City planning to install filter for contamination downtown

Tuesday, Oct. 17, 2000 | 10:23 a.m.

Las Vegas officials have until Dec. 29 to install a filter that will remove a solvent discovered in ground water underneath a portion of 61 acres of premier downtown land ripe for development.

Leo Drozdoff, chief of the state's Bureau of Water Pollution Control, said Monday that the city has agreed to install carbon filters on ground water discharged to the Las Vegas Wash.

The Nevada Division of Environmental Protection has no plans to take enforcement action, such as imposing fines, against the city for the contamination, which was found as part of city pumping of standing water at the Bonneville Avenue underpass.

The newly discovered solvent poses no significant health risk, and the cleanup should not slow development of the site, officials said.

The city has pumped ground water from the underpass next to the Clark County Government Center for more than three years to avoid standing water in the passageway.

The solvent was found in a well that discharges ground water to storm drains that flow into the Las Vegas Wash, which feeds into Lake Mead, Southern Nevada's major drinking water source.

The state wrote a letter to the city on Aug. 29, noting that the solvent tetrachloroethylene, or perchloroethylene (PCE), has been monitored in a well at Bonneville at levels above the national drinking water standard every month except August 1997.

PCE is used in dry cleaning solvents, transformer insulating fluid and as a general industrial solvent. It causes cancer in laboratory animals and is suspected of liver and central nervous system damage in humans if inhaled or swallowed.

No one knows the extent of the contamination, but the site, which for 80 years was a railroad fueling station and storage yard for Union Pacific Railroad, has been under a state cleanup order since May 27, 1987. Union Pacific quit fueling operations there in 1991.

On old maps from the 1930s and '40s, Standard Oil and Union Oil companies both had facilities at Bonneville, as well as a large fuel storage tank for the railroad west of Main Street.

The railroad has already spent more than $3 million to clean up the soil, according to state records.

The city and Union Pacific Railroad experts plan to filter the water before it enters the drain.

Contrary to earlier environmental reports that predicted contaminants would not reach the well northwest of the underpass for 10 years, tainted water was detected within seven months, the state said.