May 7, 2004
Lamm pushes water quality study
By MARK WAITE
A study of recharge to the Pahrump Valley water table from the Spring Mountains, planned by the Southern Nye County Conservation District, is being scrapped in favor of a sampling project for any possible water contamination on the valley floor. Caffeine is being viewed as one substance that would be an indicator of any septic leakage.
Members of the Southern Nye County Conservation District Wednesday approved a transfer of $5,000 originally earmarked for a study of the recharge, which would concern water quantity, to the contaminant study, or water quality. Donna Lamm, a supervisor on the conservation district and co-chairperson of the Pahrump Valley Community Action Team water and environmental task force, will prepare a proposal.
Lamm said installing several meteorological stations in the Spring Mountains to gauge the recharge to the Pahrump Valley water supply would be too expensive. The computerized stations cost about $5,000 apiece; the manual stations could be obtained for as little as $500 but would require hiring someone to check them frequently.
The U.S. Geological Survey in 2000 projected a recharge of 22,000 acre-feet per year to the Pahrump Valley water supply from the Spring Mountains, although Nye County hydrologist Tom Buqo notes in the Nye County Water Resources Plan issued in February 2002, "the quantity of recharge that is contributed each year is not known."
"It finally occurred to me I was barking up the wrong tree. One thing I know for sure, the water table is dropping valley-wide about a foot a year. So the more I thought about it, what good does it do to have meteorological stations if the water table is dropping," Lamm said.
Instead, scientists who routinely test the depth of the Pahrump Valley water table will be asked to pull a water sample as well. Buqo said 40 to 60 measurements of the water table are taken monthly at numerous locations around Pahrump Valley. He confirmed Lamm's figures.
Asked whether a dropping water table is causing a lot of well owners to drill deeper, Buqo said, "We're reaching that point. In some areas they're going to have to start deepening wells, my projections are in the next 15 years."
The water quality study would be to ensure there isn't any contamination from septic tank leakage. The push to enact a county ordinance requiring an engineer to verify percolation tests on new septic systems raised concerns over potential contamination from failed systems.
While Lamm talked about checking for nitrates, she said the study couldn't be limited to just that because nitrates can be naturally occurring in the soil. Buqo concurred the county doesn't have any comprehensive water chemistry sampling.
"We will also have to test for other substances, such as caffeine," Lamm said. "Caffeine is usually an indicator because that doesn't naturally occur in the soil. So that would be some indication there was contamination from septic tanks."
"I believe that we are OK. I don't believe that there's contamination but this will prove that there's not," Lamm said confidently.
Buqo added, "The reason we picked nitrates, No. 1 it's inexpensive to do that analysis, so we can get widespread coverage. If we come back with unfortunate circumstances and show elevated nitrate levels then we'll do more comprehensive analysis.
"There are no documented water contamination problems," Buqo said. "We have not identified any problems whatsoever but we want to know."
Buqo said the county is also studying the water flow in local springs. A good opportunity to learn about the water situation in Pahrump Valley is the upcoming Devil's Hole Workshop June 2-4; presentations by various scientists are scheduled at the Bob Ruud Community Center from 8 a.m. to 5 p.m. June 3.
The Nye County Planning Department reported as of January, the county assessor's office had recorded 47,679 parcels in Pahrump Valley, with 10,580 septic systems and 9,410 wells.
Nye County Commissioners April 6 voted to apply for a $50,000 Nevada Division of Environmental Protection grant for a wellhead protection plan. Buqo said the plan would define a capture zone for each water supply well in Pahrump Valley and potential sources of contamination in each one of those zones. As part of the wellhead protection plan Buqo will work with the Pahrump Regional Planning Commission to see if new businesses coming into Pahrump Valley could be a source of contamination for those wells.
The justification for seeking the grant, submitted by Les Bradshaw, director of the Nye County Department of Natural Resources and Federal Facilities, states, "as many as 200 to 300 septic systems are added each year. Given that the depth to water over much of the valley floor area is only 30 to 60 feet below land surface, the potential for contamination is considered high in some areas and has been identified as the most pressing water supply problem in the basin."
While her study on water quantity has been scrapped for now, Lamm took the occasion to urge Pahrump residents to practice water conservation.
"There's people moving in here in droves, they can't put in huge lawns," Lamm said. "The single biggest user of water is landscaping."