Environmentalists are warning of a potential ecological disaster for the Florida Everglades if state lawmakers approve a measure that would open the door to fracking in the sensitive wetlands.

On Tuesday, politicians in Tallahassee were debating a proposed new law that would remove the right of local municipalities to pass ordinances or resolutions banning fracking and instead place all regulation and oversight of drilling for oil into the hands of a single state agency.

Opponents fear that removing the rights of cities and counties to prohibit fracking, and voiding the dozens of resolutions already passed by them, would make it easier for the oil industry to obtain permits to drill in the ecologically fragile Everglades. That, they say, would threaten the habitat of numerous species of wildlife in the so-called River of Grass and move heavy drilling equipment closer to residential areas.

In particular, they fear that the controversial drilling practice, which uses high pressure water and acid to release contained oil or gas, could lead to the seeping of toxic chemicals into the porous limestone bedrock throughout the Everglades, and into the underground Biscayne Aquifer that is the only source of fresh water for more than three million people in south Florida.

“Florida already bans offshore drilling off its coasts. The Everglades should be treated the same way,” said Matt Schwartz, executive director of the South Florida Wildlands Association, whose members were joining a protest rally at the Florida state capitol in Tallahassee on Tuesday.

“And bringing fracking into the karst aquifer that underlies the Everglades is a kind of shortsightedness bordering on the insane. At the very least it would be highly irresponsible.”

Florida’s oil industry is decidedly small scale, producing fewer than 200m barrels per year, mostly from wells in the Panhandle, and the most recent estimates by the US Geological Survey and US Energy Information Administration both suggest limited reserves. But a number of companies have expressed interest in exploratory drilling and seismic testing in the Everglades.

The bill, which passed the Florida senate’s environmental and protection committee last week, is set for debate by the entire state senate, though similar proposals in recent years failed to attract the necessary support to get to a vote.

“Although we did stop them from creating new pro-fracking legislation, like zombies they keep raising their deadly bills again and again, now for the 2016 session,” said Amy Datz, an environmental scientist with the Democratic Environmental Caucus of Florida and an affiliate member of the Florida Climate Institute, a network of research organisations including the state’s leading public universities.

“The resolutions to ban fracking represent anyone who likes to drink, bathe in, wash their clothes and dishes in, cook, fish and swim in fresh clean water.

“For every barrel of oil produced, 10 barrels of permanently hazardous, toxic water is produced [and] there is no safe or approved method to treat the potentially millions of gallons of backflow waste water. Florida has a supply of oil and gas that would supply the world market for four days but the toxins produced in the process could last more than 100 years.”

The bill’s sponsor, Republican state senator Garrett Richter, argues that his proposal would actually protect Florida’s residents by introducing safeguards not yet in existence. The law, he said, would require the state to undertake a $1m, year-long study to determine the impact of chemicals used in the fracking process on the state’s drinking water supplies, yielding information that would help in the writing of new laws governing fracking to take effect in 2017.

Additionally, the environmental committee “tightened up” some of the language in Richter’s bill in advancing it last week, including inserting a clause that would require inspection of groundwater at each site before and after drilling takes place.

“Rather than having 400 different policies out there, this will create one uniform set of rules the entire state can follow,” Richter told fellow senators last week. “And unlike those policies, these rules will be created with a firm idea of what fracking will do, its impact on the environment.

“We need to responsibly do everything we can to be less dependent on others. For 70 years, we’ve been drilling for oil in the state of Florida without any adverse impact.” Richter did not respond to a request from the Guardian seeking comment.

He was supported by another Republican state senator, Wilton Simpson, who proposed the inspection amendment. He told the panel: “It would give our constituents who have a lot of nervousness about this a little more comfort in knowing the folks they are electing are going to take one more look before we start fracking in the state of Florida.”

Their arguments, however, did not appease opponents of the bill, which include Florida’s League of Cities and Association of Counties. A meeting of the state senate last month at which the bill was discussed attracted hundreds of protestors and commentators, including Dr Rich Templin, political director of the Florida AFL-CIO federation of labour unions, who said his members represented “all partisan stripes, a diverse cross-section of Florida”.

“It’s not a group of tree hugging liberals,” he told the Guardian, pointing to other states where abnormalities have been blamed on fracking. “People are educated on this. They see earthquakes in Oklahoma, water catching fire out of taps in New York. This isn’t your traditional environmental protest.”

Conservationists such as Schwartz, meanwhile, see a glimmer of hope in the Florida department of environmental protection’s close scrutiny of the plans of the Miami-based Kanter Corporation, one of the oil companies that wants to conduct exploratory drilling as a possible forerunner to fracking in 20,000 acres of the eastern Everglades close to populated areas.

“Kanter’s application has so far been returned to the company twice by the Florida DEP with more information and clarification about certain topics requested,” Schwartz said. “It appears DEP understands the seriousness of this project and the feelings of south Floridians towards it. They’re giving it a very hard look indeed.”