A U.S. Steel plant in Portage, Indiana has spilled wastewater containing a potentially cancer-causing chemical into Burns Waterway, a tributary about 100 yards from Lake Michigan.

The leak prompted the closure of four beaches and a riverwalk at the Indiana Dunes National Lakeshore, and Indiana American Water in Ogden Dunes—the nearest municipal water source—to shut down its water intake and switch to a reserve water supply, the U.S. Environmental Protection Agency (EPA), which is overseeing the spill, announced.

U.S. Steel reported the leak on Tuesday morning. The company informed the EPA that its release has been stopped at the source. The amount of spilled wastewater is still unknown.

The wastewater discharge, apparently caused by a pipe failure, contains hexavalent chromium (chromium-6), which is used for industrial processes. The toxic chemical was made famous by the environmental activist and 2000 movie of the same name, "Erin Brockovich."

Incidentally, as Chicago Tribune pointed out, President Donald Trump's administration has proposed a budget that would quash efforts to crack down on the dangerous pollutant nationwide:



"Trump's proposed budget would abolish the Integrated Risk Information System, the EPA office working on hexavalent chromium standards in drinking water, as well as sharply reduce funding for scientific reviews of toxic chemicals and cut back on the agency's enforcement of environmental laws."



Low levels of the chemical were found in Lake Michigan near the mouth of Burns Waterway, Sam Borries, a branch chief for Region 5 of the EPA's emergency response program, told Chicago Tribune.



Borries said that it is unclear whether or how far the chemical has spread down the shoreline. He added that officials have taken 100 samples along the waterway east and west of its entry point to the lake and results are expected Thursday.

Wednesday morning footage from NBC Chicago's Sky5 shows a dark substance spreading into the Great Lake. The EPA says the substance is sediment, not chromium-6.

According to the Associated Press, a U.S. Steel preliminary investigation determined that an expansion joint failed Tuesday in a pipe at the Portage facility. This allowed wastewater from an electroplating treatment process containing chromium-6 to escape into the wrong wastewater treatment plant at the complex. That wastewater eventually flowed into the Burns Waterway.

Andy Maguire, the EPA's on-scene coordinator, told the AP that testing is continuing at the intake areas and other nearby points, but hexavalent chromium from the spill has so far not been found in Lake Michigan.

Chromium-6 is used in chrome plating, wood and leather treatments, dyes and pigments and the water in cooling towers of electrical power plants.

The chemical has long been known to cause lung cancer when airborne particles are inhaled. Recent science has also shown that, when ingested, it can cause stomach cancer. A 2008 study by the National Toxicology Program found chromium-6 in drinking water caused cancer in rats and mice.

The Environmental Working Group (EWG) released an analysis last year finding that hexavalent chromium is in the tap water of more than 218 million Americans.

California is the only state that has set an enforceable legal limit for chromium-6 in drinking water. The state's public health goal is 0.02 parts per billion of chromium-6 in drinking water, yet the state's legal limit is 500 times higher.

The current federal drinking water standard is 100 parts per billion for total chromium, a measurement that includes the toxic chromium-6 and chromium-3, which is an essential human dietary element.

Health groups are pushing for federal regulators to set national drinking water standards.