In 1975, the EPA created controversy by naming fluoride as a contaminant in the National Interim Primary Drinking Water Regulations. A Maximum Contaminant Level (MCL) was set at 1.4 - 2.4 ppm in an effort to protect children from developing dental fluorosis, a brown/black discoloration of teeth. Now, more than thirty years later, fluoride is the most widely debated regulated contaminant on the books.

Many communities add fluoride to their drinking water to promote dental health and worry that its designation as a contaminant will interfere with this goal. Some geographic areas have large natural fluoride deposits that create high levels in drinking water, and are eager to avoid the costs associated with removing it.

The EPA began a review of its MCL in the early 1980s, attempting to balance the benefits of fluoride for dental health, the dangers of ingesting too much fluoride, and the cost of removing fluoride for those areas where high levels occur naturally. In 1985, the EPA issued a new MCL of 4 ppm for fluoride, also adding a secondary MCL of 2 ppm. Systems with fluoride levels between 2 ppm, and 4 ppm must provide the public with information about possible tooth discoloration.

Fluoride is regulated with the other IOCs addressed in the Phase II Rule, which synchronizes monitoring requirements and schedules for IOCs, SOCs, and VOCs. Depending on the results of initial monitoring, systems may be able to reduce their monitoring frequency, or even to waive monitoring requirements for fluoride and other IOCs. These reduced requirements are considered by some to be unsafe, putting children at risk for developing health and dental problems.

Our staff at Neilson Research Corporation works hard to stay abreast of this kind of evolving regulation. In order to remain compliant, public water systems must be informed of changing monitoring locations, schedules, MCLs, and treatment techniques. We are happy to provide you with information about fluoride or any other regulated contaminant.

To read more about fluoride and the MCLs for all regulated contaminants, see the EPA webpage: http://www.epa.gov/safewater/contaminants/index.html