The Flint water situation in Michigan could be the harbinger for other American water crises in the coming years, and it could be one of the worst in recent memory.

A new study published in the Proceedings of the National Academy of Sciences has found that the city’s water infrastructure was unprepared for the influx of lead-contaminated water and other contaminants, as well as for corrosion, and that the amount of lead in Flint’s water was so high it could pose a threat to human health.

The study also found that, since the city switched to Flint River water from Detroit River water in 2014, Flint’s lead levels in drinking water have jumped from the levels in the city proper to the city of Flint itself.

In the city that was so polluted by lead that it was considered the epicenter of the crisis, that means the water is still laced with the poison.

And that could pose problems for people living nearby, as the lead-tainted water could seep into the ground and leach into drinking water supplies, according to the study.

Flint is the first major American city to experience the type of water crisis that has led to widespread contamination of the water system.

Flint, Michigan, is about 60 miles (100 kilometers) east of Detroit.

Since Flint switched to the Flint River, which has lead levels well above the state average, the city has had to switch back to Detroit River.

Despite the state of emergency, the crisis was quickly resolved.

After the switchover, the state issued a state of good repair order.

However, some residents have continued to have lead in their water, according a March 2015 study by the Michigan Department of Environmental Quality.

Lead is a toxic metal that is easily absorbed by the human body, which can cause health problems, including lead poisoning, kidney disease, and other effects.

Lead levels in Flint River have continued rising since then, with some areas seeing as high as 5,000 parts per billion, or ppb, in water samples collected in September and October of this year.

But lead levels have continued dropping, which means there is more of the material left in the water.

A new study by researchers at the University of Michigan and the University at Buffalo found that lead levels were still rising, as shown in this graph:The researchers compared Flint River lead levels with other U.S. cities and found that Flint had the highest lead levels for water.

Flint’s Lead and Copper Rule, a state rule that requires municipalities to report lead in the drinking water they collect, was designed to help control lead in water.

The rule requires cities to test their water to make sure that water has not been contaminated with lead.

However the Flint City Council had been exempt from the rule, which allows them to collect and test their own water.

But it wasn’t until January that the Michigan department of environmental quality began issuing a state order, according the study by Flint researchers.

Flint did not have a similar water rule in place before, and its water had already been contaminated.

“It is likely that the current lead levels are at or above the threshold of a new elevated exposure threshold,” the researchers wrote.

In a statement, Flint Mayor Karen Weaver called the study “further evidence that Flint’s decision to switch from Detroit water to Flint river water is one of many instances of mismanagement of water resources, inadequate monitoring of lead, and the failure to maintain water service as a priority.”

She added, “I hope the new findings will inspire the city and state to work together to protect residents and communities, and to work to improve the city water supply.”

While Flint is not in the midst of a crisis, the situation is not unique, according with the findings.

The U.K. government said it had found that some cities, such as Birmingham and Leeds, England, had been exposed to elevated lead levels, and some U.N. agencies have found lead contamination in drinking tap water.

There are some U, S. cities, including Chicago, that are facing similar challenges.

As of last week, Flint had about 17,000 lead-containing water samples in the state.

A state report found that 1,500 of the city-owned water treatment plants had lead levels higher than the federal threshold for lead in drinking-water.

That’s about 20 percent of the total water systems in the U.M. That number is expected to increase in coming months as Flint continues to recover from the water crisis.

And as Flint begins to clean up the water from its lead-filled pipes, the problem of lead contamination could grow.

Lead-tainting chemicals can remain in the pipes for up to 40 years, according experts, so they’re not necessarily removed by treating them with disinfectants.

Flint has also been using lead-free tap water since February.

If Flint continues on its current path, that could lead to further lead-caused problems.

Lead contamination can also be harmful if ingested.