Experts to Study Use of Oilfield Wastewater on Food Crops
Published on by Ashantha Goonetilleke, Professor, Water/Environmental Engineering at Queensland University of Technology in Academic
More farmers in drought-stricken California are using oilfield wastewater to irrigate, and a new panel has begun taking one of the state’s deepest looks yet at the safety of using the chemical-laced water on food crops
In the fourth year of California’s drought, at least five oilfields in the state are passing along their leftover production fluid to water districts for irrigation, for recharging underground water supplies, and other uses, experts said.
In Merced County, however, irrigation water provided by the Merced Irrigation District mostly comes from the Merced River, which flows into Lake McClure. Water districts using the oilfield wastewater mostly cover Kern County and parts of Tulare County, according to the Central Valley Regional Water Quality Control Board.
Chevron and the California offshoot of Occidental Petroleum are among the oil companies supplying oilfield wastewater for irrigating tens of thousands of acres in California. Almond, pistachio and citrus growers are the main farmers already using such water.
Using the wastewater costs less for water districts than pumping groundwater or using precious surface water.
California’s aging oilfields require intensive drilling methods and generate lots of wastewater. In the San Joaquin Valley, a center of the state’s agriculture and oil businesses, oil companies in 2013 produced 150 million barrels of oil – and nearly 2 billion barrels of wastewater.
Central California leads the country in food production. It’s also the main oil-producing base in California, the country’s No. 3 oil-and-gas producing state.
For farmers coping with California’s drought, the question is “where’s the water going to come from if you want to maintain agriculture,” said Gabriele Ludwig, a representative of the Almond Board of California and a member of the new panel that met for the first time Tuesday.
In Merced County, that question remains crystal clear: Irrigation water will come from Lake McClure and be delivered through MID’s 800-mile system. The water, mostly coming from the Merced River, is probably some of the cleanest water you can get, said Mike Jensen, a spokesman for MID. The Merced River is protected by the Wild and Scenic Rivers Act, which restricts mining, construction and other activities on the river. The act also ensures water quality is maintained and, when possible, enhanced.
The state officials, academic experts and industry representatives on the panel are charged with studying the safety of irrigating food crops with oilfield wastewater that may contain chemicals and other material from hydraulic fracturing, other intensive drilling methods and oilfield maintenance.
The effect of oilfield chemicals on food is “largely unstudied and unknown,” says the nonprofit Pacific Institute, which studies water issues.
Researchers, for example, don’t know the long-term toxicity of up to 80 percent of the hundreds of materials used in oilfield production, Pacific Institute researcher Matthew Heberger told panel members.
Bob Weimer, a certified organic farmer in Merced County, said organic farmers would “absolutely not” use oilfield wastewater.
“What’s involved in using recycled water, there’s going to be chemicals involved,” he said.
Testing so far has found negligible amounts of chemicals in the recycled oilfield water, said Clay Rodgers, a manager at the Central Valley Regional Water Quality Control Board, which assembled the panel.
At least one local water district has begun growing test crops with the oilfield water to study how much of the chemicals wind up in the produce.
As of now, with so many unknowns about the hundreds of chemicals involved and their possible impact on crops, “We’re not able to answer the public definitely and say there’s no problem,” said William Stringfellow, a panel member and environmental engineer at the Lawrence Berkeley National Laboratory in Berkeley.
Source: Merced Sun - Star
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