The Department of Environmental Protection announced this week levels of total dissolved solids, or TDS, in the Monongahela River have fluctuated above the water quality standard for taste, exceeding acceptable levels for drinking water established by state and federal authorities.

"Since elevated levels of TDS were detected last year on the Monongahela River, the department has closely monitored the situation and has taken necessary action to reduce these levels," said Environmental Protection Secretary John Hanger. "Water treatment plants are not equipped to remove TDS from drinking water, and therefore the increased levels may cause drinking water to taste salty. Concerned residents may opt to use bottled water for drinking and preparing food until the levels of TDS decrease to normal levels."

TDS is a measure of all elements dissolved in water and can include carbonates, chlorides, sulfates, nitrates, sodium, potassium, calcium and magnesium. While none of these elements have exceeded its respective stream limit, sulfate, at 191 milligrams per liter, is approaching its limit of 250 milligrams per liter.

Sources of TDS can include sewage treatment plants, stormwater runoff, metal mining, mining, abandoned mine drainage, meat packing plants, vegetable processing plants, grain milling plants, bakeries, beverage processing facilities, agricultural chemical manufacturing, oil and gas drilling, petroleum refining, leather processing, primary metal industries, fabricated metal products, electric services, refuse systems, scrap and waste material industries.

The department, as well as the U.S. Environmental Protection Agency, have established secondary maximum contaminant levels of 500 parts per million of TDS for the commonwealth's drinking water and waterways.

Lab analysis of the Monongahela River water at Point Marion, where West Virginia borders Pennsylvania, and near Elizabeth, Allegheny County, showed TDS levels ranging from 500 to 600 milligrams per liter. Recent rains have caused the TDS levels to fluctuate daily.

Since elevated levels were first detected last year, DEP has taken a number of steps to address them.

DEP has been closely monitoring TDS levels in the river since October 2008 using both U.S. Geological Survey gauges and conducting confirmatory sampling for lab analysis.

In June, DEP granted $75,000 to the River Alert and Information Network, or RAIN, to develop a monitoring network and source water protection program.

The grant provided for a computer network and installation of water quality probes that will allow RAIN to remotely monitor the quality, including conductivity, pH and the temperature of the water at 11 locations along the Monongahela River. The network is being installed and, once in place, data will be available for the public to access through the department's website.

After high TDS levels were detected in October 2008, DEP directed certain sewage treatment plants, which discharge to the Monongahela River or its tributaries, to limit their discharges.

In April 2009 DEP released a proposed strategy for new discharges of high TDS wastewater to meet an effluent standard of 500 milligrams per liter by January 2011. New regulatory standards will be considered by the Environmental Quality Board on August 18 and will be available for public comment.

Finally, the department and EPA will meet with West Virginia officials to determine the scope of the problem throughout the watershed and to identify potential solutions where TDS is entering the Commonwealth from West Virginia at elevated levels.

In upcoming weeks, DEP will host one or more public meetings within the Monongahela Basin to provide detailed information and a status report to residents. Specifics about the public meeting will be announced at least two weeks in advance.