"A recent study found chemical concentrations in the wastewater met safety standards in one California county. But activists say more testing is needed."
"For decades, farmers in California's Kern County have turned to wastewater from oil production to help irrigate their crops during extended dry spells.
The wastewater provides an alternative to groundwater, which has become increasingly scarce as farmers have pumped more than they could replenish.
But the use of the recycled water, a byproduct of oil and natural gas extraction that is mixed with surface water for irrigation, has stirred controversy. Because the water, known as oilfield produced water or oilfield brine, contains chemicals like salt, boron, arsenic and radioactive elements, scientists and environmentalists worry that it poses a risk to human health."