ADELANTO • The city has added new security measures after copper thieves vandalized three water wells, causing arsenic and fluoride levels in the water to exceed EPA limits.
The city recently notified residents that arsenic and fluoride levels in their drinking water exceeded EPA limits over a two-week period, but city officials say the levels were not high enough to cause acute health hazards.
The wells were vandalized on July 15, and it took the city nearly three weeks to repair and rewire the equipment. A maintenance company was immediately called to work on the wells and install electrical wiring once officials discovered the damage, then had to wait for special parts to arrive, City Manager Jim Hart said.
“We didn’t have cameras up there and the area is too isolated for lights,” Director of Public Utilities John Sponsler said. “We had concertina wire and that had been a deterrent for some time.”
Sponsler said damage to the three wells that were broken into cost the city an estimated $60,000 in parts and repairs.
Since the break-in, the city has placed gates or dirt berms at all access points, as well as installed security cameras.
Arsenic and fluoride levels increased when the damage halted a dilution process that keeps arsenic and fluoride levels below EPA standards.
“Cutting the wire and stealing the copper out of the controls of the wells caused the wells to go down and (we) were unable to blend the well water,” said Hart, explaining that the city dilutes the levels of arsenic and fluoride in the drinking water supply by blending purified water with groundwater that naturally contains high levels of the substances.
Elevated levels of arsenic and fluoride were not identified until Aug. 7., however, samples from the water supply on Aug. 20 revealed that arsenic and fluoride levels were restored to EPA approved levels once the repaired wells functioned properly.
“The arsenic levels are back down to below EPA requirements, as well as the levels of fluoride,” Sponsler told the Daily Press on Tuesday. “There have been a lot of calls, and pretty much everybody concerned understood once I explained to them the situation.”
Hart said the city mailed out “non-emergency” public notices to residents on Sept. 6, two days prior to results of the Aug. 20 sample returning that the chemical levels were restored.
“The samples take about 15 days to get back to us, so we sent out the notice before we got the results back,” Sponsler said.
The notice complied with state requirements to inform the public its water system recently violated an EPA drinking water standard. In the notice, the city said it anticipated resolving the problem within 20 days of the notification.
“It’s just a notice telling the public that the incident occurred, but at no time was the public at risk with the levels there. The levels were not to the point where you have to stop drinking the water,” Hart said. “It was not at a dangerous level. If it had been, a more urgent notice would have been sent out to residents.”
According to the notice, water sample results received on Aug. 7 revealed arsenic levels of 0.015 milligrams per liter. The city explained that this level is above the U.S. EPA standard, which allows a maximum contaminant level of 0.010 milligrams per liter. Although the arsenic levels violated regulations, the EPA standard had been set at a MCL of 0.050 milligrams prior to 2001, well above the elevated levels in Adelanto.
The city also discovered its drinking water had a fluoride concentration of 3.1 milligrams per liter, stating, “This is above the standard, or maximum contamination level of 2.0 milligrams per liter,” according to a separate public notice. While not complying with state law, the fluoride levels remained lower than the federal regulation of 4.0 milligrams per liter.
The city warned that “some people who drink water containing arsenic in excess of the MCL over many years may experience skin damage or circulatory system problems, and may have an increased risk of getting cancer.”
With the excessive fluoride levels, the city warned that “children under the age of nine should use an alternative source of water that is low in fluoride,” but reiterating to residents that it was not an emergency.
“If it had been (an emergency), you would have been notified immediately,” the public notice stated. “Rather, this is an alert about your drinking water and a cosmetic dental problem that might affect children under nine years of age.”