It may take up to 18 months before residents in Windsor, Tecumseh and LaSalle have fluoride in their drinking water.

On Tuesday, Tecumseh council approved re-fluoridation.

Windsor's council unanimously approved its bylaw in March but needed either Tecumseh or LaSalle to approve the initiative since the neighbouring communities share the city’s drinking water supply.

The Medical Officer of Health for Windsor-Essex, Dr. Wajid Ahmed, has been pushing for re-fluoridation.

“I really hope that it happens sooner than later,” says Dr. Ahmed.

But the Windsor Utilities Commission says it may take up to 18 months before residents notice a difference.

Vice President Gary Rossi says the process will begin when the two bylaws are received from the City of Windsor and Town of Tecumseh.

Rossi tells CTV Windsor they also have to investigate how to tweet the water.

"We're going to look at sourcing a new chemical for this, so that's something we're going have to investigate,” says Rossi. “Once we either select a chemical or select a few of them, we got to make sure it's not going to affect the treatability of the water."

The price tag for fluoridation is about $850,000, most of which will cover startup costs.

Tecumseh Mayor Gary McNamara says the price tag will be proportionately shared by Tecumseh, LaSalle and Windsor.

McNamara says the town reviewed more than 1,600 emails and various reports for and against fluoridation.

“In the end, science trumps inuendos and fear,” says McNamara.

You may remember fluoride was removed from Windsor's water supply in 2013, and Dr. Ahmed says it negatively impacted residents.

“The data clearly showed a decline in oral health of our residents,” adds Dr. Ahmed.

"At the end of the day, I do believe it's the right decision” adds McNamara.