More than 100 protesters marked Earth Day on Friday by calling on the Nova Scotia government to ban hydraulic fracturing, a controversial method of extracting natural gas from underground.

The crowd gathered in front of the Nova Scotia legislature in Halifax. They held placards and chanted slogans against so-called fracking, which they say poses a threat to groundwater and people's health.

Two large banners were draped over the iron fence in front of the legislature. One said "No Compromise Ban Fracking" while the other read "We Love Nova Scotia's H2O."

Arranged at the foot of one banner were jars of fresh water, each labelled to indicate the areas of the province where they came from.

Focus on green economy

Event organizer Yuill Herbert of the citizen's group Stop Fracking in Nova Scotia said it wouldn't make sense to allow something that uses large volumes of water while pumping a mix of chemicals into the ground.

Herbert said nothing more than an outright ban would do. "I really think we need to be building a green economy in Nova Scotia and not focusing on industries which I think take us backwards," he said.

Fracking involves pumping pressurized water and a variety of chemicals into a gas well to fracture the layers of shale rock to release the natural gas.

The government has maintained that no fracking has taken place in Nova Scotia since 2008, although that's disputed by some critics.

The province announced earlier this month that it would conduct a technical and policy review of hydraulic fracturing. The review, which is expected to be completed by early next year, would examine the environmental effects and best practices in other jurisdictions.

Natural Resources Minister Charlie Parker has since asked for public input in the form of written submissions that are due June 6.

Thom Oommen of the Inverness chapter of the Council of Canadians said he doesn't trust a process that appears to limit public input.

"Just the way it stands now it seems like it's going to be a room in one of these buildings where government gets together with industry and makes the rules," said Oommen.

He said he would like to see public hearings as part of the process in order to ensure the voices of those opposed are heard.

But Annapolis Valley resident Nina Newington said it appeared that with the review process, those opposed have caught the attention of the government.

She said a moratorium needs to be put in place until a strategic environmental assessment is conducted.

"We have to keep up the pressure as citizens to make sure that we get our voices heard," said Newington.

While there's been limited shale gas exploration in Nova Scotia, the industry has experienced growth in Alberta and British Columbia over the past decade.

There's also been activity in a host of other provinces although last month the Quebec government announced that it would temporarily ban the use of fracking while it studies the process.

Important industry

Darcy Spady, managing director of Calgary-based St. Brendan's Exploration, said he's taken part in the drilling of 14 exploratory wells in New Brunswick since 2000.

He said the public should know that the Canadian industry operates responsibly in a regulated environment.

Spady believes the Nova Scotia government should consider what is going on elsewhere.

"Before we shut everything down in Nova Scotia I think we need to look at British Columbia and Saskatchewan . . . two jurisdictions that have a regulated industry that provides a lot of economic benefit and gas," said Spady.