Demonstrators in Flint, Michigan, protest over the city's contaminated water crisis in March 2016. Reuters/Rebecca Cook The water crisis in Flint, Michigan, is entering its fourth year, and residents are still a long way away from having potable tap water.

But thousands of residents are now facing a new threat — losing their homes to foreclosure because of unpaid water bills.

More than 8,000 Flint residents received notices from the city threatening to impose tax liens for six months' worth of unpaid water bills, a local NBC affiliate reported on Tuesday.

Residents have until May 19 to pay the bills, some of which total nearly $1,000, or else they'll risk foreclosure on their homes, according to the report.

Flint's water crisis began in 2014 when the city switched its water source to the Flint River, resulting in lead contamination from the city's pipes to enter the water supply. The crisis has been tied to cases of lead poisoning and 12 deaths from Legionnaires' disease.

Today, drinking water in Flint is in compliance with federal regulations, but local officials have not announced it's safe to drink. Many residents still don't use the water and oppose paying for the utility.

"I understand it’s the law, but I don’t like it because of the circumstances,” Flint Mayor Karen Weaver told HuffPost. "We are working to see if any changes or something can be done to help the residents affected by this."

But city officials are in desperate need for the millions of dollars they'd collect from paid bills.

"We have to have revenue coming in, so we can't … give people water at the tap and not get revenue coming in to pay those bills," said Flint treasury department official Al Mooney, according to NBC.