Tests Give County Wells a Clean Bill of Health

Tests on 58 of Orange County’s 225 water wells show that the ground-water supply is “virtually free” of contaminants, a county water district specialist said Tuesday.

“This marks the first time an in-depth analysis has been done to determine organic contaminants in the county’s ground water (and) results indicate our wells are still producing high-quality water for municipal use,” said David G. Argo, assistant manager and chief engineer for the Orange County Water District. “We are extremely pleased.”

Far Below Allowable Level

Only four of the wells, located in Anaheim, Orange, Fullerton and Seal Beach, showed traces of organic chemicals in two of three tests conducted from January to earlier this month. The amount of contaminants in three of the wells ranged from 0.3 to 44 parts per billion, far below the state’s maximum allowable level of 100 parts per billion.

Traces of the industrial solvent trichloroethane, a carcinogen, were detected in the Fullerton well at Orangethorpe Avenue and Raymond Street in amounts ranging from 0.3 to 30 parts per billion. The maximum allowable limit for trichloroethane is 200.

Traces of organic contaminants were initially found in 19 of the 58 wells from which samples were taken in January and February, Argo said. The amount of contaminants was far below limits set by the state Department of Health Services, he said.

Contaminants in Two Wells

The 19 wells were tested again in April, and contaminants were detected in only two of the wells, again in levels far below state standards, Argo said. The two tests were conducted by Brown & Caldwell Engineers, a state-approved laboratory in Pasadena.

A third test on the 19 wells was conducted earlier this month by James M. Montgomery Consulting Engineers of Pasadena. This time, organic chemicals far below state limits were found in four of the wells, Argo said.

Argo said he believes the large discrepancy between the results of the first test and the two subsequent samplings was due to the method of testing the initial samples. He said he is confident that the final conclusions were valid. The testing program was approved and monitored by the state Department of Health Services.

State limits indicate the levels at which the well may not be used for public consumption, Argo said. “It’s the level at which (scientists) do not know what the effect of human consumption might be,” he said. “It’s not the drop dead level.”

The testing program was required under legislation by Assemblyman Lloyd G. Connelly (D-Sacramento). Statewide, 833 large water systems are being evaluated for evidence of contamination.

Test results on 400 of the systems indicate organic pollutants in 260 of the 1,500 wells sampled, according to Peter Rodgers, chief sanitary engineer for the state health department. Thirty of the wells have been shut down because of excessive pollution levels.

‘High-Risk Areas’

Argo said the wells sampled in Orange County were those in “high-risk areas” because of their proximity to former dumps and spills. Higher producing wells were given top priority, he said. Shallow wells also were singled out, he said, because contaminants are lighter than water and rise to the surface.

“We were expecting a lot worse than what we found,” said county water district spokesman Gordon Elser.

Argo said the district will try to sample wells where pollutants were detected two to four times a year. Other wells will be tested annually.