While most people in Pennsylvania get their water from public water systems that comprehensively test the drinking water delivered at the tap, there are more than a million private water wells in Pennsylvania. And about 25% of them have been contaminated with something, manganese, biogenic or naturally occurring methane, even E-coli bacteria.
Everyone on a private water well should regularly test their water to insure that it is safe.
Sometimes contamination is caused by poor water well construction that allows natural and unnatural contaminants to impact the water well. Sometimes the ground water itself has been contaminated by pollution.
When the ground water itself is contaminated by pollution, the most common cause is more than 200 years of industrial activity and agriculture (nitrate pollution of water). By comparison to these historic, significant threats to private water wells, gas drilling has had a minor impact on private water wells, but everyone should work hard to make the impact smaller still. We should also deal with the much larger non-gas drilling sources of contamination of our groundwater
Gas drilling has probably impacted less than 100 water wells in Pennsylvania. Gas migrating from poorly constructed and designed gas wells is the biggest source of contamination within this category. A handful of water wells also may have been impacted by spills and leaks. But fracking fluids and the chemicals in them have never returned from depth in Pennsylvania to contaminate a private water well. The Duke University study found no such contamination. Lisa Jackson testified in May to Congress that frack fluids had never returned from depth to contaminate water anywhere in the country.
When a claim is made that gas drilling caused pollution to a water well, the industry and the regulators have the job of responding. Sometimes the industry and the impacted family resolve the issue. Sometimes a dispute erupts that leads to a regulatory or a court case or both.
In this situation, the regulators find themselves on the hotseat and must simply do good testing, be transparent, and let the facts answer the question. When I served as Secretary, DEP found through comprehensive testing both that gas drilling had caused gas to migrate and contaminate water wells and found that gas drilling was not the source of the contamination in a water well.
I, however, would caution anyone looking at these claims or denials against jumping to any conclusion.
To see how complex, difficult, and emotional these disputes about private water well contamination can become, please read the story at http://eidmarcellus.org/2011/06/08/crystallizing.