Tests of liq­uid used for ir­ri­ga­tion in the Cen­tral Val­ley de­tect traces of po­ten­tially harm­ful chem­i­cals.

Los Angeles Times - - CALIFORNIA - By Julie Cart

Test­ing of re­cy­cled oil field waste­water used on about 45,000 acres of farm­land in the Cen­tral Val­ley shows the wa­ter con­tains small amounts of po­ten­tially harm­ful chem­i­cals, in­clud­ing oil, ben­zene and ace­tone.

Lo­cal wa­ter reg­u­la­tors in April or­dered com­pre­hen­sive test­ing of the ir­ri­ga­tion wa­ter to check for the pres­ence of chem­i­cals used in oil pro­duc­tion.

As Cal­i­for­nia’s drought con­tin­ues, more com­pa­nies and ir­ri­ga­tion dis­tricts are seek­ing per­mits to sell and use treated oil field wa­ter. The height­ened in­ter­est has raised con­cerns over the ad­e­quacy of cur­rent safety mea­sures to pre­vent pro­duce from be­ing con­tam­i­nated by oil pro­duc­tion flu­ids.

The Cen­tral Val­ley Re­gional Wa­ter Qual­ity Con­trol Board has formed a com­mit­tee to ex­am­ine the is­sue and an­a­lyze the re­cent test re­sults. The group of ex­perts from the Cal­i­for­nia Depart­ment of Public Health and the state Depart­ment of Food and Agri­cul­ture will ad­vise wa­ter of­fi­cials about food safety.

Chevron sells 21 mil­lion gal­lons of treated oil field waste­water per day to the Cawelo Wa­ter Dis­trict, which pro­vides wa­ter to 90 Kern County farm­ers. Be­fore re­leas­ing it to the dis­trict, Chevron treats the waste­water in set­tling ponds and through other pro­cesses de­signed to re­move con­tam­i­nants.

Chevron sub­mit­ted re­sults of its waste­water tests to the wa­ter board on Mon­day, the dead­line for fil­ing the data.

Ac­cord­ing to the 138-page re­port, a lab­o­ra­tory anal­y­sis found ace­tone at lev­els rang­ing from 31 parts per bil­lion to 150 parts per bil­lion. Ace­tone is an in­dus­trial sol­vent that is a toxic car­cino­gen.

Ben­zene was present in

trace amounts in the sam­ples, ac­cord­ing to the lab re­port. Cal­i­for­nia reg­u­la­tions do not al­low ben­zene at any level in drink­ing wa­ter. There is no state stan­dard for ben­zene in ir­ri­ga­tion wa­ter.

All of Chevron’s sam­ples con­tained oil mol­e­cules called to­tal petroleum hy­dro­car­bons, but at con­cen­tra­tions con­sid­ered safe for drink­ing and well be­low the max­i­mum level set in the wa­ter re­cy­cling pro­gram’s per­mit.

“All test re­sults showed that wa­ter supplied by Chevron to the Cawelo Wa­ter Dis­trict is in com­pli­ance with its ex­ist­ing per­mit,” the com­pany said in a state­ment. “Chevron’s wa­ter re­use op­er­a­tion has run ap­pro­pri­ately for the ben­e­fit of Cal­i­for­nia agri­cul­ture and in ac­cor­dance with all reg­u­la­tory re­quire­ments.”

The sam­ples were taken from five dif­fer­ent points, in­clud­ing ponds that con­tain wa­ter from Chevron’s oil oper­a­tions and a reser­voir that con­tained wa­ter from Chevron and other oil pro­duc­ers. The sam­ples were an­a­lyzed by Amec Foster Wheeler En­vi­ron­ment & In­fra­struc­ture Inc. in Fresno.

The wa­ter board and the ad­vi­sory com­mit­tee have not yet re­viewed all the test re­sults sub­mit­ted by Chevron and other oil pro­duc­ers. Hun­dreds of sam­ples were tested from var­i­ous Kern County oil field waste­water sites.

“We are work­ing our way through the process,” said Clay Rodgers, as­sis­tant ex­ec­u­tive of­fi­cer of the re­gional wa­ter board. “This is a pri­or­ity is­sue for us. If the food safety ex­perts find a prob­lem, we will stop it and we will stop it im­me­di­ately.”

Even if ir­ri­ga­tion wa­ter con­tains toxic sub­stances, ex­perts say that micro­organ­isms in soil can con­sume some im­pu­ri­ties and plants have the abil­ity to process cer­tain con­tam­i­nants. It’s not clear whether oil field waste can make its way into the roots or leaves of ir­ri­gated plants, and then into the food chain.

“There’s not an abun­dance of knowl­edge,” on the topic, Rodgers said.

What is known, he said, is that ex­po­sure to chem­i­cals such as ace­tone may lead to long-term, chronic ail­ments and should be mon­i­tored over time.

David An­solabehere, gen­eral man­ager of the Cawelo Wa­ter Dis­trict, said the agency is eval­u­at­ing the test re­sults.

Some of the chem­i­cals iden­ti­fied in the Chevron re­port were also found in wa­ter sam­ples that were col­lected in March and tested by en­vi­ron­men­tal non­profit Wa­ter De­fense. Chevron has ques­tioned the group’s sam­pling meth­ods and the lab re­sults.

Wa­ter De­fense’s test­ing de­tected ace­tone and methy­lene chlo­ride, a pow­er­ful in­dus­trial sol­vent, in treated wa­ter drawn from Cawelo’s ir­ri­ga­tion canal. Chevron did not pro­vide lab re­sults for that chem­i­cal in test re­sults re­ported this week.

Rodgers said he asked both firms to test for methy­lene chlo­ride and re­port the re­sults to the wa­ter board.

Chevron said in its state­ment that it would pro­vide test re­sults on methy­lene chlo­ride.

The lab re­port Chevron sub­mit­ted sug­gested that the source of the ace­tone was not the com­pany’s oper­a­tions, but that it was a byprod­uct of a nat­u­rally oc­cur­ring break­down of hy­dro­car­bons.

That is one pos­si­ble ex­pla­na­tion, said John Grif­fith, co­or­di­na­tor of molec­u­lar tech­nol­ogy at the South­ern Cal­i­for­nia Coastal Wa­ter Re­search Pro­ject, a pub­licly funded re­search agency. But no mat­ter its source, he said, the ace­tone is toxic.

Un­til this spring, the wa­ter agency only re­quired test­ing for the pres­ence of nat­u­rally oc­cur­ring con­tam­i­nants such as ben­zene and salts. In part be­cause of the ur­gency to use re­cy­cled wa­ter, the agency is now ask­ing oil com­pa­nies to test the wa­ter more broadly for chem­i­cals used to drill and main­tain wells.

“We need to make sure we are sam­pling for the right stuff,” Rodgers said.

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