Fluoride and nitrates in tap water? Polk County Supervisor says it’s safe.

Editors Note 6/12: This interview was recorded before Des Moines Water Works officially announced high nitrate levels in the water.

Iowa nitrate levels fluctuate seasonally, and many Iowans wants to know: is Iowa tap water safe? Podcaster Dr. Andrew Huberman cautions listeners on tap, citing fluoride among other concerns, but the American Dental Association argues fluoridated water is the most efficient way to prevent cavities. What’s true? Polk County Supervisor Matt McCoy discusses water safety and addresses concerns.

New studies discussed on The Huberman Lab point to concerns around Disinfection by-products (DBPs) as potential endocrine disruptors and fluoridated water lowering IQ scores in children. Huberman, among other experts like Dr. Staci Whitman, have cautioned listeners to evaluate their own water quality in their area. “For most people, it will be healthier to filter their tap water,” explains Huberman. But the scientific community remains divided on issues of water fluoridation and purification. 

Supervisor McCoy is aware of the criticisms on Iowa nitrate levels and fluoride levels. He joined Justin Brady to unpack the debate around tap water safety, particularly among immigrant and refugee populations in Iowa.

Drawing on findings from a University of Iowa study, McCoy outlines how a large portion of these communities, numbering over 47,000 in Polk County, continue to rely heavily on bottled water due to distrust inherited from their countries of origin—where municipal water may have been unsafe or unreliable. Even many developed European countries choose filtered or bottled water over tap water.

The Water For All Campaign: Why?

The “Water for All” campaign, was first brought to light in The Des Moines Register. The campaign is led by Des Moines Water Works and Polk County.

Referencing lower income Iowans, McCoy said bottled water is a significant financial burden. “ They’re bringing those traditions and history of distrust of the water systems and as a result, spending a lot of their money. Up to about one hundred  dollars per person per month.” he explained.

McCoy said this behavior not only strains personal finances but also stems from cultural habits and aggressive bottled water marketing. He emphasizes that Polk County’s tap water is extensively monitored and regulated under the Safe Drinking Water Act of 1974, with Des Moines Water Works testing for up to 90 contaminants and consistently meeting EPA standards.

Bottled Water Marketing and the Fight for Trust in Municipal Water

McCoy delves into the psychological and marketing factors that perpetuate bottled water consumption, noting how companies exploit immigrant communities with advertising that casts doubt on the safety of tap water. These tactics often undercut public trust, despite rigorous U.S. regulations. He also addresses common consumer concerns, such as the occasional smell or taste variations in tap water, especially during low river levels or organic buildup, explaining these are results of safe treatment practices rather than actual contamination.

An important aspect of the conversation revolves around the financial and public health implications of rejecting tap water. With bottled water being up to 1,000 times more expensive than tap, McCoy argues that encouraging trust in municipal water is both an economic and public health imperative. He also points out that bottled water is notably less regulated than tap water, making the case that many consumers are unknowingly placing greater risk in the bottled alternatives they believe are safer.

Fluoridation, Safety Standards, and Scientific Scrutiny

McCoy affirms that fluoridation has been among the most studied public health measures and continues to receive strong support from the American Dental Association for its role in improving dental health. “  “It has probably been one of the most studied issues outside of some of the vaccines that have been analyzed as, as it relates to other health topics and it consistently comes back that  the good  far outweighs the bad of fluoridation.”

He stresses that Des Moines Water Works remains in compliance with CDC-recommended fluoride levels and closely monitors seasonal and agricultural impacts on water quality, including nitrate levels and disinfection byproducts.

While acknowledging that reverse osmosis systems and additional home filtration options can offer peace of mind for concerned residents, McCoy reiterates that Des Moines Water Works maintains one of the most robust nitrate removal systems globally. He encourages residents to engage in informed dialogue, consult trusted health professionals, and understand the rigorous standards municipal water must meet—unlike bottled alternatives which can also pose problems like BPAs and microplastics.

We will update this page with water data provided by Des Moines Water Works when it becomes available. 5/28/25