The sometimes emotional issue of adding fluoride to public water supplies in Washoe County is on tap again in a new bill before the Nevada Legislature.

Supporters of Senate Bill 311, passed April 8 by the Senate Health and Education Committee, said it’s a safe and proven means to improve dental health of the county’s residents, including those who can’t afford to see a dentist.

Opponents said fluoridation of water is unnecessary and expensive. Some said the chemical is toxic and potentially harmful to consumers.

“I support it because I think children’s teeth are important,” said state Sen. Bernice Mathews, D-Reno, a retired nurse and a primary sponsor of the bill. “Dental health affects everything else in your body, so it’s important.”

“It’s a mass medication of the public water supply,” said Dr. Michael Gerber, a Reno homeopathic medical practitioner and strong opponent of fluoridation. “It is a very toxic material.”

In 1999, the Legislature passed a bill requiring the Southern Nevada Water Authority to begin adding fluoride to the Las Vegas area municipal water supply. Clark County voters continued fluoridation the following year by a margin of 58 percent.

Fluoridation provides “valuable dental benefits,” the SNWA website says.

Lawmakers backing the legislation said they want those same benefits available to residents of Washoe County.

“It’s been very, very successful in Clark County,” said co-sponsor Assemblyman Bernie Anderson, D-Sparks. “It’s particularly helpful for those who can’t afford medical-dental plans. This will help them have improved dental health.”

While she acknowledged the issue might be “somewhat contentious,” Assemblywoman Debbie Smith, D-Sparks, described fluoridation as a practice with shown benefits for dental health.

“An ounce of prevention is worth a pound of cure,” said co-sponsor state Sen. Randolph Townsend, R-Reno. “Nothing’s changed in that adage for over a thousand years.”

In 2002, Washoe County voters rejected a ballot question to fluoridate water, with 58 percent opposed.

Because of that vote, directors of the Truckee Meadows Water Authority, the primary water purveyor serving the greater Reno-Sparks area, decided last Wednesday to oppose the legislation.

“The voters already voted on it and they voted to oppose it. That’s why we’re opposing it,” said Sparks Councilman Mike Carrigan, chairman of the TMWA board.

Paul Miller, TMWA manager of operations and water quality, said it would cost about $5 million to install equipment to fluoridate water pumped from the Truckee River and groundwater wells. Fluoridation would cost about $1 million annually afterward, adding about $1 per month to water bills across the region, Miller said.

The legislation requires fluoridation for public water systems serving more than 100,000 people, affecting only TMWA in Northern Nevada.

But because TMWA sells wholesale water supplies to other water providers, including Washoe County and the Sun Valley General Improvement District, customers of those purveyors would be affected, Miller said.

Removing fluoride from water supplied to any wholesale customers would require a process “prohibitively expensive,” he said.

Cost aside, fluoridation should be opposed for public health reasons, Gerber said. The chemical used, hydrofluosilicic acid, is toxic to human thyroid glands and can cause other health problems, he said.

Gerber said the nation’s dental health problems are most associated with poor diets high in sugar and that the problem should be addressed in other ways than adding chemicals to water.

“This is really a socioeconomic problem and not a lack of fluoride,” he said.