This image from the Flint Water Study shows water samples from a Flint, Mich. home. The bottles were collected, from left, on Jan. 15 (bottles 1 and 2), Jan. 16, and Jan. 21, 2015.

What is the Flint water crisis?

Earlier this month Rick Snyder, the governor of Michigan, declared a state of emergency in the County of Genesee and the City of Flint because of elevated levels of lead found in its general water supply. The governor declared the emergency because the contaminated drinking water poses a serious health risk to the residents of that area. The adverse health effects of lead exposure in children and adults are well documented, notes the Centers for Disease Control, and no safe blood lead threshold in children has been identified.

The crisis has been blamed on a failure of government at all levels. As Washington Postreporters Lenny Bernstein and Brady Dennis wrote, “Local, state and federal officials — including the top Environmental Protection Agency administrator in the Midwest and Michigan’s Republican governor, Rick Snyder — are accused of ignoring, denying or covering up problems that left thousands of children exposed to toxic lead in their drinking water for about 18 months.”

To date, four government officials—one from the City of Flint, two from the Michigan Department of Environmental Quality, and one from the Environmental Protection Agency—have resigned over the mishandling of the crisis.

What caused the water crisis?

According to the U.S. Census, 40.1 percent of the population of Flint, Michigan is living in poverty, making it the second most poverty-stricken city in the nation for its size. The poverty of its bined with mandatory spending on former city workers (retirees from the city government are taking 20 percent of all city spending) has led to a financial crisis that has put the city into emergency receivership.

In an attempt to save money, the city council voted in 2013 to purchase water from the Karegnondi Water Authority (KWA) rather than from the Detroit Water and Sewerage Department (DWSD). KWA was not expected to pleted until the end of 2016, so the city decided to rely on its backup, the Flint River.

The Flint River, though, contains high levels of chlorine, which is highly corrosive to iron and lead—materials used widely in the pipes carrying water in Flint.

How did the lead get into the drinking water?

Since the late 1960s, Flint purchased its water from the DWSD, which treats the water with orthophosphate, a chemical that, as Time magazine explains, “essentially coated the pipes as water flowed through them, preventing lead from leaching into the water supply.” The water from the Flint river, however, was not treated with orthosphate, even though it contains eight times more chloride than Detroit’s water.

When was the contamination discovered?

According to Shikha Dalmia, area residents plaining about the taste and color of the water right after the switch in April 2014.

In January 2015, hundreds of residents attended a public meeting plain that the city’s water was causing skin problems for some children. The state-appointed emergency manager Darnell Earley told the crowd the city “can ill-afford to switch course” by returning to purchasing the water from Detroit. That fall, General Motors announced it was discontinuing use of Flint water in one of its plants, because the high level of chlorides found in the Flint River could corrode engine parts.

In September 2015 an independent research team from Virginia Tech (a group that paid for some of the research out of their own pockets) released the Flint Water Study, which found that at least 25 percent of homes in Flint had levels of lead that was well above the federal level and nearly every home had water that was distasteful or discolored.

That same month the Hurley Medical Center in Flint released a study confirming that the proportion of infants and children with elevated levels of lead in their blood had nearly doubled since the city switched from the Detroit water system to using the Flint River as its water source.

Authorities initially disputed the findings of both studies, but local and state officials finally acknowledged the crisis in October 2015, and Flint returned to using water from Detroit.

Why wasn’t the lead detected sooner?

According to the Detroit News, a water expert with the U.S. Environmental Protection Agency (EPA) identified potential problems with Flint’s drinking water in February 2015, confirmed the suspicions in April, and summarized the looming problem in a June internal memo. But the EPA Region 5 Administrator Susan Hedman did not release the information, claiming her hands were tied in bringing the information to the public. The EPA was in conflict with Michigan’s Department of Environmental Qualityover not only what to do about the crisis, but what to tell the public.

Marc Edwards, an expert on municipal water quality that led the Virginia Tech study, said that the situation essentially amounts to a cover-up.

It was the injustice of it all and that the very agencies that are paid to protect these residents from lead in water, knew or should’ve known after June at the very latest of this year, that federal law was not being followed in Flint, and that these children and residents were not being protected. And the extent to which they went to cover this up exposes a new level of arrogance and uncaring that I have never encountered.

Rather than address the legitimate science questions, they mounted a public relations campaign to discredit the residents, to discredit us. I have never seen this level of arrogance and petence. It was mostly confined to a few key individuals, but other people are guilty of being far too trusting of those individuals, and not listening to the people who were drinking this water.

Could the crisis have been prevented?

As Shikha Dalmia notes, the problem could have potentially been avoided by simply adding phosphorous to the water. That fix would have only cost the city a mere $50,000 a year.

What happens now?

Gov. Snyder announced last week that the state of Michigan would provide Flint with $28 million in aid to pay for things like filters, replacement cartridges, bottled water, more school nurses, and additional intervention specialists.

The U.S. Attorney’s Office is also investigating the contamination of Flint’s drinking water supply to determine if government mitted any criminal wrongdoing.