THE BURNED OVER DISTRICT

They do work hard enough to put a plethora of good nutritious food on the tables of America and elsewhere but when they get home they can't drink the water. California's agricultural valleys have a new twist on an old problem.

But the debate in Sacramento feels far away in East Orosi, a farmworker community of about 500 nestled along the foot of the Sierra Nevada that is surrounded by fields of oranges. There, residents complain of conditions that resemble the developing world, not the richest state in the nation. Fears of nitrate exposure in the tap water — which numerous studies have linked to an increased risk of infant death, and at high levels, an elevated risk of cancer in adults — compound other difficult realities like faraway grocery stores and doctors, grueling work conditions, and a lack of political clout.

Veronica Corrales, the president of the East Orosi water board, wonders why more people are not outraged that, in 2019, people living in a state as wealthy as California lack such a fundamental necessity.

“Everyone is saying ‘America First,’ but what about us?” she said.

Many factors have led to the groundwater contamination reflected in the state’s data, but public health experts say the region’s agriculture industry has played an outsize role. Chemical fertilizers and dairy manure seep into the ground and cause nitrate contamination, like the kind plaguing East Orosi. Such contamination, which is common throughout the valley, takes years to materialize and even longer to clear up.

Arsenic is naturally occurring in some areas but can become worse with exhaustive groundwater pumping, which has been a longstanding problem in the valley and accelerated during the drought between 2012 and 2016.

For years, Martha Sanchez and her husband, Jose — who live in East Orosi and make their living filling crates with oranges or picking cherries — have received notices from the local water system that their taps are unsafe to drink from because of contamination. The family spends at least $60 a month for tap water they can’t use, Ms. Sanchez estimates, which is factored into the rent. To cook and wash dishes, Ms. Sanchez ladles bottled water into pots and pans from heavy blue jugs kept in the kitchen. She and her children shower using the water from the pipes, but she says it makes their skin itch.

“Some people around here drink it,” Ms. Sanchez said. “Here at home, I don’t use it at all for cooking, not even for beans.”

Ms. Sanchez’s family is given five free five-gallon jugs of water every two weeks, funded by a grant from the State Water Resources Control Board that was secured by Self-Help Enterprises, a community organization. But, Ms. Sanchez says, it is never enough to hold the family over, and they buy an additional four gallons.

These problems are not new. The failing infrastructure at the heart of the potable water crisis in these communities is tinged with the legacy of rural redlining, said Camille Pannu, the director of the Aoki Water Justice Clinic at the University of California, Davis, who likened the situation in the valley to the one in Flint, Mich. “Flint is everywhere here,” she said.

“The fact that more than a million Californians in 2019 have been left behind is really appalling,” said Jared Blumenfeld, the secretary of the California Environmental Protection Agency. “I’ll never forget talking to people in Imperial and Coachella Valley who are like, ‘You know what, it’s amazing when we go back to Mexico, the water is better.’”

Mr. Blumenfeld said the “vast majority” of water systems with unsafe water are in small communities where there are too few customers to cover the cost of water treatment and maintenance. Laying even short distances of pipe can cost millions of dollars, which is sometimes feasible when costs are spread out among many people but not so for individual families, or when towns are especially remote.

“I’ve never seen as many small drinking water systems in any other state. California is unique in that way,” Mr. Blumenfeld said.

But not unique in all ways. In Flint the people on the receiving end of the disaster are black, in California the are largely Hispanic. The results are the same and the monied crowd isn't about to do anything until it shows up on their dinner plate.