Officials dig deeper into contaminated well

Wednesday, March 29, 2000 | 11:35 a.m.

Nevada environmental officials have expanded an investigation into the source of the gasoline additive MTBE after a small amount of it was detected in two supplementary drinking-water wells in North Las Vegas.

North Las Vegas officials notified the state Environmental Protection Division last May after discovering roughly 10 parts per billion of MTBE, or methyl tertiary butyl ether, at the Gowan No. 2 well near Las Vegas Boulevard North and Cheyenne Avenue.

Since there is no state or federal drinking water limit for MTBE, Gowan Nos. 1 and 2 were shut down to protect the North Las Vegas supply. Water from 10 wells is blended with Lake Mead water during peak demands, said Dick Serdoz, chief of the Las Vegas office of the Environmental Protection Division. "The wells have been down for a year, and they are still down," he said today.

Todd Croft, project manager for the environmental division, said the federal Environmental Protection Agency has set 20 to 40 parts per billion as a range for aesthetic purposes only. MTBE can be tasted or smelled in drinking water within that range, he said.

The state will drill more wells to find out the extent of the contamination, Croft said. While the Rebel 8 station is closest to the Gowan wells, the source of the MTBE is unknown.

The gasoline stations had been under investigation by the state since 1993 after a small leak was detected from a Rebel line. In 1996 the Rebel owners improved treatment of its leak, Croft said, by enhancing the removal process.

MTBE was invented by Arco in the 1960s and used to boost gasoline performance and help clean the air. However, California and Alaska are phasing it out because it moves easily through ground water and has contaminated an estimated one-third of water supplies in 31 states.