AWWA WQTC62592

The South Tahoe Public Utility District (STPUD) purchased, permitted and installed California's first-ever advanced oxidation process (AOP) treatment system utilizing O₃/H₂O₂ to treat MTBE-contaminated groundwater for use as drinking water at its Arrowhead Well No. 3 (AH#3) in 2002. In July 2003, the STPUD shut down its Bakersfield and Country Club Wells, due to MTBE contamination. This resulted in a loss of over 1,600gpm capacity for an already stressed system. In addition, tert-butyl-alcohol (TBA) was discovered at a sentinel well within 2,500 feet of both AH#3 and Bakersfield wells. From June 2000 through July 2002, the District retained Boyle Engineering of Fresno, California to conduct a study to compare the efficacy of two types of granulated activated carbons (GAC). Although TBA contamination can be present either independently or as a breakdown byproduct of MTBE, the removal efficiency of TBA using GAC was beyond the scope of the pilot test.In October 2003, STPUD engineers began conducting an extensive study to determine the removal efficiency of GAC and AOP for low-level TBA and MTBE contamination. This study incorporates STPUD's first-hand experience with advanced oxidation treatment of MTBE to compare the operational and economic aspects of both technologies. Proposals were solicited from U.S. Filter of Oakland, California for their proprietary coconut shell carbon treatment system, and from Applied Process Technology of Pleasant Hill, California for their patented AOP system. The study utilized full-scale design, construction, and operating cost data from the existing AH#3 AOP facility, while the GAC option was estimated based upon known and estimated hard costs, information provided by U.S. Filter, Boyle Engineering, and other water utilities. Extensive literature research was also conducted to help determine infrastructure requirements and operational peculiarities of each technology. Cost data were based upon 15-year net present value for capital, operational, and maintenance expenses based upon nine probable occurrence scenarios of MTBE and TBA. Due to the environmental sensitivity of the Lake Tahoe basin, site impacts were also a significant consideration. This report provides the quantitative and qualitative results of the comparison. Includes 16 references, tables, figure.

Product Details

Edition:

Vol. - No.

Published:

11/01/2005

Number of Pages:

20

File Size:

1 file , 860 KB