Can oilfield water safely be reused for irrigation in California?

Reusing low-saline oilfield water mixed with surface water to irrigate farms in the Cawelo Water District of California does not pose major health risks, as some opponents of the practice have feared, a study led by Duke University and RTI International researchers finds. This finding only applies to questions about the safety in this water district, however. Oilfield water elsewhere will have different chemistry and salinity.