[Federal Register Volume 70, Number 245 (Thursday, December 22, 2005)]
[Proposed Rules]
[Pages 76013-76018]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E5-7696]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 122 and 123

[EPA-HQ-OW-2005-0523, FRL--8013-9]


National Pollutant Discharge Elimination System (NPDES) Permit 
Requirements for Peak Wet Weather Discharges From Publicly Owned 
Treatment Works Treatment Plants Serving Separate Sanitary Sewer 
Collection Systems

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of availability and request for comment.

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SUMMARY: Today, EPA is inviting comment on a draft policy regarding 
NPDES permit requirements for peak wet weather discharges from publicly 
owned treatment works (POTW) treatment plants serving separate sanitary 
sewer collection systems. Regulatory agencies, municipal operators of 
wastewater facilities, and representatives of environmental advocacy 
groups have expressed uncertainty about the appropriate regulatory 
interpretation for such situations. Today's draft policy describes both 
an interpretation of regulations, as well as guidance to implement such 
an interpretation. EPA's intention is to ensure that NPDES requirements 
be developed and applied in a nationally-consistent manner that 
improves the capacity, management, operation and maintenance of POTW 
treatment plants and separate sanitary sewer collection systems and 
protects human health and the environment.

DATES: Comments must be received or postmarked on or before January 23, 
2006.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-OW-
2005-0523, by one of the following methods:
     http://www.regulations.gov: Follow the on-line 
instructions for submitting comments.
     E-mail: Comments may be sent by electronic mail (e-mail) 
to [email protected], Attention Docket ID No. EPA-HQ-OW-2005-0523. 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.
     Mail: Send an original and three copies of your comments 
to: Water Docket, Environmental Protection Agency, Mailcode 4101T, 1200 
Pennsylvania Ave., NW., Washington, DC 20460, Attention Docket ID No. 
EPA-HQ-OW-2005-0523.
     Hand Delivery: Deliver your comments to: EPA Docket 
Center, EPA West, Room B102, 1301 Constitution Ave., NW., Washington, 
DC, Attention Docket ID No. EPA-HQ-OW-2005-0523. Such deliveries are 
only accepted during the Docket's normal hours of operation and special 
arrangements should be made for deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OW-2005-
0523. EPA's policy is that all comments received will be included in 
the public docket without change and may be made available online at 
http://www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
Confidential Business Information (CBI) or other information

[[Page 76014]]

whose disclosure is restricted by statute. Do not submit information 
that you consider to be CBI or otherwise protected through http://www.regulations.gov or through e-mail. The http://www.regulations.gov 
Web site is an ``anonymous access'' system, which means EPA will not 
know your identify or contact information unless you provide it in the 
body of your comment. If you send an e-mail comment directly to EPA 
without going through http://www.regulations.gov your e-mail address 
will be automatically captured and included as part of the comment that 
is placed in the public docket and made available on the Internet. If 
you submit an electronic comment, EPA recommends that you include your 
name and other contact information in the body of your comment and with 
any disk or CD-ROM you submit. 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. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses. For additional information about EPA's public 
docket visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in http://www.regulations.gov or in hard copy at the EPA Docket Center, 
EPA/DC, EPA West, Room B102, 1301 Constitution Ave., NW., Washington, 
DC. The Docket Facility 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 FURTHER INFORMATION CONTACT: For questions about the substance of 
this draft policy, contact Kevin Weiss (e-mail at [email protected] 
or phone at (202) 564-0742) at Water Permits Division, Office of 
Wastewater Management, U.S. Environmental Protection Agency (Mailcode 
4203M), 1200 Pennsylvania Ave., NW., Washington, DC 20460.

SUPPLEMENTARY INFORMATION:

I. General Information

A. What Should I Consider as I Prepare My Comments for EPA?

1. Submitting CBI
    Do not submit information that you consider to be CBI 
electronically through http://www.regulations.gov or e-mail. Clearly 
mark the part or all of the information that you claim to be CBI. For 
CBI information in a disk or CD ROM that you mail to EPA, mark the 
outside of the disk or CD ROM as CBI and then identify electronically 
within the disk or CD ROM the specific information that is claimed as 
CBI. In addition to one complete version of the comment that includes 
information claimed as CBI, a copy of the comment that does not contain 
the information claimed as CBI must be submitted for inclusion in the 
public docket. Information so marked will not be disclosed except in 
accordance with procedures set forth in 40 CFR Part 2.
2. Tips for Preparing Your Comments
    When submitting comments, remember to:
     Identify the rulemaking by docket number and other 
identifying information (subject heading, Federal Register date and 
page number).
     Follow directions--The agency may ask you to respond to 
specific questions or organize comments by referencing a Code or 
Federal Regulations (CFR) part or section number.
     Explain why you agree or disagree; suggest alternatives 
and substitute language for your requested changes.
     Describe any assumptions and provide any technical 
information and/or data that you used.
     If you estimate potential costs or burdens, explain how 
you arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
     Provide specific examples to illustrate your concerns, and 
suggest alternatives.
     Explain your views as clearly as possible, avoiding the 
use of profanity or personal threats.
     Make sure to submit your comments by the comment period 
deadline identified.
3. Docket Copying Costs
    You may copy 266 pages per day free of charge. Beginning with page 
267, you will be charged $0.15 per page plus an administrative fee of 
$25.00.

Acronyms Used

CSO Combined sewer overflow.
EPA Environmental Protection Agency.
I/I infiltration and inflow.
NPDES National Pollutant Discharge Elimination System.
POTW Publicly owned treatment works.
SSO Sanitary sewer overflow (this does not include CSOs).

II. Background

    EPA has received requests from many stakeholders to clarify the 
NPDES requirements for discharges from POTW treatment plants serving 
separate sanitary sewers where peak wet weather flow is routed around 
biological treatment units and then blended with the effluent from the 
biological units prior to discharge and where the final discharge meets 
permit effluent limitations based on the secondary treatment regulation 
(40 CFR Part 133) or any more stringent limitations necessary to attain 
water quality standards. On November 7, 2003, EPA requested public 
comment on a proposed policy addressing this issue. Under the proposed 
interpretation in the November 7, 2003 proposed policy, a wet weather 
diversion around biological treatment units that was blended with the 
wastewaters from the biological units prior to discharge would not have 
been considered to constitute a prohibited bypass if the six criteria 
specified in the November 7, 2003 proposed policy were met.
    EPA received significant public comment on the proposed policy, 
including over 98,000 comments opposing the policy due to concerns 
about human health risks. On May 19, 2005, EPA indicated that after 
consideration of the comments, the Agency had no intention of 
finalizing the 2003 proposal. On July 26, 2005, Congress enacted the FY 
2006 Department of the Interior, Environment, and Related Agencies 
Appropriations Act (P.L. 109-54). Section 203 of the Appropriations Act 
provides that none of the funds made available in the Act could be used 
to finalize, issue, implement or enforce the November 7, 2003 proposed 
blending policy.
    In October of 2005, the Natural Resources Defense Council (NRDC) 
and the National Association of Clean Water Agencies (NACWA) provided 
EPA with their joint proposal recommending further action that the 
Agency should take regarding the blending issue. The NRDC/NACWA 
recommended approach includes an interpretation of the bypass 
regulation that is significantly different from the November 7, 2003 
proposal, in that it would clarify that the bypass provision would 
apply, in all instances, to wet weather diversions at POTW treatment 
plants serving separate

[[Page 76015]]

sanitary sewers. Today's draft policy invites comment on this 
interpretation, as well as the recommended guidance to implement the 
interpretation, and reflects the approach of the NRDC/NACWA 
recommendation.

III. General Information

A. Draft Policy

    If the draft policy is made final, the following statement will be 
announced by EPA.

Draft Memorandum

From: Benjamin H. Grumbles, Assistant Administrator, Office of Water.

To: Regional Administrators, Region I-X, Granta Y. Nakayama, Assistant 
Administrator, Office of Enforcement and Compliance Assurance.

Subject: National Pollutant Discharge Elimination System Permit 
Requirements for Peak Wet Weather Discharges from Publicly Owned 
Treatment Works Treatment Plants Serving Separate Sanitary Sewer 
Collection Systems

Introduction

    Many municipalities currently have situations in which high peak 
influent flows during significant wet weather events exceed the 
treatment capacity of existing secondary treatment units. In these 
situations, wet weather flows are sometimes diverted around secondary 
treatment units and then either recombined with flows from the 
secondary treatment units or discharged directly into waterways from 
the treatment plant. This policy only applies to peak wet weather 
diversions around secondary treatment units that occur at publicly 
owned treatment works (POTW) treatment plants serving separate sanitary 
sewer systems that are recombined with flow from the secondary 
treatment unit. The process by which wet weather diversions can be 
approved in National Pollutant Discharge Elimination System (NPDES) 
permits for POTW treatment plants serving combined sewer systems was 
previously outlined in the 1994 CSO Policy, 59 FR 18,693-18,694 (April 
19, 1994). Nothing in this policy addresses the requirements for POTW 
treatment plants serving combined sewer systems.
    While EPA recognizes that peak wet weather flow diversions around 
secondary treatment units at POTW treatment plants serving separate 
sanitary sewer conveyance systems may be necessary in some 
circumstances to prevent temporary loss of function of secondary 
treatment units, the Agency and stakeholders have been concerned for 
some time that peak wet weather flow diversions could have adverse 
environmental or public health impacts because of the higher expected 
pollutant load of diverted flows.
    Accordingly, EPA strongly discourages reliance on peak wet weather 
flow diversions around secondary treatment units as a long-term wet 
weather management approach at a POTW treatment plant serving separate 
sanitary sewer conveyance systems and that such diversions should be 
minimized to the maximum extent feasible taking into account the 
factors discussed in this policy. EPA anticipates that, over time, the 
need to undertake peak wet weather flow diversions at POTW treatment 
plants serving separate sanitary sewer conveyance systems can be 
eliminated from most systems in a variety of ways, such as by enhancing 
storage and treatment capacity and reducing sources of peak wet weather 
flow volume. EPA expects that aggressive efforts by POTW treatment 
plant operators in consultation with NPDES authorities can lead to 
dramatic reductions in the volume and duration of peak wet weather 
flows and can improve the treatment and quality of peak wet weather 
flow discharges. EPA also believes that the involvement of the general 
public will improve the assessment of various options to minimize peak 
wet weather flow diversions.
    In recent years there has been substantial confusion regarding the 
regulatory status of peak wet weather flow diversions around secondary 
treatment units at POTW treatment plants serving separate sanitary 
sewer conveyance systems. In some cases, such diversions have been 
considered a bypass and held to the criteria of the NPDES bypass 
regulation (40 CFR 122.41(m)). In other cases, diversion scenarios 
around secondary treatment units at POTW treatment plants have been 
constructed and permitted at facilities without consideration of the 
bypass regulation criteria.
    In 2003, EPA proposed a policy to clarify the regulatory status of 
peak wet weather flows that are combined with secondary effluent, a 
practice known as blending. 68 FR 63,042 (Nov. 7, 2003). In that 
proposed policy, EPA stated that if certain procedures were followed, 
peak wet weather flow blending would not be considered a bypass under 
40 CFR 122.41(m). The Agency received over 98,000 comments on the 
proposed policy and on May 19, 2005 indicated that it no longer 
intended to pursue further action on the proposal.

Applicability of the Bypass Regulation to Blending

    This policy provides the Agency's interpretation that the 40 CFR 
122.41(m), the bypass regulation, applies to peak wet weather 
diversions at POTW treatment plants serving separate sanitary sewer 
conveyance systems that are recombined with flow from the secondary 
treatment units. If the criteria of 40 CFR 122.41(m)(4)(i)(A)-(C) are 
met, NPDES authorities can approve peak wet weather flow diversions 
around secondary treatment units in a NPDES permit for discharges from 
a POTW treatment plants as an anticipated bypass under 40 CFR 
122.41(m)(4)(ii).
    This policy:
    [cir] Interprets the provisions of 40 CFR 122.41(m)(4) as they 
apply to peak wet weather flow diversions around secondary treatment 
units at POTW treatment plants serving separate sanitary sewer systems 
where the diverted flow is recombined with flow from the secondary 
treatment units prior to discharge;
    [cir] Interprets the term ``no feasible alternatives'' in 40 CFR 
122.41(m)(4)(i)(B) as it applies to such peak wet weather flow 
diversions;
    [cir] Does not apply to discharges or overflows prior to the 
headworks of a POTW treatment plant; dry weather diversions; diversions 
around primary or tertiary treatment units; or diverted flow that is 
not recombined with flow from the secondary treatment units prior to 
discharge;
    [cir] Promotes use of measures to provide the highest possible 
treatment to the greatest possible peak wet weather flow; and
    [cir] Promotes reporting and public notification of peak wet 
weather diversion events.
    A combination of approaches can be used to achieve the goals of 
this policy. These approaches include:
    [cir] Ensuring full utilization of available secondary treatment 
capacity;
    [cir] Reducing infiltration and inflow (I/I);
    [cir] Maximizing the use of the collection system for storage;
    [cir] Providing off-line storage; and
    [cir] Providing sufficient secondary treatment capacity.
    EPA recognizes that these approaches, alone or in combination, may 
not be sufficient in some cases to enable a POTW treatment plant to 
process its peak wet weather flows through its secondary treatment 
units. In such cases, a POTW treatment plant operator may have no 
feasible alternative to peak wet weather flow diversions around

[[Page 76016]]

secondary treatment units. This policy sets forth a process for 
determining whether or not such feasible alternatives to peak wet 
weather flow diversions exist. If the NPDES authority determines that 
there are no feasible alternatives to peak wet weather flow diversions 
around secondary treatment units at the treatment plant using the 
analysis set forth in this policy, then the NPDES authority may approve 
peak wet weather flow diversions around secondary treatment units at a 
POTW treatment plant serving separate sanitary sewer conveyance systems 
as an anticipated bypass in accordance with 40 CFR 122.41(m) in a new 
or renewed NPDES permit. The only flow that can be approved as an 
anticipated bypass around secondary treatment units is flow that is 
anticipated to exceed the peak flow capacity of the secondary treatment 
unit(s) even after implementation of the feasible technologies and 
approaches identified via the process outlined in this policy. NPDES 
authorities should include an implementation schedule in the permit for 
the feasible technologies and approaches that would need to be 
implemented and the associated flow volumes. In NPDES permits with such 
implementation schedules, the approval of any anticipated bypass would 
be contingent upon the permittee's performance of the implementation 
schedule. This implementation schedule would be considered a permit 
condition as opposed to a schedule of compliance under 40 CFR 122.47.
    A thoughtful public planning process at the local level is 
important to minimize or eliminate overflows in the collection system, 
minimize I/I into the collection system, maximize treatment of all 
flows, and improve wet weather flow management. EPA recommends that 
POTW treatment plant operators work with their NPDES authorities and 
local communities to proactively minimize peak wet weather influent 
flow volume and improve effluent quality, reduce the frequency and 
volume of diversion events, and improve the structural integrity and 
capacity of collection systems and the reliability of POTW treatment 
plants.
    The use of diversions around secondary treatment units at POTW 
treatment plants serving separate sanitary sewer conveyance systems to 
manage peak wet weather flows is not necessary in many cases and cannot 
be approved if feasible alternatives are identified through the 
analysis described herein. Accordingly, on permit renewal, the 
presumption by the NPDES authority would be against the utility's 
continued use of diversions to manage peak wet weather flows. This 
presumption could be overcome by the POTW treatment plant operator 
again demonstrating that there are no feasible alternatives to such 
diversions through updating and resubmission of the utility analysis 
described in this policy, ensuring that the submission identifies any 
changes at the facility, progress made in relevant areas, any new 
circumstances, the timing of ongoing projects or construction, or I/I 
reduction schedules. Timely permit renewals for facilities that employ 
peak wet weather diversions around secondary treatment units at the 
POTW treatment plant should be a priority. Because of the importance of 
regular analysis of the ongoing need to utilize diversions at a 
particular facility, NPDES permits for facilities that employ or seek 
to employ peak wet weather diversions around secondary treatment units 
at their treatment plant should be timely renewed rather than 
administratively continued.
    The determination of what constitutes a `peak wet weather event,' 
during which the use of a peak wet weather diversion may be approved by 
a NPDES authority as an anticipated bypass, will be a site-specific 
determination. Certainly, EPA does not expect diversions at POTW 
treatment plants serving separate sanitary sewer conveyance systems to 
be used for routine rain events. EPA also cannot reasonably estimate or 
endorse an `acceptable' number of anticipated bypasses (e.g., five per 
year). Such a one-size-fits all approach would not recognize the site-
specific nature of peak wet weather diversions and could lead to 
excessive use of diversions in some communities. Rather, it is EPA's 
intention through this policy to ensure that POTW treatment plant 
operators, NPDES authorities, and the general public evaluate what 
constitutes a peak wet weather event for a POTW treatment plant for 
which there is no feasible alternative to a peak wet weather diversion, 
based upon past diversions, opportunities for eliminating or reducing 
diversions, and future considerations. Where such peak wet weather 
diversions at a POTW treatment plant cannot be feasibly avoided, 
additional technologies (e.g., providing supplemental biological or 
physical/chemical treatment) and approaches should be used to maximize 
treatment of diverted flows where feasible. EPA does not support the 
use of peak wet weather diversions around secondary treatment units at 
POTW treatment plants when the peak flows are largely due to poor (or 
lack of) collection system maintenance or the lack of investment in or 
upgrades to treatment capacity.
    Under this policy, NPDES authorities and POTW treatment plant 
operators need to ensure that all flows that will be diverted from the 
secondary treatment units in peak wet weather events receive a minimum 
of primary treatment and any supplemental treatment or technology shown 
feasible using the factors outlined in this policy. All discharges from 
POTW treatment plants serving separate sanitary sewer conveyance 
systems must meet effluent limitations, including the 85 percent 
removal requirement (unless the discharge from the POTW treatment plant 
meets the requirements of 40 CFR 133.103(d) (less concentrated influent 
wastewater for separate sanitary sewers)) and other secondary treatment 
requirements and any more stringent limitations necessary to meet water 
quality standards. Failure to meet effluent limitations is a permit 
violation. NPDES authorities should ensure that the facility, including 
when diverting, does not have the reasonable potential to cause or 
contribute to non-attainment of any water quality standards.
    EPA recognizes that some POTW treatment plants may be implementing 
technologies more advanced than or supplementary to secondary 
treatment. The Agency encourages the use and permitting of such 
technologies (e.g., membrane, tertiary) where they produce a higher 
quality effluent. In the case where a POTW treatment plant is using, or 
plans to use, technology that is more effective in baseline pollutant 
removal than is required to meet secondary treatment-based permit 
limits, the NPDES authority should take that improved baseline 
performance into consideration when determining whether peak flow 
diversions at a POTW treatment plant are approved and under what 
conditions.

No Feasible Alternatives Analysis Process

    An authority's determination as to whether or not there is a 
feasible alternative to peak wet weather diversions at a POTW treatment 
plant serving a separate sanitary sewer collection system should be 
made using the following inputs and criteria, which are based on 40 CFR 
122.41(m)(4)(i)(A)-(C) and 40 CFR 122.21(j). At the time of NPDES 
permit application or NPDES permit renewal:
    1. POTW treatment plant operators seeking approval of peak wet 
weather diversions at a treatment plant as an anticipated bypass should 
submit a

[[Page 76017]]

comprehensive analysis (utility analysis) to the NPDES authority that:
    a. Documents current treatment plant design capacity for all 
treatment units, the maximum flow that can be processed through those 
units, and the feasibility of increasing such treatment capacity and 
related costs;
    b. Estimates the frequency, duration, and volume of current wet 
weather diversions, and evaluates alternatives to reduce the frequency, 
duration, and volume of such occurrences and related costs;
    c. Estimates the potential for future peak wet weather diversions 
based upon information such as predicted weather patterns, population 
growth, and projected treatment plant and collection system changes 
(e.g., upgrades, extensions, deterioration) and evaluates options for 
reducing diversions based on these variables;
    d. Assesses existing storage within the collection system or on-
site and options for enhanced utilization or expansion (taking into 
account physical and technological considerations) of storage to reduce 
the frequency, duration, and volume of peak wet weather diversions, and 
the related costs;
    e. Assesses other ways to reduce peak wet weather flow volumes, 
such as limiting collection system extensions or slug loadings from 
indirect dischargers;
    f. Evaluates technologies (such as supplemental biological 
treatment, physical chemical treatment, ballasted flocculation, deep 
bed filtration, or membrane technology) that are or could be used to 
provide additional treatment to peak wet weather flows or peak wet 
weather diversions at the POTW treatment plant and the costs of 
implementing those technologies;
    g. Evaluates the extent to which the permittee is maximizing its 
ability to reduce I/I throughout the entire collection system (i.e., 
not only the portions operated by the utility, but also portions 
operated by any municipal satellite community), including the use of 
existing legal authorities, potential improvements in the timing or 
quality of such efforts, and options for obtaining or expanding legal 
authorities to reduce I/I from satellite collection systems;
    h. Evaluates peak flow reductions obtainable through implementation 
of existing Capacity, Management, Operations, and Maintenance (C-MOM) 
programs and potential improvements in the timing or enhancement of 
those programs and the related costs; or, if no such program exists, 
reductions obtainable through the development and implementation of a 
C-MOM program and the related costs;
    i. Assesses the community's ability to fund the peak wet weather 
flow improvements discussed in the utility analysis, taking into 
consideration: current sewer rates, planned rate increases, and the 
costs, schedules, anticipated financial impacts to the community of 
other planned water and wastewater expenditures, and other relevant 
factors impacting the utility's rate base, using as a guide EPA's CSO 
Guidance for Financial Capability Assessment and Schedule Development, 
EPA 832-B-97-004;
    j. Proposes a protocol for monitoring the recombined flow at least 
once daily during diversions for all parameters for which the POTW 
treatment plant has daily effluent limitations or other requirements 
(e.g., monitoring only requirements) and ensures appropriate 
representative monitoring for other monitoring requirements of the 
permit, the total volume diverted, and the duration of the peak wet 
weather diversion event; and
    k. Projects the POTW treatment plant effluent improvements and 
other improvements in collection system and treatment plant performance 
that could be expected should the technologies, practices, and/or other 
measures discussed in the utility analysis be implemented.
    2. For any POTW treatment plant operator seeking approval in an 
NPDES permit for an anticipated bypass under this policy, the NPDES 
authority should:
    a. Make the utility analysis publicly available with other draft 
permit information for public review and comment;
    b. Review and evaluate the utility analysis and require measures to 
be undertaken to provide the highest possible treatment to the greatest 
possible peak wet weather flow, taking into account the full range of 
economic, environmental, public health, and engineering considerations;
    c. Review and approve or deny the peak wet weather diversions based 
on the determination of whether there are feasible alternatives to 
those diversions using the analysis set forth in this policy;
    d. Include a permit provision recognizing any approved peak wet 
weather diversions as anticipated bypasses, and specify the conditions 
for allowing such diversions;
    e. Include a permit provision requiring any POTW treatment plant 
operator that has an approved anticipated bypass to provide notice of 
the peak wet weather diversion event consistent with 40 CFR 
122.41(m)(3);
    f. Include a permit provision requiring the operator of any POTW 
treatment plant that has an approved anticipated bypass to monitor the 
recombined flow at least once daily during diversions for all 
parameters for which the POTW treatment plant has daily effluent 
limitations or other requirements (e.g., monitoring only requirements), 
the total volume diverted, and the duration of the peak wet weather 
diversion event. For parameters for which the permit establishes non-
daily effluent limitations, include in the permit monitoring 
requirements sufficient to yield data representative of the final 
blended discharge, in order to ensure compliance with applicable 
effluent limitations. See 40 CFR 122.48(b);
    g. Describe in the permit Fact Sheet prepared under 40 CFR 124.8(b) 
how the peak wet weather event was calculated, the reason for allowing 
peak wet weather diversions, and any requirements for such peak wet 
weather diversions;
    h. Ensure that permit load limitations account for the anticipated 
flow into secondary treatment units during both wet and dry weather 
conditions;
    i. Include permit provisions for public notification (e.g., via 
utility website) of the peak wet weather diversion event within 24 
hours of the inception of each event; follow up public notification of 
the duration and volume of the event within 48 hours of its cessation; 
and for public review of the POTW treatment plant operator's peak wet 
weather flow diversion practices upon request;
    j. Include permit provisions requiring the control authority with 
an approved pretreatment program to review, and revise if necessary, 
local pretreatment limits for indirect dischargers to take into account 
peak wet weather diversion events (e.g., significant industrial users 
with batch discharging);
    k. If the discharge will be to sensitive receiving waters (i.e., 
waters used for recreation; drinking water; shellfish beds; waters 
formally designated by state or federal authorities as requiring 
special consideration or protection; waters with threatened or 
endangered species), ensure that the impact of any peak wet weather 
diversion events on these waters is minimized and additional caution 
exercised as permit limitations are set; and
    l. Rigorously review each and every POTW permit renewal request 
that seeks continued approval of peak wet weather diversions to ensure 
that a comprehensive utility analysis consistent with section 1 above 
is submitted and evaluated and that peak wet weather diversions are 
approved only when no feasible alternatives to

[[Page 76018]]

them are identified through the process set forth in this policy.
    3. EPA will:
    a. Use this policy in making NDPES permitting decisions for all 
POTW treatment plants serving separate sanitary sewer conveyance 
systems in non-authorized states;
    b. Review permits in NPDES authorized states within the timelines 
specified in 40 CFR 123.44 for all POTW treatment plant operators 
seeking approval for diversions pursuant to this policy to ensure that 
they are consistent with this interpretation of the regulations;
    c. Ensure that enforcement actions are taken, where appropriate, 
against POTW treatment plant operators that fail to move forward 
expeditiously to meet their legal obligations as determined consistent 
with this policy; and
    d. Ensure that monitoring data received concerning peak wet weather 
diversions at POTW treatment plants is available to the public on EPA's 
website in a searchable and correctable database.

    Dated: December 19, 2005.
Benjamin H. Grumbles,
Assistant Administrator, Office of Water.
 [FR Doc. E5-7696 Filed 12-21-05; 8:45 am]
BILLING CODE 6560-50-P