NDP leader Dominic Cardy is calling for a moratorium on drilling in the Stoney Creek area near Moncton.
Recent lab tests by RPC of Fredericton found well water that was contaminated with methane, diesel and barium, according to Cardy, making it unsafe for drinking.
"This report contradicts the claims made by the government of New Brunswick that there have been no incidents connected to the oil and gas industry in recent decades," Cardy said.
"Senior laboratory technicians reported that they, quote, 'lit the water on fire', and found the water sample, provided to them by Mr. Charles Doucet, found it to be super saturated with methane."
Cardy says the water came from a home in Stoney Creek, a small community in Albert County.
Stoney Creek has been explored and drilled for oil and natural gas for decades, he said. Most had been unsuccessful until recently.
Several wells are in operation now.
Cardy believes that an incident in 2006, where a drill bit broke, could have contributed to widespread contamination.
"This is a clear case of groundwater contamination," Cardy said.
"Water contaminated with thermogenic natural gas, with diesel oil, and with barium — substances that are not normally found in this area."
The substances are associated with oil and gas exploration, Cardy said.
He says the water test results will challenge the Alward government's approach to shale gas exploration in the province.
"It's possible, from what I've been told from people who have lived there, their whole lives, that as many as several dozen or even hundreds of homes are affected," said Charles Doucet, a former Green Party leader candidate who is working with families trying to get answers.
"This is a well-known problem in the area. why the government has never bother to investigate is something that eludes me, I really don't understand," Doucet said.
An email to CBC News from the Department of Environment Wednesday stated the department would look into the issue raised by the NDP, but had no comment on calls for a moratorium.