Jury selection began on Feb. 22 in a federal lawsuit in which two northeastern Pennsylvania families allege that Cabot Oil & Gas Corp. (NYSE: COG) contaminated their well water with methane when it began fracking for natural gas near their homes.

Two couples - Scott Ely and Monica Marta-Ely, and Ray and Victoria Hubert - are the only plaintiffs remaining in a case that initially involved more than 40 people. The rest have settled with Cabot, a major producer in Susquehanna County.

The two families are seeking compensatory and punitive damages from Cabot for the alleged contamination of their water supply.

According to court documents, the trial will bring to light a state law that assumes that a gas driller is responsible for water well contamination within 1,000 feet of a drilling site that develops within six months of drilling.

Cabot argues that the state law deviates too much from traditional tort law, which requires the plaintiffs to prove damages.

"The evidence will show that Cabot met or exceeded the applicable standards of care in the drilling and completion of the ... wells," according to court documents. "Cabot will present evidence that the plaintiff's water is potable."

The process of hydraulic fracturing, or fracking, to extract gas from underground shale formations has yielded widespread opposition in many parts of the country, including northeastern Pennsylvania.

Critics say fracking is responsible for environmental damage, excessive noise and even earthquakes. Its supporters say the process, which has slashed the country's dependence on foreign energy sources in recent years, is safe.

The families suing Cabot live near Dimock, Pa.a, a town made notable by "Gasland," an Oscar-nominated documentary that galvanized the anti-fracking movement. The 2010 film showed tap water in the area that could be set on fire because of the methane gas it contained. Both families say water in their homes was flammable in the past.

Scott Ely, who said his family has lived in the Dimock area since the 1800s, said he hauls in tankers of water for his family. The family showed reporters a bottle of water that they say came from their well. It was the color of coffee and cream.

"It's hard, especially in the winter, as my kids will tell you," he said.

"We haven't had clean water since he was in kindergarten," said Marta-Ely, gesturing to her 13-year-old son, Jared, at a news conference during a break in jury selection.