Colorado’s congressional delegation on Thursday endorsed fluoride in the water to fight tooth decay as Fort Collins residents are in the process of voting on ending fluoridation.

“Community water fluoridation has been cited as one of the 10 great public health achievements of the 20th century by the Centers for Disease Control,” the bipartisan group of lawmakers said.

Clean Water Advocates of Fort Collins put the issue on the ballot for the April 5 mail-in election. The city clerk said 70,000 ballots were mailed out and more than 18,000 have been returned.

The group pushing the ban, headed by chiropractor Jack Caputto and nutritionist Pati Caputto of the Mountain Center for Healing, could not be reached for comment Thursday.

On the Fort Collins Clean Water Action Web site, the group said the fluoride comes from a fertilizer company, is more toxic than lead, and since fluoride is found in many foods, residents are being over-fluoridated.

“There are good arguments on both sides,” said Ted Borstad, a Fort Collins water board member and a civil engineer. He backs the anti-fluoride side.

“I’m not convinced that kids would get cavities,” he said. “There’s fluoride in so many other things.”

Fort Collins’ supporters of the ban include a dentist, six doctors, many chiropractors, acupuncturists, nurses and midwives.

Opponents of the ballot measure include numerous doctors, nurses and dentists including John Hanck, the president-elect of the Colorado Dental Association.

The congressional delegation’s vote came after lawmakers were contacted by several members of the dental association.

“The research overwhelmingly shows the results of having fluoride in the water and the lack of problems,” Hanck said.

He said that research shows that tooth decay increased by 35 percent in towns that ended fluoridation.

“The problem of tooth decay is so much more expensive to fix and it falls heavily on the economically disadvantaged,” said Hanck.

Sen., Wayne Allard, R-Colo., Sen. Ken Salazar, D-Colo., and all six House members from the state, including Rep. Marilyn Musgrave, R-Colo., who represents Fort Collins, all agreed.

“Studies show that optimal fluoridation can reduce the amount of decay in children’s teeth by as much as 60 percent,” said the delegation’s letter to Gary Cummins, director of the Colorado Dental Association.

Fort Collins began fluoridating the water in 1967.

Colorado Springs and Telluride recently stopped fluoridation. About 65 percent of the nation’s public water systems add fluoride.

“It’s pseudo-science versus science,” said Linda Rosa, a Fort Collins nurse who wants fluoride in the water.

“What’s impressed me is conversations with grandmothers about their dental health and that of their grandchildren and they say, ‘Why would anyone not want fluoride in the water?'” said Rosa.