The Susquehanna River Basin Commission is expanding its network of electronic water-quality monitors on streams in the Marcellus Shale region to provide an early-warning system for potential gas-drilling accidents.

The commission said it was nearing an agreement to install 10 monitors on streams in Pennsylvania state forests, where more than 700,000 acres have been leased to natural-gas drilling companies. And on Tuesday, the panel announced plans to install 10 monitors in New York State.

The new devices would bring to 50 the number of electronic monitors the commission intends to install by May, spokeswoman Susan Obleski said.

The wireless devices report water-quality tests every five minutes, to alert officials to any changes that might indicate a spill or a leak. The data are available to the public on the SRBC's website,

In addition to warning officials of potential spills, the monitors will provide a baseline of water-quality information on Susquehanna tributaries in north-central Pennsylvania and New York, where drillers are escalating efforts to extract gas from the Marcellus formation.

Developing shale-gas wells involves pumping water and chemicals into each well to fracture the rock and liberate the gas. The wastewater contains high levels of salts and metals from the source rock.

Monitoring devices continuously measure water temperature, acidity, dissolved-oxygen levels, turbidity, and ability to conduct electricity, an indicator of the presence of pollutants.

Contact staff writer Andrew Maykuth at 215-854-2947 or