Experts say the discovery is the planet's largest fresh water system is alarming.

The fuel economy standards would have required new cars and light trucks to use less gas over time. The new proposal puts that on hold for another six years starting in 2020.

The company will recall about 500,000 medium- and heavy-duty trucks with model years between 2010 and 2015.

The latest recall affects 2010-2015 medium- and heavy-duty trucks with engines made by Cummins Inc.

TCE is used to degrease metal and to make other chemicals like refrigerants. It's just one of the chemicals found at the Amphenol industrial site in Franklin.

On the surface, this doesn't change much. Since the rule was on hold, farmers weren't required to report their emissions.

The EPA said in a statement that it "continues to evaluate data and hopes to announce a cleanup plan for public comment in late summer or early fall."

The soil has high levels of arsenic, lead, cadmium, and zinc. EPA estimates the cleanup will cost more than $26 million.

The standards require new cars and light trucks build after 2025 to get about 50 miles to the gallon.

The agency will update residents on residential soil sampling and cleanup work in areas of Hammond and Whiting near Federated Metals' abandoned smelter.