Even Without Fluoride, Chemicals Remain in Water

A controversial fluoride additive is just one component that’s added to Dunedin’s water, the assistant utility director says.

As commissioners of cutting the entire water fluoridation process from the city budget, a small, local and passionate group is calling the additive into question for its supposed health risks.

The to take the fluoride additive out of the water — a move that would save the city $50,000 a year. Leaders stalled the decision at a recent budget workshop and called for more public input.

Paul Stanek, assistant utility director at the water plant, spoke with Dunedin Patch about the city's water treatment process.

From groundwater to the kitchen sink, here’s what we learned:

Unlike nearly all its neighbors, Dunedin provides its own drinking water. With a few exceptions, including Dunedin, cities and counties in the area area look to Tampa Bay Water as a wholesale supplier.

“We are independent,” he said. “That means we have control of the water we give our customers.”

For that independence, Dunedin puts more work into producing its water than those connected to the regional supply that is either siphoned from rivers or pulled from wells in the aquifer, miles inland.

The water underneath Dunedin is mildly brackish, or too salty to just pump to your house, but it takes some work to make the water salt free.

It gets filtered, treated with chlorine, filtered more through sand and hit with something to keep down scale in pipes and filters. That’s all just to get it ready to be purified.

It is finally shoved through reverse osmosis membranes that trap nearly everything in the water, even salt molecules.

The product is highly pure, almost only a couple hydrogen atoms and one, lonely oxygen.

Highly pure has some drawbacks.

“It’s highly aggressive water,” Stanek said, meaning it will gnaw away any pipes. You wouldn’t want it running through your house’s plumbing.

At the water plant, in what’s called the wet well, that aggressive water from the membranes gets slapped with caustic soda to calm its nasty nature and chlorine to kill bacteria. It’s also where the city adds the controversial fluoride chemical called Hydrofluorosillic Acid.

It is added to bring the fluoride level near the concentration that federal health agencies recommend as optimum for drinking water — 0.7 parts per billion (as recommended by The U.S. Department of Health and Human Services and the Environmental Protection Agency).

Without the chemical injection of the acid, your fluoride level at the faucet would drop back to 0.1 ppb.

The soda keeps the water from stripping copper from your pipes, Stanek said, and chlorine is a standard disinfectant many utilities use.

There is nothing added to change the water’s taste and the American Water Works Association contest proves it, Stanek said. The city's water won a state and national taste test in February.

“I think our water tastes pretty good.”

Summaries of the city's Annual Water Quality Report, which is sends to the Environmental Protection Agency can be found at the water department's site.

• The report tested for 80 compounds but only a few were found in the city’s water in 2010, the most recent study. It found minute amounts of inorganic chemicals, mainly salt, but also barium and nitrate along with the background fluoride. All either come from the slow dissolving of natural deposits, or in the case of nitrate, also leeching from septic tanks and sewage, the report says.
• All are well below the federal health limits. For example, the federal limit for nitrate is 10 parts per million and city water had 0.19 parts per million.
• By comparison: A similar report for St. Petersburg shows the city water that comes from a mix of river and deep well also have tiny amounts of barium and fluoride in their water. Those customers also get some cyanide, though at 8 parts per billion, it is well below the limit of 200 ppb. St. Petersburg residents also get about a third of the salt seen in Dunedin’s water.