AWWA WQTC52753

The Southern California Water Company-Southwest District (SCWC) is locatedin the southwest portion of Los Angeles County, California. The District's sources of water supply include groundwater from 19 local wells and treated surfacewater. Approximately 25% of the 44 million gallons per day water supply is obtained from the wells. Data collected by SCWC showed that total trihalomethane (TTHM) levels in the northwest part of the system are as high as 91 ug/L and have a quarterly average of 83 ug/L during the summer months. After reviewing these results, SCWC conducted an investigation of this area to determine the source of the high TTHMs. Based on a preliminary review, SCWC took a closer look at the Yukon Plant, the site of 2 groundwater wells. Water quality analysis was conducted for totalorganic carbon and TTHM maximum formation potentials. This paper reports the results of the investigation. Includes 10 references, tables, figures.