origin, such as drinking water, and few
States have an active  outbreak
surveillance program. Consequently,
outbreaks are often not recognized in a
community or, if recognized, are not
traced to a drinking water source.
  In addition, an unknown but probably
significant portion of waterborne
disease is endemic (i.e. isolated cases
not associated with an outbreak) and,
thus, is even more difficult to recognize.
The Economic Analysis for the
proposed LT2ESWTR (USEPA 2003a)
uses data on Cryptosporidium
occurrence, infectivity, and treatment to
estimate the baseline endemic incidence
of cryptosporidiosis attributable to
drinking water, as well as the reductions
projected as a result of this rule.
  Most waterborne pathogens cause
gastrointestinal illness with diarrhea,
abdominal discomfort, nausea,
vomiting, and other symptoms. The
effects of waterborne  disease are usually
acute, resulting from  a single or small
number of exposures. Such illnesses are
generally of short duration in healthy
people. However, some pathogens,
including Giardia lamblia and
Cryptosporidium, may cause disease
lasting weeks or longer in otherwise
healthy individuals, though this is not
typical for Cryptosporidium.
Waterborne pathogens also cause more
serious  disorders such as hepatitis,
peptic ulcers, myocarditis, paralysis,
conjunctivitis, swollen lymph glands,
meningitis, and reactive arthritis, and
have been associated with diabetes,
encephalitis, and other diseases
(Lederberg 1992).
  There are populations that are at
greater risk from waterborne disease.
These sensitive subpopulations include
children (especially infants), the elderly,
the malnourished, pregnant women, the
disease impaired (e.g., diabetes, cystic
fibrosis), and a broad category of those
with  compromised immune systems,
such  as AIDS patients, those with
autoimmune disorders (e.g., rheumatoid
arthritis, lupus erythematosus, multiple
sclerosis), transplant recipients, and
those on chemotherapy (Rose 1997).
This sensitive segment represents
almost 20% of the population in the
United States (Gerba  et al. 1996). The
severity and duration of illness is often
greater in sensitive subpopulations than
in healthy individuals, and in a small
percentage of such cases, death may
result.
2. Cryptosporidium Health Effects and
Outbreaks
  Cryptosporidium is a protozoan
parasite that exists in warm-blooded
hosts and, upon excretion, may survive
for months in the environment (Kato et
al., 2001). Ingestion of Cryptosporidium
can lead to cryptosporidiosis, a
gastrointestinal illness. Transmission of
cryptosporidiosis often occurs through
consumption of feces contaminated food
or water, but may also result from direct
or indirect contact with infected persons
or animals (Casemore 1990). Surveys
(described in Section III) indicate that
Cryptosporidium is common in surface
waters used as drinking water supplies.
Sources of Cryptosporidium
contamination include animal
agriculture, wastewater treatment plant
discharges, slaughterhouses, birds,  wild
animals, and other sources of fecal
matter.
  EPA is particularly concerned about
Cryptosporidium because, unlike
pathogens such as bacteria and most
viruses, Cryptosporidium oocysts are
highly resistant to standard
disinfectants like chlorine and
chloramines. Consequently, control of
Cryptosporidium in most treatment
plants is dependent on physical removal
processes. Finished water monitoring
data indicate that Cryptosporidium is
sometimes present in filtered, treated
drinking water (LeChevallier ef al. 1991;
Aboytes et al. 2002). Moreover, as noted
later, many of the individuals sickened
by waterborne outbreaks of
cryptosporidiosis were served by
filtered surface water supplies (Solo-
Gabriele and Neumeister, 1996). In some
cases, these outbreaks were attributed to
treatment deficiencies, while in other
cases the cause was unidentified (see
Table II-l).
  These data suggest that surface water
systems that filter and disinfect may
still be vulnerable to Cryptosporidium,
depending on the source water quality
and treatment effectiveness. Today's
proposed rule addresses concern with
passage of Cryptosporidium through
physical removal processes during
water treatment, as well as in systems
lacking filtration.
  a. Health effects. Cryptosporidium
infection is characterized by mild to
severe diarrhea,  dehydration, stomach
cramps, and/or a slight fever. Symptoms
typically last from several days to two
weeks, though in a small percentage of
cases, the symptoms may persist for
months or longer in otherwise healthy
individuals. Human feeding studies
have demonstrated that a low dose of
Cryptosporidium parvum (C. parvum) is
sufficient to cause infection in healthy
adults (DuPont et a!. 1995, Chappell et
al. 1999, Messner et al. 2001). Studies
of immunosuppressed adult mice have
demonstrated that a single viable oocyst
can induce patent C. parvum infections
(Yang et al. 2000).
  There is evidence that an immune
response to Cryptosporidium exists, but
the degree and duration of this
immunity is not well characterized. In
a study  by Chappell et al. (1999),
individuals with a blood serum
antibody (IgG), which can develop from
exposure to C. parvum, demonstrated
immunity to low doses of oocysts. The
investigators found the ID50 dose (i.e.,
dose that infects 50% of the challenged
population) of one C. parvum isolate for
adult volunteers who had pre-existing
serum IgG to be 1,880 oocysts in
comparison to 132 oocysts for
individuals reported as serologically
negative. However, the implications of
these data for studies of
Cryptosporidium infectivity are unclear.
Earlier work did not observe a
correlation between the development of
antibodies after Cryptosporidium
exposure and subsequent protection
from illness (Okhuysen et al. 1998}. A
subsequent investigation by Muller et
al. (2001) observed serological
responses to Cryptosporidium antigens
in samples from individuals reported by
Chappel et al. as serologically negative.
  Cryptosporidium parvum was first
recognized as  a human pathogen in
1976  (Juranek 1995). Cases of illness
from  Cryptosporidium were rarely
reported until 1982 when documented
disease incidence increased due to the
AIDS epidemic (Current 1983). As
laboratory diagnostic techniques
improved during subsequent years,
outbreaks among immunocompetent
persons were recognized as well.
Human, cattle, dog and deer types of C.
parvum have been found in healthy
individuals (Ong et al. 2002, Morgan-
Ryan et al. 2002). Other
Cryptosporidium species (C. felis, C.
meleagridis, and possibly C. muris) have
infected healthy individuals, primarily
children (Xiao et al. 2001, Chalmers et
al. 2002, Katsumata et al 2000). Cross-
species infection occurs. The human
type of C. parvum (now named C.
hominis (Morgan-Ryan et al. 2002)) has
infected a dugong and monkeys (Spano
et al.  1998). The cattle type of C. parvum
infects humans, wild animals,  and other
livestock, such as sheep, goats and deer
(Ong  et al. 2002).
  As  noted earlier, there are sensitive
populations that are at greater risk from
pathogenic microorganisms.

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Cryptosporidiosis symptoms in
immunocompromised subpopulations
are much more severe, including
debilitating voluminous diarrhea that
may be accompanied by severe
abdominal cramps, weight loss, and low
grade fever (Juranek 1995). Mortality is
a significant threat to the
immunocompromised infected with
Cryptosporidium:
  the duration and severity of the disease are
significant: whereas 1 percent of the
immunocompetent population may be
hospitalized with very little risk of mortality,
Cryptosporidium infections are associated
with a high rate of mortality in the
immunocompromised (Rose 1997)
  A follow-up study of the 1993
Milwaukee, WI outbreak reported that at
least 50 Cryp(osporich'um-associated
deaths occurred among the severely
immunocompromised (Hoxie et al.
1997).
                        b. Waterborne cryptosporidiosis
                      outbreaks. Cryptosporidium has caused
                      a number of waterborne disease
                      outbreaks since 1984 when the first one
                      was reported in the U.S. Table 11-1 lists
                      reported outbreaks in community water
                      systems (CWS) and non-community
                      water systems (NCWS). Between 1984—
                      1998, nine outbreaks caused by
                      Cryptosporidium were reported in the-
                      U.S. with approximately 421,000 cases
                      associated cases of illness (CDC 1993,
                      1996,1998, 2000, and 2001), Solo-
                      Gabriele and Neumeister (1996)
                      characterized water supplies associated
                      with U.S. outbreaks of
                      cryptosporidiosis. They determined that
                      almost half of the outbreaks were
                      associated with ground water (untreated
                      or chlorinated springs and wells), but
                      that the majority of affected individuals
                      were served by filtered  surface water
                      supplies (rivers and lakes). They found
that during outbreaks involving treated
spring or well water, the chlorination
systems were apparently operating
satisfactorily, with a measurable
chlorine residual.
  Although the occurrence of
Cryptosporidium in U.S. drinking water
supplies has been substantiated by data
collected during outbreak
investigations, the source and density of
oocysts associated with the outbreak
have not always been detected or
reported. Furthermore, because of
limitations and uncertainties of the
immunofluorescence assay (IFA)
method used in earlier studies, negative
results in source or finished water
during these outbreaks do not
necessarily mean tbat there were no
oocysts in the water at the time of
sampling.
            TABLE 11-1.—OUTBREAKS CAUSED BY Cryptosporidium IN PUBLIC WATER SYSTEMS: 1984-1998
Year
1984 	
1987 	
1991 	
1992 	
1992 	 	 	
1993 	
1993 	
1994 	
1998 	
State
TX
GA
PA
OR
OR
NV
WI
WA
TX
Cases
117
13,000
551
tt
ft
103
403,000
134
1,400
System
CWS
CWS
NCWS
CWS
CWS
CWS
CWS
CWS
CWS
Deficiency
3
3
3
3
3
5
3
2
3
Source
Well.
River.
Welt.
Spring.
River.
Lake.
Lake.
Well.
Well.
  ft=Total estimated cases were 3,000. The locations were nearby and cases overlapped in time Definitions of deficiencies = (1) untreated sur-
face water; (2) untreated ground water; (3) treatment deficiency (e.g., temporary interruption of disinfection, chronically inadequate disinfection,
and inadequate or no filtration); (4) distribution system deficiency (e.g., cross connection, contamination of water mains during construction or re-
pair, and contamination of a storage facility); and (5) unknown or miscellaneous deficiency.
3. Remaining Public Health Concerns
Following the IESWTR and LTlESWTR

  This section presents the areas of
remaining public health concern
following implementation of the
IESWTR and LTlESWTR that EPA
proposes to address in the LT2ESWTR.
These are as follows: (a) Adequacy of
physical removal to control
Cryptosporidium and the need for risk
based treatment requirements; (b)
control of Cryptosporidium in unfiltered
systems; and (c) uncovered finished
water storage facilities.
  EPA recognized each of these issues
as a potential public health concern
during development of the IESWTR, but
could not address them at that time due
to the absence of key data. Accordingly,
this section begins with a description of
how EPA considered these issues during
development of the IESWTR, including
the data gaps that were identified at that
time. This is followed by a statement of
the extent to which new information has
filled these data gaps, thereby allowing
                      EPA to address these public health
                      concerns in the LT2ESWTR proposal.
                        a. Adequacy of physical removal to
                      control Cryptosporidium and the need
                      for risk based treatment requirements. A
                      question that received significant
                      consideration during development of
                      the IESWTR is whether physical
                      removal by filtration plants provides
                      adequate protection against
                      Cryptosporidium in drinking water, or
                      whether certain systems should be
                      required to provide inactivation of
                      Cryptosporidium based on source water
                      pathogen levels. As discussed in the
                      proposal, notice of data availability
                      (NODA), and final IESWTR, EPA and
                      stakeholders concluded that data
                      available during IESWTR development
                      were not adequate to support risk based
                      inactivation requirements for
                      Cryptosporidium. However, the Agency
                      maintained that a risk based approach to
                      Cryptosporidium control would be
                      considered for the LT2ESWTR when
                      data collected under the Information
                      Collection  Rule were available and other
critical information needs had been
addressed.
  The IESWTR proposal (59 FR 38832,
July 29,1994) (USEPA 1994) included
two treatment alternatives, labeled B
and C, that specifically addressed
Cryptosporidium. Under Alternative B,
the level of required treatment would be
based on the density of
Cryptosporidium in the source water.
The proposal noted concerns with this
approach, though, due to uncertainty in
the risk associated with
Cryptosporidium and the feasibility of
achieving higher treatment levels
through disinfection. Consequently,
EPA also proposed Alternative C, which
would require 2 log (99%) removal of
Cryptosporidium by filtration. This was
based on the determination that 2 log
Cryptosporidium removal is feasible
using conventional treatment.
  In the 1996 Information Collection
Rule (61 FR 24354, May 14,1996)
(USEPA 1996a), EPA concluded that the
analytical method prescribed for
measuring Cryptosporidium was

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                  Federal  Register/Vol. 68, No. 154/Monday, August 11, 2003/Proposed Rules          47649
 adequate for making national
 occurrence estimates, but would not
 suffice for making site specific source
 water density estimates. This finding
 further contributed to the rationale
 supporting Alternative C under the
 proposed IESWTR.
   The NODA for the IESWTR (62 FR
 59498, Nov. 3, 1997) (USEPA 1997a)
 presented the recommendations of the
 Stage 1 MDBP Federal Advisory
 Committee for the IESWTR. As stated in
 the NODA, the Committee engaged in
. extensive discussions regarding the
 adequacy of relying  solely on physical
 removal to control Cryptosporidium and
 the need for inactivation. There was an
 absence of consensus on whether it was
 possible at that time to adequately
 measure Cryptosporidium inactivation
 efficiencies for various disinfection
 technologies. This was a significant
 impediment to addressing inactivation
 in the IESWTR. However, the
 Committee recognized that inactivation
 requirements may be necessary under
 future regulatory scenarios, as shown by
 the following consensus
 recommendation from the Stage 1
 MDBP Agreement in Principle:
   EPA should issue a risk based proposal of
 the Final Enhanced Surface Water Treatment
 Rule for Cryptosporidium embodying the
 multiple barrier approach (e.g., source water
 protection, physical removal, inactivation,
 etc.), including, where  risks suggest
 appropriate, inactivation requirements (62 FR
 59557, Nov. 3,1997) (USEPA 1997a).
   The preamble to the final IESWTR  (63
 FR 69478, Dec. 16,1998) (USEPA
 1998a) states that EPA was unable to
 consider the proposed Alternative B
 (treatment requirements for
 Cryptosporidium based on source water
 occurrence levels) for the IESWTR
because occurrence data from the
Information Collection Rule  survey and
related analysis were not available in
time to meet the statutory promulgation
deadline. The Agency affirmed, though,
that further control of Cryptosporidium
would be addressed in the LT2ESWTR.
   In today's notice, EPA is proposing a
risk based approach for control of
Cryptosporidium in drinking water.
Under this approach, the required level
of additional Cryptosporidium treatment
relates to the source water pathogen
density. EPA believes many of the data
gaps that prevented the adoption of this
approach under the IESWTR have been
addressed. As described in Section III of
this preamble, information on
Cryptosporidium occurrence from the
Information Collection Rule and
Information Collection Rule
Supplemental Surveys, along with new
data on Cryptosporidium infectivity,
have provided EPA with a better
 understanding of the magnitude and
 distribution of risk for this pathogen.
 Improved analytical methods allow for
 a more accurate assessment of source
 water Cryptosporidium levels, and
 recent disinfection studies with UV,
 ozone, and chlorine dioxide provide the
 technical basis to support
 Cryptosporidium inactivation
 requirements.
   6. Control of Cryptosporidium in
 unfiltered systems. There is particular
 concern about Cryptosporidium in the
 source waters of unfiltered systems
 because this pathogen has been shown
 to be resistant to conventional
 disinfection practices. In the IESWTR,
 EPA extended watershed control
 requirements for unfiltered systems to
 include the control of Cryptosporidium.
 EPA did not establish Cryptosporidium
 treatment requirements for unfiltered
 systems because available data
 suggested an equivalency of risk in
 filtered and unfiltered systems. This is
 described in the final IESWTR as
 follows:
 it appears that unfiltered water systems that
 comply with the source water requirements
 of the SWTR have a risk of cryptosporidiosis
 equivalent to that of a water system with a
 well operated filter plant using a water
 source of average quality f63 FR 69492, Dec.
 16, 1998) (USEPA 1998a)
   The Agency noted that data from the
 Information Collection Rule would
 provide more information on
 Cryptosporidium levels in filtered and
 unfiltered systems, and that
 Cryptosporidium treatment
 requirements would be re-evaluated
 when these data became available.
   In today's notice, EPA is proposing
 Cryptosporidium inactivation
 requirements for unfiltered systems.
 These proposed requirements stem from
 an assessment of Cryptosporidium
 source water occurrence  in both filtered
 and unfiltered systems using data from
 the Information Collection Rule and
 other surveys, as  described in Section III
 of this preamble. These new data do not
 support the finding described in the
 IESWTR of equivalent risk in filtered
 and unfiltered systems. Rather,
 Cryptosporidium treatment by
 unfiltered systems is necessary to
 achieve a finished water risk level
 equivalent to that of filtered systems. In
 addition, the development of
 Cryptosporidium inactivation criteria
 for UV, ozone, and chlorine dioxide in
the LT2ESWTR has made it feasible for
unfiltered systems to provide
 Cryptosporidium treatment.
  c. Uncovered finished water storage
facilities. In the IESWTR proposal, EPA
solicited comment on a requirement that
systems cover finished water storage
 facilities to reduce the potential for
 contamination by pathogens and
 hazardous chemicals. Potential sources
 of contamination to uncovered storage
 facilities include airborne chemicals,
 runoff, animal carcasses, animal or bird
 droppings, and growth of algae and
 other aquatic organisms (59 FR 38832,
 July 29, 1994) (USEPA 1994). '
   The final IESWTR established a
 requirement  to cover all new storage
 facilities for  finished water for which
 construction began after February 16,
 1999 (63 FR 69493, Dec. 16, 1998)
 (USEPA 1998a). In preamble to the final
 IESWTR, EPA described future
 regulation of existing uncovered
 finished water storage facilities as
 follows:
   EPA needs more time to collect and
 analyze additional information to evaluate
 regulatory impacts on systems with existing
 uncovered reservoirs on a national basis . . .
 EPA will further consider whether to  require
 the covering of existing reservoirs during the
 development of subsequent microbial
 regulations when additional data and
 analysis to develop the national costs  of
 coverage are available.
   EPA continues to be concerned  about
 contamination resulting from uncovered
 finished water storage facilities,
 particularly the potential for vims
 contamination via bird droppings, and
 now has sufficient data to estimate
 national cost implications for various
 regulatory  control strategies. Therefore,
 EPA is proposing control measures for
 all systems with uncovered finished
 water storage facilities in the
 LT2ESWTR.  New data and proposed
 requirements are described in section
 IV.E of this preamble.

 D. Federal Advisory Committee Process
  In March 1999, EPA reconvened the
 M-DBP Federal Advisory Committee to
 develop recommendations for the  Stage
 2 DBPR and LT2ESWTR. The
 Committee consisted of organizational
 members representing EPA, State  and
 local public health and regulatory
 agencies, local elected officials, Indian
 Tribes, drinking water suppliers,
 chemical and equipment manufacturers,
 and public interest groups. Technical
 support for the Committee's discussions
 was provided by a technical workgroup
 established by the Committee at its first
 meeting. The Committee's activities
 resulted in the collection and evaluation
 of substantial new information related
to key elements for both rules. This
included new data on pathogenicity,
occurrence, and treatment of microbial
contaminants, specifically including
 Cryptosporidium, as well as new data on
DBF health risks, exposure, and control.
New information relevant to the

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LT2ESWTR is summarized in Section III
of this proposal.
  In September 2000, the Committee
signed an Agreement in Principle
reflecting the consensus
recommendations of the group. The
Agreement was published in a
December 29, 2000 Federal Register
notice (65 FR 83015, December 29,
2000) (USEPA 2000a). The Agreement is
divided into Parts A & B. The entire
Committee reached consensus on Part
A, which contains provisions that
directly apply to the Stage 2 DBPR and
LT2ESWTR. The full Committee, with
the exception of one member, agreed to
Part B, which has recommendations for
future activities by EPA  in the areas of
distribution systems and microbial
water quality criteria.
  The Committee reached agreement on
the following major issues discussed in
this notice and the proposed Stage 2
DBPR:
  LT2ESWTR:  (1) Additional
 Cryptosporidium treatment based on
 source water monitoring results; (2)
Filtered systems that must comply with
 additional Cryptosporidium treatment
 requirements may choose from a
 "toolbox" of treatment and control
 options; (3) Reduced monitoring burden
 for small systems; (4) Future monitoring
 to confirm source water quality
 assessments; (5) Cryptosporidium
 inactivation by all unfiltered systems;
 (6) Unfiltered systems meet overall
 inactivation requirements using a
 minimum of 2 disinfectants; (7)
 Development of criteria and guidance
 for UV disinfection and other toolbox
 options; (8) Cover or treat existing
 uncovered finished water reservoirs
 (i.e.,  storage facilities) or implement risk
 mitigation plans.
   Stage 2 DBPR: (1) Compliance
 calculation for total trihanomethanes
 (TTHM) and five haloacetic acids
 (HAA5) revised from a running annual
 average (RAA) to a locational running
 annual average (LRAA); (2) Compliance
 carried out in two phases of the rule;  (3)
 Performance of an Initial Distribution
 System Evaluation; (4) Continued
 importance of simultaneous compliance
 with DBF and microbial regulations;  (5)
 Unchanged MCL for bromate.

 III. New Information on
 Cryptosporidium Health Risks and
 Treatment
   The purpose of this section is to
 describe information related to health
 risks and treatment of Cryptosporidium
 in drinking water that has become
 available since EPA developed the
 IESWTR. Much of this information was
 evaluated by the Stage 2 M-DBP Federal
 Advisory Committee when considering
                      whether and to what degree existing
                      microbial standards should be revised to
                      protect public health. It serves as a basis
                      for the recommendations made by the
                      Advisory Committee and for provisions
                      in today's proposed rule. This section
                      begins with an overview of critical
                      factors that EPA considers when
                      evaluating regulation of microbial
                      pathogens. New information is then
                      presented on three key topics:
                      Cryptosporidium infectivity,
                      occurrence, and treatment.
                      A. Overview of Critical Factors for
                      Evaluating Regulation ofMicrobia]
                      Pathogens
                        When proposing a national primary
                      drinking water regulation that includes
                      a maximum contaminant level or
                      treatment technique,  SDWA requires
                      EPA to analyze the health risk reduction
                      benefits and costs likely to result from
                      alternative regulatory levels that are
                      being considered. For assessing risk,
                      EPA follows the paradigm described by
                      the National Academy of Science (NRC,
                      1983) which involves four steps: (1)
                      Hazard identification, (2) dose-response
                      assessment, (3) exposure assessment,
                      and (4) risk characterization. The
                      application of these steps to microbial
                      pathogens is briefly described in this
                      section, followed by a summary of how
                      EPA estimates the health benefits and
                      costs of regulatory alternatives.
                         Hazard identification for microbial
                      pathogens is a description of the nature,
                      severity, and duration of the health
                      effects stemming from infection. Under
                      SDWA, EPA must consider health
                      effects on the general population and on
                      subpopulations that are at greater risk of
                      adverse health effects. See section II.C.2
                      of this preamble for health effects
                       associated with Cryptosporidium.
                         Dose-response assessment with
                       microorganisms is commonly termed
                       infectivity and is a description of the
                       relationship between the number of
                       pathogens ingested and the probability
                       of infection. Information on
                       Cryptosporidium infectivity is presented
                       in section III.B of this preamble.
                         Exposure to microbial pathogens in
                       drinking water is generally a function of
                       the concentration of the pathogen in
                       finished water and the volume of water
                       ingested (exposure also occurs through
                       secondary routes involving infected
                       individuals). Because it is difficult to
                       directly measure pathogens at the low
                       levels typically present in finished
                       water, EPA's information on pathogen
                       exposure is primarily derived from
                       surveys of source water occurrence. EPA
                       estimates the concentration of
                       pathogens in treated water by
                       combining source water pathogen
occurrence data with information on the
performance of treatment plants in
reducing pathogen levels. Data on the
occurrence of Cryptosporidium are
described in section III.C of this
preamble and in Occurrence and
Exposure Assessment for the
LT2ESWTR {USEPA 2003b).
Cryptosporidium treatment studies are
described in section HI.D of this
preamble.
  Risk characterization is the
culminating step of the risk assessment
process. It is a description  of the nature
and magnitude of risk, and characterizes
strengths, weaknesses, and attendant
uncertainties of the assessment. EPA's
risk characterization for
Cryptosporidium is described in
Economic Analysis for the LT2ESWTR
(USEPA 2003a).
  Estimating the health benefits and
costs that would result from a new
regulatory requirement involves a
number of steps, including evaluating
the efficacy and cost of treatment
strategies to reduce exposure to the
contaminant, forecasting the number of
systems that would implement different
treatment strategies to comply with the
regulatory standard, and projecting the
reduction in exposure to the
contaminant and  consequent health risk
reduction benefits stemming from
regulatory compliance. EPA's estimates
 of health benefits and costs associated
with the proposed LT2ESWTR are
presented in Economic Analysis for the
LT2ESWTR (USEPA 2003a) and  are
 summarized in section VI  of this
 preamble.
 B. Cryptosporidium Infectivity
   This section presents information on
 the infectivity of Cryptosporidium
 oocysts. Infectivity relates the
 probability of infection by
 Cryptosporidium with the number of
 oocysts that a person ingests, and it is
 used to predict the disease burden
 associated with different
 Cryptosporidium levels in drinking
 water. Information on Cryptosporidium
 infectivity comes from dose-response
 studies where healthy human subjects
 ingest different numbers of oocysts and
 are subsequently evaluated for signs of
 infection and illness.
   Data from a human dose-response
 study of one Cryptosporidium isolate
 (the IOWA study, conducted at the
 University of Texas-Houston Health
 Science Center) had been published
 prior to the IESWTR (DuPont et al.
 1995). Following IESWTR
 promulgation, a study of two additional
 isolates (TAMU and UCP) was
 completed and published (Okhuysen et
 al, 1999). This study also presented a

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                                                                     47651
 reanalysis of the IOWA study results. As
 described in more detail later in this
 section, this new study indicates that
 the infectivity of Cryptosporidium
 oocysts varies over a wide range. The
 UCP oocysts appeared less infective
 than those of the IOWA study while the
 TAMU oocysts were much more
 infective. Although the occurrence of
 these isolates among environmental
 oocysts is unknown, a meta-analysis of
 these data conducted by EPA suggests
 the overall infectivity of
 Cryptosporidiutn may be significantly
 greater than was estimated for the
 IESWTR. (USEPA 2003a).
  This section begins with a description
 of the infectivity data considered for the
 IESWTR. This is followed by a
 presentation of additional data that have
 been evaluated for the proposed
 LT2ESWTR and  a characterization of
 the significance of these new data.
 1. Cryptosporidium Infectivity Data
 Evaluated for IESWTR
  Data from the IOWA study (DuPont et
 al. 1995) were  evaluated for the
 IESWTR. In  that  study, 29 individuals
 were given single doses ranging from 30
 oocysts to 1  million oocysts. This oocyst
 isolate was originally obtained from a
 naturally infected calf. Seven persons
 received  doses above 500, and all were
 infected. Eleven of the twenty two
 individuals receiving doses of 500 or
 fewer were classified as infected based
 on oocysts detected in stool samples.
  The IOWA study data were analyzed
using an exponential dose-response
 model established by Haas et al. (1996)
 for Cryptosporidium:
Probability {Infection/Dose}  =
    •j _ g — Dose/k
  Based on the maximum likelihood
estimate of k (238), the probability of
infection from ingesting a single oocyst
(1/k) is approximately 0.4% (4 persons
infected for every 1,000 who each ingest
one oocyst).  Based on the same estimate,
the dose at which 50% of persons
become infected (known as the median
infectious dose or ID50) is 165.
2. New Data on Cryptosporidium
Infectivity
  A study of two additional
Cryptosporidium isolates was
conducted at the University of Texas-
Houston Health Science Center
(Okhuysen et al. 1999). One of the
isolates (UCP) was originally collected
from naturally infected calves. The
other isolate (TAMU) was originally
collected from a veterinary student who
became infected during necropsy on an
infected foal.
  The TAMU and UCP studies were
conducted with 14 and 17 subjects,
respectively. Because thousands of
oocysts per gram of stool can go
undetected, researchers elected to use
both stool test results and symptoms as
markers of infection (only stool test
results had been used for the IOWA
study). Under this definition, two
additional IOWA subjects were regarded
as having been infected. As shown in
Table III-l, all but two of the TAMU
subjects were presumed infected and all
but six of the UCP subjects were
presumed infected following ingestion
of the indicated oocyst doses.

TABLE         MM.—Cryptosporidium
  Parvum   INFECTIVITY   IN  HEALTHY
  ADULT VOLUNTEERS
 TABLE         III-1.—Cryptosporidium
   Parvum   INFECTIVITY  IN  HEALTHY
   ADULT VOLUNTEERS—Continued
Isolate and dose
(# of oocysts)
IOWA:
30 	
100 	
300 	
500 	
1,000 	
10,000 	
100,000 	
1,000,000 	
TAMU:
10 	
30 	
100 	
Number of
subjects 1
5
8
3
6
2
3
1
1
3
3
3
Number in-
fected 1
2
4
2
5
2
3
1
1
2
2
3
Isolate and dose
(# of oocysts)
500 	
UCP:
500 	
1,000 	
5,000 	
10.000 	
Number of
subjects 1
5
5
3
5
4
Number in-
fected 1
5
3
2
2
4
       two right columns list the number of
 subjects belonging to each category.
  EPA conducted a meta-analysis of
 these results in which the three isolates
 were considered as a random sample (of
 size three) from a larger population of
 environmental oocysts (Messner et al.
 2001). This meta analysis was reviewed
 by the Science Advisory Board (SAB). In
 written comments from a December
 2001 meeting of the Drinking Water
 Committee, SAB members
 recommended the following: (1) two
 assumed infectivity distributions (of
 parameter r = 1/k as logit normal and
 logit-t) should be used in order to
 characterize uncertainty and (2) EPA
 should consider excluding the UCP data
 set because it seems to be an outlier (see
 Section VII.K). In response, EPA has
 used the two recommended
 distributions for infectivity and has
 conducted the meta-analysis both with
 and without the UCP data due to
 uncertainty about whether it is
 appropriate to exclude these data.
  Table HI-2 presents meta-analysis
 estimates of the probability of infection
 given one oocyst ingested. Results are
 shown for the four different analysis
 conditions (log normal and log-t
 distributions; with and without UCP
 data) as well as a combined result
derived by sampling equally from each
distribution, A more complete
description of the infectivity analysis is
provided in Economic Analysis for the
LT2ESWTR (USEPA 2003a).
                          TABLE 111-2.—RISK OF INFECTION, GIVEN ONE OOCYST INGESTED
Basis for analysis
Studies used
IOWA, TAMU, and UCP 	 	
IOWA, TAMU, and UCP 	 	 	
IOWA and TAMU 	
IOWA and TAMU 	


Distributional model

Student's t {3df}1 	

Student's t (3df) 1 	


Probability of infection,
one oocyst ingested
Mean
0.07
0.09
0.09
0.10
0.09
80% Cred-
ible interval
0.007-0.19
0.015-0.20
0.011-0.23
0.014-0.25
0.011-0.22
  ' Student's t distribution with 3 degrees of freedom (3df)-

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Federal  Register/Vol. 68, No. 154/Monday, August 11. 2003/Proposed Rules
  The results in Table III-2 show that
the mean probability of infection from
ingesting a single infectious oocyst
ranges from 7% to 10% depending on
the assumptions used. In comparison,
the best estimate in the IESWTR of this
probability was 0.4%, based on the
IOWA isolate alone, and using the
earlier definition of infection. Thus,
these data suggest that both the range
and magnitude of Cryptosporidium
infectivity is higher than was estimated
in the final IESWTR.
  It should be noted that although
significantly more data on
Cryptosporidium infectivity are
available now than when EPA
established the IESWTR, there remains
uncertainty about this parameter in
several areas. It is unknown how well
the oocysts used in the feeding studies
represent Cryptosporidium naturally
occurring in the environment, and the
analyses do not fully account for
variability in host susceptibility and the
effect of previous infections.
Furthermore, the sample sizes are
relatively small, and the confidence
bands on the estimates span more than
an order of magnitude. Another
limitation is that none of the studies
included doses below  10 oocysts, while
when people ingest oocysts in drinking
water it is usually a single oocyst.
3. Significance of New Infectivity Data
   The new infectivity  data reveal  that
oocysts vary greatly in their ability to
infect human hosts. Moreover, due to
this variability and the finding of a
highly infectious isolate, TAMU, the
overall population of oocysts appears to
be more infective than assumed for the
IESWTR. The meta-analysis described
earlier indicates the probability of
infection at low Cryptosporidium
concentrations may be about 20 times as
great as previously estimated (which
was based on the IOWA isolate alone
 and using the earlier definition of
 infection (stool-confirmed  infections)).
 C. Cryptosporidium Occurrence
   This section presents information on
 the occurrence of Cryptosporidivm
 oocysts in drinking water sources.
 Occurrence information is  important
 because it is used in assessing the risk
 associated with Cryptosporidium in
 both filtered and unfiltered systems, as
 well as in estimating the costs and
 benefits of the proposed LT2ESWTR.
   For the IESWTR, EPA had no national
 survey data and relied instead on
 several studies that were local or
 regional. Those data suggested that a
 typical (median) filtered surface water
 source had approximately  2
 Cryptosporidium oocysts per liter, while
                      a typical unfiltered surface water source
                      had about 0.01 oocysts per liter, a
                      difference of two orders of magnitude.
                        Subsequent to promulgating the
                      IESWTR, EPA obtained data from two
                      national surveys: the Information
                      Collection Rule and the Information
                      Collection Rule Supplemental Surveys
                      (ICRSSJ. These surveys were designed to
                      provide improved estimates of
                      occurrence on a national basis. As
                      described in more detail later in this
                      section, the Information Collection Rule
                      and ICRSS results show three main
                      differences in comparison to
                      Cryptosporidium occurrence data used
                      for the IESWTR:
                        (1) Average Cryptosporidium occurrence is
                      lower. Median oocyst levels for the
                      Information Collection Rule and ICRSS data
                      are approximately 0.05/L, which is more than
                      an order of magnitude lower than IESWTR
                      estimates.
                        (2) Cryptosporidium occurrence is more
                      variable from location to location than was
                      shown by the data considered for the
                      IESWTR. This indicates that although
                      median occurrence levels are below those
                      assumed for the IESWTR, there is a subset of
                      systems whose levels are considerably greater
                      than the median.
                        (3) There is a smaller difference in
                      Cryptosporidium levels between typical
                      filtered and unfiltered system water sources.
                      The Information Collection Rule data do not
                      support the IESWTR finding that unfiltered
                      water systems have a risk of
                      cryptosporidiosis equivalent to that of a filter
                      plant with average quality source water.
                        This section begins with a summary
                      of occurrence data that were used to
                      assess risk under the IESWTR  (these
                      data were also used in the main risk
                      assessment for the LTlESWTR). This is
                      followed by a discussion of the
                      Information Collection Rule and ICRSS
                      that covers the scope of the surveys,
                      analytical methods, results, and a
                      characterization of how these new data
                      impact current understanding of
                      Cryptosporidium exposure. A  more
                      detailed description of occurrence data
                      is available in Occurrence and Exposure
                      Assessment for the Long Term 2
                      Enhanced Surface Water Treatment Rule
                       (USEPA 2003b).
                       1. Occurrence Data Evaluated  for
                      IESWTR
                         Occurrence information evaluated for
                      the IESWTR is detailed in Occurrence
                      and Exposure Assessment for The
                      Interim Enhanced Surface Water
                      Treatment Rule (USEPA 1998c). This
                       information is summarized in the next
                      two paragraphs.
                         a. Filtered systems. In developing the
                       IESWTR, EPA evaluated
                       Cryptosporidium occurrence data from a
                       number of studies.  Among these studies,
LeChevallier and Norton (1995)
produced the largest data set and data
from this study were used for the
IESWTR risk assessment. This study
provided estimates of mean occurrence
at 69 locations from the eastern and
central U.S. Although limited by the
small number of samples per site (one
to sixteen samples; most sites were
sampled five times), variation within
and between sites appeared to be
lognormal.  The study's median
measured source water concentration
was 2.31 oocysts/L and the interquartile
range (i.e.,  25th and 75th percentile)
was 1.03 to 5.15 oocysts/L.
  b.  Unfiltered systems. To assess
Cryptosporidium occurrence in
unfiltered systems under the IESWTR,
EPA evaluated Cryptosporidium
monitoring results from several
unfiltered water systems that had been
summarized by the Seattle Water
Department (Montgomery Watson,
1995). The median (central tendency) of
these data was approximately 0.01
oocysts/L.  Thus, the median
concentration in these data set was
about 2 orders of magnitude less than
the median concentration in the data set
used for filtered systems. These data,
coupled with the assumption that
filtered systems will remove at least 2
log of Cryptosporidium as required by
the IESWTR, suggested that unfiltered
systems that comply with the source
water requirements of the SWTR may
have a risk of cryptosporidiosis
equivalent to that of a filter plant using
a water source of average quality (62 FR
59507, November 3,1997) (USEPA
1997a).
2. Overview of the Information
Collection Rule and Information
Collection Rule Supplemental Surveys
(ICRSS)
   The Information Collection Rule and
the Information Collection Rule
Supplemental Surveys (ICRSS) were
national monitoring studies. They were
 designed to provide EPA with a more
 comprehensive understanding of the
 occurrence of microbial pathogens in
 drinking water sources in order to
 support regulatory decision making. The
 surveys attempted to control protozoa
 measurement error through requiring
 that (1) laboratories meet certain
 qualification criteria, (2) standardized
 methods be used to collect data, and (3)
 laboratories analyze performance
 evaluation samples throughout the
 duration of the study to ensure adequate
 analytical  performance. Information
 Collection Rule monitoring took place
 from July 1997 to December 1998;
 ICRSS Cryptosporidium monitoring

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                                                                    47653
began in March 1999 and ended in
February 2000.
  a. Scope of the Information Collection
Rule. The Information Collection Rule
(61 FR 24354, May 14,1996) (USEPA
1996a) required large PWSs to collect
water quality and treatment data related
to DBFs and microbial pathogens over
an 18-month period. PWSs using surface
water or ground water under the direct
influence of surface water as sources
and serving at least 100,000 people were
required to monitor their raw water
monthly for Cryptosporidium, Giardia,
viruses, total coliforms, and E. coli.
Approximately 350 plants monitored for
microbial parameters.
  b. Scope of the ICHSS. The ICRSS
were designed to complement the
Information Collection Rule* data set
with data from systems serving fewer
than 100,000 people and by employing
an improved analytical method for
protozoa (described later). The ICRSS
included 47 large systems (serving
greater than 100,000 people), 40
medium systems (serving 10,000 to
100,000 people) and 39 small systems
(serving fewer than 10,000 people).
Medium and large systems conducted 1
year of twice-per-month sampling for
Cryptosporidium, Giardia , temperature,
pH, turbidity, and coliforms.  Other
water quality measurements were taken
once a month.  Small systems did not
test for protozoa but tested for all other
water quality parameters.
3. Analytical Methods for Protozoa in
the Information Collection Rule and
ICRSS
   This subsection describes analytical
methods for Cryptosporidium that were
used in the Information Collection Rule
and ICRSS. Information on
Cryptosporidium analytical methods is
important for the LT2ESWTR for several
reasons: (1)  It is relevant to the quality
of Cryptosporidium occurrence data
used to assess  risk and economic impact
of the LT2ESWTR proposal, (2) it
provides a basis for the statistical
procedures employed to analyze the
occurrence data, and (3) it is used to
assess the adequacy of Cryptosporidium
methods to support source-specific
decisions under the LT2ESWTR.
   The Information Collection Rule and
ICRSS data sets were generated using
different analytical methods. The
Information Collection Rule Protozoan
Method (ICR Method) was used to
analyze water samples for
Cryptosporidium during the Information
Collection Rule. For the ICRSS, a similar
but improved method, EPA Method
1622 (later 1623), was used for protozoa
analyses (samples  were analyzed for
Cryptosporidium using Method 1622 for
the first 4 months; then Method 1623
was implemented so that Giardia
concentrations could also be measured).
  a. Information Collection Rule
Protozoan Method. With the
Information Collection Rule Method
(USEPA 1996b), samples were collected
by passing water through a filter, which
was then delivered to an EPA-approved
Information Collection Rule laboratory
for analysis. The laboratory eluted the
filter, centrifuged the eluate, and
separated  Cryptosporidium oocysts and
Giardia cysts from other debris by
density-gradient centrifugation. The
oocysts and cysts were then stained and
counted. Differential interference
contrast (DIG) microscopy was used to
examine internal structures.
  The Information Collection Rule
Method provided a quantitative
measurement of Cryptosporidium
oocysts and Giardia cysts, but it is
believed to have generally
undercounted the actual occurrence
(modeling, described later, adjusted for
undercounting). This undercounting
was due to low volumes analyzed and
low method recovery. The volume
analyzed directly influences the
sensitivity of the analytical method and
the Information Collection Rule Method
did not require a specific volume
analyzed.  As a result, sample volumes
analyzed during the Information
Coilection Rule varied widely,
depending on the water matrix and
analyst discretion, with a median
volume analyzed of only 3 L.
   Method recovery characterizes the
likelihood that an oocyst present in the
original sample will be counted. Loss of
organisms may occur at any step of the
analytical process, including filtration,
elution, concentration of the eluate, and
purification of the concentrate. To
assess the performance of the
Information Collection Rule Method,
EPA implemented the Information
Collection Rule Laboratory Spiking
Program. This program involved
collection of duplicate samples on two
dates from 70 plants. On each occasion,
one of the duplicate samples was spiked
with  a known quantity of Giardia cysts
and Cryptosporidium oocysts (the
quantity was unknown to the  laboratory
performing the analysis), and  both
samples were processed according to
the method. Recovery of spiked
Cryptosporidium oocysts ranged from
0% to 65% with a mean of 12% and a
standard deviation nearly equal to the
mean (relative standard deviation (RSD)
approximately 100%) (Scheller et al
2002).
   b. Method 1622 and Method 1623.
EPA developed Method 1622  (detects
Cryptosporidium) and 1623 (detects
Cryptosporidium and Giardia) to
achieve higher recovery rates and lower
inter- and intra-laboratory variability
than previous methods. These methods
incorporate improvements in the
concentration, separation, staining, and
microscope examination procedures.
Specific improvements include the use
of more effective filters,
immunomagnetic separation (IMS) to
separate the oocysts and cysts from
extraneous materials present in the
water sample, and the addition of 4, 6-
diamidino-2-phenylindole (DAPI) stain
for microscopic analysis. The
performance of these methods was
tested through single-laboratory studies
and validated through multiple-
laboratory validation (round robin)
studies.
  The per-sample volume analyzed for
Cryptosporidium during the ICRSS was
larger than in the Information Collection
Rule, due to a requirement that
laboratories analyze a minimum of 10 L
or 2  mL of packed pellet with Methods
1622/23 (details in section IV.K). To
assess method recovery, matrix spike
samples were analyzed on five sampling
events for each plant. The protozoa
laboratory spiked the additional sample
with a known quantity of
Cryptosporidium oocysts and Giardia
cysts (the quantity was unknown to the
laboratory performing the analysis) and
filtered and analyzed both samples
using Methods 1622/23. Recovery in the
ICRSS matrix spike study averaged 43%
for Cryptosporidium with an RSD of
47% (Conneli et al. 2000). Thus, mean
Cryptosporidium recovery with
Methods 1622/23 under the ICRSS was
more than 3.5 times higher than mean
recovery in the Information Collection
Rule lab spiking program and relative
standard deviation was reduced by more
than half.
  Although Methods 1622 and 1623
have several advantages over the
Information Collection Rule method,
they also have some of the same
limitations. These methods do not
determine whether a cyst or oocyst is
viable and infectious, and both methods
require a skilled microscopist and
several hours of sample preparation and
analyses.
4. Cryptosporidium Occurrence Results
from the Information Collection Rule
and ICRSS
  This section describes
 Cryptosporidium monitoring results
from the Information Collection Rule
and ICRSS. The focus of this discussion
is the national distribution  of mean
 Cryptosporidium occurrence levels in
the sources of filtered and unfiltered
plants.

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   Federal Register/Vol. 68, No. 154/Monday, August 11, 2003/Proposed Rules
  The observed (raw, unadjusted)
Cryptosporidium data from the
Information Collection Rule and ICRSS
do not accurately characterize true
concentrations because of (a) the low
and variable recovery of the analytical
method, (b) the small volumes analyzed,
and (c) the relatively small number of
sample events. EPA employed a
statistical treatment to estimate the true
underlying occurrence that led to the
data observed in the surveys and to
place uncertainty bounds about that
estimation.
  A hierarchical model with Bayesian
parameter estimation techniques was
used to separately analyze filtered and
unfiltered system data from the
Information Collection Rule and the
                        large and medium system data from the
                        ICRSS. The model included parameters
                        for location, month, source water type,
                        and turbidity. Markov Chain Monte
                        Carlo methods were used to estimate
                        these parameters, producing a large
                        number of estimate sets that represent
                        uncertainty. This analysis is described
                        more completely in Occurrence and
                        Exposure Assessment for the Long Term
                        2 Enhanced Surface Water Treatment
                        Rule (USEPA 2003b).
                         a. Information Collection Rule results.
                        Figure HI-1 presents plant-mean
                        Cryptosporidium levels for Information
                        Collection Rule  plants as a cumulative
                        distribution. Included in Figure III-l  are
                        distributions of  both the observed raw
                        data adjusted for mean analytical
                                                                  method recovery of 12% and the
                                                                  modeled estimate of the underlying
                                                                  distribution, along with 90% confidence
                                                                  bounds. The two distributions (observed
                                                                  and modeled) are similar for plants
                                                                  where Cryptosporidium was detected
                                                                  (196 of 350 Information Collection Rule
                                                                  plants did not detect Cryptosporidium
                                                                  in any source water samples). The
                                                                  modeled distribution allows for
                                                                  estimation of Cryptosporidium
                                                                  concentrations in sources where oocysts
                                                                  may have been present but were not
                                                                  detected due to low sample volume and
                                                                  poor method recovery (this concept is
                                                                  explained further later in this section).
                                                                  BILLING CODE 6560-50-P
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                                                                                            47655
Collection Rule data is broader (i.e.,
more source-to-source variability). Also,
the occurrence of Cryptosporidium in
flowing stream sources was greater and
more variable than in reservoir/lake
sources (shown in USEPA 2003b).
  The fact that only 44% of Information
Collection Rule plants had one or more
samples positive for Cryptosporidium
and that only 7% of all Information
Collection Rule samples were positive
for Cryptosporidium suggests that
oocyst levels were relatively low in
many source waters. However, as noted
earlier, it is expected that
Cryptosporidium oocysts were present
in many more source waters at the time
                           of sampling and were not detected due
                           to poor analytical method recovery and
                           low sample volumes.
                             This concept is illustrated by Figure
                           III-2, which shows the likelihood of no
                           oocysts being detected by the
                           Information Collection Rule method as
                           a function of source water concentration
                           (assumes median Information Collection
                           Rule sample volume of 3 L). As can be
                           seen in Figure III—2, when the source
                           water concentration is 1 oocyst/L,
                           which is a relatively high level, the
                           probability of no oocysts being detected
                           in a 3 L sample is 73%; for a source
                           water with 0.1 oocyst/L, which is close
                           to the median occurrence level, the
probability of a non-detect is 97%.
Consequently, EPA has concluded that
it is appropriate and necessary to use a
statistical model to estimate the
underlying distribution.
  EPA modeled Cryptosporidium
occurrence separately for filtered and
unfiltered plants that participated in the
Information Collection Rule because
unfiltered plants comply with different
regulatory requirements than filtered
plants. As shown in Table III—3, the
occurrence of Cryptosporidium was
lower for unfiltered sources.
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       Figure 111-2.-- Probability of No Oocysts Being Detected by the Information

       Collection Rule Method as a Function of Source Water Cryptosporidium

       Concentration
BILLING CODE 6560-50-C

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Federal Register/Vol. 68, No.  154/Monday, August 11, 2003/Proposed Rules
   TABLE 111-3.—- SUMMARY OF INFORMATION COLLECTION RULE Cryptosporidium MODELED SOURCE WATER DATA FOR
                                        UNFJLTERED AND FILTERED PLANTS

                                                                                            Information collection rule
                                                                                              modeled plant-mean
                                                                                                 (oocysts/L)






Mean
0.014
0.59


Median
0.0079
0.052

90th
per-
centile
0.033
1.4

  The median Cryptosporidium
occurrence level for unfiltered systems
in the Information Collection Rule was
0.0079 oocysts/L, which is close to the
median level of 0.01 oocysts/L reported
for unfiltered systems in the IESWTR
(Montgomery Watson, 1995). However,
the Information Collection Rule data do
not show the 2 log difference in median
Cryptosporidium levels between filtered
and unfiltered systems that was
observed for the data used in the
IESWTR. The ratio of median plant-
mean occurrence in  unfiltered plants to
filtered plants is about 1:7 (see Table
III-3). Thus, based on an assumption of
a minimum 2 log removal of
Cryptosporidium by filtration plants (as
required by the IESWTR and
LT1ESWTR), these data indicate that, on
average, finished water oocysts levels
are higher in unfiltered systems than in
filtered systems.
  b. ICRSS results. Figures III-3 and III-
4 present plant-mean Cryptosporidium
                      levels for ICRSS medium and large
                      systems, respectively, as cumulative
                      distributions. Medium and large system
                      data were analyzed separately to
                      identify differences between the two
                      data sets. Similar to the Information
                      Collection Rule data plot, Figures III-3
                      and III-4 include distributions for both
                      the observed raw data adjusted for mean
                      analytical method recovery of 43% and
                      the modeled estimate of the underlying
                      distribution, along with 90% confidence
                      bounds. The observed and modeled
                      distributions are similar for the 85% of
                      ICRSS plants that detected
                      Cryptosporidium, and the modeled
                      distribution allows for estimation of
                      Cryptosporidium concentrations for
                      source waters where oocysts may have
                      been present but were not detected.
                       Plant-mean Cryptosporidium
                      concentrations for large and medium
                      systems in the ICRSS are similar at the
                      mid and lower range of the distribution
                      and differ at the upper end. ICRSS
medium and large systems both had
median plant-mean Cryptosporidium
levels of approximately 0.05 oocysts/L,
which is close to the median oocyst
level in the Information Collection Rule
data set as well. However, the 90th
percentile plant-mean was 0.33 oocysts/
L for ICRSS medium systems and 0.24
oocysts/L for ICRSS large systems. Note
that in the Information Collection Rule
distribution, the 90th percentile
Cryptosporidium concentration is 1.3
oocysts/L, which is significantly higher
than either the ICRSS medium or large
system distribution.
  The reasons for different results
between the surveys are not well
understood, but may stem from year-to-
year variation in occurrence, systematic
differences in the sampling or
measurement methods employed, and
differences in the populations sampled.
This topic is discussed further at the
end of this section.
BILLING CODE 6560-50-P

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                                                                           47657
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         detected no oocysts
                     -o-o-o-o-o/o^oy
                                                  Modeled Distribution
                                              (with 90% confidence bounds)
      1e-005   0.0001    0.001     0.01       0.1        1        10
                 Plant-Mean Cryptosporidium Concentration (oocysts/L)
                                                                        100
       Figure III-3.-- Plant-Mean Cryptosporidium Levels for ICRSS Medium Plants

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               -o-o-o-o-o-a-o-o-o-o-o-q/
                6 of 40 plants
            detected no oocysts
                                                                             0,0  o  o  o
                                                                       Modeled Distribution
                                                                 (with 90% confidence bounds)
             1e-005    0.0001     0.001       0.01         0.1          1          10
                           Plant-Mean Cryptosporidium Concentration (oocysts/L)
                                                                                              100
                Figure III-4.-- Plant-Mean Cryptosporidium Levels for ICRSS Large Plants
BILLING CODE 6560-SO-C
  5. Significance of new
Cryptosporidium occurrence data.
  The Information Collection Rule and
ICRSS data substantially improve
overall knowledge of the occurrence
distribution of Cryptosporidium in
drinking water sources. They provide
data on many more water sources than
were available when the IESWTR was
developed and the data are of more
uniform quality. In regard to filtered
systems, these new data demonstrate
two points:
  (1) The occurrence of Cryptosporidium in
many drinking water sources is lower than
was indicated by the data used in IESWTR.
Median plant-mean levels for the Information
Collection Rule and ICRSS data sets are
approximately 0.05 oocysts/L, whereas the
median oocyst concentration in the
LeChevallier and Norton (1995) data used in
the IESWTR risk assessment was 2.3 oocysts/
L.
  (2) Cryptosporidium occurrence is more
variable from plant to plant than was
indicated by the data considered for the
IESWTR (i.e., occurrence distribution is
                                broader). This is illustrated by considering
                                the ratio of the 90th percentile to the median
                                plant-mean concentration. In the
                                LeChevallier and Norton (1995) data used for
                                the IESWTR, this ratio was 4.6, whereas in
                                the Information Collection Rule data, this
                                ratio is 27.
                                  These data, therefore, support the
                                finding that Cryptosporidium levels are
                                relatively low in most water sources, but
                                there is a subset of sources with
                                relatively higher concentrations where
                                additional treatment may be
                                appropriate.
                                  In regard  to unfiltered plants, the
                                Information Collection Rule data are
                                consistent with the Cryptosporidium
                                occurrence  estimates for unfiltered
                                systems in the IESWTR. However, due
                                to the lower occurrence estimates for
                                filtered systems noted previously, the
                                Information Collection Rule data do not
                                support the IESWTR finding that
                                unfiltered water systems in compliance
                                with the source water requirements of
                                the SWTR have a risk of
                                cryptosporidiosis equivalent to that of a
                                                                  well-operated filter plant using a water
                                                                  source of average quality (63 FR 69492,
                                                                  December 16,1998) (USEPA 1998a).
                                                                  Rather, these data indicate that Agency
                                                                  conclusions regarding the risk
                                                                  comparison between unfiltered and
                                                                  filtered drinking waters must be revised.
                                                                  For protection equivalent to that
                                                                  provided by filtered systems, unfiltered
                                                                  systems must take additional steps to
                                                                  strengthen their microbial barriers.

                                                                  6. Request for Comment on Information
                                                                  Collection Rule and ICRSS Data Sets
                                                                    EPA notes that there are significant
                                                                  differences in the Information
                                                                  Collection Rule and ICRSS medium and
                                                                  large system data sets. The median
                                                                  values for these data sets are 0.048,
                                                                  0.050, and 0.045 oocysts/L, respectively,
                                                                  while the 90th percentile values are 1.3,
                                                                  0.33, and 0.24 oocysts/L. The reasons
                                                                  for these differences are not readily
                                                                  apparent. The ICRSS used a newer
                                                                  method with better  quality control that
                                                                  yields significantly  higher recovery, and
                                                                  this suggests that these data are more

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                 Federal Register/Vol.  68, No. 154/Monday, August 11, 2003/Proposed  Rules
                                                                      47659
 reliable for estimating concentrations at
 individual plants. However, the
 Information Collection Ruie included a
 much larger number of plants (350 v. 40
 each for the ICRSS medium and large
 system surveys) and, consequently, may
 be more reliable for estimating
 occurrence nationally. The surveys
 included a similar number of samples
 per plant (18 v. 24 in the ICRSS). The
 two surveys cover different time periods
 (7/97-12/98 for the Information
 Collection Rule and 3/99-2/00 for the
 ICRSS),
   In order to better understand the
 factors that may account for the
 differences in the three data sets, EPA
 conducted several additional analyses.
 First, EPA compared results for the
 subset of 40 plants that were in both the
 Information Collection Rule and ICRSS
 large system surveys. The medians for
 the two data sets were 0.13 and 0.045
 oocysts/L, respectively, while the 90th
 percentiles were 1.5 and 0.24 oocysts/L.
 Clearly, the discrepancy between the
 two surveys persists for the subsample
 of data from plants that participated in
 both surveys. This suggests that the
 different sample groups in the full data
 sets are not the primary factor that
 accounts for the different results.
   Next, EPA looked at the six month
 period (July through December) that was
 sampled in two consecutive years (1997
 and 1998) during  the Information
 Collection Rule survey to investigate
 year-to-year variations at the same
 plants. Estimated  medians for 1997 and
 1998 were 0.062 and 0.040 oocysts/L,
 respectively, while the 90th percentiles
 were 1.1 and 1.3 oocysts/L. While these
 comparisons show some interyear
 variability, it is less than the variability
 observed between the Information
 Collection Rule and ICRSS data sets.
 EPA has no data comparing the same
 plants using the same methods for the
 time periods in question (1997-98 and
 1999-2000) so it is not known if the
 variation between these time periods
 was larger than the apparent variation
 between 1997 and 1998 in the
 Information Collection Rule data set.
  The choice of data set has a
 significant effect on exposure, cost, and
 benefit estimates for the LT2ESWTR.
Due to the lack of any clear criterion for
 favoring one data set over the other,
EPA has conducted the analyses for this
proposed rule separately for each, and
presents a range of estimates based on
the three data sets. EPA requests
comment on this approach. EPA will
 continue to evaluate the relative
 strengths and limitations of the three
data sets, as well as any new data that
may become available for the final rule.
 D. Treatment
 1. Overview

   This section presents information on
 treatment processes for reducing the risk
 from Cryptosporidium in drinking
 water. Treatment information is critical
 to two aspects of the LT2ESWTR: (1)
 estimates of the efficiency of water
 filtration plants in removing
 Cryptosporidium are used in assessing
 risk in treated drinking water and (2) the
 performance and availability of
 treatment technologies like ozone, UV
 light, and membranes that effectively
 inactivate or remove Cryptosporidium
 impact the feasibility of requiring
 additional treatment for this pathogen.
   The majority of plants treating surface
 water use conventional filtration
 treatment, which is defined in 40 CFR
 141.2 as a series of processes including
 coagulation,  flocculation,
 sedimentation, and filtration. Direct
 filtration, which is typically used on
 sources with low particulate levels,
 includes coagulation and filtration but
 not sedimentation. Other common
 filtration processes are slow sand,
 diatomaceous earth (DE), membranes,
 and bag and cartridge filters.
  For the IESWTR (and later the
 LT1ESWTR), EPA evaluated results
 from pilot and full scale studies of
 Cryptosporidium removal by various
 types of filtration plants. Based on these
 studies, EPA concluded that
 conventional and direct filtration plants
 meeting IESWTR filter effluent turbidity
 standards will achieve a minimum 2 log
 (99%) removal of Cryptosporidium. The
 Agency reached the same conclusion for
 slow sand and DE filtration plants
 meeting SWTR turbidity standards.
 Treatment credit for technologies like
 membranes and bag and cartridge filters
 was to be made on a product-specific
 basis.
  Subsequent to promulgating the
 IESWTR and  LTlESWTR, EPA has
 reviewed additional studies of the
 performance of treatment plants in
 removing Cryptosporidium, as well as
 other micron  size particles (e.g., aerobic
 spores) that may serve as indicators of
 Cryptosporidium removal. As discussed
 later in this section, the Agency has
 concluded that these  studies support an
 estimate of 3 log (99.9%) for the average
 Cryptosporidium removal efficiency  of
 conventional  treatment plants in
 compliance with the IESWTR or
 LTlESWTR. Section IV.A describes how
this estimate of average removal
 efficiency is used in determining the
 need for additional Cryptosporidium
treatment under the LT2ESWTR.
Further, this estimate is consistent with
 the Stage 2 M-DBP Agreement in
 Principle, which states as follows:
  The additional treatment requirements in
 the (LT2ESWTR) bin requirement table are
 based, in part, on the assumption that
 conventional treatment plants in compliance
 with the IESWTR achieve an average of 3 logs
 removal of Cryptosporidium.
  In addition, the Agency finds that
 available  data support an estimate of 3
 log average Cryptosporidium removal
 for well operated slow sand and DE
 plants. Direct filtration plants are
 estimated to achieve a 2.5 log average
 Cryptosporidium reduction, in
 consideration of the absence of a
 sedimentation process in these plants.
  The most significant developments in
 the treatment of Cryptosporidium since
 IESWTR promulgation are in the area of
 inactivation. During IESWTR
 development, EPA determined that
 available data were not sufficient to
 identify criteria for awarding
 Cryptosporidium treatment credit for
 any disinfectant. As presented in
 section IV.C.14, EPA has now acquired
 the necessary data to specify the
 disinfectant concentrations and contact
 times necessary to achieve different
 levels of Cryptosporidium inactivation
 with chlorine dioxide and ozone.
 Additionally, recent studies have
 demonstrated that UV light will produce
 high levels of Cryptosporidium and
 Giardia lamblia inactivation at low
 doses. Section IV.C.15 provides criteria
 for systems to achieve credit for
 disinfection of Cryptosporidium,
 Giardia lamblia, and viruses by UV.
  This section begins with a summary
 of treatment information considered for
 the IESWTR and LTlESWTR, followed
 by a discussion of additional data that
 EPA has evaluated since promulgating
 those regulations. Further information
 on treatment of Cryptosporidium is
 available in Technologies and Costs for
 Control of Microbial Contaminants  and
 Disinfection Byproducts (USEPA
 2003c), Occurrence and Exposure
 Assessment for the Long Term 2
 Enhanced Surface Water Treatment Rule
 (USEPA 2003b) and section IV.C of this
 preamble.

 2. Treatment information considered for
 the IESWTR and LTlESWTR
  Treatment studies that were evaluated
 during development of the IESWTR are
 described  in the IESWTR NODA (62 FR
 59486, November 3,1997) (USEPA
 1997b), the Regulatory Impact Analysis
for the IESWTR (USEPA 1998d), and
Technologies and Costs for the
Microbial Recommendations of the M/
DBF Advisory Committee (USEPA
1997b). Treatment information
considered in development of the

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LTlESWTR is described in the proposed
rule (65 FR 59486, April 10, 2000)
(USEPA 2000b). Pertinent information is
summarized in the following
paragraphs.
  a. Physical removal. EPA evaluated
eight studies on removal of
Cryptosporidium by rapid granular
filtration for the IESWTR. These were
Patania etal. (1995), Nieminski and
Ongerth (1995), Ongerth and Pecoraro
(1995), LeChevallieT and Norton (1992),
LeChevallier et ai. (1991), Foundation
for Water Research (1994), Kelley et al.
(1995), and West et al. (1994). These
studies included both pilot and full
scale plants.
  Full scale plants in these studies
typically demonstrated 2-3 log removal
of Cryptosporidium, and pilot plants
achieved up to almost 6 log removal
under optimized conditions. In general,
the degree of removal that can be
quantified in full  scale plants is limited
because Cryptosporidium levels
following filtration are often  below the
detection limit of the analytical method.
Pilot scale studies overcome this
limitation by seeding high
concentrations of oocysts to the plant
influent, but extrapolation of the
performance of a pilot plant to the
routine performance of full scale plants
is uncertain.
   Cryptosporidium removal  efficiency
in these studies was observed to depend
on a number of factors including: water
matrix, coagulant application, treatment
optimization, filtered water turbidity,
and the filtration cycle. The highest
removal rates were observed in plants
that achieved very low effluent
turbidities.
   EPA also evaluated studies of
Cryptosporidium removal by slow sand
(Schuler and Ghosh 1991, Timms et al.
1995) and DE filtration (Schuler and
Gosh 1990) for the IESWTR. These
studies indicated that a well designed
and operated plant using these
processes could achieve 3 log or greater
removal of Cryptosporidium.
   After considering these studies, EPA
concluded that conventional and direct
filtration plants in compliance with the
effluent turbidity criteria of the
IESWTR, and slow sand and DE plants
in compliance with the effluent
turbidity criteria  established for these
processes by the SWTR, would  achieve
at  least 2 log removal of
 Cryptosporidium. Recognizing that
many plants will achieve more than the
minimum  2 log reduction, EPA
estimated median Cryptosporidium
removal among filtration plants as near
 3 log (99.9%) for the purpose of
 assessing risk.
                        The LTlESWTR proposal included
                      summaries of additional studies of
                      Cryptosporidium removal by
                      conventional treatment (Dugan et al.
                      1999), direct filtration (Swertfeger et al.
                      1998), and DE filtration (Ongerth and
                      Hutton 1997). These studies supported
                      IESWTR conclusions stated previously
                      regarding the performance of these
                      processes. The LTlESWTR proposal
                      also summarized studies of membranes,
                      bag filters, and cartridge filters
                      (Jacangelo et al. 1995, Drozd and
                      Schartzbrod 1997, Hirata and
                      Hashimoto 1998, Goodrich et al. 1995,
                      Collins et al. 1996, Lykins et al. 1994,
                      Adham et al. 1998}. This research
                      demonstrated that these technologies
                      may be capable of achieving 2 log or  .
                      greater removal of Cryptosporidium.
                      However, EPA concluded that variation
                      in performance among different
                      manufacturers and models necessitates
                      that determinations of treatment credit
                      be made on a technology-specific basis
                      (65 FR 19065, April 10,  2000) (USEPA
                      2000b).
                        b. Inactivation. In the IESWTR NODA
                      (62 FR 59486) (USEPA 1997a), EPA
                      cited studies that demonstrated that
                      chlorine is ineffective for inactivation of
                      Cryptosporidium at doses practical for
                      treatment plants (Korich et al. 1990,
                      Ransome et al. 1993, Finch et al 1997).
                      The Agency also summarized studies of
                      Cryptosporidium inactivation by UV,
                      ozone, and chlorine dioxide. EPA
                      evaluated these disinfectants  to
                      determine if sufficient data were
                      available to develop prescriptive
                      disinfection criteria for
                      Cryptosporidium.
                        the studies of UV disinfection of
                      Cryptosporidium that were available
                      during IESWTR development were
                      inconclusive due to methodological
                      factors. These studies included:
                      Lorenzo-Lorenzo et al. (1993), Ransome
                      et al. (1993), Campbell et al. (1995),
                      Finch et al. (1997), and Clancy  et al.
                      (1997). A common limitation among
                      these studies was the use of in vitro
                      assays, such as excystation and vital dye
                      staining, to measure loss of infectivity.
                      These assays subsequently were shown
                      to overestimate the UV  dose needed to
                      inactivate protozoa (Clancy et al. 1998,
                       Craik et al. 2000). In another case, a
                      reactor vessel that blocked germicidal
                       light was used (Finch et al. 1997).
                         EPA evaluated the following studies
                       of ozone inactivation of
                       Cryptosporidium for the IESWTR:
                       Peeters et al. (1989), Korich et al. (1990),
                       Parker et al. (1993), Ransome et al.
                       (1993), Finch etal. (1997), Daniel etal
                       (1993), and Miltner et al (1997). These
                       studies demonstrated that ozone could
                       achieve high levels of Cryptosporidium
inactivation, albeit at doses much higher
than those required to inactivate
Giardia. Results of these studies also
exhibited significant variability due to
factors like different infectivity assays
and methods of dose calculation.
  The status of chlorine dioxide
inactivation of Cryptosporidium during
IESWTR development was similar to
that of ozone. EPA evaluated a number
of studies that indicated that relatively
high doses of chlorine dioxide could
achieve significant inactivation of
Cryptosporidium (Peeters et al. 1989,
Korich et al. 1990, Ransome et al 1993,
Finch et al 1995 and 1997, and
LeChevallier et al 1997). Data from
these studies showed a high level of
variability  due to methodological
differences, and the feasibility of high
chlorine dioxide doses  was uncertain
due to the MCL for chlorite that was
established by the Stage 1 DBPR.
  After reviewing these studies, EPA
and the Stage 1 Federal Advisory
Committee concluded that available
data were not adequate to award
Cryptosporidium inactivation credit for
UV, ozone, or chlorine  dioxide.
3. New Information on  Treatment for
Control of Cryptosporidium
  a. Conventional filtration treatment
and direct filtration. This section
provides brief descriptions of seven
recent studies of Cryptosporidium
removal by conventional treatment and
direct  filtration, followed by a summary
of key points.
  Dugan et al (2001) evaluated the
ability of conventional treatment to
control Cryptosporidium under varying
water quality and treatment conditions,
and assessed turbidity, total particle
counts (TPC), and aerobic endospores as
indicators of Cryptosporidium removal.
Fourteen runs were conducted on a
small pilot scale plant that had been
 determined to provide equivalent
performance to a larger plant. Under
optimal coagulation conditions, oocyst
removal across the sedimentation basin
 ranged from 0.6 to 1.8 log, averaging 1.3
 log, and removal across the filters
ranged from 2.9 to greater than 4.4 log,
 averaging greater than  3.7 log. Removal
 of aerobic spores, TPC, and turbidity all
 correlated with removal of
 Cryptosporidium by sedimentation, and
 these parameters were conservative
 indicators of Cryptosporidium removal
 across filtration. Sedimentation removal
 under optimal conditions related to raw
 water quality, with the lowest
 Cryptosporidium removals observed
 when raw water turbidity was low.
   Suboptimal coagulation conditions
 (underdosed relative to jar test
 predictions) significantly reduced plant

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                                                                     47661
performance. Oocyst removal in the
sedimentation basin averaged 0.2 log,
and removal by filtration averaged 1.5
log. Under suboptimal coagulation
conditions, low sedimentation removals
of Cryptosporidium were observed
regardless of raw water turbidity.
  Nieminski and Bellamy (2000)
investigated surrogates as indicators of
Giardia and Cryptosporidium in source
water and as measures of treatment
plant effectiveness. It involved sampling
for microbial pathogens (Giardia,
Cryptosporidium, and enteric viruses),
potential surrogates (bacteria, bacteria
spores, bacterial phages, turbidity,
particles), and other water quality
parameters in the source and finished
waters of 23 surface water filtration
facilities and one unfiltered system.
  While Giardia and Cryptosporidium
were found in the majority of source
water samples, the investigators could
not establish a correlation between
either occurrence or removal of these
protozoa and any  of the surrogates
tested. This was attributed, in part, to
low concentrations of Giardia and
Cryptosporidium in raw water and high
analytical method detection limits.
Removal of Cryptosporidium and
Giardia averaged 2.2 and 2.6 log,
respectively, when conservatively
estimated using detection limits in
filtered water. Aerobic spores were
found in 85%  of filtered water samples
and were considered a measure of
general treatment effectiveness. Average
reduction of aerobic spores was 2.84 log.
Direct filtration plants removed fewer
aerobic spores than conventional or
softening plants.
  McTigue et al. (1998) conducted an
on-site survey of 100 treatment plants
for particle counts, pathogens
(Cryptosporidium and Giardia), and
operational information. The authors
also performed pilot scale spiking
studies. Median removal of particles
greater than 2 mm was 2.8 log, with
values ranging from 0.04 to 5.5 log.
Removal generally increased with
increasing raw water particle
concentration. Results were consistent
with previously collected data.
Cryptosporidium and Giardia were
found in the majority of raw water
sources, but calculation of their log
removal was limited by the
concentration present. River sources
had a higher incidence of pathogen
occurrence. Direct filtration plants had
higher levels of pathogens in the filtered
water than others  in the survey.
  Nearly all of the filter runs evaluated
in the survey exhibited spikes where
filtered water particle counts increased,
and pilot work showed that pathogens
are more likely to be released during
these spike events. Cryptosporidium
removal in the pilot scale spiking study
averaged nearly 4 log, regardless of the
influent oocyst concentration. Pilot
study results indicated a strong
relationship between removal of
Cryptosporidium and removal of
particles (> 3 \im] during runs using
optimal coagulation and similar
temperatures.
  Patania et al (1999) evaluated
removal of Cryptosporidium at varied
raw water and filter effluent turbidity
levels using direct filtration. Runs were
conducted with both low (2 NTU) and
high (10 NTU) raw water turbidity.
Targeted filtered water turbidity was
either 0.02 or 0.05 NTU. At equivalent
filtered water turbidity,
Cryptosporidium removal was slightly
higher when the raw water turbidity
was higher. Also, Cryptosporidium
removal was enhanced by an average of
1.5 log when steady-state filtered water
turbidity was 0.02 NTU compared to
0.05  NTU.
  Huck et al. (2000) evaluated filtration
efficiency during optimal and
suboptimal coagulation conditions with
two pilot scale filtration plants. One
plant employed a high coagulation dose
for both total organic carbon (TOC) and
particle removal, and the second plant
used a low dose intended for particle
removal only.  Under optimal operating
conditions, which were selected to
achieve filtered water turbidity below
0.1 NTU, median  Cryptosporidium
removal was 5.6 log at the high
coagulant dose plant and 3 log at the
low dose plant. Under suboptimal
coagulation conditions, where the
coagulant dose was reduced to achieve
filtered water turbidity of 0.2 to 0.3
NTU, median Cryptosporidium
removals dropped to 3.2 log and 1 log
at the high dose and low dose plants,
respectively. Oocyst removal also
decreased substantially at the end of the
filter cycle, although this was not
always indicated by an increase in
turbidity. Runs conducted with no
coagulant resulted in very little
Cryptosporidium removal.
  Emelko et al. (2000) investigated
Cryptosporidium removal during
vulnerable filtration periods using a
pilot scale direct filtration system. The
authors evaluated four different
operational conditions: stable, early
breakthrough,  late breakthrough, and
end of run. During stable operation,
effluent turbidity was approximately
0.04  NTU and Cryptosporidium removal
ranged from 4.7 to 5.8 log. In the early
breakthrough period, effluent turbidity
increased from approximately 0.04 to
0.2 NTU, and Cryptosporidium removal
decreased significantly, averaging 2.1
log. For the late breakthrough period,
where effluent turbidity began at
approximately 0.25 NTU and ended at
0.35 NTU, Cryptosporidium removal
dropped to an average of 1.4  log. Two
experiments tested Cryptosporidium
removal during the end-of-run
operation, when effluent turbidities
generally start increasing. Turbidity
started at about 0.04 NTU for both
experiments and ended at 0.06 NTU for
the first experiment and 0.13 NTU for
the second. Reported Cryptosporidium
removal ranged from 1.8 to 3.3 log, with
an average of 2.5 log for both
experiments.
  Harrington et al. (2001) studied the
removal of Cryptosporidium  and
emerging pathogens by filtration,
sedimentation, and dissolved air
flotation (DAF) using bench scale jar
tests and pilot scale conventional
treatment trains. In the bench scale
experiments, all run at optimized
coagulant  doses, mean log removal of
Cryptosporidium was 1.2 by
sedimentation and 1.7 by DAF.
Cryptosporidium removal was similar in
all four water sources that were
evaluated  and was not significantly
affected by lower pH or coagulant  aid
addition. However, removal  of
Cryptosporidium was greater at  22°C
than at 5°C, and was observed to be
higher with alum coagulant than with
either polyaluminum
hydroxychlorosulfate or ferric chloride.
  In the pilot scale experiments, mean
log removal of Cryptosporidium was 1.9
in filtered water with turbidity of 0.2
NTU or less. Removal increased as
filtered water turbidity dropped below
0.3 NTU. There was no apparent effect
of filtration rate on removal efficiency.
In comparing Cryptosporidium removal
by sand, dual media (anthracite/sand),
and trimedia (anthracite/sand/garnet)
filters, no  difference was observed near
neutral pH. However, at pH 5.7, removal
increased  significantly in the sand filter
and it outperformed the other filter
media configurations. The authors
found no apparent explanation for this
behavior. There was no observable effect
of a turbidity spike on Cryptosporidium
removal.
Significance of Conventional and Direct
Filtration Studies
  The performance of treatment plants
under current regulations is  a significant
factor in determining the need for
additional treatment. As described in
section IV.A, the proposed
Cryptosporidium treatment
requirements associated with
LT2ESWTR risk bins for filtered systems
are based, in part, on an estimate that
conventional plants in compliance with

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the IESWTR achieve an average of 3 log
Cryptosporidium removal. The
following discussion illustrates why
EPA believes that available data support
this estimate.
  While Cryptosporidium removal at
full scale plants is difficult to quantify
due to limitations with analytical
methods, pilot scale studies show that
reductions in aerobic spores and total
particle counts are often conservative
indicators of filtration plant removal
efficiency for Cryptosporidium (Dugan
etal 2001, McTigue etal. 1998, Yates
etal. 1998, Emelko eiaJ. 1999 and
2000). Surveys of full scale plants have
reported average reductions near 3 log
for both aerobic spores (Nieminski and
Bellamy, 2000) and total particle counts
(McTigue et al 1998). Consequently,
these findings are consistent with an
estimate that average removal of
Cryptosporidium by filtration plants is
approximately 3 log.
  Pilot scale Cryptosporidium spiking
studies (Dugan et al. 2001, Huck et al.
2000, Emelko  et al. 2000, McTigue et a].
1998, Patania et al 1995) suggest that a
conventional treatment plant has the
potential to achieve greater than 5 log
removal of Cryptosporidium under
optimal conditions. However, these high
removals are typically observed at very
low filter effluent turbidity values, and
the data show that removal efficiency
can decrease substantially over the
course of a filtration cycle or if
coagulation is not optimized (Dugan et
al 2001, Huck et al 2000, Emelko et al
2000, Harrington  et al 2001). Removal
efficiency also appears to be impacted
by source water quality (Dugan et al
2001, McTigue et al 1998). Given these
considerations, EPA believes that 3 log
is a reasonable estimate of average
Cryptosporidium  removal efficiency for
conventional treatment plants in
compliance with the IESWTR or
LT1ESWTR.
  The Stage 2 M-DBP Advisory
Committee did not address direct
filtration plants, which lack the
sedimentation basin of a conventional
treatment train, but recommended that
EPA address these plants in the
LT2ESWTR proposal (65 FR 83015,
December 29, 2000) (USEPA 2000a).
While some studies have observed
similar levels of Cryptosporidium
removal in direct  and conventional
filtration plants (Nieminski and
Ongerth, 1995, Ongerth and Pecoraro
1995), EPA has concluded that the
majority of available data support a
lower estimate of Cryptosporidium
removal efficiency for direct filtration
plants.
  As described in section IV.C.5, pilot
and full scale studies demonstrate that
                      sedimentation basins, which are absent
                      in direct filtration, can achieve 0.5 log
                      or greater Cryptosporidium reduction
                      (Dugan et al 2001, Patania et al 1995,
                      Edzwald and Kelly 1998, Payment and
                      Franco 1993, Kelley et al 1995). In
                      addition, Patania et a]. (1995) observed
                      direct filtration to achieve less
                      Cryptosporidium removal than
                      conventional treatment, and McTigue et
                      al (1998) found a higher incidence of
                      Cryptosporidium in the treated water of
                      direct filtration plants. Given these
                      findings, EPA has estimated that direct
                      filtration plants achieve an average of
                      2.5 log Cryptosporidium reduction (i.e.,
                      0.5 log less than conventional
                      treatment).
                        i. Dissolved air flotation. Dissolved air
                      flotation (DAF) is  a solid-liquid
                      separation process that can be used in
                      conventional treatment trains in place of
                      gravity sedimentation. DAF takes
                      advantage of the buoyancy of oocysts by
                      floating oocyst/particle complexes to the
                      surface for removal. In DAF, air is
                      dissolved in pressurized water, which is
                      then released into a flotation tank
                      containing flocculated particles. As the
                      water enters the tank, the dissolved air
                      forms small bubbles that collide with
                      and attach to floe particles and float to
                      the surface (Gregory and Zabel, 1990).
                        In comparing DAF with gravity
                      sedimentation, Plummer et al (1995)
                      observed up to 0.81 log removal of
                      oocysts in the gravity sedimentation
                      process, while DAF achieved 0.38 to 3.7
                      log removal, depending on coagulant
                      dose. Edzwald and Kelley (1998)
                      demonstrated a 3 log removal of oocysts
                      using DAF, compared with a 1 log
                      removal using gravity sedimentation in
                      the clarification process before
                      filtration. In bench scale testing by
                      Harrington et al (2001), DAF averaged
                      0.5 log  higher removal of
                      Cryptosporidium than gravity
                      sedimentation. Based on these results,
                      EPA has concluded that a treatment
                      plant using DAF plus filtration  can
                      achieve levels of Cryptosporidium
                      removal equivalent to or greater than a
                      conventional treatment plant with
                      gravity sedimentation.
                        b. Slow sand filtration. Slow sand
                      filtration is a process involving passage
                      of raw water through a bed of sand at
                      low velocity (generally less than 0.4 m/
                      h) resulting in substantial particulate
                      removal by physical and biological
                      mechanisms. For the LT2ESWTR
                      proposal, EPA has reviewed two
                      additional studies  of slow sand
                      filtration.
                        Fogel et al (1993) evaluated removal
                      efficiencies for Cryptosporidium and
                      Giardia with a full scale slow sand
                      filtration plant. The removals ranged
 from 0.1-0.5 log for Cryptosporidium
 and 0.9-1.4 log for Giardia. Raw water
 turbidity ranged from 1.3 to 1.6 NTU
 and decreased to 0.35-0.31 NTU after
 filtration. The authors attributed the low
 Cryptosporidium and Giardia removals
 to the relatively poor grade of filter
 media and lower water temperature.
 The sand  had a higher uniformity
 coefficient than recommended by design
 standards. This creates larger pore
 spaces within the filter bed that retard
 biological removal capacity. Lower
 water temperatures (1 °C) also decreased
 biological activity in the filter media.
  Hall et al (1994) examined the
 removal of Cryptosporidium with a pilot
 scale slow sand filtration plant.
 Cryptosporidium removals ranged from
 2.8 to 4.3  log after filter maturation,
 with an average of 3.8 log (at least one
 week after filter scraping). Raw water
 turbidity ranged from 3.0 NTU to 7.5
 NTU for three of four runs and 15.0
 NTU for a fourth run. Filtered water
 turbidity was 0.2 to 0.4 NTU, except for
 the fourth run which had 2.5 NTU
 filtered water turbidity. This study also
 included an investigation of
 Cryptosporidium removal during filter
 start-up where the filtration rate was
 slowly increased over a 4 day period.
 Results indicate that  filter ripening did
 not appear to affect Cryptosporidium
 removal.
  The study by Fogel et al is significant
 because it indicates that a slow sand
 filtration plant may achieve less than 2
 log removal of Cryptosporidium removal
 while being in compliance with the
 effluent turbidity requirements of the
 IESWTR and LTlESWTR. The authors
 attributed this poor performance to the
 filter being improperly designed, which,
 if correct,  illustrates the importance of
 proper design for removal efficiency in
 slow sand filters. In contrast, the study
 by Hall et al (1994) supports other work
 (Schuler and Ghosh 1991, Timms et al
 1995) in finding that  slow sand filtration
 can achieve Cryptosporidium removal
 greater than 3 log. Overall, this body of
 work appears to show that slow sand
 filtration has the potential to achieve
 Cryptosporidium removal efficiencies
 similar to that of a conventional plant,
but proper design and operation are
 critical to realizing treatment goals.
  c. Diatomaceous earth filtration.
Diatomaceous earth filtration is a
process in which a precoat cake of filter
media is deposited on a support
membrane and additional filter media is
continuously added to the feed water to
maintain the permeability of the filter
cake. Since the IESWTR and
LTlESWTR, EPA has reviewed one new
study of DE filtration  (Ongerth and
Hutton 2001). It supports the findings of

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                                                                      47663
earlier studies (Schuler and Gosh 1990,
Ongerth and Hutton 1997) in showing
that a well designed and operated DE
plant can achieve Cryptosporidium
removal equivalent to a conventional
treatment plant (i.e., average of 3 log).
  d.  Other filtration technologies. In
today's proposal, information about bag
filters, cartridge filters, and  membranes,
including criteria for awarding
Cryptosporidium treatment  credit, is
presented in section IV.C as part of the
microbial toolbox. Section IV.C also
addresses credit for pretreatment
options like presedimentation basins
and bank filtration.
  e. Inactivation. Substantial advances
in understanding of Cryptosporidium
inactivation by ozone, chlorine dioxide,
and UV have been made following the
IESWTR and LT1ESWTR. These
advances have allowed EPA to develop
criteria to award Cryptosporidium
treatment credit for these disinfectants.
Relevant information is summarized
next, with additional information
sources noted.
  i. Ozone and chlorine dioxide. With
the completion of several major studies,
EPA has acquired sufficient information
to develop standards for the inactivation
of Cryptosporidium by ozone and
chlorine dioxide. For both of these
disinfectants, today's proposal includes
CT tables that specify a level of
Cryptosporidium treatment credit based
on the product of disinfectant
concentration and contact time.
  For ozone, the CT tables in today's
proposal were developed through
considering four sets of experimental
data: Li et al (2001), Owens et al.
(2000), Oppenheimer et al (2000), and
Rennecker et al.  (1999). Chlorine
dioxide CT tables are based on three
experimental data sets: Li et al. (2001),
Owens et al. (1999), and Ruffell et al.
(2000). Together these studies provide a
large body of data that covers a range of
water matrices, both  laboratory and
natural. While the data exhibit
variability, EPA believes that
collectively they are  sufficient to
determine appropriate levels of
treatment credit as a function of
disinfection conditions. CT tables for
ozone and chlorine dioxide inactivation
of Cryptosporidium are presented in
Section IV.C.14 of this preamble.
  ii. Ultraviolet light. A major recent
development is the finding that UV light
is highly effective for inactivating
Cryptosporidium and Giardia at low
doses. Research prior to 1998 had
indicated that very high doses of UV
light were required to achieve
substantial disinfection of protozoa.
However, as noted previously, these
results were largely based on the use of
in vitro assays, which were later shown
to substantially overestimate the UV
doses required to prevent infection
(Clancy et al. 1998, Bukhari et al. 1999,
Craik et al. 2000). Recent research using
in vivo assays (e.g., neonatal mouse
infectivity) and cell culture techniques
to measure infectivity has provided
strong evidence that both
Cryptosporidium and Giardia are highly
sensitive to low doses of UV.
BILLING CODE 6560-50-P

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47664
Federal  Register/Vol. 68, No.  154/Monday, August 11, 2003/Proposed Rules



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                     Figure III-5.-- Inactivation of Cryptosporidium by UV Light
BILLING CODE 6560-50-C
  Figure III-5 presents data from
selected studies of UV inactivation of
Cryptosporidium. While the data in
Figure III-5 show substantial scatter,
they are consistent in demonstrating a
high level of inactivation at relatively
low UV doses. These studies generally
demonstrated at least 3 log
Cryptosporidium inactivation at UV
doses of 10 mJ/cm 2 and higher. In
comparison, typical UV dose for
drinking water disinfection are 30 to 40
mJ/cm 2. A recent investigation by
Clancy et al. (2002) showed that UV
light at 10 mJ/cm2 provided at least 4
log inactivation of five strains of
Cryptosporidium that are infectious to
humans. Studies of UV inactivation of
Giardia have reported similar results
(Craik et al. 2000, Mofidi etal. 2002,
Linden et al 2002, Campbell and Wallis
2002, Hayes etal 2003).
  In addition to efficacy for protozoa
inactivation, data indicate that UV
disinfection does not promote the
formation of DBFs (Malley et al. 1995,
                      Zheng et al 1999). Malley et al (1995)
                      evaluated DBF formation in a number of
                      surface and ground waters with UV
                      doses between 60 and 200 mJ/cm2. UV
                      light did not directly form DBFs, such
                      as trihalomethanes (THM) and
                      haloacetic acids (HAA), and did not
                      alter the concentration or species of
                      DBFs formed by post-disinfection with
                      chlorine or chloramines. A study by
                      Zheng et al (1999) reported that
                      applying UV light following chlorine
                      disinfection had little impact on THM
                      and HAA formation. In addition, data
                      suggest that photolysis of nitrate to
                      nitrite, a potential concern with certain
                      types of UV lamps, will not result in
                      nitrite levels near the MCL under
                      typical drinking water conditions
                      (Feldszus et al 2000, Sharp less and
                      Linden 2001).
                       These studies demonstrate that UV
                      light is an effective technology  for
                      inactivating Ciardia and
                      Cryptosporidium, and that it does not
                      form DBFs at levels of concern  in
                      drinking water. Section IV.G.15
describes proposed criteria for awarding
treatment credit for UV inactivation of
Cryptosporidium, Giardia lamblia, and
viruses. These criteria include UV dose
tables, validation testing, and
monitoring standards. In addition, EPA
is preparing a UV Disinfection Guidance
Manual with information on design,
testing, and operation of UV systems. A
draft of this guidance is available in the
docket for today's proposal (http://
www.epa.gov/edocket/).
  iii. Significance of new information
on inactivation. The research on ozone,
chlorine dioxide, and UV light
described in this proposal has made
these disinfectants available for systems
to use in meeting additional
Cryptosporidium treatment
requirements under LT2ESWTR. This
overcomes a significant limitation to
establishing inactivation requirements
for Cryptosporidium that existed when
the IESWTR was developed. The Stage
1 Advisory  Committee recognized the
need for inactivation criteria if EPA
were to consider a risk based proposal

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                 Federal Register/Vol. 68, No. 154/Monday, August  11,  2003/Proposed Rules
                                                                     47665
 for Cryptosporidium in future
 rulemaking (62 FR 59498, November 3,
 1997) (USEPA 2000b). The CT tables for
 ozone and chlorine dioxide provide
 such criteria. In addition, the
 availability of UV furnishes another
 relatively low cost tool to achieve
 Cryptosporidium inactivation and DBF
 control.
   While no single treatment technology
 is appropriate for all systems, EPA
 believes that these disinfectants, along
 with the other management and
 treatment options in the microbial
 toolbox presented in section IV.C, make
 it feasible for systems to meet the
 additional Cryptosporidium treatment
 requirements in today's proposal.
 IV. Discussion of Proposed LT2ESWTR
 Requirements
 A. Additional Cryptosporidium
 Treatment Technique Requirements for
 Filtered Systems
 1. What Is EPA Proposing Today?
   a. Overview of framework approach.
 EPA is proposing treatment technique
 requirements to supplement the existing
 requirements of the SWTR, IESWTR,
 and LT1ESWTR (see section II.B). The
 proposed requirements will achieve
 increased protection against
 Cryptosporidium in public water
 systems that use surface water or ground
 water under the direct influence of
 surface water as sources. Under this
 proposal, filtered systems will be
 assigned to one of four risk categories
 (or "bins"), based on the results of
 source water Cryptosporidium
 monitoring. Systems assigned to the
 lowest risk bin incur no additional
 treatment requirements, while systems
 assigned to higher risk bins must reduce
 Cryptosporidium levels beyond IESWTR
 and LT1ESWTR requirements. Systems
will comply with additional
 Cryptosporidium treatment
requirements by selecting treatment and
management strategies from a
 "microbial toolbox" of control options.
  Today's proposal reflects
recommendations from the Stage 2 M-
 DBP Federal Advisory Committee (65
 FR 83015, December 29, 2000) (USEPA
 2000a), which described this approach
 as a "microbial framework". This
 approach targets additional treatment
 requirements to those systems with the
 highest source water Cryptosporidium
 leveis and, consequently, the highest
 vulnerability to this pathogen. In so
 doing, today's proposal builds upon the
 current treatment technique
 requirement for Cryptosporidium under
 which all filtered systems must achieve
 at least a 2 log reduction, regardless of
 source water quality. The intent of this
 proposal is to assure that public water
 systems with the higher risk source
 water achieve a level of public health
 protection commensurate with systems
 with less contaminated source water.
   b. Monitoring requirements. Today's
 proposal requires systems to monitor
 their source water {influent water prior
 to treatment plant) for Cryptosporidium,
 E. coli, and turbidity. The purpose of the
 monitoring is to assess source water
 Cryptosporidium levels and, thereby,
 classify systems in different risk bins.
 Proposed monitoring requirements for
 large and small systems are summarized
 in Table IV-I and are characterized in
 the following discussion.

 Large Systems
  Large systems (serving at least 10,000
 people) must sample their source water
 at least monthly for Cryptosporidium,  E.
 coli, and turbidity for a period of 2
 years, beginning no later than 6 months
 after LT2ESWTR promulgation. Systems
 may sample  more frequently (e.g., twice-
 per-month, once-per-week), provided
 the same sampling frequency is used
 throughout the 2-year monitoring
 period. As described in section IV.A.l.c,
 systems that sample more frequently (at
 least twice-per-month) use a different
 calculation that is potentially less
conservative to determine their bin
classification.
  The purpose of requiring large
systems to collect E. coli and turbidity
data is to further evaluate these
parameters as indicators to identify
 drinking water sources that are
 susceptible to high concentrations of
 Cryptosporidium. As described next,
 these data will be applied to small
 system LT2ESWTR monitoring.

 Small Systems

   EPA is proposing a 2-phase
 monitoring strategy for small systems
 (serving fewer than 10,000 people) to
 reduce their monitoring burden. This
 approach is based on Information
 Collection Rule and ICRSS data
 indicating that systems with low source
 water E. coli levels are likely to have
 low Cryptosporidium levels, such that
 additional treatment would not be
 required under the LT2ESWTR. Under
 this approach, small systems must
 initially conduct one year of bi-weekly
 sampling (one sample every two weeks)
 for E. coli, beginning 2.5 years after
 LT2ESWTR promulgation. Small
 systems are triggered into
 Cryptosporidium monitoring only if the
 initial E. coli monitoring indicates a
 mean concentration greater than 10 E.
 coli/IQQ mL for systems using a
 reservoir or lake as their primary source
 or greater than 50 E. coli/WO mL for
 systems using a flowing stream as their
 primary source. Small systems that
 exceed these E. coli trigger values must
 conduct one year of twice-per-month
 Cryptosporidium sampling, beginning 4
 years after LT2ESWTR promulgation.
  The analysis supporting the proposed
 E. coli values that trigger
 Cryptosporidium monitoring by small
 systems is presented in  Section IV.A.2.
 However, as recommended by the Stage
 2 M-DBP Advisory Committee, EPA
 will evaluate Cryptosporidium indicator
 relationships in the LT2ESWTR
 monitoring data collected by large
 systems. If these data support the use of
 different indicator levels to trigger small
system Cryptosporidium monitoring,
EPA will issue guidance with
recommendations. The proposed
LT2ESWTR allows States to specify
alternative indicator values for small
systems, based on EPA guidance.
                              TABLE IV-1.—LT2ESWTR MONITORING REQUIREMENTS
Public water systems
Large systems (serving
10,000 or more people).
Small systems (serving
fewer than 10,000 peo-
ple).
Monitoring begins
6 months after promul-
gation of
LT2ESWTR3.
30 months (2% years)
after promulgation of
LT2ESWTR.
Monitoring dura-
tion



Monitoring parameters and sample frequency requirements
Cryptosporidium
minimum 1 sample/
month b.
See following rows 	
E. coli
minimum 1 sam-
ple/month1".
1 sample every
two weeks.
Turbidity
minimum 1 measure-
ment/month1'.
N/A

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                        TABLE IV-1.—LT2ESWTR MONITORING REQUIREMENTS—Continued
Public water systems
Monitoring begins
Monitoring dura-
tion
Monitoring parameters and sample frequency requirements
Cryptosporidium
E. coli
Turbidity

Small systems (serving
fewer than 10,000 peo-
Ple)e-

48 months (4 years)
after promulgation of
LT2ESWTR.




N/A 	

N/A.

  N/A = Not applicable. No monitoring required.
Sampling Location

  Source water samples must be
representative of the intake to the
filtration plant. Generally, sampling
must be performed individually for each
plant that treats a surface water source.
However, where multiple plants receive
all of their water from the same influent
(e.g., multiple plants  draw water from
the same pipe), the same set of
monitoring results may be applicable to
each plant. Typically, samples must be
collected prior to any treatment, with
exceptions for certain pretreatment
processes. Directions on sampling
location for plants using off-stream
storage, presedimentation, and bank
filtration are provided in section IV.C.
  Systems with plants that use multiple
water sources at the same time must
collect samples from  a tap where the
sources are combined prior to treatment
if available. If a blended source tap is
not available, systems must collect
samples from each source and either
analyze a weighted composite (blended)
sample or analyze samples from each
source separately and determine  a
weighted average of the results.

Sampling Schedule

  Large systems must submit a sampling
schedule to EPA within 3 months after
promulgation of the LT2ESWTR. Small
systems must submit a sampling
schedule for E. coli monitoring to their
primacy agency within 27 months after
rule promulgation; small systems
required to monitor for Cryptosporidium
must submit a Cryptosporidium
sampling schedule within 45 months
after promulgation. The sampling
schedules must specify the calendar
 date on which the system will collect
each sample required under the
LT2ESWTR. Scheduled sampling dates
 should be evenly distributed throughout
 the monitoring period, but may be
 arranged to accommodate holidays,
 weekends, and other events when
collecting or analyzing a sample would
be problematic.
  Systems must collect samples within
2 days before or 2 days after a scheduled
sampling date. If a system does not
sample within this 5-day window, the
system will incur a monitoring violation
unless either of the following two
conditions apply:
  (1) If extreme conditions or situations exist
that may pose danger to the sample collector,
or which are unforeseen or cannot be avoided
and which cause the system to be unable to
sample in the required time frame, the
system must sample as close to the required
date as feasible and submit an explanation
for the alternative sampling date with the
analytical results.
  (2) Systems that are unable to report a valid
Cryptosporidium analytical result for a
scheduled sampling date due to failure to
comply with analytical method  quality
control requirements (described in section
IV.K) must collect a replacement sample
within 14 days of being notified by the
laboratory or the State that a result cannot be
reported for that date. Systems must submit
an explanation for the replacement sample
with the analytical results. Where possible,
the replacement sample collection date
should not coincide with any other
scheduled LT2ESWTR sampling dates.

Approved Analytical Methods and
Laboratories
   To ensure the quality of LT2ESWTR
monitoring data, today's proposal
requires systems to use approved
methods for Cryptosporidium, E. coli,
and turbidity analyses (see section IV.K
for sample analysis requirements),  and
to have these analyses performed by
 approved laboratories (described in
 section IV.L).

 Reporting
   Because source water monitoring by
 large systems will begin 6 months after
 promulgation of the LT2ESWTR, EPA is
 proposing that monitoring results for
 large systems be reported directly to the
 Agency though an electronic data
 system (described in section 1V.J),
similar to the approach currently used
under the Unregulated Contaminants
Monitoring Rule (64 FR 50555,
September 17,1999) (USEPA 1999c).
Small systems will report data to EPA
or States, depending on whether States
have assumed  primacy for the
LT2ESWTR.
Previously Collected Monitoring Results
  EPA is proposing to allow systems to
use previously collected (i.e.,
grandfathered) Cryptosporidium
monitoring data to meet LT2ESWTR
monitoring requirements if the data are
equivalent to data that will be collected
under the rule (e.g., sample volume,
sampling frequency, analytical method
quality control). Criteria for acceptance
of previously collected data are
specified in section IV.A.l.d.
Providing Additional Treatment Instead
of Monitoring
  Filtered systems are not required to
conduct source water monitoring under
the LT2ESWTR if the system currently
provides or will provide  a total of at
least 5.5 log of treatment for
 Cryptosporidium, equivalent to meeting
the treatment  requirements of Bin 4 as
 shown in Table IV-4 (i.e., the maximum
required in today's proposal). Systems
 must notify EPA or the State not later
 than the date the system is otherwise
 required to submit a sampling schedule
 for monitoring and must install and
 operate technologies to provide a total
 of at least 5.5  log of treatment for
 Cryptosporidium by the applicable date
 in Table 1V-23. Any filtered system that
 fails to complete LT2ESWTR monitoring
 requirements must meet the treatment
 requirements for Bin  4.
 Ongoing Source Assessment and Second
 Round of Monitoring
   Because LT2ESWTR treatment
 requirements are related to the degree of
 source water contamination, today's
 proposal contains provisions to assess
 changes in a system's source water

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                 Federal Register/Vol.  68, No. 154/Monday, August 11, 2003/Proposed Rules
                                                                      47667
 quality following initial risk bin
 classification. These provisions include
 source water assessment during sanitary
 surveys and a second round of
 monitoring.
   Under 40 CFR 142.16(b)(3)(i), source
 water is one of the components that
 States must address during the sanitary
 surveys that are required for surface
 water systems. These sanitary surveys
 must be conducted every 3 years for
 community systems and every 5 years
 for non-community systems. EPA is
 proposing that if the  State  determines
 during the sanitary survey that
 significant changes have occurred in the
 watershed that could lead  to increased
 contamination of the source water,  the
 State may require systems  to implement
 specific actions to address the
 contamination. These actions include
 implementing options from the
 microbial toolbox discussed in section
 IV.C.
   EPA is proposing that systems
 conduct a second round of source water
 monitoring, beginning six years after
 systems are initially classified in
 LT2ESWTR risk bins. To prepare for
 this second round of monitoring, the
 Advisory Committee recommended that
 EPA initiate a stakeholder  process four
 years after large systems complete initial
 bin classification. The purpose of the
 stakeholder process would be to review
 risk information, and to determine the
 appropriate analytical method,
 monitoring frequency, monitoring
 location, and other criteria for the
 second round of monitoring.
   If EPA does not modify LT2ESWTR
 requirements through issuing a new
 regulation prior to the second round of
 monitoring, systems must carry out this
 monitoring according to the
 requirements that apply to the initial
 round of source water monitoring.
 Moreover, systems will be  reclassified
 in LT2ESWTR risk bins based on the
 second round monitoring results and
 using the criteria specified in this
 section for initial bin classification.
 However, if EPA changes the
 LT2ESWTR risk bin structure to reflect
 a new analytical method or new risk
 information, systems will undergo a site
 specific risk characterization in
 accordance with the revised rule.
 c. Treatment Requirements
  i. Bin classification. Under the
proposed LT2ESWTR, surface water
systems that use filtration will be
 classified in one of four
 Cryptosporidium concentration
categories (bins) based on the results of
source water monitoring. As shown in
Table IV-2, bin classification is
determined by averaging the
 Cryptosporidium concentrations
 measured for individual samples.

  TABLE IV-2.— BIN CLASSIFICATION
    TABLE FOR  FILTERED SYSTEMS
     If your average
   Cryptosporidium con-
    centration ' is .  . .
 Cryptosporidium <0.075/L
 0.075/L < Cryptosporidium
  < 1.0/L.
 1.0/L < Cryptosporidium <
  3.0/L.
 Cryptosporidium > 3.0/L ...
 Then your bin
 classification is
Bin 1.
Bin 2.

Bin 3.

Bin 4.
  1 All  concentrations  shown  in  units  of
 oocysts/L
  The approach that systems wil! use to
 average individual sample
 concentrations to determine their bin
 classification depends on the number of
 samples collected and the length of the
 monitoring period. Systems serving at
 least 10,000 people are required to
 monitor for 24 months, and their bin
 classification must be based on the
 following:
  (1) Highest twelve month running
 annual average for monthly sampling, or
  {2} two year mean if system conducts
 twice-per-month or more frequent
 sampling for 24 months (i.e., at least 48
 samples).
  Systems serving fewer than 10,000
 people are required to collect 24
 Cryptosporidium samples over 12
 months if they exceed the E. coli trigger
 level, and their bin classification must
 be based on the mean of the 24 samples.
 As noted earlier, systems that fail to
 complete the required Cryptosporidium
 monitoring will be classified in Bin 4.
  When determining LT2ESWTR bin
 classification, systems must calculate
 individual sample concentrations using
 the total number of oocysts counted,
 unadjusted for method recovery,
 divided by the volume assayed (see
 section IV.K for details). As described in
 Section IV.A.2, the ranges of
 Cryptosporidium concentrations that
 define LT2ESWTR bins reflect
 consideration of analytical method
 recovery and the percent of
 Cryptosporidium oocysts that are
 infectious. Consequently, sample
 analysis results will not be adjusted for
 these factors.
  ii.  Credit for treatment in place. A key
parameter in determining additional
 Cryptosporidium treatment
requirements is the credit that plants
receive for treatment currently provided
(i.e.,  treatment in place). For baseline
treatment requirements established by
the SWTR, IESWTR, and LT1ESWTR
that apply uniformly to filtered systems,
the Agency has awarded credit based on
the minimum removal that plants will
achieve. Specifically, in the IESWTR
and LT1ESWTR, EPA determined that
filtration plants, including
conventional, direct, slow sand, and DE,
meeting the required filter effluent
turbidity criteria will achieve at least 2
log removal of Cryptosporidium.
Consequently, these plants were
awarded a 2 log Cryptosporidium
removal credit, which equals the
maximum treatment required under
these regulations.
  The LT2ESWTR will supplement
existing regulations by mandating
additional treatment at certain plants
based on site specific conditions (i.e.,
source water Cryptosporidium level).
When assessing the need for additional
treatment beyond baseline requirements
for higher risk systems, the Agency has
determined that it is appropriate to
consider the average removal efficiency
achieved by treatment plants. As
described in section III.D, EPA has
concluded that conventional, slow sand,
and DE plants in compliance with the
SWTR, IESWTR, and LTlESWTR
achieve an average Cryptosporidium
reduction of 3 log. Consequently, EPA is
proposing to award these plants a 3 log
credit towards Cryptosporidium
treatment requirements under the
LT2ESWTR. As noted previously, this
approach is consistent with the Stage 2
M-DBP Agreement in Principle.
  For other types of filtration plants,
treatment credit under the LT2ESWTR
differs. Conventional treatment is
defined in 40 CFR 141.2 as a series of
processes including coagulation,
flocculation, sedimentation, and
filtration, with sedimentation defined as
a process for removal of solids before
filtration by gravity or separation. Thus,
plants with separation (i.e.,
clarification) processes other than
gravity sedimentation between
flocculation and filtration, such as DAF,
may be regarded as conventional
treatment for purposes of awarding
treatment credit under the LT2ESWTR.
However, for direct filtration plants,
which lack a sedimentation process,
EPA is proposing  a 2.5 log
Cryptosporidium removal credit.
Studies that support awarding direct
filtration plants less treatment credit
than conventional plants are
summarized in  section III.D.
  EPA is unable to estimate an average
log removal for other filtration
technologies like membranes, bag filters,
and cartridge filters, due to variability
among products. As a result, credit for
these  devices must be determined by the
State, based on product specific testing
described in section IV.C or other
criteria approved by the State.

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47668
Federal  Register/Vol. 68, No. 154/Monday,  August 11, 2003/Proposed Rules
  Table IV-3 presents the credit
proposed for different types of plants
towards LT2ESWTR Cryptosporidium
treatment requirements. As described in
section IV.C.18, a State may award
greater credit to a system that
                      demonstrates through a State-approved
                      protocol that it reliably achieves a
                      higher level of Cryptosporidium
                      removal. Conversely, a State may award
                      less credit to a system where the State
                      determines, based on site specific
information, that the system is not
achieving the degree of
Cryptosporidium removal indicated in
Table IV-3.
             TABLE IV-3.—Cryptosporidium TREATMENT CREDIT TOWARDS LT2ESWTR REQUIREMENTS'
Plant type
Treatment credit 	
Conventional treatment (in-
cludes softening)
3.0 log 	
Direct filtration
2.5 log 	
Slow sand or diatoma-
ceous earth filtration
3.0 log 	
Alternative filtration tech-
nologies
Determined by State2.
  | Applies to plants in full compliance with the SWTR, IESWTR, and LT1ESWTR as applicable
  2 Credit must be determined through product or site specific assessment
  iii. Treatment requirements associated
with LT2ESWTR bins
  The treatment requirements
associated with LT2ESWTR risk bins are
shown in Table IV-4. The total
Cryptosporidium treatment required for
Bins 2, 3, and 4 is 4.0 log, 5.0 log, and
5.5 log, respectively. For conventional
(including softening), slow  sand, and DE
plants that receive 3.0 log credit for
                       compliance with current regulations,
                       additional Cryptosporidium treatment of
                       1.0 to 2.5 log is required when classified
                       in Bins 2-4. Direct filtration plants that
                       receive 2.5 log credit for compliance
                       with current regulations must achieve
                       1.5 to 3.0 log of additional
                       Cryptosporidium treatment in Bins 2-4.
                        For systems using alternative
                       filtration technologies, such as
membranes or bag/cartridge filters, and
classified in Bins 2-4, the State must
determine additional treatment
requirements based on the credit
awarded to a particular technology. The
additional treatment must be such that
plants classified in Bins 2, 3, and 4
achieve the total required
Cryptosporidium reductions of 4.0, 5.0,
and 5.5 log, respectively.
                   TABLE IV-4.—TREATMENT REQUIREMENTS PER LT2ESWTR BIN CLASSIFICATION
If your bin classi-
fication is ...
Bin 1 	
Bin 2 	


And you use the following filtration treatment in full compliance with the SWTR, IESWTR, and LT1ESWTR (as applica-
ble), then your additional treatment requirements are ...
Conventionat filtration treat-
ment (includes softening)
No additional treatment 	
1 log treatment 1 	


Direct filtration
No additional treatment 	
2.5 log treatment2 	


Slow sand or diatomaceous
earth filtration
No additional treatment 	
2 log treatment2 	
2.5 log treatment2 	 	 	

Alternative filtration tech-
nologies
No additional treatment.
As determined by the
State1-3.
As determined by the
State 2- ".
As determined by the
State 2. 5.

           mav use any technology or combination of technologies from the microbial toolbox.
           must achieve at least 1 log of the required treatment using ozone, chlorine dioxide, UV, membranes, bag/cartridge fitters, or bank fil-
   3Totat Cryptosporidium removal and inactivation must be at least 4.0 tog.
   "Total Cryptosporidium removal and inactivation must be at least 5.0 log.
   5Total Cryptosporidium removal and inactivation must be at least 5.5 log.
   Plants can achieve additional
 Cryptosporidium treatment credit
 through implementing pretreatment
 processes like presedimentation or bank
 filtration, by developing a watershed
 control program, and by applying
 additional treatment steps like UV,
 ozone, chlorine dioxide, and
 membranes. In addition, plants can
 receive additional credit for existing
 treatment through achieving very low
 filter effluent turbidity or through a
 demonstration of performance. Section
 IV.C presents criteria for awarding
 Cryptosporidium treatment credit to a
 host of treatment and control options,
 including those listed here and others,
 which are collectively termed the
 "microbial toolbox".
                         Systems in Bin 2 can meet additional
                       Cryptosporidium treatment
                       requirements through using any option
                       or combination of options from the
                       microbial toolbox. In Bins 3 and 4,
                       systems must achieve at least 1 log of
                       the additional treatment requirement
                       through using ozone, chlorine dioxide,
                       UV, membranes, bag filtration, cartridge
                       filtration, or bank filtration.
                         d. Use of previously collected data.
                       Today's proposal allows systems with
                       previously collected Cryptosporidium
                       data (i.e., data collected prior to the
                       required start of monitoring under the
                       LT2ESWTR) that are equivalent in
                       sample number, frequency, and data
                       quality to data that will be collected
                       under the LT2ESWTR to use those data
                       in lieu of conducting new monitoring.
 Specifically, EPA is proposing that
 Cryptosporidium sample analysis
 results collected prior to promulgation
 of the LT2ESWTR must meet the
 following criteria to be used for bin
 classification:
   • Samples were analyzed by
 laboratories using validated versions of
 EPA Methods 1622 or 1623 and meeting
 the quality control  criteria specified in
 these methods (USEPA 1999a, USEPA
 1999b, USEPA 2001e, USEPA 2001f).
   • Samples were collected no less
 frequently than each calendar month on
 a regular schedule, beginning no earlier
 than January 1999 (when EPA Method
 1622 was first released as an
 interlaboratory-validated method).
   • Samples were  collected in equal
 intervals of time over the entire
 collection period (e.g., weekly,

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                Federal Register/Vol.  68,  No. 154/Monday, August 11, 2003/Proposed Rules
                                                                    47669
monthly). The allowances for deviations
from a sampling schedule specified
under IV.A.l.b for LT2ESWTR
monitoring apply to grandfathered data.
  • Samples were collected at the
correct location as specified for
LT2ESWTR monitoring. Systems must
report the use of bank filtration,
presedimentation, and raw water off-
stream storage during sampling.
  • For each sample, the laboratory
analyzed at least 10 L of sample or at
least 2 mL of packet pellet volume or as
much volume as two filters could
accommodate before clogging (applies
only to filters that have been approved
by EPA for use with Methods 1622 and
1623).
  • The system must certify that it is
reporting all Cryptosporidium
monitoring results generated by the
system during the time period covered
by the previously collected data. This
applies to samples that were (a)
collected from the sampling location
used for LT2ESWTR monitoring, (b) not
spiked, and (c) analyzed using the
laboratory's routine process for Method
1622 or 1623 analyses.
  • The system must also certify that
the samples were representative of a
plant's source water(s) and the source
water(s) have not changed.
  If a system has at least two years of
Cryptosporidium data collected before
promulgation of the LT2ESWTR and the
system does not intend to conduct new
monitoring under the rule, the system
must submit the data and the required
supporting documentation to EPA no
later than two months  following
promulgation of the rule. EPA will
notify the system within four months
following LT2ESWTR promulgation as
to whether the data are sufficient for bin
determination. Unless EPA notifies the
system in writing that the previously
collected data are sufficient for bin
determination, the system must conduct
source water Cryptosporidium
monitoring as described in section
IV.A.l.b of this preamble.
  If a system intends to grandfather
fewer than two years of
Cryptosporidium data, or if a system
intends to grandfather 2 or more years
of previously  collected data and also to
conduct new monitoring under the rule,
the system must submit the data and the
required supporting documentation to
EPA no later than eight months
following promulgation of the rule.
Systems must conduct monitoring as
described in section IV.A.l.b until EPA
notifies the system in writing that it has
at least 2 years of acceptable data. See
section IV.J for additional  information
on reporting requirements associated
with previously collected  data.
2. How Was This Proposal Developed?
  The monitoring and treatment
requirements for filtered systems
proposed under the LT2ESWTR stem
from the data and analyses described in
this section and reflect
recommendations made by the Stage 2
M-DBP Federal Advisory Committee
(65 FR 83015) (USEPA 2000a).
  a. Basis for targeted treatment
requirements. Under the IESWTR, EPA
established an MCLG of zero for
Cryptosporidium at the genus level
based on the public health risk
associated with this pathogen. The
IESWTR included a 2 log treatment
technique requirement for medium and
large filtered systems that controlled for
Cryptosporidium as close to the MCLG
as was then deemed technologically
feasible, taking costs into consideration.
The LT1ESWTR extended this
requirement to small systems; Given the
advances that have occurred subsequent
to the IESWTR in available technology
to measure and treat for
Cryptosporidium, a key question for the
LT2ESWTR was the extent to which
Cryptosporidium should be further
controlled to approach the MCLG of
zero, considering technical feasibility,
costs, and potential risks from DBFs.
  The data and analysis presented in
Section III of this preamble suggest wide
variability in possible risk from
Cryptosporidium among public water
systems. This variability is largely due
to three factors: (1) The broad
distribution of Cryptosporidium
occurrence levels among source waters,
(2) disparities in the efficacy of
treatment provided by plants, and (3)
differences in the infectivity among
Cryptosporidium isolates. EPA and the
Advisory Committee considered this
wide range of possible risks and the
desire to address systems where the 2
log removal requirement established by
the IESWTR and LTlESWTR may not
provide adequate public health
protection.
  A number of approaches were
evaluated for furthering control of
Cryptosporidium. One approach was to
require all systems to provide the same
degree of additional treatment for
Cryptosporidium (i.e., beyond that
required by the IESWTR and
LTlESWTR). This approach could
ensure that most systems, including
those with poor quality source water,
would be adequately protective. The
uniformity of this approach has the
advantage of minimizing transactional
costs for determining what must be
done by a particular system to comply.
However, a significant downside  is that
it may require more treatment, with
consequent costs, than is needed by
many systems with low source water
Cryptosporidium levels. In addition,
there were concerns with the feasibility
of requiring almost all surface water
treatment plants to install additional
treatment processes for
Cryptosporidium.
  A second approach was to base
additional treatment requirements on a
plant's source water Cryptosporidium
level. Under this approach, systems
monitor their source water for
Cryptosporidium, and additional
treatment is required only from those
systems that exceed specified oocyst
concentrations. This has the advantage
of targeting additional public health
protection to those systems with higher
vulnerability to Cryptosporidium, while
avoiding the imposition of higher
treatment costs on systems with the
least contaminated source water. In
consideration of these advantages, the
Advisory Committee recommended and
EPA is proposing this second approach
for filtered systems under the
LT2ESWTR.
  b. Basis for bin concentration ranges
and treatment requirements.  The
proposed LT2ESWTR will classify
plants into different risk bins based on
the source water Cryptosporidium level,
and the bin classification will determine
the extent to which additional treatment
beyond IESWTR and LTlESWTR is
required. Two questions were central in
developing the proposed bin
concentration ranges and additional
treatment requirements:
  • What is the risk associated with a
given level of Cryptosporidium in a
drinking water source?
  • What degree of additional treatment
should be required for a given source
water Cryptosporidium level?
  This section addresses these two
questions by first summarizing how
EPA assessed the risk associated with
Cryptosporidium in drinking water,
followed by a description of how EPA
and the Advisory Committee used this
type of information in identifying
LT2ESWTR bin concentration ranges
and treatment requirements.  For
additional information on these topics,
see Economic Analysis for the
LT2ESWTR (USEPA 2003a).
  i. What is the risk associated with a
given level of Cryptosporidium in a
drinking water source? The risk of
infection from Cryptosporidium in
drinking water is a function of
infectivity (i.e., dose-response
associated with ingestion) and exposure.
Section III.B summarizes available data
on Cryptosporidium infectivity. EPA
conducted a meta-analysis of reported
infection rates from human feeding

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studies with 3 Cryptosporidium isolates.
This analysis produced an estimate for
the mean probability of infection given
a dose of one oocyst near 0.09 (9%),
with 10th and 90th percentile
confidence values of 0.011 and 0.22,
respectively.
  Exposure to Cryptosporidium
depends on the concentration of oocysts
in the source water, the efficiency of
treatment plants in removing oocysts,
and the volume of water ingested
(exposure can also occur through
interactions with infected individuals).
Based on data presented in section III.D,
EPA has estimated that filtration plants
in compliance with the IESWTR or
LT1ESWTR reduce source water
Cryptosporidium levels by 2 to 5 log
(99% to 99.999%), with an average
                      reduction near 3 log. For drinking water
                      consumption, EPA uses a distribution,
                      derived from the United States
                      Department of Agriculture's (USDA)
                      1994-96 Continuing Survey of Food
                      Intakes by Individuals, with a mean
                      value of 1.2 L/day. Average annual  days
                      of exposure to drinking water in CWS,
                      non-transient non-community water
                      systems (NTNCWS), and transient non-
                      community water systems (TNCWS) are
                      estimated at 350 days, 250 days, and 10
                      days, respectively. (The Economic
                      Analysis for the LT2ESWTR (USEPA
                      2003a) provides details on all
                      parameters listed here, as well as
                      morbidity, mortality, and other risk
                      factors.)
                        Using an estimate of 1.2 L/day
                      consumption and a mean probability of
infection of 0.09 for one oocyst ingested,
the daily risk of infection (DR) is as
follows:
DR = (oocysts/L in source water) x
  (percent remaining after treatment) x
  (1.2 L/day) x (0.09).

  The annual risk (AR) of infection for
a CWS is

AR=1-(1-DR)350

where 350 represents days of exposure
in a CWS.
  Table IV-5 presents estimates of the
mean annual risk of infection by
Cryptosporidium in CWSs for selected
source water infectious oocyst
concentrations and filtration plant
removal efficiencies.
 TABLE IV-5.—ANNUAL RISK OF Cryptosporidium INFECTION IN CWSs THAT FILTER, AS A FUNCTION OF SOURCE WATER
                         INFECTIOUS OOCYST CONCENTRATION AND TREATMENT EFFICIENCY
Source water concentration
(infectious oocysts per liter)
0.0001
0.001
0.01
0.1
1
10

2 log
3.8E-05
3.7E-04
3.7E-03
3.7E-02
0.31
0.89
3 tog
3.8E-06
3.8E-05
3.7E-04
3.7E-03
3.7E-02
0.31
4 log
3.8E-07
3.8E-06
3.8E-05
3.7E-04
3.7E-03
3.7E-02
Slog
3.8E-08
3.8E-07
3.8E-06
3.8E-05
3.7E-04
3.7E-03
   Scientific notation (E"») designates 10'
  For example, Table IV-5 shows that if
a filtration plant had a mean
concentration of infectious
Cryptosporidium in the source water of
0.01 oocysts/L, and the filtration plant
averaged 3 log removal, the mean
annual risk of infection by
Cryptosporidium is estimated as 3.7 x
10~4 (3.7 infections per 10,000
consumers).
  ii. What degree of additional
treatment should be required for a given
source water Cryptosporidium level? In
order to develop targeted treatment
requirements for the LT2ESWTR, it was
necessary to identify a source water
Cryptosporidium level above which
additional treatment by filtered systems
would be required. Based on the type of
risk information shown in Table IV-5,
EPA and Advisory Committee
deliberations focused on mean source
water Cryptosporidium concentrations
in the range of 0.01 to 0.1  oocysts/L as
appropriate threshold values for
prescribing additional treatment.
  Analytical method and sampling
constraints were a significant factor in
setting the specific Cryptosporidium
level that triggers additional treatment
by filtered systems. The number of
samples that systems can be required to
                      analyze for Cryptosporidium is limited.
                      Consequently, if the bin threshold
                      concentration for additional treatment
                      was set near 0.01 oocysts/L, systems
                      could exceed this level due to a very
                      low number of oocysts being detected.
                      For example, if systems took monthly 10
                      L samples and bin classification was
                      based on a maximum running annual
                      average, then a system would exceed a
                      mean concentration of 0.01 oocysts/L by
                      counting only 2 oocysts in 12 samples.
                      Given the variability associated with
                      Cryptosporidium analytical methods,
                      the Advisory Committee did not support
                      requiring additional treatment for
                      filtered systems based on so few counts.
                        Another concern related to analytical
                      method limitations was systems being
                      misclassified in a lower bin. For
                      example, if a system had a true mean
                      concentration at or just above 0.1
                      oocysts/L, the mean that the system
                      would determine through monitoring
                      might be less than 0.1 oocyst/L. Thus,
                      if the bin threshold for additional
                      treatment was set at 0.1 oocysts/L, a
                      number of systems with true mean
                      concentrations above this level would
                      be misclassified in the lower bin with
                      no additional treatment required. This
                      type of error, described in more detail
in the next section, is a function of the
number of samples collected and
variability in method performance.
  In consideration of the available
information on Cryptosporidium risk, as
well as the performance and feasibility
of analytical methods, EPA is proposing
that the source water threshold
concentration for requiring additional
Cryptosporidium treatment by filtered
systems be established at a mean level
of 0.075 oocysts/L. This is the level
recommended by the Advisory
Committee, and it affords a high
likelihood that systems with true mean
Cryptosporidium concentrations of 0.1
oocysts/L or higher will provide
additional treatment under the rule.
  Beyond identifying this first
threshold, it was also necessary to
determine Cryptosporidium
concentrations that would demarcate
higher risk bins. With respect to the
concentration range that each bin
should comprise, EPA and the Advisory
Committee dealt with two opposing
factors: bin misclassification and
equitable risk reduction.
  As described in the next section, a
monthly monitoring program involving
EPA Methods 1622 or 1623 can
characterize  a system's mean
Cryptosporidium concentration within a

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                                                                     47671
0.5 log (factor of 3.2) margin with a high
degree of accuracy. However, the closer
a system's true mean concentration is to
a bin boundary, the greater the
likelihood that the system will be
misclassified into the wrong bin due to
limitations in sampling and analysis.
Accordingly, by establishing bins that
cover a wide concentration range, the
likelihood of system  misclassification is
reduced.
  However, a converse factor relates to
equitable protection from risk. Because
identical treatment requirements will
apply to all systems in the same bin,
systems at the higher concentration end
of a bin will achieve  less risk reduction
relative to their source water pathogen
levels than systems at the lower
concentration end of a bin. Thus, bins
with a narrow concentration range
provide a more uniform level of public
health protection.
  In balancing these  factors and to
account for the wide range of possible
source water concentrations among
different systems as indicated by
Information Collection Rule and ICRSS
data, the Advisory Committee
recommended and EPA is proposing a
second bin threshold at a mean level of
1.0 oocysts/L and a third bin threshold
at a mean level of 3.0 oocysts/L.
Information Collection Rule and ICRSS
data indicate that few, if any, systems
would measure mean Cryptosporidium
concentrations greater than 3.0 oocysts/
L, so there was not a  need to establish
a bin threshold above this value. Thus,
the LT2ESWTR proposal includes the
following four bins for classifying
filtered systems:  Bin  1: <0.075/L; Bin  2:
>0.075 to <1.0/L; Bin 3: >1.0/L to <3.0/
L; and Bin 4: >3.0/L (oocysts/L).
  With respect to additional
Cryptosporidium treatment for systems
in Bins 2-4, values were considered
ranging from 0.5  to 2.5 log and greater.
As recommended by  the Advisory
Committee, EPA is proposing 1.0 log
additional treatment  for conventional
plants in Bin 2. This  level of treatment
will ensure that systems classified in
Bin 2 will achieve treated water
Cryptosporidium levels comparable to
systems in Bin 1, the lowest risk bin. In
contrast, if systems in Bin  2 provided
only 0.5 log additional treatment then
those systems with mean source water
concentrations in the upper part of Bin
2 would have higher  levels of
Cryptosporidium in their finished water
than systems in Bin 1,
  In consideration of the much greater
potential vulnerability of systems in the
highest risk bins, the  Advisory
Committee recommended additional
treatment requirements of 2.0 log and
2.5  log for conventional plants in Bins
3 and 4, respectively. The Agency
concurs with these recommendations
and has incorporated them in today's
proposal.
  An important aspect of the proposed
additional treatment requirements is
that they are based, in part, on the
current level of treatment provided by
filtration plants. As noted earlier, the
Advisory Committee assumed when
developing its recommendations that
conventional treatment plants in
compliance with the IESWTR achieve
an average of 3 log removal of
Cryptosporidium. EPA has determined
that available data, discussed in section
III.D, support this assumption and has
proposed a 3 log Cryptosporidium
treatment credit for conventional plants
under the LT2ESWTR. Thus, the
additional treatment requirements for
conventional plants in Bins 2, 3, and 4
translate to total requirements of 4.0,
5.0, and 5.5 log, respectively.
  The Advisory Committee did not
address additional treatment
requirements for plants with treatment
trains other than conventional, but
recommended that EPA address such
plants in the proposed LT2ESWTR and
take comment. Based on treatment
studies summarized in section III.D,
EPA has concluded that plants with
slow sand or DE filtration are able to
achieve 3 log or greater removal of
Cryptosporidium when in compliance
with the IKSWTR or LTlESWTR.
Because these plants can achieve
comparable levels of performance to
conventional treatment plants, EPA is
proposing that slow sand and DE
filtration plants also apply 1 to 2.5 log
of additional treatment when  classified
in Bins 2-4.
  Direct filtration differs from
conventional treatment in that it does
not include sedimentation or an
equivalent clarification process prior to
filtration. As described in section III.D,
EPA has concluded that a sedimentation
process can consistently achieve 0.5 log
or greater removal of Cryptosporidium.
The Agency is proposing that direct
filtration plants in compliance with the
IESWTR or LTlESWTR receive a 2.5 log
Cryptosporidium removal credit
towards LT2ESWTR requirements.
Accordingly, proposed additional
treatment requirements for direct
filtration plants in bins 2, 3, and 4 are
1.5  log, 2.5 log, and 3 log, respectively.
  Section IV.C of this notice describes
proposed criteria for determining
Cryptosporidium treatment credits for
other filtration technologies like
membranes, bag filters, and cartridge
filters. Due to the proprietary and
product specific nature of these
filtration devices, EPA is not able to
propose a generally applicable credit for
them. Rather, the criteria in section IV.C
focus on challenge testing to establish
treatment credit. Systems using these
technologies that are classified in Bins
2-4 must work with their States to
assess appropriate  credit for their
existing treatment trains. This will
determine the level of additional
treatment necessary to achieve the total
treatment requirements for their
assigned bins. EPA has developed
guidance on challenge testing of bag and
cartridge filters and membranes, which
is available in draft form in the docket
(http://www.epa.gov/edocket/).
  In order to give systems flexibility in
choosing strategies to meet additional
Cryptosporidium treatment
requirements, the Advisory Committee
identified a number of management and
treatment options,  collectively called
the microbial toolbox. The toolbox,
which is described in section IV.C,
contains components relating to
watershed control, intake management,
pretreatment, additional filtration
processes, inactivation, and
demonstrations of enhanced
performance.
  As recommended by the Advisory
Committee, EPA is proposing that
systems in Bin 2 can meet additional
Cryptosporidium treatment
requirements under the LT2ESWTR
using any component or combination of
components from the microbial toolbox.
However, systems in Bins 3 and 4 must
achieve at least 1 log of the additional
treatment requirement using
inactivation {UV, ozone, chlorine
dioxide), membranes, bag filters,
cartridge filters, or bank filtration. These
specific control measures are proposed
due to their ability to serve as
significant additional treatment barriers
for systems with high levels of
pathogens.
  c. Basis for source water monitoring
requirements. The goal of monitoring
under the LT2ESWTR is to correctly
classify filtration plants into the four
LT2ESWTR risk bins. The proposed
sampling frequency, time frame, and
averaging  procedure for bin
classification are intended to ensure that
systems are accurately assigned to
appropriate risk bins while limiting the
burden of monitoring costs. The basis
for the proposed  monitoring
requirements for large and small
systems is presented in the following
discussion.
  i. Systems serving at least 10,000
people.
Sample Number and Frequency
  Systems serving at  least 10,000 people
have two options for sampling under the

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LT2ESWTR: (1) They can collect 24
monthly samples over a 2 year period
and calculate their bin classification
using the highest 12 month running
annual average, or (2) They can collect
2 or more samples per month over the
2 year period and use the mean of alt
samples for bin classification.
  These proposed requirements reflect
recommendations by the Advisory
Committee and are based on analyses of
misclassification rates associated with
different monitoring programs that were
considered. EPA is concerned about
systems with high concentrations of
Cryptosporidium being misclassified in
lower bins as well as systems with low
concentrations being misclassified in
higher bins. The first type of error could
lead to systems not providing an
adequate level of treatment while the
second type of error could lead to
systems incurring additional  costs for
unnecessary treatment.
  A primary way that EPA analyzed
misclassification rates was by
considering the likelihood that a system
with a true mean Cryptosporidium
concentration that is a factor of 3.2 (0.5
log) above or below a bin boundary
would be assigned to the wrong bin.
  Probabilities were assessed for two
cases:
  • False negative: a system with a
mean concentration of 0.24 oocysts/L
(i.e., factor of 3.2 above the Bin 1
boundary of 0.075 oocysts/L) is
misclassified low in Bin 1.
  • False positive: a system with a
mean concentration of 0.024 oocysts/L
(i.e., factor of 3.2 below the Bin 1
boundary of 0.075 oocysts/L) is
misclassified high in Bin 2.
  Table IV-6 provides false negative
and false positive rates as defined
previously for different approaches to
monitoring and bin classification that
were evaluated. Results are shown for
the following approaches:
  • 48 samples with bin assignment
based on arithmetic mean (i.e., average
of all samples).
  • 24 samples with bin assignment
based on highest 12 sample average,
equivalent to the maximum running
annual average (Max-RAA).
  • 24 samples with bin assignment
based on arithmetic mean.
  • 12 samples with bin assignment
based on the second highest sample
result.
  • 8 samples  with bin assignment
based on the maximum sample result.
  These estimated misclassification
rates were generated with a Monte Carlo
analysis that accounted  for the volume
assayed, variation in source water
Cryptosporidium occurrence, and
variable method recovery. See Economic
                      Analysis for the LT2ESWTR (USEPA
                      2003a) for details.

                      TABLE  IV-6.—FALSE  POSITIVE   AND
                        FALSE NEGATIVE RATES FOR MONI-
                        TORING  AND  BINNING  STRATEGIES
                        CONSIDERED FOR THE LT2ESWTR
                                  [In percentages]
Strategy
48 sample arithmetic
24 sample Max-RAA 	
24 sample arithmetic
12 sample second highest
8 samoe maximum 	
False
posi-
tive '
1.7
5.3
2.8
47
66
False
nega-
tive2
1.4
1.7
6.2
1.1
1.0
                        1 False positive rates calculated for systems
                      with Cryptosporidium concentrations 0.5 log
                      below the Bin 1 boundary of 0.075 oocysts/L.
                        2 False negative rates calculated for sys-
                      tems with Cryptosporidium concentrations 0.5
                      log  above the Bin  1 boundary  of  0.075
                      oocysts/L.
                        The first two of these approaches, the
                      48 sample arithmetic mean and 24
                      sample Max-RAA, were recommended
                      by the Advisory Committee and are
                      proposed for bin classification under the
                      LT2ESWTR because they have low false
                      positive and false negative rates. As
                      shown in Table IV-6, these strategies
                      have false negative rates of 1 to  2%,
                      meaning there is a 98 to 99% likelihood
                      that a plant with an oocyst
                      concentration 0.5 log above the  Bin 1
                      boundary would be correctly assigned to
                      Bin 2. The false positive rate is near 2%
                      for the 48 sample arithmetic mean and
                      5% for the 24 sample Max-RAA. These
                      rates indicate that a plant with an oocyst
                      concentration 0.5 log below the Bin 1
                      boundary would have a 95 to 98%
                      probability of being correctly assigned
                      to Bin 1. Bin misclassification rates
                      across a wide range of concentrations
                      are shown in  Economic Analysis for the
                      LT2ESWTR (USEPA 2003a).
                        The 24 sample arithmetic mean had a
                      slightly  lower false positive rate than
                      the 24 sample Max-RAA (2.8%  vs.
                      5.3%) but the false negative rate of the
                      arithmetic mean was almost 4 times
                      higher. Consequently, a plant with  a
                      mean Cryptosporidium level above the
                      Bin 1 boundary would be much more
                      likely to be misclassified in Bin 1 using
                      a 24 sample arithmetic mean than with
                      a 24 sample Max-RAA. In order to
                      increase the probability that systems
                      with mean Cryptosporidium
                      concentrations above 0.075 oocysts/L
                      will provide additional treatment, EPA
                      is proposing that if only 24 samples are
                      taken, the maximum 12 month running
                      annual average must be used to
                      determine bin assignment.
  Monitoring strategies involving only
12 and 8 samples were evaluated to
determine if lower frequency
monitoring could provide satisfactory
bin classification. The results of this
analysis indicate that these lower
sample numbers are not adequate and
could unfairly bias excessive treatment
requirements. For example, results in
Table IV-6 show that if plants were
classified in bins based on the second
highest of 12 samples or the highest of
eight samples then low false negative
rates could be achieved. A system with
a mean Cryptosporidium level 0.5 log
above the Bin 1 boundary would have
a 99% chance of being appropriately
classified in a bin requiring additional
treatment under either strategy.
However, the false positive rates
associated with these low sample
numbers are very high. A system with
a mean oocyst concentration 0.5 log
below the Bin 1 boundary would have
a 47% probability of being incorrectly
classified in Bin 2 using the second
highest result among 12 samples, or a
66% likelihood of being misclassified in
Bin 2 using the maximum result among
8 samples. Due to high false positive
rates, these strategies are not proposed.
  EPA also evaluated lower frequency
monitoring strategies that had lower
false positive rates, such as bin
classification based on the mean of 12
samples, the third highest result of 12
samples, and the second highest of 8
samples. Each of these strategies,
though, had an  unacceptably high false
negative rate, meaning that many
systems with mean oocyst
concentrations greater than the Bin 1
boundary would be misclassified low in
Bin 1. Consequently, these strategies are
inconsistent with the public health goal
of the LT2ESWTR for systems with
mean levels above 0.075 oocysts/L to
provide additional treatment.
  Increasing the number of samples
used to compute the maximum running
annual average above 24 also increased
the number of annual averages
computed, so it did not reduce the
likelihood of false positives. Raising the
number of samples used to compute an
arithmetic mean above 48 did reduce
bin misclassification rates, but the rates
were already very small (1 to 2% for
plants with levels 0.5 log above or
below bin boundaries). For sources with
Cryptosporidium concentrations very
near or at bin boundaries, increasing the
number of samples did not markedly
improve the error rates, which remained
near 50% at the bin boundaries.
  In summary, EPA believes that the
proposed sampling designs perform
well for the purpose of classifying
plants in LT2ESWTR risk bins and,

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                                                                     47673
 thereby, achieving the public health
 protection intended for the rule. More
 costly designs, involving more frequent
 sampling and analysis, provide only
 marginally improved performance. Less
 frequent sampling, though lower in cost,
 creates unacceptably high
 misclassification rates and would not
 provide for the targeted risk reduction
 goals of the rule.
 No Adjustments for Method Recovery or
 Percent of Oocysts That Are Infectious
  Two considerations in using
 Cryptosporidium monitoring data to
 project risk are (1) Fewer than 100% of
 oocysts in a sample are recovered and
 counted by the analyst and (2) not all
 the oocysts measured with Methods
 1622/23 are viable and capable of
 causing infection. These two factors are
 offsetting  in sign, in that oocyst counts
 not adjusted for recovery tend to
 underestimate the true concentration,
 while the  total oocyst count may
 overestimate  the infectious
 concentration that presents a health
 risk. Based on information described in
 this section, EPA is proposing that
 Cryptosporidium monitoring results be
 used  directly to assign systems to
 LT2ESWTR'risk bins and not be
 adjusted for either factor.
  As  described in section III.C, ICRSS
 matrix spike data indicate that average
 recovery of Cryptosporidium oocysts
 with Methods 1622/23 in a national
 monitoring program will be about 40%.
 There is no similar direct measure of the
 fraction of environmental oocysts that
 are infectious, but information related to
 this value can be derived from two
 sources: (1) A study where samples
 were  analyzed with both Method 1623
 and a cell  culture-polymerase chain
 reaction (CC-PGR) test for oocyst
 infectivity, and (2) the structure of
 oocysts counted with Methods 1622 and
 1623.
  LeChevallier et al. (2003) conducted a
 study in which six natural waters were
 frequently tested for Cryptosporidium
 using both Method 1623  and a CC-PCR
 method to test for infectivity.
 Cryptosporidium oocysts were detected
 in 60  of 593 samples (10.1%) by Method
 1623 and infectious oocysts were
 detected in 22 of 560 samples (3.9%) by
the CC-PCR procedure. Recovery
efficiencies for the two methods were
 similar. According to the authors, these
results suggest that approximately 37%
(22/60) of the Cryptosporidium oocysts
detected by Method 1623 were viable
and infectious.
  In regard to oocyst structure,
Cryptosporidium oocysts counted with
Methods 1622/23 are characterized in
one of three ways: (l) Internal
 structures, (2) amorphous structures, or
 (3) empty. Oocysts with internal
 structures are considered to have the
 highest likelihood of being infectious,
 while empty oocysts are believed to be
 non-viable (LeChevallier et al, 1997).
 During the ICRSS, 37% of the oocysts
 counted were characterized as having
 internal structures, 47% had amorphous
 structures, and 16% were empty. If it is
 assumed that empty oocysts could not
 be infectious, the mid-point value
 within the percentage range of counted
 oocysts that could have been infectious
 is 42%.
   After considering this type of
 information, the Advisory Committee
 recommended that monitoring results
 not be adjusted upward for percent
 recovery,  nor adjusted downward to
 account for the fraction of oocysts that
 are not infectious. While it is not
 possible to establish a precise value for
 either factor in individual samples, the
 data suggest that they may be of similar
 magnitude. EPA concurs with this
 recommendation and is proposing that
 systems be classified in bins under the
 LT2ESWTR using the total
 Cryptosporidium oocyst count,
 uncorrected for recovery, as measured
 using EPA Method 1622/23. The
 proposed  LT2ESWTR risk bins are
 constructed to reflect this approach.

 Data Collection To Support Use of a
 Microbial Indicator by Small Systems
  As described in the next section,
 small systems will monitor for an
 indicator, currently proposed to be E.
 coli, to determine if they are required to
 sample for Cryptosporidium. The
 proposed  E. coli levels that will trigger
 Cryptosporidium monitoring are based
 on Information Collection Rule and
 ICRSS data. However, to provide for a
 more extensive evaluation of
 Cryptosporidium  indicator criteria, EPA
 is proposing that large systems measure
 E. coli and turbidity in their source
 water when they sample for
 Cryptosporidium. This was-
 recommended by the Advisory
 Committee and will allow for possible
 development of alternative indicator
 levels or parameters (e.g., turbidity in
 combination with E. coli) to serve as
triggers for small system
 Cryptosporidium monitoring.

Time Frame for Monitoring
  In recommending a time frame for
LT2ESWTR monitoring, the Agency
considered the trade-off between
monitoring over a long period  to better
capture year-to-year fluctuations, and
the desire  to prescribe additional
treatment  quickly to systems identified
as having high source water pathogen
 levels. Reflecting Advisory Committee
 recommendations, EPA is proposing
 that large systems evaluate their source
 water Cryptosporidium levels using 2
 years of monitoring. This will account
 for some degree of yearly variability,
 without significantly delaying
 additional public health protection
 where needed.
  ii. Systems serving fewer than 10,000
 people.

 Indicator Monitoring
  In recognition of the relatively high
 cost of analyzing samples for
 Cryptosporidium, EPA and the Advisory
 Committee explored the use of indicator
 criteria to identify drinking water
 sources that may have high levels of
 Cryptosporidium occurrence. The goal
 was to find one or more parameters that
 could be analyzed at low cost and
 identify those systems likely to exceed
 the Bin 1 boundary of 0.075 oocysts/L.
 Data from the Information Collection
 Rule and ICRSS were evaluated for
 possible indicator parameters, including
 fecal coliforms, total coliforms, E. coli,
 viruses (Information Collection Rule
 only), and turbidity. Based on available
 data, E. coli was found to provide the
 best performance as a  Cryptosporidium
 indicator, and the inclusion of other
 parameters like turbidity was not found
 to improve accuracy.
  The next part of this section presents
 data that support E. coli mean
 concentrations of 10/100 mL and 50/100
 mL as proposed screening levels that
 will trigger Cryptosporidium monitoring
 in reservoir/lake and flowing stream
 systems, respectively.  It describes how
 E. coli and Cryptosporidium  data from
 the Information Collection Rule and
 ICRSS were analyzed and shows the
 performance of different concentrations
 of E. coli as an indicator for systems that
 will exceed the Bin 1 boundary of 0.075
 oocysts/L.
  Information Collection Rule data were
 evaluated as maximum running annual
 averages (Information Collection Rule
 samples were collected once per month
 for 18 months) while ICRSS data were
 evaluated using an annual mean (ICRSS
 samples were collected twice per month
 for 12 months). In addition, as
 indicators were being evaluated it
became apparent that it was necessary
to analyze plants separately based on
 source water type, due to a significantly
different relationship between E. coli
and Cryptosporidium in reservoir/lake
systems compared to flowing stream
 systems.
  Analyzing the performance of an E.
coli level as a screen to trigger
 Cryptosporidium monitoring under the
proposed LT2ESWTR involved

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47674
Federal  Register/Vol.  68,  No. 154/Monday. August 11,  20Q3/PrQposed Rules
evaluating each water treatment plant in
the data set relative to two factors: (1)
Did the plant E. coli level exceed the
trigger value being assessed? and (2) Did
the plant mean Cryptosporidium
concentration exceed 0.075 oocysts/L?
Accordingly, plants were sorted into
four categories, based on
Cryptosporidium and E. coli
concentrations:
  • Plants with Cryptosporidium <
0.075 oocysts/L that  did not exceed  the
E. coli trigger level (Figure IV-1, box A)
  • Plants with Cryptosporidium <
0,075 oocysts/L that  exceeded the E. coli
trigger level (Figure IV. 1, box B)
  • Plants with  Cryptosporidium >
0.075 oocysts/L that  did not exceed  the
E. coli trigger level (Figure IV.1. box C)
   • Plants with Cryptosporidium >
0.075 oocysts/L that exceeded the E. coli
trigger level (Figure IV.l, box D)
Summary data with  E. coli trigger
concentrations ranging from 5 to 100 per
100 mL are presented for Information
Collection Rule and  ICRSS data in
Figures W-2 and IV-3.
   The performance of each E. coli level
as  a trigger for Cryptosporidium
 monitoring was evaluated based on false
 negative and false positive rates. False
 negatives occur when plants do not
 exceed the E. coli trigger value, but
 exceed a  Cryptosporidium level of 0.075
 oocysts/L. False  positives occur when
 plants exceed the E. coli trigger value
 but do not exceed a  Cryptosporidium
 level of 0.075 oocysts/L. The false
 negative rate is critical because it
 characterizes the ability of the indicator
 to identify those plants with high
 Cryptosporidium levels. In general, low
 false negative rates can be achieved by
 lowering the E. coli trigger
 concentration. However, when the  E,
 coli trigger concentration is decreased,
 more plants with low Cryptosporidium
 levels in their source water exceed  it. As
 a result, more plants incur false
                      positives. Consequently, identifying an
                      appropriate E. coli concentration to
                      trigger Cryptosporidium monitoring
                      involves balancing false negatives and
                      false positives to minimize both.
                        Results of the indicator analysis for
                      plants with flowing stream sources are
                      shown in Figure IV-2. An E. coli trigger
                      concentration of 50/100 mL produced
                      zero false negatives for both data sets.
                      This means that in these data sets, all
                      plants that exceeded mean
                      Cryptosporidium concentrations of
                      0.075 oocysts/L also exceeded the E. coli
                      trigger concentration and would,
                      therefore, be required to monitor.
                      However, this trigger concentration had
                      a significant false positive rate (i.e., it
                      was not highly specific in targeting only
                      those plants with high Cryptosporidium
                       levels). False positive rates were 57%
                       (24/42) and 53% (9/17) with
                       Information Collection Rule and ICRSS
                       data, respectively. At a higher E. coli
                       trigger concentration, such as 100/100
                       mL, the false negative rate increased to
                       12.5% (3/24) with Information
                       Collection Rule data and 50% (2/4) with
                       ICRSS data, while the false positive rate
                       decreased to 43% (18/42) and 35% (6/
                       17), respectively. Consequently, EPA is
                       proposing a mean E. coli concentration
                       of 50/100 mL as a trigger for
                       Cryptosporidium monitoring by small
                       systems with flowing stream sources.
                         Results of the indicator analysis for
                       plants with reservoir/lake sources are
                       shown in. Figure IV-3.  An E. coli trigger
                       of 10/100 mL resulted in a false negative
                       rate of 20% (2/10) with Information
                       Collection Rule data and 67% (2/3) with
                       ICRSS data (misclassified 2 out of 3
                       plants over 0.075 oocysts/L). Going to a
                       lower concentration E. coli trigger, such
                       as 5 per 100 mL, decreased the false
                       negative rate in both the Information
                       Collection Rule and ICRSS data sets by
                       one plant,  but increased the false
                       positive rate from 20% to 43% (13/30)
in the ICRSS data and from 24% to 39%
(44/114) in the Information Collection
Rule data. Based on these results, EPA
is proposing that a mean E. coli
concentration of 10/100 mL trigger
small systems using lake/reservoir
sources into monitoring for
Cryptosporidium. While the false
negative rate associated with this trigger
value in the ICRSS data set is high, the
ICRSS data set contains only 3
reservoir/lake plants that exceeded a
Cryptosporidium level of 0.075 oocysts/
L.
  Due to limitations in the available
data, the Advisory Committee did not
recommend that large systems use the E.
coli indicator screen, as
Cryptosporidium monitoring is less of
an economic burden for large systems-
Rather, the Advisory Committee
recommended that large systems sample
for E, coli and turbidity when they
monitor for Cryptosporidium under the
LT2ESWTR. These data will then be
used to verify or, if necessary, further
refine the proposed indicator trigger
values for small systems. EPA concurs
with these recommendations and they
 are reflected in today's proposal.
   The proposed monitoring schedule
under the LT2ESWTR is set up to allow
EPA and stakeholders to evaluate large
 system monitoring data for indicator
 relationships prior to the start of small
 system E. coli monitoring. After one
 year of large system monitoring is
 completed, EPA will begin analyzing
 monitoring data to assess whether
 alternative indicator strategies would be
 appropriate. Depending on the findings
 of this analysis, EPA may issue
 guidance to States on approving
 alternative indicator trigger strategies for
 small systems. Therefore, the proposed
 rule is written with the allowance for
 States to approve alternative indicator
 strategies.
 BILLING CODE 6560-50-P

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         Federal Register/Vol. 68, No. 154/Monday, August 11, 2003/Proposed Rules
47675
Breakdown of Plants into Cryptosporidium
"bin"
< 0.075 Cryptosporidium per L
s 0.075 Cryptosporidium per L
Calculations used to Ass
What percent of plants with > 0.075
Cryptosporidium per L exceed the E. coti
trigger?
What percent of plants would be required to
monitor for Cryptosporidium1?
Breakdown of Plants Using E. coli "Trigger"
Did not exceed trigger Exceeds trigger value
value
A
C
ess Indicator Performance
D/C +
B
D

D)
(B + D) / (A •*• B + C + D)
Figure IV-1.- Microbial Indicator System Template

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47676
Federal Register/Vol.  68, No,  154/Monday, August 11, 2003 / Proposed  Rules








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                  Federal Register/Vol.  68, No.  154/Monday, August 11, 2003/Proposed Rules
                                                                      47677
 BILLING CODE 6560-50-C
 Cryptosporidium Monitoring
   Small systems that exceed the E. coli
 trigger must conduct Cryptosporidium
 monitoring, beginning 6 months after
 completion of£". coli monitoring. As
 recommended by the Advisory
 Committee, EPA is proposing that small
 systems collect 24 Cryptosporidium
 samples over a period of one year. This
 number of samples is the same as
 required for large systems, but the
 monitoring burden is targeted only on
 those plants that E. coli monitoring
 indicates to have elevated levels of fecal
 matter in the source  water. By
 completing Cryptosporidium monitoring
 in one year, small systems will conduct
 a total of 2 years of monitoring to
 determine LT2ESWTR bin classification
 (including the one year of E. coli
 monitoring). This time frame is
 equivalent to the requirement for large
 systems, which monitor for
 Cryptosporidium, E.  coli, and turbidity
 for 2 years.
   The Stage 2 M-DBP Agreement in
 Principle recommended that EPA
 explore the feasibility of alternative,
 lower frequency, Cryptosporidium
 monitoring criteria for providing a
 conservative mean estimate in small
 systems. As described earlier, EPA has
 evaluated smaller sample sizes, such as
 systems taking 12 or  8 samples instead
 of 24 (see Table IV-6). However, EPA
 has concluded that these smaller sample
 sizes result in unacceptably high
 misclassification rates. For example, bin
 classification based on the second
 highest of 12 samples produces an
 estimated false positive rate of 47% for
 systems with a mean Cryptosporidium
 concentration 0.5 log below the Bin 1
 boundary of 0.075/L. In comparison, bin
 classification based on the mean of 24
 samples achieves a false positive rate of
 2.8% for systems at this
 Cryptosporidium concentration.
 Consequently, EPA is proposing no
 alternatives to the requirement that
 small systems take at least 24 samples.
  Small system bin classification will be
 determined by the arithmetic mean of
the 24 samples collected over one year.
Because the bin structure in the
LT2ESWTR is based on annual mean
 Cryptosporidium levels, it is necessary
that bin classification involve averaging
samples over at least  one year.
Consequently, small systems will
determine their bin classification by
averaging results from all
Cryptosporidium samples collected
during their one year  of monitoring.
  iii. Future monitoring and
reassessment. EPA is  proposing that
beginning 6 years after the initial bin
 classification, large and smail systems
 conduct another round of monitoring to
 determine if source water conditions
 have changed to a degree that may
 warrant a revised bin classification. The
 Advisory Committee recommended that
 EPA convene a stakeholder process
 within 4 years after the initial bin
 classification to develop
 recommendations on how best to
 proceed with implementing this second
 round of monitoring. Unless EPA
 modifies the LT2ESWTR to allow for an
 improved analytical method or a revised
 bin structure based on new risk
 information, the second round of
 monitoring will be conducted under the
 same requirements that apply to the
 initial round of monitoring.
   In addition, EPA is proposing to use
 the required assessment of the water
 source  during sanitary surveys as an
 ongoing measure of whether significant
 changes in watersheds have occurred
 that may lead to increased
 contamination. Where the potential for
 increased contamination is identified,
 States must determine what follow-up
 actions by the system are necessary,
 including the possibility of the system
 providing additional treatment from the
 microbial toolbox.
   d. Basis for accepting previously
 collected data. Members of the Advisory
 Committee had multiple objectives in
 recommending that EPA allow the use
 of previously collected (grandfathered)
 Cryptosporidium data. These include (1)
 giving credit for data collected by
 proactive utilities, (2) facilitating early
 determination of LT2ESWTR
 compliance needs  and, thereby,
 allowing for early planning of
 appropriate treatment selection, (3)
 increasing laboratory capacity to meet
 demand for Cryptosporidium analysis
 under the LT2ESWTR, and (4) allowing
 utilities to improve their data set for bin
 determination by considering more than
 2 years  of data (i.e., include data
 collected prior to effective date of
 LT2ESWTR). The latter objective
 incorporates the assumption that
 occurrence can vary from year to year,
 so that if more years of data are used in
 the bin determination, the source water
 concentration estimate will be a more
 accurate representation of the overall
 mean.
  A significant issue with accepting
 previously collected data for making bin
 determinations is ensuring that the data
 are of equivalent quality to data that
will be collected following LT2ESWTR
promulgation. As noted previously, EPA
 is establishing requirements so that data
 collected under the LT2ESWTR will be
similar in quality to data that were
generated under the ICRSS. These
 requirements include the use of
 approved analytical methods and
 compliance with method quality control
 (QC) criteria, use of approved
 laboratories, minimum sample volume,
 and a sampling schedule with minimum
 frequency. For example, under the
 ICRSS, laboratories analyzed 10 L
 samples and (considered collectively)
 achieved a mean Cryptosporidium
 recovery of approximately 43% in
 spiked source water with a relative
 standard deviation (RSD) of 50%. EPA
 anticipates that laboratories conducting
 Cryptosporidium analysis for the
 LT2ESWTR will collectively achieve
 similar analytical method performance.
 Consequently, EPA expects previously
 collected data sets used under the
 LT2ESWTR to meet these standards and
 has established criteria for accepting
 previously collected data accordingly
 (see section IV.A.I.d).
   Systems are requested, but not
 required, to notify EPA prior to
 promulgation of the LT2ESWTR of their
 intent to submit previously collected
 data. This will  help EPA allocate the
 resources that will be needed to
 evaluate these data in order to make a
 decision on adequacy for bin
 determination. Systems that have at
 least 2 years of previously collected data
 to grandfather when the LT2ESWTR is
 promulgated and do not intend to
 conduct new monitoring under the rule
 are required to  submit the previously
 collected data to EPA within 2 months
 following promulgation. This will
 enable EPA to evaluate the  data and
 report back to the utility in sufficient
 time to allow, if needed, the utility to
 contract with a laboratory to conduct
 monitoring under the LT2ESWTR.
  Systems that have fewer than 2 years
 of previously collected data to
 grandfather when the LT2ESWTR is
 promulgated, or that intend to
 grandfather 2 or more years of
 previously collected data and also
 conduct new monitoring under the rule,
 are required to submit the previously
 collected data to EPA within 8 months
 following promulgation. This will allow
 these utilities to continue to collect
 previously collected data in the 6 month
 period between promulgation and the
 date when monitoring under the
 LT2ESWTR must begin, plus a 2 month
 period for systems to compile the data
 and supporting documentation. Utilities
may submit the data earlier than 8
months after promulgation if they
 acquire 2 years  of previously collected
 data before this date.
  Submitted grandfathered data sets
must include all routine source water
monitoring results for samples collected
during the time period covered by the

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47678
Federal Register/Vol. 68, No.  154/Monday, August 11, 2003/Proposed  Rules
grandfathered data set (i.e., the time
period between collection of the first
and last samples in the data set).
However, systems are not required
under the LT2ESWTR to submit
previously collected data for samples
outside of this time period.
3. Request for Comment
   EPA requests comments on  all aspects
of the monitoring and treatment
requirements proposed in this section.
In addition, EPA requests comment on
the following issues:
Requirements for Systems That Use
Surface Water for Only Part of the Year
   Bin classification for the LT2ESWTR
is based on the mean annual
sourcewater Cryptosporidium level.
Consequently, today's proposal requires
E. coli and Cryptosporidium monitoring
to be conducted over the full year.
However, EPA recognizes that some
 systems use surface water for only part
 of the year. This occurs with systems
that use surface water for part of the
year (e.g., during the summer) to
 supplement ground water sources and
 with systems like campgrounds that are
 in operation for only part of the year.
 Year round monitoring for these systems
 may present both logistic and economic
 difficulties. EPA is requesting comment
 on how to apply LT2ESWTR  monitoring
 requirements to surface water systems
 that operate or use surface water for
 only part of the year. Possible
 approaches that may be considered for
 comment include the following:
   Small public water systems that
 operate or use surface water for only
 part of the year could be required to
 collect E. coli samples at least bi-weekly
 during the period when they  use surface
 water. If the mean E. coli concentration
 did not exceed the trigger level (e.g., 10/
 100 mL for reservoirs/lakes or 50/100mL
 for flowing streams), systems could
 apply to the State to waive any
 additional E. coli monitoring. The State
 could grant the waiver, require
 additional E. coli monitoring, or require
 monitoring of an alternate indicator. If
 the mean E. coli concentration exceeded
 the trigger level, the State could require
 the system to provide additional
' treatment for Cryptosporidium
 consistent with Bin 4 requirements, or
 require monitoring of Cryptosporidium
 or an indicator, with the results
 potentially leading to additional
 Cryptosporidium treatment
 requirements.
    Large public water systems that
 operate or use surface water for only
 part of the year could be required to
 collect Cryptosporidium samples (along
 with E. coli and turbidity) either twice-
                      per-month during the period when they
                      use surface water or 12 samples per
                      year, whichever is smaller. Samples
                      would be collected during the two years
                      of the required monitoring period, and
                      bin classification would be based on the
                      highest average of the two years.
                        EPA requests comment on these and
                      other approaches for both small and
                      large systems.
                      Previously Collected Monitoring Data
                      That Do Not Meet QC Requirements
                        EPA is proposing requirements for
                      acceptance of previously collected
                      monitoring data that are equivalent to
                      requirements for data generated under
                      the LT2ESWTR. The Agency is aware
                      that systems will have previously
                      collected Cryptosporidium data that do
                      not meet ail  sampling and analysis
                      requirements (e.g., quality control,
                      sample frequency, sample volume)
                      proposed for data collected under the
                      LT2ESWTR. However, the Agency has
                      been unable to develop an approach for
                      allowing systems to use such data for
                      LT2ESWTR  bin classification. This is
                      due to uncertainty regarding the impact
                      of deviations from proposed sampling
                      and analysis requirements on data
                      quality and reliability. For example,
                      Methods 1622 and 1623 have been
                      validated within the limits of the QC
                      criteria specified in these methods.
                      While very minor deviations from
                      required QA/QC criteria may have only
                      a minor impact on data quality, the
                      Agency has  not identified a basis for
                      establishing alternative standards for
                      data acceptability.
                         EPA requests comment on whether or
                      under what conditions previously
                      collected data that do not meet the
                      proposed criteria for LT2ESWTR
                      monitoring  data should be accepted for
                      use in bin determination. Specifically,
                      EPA requests comment on the sampling
                      frequency requirement for previously
                      collected data, and whether EPA should
                      allow samples collected at lower or
                      varying frequencies to be used as long
                      as the data are representative of seasonal
                      variation and  include the required
                      number of samples. If so, how should
                      EPA determine whether such a data set
                      is unbiased and representative of
                       seasonal variation? How should data
                      collected at varying frequency be
                      averaged?
                       Monitoring for Systems That Recycle
                       Filter Backwash
                         Plants that recycle filter backwash
                       water may,  in effect, increase the
                       concentration of Cryptosporidium in the
                       water that enters the filtration treatment
                       train. Under the LT2ESWTR proposal,
                       microbial sampling may be conducted
on source water prior to the addition of
filter backwash water. EPA requests
comment on how the effect of recycling
filter backwash should be considered in
LT2ESWTR monitoring.
Bin Assignment for Systems That Fail
To Complete Required Monitoring
  Today's proposal classifies systems
that fail to complete required
monitoring in Bin 4, the highest
treatment bin. EPA requests comment
on alternative approaches for systems
that fail to complete required
monitoring, such as classifying the
system in a bin based on data the system
has collected, or classifying the system
in a bin one level higher than the bin
indicated by the data the system has
collected. The shortcoming to these
alternative approaches is that bin
classification becomes more uncertain,
and the likelihood of bin
misclassification increases, as systems
collect fewer than the required 24
Cryptosporidium samples.
Consequently, the proposed approach is
for systems to collect all required
samples.
   Note that under today's proposal,
systems may provide 5.5 log of
treatment for Cryptosporidium (i.e.,
comply with Bin 4 requirements) as an
alternative to monitoring. Where
systems notify the State that they will
provide treatment instead of monitoring,
they will not incur monitoring
violations.
Monitoring Requirements for New
Plants and Sources
   The proposed LT2ESWTR would
establish calendar dates when the initial
and second round of source water
 monitoring must be conducted to
 determine bin classification. EPA
 recognizes that new plants will begin
 operation, and that existing plants will
 access new sources, after these dates.
 EPA believes that new plants and plants
 switching sources should conduct
 monitoring equivalent to that required
 of existing plants to determine the
 required level of Cryptosporidium
 treatment. The monitoring could be
 conducted before a new plant or source
 is brought on-line, or initiated within
 some time period afterward. EPA
 requests comment on monitoring and
 treatment requirements for new plants
 and sources.
 Determination  of LT2ESWTR Bin
 Classification
   In today's proposal, EPA expects that
 systems will be assigned to LT2ESWTR
 risk bins based on their reported
 Cryptosporidium monitoring results and
 the calculations proposed for bin

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•    assignment described in this section.
I    EPA requests comment on whether bin
I    classifications should formally be made
I    or reviewed by States.
I    Source Water Type Classification for
I    Systems That Use Multiple Sources
• '      In today's proposal, the E, coli
|    concentrations that trigger small system
      Cryptosporidium monitoring are
      different for systems using lake/
      reservoir and flowing stream sources.
      However, EPA recognizes that some
      systems use multiple sources,
      potentially including both lake/reservoir
      and flowing stream sources, and that the
      use of different sources may vary during
      the year. Further, some systems use
      sources that are ground water under the
      direct influence (GWUD1) of surface
      water. EPA requests comment on how to
      apply the E. coli criteria for triggering
      Cryptosporidium  monitoring to systems
      using multiple sources and GWUDI
      sources.

      B. Unfiltered System Treatment
      Technique Requirements for
      Cryptosporidium

      1. What Is EPA Proposing Today?
       a.  Overview. EPA is proposing
      treatment technique requirements for
      Cryptosporidium in unfiltered systems.
      Today's proposal requires all unfiltered
      systems using surface water or ground
      water under the direct influence of
      surface water to achieve at least 2 log
      (99%) inactivation of Cryptosporidium
      prior to the distribution of finished
      water. Further, unfiltered systems must
      monitor for Cryptosporidium in their
      source water, and where monitoring
      demonstrates a mean level above  0.01
      oocysts/L, systems must provide at least
      3 log Cryptosporidium inactivation.
     Disinfectants that can be used to meet
     this treatment requirement include
     ozone,  ultraviolet (UV) light, and
     chlorine dioxide.
       All current requirements for
     unfiltered systems under 40 CFR 141.71
     and 141.72(a} remain in effect,
     including requirements to inactivate at
     least 3 log of Giardia lamblia and 4 log
     of viruses. In addition, unfiltered
     systems must meet their overall
     disinfection requirements using a
     minimum of two disinfectants. These
     proposed requirements reflect
     recommendations of the Stage 2 M-DBP
     Federal Advisory Committee. Details  of
     the proposed requirements are
     described in the following sections.
       b. Monitoring requirements.
     Requirements for Cryptosporidium
     monitoring by unfiltered systems are
     similar to requirements for filtered
     systems of the same size, as given in
                       Federal Register/Vol.  68, No. 154/Monday, August 11, 2003/-Proposed  Rules
                                                                      47679
 section IV.A.l. Unfiltered systems
 serving at least 10,000 people must
 sample their source water for
 Cryptosporidium at least monthly for
 two years, beginning no later than 6
 months after promulgation of this rule.
 Samples may be collected more
 frequently (e.g., semi-monthly, weekly)
 as long as a consistent frequency is
 maintained throughout the monitoring
 period.
   Unfiltered systems serving fewer  than
 10,000 people must conduct source
 water sampling for Cryptosporidium at
 least twice-per-month for one year,
 beginning no later than 4 years
 following promulgation of this rule  (i.e.,
 on the same schedule as small filtered
 systems). However, unlike small filtered
 systems, small unfiltered systems
 cannot monitor for an indicator (e.g., E.
 coli] to determine if they are required to
 monitor for Cryptosporidium. EPA has
 not identified indicator criteria that can
 effectively screen for plants with
 Cryptosporidium concentrations below
 0.01 oocysts/L. Consequently, al! small
 unfiltered systems must conduct
 Cryptosporidium monitoring.
   As described in section IV.K and IV.L,
 Cryptosporidium analyses must be
 performed on at least 10 L per sample
 with EPA Methods  1622 or 1623,  and
 must be conducted  by laboratories
 approved for these methods by EPA.
 Analysis of larger sample volumes is
 allowed, provided the laboratory has
 demonstrated comparable method
 performance to that achieved on a 10 L
 sample. Section IV J describes
 requirements for reporting sample
 analysis results. All Cryptosporidium
 samples must be collected in
 accordance with a schedule that is
 developed by the system and submitted
 to EPA or the State at least 3 months
 prior to initiation of sampling. Refer to
 section IV.A.l for requirements
 pertaining to any failure to report  a
 valid sample analysis result for a
 scheduled sampling date and
 procedures for collecting a replacement
 sample.
  Unfiltered systems are required  to
 participate in future Cryptosporidium
 monitoring on the same  schedule as
 filtered systems of the same size. Future
 monitoring requirements for filtered
 systems are described in section IV.A.l.
  Unfiltered systems are not required to
 conduct source water Cryptosporidium
 monitoring under the LT2ESWTR  if the
 system currently provides or will
 provide a total of at least 3 log
 Cryptosporidium inactivation,
 equivalent to meeting the treatment
requirements for unfiltered systems
with a mean Cryptosporidium
concentration of greater than 0.01
 oocysts/L. Systems must notify the State
 not later than the date the system is
 otherwise required to submit a sampling
 schedule for monitoring. Systems must
 install and operate technologies to
 provide a total of at least 3 log
 Cryptosporidium inactivation by the
 applicable date in Table IV—24.
   c. Treatment requirements. All
 unfiltered systems must provide
 treatment for Cryptosporidium, and the
 degree of required treatment depends on
 the level of Cryptosporidium in the
 source water as determined through
 monitoring. Unfiltered systems must
 calculate their average source water
 Cryptosporidium concentration using
 the arithmetic mean of all samples
 collected during the required two year
 monitoring period (or one year
 monitoring period for small systems).
 For unfiltered systems with mean
 source water Cryptosporidium levels of
 less than or equal to 0.01 oocysts/L, 2
 log Cryptosporidium inactivation is
 required. Where the mean source water
 level is greater than 0.01 oocysts/L, 3 log
 inactivation is required.
   In addition, unfiltered systems are
 required to use at least two different
 disinfectants to meet their overall
 inactivation requirements for viruses (4
 log), Giardia lamblia (3 log), and
 Cryptosporidium (2 or 3 log). Further,
 each of the two disinfectants must
 achieve by itself the total inactivation
 required for one of these three pathogen
 types. For example, a system could use
 UV light to achieve 2 log inactivation of
 Cryptosporidium and Giardia lamblia,
 and use chlorine to inactivate 1 log
 Giardia lamblia and 4 log viruses. In
 this case, chlorine would achieve the
 total inactivation required for viruses
 while UV light would achieve the total
 inactivation required for
 Cryptosporidium, and the two
 disinfectants together would meet the
 overall treatment requirements for
 viruses, Giardia lamblia, and
 Cryptosporidium. In all cases unfiltered
 systems must continue to meet
 disinfectant residual requirements for
 the distribution system.
  EPA has developed criteria, described
 in sections IV.C.14-15, for systems to
 determine Cryptosporidium inactivation
 credits for chlorine dioxide, ozone, and
 UV light. Unfiltered systems are allowed
 to use any of these disinfectants to meet
 the 2 (or 3) log Cryptosporidium
inactivation requirement. The following
paragraphs describe standards for
 demonstrating compliance with the
proposed Cryptosporidium treatment
technique requirement.  For systems
using ozone and chlorine dioxide, these
standards are similar to current
standards for compliance with Giardia

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                Federal Register/Vol.  68, No.  154/Monday, August 11. 2003/Proposed Rules
lamblia and virus treatment
requirements, as established by the
SWTR in 40 CFR 141.72 and 141.74,
However, for systems using UV light,
modified compliance standards are
proposed, due to the different way in
which UV disinfection systems will be
monitored.
  Each day a system using ozone or
chlorine dioxide serves water to the
public, the system must calculate the CT
value(s) from the system's treatment
parameters, using the procedures
specified in 40 CFR 14l.74(b)(3). The
system must determine whether this
value(s) is sufficient to achieve the
required inactivation of
Cryptosporidmm based on the CT
criteria specified in section IV.C.14. The
disinfection treatment must ensure at
least 99 percent (or 99.9 percent if
required) inactivation of
Cryptosporidium every day the system
serves water to the public, except any
one day each month. Systems are
required to report daily CT values on a
monthly basis, as described in section
1V.J.
   Each day a system using UV light
serves water to the public, the system
must monitor for the parameters,
including flow rate and UV intensity,
that demonstrate whether the system's
 UV reactors are operating within the
range of conditions that have been
 validated to achieve the required UV
 dose, as specified in section IV.C.15.
 Systems must monitor each UV reactor
 while in use and must record periods
 when any reactor operates outside  of
 validated conditions. The disinfection
 treatment must ensure at least 99
 percent (or 99.9 percent if required]
 inactivation of Cryptosporidium in at
 least 95 percent of the water delivered
 to the public every month. Systems are
 required to report periods when UV
 reactors operate outside of validated
 conditions on  a monthly basis, as
 described in section IV.].
    Unfiltered systems currently must
 comply with requirements for DBFs as
 a condition of avoiding filtration under
 40 CFR 141.71(b)(6). As described
 earlier, EPA is developing a Stage 2
 DBPR, which will further limit
 allowable levels of certain DBFs,
 specifically tribal omethanes and
 haloacetic acids. EPA intends to
 incorporate new standards for DBFs
 established under the Stage 2 DBPR into
 the criteria for filtration avoidance.
 2. How Was This Proposal Developed?
    a. Basis for Cryptosporidium
  treatment requirements. The intent of
 the proposed treatment requirements for
 unfiltered systems is to achieve public
 health protection against
Cryptosporidium equivalent to filtration
systems. As described in section III.C,
an assessment of survey data indicates
that under current treatment
requirements, finished water
Cryptosporidium levels are higher in
unfiltered systems than in filtered
systems.
  Information Collection Rule data
show an average plant-mean
Cryptosporidium level of 0.59 oocysts/L
in the source water of filtered plants and
0.014 oocysts/L in unfiltered systems.
Median plant-mean concentrations were
0.052 and 0.0079 oocysts/L in filtered
and unfiltered system sources,
respectively. Thus, these results suggest
that typical Cryptosporidium occurrence
in filtered system sources is
approximately 10 times higher than in
unfiltered system sources.
   In translating these data to assess
finished water risk, EPA and the
Advisory Committee estimated that
conventional plants in compliance with
the IESWTR achieve an average
 Cryptosporidium removal of 3 log (see
discussion in section III.D). Hence, if the
median source water Cryptosporidium
 level at conventional plants is
 approximately 10 times higher than at
unfiltered systems, and it is estimated
 that conventional plants achieve an
 average reduction of 3 log (99.9%), then
 the median finished water
 Cryptosporidium concentration at
 conventional plants is lower by a factor
 of 100 than at unfiltered systems.
 Therefore, to ensure equivalent public
 health protection, unfiltered systems
 should reduce Cryptosporidium levels
 by 2 log.
    Due to the development of criteria for
 Cryptosporidium inactivation with
 ozone, chlorine dioxide, and UV light,
 EPA has determined that it is feasible
 for unfiltered systems to comply with a
 Cryptosporidium treatment technique
 requirement. Consequently, EPA is
 proposing that all unfiltered systems
 provide at least 2 log inactivation of
 Cryptosporidium.
    The proposed treatment requirements
 for unfiltered systems with higher
 source water Cryptosporidium levels are
 consistent with proposed treatment
 requirements for filtered systems. As
 discussed previously, EPA is proposing
 that filtered plants with mean source
 water Cryptosporidium levels between
 0.075 and 1.0 oocysts/L, as measured by
 Methods 1622 and 1623, provide at least
 a 4 log reduction (with greater treatment
 required for higher source water
 pathogen levels). These requirements
 will achieve average treated water
  Cryptosporidium concentrations below
  1 oocyst/10,000 L in filtered systems.
 An unfiltered system with a mean
source water Cryptosporidium
concentration above 0.01 oocyst/L
would need to provide more than 2 log
inactivation in order to achieve an
equivalent finished water oocyst level.
Therefore, EPA is proposing that
unfiltered systems provide at least 3 log
inactivation where mean concentrations
exceed 0.01 oocysts/L.
  For unfiltered systems using UV
disinfection to meet these proposed
Cryptosporidium treatment
requirements, EPA is proposing that
compliance be based on a 95th
percentile standard (i.e., at least 95
percent of the water must be treated to
the required UV dose). This standard is
intended to be comparable with the
"every day except any one day per
month" compliance standard
established by the SWTR for chemical
disinfection (see 40 CFR 141.72(a)(l)).
Because UV disinfection  systems will
typically consist of multiple parallel
reactors that will be monitored
continuously, the Agency has
 determined that it is more appropriate
to base a compliance determination on
the percentage of water disinfected to
 the required level, rather than a single
 daily measurement. The UV
 Disinfection Guidance Manual (USEPA
 2003d) will provide advice on meeting
 this proposed standard. A draft of this
 guidance is available in the docket for
 today's proposal (http://www.epa.gov/
 edocketf).
   b. Basis for requiring the use of two
 disinfectants. EPA is proposing that
 unfiltered systems use at least two
 different disinfectants to meet the 2 (or
 3}, 3, and 4 log inactivation
 requirements for Cryptosporidium,
 Giardia lamblia, and viruses,
 respectively. The purpose of this
 requirement is to provide for multiple
 barriers of protection against pathogens.
 One benefit of this approach is that if
 one barrier were to fail then there would
 still be one remaining barrier to provide
 protection against  some of the
 pathogens that might be present. For
 example, if a plant used UV to
 inactivate Cryptosporidium and Giardia
 lamblia, along with chlorine to
 inactivate viruses, and the UV system
 were to malfunction, the chlorine would
 still meet the treatment requirement for
 viruses and would provide some degree
 of protection against Giardia lamblia.
    Another benefit of multiple barriers is
 that they will typically provide more
  effective protection against a broad
  spectrum of pathogens than a single
  disinfectant. Because the efficacy of
  disinfectants against different pathogens
  varies widely, using multiple
  disinfectants will  generally provide
  more efficient inactivation of a wide

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                  Federal Register/Vol.  68, No. 154/Monday, August 11, 2003/Proposed Rules
                                                                      47681
 range of pathogens than a single
 disinfectant.
   EPA is aware, though, that this
 requirement would not result in a
 redundant barrier for each type of
 pathogen. In the example of a plant
 using chlorine and UV, the chlorine
 would provide essentially no protection
 against Cryptosporidium and might
 achieve only a small amount of Giardia
 lamblia inactivation if it was designed
 primarily to inactivate viruses.
 However, since the watersheds of
 unfiltered systems are required to be
 protected (40 CFR 141.71), the
 probability  is tow that high levels of
 Cryptosporidium or Giardia lamblia
 would occur during the time frame
 necessary to address a short period of
 treatment failure.
   Note the request for comment on this
 topic at the end of this section.
   c. Basis for source water monitoring
 requirements. Monitoring by unfiltered
 systems is necessary to identify those
 with mean source water
 Cryptosporidium levels above 0.01
 oocysts/L. In order to allow for
 simultaneous compliance with other
 microbial and disinfection byproduct
 regulatory requirements, EPA is
 proposing that unfiltered systems
 monitor for Cryptosporidium on the
 same schedule as filtered systems of the
 same size. Because EPA was not able to
 identify indicator criteria, such as E.
 coli, that can discriminate among
 systems above and below a mean
 Cryptosporidium concentration of 0.01
 oocysts/L, EPA is proposing that all
 unfiltered systems monitor for
 Cryptosporidium.
   Consistent with requirements for
 filtered systems, unfiltered systems are
 required to analyze at least 24 samples
 of at least 10 L over the two year
 monitoring period (one year for small
 systems). However, if an unfiltered
 system collected and analyzed only 24
 samples of 10 L then a total count of 3
 oocysts among all samples would result
 in a source water concentration
 exceeding 0.01 oocysts/L. To avoid a
 relatively small number of counts
 determining an additional treatment
 implication, unfiltered systems may
 consider conducting more frequent
 sampling or  analyzing larger sample
 volumes (e.g., 50 L). Since the water
 sources of unfiltered systems tend to
 have very low turbidity (compared to
 average sources in filtered systems), it is
typically more feasible to analyze larger
 sample volumes in unfiltered systems.
 Filters have been approved for
 Cryptosporidium analysis of 50 L
 samples. Note that analysis of larger
sample volumes would not reduce the
required sampling frequency.
 3. Request for Comment

   EPA solicits comment on the
 proposed monitoring and treatment
 technique requirements for unfiltered
 systems. Specifically, the Agency seeks
 comment on the following issues:

 Use of Two Disinfectants

   EPA requests comment on the
 proposed requirement for unfiltered
 systems to use two disinfectants and for
 each disinfectant to meet by itself the
 inactivation requirement for at least one
 regulated pathogen. The requirement for
 unfiltered systems to use two
 disinfectants was recommended by the
 Advisory Committee because (1)
 disinfectants vary in their efficacy
 against different pathogens, so that the
 use of multiple disinfectants can
 provide more effective protection
 against a broad spectrum of pathogens,
 and (2) multiple disinfectants provide
 multiple barriers of protection, which
 can be more reliable  than a single
 disinfectant.
  An alternate approach would be to
 allow systems to meet the inactivation
 requirements using any combination of
 one or more disinfectants that achieved
 the required inactivation level for all
 pathogens. This would give systems
 greater flexibility and could spur the
 development of new  disinfection
 techniques that would be applicable to
 a wide range of pathogens. However,
 this approach might be less protective
 against unregulated pathogens. A
 related question is whether the
 proposed requirements for use of two
 disinfectants establish an adequate level
 of multiple barriers in the treatment
 provided by unfiltered systems.

 Treatment Requirements for Unfiltered
 Systems With Higher Cryptosporidium
 Levels

  Under the proposed LT2ESWTR, a
 filtered system that measures a mean
 source water Cryptosporidium level of
 0.075 oocysts/L or higher is required to
 provide a total of 4 log or more
 reduction of Cryptosporidium. However,
 if an unfiltered system, meeting the
 criteria for avoiding filtration were to
 measure Cryptosporidium at this level,
 it would be required to provide only 3
 log treatment. Available occurrence data
 indicate that very few, if any, unfiltered
 systems will measure mean source
water Cryptosporidium concentrations
 above 0.075 oocysts/L. However, EPA
requests comment on whether or how
this possibility should be addressed.
 G. Options for Systems To Meet
 Cryptosporidium Treatment
 Requirements

 1, Microbial Toolbox Overview
   The LT2ESWTR proposal contains a
 list of treatment processes and
 management practices for water systems
 to use in meeting additional
 Cryptosporidium treatment
 requirements under the LT2ESWTR.
 This list, termed the microbial toolbox,
 was recommended by the Stage 2 M-
 DBP Advisory Committee in the
 Agreement in Principle. Components of
 the microbial toolbox include watershed
 control programs, alternative sources,
 pretreatment processes, additional
 filtration barriers, inactivation
 technologies, and enhanced plant
 performance. The intent of the microbial
 toolbox is to provide water systems with
 broad flexibility in selecting cost-
 effective LT2ESWTR compliance
 strategies. Moreover, the toolbox allows
 systems that currently provide
 additional pathogen barriers or that can
 demonstrate enhanced performance to
 receive additional Cryptosporidium
 treatment credit.
  A key feature of the microbial toolbox
 is that many of the components cany
 presumptive credits towards
 Cryptosporidium treatment
 requirements. Plants will receive these
 credits for toolbox components by
 demonstrating compliance with
 required design and implementation
 criteria, as described in the sections that
 follow. Treatment credit greater than the
 presumptive credit may be awarded for
 a toolbox component based on a site-
 specific or technology-specific
 demonstration of performance, as
 described in section IV.C.17.
  While the Advisory Committee made
 recommendations for the degree of
 presumptive treatment credit to be
 granted to different toolbox
 components, the Committee did not
 specify the  design and implementation
 conditions under which the credit
 should be awarded.  EPA has identified
 and is proposing such conditions in
 today's notice, based on an assessment
 of available data. For certain toolbox
 components, such as raw water storage
 and roughing filters, the Agency
 concluded that available data do not
 support the credit recommended by the
Advisory Committee. Consequently,
EPA is not proposing a presumptive
credit for these options.
  For each microbial toolbox
component, EPA is requesting comment
on: (1) Whether available  data support
the proposed presumptive credits,
including the design and
implementation conditions under which

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Federal Register/Vol. 68, No. 154/Monday, August 11,  2003/Proposed Rules
the credit would be awarded, (2)
whether available data are consistent
with the decision not to award
presumptive credit for roughing filters
and raw water off-stream storage, and
(3) whether additional data are available
on treatment effectiveness of toolbox
components for reducing
Cryptosporidium levels. EPA will
consider modifying today's proposal for
microbial toolbox components based on
new information that may be provided.
   EPA particularly solicits comment on
the performance of alternative filtration
technologies that are currently being
used, as well as ones that systems are
considering for use in the future,
specifically including bag filters,
                      cartridge filters, and bank filtration, in
                      removing Cryptosporidium. The Agency
                      requests both laboratory and field data
                      that will support a determination of the
                      appropriate level of Cryptosporidium
                      removal credit to award to these
                      technologies. In addition, the Agency
                      requests information on the
                      applicability of these technologies to
                      different source water types and
                      treatment scenarios. Data submitted in
                      response to this request for comment
                      should include, where available,
                      associated quality assurance and cost
                      information. This preamble discusses
                      bank filtration in section IV.C.6 and bag
                      and cartridge filters in section 1V.C.12.
  Table IV-7 summarizes presumptive
credits and associated design and
implementation criteria for microbial
toolbox components. Each component is
then described in more detail in the
sections that follow. EPA is also
developing guidance to assist systems
with implementing toolbox
components. Pertinent guidance
documents include: UV Disinfection
Guidance Manual (USEPA 2003d),
Membrane Filtration Guidance Manual
(USEPA 2003e), and Toolbox Guidance
Manual (USEPA 2003f). Each is
available in draft form in the docket for
today's proposal (http://www.epa.gov/
edocket/).
    TABLE IV-7— MICROBIAL TOOLBOX: PROPOSED OPTIONS, LOG CREDITS, AND DESIGN/IMPLEMENTATION CRITERIA
Toolbox option



















Proposed Cryptosporidium log credit with design and implementation criteria1
0.5 log credit for State-approved program comprising EPA specified elements. Does
not apply to unfiltered systems.
No presumptive credit. Systems may conduct simultaneous monitoring for
LT2ESWTR bin classification at alternative intake locations or under alternative in-
take management strategies.
No presumptive credit. Systems using off-stream storage must conduct LT2ESWTR
sampling after raw water reservoir to determine bin classification,
0.5 log credit with continuous operation and coagulant addition; basins must achieve
0.5 log turbidity reduction based on the monthly mean of daily measurements in 11
of the 12 previous months; all flow must pass through basins. Systems using exist-
ing pre-sed basins must sample after basins to determine bin classification and are
not eligible for presumptive credit.
0.5 log additional credit for two-stage softening (single-stage softening is credited as
equivalent to conventional treatment). Coagulant must be present in both stages-
includes metal salts, polymers, lime, or magnesium precipitation. Both stages must
treat 100% of flow.
0.5 log credit for 25 ft. setback; 1.0 log credit for 50 ft. setback; aquifer must be un-
consolidated sand containing at least 10% fines; average turbidity in wells must be
< 1 NTU. Systems using existing wetls followed by filtration must monitor well efflu-
ent to determine bin classification and are not eligible for presumptive credit.
0.5 log credit for combined filter effluent turbidity < 0.15 NTU in 95% of samples
each month.
No presumptive credit proposed.
2.5 log credit as a secondary filtration step; 3.0 log credit as a primary filtration proc-
ess. No prior chlori nation.
0.5 log credit for second separate filtration stage; treatment train must include coagu-
lation prior to first filter. No presumptive credit for roughing filters.
Log credit equivalent to removal efficiency demonstrated in challenge test for device
if supported by direct integrity testing.
1 tog credit with demonstration of at least 2 log removal efficiency in challenge test.
2 log credit with demonstration of at least 3 log removal efficiency in challenge test.
Log credit based on demonstration of log inactivation using CT table.
Log credit based on demonstration of log inactivalion using CT table.
Log credit based on demonstration of inactivation with UV dose table; reactor testing
required to establish validated operating conditions.
1.0 log credit for demonstration of filtered water turbidity < 0.1 NTU in 95 percent of
daily max values from individual filters (excluding 15 min period following
backwashes) and no individual filter > 0.3 NTU in two consecutive measurements
taken 15 minutes apart.
Credit awarded to unit process or treatment train based on demonstration to the
State, through use of a State-approved protocol.
   i Table provides summary information only; refer to following preamble and regulatory language for detailed requirements.
 2. Watershed Control Program

   a. What is EPA proposing today? EPA
 is proposing a 0.5 log credit towards
 Cryptosporidium treatment
 requirements under the LT2ESWTR for
                       filtered systems that develop a State-
                       approved watershed control program
                       designed to reduce the level of
                       Cryptosporidium. The watershed
                       control program credit can be added to
 the credit awarded for any other toolbox
 component. However, this credit is not
 available to unfiltered systems, as they
 are currently required under 40 CFR
 141.171 to maintain a watershed control

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                Federal Register/Vol. 68, No.  154/Monday,  August  11,  2003/Proposed Rules
                                                                     47683
program that minimizes the potential for
contamination by Cryptosporidium as a
criterion for avoiding filtration.
  There are many potential sources of
Cryptosporidium in watersheds,
including sewage discharges and non-
point sources associated with animal
feces. The feasibility, effectiveness, and
sustainability of control measures to
reduce Cryptosporidium contamination
of water sources will be site-specific.
Consequently, the proposed watershed
control program credit centers on
systems working with stakeholders in
the watershed to develop a site-specific
program, and State review and approval
are required. In the Toolbox Guidance
Manual (USEPA 2003f), available in
draft in the docket for today's proposal,
EPA provides information on
management practices that systems may
consider in developing their watershed
control programs.
  Initial State approval of a system's
watershed control program will be
based on  State review of the system's
proposed watershed control plan and
supporting documentation. The initial
approval  can be valid until the system
completes the second round of
Cryptosporidium monitoring described
in section IV.A (systems begin a second
round of monitoring six years  after the
initial bin assignment). During this
period, the system is responsible for
implementing the approved plan and
complying with other general
requirements, such as an annual
watershed survey and program status
report. These requirements are further
described later in this section.
  The period during which State
approval of a watershed control program
is in effect is referred to as the approval
period. Systems that want to continue
their eligibility to receive the 0.5 log
Cryptosporidium treatment credit must
reapply for State approval of the
program for each subsequent approval
period. In general, the re-approval will
be based on the State's review of the
system's reapplication package, as well
as the annual status reports and
watershed surveys. Subsequent
approval(s) by the State of the
watershed control program typically
will be for a time equivalent to the first
approval period, but States have the
discretion to renew approval for a
longer or shorter time period.
Requirements for Initial State Approval
of Watershed Control Programs
  Systems that intend to pursue a 0.5
log Cryptosporidium treatment credit for
a watershed control program are
required to notify the State within one
year following initial bin assignment
that the system proposes to develop a
watershed control plan and submit it for
State approval.
  The application to the State for initial
program approval must include the
following minimum elements:
  • An analysis of the vulnerability of
each source to Cryptosporidium. The
vulnerability analysis must address the
watershed upstream of the drinking
water intake, including: A
characterization of the watershed
hydrology, identification of an "area of
influence" (the  area to be considered in
future watershed surveys) outside of
which there is no significant probability
of Cryptosporidium or fecal
contamination affecting the drinking
water intake, identification of both
potential and actual sources of
Cryptosporidium contamination, the
relative impact  of the sources of
Cryptosporidium contamination on the
system's source water quality, and an
estimate of the seasonal variability of
such contamination.
  • An analysis of control measures
that could address the sources  of
Cryptosporidium contamination
identified during the vulnerability
analysis. The analysis of control
measures must  address their relative
effectiveness in reducing
Cryptosporidium loading to the source
water and their sustainability.
  • A plan that specifies goals and
defines and prioritizes specific actions
to reduce source water  Cryptosporidium
levels.  The plan must explain how
actions are expected to contribute to
specified goals, identify partners and
their role(s), present resource
requirements and commitments
including personnel, and include a
schedule for plan implementation.
  The proposed watershed control plan
and a request for program approval and
0.5 log Cryptosporidium treatment
credit must be submitted by the system
to the State no later than 24 months
following initial bin assignment.
  The State will review the system's
initial proposed watershed control plan
and either approve, reject, or
"conditionally approve" the plan. If the
plan is approved, or if the system agrees
to implementing the State's conditions
for approval, the system will be
awarded 0.5 log credit towards
LT2ESWTR Cryptosporidium treatment
requirements. A final decision on
approval must be made no later than
three years following the system's initial
bin assignment.
  The initial State approval of the
system's watershed control program can
be valid until the system completes the
required second round of
Cryptosporidium monitoring. The
system is responsible for taking the
required steps, described as follows, to
maintain State program approval and
the 0.5 log credit during the approval
period.
Requirements for Maintaining State
Approval of Watershed Control
Programs
  Systems that have obtained State
approval of their watershed control
program are required to meet the
following ongoing requirements within
each approval period to continue their
eligibility for the 0.5 log
Cryptosporidium treatment credit:
  • Submit an annual watershed
control program status report to the
State during each year of the approval
period.
  • Conduct an annual State-approved
watershed survey and submit the survey
report to the State.
  • Submit to the State an application
for review and re-approval of the
watershed control program and for a
continuation of the 0.5 log treatment
credit for a subsequent approval period.
  The annual watershed control
program status report must describe the
system's implementation of the
approved plan and assess the adequacy
of the plan to meet its goals. It must
explain how the system is addressing
any shortcomings in plan
implementation, including those
previously identified by the State or as
the result of the watershed survey. If it
becomes necessary during
implementation to make substantial
changes in its approved watershed
control  program, the system must notify
the State and provide a rationale prior
to making any such changes . If any
change is likely to reduce the level of
source water protection, the system
must also include the actions it will take
to mitigate the effects in its notification.
  The watershed survey must be
conducted according to State guidelines
and by persons approved by the State to
conduct watershed surveys. The survey
must encompass the area of the
watershed that was identified in the
State-approved watershed control plan
as the area of influence and, as a
minimum, assess the priority activities
identified in the plan and identify any
significant new sources of
Cryptosporidium.
  The application to the State for review
and re-approval of the system's
watershed control program must be
provided to the State at least six months
before the current approval period
expires  or by a date previously
determined by the State. The request
must include a summary of activities
and issues identified during the
previous approval period and a revised

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plan that addresses activities for the
next approval period, including any
new actual or potential sources of
Cryptosporidium contamination  and
details of any proposed or expected
changes from the existing State-
approved program. The plan must
address goals, prioritize specific  actions
to reduce source water
Cryptosporidium, explain how actions
are expected to contribute to achieving
goals, identify partners and their role(s),
resource  requirements and
commitments, and the schedule for plan
implementation.
  The annual program status reports,
watershed control plan and annual
watershed sanitary surveys must be
made available to the public upon
request. These documents must be in a
plain language format and include
criteria by which to evaluate the success
of the program in achieving plan goals.
If approved by the State, the system may
withhold portions of the annual status
report, watershed control plan, and
watershed sanitary survey based on
security considerations.
  b. How was this proposal developed?
The M-DBP Advisory Committee
recommended that systems be awarded
0.5 log Cryptosporidium treatment
credit for implementing a watershed
control program. This recommendation
was based on the Committee's
recognition that some systems will be
able to reduce the level of
Cryptosporidium in their source  water
by implementing a well-designed and
focused watershed control  program.
Moreover, the control measures used in
the watershed to reduce levels of
Cryptosporidium are likely to reduce
concentrations of other pathogens as
well.
  EPA concurs that well designed
watershed control programs that focus
on reducing levels of Cryptosporidium
contamination of water sources should
be encouraged, and that implementation
of such programs will likely reduce
overall microbial risk. A broad
reduction in microbial risk will occur
through the application of control
measures and best management
practices that are effective in reducing
fecal contamination in the watershed. In
addition, plant management practices
may be enhanced by the knowledge
systems acquire regarding the watershed
and factors that affect microbial risk,
such as sources, fate, and transport of
pathogens.
  Given the highly site-specific nature
of a watershed control  program,
including the feasibility and
effectiveness of different control
measures, EPA believes that systems
should demonstrate their eligibility for
                      0.5 log Cryptosporidium treatment
                      credit by developing targeted programs
                      that account for site-specific factors. As
                      part of developing a watershed control
                      program, systems will be required to
                      assess a number of these factors,
                      including watershed hydrology, sources
                      of Cryptosporidium in the watershed,
                      human impacts, and fate and transport
                      of Cryptosporidium. Furthermore, EPA
                      believes that the State is well positioned
                      to judge  whether a system's watershed
                      control program is likely to achieve a
                      substantial reduction of
                      Cryptosporidium in source water.
                      Consequently, EPA is proposing that
                      approval of watershed control programs
                      and allowance for an associated 0.5 log
                      treatment credit be made by the State on
                      a system specific basis.
                        A watershed control program could
                      include measures such as (1) the
                      elimination, reduction, or treatment of
                      wastewater or storm water discharges,
                      (2) treatment of Cryptosporidium
                      contamination at the sites of waste
                      generation or storage, (3) prevention of
                      Cryptosporidium migration from
                      sources, or (4) any other measures that
                      are effective, sustainable, and likely to
                      reduce Cryptosporidium contamination
                      of source water. EPA recognizes that
                      many public water systems do not
                      directly control the watersheds of their
                      sources of supply. EPA expects that
                      systems  will need to develop and
                      maintain partnerships with landowners
                      within watersheds, as well as with State
                      governments and regional agencies that
                      have authority over activities in the
                      watershed that may contribute
                      Cryptosporidium to the water supply.
                      Stakeholders that have some level of
                      control over activities that could
                      contribute to Cryptosporidium
                      contamination include municipal
                      government and private operators of
                      wastewater treatment plants, livestock
                      farmers and persons who spread
                      manure, individuals with failing septic
                      systems, logging operations, and other
                      government and commercial
                      organizations.
                        EPA has initiated a number of
                      programs that address watershed
                      management and source water
                      protection. In 2002, EPA launched the
                      Watershed Initiative (67 FR 36172, May
                      23, 2002) (USEPA 2002b), which will
                      provide grants to support innovative
                      watershed based approaches to
                      preventing, reducing, and eliminating
                      water pollution. In addition, EPA has
                      recently  promulgated new regulations
                      for Concentrated Animal Feeding
                      Operations (CAFOs), which through the
                      NPDES permit process will limit
                      discharges that contribute microbial
                      pathogens to watersheds.
  SDWA section 1453 requires States to
carry out a source water quality
assessment program for the protection
and benefit of public water systems.
EPA issued program guidance in August
of 1997, and expects that most States
will complete their source water
assessments  of surface water systems by
the end of 2003. These assessments will
establish a foundation for watershed
vulnerability analyses by providing the
preliminary analyses of watershed
hydrology, a starting point for defining
the area of influence, and an inventory
and hierarchy of actual and potential
contamination sources. In some cases,
these portions of the source water
assessment may fully satisfy those
analytical needs.
  As noted earlier, EPA has published
and is continuing to develop guidance
material that addresses contamination
by Cryptosporidium and other
pathogens from both non-point sources
(e.g., agricultural and urban runoff,
septic tanks) and point sources (e.g.,
sewer overflows, POTWs, CAFOs). The
Toolbox Guidance Manual, available in
draft with today's proposal, includes a
list of programmatic resources and
guidance available to assist systems in
building partnerships and implementing
watershed protection activities. In
addition, this guidance manual
incorporates available information on
the effectiveness of different control
measures to reduce Cryptosporidium
levels and provides case studies of
watershed control programs. This
guidance is intended to assist water
systems in developing their watershed
control programs and States in their
assessment and approval of these
programs.
  In addition to guidance documents,
demonstration projects, and technical
resources, EPA provides funding  for
watershed and source water protection
through the Drinking Water State
Revolving Fund (DWSRF) and Clean
Water State Revolving Fund (CWSRF).
Under the DWSRF program, States may
provide funding directly to public water
systems for source water protection,
including watershed management and
pathogen source  reduction plans.
CWSRF funds have been used to
develop and implement agricultural best
management practices for reducing
pathogen loading to receiving waters
and to fund directly, or provide
incentives for, the replacement of failing
septic systems. EPA encourages the use
of CWSRF for source protection and has
developed guidelines for the award of
funds to address  non-point sources of
pollution (CWA section 319 Non Point
Source Pollution Program). Further, the
Agency is promoting the broader use of

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                                                                     47685
SRF funds to implement measures to
prevent and control non-point source
pollution. Detailed sanitary surveys,
with a specific analysis of sources of
Cryptosporidium in the watershed, will
facilitate the process of targeting
funding available under SRF programs
to eliminate or mitigate these sources.
  c. Request for comment. EPA requests
comment on the  proposed watershed
control program  credit and associated
program components.
  • Should the State be allowed to
reduce the frequency of the annual
watershed survey requirement for
certain systems if systems engage in
alternative activities like public
outreach?
  • The effectiveness of a watershed
control program  may be difficult to
assess because of uncertainty in the
efficacy of control measures under site-
specific conditions. In order to provide
constructive guidance, EPA welcomes
reports on scientific case studies and
research that evaluated methods for
reducing Cryptosporidium
contamination of source waters.
  • Are there confidential business
information (CBI) concerns associated
with making information  on the
watershed control program available to
the public? If so, what are these
concerns and how should they be
addressed?
  • How should the "area of influence"
(the area to be considered in future
watershed surveys) be delineated,
considering the persistence of
Cryptosporidium?
3. Alternative Source
  a. What is EPA proposing today? Plant
intake refers to the works or structures
at the head of a conduit through which
water is diverted from a source  (e.g.,
river or lake) into the treatment plant.
Plants may be able to reduce influent
Cryptosporidium levels by changing the
intake placement (either within the
same source or to an alternate source) or
managing the timing or level of
withdrawal.
  Because the effect of changing the
location or operation of a plant intake
on influent Cryptosporidium levels will
be site specific, EPA is not proposing
any presumptive credit for this option.
Rather, if a system is concerned that
Cryptosporidium levels associated with
the current plant intake location and/or
operation will result in a bin assignment
requiring additional treatment under the
LT2ESWTR, the system may conduct
concurrent Cryptosporidium monitoring
reflecting a different intake location or
different intake management strategy.
The State will then make a
determination as to whether the plant
 may be classified in an LT2ESWTR bin
 using the alternative intake location or
 management monitoring results.
   Thus, systems that intend to be
 classified in an LT2ESWTRbin based
 on a different intake location or
 management strategy must conduct
 concurrent Cryptosporidium
 monitoring. The system is still required
 to monitor its current plant intake in
 addition to any alternative intake
 location/management monitoring, and
 must submit the results of all
 monitoring to the State. In addition, the
 system must provide the State with
 supporting information documenting
 the conditions under which the
 alternative intake location/management
 samples were collected. The concurrent
 monitoring must conform to the sample
 frequency, sample volume, analytical
 method, and other requirements that
 apply to the system for Cryptosporidium
 monitoring as stated in Section IV.A.l.
   If a plant's LT2ESWTR bin
 classification is based on monitoring
 results reflecting a different intake
 location or management strategy, the
 system must relocate the intake or
 implement the intake management
 strategy within the compliance time
 frame for the LT2ESWTR,  as specified
 in section IV.F.
   b. How was this proposal developed?
 In the Stage 2 M-DBP Agreement in
 Principle, the Advisory Committee
 identified several actions related to the
 intake which potentially could reduce
 the concentration of Cryptosporidium
 entering a treatment plant. These
 actions were included in the microbial
 toolbox under the heading Alternative
 Source, and include: (1) Intake
 relocation, (2) change to alternative
 source of supply, (3) management of
 intake to reduce capture of oocysts in
 source water, (4) managing timing of
 withdrawal, and (5) managing level of
 withdrawal in water column.
   It is difficult to predict in advance the
 efficacy of any of these activities in
 reducing levels of Cryptosporidium
 entering the treatment plant. However,
 if a system relocates the plant intake or
 implements a different  intake
 management strategy, it is  appropriate
 for the plant to be assigned to  an
 LT2ESWTR bin using monitoring results
 reflecting the new intake strategy.
  EPA believes that the requirements
 specified for monitoring to determine
•bin placement are necessary to
 characterize a plant's mean source water
 Cryptosporidium level. Consequently,
 any concurrent monitoring carried out
 to characterize a different intake
 location or management strategy should
 be equivalent. For this reason, the
 sampling and analysis requirements
which apply to the current intake
monitoring also apply to any concurrent
monitoring used to characterize a new
intake location or management strategy.
  EPA also recognizes that if plant's bin
assignment is based on a new intake
operation strategy then it is important
for the plant to continue to use this new
strategy in routine operation. Therefore,
EPA is proposing that the system
document the new intake operation
strategy when submitting additional
monitoring results to the State and that
the State approve that new strategy.
  c. Request for comment. EPA requests
comment on the following issues:
  * What are intake management
strategies by which systems could
reduce levels of Cryptosporidium in the
plant influent?
  • Can representative Cryptosporidium
monitoring to demonstrate a reduction
in oocyst levels be accomplished prior
to implementation of a  new intake
strategy (e.g., monitoring a new source
prior to constructing a new intake
structure)?
  • How should this option be applied
to plants that use multiple sources
which enter a plant through a common
conduit, or which use separate sources
which enter the plant at different
points?
4. Off-Stream Raw Water Storage
  a. What is EPA proposing today? Off-
stream raw water storage reservoirs are
basins located between a water source
(typically a river) and the coagulation
and filtration processes in a treatment
plant. EPA is not proposing
presumptive treatment  credit for
Cryptosporidium removal through off-
stream raw water storage. Systems using
off-stream raw water storage must
conduct Cryptosporidium monitoring
after the reservoir for the purpose of
determining LT2ESWTR bin placement.
This will allow reductions in
Cryptosporidium levels that occur
through settling during off-stream
storage to be reflected in the monitoring
results and consequent LT2ESWTR bin
assignment.
  The use of off-stream raw water
storage reservoirs during LT2ESWTR
monitoring must be consistent with
routine plant operation and must be
recorded by the system. Guidance on
monitoring locations is provided in
Public Water System Guidance Manual
for Source Water Monitoring under the
LT2ESWTR (USEPA 2003g), which is
available in draft in the docket for
today's proposal.
  b. How was this proposal developed?
The Stage 2 M-DBP Agreement in
Principle recommends a 0.5 log credit
for off-stream raw water storage

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reservoirs with detention times on the
order of days and 1.0 log credit for
reservoirs with detention times on the
order of weeks. After a review of the
available literature, EPA is unable to
determine criteria that provide
reasonable assurance of achieving a 0.5
or 1 log removal  of oocysts.
Consequently, EPA is not proposing a
presumptive treatment credit for this
process.
  This proposal for off-stream raw water
storage represents a change from the
November 2001 pre-proposal draft of the
LT2ESWTR (USEPA 2001g), which
described 0.5 log and 1  log presumptive
credits for reservoirs with hydraulic
detention times of 21 and 60 days,
respectively. These criteria were based
on a preliminary assessment of reported
studies, described later in this section,
                      that evaluated Cryptosporidium and
                      Giardia removal in raw water storage
                      reservoirs.
                        Subsequent to the November 2001
                      pre-proposal draft, the Science Advisory
                      Board (SAB) reviewed the data that EPA
                      had acquired to support
                      Cryptosporidium treatment credits for
                      off-stream raw water storage  (see section
                      VII.K). In written comments from a
                      December 2001 meeting of the SAB
                      Drinking Water Committee, the panel
                      concluded that the available  data were
                      not adequate to demonstrate  the
                      treatment credits for off-stream raw
                      water storage described in the pre-
                      proposal draft, and recommended that
                      no presumptive credits be given for this
                      toolbox option. The panel did agree,
                      though, that a utility should be able to
                      take advantage of off-stream raw water
                storage by sampling after the reservoir
                for appropriate bin placement. EPA
                concurs with this finding by the SAB
                and today's proposal is consistent with
                their recommendation.
                  Off-stream raw water storage can
                improve the microbial quality of water
                in a number of ways. These include (1)
                reduced microbial and particulate
                loading to the plant due to settling in
                the reservoir, (2) reduced viability of
                pathogens due to die-off, and (3)
                dampening of water quality and
                hydraulic spikes. EPA has evaluated a
                number of studies that investigated the
                removal of Cryptosporidium and other
                microorganisms and particles in raw
                water storage basins. These studies are
                summarized in the following
                paragraphs, and selected results are
                presented in Table IV-8.
     TABLE IV-8.—STUDIES OF Cryptosporidium AND GIARDIA REMOVAL FROM OFF-STREAM RAW WATER STORAGE
          Researcher
                         Reservoir
                                                                   Residence time
                                Log reductions
Ketelaars et al. 1995
Van Breeman et al. 1998
Bertolucci et al. 1998

Ongerth, 1989 	
               Biesbosch reservoir system:  man-
                made pumped  storage (Nether-
                lands).
               Biesbosch reservoir system:  man-
                made pumped  storage (Nether-
                lands).
               PWN (Netherlands) 	
               Abandoned gravel  quarry used for
                storage (Italy).
               Three impoundments on  rivers with
                limited   public  access  (Seattle,
                WA).
24 weeks (average)
24 weeks (average)
10 weeks (average)
18 days (theoretical)
40, 100 and 200 days (re-
  spectively).
Cryptosporidium-^ .4 Giardia-2.3.
Cryptosporidium-2.0 G/ard/a-2.6.
Cryptosporidium^ .3 G/ard/a-0.8.
Cryptosporidium-'l .0 G/ard/a-0.8.

No Giardia removal observed.
  Ketelaars et al. (1995) evaluated
Cryptosporidium and Giardia removal
across a series of three man-made
pumped reservoirs, named the
Biesbosch reservoirs, with reported
hydraulic retention times of 11, 9, and
4 weeks (combined retention time of 24
weeks). To prevent algal growth and
hypolimnetic deoxygenation, the
reservoirs were destratified  by air-
injection. Based on weekly sampling
over one year, mean influent and
effluent concentrations of
Cryptosporidium were 0.10  and 0.004
oocysts/100 L, respectively, indicating
an average removal across the three
reservoirs of 1.4 log. Mean removal of
Giardia was 2.3 log.
  Van Breemen et al. (1998) continued
the efforts of Ketelaars et al. (1995) in
evaluating pathogen removal across the
Biesbosch reservoir system. Using a
more sensitive analytical method, Van
Breeman et al. measured mean
Cryptosporidium levels of 6.3 and 0.064
oocysts/100 L at the inlet and outlet,
respectively, indicating an average
removal of 2.0 log. For Giardia, the
                      average reduction was 2.6 log. In
                      addition, Van Breeman et al. (1998)
                      evaluated removal of Cryptosporidium,
                      Giardia, and other microorganisms in a
                      reservoir designated PWN, which had a
                      hydraulic retention time of 10 weeks.
                      Passage through this storage reservoir
                      was reported to reduce the mean
                      concentration of Cryptosporidium by 1.3
                      log and of Giardia by 0.8 log.
                        Bertolucci et al.  (1998) investigated
                      removal of Cryptosporidium, Giardia,
                      and nematodes in a reservoir derived
                      from an abandoned gravel quarry with
                      a detention time reported as around 18
                      days. Over a 2 year period, average
                      influent and effluent concentrations of
                      Cryptosporidium were  70 and 7 oocysts/
                      100 L, respectively, demonstrating a
                      mean reduction of 1 log. Average
                      Giardia levels decreased from 137 cysts/
                      100L in the inlet to 46 cysts/lOOL at the
                      outlet, resulting in a mean 0.5 log
                      removal.
                        Ongerth (1989) studied concentrations
                      of Giardia cysts in the Tolt, Cedar, and
                      Green rivers, which drain the western
                      slope of the Cascade Mountains in
                      Washington. The watersheds of each
                river are controlled by municipal water
                departments for public water supply,
                and public access is limited. The Cedar,
                Green, and Tolt rivers each have
                impoundments with reported residence
                times of 100, 30-50, and 200 days,
                respectively, in the reach studied.
                Ongerth found no statistically
                significant difference in cyst
                concentrations above and below any of
                the reservoirs. Median cyst
                concentrations above and below the
                Cedar, Green, and Tolt reservoirs were
                reported as 0.12 and 0.22, 0.27 and 0.32,
                and 0.16 and 0.21 cysts/L, respectively.
                It is unclear why no decrease in cyst
                levels was observed. It is possible that
                contamination of the water in the
                impoundments by Giardia from animal
                sources, either directly or through run-
                off, may have occurred.
                  EPA has also considered results from
                studies which evaluated the rate at
                which Cryptosporidium oocysts lose
                viability and infectivity over time. Two
                studies are summarized next, with
                selected results presented in Table IV-
                9.

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                                                                      47687
                  TABLE IV-9.—STUDIES OF Cryptosporidium DIE-OFF DURING RAW WATER STORAGE
Researcher
Medema et al. 1997 	
Sattar ef a/. 1999 	

Type of experiment

bacteria and incubated.
ers inoculated with Giardia and Cryptosporidium.
Log reduction

tion over 20-80 days at 15 °C.
30 days at 20 °C. Little reduction at 4 °C. In situ con-
ditions showed 0,4 to 1.5 log reduction at 21 days.
   Medema et al. (1997) conducted
 bench scale studies of the influence of •
 temperature and the presence of
 biological activity on  the die-off rate of
 Cryptosporidium oocysts. Die-off rates
 were determined at 5°C and 15°C, and
 in both natural and sterilized
 (autoclaved) river water. Both
 excystation and vital dye staining were
 used to determine oocyst viability. At
 5°C, the die-off rate under all conditions
 was 0.010 logio/day, assuming first-
 order kinetics. This translates to 0.5 log
 reduction at 50 days. At 15°C, the die-
 off rate in natural river water
 approximately doubled to 0.024 logic/
 day  (excystation) and  0.018 logic/day
 (dye staining). However, in autoctaved
 water at 15°C, the die-off rate was only
 0.006 logio/day (excystation) and 0.011
 logio/day (dye staining). These results
 suggest that oocyst die-off is more rapid
 at higher temperatures in natural water,
 and this behavior may be caused by
 increased biological or biochemical
 activity.
   Sattar et al. (1999) evaluated factors
 impacting Cryptosporidium and Giardia
 survival. Microtubes containing
 untreated water from the Grand and St.
 Lawrence rivers (Ontario) were
 inoculated with purified oocysts and
 cysts. Samples were incubated at
 temperatures ranging from 4°C to 30°C,
 viability of oocysts and cysts was
 measured by excystation. At 20°C and
 30°C, reductions in viable
 Cryptosporidium oocysts ranged from
 approximately 0.6 to 2.0 log after 30
 days. However, relatively little
 inactivation took place when oocysts
 were incubated at 4°C (as low as 0.2 log
 at 100 days).
  To evaluate oocyst survival under
 dynamic environmental conditions,
 Sattar et al. seeded dialysis cassettes
 with Cryptosporidium oocysts and
placed them in overflow tanks receiving
water from different rivers in Canada
 and the United States.  Reductions in the
concentration of viable oocysts ranged
 from approximately 0.4 to 1.5 log after
 21 days. Survival of oocysts was
enhanced by pre-filtering the water,
suggesting that microbial antagonism
was involved in the natural inactivation
of the parasites.
   Overall these studies indicate that off-
 stream storage of raw water has the
 potential to effect significant reductions
 in the concentration of viable
 Cryptosporidium oocysts, both through
 sedimentation and degradation of
 oocysts (i.e., die-off). However, these
 data also illustrate the challenge in
 reliably estimating the amount of
 removal that will occur in any particular
 storage reservoir. Removal and die-off
 rates reported in these studies varied
 widely, and were observed to be
 influenced by factors like temperature,
 contamination, hydraulic short
 circuiting, and biological activity (Van
 Breeman et al. 1998, Medema et al.
 1997, Sattar et al. 1999). Because of this
 variability and the relatively small
 amount of available data, it is difficult
 to extrapolate from these studies to
 develop nationally applicable criteria
 for awarding removal credits to raw
 water storage.
   c. Bequest for comment. EPA requests
 comment on the finding that the
 available data are not adequate to
 support a presumptive Cryptosporidium
 treatment credit for off-stream raw  water
 storage, and that systems using off-
 stream storage should conduct
 LT2ESWTR monitoring at the reservoir
 outlet. This monitoring approach would
 account for reductions in oocyst
 concentrations due to settling, but
 would not provide credit for die-off,
 since non-viable oocysts could still be
 counted during monitoring. In addition,
 EPA would also appreciate comment on
 the following specific issues:
   • Is additional information available
 that either supports or suggests
 modifications to this proposal
 concerning off-stream raw water
 storage?
   • How should a system address the
 concern that water in off-stream raw
 water storage reservoirs may become
 contaminated through processes like
 algal growth, run-off, roosting birds, and
 activities on the watershed?

 5. Pre-Sedimentation With Coagulant
   a. What is EPA proposing today?
Presedimentation is a preliminary
treatment process used to remove
particulate material from the source
water before the water enters primary
 sedimentation and filtration processes
 in a treatment plant. EPA is proposing
 to award a presumptive 0.5 log
 Cryptosporidium treatment credit for
 presedimentation that is installed after
 LT2ESWTR monitoring and meets the
 following three criteria:
  (1) The presedimentation basin must
 be in continuous operation and must
 treat all of the flow reaching the
 treatment plant.
  (2) The system must continuously add
 a coagulant to the presedimentation
 basin.
  (3) The system must demonstrate on
 a monthly  basis at least  0.5 log
 reduction of influent turbidity through
 the presedimentation process in at least
 11 of the 12 previous consecutive
 months. This monthly demonstration of
 turbidity reduction must be based on
 the arithmetic mean of at least daily
 turbidity measurements in the
 presedimentation basin  influent and
 effluent, and must be calculated as
 follows:
 Monthly mean turbidity log reduction =
    Iogio(monthly mean of daily
    influent turbidity) — logio(monthly
    mean of daily effluent turbidity).
 If the presedimentation process has not
 been in operation for 12 months, the
 system must verify on a monthly basis
 at least 0.5  log reduction of influent
 turbidity through the presedimentation
 process, calculated as specified in this
 paragraph,  for at least all but any one of
 the months of operation.
  Systems with presedimentation  in
 place at the time they begin LT2ESWTR
 Cryptosporidium monitoring are not
 eligible for the 0.5 log presumptive
 credit and must sample after the basin
 when in use for the purpose of
 determining their bin assignment.  The
 use of presedimentation during
 LT2ESWTR monitoring must be
 consistent with routine plant operation
 and must be recorded by the system.
 Guidance on monitoring is provided in
Public Water System Guidance Manual
 for Source Water Monitoring under the
LT2ESWTR (USEPA 2003g), which is
 available in draft in the docket for
today's proposal.
  b. How was this proposal  developed?
Presedimentation is used to remove
gravel, sand, and other gritty material

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from the raw water and dampen particle
loading to the rest of the treatment
plant. Presedimentation is similar to
conventional sedimentation, except that
presedimentation may be operated at
higher loading rates and may not
involve use of chemical coagulants.
Also, some systems operate the
presedimentation process periodically
and only in response to periods of high
particle loading.
  Because presedimentation reduces
particle concentrations, it is expected to
reduce Cryptosporidium levels. In
addition, by dampening variability in
source water quality, presedimentation
may improve the performance of
subsequent treatment processes. In
general, the efficacy of presedimentation
in lowering particle levels is influenced
by a number of water quality and
treatment parameters including surface
loading rate, temperature, particle
concentration, coagulation, and
characteristics of the sedimentation
basin.
'  The Stage 2-M-DBP Agreement in
Principle recommends 0.5 log
presumptive Cryptosporidium treatment
credit for presedimentation with the use
of coagulant. Today's proposal is
consistent with this recommendation.
However, the proposed requirement for
demonstrated turbidity reduction as a
condition for presedimentation credit
represents a change from the November
2001 pre-proposal draft of the
LT2ESWTR (USEPA 2001g). Rather than
a requirement for turbidity removal, the
2001 pre-proposal draft included
criteria for maximum overflow rate and
minimum influent turbidity as
conditions for the 0.5 log
presedimentation credit.
  The Science Advisory Board (SAB)
reviewed the criteria and supporting
information for presedimentation credit
                      in the November 2001 pre-proposal
                      draft (see section VII.K). In written
                      comments from a December 2001
                      meeting of the SAB Drinking Water
                      Committee, the panel concluded that
                      available data were minimal to support
                      a 0.5 log presumptive credit and
                      recommended that no credit be given for
                      presedimentation. Additionally, the
                      panel stated thai performance criteria
                      other than overflow rate need to be
                      included if credit is to be given for
                      presedimentati on.
                        Due to this finding by the SAB, EPA
                      further reviewed data on removal of
                      aerobic spores (as  an indicator of
                      Cryptosporidium removal) and turbidity
                      in full-scale presedimentation basins.
                      As shown later in  this section, these
                      data indicate that presedimentation
                      basins achieving a monthly mean
                      reduction in turbidity of at least 0.5 log
                      have a high likelihood of reducing mean
                      Cryptosporidium levels by 0.5 log or
                      more. Consequently, EPA has
                      determined that it is appropriate to use
                      turbidity reduction as a performance
                      criterion for awarding Cryptosporidium
                      treatment credit to presedimentation
                      basins. The Agency believes this
                      performance criterion addresses the
                      concerns raised by the SAB.
                        The Agency has concluded that it is
                      appropriate to limit eligibility for the 0.5
                      log presumptive Cryptosporidium
                      treatment credit to systems that install
                      presedimentation after LT2ESWTR
                      monitoring. Systems with
                      presedimentation in place prior to
                      initiation of LT2ESWTR
                      Cryptosporidium monitoring may
                      sample after the presedimentation basin
                      to determine their bin assignment. In
                      this case, the  effect of presedimentation
                      in reducing Cryptosporidium levels will
                      be reflected in the monitoring results
and bin assignment. Systems that
monitor after presedimentation are not
subject to the operational and
performance requirements associated
with the 0.5 log credit. The SAB agreed
that a system should be able to sample
after the presedimentation treatment
process for appropriate bin placement.
  In considering criteria for awarding
Cryptosporidium removal credit to
presedimentation, EPA has evaluated
both published studies and data
submitted by water systems using
presedimentation. There is relatively
little published data on the removal of
Cryptosporidium by presedimentation.
Consequently, EPA has reviewed
studies that investigated
Cryptosporidium removal by
conventional sedimentation basins.
These studies are informative regarding
potential levels of performance, the
influence of water quality parameters,
and correlation of Cryptosporidium
removal with removal of potential
surrogates. However, removal efficiency
in conventional sedimentation basins
may be greater than in presedimentation
due to lower surface loading rates,
higher coagulant doses, and other
factors. To supplement these studies,
EPA has evaluated data provided by
utilities on removal of other types of
particles, primarily aerobic spores, in
the presedimentation processes of full
scale plants. Data indicate that aerobic
spores may serve as a surrogate for
Cryptosporidium removal by
sedimentation (Dugan et al. 2001).
   i. Published studies of
Cryptosporidium removal by
conventional sedimentation basins.
Table IV-10 summarizes results from
published studies of Cryptosporidium
removal by conventional sedimentation
basins.
   TABLE IV-10.—SUMMARY OF PUBLISHED STUDIES OF Cryptosporidium REMOVAL BY CONVENTIONAL SEDIMENTATION
                                                     BASINS
Authors)

States et al (1997) 	


Kelly et al (1995) 	
Patania et al. (1995) 	
Plant/process type

Full scale conventional with primary and secondary
sedimentation.
Full scale conventional (2 plants) 	
Full scale conventional (two stage lime softening) 	
Full scale conventional (two stage sedimentation) 	
Pilot scale conventional {3 plants) 	
Cryptosporidium removal by sedi-
mentation
0.6 to 1.6 tog (average 1.3 log).
0.41 log.
0.8 to 1.2 log.
3.8 log and 0.7 log.
0.8 log.
0.5 log.
2.0 log (median).
   Dugan et al (2001) evaluated the
 ability of conventional treatment to
 control Cryptosporidium under different
 water quality and treatment conditions
 on a small pilot scale plant that had
                       been demonstrated to provide
                       equivalent performance to a larger plant.
                       Under optimal coagulation conditions,
                       oocyst removal across the sedimentation
                       basin ranged from 0.6 to 1.6 log,
 averaging 1.3 log. Suboptimal
 coagulation conditions (underdosed
 relative to jar test predictions)
 significantly reduced plant performance
 with oocyst removal in the

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                 Federal Register/Vol. 68, No.  154/Monday,  August 11, 2003/Proposed  Rules
                                                                     47689
sedimentation basin averaging 0.20 log.
Removal of aerobic spores, total particle
counts, and turbidity all correlated well
with removal of Cryptosporidium by
sedimentation.
  States etal (1997) monitored
Cryptosporidium removal at the
Pittsburgh Drinking Water Treatment
Plant (65-70 million gallons per day
(MGD)). The clarification process
included ferric chloride coagulation,
flocculation, and settling in both a small
primary basin and a 120 MG secondary
sedimentation basin. Geometric mean
Cryptosporidium levels in the raw and
settled water were 31 and 12 oocysts/
100 L, respectively, indicating a mean
reduction of 0.41 log.
  Edzwald and Kelly (1998) conducted
a bench-scale study to determine the
optimal coagulation conditions with
different coagulants for removing
Cryptosporidium oocysts from spiked
raw waters. Under optimal coagulation
conditions, the authors observed oocysts
reductions through sedimentation
ranging from 0.8 to 1.2 log.
  Payment and Franco (1993) measured
Cryptosporidium and other
microorganisms in raw,  settled, and
filtered water samples from drinking
water treatment plants in the Montreal
area. The geometric mean of raw and
settled water Cryptosporidium levels in
one plant were 742 and  0.12 oocysts/
100 L, respectively, suggesting a mean
removal of 3.8 log. In a second plant,
mean removal by sedimentation was
reported as 0.7 log, with raw and settled
water Cryptosporidium levels reported
as <2 and <0.2 oocysts/L, respectively.
  Kelley et al. (1995) monitored
Cryptosporidium levels in the raw,
settled, and filtered water of two water
treatment plants (designated site A and
B). Both plants included two-stage
sedimentation. At site A, mean raw and
settled water Cryptosporidium  levels
were 60 and 9.5 oocysts/100 L,
respectively, suggesting a mean removal
of 0.8 log by sedimentation. At site B,
mean raw and settled water
Cryptosporidium levels were 53 and 16
oocysts/100 L, respectively, for an
average removal by sedimentation of 0.5
log. Well water was intermittently
blended in the second stage of
sedimentation at site B, which may have
reduced settled and filtered water
pathogen levels.
  Patania et al. (1995) evaluated
removal of Cryptosporidium in four
pilot scale plants. Three of these were
conventional and one used in-line
filtration (rapid mix followed by
filtration). Cryptosporidium removal
was generally 1.4 to 1.8  log higher in the
process trains with sedimentation
compared to in-line filtration. While the
effectiveness of sedimentation for
organism removal varied widely under
the conditions tested, the median
removal of Cryptosporidium by
sedimentation was approximately 2.0
log.
  ii. Data supplied by utilities on the
removal of spores by presedimentation.
Data on the removal of Cryptosporidium
and spores (Bacillus subtilis and total
aerobic spores) during operation of full-
scale presedimentation basins were
collected independently and reported
by three utilities: St. Louis, MO, Kansas
City, MO, and Cincinnati, OH.
Cryptosporidium oocysts were not
detected in raw water at these locations
at levels sufficient to calculate log
removals of oocysts directly. However,
aerobic spores were present in the raw
water of these utilities at high enough
concentrations to measure log removals
through presedimentation as a surrogate
for Cryptosporidium removal. As noted
earlier, data from Dugan et al. (2001)
demonstrate a correlation between
removal of aerobic spores and
Cryptosporidium through sedimentation
under optimal coagulation conditions. A
summary of the spore removal data
supplied by the these utilities is shown
in Table rV-11.

TABLE  IV-11 .—MEAN   SPORE  RE-
   MOVAL       FOR       FULL-SCALE
   PRESEDIMENTATION    BASINS   RE-
   PORTED BY THREE UTILITIES
   Reporting utility
St. Louis Water Divi-
  sion.
Kansas City Water
  Services Depart-
  ment.
Cincinnati Water
  Works.
 Mean spore removal
1.1 log (B. subtilis).

0.8 log (B. subtilis)
  (with coagulant).

0.46 log 
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Federal Register/Vol. 68, No.  154/Monday, August  11, 2003/Proposed Rules
  EPA also has concluded that
presedimentation basins need to be
operated continuously and treat 100%
of the plant flow in order to reasonably
ensure that the process will reduce
influent Cryptospondium levels by at
least 0.5 log over the course of a full
year. The Agency recognizes that,
depending on influent water quality,
some systems may determine it is more
prudent to operate presedimentation
basins intermittently in response to
fluctuating turbidity levels. By
                     proposing these conditions for the
                     presumptive presedimentation credit,
                     EPA is not recommending against
                     intermittent operation of
                     presedimentation basins. Rather, EPA is
                     attempting to identify the conditions
                     under which a 0.5 log presumptive
                     credit for presedimentation is
                     warranted.
                       In response to the SAB panel
                     recommendation that performance
                     criteria other than overflow rate be
                     included if credit is to ha given for
presedimentation, EPA analyzed the
relationship between removal of spores
and reduction in turbidity through
presedimentation for the three utilities
that supplied these data. Results of this
analysis are summarized in Table IV-12,
which shows the relationship between
monthly mean turbidity reduction and
the percent of months when mean spore
removal was at least 0.5 log.
BILLING CODE 6560-50-P
              Table IV-12.- Relationship Between Mean Turbidity Reduction and the

       Percent of Months When Mean Spore Removal Was at Least 0.5 Log
Log Reduction in Turbidity
(monthly mean)
>=0.1
>=0.2
>=0.3
>=0.4
>=0.5
>=0.6
>=0.7
>=0.8
>=0.9
>=1.0
Percent of Months with at least 0.5 Log Mean
Reduction in Spores
64%
68%
73%
78%
89%
91 %
90%
89%
95%
96%
       Source: Data from Cincinnati Water Works, Kansas City Water Services Department, and St. Louis Water Division
BILLING CODE 6560-50-C
  Within the available data set,
achieving a mean turbidity reduction of
at least 0.5 log appears to provide
approximately a 90% assurance that
average spore removal will be 0.5 log or
greater. The underlying data are shown
graphically in Figure IV-4. Based on
                     this information, EPA has concluded
                     that it is appropriate to require 0.5 log
                     turbidity reduction, determined as a
                     monthly mean of daily turbidity
                     readings, as an operating condition for
                     the 0.5 log presumptive
                     Cryptospondium treatment credit for
presedimentation. Further, EPA is
proposing that systems must meet the
0.5 log turbidity reduction requirement
in at least 11 of the 12 previous months
on an ongoing basis to remain eligible
for the presedimentation credit.
BILLING CODE 6560-50-P

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                                                                    47691



f
E
o

o
|
w
K
«l
JS

O

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* *•




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*




*
*

* * ^
* / <• **» *
* A * * *
> «|'V * *
* * 4 *

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0.5 1 1.5 2 2.5
*
Monthly Mean Log Removal of Turbidity
















      Figure IV-4.~ Monthly Mean Log Removal of Spores from Presedimentation vs.

      Monthly Mean Turbidity Log Reduction
 BILLING CODE 6560-5&-C
   c. Request for comment. EPA requests
 comment on the proposed criteria for
 awarding credit to presedimentation.
 EPA would particularly appreciate
 comment on the following issues:
   • Whether the information cited in
 this proposal supports the proposed
 credit forpresedimentation and the
 operating conditions under which the
 credit will be awarded;
   * Additional information that either
 supports or suggest modifications to the
 proposed performance criteria and
 presumptive credit;
   • Today's proposal requires systems
 using presedimentation to sample after
 the presedimentation basin, and these
 systems are not eligible to receive
 additional presumptive
 Cryptosporidium removal credit for
 presedimentation. However, systems are
 also required to collect samples prior to
 chemical treatment, and EPA recognizes
that some plants provide chemical
treatment to water prior to, or during,
presedimentation. EPA requests
 comment on how this situation should
 be handled under the LT2ESWTR.
   • Whether and under what conditions
 factors like low turbidity raw water,
 infrequent sludge removal, and wind
 would make compliance with the 0.5
 log turbidity removal requirement
 infeasibie.
 6. Bank Filtration
   a. What is EPA proposing today? EPA
 is proposing to award additional
 Cryptosporidium treatment credit (0.5 or
 1.0 log) for systems that implement bank
 filtration as a pre-treatment technique if
 it meets the  design criteria specified in
 this section. To be eligible for credit as
 a pre-treatment technique, bank
 filtration collection devices must meet
 the following criteria:
  • Wells are drilled in an
 unconsolidated, predominantly sandy
 aquifer, as determined by grain-size
 analysis of recovered core material—the
recovered core must contain greater
than 10% fine-grained material (grains
less than 1.0 mm diameter) in at least
90% of its length;
  • Wells are located at least 25 feet (in
any direction) from the surface water
source to be eligible for 0.5 log credit;
wells located at least 50 feet from the
source surface water are eligible for 1.0
log credit;
  • The wellhead must be continuously
monitored for turbidity to ensure that no
system failure is occurring. If the
monthly average of daily maximum
turbidity values exceeds 1 NTU then the
system must report this finding to the
State. The system must also conduct an
assessment to determine the cause of the
high turbidity levels in the well and
consult with the State regarding
whether previously allowed credit is
still appropriate.
  Systems using existing bank filtration
as pretreatment to a filtration plant at
the time the systems are required to
conduct Cryptosporidium monitoring,
as described in section IV.A, must
sample the well effluent for the purpose
of determining bin classification. Where
bin classification is based on monitoring
the well effluent, systems are not
eligible to receive additional credit for

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Federal Register/Vol.  68, No.  154/Monday, August  11.  2003/Proposed Rules
bank filtration. In these cases, the
performance of the bank filtration
process in reducing Cryptosporidium
levels will be reflected in the
monitoring results and bin
classification.
  Systems using bank filtered water
without additional filtration typically
must collect source water samples in the
surface water (i.e., prior to bank
filtration) to determine bin
classification. This applies to systems
using bank filtration to meet the
Cryptosporidium removal requirements
of the IESWTR or LTlESWTR under the
provisions for alternative filtration
demonstration in 40 CFR 141.173(b) or
141.552(a).  Note that the proposed bank
filtration criteria for Cryptosporidium
removal credit under the LT2ESWTR do
not apply to existing State actions to
provide alternative filtration
Cryptosporidium removal credit for
IESWTR or LTlESWTR compliance.
   In the case of systems that use GWUDI
sources without additional filtration and
that meet all the criteria for avoiding
filtration in 40 CFR 141.71, samples
must be collected from the ground water
(e.g., the well). Further, such systems
must comply with the requirements of
the LT2ESWTR  that apply to unfiltered
systems, as described in  section  IV.B.
   b. How was this proposal developed?
This section describes the bank
filtration treatment process, provides
 more detail on the aquifer types and
ground water collection  devices that are
 eligible for bank filtration credit, and
 describes the data supporting the
 proposed requirements.
   Bank filtration is a water treatment
 process that makes use of surface water
 that has naturally infiltrated into ground
 water via the river bed or bank(s) and
 is recovered via a pumping well.
 Stream-bed infiltration is typically
 enhanced by the pumping action of
 near-stream wells (e.g., water supply,
 irrigation). Bank filtrate is water drawn
 into a pumping well from a nearby
 surface water source which has  traveled
 through the subsurface, either vertically,
 horizontally or both, mixing to some
 degree with other ground water.
 Through bank filtration, microorganisms
 and other particles are removed by
 contact with the aquifer materials.
   The bank filtration removal process
 performs most efficiently when  the
 aquifer is comprised of granular
 materials with open pore-space for
 water flow around the grains. In these
 granular porous aquifers, the flow path
 is meandering, thereby providing ample
 opportunity for the organism to come
 into contact with and attach to a grain
 surface. Although detachment can
 occur, it typically occurs at a very slow
                       rate so that organisms remain attached
                       to a grain for long periods. When ground
                       water travel times from .source water to
                       well are long or when little or no
                       detachment occurs, most organisms will
                       become inactivated before they can
                       enter a well. Thus, bank filtration relies
                       on removal, but also, in some cases, on
                       inactivation to protect wells from
                       pathogen contamination.
                       Only Wells Located in Unconsolidated,
                       Predominantly Sandy Aquifers Are
                       Eligible
                         Only granular aquifers are eligible for
                       bank filtration credit. Granular aquifers
                       are those comprised of sand, clay, silt,
                       rock fragments, pebbles or larger
                       particles and minor cement. The aquifer
                       material is required to be
                       unconsolidated, with subsurface
                       samples friable upon touch.
                       Uncemented granular aquifers are
                       typically formed by alluvial or glacial
                       processes. Such aquifers are usually
                       identified on a detailed geologic map
                       (e.g., labeled as Quaternary alluvium).
                         Under today's  proposal, a system
                       seeking Cryptosporidium removal credit
                       must characterize the aquifer at the well
                       site to determine aquifer properties. At
                       a minimum, the  aquifer characterization
                       must include the collection of relatively
                       undisturbed, continuous, core samples
                       from the surface to a depth  equal to the
                       bottom of the well screen. The proposed
                       site must have substantial core recovery
                       during drilling operations; specifically,
                       the recovered core length must be at
                       least 90% of the total projected depth to
                       the well screen.
                          Samples of the recovered core must be
                       submitted to a laboratory for sieve
                       analysis to determine grain size
                       distribution over the entire recovered
                       core length. Each sieve sample must be
                       acquired at regular intervals over the
                       length of the recovered core, with one
                       sample representing a composite of each
                       two feet of recovered core. A two-foot
                       sampling interval reflects the necessity
                       to sample the core frequently without
                       imposing an undue burden. Because it
                       is anticipated that wells will range from
                       50 to 100 foot in depth, a two-foot
                       sampling interval will result in about 25
                       to  50 samples for analysis. Each
                       sampled interval must be examined to
                       determine if more than ten percent of
                       the grains in that interval are less than
                       1.0 mm in diameter (#18 sieve size). In
                       the U.S. Department of Agriculture soil
                       classification system, the #18 sieve
                       separates very coarse sands from coarse
                       sands. The length of core (based on the
                       samples from two-foot intervals) with
                       more than ten percent of the grains less
                       than 1.0 mm in  diameter must be
                       summed to determine the overall core
length with sufficient fine-grained
material so as to provide adequate
removal. An aquifer is eligible for
removal credit if at least 90% of the
sampled core length contains sufficient
fine-grained material as defined in this
section.
  Cryptosporidium oocysts have  a
natural affinity for attaching to fine-
grained material. A study of oocyst
removal in sand columns shows greater
oocyst removal in finer-grained sands
than in  coarser-grained sands (Harter et
al. 2000), The core sampling procedure
described in this section is designed to
measure the proportion of fine-grained
sands (grains less than 1.0 mm in
diameter) so as to ensure that a potential
bank filtration site is capable of
retarding transport (or removing)
oocysts during ground water flow from
the source surface water to the water
supply well. The value of 1.0 mm for
the bounding size of the sand grains was
determined based on calculations
performed by Harter using data from
Harter et al. (2000). Harter showed that,
for ground water velocities typical of a
bank filtration site (1.5 to 15 m/day), a
typical bank filtration site composed of
grains with a diameter of 1.0 mm would
achieve at least 1.0 log removal over a
50 foot transport distance. Larger-sized
grains would achieve less removal, all
 other factors being equal.
   Alluvial and glacial aquifers are
 complex mixtures of sand, gravel and
 other sized particles.  Particles of similar
 size are often grouped together in the
 subsurface, due to sorting by flowing
 water that carries and then deposits the
 particles. Where there exists significant
 thickness of coarse-grained particles,
 such as gravels, with few finer
 materials, there is limited opportunity
 for oocyst removal. When the total
 gravel  thickness, as measured in a core,
 exceeds 10%, it is more likely (based on
 analysis of ground water flow within
 mixtures containing differing-sized
 grains) that the gravel-rich intervals are
 interconnected. Interconnected  gravel
 can form a continuous, preferential flow
 path from the source surface water to
 the water supply well.  Where such
 preferential flow paths exist, a
 preponderance of the total ground water
 flow occurs within the preferential flow
 path, ground water velocity is higher,
 and natural filtration is minimal. A
 proposed bank filtration site is
 acceptable if at least 90% of the core
 length contains grains with sufficient
 fine-grained material (diameter less than
  1.0 mm); that is, it is acceptable if the
 core contains less than 10% gravel-rich
 intervals.
    Aquifer  materials with significant
 fracturing  are capable of transmitting

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                   Federal Register/Vol. 68, No.  154/Monday,  August 11, 2003/Proposed Rules
                                                                        47693
  ground water at high velocity in a direct
  flow path with little time or opportunity
  for die-off or removal of microbial
  pathogens. Consolidated aquifers,
  fractured bedrock, and karst limestone
  are aquifers in which surface water may
  enter into a pumping well by flow along
  a fracture, a solution-enhanced fracture
  conduit,  or other preferential pathway.
  Microbial pathogens found in surface
  water are more likely to be transported
  to a well  via these direct or preferential
  pathways. Cryptosporidium outbreaks
  have been associated with consolidated
  aquifers,  such as a fractured chalk
  aquifer (Willocks et a!. 1998) or a karst
  limestone (solution-enhanced fractured)
  aquifer (Bergmire-Sweat et al. 1999).
  These outbreaks show that the oocyst
  removal performance of consolidated
  aquifers is undermined by preferential
  water flow and oocyst transport through
  rock fractures or through rock
  dissolution zones. Wells located in
  these aquifers are not eligible for bank
  filtration  credit because the flow paths
  are direct and the average ground water
  velocity is high, so that little
  inactivation or removal would be
  expected. Therefore, only
  unconsolidated  aquifer are eligible for
  bank filtration oocyst removal credit.
   A number of devices are used for the
  collection of ground water including
 horizontal and vertical wells, spring
 boxes, and infiltration galleries. Among
 these, only horizontal and vertical wells
 are eligible for log removal credit. The
 following  discussion presents
 characteristics of ground water
 collection devices and the basis for this
 proposed requirement.
   Horizontal wells are designed to
 capture large volumes of surface water
 recharge. They typically are constructed
 by the excavation of a central vertical
 caisson with laterals that extend
 horizontally from the caisson bottom in
 all directions or only under the
 riverbed. Horizontal wells are usually
 shallower than vertical wells because of
 the construction  expense. Ground water
 flow to a horizontal well that extends
 under surface water is predominantly
 downward. In contrast, ground water
 flow to a vertical well adjacent to
 surface water may be predominantly in
 the horizontal direction. Surface water
 may have a short ground water flow
 path to a horizontal well if the well
 extends out beyond the bank.
  Hancock et al. (1998) analyzed
 samples from eleven horizontal wells
 and found Cryptosporidium, Giardia or
 both in samples from five of those wells.
 These data  suggest that some horizontal
 wells may not be capable  of achieving
effective Cryptosporidium removal by
bank filtration. Insufficient data are
  currently available to suggest that
  horizontal well distances from surface
  water should be greater than distances
  established for vertical wells. Two
  ongoing studies in Wyoming (Clancy
  Environmental Consultants 2002) and
  Nebraska (Rice 2002) are collecting data
  at horizontal well sites.
    A spring box is located at the ground
  surface and is designed to contain
  spring outflow and protect it from
  surface contamination until the water is
  utilized. Spring boxes are typically
  located where natural processes have
  enhanced and focused ground water
  discharge into a smaller area and at a
  faster volumetric flow rate than
  elsewhere (i.e., a spring). Often,
  localized fracturing or solution
  enhanced channels are the cause  of the
  focused discharge to the spring orifice.
  Fractures and solution channels have
  significant potential to transport
  microbial contaminants so that natural
  filtration may be poor. Thus, spring
  boxes are not proposed to be eligible for
  bank filtration credit.
    Cryptosporidium monitoring results
  (Hancock et al. 1998) and outbreaks are
  used to evaluate ground water collection
  devices. Hancock et al. sampled thirty
  five  springs for Cryptosporidium oocysts
  and  Giardia cysts. Most springs were
  used as drinking water sources and
  sampling was  conducted to determine if
  the spring should be considered as a
  GWUDI source. Cryptosporidium
  oocysts were found in seven springs;
 Giardia cysts were found in five springs;
 and either oocysts or cysts were found
 in nine springs (26%). A waterborne
 cryptosporidiosis outbreak in Medford,
 Oregon (Craun et al. 1998) is associated
 with a spring water supply collection
 device. Also, a more recent, smaller
 outbreak of giardiasis in an Oregon
 campground is associated with a PWS
 using a spring. The high percentage of
 springs contaminated with pathogenic
 protozoan, the association with recent
 outbreaks, and an apparent lack of bank
 filtration capability indicate that spring
 boxes must not be eligible for bank
 filtration credit.
  An infiltration gallery (or filter crib) is
 typically a slotted pipe installed
 horizontally into a trench and backfilled
 with granular material. The gallery is
 designed to collect water infiltrating
 from the surface or to intercept ground
 water flowing naturally toward the
 surface water (Symons et al. 2000). In
 some treatment plants, surface, water is
transported to a point above an
infiltration gallery and then allowed to
infiltrate. The infiltration rate may be
manipulated by varying the properties
of the backfill or the nature of the soil-
water interface. Because the filtration
  properties of the material overlying an
  infiltration gallery may be designed or
  purposefully altered to optimize oocyst
  removal or for other reasons, this
  engineered system is not bank filtration,
  which relies solely on the natural
  properties of the system.
    A 1992 cryptosporidiosis outbreak in
  Talent, Oregon was associated with poor
  performance of an infiltration gallery
  underneath Bear Creek (Leland et al
  1993). In this case, the ground water-
  surface water interface and the
  engineered materials beneath did not
  sufficiently reduce the high oocyst
  concentration present in the source
  water. The association of an infiltration
  gallery with an outbreak, the design that
  relies on engineered materials rather
  than the filtration properties of natural
  filtration media, and the shallow depth
  of constructed infiltration galleries, such
  that they typically are not located
  greater than 25 feet from the surface and
  surface water recharge, all indicate that
  infiltration galleries must not be eligible
  for bank filtration credit.
   EPA notes that under the
  demonstration of performance credit
  described in section IV.C.17, States may
  consider awarding Cryptosporidium
 removal credit to infiltration galleries
 where the State determines, based on
 site-specific testing with a State-
 approved protocol, that such credit is
 appropriate (i.e., that the process
 reliably achieves a specified level of
 Cryptosporidium removal on a
 continuing basis).

 Wells Located 25 Feet From the Surface
 Water Source Are Eligible for 0.5 Log
 Credit; Wells Located 50 Feet From the
 Surface Water Source Are Eligible for
 1.0 Log Credit
   A vertical or horizontal well located
 adjacent to a surface water body is
 eligible for bank filtration credit if there
 is sufficient ground water flow path
 length to effectively remove oocysts. For
 vertical wells, the wellhead must be
 located at least 25 horizontal feet from
 the surface water body for 0.5 log
 Cryptosporidium removal credit and at
 least 50 horizontal feet from the surface
 water body for 1.0 log Cryptosporidium
 removal credit. For horizontal wells, the
 laterals must be located at least 25 feet
 distant from the normal-flow surface
 water riverbed for 0.5 log
 Cryptosporidium removal credit and at
 least 50 feet distant from the normal-
 flow surface water riverbed for 1.0 log
 Cryptosporidium removal credit.
  The ground water flow path to a
vertical well is the measured distance
from the edge of the surface water body,
under high flow conditions (determined
by the mapped extent of the 100 year

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floodplain elevation boundary or
floodway, as defined in Federal
Emergency Management Agency
(FEMA) flood hazard maps), to the
wellhead. The ground water flow path
to a horizontal well is the measured
distance from the bed of the river under
normal flow conditions to the closest
horizontal well lateral.
  The floodway is  defined by FEMA as
the area of the flood plain where the
water is likely to be deepest and fastest.
The floodway is shown on FEMA digital
maps (known as Q3 flood data maps),
which are available for 11,990
communities representing 1,293
counties in the United States. Systems
may identify the distance to surface
water using either  the 100 year return
period flood elevation boundary or by
determining the floodway boundary
using methods similar to those used in
preparing FEMA flood hazard maps.
The 100 year return period flood
elevation boundary is expected to be
wider than the floodway but that
difference may vary depending on local
conditions. Approximately 19,200
 communities in the United States have
 flood hazard maps that show the 100
 year return period flood elevation
 boundary. If local  FEMA floodway
 hazard maps are unavailable or do not
 show the 100 year flood elevation
 boundary, then the utility must
 determine either the floodway or 100
 year flood elevation boundary.
   The separation  distance proposed tor
 Cryptosporidium removal credit is
 based, in part, on  measured data for the
 removal of oocyst surrogate biota in full-
 scale field studies. A variety of surrogate
 and indicator organisms were analyzed
 in each study evaluated for today's
 proposal. However, only two non-
 pathogenic organisms, anaerobic
 clostridia spores and aerobic
 endospores, are resistant to inactivation
 in the subsurface, approximately  similar
 in size and shape to oocysts, and
  sufficiently ubiquitous in both surface
 water and ground water so that log
 removal can be calculated during
  passage across the surface water—
  ground water interface and during
  transport within the aquifer.
    Anaerobic spores are typically
  estimated at about 0.3-0.4 urn in
  diameter as compared with 4-6 um for
  oocysts. Aerobic  spores, such as
  endospores of the bacterium Bacillus
  subtilis, are slightly larger than
  anaerobic spores, typically 0.5 x 1.0 x
  2.0 Mm in diameter (Rice et al. 1996).
  Experiments conducted by injecting
  Bacillus subtilis spores into a gravel
  aquifer show that they can be very
  mobile in the subsurface environment
  (Pang et al. 1998). As presented in the
following discussion, available data
indicate similar removal of both aerobic
and anaerobic spores, either during
passage across the surface water-
ground water interface or during ground
water flow. These data suggest that
anaerobic spores, like aerobic spores,
may be suitable surrogate  measures of
Cryptosporidium removal by bank
filtration.
  Available data establish that during
bank filtration, significant removal of
anaerobic and aerobic spores can occur
during passage across the surface water-
ground water interface, with lesser
removal  occurring during ground water
transport within the aquifer away from
that interface. The ground water-surface
water interface is typically comprised of
finer grained material that lines the
bottom of the riverbed. Typically, the
thickness of the interface is small,
typically a few inches to a foot. The
proposed design criteria of 25 and 50
feet for 0.5 and 1.0 log Cryptosporidium
removal credit, respectively, are based
on EPA's analysis of pathogen and
surrogate monitoring data from bank
 filtration sites. Most of these data are
 from studies of aquifers developed in
 Dutch North Sea margin sand dune
 fields and, therefore, represent optimal
 removal conditions consistent with a
 homogenous, well sorted (by wind),
 uniform sand filter.
   Medema et al. (2000) measured 3.3
 log removal of anaerobic spores during
 transport over a 13 m distance from the
 Meuse River into adjacent ground water.
 Arora et al. (2000) measured greater
 than 2.0 log removal of anaerobic spores
 during transport from the Wabash River
 to a horizontal collector well. Havelaar
 etal. (1995) measured 3.1 log removal
 of anaerobic spores during transport
 over a 30 m distance from the Rhine
 River to a well and 3.6 log removal over
 a 25 m  distance from the Meuse River
 to a well. Schijven et al. (1998)
 measured 1.9 log removal of anaerobic
 spores over a 2 m distance from a canal
 to a monitoring well. Using aerobic
 spores, Wang et aL (2001) measured 1.8
 log removal over a 2 foot distance from
 the Ohio river to a monitoring well
 beneath the river.
    During transport solely within
  shallow ground water (i.e,, not
  including removal across the surface
 water-ground water interface), Medema
  et al. (2000) measured approximately
  0.6 log removal of anaerobic spores over
  a distance of 39 feet. Using aerobic
  spores, Weng et al. (2001) measured 1.0
  log removal of aerobic spores over a 48
  foot distance from a monitoring well
  beneath a river to a horizontal well
  lateral.
  At distances relatively far from an
injection well in a deep, anaerobic
aquifer, thereby minimizing the effects
of injection, Schijven et al measured
negligible removal of anaerobic spores
over a 30 m distance. However, few
bank filtration systems occur in deeper,
anaerobic ground water so these data
may not apply to a typical bank
filtration system in the United States.
  These data demonstrate that during
normal and low surface water
elevations, the surface water-ground
water interface  performs effectively to
remove microbial contamination.
However, there will typically be high
water elevation periods during the year,
especially  on uncontrolled rivers, that
alter the nature and performance of the
interface due to flood scour,  typically
for short periods. During these periods,
lower removals would be expected to
occur.
   Averaging Cryptosporidium oocyst
removal over the period of a year
 requires consideration of both high and
 low removal periods. During most of the
 year, high  log removal rates  would be
 expected to predominate (e.g., 3.3 log
 removal over 42 feet) due to the removal
 achieved during passage across the
 surface water-ground water  interface.
 During short periods of flooding,
 substantially lower removal rates may
 occur (e.g., 0.5 log removal over 39 feet)
 due to scouring of the riverbed and
 removal of the protective, fine-grained
 material. By considering all time
 intervals with differing removal rates
 over the period of a year, EPA is
 proposing that 0.5 log removal over 25
 feet (8 m)  and  1.0 log removal over 50
 feet (16 m) are reasonable estimates of
 the average performance of a bank
 filtration  system over a year. This
 proposal is generally supported by
  colloidal  filtration theory modeling
 results using data characteristic of the
  aquifers in Louisville and Cincinnati
  and column studies of oocyst transport
  in sand (Harter et al 2000).
  Wells must be continuously monitored
  for turbidity
    Under the Surface Water Treatment
  Rule (40 CFR  141.73(b)(l))  the turbidity
  level of slow sand filtered water must be
  1 NTU or less in 95% of the
  measurements taken each month.
  Turbidity sampling is required  once
  every four hours, but may be reduced to
  once per day  under certain conditions.
  Although slow sand filtration is not
  bank filtration, similar  pathogen
  removal  mechanisms are expected to
  occur in  both processes. Just as turbidity
  monitoring is used to provide assurance
  that the removal credit assigned to a
  slow sand filter is being realized, EPA

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                 Federal Register/VoL 68, No. 154/Monday, August 11, 2003/Proposed  Rules
                                                                            47695
 is proposing continuous turbidity
 monitoring for all bank filtration wells
 tbat receive credit.
   If monthly average turbidity levels
 (based on daily maximum values in the
 well) exceed 1 NTU, the system is
 required to report to the State and
            present an assessment of whether
            microbial removal has been
            compromised. If the State determines
            that microbial removal has been
            compromised, the system must not
            receive credit for bank filtration until
            the problem has been remediated. The
                        turbidity performance requirement for
                        bank filtration is less strict than that for
                        slow sand filtration because, unlike
                        slow sand filtration, bank filtration is a
                        pre-treatment technique followed by
                        conventional or direct filtration.
                        BILLING CODE 6560-50-P
       Table IV-13.- Summary Table Showing All Requirements for Bank Filtration Pre-

       treatment Log Removal Credit
          Eligible for
          Bank
          filtration
          Credit?
          Some
          GWUDI Sites
          Eligible
          Some Water
          Collection
          Devices
          Eligible
Yes, eligible for bank
filtration credit (with
continuous turbidity
monitoring*) and
State approval	
• Unconsolidated,
young, sandy**,
granular aquifer
• Vertical wells
located greater than
25 feet (0.5 log
credit) or 50 feet
(1.0 log credit) from
surface water

• Horizontal wells
with laterals that are
no closer than 25
feet (0.5 log credit)
or 50 feet (1.0 log
credit) from the river
channel under
normal flow
conditions
No, not eligible for
bank filtration credit
• Located in a
hydrogeologic setting
consisting of
consolidated material
* Spring boxes

• Infiltration galleries

• Horizontal wells
with laterals that
extend within 25 feet
of the river channel
under normal flow
conditions

• Vertical wells
located fewer than 25
feet from surface
water (measured
from the mapped
FEMA floodway
boundary)	
      "Average monthly turbidity values (based on daily maximum values) exceeding 1 NTU trigger an investigation by the
      system and consultation with the primacy agency
      **Based on laboratory analysis of continuous core samples collected at the site; At least 90% of the recovered core
      length must contain intervals in which more than 10% of the grains are less than 1.0 mm in diameter.
BILLING CODE 6560-50-C
  In summary, EPA believes that the
measured full-scale field data from
operating bank filtration systems, the
turbidity monitoring provision, and the
design criteria for aquifer material,
collection device type, and setback
distance, together provide assurance
that the presumptive log removal credit
will be achieved by bank filtration
systems that conform to the
requirements in today's proposal.
            c. Request for comment. The Agency
          requests comment on the following
          issues concerning bank filtration:
            • The performance of bank filtration
          in removing Cryptosporidium or
          surrogates to date at sites currently
          using this technology (e.g. sites with
          horizontal wells).
            • The use of other methods (e.g.,
          geophysical methods such as ground
          penetrating radar) to complement or
                        supplant core drilling to determine site
                        suitability for bank filtration credit.
                         • The number of GWUDI systems in
                        each State (i.e., the number of systems
                        having at least one GWUDI source)
                        where bank filtration has been utilized
                        as the primary filtration barrier (e.g., no
                        other physical removal technologies
                        follow); also, the method that was used
                        by the State to determine that each

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47696
Federal  Register/Vol. 68, No.  154/Monday.  August  11,  2003/Proposed Rules
system was achieving 2 log removal of
Cryptosporidium.
  • For GWUDI systems where natural
or alternative filtration (e.g. bank
filtration or artificial recharge) is used in
combination with a subsequent
filtration barrier (e.g., bag or cartridge
filters) to meet the 2 log
Cryptosporidium removal requirement
of the IESWTR or LT1ESWTR, how
much Cryptosporidium removal credit
has the State awarded (or is the State
willing to grant if the bags/cartridges
were found to be achieving < 2.0 logs)
for the natural or alternative filtration
process and how did the State
determine this value?
   •  The proposed Cryptosporidium
removal credit and associated design
criteria, including any additional
information related to this topic.
   •  Suitable separation distance(s) to be
required between vertical or horizontal
wells and adjacent surface water.
   •  Testing protocols and procedures
for making site specific determinations
of the appropriate level of
 Cryptosporidium removal credit to
award to bank filtration processes.
   •  Information on the data and
 methods suitable for predicting
 Cryptosporidium removal based on the
 available data from surrogate and
 indicator measurements in water
 collection devices.
   •  The applicability of turbidity
 monitoring or other process monitoring
 procedures to indicate the ongoing
 performance of bank filtration
 processes.
 7. Lime Softening
   a. What is EPA proposing today? Lime
 softening is a drinking water treatment
 process that uses precipitation with
 lime and other chemicals to reduce
 hardness and enhance clarification prior
 to filtration. Lime softening can be
 categorized into two general types: (1)
 Single-stage softening, which is used to
 remove calcium hardness and (2) two-
 stage softening, which is used to remove
 magnesium hardness and greater levels
 of calcium hardness. A single-stage
 softening plant includes a primary
 clarifier and filtration  components. A
 two-stage softening plant also includes
 a secondary clarifier located between
 the primary clarifier and filter. In some
 two-stage softening plants, a portion of
 the flow bypasses the first clarifier.
   EPA has determined that lime
 softening plants  in compliance with
 IESWTR or LT1ESWTR achieve a level
 of Cryptosporidium removal equivalent
                      to conventional treatment plants (i.e.,
                      average of 3 log). Consequently, lime
                      softening plants that are placed in Bins
                      2—4 as a result of Cryptosporidium
                      monitoring incur the same additional
                      treatment requirements as conventional
                      plants. However, EPA is proposing that
                      two-stage softening plants be eligible for
                      an additional 0.5 log Cryptosporidium
                      treatment credit. To receive the 0.5 log
                      credit, the plant must have a second
                      clarification stage between the primary
                      clarifier and filter that is operated
                      continuously, and both clarification
                      stages must treat 100% of the plant
                      flow. In addition, a coagulant must be
                      present in both clarifiers (may include
                      metal salts, polymers, lime, or
                      magnesium precipitation).
                        b. How was this proposal developed?
                      The lime softening process is used to
                      remove hardness, primarily calcium and
                      magnesium, through chemical
                      precipitation followed by sedimentation
                      and filtration. The addition of lime
                      increases pH, causing the metal ions to
                      precipitate. Other contaminants can
                      coalesce with the precipitates and be
                      removed in the subsequent settling and
                      filtration processes. While elevated pH
                       has been shown to inactivate some
                       microorganisms like viruses (Battigelli
                       and Sobsey, 1993, Logsdon etal 1994),
                       current research indicates that
                       Cryptosporidium and Giardia are not
                       inactivated by high pH (Logsdon et al
                       1994, Li et al. 2001). A two-stage lime
                       softening plant has the potential for
                       additional Cryptosporidium removal
                       because of the additional sedimentation
                       process.
                         Limited data are available on the
                       removal of Cryptosporidium by the lime
                       softening treatment process. EPA has
                       evaluated data from a study by Logsdon
                       et al (1994), which investigated
                       removal of Giardia and Cryptosporidium
                       in full scale lime softening plants. In
                       addition, the Agency has considered
                       data provided by utilities on the
                       removal of aerobic spores in softening
                       plants. These data are summarized in
                       the following paragraphs.
                         Logsdon et al. (1994) measured levels
                       of Cryptosporidium and Giardia in the
                       raw, settled, and filtered water of 13
                       surface water plants using lime
                       softening. Cryptosporidium was
                       detected in the raw water at 5 utilities:
                       one single-stage plant and four two-
                       stage plants. Using measured oocyst
                       levels, Cryptosporidium removal by
                       sedimentation was 1.0 log in the single-
                        stage plant and 1.1 to 2.3 log in the two-
stage plants. Cryptosporidinm was
found in two filtered water samples of
the single stage plant, leading to
calculated removals from raw to filtered
water of 0.6 and 2.2 log. None of the
two-stage plants had Cryptosporidium
detected in the filtered water. Based on
detection limits, calculated
Cryptosporidium removals from raw to
filtered water in the two-stage plants
ranged from >2.67 to >3.85 log.
  Giardia removal across sedimentation
was >0.9 log for a single-stage plant and
ranged from 0.8 to 3.2 log for two-stage
plants, based on measured cyst levels.
Removal of Giardia from raw water
through filtration was calculated using
detection limits as >1.5 log in a single-
stage plant and ranged from  >0.9 to >3.3
log in two-stage plants.
   While results from the Logsdon et al
study are constrained by sample number
and method detection limits, they
suggest that two-stage softening plants
may achieve greater removal of
Cryptosporidium than single-stage
plants. The authors concluded that two
stages of sedimentation, each preceded
by effective flocculation of particulate
 matter, may increase removal of
 protozoa. Additionally, the authors
 stated that consistent achievement of
 flocculation that results in effective
 settling in each sedimentation basin is
 the key factor in this treatment process.

 Removal of Aerobic Spores by Softening
 Plants

   Additional information on the
 microbial removal efficiency of the lime
 softening process  comes.from data
 provided by softening plants on removal
 of aerobic spores. While few treatment
 plants have sufficient concentrations of
 oocysts to directly calculate a
 Cryptosporidium removal efficiency,
 some plants have high  concentrations of
 aerobic spores in the raw water. Spores
 may serve as an indicator of
 Cryptosporidium  removal by
 sedimentation and filtration (Dugan et
 al 2001).
    The following two-stage softening
 plants provided data on removal of
 aerobic spores: St. Louis, MO, Kansas
 City, MO, and Columbus, OH (2 plants).
 Cryptosporidium data were also
 collected at these utilities, but it was not
 possible to calculate oocyst removal due
 to low raw water detection rates. Data
  on removal of aerobic spores by these
  softening plants is summarized in Table
  IV-14.

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                  Federal Register/Vol. 68, No.  154/Monday, August 11, 2003/Proposed Rules          47697

                TABLE IV-14.—SUMMARY OF AEROBIC SPORE REMOVAL DATA FROM SOFTENING PLANTS
Plant



Columbus Plant 2 	
Mean log removal of aerobic spores
Primary clari-
fier
1.7
2.4
1.2
1.3
Secondary
clarifier
1.1
0
1.6
2.4
Across plant*
3.8
3.4
3.1
4.2
   'Excludes removal in pre-sedimentation basins; calculated spore removal may underestimate actual removal due to filter effluent levels below
 quantitation limits.
   The City of St. Louis Water Division
 operates a two-stage lime softening
 process preceded by presedimentation.
 Ferric sulfate and polymer coagulants
 are added at various points in the
 process. St. Louis collected Bacillus
 subtilis spore samples between June
 1998 and September 2000. During this
 time period, the mean spore
 concentration entering the softening
 process (i.e., after presedimentation}
 was 8,132 cfu/100 mL. The log removal
 values shown in Table IV-14 are based
 on average spore concentrations
 following primary clarification,
 secondary clarification, and filtration.
 However, spore levels in some filtered
 water samples were below the method
 detection limit, so that the true mean
 spore removal across the plant may have
 been higher than indicated by the
 calculated value.
   The Kansas City Water Services
 Department plant includes two-stage
 lime softening with pre-sedimentation
 and sludge recycle. Bacillus subtilis
 spore data were collected from this
 plant during January through November
 2000. The mean spore concentration
 entering the lime softening process
 (after presedimentation) was 5,965 cfu/
 100 mL. Mean spore levels following
 primary clarification, secondary
 clarification, and filtration were 21.1,
 25.7, and 2.6 cfu/100 mL, respectively.
 Corresponding log removal values are
 shown in Table IV-14. Note that the
 average spore concentration in the
 effluent of the secondary clarifier was
 essentially equivalent to the effluent of
 the primary clarifier, indicating that
 little removal occurred in the secondary
 clarifier. This result may have been due
 to the high removal achieved in the
 primary clarifier and, consequently, the
 relatively low concentration of spores
 entering the second clarifier. As with
 the St. Louis plant, many of the filtered
water observations were below method
 detection limits, so actual log removal
 across the plant may have been higher
than the calculated value.
  The City of Columbus operates two
lime softening plants, each of which has
two clarification stages. Coagulant is
 added prior to the first clarification
 stage but lime is not added until the
 second clarifier (i.e., first clarifier is not
 a softening stage). Between 1997 and
 2000, samples for total aerobic spores
 were collected approximately monthly
 at each plant from raw water, following
 each clarification basin, and after
 filtration. Mean spore concentrations in
 the raw water sources for the two plants
 were 10,619 cfu/100 mL (Plant 1) and
 22,595 cfu/100 mL (Plant 2). Mean log
 removals occurring in the two
 clarification stages and across the plant
 are shown for each plant in Table IV-
 14.
  These data indicate that two-stage
 softening plants can remove high levels
 of Cryptosporidium, and, in particular,
 that a second clarification stage can
 achieve 0.5 log or greater removal. Three
 of the four plants that provided data on
 removal of aerobic spores achieved
 greater than 1  log reduction in the
 second clarifier. Kansas City, the one
 plant which achieved little removal in
 the second clarifier, achieved a mean
 2.4 log removal in the primary clarifier.
 This was approximately \ log more
 reduction than achieved in the primary
 clarifiers of the other three plants, so
 that the spore  concentration entering the
 second clarifier in Kansas City may have
 been too low to serve as an indicator of
 removal  efficiency. Consequently, EPA
 has concluded that these data support
 an additional Cryptosporidium
 treatment credit of 0.5 log for a two-
 stage softening plant.
  EPA is proposing as a condition of the
 0.5 log additional credit that a
 coagulant,  which could include excess
 lime and soda  ash or precipitation of
 magnesium hydroxide, be present in
 both clarifiers. This requirement is
 necessary to ensure that significant
 particulate removal occurs in both
 clarification stages. Logsdon  et al.
 (1994) identified effective flocculation
as being a key factor for removal of
protozoa in softening plants. Among the
softening plants that provided data on
aerobic spore removal, St. Louis added
ferric and polymer coagulants at
different  points in the process, and the
 two Columbus plants added lime to the
 second clarifier. Consequently, a
 requirement that plants add a coagulant,
 which may be lime, in the secondary
 clarifier is consistent with the data used
 to support the 0.5 log additional credit.
  The Science Advisory Board (SAB)
 reviewed the proposed Cryptosporidium
 treatment credit for lime softening and
 supporting information, as presented in
 the November 2001 pre-proposal draft of
 the LT2ESWTR (USEPA 2001g). In
 written comments from a December
 2001 meeting of the Drinking Water
 Committee, the SAB  panel concluded
 that both single- and  two-stage softening
 generally outperform conventional
 treatment due to the  heavy precipitation
 that occurs. Further,  the panel found
 that 0.5 log of additional
 Cryptosporidium removal is an average
 value for a two-stage  lime softening
 plant. However, the SAB stated that the
 additional credit for two-stage softening
 should be given only if all the water
 passes through both stages. Today's
 proposal is consistent with these
 recommendations by the SAB.
  EPA notes that by including a
 presumptive credit for softening plants,
 today's proposal differs from the Stage
 2 M-DBP Agreement  in Principle, which
 recommends up to 1  log additional
 Cryptosporidium treatment credit for
 softening plants based on demonstration
 of performance, but no additional
 presumptive credit.
  c.  Request for comment. EPA requests
 comment on the proposed criteria for
 awarding credit to lime softening plants.
 EPA would particularly appreciate
 comment on the following issues:
  • Whether the information and
 analyses presented in this proposal
 supports  an additional 0.5 log credit for
 two-stage softening, and the associated
 criteria necessary for  credit.
  • Additional information that either
 support or suggest modifications to the
proposed criteria and credit.

 8. Combined Filter Performance
  a. What is EPA proposing today? This
toolbox component will grant additional
credit towards Cryptosporidium

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47698         Federal Register/Vol.  68.  No. 154/Monday,  August  11. 2003/Proposed  Rules
treatment requirements to certain plants
that maintain finished water turbidity at
levels significantly lower than currently
required. EPA is proposing to award an
additional 0.5 log Cryptosporidium
treatment credit to conventional and
direct filtration plants that demonstrate
a turbidity level in the combined filter
effluent (CFE) less than or equal to 0.15
NTU in at least 95 percent of the
measurements taken each month.
Compliance with this criterion must be
based on measurements of the CFE
every four hours (or more frequently)
that the system serves water to the
public. This credit is not available to
membrane, bag/cartridge, slow sand, or
DE plants, due to the lack of
documented correlation between
effluent turbidity and  Cryptosporidium
removal in these processes.
   b. How was this proposal developed?
Turbidity is an optical property
measured from the amount of light
scattered by suspended particles in a
solution. It is a method defined
parameter that  can detect the presence
of a wide variety of particles in water
(e.g., clay, silt, mineral particles, organic
and inorganic matter, and
microorganisms), but it cannot provide
specific information on particle type,
number, or size. Turbidity is used as an
indicator of raw and finished water
quality and treatment performance.
Turbidity spikes in filtered water
indicate a potential for breakthrough of
pathogens.
  Under the IESWTR and LT1ESWTR,
combined filter effluent turbidity in
conventional and direct filtration plants
must be less than or equal to 0.3 NTU
in 95% of samples taken each month
and must never exceed 1 NTU. These
plants are also required  to conduct
continuous monitoring of turbidity for
each individual filter, and provide an
exceptions report to the State when
certain criteria for individual filter
effluent turbidity are exceeded
(described in 63 FR 69487, December
16, 1998) (USEPA 1998a).
  The Stage 2 M-DBP Advisory
Committee recommended that systems
receive an additional 0.5 log
Cryptosporidium removal credit for
maintaining 95th percentile combined
filter effluent turbidity below 0.15 NTU,
which is one half of the current required
level of 0.3 NTU. In considering the
technical basis to support this
recommendation, EPA has reviewed
studies that evaluated the efficiency of
granular media filtration in removing
Cryptosporidium when operating at
different effluent turbidity levels.
  For the IESWTR, EPA estimated that
plants would target filter effluent
turbidity in the range of 0.2 NTU in
order to ensure compliance with a
turbidity standard of 0.3 NTU.
Similarly, EPA has estimated that plants
relying on meeting a turbidity standard
of 0.15 NTU in 95% of samples will
consistently operate below 0.1 NTU in
order to ensure compliance.
Consequently, to assess the impact of
compliance with the lower finished
water turbidity standard, EPA compared
Cryptosporidium removal efficiency
when effluent turbidity is below 0.1
NTU with removal efficiency when
effluent turbidity is in the range of 0.1
to 0.2 NTU. Results from applicable
 studies are summarized in Table IV-15
 and are discussed in the following
 paragraphs.
           TABLE IV-15.—STUDIES OF Cryptosporidium REMOVAL AT DIFFERENT EFFLUENT TURBIDITY LEVELS
Microorganism
^ 	 . 	 •" —




Average of log
removals
4.39
3.55
4.23
3.22
4.09
3.58
3.76
2.56
Filtered effluent turbidity
<0 1 NTU 	
>0.1 and <0.2 NTU
<0.1 NTU
>0.1 and <0.2 NTU
<0 1 NTU 	
>0.1 and <0.2 NTU
<0.1 NTU
>0.1 and <0.2 NTU
Experiment design
Pilot-scale 	
Bench-scale 	


Researcher
Pataniaetal. {1995).
Emelkoetal. (1999).
Dugan et al. (2001).
   Patania et al. (1995) conducted pilot-
 scale studies at four locations to
 evaluate the removal  of seeded
 Cryptosporidium and Giardia, turbidity,
 and particles. Treatment processes,
 coagulants, and coagulant doses differed
 among the four locations. Samples of
 filter effluent were taken at times of
 stable operation and filter maturation.
 Analysis of summary data from the
 seeded runs at all locations shows  that
 average Cryptosporidium removal was
 greater by more than  0.5 log when
 effluent turbidity was less than 0.1
 NTU, in comparison  to removal with
 effluent turbidity in the range 0.1 to 0.2
 NTU (see Table IV-15).
   Emelko et al. (1999) used a bench
 scale dual media filter to study
 Cryptosporidium removal during both
 optimal and challenged operating
 conditions. Water containing a
 suspension of kaolinite (clay) was
 spiked with oocysts,  coagulated in-line
 with alum, and filtered. Oocyst removal
 was evaluated during stable operation
 when effluent turbidity was below 0.1
 NTU. Removal was also measured after
 a hydraulic surge that caused process
 upset, and with coagulant addition
 terminated. These later two conditions
 resulted in effluent turbidities greater
 than 0.1 NTU and decreased removal of
 Cryptosporidium. As shown in Table
 IV-15, average removal of
 Cryptosporidium during periods with
 effluent turbidity below 0.1 NTU was
 approximately 0,5 log greater than when
 effluent turbidity was between 0.1 to 0.2
 NTU.
   Dugan etal (2001) evaluated
 Cryptosporidium removal in a pilot
 scale conventional treatment plant.
 Sixteen filtration runs seeded with
 Cryptosporidium were conducted at
 different raw water turbidities and
 coagulation conditions. Eleven of the
 runs had an effluent turbidity below 0.1
 NTU, and five runs had effluent
 turbidity between 0.1 and 0.2 NTU. For
 runs where the calculated
 Cryptosporidium removal was
 concentration limited (i.e., effluent
 values were non-detect), the method
 detection limit was used to calculate the
 values shown in Table IV-15. Using this
 conservative estimate, average
 Cryptosporidium removal with effluent
 turbidity below 0.1 NTU exceeded by
 more than 1 log the average removal
 observed with effluent turbidity
 between 0.1 to 0.2 NTU.
    In summary, these three studies all
 support today's proposal in showing
 that plants consistently operating below
 0.1 NTU can achieve an additional 0.5
 log or greater removal of
 Cryptosporidium than when operating
 between 0.1 and 0.2 NTU. Because EPA
 expects plants relying on compliance
 with a 0.15 NTU standard will
  consistently operate below 0.1 NTU, the

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                 Federal  Register/Vol. 68, No.  154/Monday,  August  11,  2003/Proposed Rules
                                                                     47699
 Agency has determined it is appropriate
 to propose an additional 0.5 log
 treatment credit for plants meeting this
 standard.
  The SAB reviewed the proposed
 additional 0.5 log Cryptosporidium
 removal credit for systems maintaining
 very low CFE turbidity, as presented in
 the November 2001 pre-proposal draft of
 the LT2ESWTR (USEPA 2001gj. The
 SAB also reviewed a potential
 additional 1.0 log Cryptosporidium
 removal credit for systems achieving
 very low individual filter effluent (IFE)
 turbidity, which is addressed in section
 IV.G.16 of today's proposal.
  In written comments from a December
 2001 meeting of the Drinking Water
 Committee, the SAB panel stated that
 additional credit for lower finished
 water turbidity is consistent with what
 is known in both pilot and full-scale
 operational experiences for
 Cryptosporidium removal. Recognizing
 that IESWTR requirements for lowering
 turbidity in the treated water will result
 in lower concentrations of
 Cryptosporidium, the panel affirmed
 that even further lowering of turbidity
 will result in further reductions in
 Cryptosporidium in the filter effluent.
 However, the SAB concluded that
 limited data were presented to show the
 exact removal that can be achieved, and
 recommended that no additional credit
 be given to plants that demonstrate CFE
turbidity of 0.15 NTU or less. The SAB
recommended that 0.5 log credit be
given to plants achieving IFE turbidity
in each filter less than 0.15 NTU in 95%
of samples each month.
  In responding to this recommendation
from the SAB, EPA acknowledges the
difficulty in precisely quantifying
Cryptosporidium removal through
filtration based on effluent turbidity
levels. Nevertheless, EPA finds that
available data consistently show that
removal of Cryptosporidium is
increased by 0.5 log or greater when
filter effluent turbidity is reduced to
levels reflecting compliance with a 0.15
NTU standard, in comparison to
compliance with a 0.3 NTU standard.
Consequently, EPA has concluded that
it is appropriate to propose this 0.5 log
presumptive treatment credit for
systems achieving very low CFE
turbidity.

Measurement of Low Level Turbidity
  Another important aspect of
proposing to award additional removal
credit for lower finished  water turbidity
is the performance of turbidimeters in
measuring turbidity below 0.3 NTU. The
following paragraphs summarize results
from several studies that evaluated low
level measurement of turbidity by
different on-line and bench top
instruments. Note that because
compliance with the CFE turbidity limit
is based on 4-hour readings, either on-
line or bench top turbidimeters may be
used, EPA believes that results from
these studies indicate that currently
available turbidity monitoring
equipment is capable of reliably
assessing turbidity at levels below 0.1
NTU, provided instruments are well
calibrated and maintained.
  The 1997 NODA for the IESWTR (67
FR 59502, Nov. 3, 1997) (USEPA 1997a)
discusses issues relating to the accuracy
and precision of low level turbidity
measurements. This document cites
studies (Hart et al 1992, Sethi et al
1997) suggesting that large tolerances in
instrument design criteria have led to
turbidimeters that provide different
turbidity readings for a given
suspension.
  At the time of IESWTR  NODA, EPA
had conducted performance evaluation
(PE) studies of turbidity samples above
0.3 NTU. A subsequent PE study
(USEPA 1998e), labeled WS041, was
carried out to address concern among
the Stage 1 M-DBP Federal Advisory
Committee regarding the ability to
reliably measure lower turbidity levels.
The study involved distribution of
different types of laboratory prepared
standard solutions with reported
turbidity values of 0.150 NTU or 0.160
NTU. The results of this study are
summarized in Table IV-16.
BILLING CODE 6560-50-P
      Table IV-16.-- Performance Evaluation - WS041 Data for Low Level Turbidity

      Analysis (USEPA 1998e)
Type of
Instrument
Bench Top
Portable or IR
Portable or IR
On-Line
Sample
Solution
Type
Polystyrene
Spheres
Polystyrene
Spheres
Formazin
Polystyrene
Spheres
"True"
Value
(NTU)
0.150
0.150
0.160
0.150
No. of
Results
Available
292
340
335
52
Mean*
(NTU)
0.203
0.200
0.176
0.228
Std. Dev*
(NTU)
0.0558
0.0439
0.0431
0.0773
95%
Prediction
Interval
(NTU)
0.093-0.313
0.113-0.286
0.091-0.261
0.072-0.385
      'Calculated using biweight transformation
BILLING CODE 6S60-5
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Federal  Register/Vol. 68, No.  154/Monday, August  11.  2003/Proposed Rules
at lower than required effluent turbidity
levels).
  Letterman et al, (2001) evaluated the
effect of turbidimeter design and
calibration methods on Inter-instrument
performance, comparing bench top to
on-line instruments and instruments
within each of those categories from
different manufacturers, The study used
treated water collected from the filter
effluent of water treatment plants.
Reported sample turbidity values ranged
from 0.05  to 1 NTU. Samples were
analyzed in a laboratory environment.
The results are consistent with those of
the WS041 study, specifically the
positive bias of on-line instruments.
However,  Letterman et al. found
generally poor agreement among
different on-line instruments and
between bench-top and on-line
instruments. The authors also observed
that results were independent  of the
calibration method, though certain
experiments suggested that analyst
experience may have some effect on
turbidity readings from bench-top
instruments.
  Sadar (1999) conducted an infra-
instrument study of low level turbidity
measurements among instruments from
the same manufacturer. This study was
performed under well-controlled
laboratory conditions, //rtra-instrument
variation among different models and
between bench top and on-line
instruments occurred but at
significantly lower levels than the
Letterman et al. j'n tor-instrument study.
Newer instruments also tended to read
lower than older instruments,  which the
author attributed to a reduction in stray
light and lower sensitivities in the
newer instruments. Sadar also found a
generally  positive bias when comparing
on-line to bench-top and when
comparing all instruments to a prepared
standard.
  The American Society for Testing and
Materials  (ASTM) has issued standard
test methods for measurement of
turbidity below 5 NTU by on-line
(ASTM 2001) and static (ASTM 2003)
instrument modes. The methods specify
that the instrument should permit
detection of turbidity differences of 0.01
NTU or less in waters having turbidities
of less than 1.00 NTU (ASTM 2001) and
5.0 NTU (ASTM 2003), respectively.
/nter-laboratory study data included
with the method for a known turbidity
standard of 0.122 NTU show an analyst
relative deviation of 7.5% and a
laboratory relative deviation of 16%
(ASTM 2003).
  In summary, the data collected in
these studies of turbidity measurement
indicate that currently available
monitoring equipment can reliably
                      measure turbidity at levels of 0.1 NTU
                      and lower. However, this requires
                      rigorous calibration and verification
                      procedures, as well as diligent
                      maintenance of turbidity monitoring
                      equipment (Burlingame 1998, Sadar
                      1999). Systems that pursue additional
                      treatment credit for lower finished water
                      turbidity must develop the procedures
                      necessary to ensure accurate and
                      reliable measurement of turbidity at
                      levels of 0.1 NTU and less. EPA
                      guidance for the microbial toolbox will
                      provide direction to water systems on
                      developing these procedures.
                        c. Request for comment. EPA invites
                      comment on the following issues
                      regarding the proposed
                      Cryptosporidium treatment credit for
                      combined filter performance:
                        • Do the studies cited here support
                      awarding 0.5  log credit for CFE < 0.15
                      NTU 95% of the time?
                        • Does currently available turbidity
                      monitoring technology accurately
                      distinguish differences between values
                      measured near 0.15 NTU?
                      9. Roughing Filter
                        a, What is EPA proposing todoy?The
                      Stage 2 M-DBP Agreement in Principle
                      recommends  a 0.5 log presumptive
                      credit towards additional
                      Cryptosporidium treatment
                      requirements for roughing filters.
                      However, the Agreement  further
                      specifies that EPA is to determine the
                      design and implementation criteria
                      under which the credit would be
                      awarded. Upon subsequent review of
                      available literature, EPA is unable to
                      identify design and implementation
                      conditions for roughing filters that
                      would provide reasonable assurance of
                      achieving a 0.5 log removal of oocysts.
                      Consequently, EPA is not proposing
                      presumptive credit for Cryptosporidium
                      removal by roughing filters. Today's
                      proposal does, though,  include a 0.5 log
                      credit for a second granular media filter
                      following coagulation and primary
                      filtration (see section IV.C.13).
                        b. How was this proposal developed?
                      Roughing filtration is a technique used
                      primarily in developing countries to
                      remove solids from high turbidity
                      source waters prior to treatment with
                      slow sand filters. Typically, roughing
                      filters consist of a series of
                      sedimentation tanks filled with
                      progressively smaller diameter media in
                      the direction of flow. The media can be
                      gravel, plastic, crushed coconut, rice
                      husks, or a similar locally available
                      material. The flow direction in roughing
                      filters can be either horizontal or
                      vertical, and vertical roughing filters can
                      be either upflow or downflow. The
                      media in the tanks effectively reduce the
vertical settling distance of particles to
a distance of a few millimeters. As
sediment builds on the media, it
eventually sloughs off and begins to
accumulate in the lower section of the
filter, while simultaneously regenerating
the upper portions of the filter. The
filters require periodic cleaning to
remove the collected silt.
  Review of the scientific and technical
literature pertaining to roughing filters
has identified no information on
removal of Cryptosporidium.
Information is available on removal of
suspended solids, turbidity, particles,
fecal coliforms and some algae, but none
of these has been demonstrated to be an
indicator of Cryptosporidium removal
by roughing filters. Moreover, roughing
filters are not preceded by a coagulation
step, and studies have found that some
potential surrogates, such as aerobic
spores, are not conservative indicators
of Cryptosporidium removal by
filtration when a coagulant is not
present (Yates et al. 1998, Dugan et al.
2001). Thus, it is unclear how to relate
results from studies of the removal of
other particles by roughing filters to
potential removal of Cryptosporidium.
   In addition, some studies have
observed very poor removal of
Cryptosporidium by rapid sand filters
when a coagulant is not used (Patania et
al. 1995, Huck et al 2000). Based on
these findings, it is expected that there
would be situations where a roughing
filter would not achieve 0.5 log
Cryptosporidium removal. Because
available data are insufficient to
determine the conditions that would be
necessary for a roughing filter to achieve
0.5 log Cryptosporidium removal, EPA
is unable to propose this credit. The
following discussion describes four
studies that analyzed the effectiveness
of roughing filters for removing solids,
turbidity, particles, fecal coliforms, and
algae.
   Wegelin et al. (1987) conducted pilot-
scale studies on the use of horizontal
roughing filters to reduce solids,
turbidity, and particles. Testing was
performed to determine the influence of
 different design parameters on filter
performance. Data from the parameter
testing was used to establish an
empirical model to simulate filtrate
 quality as a function of filter length and
time for a given filter configuration.
Using the mathematical model, the
researchers found that long filters (10 m)
 at low filtration rates (0.5 m/h) were
 capable of reducing high suspended
 solids concentrations (1000 mg/L TSS)
 down to less than 3 mg/L.
   Further work by Wegelin (1988)
 evaluated roughing filters as
 pretreatment for slow sand filters for

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                 Federal Register/VoI. 68, No. 154/Monday, August 11, 2003/Proposed Rules
                                                                            47701
waters with variable and seasonably
high suspended solids concentrations.
This study collected data on roughing
filters in Peru, Colombia, Sudan, and
Ghana. Table IV-17 summarizes data for
three of the roughing filters. These
filters were capable of reducing peak
turbidities by 80 to 90 percent. Further,
the Peruvian and Colombian filters
        reduced fecal coliforms by 77 and 89
        percent, respectively. The Sudanese
        filter may have removed around 90
        percent of the fecal coliforms, but
        specific values were not given. Data
        collected from roughing filters in Ghana
        on algae removal indicate that the
        Merismopedia (0.5 um) and Chlorophyta
        (2-10 um), which are comparable in size
                to Cryptosporidium oocysts, were
                completely removed from the water in
                mature filters, and that some removal of
                Chlorophyta, but not Merismopedia,
                occurred in filters after three days of
                operation.  However, the removal of
                these organisms has  not been correlated
                with Cryptosporidium oocyst removal.
                            TABLE IV-17.—ROUGHING FILTER DATA FROM WEGELIN, 1988
Location




Azpita, Peru

0 30 m/h {0 98 ft/hr) 	
35 mVd 	

El Retire, Colombia
Upflow (multi-layer filter) 	 	
0.74 m/h (2.43 f/hr) 	
790 mVd 	

Blue Nile Health Project,
Sudan
Horizontal-flow.
0.3 m/h (0.98 ft/hr).
5 nP/d.
                                                   Turbidity (NTU)
Raw Water 	
Roughing Filter Effluent
50-200
15-40 .
10-150
5-15 ...
40-500
5-50
                                               Fecal Coliforms (/100 mL)



700 	
160 .. 	

16,000 	
1,680 	

>300
<25
  oiler (1993) details the mechanisms of
particle removal that occur in roughing
filters. The conclusions are similar to
those drawn by Wegelin et al. (1987).
Particle analysis reviewed by Boiler
indicates that after seven days of
operation, the four stage pilot filter
utilized by Wegelin et al (1987)
removed more than 98 percent of
particles sized 1.1 um, and greater than
99 percent of particles sized 3.6 um.
After 62 days, only 80 percent of
particles sized 1.1 um were removed,
while 90 percent of particles sized 3.6
um were removed. Boiler did not give
the solids loading on the tested filter,
and particle removal was not correlated
to Cryptosporidium oocyst removal.
  Collins et al. (1994) investigated
solids and algae removal with pilot
scale vertical downflow roughing filters.
Gravel media size, filter depth, and flow
rate were varied to determine which
design variables had the greatest effect
on filter performance. Results indicated
that the most influential design
parameters for removing solids from
water, .in order of importance, were
filter length, gravel size, and hydraulic
flow rate. For algae removal, the most
influential design parameters were
hydraulic flow rate, filter length, and
gravel size. Solids removal was better in
filters that had been ripened with algae
for 5-7 days. However, extrapolation of
these results to Cryptosporidium
removal could not be made,  .
  c. Request for comment. The Agency
requests comment on the information
that has been presented about roughing
        filters, and specifically the question of
        whether and under what conditions
        roughing filters should be awarded a 0.5
        log credit for removal of
        Cryptosporidium. EPA also requests
        information on specific studies of
        Cryptosporidium oocyst removal by
        roughing filters, or from studies of the
        removal of surrogate parameters that
        have been shown to correlate with
        oocyst removal in roughing filters.

        10. Slow Sand Filtration

         a. What is EPA proposing today? Slow
        sand filtration is defined in 40 CFR
        141.2 as a process involving passage of
        raw water through a bed of sand at low
        velocity (generally less than 0.4 m/h)
        resulting in substantial particulate
        removal by physical and biological
        mechanisms. Today's proposal allows
        systems using slow sand filtration as a
        secondary filtration step following a
        primary filtration process (e.g.,
        conventional treatment) to receive an
        additional 2.5 log Cryptosporidium
        treatment credit. There must be no
        disinfectant residual in the influent
        water to the slow sand filtration process
        to be eligible for credit.
         Note that this proposed credit differs
        from the credit proposed for slow sand
        filtration as a primary filtration process.
        EPA has concluded, based on treatment
        studies  described in section III.D, that
        plants using well designed and well
        operated slow sand filtration as a
        primary filtration process can achieve
        an average Cryptosporidium removal of
        3 log (Schuler and Ghosh, 1991, Timms
                et al. 1995, Hall et al. 1994).
                Consequently, as described in section
                IV.A, EPA is proposing that plants using
                slow sand filtration as a primary
                filtration process receive a 3 log credit
                towards Cryptosporidium treatment
                requirements  associated with Bins 2-4
                under the LT2ESWTR (i.e., credit
                equivalent to a conventional treatment
                plant).
                 The proposed 2.5 log credit for slow
                sand filtration as part of the microbial
                toolbox applies only when it is used as
                a secondary filtration step, following a
                primary filtration process like
                conventional treatment.' While the
                removal mechanisms that make slow
                sand filtration effective as a primary
                filtration process would also be
                operative when used as a secondary
                filtration step, EPA has little data on
                this specific application. The Agency is
                proposing 2.5 log credit for slow sand
                filtration as a secondary filtration step,
                in comparison to 3 log credit as a
                primary filtration process, as a
                conservative measure reflecting greater
                uncertainty. In addition, the proposed
                2.5 log credit for slow sand filtration as
                part of the microbial toolbox is
                consistent with the recommendation in
                the Stage 2 M-DBP Agreement in
                Principle.
                 b. How was this proposal developed?
                The Stage 2 M-DBP Agreement in
                Principle recommends that slow sand
                filtration receive 2.5 log or greater
                Cryptosporidium treatment credit when
                used in addition to existing treatment
                that achieves compliance with the

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Federal  Register/Vol. 68, No. 154/Monday,  August  11,  2003/Proposed Rules
IESWTR or LT1ESWTR. Slow sand
filtration is not typically used as a
secondary filtration step following
conventional treatment or other primary
filtration processes of similar efficacy.
However, EPA expects that slow sand
filtration would achieve significant
removal of Cryptosporidium in such a
treatment train.
  While there is a significant body of
data demonstrating the effectiveness of
slow sand filtration for Cryptosporidium
removal as a primary filtration process,
as described in section III.D, EPA has
limited data on the effectiveness of slow
sand filtration  when used as a
secondary filtration step. Hall et al
(1994) evaluated oocyst removal for a
pilot scale slow sand filter following a
primary filtration process identified as a
rapid gravity filter. The combined
treatment train of a primary filtration
process followed by slow sand filtration
achieved greater than 3 log
Cryptosporidium removal in three of
five experimental runs, while
approximately 2.5 log reduction was
observed in the other two runs. In
comparison, Hall  et al.  (1994) reported
slow sand filtration alone to achieve at
least a 3 log removal of oocysts in each
of four experimental runs when not
preceded by a primary filtration process.
The authors offered no explanation for
these results, but measured oocyst
removals may have been impacted by
limitations with the analytical method.
  Removal of microbial pathogens in
slow sand filters is complex and is
believed to occur through a combination
of physical, chemical, and biological
mechanisms, both on the surface
(schmutzdecke) and in the interior of
the filter bed. It is unknown if the
higher quality  of the water that would
be influent to a slow sand filter when
used as a secondary filtration step
would impact the efficiency of the filter
in removing Cryptosporidium. Based on
the limited data on the performance of
slow sand filtration as a secondary
filtration step,  and in consideration  of
the recommendation of the Advisory
Committee, EPA is proposing only a 2.5
log additional Cryptosporidium
treatment credit for this application,
  c. Request for comment. The Agency
requests comment on whether the
available data are adequate to support
awarding a 2.5 log Cryptosporidium
removal credit for slow sand filtration
applied as a secondary filtration step,
along with any additional information
related to this application.
11. Membrane  Filtration
  a. What is EPA proposing today? EPA
is proposing criteria for awarding credit
to membrane filtration processes for
                      removal of Cryptosporidium. To receive
                      removal credit, the membrane filtration
                      process must: (1) Meet the basic
                      definition of a membrane filtration
                      process, (2) have removal efficiency
                      established through challenge testing
                      and verified by direct integrity testing,
                      and (3) undergo periodic direct integrity
                      testing and continuous indirect integrity
                      monitoring during use. The maximum
                      removal credit that a membrane
                      filtration process is eligible to receive is
                      equal to the lower value of either:
                      —The removal efficiency demonstrated
                        during challenge testing OR
                      —The maximum log removal value that
                        can be verified through the direct
                        integrity test (i.e., integrity test
                        sensitivity) used to monitor the
                        membrane filtration process.
                        By the criteria in today's proposal, a
                      membrane filtration process could
                      potentially meet the Bin 4
                      Cryptosporidium treatment
                      requirements of this proposal. These
                      criteria are described in more detail
                      below. EPA is developing a Membrane
                      Filtration Guidance Manual that
                      provides additional information and
                      procedures for meeting these criteria
                      (USEPA 2003e). A draft of this guidance
                      is available in the docket for today's
                      proposal (http://www.epa.gov/edocket/).

                      Definition of a Membrane Filtration
                      Process
                        For the purpose of this proposed rule,
                      membrane filtration is defined as a
                      pressure or vacuum driven separation
                      process in which paniculate matter
                      larger than 1 urn is rejected by a
                      nonfibrous, engineered barrier,
                      primarily through a size exclusion
                      mechanism, and which has a
                      measurable removal efficiency of a
                      target organism that can be verified
                      through the application of a direct
                      integrity test. This definition is intended
                      to include the common membrane
                      technology classifications:
                      microfiltration (MF), ultrafiltration (UF),
                      nanofiltration (NF), and reverse osmosis
                      (RO). MF and UF are low-pressure
                      membrane filtration processes that are
                      primarily used to remove particulate
                      matter and microbial contaminants. NF
                      and RO are membrane separation
                      processes that are primarily used to
                      remove dissolved contaminants through
                      a variety of mechanisms, but which also
                      remove particulate matter via a size
                      exclusion mechanism.
                        In today's proposal, the critical
                      distinction between membrane filtration
                      processes and bag and cartridge filters,
                      described in section IV.C.12, is that the
                      integrity of membrane filtration
                      processes can be directly tested. Based
on this distinction, EPA is proposing
that membrane material configured into
a cartridge filtration device that meets
the definition of membrane filtration
and that can be direct integrity tested
according to the criteria specified in this
section is eligible for the same removal
credit as a membrane filtration process.
  Membrane devices can be designed in
a variety  of configurations including
hollow-fiber modules, hollow-fiber
cassettes, spiral-wound elements,
cartridge filter elements, plate and frame
modules, and tubular modules among
others. In today's proposal, the generic
term module is used to refer to all of
these various configurations and is
defined as the smallest component of a
membrane unit in which a specific
membrane surface area is housed in a
device with a filtrate outlet structure. A
membrane unit is defined as a group of
membrane modules that share common
valving that allows the unit to be
isolated from the rest of the system for
the purpose of integrity testing or other
maintenance.
Challenge Testing
  A challenge test is defined as a study
conducted to determine the removal
efficiency (i.e., log removal value) of the
membrane filtration media.  The removal
efficiency demonstrated during
challenge testing establishes the
maximum removal credit that a
membrane filtration process is eligible
to receive, provided this value is less
than or equal to the maximum log
removal value that can be verified by
the direct integrity test (as described in
the following subsection). Challenge
testing is a product specific rather than
a site specific requirement. At the
discretion of the State, data from
challenge studies conducted prior to
promulgation of this regulation maybe
considered in lieu of additional testing.
However, the prior testing must have
been conducted in a manner that
demonstrates a removal  efficiency for
Cryptosporidium commensurate with
the treatment credit awarded to the
process. Guidance for conducting
challenge testing to meet the
requirements of the rule is provided in
the Membrane Filtration Guidance
Manual (USEPA 2003e). Challenge
testing must be conducted according to
the following criteria:
   • Challenge testing must be
conducted on a full-scale membrane
module identical in material and
construction to the membrane modules
proposed for use in full-scale treatment
facilities. Alternatively, challenge
testing may be conducted on a smaller
membrane module, identical in material
and similar in construction to the full-

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                                                                     47703
scale module, if testing meets the other
requirements listed in this section.
  • Challenge testing must be
conducted using Cryptosporidium
oocysts or a surrogate that has been
determined to be removed no more
efficiently than Cryptosporidium
oocysts. The organism or surrogate used
during challenge testing is referred to as
the challenge particulate. The
concentration of the challenge
particulate must be determined using a
method capable of discretely
quantifying the specific challenge
particulate used in the test. Thus, gross
water quality measurements such as
turbidity or conductivity cannot be
used.
  • The maximum allowable feed water
concentration used during a challenge
test is based on the detection limit of the
challenge particulate in the filtrate, and
is determined according to the following
equation:
Maximum Feed Concentration = 3.16 x
    10B x (Filtrate Detection Limit)
This will allow the demonstration of up
to 6.5 log removal during challenge
testing if the challenge particulate is
removed to the detection limit.
  • Challenge testing must be
conducted under representative
hydraulic conditions at the maximum
design flux and maximum design
system recovery as specified by the
manufacturer. Flux is defined as the
flow per unit of membrane area.
Recovery is defined as the ratio of
filtrate volume produced by a
membrane to feed water volume applied
to a membrane over the course of an
uninterrupted operating cycle. An
operating cycle is bounded by two
consecutive backwash or cleaning
events. In the context of this rule,
recovery does not consider losses that
occur due to the use of filtrate in
backwashing or cleaning operations.
   • Removal efficiency of a membrane
filtration process is determined from the
results of the challenge test, and
expressed in terms of log removal values
as  defined by the following equation;
LRV = LOG,o(Cf} - LOG,o(Cp)
where LRV = log removal value
demonstrated during challenge testing;
Cf = the feed concentration used during
the challenge test; and Cp = the filtrate
concentration observed during the
challenge test. For this equation to be
valid, equivalent units must be used for
the feed and filtrate concentrations. If
the challenge particulate is not detected
in  the filtrate, then the term Cp is set
equal to the detection limit. A single
LRV is calculated for each membrane
module evaluated during the test.
  * The removal efficiency of a
membrane filtration process
demonstrated during challenge testing is
expressed as a log removal value
(LRVc-Tesi). If fewer than twenty
modules are tested, then LRVc-Tcst is
assigned a value equal to the lowest of
the representative LRVs among the
various modules tested. If twenty or
more modules are tested, then LRVc-Tcst
is assigned a value equal to the 10th
percentile of the representative LRVs
among the various modules tested. The
percentile is defined by [i/(n+l)] where
i is the rank of n individual data points
ordered lowest to highest. It may be
necessary to calculate the 10th
percentile using linear interpolation.
  • A quality control release value
(QCRV) must be established for a non-
destructive performance test (e.g.,
bubble point test, diffusive airflow test,
pressure/vacuum decay test) that
demonstrates the Cryptosporidium
removal capability of the membrane
module. The performance test must be
applied to each production membrane
module that did not undergo a challenge
test in  order to verify Cryptosporidium
removal capability. Production
membrane modules that do not meet the
established QCRV are not eligible for the
removal credit demonstrated during
challenge testing.
  • Any significant modification to the
membrane filtration device (e.g., change
in the polymer chemistry of the
membrane) requires additional
challenge testing to demonstrate
removal efficiency of the modified
module and to define a new QCRV for
the nondestructive performance test.
Direct  Integrity Testing
  In order to receive removal credit for
Cryptosporidium, the removal efficiency
of a membrane filtration process must
be routinely verified through direct
integrity testing. A direct integrity test is
defined as a physical test applied to a
membrane unit in order to identify and
isolate integrity breaches. An integrity
breach is defined as one or more leaks
that could result in contamination of the
filtrate. The direct integrity test method
must be applied to the physical
elements of the entire membrane unit
including membranes,  seals, potting
material, associated valving and piping,
and all other components which under
compromised conditions could result in
contamination of the filtrate.
  The  direct integrity tests commonly
used at the time of this proposal include
those that use an applied pressure or
vacuum (such as the pressure decay test
 and diffusive airflow test), and those
that measure the rejection of a
 particulate or molecular marker (such as
spiked particle monitoring). Today's
proposal does not stipulate the use of a
particular direct integrity test. Instead,
the direct integrity test must meet
performance criteria for resolution,
sensitivity, and frequency.
  Resolution is defined as the smallest
leak that contributes to the response
from a direct integrity test. Any direct
integrity test applied to meet the
requirements of this proposed rule must
have a resolution of 3 urn or less.  The
manner in which the resolution
criterion is met will depend on the type
of direct integrity test used. For
example, a pressure decay test can meet
the resolution criterion by applying a
net test pressure great enough to
overcome the bubble point of a 3  (im
hole. A direct integrity test that uses a
particulate or molecular marker can
meet the resolution criterion by
applying a  marker of 3 u.m or smaller.
  Sensitivity is defined as the maximum
log removal value that can be reliably
verified by the direct integrity test
(LRVoiT). The sensitivity of the direct
integrity test applied to meet the
requirements of this proposed rule must
be equal to or greater than the removal
credit awarded to the membrane
filtration process. The manner in which
LRVoir is determined will depend on
the type of direct integrity test used.
Direct integrity tests that use an applied
pressure or vacuum typically measure
the rate of pressure/vacuum decay or
the flow of air through an integrity
breach. The response from this type of
integrity test can be related to the flow
of water through an integrity breach
(Qbreach) during normal operation, using
procedures such as those described in
the Membrane Filtration Guidance
Manual (USEPA 2003e). Once Qbreach
has been determined, a simple dilution
model is used  to calculate LRVorr for
the specific integrity test application, as
shown by the following equation:
LRVDIT = LOG,0(Qp/(VCF x Qbrcach))
where LRVDjr = maximum log removal
value that can be verified by a direct
integrity test; Qp = total design filtrate
flow from the membrane unit; Qbrcach =
flow of water from an integrity breach
associated  with the smallest integrity
test response that can be reliably
measured;  and VCF = volumetric
concentration  factor.
   The volumetric concentration factor is
the ratio of the suspended solids
concentration  on the high pressure side
of the membrane relative to the feed
water, and is defined by the following
equation:
VCF = Cm/Cf
where Cm is the concentration of
particulate matter on the high pressure

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 side of the membrane that remains in
 suspension; and Cf is the concentration
 of suspended particulate matter in the
 feed water. The magnitude of the
 concentration factor depends on the
 mode of system operation and typically
 ranges from 1 to 20. The Membrane
 Filtration Guidance Manual presents
 approaches for determining the
 volumetric concentration factor for
 different operating modes (USEPA
 2003e).
   Sensitivity  of direct integrity tests that
 use a particulate or molecular marker is
 determined from the feed and filtrate
 concentrations of the marker. The
 LRVpiT for this type of direct integrity
 test is calculated according to  the
 following equation:
 LRVDIT = LOG,o{Cf} - LOG,o(Cp)
 where LRVoiT = maximum log removal
 value that can be verified by a direct
 integrity test;  Cr= the typical feed
 concentration of the marker used in the
 test; and Cp =  the filtrate concentration
 of the marker from an integral
 membrane unit. For this equation to be
 valid, equivalent units must be used for
 the feed and filtrate concentrations. An
 ideal particulate or molecular  marker
 would be completely removed by an
 integral membrane unit.
   If the sensitivity of the direct integrity
 test is such that LRVDir is less than
 LRVc-Tesi, LRVD]T establishes the
 maximum removal credit that  a
 membrane filtration process is eligible
 to receive. Conversely, if LRVoir for a
 direct integrity test is greater than
 LRVc-jcst, LRVc-Tcsi establishes the
 maximum removal credit.
   A control limit is defined as an
 integrity test response which, if
 exceeded, indicates a potential problem
 with the system and triggers a response.
 Under this proposal, a control limit for
 a direct integrity test must be
 established that is indicative of an
 integral membrane unit capable of
 meeting the Cryptosporidium removal
, credit awarded by the State. If the
 control limit for the direct integrity test
 is exceeded, the membrane unit must be
 taken  off-line  for diagnostic testing and
 repair. The membrane unit could only
 be returned to service after the repair
 has been completed and confirmed
 through the application of a direct
 integrity test.
   The frequency of direct integrity
 testing specifies how often the test is
 performed over an established time
 interval. Most direct integrity tests
 available at the time of this proposal are
 applied periodically and must be
 conducted on  each membrane  unit at a
 frequency of not less than once every 24
 hours  while the unit is in operation. If
                      continuous direct integrity test methods
                      become available that also meet the
                      sensitivity and resolution criteria
                      described earlier, they may be used in
                      lieu of periodic testing.
                        EPA is proposing that at a minimum,
                      a monthly report must be submitted to
                      the State summarizing all direct
                      integrity test results above the control
                      limit associated with the
                      Cryptosporidium removal credit
                      awarded to the process and the
                      corrective action that was taken in each
                      case.
                      Continuous Indirect Integrity
                      Monitoring
                        The majority of currently available
                      direct integrity test methods are applied
                      periodically since the membrane unit
                      must be taken out of service to conduct
                      the test. In order to provide some
                      measure of process performance
                      between direct integrity testing events,
                      continuous indirect integrity monitoring
                      is required. Indirect integrity monitoring
                      is defined as monitoring some aspect of
                      filtrate water quality that is indicative of
                      the removal of particulate matter. If a
                      continuous direct integrity test is
                      implemented that meets the resolution
                      and sensitivity criteria described
                      previously, continuous indirect integrity
                      monitoring is not required. Continuous
                      indirect integrity monitoring must be
                      conducted according to the following
                      criteria:
                        • Unless the State approves an
                      alternative parameter, continuous
                      indirect integrity monitoring must
                      include continuous filtrate turbidity
                      monitoring.
                        • Continuous monitoring is defined
                      as monitoring conducted at a frequency
                      of no less than once every 15 minutes.
                        • Continuous monitoring must be
                      separately conducted on each
                      membrane unit.
                        • If indirect integrity monitoring
                      includes turbidity and if the filtrate
                      turbidity readings are above 0.15 NTU
                      for a period greater than 15 minutes (i.e.,
                      two consecutive 15-minute readings
                      above 0.15 NTU), direct integrity testing
                      must be performed on the associated
                      membrane units.
                        • If indirect integrity monitoring
                      includes a State-approved alternative
                      parameter and if the alternative
                      parameter exceeds a State-approved
                      control limit for a period greater than 15
                      minutes, direct integrity testing must be
                      performed on the associated membrane
                      units.
                        • EPA is proposing that at a
                      minimum, a monthly report must be
                      submitted to the primacy agency
                      summarizing all indirect integrity
                      monitoring results triggering direct
integrity testing and the corrective
action that was taken in each case.
  b. How was this proposal developed?
The Stage 2 M-DBP Agreement in
Principle recommends that EPA develop
criteria to award Cryptosporidium
removal credit to membrane filtration
processes. Today's proposal and the
supporting guidance are consistent with
the Agreement.
  A number of studies have been
conducted which have demonstrated
the ability of membrane filtration
processes to remove pathogens,
including Cryptosporidium, to below
detection levels. A literature review
summarizing the results of several
comprehensive studies was conducted
by EPA and is presented in Low-
Pressure Membrane Filtration for
Pathogen Removal: Application,
Implementation, and Regulatory Issues
(USEPA 2001h).  Many of these studies
used Cryptosporidium seeding to
demonstrate removal efficiencies as
high as 7 log. The collective results from
these studies demonstrate that an
integral membrane module, i.e.,  a
membrane module without any leaks or
defects, with an exclusion  characteristic
smaller than Cryptosporidium, is
capable of removing this pathogen to
below detection in the filtrate,
independent of the feed concentration.
  Some filtration devices have used
membrane media in a  cartridge filter
configuration; however, few data are
available documenting their ability to
meet the requirements for membrane
filtration described in  section  IV.C.ll.a
of this preamble. However, in one study
reported by Dwyer et a]. (2001), a
membrane cartridge filter demonstrated
Cryptosporidium removal efficiencies in
excess of 6 log. This study  illustrates the
potentially high removal capabilities of
membrane filtration media configured
into a cartridge filtration device, thus
providing a basis for awarding removal
credits to these devices under the
membrane filtration provision of the
rule, assuming that the device meets the
definition of a membrane filtration
process as well as the direct integrity
test requirements.
  Today's proposal requires challenge
testing of membrane filtration  processes
used to remove Cryptosporidium. As
noted in section III.D, EPA believes this
is necessary due  to the proprietary
nature of these systems and the lack of
any uniform criteria for establishing the
exclusion  characteristic of a membrane.
Challenge testing addresses the lack of
a standard approach for characterizing
membranes by requiring direct
verification of removal efficiency. The
proposed challenge testing is product-
specific and not site-specific since the

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                                                                     47705
intent of this testing is to demonstrate
the removal capabilities of the
membrane product rather than evaluate
the feasibility of implementing
membrane treatment at a specific plant.
  Testing can be conducted using a full-
scale module or a smaller module if the
results from the small-scale module test
.can be related to full-scale module
performance. Most challenge studies
presented in the literature have used
full-scale modules, which provide
results that can be directly related to
full-scale performance. However, use of
smaller modules is considered feasible
in the evaluation of removal efficiency,
and a protocol for challenge testing
using small-scale modules has been
proposed (NSF, 2002a). Since the
removal efficiency of an integral
membrane is a direct function of the
membrane material, it may be possible
to use a small-scale module containing
the same membrane fibers or sheets
used in full-scale modules for this
evaluation. However, it will be
necessary to relate the results of the
small-scale module test to the
nondestructive performance test quality
control release value that will be used
to validate full-scale production
modules.
   Challenge testing with either
Cryptosporidium oocysts or a surrogate
is permitted. Challenge testing with
Cryptosporidium clearly provides direct
verification of removal efficiency for
this pathogen; however, several studies
have demonstrated that surrogates can
provide an accurate or conservative
measure of Cryptosporidium removal
efficiency. Since removal of paniculate
matter larger than  1 urn by a membrane
filtration process occurs primarily via a
size exclusion mechanism, the shape
and size distribution of the surrogate
must be selected such that the surrogate
is not removed to a greater extent than
the target organism. Surrogates that have
been successfully used in challenge
studies include polystyrene
microspheres and bacterial endospores.
The bacterial endospore, Bacillus
subtilis, has been used as a surrogate for
Cryptosporidium oocysts during
challenge studies evaluating pathogen
removal by  physical treatment
processes, including membrane
filtration (Rice  et al.  1996, Fox et al
1998, Trimboli et al 1999, Owen  et al,
1999). Studies evaluating cartridge
filters have  demonstrated that
polystyrene microspheres can provide
an accurate or conservative measure of
removal efficiency (Long, 1983, Li et al.
1997). Furthermore, the National
Sanitation Foundation (NSF)
Environmental Technology Verification
(ETV) protocol for verification testing
for physical removal of microbiological
and particulate contaminants specifies
the use of polymeric microspheres of a
known size distribution (NSF 2002b).
Guidance on selection of an appropriate
surrogate for establishing a removal
efficiency for Cryptosporidium during
challenge testing is presented in the
Membrane Filtration Guidance Manual
(USEPA 2003e).
  The design of the proposed challenge
studies is similar to the design  of the
seeding studies described in the
literature cited earlier. Seeding studies
are used  to challenge the membrane
module with pathogen levels orders  of
magnitude higher than those
encountered in natural waters.
However, elevated feed concentrations
can lead  to artificially high estimates of
removal efficiency. To address this
issue, the feed concentration applied to
the membrane during challenge studies
is capped at a level that will allow the
demonstration of up to 6.5 log  removal
efficiency if the challenge particulate is
removed to the detection level.
   Because challenge testing with
Cryptosporidium or a surrogate is not
conducted on every membrane module,
it is necessary to establish criteria for a
non-destructive performance test that
can be applied to all production
membrane modules. Results from a non-
destructive test, such as a bubble point
test, that are correlated with the results
of challenge testing can be used to
establish a quality control release value
(QCRV) that is indicative of the ability
of a membrane filtration process to
remove Cryptosporidium. The  non-
destructive test and QCRV can be used
to verify the Cryptosporidium removal
capability of modules that are not
challenge tested. Most membrane
manufacturers have already adapted
some form of non-destructive testing for
product quality control purposes and
have established a quality control
release value that is indicative of an
acceptable product. It may be possible
to apply these existing practices for  the
purpose of verifying the capability of a
membrane filtration process to remove
Cryptosporidium.
   Challenge testing provides a means of
demonstrating the removal efficiency of
an integral membrane module; however,
defects or leaks in the membrane or
other system components can result in
contamination of the filtrate unless they
are identified, isolated, and repaired. In
order to verify continued performance
of a membrane system, today's proposal
requires direct integrity testing of
membrane filtration processes used  to
meet Cryptosporidium treatment
requirements. Direct integrity testing is
required because it is a test applied  to
the physical membrane module and,
thus, a direct evaluation of integrity.
Furthermore, direct integrity methods
are the most sensitive integrity
monitoring methods commonly used at
the time of this proposal (Adham et al
1995).
  The most common direct integrity
tests apply a pressure or a vacuum to
one side of a fully wetted membrane
and monitor either the pressure decay or
the volume of displaced fluid over time.
However, the proprietary nature of these
systems makes it impractical to define a
single direct integrity test methodology
that is applicable to all existing and
future membrane products. Therefore,
performance criteria have been
established for any direct integrity test
methodology used to verify the removal
efficiency of a membrane system. These
performance criteria are resolution,
sensitivity, and frequency.
  As  stated previously, the resolution of
an integrity test refers to the smallest
leak that contributes to the response
from  an integrity test. For example, in
a pressure decay integrity test,
resolution is the smallest leak that
contributes to pressure loss during the
test. Today's proposal specifies a
resolution of 3 um or less, which is
based on the size of Cryptosporidium
oocysts. This requirement ensures that a
leak that could pass a Cryptosporidium
oocyst would contribute to the response
from  an integrity test.
  The sensitivity of an integrity test
refers to the maximum log removal that
can be reliably verified by the test.
Again using the pressure decay integrity
test as an example, the method
sensitivity is a function of the smallest
pressure loss that can be detected over
a membrane unit. Today's proposal
limits the log removal credit that a
membrane filtration process is eligible
to receive to the maximum log removal
value that can be verified by a direct
integrity test.
  In order to serve as a useful process
monitoring tool for assuring system
integrity, it is necessary to establish a
site-specific control limit for the
integrity test that corresponds to the log
removal awarded to the process. A
general approach for establishing this
control limit for some integrity test
methods is presented in guidance;
however, the utility will need to work
with  the membrane manufacturer and
State to establish a site-specific control
limit appropriate for the integrity test
used and level of credit awarded.
Excursions above this limit indicate a
potential integrity breach and would
trigger removal of the suspect unit from
service followed by diagnostic testing
and subsequent repair, as necessary.

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   Most direct integrity tests available at
 the time of this proposal must be
 applied periodically since it is
 necessary to take the membrane unit out
 of service to conduct the test. Today's
 proposal establishes the minimum
 frequency for performing a direct
 integrity test at once per 24 hours.
 Currently, there is no standard
 frequency for direct integrity testing that
 has been adopted by all States and
 membrane treatment facilities. In a
 recent survey, the required frequency of
 integrity testing was found to vary from
 once every four hours to once  per week;
 however, the most common frequency
 for conducting a direct integrity test was
 once every 24 hours (USEPA 2001h).
 Specifically, 10 out of 14 States that
 require periodic direct integrity testing
 specify a frequency of once every 24
 hours. Furthermore, many membrane
 manufacturers of systems with
 automated integrity test systems set up
 the membrane units to automatically
 perform a direct integrity test once per
 24 hours. EPA has concluded that the 24
 hour direct integrity test frequency
 ensures that removal efficiency is
 verified on a routine basis without
 resulting in excessive system downtime.
   Since most direct integrity tests are
 applied periodically, it is necessary to
 implement some level of continuous
 monitoring to assess process
 performance between direct integrity
 test events. In the absence of a
 continuous direct integrity test,
 continuous indirect integrity monitoring
 is required. Although  it has been shown
 that commonly used indirect integrity
 monitoring methods lack the sensitivity
 to detect small integrity breaches that
 are of concern (Adham etal 1995), they
 can detect large breaches and provide
 some assurance that a major failure has
 not occurred between direct integrity
 test events. Turbidity monitoring is
 proposed as the method of indirect
 integrity monitoring unless the State
 approves an alternate approach.
 Available data indicate that an integral
 membrane filtration process can
 consistently produce water with a
 turbidity less than 0.10 NTU, regardless
 of the feedwater quality. Consequently,
 EPA is proposing that exceedance of a
 filtrate turbidity value of 0.15 NTU
 triggers direct  integrity testing  to verify
 and isolate the integrity breach.
  c. Request for comment. EPA requests
 comment on the following issues:
  • EPA is proposing to include
 membrane cartridge filters that can be
 direct integrity tested under the
 definition of a membrane filtration
process since one of the key differences
between membrane filtration processes
and bag and cartridge filters, within the
                      context of this regulation, is the
                      applicability of direct integrity test
                      methods to the filtration process. EPA
                      requests comment on the inclusion of
                      membrane cartridge filters that can be
                      direct integrity tested under the
                      definition of a membrane filtration
                      process in this rule.
                        • The applicability of the proposed
                      Cryptosporidium removal credits and
                      performance criteria to Giardia lamblia,
                        • Appropriate surrogates, or the
                      characteristics of appropriate surrogates,
                      for use in challenge testing. EPA
                      requests data or  information
                      demonstrating the correlation between
                      removal of a proposed surrogate and
                      removal of Cryptosporidium oocysts.
                        • The use of a non-destructive
                      performance test and associated quality
                      control  release values for demonstrating
                      the Cryptosporidium removal capability
                      of membrane modules that are not
                      directly challenge tested.
                        • The appropriateness of the
                      minimum direct integrity test frequency
                      of once  per 24 hours.
                        • The proposed minimum reporting
                      frequency for direct integrity testing
                      results above the control limit and
                      indirect integrity monitoring results that
                      trigger direct integrity monitoring.
                      12. Bag  and  Cartridge Filtration
                        a. What is EPA proposing today? EPA
                      is proposing criteria for awarding
                      Cryptosporidium removal credit of 1 log
                      for bag filtration processes and 2 log for
                      cartridge filtration processes. To receive
                      removal credit the process must: (1)
                      Meet the basic definition of a bag or
                      cartridge filter and (2) have removal
                      efficiency established through challenge
                      testing.
                      Definition of a Bag or Cartridge Filter
                        For the purpose of this rule, bag and
                      cartridge filters are defined as pressure
                      driven separation processes that remove
                      particulate matter larger than 1 um
                      using an engineered porous filtration
                      media through either surface or depth
                      filtration.
                        The distinction between bag filters
                      and cartridge filters is based on the type
                      of filtration media used and the manner
                      in which the devices are constructed.
                      Bag filters are typically constructed of a
                      non-rigid, fabric  filtration media housed
                      in a pressure vessel in which the
                      direction of flow is from the inside of
                      the bag to outside. Cartridge filters are
                      typically constructed as rigid or semi-
                      rigid, self-supporting filter elements
                      housed in pressure vessels in which
                      flow is from  the outside of the cartridge
                      to the inside.
                       Although all filters classified as
                      cartridge filters share similarities with
respect to their construction, there are
significant differences among the
various commercial cartridge filtration
devices. From a public health
perspective, an important distinction
among these filters is the ability to
directly test the integrity of the filtration
system in order to verify that there are
no leaks that could result in
contamination of the filtrate. Any
membrane cartridge filtration device
that can be direct integrity tested
according to the criteria specified in
section IV.C.ll.a  is eligible for removal
credit as a membrane, subject to the
criteria specified  in that section. Section
IV.C.12 applies to all bag filters, as well
as to cartridge filters which cannot be
direct integrity tested.
Challenge Testing
  In order to receive 1 log removal
credit, a bag filter must have a
demonstrated  removal efficiency of 2
log or greater for Cryptosporidium.
Similarly, to receive 2 log removal
credit, a cartridge filter must have a
demonstrated  removal efficiency of 3
log or greater for Cryptosporidium. The
1 log factor of  safety is applied to the
removal credit awarded to these
filtration devices  based on two primary
considerations. First, the removal
efficiency of some bag and cartridge
filters has been observed to vary by
more than 1 log over the course of
operation (Li etal 1997, NSF 2001a,
NSF 200lb). Second, bag and cartridge
filters are not routinely direct integrity
tested during operation in the field;
hence, there is no means of verifying the
removal efficiency of filtration units
during routine use. Based on these
considerations, a  conservative approach
to awarding removal credit based on
challenge test results is warranted.
  Removal efficiency must be
demonstrated through a challenge test
conducted on the bag or cartridge filter
proposed for use in full-scale drinking
water treatment facilities for removal of
Cryptosporidium. Challenge testing is
required for specific products and is not
intended to be site specific. At the
discretion of the State, data from
challenge  studies  conducted prior to
promulgation of this regulation may be
considered in lieu of additional testing.
However, the prior testing must have
been conducted in a manner that
demonstrates a removal efficiency for
Cryptosporidium  commensurate with
the treatment credit awarded to the
process. Guidance on conducting
challenge studies  to demonstrate the
Cryptosporidium removal efficiency of
filtration units is presented in the
Membrane Filtration Guidance Manual
(USEPA 2003e). Challenge testing must

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                                                                                47707
be conducted according to the following
criteria:
  • Challenge testing must be
conducted on a full-scale filter element
identical in material and construction to
the filter elements proposed for use in
full-scale treatment facilities.
  • Challenge testing must be
conducted using Cryptosporidium
oocysts or a surrogate which is removed
no more efficiently than
Cryptosporidium oocysts. The organism
or surrogate used during challenge
testing is referred to as the challenge
particulate. The concentration of the
challenge particulate must be
determined using a method capable of
discretely quantifying the specific
organism or surrogate used in the test,
i.e., gross water quality measurements
such as turbidity cannot be used.
  • The maximum allowable feed water
concentration used  during a challenge
test is based on the detection limit of the
challenge particulate in the filtrate and
calculated using one of the following
equations.
  For bag filters:
Maximum Feed Concentration = 3.16 x
    103 x (Filtrate Detection Limit)
  For cartridge filters:
Maximum Feed Concentration = 3.16 x
    10" x (Filtrate Detection Limit)
  This will allow the demonstration of
up  to 3.5 log removal for bag filters and
4.5 log removal for cartridge filters
during challenge testing if the challenge
particulate is removed to the detection
limit.
  • Challenge testing must be
conducted at the maximum design flow
rate specified by the manufacturer.
           • Each filter must be tested for a
         duration sufficient to reach 100% of the
         terminal pressure drop, a parameter
         specified by tbe manufacturer which
         establishes the end of the useful life of
         the filter. In order to achieve terminal
         pressure drop during the test, it will be
         necessary to add particulate matter to
         the test solution, such  as fine carbon test
         dust or bentonite clay particles.
           • Each filter must be challenged with
         the challenge particulate during three
         periods over the filtration  cycle: within
         2 hours of start-up after a new bag or
         cartridge filter has been installed, when
         the pressure drop is  between 45 and
         55% of the terminal  pressure drop, and
         at the end of the run after the pressure
         drop has reached 100% of the terminal
         pressure drop.
           • Removal efficiency of a bag or
         cartridge filtration process is
         determined from the results of the
         challenge test, and expressed in terms of
         log removal values as defined by the
         following equation:
         LRV = LOGlo(Cf)-LOGio(Cp)
         where LRV - log removal value
         demonstrated during challenge testing;
         Cf = the feed concentration used during
         the challenge test; and Cp = the filtrate
         concentration observed during the
         challenge test. For this equation to be
         valid, equivalent units must be used for
         the feed and filtrate  concentrations. If
         the challenge particulate is not detected
         in the filtrate, then the term Cp is set
         equal to the detection limit. An LRV is
         calculated for each filter evaluated
         during the test.
           • In order to receive treatment credit
         for Cryptosporidium under this
                   proposed rule, challenge testing must
                   demonstrate a removal efficiency of 2
                   log or greater for bag filtration and 3 log
                   or greater for cartridge filtration. If fewer
                   than twenty filters are tested, then
                   removal efficiency of the process is set
                   equal to the lowest of the representative
                   LRVs among the various filters tested. If
                   twenty or more filters are tested, then
                   removal efficiency of the process is set
                   equal to the 10th percentile of the
                   representative LRVs among the various
                   filters tested. The percentile is defined
                   by (i/(n+l)] where i is the rank of n
                   individual data points ordered lowest to
                   highest. It may be necessary to calculate
                   the 10th percentile using linear
                   interpolation.
                      • Any significant modification to the
                   filtration unit (e.g., changes to the
                   filtration media, changes to the
                   configuration of the filtration  media,
                   significant modifications to the sealing
                   system) would require additional
                   challenge testing to demonstrate
                   removal efficiency of the modified unit.
                      b. How was this proposal developed?
                   The Stage 2 M-DBP Agreement in
                   Principle recommended that EPA
                   develop criteria for awarding
                   Cryptosporidium removal credits of 1
                   log for bag filters and 2  log for cartridge
                   filters. Today's proposal is consistent
                   with the Agreement.
                      A limited amount of published data
                   are available regarding the removal
                   efficiency of bag and cartridge filters
                   with respect to Cryptosporidium oocysts
                   or suitable surrogates. The relevant
                   studies identified in the literature are
                   summarized in Table IV-18.
    TABLE IV-18— RESULTS FROM STUDIES OF Cryptosporidium OR SURROGATE REMOVAL BY BAG AND CARTRIDGE
                                                       FILTERS
           Process
         Log removal
                                                                  Organism/surrogate
                                                                                                    Reference
Bag  and cartridge filtration in se-
  ries.
Cartridge filtration  	
Cartridge filtration  	
Cartridge filtration  	
Cartridge filtration  	
Cartridge filtration  	
Cartridge filtration  	
Prefilter and bag filter in series	
Bag filtration	
Bag filtration 	
Bag filtration 	
1.1 to 2.1
                                                            3 to 6 jim spheres
3.5 (average)
3.3 (average)
1.1 to 3.3 	
0.5 to 3.6 	
2.3 to 2.8 	
2.7 to 3.7 	
1.9 to 3.2 	
-3.0	
0.5 to 3.6
0.5 to 2.0
Cryptosporidium
Cryptosporidium
Cryptosporidium
5.7 jim spheres .
Cryptosporidium
Cryptosporidium
3.7 jim spheres .
Cryptosporidium
Cryptosporidium
4.5 jam spheres .
NSF 2001a.

Enriquez et al. 1999.
Roessler, 1998.
Schaubetal. 1993.
Long, 1983.
Ciardelli, 1996 a.
Ciardelli, 1996b.
NSF 2001b.
Cornwell and LeChevallier, 2002.
Li et al. 1997.
Goodrich et al. 1995.
  These data demonstrate highly
variable removal performance for these
processes, ranging from 0.5 log to 3.6 log
for both bag and cartridge filtration.
Results of these studies also show no
correlation between the pore size rating
established by the manufacturer and the
         removal efficiency of a filtration device.
         In a study evaluating two cartridge
         filters, both with a pore size rating of 3
         jj.m, a 2 log difference in
         Cryptosporidium oocyst removal was
         observed between the two filters
         (Schaub et al. 1993). Another study
                    evaluated seventeen cartridge filters
                    with a range of pore size ratings from 1
                    u.m to 10 jam and found no correlation
                    with removal efficiency (Long, 1983). Li
                    et al. (1997) evaluated three bag filters
                    with similar pore size ratings and
                    observed a  3 log difference in

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Federal Register/Vol.  68,  No. 154/Monday, August 11, 20Q3/Proposed Rules
Cryptosporidium oocyst removal among
them. These results indicate that bag
and cartridge filters may be capable of
achieving removal of oocysts in excess
of 3 log; however, performance can vary
significantly among products and there
appears to be no correlation between
pore size rating and removal efficiency.
  Based on available data, specific
design criteria that correlate to removal
efficiency cannot be derived for bag and
cartridge filters. Furthermore, the
removal efficiency of these proprietary
devices can be impacted by product
variability, increasing pressure drop
over the filtration cycle, flow rate, and
other operating conditions. The data in
Table IV-18 were generated from
studies performed under a variety of
operating conditions, many of which
could not be considered conservative (or
worst-case) operation. These
considerations lead to the proposed
challenge testing requirements which
are intended to establish a product-
specific removal efficiency.
  The proposed challenge testing is
product-specific and not site-specific
since the intent of this testing is to
demonstrate the removal capabilities of
the filtration device rather than evaluate
the feasibility of implementing the
technology at a specific plant. Challenge
testing must be conducted using full-
scale filter elements in order to evaluate
the performance of the entire unit,
including the filtration media, seals,
filter housing and other components
integral to the filtration system. This
will  improve the applicability of
challenge test results to full-scale
performance. Multiple filters of the
same type can be tested to provide a
better statistical basis for estimating
removal efficiency.
  Either Cryptosporidium oocysts or a
suitable surrogate could  be used as the
challenge particulate during the test.
Challenge testing with Cryptosporidium
provides direct verification of removal
efficiency; however, some studies have
demonstrated that surrogates, such as
polystyrene microspheres, can provide
an accurate or conservative measure  of
removal efficiency (Long 1983, Li et al.
1997). Furthermore, the National
Sanitation Foundation (NSF)
Environmental Technology Verification
(ETV) protocol for verification testing
for physical removal of microbiological
and particulate contaminants specifies
the use of polymeric microspheres of a
known size distribution (NSF 2002b).
Guidance on selection of an appropriate
surrogate for establishing a removal
efficiency for Cryptosporidium during
challenge testing is presented in the
Membrane Filtration Guidance Manual
(USEPA 2003e).
                        In order to demonstrate a removal
                      efficiency of at least 2 or 3 log for bag
                      or cartridge filters, respectively, it will
                      likely be necessary to seed the challenge
                      particulate into the test solution. A
                      criticism of published studies that use
                      this approach is that the seeded levels
                      are orders of magnitude higher than
                      those encountered in natural waters and
                      this could potentially lead to artificially
                      high estimates of removal efficiency. To
                      address this issue, the feed
                      concentration applied to the filter
                      during challenge studies is capped at a
                      level that will  allow the demonstration
                      of a removal efficiency up to 4.5 log for
                      cartridge filters and 3.5 log for bag filters
                      if the challenge particulate is removed
                      to the detection level.
                        The removal efficiency of some bag
                      and cartridge filtration devices has been
                     . shown to decrease over the course of a
                      filtration cycle due to the accumulation
                      of solids and resulting increase in
                      pressure drop. As an example, Li et al.
                      (1997) observed that the removal of 4.5
                      um microspheres by a bag filter
                      decreased from 3.4 log to 1.3 log over
                      the course of a filtration cycle. Studies
                      evaluating bag and cartridge filtration
                      under the NSF ETV program have also
                      shown a degradation in removal
                      efficiency over the course of the
                      filtration cycle (NSF 2001a and  2001b).
                      In order to evaluate this potential
                      variability, the challenge studies are
                      designed to assess removal efficiency
                      during three periods of a filtration cycle:
                      within two hours of startup following
                      installation  of a new filter, between 45%
                      and 55% of terminal pressure drop, and
                      at the end of the run after 100% of
                      terminal pressure drop is realized.
                        Although challenge testing can
                      provide an estimate of removal
                      efficiency for a bag or cartridge filtration
                      process, it is not feasible to conduct a
                      challenge test on every production filter.
                      This, coupled with variability within a
                      product line, could result in some
                      production filters that do not meet the
                      removal efficiency demonstrated during
                      challenge testing. For membrane
                      filtration processes, this problem is
                      addressed through the use of a quality
                      control release value established for a
                      non-destructive test, such as a bubble
                      point test or pressure hold test, that is
                      correlated to removal efficiency. Since
                      the non-destructive test can be applied
                      to all production membrane modules,
                      this provides a feasible means of
                      verifying the performance  of every
                      membrane module used by a PWS.
                      However, the non-destructive tests
                      applied to membrane filtration
                      processes cannot be applied to most bag
                      and cartridge filtration devices,  and EPA
                      is not aware of an alternative non-
destructive test that can be used with
these devices.
  Typical process monitoring for bag
and cartridge filtration systems includes
turbidity and pressure drop to
determine when filters must be
replaced. However, the applicability of
either of these  process monitoring
parameters as tools for verifying
removal of Cryptosporidium has not
been demonstrated. Only a few bag or
cartridge filtration studies have
attempted to correlate turbidity removal
with removal of Cryptosporidium
oocysts or surrogates. Li  et a/. (1997)
found that the  removal efficiency for
turbidity was consistently lower than
removal efficiency for oocysts or
microspheres for the three bag filters
evaluated. Furthermore,  none of the
filters was capable of consistently
producing a filtered water turbidity
below 0.3 NTU for the waters evaluated.
The contribution to turbidity from
particles much smaller than
Cryptosporidium oocysts, and much
smaller than the mesh size of the filter,
make it difficult to correlate removal of
turbidity with  removal of
Cryptosporidium. Consequently, EPA is
proposing a 1 log factor of safety to be
applied to challenge test results in
awarding treatment credit to bag and
cartridge filters, and is not proposing
integrity monitoring requirements for
these devices.
  c. Request for comment. EPA requests
comment on the following issues
concerning bag and cartridge filters:
  • The performance of bag and
cartridge filters in removing
Cryptosporidium through all differential
pressure ranges in a filter run—EPA
requests laboratory and field data, along
with associated quality assurance and
quality control information, that  will
support a determination of the
appropriate level of Cryptosporidium
removal credit to award  to these
technologies.
  • The performance of bag and
cartridge filters in removing
Cryptosporidium when used in series
with other bag or cartridge filters—EPA
requests laboratory and field data, along
with associated quality assurance and
quality control information, that  will
support a determination of the
appropriate level of Cryptosporidium
removal credit to award  to these
technologies when used in series.
  • Appropriate surrogates, or the
characteristics of appropriate surrogates,
for use in challenge testing bag and
cartridge filters—EPA requests data or
information demonstrating the
correlation between removal of a
proposed surrogate and removal of
Cryptosporidium oocysts.

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                                                                     47709
  • The availability of non-destructive
tests that can be applied to bag and
cartridge filters to verify the removal
efficiency of production filters that are
not directly challenge tested—EPA
requests data or information
demonstrating the correlation between a
proposed non-destructive test and the
removal of Cryptosporidium oocysts.
  • The applicability of pressure drop
monitoring, filtrate turbidity
monitoring, or other process monitoring
and process control procedures to verify
the integrity of bag and cartridge
filters—EPA requests data or
information demonstrating the
correlation between a proposed process
monitoring tool and the removal of
Cryptosporidium oocysts.
  • The applicability of bag and
cartridge filters to different source water
types and treatment scenarios.
  • The applicability of the proposed
Cryptosporidium removal credits and
testing criteria to Giardia lamblia.
  • The use of a 1 log factor of safety
for awarding credit to bag and cartridge
filters—EPA requests comment on
whether this is an appropriate factor of
safety to account for the inability to
conduct integrity monitoring of these
devices, as well as the variability in
removal efficiency observed over the
course of a filtration cycle for some
filtration devices. This inability creates
uncertainty regarding both changes in
the performance of a given filter during
use and variability in performance
among filters in a  given product line. If
the 1 log factor of safety is higher than
necessary to account  for these factors,
should the Agency establish a lower
value, such as  a 0.5 log factor of safety?

13. Secondary Filtration
  a. What is EPA proposing today?
Today's proposal allows systems using
a second filtration stage to receive an
additional 0.5 log Cryptosporidium
removal credit. To be eligible for this
credit, the secondary filtration must
consist of rapid sand,  dual media,
granular activated carbon (GAG), or
other fine grain media in a separate
stage following rapid sand or dual
media filtration. A cap, such  as GAG, on
a single stage of filtration will not
qualify for this credit. In addition, the
first stage of filtration must be preceded
by a coagulation step, and both stages
must treat 100% of the flow.
  b. How was this proposal developed?
Although not addressed in the
Agreement in Principle, EPA has
determined that secondary filtration
meeting the criteria described in this
section will achieve additional removal
of Cryptosporidium oocysts.
Consequently,  additional removal credit
may be appropriate. As reported in
section III.D, many studies have shown
that rapid sand filtration preceded by
coagulation can achieve significant
removal of Cryptosporidium (Patania et
al 1995, Nieminski and Ongerth 1995,
Ongerth and Pecoraro 1995,
LeChevallier and Norton 1992,
LeChevallier et al. 1991, Dugan et al
2001, Nieminski and Bellamy 2000,
McTigue et al 1998, Patania et al.  1999,
Huck et al. 2000, Emelko et al 2000).
While these studies evaluated only a
single stage of filtration, the same
mechanisms of removal are expected to
occur in a second stage of granular
media filtration.
  EPA received data from the City of
Cincinnati, OH, on the removal of
aerobic spores through  a conventional
treatment facility that employs GAG
contactors for DBF, taste, and odor
control after rapid sand filtration. As
described previously, a number of
studies (Dugan et al. 2001, Emelko et al
1999 and 2000, Yates et al 1998,
Mazounie et al 2000} have
demonstrated that aerobic spores are a
conservative indicator of
Cryptosporidium removal by granular
media filtration when preceded by
coagulation.
  During the period of 1999 and 2000,
the mean values of reported spore
concentrations in the influent and
effluent of the Cincinnati GAG
contactors were 35.7 and 6.4 cfu/100
mL, respectively, indicating an average
removal of 0.75 log across the
contactors. Approximately 16% of the
GAG filtered water results were below
detection  limit (1 cfu/100 mL) so the
actual log spore removal may have been
greater than indicated by these results.
  In summary, studies in the cited
literature demonstrate that a fine
granular media filter preceded by
coagulation can achieve high levels of
Cryptosporidium removal. Data on
increased removal resulting from a
second stage of filtration are limited,
and there  is uncertainty regarding how
effective a second stage of filtration will
be in reducing levels of microbial
pathogens that are not removed by the
first stage of filtration. However, EPA
has concluded that a secondary
filtration process can achieve 0.5 log or
greater removal of Cryptosporidium
based on (l) the theoretical
consideration that the same mechanisms
of pathogen removal will be operative in
both a primary and secondary filtration
stage, and (2) data from the City of
Cincinnati showing aerobic spore
removal in GAG contactors following
rapid  sand filtration. Therefore, EPA
believes it is appropriate to propose 0.5
log additional  Cryptosporidium
treatment credit for systems using
secondary filtration which meets the
criteria of this section.
  c. Request for comment. The Agency
requests comment on awarding a 0.5 log
Cryptosporidium removal credit for
systems using secondary filtration,
including the design and operational
criteria required to receive the log
removal credit. EPA specifically
requests comment on the following
issues:
  • Should there be a minimum
required  depth for the secondary filter
(e.g., 24 inches) in order for the system
to receive credit?
  • Should systems be eligible to
receive additional Cryptosporidium
treatment credit within the microbial
toolbox for both a second clarification
stage (e.g., secondary filtration, second
stage sedimentation) and lower finished
water turbidity, given that additional
particle removal achieved by the second
clarification stage will reduce finished
water turbidity?
14. Ozone and Chlorine Dioxide
  a. What is EPA proposing today?
Similar to the methodology used for
estimating log inactivation of Giardia
lamblia by various chemical
disinfectants in 40 CFR 141.74, EPA is
proposing the CT concept for estimating
log inactivation of  Cryptosporidium by
chlorine  dioxide or ozone. In today's
proposal, systems must determine the
total inactivation of Cryptosporidium
each day the system is in operation,
based on the CT values in Table IV-19
for ozone and Table IV-20 for chlorine
dioxide.  The parameters necessary to
determine the total inactivation of
Cryptosporidium must be  monitored as
stated in 40 CFR 141.74(b)(3)(i), (iii),
and (iv),  which is as follows:
  * The  temperature of the disinfected
water must be measured at least once
per day at each residual disinfectant
concentration sampling point.
  • The  disinfectant contact time(s)
("T") must be determined for each day
during peak hourly flow.
  • The  residual disinfectant
concentration(s) ("C") of the water
before or at the first customer must be
measured each day during peak hourly
flow.
  Systems may have several
disinfection segments (the segment is
defined as a treatment unit process with
a measurable disinfectant residual level
and a liquid volume) in sequence along
the treatment train. In determining the
total log  inactivation, the system may
calculate the log inactivation for each
disinfection segment and use the sum of
the log inactivation estimates of
Cryptosporidium achieved through the

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plant. The Toolbox Guidance Manual,
available in draft with today's proposal,
provides guidance on methodologies for
                       determining CT values and estimating
                       log inactivation for different
disinfection reactor designs and
operations.
                      TABLE IV-19 — CT VALUES FOR Cryptosporidium INACTIVATION BY OZONE
Log credit
0 5 	
1 o 	
1 5 	 	 	
2 0 	
2 5 	
3.0 	
Water Temperature, °C 1
<=0.5
12
24
36
48
60
72
1
12
23
35
46
58
69
2
10
21
31
42
52
63
3
9.5
19
29
38
48
57
5
7.9
16
24
32
40
47
7
6.5
13
20
26
33
39
10
4.9
9.9
15
20
25
30
15
3.1
6.2
9.3
12
16
19
20
2.0
3.9
5.9
7.8
9.8
12
25
1.2
2.5
3.7
4.9
6.2
7.4
  1 CT values between the indicated temperatures may be determined by interpolation.

                 TABLE  IV-20 — CT VALUES FOR Cryptosporidium INACTIVATION BY CHLORINE DIOXIDE
Log credit
0 5 	
1 o 	
1 5 	
2 0 	
2 5 	
3.0 	
Water Temperature, °C 1
<=0.5
319
637
956
1275
1594
1912
1
305
610
915
1220
1525
1830
2
279
558
838
1117
1396
1675
3
256
511
767
1023
1278
1534
5
214
429
643
858
1072
1286
7
180
360
539
719
899
1079
10
138
277
415
553
691
830
15
89
179
268
357
447
536
20
58
116
174
232
289
347
25
38
75
113
150
188
226
  1 CT values between the indicated temperatures may be determined by interpolation.
  The system may demonstrate to the
State, through the use of a State-
approved protocol for on-site
disinfection challenge studies or other
information satisfactory to the State,
that CT values other than those
specified in Tables IV-19 or IV-20 are
adequate to demonstrate that the system
is achieving the required log
inactivation of Cryptosporidium.
Protocols for making such
demonstrations are available in the
Toolbox Guidance Manual.
  b. How was this proposal  developed?
EPA relied in part on analyses by Clark
et al (2002a and 2002b) to develop the
CT values for ozone and chlorine
dioxide inactivation of Cryptosporidium
in today's proposal. Clark et al. (2002a)
used data from studies of ozone
inactivation of Cryptosporidium in
laboratory water to develop  predictive
equations for estimating inactivation
(Rennecker et al. 1999, Li et al. 2001)
and data from studies in natural water
to validate the equations (Owens et al.
2000, Oppenheimer et al 2000). For
chlorine dioxide, Clark et al. (2002b)
employed data from Li et al. (2001) to
develop equations for predicting
inactivation, and used data from Owens
et al. (1999) and Ruffell et al. (2000) to
validate the equations.
  Another step in developing the CT
values for Cryptosporidium  inactivation
in today's proposal involved
consideration of the appropriate
                      confidence bound to apply when
                      analyzing the inactivation data. A
                      confidence bound represents a safety
                      margin that accounts for variability and
                      uncertainty in the data that underlie the
                      analysis. Confidence bounds are
                      intended to provide a high likelihood
                      that systems operating at a given CT
                      value will achieve at least the
                      corresponding log inactivation level in
                      the CT table.
                        Two types of confidence bounds that
                      are used when assessing relationships
                      between variables, such as disinfectant
                      dose (CT) and log inactivation, are
                      confidence in the regression and
                      confidence in the prediction.
                      Confidence in the regression accounts
                      for uncertainty in the regression line
                      (e.g., a linear relationship between
                      temperature and the log of the ratio of
                      CT to log inactivation). Confidence in
                      the prediction accounts for both
                      uncertainty in the regression line and
                      variability in experimental
                      observations—it  describes the
                      likelihood of a single future data point
                      falling within a range. Bounds for
                      confidence in prediction are wider (i.e.,
                      more conservative) than those for
                      confidence in the regression. Depending
                      on the degree of confidence applied,
                      most points in a data set typically will
                      fall within the bounds for confidence in
                      the prediction, while a significant
                      fraction  will fall outside the bounds for
                      confidence in the regression.
  In developing earlier CT tables, EPA
has used bounds for confidence in the
prediction. This was a conservative
approach that was taken with
consideration of the limited inactivation
data that were available and that
reasonably ensured systems would
achieve the required inactivation level.
The November 2001 draft of the
LT2ESWTR included CT tables for
Cryptosporidium inactivation by ozone
and chlorine  dioxide that were derived
using confidence in prediction (USEPA
2001g). However, based on comments
received on those draft tables, along
with further analyses described next,
EPA has revised this approach in
today's proposal.
  The underlying Cryptosporidium
inactivation data used to develop the CT
tables exhibit significant variability.
This variability is due to both
experimental error and potential true
variability in  the inactivation rate.
Experimental error is associated with
the assays used to measure loss of
infectivity, measurement of the
disinfectant concentration, differences
in technique among researchers, and
other factors.  True variability in the
inactivation rate would be associated
with variability in resistance to the
disinfectant between different
populations of oocysts and variability in
the effect of water matrix on the
inactivation process.

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                                                                      47711
   In considering the appropriate
 confidence bounds to use for developing
 the CT tables in today's proposal, EPA
 was primarily concerned with
 accounting for uncertainty in the
 regression and for true variability in the
 inactivation rate. Variability associated
 with experimental error was a lessor
 concern, as the purpose of the CT tables
 is to ensure a given level of inactivation
 and not  predict the measured result of
 an individual experiment.
   Because confidence in the prediction
 accounts for all variability in the data
 sets (both true variability and
 experimental error), it may provide a
 higher margin of safety than is
 necessary. Nevertheless, in other
 disinfection applications, the use of
 confidence in the prediction may be
 appropriate, given limited data sets and
 uncertainty in the source of the
 variability. However, the high doses of
 ozone and chlorine dioxide that are
 needed to inactivate Cryptosporidium
 create an offsetting concern with the
 formation of DBFs (e.g., bromate and
 chlorite). In consideration of these
 factors and the statutory provision for
 balancing risks among contaminants,
 EPA attempted to exclude experimental
 error from  the confidence bound when
 developing the CT tables in today's
 proposal (i.e., used a less conservative
 approach than confidence in the
 prediction).
  In order to select confidence bounds
 reflecting potential true variability
 between different oocyst populations
 (lots) but not variability due to
 measurement and experimental
 imprecision, it was necessary to
 estimate the relative contributions of
 these variance components. This was
 done by first separating inactivation
 data points into groups having the same
 Cryptosporidium oocyst lot and
 experimental conditions (e.g., water
 matrix, pH, temperature). Next, the
 variance within each group was
 determined. It was assumed that this
 within-group variance could be
 attributed entirely to experimental error,
 as neither of the factors expected to
 account for true variability in the
 inactivation rate  (i.e., oocyst lot or water
 matrix) changed within a group. Finally,
 comparing  the average within-group
variance  to the total variance in a data
 set provided an indication of the
fraction of total variance that was due to
 experimental error (see Sivaganesan
 2003 and Messner 2003 for details).
  In carrying out this analysis on the Li
et a], (2001) and Rennecker et al (1999)
data sets  for ozone inactivation of
Cryptosporidium, EPA estimated that
87.5%  of the total variance could be
attributed to experimental error
 (Sivaganesan 2003). A similar analysis
 done by Najm et al (2002) on the
 Oppenheimer et al. (2000) data set for
 ozone produced an estimate of 89% of
 the total variance due to experimental
 error. For chlorine  dioxide inactivation
 of Cryptosporidium, EPA estimated that
 62% of the total variance in the Li et al.
 (2001) and Ruffle et al (1999) data sets
 could be attributed to experimental
 error (Messner 2003). The different
 fractions attributed to experimental
 error between the chlorine dioxide and
 ozone data sets presumably relates to
 the use of different experimental
 techniques (e.g., infectivity assays).
   EPA employed estimates of the
 fraction of variance not attributable to
 experimental error  (12.5% for ozone  and
 38% for chlorine dioxide) in a modified
 form of the equation used to calculate a
 bound for confidence in prediction
 (Messner 2003). These were applied to
 the regression equations developed by
 Clark et al (2002a and 2002b) in order
 to estimate CT values for an upper 90%
 confidence bound (Sivaganesan 2003,
 Messner 2003). These are the CT values
 shown in Tables IV-19 and IV-20 for
 ozone and chlorine dioxide,
 respectively.
   Since the available data are not
 sufficient to support the CT calculation
 for an inactivation level greater than  3
 log, the use of Tables IV-19 and IV-20
 is limited to inactivation less than or
 equal to 3 log. In addition, the
 temperature limitation for these tables is
 1 to 25 °C. If the water temperature is
 higher than 25 °C, temperature should  .
 be set to 25 °C for the log inactivation
 calcuiation.
  EPA recognizes that inactivation rates
 may be sensitive to  water quality and
 operational conditions in the plant. To
 reflect this potential, systems are given
 the option to perform a site specific
 inactivation study to determine CT
 requirements. The State must approve
 the protocols or other information used
 to derive alternative CT values.
 However, EPA has provided guidance
 for systems in making such
 demonstrations in the Toolbox
 Guidance Manual.
  During meetings of the Stage 2 M-DBP
 Advisory Committee, CT values were
 used in the model for impact analysis of
 different regulatory  options (the model
 Surface Water Analytical Tool (SWAT),
 as described in Economic Analysis for
the LT2ESWTR, USEPA 2003a). Those
 preliminary CT values were based on a
subset of the data from the Li et al
 (2001) study with laboratory waters and
were adjusted with a factor to match the
mean CT values derived from the
Oppenheimer et al (2000) study with
natural waters. In comparison, the CT
 values in today's proposal are higher.
 However, the current CT values are
 based on larger data sets and more
 comprehensive analyses. Consequently,
 they provide more confidence in
 estimates of Cryptosporidium log
 inactivation than the preliminary
 estimates used in earlier SWAT
 modeling. EPA has subsequently re-run
 analyses for LT2ESWTR impact
 assessments with the updated CT  values
 (USEPA 2003a).
   c. Request for comments. EPA
 requests comment on the proposed
 approach to awarding credit for
 inactivation of Cryptosporidium by
 chlorine dioxide and ozone, including
 the following specific issues:
   •  Determination of CT and the
 confidence  bounds used for estimating
 log inactivation of Cryptosporidium;
   •  The ability of systems to apply
 these CT tables in consideration of the
 MCLs for bromate and chlorite; and
   •  Any additional data that may be
 used to confirm or refine the proposed
 CT tables.

 15. Ultra violet Light
   a. What is EPA proposing today? EPA
 is proposing criteria for awarding  credit
 to ultraviolet (UV)  disinfection
 processes for inactivation of
 Cryptosporidium, Giardia lamblia, and
 viruses. The inactivation credit a system
 can receive  for each target pathogen is
 based on the UV dose applied by the
 system in relation to the UV dose
 requirements in this section (see Table
 IV-21).
  To receive UV disinfection credit, a
 system must demonstrate a UV dose
 using the results of a UV reactor
 validation test and ongoing monitoring.
 The reactor  validation test establishes
 the operating conditions under which a
 reactor can deliver a required UV dose.
 Monitoring is used to demonstrate that
 the system maintains these validated
 operating conditions during routine use.
  UV dose (fluence) is defined as the
 product of the UV intensity over a
 surface area {fluence rate) and the
 exposure time. In practice, UV reactors
 deliver a distribution of doses due to
 variation in  light intensity and flow
 path as particles pass through the
 reactor. However, for the purpose of
 determining compliance with the dose
requirements in Table IV-21, UV dose
must be assigned to a reactor based on
the degree of inactivation of a
microorganism achieved during a
reactor validation test. This  assigned UV
 dose is determined through  comparing
the reactor validation test results with a
known dose-response relationship for
the test microorganism. The State may

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                Federal  Register/Vol. 68. No.  154/Monday, August 11.  2003 / Proposed Rules
designate an alternative basis for
awarding UV disinfection credit.
  EPA is developing the UV
Disinfection Guidance Manual (USEPA
2003d) to assist systems and States with
implementing UV disinfection,
including validation testing of UV
reactors. This guidance is available in
draft in the docket for today's proposal
(h ftp ://www. epa.gov/edocket/).
UV Dose Tables

  Table IV-21 shows the UV doses that
systems must apply to receive credit for
up to 3 log inactivation of
Cryptosporidium and Giardia lamblia
and up to 4 log inactivation of viruses.
These dose values are for UV light at a
wavelength of 254 nm as delivered by
a low pressure mercury vapor lamp.
However, the dose values can be
applied to other UV lamp types (e.g.,
medium pressure mercury vapor lamps)
through reactor validation testing, such
as is described in the draft UV
Disinfection Guidance Manual (USEPA
2003d). In addition, the dose values in
Table IV-21 are intended for post-filter
application of UV in filtration plants
and for systems that meet the filtration
avoidance criteria in 40 CFR 141.71.
BILLING CODE 656&-50-P
       Table IV-21.-  UV Dose Requirements for Cryptosporidium,  Giardia lamblia, and
       Virus Inactivation Credit
Log credit
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Cryptosporidium
UV dose (mJ/cm2)
1.6
2.5
3.9
5.8
8.5
12
NA
NA
Giardia lamblia
UV dose (m J/cm2)
1.5
2.1
3.0
5.2
7.7
11
NA
NA
Virus
UV dose (mJ/cm2)
39
58
79
100
121
143
163
186
 BILLING CODE 6560-50-C

 Reactor Validation Testing
   For a system to receive UV
 disinfection credit, the UV reactor type
 used by the system must undergo
 validation testing to demonstrate the
 operating conditions under which the
 reactor can deliver the required UV
 dose. Unless the State approves an
 alternative approach, this testing must
 involve the following: (1) Full scale
 testing of a reactor that conforms
 uniformly to the UV reactors used by
 the system and (2) inactivation of a test
 microorganism whose dose response
 characteristics have been quantified
 with a low pressure mercury vapor
 lamp.
   Validation testing must determine a
 set of operating conditions that can be
 monitored by the  system to ensure that
 the required UV dose is delivered under
 the range of operating conditions
 applicable to the system. At a minimum,
 these operating conditions must include
 flow rate, UV intensity as measured by
 a UV sensor, and UV lamp status. The
 validated operating conditions
 determined by testing must account for
 the following factors: (1) UV absorbance
 of the water, (2) lamp fouling and aging,
 (3) measurement uncertainty of on-line
 sensors, (4) dose distributions arising
 from the velocity profiles through the
 reactor, (5) failure of UV lamps or other
 critical system components, and (6)
 inlet and outlet piping or channel
 configurations of the UV reactor. In the
 draft UV Disinfection Guidance Manual
 (USEPA 2003d), EPA describes testing
 protocols for reactor validation that are
 intended to meet these criteria.
 Reactor Monitoring
   Systems must monitor for parameters
 necessary to demonstrate compliance
 with the operating conditions that  were
 validated for the required UV dose. At
 a minimum systems must monitor for
 UV intensity as measured by a UV
 sensor, flow rate, and lamp outage. As
 part of this, systems must check the
 calibration of UV sensors and recalibrate
 in accordance with a protocol approved
 by the State.
    b. How was this proposal developed?
 UV disinfection is a physical process
 relying on the transference of
 electromagnetic energy from a source
 (lamp) to an organism's cellular material
 (USEPA  1986). In the Stage 2 M-DBP
 Agreement in Principle, the Advisory
 Committee recommended that EPA
 determine the UV doses needed to
 achieve up to 3 log inactivation of
 Giardia lamblia and Cryptosporidium
 and up to 4 log inactivation of viruses.
    The Agreement further recommends
 that EPA develop standards to
 determine if UV systems are acceptable
 for compliance with drinking water
 disinfection requirements, including (1)
 a validation protocol for drinking water
 applications of UV technology and (2)
  on-site monitoring requirements to
  ensure ongoing compliance with UV
  dose tables. EPA also agreed to develop
  a UV guidance manual to facilitate
  design and operation of UV
  installations. Today's proposal and

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                                                                     47713
accompanying guidance for UV are
consistent with the Agreement.

UV Dose Tables
  The UV dose values in Table IV-21
are based on meta-analyses of UV
inactivation studies with
Cryptosporidium parvum, Giardia
lamblia, Giardia muris, and adenovirus
(Qian et al, 2003, USEPA 2003d).
Proposed UV doses for inactivation of
viruses are based on the dose-response
of adenovirus because, among viruses
that have been studied, it appears to be
the most UV resistant and is a
widespread waterborne pathogen
(health effects of adenovirus are
described in Embrey 1999).
  The data supporting the dose values
in Table IV-21 are from.bench-scale
studies using low pressure mercury
vapor lamps. These data were chosen
because the experimental conditions
allow UV dose to be accurately
quantified. Low pressure lamps emit
light primarily at a single wavelength
(254 nm) within the germicidal range of
200-300 nm. However, as noted earlier,
these dose tables can be applied to
reactors with  other lamp types through
reactor challenge testing, as described in
the draft guidance manual. Bench scale
studies are preferable for determining
pathogen dose-response characteristics,
due to the uniform dose distribution.
  The data sets and statistical
evaluation that were used to develop the
UV dose table for Cryptosporidium,
Giardia lamblia, and viruses are
described in the draft UV Disinfection
Guidance Manual (USEPA 2003d) and
Qianef al. 2003.
Reactor Validation Testing
  Today's proposal requires testing of
full-scale UV reactors because of the
difficulty in predicting reactor
disinfection performance based on
modeled results or on the results of
testing at a reduced scale. All flow-
through UV reactors deliver a
distribution of doses due to variation in
light intensity within the reactor and the
different flow paths of particles passing
through the reactor. Moreover, the
reactor dose distribution varies
temporally due to processes like lamp
aging and fouling, changes in UV
absorbance of the water, and
fluctuations in flow rate. Consequently,
it is more reliable to evaluate reactor
performance through a full scale test
under conditions that can be
characterized as "worst case" for a given
application. Such conditions include
maximum and minimum flow rate and
reduced light intensity within the
reactor that accounts for lamp aging,
fouling, and UV absorbance  of the
water. Protocols for reactor validation
testing are presented in the draft UV
guidance manual.
  c. Request for comment. The Agency
requests comment on whether the
criteria  described in this section for
awarding treatment credit for UV
disinfection are appropriate, and
whether additional criteria, or more
specific criteria, should be included.
16. Individual Filter Performance
  a. What is EPA proposing today? EPA
is proposing an additional 1.0 log
Cryptosporidium treatment credit for
systems that achieve individual filter
performance consistent with the goals
established for the Partnership for Safe
Water Phase IV in August 2001 (AWWA
etal.  2001). Specifically,  systems must
demonstrate ongoing compliance with
the following turbidity criteria, based on
continuous monitoring of turbidity for
each individual filter as required under
40 CFR  141.174 or 141.560, as
applicable:
  (1) Filtered water turbidity less than 0.1
NTU in at least 95% of the maximum daily
values recorded at each filter in each month,
excluding the 15 minute period following
backwashes, and
  (2) No individual filter with a measured
turbidity level of greater than 0.3 NTU in two
consecutive measurements taken 15 minutes
apart.
  Note that today's proposal does not
include a required peer review step as
a condition for receiving additional
credit. Rather, EPA is proposing to
award additional credit to systems that
meet the performance goals of a peer
review program (Phase IV). Systems that
receive  the 1 log additional treatment
credit for individual filter performance,
as described in this section, cannot also
receive  an additional 0.5  log additional
credit for lower finished water turbidity
as described in section IV.C.8.
  b. How was this proposal developed?
In the Stage 2 M-DBP Agreement in
Principle, the Advisory Committee
recommended a peer review program as
a microbial toolbox component that
should receive a 1.0 log
Cryptosporidium treatment credit. The
Committee specified Phase IV of the
Partnership for Safe Water (Partnership)
as an  example of the type of peer review
program where a 1.0 log credit would be
appropriate.
  The Partnership is a voluntary
cooperative program involving EPA, the
Association of Metropolitan Water
Agencies (AMWA), the American Water
Works Association (AWWA), the
National Association of Water
Companies (NAWC), the Association of
State Drinking Water Administrators
(ASDWA), the American Water Works
Association Research Foundation
(AWWARFJ, and surface water utilities
throughout the United States. The intent
of the Partnership is to increase
protection against microbial
contaminants by optimizing treatment
plant performance.
  At the time of the Advisory
Committee recommendation, Phase IV
was under development by the
Partnership. It was to be based on
Composite Correction Program (CCP)
(USEPA 1991) procedures and
performance goals, and was to be
awarded based on an on-site evaluation
by a third-party team. The performance
goals for Phase IV were such that, over
a year, each sedimentation basin and
each filter would need to  produce
specified turbidity levels based on the
maximum of all the values recorded
during the day.  Sedimentation
performance goals were set at 2.0 NTU
if the raw water was greater than 10
NTU on an annual basis and  1.0 NTU
if the raw water was less than 10 NTU.
Each filter was to meet 0.1 NTU 95% of
the time except for the 15 minute period
following placing the filter in operation.
In addition, filters were expected to
have maximum turbidity  of 0.3 NTU
and return to less than 0.1 NTU  within
15 minutes of the filter being placed in
service.
  The primary purpose of the on-site
evaluation was to confirm that the
performance of the plant was consistent
with Phase IV performance goals and
that the system had the administrative
support and operational capabilities to
sustain the performance long-term. The
on-site evaluation in Phase IV also
allowed utilities that could not meet the
desired performance goals to
demonstrate to the third-party that they
had achieved the highest  level of
performance given their unique  raw
water quality.
  After the signing of the Stage 2 M-
DBP Agreement in Principle in
September 2000, the Partnership
decided to eliminate the on-site third-
party evaluation as a component of
Phase IV. Instead, the requirement for
Phase IV is for the water system to
complete an application package that
will be reviewed by trained utility
volunteers. Included in the application
package is an Optimization Assessment
Spreadsheet in which the system enters
water quality and treatment data to
demonstrate that Phase IV performance
levels have been achieved. The
application also requires narratives
related to administrative support and
operational capabilities to sustain
performance long-term.
  Today's proposal is consistent with
the performance goals of Phase IV.

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Federal  Register/Vol. 68, No.  154/Monday, August 11, 2003/Proposed Rules
Rather than require systems to complete
an application package with historical
data and narratives, the LT2ESWTR
requires systems to demonstrate to the
State that they meet the individual filter
performance goals of Phase IV on an
ongoing basis to receive the 1.0 log
additional Cryptosporidium treatment
credit. EPA is not requiring systems to
demonstrate that they meet
sedimentation performance goals of
Phase W. While EPA recognizes that
settled water turbidity is an important
operational performance measure for a
plant, the Agency does not have data
directly relating it to finished  water
quality and pathogen risk.
  The November 2001 pre-proposal
draft of the LT2ESWTR described a
potential 1.0 log credit for systems that
achieved individual filter effluent (IFE)
turbidity below 0.15 NTU in 95 percent
of samples [USEPA 2001g). The Science
Advisory Board (SAB) subsequently
reviewed this credit and supporting data
on the relationship between filter
effluent turbidity and  Cryptosporidium
removal efficiency (described  in section
IV.G.8). In written comments from a
December 2001 meeting of the Drinking
Water Committee, an SAB panel
recommended only a 0.5 log credit for
95th percentile IFE turbidity below 0.15
NTU.
  To address this recommendation from
the SAB, EPA is proposing that systems
meet the individual filter performance
criteria of Phase IV of the Partnership  in
order to be eligible for a 1.0 log
additional Cryptosporidium treatment
credit.  This proposed approach
responds to the concerns raised by the
SAB because the Phase IV criteria are
more stringent than those in the 2001
pre-proposal draft of the LT2ESWTR.
For example, today's proposal sets a
maximum limit on individual  filter
effluent turbidity of 0.3 NTU, whereas
no such upper limit was described in
the 2001 pre-proposal  draft.
  In summary, EPA has concluded that
it is appropriate to award additional
Cryptosporidium treatment credit for
systems meeting stringent individual
filter performance standards. Modestly
elevated turbidity from a single filter
may not significantly impact combined
filter effluent turbidity levels, which are
regulated under IESWTR and
LT1ESWTR, but may indicate a
substantial reduction in the overall
pathogen removal efficiency of the
filtration process. Consequently,
systems that continually achieve very
low turbidity in each individual filter
are likely to provide a significantly more
effective microbial barrier. EPA expects
that systems that select this toolbox
option will have achieved a high level
                      of treatment process optimization and
                      process control, and will have both a
                      history of consistent performance over a
                      range of raw water quality conditions
                      and the capability and resources to
                      maintain this performance long-term.
                        c. Request for comment. The Agency
                      invites comment on the following issues
                      related to the proposed credit for
                      individual filter performance.
                        • Are there different or additional
                      performance measures that a utility
                      should be required to meet for the 1 log
                      additional credit?
                        • Are there existing peer review
                      programs for which treatment credit
                      should be awarded under the
                      LT2ESWTR? If so, what role should
                      primacy agencies play in establishing
                      and managing any such peer review
                      program?
                        • The individual filter effluent
                      turbidity criterion of 0.1 NTU is
                      proposed because it is consistent with
                      Phase IV Partnership standards, as
                      based on CCP goals. However, with
                      allowable rounding, turbidity levels less
                      than 0.15 NTU are in compliance with
                      a standard of 0.1. Consequently, EPA
                      requests comment on  whether 0.15 NTU
                      should be the standard for individual
                      filter performance credit, as this would
                      be consistent with the standard of 0.15
                      NTU that is proposed  for combined
                      filter performance credit in section
                      IV.C.8.
                      17. Other Demonstration of Performance
                        a. What is EPA proposing today? The
                      purpose of the "demonstration of
                      performance" toolbox component is to
                      allow a system to demonstrate that a
                      plant, or a unit process within a plant,
                      should receive a higher
                      Cryptosporidium treatment credit than
                      is presumptively awarded  under the
                      LT2ESWTR. For example,  as described
                      in section IV.A, plants using
                      conventional treatment receive a
                      presumptive 3 log credit towards the
                      Cryptosporidium treatment
                      requirements in Bins 2-4 of the
                      LT2ESWTR. This credit is  based on a
                      determination by EPA that conventional
                      treatment plants achieve an average
                      Cryptosporidium removal of 3 log when
                      in compliance with the IESWTR or
                      LT1ESWTR. However, EPA recognizes
                      that some conventional treatment plants
                      may achieve average Cryptosporidium
                      removal efficiencies greater than 3 log.
                      Similarly, some systems may achieve
                      Cryptosporidium reductions with
                      certain toolbox components that are
                      greater than the presumptive credits
                      awarded under the LT2ESWTR, as
                      described in this section (IV.C).
                       Where a system can demonstrate that
                      a plant, or a unit process within a plant,
achieves a Cryptosporidium reduction
efficiency greater than the presumptive
credit specified in the LT2ESWTR, it
may be appropriate for the system to
receive a higher Cryptosporidium
treatment credit. Today's proposal does
not include specific protocols for
systems to make such a demonstration,
due to the potentially complex and site
specific nature of the testing that would
be required. Rather, today's  proposal
allows a State to award a higher level of
Cryptosporidium treatment credit to a
system where the State determines,
based on site-specific testing with a
State-approved protocol, that a
treatment plant or a unit process within
a plant reliably achieves a higher level
of Cryptosporidium removal on a
continuing basis. Also, States may
award a lower level of Cryptosporidium
treatment credit to a system where a
State determines, based on site specific
information, that a plant or a unit
process within a plant achieves a
Cryptosporidium removal efficiency less
than a presumptive credit specified in
the LT2ESWTR.
  Systems receiving additional
Cryptosporidium treatment credit
through a demonstration of performance
may be required by the State to report
operational data on a monthly basis to
establish that conditions under which
demonstration of performance credit
was awarded are maintained during
routine operation. The Toolbox
Guidance Manual (USEPA 2003f) will
describe potential approaches to
demonstration of performance testing.
This guidance is available in draft in the
docket for today's proposal (http://
www.epa.gov/edocket/).
  Note that as described in section IV.C,
today's proposal allows treatment plants
to achieve additional Cryptosporidium
treatment credit through meeting the
design and/or operational criteria of
microbial toolbox components, such as
combined and individual filter
performance, presedimentation, bank
filtration, two-stage softening, secondary
filtration, etc. Plants that receive
additional Cryptosporidium treatment
credit through a demonstration of
performance are not also eligible for the
presumptive credit associated with
microbial toolbox  components if the
additional removal due to the toolbox
component is captured in the
demonstration of performance credit.
For example, if a plant receives a
demonstration of performance credit
based on removal of Cryptosporidium or
an indicator while operating under
conditions of lower finished water
turbidity, the plant may not  also receive
additional presumptive credit for lower

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                  Federal  Register/Vol. 68, No.  154/Monday,  August  11,  2003/Proposed Rules
                                                                      47715
  finished water turbidity toolbox
  components.
   This demonstration of performance
  credit does not apply to the use of
  chlorine dioxide, ozone, or UV light,
  because today's proposal includes
  specific provisions allowing the State to
  modify the standards for awarding
  disinfection credit to these technologies.
  As described in section IV.C.14, States
  can approve site-specific CT values for
  inactivation of Cryptosporidium by
  chlorine dioxide and ozone; as
  described in section IV.C.15, States can
  approve an alternative approach for
  validating the performance of UV
 reactors.
   b. How was this proposal developed?
 The Stage 2 M-DBP Agreement in
 Principle recommends demonstration of
 performance as a process for systems to
 receive Cryptosporidium treatment
 credit higher than the presumptive
 credit for many microbial toolbox
 components, as well as credit for
 technologies not listed in the toolbox.
 EPA is aware that there may be plants
 where particular unit processes, or
 combinations of unit processes, achieve
 greater Cryptosporidium removal than
 the presumptive credit awarded under
 the LT2ESWTR. In addition, the Agency
 would like to allow for the use of
 Cryptosporidium treatment processes
 not addressed in the LT2ESWTR, where
 such processes can demonstrate a
 reliable specific !og removal. Due to
 these factors, EPA is proposing a
 demonstration of performance
 component in the microbial toolbox,
 consistent with the Advisory Committee
 recommen dation.
   The Agreement in Principle makes no
 recommendations for how a
 demonstration of performance should be
 conducted. It is generally not practical
 for systems to directly quantify high log
 removal of Cryptosporidium in
 treatment plants because of the
 relatively low occurrence of
 Cryptosporidium in many raw water
 sources and limitations with analytical
 methods. Consequently, if systems are
 to demonstrate the performance of full
 scale plants in removing
 Cryptosporidium, this typically will
 require the use of indicators, where the
 removal of the indicator has been
 correlated with the removal  of
 Cryptosporidium. As described
 previously, a number of studies have
 shown that aerobic spores are an
 indicator of Cryptosporidium removal
by sedimentation and filtration (Dugan
 et al 2001, Emelko et al 1999 and 2000,
Yates et al 1998, Mazounie et al. 2000).
  The nature of demonstration of
performance testing that will be
appropriate at a given facility will
  depend on site specific factors, such as
  water quality, the particular process(es)
  being evaluated, resources and '
  infrastructure, and the discretion of the
  State. Consequently, EPA is not
  proposing specific criteria for
  demonstration of performance testing.
  Instead, systems must develop a testing
  protocol that is approved by the State,
  including any requirements for ongoing
  reporting if demonstration of
  performance credit is approved. EPA
  has developed a draft document,
  Toolbox Guidance Manual (USEPA
  2003f), that is available with today's
  proposal and provides guidance on
  demonstration of performance testing.
   c. Request for comment. The Agency
  requests comment on today's proposal
  for systems to demonstrate higher
  Cryptosporidium removal levels. EPA
  specifically requests comment on the
 following issues:
   • Approaches that should be
 considered or excluded for
 demonstration of performance testing;
   • Whether EPA should propose
 minimum elements that demonstration
 of performance testing must include;
   • Whether a factor of safety should be
 applied to the results of demonstration
 of performance testing to account for
 potential differences in removal of an
 indicator and removal of
 Cryptosporidium, or uncertainty in the
 application of pilot-scale results to full-
 scale plants;
   • Whether or under what conditions
 a demonstration of performance credit
 should be allowed for a unit process
 within a plant—a potential concern is
 that certain unit processes, such as a
 sedimentation basin, can be operated in
 a manner that will increase removal in
 the unit process but decrease removal in
 subsequent  treatment processes and,
 therefore, lead to no overall increase in
 removal through the plant. An approach
 to address this concern is to limit
 demonstration of performance credit to
 removal demonstrated across the entire
 treatment plant.
 D. Disinfection Benchmarks for Giardia
 lamblia and Viruses
 1. What Is EPA Proposing Today?
  EPA proposes to establish the
 disinfection benchmark under the
LT2ESWTR  as a procedure to ensure
that systems maintain protection against
microbial pathogens as they implement
the Stage 2 M-DBP rules (i.e., Stage 2
DBPR and LT2ESWTR). The
disinfection benchmark serves as a tool
for systems and States to evaluate the
impact on microbial risk of proposed
changes in disinfection practice. EPA
established the disinfection benchmark
 under the IESWTR and LTlESWTR for
 the Stage 1 M-DBP rules, as
 recommended by the Stage 1 M-DBP
 Advisory Committee. Today's proposal
 extends disinfection benchmark
 requirements to apply to the Stage 2 M-
 DBP rules.
   Under the proposed LT2ESWTR, the
 disinfection benchmark procedure
 involves a system charting levels of
 Giardia lambJia and virus inactivation
 at least once per week over a period of
 at least one year. This creates a profile
 of inactivation performance that the
 System must use to determine a baseline
 or benchmark of inactivation against
 which proposed changes in disinfection
 practice can be measured. Only certain
 systems are required to develop profiles
 and keep them on file for State review
 during sanitary surveys. When those
 systems that are required to develop a
 profile plan a significant change  in
 disinfection practice (defined later in
 this section), they must submit the
 profile and an analysis of how the
 proposed change will affect the current
 disinfection benchmark to the State for
 review.
   Systems that developed disinfection
 profiles under the IESWTR or
 LTlESWTR and have not made
 significant changes in their disinfection
 practice or changed sources are not
 required to collect additional
 operational data to create disinfection
 profiles under the LT2ESWTR. Systems
 that produced a disinfection profile for
 Giardia lamblia but not viruses under
 the IESWTR or LTlESWTR may be
 required to develop a profile for viruses
 under the LT2ESWTR. Where a
 previously developed Giardia lamblia
 profile is acceptable, systems may
 develop a virus profile using the same
 operational data (i.e., CT values) on
 which the Giardia lamblia profile is
 based. Spreadsheets developed by EPA
 and States automatically calculate
 Giardia lamblia and virus profiles using
 the same operational data. EPA believes
 that virus profiling is necessary because
 many of the disinfection processes that
 systems will select to comply with the
 Stage 2 DBPR and LT2ESWTR (e.g.,
 chloramines, UV, MF/UF) are relatively
 less effective against viruses than
 Giardia lamblia in comparison to free
 chlorine.
  The disinfection benchmark
 provisions contain three major
 components: (a) Applicability
requirements  and schedule, (b)
 characterization of disinfection practice,
 and (c) State review of proposed
 changes in disinfection practice. Each of
these components is discussed in the
following paragraphs.

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Federal  Register/Vol. 68, No.  154/Monday. August 11, 2003/Proposed  Rules
  a. Applicability and schedule.
Proposed disinfection profiling and
benchmarking requirements apply to
surface water systems only. Systems
serving only ground water are not
subject to the requirements of the
LT2ESWTR. The determination of
whether  a surface water system is
required to develop a disinfection
profile is based on whether DBF levels
(TTHM or HAA5) exceed specified
values, described later in this section,
and whether a system is required to
monitor  for Cryptosporidium. These
criteria trigger profiling because they
identify  systems that may be required to
make treatment changes under the Stage
2 DBPR or LT2ESWTR. Note that it is
not practical to wait until a system has
completed Cryptosporidium monitoring
to identify which systems should
prepare a disinfection profile. A
completed disinfection profile should
be available at the point when a system
is classified in a treatment bin and must
begin developing plans to comply with
any additional treatment requirements.
   Unless the system developed a
disinfection profile under the IESWTR
or LTlESWTR, all systems required to
                      monitor for Cryptosporidium must
                      develop Giardia lamblia and virus
                      disinfection profiles under the
                      LT2ESWTR. This includes all surface
                      water systems except (1) systems that
                      provide 5.5 log total treatment for
                      Cryptosporidium, equivalent to meeting
                      the treatment requirements of Bin 4 and
                      (2) small systems (<10,000 people
                      served) that do not exceed the E. coll
                      trigger (see section 1V.A for details).
                      Systems not required to monitor for
                      Cryptosporidium as a result of providing
                      5.5 log of treatment are not required to
                      prepare disinfection profiles. However,
                      small systems that do not exceed the E.
                      coli trigger are required to prepare
                      Giardia lamblia and virus disinfection
                      profiles if one of the following criteria
                      apply, based on DBF levels in their
                      distribution systems:
                        (i)* TTHM levels in the distribution
                      system, based on samples collected for
                      compliance with the Stage 1 DBPR, are
                      at least 80% of the MCL (0.064 mg/L)  at
                      any Stage 1 DBPR sampling point based
                      on a locational running annual average
                      (LRAA).
                         (2)* HAA5 levels in the distribution
                      system, based on the samples collected
for compliance with the Stage 1 DBPR,
are at least 80% of the MCL (0.048 mg/
L) at any Stage 1 DBPR sampling point
based on an LRAA.
*These criteria only apply to systems
that are required to comply with the
DBP rules, i.e., community and non-
transient non-community systems.
  Table IV-22 presents a summary
schedule of the required deadlines for
disinfection profiling activities,
categorized by system size and whether
a small system is required to monitor for
Cryptosporidium. The deadlines are
based on the expectation that a system
should have a disinfection profile at the
time the system is classified in a
Cryptosporidium treatment bin under
LT2ESWTR and/or has determined the
need to make treatment changes for the
Stage 2 DBPR. Systems have three years
from this date, with a possible two year
extension for capital improvements if
granted by the State, within which to
complete their evaluation, design, and
implementation of treatment changes to
meet the requirements of the
LT2ESWTR and the Stage 2 DBPR.
           TABLE IV-22.—SCHEDULE OF IMPLEMENTATION DEADLINES RELATED TO DISINFECTION PROFILING
Activity
.. .
Complete 1 year oft. cort monitoring 	 "•"""; 	 ', 	 'j"""t'.'t""~t * «
Determine whether required to profile oasea on uer ieveis anu numy oimo 	

Complete disinfection profiling based on at least one year's data5 	 ••-_
Systems serv-
ing >1 0,000
people2
NA
NA
24
30
36
Systems serving <10,000 peo-
ple
Required to
monitor for
Cryptosporidium
42
NA
54
60
66
Not required to
monitor for
Cryptosporidi-
um2 36
42
42
42
NA
54
                                                                 "-ing Bin 4 treatment requirements) are not required to de-

                          10,000 people are not required to monitor for Cryptosporidium if mean E coff levels are less than 10/100 mL for
                          'W> or less than 50/100 mL for systems using flowing stream sources.

                 ^                          ?ear!oadreata?hCeefendleof which compliance with the LT2ESWTR and Stage 2 DBPR is re-
       required to conduct profiling unless TTHM or HAAS exceeds trigger values of 80% of MCL at any sampling point based on LRAA.
   As described in the next section,
 systems can meet profiling requirements
 under the proposed LT2ESWTR using
 previously collected data (i.e.,
 grandfathered data). Use of
 grandfathered data is allowed if the
 system has not made a significant
 change in disinfection practice or
 changed sources since the data were
 collected. This will permit most systems
 that prepared a disinfection profile
 under the IESWTR or the LTlESWTR to
 avoid collecting  any new operational
 data to develop profiles under the
 LT2ESWTR.
                         The locational running annual
                       average (LRAA) of TTHM and HAAS
                       levels used by small systems that do not
                       monitor for Cryptosporidium to
                       determine whether profiling is required
                       must be based on one year of DBP data
                       collected during the period following
                       promulgation of the LT2ESWTR, or as
                       determined by the State. By the date
                       indicated in Table IV-22, these systems
                       must report to the State on their DBP
                       LRAAs and whether the disinfection
                       profiling requirements apply. If either
                       DBP LRAA meets the criteria specified
                       previously, the system must begin
 disinfection profiling by the date
 proposed in Table IV-22.
   b. Developing the disinfection profile
 and benchmark. Under the LT2ESWTR,
 a disinfection profile consists of a
 compilation of Giardia lamblia and
 virus log inactivation levels computed
 at least weekly over a period of at least
 one year, as based on operational and
 water quality data (disinfectant residual
 concentration (s),  contact time(s),
 temperature (s), and, where necessary,
 pH). The system may create the profile
 by conducting new  weekly (or more
 frequent) monitoring and/or by using

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                 Federal  Register/Vol. 68, No. 154/Monday, August 11, 2003/Proposed Rules
                                                                     47717
grandfathered data. A system that
created a Giardia lamblia disinfection
profile under the IESWTR or
LT1ESWTR may use.the operational
data collected for the Giardia lamblia
profile to create a virus disinfection
profile.
  Grandfathered data are those
operational data that a system has
previously collected at a treatment plant
during the course of normal operation.
Those systems that have all the
necessary information to determine
profiles using existing operational data
collected prior to the date when the
system is required  to begin profiling
may use these data in developing
profiles. However,  grandfathered data
must be substantially equivalent to
operational data that would be collected
under this rule. These data must be
representative of inactivation through
the entire treatment plant and not just
of certain treatment segments.
  To develop disinfection profiles
under this rule, systems are required to
exercise one of the following three
options:
  Option 1—Systems conduct
monitoring at least once per week
following the process described later in
this section.
  Option 2—Systems that conduct
monitoring under this rule,  as described
under Option 1, can also use one or two
years of acceptable grandfathered data,
in addition to one year of new
operational data, in developing the
disinfection profile.
  Option 3—Systems that have at least
one year of acceptable existing
operational data are not required to
conduct new monitoring to  develop the
disinfection profile under this rule.
Instead, they can use a disinfection
profile based oh one to three years of
grandfathered data.
  Process to be followed by PWS for
developing the disinfection profile:
—Measure disinfectant residual
  concentration (C, in mg/L) before or at
  the first customer and just prior to
  each additional point of disinfectant
  addition, whether with the same or a
  different disinfectant.
—Determine contact time (T, in
  minutes} for each residual
  disinfectant monitoring point during
  peak flow conditions. T could be
  based on either a tracer study or
  assumptions based on contactor basin
  geometry and baffling. However,
  systems must use the same method for
  both grandfathered data and new data.
—Measure water temperature (°C) (for
  disinfectants other than UV).
—Measure pH (for  chlorine only).
  To determine the weekly log
inactivation, the system must convert
operational data from one day each
week to the corresponding log
inactivation values for Giardia lamblia
and viruses. The procedure for Giardia
lamblia is as follows:
—Determine CTca1c for each disinfection
  segment.
—Determine CT99.9 0*.e., 3 log
  inactivation) from tables in the SWTR
  (40 CFR 141.74) using temperature
  (and pH for chlorine) for each
  disinfection segment. States can allow
  an alternate  calculation procedure
  (e.g., use of a spreadsheet).
—For each segment, log inactivation =
  (CTcalc/CT99.9)x3.0.
—Sum the log inactivation values for
  each segment to get the log
  inactivation for the day (or week).
  For calculating the virus log
inactivation, systems should use the
procedures approved by States under
the IESWTR or LT1ESWTR. Log
inactivation benchmark is calculated as
follows:
—Determine the calendar month with
  the lowest log inactivation.
—The lowest month becomes the
  critical period for that year.
—If acceptable data from multiple years
  are available, the average of critical
  periods for each year becomes the
  benchmark.
—If only one year of data is available,
  the critical period for that year is the
  benchmark.
  c. State review. If a system that is
required to produce a disinfection
profile proposes to make a significant
change in disinfection practice, it must
calculate Giardia lamblia and virus
inactivation benchmarks and must
notify the State before implementing
such a change. Significant changes in
disinfection practice are defined as (1)
moving the point of disinfection (this is
not intended to include 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. When
notifying the State, the system must
provide a description of the proposed
change, the disinfection profiles and
inactivation benchmarks for  Giardia
lamblia and viruses, and an analysis of
how the proposed change will affect the
current inactivation benchmarks. In
addition, the system should have
disinfection profiles and, if applicable,
inactivation  benchmarking
documentation, available for the State to
review as part  of its periodic sanitary
survey.
  EPA developed for the IESWTR, with
stakeholder input, the Disinfection
Profiling and Benchmarking Guidance
Manual (USEPA 1999d). This manual
provides guidance to systems and States
on the development of disinfection
profiles, identification and evaluation of
significant changes in disinfection
practices, and considerations for setting
an alternative benchmark. If necessary,
EPA will produce an addendum to
reflect changes in the profiling and
benchmarking requirements necessary
to comply with  LT2ESWTR.
2. How Was This Proposal Developed?
  A fundamental premise in the
development of the M-DBP rules is the
concept of balancing risks between
DBFs and microbial pathogens.
Disinfection profiling and
benchmarking were established under
the IESWTR and LTlESWTR, based on
a recommendation by the Stage 1 M-
DBP Federal Advisory Committee, to
ensure that systems maintained
adequate control of pathogen risk as
they reduced risk from DBPs. Today's
proposal would extend disinfection
benchmarking requirements to the
LT2ESWTR.
  EPA believes this extension is
necessary because some systems will
make significant changes in their
current disinfection practice to meet
more stringent limits on TTHM and
HAAS levels  under the Stage 2 DBPR
and additional Cryptosporidium
treatment requirements under the
LT2ESWTR. In order to ensure that
these systems continue to provide
adequate protection against the full
spectrum of microbial pathogens, it is
appropriate for  systems and States to
evaluate the effects of such treatment
changes on microbial drinking water
quality. The disinfection benchmark
serves as a tool for making such
evaluations.
  EPA projects that to comply with the
Stage 2 DBPR, systems will  make
changes to their disinfection practice,
including switching from free chlorine
to chloramines and, to a lesser extent,
installing technologies like ozone,
membranes, and UV. Similarly, to
provide additional treatment for
Cryptosporidium, some systems will
install technologies like UV, ozone, and
micro filtration. While these processes
are all effective disinfectants,
chloramines are a weaker disinfectant
than free chlorine for Giardia lamblia.
Ozone, UV, and membranes can provide
highly effective treatment for Giardia
lamblia, but they, as well as
chloramines, are less efficient for
treating viruses than free chlorine,
relative to their efficacy for  Giardia
lamblia. Because of this, a system
switching from  free chlorine to one of
these alternative disinfection

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Federal  Register/Vol.  68, No. 154/Monday, August 11, 2003/Proposed Rules
technologies could experience a
reduction in the level of virus and/or
Giardia lamblia (for chloramines)
treatment it is achieving. Consequently,
EPA believes that systems making
significant changes in their disinfection
practice under the Stage 2 M-DBP rules
should assess the impact of these
changes with disinfection benchmarks
for Giardia lamblia and viruses.
  Changes in the proposed
benchmarking requirements under the
LT2ESWTR in comparison to IESWTR
requirements include decreasing the
frequency of calculating CT values for
the disinfection profile from daily to
weekly  and requiring al! systems to
prepare a profile for viruses as well as
Giardia lamblia. The proposal of a
weekly  frequency for CT calculations
was made to accommodate existing
profiles from small systems, which are
required to make weekly CT
calculations for profiling under the
LTlESWTR. As described earlier, EPA
would like for systems that have
prepared a disinfection profile under
the IESWTR or LTlESWTR and have
not subsequently made significant
changes in disinfection practice to be
able to grandfather this profile for the
LT2ESWTR. Allowing weekly
calculation of CT  values under the
LT2ESWTR will make this possible.
  The IESWTR and LTlESWTR
required virus inactivation profiling
only for systems using ozone or
chloramine as their primary
disinfectant. However, as noted earlier,
EPA has projected that under the Stage
2 DBPR and LT2ESWTR, systems will
switch from free chlorine to disinfection
processes like chloramines, UV, ozone,
and micron'Itration. The efficiency of
these processes for virus treatment
relative to protozoa treatment is lower
in comparison to free chlorine. As a
result, a disinfection benchmark for
Giardia lamblia would not necessarily
provide an indication of the level or
adequacy of treatment for viruses.
Consequently, EPA believes it is
appropriate for systems to develop
profiles for both Giardia lamblia and
viruses. Moreover, developing a profile
for viruses involves a minimal increase
in effort and no additional  data
collection for those systems that have
disinfection profiles for Giardia lamblia.
Systems will  use the same calculated CT
values for viruses as would be used for
the Giardia lamblia profile.
  The strategy of disinfection profiling
and benchmarking stemmed from data
provided to the Stagel M-DBP Advisory
Committee, in which the baseline of
microbial inactivation (expressed as logs
of Giardia lamblia inactivation}
demonstrated high variability.
                      Inactivation varied by several logs (i.e.,
                      orders of magnitude) on a day-to-day
                      basis at particular treatment plants and
                      by as much as tens of logs over a year
                      due to changes in water temperature,
                      flow rate, seasonal changes, pH, and
                      disinfectant demand. There were also
                      differences between years at individual
                      plants. To address these variations, M--
                      DBP stakeholders developed the
                      procedure of profiling a plant's
                      inactivation levels over a period of at
                      least one year, and then establishing a
                      benchmark of minimum inactivation as
                      a way to characterize disinfection
                      practice.
                        Benchmarking of inactivation levels,
                      an assessment of the impact of proposed
                      changes on the level of microbial
                      inactivation of Giardia lamblia and
                      viruses, and State review prior to
                      approval of substantial  changes in
                      treatment are important steps in
                      avoiding conditions that present an
                      increase in microbial risk. In its
                      assessment of the microbial risk
                      associated with the proposed changes,
                      States could consider site-specific
                      knowledge of the watershed and
                      hydrologic factors as well as variability,
                      flexibility and reliability of treatment to
                      ensure that treatment for both protozoan
                      and viral pathogens is appropriate.
                        EPA emphasizes that benchmarking is
                      not intended to function as a regulatory
                      standard. Rather, the objective of the
                      disinfection benchmark is to facilitate
                      interactions between the States and
                      systems for the purpose of assessing the
                      impact on microbial risk of proposed
                      significant changes to current
                      disinfection practices. Final decisions
                      regarding levels of disinfection for
                      Giardia lamblia and viruses beyond
                      those required by the SWTR that  are
                      necessary to protect public health will
                      continue to be left to the States. For this
                      reason EPA has not mandated specific
                      evaluation protocols or decision
                      matrices  for analyzing changes in
                      disinfection practice. EPA, however,
                      will provide support to the States in
                      making these analyses through the
                      issuance  of guidance.

                      3. Request for Comments
                        EPA requests comment on the
                      proposed provisions of the inactivation
                      profiling and benchmarking
                      requirement.
                      E. Additional Treatment Technique
                      Requirements for Systems With
                      Uncovered Finished Water Storage
                      Facilities
                      1. What Is EPA Proposing Today?
                        EPA is proposing requirements for
                      systems with uncovered finished water
storage facilities. The proposed rule
requires that systems with uncovered
finished water storage facilities must (1)
cover the uncovered finished water
storage facility, or (2) treat storage
facility discharge to the distribution
system to achieve a 4 log virus
inactivation, unless (3) the system
implements a State-approved risk
mitigation plan that addresses physical
access and site security, surface water
runoff, animal and bird waste, and
ongoing water quality assessment, and
includes a schedule for plan
implementation. Where applicable, the
plans should account for cultural uses
by Indian Tribes.
  Systems must notify the State if they
use uncovered finished water storage
facilities no later than 2 years following
LT2ESWTR promulgation. Systems
must cover or treat uncovered finished
facilities or have a State-approved risk
mitigation plan within 3 years following
LT2ESWTR promulgation, with the
possibility of a two year extension
granted by States for  systems making
capital improvements. Systems seeking
approval for a risk mitigation plan must
submit the plan to the State within 2
years following LT2ESWTR
promulgation.
  These provisions apply to uncovered
tanks, reservoirs, or other facilities
where water is stored after it has
undergone treatment to satisfy microbial
treatment technique requirements for
Giardia lamblia, Cryptosporidium, and
viruses. In most cases, this refers  to
storage of water following all filtration
steps, where required, and primary
disinfection.

2. How Was This Proposal Developed?
  Today's proposal is intended to
mitigate the water quality degradation
and increased health risks that can
result from uncovered finished water
storage facilities. In addition, these
proposed requirements for uncovered
finished water storage facilities are
consistent with recommendations of the
Stage 2 M-DBP Advisory Committee in
the Agreement in Principle (USEPA
2000a).
  The use of uncovered finished water
storage facilities  has been questioned
since 1930 due to their  susceptibility to
contamination and subsequent threats to
public health (LeChevallier etal  1997).
Many potential sources of
contamination can lead to the
degradation of water quality in
uncovered finished water storage
facilities. These include surface water
runoff, algal growth, insects and fish,
bird and animal waste,  airborne
deposition, and human activity.

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                   Federal Register/Vol. 68, No.  154/Monday, August  11,  2003/Proposed Rules
                                                                       47719
    Algal blooms are the most common
  problem in open reservoirs and can
  become a public health risk, as they
  increase the presence of bacteria in the
  water. Algae growth also leads to the
  formation of disinfection byproducts
  and causes taste and odor problems.
  Some algae produce toxins that can
  induce headache, fever, diarrhea,
  abdominal pain, nausea, and vomiting.
  Bird and animal wastes are also
  common and significant sources of
  contamination. These wastes may carry
  microbial contaminants such as
  coliform bacteria, viruses, and human
  pathogens, including Vibrio cholera,
  Salmonella, Mycobacteria, Typhoid,
  Giardia lamblia, and Cryptosporidium
  (USEPA 1999e). Microbial pathogens are
  found in surface water runoff, along
  with agricultural chemicals, automotive
  wastes, turbidity, metals, and organic
  matter (USEPA I999e, LeChevallier et
  al 1997).
   In an effort to minimize
  contamination, systems have
  implemented various controls such as
  reservoir covers and liners, regular
  draining and washing, security and
 monitoring, bird and insect control
 programs, and drainage design  to
 prevent surface runoff from entering the
 facility (USEPA 1999e).
   A number of studies have evaluated
 the degradation of water quality in
 uncovered finished water storage
 facilities. LeChevallier et al. (1997)
 compared influent and effluent samples
 from six uncovered finished water
 storage reservoirs in New Jersey for a
 one year period. There were significant
 increases in the turbidity, particle
 count, total coliform, fecal  coliform, and
 heterotrophic plate count bacteria in the
 effluent relative to the influent. Of
 particular concern were fecal coliforms,
 which were detected in 18 percent of
 effluent samples (no influent samples
 were positive for coliforms). Fecal
 coliforms are used as an indicator of the
 potential for contamination by
 pathogens. Giardia and/or
 Cryptosporidium were detected in 15%
 of inlet samples and  25% of effluent
 samples, demonstrating a significant
 increase in the effluent. There was a
 significant decrease in the chlorine
 residual concentration in some effluent
 samples.
  Increases in  algal cells, heterotrophic
 plate count (HPC) bacteria, turbidity,
 color, particle counts, and biomass, and
 decreases in residual chlorine levels,
 have been reported in other studies of
 uncovered finished water reservoirs as
well (Pluntze 1974, AWWA Committee
 1983, Silverman etal. 1983).
Researchers have shown that small
mammals, birds, fish, and algal growth
  contribute to the microbial degradation
  of an open finished water reservoir
  (Graczyk et al. 1996, Geldreich 1990,
  Payer and Ungar 1986, Current 1986).
    As described in section II, the
  IESWTR and LTlESWTR require water
  systems to cover all new reservoirs,
  holding tanks, or other storage facilities
  for finished water. However, these rules
  do not require systems to cover existing
  finished water storage facilities. EPA
  stated in the preamble to the final
  IESWTR (63 FR 69494, December 16,
  1998) (USEPA 1998a) that with respect
  to requirements for existing uncovered
  finished water storage facilities, the
  Agency needed more time to collect and
  analyze additional information to
  evaluate regulatory impact. The
  IESWTR preamble affirmed that EPA
  would consider whether to  require the
  covering of existing storage facilities
  during the development of subsequent
  microbial regulations when additional
  data to estimate national costs were
  available.
   Since promulgation of the IESWTR,
  EPA has collected sufficient data to
  estimate national cost implications of
  regulatory control strategies for
  uncovered finished water storage
  facilities. Based on information
 provided by States, EPA estimates that
 there are approximately 138 uncovered
 finished water storage facilities in the
 United States and territories, not
 including reservoirs that systems
 currently plan to cover or take off-line.
 Costs for covering these storage facilities
 or treating the effluent, consistent with
 today's proposed requirements, are
 presented in section VI of this preamble
 and in the Economic Analysis for the
 LT2ESWTR (USEPA 2003a). Briefly,
 total capital costs were estimated as
 $64.4 million, resulting in annualized
 present value costs of $5.4 million at a
 three percent discount rate and $6.4
 million at a seven percent discount rate.
   Based  on the findings of studies cited
 in this section, EPA continues to be
 concerned about contamination
 occurring in uncovered finished water
 storage facilities. Therefore, as
 recommended by the Advisory
 Committee, EPA is proposing control
 measures for all systems with uncovered
 finished water storage facilities. This
 proposal is intended to represent a
 balanced approach, recognizing both the
 potentially significant but uncertain
 risks associated with uncovered
 finished water storage facilities and the
 substantial costs of either covering them
 or building alternative storage. Today's
proposal allows systems to treat the
 storage facility effluent instead of
providing a cover. Alternatively, States
may determine that existing risk
 mitigation is adequate, provided a
 system implements a risk mitigation
 plan as described in this section.
 3, Request for Comments
    EPA requests comment on the
 proposed requirements pertaining to
 uncovered finished water storage
 facilities. Specifically, the Agency
 would like comment on the following
 issues, and requests that comments
 include available supporting data or
 other technical information:
   • Is it appropriate to allow systems
 with uncovered finished water storage
 facilities  to implement a risk
 management plan or treat the effluent to
 inactivate viruses instead of covering
 the facility?
   • If systems treat the effluent of an
 uncovered finished water storage
 facility instead of covering it, should
 systems be required to inactivate
 Cryptosporidium and Giardia lamblia,
 since these protozoa have been found to
 increase in uncovered storage facilities?
   • Additional information on
 contamination or health risks that may
 be associated with uncovered finished
 water storage facilities.
   • Additional data on how
 climatological conditions affect water
 quality, including daily fluctuations in
 the stability of the water related to
 corrosion control.
   * The definition  of an uncovered
 finished water storage facility in 40 CFR
 141.2 is a tank, reservoir, or other
 facility used  to store water that will
 undergo no further treatment except
 residual disinfection and is open to the
 atmosphere. There is a concern that this
 definition may not include certain
 systems using what would generally be
 considered an uncovered finished water
 storage facility. An example is a system
 that applies a corrosion inhibitor
 compound to the effluent of an
 uncovered storage facility where water
 is stored after filtration and primary
 disinfection.  In this case, the system
 may claim that the corrosion inhibitor
 constitutes additional treatment and,
 consequently, the reservoir does not
 meet EPA's definition of an uncovered
 finished water storage facility. EPA
 requests comment on whether the
 definition of an uncovered finished
 water storage facility should be revised
 to specifically include systems that
 apply a treatment such as corrosion
 control to  water stored in an uncovered
reservoir after the water has undergone
 filtration, where required, and primary
 disinfection.
F.  Compliance Schedules
  Today's proposal includes deadlines
for public  water systems to comply with

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Federal Register/Vol. 68, No.  154/Monday,  August  11, 2003/Proposed  Rules
the proposed monitoring, reporting, and
treatment requirements. These
deadlines stem from the microbial
framework approach of the proposed
LT2ESWTR, which involves a system-
specific risk characterization through
monitoring to determine the need for
additional  treatment.
1. What Is EPA Proposing Today?
   a. Source water monitoring.
   i. Filtered systems. Under today's
proposal, filtered systems conduct
source water Cryptosporidium
monitoring for the purpose of being
classified in one of four risk bins that
determine  the extent of any additional
treatment requirements. Small filtered
systems first monitor for E. coli as a
screening analysis and are only required
to monitor for Cryptosporidium if the
mean E. coli level exceeds specified
trigger values. Note that systems that
currently provide or will provide a total
of at least 5.5 log of treatment for
Cryptosporidium are exempt from
monitoring requirements.
   Large surface water systems (serving
at least 10,000-people) that filter must
                       sample at least monthly for
                       Cryptosporidium, E. coli, and turbidity
                       in their source water for 24 months,
                       beginning 6 months after promulgation
                       of the LT2ESWTR. Large systems must
                       submit a sampling schedule to their
                       primacy agency (in this case, EPA) no
                       later than 3 months after promulgation
                       oftheLT2ESWTR.
                         Small surface water systems (fewer
                       than 10,000 people served) that filter
                       must conduct biweekly E. coli sampling
                       in their source water for 1 year,
                       beginning 30 months after LT2ESWTR
                       promulgation. States may designate an
                       alternate indicator monitoring strategy
                       based on EPA guidance, but compliance
                       schedules will not change. Small
                       systems that exceed the indicator trigger
                       value (i.e., mean E. coli > 10/100 mL for
                       lake/reservoir sources or > 50/100 mL
                       for flowing stream sources) must
                       conduct source water Cryptosporidium
                       sampling twice-per-month for 1 year,
                       beginning 48 months after LT2ESWTR
                       promulgation (i.e., beginning 6 months
                       following the completion of E. coli
                       sampling). Small systems must submit
    an E. coli sampling schedule to their
    primacy agency no later than 27 months
    after LT2ESWTR promulgation. If
    Cryptosporidium monitoring is
    required, small systems must submit a
    Cryptosporidium sampling schedule no.
    later than 45 months after LT2ESWTR
    promulgation.
      Large systems must carry out a second
    round of source water monitoring
    beginning 108 months after LT2ESWTR
    promulgation, which is 6 years after
    initial bin classification. Similarly,
    small systems must conduct a second
    round of indicator monitoring (E. coli or
    other as designated by the State)
    beginning 138 months after LT2ESWTR
    promulgation, which is 6 years after
    their initial bin classification. Small
    systems that exceed the indicator trigger
    value in the second round of indicator
    monitoring must conduct a second
    round of Cryptosporidium monitoring,
    beginning 156 months after LT2ESWTR
    promulgation.
      Compliance dates for filtered systems
    are summarized in Table IV-23.
                       TABLE iv-23.—SUMMARY OF COMPLIANCE DATES FOR FILTERED SYSTEMS
          System type
                                               Requirement
                                                                                         Compliance date
 Large Systems (serve >10,000 peo-
   ple).
 Small Systems (serve <10,000 peo-
   ple).
               Submit sampling schedule '-2 	

               Source water Cryptosporidium, E. coli and turbidity
                 monitoring.
               Comply with additional Cryptosporidium treatment
                 requirements.
               Second round of source water Cryptosporidium, E.
                 coli, and turbidity monitoring2.
               Submit E. coli sampling schedule2	
                                Source water £ coli monitoring	

                                Second round of source water £ coli monitoring2 ...
No later than 3 months after promulgation.

Begin monthly monitoring 6 months after promulga-
  tion for 24 months.
No later than 72 months after promulgation.3

Begin monthly monitoring 108 months after promul-
  gation for 24 months.
No later than 27 months after promulgation.

Begin biweekly monitoring 30 months after promul-
  gation for 1 year.
Begin biweekly monitoring 138 months after promul-
  gation for 1 year.
                                             Additional requirements if indicator (e.g., E. coli) trigger level is exceeded"
                                Submit Cryptosporidium sampling schedule '-2 ..
                                Source water Cryptosporidium monitoring 	
                                Comply with additional Cryptosporidium treatment
                                  requirements.
                                Second round of source  water  Cryptosporidium
                                  monitoring.                       	
                                                           No later than 45 months after promulgation.
                                                           Begin twice-per-month monitoring no later than 48
                                                            months after promulgation for 1 year.
                                                           No later than 102 months after promulgation.3'5

                                                           Begin twice-per-month monitoring no later than 156
                                                            months after promulgation for 1 year.	
    systems may be eligible to use previously collected (grandfathered) data to meet LT2ESWTR requirements if specified quality control criteria

                         to mon&r if they will provide at least 5.5 log Cryptosporidium^reatment and notify EPA or the State.
                                                                                  -rces or exceeds 50/100 mL for systems

                                                           Bin 1 and are not required to provide Cryptospondium treatment beyond
  LT1ESWTR levels.
    ii. UnfiHered systems. Surface water
  systems that do not filter and meet the
  criteria for avoidance of filtration [40
  CFR 141.71) (i.e., unfiltered systems) are
                        required to conduct source water
                        Cryptosporidium monitoring to
                        determine if their mean source water
                        Cryptosporidium level exceeds 0.01
     oocysts/L. There is no E. coli screening
     analysis available to small unfiltered
     systems. However, both large and small
     unfiltered systems conduct

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                  Federal Register/Vol. 68, No.  154/Monday,  August  11,  2003/Proposed Rules
                                                                              47721
 Cryptosporidium monitoring on the
 same schedule as filtered systems of the
 same size. Note that unfiltered systems
 that currently provide or will provide a
 total of at least 3 log Cryptosporidium
 inactivation are exempt from monitoring
 requirements.
   Large unfiltered systems (serving at
 least 10,000 people) must conduct at
 least monthly Cryptosporidium
 sampling for 24 months, beginning 6
 months after LT2ESWTR promulgation.
 Small unfiltered systems (serving fewer
         than 10,000 people) must conduct at
         Jeast twice-per-month Cryptosporidium
         sampling for 12 months, beginning 48
         months after LT2ESWTR promulgation.
         Large systems must submit a
         Cryptosporidium sampling schedule to
         EPA no later than 3 months after
         LT2ESWTR promulgation, and small
         systems must submit  a sampling
         schedule to their State no later than 45
         months after LT2ESWTR promulgation.
           Unfiltered systems  are required to
         conduct a second round of
     Cryptosporidium monitoring on the
     same schedule as filtered systems of the
     same size. Large systems must carry out
     a second round of Cryptosporidium
     monitoring, beginning 108 months after
     LT2ESWTR promulgation. Small
     systems must perform a second round of
     Cryptosporidium monitoring, beginning
     156 months after LT2ESWTR
     promulgation.
      Compliance dates for unfiltered
     systems are summarized in Table IV-24.
                      TABLE IV-24.—SUMMARY OF COMPLIANCE DATES FOR UNFILTERED SYSTEMS
          System type
                Requirement
              Compliance date
 Large Systems (serve >10,000 peo-
   ple).
Submit sampling schedule1 	...

Source water Cryptosporidium monitoring
 Small  Systems  (serve <  10,000
  people).
Comply with Cryptosporidium inactivation require-
  ments.
Second round  of source  water Cryptosporidium
  monitoring.
Submit sampling schedule1  	

Source water Cryptosporidium monitoring 	
                               Comply with Cryptosporidium inactivation require-
                                 ments.
                               Second round  of  source water Cryptosporidium
                                 monitoring.
No later than 3 months after promulgation.

Begin monthly monitoring [6 months after promulga-
  tion for 24 months.
No later than 72 months after promulgation.2

Begin monthly monitoring 108 months after promul-
  gation for 24 months.
No later than 45 months after promulgation.

Begin twice-per-month monitoring no later than 48
  months after promulgation for 1 year.
No later than 102 months after promulgation.2

Begin twice-per-month monitoring no later than 156
  months after promulgation for 1 year.
  1 Systems may be eligible to use previously collected (grandfathered) data to meet LT2ESWTR requirements if specified quality control criteria
 are met (described in section IV.A.I.d).
  2 States may grant up to an additional two years for systems making capital improvements.
  b. Treatment requirements. Filtered
 systems must determine their bin
 classification and unfiltered systems
 must determine their mean source water
 Cryptosporidium level within 6 months
 of the scheduled month for collection of
 their final Cryptosporidium sample in
 the first round of monitoring. This 6
 month period provides time for systems
 to receive all sample analysis results
 from the laboratory, analyze the data,
 and work with their primacy agency.
  Filtered systems have 3 years
 following initial bin classification to
 meet any additional Cryptosporidium
 treatment requirements. This equates to
 compliance dates of 72 months after
 LT2ESWTR promulgation for large
 systems and 102 months after
 LT2ESWTR promulgation for small
 systems (see Table IV-23). Unfiltered
 systems must comply with
 Cryptosporidium treatment
 requirements on the same schedule as
 filtered systems of the same size (see
Table IV-24). The State may grant
 systems an additional two years to
 comply when capital investments are
necessary, as specified in the Safe
Drinking Water Act (section
          Systems with uncovered finished
         water storage facilities are required to
         comply with the provisions described in
         section IV.E by 36 months following
         LT2ESWTR promulgation, with the
         possibility of a 2 year extension granted
         by the State for systems making capital
         improvements. Systems seeking
         approval for a risk mitigation plan must
         submit the plan to the State within 24
         months following LT2ESWTR
         promulgation.
          Systems must comply with additional
         Cryptosporidium treatment
         requirements by implementing one or
         more treatment processes or control
         strategies from the microbial toolbox.
         Most of the toolbox components require
         submission of documentation to the
         State demonstrating compliance with
         design and/or implementation criteria
         required to receive credit. Compliance
         dates for reporting requirements
        associated with microbial toolbox
         components are presented in detail in
        section IV.], Reporting and
        Recordkeeping Requirements.
          c. Disinfection benchmarks for
         Giardia lamblia and viruses. Today's
        proposed LT2ESWTR includes
        disinfection profiling and benchmarking
        requirements, which consist of three
    major components: applicability
    determination, characterization of
    disinfection practice, and State review
    of proposed changes in disinfection
    practice. Each of these components is
    discussed in detail in section W.D.
    Compliance deadlines associated with
    each of these components, including
    associated reporting requirements, are
    stated in section IV J, Reporting and
    Recordkeeping Requirements.
    2. How Was This Proposal Developed?
      The compliance dates in today's
    proposal reflects the risk-targeted
    approach of the proposed LT2ESWTR,
    wherein additional treatment
    requirements are based on a system
    specific risk characterization as
    determined through source water
    monitoring. Additionally, they are
    designed to allow for systems to
    simultaneously comply with the
    LT2ESWTR and Stage 2 DBPR in order
    to balance risks in the control of
    microbial pathogens and DBPs. These
    dates are consistent with
    recommendations from the Stage 2 M-
    DBP Federal Advisory Committee.
      Under the LT2ESWTR, large systems
    will sample for Cryptosporidium for a
    period of two years in order  to

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Federal  Register/Vol. 68, No. 154/Monday, August  11, 2003/Proposed  Rules
characterize source water pathogen
levels and capture a degree of annual
variability. To expedite the date by
which systems will provide additional
treatment where high risk source waters
are identified, large system
Cryptosporidium monitoring will begin
six months after promulgation of the
LT2ESWTR. Upon completion of
Cryptosporidium monitoring, systems
will have six months to work with their
primacy agency to determine their bin
classification. Beginning at this point,
which is three years following
LT2ESWTR promulgation, large systems
will have three years to implement the
treatment processes or control strategies
necessary'to comply with any additional
treatment requirements stemming from
bin classification.
   Other large system compliance dates
in areas like approval of grandfathered
monitoring data, disinfection profiling
and benchmarking, and reporting
deadlines associated with microbial
toolbox components all stem from the
Cryptosporidium monitoring and
treatment compliance schedule.
   With respect to small systems under
the LT2ESWTR, EPA is proposing that
small systems first monitor for E. coli as
a screening analysis in  order to reduce
the number of small systems that incur
the cost of Cryptosporidium monitoring.
However, due to limitations in available
data, the Agency has determined that it
is necessary to use data generated by
large systems under the LT2ESWTR to
confirm or refine the E. coli indicator
criteria that will trigger small system
 Cryptosporidium monitoring.
 Consequently, small system indicator
 monitoring will begin at the conclusion
 of large system monitoring. This
 approach was recommended by the
 Advisory Committee.
   Accordingly, small systems will
 monitor for E. coli for one year,
 beginning 30 months after LT2ESWTR
 promulgation. Following this, small
 systems will have six months to
 determine if they are required to
 monitor for Cryptosporidium and, if so,
 contract with an approved analytical
 laboratory. Cryptosporidium monitoring
 by small systems will be conducted for
 one year, which, when added to the one
 year of E. coli monitoring, equals two
 years of source water monitoring. This
 is equivalent to the time period large
 systems spend in source water
 monitoring.
    The  time periods associated with bin
 assignment and compliance with
 additional treatment requirements for
 small systems are the same as those
 proposed for large systems. Specifically,
 small systems will have six months to
 work with their States  to determine
                      their bin classification following the
                      conclusion of Cryptosporidium
                      sampling. From this point, which is 5.5
                      years after LT2ESWTR promulgation,
                      small systems have three years to meet
                      any additional treatment requirements
                      resulting from bin classification. States
                      can grant additional time to small
                      systems for compliance with treatment
                      technique requirements  through
                      granting exemptions (see SDWA section
                      1416).
                      3. Request for Comments
                        EPA requests comments on the
                      treatment technique compliance
                      schedules for large and small systems in
                      today's proposal, including the
                      following issues:
                      Time Window Between  Large and Small
                      System Monitoring
                        Under the current proposal, small
                      filtered system E. coli monitoring begins
                      in the month following the end of large
                      system Cryptosporidium, E. coli, and
                      turbidity monitoring. EPA plans to
                      evaluate large system monitoring results
                      on an ongoing basis as the data are
                      reported to determine if any refinements
                      to the E. coli levels that  trigger small
                      system Cryptosporidium monitoring are
                      necessary. If such refinements were
                      deemed appropriate, EPA would issue
                      guidance to States, which can establish
                      alternative trigger values for small
                      system monitoring under the
                      LT2ESWTR.
                         This implementation  schedule does
                      not leave any time between the end of
                      large system monitoring and the
                      initiation of small system monitoring.
                      Consequently, if it is necessary to
                      provide guidance on alternative trigger
                      values prior to when small system
                      monitoring begins, such guidance
                      would be based on less  than the full set
                      of large system results (e.g., first 18
                      months of large system  data). EPA
                      requests comment on whether an
                      additional time window between the
                      end of large system monitoring and the
                      beginning of small system monitoring is
                      appropriate and, if so, how long such a
                      window should be.
                      Implementation Schedule for
                      Consecutive Systems
                         The Stage 2 M-DBP Agreement in
                      Principle (65 FR 83015, December 29,
                      2000) (USEPA 2000a) continues the
                      principle of simultaneous compliance to
                      address microbial pathogens and
                      disinfection byproducts. Systems are
                      generally expected to address
                      LT2ESTWR requirements concurrently
                      with those of the Stage  2 DBPR (as noted
                      earlier, the Stage 2 DBPR is scheduled
                      to be proposed later this year and to be
promulgated at the same time as the
LT2ESWTR).
  As with the LT2ESWTR, small water
systems (< 10,000 served) generally
begin monitoring and must be in
compliance with the Stage 2 DBPR at a
date later than that for large systems.
However, the Advisory Committee
recommended that small systems that
buy/receive from or sell/deliver finished
water to a large system (that is, they are
part of the same "combined distribution
system") comply with Stage 2 DBPR
requirements on the same schedule as
the largest system in the combined
distribution system. This approach is
intended to ensure that systems
consider impacts throughout the
combined distribution system when
making compliance decisions (e.g.
selecting new technologies or making
operational modifications) and to
facilitate all systems meeting the
compliance deadlines for the rule.
  The  issue of combined distribution
systems associated with systems buying
and selling water is expected to be of
less significance for the LT2ESWTR.
The requirements of the LT2ESWTR
apply to systems treating raw surface
water and generally will not involve
compliance steps when systems
purchase treated water. Consequently,
the compliance schedule for today's
proposal does not address combined
distribution systems. However, this
proposed approach raises the possibility
that a small system treating surface
water and selling it to a large system
 could be required to take compliance
 steps at an earlier date under the Stage
 2 DBPR than under the LT2ESWTR.
 While a small system in this situation
 could  choose to comply with the
 LT2ESWTR on an earlier schedule, the
 two rules would not require
 simultaneous compliance. EPA requests
 comment on how this scenario should
 be addressed in the LT2ESWTR.

 G. Public Notice Requirements

 1. What Is EPA Proposing Today?

   EPA is proposing that under the
 LT2ESWTR, a Tier 2 public notice will
 be required for violations of additional
 treatment requirements and a Tier 3
 public notice will be required for
 violations of monitoring and testing
 requirements. Where systems violate
 LT2ESWTR treatment requirements,
 today's proposal requires the use of the
 existing health effects language for
 microbiological contaminant treatment
 technique violations, as stated in 40
 CFR 141 Subpart Q, Appendix B.

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                  Federal Register/Vol.  68,  No. 154/Monday, August 11, 2003/Proposed Rules
                                                                      47723
  2. How Was This Proposal Developed?
    In 2000, EPA published the Public
  Notification Rule (65 FR 25982, May 4,
  2000) (USEPA 2000d), which revised
  the general public notification
  regulations for public water systems in
  order to implement the public
  notification requirements of the 1996
  SDWA amendments. This regulation
  established the requirements that public
  water systems must follow regarding the
  form, manner, frequency, and content of
  a public notice. Public notification of
  violations is an integral part of the
  public health protection and consumer
  right-to-know provisions of the 1996
  SDWA Amendments.
   Owners and operators of public water
  systems are required to notify persons
  served when they fail to comply with
  the requirements of a NPDWR, have a
  variance or exemption from the drinking
  water regulations, or are facing other
  situations posing a risk to public health.
  The public notification requirements
  divide violations into three categories
  (Tier 1, Tier 2 and Tier 3) based on the
  seriousness of the violations, with each
 tier having different public notification
 requirements,
   EPA has limited its list of violations
 and situations routinely requiring a Tier
 1 notice to those with a significant
 potential for serious adverse health
 effects from short term exposure. Tier l
 violations contain language specified by
 EPA that concisely and in non-technical
 terms conveys to the public the adverse
 health effects that may occur as a result
 of the violation. States and water
 utilities may add additional information
 to each notice, as deemed appropriate
 for specific situations. A State may
 elevate to Tier 1 other violations and
 situations with significant potential to
 have serious adverse health effects from
 short-term exposure, as determined by
 the State.
  Tier 2 public notices address other
 violations with potential to have  serious
 adverse health effects on human health.
 Tier 2 notices are required for the
 following situations:
  • All violations of the MCL,
 maximum residual disinfectant level
 (MRDL) and treatment technique
 requirements, except where a Tier 1
 notice is  required or where the State
 determines that a Tier 1 notice is
required; and
  * Failure to comply with the terms
and conditions of any existing variance
or exemption.
  Tier 3 public notices include all other
violations and  situations requiring
public notice, including the following
situations:
  •  A monitoring or testing procedure
violation, except where a Tier 1 or 2
  notice is already required or where the
  State has elevated the notice to Tier 1
  or 2; and
   • Operation under a variance or
  exemption.
   The State, at its discretion, may
  elevate the notice requirement for
  specific monitoring or testing
  procedures from a Tier 3 to a Tier 2
  notice, taking into account the potential
  health impacts and persistence of the
  violation.
   As part of the IESWTR, EPA
  established health effects language for
  violations of treatment technique
  requirements for microbiological
  contaminants. EPA believes this
  language, which was developed with
  consideration of Cryptosporidium
  health effects, is appropriate for
  violations of additional
  Cryptosporidium treatment
  requirements under the LT2ESWTR.
  3. Request for Comment
   EPA requests comment on whether
 the violations of additional treatment
 requirements  for Cryptosporidium
 under the LT2ESWTR should require a
 Tier 2 public notice and  whether the
 proposed health effects language is
 appropriate.

 H. Variances and Exemptions
   SDWA section 1415  allows States to
 grant variances from national primary
 drinking water regulations under certain
 conditions; section 1416 establishes the
 conditions under which  States may
 grant exemptions to MCL or treatment
 technique requirements.  For the reasons
 presented in the following discussion,
 EPA has determined that systems will
 not be eligible for variances or
 exemptions to the requirements of the
 LT2ESWTR.
 1 . Variances
   Section 1415 specifies  two provisions
 under which general variances to
 treatment technique requirements may
 be granted:
   (1) A State that has primacy may grant
 a variance to a system from any
 requirement to use a  specified treatment
 technique for a contaminant if the
 system demonstrates to the satisfaction
 of the State that the treatment technique
 is not necessary to protect public health
because of the  nature of the system's
raw water source. EPA  may prescribe
monitoring and other requirements as
conditions of the variance (section
  (2) EPA may grant a variance from any
treatment technique requirement upon a
showing by any person that an
alternative treatment technique not
included in such requirement is at least
  as efficient in lowering the level of the
  contaminant (section 1415(a)(3)).
   EPA does not believe the first
  provision for granting a variance is
  applicable to the LT2ESWTR because
  Cryptosporidium treatment technique
  requirements under this rule account for
  the degree of source water
  contamination. Systems initially comply
  with the LT2ESWTR by conducting
  source water monitoring for
  Cryptosporidium. Filtered systems are
  required to provide additional treatment
  for Cryptosporidium only if the source
  water concentration exceeds a level
  where current treatment does not
  provide sufficient protection. All
  unfiltered systems are required to
 provide a baseline of 2 log inactivation
  of Cryptosporidium to achieve finished
 water risk levels comparable to filtered
 systems; however, unfiltered systems
 are required to achieve  3 log
 inactivation only if the  source water
 level exceeds 0.01 oocysts/L.
   The second provision for granting a
 variance is not applicable to the
 LT2ESWTR because the treatment
 technique requirements of this rule
 specify the degree to which systems
 must lower their source water
 Cryptosporidium level (e.g., 4, 5, and 5.5
 log reduction in Bins 2,  3, and 4,
 respectively). The LT2ESWTR provides
 broad flexibility in how systems achieve
 the required level of Cryptosporidium
 reduction, as shown in the discussion of
 the microbial toolbox in section VI.C
 Moreover, the microbial toolbox
 contains an option for Demonstration of
 Performance, under which States can
 award treatment credit based on the
 demonstrated efficiency of a treatment
 process in reducing Cryptosporidium
 levels. Thus, there is no need for this
 type of variance under the LT2ESWTR.
   SDWA section 1415(e) describes  small
 system variances, but these cannot  be
 granted for a treatment technique for a
 microbial contaminant. Hence, small
 system variances are not allowed for the
 LT2ESWTR.
 2. Exemptions
  Under SDWA section  1416(a), a State
 may exempt any public water system
 from a treatment technique requirement
 upon a finding that (1) due to
 compelling factors (which may include
 economic factors such as qualification
 of the system as serving  a disadvantaged
 community), the system  is unable to
 comply with the requirement or
 implement measures to develop an
 alternative  source of water supply; (2)
the system  was in operation on the
 effective date of the treatment technique
requirement, or  for a system that was
not in operation by that date, no

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Federal  Register/Vol. 68, No. 154/Monday.  August  11.  2003/Proposed Rules
reasonable alternative source of
drinking water is available to the new
system; (3) the exemption will not result
in an unreasonable risk to health; and
(4) management or restructuring
changes (or both) cannot reasonably
result in compliance with the Act or
improve the quality of drinking water.
  IT EPA or the State grants an
exemption to a public water system, it
must at the same time prescribe a
schedule for compliance (including
increments of progress or measures to
develop an alternative source of water
supply) and implementation of
appropriate control measures that the
State requires the system to meet while
the exemption is in effect. Under section
1416(b)(2}(A), the schedule shall require
compliance as expeditiously as
practicable (to be determined by the
State), but no later than three years after
the otherwise applicable compliance
date for the regulations established
pursuant to section 1412(b)(10), For
public water systems that do not  serve
more than a population of 3,300 and
that need financial assistance for the
necessary improvements, EPA or the
State may renew an exemption for one
or more additional two-year periods, but
not to exceed a total of six years.
   A public water system shall not be
granted an exemption unless it can
establish that: (1) The system cannot
meet the standard without capital
improvements that cannot be completed
prior to the date established pursuant to
 section 1412(b)(10); or (2) in the case of
 a system that needs financial  assistance
 for the necessary implementation, the
 system has entered into an agreement to
 obtain financial assistance pursuant to
 section 1452 or any other Federal or
 state program; or (3) the system has
 entered into an enforceable agreement to
 become part of a regional public water
 system.
   EPA believes that granting an
 exemption to the Ctyptosporidium
 treatment requirements of the
 LT2ESWTR would result in an
 unreasonable risk to health. As
 described in section 1I.C,
 Cryptosporidium causes acute health
 effects, which may be severe in sensitive
 subpopulations and include risk of
 mortality. Moreover, the additional
 Cryptosporidium treatment
 requirements of the LT2ESWTR are
 targeted to systems with the highest
 degree of risk. Due to these factors, EPA
 is not proposing to allow exemptions
 under the LT2ESWTR.
 3. Request for Comment
   a. Variances. EPA requests comment
 on the determination that the provisions
 for granting variances are not applicable
                      to the proposed LT2ESWTR, specifically
                      including Cryptosporidium inactivation
                      requirements for unfiltered systems.
                         In theory it would be possible for an
                      unfiltered system to demonstrate raw
                      water Cryptosporidium levels that were
                      3 log lower than the cutoff for bin \ for
                      filtered systems and, thus, that it may be
                      providing comparable public health
                      protection without additional
                      inactivation. However, EPA has
                      determined that in practice it is not
                      currently economically or
                      technologically feasible for systems to
                      ascertain the level of Cryptosporidium
                      at this concentration. This is due to the
                      extremely large number and volume of
                      samples that would be necessary to
                      make this demonstration with sufficient
                      confidence. Based on this determination
                      and the Cryptosporidium occurrence
                      data described in section III.C, EPA is
                      not proposing to allow unfiltered
                      systems to demonstrate raw water
                       Cryptosporidium levels low enough  to
                      avoid inactivation requirements. EPA
                      .requests comment on this approach.
                         b. Exemptions. EPA requests
                       comment on the determination that
                       granting an exemption to the
                       Cryptosporidium treatment
                       requirements of the LT2ESWTR would
                       result in an unreasonable risk to health.

                       /, Requirements for Systems To Use
                       Qualified Operators

                         The SWTR established a requirement
                       that each public water system using a
                       surface water source or a ground water
                       source under the direct influence of
                       surface water must be operated by
                       qualified personnel who meet the
                       requirements specified by the State  (40
                       CFR 141.70). The Stage 1 DBPR
                       extended this requirement to include  all
                       systems affected by that rule, and
                       required that States maintain a register
                       of qualified operators (40 CFR
                       141.130(c)). While the proposed
                       LT2ESWTR establishes no new
                       requirements regarding the operation of
                       systems by qualified personnel, the
                       Agency would like to emphasize the
                       important role that qualified operators
                       play in delivering safe drinking water to
                       the public. EPA encourages States that
                       do not already have operator
                       certification programs in effect to
                       develop such programs. States should
                       also review and modify, as required,
                       their qualification standards to take into
                       account new technologies (e.g.,
                       ultraviolet disinfection) and new
                       compliance requirements.
/. System Reporting and Recordkeeping
Requirements
1. Overview
  Today's proposal includes reporting
and recordkeeping requirements
associated with proposed monitoring
and treatment requirements. As
described earlier, systems must conduct
source water monitoring to determine a
treatment bin classification for filtered
systems or a mean Cryptosporidium
level for unfiltered systems. Systems
with previously collected monitoring
data may be able to use (i.e.,
grandfather) those data in lieu of
conducting new monitoring. Following
source water monitoring, systems will
be required to comply with any
additional Cryptosporidium treatment
requirements by implementing
treatment and control strategies from a
microbial toolbox of options. Systems
must conduct a second round of source
water monitoring six years after bin
classification.
  In addition, systems using uncovered
finished water storage facilities must
 cover the facility or provide treatment
 unless the system implements a State-
 approved risk management strategy.
 Certain systems will be required to
 conduct disinfection profiling and
 benchmarking.
   The proposed rule requires public
 water systems to submit schedules for
 Cryptosporidium, E. coli, and turbidity
 sampling at least 3 months before
 monitoring must begin. Source water
 sample analysis results must be reported
 not later than ten days after the end of
 first month following the month when
 the sample is collected. As described
 later, large systems (at least 10,000
 people served) will report monitoring
 results from the initial round of
 monitoring directly to EPA through an
 electronic data system. Small systems
 will report monitoring results to the
 State. Both small and large systems will
 report monitoring results from the
 second round of monitoring to the State.
   Systems must report a bin
 classification (filtered systems) or mean
 Cryptosporidium level (unfiltered
 systems) within six months following
 the month when the last sample in  a
 particular round of monitoring is
 ^scheduled to be collected. If systems are
 Required to provide additional treatment
 for Cryptosporidium, they must report
 regarding the use of microbial toolbox
  components. Systems must notify the
  State within 24 months following
  promulgation of the rule if they use
  uncovered finished water storage
  facilities. Systems must also make
  reports related to disinfection profiling
  and benchmarking. Reporting

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                   Federal  Register/Vol.  68, No. 154/Monday, August 11, 2003/Proposed Rules
                                                                                                                    47725
                                           activities are summarized in Tables IV-
                                           25 to IV-28.
requirements associated with these


               TABLE IV-25.— SUMMARY OF  INITIAL LARGE FILTERED SYSTEM REPORTING REQUIREMENTS
             You must report the following items
                                                                               On the following schedule
 Sampling schedule for Cryptosporidium, E. coli, and  turbidity  No later than 3 months after promulgation.
   monitoring.
 Results of Cryptosporidium, E. coli, and turbidity analyses 	  No later than  10 days after the end of the first month following the month in
                                                           which the sample is collected.
 Bin determination 	  No later than 36 months after promulgation.
 Demonstration of compliance with additional treatment require-  Beginning 72 months after promulgation1 (See table IV-34).
   ments.
 Disinfection profiling component reports	  See Table IV-35.

   1 States may grant an additional two years for systems making capital improvements.

                TABLE IV-26.—SUMMARY OF INITIAL SMALL FILTERED SYSTEM REPORTING REQUIREMENTS

             You must report the following  items                                     On the following schedule

 Sampling schedule for E. coli monitoring 	  No later than 27 months after promulgation.
 Results of E. coli analyses (unless State approves a different  No later than  10 days after the end of the first month following the month in
   indicator).                                                 which the  sample was collected.
 Mean E coli concentration (unless State approves a different  No later than 45 months after promulgation.
   indicator).
 Disinfection profiling component reports	  See Table IV-36.

                                   Additional requirements if E. coli trigger level is exceeded1

 Sampling schedule for Cryptosporidium monitoring 	  No later than 45 months after promulgation.
 Results of Cryptosporidium analyses	  No later than 10 days after the end of the first month following the month in
                                                           which the  sample is collected.
 Bin determination 	  No later than 66 months after promulgation.
 Demonstration of compliance with additional treatment require-  Beginning 102 months after promulgation2 (See Table IV-34).
   ments.

   11f the E. coli annual mean concentration exceeds 10/100 mL for systems using lakes/reservoirs or exceeds 50/100 mL for systems using flow-
 ing streams,  then systems must conduct Cryptosporidium monitoring. States may approve alternative indicator criteria to trigger Cryptosporidium
 monitoring.
   2 States may grant an additional two years for systems making capital improvements.

              TABLE IV-27 — SUMMARY OF INITIAL LARGE UNFILTERED  SYSTEM REPORTING REQUIREMENTS

            You must report the following items                                     On the following schedule

 Cryptosporidium sampling schedule 	  No later than 3 months after promulgation.
 Results of Cryptosporidium analyses	  No later than 10 days after the end of the first month following the month in
                                                          which the sample was collected.
 Determination of mean Cryptosporidium concentration	  No later than 36 months after promulgation.
 Disinfection profiling component reports	  See Table IV-35.
 Demonstration of compliance with Cryptosporidium inactivation  Beginning 72 months after promulgation1 (see Table IV-34).
  requirements.

  1 States may grant an additional two years for systems making capital improvements.

              TABLE IV-28.-—SUMMARY OF INITIAL SMALL UNFILTERED SYSTEM REPORTING REQUIREMENTS

            You must report the following items                                     On the following schedule

 Cryptosporidium sampling schedule 	  No later than 45 months after promulgation.
Results of Cryptosporidium analyses	  No later than 10 days after the end of the first month following the month in
                                                          which the sample was collected.
Determination of mean Cryptosporidium concentration	  No later than 66 months after promulgation.
Disinfection profiling component reports	  See Table IV-35.
Demonstration of compliance with Cryptosporidium inactivation  Beginning 102 months after promulgation1 (see Table IV-34).
  requirements.                                           	

  1 States may grant an additional two years  for systems making capital improvements.

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47726
Federal Register/Vol.  68, No. 154/Monday. August 11. 2003 / Proposed Rules
2. Reporting Requirements for Source
Water Monitoring

  a. Data elements to be reported.
Proposed reporting requirements for
LT2ESWTR monitoring stem from
proposed analytical method
requirements. As stated in sections IV.K
and 1V.L, systems must have
Cryptosporidium analyses conducted by
EPA-approved laboratories using
Methods 1622 or 1623. E. coli analyses
must be performed by State-approved
laboratories using the E. coli methods
proposed for approval in section IV.K.
Systems are required to report the data
                       elements specified in Table IV-29 for
                       each Cryptosporidium analysis. To
                       comply with LT2ESWTR requirements,
                       only the sample volume filtered and the
                       number of oocysts counted must be
                       reported for samples in which at least
                       10 L is filtered and all of the sample
                       volume is analyzed. Additional
                       information is required for samples
                       where the laboratory analyzes less than
                       10 L or less than the full sample volume
                       collected. Table IV-30 presents the data
                       elements that systems must report for E.
                       coli analyses.
                         As described in the following section,
                       EPA is developing a data system to
manage and analyze the microbial
monitoring data that will be reported by
large systems under the LT2ESWTR.
EPA is exploring approaches for
application of this data system to
support small system data reporting as
well. Systems, or laboratories acting as
the systems' agents, must keep Method
1622/1623 bench sheets and slide
examination report forms until 36
months after an equivalent round of
source water monitoring has been
completed (e.g., second round of
Cryptosporidium monitoring).
                    TABLE IV-29.—PROPOSED Cryptosporidium DATA ELEMENTS TO BE REPORTED
                 Data element
                                                                      Reason for data element
 Identifying information
  PWSID	
  Facility ID 	
  Sample collection point 	
  Sample collection date	
  Sample type (field or matrix spike)1
                            Needed to associate plant with public water system.
                            Needed to associate sample result with facility.
                            Needed to associate sample result with sampling point.
                            Needed to determine that utilities are collecting samples at the frequency required.
                            Needed to distinguish field samples from matrix samples for recovery calculations.
 Sample results
   Sample volume filtered (L), to nearest 1/4 L2
   Was 100% of filtered volume examined?3 ...
 •  Number of oocysts counted
                             Needed to verify compliance with sample volume requirements.
                             Needed to calculate the final concentration of oocysts/L and determine if volume ana-
                              lyzed requirements are met.
                             Needed to calculate the final concentration of oocysts/L.	
    For matrix spike samples, sample volume spiked and estimated number of oocysts spiked must be reported. These data are not required for
                                   ^

                                                                                                            processed
TABLE IV-30.— PROPOSED E. coli DATA ELEMENTS TO BE REPORTED
Data element
Reason for collecting data element
Identifying Information 	 	 	 __ 	
PWS ID 	








Needed to associate analytical result with public water system.
Needed to associate plant with public water system.
Needed to associate sample result with sampling point.
Needed to determine that utilities are collecting samples at the frequency required.
Needed to associate analytical result with analytical method.
Needed to verify that an approved method was used and call up correct web entry form.
Needed to assess Cryptosporidium indicator relationships.
Sample result {although not required, the laboratory also will have the option of entering primary measure-
ments for a sample into the LT2ESWTR internet-based database to have the database automatically cal-
culate the sample result).
Turbldltv Information 	 . 	
Turbidity result 	
Needed to assess Cryptosporidium indicator relationships.
   b. Data system. Because source water
 monitoring by large systems (serving at
 least 10,000 people) will begin 6 months
 following promulgation of the
 LT2ESWTR, EPA expects to act as the
 primacy agency with oversight
 responsibility for large system sampling,
                        analysis, and data reporting. To
                        facilitate collection and analysis of large
                        system monitoring data, EPA is
                        developing an Internet-based electronic
                        data collection and management system.
                        This approach is similar to that used
                        under the Unregulated Contaminants
  Monitoring Rule (UCMR) (64 FR 50556,
  September 17,1999) (USEPA 1999c).
   Analytical results for
  Cryptosporidium, E. coli, and turbidity
  analyses will be reported directly to this
  database using web forms and software
  that can be downloaded free of charge.

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                  Federal Register/Vol.  68,  No. 154/Monday, August 11, 2003/Proposed Rules
                                                                                    47727
 The data system will perform logic
 checks on data entered and calculate
 final results from primary data (where
 necessary). This is intended to reduce
 reporting errors and limit the time
 involved in investigating, checking, and
 correcting errors at all levels. EPA will
 make large system monitoring data
 available to States when States assume
 primacy for the LT2ESWTR or earlier
 under State agreements with EPA.
   Large systems should instruct their
 laboratories to electronically enter
 monitoring results into the EPA data
 system using web-based manual entry
 forms or by uploading XML files from
 laboratory information management
 systems (LIMS). After data are
 submitted by a laboratory, systems may
 review the results on-line. If a system
 believes that a result was entered  into
 the data system erroneously, the system
 may notify the laboratory to rectify the
 entry. In addition, if a system believes
 that a result is incorrect, the system may
 submit the result as a contested result
               and petition EPA or the State to
               invalidate the sample. If a system
               contests a sample result, the system
               must submit a rationale to the primacy
               agency, including a supporting
               statement from the laboratory, providing
               a justification. Systems may arrange
               with laboratories to review their sample
               results prior to the results being entered
               into the EPA data system. Also, if a
               system determines that its laboratory
               does not have the capability to report
               data electronically, the system can
               submit a request to EPA to use an
               alternate reporting format.
                Regardless of the reporting process
               used, systems are required to report an
               analytical monitoring result to the
               primacy agency no later than 10 days
               after the end of the  first month
               following the month when the sample
               was collected. As described in section
               IV.A.l, if a system is unable to report a
               valid Cryptosporidium analytical result
               for a scheduled sampling date  due to
               failure to comply with the analytical
 method requirements (e.g., violation of
 quality control requirements), the
 system must collect a replacement
 sample within 14 days of being notified
 by the laboratory or the State that a
 result cannot be reported for that date
 and must submit an explanation for the
 replacement sample with the analytical
 results. A system will not incur a
 monitoring violation if the  State
 determines that the failure  to report a
 valid analysis result was due to
 circumstances beyond the control of the
 system. However, in all cases the system
 must collect a replacement sample.
   The data elements to be collected by
 the electronic data system will enhance
 the reliability of the microbial data
 generated under the LT2ESWTR, while
 reducing the burden on the analytical
 laboratories and public water systems.
 Tables IV-31 and IV-32 summarize the
 system's data analysis functions for
 Cryptosporidium measurements.
                  TABLE IV-31— LT2ESWTR DATA SYSTEM FUNCTIONS FOR Cryptosporidium DATA
         Value calculated
                                   Formula
                                                                                                 Applicability to sample
                                                                                                        types
                                                                                                   Field
                                                                                    Matrix
                                                                                    spike
 Calculation  of  sample  volume  ana-
  lyzed.
 Pellet volume analyzed	

 Calculation of oocysts/L	
 Calculation  of  estimated  number of
  oocysts spiked/L.
 Calculation  of percent recoveries for
  MS samples.
        (Volume filtered) * (resuspended concentrate volume transferred to IMS/re-
          suspended concentrate volume).
        (pellet volume)*(resuspended concentrated volume transferred to IMS/resus-
          pended concentrate volume).
        (Number of oocysts counted)/(sample volume analyzed)  	,	
        (Number of oocysts spiked)/(sample volume spiked)	
                  Yes

                  Yes

                  Yes
                  No .
        ((Calculated # of oocysts/L for the MS sample)—(Calculated # of oocysts/L
          in the associated field sample)) / (Estimated number of oocysts spiked/L)*
          100%.
                  No
Yes.

Yes.

Yes.
Yes.

Yes.
           TABLE IV-32 — LT2ESWTR DATA SYSTEM FUNCTIONS FOR Cryptosporidium COMPLIANCE CHECKS
     LT2 requirements
                                         Description
Sample volume analysis
Schedule met
Specifies that the LT2 requirements for sample volume analyzed were met when:
• volume analyzed is > 10 L.
» volume analyzed is < 10 L and pellet volume analyzed is at least 2 ml.
• volume analyzed < 10 L and pellet volume analyzed < 2 mL and 100% of filtered volume examined= Y and two
  filters were used.
Specifies that the LT2 requirements for sample volume analyzed were not met when;
• volume analyzed < 10 L and pellet volume analyzed is < 2 ml and 100% of filtered volume examined= N.
• volume analyzed is < 10 L and pellet volume analyzed < 2 mL and only 1 filter used.
Specifies that the predetermined sampling schedule is met when the sample  collection data is within ± 2 days of
  the scheduled date.
  c. Previously collected monitoring
data. Table IV-33 provides a summary
of the items that systems must report to
EPA for consideration of previously
collected (grandfathered) monitoring
data under the LT2ESWTR. For each
field and matrix spike (MS) sample,
systems must report the data elements
specified in Table IV-29. In addition,
              the laboratory that analyzed the samples
              must submit a letter certifying that all
              Method 1622 and 1623 quality control
              requirements (including ongoing
              precision and recovery (OPR) and
              method blank (MB) results, holding
              times, and positive and negative
              staining controls) were performed at the
              required frequency and were acceptable.
Alternatively, the laboratory may
provide for each field, MS, OPR, and
MB sample a bench sheet and sample
examination report form (Method 1622
and 1623 bench sheets are shown in
USEPA 2003h).
  Systems must report all routine
source water  Cryptosporidium
monitoring results collected during the

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47728
Federal Register/Vol. 68, No.  154/Monday, August  11,  2003 / Proposed Rules
period covered by the previously
collected data that have been submitted.
This applies to all samples that were
collected from the sampling location
used for monitoring, not spiked, and
analyzed using the laboratory's routine
process for Method 1622 or 1623
analyses, including analytical technique
                       and QA/QC. Other requirements
                       associated with use of previously
                       collected data are specified in section
                       IV.A.l.d. Where applicable, systems
                       must provide documentation addressing
                       the dates and reason(s) for re-sampling,
                       as well as the use of presedimentation,
                       off-stream storage, or bank filtration
during monitoring. Review of the
submitted information, along with the
results of the quality assurance audits of
the laboratory that produced the data,
will be used to determine whether the
data meet the requirements for
grandfathering.
     TABLE iv-33.—ITEMS THAT MUST BE REPORTED FOR CONSIDERATION OF GRANDFATHERED MONITORING  DATA
                  The following items must be reported
                                                                                 On the following schedule
Data elements listed in Table IV-29 for each field and MS sample
Letter from laboratory certifying that method-specified QC was  performed  at re-
  quired frequency and was acceptable.
OR
Method 1622/1623 bench sheet and sample examination report form for each field,
  MS, OPR, and method blank sample.
Letter from system certifying (1) that all source water data collected during the time
  period covered by the previously collected data have been submitted and (2) that
  the data represent the plant's current source water.
Where applicable,  documentation addressing the dates and reason(s) for re-sam-
  pling, as well as  the use of presedimentation, off-stream storage, or bank filtration
  during monitoring.               	
                                                    No later than 2 months after promulgation if the system
                                                      does not intend to conduct new monitoring under the
                                                      LT2ESWTR.
                                                    OR
                                                    No later than 8 months after promulgation if the system in-
                                                      tends to conduct new monitoring under the LT2ESWTR.
  1 See section IV.A.1. for details.
3. Compliance With Additional
Treatment Requirements

   Under the proposed LT2ESWTR,
systems may choose from a "toolbox" of
management and treatment options to
meet their additional Cryptosporidium
treatment requirements. In order to
                       receive credit for toolbox components,
                       systems must initially demonstrate that
                       they comply with any required design
                       and implementation criteria, including
                       performance validation testing.
                       Additionally, systems must provide
                       monthly verification of compliance with
                       any required operational criteria, as
 shown through ongoing monitoring.
 Required design, implementation,
 operational, and monitoring criteria for
 toolbox components are described in
 section IV.C. Proposed reporting
 requirements associated with these
 criteria are shown in Table IV-34 for
 both large and small systems.
                                 TABLE IV-34.—TOOLBOX REPORTING REQUIREMENTS
Toolbox option
(potential
Cryptosporidium re-
duction log credit)

Watershed Control
Program (WCP)
(0 5 loa)
\V'X* tuyf










Pre-sedimentation ,
{0.5 log) {new ba-
sins)




Two-Stage Lime Soft-
ening (0.5 log)




You must submit the following items
Notify State of intention to develop WCP 	
9nhmit initial WCP olan to State 	 	 	


Annual program status report and State-approved watershed
survey report.



Request for re-approval and report on the previous approval
period.



Monthly verification of:
Continuous basin operation
Treatment of 100% of the flow
Continuous addition of a coagulant
At least 0.5 log removal of influent turbidity based on the
monthly mean of daily turbidity readings for 11 of the 12
previous months
Monthly verification of:
Continuous operation of a second clarification step between
the primary clarifier and fitter
Presence of coagulant (may be lime) in first and second stage
clarifiers
Both clarifiers treat 100% of the plant flow
On the following sched-
ule1
(systems serving £10,000
people)
No later than 48 months
after promulgation
No later than 60 months
after promulgation
By a date determined by
the State, every 12
months, beginning 84
months after promulga-
tion
No later than 6 months
prior to the end of the
current approval period
or by a date previously
determined by the State
Monthly reporting within
10 days following the
month in which the
monitoring was con-
ducted, beginning 72
months after promulga-
tion
No later than 72 months
after promulgation




On the following sched-
ule i
(systems serving < 10,000
people)
No later than 78 months
after promulgation.
No later than 90 months
after promulgation.
By a date determined by
the State, every 12
months, beginning 114
months after promulga-
tion.
No later than 6 months
prior to the end of the
current approval period
or by a date previously
determined by the State.
Monthly reporting within
10 days following the
month in which the
monitoring was con-
ducted, beginning 102
months after promulga-
tion.
No later than 102 months
after promulgation.





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Federal Register/Vol. 68, No. 154/Monday, August 11, 2003/Proposed Rules
47729
        TABLE IV-34.—TOOLBOX REPORTING REQUIREMENTS—Continued
toolbox option
(potential
Cryptosporidium re-
duction log credit)
Bank filtration (0.5 or
1.0 log) (new)







Combined filter per-
formance (0.5 log)





Membranes (MF, UF,
NF, RO) (2.5 log or
greater based on
verification/integrity
testing)






Bag filters (1.0 log)
and Cartridge filters
(2.0 log)




Chlorine dioxide (log
credit based on
CT)



Ozone (log credit
based on CT)




UV (log credit based
UV dose and oper-
ating within vali-
dated conditions)






Individual filter per-
formance (1.0 log)







Demonstration of Per-
formance
You must submit the following items
Initial demonstration of:
Unconsolidated, predominantly sandy aquifer
Setback distance of at least 25 ft. (0.5 log) or 50 ft. (1 .0 log)
If monthly average of daily max turbidity is greater than 1 NTU
then system must report result and submit an assessment
of the cause



Monthly verification of:
Combined filter effluent (CFE) turbidity levels less than or
equal to 0.15 NTU in at least 95 percent of the 4 hour CFE
measurements taken each month



Initial demonstration of:
Removal efficiency through challenge studies
Methods of challenge studies meet rule criteria
Integrity test results and baseline

Monthly report summarizing:
All direct integrity test results above the control limit and the
corrective action that was taken
All indirect integrity monitoring results triggering direct integrity
testing and the corrective action that was taken

Initial demonstration that the following criteria are met:
Process meets the basic definition of bag or cartridge filtra-
tion;
Removal efficiency established through challenge testing that
meets rule criteria
Challenge test shows at least 2 and 3 log removal for bag and
cartridge filters, respectively
Summary of CT values for each day and log inactivation
based on tables in section IV.C.14




Summary of CT values for each day and log inactivation
based on tables in section IV.C.14




Results from reactor validation testing demonstrating oper-
ating conditions that achieve required UV dose


Monthly report summarizing the percentage of water entering
the distribution system that was not treated by UV reactors
operating within validated conditions for the required UV
dose in section IV.C.15


Monthly verification of the following, based on continuous
monitoring of turbidity for each individual filter:
Filtered water turbidity less than 0.1 NTU in at least 95 per-
cent of the daily maximum values from individual filters (ex-
cluding 15 minute period following start up after
backwashes)
Jo individual filter with a measured turbidity greater than 0.3
NTU in two consecutive measurements taken 15 minutes
apart
Results from testing following State approved protocol 	

On the following sched-
ule1
(systems serving >10,000
people)
Initial demonstration no
later than 72 months
after promulgation
Report within 30 days fol-
lowing the month in
which the monitoring
was conducted, begin-
ning 72 months after
promulgation
Monthly reporting within
10 days following the
month in which the
monitoring was con-
ducted, beginning on 72
months after promulga-
tion
No later than 72 months.
after promulgation



Within 10 days following
the month in which
monitoring was con-
ducted, beginning 72
months after promulga-
tion
No later than 72 months
after promulgation





Within 10 days following
the month in which
monitoring was con-
ducted, beginning 72
months after promulga-
tion
Within 10 days following
the month in which
monitoring was con-
ducted, beginning 72
months after promulga-
tion
No later than 72 months
after promulgation


Within 10 days following
the month in which
monitoring was con-
ducted, beginning 72
months after promulga-
tion
Monthly reporting within
10 days following the
month in which the
monitoring was con-
ducted, beginning on 72
months after promulga-
tion


'Jo later than 72 months
after promulgation
On the following sched-
ule1
(systems serving < 10,000
people)
Initial demonstration no
later than 102 months
after promulgation.
Report within 30 days fol-
lowing the month in
which the monitoring
was conducted, begin-
ning 102 months after
promulgation.
Monthly reporting: within
10 days following the
month in which the
monitoring was con-
ducted, beginning on
102 months after pro-
mulgation.
No later than 102 months
after promulgation.



Within 10 days following
the month in which
monitoring was con-
ducted, beginning 102
months after promulga-
tion.
No later than 102 months
after promulgation.





Within 10 days following
the month in which
monitoring was con-
ducted, beginning 102
months after promulga-
tion.
Within 10 days following
the month in which
monitoring was con-
ducted, beginning 102
months after promulga-
tion.
No later than 102 months
after promulgation.


Within 10 days following
the month in which
monitoring was con-
ducted, beginning 102
months after promulga-
tion.
Monthly reporting: within
10 days following the
month in which the
monitoring was con-
ducted, beginning 102
months after promulga-
tion.


No later than 102 months
after promulgation.

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Federal  Register/Vol. 68, No.  154/Monday,  August  11, 2003/Proposed Rules
                            TABLE IV-34—TOOLBOX REPORTING REQUIREMENTS—Continued
Toolbox option
(potential
Cryptosporidium re-
duction log credit)

You must submit the following items
Monthly verification of operation within State-approved condi-
tions for demonstration of performance credit
On the following sched-
ule1
(systems serving £10,000
people)
Within 10 days following
the month in which
monitoring was con-
ducted, beginning 72
months after promulga-
tion
On the following sched-
ule1
(systems serving < 10,000
people)
Within 10 days following
the month in which
monitoring was con-
ducted, beginning 102
months after promulga-
tion.
  1 States may allow an additional two years for systems making capital improvements.
  Reporting requirements associated with disinfection profiling and benchmarking are summarized in Table IV-35 for large
systems and in Table IV-36 for small systems.

             TABLE  IV-35.—DISINFECTION BENCHMARKING REPORTING REQUIREMENTS FOR LARGE SYSTEMS
     System type
               Benchmark component
                                                                    Submit the following items
                                                                                  On the following schedule
Systems required to
  conduct
  Cryptosporidium
  monitoring.
Systems not required
  to conduct
  Cryptosporidium
  monitoring1.
     Characterization of Disinfection Practices 	
     State Review of Proposed Changes to Dis-
       infection Practices.
     Applicability 	
                       Characterization of Disinfection Practices  	
                       State  Review of Proposed Changes  to  Dis-
                         infection Practices.
Giardia lamblia and virus inactiva-
  tion profiles must be on file for
  State  review  during  sanitary
  survey.
Inactivation profiles and  bench-
  mark determinations.
None 	
                                               None
                                               None
No later than 36 months after pro-
  mulgation.
                                                                                                 Prior to significant modification of
                                                                                                   disinfection practice.
                                                                                                 None.
                                None.
                                None.
  1Systems that provide at least 5.5 log of Cryptosporidium treatment consistent with a Bin 4 treatment implication are not required to conduct
Cryptosporidium monitoring.

             TABLE IV-36.—DISINFECTION BENCHMARKING REPORTING REQUIREMENTS  FOR SMALL SYSTEMS
     System type
               Benchmark component
                                                                    Submit the following items
                                                                                  On the following schedule
Systems required to
  conduct
  Cryptosporidium
  monitoring.
Systems not required
  to conduct
  Cryptosporidium
  monitoring and that
  exceed DBP trig-
  gers 1'2'3.
                       Characterization of Disinfection Practices 	
     State Review of Proposed Changes to Dis-
       infection Practices.
     Applicability Period	
Systems not required
  to conduct
  Cryptosporidium
  monitoring and that
  do not exceed DBP
  triggers2'3.
                       Characterization of Disinfection Practices 	
     State Review of Proposed Changes to Dis-
       infection Practices.
     Applicability Period	
Giardia lamblia and virus inactiva-
  tion profiles must be on file for
  State  review  during  sanitary
  survey.
tnactivation  profiles and  bench-
  mark determinations.
Notify State that profiling  is  re-
  quired based on DBP levels.
Giardia lamblia and virus inactiva-
  tion profiles must be on  file for
  State   review  during  sanitary
  survey.
Inactivation  profiles and bench-
  mark determinations.
Notify State that profiling  is  not re-
  quired based on DBP levels.
                       Characterization of Disinfection Practices 	
                       State  Review of Proposed Changes to Dis-
                         infection Practices.
                                               None
                                               None
                                                                               No later than 66 months after pro-
                                                                                 mulgation.
Prior to significant modification of
  disinfection practice.
No later than 42 months after pro-
  mulgation.
                                                                               No later than 54 months after pro-
                                                                                 mulgation.
Prior to significant modification of
  disinfection practice.
No later than 42 months after pro-
  mulgation.
                                None.
                                None.
  1 Systems that provide at least 5.5 log of Cryptosporidium treatment consistent with a Bin 4 treatment implication are not required to conduct
Cryptosporidium monitoring.                                                         .              „„,..„«   ,  ,      .          „
  2|f the E coli annual mean concentration is < 10/100 mL for systems using lakes/reservoir sources or <, 50/100 mL for systems using flowing
stream sources, the system is not required to conduct Cryptosporidium monitoring and will only be required to characterize disinfection practices
if DBP triggers are exceeded.

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                  Federal  Register/Vol. 68, No. 154/Monday, August 11, 2003/Proposed Rules
                                                                      47731
  . 3lf the system is a CWS or NTNCWSs and TTHM or HAA5 levels in the distribution system are at least 0.064 mg/L or 0.048 mg/L, respec-
  tively, calculated as an LRAA at any Stage 1 DBPR sampling site, then the system is triggered into disinfection profiling.
  4. Request for Comment
    EPA requests comment on the
  reporting and recordkeeping
  requirements proposed for the
  LT2ESWTR.
    Specifically, the Agency requests
  comment on the proposed requirement
  that systems report monthly on the use
  of microbial toolbox components to
  demonstrate compliance with their
  Cryptosporidium treatment
  requirements. An alternative may be for
  systems to keep records on site for State
  review instead of reporting the data.

  K. Analytical Methods
   EPA is proposing to require public
  water systems to conduct LT2ESWTR
  monitoring using approved methods for
  Cryptosporidium, E. coli, and turbidity
  analyses. This includes meeting quality
  control criteria stipulated by the
 approved methods and additional
 method-specific requirements, as stated
 later in this section. Related
 requirements on the use of approved
 laboratories are discussed in section
 IVX, and proposed requirements for
 reporting of data were stated previously
 in section IV.J. EPA has developed draft
 guidance for sampling and analyses
 under the LT2ESWTR (see USEPA
 2003g and 2003h). This guidance is
 available in draft form in the docket for
 today's proposal (http://www.epa.gov/
 edocketf).

 1. Cryptosporidium
   a. What is EPA proposing today?
 Method 1622: "Cryptosporidium in
 Water by Filtration/IMS/FA" (EPA-821-
 R-01-026, April 2001) (USEPA 2001e)
 and Method 1623: "Cryptosporidium
 and Giardia in Water by Filtration/IMS/
 FA" (EPA 821-R-01-025, April 2001)
 (USEPA 2001f) are proposed for
 Cryptosporidium analysis under this
 rule. Methods 1622 and 1623 require
 filtration, immunomagnetic separation
 (IMS) of the oocysts from the captured
 material, and examination based on  IFA,
 DAPI staining results, and differential
 interference contrast (DIG) microscopy
 for determination of oocyst
 concentrations.

 Method Requirements
  For each Cryptosporidium sample
 under this proposal, all systems must
 analyze at least a 10-L sample volume.
 Systems may collect and analyze greater
than a 10-L sample volume. If a sample
is very turbid, it may generate a large
packed pellet volume upon
centrifugation (a packed pellet refers to
  the concentrated sample after
  centrifugation has been performed in
  EPA Methods 1622 and 1623). Based on
  IMS purification limitations, samples
  resulting in large packed pellets will
  require that the sample concentrate be
  aliquoted into multiple "subsamples"
  for independent processing through
  IMS, staining, and examination. Because
  of the expense of the IMS reagents and
  analyst time to examine multiple slides
  per sample, systems are not required to
  analyze more than 2 mL of packed pellet
  volume per sample.
   In cases where it is not feasible for a
  system to process a 10-L sample for
  Cryptosporidium analysis (e.g., filter
  clogs prior to  filtration of 10 L) the
  system must analyze as much sample
  volume as can be filtered by 2 filters, up
 to a packed pellet volume of 2 mL. This
  condition applies only to filters that
 have been approved  by EPA for
 nationwide use with Methods 1622 and
  1623—the Pall Gelman Envirochek™
 and Envirochek™ HV filters, the IDEXX
 Filta-Max™ foam filter, and the
 Whatman CrypTest™ cartridge filter.
   Methods 1622 and 1623 include
 fluorescein isothiocyanate (FITC) as the
 primary antibody stain for
 Cryptosporidium detection, DAPI
 staining to detect nuclei, and DIG to
 detect internal structures. For purposes
 of the LT2ESWTR, systems must report
 total Cryptosporidium oocysts as
 detected by FITC as determined by the
 color (apple green or alternative stain
 color approved for the laboratory under
 the Lab QA Program  described in
 section VI.L), size (4-6 urn) and shape
 (round to  oval). This  total includes all
 of the oocysts  identified as described
 here, less  atypical organisms identified
 by FITC, DIG, or DAPI (e.g., possessing
 spikes, stalks,  appendages, pores, one or
 two large nuclei filling the cell, red
 fluorescing chloroplasts, crystals,
 spores, etc.).
 Matrix Spike Samples
   As required by Method 1622 and
 1623, systems must have 1 matrix spike
 (MS) sample analyzed for each 20
 source water samples. The volume of
 the MS sample must be within ten
 percent of the volume of the unspiked
 sample that is collected at the same
 time, and the samples must be collected
 by splitting the sample stream or
 collecting  the samples sequentially. The
MS sample and the associated unspiked
sample must be analyzed by the same
procedure. MS samples must be spiked
and filtered in the laboratory. However,
 if the volume of the MS sample is
 greater than 10 L, the system is
 permitted to filter all but 10 L of the MS
 sample in the field, and ship the filtered
 sample and the remaining 10 L of source
 water to the laboratory. In this case, the
 laboratory must spike the remaining 10
 L of water and filter it through the filter
 used to collect the balance of the sample
 in the field.
   EPA is proposing to require the use of
 flow cytometer-counted spiking
 suspensions for spiked QC samples
 during the LT2ESWTR. This provision
 is based on the improved precision
 expected for spiking suspensions
 counted with a flow cytometer, as
 compared to those counted using well
 slides or hemacytometers. During the
 Information Collection Rule
 Supplemental Surveys, the mean
 relative standard  deviation (RSD) across
 25 batches of flow cytometer-sorted
 Cryptosporidium spiking suspensions
 was 1.8%, with a median of 1.7%
 (Connell et  a}. 2000). In EPA
 Performance Evaluation (PE) studies,
 the mean RSD for flow cytometer sorted
 Cryptosporidium  spiking suspensions
 was 3.4%. In comparison, the mean RSD
 for Cryptosporidium spiking
 suspensions enumerated manually by
 20 laboratories using well slides or
 hemacytometers was 17% across 108
 rounds of 10-replicate counts.
   QC requirements in Methods 1622
 and 1623 must be met by laboratories
 analyzing Cryptosporidium samples
 under the LT2ESWTR. The QC
 acceptance criteria are the same as
 stipulated in the method. For the initial
 precision and recovery (IPR) test, the
 mean Cryptosporidium recovery must
 be 24% to 100% with maximum relative
 standard deviation (i.e., precision) of
 55%. For each ongoing precision and
 recovery (OPR) sample, recovery must
 be in the range of  11% to 100%. For
 each method blank, oocysts must be
 undetected.
  Methods 1622 and 1623 are
 performance-based methods and,
 therefore, allow multiple options to
 perform the  sample processing steps in
 the methods if a laboratory can meet
 applicable QC criteria and uses the same
 determinative technique. If a laboratory
uses the same procedures for all
 samples, then all field samples and QC
 samples must be analyzed in that same
manner. However, if a laboratory uses
more than one set  of procedures for
CTyptosporidium analyses under
LT2ESWTR then the laboratory must
analyze separate QC samples for each

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Federal Register/Vol.  68,  No. 154/Monday. August 11, 2003/Proposed  Rules
option to verify compliance with the QC
criteria. For example, if the laboratory
analyzes samples using both the
Envirochek™ and Filta-Max™ filters, a
separate set of IPR, OPR, method blank,
and MS samples must be analyzed for
each filtration option.
  b. How was this proposal developed?
EPA is proposing EPA Methods 1622
and 1623 for  Cryptosporidium analyses
under the LT2ESWTR because these are
the best available methods that have
undergone full validation testing. In
addition, these methods have been used
successfully in a national source water
monitoring program as part of the
Information Collection Rule
Supplemental Surveys (ICRSS). The
minimum sample volume and other
quality control requirements are
intended to ensure that data are of
sufficient quality to assign systems to
LT2ESWTR risk bins. Further, the
proposed method requirements for
analysis of Cryptosporidium are
consistent with recommendations by the
Stage 2 M-DBP Advisory Committee. In
the Agreement in Principle, the
Committee recommended that source
water Cryptosporidium monitoring
under the LT2ESWTR be conducted
using EPA Methods 1622 and 1623 with
no less than 10  L samples. EPA also has
proposed these methods for approval for
ambient water monitoring under
Guidelines Establishing Test Procedures
for the Analysis of Pollutants;
Analytical Methods for Biological
Pollutants  in Ambient Water (66 FR
45811, August 30, 2001) (USEPA 2001i).
   When considering the method
performance that could be achieved for
analysis of Cryptosporidium under the
LT2ESWTR,  EPA and the Advisory
Committee evaluated the
Cryptosporidium recoveries reported for
Methods 1622 and 1623 in the ICRSS.
As described in section III.C, the ICRSS
was a national monitoring program that
involved 87 utilities sampling twice per
month over 1 year for Cryptosporidium
and other microorganisms and water
quality parameters. During the ICRSS,
the mean recovery and relative standard
deviation associated with enumeration
of MS samples for total oocysts by
Methods 1622 and 1623 were 43% and
47%, respectively (Connell et al. 2000).
   EPA believes that with provisions like
the Laboratory QA Program for
Cryptosporidium laboratories (see
section IV.L), comparable performance
to that observed in the ICRSS can be
achieved in LT2ESWTR monitoring
with the use  of Methods 1622 and 1623,
and that this level of performance will
be sufficient to realize the public health
goals intended by EPA and the Advisory
Committee for the LT2ESWTR. Other
                      methods would need to achieve
                      comparable performance to be
                      considered for use under the
                      LT2ESWTR. For example, EPA does not
                      expect the Information Collection Rule
                      Method, which resulted in 12% mean
                      recovery for MS samples during the
                      Information Collection Rule Laboratory
                      Spiking Program (Scheller, 2002), to
                      meet LT2ESWTR data quality
                      objectives.
                        For systems collecting samples larger
                      than 10 L, EPA is proposing the
                      approach of allowing systems to filter
                      all but 10 L of the corresponding MS
                      sample in the field, and ship the filtered
                      sample and the remaining 10 L of source
                      water to the laboratory for spiking and
                      analysis. The Agency has determined
                      that the added costs associated with
                      shipping entire high-volume (e.g. 50-L)
                      samples to a laboratory for spiking and
                      analysis are not merited by improved
                      data quality relative to the use of
                      Cryptosporidium MS data under the
                      LT2ESWTR. EPA estimates that the
                      average cost  for shipping a 50-L bulk
                      water sample is $350 more than the cost
                      of shipping a 10-L sample and a filter.
                      A study comparing these two
                      approaches (i.e., spiking and filtering 50
                      L vs. field filtering 40 L and spiking 10
                      L) indicated  that spiking the 10-L
                      sample produced somewhat higher
                      recoveries (USEPA 2003i). However, the
                      differences were not significant enough
                      to offset the greatly increased shipping
                      costs, given the limited use of MS data
                      in LT2ESWTR monitoring.
                        c. Request for comment. EPA requests
                      comment on the proposed method
                      requirements for Cryptosporidium
                      analysis, including the following
                      specific issues:
                      Minimum Sample Volume
                        It is the intent of EPA that LT2ESWTR
                      sampling provide representative annual
                      mean source water concentrations. If
                      systems were unable to analyze an
                       entire sample volume during certain
                      periods of the year due to elevated
                      turbidity or other water quality factors,
                      this could result in systems analyzing
                      different volumes in different samples.
                      Today's proposal requires systems to
                      analyze  at least 10 L of sample or the
                      maximum amount of sample that can be
                       filtered through two filters, up to a
                      packed pellet volume of 2 mL. EPA
                      requests comment on whether these
                      requirements are appropriate for
                      systems with source waters that are
                      difficult to filter or that generate a large
                      packed pellet volume. Alternatively,
                       systems could be required to filter and
                      analyze at least 10 L of sample with no
                      exceptions.
Approval of Updated Versions of EPA
Methods 1622 and 1623
  EPA has developed draft revised
versions of EPA Methods 1622 and 1623
in order to consolidate several method-
related changes EPA believes may be
necessary to address LT2ESWTR
monitoring requirements (see USEPA
2003J and USEPA 2003k). EPA is
requesting comment on whether these
revised versions should be approved for
monitoring under the LT2ESWTR,
rather than the April 2001 versions
proposed in today's rule. If the revised
versions were approved, previously
collected data generated using the
earlier versions of the methods would
still be acceptable for grandfathering,
provided the other criteria described in
section IV.A.l.d were met. Drafts of the
updated methods are provided in the
docket for today's rule, and differences
between these versions and the  April
2001  versions of the methods are clearly
indicated for evaluation and comment.
Changes to the methods include the
following:
  (1) Increased flexibility in matrix spike
(MS) and initial precision and recovery (IPR)
requirements—the requirement that the
laboratory must analyze an MS sample on the
first sampling event for a  new PWS would be
changed to a recommendation; the revised
method would allow the IPR test to be
performed across four different days, rather
than restrict analyses to 1 day;
  (2) Clarification of some method
procedures, including the spiking suspension
vortexing procedure and the buffer  volumes
used during immunomagnetic separation
(IMS); requiring (rather than recommending)
that laboratories purchase HC1 and  NaOH
standards at the normality specified in the
method; and clarification that the use of
methanol during slide staining in section
14.2 of the method is as per manufacturer's
instructions;
  (3)  Additional recommendations for
minimizing carry-over of debris onto
microscope slides after IMS and information
on microscope cleaning;
  (4)  Clarification in the method of the
actions to take in the event of QC failures,
such  as that any positive  sample in a batch
associated with an unacceptable method
blank is unacceptable and that any sample in
a batch associated with an unacceptable
ongoing precision and recovery (OPR) sample
 is unacceptable;
  (5)  Changes to the sample storage and
shipping temperature to "less than  10°C and
 not frozen", and additional guidance on
 sample storage and shipping procedures that
 addresses time of collection, and includes
 suggestions for monitoring sample
 temperature during shipment and upon
receipt at the laboratory.
  (6)  Additional analyst verification
 procedures—adding examination using
 differential interference contrast (DIG)
 microscopy to the analyst verification
 requirements.

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                   Federal Register/Vol. 68, No, 154/Monday, August  11,  2003/Proposed Rules
                                                                        47733
    (7) Addition of an approved method
  modification using the Pall Gelman
  Envirochek HV filter. This approval was
  based on an interlaboratory validation study
  demonstrating that three laboratories, each
  analyzing reagent water and a different
  source water, met all method acceptance
  criteria for Cryptosporidium. EPA issued a
  letter (dated March 21, 2002) under the
  Alternative Test Procedures program
  approving the procedure as an acceptable
  version of Method 1623 for Cryptosporidium
  (but not for Giardia). EPA also noted in the
  letter that the procedure was considered to be
  an acceptable modification of EPA Method
  1622.
    (8) Incorporation of detailed procedures for
  concentrating samples using an IDEXX Filta-
  Max™ foam filter. A method modification
  using this filter already is approved by EPA
  in the April 2001 versions of the methods.
    (9) Addition of BTP EasySeed™ irradiated
  oocysts and cysts as acceptable materials for
  spiking routine QC samples. EPA approved
  the use of EasySeed™ based on side-by-side
  comparison tests of method recoveries using
  EasySeed™ and live, untreated organisms.
  EPA issued a letter (dated August 1, 2002)
  approving EasySeed™ for use in routine QC
  samples for EPA Methods 1622 and 1623 and
  for demonstrating comparability of method
  modifications in a single laboratory.
    (10) Removal of the Whatman Nuclepore
  CrypTest™ cartridge filter. Although a
  method modification using this filter was
  approved by EPA in the April 2001 versions
  of (he methods, the filter is no longer
  available from the manufacturer, and so is no
  longer an option for sample filtration.

    The changes in the June 2003 draft
  revisions of EPA Methods 1622 and
  1623 reflect method-related
  clarifications, modifications, and
  additions that EPA believes should be
  addressed for LT2ESWTR
  Cryptosporidium monitoring.
  Alternatively, these issues could be
  addressed through regulatory
  requirements in the final LT2ESWTR
  (for required changes and additions) and
  through guidance (for recommended
  changes and clarifications). However,
  EPA believes that addressing these
  issues through a single source in
  updated versions of EPA Methods 1622
  and 1623 (which could be approved in
  the final LT2ESWTR) may be more
  straightforward and easier for systems
  and laboratories to follow than
  addressing them in multiple sources
  (i.e., existing methods, the final rule,
  and laboratory guidance).
  2. E. coli
    a. What is EPA proposing today? For
  enumerating source water E. coli density
  under the LT2ESWTR, EPA is proposing
  to approve the same methods that were
  proposed by EPA under Guidelines
  Establishing Test Procedures for the
  Analysis of Pollutants; Analytical
  Methods for Biological Pollutants in
  Ambient Water (66 FR 45811, August
  30, 2001) (USEPA  2001i). These
  methods are summarized in Table IV-
  37. Methods are listed within the
  general categories of most probable
  number tests and membrane filtration
  tests. Method identification  numbers are
  provided for applicable standards
 published by EPA  and voluntary
 consensus standards bodies  (VCSB)
 including Standard Methods, American
 Society of Testing Materials  (ASTM),
 and the Association of Analytical
 Chemists (AOACJ.
                           TABLE IV-37.— PROPOSED METHODS FOR E. COLI ENUMERATION 1

Technique

(MPN).








Method1
LTB, EC-MUG 	
ONPG-MUG 	
ONPG-MUG 	
mFC-*NA-MUG 	
mENDO or LES-
ENDO-NA-MUG.


m-ColiBlue24 broth 	

EPA





1103 1
1603
1604


Standard
methods2
9221B.1/
9221 F
9223B
9223B
9222D/
9222G
9222B/
9222G
921 3D



VCSB methods
ASTM3





D5392 93




AOAC4

991 15








Commercial example








m-ColiBlue246.
   1 Tests must be conducted in a format that provides organism enumeration.
   2Standard Methods for the Examination of Water and Wastewater. American Public Health Association. 20th, 19th, and 18th Editions. Amer
 Publ. Hlth. Assoc., Washington, DC.
   3Annuai  Book of ASTM Standards—Water  and Environmental Technology.  Section 11.02. ASTM.  100  Barr  Harbor  Drive, West
 Conshohocken, PA 19428.
   4Official Methods of Analysis of AOAC International, 16th Edition, Volume I, Chapter 17. AOAC international. 481 North Frederick Avenue
 Suite 500, Gaithersburg, Maryland 20877-2417.
   5 Manufactured by IDEXX Laboratories, Inc., One tDEXX Drive, Westbrook, Maine 04092.
   6 Manufactured by Hach Company, 100 Dayton Aye., Ames, IA 50010.
   7 Acceptable version of method approved as a drinking water alternative test procedure.
  EPA is proposing to allow a holding
time of 24 hours for E. coli samples. The
holding time refers to the time between
sample collection and initiation of
analysis. Currently, 40 CFR 141.74(a)
limits the holding time for source water
coliform samples to 8 hours and
requires that samples be kept below
10°C during transit. EPA believes that
new studies, described later in this
section, demonstrate that E. coli analysis
results for samples held for 24 hours
will be comparable to samples held for
8 hours, provided the samples are held
below 10°C and are not allowed to
freeze. This proposed increase in
holding time is significant for the
LT2ESWTR because typically it is not
feasible for systems to meet an 8-hour
holding time when samples cannot be
analyzed on-site. Many small systems
that will conduct E. coli monitoring
under the LT2ESWTR lack a certified
on-site laboratory for E. coli analyses
and will be required to ship samples to
a certified laboratory. EPA believes that
it is feasible for these systems to comply
with a 24 hour holding time for E. coli
samples through using overnight
delivery services.
  b. How was this proposal developed?
As noted, EPA recently proposed
methods for ambient water E. coli
analysis under Guidelines Establishing
Test Procedures for the Analysis of
Pollutants; Analytical Methods for

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47734
Federal  Register/Vol. 68, No.  154/Monday, August 11. 2003/Proposed Rules
Biological Pollutants in Ambient Water
(66 FR 45811, August 30, 2001) (USEPA
2001i). These proposed methods were
selected based on data generated by EPA
laboratories, submissions to the
alternate test procedures (ATP) program
and voluntary consensus standards
bodies, published peer reviewed journal
articles, and publicly available study
reports.
  The source water analysis for E. coli
that will be conducted under the
LT2ESWTR is similar to the type of
ambient water analyses for which these
methods were previously proposed (66
FR 45811, August 30, 2001) (USEPA
2001i). EPA continues to support the
findings of this earlier proposal and
believes that these methods have the
necessary sensitivity and specificity to
meet the data quality objectives  of the
LT2ESWTR.
New Information on E. coli Sample
Holding Time
   It is generally not feasible for systems
that must ship E. coli samples to an off-
site laboratory to comply with an 8-hour
holding time requirement. During the
 ICRSS, 100% of the systems that
 shipped samples off-site for E. coli
 analysis exceeded the 8 hour holding
 time; 12% of these samples had holding
 times in excess of 30 hours. Most large
 systems that will be required to monitor
 for E. coli under the LT2ESWTR could
 conduct these analyses on-site, but
 many small systems will need to ship
 samples off-site to a certified contract
 laboratory.
   EPA participated in three phases of
 studies to assess the effect of increased
 sample holding time on E. coli analysis
 results. These are summarized as
 follows, and are described in detail in
 Pope et al  (2003).
   •  Phase 1-EPA, the Wisconsin State
 Laboratory of Hygiene (WSLH), and
 DynCorp conducted a study to evaluate
 E. coli sample concentrations from four
 sites at 8, 24, 30, and 48 hours after
 sample collection for samples stored at
 4°G, 10°C, 20°C, and 35°C. Temperature
 was varied to assess the effect of
 different shipping conditions. Samples
 were analyzed in  triplicate by
 membrane filtration (mFC followed by
 transfer to NA-MUG) and Colilert
 (Quanti-Tray 2000} (Pope eta]. 2003).
   •  Phase  2-EPA conducted a study to
 evaluate E, coli sample concentrations
 from seven sites at 8, 24, 30, and 48
 hours after sample collection for
 samples stored in coolers containing
 wet ice or Utek ice packs (to assess real-
 world storage conditions). Samples were
 analyzed in triplicate by membrane
 filtration (mFC followed by transfer to
                      NA-MUG) and Colilert (Quanti-Tray
                      2000) (Pope et al. 2003).
                        • Phase 3-EPA, through cooperation
                      with AWWA, obtained E. coli holding
                      time data from ten drinking water
                      utilities that evaluated samples from 12
                      source waters. Each utility used an E.
                      coli method of its choice (Colilert,
                      mTEC, mEndo to NA-MUG, or mFC to
                      NA-MUG). Samples were stored in
                      coolers with wet ice, Utek ice packs, or
                      Blue ice (Pope et al.  2003}.
                        Phase 1 results indicated that E, coli
                      concentrations were not significantly
                      different after 24 hours at most sites
                      when samples were  stored at lower
                      temperatures. Results from Phase 2,
                      which evaluated actual sample storage
                      practices, verified the Phase 1
                      observations at most sites. Similar
                      results were observed during Phase 3,
                      which evaluated a wider variety of
                      surface waters from  different regions
                      throughout the U.S.  During Phase 3, E.
                      coli concentrations were not
                      significantly different after 24 hours at
                      most sites when samples were
                      maintained below 10°C and did not
                      freeze during storage. At longer holding
                      times (e.g., 48 hours), larger differences
                      were observed.
                         Based on these studies, EPA has
                      concluded that E. coli samples can be
                      held for up to 24 hours prior to analysis
                      without compromising the data quality
                      objectives of LT2ESWTR E. coli
                      monitoring. Further, EPA believes that it
                      is feasible for systems that must ship E.
                       coli samples to an off-site laboratory for
                      analysis to meet a 24 hour holding time.
                       EPA is developing guidance for systems
                       on packing and shipping E. coli samples
                       so that samples are  maintained below
                       10°C and not allowed to freeze (USEPA
                       2003g). This guidance is available in
                       draft in the docket for today's proposal
                       (h tip://www. epa.gov/edocket/).
                         c. Bequest for comment. EPA requests
                       comment on whether the E. coli
                       methods proposed  for approval under
                       the LT2ESWTR are appropriate, and
                       whether there are additional methods
                       not proposed that should be considered.
                       Comments concerning method approval
                       should be accompanied by supporting
                       data where possible.
                         EPA also requests comment on the
                       proposal to extend  the holding time for
                       E. coli source water sample analyses to
                       24 hours, including any data or other
                       information that would support, modify,
                       or repudiate such an extension. Should
                       EPA limit the extended holding time to
                       only those E. coli analytical methods
                       that were evaluated in the holding time
                       studies noted in this section? The
                       results in Pope et al. (2003) indicate that
                       most E. coli samples analyzed using
                       ONPG-MUG (see methods in Table IV-
37) incurred no significant degradation
after a 30 to 48 hour holding time. As
a result, should EPA increase the source
water E. coli holding time to 30 or 48
hours for samples evaluated by ONPG-
MUG, and retain a 24-hour holding time
for samples analyzed by other methods?
EPA also requests comment  on the cost
and availability of overnight delivery
services for E. coli samples, especially
in rural areas.
3. Turbidity
   a. What is EPA proposing today? For
turbidity analyses that will be
conducted under the LT2ESWTR, EPA
is proposing to require systems to use
the analytical methods that have been
previously approved by EPA for
analysis of turbidity in drinking water,
as listed in 40 CFR Part 141.74. These
are Method  2130B as published in
Standard Methods for the Examination
of Water and Wastewater (APHA 1992),
EPA Method 180.1 (USEPA 1993), and
Great Lakes Instruments Method 2
 (Great Lakes Instruments, 1992), and
Hach FilterTrak Method 10133.
   EPA method 180-1 and Standard
 Method 2130B are both nephelometric
 methods and are based upon a
 comparison of the intensity of light
 scattered by the sample under defined
 conditions with the intensity of light
 scattered by a standard reference
 suspension. Great Lakes Instruments
 Method 2 is a modulated four beam
 infrared method using a ratiometric
 algorithm to calculate the turbidity
 value from the four readings that are
 produced. Hach Filter Trak (Method
 10133) is a  laser-based nephelometric
 method used to determine the turbidity
 of finished drinking waters.
 Turbi dimeters
   Systems are required to use
 turbidimeters described in EPA-
  approved methods for measuring
  turbidity. For regulatory reporting
  purposes, either an on-line or a bench
  top turbidimeter can be used. If a system
  chooses to use on-line units for
  monitoring, the system must validate
  the continuous measurements for
  accuracy on a regular basis using a
  protocol approved by the State.
    b. How was this proposal developed?
  EPA believes the currently approved
  methods for analysis of turbidity in
  drinking water are appropriate for
  turbidity analyses that will be
  conducted under the LT2ESWTR.
    c. Request for comment. EPA requests
  comment on whether the turbidity
  methods proposed today for the
  LT2ESWTR should be approved, and
  whether there are additional methods
  not proposed that should be approved.

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                 Federal Register/Vol. 68, No.  154/Monday, August 11, 2003/Proposed Rules          47735
 L. Laboratory Approval
   Given the potentially significant
 implications in terms of both cost and
 public health protection of microbial
 monitoring under the LT2ESWTR,
 laboratory analyses for
 Cryptosporidium, E. coli, and turbidity
 must be accurate and reliable within the
 limits of approved methods. Therefore,
 EPA proposes to require public water
 systems to use laboratories that have
 been approved to conduct analyses for
 these parameters by EPA or the State.
 The following criteria are proposed for
 laboratory approval under the
 LT2ESWTR:
   * For Cryptosporidium analyses
 under the LT2ESWTR, EPA proposes to
 approve laboratories that have passed  a
 quality assurance evaluation under
 EPA's Laboratory Quality Assurance
 Evaluation Program (Lab QA Program)
 for Analysis of Cryptosporidium in
 Water (described in 67 FR 9731, March
 4, 2002) (USEPA 2002c). If States adopt
 an equivalent approval process under
 State laboratory certification programs,
 then systems can use laboratories
 approved by the State.
   • For E. coli analyses, EPA proposes
 to approve laboratories that have been
 certified by EPA, the National
 Environmental Laboratory Accreditation
 Conference, or the State for total
 coliform or fecal coliform analysis  in
 source water under 40 CFR 141.74. The
 laboratory must use the same analytical
 technique for E. coli that the laboratory
 uses for total coliform or fecal coliform
 analysis under 40 CFR 141.74.
   • Turbidity analyses must be
 conducted by a person approved by the
 State for analysis of turbidity in
 drinking water under 40 CFR 141.74.
   These criteria are further described in
 the following paragraphs.
 1. Cryptosporidium Laboratory
 Approval
  Because States do not currently
 approve laboratories for
 Cryptosporidium analyses and
 LT2ESWTR monitoring will begin  6
 months after rule promulgation, EPA
will initially assume responsibility for
 Cryptosporidium laboratory approval.
EPA expects, however, that States will
include Cryptosporidium analysis in
their State laboratory certification
programs in the future. EPA has
established the Lab QA Program for
 Cryptosporidium analysis to identify
laboratories that can meet LT2ESWTR
data quality objectives. This is a
voluntary program open to laboratories
involved in analyzing Cryptosporidium
in water. Under this program, EPA
assesses the ability of laboratories to
 reliably measure Cryptosporidium
 occurrence with EPA Methods 1622 and
 1623, using both performance testing
 samples and an on-site evaluation.
  EPA initiated the Lab QA Program for
 Cryptosporidium analysis prior to
 promulgation of the LT2ESWTR to
 ensure that adequate sample analysis
 capacity will be available at qualified
 laboratories to support the required
 monitoring. The Agency is monitoring
 sample analysis capacity at approved
 laboratories through the Lab QA
 Program, and does not plan to
 implement LT2ESWTR monitoring until
 the Agency determines that there is
 adequate laboratory capacity. In
 addition, utilities that choose to conduct
 Cryptosporidium monitoring prior to
 LT2ESWTR promulgation with the
 intent of grandfathering the data may
 elect to use laboratories that  have
 passed the EPA quality assurance
 evaluation.
  Laboratories seeking to participate in
 the EPA Lab QA Program for
 Cryptosporidium analysis must submit
 an interest application to EPA,
 successfully analyze a set of initial
 performance testing samples, and
 undergo an on-site evaluation. The on-
 site evaluation includes two separate
 but concurrent assessments:  (1)
 Assessment of the laboratory's sample
 processing and analysis procedures,
 including microscopic examination, and
 (2) evaluation of the laboratory's
 personnel qualifications, quality
 assurance/quality control program,
 equipment, and recordkeeping
 procedures.
  Laboratories that pass the quality
 assurance evaluation will be eligible for
 approval for Cryptosporidium analysis
 under the LT2ESWTR. The Lab QA
 Program is described in detail in a
 Federal Register Notice (67 FR 9731,
 March 4, 2002) (USEPA 2002c) and
 additional information can be found
 online at:  www.epa.gov/safewater/h2/
 cla_int.html.
  Laboratories in the Lab QA Program
 will receive a set of three ongoing
 proficiency testing (OPT) samples
 approximately every four months. EPA
 will evaluate the precision and recovery
 data for OPT samples to determine if the
 laboratory continues to meet the
 performance criteria of the Laboratory
 QA Program.
 2. E. coli Laboratory Approval
  Pubic water systems are required to
have samples analyzed for E. coli by
 laboratories certified under the State
 drinking water certification program to
perform total coliform and fecai
coliform analyses under 40 CFR 141.74.
EPA is proposing that the general
analytical techniques the laboratory is
certified to use under the drinking water
certification program (e.g., membrane
filtration, multiple-well, multiple-tube)
will be the methods the laboratory can
use to conduct E. coli source water
analyses under the LT2ESWTR.
3. Turbidity Analyst Approval
  Measurements of turbidity must be
conducted by a party approved by the
State. This is consistent with current
requirements for turbidity
measurements in drinking water (40
CFR 141.74).
4. Request for Comment
  EPA requests comment on the
laboratory approval requirements
proposed today, including the following
specific issues:
Analyst Experience Criteria
  The Lab QA Program, which EPA will
use to approve laboratories for
Cryptosporidium analyses under the
LT2ESWTR, includes criteria for analyst
experience. Principal analyst/
supervisors (minimum of one per
laboratory) should have a minimum of
one year of continuous bench
experience with Cryptosporidium and
immunofluorescent assay (IFA)
microscopy, a minimum of six months
experience using EPA Method 1622
and/or 1623, and a minimum of 100
samples analyzed using EPA Method
1622 and/or 1623 (minimum 50 samples
if the person was an analyst approved
to'conduct analysis for the Information
Collection Rule Protozoan Method)  for
the specific analytical procedure they
will be using.
  Under the Lab QA Program, other
analysts (no minimum number of
analysts per laboratory) should have a
minimum of six months of continuous
bench experience with Cryptosporidium
and IFA microscopy, a minimum of
three months experience using EPA
Method 1622 and/or 1623, and a
minimum of 50 samples analyzed using
EPA Method 1622 and/or 1623
(minimum 25 samples if the person was
an analyst approved to conduct analysis
for the Information Collection Rule
Protozoan Method) for the specific
analytical procedures they will be using.
  The Lab QA Program criteria for
principal analyst/supervisor experience
are more rigorous than those in Methods
1622 and 1623, which are as follows:
the analyst must have at least 2 years of
college lecture and laboratory course
work in microbiology or a closely
related field. The analyst also must have
at least 6 months of continuous bench
experience with environmental protozoa
detection techniques and IFA

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Federal Register/Vol.  68,  No. 154/Monday, August 11, 2003/Proposed Rules
microscopy, and must have successfully
analyzed at least 50 water and/or
wastewater samples for
Cryptosporidium. Six months of
additional experience in the above areas
may be substituted for two years of
college.
  In seeking approval for an Information
Collection Request, EPA requested
comment on the Lab QA Program (67 FR
9731, March 4, 2002} (USEPA 2002c). A
number of commenters stated that the
analyst qualification criteria are
restrictive and could make it difficult
for laboratories to maintain adequate
analyst staffing (and, hence, sample
analysis capacity) in the event of staff
turnover or competing priorities. Some
commenters suggested that laboratories
and analysts should be evaluated based
on proficiency testing, and that analyst
experience standards should be reduced
or eliminated. (Comments are available
in Office of Water docket, number W-
01-17).
  Another aspect of the analyst
experience criteria is that systems may
generate Cryptosporidium data for
grandfathering under the LT2ESWTR
using laboratories that meet the analyst
experience requirement of Methods
1622 or 1623 but not the more rigorous
principal analyst/supervisor experience
requirement of the Lab QA Program.
  EPA requests comment on whether
the criteria for analyst experience in the
Lab QA Program are necessary, whether
systems are experiencing difficulty in
finding laboratories that have passed the
Lab QA Program to conduct
Cryptosporidium analysis, and whether
any of the Lab QA Program criteria
should be revised to improve the
LT2ESWTR lab approval process.
State Programs To Approve Laboratories
for Cryptosporidium Analysis
  Under today's proposal, systems must
have Cryptosporidium samples analyzed
by a  laboratory approved under EPA's
Lab QA Program, or an equivalent State
laboratory approval program. Because
States do not currently approve
laboratories for Cryptosporidium
analyses, EPA will initially assume
responsibility for Cryptosporidium
laboratory approval. EPA expects,
however, that States will adopt
equivalent approval programs for
Cryptosporidium analysis under State
laboratory certification programs. EPA
requests comment on how to establish
that a State approval program for
Cryptosporidium analysis is equivalent
to the Lab QA Program.
  Specifically, should EPA evaluate
State Approval programs to determine if
they  are equivalent to the Lab QA
Program? EPA also requests comment
                      on the elements that would constitute
                      an equivalent State approval program
                      for Cryptosporidium analyses, including
                      the following: (1) Successful analysis of
                      initial and ongoing blind proficiency
                      testing samples prepared using flow
                      cytometry, including a matrix and
                      meeting EPA's pass/fail criteria
                      (described in USEPA 2002c); (2) an on-
                      site evaluation of the laboratory's
                      sample processing and analysis
                      procedures, including microscopic
                      examination skills, by auditors who
                      meet the qualifications of a principal
                      analyst as set forth in the Lab QA
                      Program (described in USEPA 2002c);
                      (3) an on-site evaluation of the
                      laboratory's personnel qualifications,
                      quality assurance/quality control
                      program, equipment, and recordkeeping
                      procedures; (4) a data audit of the
                      laboratories' QC data and monitoring
                      data; and (5) use of the audit checklist
                      used in the Lab QA Program or
                      equivalent.
                      M. Requirements for Sanitary Surveys
                      Conducted by EPA
                      1. Overview
                        In today's proposal, EPA is requesting
                      comment on establishing requirements
                      for public water systems with
                      significant deficiencies as identified in
                      a sanitary survey conducted by EPA
                      under-SDWA section 1445. These
                      requirements would apply to surface
                      water systems for which EPA is
                      responsible for directly implementing
                      national  primary drinking water
                      regulations (i.e., systems not regulated
                      by States with primacy). As described in
                      this section, these requirements would
                      ensure that systems in non-primacy
                      States, currently Wyoming, and systems
                      not regulated by States, such as Tribal
                      systems, are subject to standards for
                      sanitary surveys similar to those that
                      apply to  systems regulated by States
                      with primacy.

                      2. Background
                        As established by the IESWTR in 40
                      CFR 142.16(b)(3), primacy States must
                      conduct sanitary surveys for all surface
                      water systems no less frequently than
                      every three years for community water
                      systems and no less frequently than
                      every five years for noncommunity
                      water systems. The sanitary survey is an
                      onsite review and must address the
                      following eight components: (1) Source,
                      (2} treatment, (3) distribution system, (4)
                      finished water storage, (5) pumps,  pump
                      facilities, and controls, (6) monitoring,
                      reporting, and data verification, (7)
                      system management and operation, and
                      (8) operator compliance with State
                      requirements.
  Under the IESWTR, primacy States
are required to have the appropriate
rules or other authority to assure that
systems respond in writing to
significant deficiencies outlined in
sanitary survey reports no later than  45
days after receipt of the report,
indicating how and on what schedule
the system will address significant
deficiencies noted in the survey (40 CFR
142.16(b)(l)(ii)).  Further, primacy States
must have the authority to assure that
systems take necessary steps to address
significant deficiencies identified in
sanitary survey reports if such
deficiencies are within the control of the
system and its governing body (40 CFR
142.16(b)(l)(iii)). The IESWTR did not
define a significant deficiency, but
required that primacy  States describe in
their primacy applications how they
will decide whether a  deficiency
identified during a sanitary survey is
significant for the purposes of the
requirements stated in this paragraph
(40CFRl42.16(b)(3)(v)).
  EPA conducts sanitary surveys under
SDWA section 1445 for public water
systems not regulated by primacy States
(e.g., Tribal systems, Wyoming).
However, EPA does not have the
authority required of primacy States
under 40 CFR 142 to ensure that
systems address  significant deficiencies
identified during sanitary surveys.
Consequently, the sanitary survey
requirements established by the
IESWTR create an unequal standard.
Systems regulated by primacy States are
subject to the States' authority to require
correction of significant deficiencies
noted in sanitary survey reports, while
systems for which EPA has direct
implementation  authority do not have to
meet an equivalent requirement.
3. Request for Comment

  In order to ensure that systems for
which EPA has direct  implementation
authority address significant
deficiencies identified during sanitary
surveys, EPA requests comment on
establishing either or both of the
following requirements under 40 CFR
141 as part  of the NPDWR established
in the final  LT2ESWTR:
  (1) For sanitary surveys conducted by EPA
under SDWA section 1445, systems would be
required to respond in writing to significant
deficiencies outlined in sanitary survey
reports no later than 45 days after receipt of
the report, indicating how and on what
schedule the system will address significant
deficiencies noted in the survey.
  (2) Systems would be required to correct
significant deficiencies identified in sanitary
survey reports if such deficiencies are within
the control of the system and its governing
body.

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                   Federal Register/Vol. 68, No.  154/Monday, August 11, 2003/Proposed Rules
                                                                       47737
    For the purposes of these
  requirements, a sanitary survey, as
  conducted hy EPA, is an onsite review
  of the water source (identifying sources
  of contamination by using results of
  source water assessments where
  available), facilities, equipment,
  operation, maintenance, and monitoring
  compliance of a public water system to
  evaluate the adequacy of the system, its
  sources and operations, and the
  distribution of safe drinking water. A
  significant deficiency includes a defect
  in design, operation, or maintenance, or
  a failure or malfunction of the sources,
  treatment, storage, or distribution
  system that EPA determines to be
  causing, or has the potential for causing
  the introduction of contamination into
  the water delivered to consumers.

  V. State Implementation

   This section describes the regulations
  and other procedures and policies States
  will be required to adopt to implement
  the LT2ESWTR, if finalized as proposed
  today. States must continue to meet all
  other conditions of primacy in 40 CFR
  Part 142.
   The Safe Drinking Water Act (Act)
  establishes requirements that a State or
  eligible Indian tribe must meet to
  assume and maintain primary
  enforcement responsibility (primacy) for
 its public water systems. These
 requirements include: (1) Adopting
 drinking water regulations that are no
 less stringent than Federal drinking
 water regulations, (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 under the
 Act, and (5) adopting and being capable
 of implementing an adequate plan for
 the provisions 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
 basic primacy requirements specified in
 40 CFR Part 142, States may be required
 to adopt special primacy provisions
 pertaining to specific regulations where
 implementation of the rule involves
 activities beyond general primacy
 provisions. States must include these
 regulation specific provisions in an
 application for approval of their
 program revision. Primacy requirements
 for today's proposal are discussed
below.
    To implement the proposed
  LT2ESWTR, States will be required to
  adopt revisions to:
  §141.2—Definitions
  § 141.71—Criteria for avoiding filtration
  § 141.153—Content of the reports
  § 141.170—Enhanced filtration and
    disinfection
  Subpart Q—Public Notification
  New Subpart W—Additional treatment
    technique requirements for
    Cryptosporidium
  § 142.14—Records kept by States
  § 142.15—Reports by States
  § 142.16—Special primacy requirements

  A. Special State Primacy Requirements
   To ensure that a State program
  includes all the elements necessary for
  an effective and enforceable program
  under  today's rule, a State primacy
  application must include a description
  of how the State will perform the
  following:
   (1) Approve watershed control
  programs for the 0.5 log watershed
  control program credit in the microbial
 toolbox (see section IV.C.2);
   (2) Assess significant changes in the
 watershed and source water as part of
 the sanitary survey process and
 determine appropriate follow-up action
 (see section IV.AJ;
   (3) Determine that a system with an
 uncovered finished water storage
 facility has a risk mitigation plan that  is
 adequate for purposes of waiving the
 requirement to cover  the storage facility
 or treat the effluent (see section IV.E);
   (4) Approve protocols for removal
 credits under the Demonstration of
 Performance toolbox option (see section
 IV.C.17) and for site specific chlorine
 dioxide and ozone CT tables (see section
 IV.C.14); and
   (5) Approve laboratories to analyze for
 Cryptosporidium.
   Note that a State program can be
 more, but not less, stringent than
 Federal regulations. As such, some of
 the elements listed here may not be
 applicable to a specific State program.
 For example, if a State chooses to
 require all finished water storage
 facilities to be covered or provide
 treatment and not to allow a risk
 mitigation plan to substitute for this
 requirement, then the description for
 item (3) would be inapplicable.

 B. State Recordkeeping Requirements
  The current  regulations in § 142.14
 require  States with primacy to keep
 various  records,  including the
 following: Analytical results to
 determine compliance with MCLs,
MRDLs, and treatment technique
requirements; system inventories; State
approvals; enforcement actions; and the
  issuance of variances and exemptions.
  The proposed LT2ESWTR will require
  States to keep additional records of the
  following, including all supporting
  information and an explanation of the
  technical basis for each decision:
    • Results of source water E. coli and
  Cryptosporidium monitoring;
    • Cryptosporidium bin classification
  for each filtered system, including any
  changes to initial bin classification
  based on review of the watershed during
  sanitary surveys or the second round of
  monitoring;
    • Determination of whether each
  unfiltered system has a mean source
  water Cryptosporidium level above 0.01
  oocysts/L;
    •  The treatment processes or control
  measures that each system employs to
  meet Cryptosporidium treatment
  requirements under the LT2ESWTR;
  this includes documentation to
  demonstrate compliance with required
  design and implementation criteria for
  receiving credit for microbial toolbox
  options, as specified in section IV.C;
    • A list of systems required to cover
  or treat the effluent of an uncovered
  finished water storage facilities; and
    • A list of systems for which the State
 has waived the requirement to cover or
 treat the effluent of an uncovered
 finished water storage facility, along
 with supporting documentation of the
 risk mitigation plan.

 C. State Reporting Requirements
   EPA currently requires in § 142,15
 that States report to EPA information
 such as violations, variance and
 exemption status, and enforcement
 actions. The LT2ESWTR, as proposed,
 will add additional reporting
 requirements in the following area;
   • The  Cryptosporidium bin
 classification for each filtered system,
 including any changes to initial bin
 classification based on review of the
 watershed during sanitary surveys or
, the second round of monitoring;
   • The determination of whether each
 unfiltered system has a mean source
 water Cryptosporidium level above 0.01
 oocysts/L, including any changes to this
 determination based on the second
 round of monitoring.
 D. Interim Primacy
  On April 28, 1998, EPA amended its
 State primacy regulations at 40 CFR
 142.12 to incorporate the new process
 identified in the 1996 SDWA
Amendments for granting primary
 enforcement authority to States while
their applications to modify their
primacy programs are under review (63
FR 23362, April 28, 1998) (USEPA
1998f). The new process grants interim

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Federal Register/Vol. 68, No. 154/Monday. August  11,  2003/Proposed Rules
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 final determination. However,
this interim primacy authority is only
available to  a State that has  primacy
(including interim primacy) for every
existing NPDWR 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 the application for this
rule to USEPA, or the effective date of
its revised regulations, whichever is
later. In addition, a State that wishes to
obtain interim primacy for future
NPDWRs must obtain primacy for this
rule. As described in Section IV.A, EPA
expects to oversee the initial source
water monitoring that will be conducted
under the LT2ESWTR by systems
serving at least 10,000 people, beginning
6 months following rule promulgation.

VI. Economic Analysis
   This section summarizes  the
economic analysis (EA) for  the
LT2ESWTR proposal. The EA is an
assessment of the benefits, both health
and non-health related, and costs to the
regulated community of the proposed
regulation, along with those of
regulatory alternatives that the Agency
 considered. EPA developed this EA to
 meet the  requirement of SOW A section
 1412(b)(3)(C) for a Health Risk
 Reduction and Cost Analysis (HRRCA),
 as well as the requirements of Executive
 Order 12866, Regulatory Planning and
 Review, under which EPA must
 estimate  the costs and  benefits of the
 LT2ESWTR. The full EA is presented in
 Economic Analysis for the  Long Term 2
 Enhanced Surface Water Treatment Rule
 (USEPA 2003a), which is available in
 the docket for today's proposal
 (www. epa .gov.edocketl).
   Today's proposed LT2ESWTR is the
 second in a staged set of rules that
                      address public health risks from
                      microbial contamination of surface and
                      GWUDI drinking water supplies and,
                      more specifically, prevent
                      Cryptosporidium from reaching
                      consumers. As described in section I,
                      the Agency promulgated the IESWTR
                      and LT1ESWTR to provide a baseline of
                      protection against Cryptosporidium in
                      large and small drinking water systems,
                      respectively. Today's proposed rule
                      would achieve further reductions in
                      Cryptosporidium exposure for systems
                      with the  highest vulnerability. This
                      economic analysis considers only the
                      incremental reduction in exposure from
                      the two previously promulgated rules
                      (IESWTR and LTlESWTR) to the
                      alternatives evaluated for the
                      LT2ESWTR.
                         Both benefits and costs are
                      determined as annualized present
                      values. The process allows comparison
                      of cost and benefit streams that are
                      variable  over a given time period. The
                      time frame used for both benefit and
                      cost comparisons is 25 years;
                      approximately five years account for
                      rule implementation and 20 years for
                      the average useful life of the equipment
                      used to comply with treatment
                      technique requirements. The Agency
                      uses social discount rates of both three
                      percent and seven percent to calculate
                      present values from the stream of
                      benefits  and costs and also to annualize
                      the present value estimates (seeEPA's
                      Guidelines for Preparing Economic
                       Analyses (USEPA 2000c) for a
                       discussion of social discount rates). The
                       LT2ESWTR EA (USEPA 2003a) also
                       shows the undiscounted stream of both
                       benefits and costs over the 25 year time
                       frame.
                       A. What Regulatory Alternatives Did the
                       Agency  Consider?
                         Regulatory alternatives considered by
                       Agency  for the LT2ESWTR were
                       developed through the deliberations of
                       the Stage 2 M-DBP Federal Advisory
                       Committee (described in section II). The
                       Committee considered several general
                       approaches for reducing the risk from
                       Cryptosporidium in drinking water. As
                       discussed in section IV.A.2, these
                       approaches included both additional
                       treatment requirements for all systems
and risk-targeted treatment
requirements for systems with the
highest vulnerability to
Cryptosporidium following
implementation of the IESWTR and
LTlESWTR. In addition, the Committee
considered related factors such as
surrogates for Cryptosporidium
monitoring and alternative monitoring
strategies to  minimize costs to small
drinking water systems.
  After considering these general
approaches, the Committee focused on
four specific regulatory alternatives for
filtered systems (see Table VI-1). With
the exception of Alternative 1, which
requires all systems to achieve an
additional 2 log (99%) reduction in
Cryptosporidium levels,  these
alternatives  incorporate a microbial
framework approach. In  this approach,
systems are  classified in different risk
bins based on the results of source water
monitoring. Additional treatment
requirements are directly linked to the
risk bin classification. Accordingly,
these rule alternatives are differentiated
by two criteria: (1) The Cryptosporidium
concentrations that define the bin
boundaries  and  (2) the degree of
treatment required for each bin.
   In assessing regulatory alternatives,
EPA and the Advisory Committee were
 concerned with the following questions:
 (1) Do the treatment requirements
 adequately  control Cryptosporidium
 concentrations in finished water? (2)
 How many  systems will be required to
 add treatment? (3) What is the
 likelihood that systems with high source
 water Cryptosporidium concentrations
 will not be  required to provide
 additional treatment (i.e., be
 misclassified in a low risk bin)? and (4)
 What is the likelihood that systems with
 low source  water Cryptosporidium
 concentrations will be required to
 provide unnecessary additional
 treatment (i.e., misclassified in a high
 risk bin)?
   The Committee reached consensus
 regarding additional treatment
 requirements for unfiltered systems and
 uncovered  finished water storage
 facilities without formally identifying
 regulatory alternatives.  Table VI-1
 summarizes the four alternatives that
 were considered for filtered systems.

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                 Federal Register/Vol. 68, No.  154/Monday,  August 11, 2003/Proposed  Rules
                                                                      47739
                   TABLE VI-1.—SUMMARY OF REGULATORY ALTERNATIVES FOR FILTERED SYSTEMS
                        Average source water Cryptosporidium monitoring result (oocysts/L)
                                                                   Additional
                                                                  treatment re-
                                                                  quirements 1
                                                    Alternative A1
                                         2.0 log inactivation required for all systems
                                                    Alternative A2



>1.0 	
No action.
0.5 log.
1.5 log.
2.5 log.
                                          Alternative A3—Preferred Alternative
 < 0.075  	
 > 0.075 and < 1.0
 > 1.0 and <3.0 ....
 >3.0  	
                                                                 No action.
                                                                 1 log.
                                                                 2 log.
                                                                 2.5 log.
                                                    Alternative A4
>0.1 and< 1.0
                                                                 No action.
                                                                 0.5-log.
                                                                 1.0 log.
   Note: "Additional treatment requirements" are in addition to levels already required under existing rules (e.g., the IESWTR and LT1ESWTR).
B. What Analyses Support Selecting the
Proposed Rule Option?
  EPA has quantified benefits and costs
of each of the regulatory alternatives in
Table VI-1, as well as for the proposed
requirements for unfiltered systems.
Quantified benefits stem from estimated
reductions in the incidence of
cryptosporidiosis resulting from the
regulation. To make these estimates, the
Agency developed a two-dimensional
Monte Carlo model that accounts for
uncertainty and variability in key
parameters like Cryptosporidium
occurrence, infectivity, and treatment
efficiency. Analyses involved estimating
the baseline (pre-LT2ESWTR) risk from
Cryptosporidium in drinking water, and
then projecting the reductions in
exposure and risk resulting from the
additional treatment requirements of the
LT2ESWTR. Costs result largely from
the installation of additional treatment,
with lesser costs due to monitoring and
other implementation activities. Results
of these analyses are summarized in the
following subsections, and details are
shown in trie LT2ESWTR EA (USEPA
2003a).
  Cryptosporidium occurrence
significantly influences the estimated
benefits and costs of regulatory
alternatives. As discussed in section
III.C, EPA analyzed data collected under
the Information Collection Rule, the
Information Collection Rule
Supplemental Surveys of medium
systems (ICRSSM), and the Information
Collection Rule Supplemental Surveys
of large systems (ICRSSL) to estimate
the national occurrence distribution of
 Cryptosporidium in surface water. EPA
 evaluated these distributions
 independently when assessing benefits
 and costs for different regulatory
 alternatives. In most cases, results from
 the ICRSSM data set are within the
 range of results of the Information
 Collection Rule and ICRSSL data sets.
  EPA selected a Preferred Regulatory
 Alternative for the LT2ESWTR,
 consistent with the recommendations of
 the Advisory Committee. As described
 next, this selection was based on the
 estimated impacts and feasibility of the
 alternatives shown in Table VI-1.
  Alternative Al (across-the-board 2-log
 inactivation) was not selected because it
 was the highest cost option and
 imposed costs but provided few benefits
 to systems with high quality source
 water (i.e., relatively low
 Cryptosporidium risk). In addition,
 there were concerns about the feasibility
 of requiring almost every surface water
 treatment plant to install additional
 treatment processes (e.g., UV or ozone)
 for Cryptosporidium.
  Alternatives A2-A4 were evaluated
 based on several factors, including
 predictions of costs and benefits,
 performance  of analytical methods for
 classifying systems in the risk bins, and
 other specific impacts (e.g., impacts on
 small systems or sensitive
 subpopulations). Alternative A3 was
 recommended by the Advisory
 Committee because it provides
 significant health benefits in terms of
avoided illnesses and deaths for an
 acceptable cost. In addition, the Agency
believes this alternative is feasible with
available analytical methods and
treatment technologies.
  Incremental costs and benefits of
regulatory alternatives for the
LT2ESWTR are shown in section VI.F,
and the LT2ESWTR EA contains more
detailed information about the benefits
and costs of each regulatory option
EUSEPA 2003a).

C. What Are the Benefits of the
Proposed LT2ESWTR?

  As discussed previously, the
LT2ESWTR is expected to substantially
reduce drinking water related exposure
to Cryptosporidium, thereby reducing
both illness and death associated with
cryptosporidiosis. As described in
section II, cryptosporidiosis is an
infection caused by Cryptosporidium
and is an acute, typically self-limiting,
illness with symptoms that include
diarrhea, abdominal cramping, nausea,
vomiting, and fever (Juranek, 1995).
Cryptosporidiosis patients in sensitive
subpopulations, such as infants, the
elderly, and AIDS patients, are at risk
for severe illness, including risk of
death. While EPA has quantified and
monetized the health benefits for
reductions in endemic cryptosporidiosis
that would result from the LT2ESWTR,
the Agency was unable to quantify or
monetize other health and non-health
related benefits associated with  this
rule. These unquantified benefits are
characterized next, followed by  a
summary of the quantified benefits.

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47740
Federal Register/Vol. 68, No.  154/Monday, August 11, 2003/Proposed Rules
 1. Non-Quantifiable Health and Non-
 health Related Benefits
   Although there are substantial
 monetized benefits that result from this
                       rule due to reduced rates of endemic
                       cryptosporidiosis, other potentially
                       significant benefits of this rule remain
                       unquantified and non-monetized. The
       unquantified benefits that result from
       this rule are summarized in Table VI-
       2 and are described in greater detail in
       the LT2ESWTR EA (USEPA 2003a).
                                 TABLE VI-2.—SUMMARY OF NONQUALIFIED BENEFITS
                   Benefit type
                                                 Potential effect on benefits
                                                                         Comments
 Reducing outbreak risks and response costs
                               Increase
Reducing averting  behavior (e.g.,  boiling tap water or
  purchasing bottled water).
 Improving aesthetic water quality
Reducing risk from  co-occurring  and  emerging patho-
  gens.
Increased source water monitoring
                               Increase / No Change
                               Increase

                               Increase
Reduced contamination due to covering on treating fin-
  ished water storage facilities.
                               Increase
                               Increase
Some outbreaks are caused by human or equipment
  failures that may occur even with the proposed new
  requirements; however, by adding barriers of protec-
  tion for some systems, the rule will reduce the possi-
  bility of such failures leading to outbreaks.
Averting behavior is associated with both  out-of-pocket
  costs (e.g., purchase of  bottled water) and oppor-
  tunity costs (e.g., time requiring to boil  water) to the
  consumer. Reductions  in  averting behavior are ex-
  pected to have a positive impact on benefits from the
  rule.
Some technologies  installed for this  rule  (e.g., ozone)
  are likely to reduce taste quality and odor problems.
Although focused on removal of Cryptosporidium from
  drinking  water, systems that change treatment proc-
  esses will also increase removal of  pathogens that
  the rule does not specifically regulate. Additional ben-
  efits will accrue.
The greater understanding of source water quality that
  results from monitoring may  enhance  the ability of
  plants to optimize treatment operations in ways other
  than those addressed in this rule.
Although insufficient data were available to quantify
  benefits,  the reduction of contaminants  introduced
  through  uncovered  finished water storage facilities
  would produce positive public health benefits.
  Source: Chapter 5 of the LT2ESWTR Economic Analysis (USEPA 2003a).
2. Quantifiable Health Benefits

   EPA quantified benefits for the
LT2ESWTR based on reductions in the
risk of endemic cryptosporidiosis.
Several categories of monetized benefits
were considered in this analysis.
   First, EPA estimated the number of
cases expected to result in premature
mortality (primarily for members of
sensitive subpopulations such as AIDS
patients). In order to estimate the
benefits from deaths avoided as a result
of the rule, EPA multiplied the
estimates for number of illnesses
avoided by a projected mortality rate.
This mortality rate was developed using
mortality data from the Milwaukee
cryptosporidiosis outbreak of 1993
(described in section II), with
adjustments to account for the
subsequent decrease in the mortality
rate among people with AIDS and for
the difference between the 1993
Milwaukee AIDS rate and the current
national rate. EPA estimated a mortality
rate of 16.6 deaths per 100,000 illnesses
for those served by unaltered systems
and a mortality rate of 10.6 deaths per
100,000 illnesses for those served by
filtered systems. These different rates
are associated with the incidence of
AIDS in populations served by
                       unfiltered and filtered systems. A
                       complete discussion on how EPA
                       derived these rates can be found in
                       subchapter 5.2 of the LT2ESWTR EA
                       (USEPA 2003a).
                        Reductions in mortalities were
                       monetized using EPA's standard
                       methodology for monetizing mortality
                       risk reduction. This methodology is
                       based on a distribution of value of
                       statistical life (VSL) estimates from 26
                       labor market and stated preference
                       studies, with a mean VSL of S6.3M in
                       2000, and a 5th to 95th percentile range
                       of $1.0 to $14.5. A more detailed
                       discussion of these studies and the  VSL
                       estimate can be found  in EPA's
                       Guidelines for Preparing Economic
                       Analyses (USEPA 2000c). A real income
                       growth factor was applied to these
                       estimates of approximately 2.3% per
                       year for the 20 year time span following
                       implementation. Income elasticity for
                       VSL was estimated as a triangular
                       distribution that ranged from 0.08 to
                       1.00, with a mode of 0.40. VSL values
                       for the 20 year span are shown in the
                       LT2 EA in Exhibit C.13 (USEPA 2003a).
                        The substantial majority of cases  are
                       not expected to be fatal and the Agency
                       separately estimated the value of non-
                       fatal illnesses avoided  that would result
                       from the LT2ESWTR. For these, EPA
       first divided projected cases into three
       categories, mild, moderate, and severe,
       and then calculated a monetized value
       per case avoided for each severity level.
       These were then combined into  a
       weighted average value per case based
       on the relative frequency of each
       severity level. According to a study
       conducted by Corso et al (2003), the
       majority of illness falls into the mild
       category (88 percent). Approximately 11
       percent of illness falls into the moderate
       category, which is defined as those who
       seek medical treatment but are not
       hospitalized. The final one percent have
       severe symptoms that result in
       hospitalization. EPA estimated different
       medical expenses and time losses for
       each category.
          Benefits for non-fatal cases were
       calculated using a cost-of-illness (COI)
       approach. Traditional COI valuations
       focus on medical costs and lost work
       time, and leave out significant
       categories of benefits, specifically the
       reduced utility from being sick (i.e., lost
       personal or non-work time, including
       activities such as child care,
       homemaking, community service, time
       spent with family, and recreation),
       although some COI studies also include
       an estimate for unpaid labor (household
       production) valued at an estimated wage

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                  Federal Register/Vol.  68,  No. 154/Monday, August 11, 2003/Proposed  Rules
                                                                      47741
  rate designed to reflect the market value
  of such labor (e.g., median wage for
  household domestic labor). This
  reduced utility is variously referred to
  as lost leisure or a component of pain
  and suffering. Ideally, a comprehensive
  willingness to pay (WTP) estimate
  would be used that includes all
  categories of loss in a single number.
  However, a review of the literature
  indicated that the available studies were
  not suitable for valuing
  cryptosporidiosis; hence, estimates from
  this literature are inappropriate for use
  in this analysis. Instead, EPA presents
  two COI estimates: a traditional
  approach that only includes valuation
  for medical costs and lost work time
  (including some portion of unpaid
  household production); and an
  enhanced approach that also factors in
  valuations for lost unpaid work time for
  employed people, reduced utility (or
  sense of well-being) associated with
 decreased enjoyment of time spent in
 non-work activities, and lost
 productivity at work on days when
 workers are ill but go to work anyway.
   Table Vl-3 shows the various
 categories of loss and how they were
 valued for each  estimate for a "typical"
 case (weighted average of severity
 level—see LT2ESWTR EA—Chapter 5
 for more details (USEPA 2003a).
                       TABLE Vl-3.—TRADITIONAL AND ENHANCED COI FOR CRYPTOSPORIDIOSIS
Loss category

Lost Paid Work Days 	 	 	
Lost Unpaid Work Days1 	 '. 	



Total4 	 	 	

Traditional
COI
$9382
10988
2022
20 70
5
5
24462

Enhanced COI
$93 82
109 88
4044
54 31
333 96
11249
744 89

   1 Assigned to 38.2% of the population not engaged in market work; assumes 40 hr, unpaid work week, valued at $5.46/hr in traditional COI
 and $10.92/hr in enhanced COI. Does not include lost unpaid work for employed people and may not include all unpaid work for people outside
 the paid labor force.
   2 Values lost work or leisure time for people caring for  the ill. Traditional approach does not include lost leisure time.
   3 Includes child care and homemaking (to the extent not covered in lost unpaid work days above), time with family, and recreation for people
 within and outside the paid labor force.
   4 Detail may not calculate to totals due to independent rounding; Source: Appendix L in LT2ESWTR EA (USEPA 2003a).
   5 Not included.
   The various loss categories were
 calculated as follows: Medical costs are
 a weighted average across the three
 illness severity levels of actual costs for
 doctor and emergency room visits,
 medication, and hospital stays. Lost
 paid work represents missed work time
 of paid employees, valued at the median
 pre-tax wage, plus benefits of $18.47
 hour. The average number of lost work
 hours per case is 5.95 (this assumes that
 62 percent of the population is in the
 paid labor force and the loss is averaged
 over seven days). Medical costs and lost
 work days reflect market transactions.
 Medical costs are always included in
 COI estimates and lost work days are
 usually included in COI estimates.
  In the traditional COI estimate, an
 equivalent amount of lost unpaid work
 time was assigned to the 38% of the
 population that are not in the paid labor
 force. This includes homemakers,
 students, children, retires, and
 unemployed persons. EPA did not
 attempt to calculate what percent of
 cases falls in each of these five groups,
 or how many hours per week each
 group works, but rather assumed  an
 across-the-board 40 hour unpaid work
 week. This time is valued at $5.46 per
 hour, which is one half the median post-
tax wage, (since work performed by
these groups is not taxed). This is
approximately the median wage for paid
household domestic labor.
   In the enhanced COI estimate, all time
 other than paid work and sleep (8 hours
 per day) is valued at the median after
 tax wage, or $10.92 per hour. This
 includes lost unpaid work (e.g.,
 household production) and leisure time
 for people within and outside the paid
 labor force. Implicit in this approach, is
 that people would pay the same amount
 not to be sick during their leisure time
 as they require to give up their leisure
 time to work (i.e., the after tax wage). In
 reality, people might be willing to pay
 either more than this amount (if they
 were very sick and suffering a lot) or
 less than this amount (if they were not
 very sick and still got some enjoyment
 out of activities such as resting, reading
 and watching TV), not to be sick.
 Multiplying 16 hours by $10.92 gives a
 value of about $175.00 for a day of
 "lost" unpaid work and leisure (i.e., lost
 utility of being sick).
  An estimate of lost unpaid work days
 for the enhanced approach was made by
 assigning the value of $10.92 per hour
 to the same number of unpaid work
 hours valued in the traditional COI
 approach (i.e., 40 unpaid work hours
 per week for people outside the paid
 labor force). Lost unpaid work for
 employed people and  any unpaid labor
beyond  40 hours per week for those not
in the labor market is shown as lost
leisure time in Table VI-3 for the
enhanced approach and is not included
 in the traditional approach. In addition,
 for days when an individual is well
 enough to work but still experiencing
 symptoms, such as diarrhea, the
 enhanced estimate also includes a 30%
 loss of work and leisure productivity,
 based on  a study of giardiasis illness
 (Harrington et al. 1985) which is similar
 to cryptosporidiosis. Appendix P in the
 EA describes similar productivity losses
 for other illnesses such as influenza
 (35%-73% productivity losses). In the
 traditional COI analysis, productivity
 losses are not included for either work
 or non-work time.
  The Agency believes that losses in
 productivity and lost leisure time are
 unquestionably present and that these
 categories have positive value;
 consequently, the traditional COI
 estimate understates the true value of
 these loss categories. EPA notes that
 these estimates should not be regarded
 as upper and lower bounds. In
 particular, the enhanced COI estimate
 may not fully incorporate the value of
 pain and suffering, as people may be
 willing to pay more than $201 to avoid
 a day of illness. The traditional COI
 estimate includes a valuation for a lost
 40 hour work week for all persons not
 in the labor force, including children
and retirees. This may be an
overstatement of lost productivity for
these groups, which would depend on
the impact of such things as missed

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47742
Federal Register/Vol. 68, No. 154/Monday, August 11, 2003/Proposed Rules
school work or volunteer activities that
may be affected by illness.
  As with the avoided mortality
valuation, the real wages used in the
COI estimates were increased by a real
income growth factor that varies by
year, but is the equivalent of about 2.3%
over the 20 year period. This approach
of adjusting for real income growth was
recommended by the SAB (USEPA
2000e) because the median real wage is
expected to grow each year (by
approximately 2.3%)—the median real
wage is projected to be $38,902 in 2008
                      and $59,749 in 2027. Correspondingly,
                      the real income growth factor of the COI
                      estimates increases by the equivalent of
                      2.3% per year (except for medical costs,
                      which are not directly tied to wages).
                      This approacb gives a total COI
                      valuation in 2008 of $268.92 for the
                      traditional COI estimate and $931.06 for
                      the enhanced COI  estimate; the
                      valuation in 2027 is $362.75 for the
                      traditional COI estimate and $1,429.99
                      for the enhanced COI estimate. There is
                      no difference in the methodology for
                      calculating the COI over this 20 year
period of implementation; the change in
valuation is due to the underlying
change in projected real wages.
  Table VI-4 summarizes the annual
cases of cryptosporidiosis illness and
associated deaths avoided due to the
LT2ESWTR proposal. The proposed
rule, on average, is expected to reduce
256,000 to 1,019,000 illnesses and 37 to
141 deaths annually after full
implementation (range based on the
ICRSSL, ICRSSM, and Information
Collection Rule data sets).
                         TABLE VI-4,—SUMMARY OF ANNUAL AVOIDED ILLNESS AND DEATHS
Data set
Annual illinesses avoided
Mean
90 percent confidence
bound
Lower
(5th %ile)
Upper
(95th %ile)
Annual deaths avoided
Mean
90 percent confidence
bound
Lower
(5th %ile)
Upper
(95th %He)
                                         Annual Total After Full Implementation
ICR 	

ICRSSM 	
1,018,915
256,173
498,363
169,358
45,292
84,724
2,331 ,467
560,648
1,177,415
141
37
70
25
7
13
308
78
157
                                            Annual Average Over 25 years


ICRSSM 	
720,668
181,387
352,611
119,694
32,179
59,942
1,647,796
396,845
833,290
100
26
50
18
5
9
218
55
111
  Source: The LT2ESWTR Economic Analysis (USEPA 2003a).
  Tables VI-5a and VI-5b show the
 monetized present value of the benefit
 for reductions in endemic
 cryptosporidiosis estimated to result
 from the LT2ESWTR for the enhanced
 and traditional COI values, respectively.
 Estimates are given for the Information
 Collection Rule, ICRSSL,  and ICRSSM
 occurrence data sets.
  With the enhanced COI and a three
 percent discount rate, the annual
 present value of the mean benefit
 estimate ranges from $374 million to
 $1.4 billion, with a 90 percent
                      confidence bound of $52 million to
                      $198 million at the lower 5th percentile
                      and $959 million to $3.7 billion at the
                      upper 95th percentile; at a seven
                      percent discount rate, this estimate
                      ranges from $318 million to $1.2 billion,
                      with a 90 percent confidence bound of
                      $44 million to $168 million at the lower
                      5th percentile and $816 million to $3.1
                      billion at the upper 95th percentile.
                      With the traditional COI, the
                      corresponding benefit estimate at a three
                      percent discount rate ranges from $253
                      million to $967 million, with a 90
 percent confidence bound of $27
 million to $105 million at the lower 5th
 percentile and $713 million to $2.7
 billion at the upper 95th percentile; for
 a seven percent discount rate, this
 estimate ranges from $216 million to
 $826 million, with a 90 percent
 confidence bound of $23 million to $89
 million at the lower 5th percentile and
 $610 million to $2.3 billion at the upper
 95th percentile. None of these values
 include the unquantified and non-
 monetized benefits discussed
 previously:
                        TABLE VI-5A.—:
                       SUMMARY OF QUANTIFIED BENEFITS—ENHANCED COI
                                  [Smillions, 2000$]
Data set
Value of benefits— Enhanced COI 1
Mean
90 percent confidence bound
Lower
(5th %ile)
Upper
{95th %ile)
                                          Annuallzed Value (at 3%, 25 Years)


ICRSSM 	
$1,445
374
715
$198
52
96
3,666
959
1,849
                                          Annualized Value (at 7%, 25 Years)
 ICR
                                                                                  1,230
                                                                                 168
                                 3,120

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                 Federal Register/Vol. 68, No. 154/Monday, August 11, 2003/Proposed  Rules
                                                                     47743
                  TABLE VI-5A.—SUMMARY OF QUANTIFIED BENEFITS—ENHANCED COI—Continued
                                                   [Smillions, 2000$]
Data set

1CRSSM 	
Value of benefits— Enhanced COI 1
Mean
318
609
90 percent confidence bound
Lower
(5th %ile)
44
81
Upper
(95th %ile)
816
1,577
   The traditional COt only includes valuation for medical costs and lost work time (including some portion of unpaid household production). The
enhanced COI also factors in valuations for lost personal time (non-worktime) such as child care and homemakmg (to the extent not covered by
the traditional COI), time with family, and recreation, and lost productivity at work on days when workers are ill but go to work anyway. Source:
The LT2ESWR Economic Analysis (USEPA 2003a).

                       TABLE VI-5B.—SUMMARY OF QUANTIFIED BENEFITS—TRADITIONAL COI
                                                  [(SMillions, 2000$]
Data Set
Value of Benefits — Traditional
con
Mean
90 percent con-
fidence bound
Lower
(5th %ile)
Upper
95th %ile)
                                           Annualized Value (at 3%, 25 Years)


ICRSSM 	
$967
253
481
$105
27
50
$2,713
713
1,372
                                           Annualized Value (at 7%, 25 Years)


ICRSSM 	
826
216
411
89
23
43
2,315
610
1,172
  1 The traditional COI only includes valuation for medical costs and lost work time (including some portion of unpaid household production). The
enhanced COI also factors in valuations for lost personal time (non-worktime) such as child care and homemaking (to the extent not covered by
the traditional COI), time with family, and recreation, and lost productivity at work on days when workers are ill but go to work anyway. Source:
The LT2ESWTR Economic Analysis (USEPA 2003a).
  a. Filtered systems. Benefits to the
approximately 161 million people
served by filtered surface water and
GWUDI systems range from 88,000 to
472,000 reduction in mean annual cases
of endemic illness based on ICRSSL,
ICRSSM, and ICR data sets. In addition,
premature mortality is expected to be
reduced by an average of 9 to 50 deaths
annually.
  b. Unfihered systems. The 12 million
people served by unfiltered surface
water or GWUDI systems will see a
significant reduction in
cryptosporidiosis as a result of the
LT2ESWTR. In this population, the rule
is expected to reduce approximately
168,000 to 547,000 cases of illness and
28 to 91 premature deaths annually.
  For unfiltered systems, only the
Information Collection Rule data set is
used to directly calculate illness
reduction because it is the only data set
that includes sufficient information on
unfiltered systems. Illness reduction in
unfiltered systems was estimated for the
ICRSSL and ICRSSM data sets by
multiplying the Information Collection
Rule unfiltered system result by the
ratio, for the quantity estimated,
between filtered system results from the
supplemental survey data set (SSM or
SSL) and filtered system results from
the Information Collection Rule.

3. Timing of Benefits Accrual (Latency)

  In previous rulemakings, some
commenters have argued that the
Agency should consider an assumed
time lag or latency period in its benefits
calculations. The Agency has not
conducted a latency analysis for this
rule because cryptosporidiosis is an
acute illness; therefore, very little time
elapses between exposure, illness, and
mortality. However, EPA does account
for benefits and costs that occur in
future years by converting these to
present value estimates.
D. What Are the Costs of the Proposed
LT2ESWTR?

  In order to estimate the costs of
today's proposed rule, the Agency
considered impacts on public water
systems and on States (including
territories and EPA implementation in
non-primacy States).  EPA assumed that
systems would be in  compliance with
the IESWTR, which has a compliance
date of January 2002  for large systems
and the LTlESWTR,  which has a
compliance date of January 2005 for
small systems. Therefore, this cost
estimate only considers the additional
requirements that are a direct result of
the LT2ESWTR. More detailed
information on cost estimates are
described next and a  complete
discussion can be found in chapter 6 of
the LT2ESWTR EA (USEPA 2003a). An
detailed discussion of the proposed rule
provisions is located  in section IV of
this preamble.

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47744
Federal  Register/Vol. 68, No.  154/Monday, August  11,  2003/Proposed Rules
1. Total Annualized Present Value Costs
  Tables VI-6a and VI-6b summarize
the annualized present value cost
estimates for the proposed LT2ESWTR
at three percent and seven percent
discount rates, respectively. The mean
annualized present value costs of the
proposed LT2ESWTR are estimated to
range from approximately $73 to $111
million using a three percent discount
rate and $81 to $121 million using a
seven percent discount rate. This range
in mean cost estimates is associated
with the ICRSSL and Information
Collection Rule Cryptosporidium
occurrence data sets. Using different
occurrence data sets results  in different
                      bin classifications and, thus, impacts
                      the cost of the rule. Results for the
                      ICRSSM fall within the range of results
                      for the Information Collection Rule and
                      ICRSSL. In addition to mean estimates
                      of costs, the Agency calculated 90
                      percent confidence bounds by
                      considering the uncertainty in
                      Cryptosporidium occurrence estimates
                      and around the mean unit technology
                      costs (USEPA 2003a).
                        Public water systems will incur
                      approximately 99 percent of the rule's
                      total annualized present value costs.
                      States incur the remaining rule costs.
                      Table VI-7 shows the undiscounted
                      initial capital and one-time costs broken
out by rule component. A comparison of
annualized present value costs among
the rule alternatives considered by the
Agency is located in subsection VI.F.
and in the LT2ESWTR EA (USEPA
2003a). Using a present value allows
costs and benefits that occur during
different time periods to be compared.
For any future cost, the higher the
discount rate, the lower the present
value. Specifically, a future cost
evaluated at a seven percent discount
rate will always result in a lower total
present value cost than the same future
cost evaluated at a three percent
discount rate,
BILLING CODE 6560-50-P

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Federal Register/Vol. 68, No. 154/Monday, August 11, 2003/Froposed Rules
47745
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Federal Register/Vol. 68, No.  154/Monday, August 11,  2003/Proposed Rules
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-------
47748
Federal Register/Vol. 68, No.  154/Monday, August 11, 2003/Proposed Rules
BILLING CODE 6560-50-C
2. Water System Costs

  The proposed LT2ESWTR applies to
all community, non-transient non-
community, and transient non-
community water systems that use
surface water or GWUDI as a source
(including both filtered and unfiltered
systems). EPA has estimated the cost
impacts for these three types of public
drinking water systems. As shown in
Table VI-6a and VI-6b, the mean
annualized present value costs for all
drinking water systems range from
                      approximately $73 to $111 million
                      using a three percent discount rate ($81
                      to $121 million using a seven percent
                      discount rates).
                        The majority of costs of the rule result
                      from treatment changes incurred by
                      filtered and unfiltered systems. Table
                      Vl-8 shows the number of filtered and
                      unfiltered systems that will incur costs
                      by rule provision. Subsection VI.D.2.b
                      discusses treatment costs for filtered
                      system and subsection VI.D.2.C
                      discusses treatment options for
                      unfiltered systems. All non-purchased
                      surface water and GWUDI systems
subject to the LT2ESWTR (including
filtered and unfiltered systems) will
incur one-time costs that include time
for staff training on rule requirements.
Systems will incur monitoring costs to
assess source water Cryptosporidium
levels, though monitoring requirements
vary by system size (large vs. small) and
system type (filtered vs. unfiltered). A
discussion of future monitoring that will
occur six years after initial bin
assignments can be found in subsection
VI.D.2.e.
BILLING CODE 6560-SO-P
      Tgble Vl-8.- Number of Filtered and Unfiltered Systems and Plants Expected to

      Incur Costs1
Dataset

ICR
ICRSSL
ICRSSM
Nonpurchased Systems and Plants
System Size
(population
served)

< 10,000
> 10,000
Total
< 10.000
> 10.000
Total
< 10,000
> 10,000
Total
Systems
Incurring
Implementation
Costs
A
5,662
1,384
7,066
Source Water Monitoring - Plants
Initial E.
Coll
Monitoring
B
5,792
1,774
7,565
Same as ICR
Same as ICR
Initial
Crypto
Monitoring
C
2,016
1,774
3,789
1,295
1,774
3,069
1,575
1,774
3,349
Future
E coli
Monitoring
D
5,122
1,273
6,395
5,409
1,453
6,862
5,347
1,386
6,733
Future
Crypto
Monitoring
E
1,782
1,273
3,056
1,209
1,453
2,662
1,454
1,386
2,840

Plants
Adding
Treatment
F
2.251
733
2,984
1,463
481
1,944
1,768
578
2,346
Systems
with
Uncovered
Reservoirs
G
32
106
138
Same as ICR
Same as ICR
       'Numbers shown for plants monitoring include nonpurchased plants only. Numbers shown for plants adding
       treatment include both nonpurchased plants and a fraction of plants purchasing water that could not be linked to a
       nonpurchased plant.  Source: Chapter 6 of the LT2ESWTR Economic Analysis (USEPA 2003a)
BILLING CODE 6560-50-C
  a. Source water monitoring costs.
Source water monitoring costs are
structured on a per-plant basis. Also, as
with implementation activities,
purchased plants are assumed not to
treat source water and will not have any
monitoring costs. There are three types
of monitoring that plants may be
required to conduct—turbidity, E. coli
and Cryptosporidium. Source water
turbidity is a common water quality
parameter used for plant operational
control. Also, to meet SWTR,
LT1ESWTR and IESWTR requirements,
most water systems have turbidity
analytical equipment in-house and
operators are experienced with turbidity
                      measurement. Thus, EPA assumes that
                      the incremental turbidity monitoring
                      burden associated with the LT2ESWTR
                      is negligible.
                        Filtered plants in small systems
                      initially will be required to conduct one
                      year of biweekly E. coli source water
                      monitoring. These plants will be
                      required to monitor for Cryptosporidium
                      if, as a result of initial bin classification,
                      E. coli levels exceed the following
                      concentrations: (1) Annual mean > 10 E.
                      co/i/100 mL for lakes and reservoir
                      sources, and (2) annual mean > 50 E.
                      co/j/100 mL for flowing stream sources.
                      EPA estimated the percent of small
                      plants that would be triggered into
                      Cryptosporidium monitoring as being
equal to the percent of large plants that
would fall into any bin requiring
additional treatment.
  Estimates of laboratory fees, shipping
costs, labor hours for sample collection,
and hours for reporting results were
used to predict system costs for initial
source water monitoring under the
LT2ESWTR. Table VI-9 summarizes the
present value of monitoring costs for
initial bin classification. Total present
value monitoring costs for initial bin
classification range from $46 million to
$60 million depending on the
occurrence data set and discount rate.
Appendix D of the LT2ESWTR EA
provides a full explanation of how these
costs were developed (USEPA 2003a).

-------
                Federal  Register/Vol. 68, No. 154/Monday,  August  11,  2003/Proposed Rules
                                                                    47749
           TABLE VI-9.— SUMMARY OF PRESENT VALUE MONITORING COSTS FOR INITIAL BIN CLASSIFICATION
                                                  (Smillions, 2000$)
System Size
<10K 	
10K 	
Total 	
ICR (3%)
A
$34.6
25.7
60.3
ICR (7%)
B
$29.7
24.3
54.0
ICRSSL (3%)
C
$25.7
25.7
51.4
ICRSSL (7%)
D
$22.2
24.3
46.5
ICRSSM (3%)
E
$29.2
25.7
54.9
ICRSSM (7%)
F
$25.1
24.3
49.4
  Source: Chapter 6 of the LT2ESWTR Economic Analysis (USEPA 2003a).
  b. Filtered systems treatment costs.
The Agency calculated treatment costs
by estimating the number of plants that
will be adding treatment technologies
and coupling these estimates with unit
costs (S/plant) of the selected
technologies. Table VI-10 shows the
number of plants estimated to select
different treatment technologies; Table
VI-11 summarizes the present value
treatment costs and annualized present
value costs for both filtered and
unfiltered systems.
  To estimate the number of filtered
plants that would select a particular
treatment technology, the Agency
followed a two step process. First, the
number of plants that must make
treatment changes to meet the proposed
LT2ESWTR requirement was
determined by the binning process.
Second, EPA predicted the treatment
technologies that plants would choose
to meet the proposed requirements. The
Agency used a "least-cost decision tree"
as the basic framework for determining
the treatment technology selection. In
other words, EPA assumed that drinking
water plants would select the least
expensive technology or combination of
technologies to meet the log removal
requirements of a given action bin.
However, these technology selections
were constrained by maximum use
percentages, which recognize that some
plants will not be able to implement
certain technologies because of site-
specific conditions. In addition, certain
potentially lower cost components of
the microbial toolbox, such as changes
to the plant intake, were not included
because the Agency Jacked data to
estimate the number of plants that could
select it. These limitations on
technology use may result in an
overestimate of costs. An in-depth
discussion of the technology selection
methodology and unit cost estimates
can be found in appendices E and F of
the proposed LT2ESWTR EA (USEPA
2003a).
                     TABLE VI-10.—TECHNOLOGY SELECTION FORECASTS FOR FILTERED PLANTS

Technology Selections





Technology Selections 1





Total Plants Selecting Technologies 	
Data set
ICR
1,545
190
77
16
5
10
26
24
9
0
998
0
2,893
ICRSSL
1,236
17
60
12
3
3
17
18
1
0
490
0
1,852
ICRSSM
1,441
52
70
14
4
5
21
21
2
0
632
0
2,255
   Some plants are projected to select more than one technology to meet LT2ESWTR bin requirements; consequently the value for total plants
does not equal the sum of all technologies selected. Source: Chapter 6 of the LT2ESWTR Economic Analysis {USEPA 2003a).
  c. Unfiltered systems treatment costs.
The proposed LT2ESWTR requires all
unfiltered plants to achieve 2 logs of
inactivation if their mean source water
Cryptosporidium concentration is less
than or equal to 0.01 oocysts/L and 3
logs of inactivation if it is greater than
0.01 oocysts/L. For most systems, UV
appears to be the least expensive
technology  that can achieve the required
log inactivation of Cryptosporidium,
and it is expected to be widely used by
unfiltered systems to meet the rule
requirement. However, as with filtered
systems, EPA estimated that a small
percentage of plants would elect to
install a technology more expensive
than UV due to the configuration of
existing equipment or other factors.
Ozone is the next least expensive
technology that will meet the
inactivation requirements for some
systems, and is estimated to be used by
plants that do not use UV.
  All unfiltered plants must meet
requirements of the LT2ESWTR;
therefore, the percent of plants adding
technology is 100 percent. This also
assumes that no unfiltered systems
currently use these additional treatment
technologies. For this cost analysis, the
Agency assumed 100 percent of very
small unfiltered systems will use UV;
for all other unfiltered system sizes, the
Agency estimated that 90 percent would
install UV and 10 percent would add
ozone. This analysis is discussed in
more detail in the LT2ESWTR EA
(USEPA 2003a). Treatment costs for
unfiltered systems are included in Table
VI-11.

-------
47750
Federal Register/Vol.  68,  No. 154/Monday, August 11, 2003/Proposed Rules
    TABLE VI-11 .—TOTAL PRESENT VALUE AND ANNUALIZED PRESENT VALUE TREATMENT COSTS FOR FILTERED AND
                                                UNFILTERED PLANTS
Data Set
ICR 	
TOTAL 	
ICRSSL 	
TOTAL 	
ICRSSM 	 	
TOTAL 	
	 1
System Size
(population
served)
<10,000
> 10,000
<10,000
>1 0,000
<10,000
>10,000
I 	 ,
Present
Value Cap-
ital Costs at
3%
A
$76.1
1,092.4
1,168.5
42.8
707.1
749.8
52.6
842.4
894.9
I 	 I
Present
Value Cap-
ital Costs at
7%
B
$56.0
868.0
924.0
31.5
561.8
593.3
38.7
669.3
. 708.0

Annualized
O&M Costs
at 3%
C
$5.2
26.1
31.3
2.9
16.2
19.0
3.5
19.4
23.0

Annualized
O&M Costs
at 7%
D
$4.3
22.7
26.9
2.4
14.0
16.4
2.9
16.9
19.8

Total
Annuallized
Costs at 3%
E
$9.6
88.8
98.4
5.3
56.8
62.1
6.6
67.8
74.4

Total
Annualized
Costs at 7%
F
$9.1
97.1
106.2
5.1
62.3
67.3
6.2
74.3
80.6

  Source: Chapter 6 of the LT2ESWTR Economic Analysis (USEPA 2003a)
  d. Uncovered finished water storage
facilities. As part of the LT2ESWTR,
systems with uncovered finished water
storage facilities have the option to
cover the storage facility or provide
disinfection after the storage facility,
unless the State has determined that
existing risk mitigation is adequate.
Disinfection alternatives must achieve at
least four logs of virus inactivation. To
develop national cost estimates for
systems to comply with this provision
of the LT2ESWTR, unit costs for each
treatment alternative and the percentage
of systems selecting each alternative
were estimated for the inventory of
systems with uncovered finished water
storage facilities. A full description of
the unit costs and other assumptions
                      used in this analysis is presented in
                      Chapter 6 and Appendix I of the
                      LT2ESWTR EA (USEPA 2003a).
                        The Agency assumed that all systems
                      with uncovered finished water storage
                      facilities will have to either install a
                      cover or treat their discharge. This
                      overestimates the cost of this provision
                      because States can determine that
                      systems with uncovered finished storage
                      facilities do not need to take these
                      additional measures. The technology
                      selection for the uncovered finished
                      water storage facilities was developed
                      through a least-cost approach.
                        For systems with uncovered storage
                      facility  capacities of five million gallons
                      (MG) or less, covering the storage
                      facilities is the least expensive
                      alternative. Although chlorination is the
least expensive alternative for the
remaining systems, the ability of a
system to use booster chlorination
depends on their current residual
disinfectant type. Less than half of all
surface water systems are predicted to
use chloramination following
implementation of the Stage 2 DBPR.
Adding chlorine to water that has been
treated with chloramines is not a
feasible alternative; therefore, the
fraction of systems projected to add
booster chlorination to the effluent from
the storage facility was estimated at 50
percent, with the remaining 50 percent
estimated to add covers.  The technology
selection for uncovered finished water
storage facilities is presented in Table
VI-12.
              TABLE VM 2.—ESTIMATED TECHNOLOGY SELECTION FOR UNCOVERED STORAGE FACILITIES
Size category (MG)


>1 5 	
>5-10 	 	 	
>10-20 	
>20-40 	
>40-60 	 	 	
>60-80 	 • 	
>80-100 	
>100-150 	 	 	
>150-200 	 • 	
>2QO-250 	
>250-1 000 	 • 	
>1.000 	
Number of uncovered
storage facilities
25
7
44
12
10
9
4
4
6
6
2
4
4
1
Floating
cover
(%)
100
100
100
100
100
50
50
50
50
50
50
50
50
50
Booster
chlorination
(%)





50
50
50
50
50
50
50
50
50
  Source: Appendix I of the LT2ESWTR Economic Analysis (USEPA 2003a)
  Table VI-13 summarizes total
annualized present value costs for the
uncovered storage facility provision
using both three and seven percent
                      discount rates. The Agency estimates
                      the total annualized present value cost
                      for covering or treating uncovered
                      finished water storage facilities to be
approximately $5.4 million at a three
percent discount rate and $6.4 million
at a seven percent discount rate.

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                Federal  Register/Vol. 68, No.  154/Monday. August 11, 2003 / Proposed Rules
                                                                   47751
 TABLE VI-13— ESTIMATED ANNUALIZED PRESENT VALUE COST FOR UNCOVERED FINISHED WATER STORAGE FACILITY
                                               PROVISION (2000$)
System size (population served)

>10,000 	 	
Total 	
Annualized cost at 3%
Capital
$3,520
3,349,320
3,352,840
O&M
$1,649
2,046,425
2,048,074
Total
$5,169
5,395,745
5,400,915
Annualized cost at 7%
Capital
$4,713
4,483,927
4,488,639
O&M
$1,552
1,925,203
1,926,754
Total
$6,264
6,409,129
6,415,393
  Source: Appendix I of the LT2ESWTR Economic Analysis (USEPA 2003a)
  e. Future monitoring costs. Six years
after initial bin classification, filtered
and unfiltered plants will be required to
conduct a second round of monitoring
to assess whether source water
Cryptosporidium levels have changed
significantly. EPA will evaluate new
analytical methods and surrogate
indicators of microbial water quality in
the interim. While the costs of
monitoring are likely to change in the
six years following rule promulgation, it
is difficult to predict how they will
change. In the absence of any other
information, it was assumed that the
laboratory costs would be the same as
for the initial monitoring.
  All plants that conducted initial
monitoring were assumed to conduct
the second round of monitoring as well,
except for those systems that installed
treatment that reduces 2.5 logs of
Cryptosporidium or greater as a result of
the rule. These systems are exempt from
monitoring under the LT2ESWTR. Table
VI-8 shows the number of systems that
are estimated to conduct the second
round of monitoring (listed as "future"
monitoring in the table). EPA estimates
the cost of re-binning will range from
$23 million to $38 million depending
on the occurrence data set and discount
rate used in the estimate (see Table VI-
14). Costs differ among Cryptosporidium
occurrence data sets due to differences
in estimates of the number of plants that
will add technologies to achieve at least
2.5 log Cryptosporidium reduction and
the number of small plants that will be
triggered into monitoring  for
Cryptosporidium. Appendix D of the EA
provides further  details (USEPA 2003a).
                   TABLE vi-14.—PRESENT VALUE OF MONITORING COSTS OF FUTURE RE-BINNING
                                                  [Smillions, 2000$]




Total 	
ICR
(3%)
A
$23.5
14.4
37.8
ICR
(7%)
B
$14.3
9.8
24.1
ICRSSL
(3%)
C
$18.4
16.4
34.8
ICRSSL
(7%)
D
$11.3
11.2
22.5
ICRSSM
(3%)
E
$20.7
15.6
36.3
ICRSSM
(7%)
F
$12.6
10.7
23.3
  Source: Chapter 6 of the LT2ESWTR Economic Analysis (USEPA 2003a
  f. Sensitivity analysis—influent
bromide levels on technology selection
for filtered plants. One concern about
the ICR data set was that it may not
actually reflect influent bromide levels
in some plants during droughts. High
influent bromide levels (the precursor
forbromate formation) limits ozone use
because the plant would not be able to
meet the MCL for bromate. The Agency
conducted a sensitivity analysis to
estimate an impact of higher influent
bromide levels would have on
technology decisions. The sensitivity
analysis assumes influent bromide
concentrations of 50 parts per billion
(ppb) above the ICR concentrations.
Overall, the impact of these
assumptions have a minimal impact on
costs. A complete discussion of this
sensitivity analysis is located in
LT2ESWTR EA (USEPA 2003a).

3. State/Primacy Agency Costs
  The Agency estimates that States and
primacy agencies will incur an
annualized present value cost of $0.9 to
$1.0 million using a three percent
discount rate and $1.2 million at seven
percent. State implementation activities
include regulation adoption and
program implementation, training State
staff, training PWS staff, providing
technical assistance to PWSs, and
updating the management system. To
estimate implementation costs to States/
Primacy Agencies, the number of full-
time employees (FTEs) per activity is
multiplied by the number of labor hours
per FTE, the cost per labor hour, and the
number of States and Territories.
  In addition to implementation costs,
States and primacy agencies will also
incur costs associated with monitoring
data management. Because EPA will
directly manage the first round of
monitoring by  large  systems (serving at
least 10,000  people), States are not
predicted to incur costs for these
activities. States will, however, incur
costs associated with small system
monitoring.  This is a result of the
delayed start of small system
monitoring,  which will mean that some
 States will assume primacy for small
 system monitoring. In addition, States
 will review of the second round of
 monitoring results. States will also incur
 costs in reviewing technology
 compliance data and consulting with
 systems regarding benchmarking for
 systems that change their disinfection
 procedures to comply with the rule.
 Appendix D of the LT2ESWTR EA
 provides more information about the
 State and primacy agency cost analysis
 (USEPA 2003a).
 4. Non-Quantified Costs
   EPA has quantified all the major costs
 for this rule and has provided
 uncertainty analyses to bound the over
 or underestimates in the costs.  There are
 some costs that EPA has not quantified,
 however, because of lack of data. For
 example, some systems may merge with
 neighboring systems to comply with this
 rule. Such changes have both costs
 (legal fees and connecting
 infrastructure) and benefits (economies
 of scale). Likewise, systems would incur

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47752
Federal Register/Vol.  68,  No. 154/Monday,  August  11,  2QQ3/Proposed Rules
costs for procuring a new source of
water that may result in lower overall
treatment costs.
  In addition, the Agency was unable to
predict the usage or estimate the costs
of several toolbox options. These
options include intake management and
demonstrations of performance. They
have not  been included in the
quantified analysis because data are not
available to estimate the number of
systems that may use these toolbox
options to comply with the LT2ESWTR.
Not including these generally low-cost
options may result in overestimation of
costs.
E. What Are the Household Costs of the
Proposed Rule?
  Another way to assess a rule's impact
is to consider how it might impact
residential water bills. This analysis
considers the potential increase in a
household's water bill if a CWS passed
the entire cost  increase resulting from
this rule  on to its customers. It is a tool
to gauge potential impacts and should
not be construed as precise estimates of
potential changes to individual water
bills.
  Included in this analysis are all CWS
costs, including rule implementation,
initial and future monitoring for bin
classification, additional
Cryptosporidium treatment, and treating
or covering uncovered finished water
                      storage facilities. Costs for small systems
                      Cryptosporidium monitoring, additional
                      Cryptosporidium treatment, and
                      uncovered finished water storage
                      facilities are assigned only to the subset
                      of systems expected to incur them.
                      Although  implementation and
                      monitoring represent relatively small,
                      one-time costs, they have been included
                      in the analysis to provide a complete
                      distribution of the potential household
                      cost. A detailed description of the
                      derivation of household costs is in
                      section 6.10 and Appendix J of the
                      LT2ESTWR EA (USEPA 2003a).
                        For purchased systems that are linked
                      to larger nonpurchased systems, the
                      households costs are calculated based
                      on the unit costs of the larger system but
                      included in the distribution from the
                      size category of the purchased system.
                      Households costs for these purchased
                      systems are based on the household
                      usage rates appropriate for the retail
                      system and not the system selling the
                      water. This approach for the purchased
                      systems reflects the fact that although
                      they will not face increased costs from
                      adding their own treatment, whatever
                      costs the wholesale utility incurs would
                      likely be passed on as higher water
                      costs.
                        Table VI-15 shows the results of the
                      household cost analysis. In addition to
                      mean and median estimates, the Agency
                      calculated the 90th and 95th percentile.
EPA estimates that all households
served by surface and GWUDI sources
will face some increase in household
costs due to implementation of the
LT2ESWTR (except for those few served
by systems that have already installed
5.5 logs of treatment for
Cryptosporidium). Of all the households
subject to the rule, from 24 to 35 percent
are projected to incur costs for adding
treatment, depending on the
Cryptosporidium occurrence data set
used.
  Approximately 95 percent of the
households potentially subject to the
rule are served by systems serving at
least 10,000 people; these systems
experience the lowest increases in costs
due to significant economies of scale.
Over 90 percent of all households will
face an annual cost increase of less than
$5. Households served by small systems
that install advanced technologies will
face the greatest increases in annual
costs. EPA expects that the model's
projections for these systems are, in
some cases, overstated. Some systems
are likely to find alternative treatment
techniques such as other toolbox
options not included in this analysis, or
sources of water (ground water,
purchased water, or consolidating with
another system) that would be less
costly than installing more expensive
treatment techniques.
   TABLE VM 5.—POTENTIAL ANNUAL HOUSEHOLD COSTS IMPACTS FOR THE PREFERRED REGULATORY OPTION (2000$)

System; type/size


Households


Mean


Median


90th
Percentile


95th
Percentile

Percent of
systems with
household
cost increase
<$12
Percent of
systems with
household
cost increase
<$120
                                                  All Systems—ICR
All CWS 	
CWS < 10,000 	
65,816,979
3,318,012
$1.68
4.61
$0.13
1.34
$4.06
13.04
$7.57
14.92
98.37
87.88
99.99
99.88
                                                All Systems—ICRSSL
All CWS 	
CWS < 10,000 	
65,816,979
3,318,012
$1.07
2.68
$0.03
0.80
$3.24
6.10
$5.43
9.39
98.31
95.71
100.00
99.95
                                                AH Systems—1C RSSM
AH CWS 	
CWS< 10,000 	
65,816,979
3,318,012
$1.28
3.27
$0.03
0.80
$3.48
6.62
$6.47
13.04
99.07
93.90
100.00
99.93
  Source: Chapter 6 of the LT2ESWTR Economic Analysis (USEPA 2003a).
F. What Are the Incremental Costs and
Benefits of the Proposed LT2ESWTR?
  Incremental costs and benefits are
those that are incurred or realized in
reducing Cryptosporidium exposures
from one alternative to the next.
Estimates of incremental costs and
benefits are useful in considering the
economic efficiency of different
                      regulatory options considered by the
                      Agency. Generally, the goal of an
                      incremental analysis is to identify the
                      regulatory option where incremental
                      benefits most closely equal incremental
                      costs. However, the usefulness of this
                      analysis is limited because many
                      benefits from this rule are unquantified
                      and not monetized. Incremental
analyses should consider both
quantified and non-quantified (where
possible) benefits and costs.
  Usually an incremental analysis
implies increasing levels of stringency
along a single parameter, with each
alternative providing all the protection
of the previous alternative, plus
additional protection. However, the

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                Federal Register/Vol. 68, No. 154/Monday, August 11, 2003/Proposed Rules
                                                                  47753
regulatory alternatives in this rule vary
by multiple parameters (e.g, risk bin
boundaries, treatment requirements).
The comparison between any two
alternatives is, therefore, between two
separate sets of benefits, in the sense
that they may be distributed to
somewhat different population groups.
  The regulatory alternatives, however,
do achieve increasing levels of benefits
at increasing levels of costs. As a  result,
it is possible to display incremental net
benefits from the baseline and
alternative to alternative. Tables VI—16a
and VI-16b show incremental costs,
benefits, and net benefits for the four
regulatory alternatives shown in Table
VI-1, using the enhanced and
traditional COI, respectively. All values
are annualized present values expressed
in Year 2000 dollars. The displayed
values are the  mean estimates for the
different occurrence distributions.
  With the enhanced COI, incremental
costs are generally closest to
incremental benefits for A2, a more
stringent alternative than the Preferred
Alternative, A3. For the traditional COI,
incremental costs most closely equal
incremental benefits for A3, the
Preferred Alternative, under the
majority of conditions evaluated.
BILLING CODE 6560-50-P
      Table Vl-16a.- Incremental Net Benefits by Rule Alternative—Enhanced COI
                              (Annualized Present Value, $millions, 2000$)
Data
Set
Rule
Alternative
Annual
Costs
A
Annual
Benefits
B
Incremental
Costs[1]
C
Incremental
Benefits
D
Incremental Net
Benefits
E=D-C
3 Percent Discount Rate
ICR
A4
A3 - Preferred
A2
A1
$ 55
$ 111
$ 134
$ 361
$ 1,349
$ 1,445
$ 1,461
$ 1,482
$ 58
$ 52
$ 23
$ 227
* 1,349
$ 96
$ 16
$ 21
* i,yyu
$ 44
id -8
1 -206

ICRSSL
A4
A3 - Preferred
A2
A1
$ 37
$ 73
$ 100
$ 361
* 328
$ 374
$ 397
$ 457
$ . 37
$ 37
$ ' 26
$ 261
$ ^32B
$ 46
$ 24
$ 59
* 291
•p '
S -2
$ -202

ICRSSM
A4
A3 - Preferred
A2
A1
$ 44
$ 86
$ 113
$ 361
$ 635
$ 715
$ 742
$ 796
$ 44
$ 42
$ • 26
$ 246
$ 635
$ 80
$ 27
$ 53
$ 592
$ 38
$ 1
1 -195
7 Percent Discount Rate
ICR
A4
A3 - Preferred
A2
A1
$ bt>
$ 121
$ 145
$ 388
$ 1,148
$ 1 ,230
$ 1 ,243
$ 1 ,260
$ bb
$ 56
$ 25
$ 242
» 1,148
$ 82
$ 13
$ 18
» 1 ,UB3
5 26
* -11
* -225


ICRSSL


A4
A3 - Preferred
A2
A1
$ 41
$ 81
$ 108
$ 388
$ 279
$ 318
$ 338
$ 389
$ 41
$ 40
$ 27
$ 279
$ 279
$ 39
$ 20
$ 50
* 238
* -1
* -7
$ -229


ICRSSM


A4
A3 - Preferred
A2
A1
$^ 48
$ 94
$ 122
$ 388
$ 541
$ 609
$ 632
$ 677
$ 48
$ 47
$ 28
$ 265
$ 541
$ 68
$ 23
$ 45
* 493
-* 21
$ -5
* -220

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47754
Federal Register/Vol.  68, No.  154/Monday, August 11, 2003/Proposed Rules
      Table Vl-16b.- Incremental Net Benefits by Rule Alternative—Traditional COI
                              (Annualized Present Value, Smillions, 2000$)
Data
Set
Rule
Alternative
Annual
Costs
A
Annual
Benefits
B
incremental
Costs [1]
C
incremental
Benefits

Benefits
=D-C
	 ' 	 3 Percent Discount Kate
ICR
A4
A3 - Preferred
A2
A1
$ 58
$ 111
$ 134
$ 361
$ 907
$ §67
$ 977
$ 369
$ 5B
$ 52
$ 23
$ 227

60
10
$ T3~


-
-2

ICRSSL
A4
A3 - Preferred
A2
A1
$ 37
•$- 73
$ 100
$ 361
$ 225
$ 253
$ 266
$ 305
$ 37
-5 37
'$ 26
$ 261

29
T5
37
» i

-
-2

ICRSSM
A4
A3 - Preferred
A2
A1
$ 44
$ 66
$ 113
$ 361
$ 432
$ 461
$ 498
$ 531
$ 44
$ 42
$ 26
$ 246
* *•"
$ ~~ 50
$ T7
33
$ j

-
-2
	 	 -1 	 7 Percent Discount Kate
ICR
A4
A3 - Preferred
A2
A1
$ 65
$ 121
$ 145
$ 336
$ 775
$ 826
$ 834
$ 645
$ 65
$ 56
$ 25
"$ 242
$ /YD
$ 5T
$ ~s
$ ^


-
-2

ICRSSL
A4
A3 - Preferred
A2
A1
$ 41
$ 81
$ 106
$ 366
$ 192
$ 218
$ 229
$ 260
^ 41
$ 40
$ 27
$ 279

24
$ T2
3T
> 1
-
-
- -2

ICRSSM
A4
A3 - Preferred
A2
A*
$ 43
$ 54
$ 122
$ 368
$ 369
$ 411
$ 425
$ 454
^ 48
S 47
$ 26
$ 235
$ Joy
42
14
$ 55
> o

•
-2



U

4
14
TTfT
00

IT
*.j

00

1
15

ID

16
Jl

ol

5



^4
•14
37
       'The traditional COI only includes valuation for medical costs and lost work time (including some portion of unpaid
       household production). The enhanced COI also factors in valuations for lost personal time (non-vrarktime such as
       child care and homemaking (to the extent not covered by the traditional COI), time with family, and mcnafem. and
       lost productivity at work on days when workers are ill but go to work anyway. Source: Chapter 8 of the LJ2ESWTR
       Economic Analysis (USEPA 2003a)
 BILLING CODE B560-50-C
 G. Are There Benefits From the
 Reduction of Co-Occurring
 Contaminants?
   This section presents information on
 the unqualified benefits that will
 accrue from removal of other
 contaminants, primarily pathogens, due
 to improved control of
 Cryptosporidium. While the benefits
 analysis for the LT2ESWTR only
 includes reductions in illness and
 mortality attributable to
                      Cryptosporidium, the LT2ESWTR is
                      expected to reduce exposure to other
                      parasitic protozoans that EPA regulates,
                      or is considering for future regulation.
                      For example, it is expected that the
                      LT2ESWTR will improve control of
                      Giardia lamblia, Cyclospora sp. and
                      members of the Microsporididea class,
                      seven genera (10 species) of which have
                      been recovered in humans (Mota et al.,
                      2000). In addition, greater
                      Cryptosporidium control may improve
                      control of the pathogenic bacteria and
viruses. Chemical contaminants such as
arsenic, DBFs and atrazine may also be
controlled, in part, by control of
Cryptosporidium, depending on the
technologies selected.
  Giardia lamblia and Cyclospora sp.
are larger than Cryptosporidium, while
Microsporididea, bacteria, and the
viruses are smaller than
Cryptosporidium. The expected removal
of co-occurring microorganisms can
often be predicted for those treatment
unit processes whose removal efficiency

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                  Federal  Register/Vol. 68, No, 154/Monday,  August  11,  2003/Proposed Rules
                                                                      47755
 depends in part, or entirely, on the size
 of the organism. For example, a study by
 Goodrich and Lykins (1995) evaluating
 bag filters showed that any microbe or
 object greater than 4.5 microns in size
 (the average size of Cryptosporidium}
 would be subject to removal ranging
 from 0.5 to 2.0 logs.
   Although not directly dependent on
 organism size,  other treatment
 technologies identified in the
 LT2ESWTR should also provide
 additional control of co-occurring
 microbial pathogens. Membrane
 processes that remove Cryptosporidium
 are shown to achieve equivalent log
 removal of Giardia under worst-case and
 normal operating conditions (USEPA
 2003c). Reduction in individual filter
 turbidities will reduce concentrations of
 other pathogens as well as
 Cryptosporidium. For example, in Dutch
 surface water, Giardia and
 Cryptosporidium occurrence appeared
 to correlate well with each other and for
 the Rhine River, with turbidity
 (Medema et al 2001). Thus, improved
 control of Cryptosporidium should also
 result in improved control of Giardia
 lamblia.
   Some membrane technologies that
 might be installed to comply with the
 LT2ESWTR can also reduce or eliminate
 chemical contaminants including
 arsenic, DBFs and atrazine. EPA has
 recently finalized a rule to further
 control arsenic levels in drinking-water
 and is concurrently proposing the Stage
 2 DBPR to address DBF control.
   The extent to which the LT2ESWTR
 can reduce the overall risk from other
 contaminants has not been
 quantitatively evaluated because of the
 Agency's lack of data regarding the co-
 occurrence among Cryptosporidium and
 other microbial pathogens and
 contaminants. Because of the difficulties
 in establishing which systems would
 have multiple problems, such as
 microbial contamination, arsenic, and
 DBFs or any combination of the three,
 no estimate was made of the potential
 cost savings from addressing more than
 one contaminant simultaneously.
 H. Are There Increased Risks From
 Other Contaminants?
  It is unlikely that the LT2ESWTR will
 result in a significant increase in risk
 from other contaminants. Many of the
 options that systems will select to
 comply with the LT2ESWTR, such as
 UV, improved filtration performance,
 and watershed control, do not form
DBFs, Other technologies that are
 effective against Cryptosporidium, such
as  ozone and chlorine dioxide, do form
DBFs. However, these DBFs are
currently regulated under the Stage 1
 DBPR, and systems will have to comply
 with these regulations when
 implementing technologies to meet the
 LT2ESWTR.
 I. What Are The Effects of the
 Contaminant on the Genera] Population
 and Groups Within the Genera!
 Populations That Are Identified as
 Likely To Be at Greater Risk of Adverse
 Health Effects?
   Section II of this preamble discusses
 the health effects associated with
 Cryptosporidium on the general
 population as well as the effects on
 other sensitive sub-populations. In
 addition, health effects associated with
 children and pregnant women are
 discussed in greater detail in section
 VII.G of this preamble.
 /. What Are the Uncertainties in the
 Baseline, Risk, Benefit, and Cost
 Estimates for the Proposed LT2ESWTR
 as Well as the Quality and Extent of the
 Information?
   Today's proposal models the current
 baseline risk from Cryptosporidium
 exposure, as well as the reduction in
 risk and the cost for various rule
 options. There is uncertainty in the risk
 calculation, the benefit estimate, the
 cost estimates, and the interaction of
 other upcoming rules. Section IV of the
 proposed rule considers the uncertainty
 with the risk estimates; however, a brief
 summary of the major risk uncertainties
 as they relate to benefit estimation is
 provided  next. In addition, the
 LT2ESWTR EA has a more extensive
 discussion of all of the uncertainties
 (USEPA 2003a).
  In addition, the Agency conducted
 sensitivity analyses to address
 uncertainty. The sensitivity analyses
 focus on various occurrence, benefit and
 cost factors that may have a significant
 effect on the estimated impacts of the
 rule. All of these sensitivity analyses are
 explained in more detail in the EA for
 the LT2ESWTR (USEPA 2003a).
  One area of uncertainty is  associated
 with the estimate of Cryptosporidium
 occurrence on a national basis. The
 Information Collection Rule plant-mean
 data were higher than  the ICRSS
 medium or large system plant-mean
 data at the 90th percentile. The reasons
 for these differing results are not well
 understood but may stem from
 differences in the populations sampled,
 year-to-year variation in occurrence, and
 systematic differences in the sampling
 and measurement methods employed.
These data suggest that
 Cryptosporidium levels are relatively
low in most water sources, but there is
a subset of sources with significantly
higher concentrations. Additional
 uncertainty is associated with
 estimating finished water occurrence
 because the analysis is based on
 assumptions about treatment plant
 performance. To account for these
 uncertainties, the Agency used Monte
 CarJo simulation models that allow
 substantial variation in each estimate
 and computed finished water
 occurrence values based on statistical
 sampling of the variable estimates.
   The risk associated with finished
 water occurrence is of lesser uncertainty
 than is typical for many contaminants
 because the health effects are measured
 based on Cryptosporidium challenge
 studies to human volunteer populations.
 Nevertheless, there is significant
 uncertainty about the dose-response
 associated with Cryptosporidium
 because there exists considerable
 differences in infectivity among the
 various tested Cryptosporidium parvum
 isolates. As described in section III.B,
 the Agency accounted for these
 differences using Monte Carlo
 simulations that randomly sampled
 from infectivity distributions for.the
 three tested isolates. The different
 simulations were designed to account
 for the limited number of challenge
 studies and the variability in the
 infectivity of the isolates themselves. In
 addition, because the Cryptosporidium
 dosing levels in the human feeding
 studies were above typical drinking
 water exposure levels (e.g., one oocyst),
 there remains significant uncertainty
 that could not be quantified into the
 analysis.
   While all of the significant costs of
 today's proposed rule have been
 identified by EPA, there are
 uncertainties about some of the
 estimates. However, the Agency
 explored the impact of the uncertainties
 that might have the greatest impact by
 conducting sensitivity analyses and
 using Monte Carlo techniques. For
 example, section VI.D.2.f of today's rule
 explores the impact of influent bromide
 levels on technology selection. As
 shown in the EA for this rule, the
 impact of higher influent bromide levels
will  not have a significant impact on the
rule's costs. In addition, subsection 6.12
of the EA summarizes other cost
uncertainties including the Agency's
inability to include some lower cost
toolbox options in the cost analysis
(USEPA 2003a).
  Last, EPA has recently finalized new
regulations for arsenic, radon,
Cryptosporidium in small surface water
systems, and filter backwash in all
system sizes (LTlESWTR and Filter
Backwash Rule); proposed a rule  for
microbials in ground water systems
(Ground Water Rule); and is

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                Federal Register/Vol. 68, No.  154/Monday.  August  11.  2003/Proposed Rules
concurrently proposing additional
control of disinfection byproducts
(Stage 2 Disinfection Byproducts Rule).
These rules may have overlapping
impacts on some drinking water systems
but the extent is not possible to estimate
because of lack of information on co-
occurrence. However, it is possible for
a system to choose treatment
technologies that would address
multiple contaminants. Therefore, while
the total cost impact of these drinking
water rules is uncertain, it is most likely
less than the estimated total cost of all
individual rules combined.
K. What is the Benefit/Cost
Determination for the Proposed
LT2ESWTR?
  The Agency has determined that the
benefits of the proposed LT2ESWTR
justify the costs. As discussed in section
VI.C, the proposed rule provides a large
reduction in endemic cryptosporidiosis
illness and mortalities. More stringent
alternatives provide greater reductions
but at higher costs. Alternative Al
provides the greatest overall reduction
in illnesses and mortalities but the
incremental benefits between this
option and the preferred option are
relatively small while the incremental
costs are significant. In addition, the
preferred regulatory option, unlike
option Al, specifically targets those
systems whose source water requires
higher levels of treatment.
  Tables VI-17a and VI-17b present net
benefits for the four regulatory
alternatives that were evaluated.
Generally, analysis of net benefits is
used to identify alternatives where
benefits exceed costs, as well as the
alternative that maximizes net benefits.
However, as with the analysis of
incremental net benefits discussed
previously, the usefulness of this
analysis in evaluating regulatory
alternatives for the LT2ESWTR is
limited because many benefits from this
rule are un-quantified and non-
monetized. Analyses of net benefits
should consider both quantified and
non-quantified (where possible) benefits
and costs.
   Also, as noted earlier, the regulatory
alternatives considered for the
LT2ESWTR vary  both in the population
that experiences benefits and costs (i.e.,
risk bin boundaries) and the magnitude
of the benefits and costs (i.e., treatment
requirements). Consequently, the more
stringent regulatory alternatives provide
benefits to population groups that do
not experience any benefit under less
stringent alternatives.
  As shown by Tables VI-17a and VI-
17b, net benefits are positive for all four
regulatory alternatives evaluated. With
the enhanced COI [Table VI-17a), net
benefits are highest for the Preferred
Alternative, A3, under the majority of
occurrence distributions and discount
rates evaluated. When the traditional
COI (Table VI-17b) is used, the
Preferred Alternative has the highest net
benefits at a three percent discount rate
for the two of the occurrence
distributions, the Information Collection
Rule and ICRSSM, while the least
stringent alternative, A4, is highest for
the ICRSSL. At a seven percent discount
rate, A4 maximizes net benefits under
all occurrence distributions.
Table VI-17a.— Mean Net Benefits by
 Rule Option—Enhanced COI (Smillions,
 2000$)

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               Federal  Register/Vol.  68, No. 154/Monday.  August 11, 2003/Proposed Rules
                                                                 47757
Data
Set
ICR
Rule
Alternative
A1
A2
A3 - Preferred
A4
Annualized Value
3%, 25 Years
$ 1,121
$ 1,327
$ 1 ,335
$ 1,290
7%, 25 Years
$ 873
$ 1,098
$ 1,109
$ 1,083

ICRSSL
A1
A2
A3 - Preferred
A4
$ 96
$ 298
$ 300
$ 291
$ 1
$ 230
$ 237
$ 238

ICRSSM
A1
A2
A3 - Preferred
A4
$ 435
$ t>3U
$ o^y
$ 592
$ 289
$ 509
$ M4
$ 403
       Table VM7b.~ Mean Net Benefits by Rule Option—Traditional COI ($millions,

       2000$)
Data
Set
ICR
Rule
Alternative
A1
A2
A3 - Preferred
A4
Annualized value
3%, 25 Years
$ 628
$ 843
$ Ubti
$ two
7%, 25 Years
$ 457
$ 688
$ 705
$ /1U

ICRSSL
M
A2
A3 - Preferred
A4
$ -56
$ 168
$ 180
$ itse
$ -128
$ 120
$ 135
3> ibl

ICRSSM
A1
A2
A3 - Preferred
A4
$ 170
$ 386
$ -&b
$ 388
$ 66
$ 303
$ 317
$ 3*H
       'The traditional COI only includes valuation for medical costs and lost work time (including some portion of unpaid
       household production). The enhanced COI also factors in valuations for lost personal time (non-worktime) such as
       child care and homemaking (to the extent not covered by the traditional COt), time with family, and recreation, and
       lost productivity at work on days when workers are ill but go to work anyway. Source: Chapter 8 of the LT2ESWTR
       Economic Analysis (USEPA 2003a)
BILLING CODE 6560-50-C

  In addition to the net benefits of the
proposed LT2ESWTR, the Agency used
several other techniques to compare
costs and benefits. For example, EPA
calculated the cost of the rule per case
avoided. Table VI-18 shows both the
cost of the rule per illness avoided and
cost of the rule per death avoided. This
cost effectiveness measure is another
way of examining the benefits and costs
of the rule but should not be used to

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Federal Register/Vol. 68, No.  154/Monday, August 11, 2003/Proposed Rules
compare alternatives because an
alternative with the lowest cost per
illness/death avoided may not result in
the highest net benefits. With the
exception of alternative Al, the rule
options look favorable from a cost
                      effectiveness analysis when you
                      compare them to both the average cost
                      of cryptosporidiosis illness ($745 and
                      $245 for the two COI approaches) and
                      the mean value of a death avoided—
                      approximately $7 million dollars.
Additional information about this
analysis and other methods of
comparing benefits and costs can be
found in chapter 8 to the LT2ESWTR
EA (USEPA 2003a).
                               TABLE VI-18.—COST PER ILLNESS OR DEATH AVOIDED
Data set






• Rule alternative
A1 	
A2 	
A3 — Preferred 	
A4 , 	 	 	

A1 	 	 	
A2 	

A4 	 	 	

A1 	
A2 	

A4 	
Cost per illness
avoided ($)
3%
339
128
107
62
1,098
356
282
165
631
213
170
99
7%
244
93
78
45
789
259
208
122
453
155
125
73
Cost per death
avoided {$ mil-
lions, 2000$)
3%
2.5
0.9
0.8
0.4
8.0
2.5
1.9
1.1
4.6
1.6
1.2
0.7
7%
1.8
0.7
0.6
0.3
5.7
1.8
1.4
0.8
3.3
1.1
0.9
0.5
  Source: Chapter 8 of the LT2ESWTR Economic Analysis (USEPA 2003a)
L. Request for Comment

  The Agency requests comment on all
aspects of the proposed rule's economic
impact analysis. Specifically, EPA seeks
input into the following issues:
  • Both of the methodologies for
valuing non-fatal cryptosporidiosis and
the use of a real income growth factor
to adjust these estimates for the years
2008 through 2027;
  • How can the Agency fully
incorporate all toolbox options into the
economic analysis?
  • How can the Agency estimate the
potential benefits from reduced
epidemic outbreaks of
cryptosporidiosis?

VII. Statutory and Executive Order
Reviews
A. 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, or 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 entitlements, 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.
                      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. The
                      Information Collection Request (ICR)
                      document prepared by EPA has been
                      assigned EPA ICR number 2097.01.
                        The information collected as a result
                      of this rule will allow the States and
                      EPA to determine appropriate
                      requirements for specific systems, and
                      to evaluate compliance with the rule.
                      For the first 3 years after LT2ESWTR
                      promulgation, the major information
requirements concern monitoring
activities and compliance tracking. The
information collection requirements are
mandatory (part 141), and the
information collected is not
confidential.
  The estimate of annual average
burden hours for the LT2ESWTR during
the first three years following
promulgation is 145,854 hours. The
annual average cost estimate is $3.9
million for labor and $9.8 million per
year for operation and maintenance
including lab costs (which is a purchase
of service). The burden hours per
response is 1.47 hours and the cost per
response is $138.12. The frequency of
response (average responses per
respondent) is 39, annually. The
estimated number of likely respondents
is 2,560 (the product of burden hours
per response, frequency, and
respondents does not total the annual
average burden hours due to rounding).
Note that the burden hour estimates for
the first 3-year cycle include large
system but not small system monitoring.
Conversely, burden estimate for the
second 3-year cycle will include small
system monitoring but not large system,
which will have been completed by
then.
   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

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                Federal Register/Vol.  68,  No. 154/Monday, August 11, 2003/Proposed Rules
                                                                    47759
and systems for the 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.
  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 in 40
CFR are listed in 40 CFR part 9.
  To comment on the Agency's  need for
this information, the accuracy of the
provided burden estimates, and any
suggested methods  for minimizing
respondent burden, including the use of
automated collection techniques, EPA
has established a public docket  for this
rule, which includes this ICR, under
Docket ID No. OW-2002-0039.  Submit
any comments related to the ICR for this
proposed rule to EPA and  OMB. See
ADDRESSES section at the beginning of
this notice for where to  submit
comments to EPA. Send comments to
OMB at the Office of Information and
Regulatory Affairs, Office of
Management and Budget, 725 17th
Street, NW., Washington, DC 20503,
Attention: Desk Office for EPA. Since
OMB is required to make a decision
concerning the ICR between 30 and 60
days after August 11, 2003, a comment
to OMB is best assured of having its full
effect if OMB receives it by September
10, 2003. The final rule will respond to
any OMB or public comments on the
information collection requirements
contained in this proposal.
C. Regulatory Flexibility Act
  The Regulatory Flexibility Act (RFA)
generally requires an agency to prepare
a regulatory flexibility analysis for any
rule subject to notice and comment
rulemaking requirements  under the
Administrative Procedure Act or 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.
  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 (3H5). In addition to
the above, to establish an alternative
small business definition, agencies must
consult with SBA's Chief Council for
Advocacy.
  For purposes of assessing the impacts
of today's proposed rule on small
entities, EPA considered small entities
to be public water systems serving
10,000 or fewer 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. In accordance with  the RFA
requirements, EPA proposed using this
alternative definition in the Federal
Register, (63 FR 7620, February 13,
1998), requested public comment,
consulted with the Small Business
Administration (SBA), and expressed its
intention to use the alternative
definition for all future drinking water
regulations in the Consumer Confidence
Reports regulation  (63 FR 44511, August
19,1998). As stated in that final rule,
the alternative definition is applied to
this proposed regulation.
  After considering the economic
impacts of today's proposed rule on
small entities, I certify that this action
will not have a significant economic
impact on a substantial number of small
entities. We have determined that 274
small systems, which are 2.32% of the
11,820 small systems regulated by the
LT2ESWTR, will experience an impact
of one percent or greater of average
annual revenues; further, 31 systems,
which are 0.26% of the systems
regulated by this rule, will experience
an impact of three percent or greater of
average annual revenues (see Table VII-
1).
     TABLE VIM.—ANNUALIZED COMPLIANCE COST AS A PERCENTAGE OF REVENUES FOR SMALL ENTITIES ($2000)
Entity by system size



All Small Entities 	
Number of smalt
systems
(Percent)
A
5,910 50
4,846 41
1,064 9
11,820 100
Average annual
estimated
revenuses per
system ($)
B
2,434,200
2,391,978
4,446,165
2,597,966
Systems experiencing
costs of >% their revenues
Percent of
sustem
E
2.4
2.4
1.2
2.3
Number of
systems
F=A'E
140
115
13
274
Systems experiencing
costs of >% of their reve-
nues
Percent of
systems
G
0.3
0.3
0.1
0.3
Number of
systems
H=A*G
15
13
1
31
  Note- Detail may not add due to independent rounding. Data are based on the means of the highest modeled distributions us.ng Information
Collection Rule occurrence data set. Costs are discounted at 3 percent, summed to present value, and annualized over 25 years. Source: Chap-
ter 7 of the LT2ESWTR EA {USEPA 2003a).
  The LT2ESWTR contains provisions
that will affect systems serving fewer
than 10,000 people that use surface
water or GWUDI as a source. In order to
meet the LT2ESWTR requirements,
approximately 1,382 to 2,127 small
systems would need to make capital
improvements. Impacts on small entities
are described in more detail in Chapters
6 and 7 of the Economic Analysis for the
LT2ESWTR (USEPA 2003a). Table VII-
2 shows the annual compliance costs of
the LT2ESWTR on the small entities by
system size and type based on a three
percent discount rate (other estimates
based on different data sets and
 discount rates produce lower costs).
 EPA has determined that in each size
 category, fewer than 20% of systems
 and fewer than 1000 systems will
 experience an impact of one percent or
 greater of average annual revenues
 (USEPA 2003a).

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       TABLE VI1-2.—ANNUAL COMPLIANCE COSTS FOR THE PROPOSED LT2ESWTR BY SYSTEM SIZE AND TYPE
                                                 [SMillions, 2000$]
System type


All systems 	
System size (population served)
<100
$0.46
1.00
1.45
101-500
$0.88
0.71
1.59
501-1,000
$0.94
0.22
1.07
1,001-
3,300
$2.62
0.31
2.92
3,301-
10,000
$5.57
0.36
5.93
Total
$10.37
2.60
12.97
  Note: Results are based on .the mean of the Information Collection Rule Cryptosporidium occurrence distribution. Costs are annuatized at a
three percent discount rate.
  Source; Appendix D and Q of the LT2ESWTR EA (USEPA 2003a).
  Although this proposed rule will not
have a significant economic impact on
a substantial number of small entities,
EPA nonetheless has tried to reduce the
impact of this rule on small entities. The
LT2ESWTR contains a number of
provisions to minimize the impact of
the rule on systems generally, and on
small systems in particular. The risk-
targeted approach of the LT2ESWTR
will impose additional treatment
requirements only on the subset of
systems with the highest vulnerability
to Cryptosporidium, as indicated by
source water pathogen levels. This
approach will spare the majority of
systems from the cost of installing
additional treatment. Also, development
of the microbial toolbox under the
LT2ESWTR will provide both large and
small systems with broad flexibility in
selecting  cost-effective compliance
options to meet additional treatment
requirements.
  Small systems will monitor for E, coli
as a screening analysis for .source waters
with low  levels of fecal contamination.
Cryptosporidium monitoring will only
be required of small systems if they
exceed the E. coli trigger value. Because
E. coli analysis is much cheaper than
Cryptosporidium analysis, the use of E.
coli as a screen will significantly reduce
monitoring costs for the majority of
small systems. In order to allow EPA to
review Cryptosporidiutn indicator
relationships in large system monitoring
data, small systems will not be required
to initiate their monitoring until large
system monitoring has been completed.
This will  provide small systems with
additional time to become familiar with
the rule and to prepare for monitoring
and other compliance activities.
  Funding would be available from
programs administered by EPA and
other Federal agencies to assist small
public water systems (PWSs) in
complying with the LT2ESWTR. The
Drinking Water State Revolving Fund
(DWSRF) assists PWSs with financing
the costs of infrastructure needed to
achieve or maintain compliance with
                      SDWA requirements. Through the
                      DWSRF, EPA awards capitalization
                      grants to States, which in turn can
                      provide low-cost loans and other types
                      of assistance to eligible PWSs. Loans
                      made under the program can have
                      interest rates between 0 percent and
                      market rate and repayment terms of up
                      to 20 years. States prioritize funding
                      based on projects that address the most
                      serious risks to human health and assist
                      systems most in need. Congress
                      provided $1.275 billion for the DWSRF
                      program in fiscal year 1997, and has
                      provided an additional $3.145 billion
                      for the DWSRF program for fiscal years
                      1998 through 2001.
                        The DWSRF places an emphasis on
                      small and disadvantaged communities.
                      States must provide a minimum of 15%
                      of the available funds for loans to small
                      communities. A State has the option of
                      providing up to 30% of the grant
                      awarded to the State to furnish
                      additional assistance to State-defined
                      disadvantaged communities. This
                      assistance can take the form of lower
                      interest rates, principal forgiveness, or
                      negative interest rate loans. The State
                      may also extend repayment terms of
                      loans for disadvantaged communities to
                      up to 30 years. A State can set aside up
                      to 2% of the grant to provide technical
                      assistance to systems serving
                      communities with populations fewer
                      than  10,000.
                        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
                      Development 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 of up to 10,000 people. In fiscal
                      year 2002, RUS had over $1.5 billion of
                      available funds for water and
                      environmental programs. The CDBG
                      program includes direct grants to States,
                      which in turn are awarded to smaller
                      communities, rural areas, and colon as
in Arizona, California, New Mexico, and
Texas and direct grants to U.S.
territories and trusts. The CDBG budget
for fiscal year 2002 totaled over $4.3
billion.
  Although not required by the RFA to
convene a Small Business Advocacy
Review  (SBAR) Panel because EPA
determined that this proposal would not
have a significant economic impact on
a substantial number of small entities,
EPA did convene a panel to obtain
advice and recommendations from
representatives of the small entities
potentially subject to this rule's
requirements.
  Before convening the SBAR Panel,
EPA consulted with a group of 24 small
entity stakeholders likely to be impacted
by the LT2ESWTR and who were asked
to serve as Small Entity Representatives
(SERs) after the Panel was convened.
The small entity stakeholders included
small system operators, local
government representatives, and
representatives of small nonprofit
organizations. The small entity
stakeholders were provided with
background information on SDWA and
potential alternatives for the LT2ESWTR
in preparation for teleconferences on
January 28, 2000, February 25, 2000,
and April 7, 2000. This information
package included data on preliminary
unit costs for treatment enhancements
under consideration.
  During these three conference calls,
the information that had been provided
to the small entity stakeholders was
discussed and EPA responded to
questions and recorded initial
comments. Following the three calls, the
small entity stakeholders were asked to
provide input on the potential impacts
of the rule from their perspective. Seven
small entity stakeholders provided
written  comments on these materials.
  The SBAR Panel convened on April
25, 2000. The small entity stakeholders
comments were provided to the SBAR
Panel when it convened. After a
teleconference between the SERs and
the SBAR Panel on May 25, 2000, the
SERs were invited to provide additional

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                                                                    47761
 comments on the information provided.
 Seven SERs provided additional
 comments on the rule components.
   The SBAR Panel's report, Final Report
 of the Small Business Advocacy Review
 Panel on Stage 2 Disinfectants and
 Disinfection Byproducts Rule (Stage 2
 DBPR) and Long Term 2 Enhanced
 Surface Water Treatment Rule
 (LT2ESWTR)  (USEPA 2000f), the SERs
 comments on the LT2ESWTR, and the
 background information provided to the
 SBAR Panel and the SERs are available
 for review in the docket for today's
 proposal (http://www.epa.gov.edocket/).
   In general, the SERs who were
 consulted on the LT2ESWTR were
 concerned about the impact of these
 proposed rules on small water systems,
 the ability of small systems to acquire
 the technical and financial capability to
 implement requirements while
 maintaining flexibility to tailor the
 requirements to their needs, and the
 limitations of small systems. The SBAR
 Panel evaluated information and small-
 entity comments on issues related to the
 impact of the LT2ESWTR.
   The LT2ESWTR takes into
 consideration  the recordkeeping and
 reporting concerns identified by the
 SBAR Panel and the SERs. The SBAR
 Panel recommended that EPA evaluate
 ways to minimize the recordkeeping
 and reporting burdens under the rule by
 ensuring that the States have
 appropriate capacity for rule
 implementation, and that EPA provide
 as much monitoring flexibility as
 possible to small systems. EPA believes
 that the continuity with the IESWTR
 and LTlESWTR was maintained to the
 extent possible to ease the transition to
 the LT2ESWTR, especially for small
 systems.  The LT2ESWTR builds on the
 protection afforded under the IESWTR
 and LTlESWTR, while minimizing the
 impact on small systems by using a risk-
 targeted approach (i.e., source water
 monitoring) to identify systems that are
 still at risk from Cryptosporidium
 exposure.
  The SBAR Panel noted the concern of
 several SERs that flexibility be provided
 in the compliance schedule of the rule.
 SERs commented on the technical and
 financial limitations of some small
 systems, 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 SBAR
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 SDWA.
   EPA has concluded that the proposed
 schedule for the LT2ESWTR provides
 sufficient time for small systems to
 achieve compliance. The schedule for
 small system monitoring and
 compliance with additional treatment
 requirements lags behind the schedule
 for large systems. The basis for the
 lagging schedule for small systems is
 that it allows EPA to confirm or refine
 the E. coli screening criteria that small
 systems will use to reduce monitoring
 costs. However, the lagging schedule
 also provides greater time for small
 systems to become knowledgeable about
 the LT2ESWTR, including the new
 monitoring requirements, and to become
 familiar with innovative technologies,
 like UV, that may be used by some small
 systems to meet additional treatment
 requirements.
   Some SERs emphasized that EPA
 needs to maintain an appropriate
 balance between control of known
 microbial risks through adequate
 disinfection and for the more uncertain
 risks that  may be associated with DBFs.
 The SBAR Panel did not foresee any
 potential conflict between rules
 regulating control of microbial
 contaminants and those regulating
 DBFs. EPA also believes that  today's
 proposal and the accompanying
 proposed  Stage 2 DBPR achieve an
 appropriate balance between microbial
 and DBF risks. The profiling and
 benchmarking requirements described
 in section IV.D of this preamble will
 ensure that systems  maintain protection
 against pathogens as they make
 treatment changes to control the
 formation of DBFs.
  The SBAR Panel considered a wide
 range of options and regulatory
 alternatives for providing small
 businesses with flexibility in complying
 with the LT2ESWTR. The SBAR Panel
 was concerned with the option of an
 across-the-board additional
 Cryptosporidium inactivation
 requirement because of the potential
 high cost to small systems and the
 uncertainty regarding the extent to
 which implementation of the
 LTlESWTR will adequately address
 Cryptosporidium contamination at small
 systems. The SBAR Panel noted that, at
 the time, the Stage 2 M-DBP Federal
 Advisory Committee was exploring a
 targeted approach to Cryptosporidium
 control based on limited monitoring and
 system assessment, which would
 identify a subset of vulnerable systems
 to provide additional treatment in the
range of 0,5-to 2.5-log reduction.
Further, this approach would allow E.
 coli monitoring in lieu of
Cryptosporidium monitoring as a
screening device for small systems. The
 SBAR Panel was also encouraged by
 recent developments suggesting that UV
 is a viable, cost-effective means of
 fulfilling any additional inactivation
 requirements.
   The SBAR Panel recommended that,
 in developing any additional
 inactivation requirements based on a
 targeted approach, EPA carefully
 consider the potential impacts on small
 systems and attempt to structure the
 regulatory requirements in a way that
 would minimize burden on this group.
 The SBAR Panel supported E. coli as an
 indicator parameter if additional
 monitoring is required. The SBAR Panel
 further recommended that, among the
 options EPA analyzes, the Agency also
 evaluate the option of not imposing any
 additional Cryptosporidium control
 requirements on small systems  at this
 time, as it considers various options to
 address microbial concerns. Under this
 option,  EPA would evaluate the effects
 of LTlESWTR, once implemented, and
 then consider whether to impose
 additional requirements during its next
 6-year review of the standard, as
 required by SDWA.
   EPA considered these
 recommendations and has concluded
 that available information on the health
 risk associated with Cryptosporidium in
 drinking water warrant moving forward
 with today's proposal to address higher
 risk systems. In developing the
 proposed LT2ESWTR, EPA has
 implemented the Advisory Committee's
 recommendations to minimize burden
 on small systems. Specifically, the risk-
 targeted treatment requirements will
 substantially reduce overall costs for
 small systems in comparison to
 requiring additional treatment by all
 systems, and the use of E. coli screening
 will allow most small systems to avoid
 the cost of Cryptosporidium monitoring.
 Consequently, the Agency has
 concluded that today's proposal
 achieves an appropriate balance
 between public health protection and
 limiting the economic burden imposed
 on small entities.
  We continue to be interested in the
 potential impacts of the proposed rule
 on small entities and welcome
 comments on issues related to such
impacts.

D. 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 section 202 of UMRA,

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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 to 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 notifying
                      potentially affected small governments,
                      enabling officials of affected small
                      governments to have 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
contains a Federal mandate that may
result in expenditures of $100 million or
more for State, local, and Tribal
governments, in the aggregate, or the
private sector in any one year.
Accordingly, EPA has prepared under
section 202 of the UMRA a written
statement which is summarized in this
section. Table VII-3 illustrates the
annualized public and private costs for
the LT2ESWTR.
                     TABLE VII-3.—PUBLIC AND PRIVATE COSTS OF THE PROPOSED LT2ESWTR






Total Costs 	
Range of annualized costs (Mil-
lion $, 2000$)
3% Discount
rate
$45.7-69.0
0.9-1.0
0.1-0.2
46.7-70.1
26.8-40.4
73.5-110.5
7% Discount
rate
$50.2-75.2
1.2-1.2
0.1-0.2
51.5-76.6
29.4-44.1
80.9-120.7
Percent of
total cost
62.2-62.4
1.3-0.9
0.1-0.1
63.6-63.4
36.4-36.6
100.0-100.0
       The,-..
 DetaShriay ncrt'aSd'due to independent rounding.
   Source: The LT2ESWTR Economic Analysis (USEPA 2003a).
   A more detailed description of this
 analysis is presented in Economic
 Analysis for the LT2ESWTR {USEPA
 2003a).
   a. Authorizing legislation. As noted in
 section II, today's proposed rule is
 promulgated pursuant to section 1412
 (b)(l){A) of the Safe Drinking Water Act
 (SDWA), as amended in 1996, which
 directs EPA to promulgate a national
                       primary drinking water regulation for a
                       contaminant if EPA determines that the
                       contaminant may have an adverse effect
                       on the health of persons, occurs in
                       public water systems with a frequency
                       and at levels of public health concern,
                       and regulation presents a meaningful
                       opportunity for health risk reduction.
                         b. Cost-benefit analysis. Section VI of
                       this preamble discusses the cost and
 benefits associated with the LT2ESWTR
 Details are presented in the Economic
 Analysis for the LT2ESTWR (USEPA
 2003a). For the LT2ESWTR proposal,
 EPA quantified costs and benefits for
 four regulatory alternatives. The four
 alternatives are described in section VI.
 Table VII-4 summarizes  the range of
 annual costs and benefits for each
 alternative.
                         TABLE VII-4.—ANNUAL BENEFITS AND COSTS OF RULE ALTERNATIVES
                                                      [SMillion]
Regulatory Alternative




Alternative A4 	 •_ 	
Enhanced COI
range of
annualized
benefits (3%)
$457-1,492
397-1,461
374-1,445
328-1,349
Traditional
COI range of
annualized
benefits (3%)
$305-989
268-977
253-967
225-907
Enahnced COI
range of
annualized
benefits (7%)
$389-1,260
338-1,243
318-1,230
279-1,148
Tradition COI
range of
annuitized
benefits (7%)
$260-845
229-834
216-826
192-775
Range of
annualized
costs (3%)
$361
100-134
73-111
37-59
Range of
annualized
costs (7%)
$388
108-145
81-121
41-65
   Source: The LT2ESWTR Economic Analysis (USEPA 2003a).
   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 earlier and discussed in more
 detail in section VI of this preamble,

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                                                                      47763
  accurately characterize future
  compliance costs of the proposed rule.
    In analyzing disproportionate
  impacts, the Agency considered the
  impact on (1) different regions of the
  United States, (2) State, local, and Tribal
  governments, (3) urban, rural and other
  types of communities, and (4) any
  segment  of the private sector. This
  analysis  is presented in section 7 of
  Economic Analysis for the LT2ESWTR
  (USEPA  2003a).
    EPA has concluded that the
  LT2ESWTR  will not cause a
  disproportionate budgetary effect. This
  rule imposes the same requirements on
  systems nationally and does not
  disproportionately affect any segment.
  This rule will treat similarly situated
  systems (in terms of size, water quality,
  available data, installed technology, and
  presence of uncovered finished storage
  facilities) in  similar (proportionate)
  ways, without regard to geographic
  location, type of community, or segment
  of industry. The LT2ESWTR is a rule
 where requirements are proportionate to
 risk. Although some groups may have
 differing budgetary effects as  a result of
 LT2ESWTR, those costs are proportional
 to the need for greater information
 (monitoring) and risk posed (degree of
 treatment required). The variation in
 cost between large and small  systems is
 due to economies  of scale (a larger
 system can distribute cost across more
 customers). Regions will have varying
 impacts due  to the number of affected
 systems.
   d. Macro-economic effects.  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 2000,
 real GDP was $9,224 billion, so a rule
 would have to cost at least $23 billion
 to have a measurable effect. A regulation
 with a smaller aggregate effect is
 unlikely to have any measurable impact
 unless it is highly focused on a
 particular geographic region or
 economic sector.
  The macro-economic effects on the
 national economy from the LT2ESWTR
 should not have a measurable  effect
 because the total annual costs  for the
 proposed option range from $73 million
to $111 million based on median
 Cryptosporidium occurrence
distributions from the ICRSSL and
Information Collection Rule data sets
  and a discount rate of 3 percent ($81 to
  $121 million at a 7 percent discount
  rate). These annualized figures will
  remain constant over the 25-year
  implementation period that was
  evaluated, while GDP will probably
  continue to rise. Thus, LT2ESWTR costs
  measures as a percentage of the national
  GDP will only decline over time. Costs
  will not be highly focused on a
  particular geographic region or sector.
   e. Summary of EPA 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 consultations with
  the governmental entities affected by
  this rule. A variety of stakeholders,
  including small governments, were
  provided the opportunity for timely and
  meaningful participation in  the
  regulatory development process. EPA
  used these opportunities to notify
  potentially affected governments of
 regulatory requirements being
 considered.
   The Stage  2 M-DBP Federal Advisory
 Committee included representatives
 from State government (Association of
 State Drinking Water Administrators,
 Environmental Commissioners of
 States), local government (National
 League of Cities), and Tribes (All Indian
 Pueblo Council (AIPC)). Government
 and Tribal representatives on the
 Advisory Committee were generally
 concerned with ensuring that drinking
 water regulations are adequately
 protective of public health and that any
 additional public health expenditures
 due to new regulations achieve
 significant risk reduction. The proposed
 LT2ESWTR reflects the consensus
 recommendations of the Advisory
 Committee, as stated in the Agreement
 in Principle (65 FR 83015, December 29,
 2000). Consequently, EPA believes that
 the risk-targeted approach for additional
 Cryptosporidium treatment
 requirements and other provisions  in
 today's proposal satisfies the concerns
 of the government and Tribal
 representatives on the Advisory
 Committee.
  As described in section VII,C of this
 preamble, the Agency 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 to address the concerns of
 small entities, including small local
 governments specifically. Small entity
representatives (SERs) to the  SBAR
panel, including representatives of
small local governments, were
concerned about the cost of the rule, the
technical capability of small systems to
 implement requirements, and flexibility
 in regulatory requirements and in the
 compliance schedule. SERs also
 emphasized that EPA needs to balance
 the control of known microbial risks
 with the risks associated with DBFs.
   Today's proposal is responsive to
 these concerns, as stated in section
 VII.C. The LT2ESWTR will impose costs
 for additional treatment on only the
 fraction of systems identified through
 monitoring as being at higher risk, and
 overall monitoring costs for small
 systems will be greatly reduced through
 use of the E. coll screening to waive
 small systems from Cryptosporidium
 monitoring. The microbial toolbox of
 treatment options will provide
 significant flexibility to systems to
 identify cost-effective solutions for
 meeting additional Cryptosporidium
 treatment requirements. The compliance
 schedule for small systems is delayed in
 relation to large systems, which will
 allow small systems additional time to
 become knowledgeable about and
 prepare to implement the LT2ESWTR.
 The intent of the proposed disinfection
 profiling provisions is to ensure that
 when systems make treatment changes
 to control DBF formation, they maintain
 protection against pathogens.
  EPA held a meeting on the
 LT2ESWTR in February 2001 with
 representatives of State and local
 governments. Representatives of the
 following organizations attended:
 Association of State Drinking Water
 Administrators (ASDWA), the National
 Governors' Association (NGA), the
 National Conference of State
 Legislatures (NCSL), the International
 City/County Management Association
 (ICMA), the National League of Cities
 (NLC), the County Executives of
 America, and health departments.
 Representatives asked questions
 regarding how Cryptosporidium gets
 into the water, whether EPA would add
 laboratory approval for Cryptosporidium
 to State certification programs, the
 effectiveness of ozone and UV, and the
 development of ambient water quality
 criteria for Cryptosporidium.
  EPA has largely addressed these
 questions in this preamble. Section II
 characterizes sources of
 Cryptosporidium. As described in
 section IV.K, EPA is currently carrying
 out a laboratory approval program for
 Cryptosporidium analyses but expects
that this will be included in State
laboratory certification programs in the
future. In section IV.C., EPA describes
the effectiveness of ozone and UV for
Cryptosporidium inactivation and
provides criteria for how these
technologies may be used to comply
with the treatment requirements in

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today's proposal. The Agency is
currently exploring the development of
ambient water quality criteria for
Cryptospondium, but such criteria are
not available at this time and are not
included in today's proposal.
  In addition to the Tribal
representative on the Advisory
Committee, EPA conducted outreach
and consultation with Tribal
representatives on a number of
occasions regarding the LT2ESWTR.
EPA presented the LT2ESWTR at the
following forums: the 16th Annual
Consumer Conference of the National
Indian Health Board, which included
over 900 representatives of Tribes across
the nation; the annual  conference of the
National Tribal Environmental Council,
at which over 100 Tribes were
represented; and the 1999 EPA/Inter-
Tribal Council of Arizona, which
included representatives from 15 Tribes.
EPA also sent the presentation materials
used in the first two meetings and
meeting summaries to over 500 Tribes
and Tribal organizations.
  Fact sheets describing the
requirements of the LT2ESWTR and
requesting Tribal input were  distributed
at an annual EPA Tribal meeting in San
Francisco and at a Native American
Water Works Association meeting in
Scottsdale, Arizona. EPA also worked
through its Regional Indian
Coordinators and the National Tribal
Operations Committee to raise
awareness of the development of the
proposed rule. EPA mailed all Federal
Tribes LT2ESWTR fact sheets in
November 2000. The Tribal
representative to the Advisory
Committee also presented the Stage 2
Agreement in Principle prior to
signature in at least one political forum
for various Tribes not affiliated with
AIPC.
  EPA held a teleconference  in January
2002 with 12 Tribal representatives and
four Regional Tribal Program
Coordinators. Prior to the
teleconference, EPA sent invitations to
all  Federal Tribes, along with a fact
sheet explaining the LT2ESWTR.
  Through this consultation, Tribal
representatives expressed concern about
implementing new regulations without
additional funding sources. However,
they also stated that the LT2ESWTR
would have a benefit, and  asserted that
people served by small systems should
receive equivalent public health
protection. Questions were asked
regarding the impact of the rule (e.g.,
number of Tribal surface water systems)
and the date for finalizing the rule. The
Tribal representative to the M-DBP
Advisory Committee advocated that risk
mitigation plans for uncovered finished
                      water storage facilities should account
                      for cultural uses by Tribes.
                        In response to the concerns expressed
                      by Tribal representatives, EPA noted
                      that the LT2ESWTR proposal is
                      designed to minimize costs by targeting
                      higher risk systems, and includes other
                      provisions, described earlier, to reduce
                      burden. Moreover, the projected benefits
                      of the rule substantially exceed costs.
                      EPA also explained that capital projects
                      related to the rule would be eligible for
                      Federal funding sources, such as the
                      Drinking Water State Revolving Fund,
                      due to the health risks associated with
                      Cryptospondium. The LT2ESWTR
                      Economic Analysis {USEPA 2003a)
                      provides an analysis of the impact of the
                      LT2ESWTR on Tribes. EPA has
                      identified 67 Tribal water systems that
                      would be subject to the LT2ESWTR.
                        In addition to these direct
                      consultations with State, local, and
                      Tribal governments, EPA posted a pre-
                      proposal draft of the LT2ESWTR
                      proposal on an EPA Internet site (http:/
                      /www.epa.gov/safewaterf) in November
                      2001. EPA received comments on this
                      pre-proposal draft from ASDWA and six
                      States, several public water systems
                      owned by local governments, as well as
                      private water systems, laboratories, and
                      other stakeholders. Among the concerns
                      raised by commenters representing  State
                      and local governments were the
                      following: early implementation of
                      monitoring by large systems; flexibility
                      for States in awarding treatment credits
                      to different Cryptospondium control
                      technologies; and the added burden of
                      the rule on systems and States.
                         EPA has addressed these concerns in
                      developing the LT2ESWTR proposal. As
                      described in section IV.], EPA is
                      planning to directly implement the large
                      system monitoring requirements that
                      occur during the first 2.5 years after
                      promulgation. The planned approach is
                      similar to that used for the UCMR,
                      including an electronic data reporting
                      system for storing monitoring results
                      and tracking compliance. With this
                      approach, States will be able to access
                      data reported by their systems, thereby
                      allowing States to exercise oversight of
                      their systems during early
                      implementation if they chose. However,
                      EPA will take primary responsibility for
                      providing technical assistance to
                      systems and assessing compliance with
                      monitoring requirements.
                         In regard to treatment credit for
                      Cryptospondium control technologies,
                      the Agency has made substantial efforts
                      to ensure that the criteria in today's
                      proposal are based on the best available
                      data.  EPA has worked in partnership
                      with industry and researchers to gather
                      information, and proposed criteria  for
several microbial toolbox options reflect
comments by the Science Advisory
Board. In addition, today's proposal
gives flexibility to States by allowing
them to award different levels of
Cryptospondium treatment credit to
their systems based on site-specific
demonstrations.
  With respect to the burden the
LT2ESWTR would place on water
systems and States, EPA has, as
described previously in this preamble,
attempted to minimize overall costs
under the proposed LT2ESWTR. This is
achieved through risk-targeting of
additional treatment requirements,
allowing most small systems  to avoid
Cryptospondium monitoring costs
through E. coli screening, and
facilitating the use of lower cost
treatment technologies like UV.
  In summary, EPA has concluded that
the proposed option for the LT2ESWTR
is needed to provide a significant public
health benefit by reducing exposure to
Cryptospondium. While many public
water systems achieve adequate control
of Cryptospondium, additional
treatment should be required for filtered
systems with elevated source water
pathogen levels and for unfiltered
systems. The availability of improved
analytical methods allows additional
treatment requirements to be targeted to
higher risk systems, and the
development of technologies like UV
makes it feasible for systems to provide
additional treatment. The monetized
benefits of today's proposal significantly
exceed total costs, and EPA believes
there will be substantial unquantified
benefits as well.
   f. Regulatory alternatives considered.
As required under section 205 of
UMRA, EPA considered several
regulatory alternatives to address
systems at risk for contamination by
microbial pathogens, specifically
including Cryptospondium. A detailed
discussion of these alternatives can be
found in section VI of the preamble and
also in the Economic Analysis for the
LT2ESWTR (USEPA 2003a).
   g. Selection of the hast costly, most
cost-effective, or least burdensome
alternative that achieves the objectives
 of the rule. Among the regulatory
alternatives considered for the
LT2ESWTR, as described in  section VI,
the Agency believes the proposed
 alternative is  the most cost-effective that
achieves the objectives of the rule. The
objective of the LT2ESWTR is to reduce
risk from Cryptospondium and other
pathogens in  systems where current
regulations do not provide sufficient
 protection.
   The Agency evaluated a less costly
 and less burdensome alternative.

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                                                                     47765
 However, this alternative would provide
 no benefit to several thousand
 consumers who, under the proposed
 alternative, would receive benefits that
 most likely exceed their costs, based on
 Agency estimates. This is illustrated in
 the LT2ESWTR Economic Analysis
 (USEPA 2003a). By failing to reduce risk
 for consumers where additional
 treatment requirements would be cost-
 effective, the less costly alternative does
 not appear to achieve the objectives of
 the LT2ESWTR.
   The other alternatives considered by
 the Agency achieve the objectives of the
 rule, but are more costly, more
 burdensome, and potentially less cost-
 effective. The proposed alternative
 targets additional treatment
 requirements to systems with the
 highest vulnerability to
 Cryptosporidium, and maximizes net
 benefits under a broad range of
 conditions (USEPA 2003a).
 Consequently, the Agency has found the
 proposed alternative to be the most cost-
 effective among those that achieve the
 objectives of the rule.
 3. Impacts on Small Governments
   EPA has determined that this rule
 contains no regulatory requirements that
 might significantly or uniquely affect
 small governments. Thus, today's rule is
 not subject to the requirements of
 section 203 of UMRA. As described in
 section VII.C, EPA has certified that this
 proposed rule will not have a significant
 economic impact on a substantial
 number of small entities. Estimated
 annual expenditures by small systems
 for the LT2ESWTR range from $7.9 to
 $13.0 million at a 3% discount rate and
 $8.0 to $13.0 million at a 7% discount
 rate. While the treatment requirements
 of the LT2ESWTR apply uniformly to
 both small and large public water
 systems, large systems bear a majority of
 the total costs of compliance with the
 rule. This is due to the fact that large
 systems treat a majority of the drinking
 water that originates from surface water
 sources.
 E. Executive Order 13132: 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 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 has concluded that this proposed
 rule may have federalism implications,
 because it may impose substantial direct
 compliance costs on State or local
 governments, and  the Federal
 government will not provide the funds
 necessary to pay those costs. The
 proposed rule may result in
 expenditures by State, local, and Tribal
 governments, in the aggregate of $100
 million or more in any one year. Costs
 are estimated to range from $73 to $111
 million at a 3 percent discount rate and
 $81 to $121 million using a 7 percent
 discount rates based on the median
 distribution modeled from 1CRSSL and
 Information Collection Rule
 Cryptosporidium occurrence data sets.
 Accordingly, EPA provides the
 following federalism summary impact
 statement as required by section 6(b) of
 Executive Order 13132.
   EPA consulted with representatives of
 State and local officials early in the
 process of developing the proposed
 regulation to permit them to have
 meaningful and timely input into its
 development. Section VII.D.2.e
 describes EPA's consultation with
 representatives of State and local
 officials. This consultation included
 State and local government
 representatives on the Stage  2 M-DBP
 Federal Advisory Committee, the
 representatives from small local
 governments to the SBAR panel, a
 meeting with representatives from
 ASDWA, NGA, NCSL, 1CMA, NLC, the
 County Executives of America, and
 health departments, consultation with
 Tribal  governments at four meetings,
 and comments from State and local
 governments on a pre-proposal draft of
 the LT2ESWTR.
  Representatives of State and local
 officials were generally concerned with
 ensuring that drinking water regulations
 are adequately protective of public
 health  and that any additional
regulations achieve significant health
benefits in return for required
expenditures. They were specifically
concerned with the burden of the
proposed rule, both in cost and
technical complexity, giving  flexibility
to systems and States, balancing the
control of microbial risks and DBF risks,
funding for implementing new
regulations, equal protection for small
systems, and early implementation of
monitoring by large systems.
  EPA has concluded that the proposed
LT2ESWTR is needed to reduce the
public health risk associated with
Cryptosporidium in drinking water.
Estimated benefits for the rule are
significantly higher than costs. Further,
as described in this section and in
section VII.D.2.e, the Agency believes
that today's  proposal addresses many of
the concerns expressed by
representatives of government officials.
  Under the proposed LT2ESWTR,
expenditures for additional treatment
are targeted  to the fraction of systems
with the highest vulnerability to
Cryptosporidium, thereby minimizing
burden for the majority of systems that
will not be required to provide
additional treatment. The microbial
toolbox of compliance options will
provide flexibility to systems in meeting
additional treatment requirements, and
States have the flexibility to award
treatment credits based on site-specific
demonstrations,  Disinfection profiling
provisions are intended to ensure that
systems do not reduce microbial
protection as they take steps  to reduce
exposures to DBFs.
  The LT2ESWTR achieves equal public
health protection for smal! systems.
However, the use of E. coli monitoring
by small systems as a screening analysis
to determine the need for
Cryptosporidium monitoring will
reduce monitoring costs for most small
systems. Capital  projects related to the
rule would be eligible for funding from
the Drinking Water State Revolving
Fund, which includes specific funding
for small communities.  EPA is planning
to support the initial monitoring by
large systems that takes place within the
first 2.5 years after promulgation. This
will substantially reduce the  burden on
States associated with early
implementation of monitoring
requirements.
  In the spirit of Executive Order 13132,
and consistent with EPA policy to
promote communications between EPA
and State and local governments, EPA
specifically solicits comment on this
proposed rule from State and local
officials.
F. Executive Order 13175: Consultation
and Coordination With  Indian Tribal
Governments
  Executive  Order 13175, entitled
"Consultation and Coordination with
Indian Tribal Governments" (65 FR
67249, November 9, 2000), requires EPA

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47766          Federal Register/Vol. 68. No.  154/Monday. August 11, 2003/Proposed Rules
to develop "an accountable process to
ensure meaningful and timely input by
Tribal officials in the development of
regulatory policies that have Tribal
implications." "Policies that have Tribal
implications" is defined in the
Executive Order to include regulations
that have "substantial direct effects on
one or more Indian tribes, on the
relationship between the Federal
government and the Indian tribes, or on
the distribution of power and
responsibilities between the Federal
government and Indian tribes."
  Under Executive Order 13175, EPA
may not issue a regulation that has
Tribal 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 Tribal
governments, or EPA consults with
Tribal officials early in the process of
developing the proposed regulation and
develops a Tribal summary impact
statement.
  EPA has concluded that this proposed
rule may have Tribal implications,
because it may impose substantial direct
compliance costs on Tribal
governments, and the Federal
government will not provide the funds
necessary to pay those costs. EPA has
identified 67 Tribal water systems
serving a total population of 78,956 that
may be subject to the LT2ESWTR. They
will bear an estimated total annualized
cost of $135,974 at a 3 percent discount
rate ($138,910 at 7 percent) to
implement this rule as proposed.
Estimated mean annualized cost per
system ranges from $792 to $23,979 at
a 3 percent discount rate ($844 to
$26,194 at 7 percent) depending on
system size (see section 7 of the
LT2ESWTR Economic Analysis (USEPA
2003a) for details). Accordingly, EPA
provides the following Tribal summary
impact statement as required by section
5(b) of Executive Order 13175.
  EPA consulted with representatives of
Tribal officials early in the process of
developing this regulation to permit
them to have meaningful and timely
input into its development. Section
VII.D.2.e describes EPA's outreach and
consultation with Tribes, which
included presentations on the
LT2ESWTR at four Tribal conferences
and meetings, mailing fact sheets and
presentation materials regarding the
proposal to Tribes on several occasions,
and a teleconference with
representatives of Tribal officials to
comment on the proposed rule.
  As discussed in section VII.D.2.e,
Tribal representatives stated that
protection of public health is important
regardless of the number of people a
system is serving, and they recognized
that the LT2ESWTR would provide a
public health benefit. However, Tribal
representatives were concerned about
the availability of funding to implement
the regulation and asked about the
projected impact on Tribes (e.g., number
of Tribal surface water systems that
would be affected). Also, the Tribal
representative to the Federal Advisory
Committee was concerned that risk
mitigation plans for uncovered finished
water storage facilities account for
cultural uses by Tribes.
  EPA has concluded that the proposed
LT2ESWTR is needed to reduce the risk
associated with Cryptosporidium in
public water systems using surface
water sources. Projected benefits for
today's proposal are substantially
greater than costs. Moreover, as
described in this section and in section
VII.D,2.e, today's proposal addresses
many of the  concerns stated by Tribal
representatives.
  The LT2ESWTR will provide
equivalent public health protection to
all system sizes, including Tribal
systems. By targeting additional
treatment requirements to higher risk
systems, the LT2ESWTR will minimize
overall burden in comparison with
requiring additional treatment by all
systems. In addition, the provision in
the proposal allowing E. coli screening
to determine if Cryptosporidium
monitoring is necessary will reduce
monitoring costs for many small Tribal
systems.  (EPA notes that 66 of the 67
Tribal systems identified by the Agency
as subject to the LT2ESWTR are small
systems.) Due to the health risks
associated with Cryptosporidium,
capital expenditures needed for
compliance  with the rule will be eligible
for Federal funding sources, specifically
the Drinking Water State Revolving
Fund. EPA is developing guidance that
will address consideration of Tribal
cultural uses of uncovered finished
water storage facilities.
  In the spirit of Executive Order 13175,
and  consistent with EPA policy to
promote communications between EPA
and  Tribal governments, EPA
specifically  solicits additional comment
on this proposed rule from Tribal
officials,
G. Executive Order 13045: Protection of
Children from Environmental Health
and Safety Risks
  Executive Order 13045: "Protection  of
Children from Environmental Health
Risks and Safety Risks" (62 FR 19885,
April 23,1997) applies to any rule that:
(1) Is determined to be "economically
significant" as defined under Executive
Order 12866, and (2) concerns an
environmental health or safety risk that
EPA has reason to believe may have a
disproportionate effect on children. If
the regulatory action meets both criteria,
the Agency must evaluate the
environmental health or safety 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.
  This proposed rule is subject to the
Executive Order because it is an
economically significant regulatory
action as defined in Executive Order
12866, and we believe that the
environmental health or safety risk
addressed by this action may have a
disproportionate effect on children.
Accordingly, we have evaluated the
environmental health or safety effects of
Cryptosporidium on children. The
results of this evaluation are contained
in Cryptosporidium: Risk for Infants and
Children (USEPA 2001d)  and described
in this section of this preamble. Further,
while available information  is not
adequate to conduct a quantitative risk
assessment specifically on children,
EPA has assessed the risk associated
with Cryptosporidium in  drinking water
for the general population, including
children. This assessment is described
in the Economic Analysis for the
LT2ESWTR (USEPA 2003a)  and is
summarized in section VI of this
preamble. Copies of these documents
and supporting information  are
available in the public docket for
today's proposal.
   Cryptosporidiosis in children is
similar to adult disease (USEPA 2001d).
Diarrhea is the most common symptom.
Other common symptoms in otherwise
healthy (i.e., immunocompetent)
children include anorexia, vomiting,
abdominal pain, fever, dehydration and
 weight loss.
   The risk of illness and  death due to
 cryptosporidiosis depends on several
 factors, including age, nutrition,
 exposure, genetic variability, disease
 and the immune status of the
 individual. Mortality resulting from
 diarrhea generally occurs at a greater
 rate among the very young and elderly
 (Gerba et al, 1996). During the 1993
 Milwaukee drinking water outbreak,
 associated mortalities in  children were
 reported. Also, children with laboratory-
 confirmed cryptosporidiosis were more
 likely to have an underlying disease that
 altered their immune status (Cicirello et
 al., 1997). In that study, the observed
 association between increasing age of
 children and increased numbers of
 laboratory-con firmed cryptosporidiosis
 suggested to the authors  that the data

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                                                                     47767
are consistent with increased tap water
consumption of older children.
However, due to data limitations, this
observation could not be adequately
analyzed. Asymptomatic infection,
especially in underdeveloped
communities, can have a substantial
effect on childhood growth (Bern et al,
2002).
  Cryptosporidiosis appears to be more
prevalent in populations, such as
children, that may not have established
immunity against the disease and may
be in greater contact with
environmentally contaminated surfaces
(DuPont et al, 1995). In the United
States, children aged one to four years
are more likely than adults to have the
disease. The most recent reported data
on cryptosporidiosis shows the
occurrence rate (for the year 1999) is
higher in children ages one to four (3.03
incidence rate per 100,000) than in any
adult age group (CDC, 2001). Evidence
from blood sera antibodies collected
from children during the 1993
Milwaukee outbreak suggest that
children had greater levels of
Cryptosporidium infection than
predicted for the general community
(based on the random-digit dialing
telephone survey method) (McDonald et
al, 2001).
  Data indicate a lower incidence of
cryptosporidiosis infection during the
first  year of life. This is attributed to
breast-fed infants consuming less tap
water and, hence, having less exposure
to Cryptosporidium, as well as the
possibility that mothers confer short
term immunity to their children. For
example, in a survey of over 30,000
stool sample analyses from different
patients in the United Kingdom, the one
to five 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
six months of age showed a higher rate
of infection than individuals aged less
than six months (Casemore, 1990).
Similarly, in the U.S., of 2,566 reported
Cryptosporidium illnesses in 1999, 525
occurred in ages one to four (incidence
rate  of 3.03 per 100,000) compared with
58 cases in infants under one year
(incidence rate of 1.42 per 100,000)
(CDC, 2001).
  An infected child may spread the
disease to other children or family
members (Heijbel et al., 1987, Osewe  et
a]., 1996). Millard etal (1994)
documented greater household
secondary transmission of
cryptosporidiosis from children than
from adults to household and other
close contacts. Children continued to
shed oocysts for more than two weeks
(mean 16.5 days) after diarrhea
cessation (Tangerman etal, 1991).
  While Cryptosporidium may have a
disproportionate effect on children,
available data are not adequate to
distinctly assess the health risk for
children resulting from
Qyptospor;'c/j urn-contaminated drinking
water. In assessing risk to children
when evaluating regulatory alternatives
for the LT2ESWTR, EPA assumed the
same risk for children as for the
population as a whole.
  Section VI of this preamble presents
the regulatory alternatives that EPA
evaluated for the proposed LT2ESWTR.
Among the four alternatives the Agency
considered, three involved a risk-
targeting approach in which additional
Cryptosporidium treatment
requirements are based on source water
monitoring results. A fourth alternative
involved additional treatment
requirements for all systems.
  The alternative requiring additional
treatment by all systems was not
selected because of concerns about
feasibility and because it imposed costs
but provided few benefits to systems
with high quality source water (i.e.,
relatively low Cryptosporidium risk).
The three risk-targeting alternatives
were evaluated based on several factors,
including costs, benefits, net benefits,
feasibility of implementation, and other
specific impacts (e.g., impacts on small
systems or sensitive subpopulations).
  The proposed alternative was
recommended by the M-DBP  Federal
Advisory Committee and selected by
EPA as the Preferred Regulatory
Alternative because it was deemed
feasible and provides significant public
health benefits in terms of avoided
illnesses and deaths. EPA's analysis of
benefits and costs indicates that the
proposed alternative ranks highly
among those evaluated with respect to
maximizing net benefits, as shown in
the LT2ESWTR Economic Analysis
(USEPA 2003a).  This document is
available in  the docket for this action.
  The result of the LT2ESWTR will be
a reduction  in the risk of illness for the
entire population, including children.
Because available evidence indicates
that  children may be more vulnerable to
cryptosporidiosis than the rest of the
population,  the LT2ESWTR may,
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
Cryp tosporidium.
H. Executive Order 13211: Actions That
Significantly Affect Energy Supply,
Distribution, or Use
  This rule is not a "significant energy
action" as defined in Executive Order
13211, "Actions Concerning Regulations
That Significantly Affect Energy Supply,
Distribution, or Use" (66 FR 28355 (May
22, 2001)) because it is not likely to
have a significant adverse effect on the
supply, distribution, or use of energy.
This determination is based on the
following analysis.
  The first consideration is whether the
LT2ESWTR would adversely affect the
supply of energy. The LT2ESWTR does
not regulate power generation, either
directly or indirectly. The public and
private utilities that the LT2ESWTR
regulates do not, as a rule, generate
power. Further, the cost increases borne
by customers of water utilities as a
result of the LT2ESWTR are a low
percentage of the total cost  of water,
except for a very few small  systems that
might install advanced technologies and
then need to spread that cost over a
narrow customer base. Therefore, the
customers that are power generation
utilities are unlikely to face any
significant effects as a result of the
LT2ESWTR. In sum, the LT2ESWTR
does  not regulate the supply of energy,
does  not generally regulate the utilities
that supply energy, and is unlikely to
affect significantly the customer base of
energy suppliers. Thus, the LT2ESWTR
would not translate into adverse effects
on the supply of energy.
   The second consideration is whether
the LT2ESWTR would adversely affect
the distribution of energy. The
LT2ESWTR does not regulate any aspect
of energy distribution. The utilities that
are regulated by the LT2ESWTR already
have electrical service. As derived later
in .this section, the proposed rule is
projected to increase peak electricity
demand at water utilities by only 0.02
percent. Therefore, EPA estimates that
the existing connections are adequate
and that the LT2ESWTR has no
discernable adverse effect on energy
distribution.
   The third consideration is whether
the LT2ESWTR would adversely affect
the use of energy. Because  some
drinking water utilities are expected to
add treatment technologies that use
electrical power, this potential impact is
evaluated in more detail. The analyses
that underlay the estimation of costs for
the LT2ESWTR are national in scope
and do not identify specific plants or
utilities that may install treatment in
response to the rule. As a result, no
analysis of the effect on specific energy
suppliers is possible with the available

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 data. The approach used to estimate the
 impact of energy use, therefore, focuses
 on national-level impacts. The analysis
 estimates the additional energy use due
 to the LT2ESWTR, and compares that to
 the national levels of power generation
 in terms of average and peak loads.
  The first step in the analysis is to
 estimate the energy used by the
 technologies expected to be installed as
 a result of the LT2ESWTR. Energy use
 is not directly stated  in Technologies
 and Costs for Control of Microbial
 Contaminants and Disinfection By-
 products (USEPA 2003c), but the annual
 cost of energy for each technology
                      addition or upgrade necessitated by the
                      LT2ESWTR is provided. An estimate of
                      plant-level energy use is derived by
                      dividing the total energy cost per plant
                      for a range of flows by an average
                      national cost of electricity of $0.076/
                      kWh (USDOE EIA, 2002). These
                      calculations are shown in detail in
                      Chapter 7 of the Economic Analysis for
                      the LT2ESWTR (USEPA 2003a). The
                      energy use per plant for each flow range
                      and technology is then multiplied by
                      the number of plants predicted to install
                      each technology in a given flow range.
                      The energy requirements for each flow
                      range are then added to produce a
national total. No electricity use is
subtracted to account for the
technologies that may be replaced by
new technologies, resulting in a
conservative estimate of the increase in
energy use. Results of the analysis are
shown in Table VII-5 for each of the
modeled Cryptosporidium occurrence
distributions. The results range from an
incremental national annual energy
usage of 0.12 million megawatt-hours
(mW) for the modeled Information
Collection Rule occurrence distribution
to 0.07 million mW for the modeled
ICRSSL occurrence distribution.
        TABLE VII-5.—TOTAL INCREASED ANNUAL NATIONAL ENERGY USAGE ATTRIBUTABLE TO THE LT2ESWTR
Technology
CtO2 	
uv 	
O3 (0 5 log) 	
O3 (1 0 log) 	
Os {2.0 log) 	
MF/UF 	



Total 	
ICR
Plants select-
ing technology
A
77
998
26
24
9
10
1,545
190
2.878
Total annual
energy re-
quired
(kWh/yr)
B
343,297
86,827,218
12,524,670
12,456,132
7,324,561
5,691,144
1,631,873
76,793
126.875.687
ICRSSL
Plants select-
ing technology
C
61
490
19
12
0
8
1,236
17
1.844
Total annual
energy re-
quired
(kWh/yr)
D
268,861
52,212,046
10,328,359
6,119,824
35,259
4,507,577
1,306,067
6,254
74.784.249
ICRSSM
Plants select-
ing technology
E
70
632
21
21
2
5
1,441
52
2.244
Total annual
energy re-
quired
(kWh/yr)
F
312,036
64,515,863
11,467,703
10,759,696
1,787,144
2,790,401
1,522,243
19,686
93.174.772
  Source; The LT2ESWTR Economic Analysis {USEPA 2003a).
  To determine if the additional energy
required for systems to comply with the
rule would have a significant adverse
effect on the use of energy, the numbers
in Table VII-5 are compared to the
national production figures for
electricity. According to the U.S.
Department of Energy's Information
Administration, electricity producers
generated 3,800 million mW of
electricity in 2001 {USDOE EIA, 2002).
Therefore, even using the highest
assumed energy use for the LT2ESWTR,
the rule when fully implemented would
result in only a 0.003 percent increase
in annual average energy use.
  In addition to average energy use, the
impact at times of peak power demand
is important. To examine whether
increased energy usage might
significantly affect the  capacity margins
of energy suppliers, their peak season
generating capacity reserve was
compared to an estimate of peak
incremental power demand by water
utilities.
  Both energy use and  water use are
highest in the summer  months, so the
most significant effects on supply would
be seen then. In the summer of 2001,
U.S. generation capacity exceeded
                     consumption by 15 percent, or
                     approximately 120,000 mW (USDOE
                     EIA 2002). Assuming around-the-clock
                     operation of water treatment plants, the
                     total energy requirement can be divided
                     by 8,760 hours per year to obtain an
                     average power demand of 15 mW for the
                     modeled Information Collection Rule
                     occurrence distribution. A more
                     detailed derivation of this value is
                     shown in Appendix P of the Economic
                     Analysis for the LT2ESWTR (USEPA
                     2003a). Assuming that power demand is
                     proportional to water flow through the
                     plant, and that peak flow can be as high
                     as twice the average daily flow during
                     the summer months, about 30 mW
                     could be needed for treatment
                     technologies installed to comply with
                     the LT2ESWTR. This is only 0.024
                     percent of the capacity margin available
                     at peak use.
                       Although EPA recognizes that not all
                     areas have a 15 percent capacity margin
                     and that this margin varies across
                     regions and through time, this analysis
                     reflects the effect of the rule on national
                     energy supply, distribution, or use.
                     While certain areas, notably California,
                     have experienced shortfalls in
                     generating capacity in the recent past, a
peak incremental power requirement of
30 mW nationwide is not likely to
significantly change the energy supply,
distribution, or use in any given area.
Considering this analysis, EPA has
concluded that LT2ESWTR is not likely
to have a significant adverse effect on
the supply, distribution, or use of
energy.
/. National Technology Transfer and
Advancement Act
  Section 12(d) of the National
Technology Transfer and Advancement
Act (NTTAA) of 1995, Public Law 104-
113, section 12(d) (15 U.S.C. 272 note),
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.,
material specifications, test methods,
sampling procedures, and business
practices) that are developed or adopted
by voluntary consensus standard bodies.
The NTTAA directs EPA to provide
Congress, through OMB, explanations
when  the Agency decides not to use
available and  applicable voluntary
consensus standards.

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                                                                    47769
   The proposed rulemaking involves
 technical standards. EPA proposes to
 use several voluntary consensus
 standards (VCS) methods for
 enumerating E. coli in surface waters.
 These methods are listed in section
 IV.K.2, Table IV-37, and were
 developed or adopted by the following
 organizations:  American Public Health
 Association in Standard Methods for the
 Examination of Water and Wastewater,
 20th, 19th, and 18th Editions, the
 American Society of Testing Materials
 in Annual Book of ASTM Standards—
 Water and Environmental Technology,
 and the Association of Analytical
 Chemists in Official Methods of
 Analysis of AOAC International, 16th
 Edition. These methods are available in
 the docket for today's proposal. EPA has
 concluded that these methods have the
 necessary sensitivity and specificity to
 meet the data quality objectives of the
 LT2ESWTR.
  The Agency  conducted a search to
 identify potentially applicable voluntary
 consensus standards for analysis of
 Cryptosporidium. However, we
 identified no such standards. Therefore,
 EPA proposes to use the  following
 methods for Cryptosporidium analysis:
 Method 1622: "Cryptosporidium in
 Water by Filtration/IMS/FA" (EPA-821-
 R-01-026, April 2001) (USEPA 2001e)
 and Method 1623: "Cryptosporidium
 and Giardia in Water by Filtration/IMS/
 FA" (EPA 821-R-01-025, April 2001)
 (USEPA 2001f).
  EPA welcomes comments on this
 aspect of the proposed rulemaking and,
 specifically, invites the public to
 identify additional potentially
 applicable voluntary consensus
 standards, and to explain why such
 standards should be used in this
 regulation.
 /. Executive Order 12898: Federal
 Actions To Address Environmental
 Justice in Minority Populations or Low-
 Income Populations
  Executive Order 12898 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.
  Two aspects  of the LT2ESWTR
comply with the order that requires the
Agency to consider environmental
justice issues in the rulemaking and to
 consult with stakeholders representing a
 variety of economic and ethnic
 backgrounds. These are: (1) The overall
 nature of the rule, and (2) the convening
 of a stakeholder meeting specifically to
 address environmental justice issues.
  The Agency built on the efforts
 conducted during the development of
 the IESWTR to comply with Executive
 Order 12898. On March 12,1998, the
 Agency held a stakeholder meeting to
 address various components of pending
 drinking water regulations and how
 they might impact sensitive
 subpopulations, minority  populations,
 and low-income populations. This
 meeting was a continuation of
 stakeholder meetings that started in
 1995 to obtain input on the Agency's
 Drinking Water Programs. Topics
 discussed included treatment
 techniques, costs and benefits, data
 quality, health effects, and the
 regulatory process. Participants were
 national, State, Tribal, municipal, and
 individual stakeholders. EPA conducted
 the meeting by video conference call
 between eleven cities. The major
 objectives for the March 12,1998,
 meeting were the following:
  • Solicit ideas from stakeholders on
 known issues concerning  current
 drinking water regulatory efforts;
  • Identify key areas of concern to
 stakeholders; and
  • Receive suggestions from
 stakeholders concerning ways to
 increase representation of communities
 in OGWDW regulatory efforts.
  In addition, EPA developed a plain-
 English guide for this meeting to assist
 stakeholders in understanding the
 multiple and sometimes complex issues
 surrounding drinking water regulations.
  The LT2ESWTR and other drinking
 water regulations promulgated or under
 development are expected to have a
 positive effect on human health
 regardless of the social or  economic
 status of a specific population. The
 LT2ESWTR serves to provide a similar
 level of drinking water protection to all
 groups. Where water systems have high
 Cryptosporidium levels, they must treat
 their water to achieve a specified level
 of protection. Further, to the extent that
 levels of Cryptosporidium in drinking •
 water might be disproportionately high
 among minority or low-income
 populations (which is unknown), the
LT2ESWTR will work to remove  those
 differences. Thus, the LT2ESWTR meets
the intent of Federal policy requiring
incorporation of environmental justice
into Federal agency missions.
  The LT2ESWTR applies uniformly to
CWSs, NTNCWSs, and TNCWSs  that
use surface water or GWUDI as their
source. Consequently, this rule provides
health protection from pathogen
exposure equally to all income and
minority groups served by surface water
and GWUDI systems.

K. Consultations with the Science
Advisory Board, National Drinking
Water Advisory Council, and the
Secretary of Health and Human Services
  In accordance with sections 1412 (d)
and (e) of SDWA, the Agency has
consulted with the Science Advisory
Board (SAB), theNational Drinking
Water Advisory Council (NDWAC), and
will consult with the Secretary of Health
and Human Services regarding the
proposed LT2ESWTR during the public
comment period. EPA charged the SAB
panel with reviewing the following
aspects of the LT2ESWTR proposal:
  • The analysis of Cryptosporidium
occurrence, as described in Occurrence
and Exposure Assessment for the
LT2ESWTR (USEPA 2003b);
  • The pre- and post-LT2ESWTR
Cryptosporidium risk assessment, as
described in Economic Analysis for the
LT2ESWTR (USEPA 2003a); and
  • The treatment credits for the
following four microbial toolbox
components: raw water off-stream
storage, pre-sedimentation, lime
softening, and lower finished water
turbidity (described  in section IV.C of
this preamble).
  EPA met with the  SAB to discuss the
LT2ESWTR on June  13, 2001
(Washington, DC), September 25-26,
2001 (teleconference), and December
10-12, 2001 (Los Angeles, CA). Written
comments from the December 2001
meeting of the SAB addressing the
occurrence  analysis and risk assessment
were generally supportive. EPA has
responded to the SAB's
recommendations for Cryptosporidium
occurrence  analysis in the current draft
of Occurrence and Exposure Assessment
for the LT2ESWTR (USEPA 2003b), and
EPA has addressed the SAB's comments
on risk assessment in the current draft
of Economic Analysis for the
LT2ESWTR (USEPA 2003a). Comments
from the SAB on the microbial toolbox
components and the Agency's responses
to those comments are described in
section IV.C of this preamble.
  EPA met with the NDWAC on
November 8, 2001, in Washington, DC,
to discuss the LT2ESWTR proposal.
EPA specifically requested comments
from the NDWAC on the regulatory
approach taken in the proposed
microbial toolbox (e.g., proposal of
specific design and implementation
criteria for treatment credits). The
Council was generally supportive of
EPA establishing criteria for awarding

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Federal  Register/Vol.  68, No. 154/Monday, August 11,  2003/Proposed  Rules
treatment credit to toolbox components,
but recommended that EPA provide
flexibility for States to address system
specific situations. EPA believes that the
demonstration of performance credit,
described in section IV.C.17, provides
this flexibility by allowing States to
award higher or lower levels of
treatment credit for microbial toolbox
components based on site specific
conditions. Minutes of the NDWAC and
SAB meetings are in the docket for
today's proposal.
L. Plain Language
   Executive Order 12866 encourages
Federal agencies to write rules in plain
language. EPA invites comments  on
how to make this proposed rule easier
to understand. For example: Has  EPA
organized the material to suit
commenters' 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 ordering
of sections, use of headings, paragraphs)
make the rule easier to understand?
Could EPA improve clarity by adding
tables, lists, or diagrams? What else
could EPA do to make the rule easier to
understand?
VIII. References
Aboytes R., F.A. Abrams, W.E. McElroy, C.
   Rheinecker, G.D. DiGiovanni, R. Seeny, M.
   LeChevallier, and R. Kozik. 2002.
   Continuous monitoring for detection of
   infectious Cryptosporidium parvum
   oocysts in drinking water. Abstracts of the
   102nd General Meeting of the American
   Society for Microbiology, Salt Lake City,
   UT, May 19-22.
Adham, S., J. Jacangelo, and J. Laine.  1995.
   Low pressure membranes; assessing
   integrity. J. AWWA. 03:3:62.
Adham, S., P. Gagliado, D.  Smith, D.  Ross, K.
   Gramith, and R. Trussell. 1998. Monitoring
   of reverse osmosis for virus rejection.
   Proceedings of the Water Quality
   Technology Conference of the American
   Waterworks Association, Denver,  CO.
APHA. 1992. Standard  Methods for the
   Examination of Water and Wastewater;
   18th Edition. American Public Health
   Association, Washington B.C.
Arora, H., M. LeChevallier, R. Aboytes, E.
   Bouwer, C. O'Melia, W. Ball, W. Weiss,
   and T. Speth. 2000. Full-scale evaluation of
   riverbank filtration at three Midwest water
   treatment plants. Proceedings of the Water
   Quality Technology Conference, Salt Lake
   City, Utah, American Water Works
   Association, Denver,  Colorado.
ASTM. 2001. Standard  test method for on-
   line measurement of turbidity below 5
   NTU in water. 0-6698-01.
ASTM. 2003. Standard  test method for
   determination of turbidity below 5 NTU in
   static mode. D-6855-03.
AWWA Committee. 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, pg. 313-8.
                        AWWA, USEPA, AWWARF, AMWA,
                          ASDWA, and NAWC. 2001. Partnership for
                          Safe Water, Phase IV Procedures and
                          Application Package. August.
                        Barwick, R.S., D.A. Levy, G.F. Craun, M.J.
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   Technology Verification Protocol for
   Equipment Verification Testing for
   Physical Removal of Microbiological and

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                    Federal  Register/Vol. 68,  No. 154/Monday,  August  11, 2003/Proposed  Rules
                                                                              47773
   Participate Contaminants. (40CFR35.6450),
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                   Federal  Register/Vol. 68, No.  154/Monday, August  11,  2003/Proposed  Rules
                                                                                                                 47775
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 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: July 11, 2003.
Linda J. Fisher,
Acting 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

                                            1. The authority citation for Part 141
                                          continues to read as follows:
                                            Authority: 42 U.S.C. 300f, 300g-l, 300g-2,
                                          300g-3,300g-4, 300g-5, 300g-6,300J-1,
                                          300J-9, and300j-ll.

                                            2. Section 141.2 is amended by
                                          adding, in alphabetical order,
                                          definitions for Bag filters, Bank
                                          filtration, Cartridge filters, Flowing
                                          stream, Lake/reservoir, Membrane
                                          filtration, Off-stream raw water storage,
                                          Plant intake, Presedimentation, and
                                          Two-stage lime softening to read as
                                          follows:

                                          §141.2  Definitions.
                                          *****
                                            Bag filters are pressure-driven
                                          separation devices that remove
                                          particulate matter larger than 1 |im
                                          using an engineered porous filtration
                                          media through either surface or depth
                                          filtration. Bag  filters are typically
                                          constructed of a non-rigid, fabric
                                          filtration media housed in a pressure
                                          vessel in which the direction of flow is
                                          from the inside of the bag to outside.
                                           Bank  filtration is a water treatment
                                         process  that uses a pumping well to
                                         recover  surface water that has naturally
                                         infiltrated into ground water through a
                                         river bed or bank(s). Infiltration is
                                         typically enhanced by the hydraulic
                                         gradient imposed by a nearby pumping
                                         water supply or other well(s).
                                         *****
                                           Cartridge filters are pressure-driven
                                         separation devices that remove
                                         particulate matter larger than 1 um
                                         using an engineered porous filtration
                                         media through either surface or depth
                                         filtration. Cartridge filters are typically
                                         constructed as rigid or semi-rigid, self-
                                         supporting filter elements housed in
                                         pressure vessels in which flow is from
                                         the outside of the cartridge to the inside.
                                         *****
                                          Flowing stream is a course of running
                                         water flowing in a definite channel.
        Lake/reservoir refers to a natural or
      man made basin or hollow on the
      Earth's surface in which water collects
      or is stored that may or may not have
      a current or single direction of flow.
      *    *    *     *    *

        Membrane filtration is a pressure-
      driven or vacuum-driven separation
      process in which particulate matter
      larger than 1 um is rejected by an
      engineered barrier primarily through a
      size exclusion mechanism, and which
      has a measurable removal efficiency of
      a target organism that can be verified
      through the application of a direct
      integrity test. This definition includes
      the common membrane technologies of
      microfiltration (MF), ultrafiltration (UF),
      nanofiltration (NF), and reverse osmosis
      ERO).
      *****

       Off-stream raw water storage refers to
      an impoundment in which water is
      stored prior to treatment and from
      which outflow is controlled.
      *****

       Plant intake refers to the works or
      structures at the head of a conduit
      through which water is diverted from a
      source (e.g., river or lake) into the
      treatment plant.
      *****

       Presedimentation is a preliminary
     unit process used to remove gravel, sand
     and other particulate material from the
     source water through settling before it
     enters the main treatment plant.
      *****

       Two-stage lime softening refers to a
     process for the removal of hardness by
     the addition of lime and consisting of
     two distinct unit clarification processes
     in series prior to filtration.
     *****

       3. Appendix A to Subpart Q of part
     141 is amended in section I, Part A by
     adding entry number 10:
       Subpart Q—Public Notification of
     Drinking Water Violations.
 APPENDIX A TO SUBPART Q OF PART 141—NPDWR VIOLATIONS AND OTHER SITUATIONS REQUIRING PUBLIC NOTICE
                                          MCL/MRDL/TT violations2
                                                                               Monitoring and testing procedure violations
         Contaminant
                                Tier of public
                               notice required
                                                         Citation
 Tier of public
notice required
                                                                                                     Citation
            of  National  Primary
           Water   Regulations
I.  Violations
  Drinking
  (NPDWR)3.
A. Microbiological Contaminants

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47776          Federal Register/Vol.  68,  No.  154/Monday,  August 11, 2003/Proposed Rules

APPENDIX A TO SUBPART Q OF PART 141-NPDWR VIOLATIONS AND OTHER SITUATIONS REQUIRING PUBLIC NOTICE '-
                                          MCL/MRDL/TT violations'
          Contaminant
 10. LT2ESWTR violations
                                Tier of public
                                notice required
Citation
                                           2  141.720-141.729
                                      Monitoring and testing procedure violations
                                    Tier of public
                                   notice required
                                                                                                     Citation
                                              3  141.701-141.707;
                                                   141.713; 141.730
                                                                                                               141.711-
   .Violations and other stations no, Hsted in ,hs

                                                                                                  °f
 technique, monitoring, and testing procedure requirements.
   4. Part 141 is amended by adding a
 new subpart W to read as follows:

 SubpartW—Enhanced Filtration and
 Disinfection for Cryptoaporidium

 General Requirements
 141.700  Applicability.
 141.701  General requirements.

 Source Water Monitoring Requirements
 141.702  Source water monitoring.
 141.703  Sampling schedules.
 141.704  Sampling locations.
 141.705  Analytical methods.
 141.706  Requirements for use of an
     approved laboratory.
 141.707  Reporting source water monitoring
     results.
 141.708  Previously collected data.
 141.709  Bin classification for filtered
     systems.
 Disinfection Profiling and Benchmarking
 Requirements
  141.710  [Reserved]
  141.711  Determination of systems required
     to profile.
  141.712  Schedule for disinfection profiling
     requirements.
  141.713  Developing a profile.
  141.714  Requirements when making a
     significant change in disinfection
     practice.
  Treatment Technique Requirements
  141.720  Treatment requirements for filtered
      systems.
  141.721  Treatment requirements for
      unfiltered systems.
  141.722  Microbial toolbox options for
      meeting Cryptoaporidium treatment
      requirements.
  141.723  [Reserved]
141.724  Requirements for uncovered
    finished water storage facilities.
Requirements for Microbial Toolbox
Components
141.725  Source toolbox components,
141.726  Pre-filtration treatment toolbox
    components.
141.727  Treatment performance toolbox
    components.
141.728  Additional filtration toolbox
    components.
141.729  Inactivation toolbox components.
Reporting and Recordkeeping Requirements
141.730  Reporting requirements.
141.731  Recordkeeping requirements.

Subpart W—Enhanced Filtration and
Disinfection for Cryptosporidium

General Requirements

§ 141.700  Applicability.
   The requirements of this subpart
 apply to all subpart H systems. Failure
 to comply with any requirement of this
 subpart is a violation and requires
 public  notification.
 §141.701  General requirements.
   (a) All subpart  H systems, including
 wholesale systems, must characterize
 their source water to determine what (if
 any) additional treatment is necessary
 for Cryptosporidium, unless they meet
 the criteria in either paragraph (f) or (g)
 of this section.
   (b] Systems serving at least 10,000
 people that currently provide filtration
 or that are  unfiltered  and required to
 install filtration must conduct source
 water monitoring that includes
                         Cryptosporidium, E. coh, and turbidity
                         sampling and comply with the
                         treatment requirements in § 141.720.
                           (c) Systems serving fewer than 10,000
                         people that currently provide filtration
                         or that are unfiltered and required to
                         install filtration must conduct source
                         water monitoring consisting of E. coli
                         sampling or sampling of an alternative
                         indicator approved by the State. If the
                         annual mean concentration of E, coli
                         exceeds the levels specified in
                         §141.702(b),orifthelevel of a  State-
                         approved alternate indicator exceeds a
                         State-approved alternative indicator
                         trigger level, systems must conduct
                         Cryptosporidium monitoring to
                         complete the source water monitoring
                         requirements and comply with the
                         treatment requirements in § 141.720.
                           (d) Systems that are unfiltered and
                         meet all the filtration avoidance criteria
                         of § 141.71  must conduct source water
                         monitoring consisting of
                         Cryptosporidium sampling and comply
                         with the treatment requirements in
                         §141.721.
                            (e) Systems must comply with the
                         requirements in this subpart based on
                         the schedule in the following table,
                         except that systems are not required to
                         conduct source water monitoring if they
                         meet the criteria in paragraph  (f) of this
                         section for systems that currently
                         provide filtration or that are unfiltered
                          and required to install  filtration or
                          paragraph  (g) of this section for systems
                          that are unfiltered and meet all the
                          filtration avoidance criteria of §141.71:

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                    Federal Register/Vol. 68, No.  154/Monday, August 11, 2003/Proposed Rules
                                                                                     47777
                                              COMPLIANCE REQUIREMENTS TABLE
       Systems that are
              Must perform .  . ,a'b
              And comply by
  (1)  Subpart  H  systems  serving
   >10,000  people  that  currently
   provide  filtration   or  that  are
   unfiltered and required to  install
   filtration.
 (2)  Subpart  H  systems  serving
   >10,000    people    that    are
   unfiltered and meet the  filtration
   avoidance criteria of § 141.71.
 (3)  Subpart  H  systems  serving
   <10,000  people  that  currently
   provide  filtration  or  that  are
   unfiltered and required  to install
   filtration  and are not  required to
   monitor   for   Cryptosporidium
   based on  E.  coli or  other indi-
   cator monitoring results'3.
 (4)  Subpart  H  systems  serving
   <10,000   people  that  currently
   provide  filtration  or   that  are
   unfiltered and required  to install
   filtration   and   must  perform
   Cryptosporidium      monitoring
   based on E.  coli  or  other indi-
   cator monitoring results d.
 (5)  Subpart  H  systems  serving
   <10,000    people   that   are
   unfiltered  and meet the filtration
   avoidance criteria of § 141.71.
 (i)  24  months  of  source water  monitoring for
   Cryptosporidium, E.  coli and turbidity  at  least
  once each month beginning no later than [Date  6
  Months After Date of Publication of Final Rule in
  the Federal Register].
 (ii)  Treatment  technique  implementation, if  nec-
  essary.
 (i)  24  months  of  source  water  monitoring  for
  Cryptosporidium at least once each month begin-
  ning no later than [Date 6 Months After Date of
  Publication of Final Rule in the Federal Register].
 (ii)  Treatment  technique  implementation, if  nec-
  essary.
12 months of source water monitoring for E. coli at
  least once every two weeks beginning no  later
  than [Date 30 Months After Date of Publication of
  Final Rule in the Federal Register].
(i) 12 months of source water monitoring for 5. coli
  at least once every two weeks beginning no later
  than [Date 30 Months After Date of Publication of
  Final  Rule in the  Federal  Register] and  12
  months   of  source   water  monitoring   for
  Cryptosporidium at least twice each month begin-
  ning no later than [Date 48 Months After Date of
  Publication of Final Rule in the Federal Register].
(ii)  Treatment technique  implementation,  if nec-
  essary.
(i) 12  months  of source  water  monitoring  for
  Cryptosporidium at least twice each month begin-
  ning no later than [Date 48 Months After Date of
  Publication of Final Rule in the Federal Register}.
 ii) Treatment  technique  implementation,  if nec-
  essary.
Submitting a  monthly report to EPA no later than
  ten days after the end of the first month following
  the month when the sample is taken.
Installing treatment and  complying with the treat-
  ment  technique no later than [Date 72 Months
  After Date of Publication of Final Rule in the Fed-
  eral Register]0.
Submitting a monthly report to EPA  no later than
  ten days after the end of the first month following
  the month when the sample is taken.

Installing treatment and  complying with the treat-
  ment  technique no later than [Date 72 Months
  After Date of Publication of Final rule in the Fed-
  eral Register]c.
Submitting a monthly report to the State no later
  than ten days after the end of the first month  fol-
  lowing the month when the sample is taken.
Submitting a monthly report to the  State no  later
  than ten days after the end of the  first month fol-
  lowing the month when the sample is taken.
Installing  treatment and complying with the  treat-
  ment technique  no  later than [Date  102 Months
  After Date of Publication of Final Rule in the Fed-
  eral Register]c.
Submitting a monthly report to the State no later
  than ten days after the end of the first month fol-
  lowing the month when the sample is taken.

Installing  treatment and complying with the  treat-
  ment technique  no  later than [Date  102 Months
  After Date of Publication of Final Rule in the Fed-
  eral Register]0.
  aAny sampling performed more frequently than required must be evenly distributed over the sampling period.
  bSystems may use data that meet the requirements in §141.708 collected prior to the monitoring start date to substitute for an equivalent
 number of months at the end of the monitoring period.
  c States may allow up to an additional two years for complying with the treatment technique requirement for systems making capital improve-
 ments.
  dSee §141.702(b) to determine if Cryptosporidium monitoring is required.
   (f) Systems that currently provide
filtration or that are unfiltered and
required to install filtration are not
required to conduct source water
monitoring under this subpart if the
system currently provides or will
provide a total of at least 5.5 log of
treatment for Cryptosporidium,
equivalent to meeting the treatment
requirements of Bin 4 in §141.720.
Systems must notify the State not later
than the date the system is otherwise
required to  submit a sampling schedule
for monitoring under § 141.703 and
must install and operate technologies to
provide a total of at least 5.5 log of
         treatment for Cryptosporidium by the
         applicable date in paragraph (e) of this
         section.

           (g) Systems that are unfiltered and
         meet all the filtration avoidance criteria
         of § 141.71 are not required to conduct
         source water monitoring under this
         subpart if the system currently provides
         or will provide a total of at least 3 log
         Cryptosporidium inactivation,
         equivalent to meeting the treatment
         requirements for unfiltered  systems
         with a mean Cryptosporidium
         concentration of greater than 0.01
         oocysts/L in § 141.721. Systems must
         notify the State not later than the date
     the system is otherwise required to
     submit a sampling schedule for
     monitoring under § 141.703. Systems
     must install and operate technologies to
     provide a total of at least 3 log
     Cryptosporidium inactivation by the
     applicable  date in paragraph (e)  of this
     section.

       (h) Systems must comply with the
     uncovered  finished water storage
     facility requirements in § 141.724 no
     later than [Date 36 Months After Date of
     Publication of Final Rule in the Federal
     Register].

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                                                 154/Monday, August  11,  2003/Proposed Rules
Source Water Monitoring Requirements

§141.702 Source water monitoring.
  (a) Systems must conduct initial
source water monitoring as specified in
§ 141.701(b) through (f).
  (b) Systems serving fewer than 10,000
people that provide filtration or that are
unfiltered and required to  install
filtration must perform Cryptosporidium
monitoring in accordance with
§ 141.701(e) if they meet any of the
criteria in paragraphs (b)(l) through (4)
of this section.
  (1) For systems using lake/reservoir
sources, an annual mean £", coli
concentration greater than 10 E. coli/WO
mL, based on monitoring conducted
under this section, unless  the State
approves an alternative indicator trigger.
   (2) For systems using flowing stream
sources, an annual mean E. coli
concentration greater than 50 E. coli/lOO
mL, based on monitoring conducted
under this section, unless the Stale
approves an alternative indicator trigger.
   (3) If the State approves an alternative
to the indicator trigger in paragraph
 (b)(l) or (b)(2) of this section, an annual
concentration that exceeds a State-
approved trigger level, including an
 alternative E. coli level, based on
 monitoring conducted under this
 section,
   (4) The system does not conduct b.
 coli or other State-approved indicator
 monitoring as specified in § 141,701(e).
   (c) Systems may  submit
 Cryptosporidium data collected prior to
 the monitoring start date to meet the
 initial  source water monitoring
 requirements of paragraphs (a) through
 (b) of this section. Systems may also use
  Cryptosporidium data collected prior to
 the monitoring start date to substitute
 for an equivalent number of months  at
 the end of the monitoring period. All
  data submitted under this paragraph
  must meet the requirements in
  §141.708.
    (d) Systems must conduct a second
  round of source water monitoring in
  accordance with the requirements in
  § 141.701(b) through (e) of this section,
  beginning no later than the dates
  specified in paragraphs (d)(l) through
  (3) of this section,  unless they meet the
  criteria in either paragraph § 141.701(f)
  or (e).
    (1) Systems that serve at least 10,000
  people must begin a second round of
  source water monitoring  no later than
  [Date 108 Months After Date of
  Publication of Final Rule in the Federal
  Register).
    (2) Systems serving fewer than 10,000
  people that provide filtration or that are
  unfiltered and required to install
  filtration must begin a second round of
source water monitoring no later than
[Date 138 Months After Date of
Publication of Final Rule in the Federal
Register] and, if required to monitor for
Cryptosporidium under paragraph (b) of
this section, must begin
Cryptosporidium monitoring no later
than [Date 156 Months After Date of
Publication of Final Rule in the Federal
Register].
  (3) Systems serving fewer than 10,000
people that are unfiltered and meet the
filtration avoidance requirements of
§ 141.71 must begin a second round of
source water monitoring no later than
[Date 156 Months After Date of
Publication of Final Rule in the Federal
Register].
§ 141.703  Sampling schedules.
   (a) Systems required to sample under
§ § 141.701 through 141.702 must
submit a sampling schedule that
specifies the calendar dates that all
required samples will be taken.
   (1) Systems serving at least 10,000
people must submit their sampling
schedule for initial source water
monitoring to EPA electronically at
 [insert Internet address] no later than
 [Date 3 Months After Date of Publication
 of Final Rule in tbe Federal Register].
   (2) Systems serving fewer than 10,000
 people that are filtered or that are
 unfiltered and  required to install
 filtration must submit a sampling
 schedule for initial source  water
 monitoring of E.  coli or an  alternative
 State-approved indicator to the State no
 later than [Date 27 Months After Date of
 Publication of Final Rule in the Federal
 Register].
   (3} Filtered systems serving fewer
 than 10,000 people that are required to
 conduct Cryptosporidium monitoring
 and unfiltered systems serving fewer
 than 10,000 people must submit a
 sampling schedule for initial source
 water Cryptosporidium monitoring to
 the State no later than [Date 45 Months
 After Date of Publication of Final Rule
 in the Federal Register].
   (4) Systems  must submit a sampling
 schedule for the second round of source
 water monitoring to the State no later
 than 3 months prior to the date the
 system is required to begin the second
 round of monitoring under § 141.702(d).
   (b) Systems must collect samples
 within two days of the dates indicated
 in theiT sampling schedule.
    (c) Jf extreme conditions or situations
 exist that may pose danger to the sample
 collector, or which are unforeseen or
 cannot be avoided and which cause the
 system to be unable to sample in the
 required time frame, the system must
 sample as close to the required date as
 feasible and submit an explanation for
the alternative sampling date with the
analytical results.
  (dj Systems that are unable to report
a valid Cryptosporidium analytical
result for a scheduled sampling date due
to failure to comply with the analytical
method requirements, including the
quality control requirements in
§ 141.705, must collect a replacement
sample within 14 days  of being notified
by the laboratory or the State that a
result cannot be reported for that date
and must submit an explanation for the
replacement sample with the analytical
results.
 §141.704  Sampling locations.
   (a) Unless specified otherwise in this
 section, systems required to sample
 under §§ 141.701 through 141.702 must
 collect source water samples from the
 plant intake prior to any treatment.
 Where treatment is applied in an intake
 pipe such that sampling in the pipe
 prior to treatment is not feasible,
 systems must collect samples as close to
 the intake as is feasible, at a similar
 depth and distance from shore.
   (b) Presedimentation. Systems using a
 presedimentation basin must collect
 source water samples after the
 presedimentation basin but before any
 other treatment. Use of
 presedimentation basins during
 monitoring must be consistent with
 routine operational practice and the
 State may place reporting requirements
 to verify operational practices.  Systems
 collecting samples after a
 presedimentation basin may not receive
 credit for the presedimentation basin
 under § 141.726(a).
    (c) flaw water off-stream storage.
 Systems using an off-stream raw water
 storage reservoir must collect source
 water samples after the off-stream
 storage reservoir. Use of off-stream
 storage during monitoring must be
 consistent with routine operational
 practice, and the State may place
 reporting requirements to verify
 operational practices.
    (d) Bank filtration. The required
 sampling location for systems using
 bank filtration differs depending on
 whether the bank filtered water is
 treated by subsequent  filtration for
 compliance with § 141.173(b) or
  § 141.552(a), as applicable.
    (1) Systems using bank filtered water
  that is treated by subsequent filtration
  for compliance with § 141.173(b) or
  § 141.552(a), as applicable, must collect
  source water samples from the well (i.e.,
  after bank filtration), but before any
  other treatment. Use of bank filtration
  during monitoring must be consistent
  with routine operational practice and
  the State may place reporting

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                 Federal Register/Vol. 68, No. 154/Monday, August 11. 2003/Proposed .Rules
                                                                    47779
requirements to verify operational
practices. Systems collecting samples
after a bank fihration process may not
receive credit for the bank filtration
under §141.726(c).
  (2) Systems using bank filtration as an
alternative  filtration demonstration to
meet their Cryptosporidium removal
requirements under §141.173(b) or
§ 141.552(a), as applicable, must collect
source water samples in the surface
water (i.e., prior to bank filtration).
  (3) Systems using a ground water
source under the direct influence of
surface water that meet all the criteria
for avoiding filtration in § 141.71 and
that do not provide filtration treatment
must collect source water samples from
the ground water (e.g., the well).
  (e) Multiple sources. Systems with
plants that  use multiple water sources at
the same time, including multiple
surface water sources and blended
surface water and ground water sources,
must collect samples as specified in
paragraph (e)(l) or (2) of this section.
The use of multiple sources during
monitoring must be consistent with
routine operational practice and the
State may place reporting requirements
to verify operational practices.
  (1) If a sampling tap is available
where the sources are combined prior to
treatment, the sample must be collected
from the tap.
  (2) If there is not a sampling tap
where the sources are combined prior to
treatment, systems must collect samples
at each source near the intake on the
same day and must follow either
paragraph (e)(2)(i) or (e)(2)(ii) of this
section for  sample analysis.
  (i) Composite samples from each
source into one sample prior to analysis.
In the composite, the volume of sample
from each source  must be weighted
according to the proportion of the
source in the total plant flow at the time
the sample is collected.
  (ii) Analyze samples from each source
separately as specified in § 141.705, and
calculate a weighted average of the
analysis results for each sampling date.
The weighted average must be
calculated by multiplying the analysis
result for each source by the fraction the
source contributed to total plant flow at
the time the sample was collected, and
then summing these values.

§141.705   Analytical methods.
  (a) Cryptosporidium. Systems must
use Method 1622 Cryptosporidium in
Water by Filtration/IMS/FA, EPA 821-
R-01-026, April 2001, or Method 1623
Cryptosporidium and Giardia in Water
by Filtration/IMS/FA, EPA 821-R-01-
025, April 2001, for Cryptosporidium
analysis.
  (1) Systems are required to analyze at
least a 10 L sample or a packed pellet
volume of at least 2 mL as generated by
the methods listed in paragraph (a) of
this section. Systems unable to process
a 10 L sample must analyze as much
sample volume as can  be filtered by two
filters approved by EPA for the .methods
listed in paragraph (a)  of this section, up
to a packed pellet volume of 2 mL.
  (2)(i) Matrix spikes (MS) samples as
required by the methods in paragraph
(a) of this section must be spiked and
filtered by a laboratory approved for
Cryptosporidium analysis under
§ 141.706. The volume of the MS sample
must be within 10 percent of the volume
of the unspiked sample that is collected
at the same time, and the samples must
be collected by splitting the sample
stream or collecting the samples
sequentially. The MS sample and the
associated unspiked sample must be
analyzed by the same procedure.

 METHODS FOR £ coli ENUMERATION 1
  (ii) If the volume of the MS sample is
greater than 10 L, the system is
permitted to filter all but 10 L of the MS
sample in the field, and ship the filtered
sample and the remaining 10 L of source
water to the laboratory. In this case, the
laboratory must spike the remaining 10
L of water and filter it through the filter
used to collect the balance of the sample
in the field.
  (3) Each sample batch must meet the
quality control criteria for the methods
listed in paragraph (a) of this section.
Flow cytometer-counted spiking
suspensions must be used for MS
samples and ongoing precision and
recovery (OPR) samples; recovery for
OPR samples must be 11% to 100%; for
each method blank, oocysts must not be
detected.
  (4) Total Cryptosporidium oocysts as
detected by fluorescein isothiocyanate
(FITC) must be reported as determined
by the color (apple green or alternative
stain color approved under  § 141.706(a)
for the laboratory), size (4-6 um) and
shape (round to oval). This  total
includes all of the oocysts identified,
less any atypical organisms identified
by FITC, differential interference
contrast (DIG) or 4',6-diamindino-2-
phenylindole (DAPI), including those
possessing spikes, stalks, appendages,
pores, one or two large nuclei filling the
cell, red fluorescing chloroplasts,
crystals, and spores.
   (b) E. coli. Systems must use the
following methods listed in this
paragraph for enumeration  of E. coli in
source water (table will be replaced
with CFR cite from Guidelines
Establishing Test Procedures for the
Analysis of Pollutants; Analytical
Methods for Biological Pollutants in
Ambient Water when finalized—
expected 2003):
Technique
Most Probable Number (MPN)

Method 1








m-ColiB!ue24 broth
EPA





1103.1 	
Modified 1103.1
EPA-600-R-013
VCSB methods
Standard meth-
ods
9221B.1/9221F
9223B
9223B
9222D/9222G
9222B/9222G
921 3D
ASTM

D5392-93
AOAC
991.15
   Tests must be conducted in a format that provides organism enumeration.
   (1) The time from sample collection to
 initiation of analysis may not exceed 24
hours. Systems must maintain samples
between 0°C and 10°C during transit.
  (2) [Reserved]
   (c) Turbidity. Systems must use
 methods for turbidity measurement
 approved in § 141.74.

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 47780
Federal Register/Vol. 68, No.  154/Monday, August 11, 2003/Proposed Rules
 § 141.706  Requirements for use of an
 approved laboratory.
   (a) Cryptosporidium. Systems must
 have Cryptosporidium samples analyzed
 by a laboratory that has passed a quality
 assurance evaluation under EPA's
 Laboratory Quality Assurance
 Evaluation Program for Analysis of
 Cryptosporidium in Water or a
 laboratory that has been certified for
 Cryptosporidium analysis by an
 equivalent State laboratory certification
 program.
   (b) E. coli. Any laboratory  certified by
 the EPA, the National Environmental
 Laboratory Accreditation Conference or
 the State for total coliform or fecal
 coliform analysis in source water under
 § 141.74 is deemed approved for E. coli
 analysis under this subpart when the
 laboratory uses the same technique for
 E. coli that the laboratory uses for source
 water in §141.74.
   (c) Turbidity. Measurements of
 turbidity must be made by a  party
 approved by the State.

 §141.707  Reporting source water
 monitoring results.
   (a) All systems serving at least 10,000
 people must submit the results of all
 initial  source water monitoring required
 under  § 141,702(a) to EPA electronically
 at [insert Internet address]. Systems that
 do not have the ability to submit data
 electronically may use an alternative
 format approved by EPA.
   (b) Systems serving fewer than 10,000
 people must submit the results of all
 initial  source water monitoring required
 under  § 141.702(a)-(b) to the State.
   (c) All systems must submit the
 results from the second round of source
 water monitoring required under
 § 141.702(d) to the State.
   (d) Source water monitoring analysis
 results must be submitted not later than
 ten days after the end of first  month
 following the month when the sample is
 collected. The submission must include
 the applicable information in
 paragraphs (e)(l) and (2) of this section.
   (e)(l) Systems must report  the
 following data elements for each
 Cryptosporidium analysis:
 (i) PWS ID
 (ii) Facility ID
 (iii) Sample collection point
 (iv) Sample collection date
 (v) Sample type (field or matrix spike)
 (vi) Sample volume filtered (L), to
  nearest */> L
 (vii) Was 100%  of filtered volume
  examined
 (viii) Number of oocysts counted
  (i) For matrix spike samples, systems
must also report the sample volume
spiked  and estimated number of oocysts
spiked. These data are not required for
field samples.
                        (ii) For samples in which less than 10
                      L is filtered or less than 100% of the
                      sample volume is examined, systems
                      must also report the number of filters
                      used and the packed pellet volume.
                        (iii) For samples in which less than
                      100% of sample volume is examined,
                      systems must also report the volume of
                      resuspended concentrate and volume of
                      this resuspension processed through
                      immunomagnetic separation.
                        (2) Systems must report the following
                      data elements for each E, coli analysis:
                      (i) PWS  ID
                      (ii) Facility ID
                      (iii) Sample collection point
                      (iv) Sample collection date
                      (v) Analytical method number
                      (vi) Method type
                      (vii) Source type
                      (viii)E. co7i/100mL
                      (ix) Turbidity (Systems serving fewer
                        than 10,000 people that are not
                        required to monitor for turbidity
                        under § 141.701(c) are not required to
                        report turbidity with their E. coli
                        results.)

                      §141.708 Previously collected data.
                        (a) Systems may comply with the
                      initial monitoring requirements of
                      § 141.702(a) using Cryptosporidium data
                      collected before the system is required
                      to begin monitoring if the system meets
                      the conditions in paragraphs (b) through
                      (h) of this section and EPA notifies the
                      system that the data are acceptable.
                        (b) To be accepted, previously
                      collected Cryptosporidium data must
                      meet the conditions in paragraphs (b)(l)
                      through  (5) of this section.
                        (1) Samples were analyzed by
                      laboratories using one of the analytical
                      methods in paragraphs (b)(l)(i) through
                      (iv) of this section.
                        (i) Method 1623: Cryptosporidium
                      and Giardia in Water by Filtration/IMS/
                      FA,  2001, EPA-821-R-01-025.
                        (ii) Method 1622: Cryptosporidium in
                      Water by Filtration/IMS7FA, 2001, EPA-
                      821-R-01-026.
                        (iii) Method 1623: Cryptosporidium
                      and Giardia in Water by Filtration/IMS/
                      FA,  1999, EPA-821-R-99-006.
                        (iv) Method 1622: Cryptosporidium in
                      Water by Filtration/IMS/FA, 1999, EPA-
                      821-R-99-001.
                       (2) Samples were collected no less
                      frequently than each calendar month on
                      a regular schedule, beginning no earlier
                      than January 1999.
                       (3) Samples were collected in equal
                      intervals of time over the entire
                      collection period (e.g., weekly,
                      monthly). Sample collection interval
                      may vary for the conditions specified in
                      § 141.703(c) and (d) if the system
                      provides documentation of the
                      condition.
  (4) Samples met the conditions for
sampling location specified in
§ 141.704. The system must report the
use of bank filtration, presedimentation,
and raw water off-stream storage during
sampling.
  (5) For each sample, the laboratory
analyzed at least 10 L of sample or at
least 2 mL of packed pellet or as much
volume as could be filtered by 2 filters
approved by EPA for the methods listed
in paragraph (b)(l) of this section, up  to
a packed pellet volume of 2 mL.
  (c) The system must submit a letter to
EPA concurrent with the submission of
previously collected data certifying that
the data meet the conditions in
paragraphs (c)(l) and (2) of this section.
  (1) The reported Cryptosporidium
analysis results include all results
generated by the system during the time
period beginning with the first reported
result and ending with the final
reported result. This applies to samples
that were collected from the sampling
location specified for source water
monitoring under this subpart, not
spiked, and analyzed using the
laboratory's routine process for the
analytical methods listed in paragraph
(a)(l) of this section.
  (2) The samples were representative
of a plant's source water(s) and the
source water(s) have not changed.
  (d) For each sample, the system must
report the data elements in
§141.707(e)(l).
  (e) The laboratory or laboratories that
generated the data must submit a letter
to EPA concurrent with the  submission
of previously collected data certifying
that the quality control criteria specified
in the methods listed in paragraph (b)(l)
of this section were met for each sample
batch associated  with the previously
collected data. Alternatively, the
laboratory may provide bench sheets
and sample examination report forms
for each field, matrix spike, IPR, OPR,
and method blank sample associated
with the previously collected data.
  (f) If a system has at least two years
of Cryptosporidium data collected
before [Date of Publication of Final Rule
in the Federal Register] and the system
intends to use these data to comply with
the initial source water monitoring
required under § 141.702(a) in lieu of
conducting new monitoring, the system
must submit to EPA, no later than [Date
2 Months After Date of Publication of
Final Rule in the Federal Register], the
previously collected data and the
supporting information specified in this
section. EPA will notify the system by
[Date 4 Months After Date of Publication
of Final Rule in the Federal Register] as
to whether the data are acceptable. If
EPA does not notify the system that the

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                                                                      47781
submitted data are acceptable, the
system must carry out initial source
water as specified in §§141.701 through
141.707 until EPA notifies the system
that it has at least two years of
acceptable data.
  (g) If a system has fewer than two
years of Cryptosporidium data collected
before [Date of Publication of Final Rule
in the Federal Register] and the system
intends to use these data to meet, in
part, the initial source water monitoring
required under § 141.702(a), the system
must submit to EPA, no later than [Date
8 Months After Date of Publication of
Final Rule in the Federal Register], the
previously collected data and the
supporting information specified in this
section. The system must carry out
initial source water monitoring
according to the requirements in
§§ 141.701 through 141.707 until EPA
notifies the system that it has at least
two years  of acceptable data.
  (h) If a system has two or more years
of previously collected data and the
system intends to use these data to
comply with the initial source water
monitoring required under § 141.702(a),
but the system also intends to carry out
additional initial source water
monitoring in order to base its
determination of average
Cryptosporidium concentration under
§ 141.709 or § 141.721 on more than two
years of monitoring data, the system
must submit to EPA, no later than [Date
8 Months After Date of Publication of
Final Rule in the Federal Register], the
previously collected data and the
supporting information specified in this
section. The system must carry out
initial source water monitoring
according to the requirements in
§ § 141.701 through 141.707 until EPA
notifies the system that it has at least
two years of acceptable data.

§ 141.709 Bin classification for filtered
systems.
  (a) Following completion of the initial
source water monitoring required under
§ 141.702(a), filtered systems  and
unfiltered systems that are required to
install filtration must calculate their
initial Cryptosporidium bin
concentration using the
Cryptosporidium results reported under
§ 141.702(a), along with any previously
collected data that satisfy the
requirements of § 141.708, and
following the procedures in paragraphs
(b)(l) through (3) of this section.
  (b)(l) For systems that collect a total
of at least 48 samples, the
Cryptosporidium bin concentration is
equal to the arithmetic mean of all
sample concentrations.
  (2) For systems that serve at least
10T000 people and collect a total of at
least 24 samples, but not more than 47
samples, the Cryptosporidium bin
concentration is equal to the highest
arithmetic mean of all sample
concentrations in any 12 consecutive
months during which Cryptosporidium
samples were collected.
  (3) For systems that serve fewer than
10,000 people and take at least 24
samples, the Cryptosporidium bin
concentration is equal to the arithmetic
mean of all sample concentrations.
  (c) Filtered systems and unfiltered
systems that are required to install
filtration must  determine their initial
bin classification from the following
table and using the Cryptosporidium bin
concentration calculated under
paragraph (a) of this section:
                                  BIN CLASSIFICATION TABLE FOR  FILTERED SYSTEMS
                  For systems that are:
                     With a Cryptosporidium bin concentration of.  . .1
                               The bin
                              classifica-
                               tion is
  *  * required to monitor for Cryptosporidium under §§141.701
  to 141.702.
  *  * serving fewer than 10,000 people and NOT  required to
  monitor for Cryptosporidium under §142.702(b).	
               Cryptosporidium < 0.075 oocyst/L
               0.075 oocysts/L  3.0 oocysts/L 	
               NA 	
                              Bin 1

                              Bin 2
                              Bin 3
                              Bin 4
                              Bint
   Based on calculations in paragraph (a) or (d) of this section, as applicable.
  (d) Following completion of the
second round of source water
monitoring required under § 141.702(d),
filtered systems and unfiltered systems
that are required to  install filtration
must recalculate their Cryptosporidium
bin concentration using the
Cryptosporidium results reported under
§ 141.702(d) and following the
procedures in paragraphs (b)(l) through
(3) of this section. Systems must then
determine their bin  classification a
second time using this Cryptosporidium
bin concentration and the table in
paragraph (c) of this section.
  (e) Any filtered system or unfiltered
system that is required to install
filtration that fails to complete the
monitoring requirements of § § 141.701
through 141.707 or choses not to
monitor pursuant to § 141.701(0 must
meet the treatment requirements for Bin
4 under § 141.720 by the date applicable
under § 141.70l(e).

Disinfection Profiling and
Benchmarking Requirements

§141.710  [Reserved].

§ 141.711  Determination of systems
required to profile.
  (a) Subpart H of this part community
and nontransient noncommunity water
systems serving at least 10,000 people
that do not have at least 5.5 log of
Cryptosporidium treatment, equivalent
to compliance with Bin 4 in § 141.720,
in place prior to the date when the
system is required to begin profiling in
§ 141.712 are required to develop
Giardia lamblia and virus disinfection
profiles.
  (b) Subpart H community and
nontransient noncommunity water
systems serving fewer than 10,000
people that do not have at least 5.5 log
of Cryptosporidium treatment,
equivalent to compliance with Bin 4 in
§ 141.720, in place  prior to the date
when the system is required to begin
profiling in § 141.712 are required to
develop Giardia lamblia and virus
disinfection profiles if any of the criteria
in paragraphs (b)(l) through (3) of this
section apply.
  (1) TTHM levels  in the distribution
system are at least 0.064 mg/L as a
locational running  annual average
(LRAA) at any monitoring site. Systems
must base their TTHM LRAA
calculation on data collected for
compliance under subpart L of this part
after [Date of Publication of Final Rule
in the Federal Register], or as
determined by the State.  .

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   (2) HAAS levels in the distribution
 system are at least 0.048 mg/L as an
 LRAA at any monitoring site. Systems
 must base their HAAS LRAA calculation
 on data collected for compliance under
 subpart L of this part after [Date of
                      Publication of Final Rule in the Federal
                      Register], or as determined by the State.
                        (3) The system is required to monitor
                      for Cryptosporidium under § 141.701(c).
                        (c) In lieu of developing a new profile,
                      systems may use the profile(s)
                      developed under § 141.172 or
                      § § 141.530 through 141.536 if the
 profile(s) meets the requirements of
 §141.713(c).

 § 141.712 Schedule for disinfection
 profiling requirements.
   (a) Systems must comply with the
 following schedule in the table in this
 paragraph:
                             SCHEDULE OF REQUIRED DISINFECTION PROFILING MILESTONES 1
Activity
1. Report TTHM and HAAS LRAA
results to State.
2. Begin disinfection profiling1'2 ..
3. Complete disinfection profiling
based on at least one year of
data.
Date
Subpart H systems serving at
least 10,000 people
NA 	
[Date 24 Months After Date of
Publication of Final Rule in the
Federal Register].
[Date 36 Months After Date of
Publication of Final Rule in the
Federal Register].
Subpart H systems serving fewer than 10,000 people
Required to monitor for
Cryptosporidium
NA 	
[Date 54 Months After Date of Pub-
lication of Final Rule in the Fed-
eral Register].
[Date 66 Months After Date of Pub-
lication of Final Rule in the Fed-
eral Register].
Not required to monitor for
Cryptosporidium
[Date 42 Months After Date of Pub-
lication of Final Rule in the Fed-
eral Register].
[Date 42 Months After Date of Pub-
lication of Final Rule in the Fed-
eral Register] if required3.
[Date 54 Months After Date of Pub-
lication of Final Rule in the Fed-
eral Register] if required3.
   1 Systems with at least 5.5 log of Cryptosporidium treatment in place are not required to do disinfection profiling.
   2Systems may use existing operational data and profiles as described in § 141.713(c).
   3Systems serving  fewer than  10,000 people  are not required to conduct disinfection  profiling if they are not required to monitor for
 Cryptosporidium and if their TTHM and HAAS LRAAs do not exceed the levels specified in §141.711(b).
   (b) [Reserved]

 §141.713  Developing a profile.
   (a) Systems required to develop
 disinfection profiles under § 141,711
 must follow the requirements of this
 section. Systems must monitor at least
 weekly for a period of 32 consecutive
 months to determeine the total log
 inactivation for Giardia lamblia and
 viruses. Systems must determine log
 inactivation for Giardia lamblia through
 the entire plant, based on CTVs values
 in Tables 1.1 through 1.6, 2.1 and 3.1 of
 §141.74(b) as applicable. Systems must
 determine log inactivation for viruses
 through the entire treatment plant based
 on a protocol approved by the State.
   (b) Systems with a single point of
 disinfectant application prior to the
 entrance to the distribution system must
 conduct the monitoring in paragraphs
 (b)(l) through (4) of this section.
 Systems with more than one point of
 disinfectant application must conduct
 the monitoring in paragraphs (b)(l)
 through (4) of this section for each
 disinfection segment. Systems must
 monitor the parameters necessary to
 determine the total inactivation ratio,
 using analytical methods in § 141.74(a).
  (1) For systems using a disinfectant
 other than UV, the temperature of the
 disinfected water must be measured at
 each residual disinfectant concentration
sampling point during peak hourly flow
or at an alternative location approved by
the State.
                        (2) For systems using chlorine, the pH
                      of the disinfected water must be
                      measured at each chlorine residual
                      disinfectant concentration sampling
                      point during peak hourly flow or at an
                      alternative location approved by the
                      State.
                        (3) The disinfectant contact time(s) (T)
                      must be determined during peak hourly
                      flow.
                        {4J 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.
                        (c) In lieu of conducting new
                      monitoring under paragraph (b) of this
                      section, systems may elect to meet the
                      requirements of paragrphs (c}(l) or (2) of
                      this section.
                        (1) Systems that have at least 12
                      consecutive months of existing
                      operational data that are substantially
                      equivalent to data collected under the
                      provisions of paragraph (b) of this
                      section may use these data to develop
                      disinfection profiles as specified in this
                      section if the system has neither made
                      a significant change to its treatment
                      practice nor changed sources since the
                      data were collected. Systems using
                      existing operational data may develop
                      disinfection profiles for a period of up
                     to three years.
                       (2) Systems may use disinfection
                     profile(s) developed under § 141.172 or
                     §§ 141.530 through 141.536 in lieu of
                     developing a new profile if the system
 has neither made a significant change to
 its treatment practice nor changed
 sources since the profile was developed.
 Systems that have not developed a virus
 profile under § 141.172 or §§ 141.530
 through  141.536 must develop a virus
 profile using the same monitoring data
 on which the Giardia lamblia profile is
 based.
   (d) Systems must calculate the total
 inactivation ratio for Giardia lamblia as
 specified in paragraphs (d}(l) through
 (3) of this section.
   (1) Systems using only one point of
 disinfectant application may determine
 the total  inactivation ratio for the
 disinfection segment based on either of
 the methods in paragraph (d)(l)[i) or (ii)
 of this section.
   (i) Determine one inactivation ratio
 (CTcalc/CTgg.g) before or at the first
 customer during peak hourly flow.
   (ii) Determine successive CTcalc/
 CT99.9 values, representing sequential
 inactivation ratios, between the point of
 disinfectant application and a point
 before or at the  first customer during
 peak hourly flow. The system must
 calculate the total inactivation ratio by
 determining (CTcalc/CT^.g) for each
 sequence and then adding the (CTcalc/
CT99.9) values together to determine (2
 (CTcaIc/CT99.9)).
  (2) Systems using more than one point
of disinfectant application before the
first customer must determine the CT
value of each disinfection segment
immediately prior to the next point of

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                  Federal Register/Vol. 68, No. 154/Monday, August  11,  2003/Proposed Rules
                                                                       47783
 disinfectant application, or for the final
 segment, before or at the first customer,
 during peak hourly flow. The (CTcalc/
 0X99.9) value of each segment and
 (S(CTcalc/CT99.9)) must be calculated
 using the method in paragraph (d)(l)(ii)
 of this section.
  (3) The system must determine the
 total logs of inactivation by multiplying
 the value calculated in paragraph (d}(l)
 or (d)(2) of this section by 3.0.
  (4) Systems must calculate the log of
 inactivation for viruses using a protocol
 approved by the State.
  (5) Systems 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.

 § 141.714  Requirements when making a
 significant change in disinfection practice.
  (a) A system that is required to
 develop a disinfection profile under the
 provisions of this subpart and that plans
 to make a significant change to its
 disinfection practice must calculate a
 disinfection benchmark and must notify
 the State prior to making such a change.
 Significant changes to disinfection
 practice are defined in paragraphs (a)(l)
 through (4) of this section.
   (1} Changes to the point of
 disinfection;
   (2) Changes to the disinfectant(s) used
 in the treatment plant;
   (3) Changes to the disinfection
 process; and
   (4) Any other modification identified
 by the State.
   (5) Systems must use the procedures
 specified in paragraphs (a)(5)(i) and (ii)
 of this section to calculate a disinfection
 benchmark.
   (i) For the year of profiling data
 collected and calculated under
 §141.713, or for each year with profiles
 covering more than one year, systems
 must determine the lowest mean
 monthly level of both Giardia lamblia
 and virus inactivation. Systems must
 determine the mean Giardia lamblia and
 virus inactivation for each calendar
 month for each year of profiling data by
 dividing the sum of daily or weekly
 Giardia lamblia and virus log
 inactivation by the number of values
 calculated for that month.
   (ii) The disinfection benchmark is the
 lowest monthly mean value (for systems
 with one year of profiling data) or the
 mean of the lowest monthly mean
 values (for systems with more than one
 year of profiling data) of Giardia lamblia
 and virus log inactivation in each year
 of profiling data.
  (6) Systems must submit the
 information in paragraphs (a)(6)(i)
 through (iii) of this section when
 notifying the State that they are
 planning to make a significant change in
 disinfection practice.
  (i) A description of the proposed
 change.
  (ii) The disinfection profile and
 benchmark for Giardia lamblia and
 viruses determined under §§ 141.713
 and 141.714.
  (iii) An analysis of how the proposed
 change will affect the current level of
 disinfection.

 Treatment Technique Requirements

 §141.720  Treatment requirements for
 filtered systems.
  (a) Filtered systems or systems that
 are unfiltered  and required to install
 filtration must provide the level of
 treatment for Cryptosporidium specified
 in this paragraph, based on their bin
 classification as determined under
 § 141.709 and their existing treatment:
tf the system bin classifica-
tion is ...
(1) Bin 1 	
(2) Bin 2
(3) Bin 3
(4) Bin 4 	
And the system uses the following filtration treatment in full compliance with subpart H, P, and T of this section
(as applicable), then the additional treatment requirements are ...
Conventional filtration
treatment (including soft-
ening)
No additional treatment 	

2.5 log treatment 	
Direct filtration
No additional treatment 	

3 log treatment 	
Slow sand or diatoma-
ceous earth filtration
No additional treatment 	
1 log treatment 	
2 log treatment 	
2.5 log treatment 	
Alternative filtration tech-
nologies
No additional treatment
(1)
(2)
(3)
  1 As determined by the State such that the total Cryptosporidium removal and inactivation is at least 4.0 log.
  2 As determined by the State such that the total Cryptosporidium removal and inactivation is at least 5.0 tog.
  3 As determined by the State such that the total Cryptosporidium removal and inactivation is at least 5.5 log.
  (b) Filtered systems must use one, or
a combination, of the management and
treatment options listed in § 141.722,
termed the microbial toolbox, to meet
the additional Cryptosporidium
treatment requirements identified for
each bin in paragraph (a) of this section.
  (c) Systems classified in Bin 3 and Bin
4 must achieve at least 1 log of the
additional treatment required under
paragraph (a) of this section using either
one or a combination of the following:
bag filters, bank filtration, cartridge
filters, chlorine dioxide, membranes,
ozone, and/or UV as specified in
§141.722.

§141.721   Treatment requirements for
unfiltered systems.
  (a) Following completion of the initial
source water monitoring required under
§ 141.702(a), unfiltered systems that
meet all filtration avoidance criteria of
§ 141.71 must calculate the arithmetic
mean of all Cryptosporidium sample
concentrations reported under
§ 141.702(a), along with any previously
collected data that satisfy the
requirements of § 141.708, and must
meet the treatment requirements in
paragraph (b)(l) or (2) of this section, as
applicable, based on this concentration.
  (b)(l) Unfiltered systems with a mean
Cryptosporidium concentration of 0.01
oocysts/L or less must provide at least
2 log Cryptosporidium inactivation.
  (2) Unfiltered systems with a mean
Cryptosporidium concentration of
greater than 0.01 oocysts/L must
provide at least 3 log Cryptosporidium
inactivation.
  (c) Unfiltered systems must use
chlorine dioxide, ozone, or UV as
specified in § 141.722 to meet the
Cryptosporidium inactivation
requirements of this section.
  (1) Unfiltered systems that use
chlorine dioxide or ozone and fail to
achieve the Cryptosporidium log
inactivation required in paragraph (b){l)
or (2) of this section, as applicable, on
more than one day in the calendar
month are in violation of the treatment
technique requirement.
  (2) Unfiltered systems that use UV
light and fail to achieve the
Cryptosporidium log inactivation
required in paragraph (b)(l) or (2) of this
section, as applicable, in at least 95% of
the water that is delivered to the public
during each calendar month, based on
monitoring required under paragraph
§ 141.729(d)(4), are in violation of the
treatment technique requirement.
  (d) Unfiltered systems must meet the
combined Cryptosporidium,  Giardia

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Federal Register/Vol. 68, No. 154/Monday, August  11, 2003/Proposed  Rules
 lamblia, and virus inactivation
 requirements of this section and
 § 141.72(a) using a minimum of two
 disinfectants, and each disinfectant
 must separately achieve the total
 inactivation required for either
 Cryptosporidium, Giardia lamblia, or
 viruses.
   (e) Following completion of the
 second round of source water
 monitoring required under § 141.702(d),
 unfiltered systems that meet all
 filtration avoidance criteria of § 141.71
 must calculate the arithmetic mean of
                        all Cryptosporidium sample
                        concentrations reported under
                        § 141.702(d) and must meet the
                        treatment requirements in paragraph
                        (b)(l) or (2) of this section, as
                        applicable, based on this concentration.
                          (f) Any unfiltered system that meets
                        all filtration avoidance criteria of
                        § 141.71 and fails to complete the
                        monitoring requirements of § § 141.701
                        through 141.707 or choses not to
                        monitor pursuant to § 141.701(g) must
                        meet the treatment requirements of
 paragraph (b)(2) of this section by the
 date applicable under § 141.701(e).

 §141.722  Microbial toolbox options for
 meeting Cryptosporidium treatment
 requirements.

   (a) To meet the additional
 Cryptosporidium treatment
 requirements of §§141.720 and
 141.721, systems must use microbial
 toolbox options listed in this follwing
 table that are designed, implemented,
 and operated in accordance with the
 requirements of this subpart.
                                  MICROBIAL TOOLBOX: OPTIONS, CREDITS AND CRITERIA
          Toolbox option
                         Proposed Cryptosporidium treatment credit with design and implementation criteria
                                                 Source Toolbox Components
 (1) Watershed control program	

 (2) Alternative source/intake  man-
   agement.
              0.5 log credit for State approved program comprising EPA specified elements.  Specific criteria  are in
                §141.725(3).
              Bin classification based on concurrent Cryptosporidium monitoring. No presumptive credit. Specific criteria
                are in §141J25(b).
                                              Pre-Fi It ration Toolbox Components
 (3) Presed[mentation basin with co-
   agulation.
 (4) Two-stage lime softening  	
 (5) Bank filtration	
              0.5 log credit for new basins with continuous operation and coagulant addition. No presumptive credit for
                basins existing when monitoring is required under §141.702. Specific criteria are in §141.726(a).
              0.5 log credit for two-stage softening with coagulant addition. Specific criteria are in § 141.726(b).
              0.5 log credit for 25 foot setback; 1.0 log credit for 50 foot setback. No presumptive credit for bank filtration
                existing when monitoring is required under §141.704(d)(1). Specific criteria are in §141.726(c).
                                         Treatment Performance Toolbox Components
 (6) Combined filter performance 	

 (7) Individual filter performance 	

 (8) Demonstration of performance ..
              0.5 log credit for combined filter effluent turbidity £ 0.15 NTU in 95% of samples each month. Specific cri-
                teria are in §141.727{a).
              1.0 log credit for individual filter effluent turbidity £0.1  NTU in 95% of daily maximum samples each month
                and no filter >0.3 NTU in two consecutive measurements. Specific criteria are in §141.727(b).
              Credit based on a demonstration to the State through State approved  protocol. Specific criteria are in
                §141.727(c).
                                           Additional Filtration Toolbox Components
 (9) Bag filters 	,

 (10) Cartridge filters 	

 (11) Membrane filtration	

 (12) Second stage filtration

 (13) Slow sand filers  	
              1 log credit with demonstration of at least 2 log removal efficiency in challenge test; Specific criteria are in
               §141.728(a).
              2 log credit with demonstration of at least 3 log removal efficiency in challenge test; Specific criteria are in
               §141.728(a).
              Log removal credit up to the lower value of the removal efficiency demonstrated during the challenge test
               or verified by the direct integrity test applied to the system. Specific criteria are in § 141.728(b).
              0.5 log credit for a second separate filtration stage in treatment process following coagulation. Specific cri-
               teria are in §141.728(c).
              2.5 log credit for second separate filtration process.  Specific criteria are in § 141.728(d).
                                              Inactivation Toolbox Components
(14) Chlorine dioxide
(15) Ozone 	
(16) UV	
             Log credit based on demonstration of compliance with CT table. Specific criteria are in § 141.729(b).
             Log credit based on demonstration of compliance with CT table. Specific criteria are in § 141.729(c).
             Log credit based on demonstration of compliance with UV dose table. Specific criteria are in § 141.729(d).
  (b) Failure to comply with the
requirements of this section in
accordance with the schedule in
§ 141.701(e) is a treatment technique
violation.

§141.723  [Reserved]

§ 141.724  Requirements for uncovered
finished water storage facilities.
  (a) Systems using uncovered finished
water storage facilities must comply
                       with the conditions of one of the
                       paragraphs (a)(l) through (3) of this
                       section for each facility no later than the
                       date specified in §141.701(h).
                         (1) Systems must cover any uncovered
                       finished water storage facility.
                         (2) Systems must treat the discharge
                       from the uncovered finished  water
                       storage facility to the distribution
                       system to achieve at least 4 log virus
inactivation using a protocol approved
by the State.
  (3) Systems must have a State-
approved risk mitigation plan for the
uncovered finished water storage
facility that addresses physical access
and site security, surface water runoff,
animal and bird waste, and ongoing
water quality assessment, and includes
a schedule for plan implementation.
Systems must implement the risk

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                  Federal Register/Vol. 68, No.  154/Monday, August  11,  2003/Proposed Rules
                                                                      47785
 mitigation plan approved by the State.
 Systems must submit risk mitigation
 plans to the State for approval no later
 than [Date 24 Months After Date of
 Publication of Final Rule in the Federal
 Register].
   (b) Failure to comply with the
 requirements of this section in
 accordance with  the schedule in
 § 141.701(h) is a treatment technique
 violation.
 Requirements for Microbial Toolbox
 Components

 § 141.725  Source toolbox components.
   (a) Watershed control program.
   (1) Systems that intend to qualify for
 a 0.5 log credit for Cryptosporidium
 removal for a watershed control
 program must notify the State no later
 than one year after completing the
 source water monitoring requirements
 of § 141.702(b) that they intend to
 develop a watershed control program
 and to submit it for State approval.
  (2) Systems must submit a proposed
 initial watershed  control plan and a
 request for plan approval and 0.5 log
 Cryptosporidium removal credit to the
 State no later than two years after
 completing the source water monitoring
 requirements of § 141.702(b). Based on a
 review of the initial proposed watershed
 control plan, the State may approve,
 reject, or conditionally approve the
 plan. If the plan is approved, or if the
 system agrees to implement the State's
 conditions for approval, the system is
 awarded a 0.5 log credit for
 Cryptosporidium  removal to apply
 against additional treatment
 requirements.
  (3) The application to the State for
 initial program approval must include
 elements in paragraphs (a)(3)(i) through
 (iii) of this section.
  (i) An analysis of the vulnerability of
 each source to Cryptosporidium.  The
 vulnerability analysis must address the
 watershed upstream of the drinking
 water intake and must include the
 following: a characterization of the
 watershed hydrology, identification of
 an "area of influence" (the area to be
 considered in future watershed surveys)
 outside of which there is no significant
 probability of Cryptosporidium or fecal
 contamination affecting the drinking
 water intake, identification of both
 potential and actual sources of
 Cryptosporidium contamination, the
 relative impact of the sources of
 Cryptosporidium contamination on the
 system's source water quality, and an
 estimate of the seasonal variability of
such contamination.
  (ii) An analysis  of control measures
that could mitigate the sources of
 Cryptosporidium contamination
 identified during the vulnerability
 analysis. The analysis of control
 measures must address their relative
 effectiveness in reducing
 Cryptosporidium loading to the source
 water and their feasability and
 sustainability.
   (iii) A plan that establishes goals and
 defines and prioritizes specific actions
 to reduce source water Cryptosporidium
 levels. The plan must explain how the
 actions are expected to contribute to
 specific goals, identify watershed
 partners and their role(s), identify
 resource requirements and
 commitments, and include a schedule
 for plan implementation.
   (4) Initial State approval of a
 watershed control plan and its
 associated 0.5 log Cryptosporidium
 removal credit is  valid until the system
 completes the second round of
 Cryptosporidium monitoring required
 under § 141.702(d). Systems must
 complete  the actions in paragraphs
 (a)(4)(i) through (iv) of this section to
 maintain State approval and the 0.5 log
 credit.
   (i) Submit an annual watershed
 control program status report to the
 State by a date determined by the State.
 The annual  watershed control program
 status report must describe the system's
 implementation of the approved plan
 and assess the adequacy of the plan to
 meet  its goals. It must explain how the
 system is addressing any shortcomings
 in plan implementation, including those
 previously identified by the State or as
 the result  of the watershed survey
 conducted under paragraph (a)(4)(ii) of
 this section. If it becomes necessary
 during implementation to make
 substantial changes in its approved
 watershed control program, the  system
 must  notify the State and provide a
 rationale prior to making any such
 changes. If any change is likely to
 reduce the level of source water
 protection, the system must also include
 the actions it will take to mitigate the
 effects in its notification.
  (ii)  Conduct an  annual watershed
 sanitary survey and submit the survey
 report to the State for approval. The
 survey must be conducted according to
 State guidelines and by persons
 approved by the State to conduct
 watershed surveys. The survey must
 encompass the area of the watershed
that was identified in the State-
 approved watershed control plan as the
area of influence and, at a minimum,
assess the  priority activities identified
in the plan and identify any significant
new sources of Cryptosporidium.
  {iii) Submit to the State a request for
review and re-approval of the watershed
 control program and for a continuation
 of the 0.5 log removal credit for a
 subsequent approval period. The
 request must be provided to the State at
 least six months before the current
 approval period expires or by a date
 previously determined by the State. The
 request must include a summary of
 activities and issues identified during
 the previous approval period and a
 revised plan that addresses activities for
 the next approval period, including any
 new actual or potential sources of
 Cryptosporidium contamination and
 details of any proposed or expected
 changes from the existing State-
 approved program. The plan must
 address goals, prioritize specific actions
 to reduce source water
 Cryptosporidium, explain how actions
 are expected to contribute to achieving
 goals, identify partners and their role(s),
 resource requirements and
 commitments, and the schedule for plan
 implementation.
  (iv) The annual status reports,
 watershed control plan and annual
 watershed sanitary surveys must be
 made available to the public upon
 request. These documents must be in a
 plain language style and include criteria
 by which to evaluate the success of the
 program in achieving plan goals. If
 approved by the State, the system may
 withhold portions of the annual status
 report, watershed control plan, and
 watershed sanitary survey based on
 security considerations.
  (5) Unfiltered systems may not claim
 credit for Cryptosporidium removal
 under this option.
  (b) Alternative source. (1) If approved
 by the State, a system may be classified
 in a bin under § 141.709 based on
 monitoring that is conducted
 concurrently with source water
 monitoring under § 141.701 and reflects
 a different intake location (either in the
 same source or for an alternate source)
 or a different procedure for managing
 the timing or level of withdrawal from
 the source.
  (2) Sampling and analysis of
 Cryptosporidium in the concurrent
 round of monitoring must conform to
 the requirements for monitoring
 conducted under this subpart to
 determine bin classification. Systems
 must submit the results of all
 monitoring to the State, along with
 supporting information documenting
the operating conditions under which
the samples were collected.
  (3) If me State classifies the system in
a bin based on monitoring that reflects
a different intake location or a different
procedure for managing the timing or
level of withdrawal from the source, the
system must relocate the intake or use

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 the intake management strategy, as
 applicable, no later than the applicable
 date for treatment technique
 implementation in § 141.701. The State
 may specify reporting requirements to
 verify operational practices.

 § 141.726  Pre-filtration treatment toolbox
 components.
   (a) Presedimentation. New
 presedimentation basins that meet the
 criteria in paragraphs (a)(l) through (4)
 of this section are eligible for 0.5 log
 Cryptosporidium removal credit.
 Systems with presedimentation basins
 existing when the system is required to
 conduct monitoring under § 141.702(a)
 may not claim this credit and, during
 periods when the basins are in use,
 must collect samples after the basins for
 the purpose of determining bin
 classification under §141.709.
   (1) The presedimentation basin must
 be in continuous operation and must
 treat all of the flow reaching the
 treatment plant.
   (2) The system must continuously add
 a coagulant to the presedimentation
 basin.
   (3) Presedimentation basin influent
 and effluent turbidity must be measured
 at least once per day or more frequently
 as determined by the State.
   (4) The system must demonstrate on
 a monthly basis at least 0.5 log
 reduction of influent turbidity through
 the presedimentation process in at least
 11  of the 12 previous consecutive
 months.
  (i) The monthly demonstration of
 turbidity reduction must be based on
 the mean of daily turbidity readings
 collected under paragraph (a)(3) of this
 section and calculated as follows:
 logio(monthly mean of daily influent
 turbidity)—logiolmonthly mean of daily
 effluent turbidity).
  (ii) If the presedimentation process
 has not been in operation for 12 months,
 the system must verify on a monthly
 basis at least 0.5 log reduction of
 influent turbidity through the
 presedimentation process, calculated as
 specified in this paragraph, for at least
 all but any one of the months of
 operation.
  (b) Two-stage lime softening. Systems
 that operate a two-stage lime softening
 plant are eligible for an additional 0.5
 log Cryptosporidium removal credit if
 there is a second clarification step
between the primary clarifier and
 filter{s) that  is  operated continuously.
Both clarifiers must treat all of the plant
flow and a coagulant, which may be
excess  lime or magnesium hydroxide,
must be present in both clarifiers.
  (c) Bank filtration. New bank filtration
that serves as pretreatment to a filtration
                      plant is eligible for either a 0.5 or a 1.0
                      log Cryptosporidium removal credit
                      towards the requirements of this subpart
                      if it meets the design criteria specified
                      in paragraphs (c)(l) through (c)(5) of this
                      section and the monitoring and
                      reporting criteria of paragraph (c)(6) of
                      this section. Wells with a ground water
                      flow path of at least 25 feet are eligible
                      for 0.5 log removal credit; wells with a
                      ground water flow path of at least 50
                      feet are eligible for 1.0 log removal
                      credit. The ground water flow path must
                      be determined as specified in paragraph
                      (c)(5) of this section.
                        (1) Only horizontal and vertical wells
                      are eligible for bank filtration removal
                      credit.
                        (2) Only wells in granular aquifers are
                      eligible for bank filtration removal
                      credit. Granular aquifers are those
                      comprised of sand, clay, silt, rock
                      fragments, pebbles or larger particles,
                      and minor cement. The  aquifer material
                      must be unconsolidated as
                      demonstrated by the aquifer
                      characterization specified in paragraph
                      (c)(3)  of this section, unless the system
                      meets the conditions of paragraph (c)(4)
                      of this section. Wells located in
                      consolidated aquifers, fractured
                      bedrock, karst limestone, and gravel
                      aquifers are not eligible  for bank
                      filtration removal credit.
                        (3) A system seeking removal credit
                      for bank filtration must characterize the
                      aquifer at the well site to determine
                      aquifer properties. The aquifer
                      characterization must include the
                      collection of relatively undisturbed
                      continuous core samples from the
                      surface to a depth at least equal to the
                      bottom of the well screen. The
                      recovered core  length must be at least 90
                      percent of the total projected depth to
                      the well screen, and each sampled
                      interval must be a composite of no more
                      than 2 feet in length. A well is eligible
                      for removal credit if at least 90 percent
                      of the composited intervals from the
                      aquifer contain at least 10 percent fine
                      grained material, which  is defined as
                      grains less than 1.0 mm  in diameter.
                        (4) Wells constructed in partially
                      consolidated granular aquifers are
                      eligible for removal credit if approved
                      by the State based on a demonstraton by
                      the system that the aquifer provides
                      sufficient natural filtration. The
                      demonstration must include a
                      characterization of the extent of
                      cementation and fractures present in the
                      aquifer.
                        (5) For vertical wells, the ground
                      water flow path is the measured
                      horizontal distance from the edge of the
                      surface water body to the well. This
                      horzontal distance to the surface water
                     must be determined using the floodway
 boundary or 100 year flood elevation
 boundary as delineated on Federal
 Emergency Management Agency
 (FEMA) Flood Insurance Rate maps. If
 the floodway boundary or 100 year
 flood elevation boundary is not
 delineated, systems must determine the
 floodway or 100 year flood elevation
 boundary using methods substantially
 equilvalent to those used in preparing
 FEMA Flood Insurance Rate maps. For
 horizontal wells, the ground water flow
 path is the closest measured distance
 from the bed of the river under normal
 flow conditions to the closest horizontal
 well lateral intake.
   (6) Turbidity measurements must be
 performed on representative samples
 from each wellhead at least every four
 hours that the bank filtration is in
 operation. Continuous  turbidity
 monitoring at each wellhead  may be
 used if the system validates the
 continuous measurement for accuracy
 on a regular basis using a protocol
 approved by the State.  If the monthly
 average of daily maximum turbidity
 values at any well exceeds 1 NTU, the
 system must report this finding to the
 State within 30 days. In addition, within
 30 days of the exceedance, the system
 must conduct an assessment to
 determine the cause of the high
 turbidity levels and submit that
 assessment to the State for a
 determination of whether  any
 previously allowed credit  is still
 appropriate.
   (7) Systems with bank filtration that
 serves as pretreatment to a filtration
 plant and that exists when the system is
 required to conduct monitoring under
 § 141,702(a) may not claim this credit.
 During periods when the bank filtration
 is in use, systems must collect samples
 after the bank filtration for the purpose
 of determining bin classification under
 §141.709.

 §141.727  Treatment performance toolbox
 components.
  (a) Combined filter performance.
 Systems using conventional filtration
 treatment or direct filtration treatment
 may claim an additional 0.5 log
 Cryptosporidium removal  credit for any
 month at each plant that demonstrates
 that combined filter effluent (CFE)
 turbidity levels are less than or equal to
 0.15 NTU in at least 95 percent of the
 measurements taken each month, based
 on sample measurements collected
 under §§ 141.73,141.173(a) and
 141.551. Systems may not  claim credit
under this paragraph and paragraph (b)
 in the same month.
  (b) Individual filter performance.
 Systems using conventional filtration
treatment or direct filtration treatment

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                                                                       47787
 may claim an additional 1.0 log
 Cryptosporidiutn removal credit for any
 month at each plant that meets both the
 individual filter effluent (IFE) turbidity
 requirements of paragraphs (b)(l) and
 (2) of this section, based on monitoring
 conducted under § § 141.174(a) and
 141.560.
   (1} IFE turbidity must be less than 0.1
 MTU in at least 95% of the maximum
 daily values recorded at each filter in
 each month, excluding the 15 minute
 period following return to service from
 a filter backwash.
   (2) No individual filter may have a
 measured turbidity greater than 0.3 NTU
 in two consecutive measurements taken
 15 minutes apart.
   (c)(l) Demonstration of performance.
 Systems may demonstrate to the State,
 through the use of State-approved
 protocols, that a plant, or unit process
 of a plant, achieves a mean
 Cryptosporidium removal efficiency
 greater than any presumptive credit
 specified under § 141.720 or § § 141.725
 through 141.728. Systems are eligible
 for an increased  Cryptosporidium
 removal credit if the State determines
 that the plant or process can reliably
 achieve such a removal efficiency on a
 continuing basis and the State provides
 written notification of its determination
 to the system. States may establish
 ongoing monitoring and/or performance
 requirements the State determines  are
 necessary to demonstrate the greater
 credit and may require the system to
 report operational data on a monthly
 basis to verify that conditions under
 which the demonstration of
 performance was awarded are
 maintained during routine operations. If
 the State determines that a plant, or unit
 process of a plant, achieves an average
 Cryptosporidium removal efficiency less
 than any presumptive credit specified
 under § 141.720 or § § 141.725  through
 141.728, the State may assign the lower
 credit to the plant or unit process.
   (2) Systems may not claim
 presumptive credit for any toolbox box
 component in §§141.726,141.727(a)
 and (b), or 141,728 if that component is
 also included in the demonstration of
 performance credit.

 §141.728  Additional filtration toolbox
 components.
   (a) Bag and cartridge filters. Systems
 are eligible for a 1 log Cryptosporidium
removal credit for bag filters and a 2 log
 Cryptosporidium removal credit for
 cartridge filters by meeting the  criteria
in paragraphs (a)(l) through (a)(10) of
this section. The request to the  State for
this credit must include the results of
challenge testing that meets the
 requirements of paragraphs (a)(2)
 through (a)(9) of this section.
   (1) To receive a 1 log Cryptosporidium
 removal credit for a bag filter, the filter
 must demonstrate a removal efficiency
 of 2 log or greater for Cryptosporidium.
 To receive a 2 log Cryptosporidium
 removal credit for a cartridge filter, the
 filter must demonstrate a removal
 efficiency of 3 log or greater for
 Cryptosporidium. Removal efficiency
 must be demonstrated through
 challenge testing conducted according
 to the criteria in paragraphs (a)(2)
 through (a)(9) of this section. The State
 may accept data from challenge testing
 conducted prior to [Date of Publication
 of Final Rule in the Federal Register] in
 lieu of additional testing if the prior
 testing was consistent with the criteria
 specified in paragraphs (a)(2) through
 (a)(9) of this section.
   (2) Challenge testing must be
 performed on full-scale bag or cartridge
 filters that are identical in material and
 construction to the filters proposed for
 use in full-scale treatment facilities for
 removal of Cryptosporidium.
   (3) Challenge testing must be
 conducted using Cryptosporidium
 oocysts or a surrogate that is removed
 no more efficiently than
 Cryptosporidium oocysts. The organism
 or surrogate used during challenge
 testing is referred to as the challenge
 particulate. The concentration of the
 challenge particulate must be
 determined using a method capable of
 discreetly quantifying the specific
 organism or surrogate used in the test;
 gross measurements such  as turbidity
 may not be used.
   (4) The maximum feed water
 concentration that can be used during a
 challenge test must be based on the
 detection limit of the challenge
 particulate in the filtrate (i.e., filtrate
 detection limit) and must be calculated
 using the equation in either paragraph
 (a)(4)(i) or (a)(4)(ii) of this  section as
 applicable.
   (i) For cartridge filters: Maximum
 Feed Concentration = 3.16xlO4 x
 (Filtrate Detection Limit).
   (ii) For bag filters: Maximum Feed
 Concentration = 3.16xl03 x (Filtrate
 Detection Limit).
   (5) Challenge testing must be
 conducted at the maximum design flow
 rate for the filter as specified by the
 manufacturer.
   (6) Each filter evaluated  must be
 tested for a duration sufficient to reach
 100 percent of the terminal pressure
drop, which establishes the maximum
pressure drop under which the filter
may be used to comply with the
requirements of this subpart.
   (7) Each filter evaluated must be
 challenged with the challenge
 particulate during three periods over the
 filtration cycle: within two hours of
 start-up after a new bag or cartridge
 filter has been installed; when the
 pressure drop is between  45 and 55
 percent of the terminal pressure drop;
 and at the end of the run after the
 pressure drop has reached 100 percent
 of the terminal pressure drop.
   (8) Removal efficiency of a bag or
 cartridge filter must be determined from
 the results of the challenge test and
 expressed in terms  of log removal values
 using the following equation:
 LRV = LOG,o(Cf)-LOG10(Cp)
 where LRV = log removal value
 demonstrated during challenge testing;
 Cf = the feed concentration used during
 the challenge test; and Cp  = the filtrate
 concentration observed during the
 challenge test. In applying this equation,
 the same units must be used for the feed
 and filtrate concentrations. If the
 challenge participate is  not detected in
 the filtrate, then the term Cp must be set
 equal to the detection limit. An LRV
 must be calculated  for each filter
 evaluated during the testing.
   (9) If fewer than 20 filters are tested,
 the removal efficiency for the filtration
 device must be set equal to the lowest
 of the representative LRVs among the
 filters tested. If 20 or more filters are
 tested, then removal efficiency of the
 filtration device must be set equal to the
 10th percentile of the representative
 LRVs among the various filters tested.
 The percentile is  defined by (i/(n+l))
 where i is the rank of n individual data
 points ordered lowest to highest. If
 necessary, the system may calculate the
 10th percentile using linear
 interpolation.
   (10) If a previously tested bag or
 cartidge filter is modified in a manner
 that could change the removal efficiency
 of the filter, addition challenge testing
 to demonstrate the removal efficiency of
 the modified filter must be conducted
 and submitted to the State.
   (b) Membrane filtration. (1) Systems
 using a membrane filtration process,
 including a membrane cartridge filter
 that meets the definition of membrane
 filtration and the integrity testing
 requirements of this subpart, are eligible
 for a Cryptosporidium removal credit
 equal to the lower value of paragraph
 (b)(l)(i)  or (b)(l) (ii)  of this section:
   (i) The removal efficiency
 demonstrated during challenge testing
 conducted under the conditions in
paragraph (b)(2) of this section.
  (ii) The maximum removal efficiency
that can be verified through direct
integrity testing used with the

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membrane filtration process under the
conditions in paragraph (b)(3) of this
section.
  (2) Challenge Testing. The membrane
used by the system must undergo
challenge testing to evaluate removal
efficiency, and the system must submit
the results of challenge testing to the
State. Challenge testing must be
conducted according to the criteria in  .
paragraphs (b)(2)(i) through (b)(2)(vii) of
this section. The State may accept data
from challenge testing conducted prior
to [Date of Publication of Final Rule in
the Federal Register] in lieu of
additional testing if the prior testing was
consistent with the criteria in
paragraphs (b)(2)(i) through (b}(2) (vii)
of this section.
  (i) Challenge testing must be
conducted on either a full-scale
membrane module, identical in material
and construction to the membrane
modules used in the system's treatment
facility, or a smaller-scale membrane
module, identical in material and
similar in construction to the full-scale
module,
  (ii) Challenge testing must be
conducted using Cryptosporidium
oocysts or a  surrogate that is removed
no more efficiently than
Cryptosporidium oocysts. The organism
or surrogate used during challenge
testing is referred to as the challenge
particulate. The concentration of the
challenge particulate must be
determined using a method capable of
discretely quantifying the specific
challenge particulate used in the test;
gross measurements such as turbidity
may not be used.
  (iii) The maximum feed water
concentration that can be used during a
challenge test is based on the detection
limit of the challenge particulate in the
filtrate and must be determined
according to the following equation:
Maximum Feed Concentration =
    3.16X106 x (Filtrate Detection Limit)
  (iv) Challenge testing must be
conducted under representative
hydraulic conditions at the maximum
design flux and maximum design
process recovery specified by the
manufacture for the membrane module.
Flux is defined as the rate of flow per
unit of membrane area. Recovery is
defined as the ratio of filtrate volume
produced by a membrane to feed water
volume applied to a membrane over the
course of an uninterrupted operating
cycle. An operating cycle is bounded by
two consecutive backwash or cleaning
events. For the purpose of challenge
testing in this section, recovery does  not
consider losses that occur due to the  use
                      of filtrate in backwashing or cleaning
                      operations.
                        (v) Removal efficiency of a membrane
                      module during challenge testing must
                      be determined as a log removal using
                      the following equation:
                          = LOGio(Cf) - LOG,o(Cp)
                      where LRV = log removal value
                      demonstrated during challenge testing;
                      Cr = the feed concentration used during
                      the challenge test; and Cp - the filtrate
                      concentration observed during the
                      challenge test. Equivalent units must be
                      used for the feed and filtrate
                      concentrations. If the challenge
                      particulate is not detected in the filtrate,
                      the term Cp is set equal to the detection
                      limit. An LRV must be calculated for
                      each membrane module evaluated
                      during the test.
                        (vi) The removal efficiency of a
                      membrane  filtration process
                      demonstrated during challenge testing
                      must be expressed as a log removal
                      value (LRVc-Tcst). If fewer than 20
                      modules are tested, then LRVC-Tcsi is
                      equal to the lowest of the representative
                      LRVs among the applicable modules
                      tested. If 20 or more modules are tested,
                      then LRVc-Tesi is equal to the 10th
                      percentile of the representative LRVs
                      among the  applicable modules tested.
                      The percentile is defined by (i/(n+l))
                      where i is the rank of n individual data
                      points ordered lowest to highest. If
                      necessary, the 10th percentile may be
                      calculated using linear interpolation.
                        (vii) The challenge test must establish
                      a quality control release value (QCRV)
                      for a non-destructive performance test
                      that demonstrates the Cryptosporidium
                      removal capability of the membrane
                      filtration process. This performance test
                      must be applied to each production
                      membrane module used by the system
                      that did not undergo a challenge test in
                      order to verify Cryptosporidium removal
                      capability.  Production modules that do
                      not meet the established QCRV are not
                      eligible for the removal credit
                      demonstrated during the challenge test.
                        (viii) If a previously tested membrane
                      is modified in a manner that could
                      change the removal efficiency of the
                      membrane or the applicability of the
                      non-destructive performance test and
                      associated QCRV, addition challenge
                      testing to demonstrate the removal
                      efficiency of, and determine a new
                      QCRV for, the modified membrane must
                      be conducted and submitted to the
                      State.
                        (3) Direct integrity testing. Systems
                      must conduct direct integrity testing in
                      a manner that demonstrates a  removal
                      efficiency equal to or greater than the
                      removal credit awarded to the
                      membrane filtration process and meets
the requirements described in
paragraphs (b)(3)(i) through (b)(3)(vi) of
this section.
  (i) The direct integrity test must be
independently applied to each
membrane unit in service. A membrane
unit is a group of membrane modules
that share common valving that allows
the unit to be isolated from the rest of
the system for the purpose of integrity
testing or maintenance.
  (ii) The direct integrity  method must
have a resolution of 3 um or less, where
resolution is defined as the smallest leak
size that contributes to a response from
the direct integrity test.
  (iii) The system must demonstrate
that the direct integrity test can verify
the log removal credit awarded to the
membrane filtration process by the State
using the approach in either paragraph
(b)(2)(iii)(A) or (b}(2)(iii)(B) of this
section as applicable based on the type
of direct integrity test.
  (A) For direct integrity  tests that use
an applied pressure or vacuum, the
maximum log removal value that can be
verified by the test must be calculated
according to the following equation:
LRVplT = LOGIO(Qp /(VCF X Qbreach))
where LRVou = maximum log removal
value that can be verified by a direct
integrity test; Qp = total design filtrate
flow from the membrane  unit; Qbicach =
flow of water from an integrity breach
associated with the smallest integrity
test response that can be reliably
measured, and VCF = volumetric
concentration factor. The volumetric
concentration factor is the ratio of the
suspended solids concentration on the
high pressure side of the  membrane
relative to that in the feed water.
   (B) For direct integrity  tests that use
a particulate or molecular marker, the
maximum log removal value that can be
verified by the test must be calculated
according to the following equation:
  LRVDJT = LOG, o(Cf) - LOG, 0(CP)
where LRVoir = maximum log removal
value that can be verified by a direct
integrity test; Cf = the typical feed
concentration of the marker used in the
test; and Cp - the filtrate  concentration
of the marker from an integral
membrane unit.
   (iv) Systems must establish a control
limit for the direct integrity test that is
indicative of an integral membrane unit
capable of meeting the removal credit
awarded by the State.
   (v) If the result of a direct integrity
test is outside the control limit
established under paragraphs (b)(3)(i)
through (b)(3)(iv) of this section, the
membrane unit must be removed from
service. A direct integrity test must be

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                                                                      47789
conducted to verify any repairs, and the
membrane unit may be returned to
service only if the direct integrity test is
within the established control limit.
   (vi) Direct integrity testing must be
conducted on each membrane unit at a
frequency of not less than once each day
that the membrane unit is in operation.
   (4) Indirect integrity monitoring.
Systems must conduct continuous
indirect integrity monitoring on each
membrane unit according to the criteria
in paragraphs  (b)(4)(i) through (b)(4)(v)
of this section. A system that
implements continuous direct integrity
testing of membrane units in accordance
with the criteria in paragraphs (b)(3)(i)
through (b)(3)(v) of this  section is not
subject to the requirements for
continuous indirect integrity
monitoring.
   (ij Unless the State approves an
alternative parameter, continuous
indirect integrity monitoring must
include continuous filtrate turbidity
monitoring.
   (ii) Continuous monitoring must be
conducted  at a frequency of no less than
once every 15  minutes.
   (iii) Continuous monitoring must be
separately conducted on each
membrane  unit.
  (iv) If indirect integrity monitoring
includes turbidity and if the filtrate
turbidity readings are above 0.15 NTU
 for a period greater than 15 minutes (i.e.,
 two consecutive 15-minute readings
 above 0.15 NTU), direct integrity testing
 must be performed on the associated
 membrane units as specified in
 paragraphs (b){3)(i) through (b)(3)(v) of
 this section.
   (v) If indirect integrity monitoring
 includes a State-approved alternative
 parameter and if the alternative
 parameter exceeds a State-approved
 control limit for a period greater than 15
 minutes, direct integrity testing must be
 performed on the associated membrane
 units as specified in  paragraphs (b)(3)(i)
 through (b)(3)(v) of this section.
   (c) Second stage filtration. Systems
 are eligible for an additional 0.5 log
 Cryptosporidium removal  credit if they
 have a separate second stage filtration
 process consisting of rapid sand, dual
 media, GAG, or other fine  grain media
 in a separate stage following rapid sand
 or dual media filtration. To be eligible
 for this credit, the first stage of filtration
 must be preceded by a coagulation step
 and both filtration stages must treat
 100% of the flow. A  cap, such as GAG,
 on a single stage of filtration is not
 eligible for this credit.
  (d)  Slow sand filtration.  Systems may
 claim a 2.5 log Cryptosporidium
 removal credit for a slow sand filtration
 process that follows  another separate
 filtration process if all the  flow is
treated by both processes and no
disinfectant residual is present in the
influent water to the slow sand filtration
process.

§141.729  Inactivation toolbox
components.
  (a) Calculation ofCTvalues. (1) CT is
the product of the disinfectant contact
time (T, in minutes) and disinfectant
concentration (C, in milligrams per
liter). Systems must calculate CT at least
once each day,  with both C and T
measured during peak hourly flow as
specified in §§  141.74(a) and 141.74(b).
  (2) Systems with several disinfection
segments (a segment is defined as a
treatment unit process with a
measurable disinfectant residual level
and a liquid volume) in sequence along
the treatment train, may calculate the
CT for each disinfection segment and
use the sum of the Cryptosporidium log
inactivation values achieved through
the plant.
  (b) CT values for chlorine dioxide, (I)
Systems using chlorine dioxide must
calculate CT in accordance with
§141.729(a).
  (2) Unless the State approves
alternative CT values for a system under
paragraph (b)(3) of this section, systems
must use the following table to
determine Cryptosporidium log
inactivation credit:
                        CT VALUES FOR Cryptosporidium INACTIVATION BY CHLORINE DIOXIDE
     Log credit
                                                          Water Temperature, ° C1
                      <=0.5
                                                                                  10
                                                     15
                       20
25
0.5 	
1.0 	
1 5 	
2 0 	
2.5 	
3.0 	
	 319
	 637
	 956
	 1275
	 1594
	 1912
305
610
915
1220
1525
1830
279
558
838
1117
1396
1675
256
511
767
1023
1278
1534
214
429
643
858
1072
1286
180
360
539
719
899
1079
138
277
415
553
691
830
89
179
268
357
447
536
58
116
174
232
289
347
38
75
113
150
188
226
  1 CT values between the indicated temperatures may be determined by interpolation.
  (3) Systems may conduct a site-
specific inactivation study to determine
the CT values necessary to meet a
specified Cryptosporidium log
inactivation level, using a State-
approved protocol. The alternative CT
values determined from the site-specific
study and the method of calculation
must be approved by the State.
  (c) CT values for ozone. (1) Systems
using ozone must calculate CT in
accordance with § 141.729(a).
  (2) Unless the State approves
alternative CT values for a system under
paragraph (c)(3) of this section, systems
must use the following table to
determine Cryptosporidium log
inactivation credit:
                              CT VALUES FOR Cryptosporidium INACTIVATION BY OZONE
Log credit
0.5 	
1.0 	
1 5 	
20 	
2.5 	
Water Temperature, °C1 1
<=0.5
12
24
36
48
60
1
12
23
35
46
58
2
10
21
31
42
52
3
9.5
19
29
38
48
5
7.9
16
24
32
40
7
6.5
13
20
26
33
10
4.9
9.9
15
20
25
15
3.1
6.2
9.3
12
16
20
2.0
3.9
5.9
7.8
9.8
25
1.2
2.5
3.7
4.9
6.2

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 47790
Federal Register/Vol. 68, No. 154/Monday, August 11, 2003/Proposed Rules
                        CT VALUES FOR Cryptosporidium INACTIVATION BY OZONE—Continued
                                                      Water Temperature, °C1

3.0 	
<=0.5
72
1
69
2
63
3
57
5
47
7
39
10
30
15
19
20
12
25
7.4
   CT values between the indicated temperatures may be determined by interpolation
   (3) Systems may conduct a site-
 specific inactivation study to determine
 the CT values necessary to meet a
 specified Cryptosporidium log
 inactivation level, using a State-
 approved protocol. The alternative CT
 values determined from the site-specific
 study and the method of calculation
 must be approved by the State.
   (d) Ultraviolet light. (1) Systems may
 claim credit for ultraviolet (UV)
 processes for inactivation of
                      Cryptosporidium, Giardia lamblia, and
                      viruses. The allowable inactivation
                      credit for each pathogen must be based
                      on the UV dose delivered by the
                      system's UV reactors in relation to the
                      UV dose table in paragraph (d)(2) of this
                      section.
                        (2) UV dose table. The log credits
                      given in this UV  dose table are for UV
                      light at a wavelength of 254 nm as
                      produced by a low pressure mercury
                      vapor lamp. Systems may apply this
table to UV reactors with other lamp
types through reactor validation testing
(i.e., performance demonstration) as
described in paragraph (d)(3) of this
section. The UV dose values in this
table are applicable only to post-filter
application of UV in systems that filter
under subpart H of this part and to
unfiltered systems meeting the filtration
avoidance criteria in subparts H,  P, and
T of this part:
               UV DOSE TABLE FOR Cryptosporidium, GIARDIA LAMBLIA, AND VIRUS INACTIVATION CREDIT
Log credit
0 5 	
1 o 	
1 5 	 	 	
2 0 	 	 	
25 	 	
3 0 	 	 	
3 5 	
40 	

Cryptosporidium
UV Dose (mJ/
cm2)
1.6
2.5
3.9
5.8
8.5
12
NA
NA

Giardia lamblia
UV dose (mJ/
cm2)
1.5
2.1
3.0
5.2
7.7
11
NA
NA

Virus UV dose
{mJ/cm 2)
39
58
79
100
121
143
163
186

  (3) Reactor validation testing. For a
system to receive inactivation credit for
a UV reactor, the reactor must undergo
the validation testing in paragraphs
(d)(3)(i) and (d)(3)(ii) of this section,
unless the State approves an alternative
approach. The validation testing must
demonstrate the  operating conditions
under which the reactor can deliver the
LTV dose required in paragraph (d)(2) of
this section.
  (i) Validation testing of UV reactors
must determine a range of operating
conditions that can be monitored by the
system and under which the reactor
delivers the required UV dose. At a
minimum, these  operating conditions
must include flow rate, UV intensity as
measured by a UV sensor, and UV lamp
status. The validated operating
conditions determined by this testing
must account for the following: UV
absorbance of the water; lamp fouling
and aging; measurement uncertainty of
on-line sensors; UV dose distributions
arising from the velocity profiles
through the reactor; failure of UV lamps
or other critical system components;
and inlet and outlet piping or channel
configurations of the UV reactor.
                        (ii) Validation testing must include
                      the following: full scale testing of a
                      reactor that conforms uniformly to the
                      UV reactors used by the system; and
                      inactivation of a test microorganism
                      whose dose response  characteristics
                      have been quantified  with a low
                      pressure mercury vapor lamp.
                        (4) Reactor monitoring. Systems must
                      monitor their UV reactors to
                      demonstrate that they are operating
                      within the range of conditions that were
                      validated by the testing described in
                      paragraphs (d)(3)(ij and (d)(3)(ii) of this
                      section to achieve the required UV dose
                      in paragraph (d)(2) of this section.
                      Systems must monitor for UV intensity
                      as measured by a UV sensor, flow rate,
                      and lamp outage and for any other
                      parameters required by the State.
                      Systems must verify the calibration of
                      UV sensors and must  recalibrate sensors
                      in accordance with a protocol approved
                      by the State.
                      Reporting and Recordkeeping
                      Requirements

                      §141.730  Reporting requirements.
                       (a) Systems must follow the
                      requirements for reporting sampling
                      schedules under § 141.703 and for
reporting source water monitoring
results under § 141.707 unless they
notify the State that they will not
conduct source water monitoring due to
meeting the criteria of § 141.701{f) or (g).
  (b) Systems using uncovered finished
water storage facilities must notify the
State of the use of each facility no later
than [Date 24 Months After Date of
Publication of Final Rule in the Federal
Register].
  (c) Filtered systems and unfiltered
systems that are required to install
filtration must report their
Cryptosporidium bin classification, as
determined under using the procedures
in § 141.709, to the State by the
applicable dates in paragraph (c)(l) or
(2) of this section.
  (1) Systems that serve at least 10,000
people must report their initial bin
classification no later than [Date 36
Months After Date of Publication of
Final Rule in the Federal Register] and
must report their bin classification
determined using results from the
second round of source water
monitoring no later than [Date 138
Months After Date of Publication of
Final Rule in the Federal Register].

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                  Federal Register/Vol. 68,  No.  154/Monday,  August  11, 2003/Proposed Rules
                                                                                     47791
  (2) Systems that serve fewer than
10,000 people must report their initial
bin classification no later than [Date 66
Months After Date of Publication of
Final Rule in the Federal Register] and
must report their bin classification
determined using results from the
second round of source water
monitoring no later than [Date 174
Months After Date of Publication of
Final Rule in the Federal Register].
  (d) Unfiltered systems  that meet all
filtration avoidance criteria of §141.71
must report their mean Cryptosporidium
concentration, as determined under
§ 141.721, to the State by the applicable
dates in paragraph (d)(l) or (2) of this
section.
            (1) Systems that serve at least 10,000
          people must report their initial mean
          Cryptosporidium concentration no later
          than [Date 36 Months After Date of
          Publication of Final Rule in the Federal
          Register] and must report their mean
          Cryptosporidium concentration
          determined using results from Ae
          second round of source water
          monitoring no later than [Date 138
          Months After Date of Publication of
          Final Rule in the Federal Register].
            (2) Systems that serve fewer than
          10,000 people must report their initial
          mean Cryptosporidium concentration no
          later than [Date 66 Months After Date of
          Publication of Final Rule in the Federal
          Register] and must report their mean
                     Cryptosporidium concentration
                     determined using results from the
                     second round of source water
                     monitoring no later than [Date 174
                     Months After Date  of Publication of
                     Final Rule in the Federal Register],

                       (e) Systems must report to the State in
                     accordance with the following table in
                     this paragraph for any toolbox options
                     used to  comply with the
                     Cryptosporidium treatment technique
                     requirements under § 141.720 or
                     § 141.721. The State may place
                     additional reporting requirements it
                     determines to be necessary to verify
                     operation in accordance with required
                     criteria  for all toolbox options:
                                     MICROBIAL TOOLBOX REPORTING REQUIREMENTS
         Toolbox option
  Systems must submit the fol-
       lowing information
On the following schedule1—sys-
  tems serving > 10,000 people
On the following schedule1—sys-
  tems serving < 10,000 people
(1)  Watershed  control  program
  (WCP).
(2) Bank filtration
(3) Presedimentation
(4) Two-sage lime softening
(i) Notify State of intention to de-
  velop WCP.
                                (ii)  Submit  initial  WCP  plan  to
                                  State.
                                (iii)  Annual report and State-ap-
                                  proved watershed survey report.
(iv) Request for  re-approval and
  report on the previous approval
  period.

(i) Initial demonstration of the fol-
  lowing:  unconsolidated,   pre-
  dominantly  sandy aquifer and
  setback  distance  of at least 25
  ft. {0.5 log credit) or 50 ft. (1.0
  log credit).
(ii) If  monthly average of  daily
  max turbidity is greater than 1
  NTU  then system must  report
  result  and  submit an assess-
  ment of the cause.

Monthly  verification of the  fol-
  lowing; Continuous basin  oper-
  ation;  treatment of 100%  of the
  flow;  continuous  addition  of a
  coagulant;  and  at least 0.5 log
  removal   of  influent turbidity
  based on the monthly mean of
  daily turbidity readings for 11 of
  the 12 previous months.
Monthly  verification  of the  fol-
  lowing: Continuous operation of
  a second clarification step be-
  tween the  primary clarifier and
  filter;  continuous presence of a
  coagulant in both primary and
  secondary  clarifiers;  and  both
  clarifiers treated  100% of the
  plant flow.
No  later  than  [Date 48 Months
  After Date  of  Publication  of
  Final Rule in the Federal Reg-
  ister].
No  later  than  [Date 60 Months
  After Date  of  Publication  of
  Final Rule in the Federal Reg-
  ister].
By  a  date  determined  by  the
  State, every 12  months, begin-
  ning  on [Date 84 Months After
  Date of  Publication  of  Final
  Rule in  the Federal Register].
Six  months prior to the  end of the
  current  approval period or by a
  date previously  determined by
  the State.
Initial demonstration no later than
  [Date 72 Months after Date of
  Publication of Final Rule in  the
  Federal Register].
Report within 30  days following
  the  month in  which  the  moni-
  toring was conducted,  begin-
  ning  on  [Date 72 Months After
  Date  of  Publication  of  Final
  Rule in the Federal Register].
Monthly reporting within 10 days
  following  the  month  in which
  the  monitoring was conducted,
  beginning on [Date 72 Months
  After  Date of  Publication  of
  Final Rule in the Federal Reg-
  ister],
Monthly reporting within 10 days
  following  the  month  in which
  the monitoring was conducted,
  beginning on [Date 72 Months
  After   Date  of  Publication  of
  Final  Rule in the Federal Reg-
  ister].
No  later  than  [Date  78 Months
  After  Date of  Publication  of
  Final Rule in the Federal Reg-
  ister].
No  later -than  [Date  90 Months
  After  Date of  Publication  of
  Final Rule in the Federal Reg-
  ister].
By  a  date  determined by  the
  State, every 12  months, begin-
  ning on [Date  114 Months After
  Date  of  Publication  of Final
  Rule in the Federal  Register].
Six  months prior to the end of the
  current approval period or by a
  date previously  determined  by
  the State.
Initial demonstration no  later than
  [Date 102 Months after Date of
  Publication of Final  Rule in  the
  Federal Register].
Report within 30  days following
  the month in  which the  moni-
  toring was conducted,  begin-
  ning on [Date  102 Months After
  Date  of  Publication  of  Final
  Rule in the Federal  Register].
Monthly reporting within 10 days
  following  the  month  in  which
  the monitoring was conducted,
  beginning on [Date  102 Months
  After  Date of  Publication  of
  Final Rule in the Federal Reg-
  ister].
Monthly reporting within 10 days
  following  the  month  in which
  the  monitoring was conducted,
  beginning on [Date 102 Months
  After  Date of  Publication  of
  Final Rule in the Federal Reg-
  ister].

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47792
Federal Register/Vol.  68, No.  154/Monday,  August  11,  2003/Proposed Rules
                                 MICROBIAL TOOLBOX REPORTING REQUIREMENTS—Continued
          Toolbox option
                 Systems must submit the fol-
                      lowing information
 On the following schedule1—sys-
   tems serving > 10,000 people
 On the following schedule1—sys-
  tems serving < 10,000 people
 (5) Combined filter performance
 (6) Individual filter performance
(7) Membrane filtration
(8) Bag filters and cartridge filters
(9) Second stage filtration
(10) Slow and filtration
(11) Chlorine dioxide
               Monthly verification of combined
                 filter effluent (CFE) turbidity lev-
                 els  less than or equal to 0.15
                 NTU in  at  least 95 percent of
                 the  4 hour  CFE measurements
                 taken each  month.

               Monthly verification  of  the  fol-
                 lowing:  Individual filter effluent
                 (IFE) turbidity  levels less than
                 or equal to  0.1  NTU in at least
                 95 percent of all daily maximum
                 IFE measurements  taken  each
                 month (excluding 15 min period
                 following start-up  after  back-
                 wash);  and  no individual filter
                 greater  than  0.3 NTU in two
                 consecutive  readings  15  min-
                 utes apart.
               (i) Results of verification testing
                 demonstrating   the  following:
                 Removal efficiency  established
                 through  challenge  testing that
                 meets criteria  in  this subpart;
                 and integrity testing and associ-
                 ated baseline.
               (ii) Monthly report summarizing  all
                 direct integrity  tests above the
                 control  limit and,  if applicable,
                 any indirect integrity monitoring
                 results triggering direct integrity
                 testing and the corrective action
                 that was taken.
               (i)  Demonstration  that  the fol-
                 lowing criteria are met: process
                 meets the definition of bag  or
                 cartridge filtration; removal effi-
                 ciency   established  through
                 challenge testing that meets cri-
                 teria in this subpart; and chal-
                 lenge test shows at least  2 log
                 removal  for  bag filters and 3 log
                 removal  for cartridge filters.
               (ii) Monthly verification that  100%
                 of flow was filtered.
              Monthly  verification that  100%  of
                flow was filtered through both
                stages.
              Monthly verification that 100%  of
                flow was filtered.
              Summary of CT values for each
                day   based  on   Table   in
                §141.729(b).
 Monthly reporting within 10 days
   following  the month in which
   the  monitoring was  conducted,
   beginning on [Date  72 Months
   After  Date  of  Publication  of
   Final Rule in the Federal Reg-
   ister].
 Monthly reporting within 10 days
   following  the month in which
   the  monitoring was  conducted,
   beginning on [Date  72 Months
   After  Date  of  Publication  of
   Final Rule in the Federal Reg-
   ister}.
 No  later  than  [Date 72  Months
  After Date  of  Publication  of
  Final Rule in the Federal Reg-
  ister].
Within  10  days  following   the
  month in which monitoring was
  conducted, beginning [Date 72
  Months After  Date of Publica-
  tion of Final Rule in the Federal
  Register].

No later  than  [Date 72  Months
  After  Date  of  Publication of
  Final  Rule in the Federal Reg-
  ister].
Within  10  days   following  the
  month in which monitoring  was
  conducted, beginning [Date 72
  Months After  Date of Publica-
  tion of Final Rule  in the Federal
  Register],
Within  10  days   following  the
  month in which monitoring  was
  conducted, beginning [Date 72
  Months After  Date of Publica-
  tion of Final Rule  in the Federal
  Register].
Within  10  days   following  the
  month in which monitoring  was
  conducted, beginning [Date 72
  Months After  Dale of Publica-
  tion of Final Rule  in the Federal
  Register].
Within  10  days   following  the
  month in which monitoring  was
  conducted, beginning [Date 72
  Months After  Date of Publica-
  tion of Final Rule  in the Federal
  Register].
Monthly reporting within 10 days
  following  the  month in which
  the monitoring  was  conducted,
  beginning on [Date 102 Months
  After  Date  of  Publication  of
  Final  Rule in the Federal Reg-
  ister].
Monthly reporting within 10 days
  following  the  month in which
  the monitoring  was  conducted,
  beginning on [Date 102 Months
  After  Date  of  Publication  of
  Final  Rule in the Federal Reg-
  ister].
No later than [Date 102  Months
  After Date of  Publication  of
  Final Rule in the Federal Reg-
  ister].
Within  10  days   following   the
  month in which monitoring  was
  conducted, beginning [Date 102
  Months After  Date of Publica-
  tion of Final Rule  in the Federal
  Register].

No later than [Date 102  Months
  After  Date  of  Publication  of
  Final  Rule in the  Federal Reg*
  Isterj.
Within  10  days  following  the
  month in which monitoring  was
  conducted, beginning [Date 102
  Months After  Date of Publica-
  tion of Final Rule in the Federal
  Register].
Within  10  days  following  the
  month in which monitoring  was
  conducted, beginning [Date 102
  Months After  Date of Publica-
  tion of Final Rule in the Federal
  Register].
Within  10  days  following  the
  month in which monitoring  was
  conducted, beginning [Date 102
  Months After  Date of Publica-
  tion of Final Rule in the Federal
  Register].
Within  10  days  following  the
  month in which monitoring  was
  conducted, beginning [Date  102
  Months After  Date of  Publica-
  tion of Final Rule in the Federal
  Register].

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                   Federal  Register/Vol.  68, No.  154/Monday, August 11, 2003/Proposed  Rules
                                                                                       47793
                                MICROBIAL TOOLBOX REPORTING REQUIREMENTS—Continued
          Toolbox option
   Systems must submit the fol-
        lowing information
 On the following schedule1—sys-
  tems serving > 10,000 people
 On the following schedule1—sys-
  tems serving < 10,000 people
 (12) Ozone
(13) UV
(14) Demonstration of performance
 Summary of CT values for each
   day   based  on  Table   in
   §141.729(c).
 (i)  Validation  test  results  dem-
  onstrating operating  conditions
  that achieve required UV dose.

 (ii)  Monthly  report summarizing
  the percentage of water enter-
  ing the distribution system that
  was not treated by UV reactors
  operating  within  validated  con-
  ditions for the required dose  as
  specified in § 141.729(d).
 (i) Results from testing following a
  State approved protocol.
                                 (ii)  As  required  by  the  State,
                                   monthly verification of operation
                                   within conditions  of State ap-
                                   proval for demonstration of per-
                                   formance credit.
Within  10  days  following  the
  month in which monitoring  was
  conducted, beginning [Date 72
  Months After Date of Publica-
  tion of Final Rule in the Federal
  Register].
No later than [Date 72  Months
  After  Date  of Publication  of
  Final  Rule in the Federal Reg-
  ister].
Within  10  days  following  the
  month in which monitoring  was
  conducted, beginning pate 72
  Months After Date of Publica-
  tion of Final Rule in the Federal
  Register].

No later than [Date 72  Months
  After  Date  of Publication  of
  Final  Rule in the Federal Reg-
  ister].
Within  10  days  following  the
  month in which monitoring  was
  conducted, beginning [Date 72
  Months After Date of Publica-
  tion of Final Rule in the Federal
  Register].
Within  10  days  following  the
  month in which monitoring was
  conducted, beginning [Date  102
  Months After Date  of Publica-
  tion of Final Rule in the Federal
  Register].
No later than [Date  102 Months
  After   Date  of Publication  of
  Final  Rule in the Federal Reg-
  ister].
Within  10  days  following  the
  month in which monitoring was
  conducted, beginning [Date  102
  Months After Date  of Publica-
  tion of Final Rule in the Federal
  Register].

No later than [Date  102 Months
  After   Date  of Publication  of
  Final  Rule in the Federal Reg-
  ister].
Within  10  days  following  the
  month in which monitoring was
  conducted, beginning [Date  102
  Months After Date  of Publica-
  tion of Final Rule in the Federal
  Register].
  1 States may allow  up to  an additional two years to the date when  the  first submittal  must be completed for systems making  capital
improvements.
  (f) Systems must report to the State
the information associated with
           disinfection profiling and benchmarking   accordance with the tables in this
           requirements of §§141.711 to 141.714 in   paragraph.
                   TABLE 1.—DISINFECTION PROFILING REPORTING REQUIREMENTS FOR URGE SYSTEMS
                                                     [Serving >10,000 people]
          System type
     Benchmark component
    Submit the following items
    On the following schedule
(1)  Systems  required to conduct
  Cyrptosporidium monitoring.
(2)  Systems not required to con-
  duct   Cryptosporidium   moni-
  toring a.
(i) Characterization of disinfection
  practices. See §141.713.
(ii) State review  of proposed sig-
  nificant changes to  disinfection
  practice. See §141.714.
(i) Applicability 	
                                 (ii) Characterization of Disinfection
                                   Practices.
                                 (iii)  State Review of  Proposed
                                   Changes  to  Disinfection Prac-
                                   tices.
Giardia lambda and virus inactiva-
  tion profiles must be on file for
  State   review  during  sanitary
  survey.
Inactivation profile and benchmark
  determinations.
None


None

None
No later than [Date 36 Months
  After  Date  of Publication  of
  Final Rule in the Federal Reg-
  ister].
Prior to significant modification of
  disinfection practice.

None.
                                                                None.

                                                                None.
  aSystems that provide at least 5.5 log of Cryptosporidium treatment, consistent with a Bin 4 treatment requirement, are not required to conduct
Cryptosporidium monitoring.

                  TABLE 2.—DISINFECTION PROFILING REPORTING REQUIREMENTS FOR SMALL SYSTEMS
                                                    [Serving < 10,000 people]
          System type
     Benchmark component
   Submit the following items
    On the following schedule
(1)  Systems required  to  conduct
  Cryptosporidium monitoring.
(i) Characterization of disinfection
  practices. See §141.713.
Giardia lamblia and virus disinfec-
  tion profiles must be on file for
  State  review  during  sanitary
  survey.
No  later than [Date 66  Months
  After  Date  of  Publication of
  Final Rule in the Federal Reg-
  ister].

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Federal Register/Vol.  68,  No.  154/Monday, August  11,  2003/Proposed Rules
            TABLE 2.—DISINFECTION PROFILING REPORTING REQUIREMENTS FOR SMALL SYSTEMS—Continued
                                                  [Serving < 10,000 people]
          System type
                  Benchmark component
   Submit the following items
    On the following schedule
 (2) Systems not required to con-
   duct Cryptosporidium monitoring
   and  that exceed DBP triggers
 (3) Systems not required to con-
   duct Cryptosporidium monitoring
   and  that do  not  exceed  DBP
   triggers b'°.
              (ii) State review of proposed sig-
               nificant changes to  disinfection
               practices. See §141.714.
              (i) Determination of  requirement
               to profile. See §141.711(b).
                               (ii) Characterization of disinfection
                                 practices. See §141.713.
             (iij) State review of proposed sig-
               nificant changes to  disinfection
               practices. See §141.714.
             (i)  Determination of  no require-
               ment    to    profile.     See
                               (ii) Characterization of disinfection
                                 practices. See §141.713.
                               (iii) State review of proposed sig-
                                 nificant changes to disinfection
                                 practice. See §141. 714.
Disinfection  profiles and  bench-
  mark determinations.

Report on TTHM and HAA5 LRAA
  values  from  monitoring  under
  subpart L.

Giardia lambia and virus disinfec-
  tion profiles must be on file for
  State  review  during  sanitary
  survey.
Disinfection  profiles and  bench-
  mark determinations.

Report on TTHM and HAAS LRAA
  values  from  monitoring  under
  subpart L.

None  	
                                            None
Prior to significant modification of
  disinfection practice.

No  later than [Date  42 Months
  After Date  of  Publication  of
  Final Rule in the Federal Reg-
  ister].
No  later than [Date  54 Months
  after Date  of  Publication  of
  Final Rule in the Federal Reg-
  ister].
Prior to significant modification of
  disinfection practice.

No  later than [Date  42 Months
  After Date  of  Publication  of
  Final Rule in the Federal Reg-
  ister].
None.

None.
  "Systems that provide at least 5.5 log of Cryptosporidium treatment, consistent with a Bin 4 treatment requirement, are not required to conduct
 Cryptosporidium monitoring.
  6 See § 141.702(b) to determine if Cryptosporidium monitoring is required.
  cSee § 141.711(b) to determine if disinfection profiling is required based on TTHM or HAAS LRAA.
§ 141.731  Recordkeeping requirements.
   (a) Systems must keep results from
monitoring required under § 141.702
until 36 months after all source water
monitoring required under this section
has been completed.
   (b) Systems must keep a record of any
notification to the State that they will
not conduct source water monitoring
due to meeting the criteria of
§141.701(f)or(g).
   (c]  Systems required to develop
disinfection profiles under § 141.711
must keep disinfection profiles on file
for State review during sanitary surveys.

PART 142—NATIONAL PRIMARY
DRINKING WATER REGULATIONS
IMPLEMENTATION

   5. 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, 300g-6, 300J-4,
300j-9and300j-ll.
   6. Section 142.14 is amended by
adding paragraphs (a)(8) and (a)(9) to
read as follows:

§ 142.14 Records kept by States.
*     *    *    *     *
   (a)  * *  *
   (8)  [Reserved]
   (9) Any decisions made pursuant to
the provisions of part 141, subpart W of
this chapter.
   (i) Results of source water E.  coli and
Cryptosporidium monitoring.
                         (ii) Initial bin classification for each
                       system that currently provides filtration
                       or that is unfiltered and required to
                       install filtration, along with any change
                       in bin classification due to watershed
                       assessment during sanitary surveys or
                       the second round of source water
                       monitoring.
                         (iii) A determination of whether each
                       system that is unfiltered and meets all
                       the filtration avoidance criteria of
                       §141.71 of this chapter has a mean
                       source water Cryptosporidium level
                       above 0.01 oocysts/L, along with any
                       changes in this determination due to the
                       second round of source water
                       monitoring.
                         (iv) The treatment or control measures
                       that systems use to meet their
                       Cryptosporidium treatment
                       requirements under § 141.720 or
                       § 141.721 of this section.
                         (v) A list of systems required to cover
                       or treat the effluent of an uncovered
                       finished water reservoir.
                         (vi) A list of systems for which the
                       State has waived the requirement to
                       cover or treat the effluent of uncovered
                       finished water storage facilities and
                       supporting documentation of the risk
                       mitigation plan.
                       *****

                         7. Section 142.15 is amended by
                       adding paragraph (c)(6) to read as
                       follows:
                    § 142.15  Reports by States.
                      (c) * *  *
                      (6) Subpart W. (i) The initial bin
                    classification for each system that
                    currently provides filtration or that is
                    unfiltered and required to install
                    filtration, along with any change in bin
                    classification due to watershed
                    assessment during sanitary surveys or
                    the second round of source water
                    monitoring.
                      (ii) A determination of whether each
                    system that is unfiltered and meets all
                    the filtration avoidance criteria of
                    § 141.71 of this chapter has a mean
                    source water Cryptosporidium level
                    above 0.01 oocysts/L, along with any
                    changes in this determination due to the
                    second round of source water
                    monitoring.
                    *****
                      8. Section 142.16 is amended by
                    adding paragraphs (m) and (n) to read as
                    follows:

                    §142.16 Special primacy conditions.
                    *****
                      (m)   [Reserved]
                      (n) Requirements for States to adopt
                    40 CFR part 141, subpart W, In addition
                    to the general primacy requirements
                    elsewhere in this part, including the
                    requirements that State regulations be at
                    least as stringent as federal
                    requirements, an application for
                    approval of a State program revision
                    that adopts 40 CFR part 141, subpart W,

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                Federal Register/Vol. 68, No.  154/Monday,  August 11,  2003/Proposed Rules
                                                                    47795
must contain a description of how the
State will accomplish the following
program requirements where allowed in
State programs.
  (1) Assess significant changes in the
watershed and source water as part of
the sanitary survey process and
determine appropriate follow-up action.
  (2) Approve watershed control
programs for the 0.5 log watershed
control program credit in the microbial
toolbox.
  (3) Approval protocols for treatment
credits under the Demonstration of
Performance toolbox option and for
alternative ozone and chlorine dioxide
CT values.
  (4) Determine that a system with an
uncovered finished water reservoir has
a risk mitigation plan that is adequate
for purposes of waiving the requirement
to cover or treat the reservoir.
[FR Doc. 03-18295 Filed 8-8-03; 8:45 am]
BILLING CODE 6560-50-P

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