SOUTH LAKE TAHOE, Calif., Oct. 8, 2002 -- The South Tahoe Public Utility District (District) recently won settlements totaling more than $69 million from oil companies responsible for the contamination of drinking water wells with the gasoline additive MTBE.
While the recent settlements marked the end of the District's four-year battle to recoup the cost of damages wrought by MTBE on its water supply, a new chapter in the region's recovery has just begun - the process of actually removing the MTBE from its drinking water.
MTBE, or methyl tertiary butyl ether, is most commonly released into the environment from leaking underground storage tanks (USTs) at gas stations. Since MTBE degrades slowly and is highly mobile in subsurface environments, it spreads through groundwater very quickly, covering greater distances than other waterborne contaminants.
According to a study published in 2001 by the U.S. Geological Survey, MTBE has been detected in approximately 14 percent of surface water sources and 5 percent of groundwater wells tested across the country.
More than one-third of South Tahoe's 34 drinking water wells were taken out of service in 1998 due to MTBE contamination. The District is working diligently to identify and implement the best treatment methods possible and is tackling the behemoth problem one well at a time.
"Removing all of the MTBE from all of this water is not something we are going to accomplish overnight," says Dennis Cocking, the District's Information Officer. "But we will take it step by step and ultimately restore the affected water."
But the District is faced with a particularly challenging contaminant, since MTBE is not easily removed by traditional treatment methods such as carbon filtration or air stripping.
So, the District broadened its search for a solution beyond the scope of these standard methods. "We didn't want just any system," said Rick Hydrick, the District's Manager of Water Operations. "We wanted something that would completely destroy all traces of MTBE and would produce the purest drinking water possible."
The District purchased an 800-gallon-per-minute advanced oxidation treatment system from Applied Process Technology Inc. based in Pleasant Hill, California. The portable system, called HiPOx, was purchased after site tests demonstrated that HiPOx could destroy MTBE in potable water and would meet the District's stringent water quality requirements.
"The Arrowhead well is the first MTBE-contaminated well to be brought back on line. Its restoration marks an important milestone in the total recovery of South Lake Tahoe's drinking water supply," said Cocking.
The HiPOx advanced oxidation technology mixes hydrogen peroxide and ozone to form hydroxyl radicals, an aggressive oxidant that reacts chemically with MTBE, breaking it down into carbon dioxide and water. The carbon dioxide is vented off while the cleansed water is returned to the drinking water system for distribution.
The HiPOx system is the first advanced oxidation treatment system approved by California's Department of Health Services (DHS) to completely eliminate MTBE contamination in drinking water. Since the system's commissioning on June 26, 2002, the previously unusable Arrowhead well has been providing clean, MTBE-free drinking water to the South Lake Tahoe public and its surrounding communities.
Miller Environmental Group, Inc. (MEG) of Calverton, New York has developed an exclusive partnership with Applied to bring the HiPOx technology to the east coast. MEG has over 30 years of experience specializing in environmental remediation services with multiple office locations throughout the Northeastern United States.
Mark Miller, MEG's President stated, "We are pleased to partner with Applied as we have finally found an operationally effective and cost efficient solution to MTBE contamination."
