Sewage treatment plants in southwestern Pennsylvania are rejecting gas well drilling water while authorities seek the source of pollution in the Monongahela River.

High levels of total dissolved solids that showed up in October seem to be easy to explain in the abstract and hard to solve on the ground.

"I think it's safe to say it's largely the mining and drilling activities -- oil and gas or mining," said John Wirts, Watershed Assessment Program manager for the West Virginia Department of Environmental Protection.

That view agrees with actions taken by the Pennsylvania Department of Environmental Protection -- yet the problem persists.

"Total dissolved solids" is a measure of everything dissolved in water. It includes chlorides and sulfates, substances that commonly enter waterways through mining and drilling activities and are not removed by conventional wastewater treatment.

While not considered to be a threat to human health by the U.S. Environmental Protection Agency, TDS can affect the taste and odor of water; they also may impair the operation of industrial equipment.

Samples taken by PADEP at 28 of 40 sites in the past month exceeded Pennsylvania's maximum water quality standard of 700 parts per million TDS, with one as high as 908 ppm, according to data posted on the agency's Web site.

An additional seven sites tested above the standard of 500 ppm as an average of samples taken at a site.

PADEP officials said in an Oct. 22 news release that they were investigating four contributing factors:

• First mentioned was high TDS levels where the Monongahela River flows from West Virginia into Pennsylvania.

  Water at that point tested at 486 ppm TDS in mid-October and 516 ppm early this month. WVDEP's Water Quality Assessment office did not have comparable current or historical data available.

• Second, low flow conditions. PADEP asked the U.S. Army Corps of Engineers in October to help dilute the TDS by increasing releases from the Tygart Lake and Stonewall Jackson Lake. However, PADEP spokeswoman Teresa Candori said Nov. 6 dam releases are on hold because of low water levels.
• Third was drainage from abandoned coal mines. PADEP's media release said that the rates of discharge have been relatively constant.
• And finally, high volumes of gas well drilling water are being treated by sewage treatment plants in the Monongahela River basin.

On Oct. 22, PADEP ordered nine sewage treatment plants to reduce their volumes of gas well drilling water, which contains high concentrations of TDS, from in some cases as much as 20 percent of volume to 1 percent until the problem is resolved.

Drilling companies can store drilling water at their sites until the concentration of solids in the Monongahela River returns to normal, Candori said, or they can truck it elsewhere for treatment and disposal.

A Nov. 14 public meeting at 10 a.m. at the Morgantown Municipal Airport will gather West Virginia and Pennsylvania agency officials to share information toward a solution for the high TDS levels. The Mon River Recreation and Commerce Committee of the chamber's Vision 2020 program and by the Upper Monongahela River Association will host the meeting.