Efficacy of Stringfellow’s Treatment Plant Praised

A plant built to extract toxins from water at the Stringfellow Acid Pits before it is pumped through Orange County’s sewer system and into the ocean off Huntington Beach is exceeding performance requirements, according to an independent audit.

The audit, conducted over an 18-month period by K.S. Dunbar & Associates, a Rancho Murietta-based engineering firm, “found that the treatment plant was performing excellently,” said P. Ravishanker, project manager for the Santa Ana Watershed Project Authority.

“All promises and monitoring requirements are being enforced,” Ravishanker said. “Everything is according to permit.”

The $5-million plant began operating in 1985 after health officials concluded that the contaminated water near the long-dormant toxic dump in Riverside County was threatening safe ground water supplies in the area. Some Orange County officials, including the Board of Supervisors, initially objected to the plan when it was announced in 1983.

But modification of the plan that kept any of the water from Stringfellow from being injected into the underground water supply in Orange County quelled most of the environmental objections. The Orange County Sanitation Districts placed additional requirements on the project before allowing the water to be pumped through its facilities.

The audit was conducted to ensure participating agencies such as the sanitation districts that the plant was complying with all requirements. The plant’s permit expires this year, and the auditors’ findings will be reviewed before watershed project authority considers granting a renewal, probably in December, Ravishanker said.

Wayne Sylvester, general manager of the Orange County Sanitation Districts, said he had not yet seen a copy of the audit, but periodic reports have indicated that the Stringfellow treatment plant has “more than met . . . our requirements.”

The plant, which is operated by the federal Environmental Protection Agency, filters out industrial solvents and dissolves heavy metals such as chromium and cadmium from the contaminated ground water. Then the water is trucked to intake lines for a giant sewer line, paralleling the Santa Ana River, through which it is sent to Huntington Beach, the site of Orange County’s main waste water treatment plant, before being discharged five miles offshore.

The audit found that concentrations of about two dozen contaminants in the water treated at Stringfellow are well within permit requirements, Ravishanker said.

About 40,000 gallons of treated water are sent to Orange County daily, although the plant’s capacity is 187,000 gallons a day, Ravishanker said.

The Huntington Beach plant treats 250 million gallons of waste water each day, Sylvester said.