Fluoride levels in the Crescent City municipal water supply have fluctuated since February due to equipment issues, according to public works officials.
Levels have been a bit above the 0.7 milligrams per liter mark — which the City Council adopted as a new, reduced level Feb. 7. Before then, the city added about 1 milligram of fluoride per liter of water.
The change came after the U.S. Department of Health and Human Services and the U.S. Environmental Protection Agency recommended that drinking water systems reduce the level of added fluoride to the lowest end of the dosing scale, which ranges from 0.7 to 1.2 milligrams of fluoride per liter of water.
Eric Wier, city associate engineer and utilities director, said the city replaced a check valve last month that was posing problems. He said the valve helps keep fluoride in a pump between the water supply and storage tank.
“It wasn’t quite strong enough to dose at that reduced rate,” Wier said about the valve. “It allowed air into the line.”
He said the new valve has allowed the city to dose at the requested rate of 0.7 milligrams of fluoride per liter of water since about April 15.
Council members voted 3-2 in February to follow the new federal dosing recommendations after learning from City Attorney Bob Black that they could direct city staff to do so.
Black said the council can’t add or completely remove fluoride from the municipal water system, as that is in the hands of city voters, but that they could follow the latest guidelines.
City voters made their stance known last November by rejecting Measure A, which would have removed fluoride from the municipal water system, with 555 “no” votes and 418 “yes” votes.
However, the issue has continued to permeate both city and county meetings, and City Councilwoman Donna Westfall alluded to another possible vote on fluoride in 2012.
According to the city’s monthly fluoridation operations report, the lowest daily dose was 0.61 milligrams and the highest was 1.02 milligrams of fluoride per liter of water during the time period of Feb. 11-April 15.
The reports show the daily dosage during this time period averaged about 0.8 to 0.9 milligrams per liter. Wier said the fluctuations are miniscule.
“You’re talking about one-tenth of one part per million,” Wier said.
The city has about 4,000 gallons of fluoride on hand, which Wier said will last the city a long time at the reduced additive rate.
“It’ll last about a year and a half,” Wier said.
Crescent City is currently operating outside the state’s recommended dosing scale of 0.9 to 1.5 milligrams of fluoride per liter of water. Wier said the city has been “very forthright with the state” about this.
The state hasn’t taken any punitive action against the city, although Wier said state officials told him the city is outside the control range. The state has yet to align itself with the EPA’s recommendations.
Wier said the city could potentially be forced to follow state guidelines and add at least 0.9 milligrams of fluoride per liter of water if people were to complain to the California Department of Public Health’s Division of Drinking Water.