A Palomar College tutor and some local residents say Escondido’s tap-water fluoridation program might be to blame for a March 26 chemical spill that could cost the city more than $2 million.

They said the spill, which contaminated 1,700 tons of soil in northeastern Escondido, should prompt the city to reconsider a controversial 2004 decision to become the first water provider in San Diego County to add fluoride to tap water.

But Utilities Director Chris McKinney said this week that the spill and resulting damage would have occurred with or without water fluoridation.

McKinney said the residents and Richard Sauerheber, a Palomar math and chemistry tutor, are correct that the corrosive chemical released during the spill, sodium hydroxide, helps the city safely add fluoride to its water.

Without it, the fluoridated water could be dangerous for people to drink and could corrode the city’s pipes and other water infrastructure, he said.

But McKinney said sodium hydroxide, which is the main ingredient in Drano, also plays a crucial role in helping the city filter coagulants, such as plant life and dead fish matter, out of the water.

“If we weren’t fluoridating, we’d still have the same amount of sodium hydroxide at the plant in the same concentration,” said McKinney. “Sodium hydroxide is critical to our process.”

Debate revived

Nevertheless, the spill has helped revive a local debate about water fluoridation that began in late 1995 when California began requiring water providers with at least 10,000 customers to add fluoride.

State officials said adding fluoride to tap water was a safe, effective way to prevent cavities and other dental problems and thus youth malnutrition.

The American Dental Association has conducted studies showing that fluoridation reduces cavities.

But other groups claim those studies are flawed and contend that fluoride is toxic, could retard the cognitive development of infants and might make bones more brittle in senior citizens.

Because the state didn’t provide money needed for equipment upgrades, water providers were told to seek grants and given time to secure necessary funding.

After securing some grants, the Escondido City Council voted 3-2 in June 2001 to begin adding fluoride to the city’s water.

Three months later, 10 residents filed suit claiming fluoridation would jeopardize their health.

But in October 2004, Vista Superior Court Judge Jacqueline Stern ruled in favor of the city, and fluoride has been added to Escondido’s tap water ever since.

Since then, the San Diego County Dental Society says fluoride has been added to tap water in Carlsbad, Vista, San Marcos, Fallbrook, Ramona and Valley Center. But the society says there is no fluoride in the tap water in Oceanside, Poway, Encinitas, Camp Pendleton and Rancho Santa Fe.

In February 2011, the city of San Diego began adding fluoride to its water.

Study requested

Some Escondido residents say they still have their doubts.

Last summer, Escondido resident Barbara Takahara lobbied Mayor Sam Abed during a “town hall” meeting to have the city study the health effects of fluoride on city residents since 2004.

At the time, Abed said he wasn’t interested in reviving an old issue. And he reiterated that position this week.

“There are strong arguments on both sides, but this was a City Council decision of the past that I’m not interested in revisiting,” said Abed, who was elected to the council nearly three years after the council decided to begin adding fluoride. “Our energy and efforts as a city should be focused on economic development.”

But Takahara said this week that she still wants the city to study the local effects of fluoride, suggesting that Escondido-area dentists could be surveyed about whether their patients have fewer cavities.

Takahara said she also plans to post all available information on fluoridation at the website of Escondido’s Future, a group focused on local quality-of-life issues, sometime in the near future.

San Marcos resident David Banks wrote a letter to the editor last month in the North County Times warning that the city was at risk for spills involving fluoride, which is also known as fluorosilicic acid, as much as spills involving sodium hydroxide, which is known as caustic soda.

“We are extremely fortunate that it was caustic soda and not the highly toxic fluorosilicic acid that spilled and potentially ended up in our water,” he wrote.

Sauerheber said this week that the city should abandon fluoridation as soon as possible.

He said the sodium hydroxide needed to treat it is dangerous, noting that the March spill narrowly missed Escondido Creek and that the Dixon Lake reservoir was also nearby.

In addition, Sauerheber said swallowing fluoride hasn’t been shown to improve dental health.

“This makes no sense, and it’s all for a chemical that doesn’t decrease cavities,” he said.

Flawed system

Sauerheber also suggested that the sodium hydroxide might have helped cause the March spill by corroding aluminum inside the tank that ruptured.

But McKinney said the tanks are sealed in fiberglass coated with epoxy, not aluminum.

McKinney said investigators are still trying to determine what caused the March spill, but that police had ruled out terrorism and foul play.

He said his best guess was that a crack developed in a tank wall and that pressure from liquid widened the crack and eventually ruptured the tank.

Because the tank was connected by an open pipe to a twin tank nearby, both tanks emptied.

In the future, McKinney said, the connecting-pipe problem would be eliminated, sharply reducing the risk of another spill.

He said a circular wall surrounding both tanks was designed to contain the contents of one full tank but not both, based on the assumption that both tanks wouldn’t empty simultaneously.

But because they did empty at the same time, about 4,000 gallons of sodium hydroxide flowed over the containment wall and down the hill toward the Escondido Humane Society.

No animals were injured and no private property was damaged. In addition, McKinney said he was confident the city would recover nearly all of roughly $2 million in cleanup costs from its insurance company.

Crews are in the process of replacing 1,700 tons of contaminated soil that was removed and cleaned after the spill.

Correction: Richard Sauerheber is a math and science tutor at Palomar College. An earlier version of this story incorrectly identified Sauerheber as a Palomar College professor. We apologize.