The Department of Environmental Protection Thursday released a table listing the 243 water supplies found by DEP to be contaminated by oil and natural gas drilling from 2008 to 2014, about 1.2 percent of new wells drilled during that time period.
Other complaints are still being investigated.
According to Scott Perry, DEP Deputy Secretary for Oil and Gas Management, about half the water supplies were damaged by conventional oil and gas wells and about half were unconventional (Marcellus Shale) gas wells.
The problems include methane gas contamination, spills of wastewater and other pollutants, and wells that went dry or were otherwise rendered undrinkable.
The records show that some of the problems were temporary.
The table with links to the letters of determination by DEP or the orders issued to correct the problems.
DEP also posted a list of 19 oil and gas wells that have high levels of hydrogen sulfide emissions-- greater than 20 ppm. 14 of the wells with high emissions were conventional oil and gas wells and 5 were unconventional (Marcellus Shale) wells.
7 of the wells are still active, 8 have been plugged, 2 were abandoned wells and 2 are in regulatory inactive status (inactive, but not abandoned or producing).
Hydrogen sulfide can cause conjunctivitis and respiratory tract irritation at levels of 50 to 100 ppm and loss of consciousness and possibly death after 30 minutes of exposure at levels of 500 to 700 ppm.
DEP reports 20,178 conventional and unconventional oil and gas wells were drilled between January 2008 and the end of July 2014. There were 12,098 conventional wells and 8,080 unconventional (Marcellus Shale) wells.
Copies of the list of damaged water supplies and the wells with hydrogen sulfide emissions are available online.
