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OVERVIEW OF THE PROBLEM
The Pittsburgh region's frequent rainfall brings an underground,
out-of-sight problem into clear view. As little as one-tenth of
an inch of rain—an average Pittsburgh rainfall is one-quarter
inch—can cause raw sewage to overflow into our rivers and streams.
Melting snow can cause the same effect.
During dry weather, the sewage collection system, which transports
wastewater from thousands of homes to the wastewater treatment plant,
operates effectively.
However, when it rains or snow melts, extra stormwater gets into
the sewage collection system through direct connections or through
leaky, cracked pipes. This extra volume of water overloads the sewage
collection system pipes and raw sewage overflows at hundreds of
locations before it reaches the treatment plant. Untreated sewage
streams into waterways, overflows from manholes or backs up into
homeowners' basements.
And the effects of wet weather can last for days. During the recreational
boating season, May 15-September 30, Allegheny County issues river
advisories to warn individuals using the rivers to limit water contact
when sewage overflows have likely contaminated the water with bacteria
and viruses. Each time a river advisory is issued, it could last
for several days after a rainfall.
Since the program began in 1995, river advisories issued by the
Allegheny County Health Department have been in effect for nearly
50% (70 days) of each recreational season.
Sewage overflows present a public health risk. While exposure
to bacteria, such as giardiasis or cryptosporidiosis, are not considered
fatal for a healthy adult, they can be deadly for those with weaker
immune systems, the elderly and small children. In addition, Pittsburgh's
three rivers serve as the main source of drinking water for 90%
of Allegheny County residents. While the public water systems do
an excellent job of purifying water before sending it to homes,
source protection is the cheapest and most effective way to ensure
drinking water quality.
Water is an important resource for the economic development of
the Pittsburgh region and sewage overflows hinder growth. Because
these overflows violate the Clean Water Act, regulatory agencies,
such as the U.S. Environmental Protection Agency and PA Department
of Environmental Protection, will not permit municipalities to add
new connections to the existing sewer system until the overflow
problem is fixed. This restriction limits the construction of new
businesses and homes in many communities throughout the region.
Fixing the problem is going to require a substantial long-term
investment. Some estimates for the cost of rehabilitating the sewage
collection and treatment system total up to $3 billion. State and
federal support may be available to help offset a portion of the
bill, but municipalities must share resources and work cooperatively
across geographic boundaries in order to significantly trim the
total bill for ratepayers who will have to bear sewer rate increases
in the coming years.
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