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EPA Proposes Limited Relief to City Sewer Plants Experiencing Storm Water Problems
Apr 1, 2004 U.S. Mayor Newspaper
EPA Proposes Limited Relief to City Sewer Plants Experiencing Storm Water
Problems
By Rich Anderson
March 29, 2004
The U. S. Conference of Mayors' Environment Committee and Urban Water Council
urged James Hanlon of the U. S. Environmental Protection Agency (EPA) to adopt a
proposed clarification of the so-called "bypass and blending" policy. When
wastewater treatment plant operators experience major storms and flooding they
will divert ("bypass") storm water around certain treatment processes that could
be damaged by flooding. Operators then "blend" the bypassed storm water into
various parts of the treatment works with normal wastewater. Critics of the
practice, and some EPA Regional Offices have expressed concern over the
resulting water quality of the blended effluent.
Citing great uncertainty related to regulatory compliance and the need for
costly capital improvements, mayors at the U. S. Conference of Mayors- Winter
Meeting held in Washington, DC hand delivered a letter of support for EPA's
proposed policy clarification. The National League of Cities, the Association of
Metropolitan Sewerage Agencies and the Water Environment Foundation Similar
submitted similar petitions to EPA.
Cities responsible for sewer plants (Publicly Owned Treatment Works-POTWs) have
anxiously awaited action by the EPA concerning regulations governing storm
related overflows. Regulations either in effect or being shaped now by the EPA
could result in costly changes for cities. Even if a city is not responsible for
the sewer works citizens ratepayers will shoulder the potential cost increases
for water diversion systems or mandated capital improvements. The "bypass and
blending" policy could substantially disrupt current wet weather overflow
management practices.
The EPA proposed both an interpretation of and guidance for wet weather peak
flow policy for POTWs on November 7, 2003. EPA acknowledged that cities and
water authorities that hold National Pollutant Discharge Elimination System
permits (NPDES) are experiencing confusion with state regulators and
environmental activist groups over what the legal requirements are for handling
potential overflows during and after wet weather episodes. What made the
situation particularly difficult for the many cities around the nation trying to
comply with the regulations was the fact that the 10 EPA Regions did not
interpret or enforce the policy consistently.
"Bypass and Blending" ? an Operational Practice
The heart of the issue involves wet weather peak flows where storm waters enter
into the sewer collection systems and overwhelm the secondary and/or advanced
treatment systems. Often times such overflows damage the treatment units and
result in discharges of untreated sewage into receiving waters. Plant operators
have for some time diverted some or all of the storm-flow around the secondary
(biological) treatment units into excess primary clarification units for storage
or to retention basins. This practice is called "bypass. " When flows return to
normal conditions the operators blend the stored storm water in with wastewaters
that have been processed through the treatment system. This practice is called
"blending. " Some operators discharge the bypassed storm water directly into
receiving waters.
EPA regulators in EPA's Regional Offices and state regulators have interpreted
bypass and blending policy differently. Some regulators agree with plant
operators that as long as the blended discharge meets effluent standards and the
water quality standards of receiving waters there is no environmental
degradation and all permit requirements have been met. Other regulators,
however, contend that the bypass storm water must be re-directed to the
treatment systems and undergo secondary and/or advanced treatment in the plant.
The blended effluent must meet effluent limitations as well as the water quality
standards of the receiving waters.
Plant operators argue that re-directing the bypass storm water to the
secondary/advanced treatment systems of the plant is an unnecessary and costly
step. They also argue that the bypass approach is necessary to prevent the
secondary treatment from being damaged. Due to the unique conditions at various
wastewater treatment plants operators have long advocated for bypass and
blending policies that work for their particular situation, and that a "one size
fits all" policy is unacceptable. In short, site'specific plans are necessary to
identify the optimal mix of wet weather management flows.
EPA Proposes Policy Changes
Current EPA regulations prohibit bypass ("the intentional diversion of waste
streams from any portion of a treatment facility") except when it is necessary
to maintain or ensure the efficient operation of a plant. The prohibition
against bypass may be waived if the resulting bypass does not exceed effluent
limitations. Thus, water quality degradation is not likely.
The proposed policy addresses: 1) interpretation of the bypass provision as it
applies to alternative wet weather treatment scenarios; and, 2) draft guidance
on how the interpretation should be implemented at the permit level.
EPA elaborated six "principles" that must be followed in order for cities to
take advantage of the bypass provision and protect water quality at the same
time. The principles require that final discharges must meet effluent standards;
permits must describe the bypass and blending plans including a demonstration
that no feasible alternatives are available; monitoring and record keeping must
be implemented to describe the bypass and blending activities; and, permits must
provide plans to properly operate and maintain all treatment equipment at all
times. that must be followed in order for cities to take advantage of the bypass
provision and protect water quality at the same time. The principles require
that final discharges must meet effluent standards; permits must describe the
bypass and blending plans including a demonstration that no feasible
alternatives are available; monitoring and record keeping must be implemented to
describe the bypass and blending activities; and, permits must provide plans to
properly operate and maintain all treatment equipment at all times. that must be
followed in order for cities to take advantage of the bypass provision and
protect water quality at the same time. The principles require that final
discharges must meet effluent standards; permits must describe the bypass and
blending plans including a demonstration that no feasible alternatives are
available; monitoring and record keeping must be implemented to describe the
bypass and blending activities; and, permits must provide plans to properly
operate and maintain all treatment equipment at all times.
The EPA extended the comment period on the proposed rule to early February. Jim
Hanlon, EPA's Director of the Office of Wastewater, told mayors attending the
Urban Water Council meeting that the Agency will review public comments and make
a determination if any changes to the proposal are warranted. No particular time
frame was identified for completion of the proposed policy changes.
For more information, contact Kevin Weiss at 202-564-0742 or by email at . The
official Docket ID for the bypass and blending policy is ID No. OW-2003-0025.
The United States Conference of Mayors
J. Thomas Cochran, Executive Director
1620 Eye Street, NW, Washington, DC 20006
Telephone (202) 293-7330, FAX (202) 293-2352