High levels of total dissolved solids are polluting the lower five miles of Dunkard Creek, site of a massive 2009 fish kill, and adversely affecting water quality in the Monongahela River, according to state environmental officials.
TDS levels in the Mon, a water source for 11 water treatment plants with 350,000 customers, are elevated but do not yet exceed the state standard of 500 parts per million, according to the Department of Environmental Protection.
The high TDS concentrations on Dunkard Creek, a tributary of the Mon 87 river miles from Pittsburgh's Point, are caused by a combination of low stream flow due to drought conditions, abandoned mine discharges and the discharges from Dana Mining's Steele Shaft treatment plants.
John Poister, a DEP spokesman, said the department's water quality and mining divisions are aware of the problem, have investigated the cause and asked Dana Mining to halt its discharges, which he said has been done.
"We have an agreement with Dana that requires the company to cut back on its discharges, but it normally isn't implemented until August," Mr. Poister said. "But the creek flow is already at August levels because of the drought."
The DEP has not issued any warnings about water quality to the public water suppliers on the river or heard any complaints, he said.
Mr. Poister said precipitation in the Dunkard Creek watershed is 3 inches below normal for the year, and predictions say the TDS problem will get worse before it gets better.
"Even with the discharge controls there's not a lot more we can do because of the low stream flow rates and continued abandoned mine discharges," he said.
A U.S. Geological Survey monitor on Dunkard Creek, at Shannopin, Greene County, below the Steele Shaft discharges, found TDS concentrations of approximately 5,200 parts per million or seven times the state standard Friday.
Sampling done on Dunkard Creek Thursday above the Steele Shaft discharges by the Greene County Watershed Alliance found TDS levels just slightly above the standard.
Dana Mining did not return phone calls requesting comment on Friday.
High levels of dissolved solids in the Mon in 2008 and 2009 caused problems for industries that cannot use the contaminated water and also affected the taste of public drinking water supplies.
Don Hopey: email@example.com or 412-263-1983.