City of San Marcos, Texas (SMTX Utilities) Water Quality Report

DID YOU KNOW water quality reports, also known as “Consumer Confidence Reports (CCRs),” are annual documents that all public water systems are required to provide to you via mail and online. These reports are supposed to provide important information about the quality of the drinking water delivered over the previous year.

They can be difficult to read or understand. They are often many pages long and contain complex tables and charts. Culligan Water wants to change this and help you MAKE SENSE OF YOUR WATER.

This easy-to-read report will provide you with the following:

1) Infrastructure & Water System Overview

The City of San Marcos Water/Wastewater Utilities provides drinking water to approximately 68,500 residents throughout the area. The system uses a combination of groundwater and surface water sources to support long-term water reliability across Central Texas.

San Marcos continues monitoring and testing its water supply under federal and state drinking water regulations to help maintain safe drinking water standards throughout the distribution system.

2) Water Sources and Usage

San Marcos receives drinking water from multiple regional water sources, including:

Because San Marcos uses both groundwater and surface water, mineral levels and overall water characteristics can fluctuate throughout the year depending on rainfall, drought conditions, seasonal demand, and source blending.

As water moves through rivers, lakes, aquifers, and underground formations, it can naturally collect dissolved minerals and trace substances before treatment and distribution.

3) Disinfection and Water Treatment

San Marcos uses a multi-stage treatment process designed to reduce contaminants and maintain drinking water safety before distribution to homes and businesses.

Recent testing showed:

These disinfectant byproducts form during the water treatment process when disinfectants interact with naturally occurring organic material in the water supply.

4) Minerals and Water Quality Highlights

San Marcos water naturally contains dissolved minerals from the region’s aquifers and surface water sources.

Recent testing reported:

The San Marcos water supply meets federal drinking water standards but still contains trace levels of minerals, disinfectant byproducts, and emerging contaminants that may impact taste, odor, plumbing fixtures, and overall water quality. Recent testing detected substances such as HAA5 disinfectant byproducts, TTHMs, lithium, fluoride, and trace PFAS compounds throughout the system. Because San Marcos uses a combination of groundwater and surface water sources, mineral content and water characteristics can vary throughout the year.

Unregulated contaminants are substances that the EPA monitors but has not yet assigned enforceable limits for. San Marcos Texas Water Utilities tests for these compounds to track potential risks and ensure long-term water safety. While levels remain below federal thresholds, these byproducts can still affect water taste, overall health, and household performance over time.

Yes. San Marcos water is considered very hard water, averaging approximately 269 mg/L (about 16 grains per gallon). Hard water is not considered a health concern, but it can lead to heavy mineral buildup on faucets, dishes, plumbing fixtures, and water-using appliances over time. Very hard water can also make soaps and detergents less effective while contributing to dry-feeling skin and hair. A water softener can help reduce scaling and keep plumbing systems and appliances running more efficiently.

PFAS (per- and polyfluoroalkyl substances), often referred to as “forever chemicals,” have been detected at trace levels in the San Marcos water supply. These man-made compounds are commonly associated with stain-resistant coatings, food packaging materials, firefighting foams, textiles, and industrial manufacturing processes. Recent water quality monitoring in San Marcos detected PFBA levels as high as 11.4 ppt, PFPeA at 3.75 ppt, PFHxA at 2.8 ppt, and PFHxS at 3.7ppt. While these levels remain relatively low, PFAS compounds continue to receive increased national attention because they break down very slowly in the environment and can accumulate over time.