Two city councilmen in Los Angeles on Wednesday proposed a moratorium on the controversial practice of fracking within Los Angeles city limits.

Councilmen Mike Bonin and Paul Koretz introduced a motion at Wednesday’s City Council meeting calling for a moratorium on the practice of oil and gas exploration using hydraulic fracturing, or fracking, as well as other “well stimulation” activities within the city. The motion says the moratorium should remain in place until federal and state regulations are in place to assure that all environmental and health impacts of fracking can be mitigated.

In their motion, Bonin and Koretz said that the chemicals used in fracking cause harm to the environment and threaten contamination of local water supplies.

“These practices threaten to contaminate drinking water supplies, cost taxpayers in Los Angeles hundreds of millions of dollars, release potent and dangerous greenhouse gases into the atmosphere and cause earthquakes,” the councilmen wrote in their motion.

The oil and gas industry has maintained that fracking has long been used in California and that no environmental or health impacts have been directly tied to the practice.

Fracking, or the injection of a mixture of water, sand and various chemicals at high pressure, is used to extract otherwise hard-to-reach oil and gas in shale and rock formations.

Currently, fracking is taking place on a very limited scale within Los Angeles city limits. Plains Exploration and Production Co., or PXP, of Houston has reportedly used the technique in its operations in the Baldwin Hills in the county of Los Angeles, Culver City and adjacent to the city of Los Angeles.

The proposed moratorium appears intended to head off any future fracking within Los Angeles, especially in areas next to water supplies.

In Sacramento, several measures that would lead to a statewide moratorium and more regulation of fracking are pending. The legislative session ends next week.