In a statement released yesterday, John Hanger, Secretary of the Pennsylvania Department of Environmental Protection, championed the proposal of new rules aimed at keeping Pennsylvania streams, drinking water, and rivers free from a pollutant known as "total dissolved solid" (TDS), which is a measure of chemical substances dissolved in water. In addition to natural gas drilling, sources of TDS include abandoned mine drainage, agricultural runoff, and discharges from industrial or sewage treatment plants. Mr. Hanger's hope is to establish the necessary regulations now that will prevent TDS from becoming a source of contamination later. In the press release, Mr. Hanger focused on the high TDS concentrations related to natural gas drilling, stating that “Marcellus drilling is growing rapidly and our rules must be strengthened now to prevent our waterways from being seriously harmed in the future.”