California is America’s fruit and veggie bowl: The state produces about 70% of the all fruits and nuts in the country and 55% of all vegetables. Over the past few years, a lot of attention has been focused on how water intensive these farms are, but there’s another huge water-related cost for California’s massive agricultural production: contaminated drinking water from decades of pesticide runoff.

A recent report from the Environmental Working Group (EWG) outlines how 1,2,3-trichloropropane (TCP), a carcinogenic ingredient found in pesticides sold by Shell and Dow Chemical, has been “detected in water systems serving more than 8 million Californians.” TCP is just one of a slew of contaminates in California drinking water forcing millions of people to choose between buying bottled water or risking exposure to dangerous chemicals. Reports like this EWG one have helped increase pressure from citizens and conservation groups, which has in turn spurred state legislators to take action, and a vote to place a legally enforceable Maximum Contaminant Level (MCL) for TCP is set for April 19th. This votes come as progressive states like California and New York, exasperated by Trump’s lackluster environmental policies, have begun to take environmental regulation into their own hands even more than in the past.

“There is little hope of action from the EPA on the national level.”

While the Environmental Protection Agency (EPA) has classified TCP as “likely to be carcinogenic to humans,” the toxin still isn’t regulated on the federal level. And even though TCP is on the EPA’s Contaminant Candidate List, which positions the chemical to be investigated and possibly regulated, federal regulation is unlikely to occur; “In theory the EPA uses this information [from the Contaminant Candidate list] to decide which chemicals to set regulations on,” explained Bill Walker, EWG’s managing editor and co-author of the report. “In practice, in 25 years, they’ve tested for more than 80 contaminants and only moved forward on one…so there is little hope of action from the EPA on the national level.”

Action from Scott Pruitt’s EPA is even less likely, as Trump’s proposed budget would slash EPA funds by 31%, gutting many programs that are important for enforcing clean water standards. That includes the EPA’s Integrated Risk Information System, which works to identify and characterize hazardous chemicals that pose risks of consumption by the public. Additionally, Trump has called for shrinking the EPA’s enforcement office, which would significantly diminish the EPA’s ability to prosecute any environmental violations. This is especially troubling given the fact that the EPA already rarely prosecutes violations; in 2015, the EPA took formal enforcement action against roughly 11% of the over 8,000 violations. Without an enforcement arm, it will likely be very difficult to enforce clean water standards.

This is even more concerning as data from the EPA shows that TCP contamination isn’t just a problem for California; TCP has been detected in the drinking water of 13 other states, including New York, Pennsylvania, and Florida.

While California prepares to regulate TCP, communities in the San Joaquin Valley have taken legal action against Shell and Dow, two companies that continued using TCP in their pesticides well into the 1980s even when the ill-effects were becoming known. Both companies have continued to deny wrongdoing, but, according to the EWG report, they “have paid multi-million dollar settlements” to cities located in San Joaquin Valley.

In an emailed statement, Shell defended the use of its pesticide, stating that TPC was “a trace component” in their soil fumigant, which itself was “a highly beneficial product used by farmers to control nematodes that attacked crops and caused millions of dollars a year of crop loss, and was approved by the U.S. government and the State of California.” The statements says that while Shell will not comment on past or pending lawsuits, the company “is vigorously defending the claims made against it in lawsuits initiated by water purveyors.”

“How many other hidden examples are there of chemical companies endangering communities through toxic deception?”

Although both Dow and Shell stopped using TCP in their pesticides in the 1980s, the chemical is still found in water systems in regions where the pesticides were widely used. Since 2001, California’s State Water Resource Control Board has detected 94 public water systems that have higher than acceptable levels of TCP. A majority of these contaminated water systems are found in California’s San Joaquin Valley, one of the most productive agricultural regions in the world.

“This is an outrageous story of how Shell and Dow essentially got farmers who bought the pesticide to pay to help them get rid of a hazardous waste,” said Walker, in a statement published by the EWG. “How many other hidden examples are there of chemical companies endangering communities through toxic deception? TCP is just one of the many unregulated contaminants that most Americans have no idea are in their tap water. In the face of the federal government’s abrogation of responsibility, states like California must step up to protect citizens.”

A long history of toxic waste

TCP first came onto the scene in the 1940s, when Dow and Shell began marketing two soil fumigants, D-D and Telone, to combat parasitic worms called nematodes. The active nematode killing ingredient in D-D- and Telone was 1-3 dichloropropene, which was a byproduct of the allyl chloride manufacturing process, a chemical used to create plastic. Dichloropropene itself is classified by the EPA as a “probable human carcinogen,” and there are restrictions on where and how it can be used. But the worst toxin in the soup of chemicals that made up D-D and Telone was TCP.

Like dichloropropene, TCP was an unwanted byproduct from the manufacturing of allyl chloride. But, unlike dichloropropene, TCP wasn’t the active ingredient in the pesticide, and could have been removed from D-D and Telone without reducing their effectiveness. However, both Shell and Dow claimed the opposite, that TCP was an active ingredient, and that removing it would diminish D-D and Telone’s effectiveness as a pesticide. Lawsuits against both companies claim that as early as the 1950s, both Shell and Dow knew that TCP wasn’t an active ingredient for the pesticide, and that TCP wouldn’t break down in soil, and could contaminate drinking water.

Still, the companies didn’t change their manufacturing process, likely because D-D and Telone were easy money makers; they allowed the toxic byproducts from the manufacturing of plastic to be sold for profit. A Shell internal memo from 1983 spells this out, stating that annual sales of D-D earned $6.3 million, while also netting “a savings of $3.2 [million] for cost avoidance for disposal in the allyl chloride operation,” leading to a total benefit of $9.5 million.

“It’s a tragedy that farmworkers bust their backs in the fields all day, are exposed to pesticides on the job and then, years down the road, find that their families are in danger from the same chemicals they use to make a living,” said Raul Barraza Jr., general manager of the Arvin Community Services District, the water provider for the city of Arvin, in an interview with the EWG. “This is a disadvantaged community and we try to keep the rates as low as possible, because you can’t live without water.”

Just how bad is TCP? In 2009, OEHHA set a public health goal for TCP for California’s drinking water of less than one part per trillion. This is the second lowest public health goal ever set by OEHHA, indicating the significant human health risks posed by TCP consumption. However, the public health goal is based on public health concerns, and isn’t a legally enforceable regulation. The National Toxicology Program has classified TCP as “reasonably anticipated to be a human carcinogen,” and a toxicologist from the California Office of Environmental Health Hazard Assessment (OEHHA) stated in a radio interview last year that “there is no absolutely no question that is a genotoxic carcinogen.”

“It’s a disgrace, but the great thing about this country is that you can fight back,” said Barraza to the EWG. “You can go to court. You can go to Sacramento or D.C. and say, ‘Hey, what are you going to do about this?” While some lawsuits have been settled, many communities in the Valley are waiting for their day in court. In the meantime, they continue to face the risks of TCP in their water.”

At the time of publication, Dow Chemical had not returned requests for comments regarding its role in TPC contamination.