Clean Water Advocacy - Newsroom - AMSA in the News
Lack of Data on Health Impacts, Overflows
Should Be Cited in EPA Report, Group Says
An upcoming report to Congress by the Environmental Protection Agency on the
impacts of sewer overflows should indicate that little data exist to directly
link overflows to public health problems, wastewater treatment officials said in
a letter to the agency.
While overflows from combined sewers and sanitary sewers may contain pathogens,
the report should articulate the potential risk, if any, to public health from
exposure to these contaminants, the Association of Metropolitan Sewerage
Agencies said in the Aug. 21 letter to G. Tracy Mehan, EPA assistant
administrator for water.
The agency is required under the Wet Weather Water Quality Act of 2000 to submit
the Report to Congress on the Impacts and Controls of Combined Sewer Overflows (CSOs)
and Sanitary Sewer Overflows to Congress by Dec. 15.
Among the items contained in the report will be a listing of pollutants and
pathogens found in overflows, the associated human health threats, sources of
pathogens, and indicators of human health threats from polluted waters.
"The Report should not imply that a link can be made between CSOs and SSOs and
public health impacts simply because CSOs and SSOs contain pathogens," the AMSA
letter said. "To avoid making unsupported conclusions, the Report must clearly
identify the expected levels of pathogens in CSOs and SSOs, the probability of
pathogen viability and anticipated intensity of exposure, and the resulting
probability of illness."
Only Two Illnesses Linked to Pathogens
AMSA said only two cases of waterborne illness have a documented link with
exposure to pathogens from sanitary sewer overflows and none from combined sewer
overflows.
Moreover, EPA data on the number of outbreaks of waterborne disease between 1985
and 2000 came from a single event--the 1993 Milwaukee case when more than 100
people died and 400,000 people were made sick from exposure to cryptosporidium
that had gotten into the city's drinking water, AMSA said. Most of the
incidences of illness associated with water recreation resulted from exposure to
pathogens in swimming pools and hot tubs, the group said.
At its annual meeting in July, some AMSA officials said they were concerned that
EPA had already concluded that a substantial link existed between sewer
overflows and human health impacts and were only looking for the data to support
it (136 DEN A-11, 7/16/03
).
An EPA official, who asked not to be named, told BNA the agency recognizes the
inadequacies of the data but will try to compile as much information as possible
and present it in an objective format. Representatives from various interest
groups provided information to the agency at a stakeholder meeting in June, and
these comments as well as written comments will be considered in developing the
final report, the official said.
However, the official said he did not think it was as bad as some organizations
would portray it, but added that so much of the agency's work "contends with
uncertainty on scientific issues."
AMSA Cites Errors in Key Data
AMSA also pointed out what it said were errors in key data sets that would be
used in the report, including inaccurately entered data submitted by an Ohio
wastewater treatment plant.
"These errors call into question the quality of the other databases and
information sources used in support of the Report," the AMSA letter said.
The association also urged the agency not to try to establish national estimates
on the combined impacts from SSOs and CSOs because regional differences could
skew the conclusions. The report also should distinguish between overflows that
occur in dry weather and wet weather because they differ in cause, volume,
frequency, and relative impact, AMSA said.
The agency official said EPA hopes to send a draft of the final report to the
White House Office of Management and Budget for review soon.