PITTSBURGH (AP) — High levels of an ultra-salty compound
that could be linked to oil and gas drilling persist in the Allegheny
River's Pittsburgh-area watershed, while the levels declined in the
nearby Monongahela River, recent research shows.
Officials at
public water utilities in both watersheds grew concerned in 2009 and
2010 when bromide levels soared during a surge of Marcellus Shale gas
drilling. Although not considered a pollutant by themselves, the
bromides combine with chlorine used in water treatment to produce
compounds that can threaten public health.
A recent Pittsburgh
Water and Sewer Authority report found that high levels of bromides
persisted this year in the Allegheny just downstream from industrial
brine treatment plants. The plants accept wastewater from oil and gas
drilling and other industrial activities.
Also, preliminary
research by a Duke University team found a similar problem in a
tributary of the Allegheny, professor Avner Vengosh told The Associated
Press on Monday. Vengosh said the source there appears to be from
conventional oil or gas wells, not shale wells.
But on the
Monongahela River, a Carnegie Mellon University team said last week,
preliminary research found that bromide levels declined significantly
this year, after Marcellus Shale gas drillers responded to warnings from
scientists and environmental groups and voluntarily stopped taking
waste to treatment plants there. The Monongahela merges with the
Allegheny in Pittsburgh.
In early 2011, the state Department of
Environmental Protection called on shale gas drillers to voluntarily
stop taking wastewater to public water treatment plants along rivers,
and major companies and industry groups agreed to the request. Now, most
shale wastewater is sent to deep underground waste wells in Ohio or
recycled.
The DEP wastewater request doesn't apply to conventional oil and gas well wastewater, and Vengosh said that doesn't make sense.
"I
think the focus on only shale gas is kind of misleading," Vengosh said,
noting that all the wells produce naturally-occurring brine water,
which can be much saltier than seawater, and also contain heavy metals
and natural radiation.
"It's all psychological," Vengosh said of
the distinction between shale gas waste and other drilling waste. "That
for me doesn't make any sense."
The Marcellus Shale lies under
parts of Pennsylvania, Maryland, New York, Ohio and West Virginia, and
the procedure called hydraulic fracturing, or fracking, has made it
possible to tap into deep reserves of oil and gas. But the boom in shale
gas fracking raised concerns about pollution. Large volumes of water,
along with sand and hazardous chemicals, are injected underground to
break rock apart and free the oil and gas.
Regulators contend that
water and air pollution problems are rare, but environmental groups and
some scientists say there hasn't been enough research on these issues.
The industry and many federal and state officials say the practice is
safe when done properly.
The Water and Sewer Authority report also
noted that bromide levels rose in rivers below where some coal-fired
power plants discharge wastewater, which can also include bromides.
Dave
Mashek, a spokesman for the Pennsylvania Independent Oil and Gas
Association, said that state regulators don't set a limit on bromide
discharges and that the amount of wastewater that comes from
conventional wells is decreasing.
He also noted that the Water and
Sewer Authority testing only identified elevated bromide levels in the
Allegheny for part of the year, during periods of low river flow.
Kevin
Sunday, a spokesman for the Department of Environmental Protection,
said many other sources of bromide exist beyond oil and gas wells. He
said the volume of wastewater produced by conventional oil and gas wells
is substantially lower than what comes from shale gas wells.