WASHINGTON– Thousands of protesters traveled to Washington on Saturday to demand that Congress to take action against hydraulic fracturing, or fracking, a controversial technology that involves injecting water, sand and chemicals underground to extract natural gas.

More than 130 organizations nationwide supported the rally, includingand Josh Fox, director of Gasland, an Oscar best documentary nominee in 2011.

Opponents of the technology say fracking pollutes underground water and emits a lot of greenhouse gases. Industries say there is no real evidence of environmental damage and defend fracking as a game changer that has led a natural gas boom in the country.

The Environmental Protection Agency is conducting ongoing studies focusing on the technology’s potential impact on water. A final draft is expected in 2014.