Clean Water Advocacy - Newsroom - AMSA in the News
'No Feasible Alternative' Showing Needed
To Justify Blending Practice, Conference Told
BOSTON--Enforcement officials in the Environmental Protection Agency want a
rigorous analysis of "feasible alternatives" before they would allow sewage
treatment facilities to blend partially treated wastewater with fully treated
effluent, municipal officials said at a conference July 15.
The feasible alternatives concern was one of several issues raised by the top
EPA officials, including those in the Office of Enforcement and Compliance
Assurance, regarding guidance being drafted to establish policy on the practice
known as "blending."
The practice is used during wet weather and allows wastewater treatment plants
to route excess flows around the biological, or secondary treatment, process
after they have undergone primary treatment. These flows are then blended with
the treated flows before being discharged.
This practice is done to keep the biological treatment process, which is used to
remove biochemical oxygen demand compounds, from being overwhelmed by the high
volumes of water. The rerouted flows are blended with the treated flows and meet
permit limits once they are discharged.
EPA has been working on a policy outlining specifically when this practice can
be allowed and not violate the Clean Water Act. Representatives from publicly
owned treatment works (POTWs) want a clear policy stating that the practice is
allowed.
They discussed the subject at a conference of the Association of Metropolitan
Sewerage Agencies and shared information from a May meeting they held with EPA
officials. The theme of the conference was "Water Quality and the Wastewater
Community--Emerging Pollutants, New Challenges."
Possible Conflict With CWA
OECA officials said they were concerned the practice of blending may run counter
to Clean Water Act regulations prohibiting bypasses of any phase of the
treatment process except in extreme situations such as someone's life may be at
risk or if there are "no feasible alternatives."
While the Office of Water has generally agreed that blending is an acceptable
way to handle excess flows, the enforcement side of the agency is concerned that
the practice is not enforceable without certain restrictions and that permitting
the practice can be too confusing and complex.
To help address these problems, the enforcement officials support requiring
treatment facilities to do rigorous analyses indicating there are no feasible
alternatives to the practice. They do not want blending to become the "natural
default" for treating wastewater during wet weather events, AMSA officials said
of the meeting with EPA.
David Williams, director of Wastewater for the East Bay Municipal Utility
District in Oakland, Calif., said most POTWs already do these analyses as part
of their master planning. EPA enforcement officials also said they were
concerned about the lack of science on the impacts to human health and
environment caused by blending.
AMSA officials told the agency that blending has been going on since the early
1970s with no scientific studies pointing to a problem. The Clean Water Act
mandates that all discharges from wastewater treatment plants be treated to
secondary treatment standards, which AMSA officials said is a performance
standard.
The act should not be interpreted to mean permit writers should dictate "what is
going on inside the treatment plant" to meet the standard, as they said would be
happening if blending were allowed.
"If you need to change the standard, change the standard. Don't get inside the
treatment works," Williams said.
More Data Sought
The AMSA officials agreed with the agency's enforcement personnel that not
enough data is available regarding whether blending causes an increase in
pathogens. AMSA said it has several factors on its side in support of the
practice, including that many large treatment facilities were built using
federal money under the now-defunct construction grants program.
The money was authorized for treatment plants specifically designed to blend,
Chris Hornback, AMSA's director of regulatory affairs, said at the conference.
"It was approved by the federal government in the 1970s because they gave us the
federal money to build it," he said.
AMSA is also beginning work on a report about the human health and environmental
impacts of pathogens from sewer overflows. The report will be released near the
time EPA submits its mandated report to Congress Dec. 15 on the impacts from
combined sewer overflows and sanitary sewer overflows.
EPA Report Coming
Based on meetings with EPA and information from two agency-sponsored sessions,
AMSA representatives are concerned EPA is going to release a report attempting
to link sewer overflows to outbreaks of illness and other adverse effects.
However, they argued the data is not there to make that connection and cited
only two documented cases where people were made sick as a result of a sewer
overflow.
"EPA has a clear end result, and they're looking for data to support it," Chris
Westhoff, assistant city attorney for the Los Angeles Department of Public
Works, said.
Publicly owned treatment works were urged to supply AMSA with pathogen
concentration data and other information to counter the claims.
"It's imperative that we lay out the real truth that there isn't any data to
make that connection," Westhoff said.
In Philadelphia, wastewater officials collected information from their public
health department and found that illnesses from waterborne pathogens, such as
cryptosporidium, mostly came from exposures in swimming pools and hot tubs,
David Katz, deputy water commissioner for the Philadelphia Water Department,
told the conference.