Oil field water: In the May 3 Section A, an article about the use of recycled oil field water in California agriculture said that samples contained acetone and methylene chloride after treatment. Acetone was found in testing in 2014, but not in a March 2015 test. An accompanying graphic cited the levels of three chemicals found in untreated oil field water: oil, 240,000-480,000 parts per million; acetone, 440-530 parts per billion; and methylene chloride, 82-89 parts per billion. However, the graphic omitted the levels found in tests of treated water: oil, 130-1,300 parts per million; acetone, 57-79 parts per billion; and methylene chloride, 26-56 parts per billion. Also, the source of the untreated water was misidentified. The samples were from the Poso Creek Oil Field, not an oil field owned by Chevron. And Blake Sanden was identified as an agriculture extension agent for UC Davis. Sanden works for the statewide UC Agriculture and Natural Resources program. —