Is it safe to drink trace amounts of it? Yes, according to state and federal standards. Do we want any of it in drinking water? No, says Duane Wallace, board member of the South Tahoe Public Utility District.
The district probably has the strictest standards for MTBE in the country. But with the additive spreading faster underground than anticipated, the largest supplier of drinking water in the Lake Tahoe Basin has had to rely on water restrictions and new wells to meet peak demand.
Wallace and board member Mary Lou Mosbacher argued in support of the district's nondetect policy for MTBE last week at a workshop. The meeting was called to discuss whether the district should eliminate or alter the policy so it won't be as challenging to provide water for its 17,000 customers.
The gasoline additive, which entered groundwater mostly by leaking from underground tanks and pipes, has contaminated 14 district wells, none of which is in use today.
"My adamant position is to not change the policy as hard as it is to meet," Wallace said. "It's outlawed in the county and in the gasoline. We sure as hell ought to keep it out of the water."
The nondetect policy adopted in 1999 dictates that water should not be served if it contains more than 0.2 parts per billion of methyl tertiary butyl ether. That's an amount so small that today's testing equipment cannot detect any lower.
Wallace acknowledged that state and federal limits for MTBE are much higher than the district's. But, he said, the district made a promise to its customers it needs to keep. Especially because no one knows what impact the additive has on human health.
"I don't think there have been any conclusive studies done," Wallace said.
MTBE, a byproduct of petroleum that was added to gasoline to reduce auto emissions, is listed as a possible carcinogen by the Environmental Protection Agency.
Wallace said the answer lies in the $69 million settlement the district got from oil companies which produced gasoline containing MTBE that was sold at South Shore. The district should rely on those funds to pay for treatment systems and drill new wells, Wallace said. This is the direction district staff is already pursuing.
As a result of the workshop, the district has decided to form a committee to tackle tough water issues created by MTBE. Wallace is a member of the committee which plans to bring recommendations back to the board next month.
"Our strategy is going to be constantly evolving until we understand how this chemical behaves in Tahoe," said district spokesman Dennis Cocking.
The state says water should not be served if it contains more than 13 parts per billion. California allows water districts to serve water containing up to 5 parts per billion without notifying the state.
Detection of MTBE in two district wells in August led to the workshop last week. Scientists from UC Davis had predicted the wells, one near Country Club Drive and one near Bakersfield Street, wouldn't be affected by MTBE until 2020, said Cocking. Tests at both wells detected the fuel additive at 0.3 parts per billion.
The Country Club well did not produce much water and will likely be shut down permanently. The Bakersfield well is a crucial one. It produces about 1,000 gallons a water a minute.
The district aims to have the well back online by June once an MTBE treatment system is in place. A well at Elks Club is also slated to be ready by early summer. An MTBE treatment system in place at the district's well near Arrowhead Avenue has successfully eliminated the chemical.
- Gregory Crofton can be reached at (530) 542-8045 or by e-mail at email@example.com