Scientists study safety of oilfield wastewater on Californian cropsStaff writer ▼ | January 13, 2016
At least five oilfields in California are passing along their leftover production fluid to help farmers with irrigation, during the fourth year of California's drought.
Public health Only negligible amounts of chemicals
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.
California's aging oilfields generate lots of wastewater. In Central California's San Joaquin Valley, a center of the state's agriculture and oil businesses, oil companies in 2013 produced nearly 2 billion barrels of wastewater.
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.
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.
Testing so far has found only 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 also has begun growing test crops with the oilfield water to study how much of the chemicals wind up in the produce. ■