Water from a private well in the foothills off Old Santa Fe Trail is so contaminated by water softener salts that the property owners can't drink it or use it to water their trees, wash clothes or shower.

The chloride levels in their well water exceed the federal safe drinking water standards by more than eight times.

Salts aren't the only problem in domestic wells around Santa Fe.

Dozens of private domestic wells ringing Santa Fe have uranium, arsenic or chloride levels above the maximums allowed under federal drinking water standards, according to a study of 475 wells conducted by the New Mexico Environment Department, the city, the county and the Good Water Company.

Unlike public drinking water systems, domestic wells don't have to meet the federal or state drinking water standards. But Dennis McQuillan, an environmental geologist with the New Mexico Environment Department, said well owners should know what's in their water so they can make decisions about treating it.

Arsenic and uranium found in the wells occur naturally in New Mexico rocks and leach into water. But the salt levels are coming primarily from water softeners, McQuillan said.

The foothills couple, who asked not to be named because of the issue's sensitivity among neighbors and ongoing legal issues, said the day they moved into their home and tasted their water, it was so salty they had to spit it out. Their house, well and septic system met all the requirements for protecting groundwater. The person who sold them the home didn't tell them there was a problem, and basic well tests only look for indications of septic system contamination, such as nitrates and coliform bacteria, not salts.

"Theirs is an example of someone whose place met all the state requirements and they still have contaminated water," said McQuillan, who worries the problem of chloride in domestic wells will only increase. Softeners use sodium chloride or potassium chloride to soften hard water, but the machines regularly purge the brine into septic systems or underground brine pits. Fractured granite underground along Old Santa Fe Trail could be making it easier for the brine water and septic waste to migrate, he said. "The average house uses 5 pounds of salt per month," McQuillan said. "That is a lot of salt going into a fractured granite aquifer."

The foothills property owners stopped using the home's water softener, drilled a second well with the same salty results, and are now spending thousands more dollars seeking an alternate water source.

McQuillan said the massive well sampling occurred after Santa Fe-area domestic well owners were invited to schedule a visit from a team of water testers in June.

Los Alamos National Lab technicians tested the samples for 50 parameters. "This type of comprehensive testing has never been done in the state of New Mexico with this many parameters from so many private domestic wells," McQuillan said. "We're going to be able to map the groundwater of Santa Fe like it has never been mapped before."

The results of the tests were posted on the New Mexico Environment Department's Web site this week and results mailed to individual well owners.

McQuillan said 50 well tests came back with elevated levels of arsenic and 30 with levels of uranium higher than the standard set by the U.S. Environmental Protection Agency. Other wells had levels of sulfates, nitrates and total dissolved solids (anything present in the water other than the water molecule and suspended solids) that exceeded federal drinking water standards.

Some wells tested around Cañada de los Alamos had high nitrate levels, often a sign that cesspools or septic tanks are seeping into groundwater.

Several wells tested in Tesuque, Canyon Road, Wilderness Gate, Cañada de los Alamos, and Glorieta had uranium levels two to three times higher than the federal maximum.

Wells on Santa Fe's west side exceeded the arsenic standard. Volcanic rock and faults leach arsenic up to the shallow aquifer, McQuillan said. About 15 percent of wells tested in Eldorado had elevated arsenic levels.

Sarah Connelly's Eldorado well turned out to have elevated arsenic. But she hasn't run out to buy a water-treatment system or purchase drinking water yet. "My husband said he hadn't heard of anyone around here dying of arsenic poisoning, so we shouldn't worry too much," Connelly said.

"People on wells in Santa Fe's metro area have some of the best water in the state," McQuillan said.

McQuillan said reverse osmosis will take care of uranium, arsenic and any other dissolved solids in well water. The drawback: It takes three to five gallons of water to produce one gallon of treated water. "In an area like Santa Fe, that's a lot of wasted water," he said.

Contact Staci Matlock at 986-3055 or smatlock@sfnewmexican.com.