Engelder said at least some of the industry's missteps have been unintentional and come from inexperience.
In Dimock, the land had so many layers of rock and the drilling boom was so new that both the industry and regulators struggled to understand and explain the problems with the water wells, Engelder said.
Cabot spokesman George Stark said that in retrospect, the company realized that the geology around Dimock was "highly unusual" and that pre-drilling tests for methane would have helped determine which wells had natural contamination of methane.
In 2010, Cabot began holding summer picnics in the Dimock area to answer questions about the industry, drilling and local geology, Stark said. More than 8,000 people attended last week's event, up from about 2,000 the first year, he said.
While many issues were at play, Engelder said, experts came to believe that the well construction techniques used in the early years of Pennsylvania's drilling boom "were just inadequate to the task" of protecting groundwater in that area. Regulations for well cement jobs were later strengthened considerably, but by that time, anger and negative publicity had started building, and the damage was done.
Engelder and Hofmeister say that to the industry's credit, the drilling boom has brought many benefits. Many communities haven't had major problems and welcome the jobs and the royalty payments that can reach hundreds of thousands or even millions of dollars for a single landowner.
But Engelder said the industry can't just focus on positives.
"There never will be a risk-free gas industry in Pennsylvania, just like there never will be risk-free driving a car," he said.
Engelder said he believes the industry should work more closely with opponents and give them detailed explanations of the geology, the risks and the benefits of drilling. "I would do whatever it took to try and engage these people over a period of time," he said.