The first truckloads of partially treated but still contaminated groundwater from the Stringfellow acid pits in Glen Avon, Riverside County, have been discharged into the Santa Ana Regional Interceptor, a large sewer line paralleling the Santa Ana River, federal officials announced Saturday.
Officials from the Environmental Protection Agency in San Francisco said Friday's discharge was approved after a laboratory analysis showed that water being held in a Glen Avon "pre-treatment plant" was "much cleaner than is required for disposal" into the line that flows into Orange County. The water will receive additional treatment at a plant in Huntington Beach before it is discharged into the sea.
Orange County officials, including Supervisor Roger Stanton, had expressed concern that the discharge might contaminate the county's groundwater supplies. The Stringfellow water contains toxic heavy metals and organic compounds, some of them carcinogenic.
However, the current discharge process will divert the contaminated water from local water supplies, EPA officials said.
The officials said that the water is being tested at several points during the process by EPA scientists, officials from the Santa Ana Watershed Project Authority and the county sanitation districts.