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Is it safe to use oilfield wastewater on crops?

by Marilyn Saarni

Energy Geosciences Division Geochemistry Department In The Press
California almond orchard in bloom on left; Kern county oilfield on right

California almond orchard in bloom and a Kern County oilfield. Photo credits: Kern Oilfield: Christopher Halloran / Shutterstock.com – Almond orchard: David Scheuber / Shutterstock.com

Is it safe to use treated oilfield wastewater to irrigate almond, pistachio and citrus groves? William Stringfellow, environmental engineer in Earth and Environmental Sciences (Energy Geosciences Division), says, “We’re not able to answer the public definitely, and say there’s no problem.” Dr. Stringfellow joins a new panel, “Regional Water Quality Control Board Food Safety Expert Panel,” that has been charged to study the safety of irrigating food crops with oilfield wastewater from hydraulic fracturing, other drilling methods, and oilfield maintenance that contain chemicals, not only those naturally occurring in underground formations, but proprietary additives used to maximize oil extraction.

California’s oilfields generate lots of wastewater—nearly two billion barrels in 2013. With the extended California drought, the recycled wastewater is already irrigating tens of thousands of acres in California. In the Cawelo Water District, which has used treated water from Chevron and Valley Water Management since 1995, the water accounts for roughly 30% of the district’s supply.

The Central Valley Regional Water Quality Control Board has assembled this panel to study the safety of produce irrigated with this recycled water which may contain hundreds of chemicals, many unidentified or of known toxicity. The panel’s first public meeting was held on January 12 in Sacramento, California.

California Water Board to Investigate Use of Oilfield Wastewater to Irrigate Crops

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