Clean Water Advocacy - Newsroom - AMSA in the News
EPA Report Cites Environmental, Health Problems from Sewer Overflows
Marty Coyne, Greenwire senior reporter
Sewer overflows from cities have made thousands of people sick and killed
thousands of fish, but the causes of many outbreaks of waterborne illness and
water quality problems from rainstorms remain unknown, according to a U.S. EPA
report issued Thursday.
The report estimates that more than 9,000 combined sewer systems in the country
spill 850 billion gallons of untreated waste mixed with stormwater each year. In
communities where storm sewers and sanitary sewers are separated, between 23,000
and 75,000 sanitary sewer overflows account for 10 billion gallons of sewage
that cities spill annually.
Toxics and two types of microbial pathogens -- bacteria and viruses -- in sewage
can make people sick, according to the report. Viruses -- such as giardia and
cryptosporidia -- and intestinal bacteria cause problems including skin rash,
abdominal cramps, diarrhea, fever and vomiting. Drinking water or fish
contaminated with heavy metals and synthetic chemicals may cause anemia, nervous
system and blood problems, reproductive troubles and an increased risk of
cancer. People become ill when they come in contact with or ingest water or fish
contaminated with these pollutants from human waste. Exposure to waters
contaminated by sewer overflows is common among swimmers, boaters and homeowners
with flooded basements. Ingestion of sewage pathogens and toxics in unsafe
amounts usually occurs through consumption of tap water.
EPA found that Shigella -- bacteria that cause diarrhea, fever and stomach
cramps -- from sewer overflows caused nearly 1,200 documented cases of illness
from recreational water use during that 15-year period. Most who are infected
with Shigella develop diarrhea, fever, and stomach cramps starting a day or two
after exposure.
The report, however, comes with a large caveat for the human health consequences
of sewer overflows. "In developing this report to Congress, EPA found an absence
of direct cause-and-effect data" relating overflows to specific health problems
because of a lack of a comprehensive tracking system for sewer overflows and
waterborne disease outbreaks. As a result, EPA based its report in large part on
existing data from the CDC and states.
Pathogens in swimming pools and hot tubs pose a greater human risk than
recreation in contaminated lakes, rivers, streams and estuaries, according to
the report. "For swimming pools and hot tubs, 191 recreational waterborne
disease outbreaks with 14,836 cases of illness were reported to the CDC between
1985 and 2000. This is 265 times the number of illnesses reported for open
recreational waters."
The EPA report also cites limited data on environmental problems caused by sewer
overflows, which "are clearly the cause of documented environmental impacts in
some cases and are a contributing factor in others." For example, the North
Carolina Department of Environment and Natural Resources attributed the deaths
of nearly 10,000 fish to sanitary sewer overflows between 1997 and 2002. And a
combined sewer overflow from Marine Corps Base Camp Pendleton in California
spilled 2.73 million gallons of sewage into coastal waters near the city of
Oceanside, killing 556 fish and shellfish. More broadly, the report cites 1995
data from the National Oceanic and Atmospheric Administration that attributed 24
percent of shellfishing restrictions to "routine and accidental sewage discharge
from public and private wastewater treatment plants."
While urban water pollution is often cited for beach closures, the EPA report
confirms that sewer overflows play a small role in this problem. Combined sewer
overflows cause 1 percent of beach closings and 2 percent of swimming
advisories, while sanitary sewer overflows cause 6 percent of closings and
advisories. The Natural Resources Defense Council, in the latest of its annual
report on beach closures, noted that 70 percent of the sources of pollution
responsible for all closures and advisories were unknown (Greenwire, Aug. 6).
Although NRDC concluded that 88 percent of closing and advisories are from
bacteria prevalent in sewer spills other sources of these pathogens include
runoff from animal feedlots.
Nonetheless, NRDC thinks the paucity of information acknowledged by EPA in the
report has hamstrung the agency. "It is abundantly clear, I think, that EPA
doesn't have sufficient data to effectively manage this program to target
environmental or public health risk reduction," said Nancy Stoner, director of
the NRDC Clean Water Project. Cities should face tougher requirements for
monitoring sewer overflows within their systems and at outfalls to waterbodies,
she said.
Such requirements could be expensive and wastewater treatment plant operators
seized on the EPA report's conclusion that cities are already spending billions
of dollars to control overflows. The report demonstrates that "clean water
facilities have done an outstanding job in reducing sewer overflows, but federal
funding is needed to address the $88 billion and $50.6 billion EPA-estimated
cost to fully control SSOs and CSOs, respectively, over the next 20 years," said
Ken Kirk, the executive director of the Association of Metropolitan Sewerage
Agencies.
A good chunk of the money spent by cities has come from EPA enforcement actions,
which recently yielded a $2 billion sewer overflow settlement with Los Angeles (Greenwire,
Aug. 13). Although the Los Angeles agreement does not limit overflows
specifically, EPA estimates that enforcement actions and clean water permits
have so far reduced overflows by 14 billion gallons annually.