For 50 years Flint, Mich., relied on a vast resource of clean, dependable drinking water from Lake Huron, delivered by the Detroit Water and Sewage Department. Yet, the price of that water kept rising for Flint, a former manufacturing jewel whose fortunes had declined significantly and where, by 2014, 42 percent of the population lived below the federal poverty level.

When monthly rates became the highest in the United States, city officials made the decision to create a local water board. The city also decided to switch to an unlikely water source: the Flint River. The city would fatefully rely on an antiquated system that was poorly equipped to handle the polluted and corrosive water.

What followed was a modern-day urban crisis that Detroit journalist and author of "The Poisoned City" Anna Clark concludes from her dogged reporting was complicated by "environmental racism," a continuation of the systematic prejudice against urban blacks that has its seeds in "redlining and racially restrictive covenants."

The tragedy of Flint, Clark writes, was "a disastrous choice to break a crucial environmental law, followed by eighteen months of delay and cover-up by the city, state, and federal governments, [which] put a staggering number of citizens in peril."

That peril included astronomical lead levels that will no doubt cause permanent damage, positive tests for coliforms such as E. coli and an outbreak of the deadly Legionnaires' disease.

For a year and a half, until the city switched back to Lake Huron water, officials dismissed residents' complaints while deliberately obfuscating test results.

What turned the tide were heroes from journalism and science.

Environmental engineer and MacArthur Fellow Marc Edwards sent out 300 water testing kits throughout Flint. Results were indisputable: "poison was spread across the city," with the average lead levels "ten times the federal action level."

Journalist Curt Guyette was given free rein to investigate by his employer, the Detroit chapter of the American Civil Liberties Union. Additionally, reporters from NPR's Michigan Radio kept the story alive to its 450,000 weekly listeners.

"The Poisoned City," an anger-inducing story, shows that Flint is hardly an outlier. The United States has a crumbling water infrastructure, in which 5,300 water systems are in violation of federal lead level rules, and Flint is a harbinger of environmental crises yet to come.

Stephen J. Lyons is the author of four books of essays and journalism. His most recent book is "Going Driftless: Life Lessons From the Heartland for Unraveling Times."

The Poisoned City
By: Anna Clark.
Publisher: Metropolitan Books, 305 pages, $30.