The federal government will begin testing water supplies for 61 homes in Dimock Twp. as soon as tomorrow in a dramatic expansion of the Environmental Protection Agency's current investigation into potential contamination of water supplies in the Susquehanna County village by natural gas drilling and hydraulic fracturing.
Citing its authority under the federal Superfund Act, the EPA will also begin providing replacement drinking water supplies to four township homes where water tests taken by outside firms raised health concerns, the agency said.
The EPA said it has reached out to both the state Department of Environmental Protection and Cabot Oil and Gas Corp., the Marcellus Shale driller active in the area, to ask if they would be interested in working with the EPA as it collects data.
State regulators have found Cabot responsible for contaminating water supplies for 19 Dimock homes with methane from faulty gas wells.
Cabot halted bulk and bottled water deliveries to the homes on Dec. 1 after the state said the company had met the relevant terms of a December 2010 settlement over the contamination - including offering to install methane-removal systems that many residents have rejected saying they do not remove metals and other contaminants in their water.
Federal environmental regulators reopened their investigation of Dimock water wells in late December after declaring on Dec. 2 that the water posed no "immediate health threat." The agency reversed course after reviewing water test results released only after the agency's announcement.
Those tests, taken in August and September by a Cabot contractor, showed elevated levels of metals and bis(2-ethylhexyl) phthalate, a plasticizer commonly called DEHP. They also detected other chemicals including glycols, which are used in antifreeze, surfactants and 2-methoxyethanol, a solvent, in the drinking water wells.
Cabot denies it caused contamination in Dimock, which it says occurs naturally or can be attributed to other sources.
The EPA's water sampling will cover a broad array of chemicals and other constituents that may be in the water, with a focus on about a dozen parameters that have shown up in Dimock water wells.
The EPA said it wants to perform its own testing to fill "gaps" in the data gathered by Cabot, the state and other testing firms. The existing data do not all meet quality controls, the agency said, and some samples have been analyzed for parameters not studied elsewhere in the township.