Some people remain passionately opposed to fracking, particularly in areas of Pennsylvania and New York, where celebrities, artists and ordinary citizens have banded together to condemn the practice. At the Shale Gas Insight conference held last month in Philadelphia, a large crowd of people held signs and chanted slogans in protest of fracking and shale gas development.

At the conference, Philadelphia Mayor Michael Nutter, known for supporting sustainable development, was not particularly sympathetic to the industry.  “You need to earn our trust,” he said.  Although he said that jobs and economic opportunities might arise in Philadelphia and Southeast Pennsylvania out of natural gas extraction from the Marcellus shale, “there is no economic opportunity for which jeopardizing our water quality is acceptable. I have yet to see progress from industry in the most important issues to build public confidence in your practices.”

Public confidence is a significant hurdle the industry must overcome, members of the Marcellus Shale Coalition acknowledged at the conference. To that end, the coalition has developed a website to answer questions to related to shale gas production. They are equally passionate in their belief that fracking and shale gas production is safe, and an important tool for economic development and growth.

What are people concerned about? Although no study has shown definitively that fracking itself poisons the water with methane and other chemicals, residents of town like Dimock and Bradford, Pa. have complained that the production of shale gas wells has contaminated their drinking wells. EPA has sampled the water wells in Dimock, and found the water to be safe. But doubts still linger.

A recent study casts some additional concerns. A Duke University study released in July found that some drinking water supplies in Northeastern Pennsylvania could—at least theoretically—be at an increased risk for contamination from “fugitive” gases that leak from shale gas well casings. This is primarily because of networks of naturally occurring pathway that could allow salt and methane to migrate up into shallow groundwater aquifers from deeper underground shale gas deposits.

However, the Duke study did not find any correlation between fracking and elevated levels of methane in the wells. But Kate Sinding, a senior attorney with the Natural Resources Defense Council, says, “It begs the question: if you are down there fracking and stirring this stuff up, are you increasing the potential that you are establishing potential migration pathways for methane?”

The industry should recognize that environmental and citizens groups are part of the dialogue, and perhaps necessary for driving more stringent regulation and evolution in the industry.

The shale gas industry has made great strides in improving practices and in working to find solutions to address the public’s concerns, and they owe that in part to the ingenuity of the engineering community (see related cover story in this week's issue online), as well as the concerns of ordinary citizens who, like everybody else, just want water that is clean and safe to drink.