The Municipal Authority of Westmoreland County won’t be adding fluoride to its drinking water unless a bill in the state Legislature becomes law.

The measure would require all public water suppliers with 500 or more customers — such as the Westmoreland authority — to add fluoride. It is the first time in nearly 20 years that a bill attempts to make water fluoridation mandatory in Pennsylvania.

That has drawn objections from some groups, including township supervisors who say the decision should be up to them.

“Our position is a very simple one: We do whatever the state requires us to do, and currently the state does not require public-water suppliers to add fluoride to water,” said Chris Kerr, authority manager. “If they require us … we’ll do it immediately.”

The bill, under review in the state House Appropriations Committee, is being pushed by the Pennsylvania Dental Association as a safe way to reduce tooth decay.

Other groups question the safety of adding the compound to water.

Still, Dr. Jon Johnston, president of the state dental association and a Punxsutawney dentist, said studies show that fluoride added to water in proper amounts helps to prevent tooth decay for all ages.

“All the studies that have been done — scientifically controlled ones — show it’s safe at levels of 0.7 to 1 part per million,” Johnston said.

He explained fluoride prevents cavities by making tooth enamel harder and more resistant to acids that cause decay.

Johnston said the average cost to fluoridate water ranges from 50 cents to $3 per person per year.

Most medical and dental organizations support the addition of fluoride to drinking water. They include the American Dental Association, the Centers for Disease Control and Prevention, the American Medical Association and the World Health Organization.

Officials at the state Department of Environmental Protection believe that fluoride added to water in proper levels is safe, said spokeswoman Helen Humphreys. The agency oversees public water suppliers.

The House bill sponsored by Rep. Stephen Barrar, a Delaware County Republican, notes that the CDC calls water fluoridation “one of the 10 most significant public health achievements of the 20th century.”

But others, including environmental groups and believers in holistic health, reject fluoride’s use. They question its effects on the body and say water fluoridation is unnecessary because the compound can be obtained through toothpaste and other means.

They contend much of the fluoridated water is wasted because it is used for purposes other than drinking, such as watering lawns or washing cars.

“It’s not safe,” said Mike Ewall, of ActionPA, a group opposed to adding fluoride to drinking water. “It’s not effective. It’s costly, and it’s not ethical.”

The Westmoreland authority serves about 400,000 people, most in central Westmoreland County or eastern Allegheny County, and others in Fayette and Indiana counties, Kerr said.

Others supplying water to the area include the Pennsylvania American Water Co., with nearly 330,000 customers, most in Allegheny and Washington counties. About 287,000 of American’s customers here receive fluoridated water, said company spokesman Terry Maenza.

The Pittsburgh Water and Sewer Authority supplies fluoridated water to about 250,000 customers.

John Hood, executive director of the Pennsylvania Rural Water Association, and Elam Herr, assistant executive director of the Pennsylvania Association of Township Supervisors, said their memberships don’t oppose the use of fluoride in water.

But they do oppose being forced to add it, they said.

“We think it should be a local choice,” said Hood, whose group represents nearly 1,000 water suppliers, large and small.

Herr’s group has objected to mandatory fluoridation for more than two decades.

“(Most supervisors) were all saying, If we want fluoride in our water supply … then that’s for us to make the decision,” Herr said. “The state shouldn’t mandate.”

They believe adding fluoride will cost too much and could lead to more liability concerns, he said.

“And this is something that is not necessarily needed,” Herr said.

Johnston said the choice can’t be left to water suppliers. It has to be forced by law.

“There’s not enough incentive for them to do it,” Herr said.

Paul Zielinski, a quality and environmental management specialist with the Pennsylvania American Water Co., said his company either adds dry or liquid fluoride to its system at 1 part per million. A pump that carefully measures amounts is used, he said.

The level of fluoride is tested regularly, Zielinski said.

“That’s checked at least daily for every day we’re in operation,” he said.

Maenza said the cost to set up a fluoridation system for a medium-size facility serving 1,300 to 4,000 customers is about $17 per household. That cost reflects various equipment needed to add the substance, the chemical and labor.

Costs in subsequent years go down, Maenza said.

Kerr said his Westmoreland authority receives about a dozen letters a year on fluoride when legislation is pending.

“We have probably as many proponents for fluoride as we do not wanting fluoride,” Kerr said.

Fluoride

• Fluoride, a compound of the chemical element fluorine, was first used purposely to prevent tooth decay in Grand Rapids, Mich., in 1945. Fluoridation of drinking water has been common in the United States for more than 50 years.

• Armstrong County’s Ford City was the first community in Pennsylvania to adopt water fluoridation in 1951. Pittsburgh became the second the next year.

• Of the 50 largest cities in the United States, 43 have community water fluoridation.

• About half of the state’s residents drink fluoridated water.

• In Allegheny County about 94 percent of residents who are customers of public suppliers have fluoride in their drinking water. The number drops to about 67 percent in Indiana County, to about 31,000 of 46,409 public-water consumers. In Fayette County, it’s 30 percent of public-water customers, or nearly 77,000 people. About 20 percent of Westmoreland County’s 245,598 public-water customers, or nearly 47,800 people, have fluoridated water.

Sources: Centers for Disease Control and Prevention 2001 report; Pennsylvania Department of Environmental Protection, 2008 figures.