Quality of Drinking Water Drops in Allegheny
Aspinwall Hearld
17 November 2010
By Mary Ann Thomas
Drinking water drawn from the lower Allegheny River contains rising
levels of a contaminant but is safe to drink, say health officials who
are trying to determine the cause.
The Pittsburgh Water and Sewer Authority detected significant increases
in trihalomethanes, or THMs, over the past two months. But the levels
don't exceed health standards, said Guillermo Cole, spokesman for the
Allegheny County Health Department.
"It's obviously going in the wrong direction, but it's not that close
to exceeding the standard," Cole said.
Long-term exposure to THMs might cause liver, kidney or central nervous
system problems and increase the risk of cancer, according to the
Environmental Protection Agency.
Health Department and state Department of Environmental Protection
officials are monitoring the problem. PWSA officials sampled the river
and its tributaries to test for bromides, which can help form THMs.
Preliminary results show a high concentration coming from the
Kiskiminetas River, said Stanley States, the authority's director of
water quality and production.
Eight surface water systems have intakes on the Allegheny, serving
about 486,000 people from Pittsburgh to just south of the Kiski River
in Armstrong County, said Ronald Schwartz, the DEP's assistant regional
director in Pittsburgh.
"Based on tests, there's not a risk to the public at this point,"
Schwartz said. "The issue is how to prepare for the future if we see
this year and year after."
The DEP studied this problem before. High levels of THMs were flagged
on the Monongahela River two years ago and appear to be tapering off,
Schwartz said.
In that case, bromides helped form the THMs. Found naturally in
seawater and underground rock formations, bromides are used in
industrial processes and products such as flame retardants. The
bromides themselves don't pose a health risk and are unregulated,
Schwartz said.
Schwartz attributed the bromide concentrations in the Mon to possible
sources such as water from power plants, acid mine drainage and
treatment facilities that discharge water used for gas drilling in the
Marcellus shale. The agency found its highest concentration of bromides
in the Mon at Whiteley Creek, a tributary where an acid mine drainage
cleanup project is located.
Data show bromides were found in water from the deep shale gas
drilling, said Katy Gresh, a DEP spokeswoman. Water used in hydraulic
fracturing of the shale, or fracking, contains additives.
Preliminary tests by PWSA suggest an excess of bromides in the
Allegheny could be fueling the elevated THM concentrations in drinking
water. It's too early to determine a source or sources, said Melissa
Rubin, PWSA spokeswoman.
Mary Ann Thomas can be reached at mthomas@tribweb.com or 412-782-2121
x1510.