In California, Farmers Rely on Oil Wastewater to Weather Drought

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Overlooking Chevron's Kern River oil field with the Sierra Nevada in the background, March 30, 2015. Percy Feinstein/Corbis

Updated | The wet, white noise of gushing water rises above a background track of twangy guitar. Water is tumbling out of a pipe into a holding pond that looks as though it has sat nearly empty for ages, its sandy sides the color of parched desert. It looks like the California of recent headlines: drought so bad the ground is blowing away. Except now, here, in this promotional video for Chevron, there is water. Lots of it.

“The sound of that water is music to my ears,” David Ansolabehere, the general manager of the Cawelo Water District in Kern County, says in the video, gazing out over the rapidly filling pond. “Chevron is being environmentally conscious, and this is a very beneficial program, and it’s helped a lot of our farmers, helped our district, tremendously.”

The oil fields of Kern County, where Chevron is the largest producer, pump out more oil than those of any other county in the United States. It also happens to be one of the country’s most prolific agricultural counties, producing over $6 billion in crop value every year. But after three years of strangling drought, all that agriculture is on life support.

That’s where Chevron comes in. For every barrel of oil Chevron produces in its Kern River oil field, another 10 barrels of salty wastewater come up with it. So Chevron is selling about 500,000 barrels of water per day, or 21 million gallons, back to the Cawelo Water District—the local water district that delivers water to farmers within a seven-mile slice of Kern County—at an undisclosed amount, but “essentially ‘at cost,’” according to Chevron spokesman Cameron Van Ast. In a time when freshwater in the Central Valley is selling at up to 10 times the typical cost, it’s a good deal for farmers.

The wastewater Chevron is selling flows, without municipal treatment (though the oil products are removed), to 90 local farmers who spread it on their citrus, nut and grape crops. The Cawelo Water District might first mix the wastewater with freshwater, or it might not, depending on what crop the wastewater will be used on—and on how much freshwater is available at the time. In the midst of a drought, there is less freshwater, so the water the farmers get is saltier than in a wet year. But the farmers understand that using the salty wastewater on their crops is an emergency measure. If all goes as planned, when the rains come back the excess salt will be flushed through the soil.

But it’s a risky dance; over time, high sodium can change the properties of the soil, making it impermeable, unable to take in any more water. Trees would start to get “salt burn.” Their leaves would turn yellow, and yields would decline. Eventually, the soil becomes barren.

Ansolabehere says the wastewater mixture sent to farmers is rigorously monitored to keep from salting the soil to that degree. It is tested quarterly for salts and boron, he says. “The only reason this program works is because [Chevron’s] production water is of very good quality,” he says. “So maybe we’ll have a little salt buildup. But the next rain will flush it out.”

But the National Weather Service doesn’t foresee much rain in the immediate future. In fact, drought conditions may “intensify.”

For local farmers, dwindling water is a noose slowly tightening. Most take relief wherever they can get it, but not Tom Frantz. “I would rather let my trees die” than use the Chevron water, he says. Frantz is a small-time almond farmer who lives about six miles from the oilfields where the wastewater is pumped into mixing basins. His 36 acres are a speck in the shadow of much larger operations; vast orange groves, pistachio trees, rows and rows of almond trees. But Frantz knows farming. He’s been in Kern County, just west of the town Shafter, for all of his 65 years. His grandparents were farmers a few miles away. His parents farmed, too. There’s a generation below him, he says, who look as if they’ll take it up soon.

In normal years, Frantz depends on groundwater pumped from wells, as well as “surface water,” the water held in municipal reservoirs that flows in frigid streams from the melting snowpack in the Sierra Nevada mountains. But with the Sierra snowpack this winter at a paltry 6 percent of its typical heft, there won’t be much to melt. Chevron’s wastewater is an option, but Frantz knows what all farmers know: You can’t grow food with salty water for very long.

04_10_CaliWater_02 Irrigation water runs along the dried-up ditch between the rice farms to provide water for the rice fields in Richvale, California, May 1, 2014. Jae C. Hong/AP

“It’s just not sustainable at all to use salty water, no matter how much you dilute it.... We can farm here a long time, if we’re careful about the salts that we apply,” he says. “I’ve seen the farms that have saltier groundwater, and they have severe difficulties after 50 years. That’s very low levels of salts that’ll do that.”

Frantz has little confidence in how oil industry wastewater is regulated in his area, and he is concerned by what still isn’t known about the contents of the wastewater. Recently, there was a scandal over news that state oil and gas officials for years let oil companies inject drilling and fracking wastewater into hundreds of wells in protected aquifers. The water was laden with the benzene, a carcinogen, according to a Los Angeles Times investigation. “What it shows me is that we have to look out for ourselves,” Frantz says.

California doesn’t have statewide regulations for recycling wastewater for agriculture. Instead, nine regional water boards issue permits to local water districts. Once a year, the Cawelo Water District is required to send data about the salt and boron content to the Central Valley Water Board, according to Clay Rodgers, the board’s assistant executive officer. But the district isn’t obligated to test for other components, like heavy metals, arsenic, radioactive materials and chemicals that might be used in the drilling process. Ansolabehere says Cawelo has tested for radioactive elements “a couple of times” over the past 20 years, since “it’s very expensive” to test for, and it isn’t required by the board. Those tests have not turned up any positive results.

Chevron, for its part, says testing last month showed no heavy metals or chemical toxins were present in the water above maximum allowable levels. The arsenic levels were high, however, but “issues related to the arsenic concentrations in the water were fully addressed in the process of obtaining the permit from the Central Valley Regional Water Quality Control Board,” Chevron said in a statement. “Protection of people and the environment is a core value for Chevron, and we take all necessary steps to ensure the protection of our water resources.”

The Central Valley Regional Water Quality Control Board came to the conclusion that the high arsenic in the waste water was acceptable because most of the arsenic appeared in models to get “tied up” in the soil as it made its way down to the water table, says Rodgers. In other words, the Board sees no threat of tainting the groundwater with arsenic, because it largely stays in the soil. But no monitoring is in place to see if that arsenic is building up to unsafe levels in the agricultural soils themselves.

Little to no independent scientific research has been done on this type of water and how it interacts with crops, soil and surrounding bodies of water. Some scientists say there are too many unknowns associated with the wastewater from oilfields. If it is being used on food, and to irrigate land that lies above drinking water aquifers, we need to know more about it, they say—especially in light of the fact that, as Rodgers notes, the Central Valley hopes to expand its use for farm irrigation during the drought.

“There might not be a single risk out there with this practice. But the biggest risk that we have right now is that we just don’t know,” says Seth Shonkoff, an environmental public health scientist and a visiting scholar at the University of California, Berkeley. “So until we know, we definitely have reason for concern. We know that there are compounds being put down oil and gas wells that you would not want in your food.”

To Shonkoff’s knowledge, no scientist has ever published a study on what compounds from the oil development process—examples he gives are methanol, biocides and surfactants—might be in oilfield wastewater used on crops. Chevron says these constituents are kept separate from the water delivered to farmers.

Avner Vengosh, a Duke University geochemist, is serving on an expert panel for the U.S. Geological Survey while it begins to look into the quality of produced oil-field water from Kern County. His data are “only preliminary,” but he has found “high levels of vanadium, chromium and selenium” in the samples of wastewater he has tested (although he was unable to say if the water was produced from Chevron’s operations or another of the many operators in the area). Those levels are consistent with data from oil- and gas-produced water from other basins in the U.S., according to Vengosh.

Vanadium, a metal, is classified as “possibly carcinogenic” by the International Agency for Research on Cancer. Certain forms of chromium and selenium, both heavy metals, are associated with myriad health problems, including cancer, from chronic high exposure. Ansolabehere says the Cawelo Water District tested for chromium and selenium once, last year, and found none. It has never tested for vanadium. None of these metals are required to be tested for by the Central Valley Water Board.

Could the crops be absorbing these metals? The California Department of Food and Agriculture says it doesn’t have the jurisdiction to look. The Central Valley Water Board doesn’t sample crop residues where the water is used, either.

For Vengosh, what is most worrisome is the possibility that the water is seeping through the farmland into the water table. “It would end up in underlying groundwater. If the groundwater is moving to a drinking water source, you would end up with that in the drinking water eventually,” he says.

No matter how tough the drought gets, Frantz says, he won’t be taking the Chevron water. “It just doesn’t make sense to ruin something,” he says. “To get through years like this, we have to take some land out of production.”

But for Roy Pierucci, a farmer who manages a 160-acre pistachio farm that falls within the Cawelo Water District, the unknowns about the Chevron water won’t deter him from using it. If the water contains some as of yet unknown elements, “it would be a risk we’d be willing to take,” he says, without hesitation. He’s been using the Chevron water for 10 years and has never seen a problem with his crops. (Pierucci was featured in the Chevron promotional video, though he wasn’t paid for the appearance—he says he participated because he values what the company does for the water district.)

“I’ve really never asked what the analysis of the water is. I just know it’s available. There hasn’t been any complaints about it. I don’t think they recommend drinking it,” Pierucci says. “If [the drought] keeps up year after year, I think it would be a concern. I think the salt levels would be higher. They blend it for a reason.”

The Chevron water is vital to Pierucci’s operation, but it isn’t a game changer. “It’s not going to save us,” he says. Three years of brutal drought have left his pistachio trees teetering on the edge of survival. If the drought persists another two or three years, he says, he’ll have to start ripping out his trees and reducing the number of acres he irrigates. On another property he manages, where there is no pumping well on-site, he imagines he’ll be pulling out trees within a year. “You can’t chase water forever. Sooner or later you’re going to lose.”

This article has been updated to include a statement from Chevron regarding their internal water testing processes and results, as well as information about arsenic monitoring from the Central Valley Regional Water Quality Control Board.

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