By Sara Jerome,

@sarmje

Flint, MI, has a bad track record for changing water sources. When the city switched sources two years ago in an attempt to cut costs, it underwent a major water-contamination crisis.

That’s why all eyes are on Flint as the city makes plans to change its water source again — and unlike last time, the federal government appears to be watching closely, too.

The U.S. EPA ordered officials overseeing water treatment in Flint to submit new plans for treating the city’s drinking water and to take several preparation steps before it can proceed with the upcoming switch from city of Detroit water to Lake Huron water.

In a November directive, the EPA called on Flint “to complete a three-mile interconnection so it can test water from the new source for three months while continuing to provide water from Detroit’s system. The city also must submit a new water-treatment plan,” the Associated Press reported.

The means the city’s treatment plant “will be required to test-run raw Lake Huron water for three months before it can deliver a single drop to city residents and businesses,” Michigan Live reported.

The city was also told to submit a "new water source treatment plan" to state and federal regulators, according to The Detroit News. The city was told to submit the plan within three weeks.

Robert Kaplan, acting regional administrator for EPA said: "It led to a whole series of problems [when there was no trial run previously]. [The city] didn't have a handle on how to run the plant to provide safe water before they threw the switch."

Flint’s lead crisis, which left hundreds of children with high blood lead levels, followed the city’s switch from the Detroit water supply to Flint River water. When Flint changed sources, it became responsible for its own treatment processes. The city has since returned to Detroit water.

“[During the previous switch], the plant operator warned the state Department of Environmental Quality that the facility was not ready to function full-time, but the plant was allowed to distribute water without first treating it to make it less corrosive,” Michigan Live reported.

“The use of the river water, estimated to save the city millions of dollars in the short term, caused lead to leach from transmission lines and from home plumbing and lead levels spiked, leading to a nationally recognized emergency,” Michigan Live reported.

Image caption, per USDA: City of Flint, MI, water, filter distribution, and sample turn-in, on October 5, 2016.