CUMBERLAND – After decades of debate, an engineer will turn on a small electric pump this week or next to begin fluoridating this city’s water – an event that is being welcomed by dentists but will be hard to swallow for a steadfast citizens group still wary of science’s leading answer to cavities.

“I won’t drink it,” says Cumberland retiree Mel Collins, who has purchased a water distiller to remove the offending additive.

The federal government calls fluoride “safe and effective” and credits it for the steady decline of tooth decay during the past half-century. Critics brand it a “poison,” blaming it for ailments ranging from kidney damage, brittle bones and cancer to increased levels of lead in the blood.

The Internet is rife with results from studies on fluoride’s alleged ills, but it’s hard to find more determined opposition than in industrial Cumberland, where a pro-fluoride mayor was ousted a decade ago. The current mayor, Lee N. Fiedler, who holds a bachelor’s degree in chemistry, receives several letters a week from fluoride foes, including one advising him to “burn in Hell” for backing the change.

Fiedler, who is trying to use tourism to revive a blue-collar city that has seen the departure of leading employers, including the Kelly-Springfield tire plant, is delighted at the prospect of ending the fluoride fuss. He believes that most residents favor the change and that the debate sends an inaccurate message that his town is some sort of throwback. As in: If fluoride is coming, can electricity be far behind?

Even last month’s official notice about the fluoride, sent to about 50,000 area residents, seems to betray a hint of exasperation. “This is an exciting time for the residents of the City of Cumberland to finally be able to improve the dental health of the community,” the Allegany County Health Department wrote. The one-page letter advised that the city would be fluoridating the water “on or around Aug. 7,” and that citizens should discontinue the fluoride supplements that many have been taking in tablet form.

For Collins and the other half-dozen hard-core activists of the Pure Water Committee, the bad news has only made their circle more tightly knit.

They convened recently at the 156-year-old home known as Terra Angelica (Land of Angels) that is owned by one of their members, Mary C. Miltenberger, who rents it out for weddings. The group sat in a circle in the lace-curtained living room and discussed plans for a possible federal lawsuit to halt the planned fluoride release.

“We’re against mass medication without informed consent. That’s what this is,” said Mary’s son Bernard, who runs a florist and gift shop. “But this has become a personality thing. [City officials] want to defeat us.”

Asked whether the committee in its correspondence has wished the mayor eternal damnation, Mary Miltenberger says, “We don’t write those kinds of letters.”

“It wouldn’t hurt, though,” replies M. Virginia Rosenbaum, 80, a property-line surveyor and the committee’s president, with a smile.

The group has grown accustomed to adversity. Fluoride opponents have not been treated kindly in films – from 1964’s Dr. Strangelove, featuring a general who considers fluoride a communist plot, to 1997’s Conspiracy Theory, in which Mel Gibson’s character says the chemical makes people lose their will.

Rosenbaum flinches at the mention of Dr. Strangelove and says she knows the plot. “Once you laugh at something, it becomes foolish,” she says. “We don’t plan to give up. If I have another 20 years, we’ll really lick this. I hope before I die, it’ll be banned in the whole country.”

About two-thirds of Americans use water systems containing fluoride – a percentage the federal government hopes to increase by convincing more municipalities of its benefits.

Although the number of Americans drinking fluoridated water rose rapidly from 1945 through the 1970s, the rate of increase has slowed since then. A Centers for Disease Control and Prevention report in 1999 blamed that partly on the fact that many of the remaining nonfluoridated areas serve small populations with little money for the required chemicals and equipment.

But the report offered another theory: “Opponents of water fluoridation often make unsubstantiated claims about adverse health effects of fluoridation in attempts to influence public opinion.”

The Cumberland committee members say they’re not in that category. They say their concerns stem largely from the compound the city intends to use to get the fluoride in the water: hydrofluosilicic acid. When added to water, the acid reacts to produce fluoride.

The U.S. Department of Health and Human Services says hydro- fluosilicic acid is “a straw-colored, transparent, fuming, corrosive liquid having a pungent odor and irritating action on the skin.”

“It’s one of the most corrosive chemicals known to man,” Rosenbaum says.

But Cumberland officials say that, in very small amounts diluted in water, the acid won’t do any harm.

Following a final inspection and the issuance of a state permit, the acid will be put in a 6,000-gallon tank near the two Pennsylvania reservoirs that provide Cumberland’s water supply, about nine miles north of the city. Each day, fewer than 50 gallons will be transferred into a smaller tank – about the size of a residential hot-water heater – the output of which will be regulated by a toaster-sized pump.

The idea is to ensure that, in the event of an accident, there will never be more than 50 gallons hooked to the city’s water supply.

The date of the fluoride start-up depends on when the Pennsylvania Department of Environmental Protection issues the operating permit – likely this week, but possibly the week after. About 500 Pennsylvanians are on the water system, but most users are in Cumberland and nearby LaVale.

“This is going to be a good moment,” says William C. Tompkins, president of the Allegany-Garrett Dental Society. He says even the most diligent parents fail to ensure that their kids take fluoride tablets regularly, and the result has been one of the state’s highest cavity rates. “You’d have to take 4,000 tablets to gain the same kind of benefit as fluoridated water, so you have a problem with compliance,” he says.

Cumberland first voted to prohibit fluoride in its water in 1962. The mayor and City Council lifted that ban in 1988. After a lengthy court battle, the city’s water was treated for two months until voters reinstated the ban and threw out a pro-fluoride mayor.

But the issue didn’t die. The path for fluoride’s return was cleared last year with voters’ repeal of a city charter provision barring the addition of fluoride or any other new “substance.”

By backing the fluoride, Fiedler says he’s simply doing the constituents’ will – and he’s glad to do it.

The mayor says he doesn’t want his city to be stuck in the past. Cumberland once thrived as a gateway to the west because of a railroad line and a gap in the Appalachian Mountains. But the construction of the Pennsylvania Turnpike in 1940 diminished the area’s significance as a transportation route.

The lesson is to look ahead, Fiedler says. “We seem to re-fight old battles in Cumberland. The thing that makes me maddest about this [continued debate] is that it throws the whole community back. It’s, ‘Let’s go fight the Civil War again!'”