The City of San Marcos water system follows federal drinking water standards established by the Environmental Protection Agency (EPA). Recent water quality testing reported fluoride levels in San Marcos drinking water at approximately 0.2 ppm (parts per million).

San Marcos receives water from multiple sources, including the Edwards Aquifer, Carrizo-Wilcox Aquifer, and Canyon Lake. Naturally occurring minerals, including fluoride, can be present in these groundwater and surface water sources.

Fluoride is commonly added to public water systems across the United States to help support dental health and reduce tooth decay. The EPA currently sets the maximum contaminant level for fluoride in drinking water at 4.0 ppm, meaning San Marcos’ reported fluoride level remains well below federal safety limits.

Many communities are taking a second look at fluoridation levels and motivations, and as the debate continues, it’s a good idea to know some basics about fluoride and its legacy in this country.

In 2015, the U.S. Department of Health and Human Services Agency (HHS) revised what defined acceptable fluoride levels:

“…water systems practicing fluoridation adjust their fluoride content to 0.7 mg/L (parts per million), as opposed to the previous temperature-dependent optimal levels ranging from 0.7 mg/L to 1.2 mg/L. There is no change regarding federal health officials’ strong and long-standing support regarding the value of fluoridation of drinking water.”

Since plant life relies heavily on water, most forms of plants and vegetation contain various levels of fluoride.

The most common use for artificially-created fluoride is the treatment of cavities and supporting dental health. Fluoride has been widely shown to prevent, and even reverse, tooth decay, and has been added to many city water supplies throughout the country as a result.

Fluoride is a naturally occurring mineral that can enter drinking water through rock, soil, and groundwater sources. In many communities, small amounts are also maintained in public water supplies to help strengthen tooth enamel and reduce cavities.

Because San Marcos relies on both aquifer groundwater and treated surface water, mineral content can vary slightly throughout the year depending on source blending, rainfall conditions, and overall water demand.

When maintained at recommended levels, fluoride may provide several dental health benefits, including:

While fluoride is considered safe at regulated levels, some homeowners still prefer to reduce fluoride and other contaminants from their drinking water. Concerns are typically tied to long-term exposure at elevated levels or to the presence of additional contaminants that may exist alongside fluoride in municipal water supplies.

Homeowners may also choose additional filtration to help reduce:

If your home has fluoridated water and you’re concerned about it, there are water treatment methods available that specifically address and remove water additives like fluoride.

Reverse osmosis systems for example, are designed to remove hard-to-filter chemicals like fluoride, that many other filtration devices in big box stores and online retailers cannot.

San Marcos drinking water meets current state and federal drinking water standards. However, many homeowners still choose to install additional water filtration systems to improve taste, reduce contaminants of concern, and gain added peace of mind for their household water.

If you want to reduce fluoride, chlorine, PFAS, or other contaminants in your San Marcos water, treatment solutions such as reverse osmosis systems and whole-home filtration systems can help improve overall water quality.

A free in-home water test can help identify what is in your water and determine the best filtration option for your home.