Schertz TX Water Quality 2026: What the SSLGC Data Shows for Carrizo-Wilcox Aquifer Homes

Where does Schertz get its drinking water?

In the late 1990s, the City of Schertz supplied water through two Edwards Aquifer wells. City leadership recognized that a growing community needed a more secure long-term supply, so in December 1998 Schertz partnered with Seguin to form the Schertz-Seguin Local Government Corporation (SSLGC). SSLGC is a nonprofit wholesale water provider owned equally by both cities and formed under Subchapter D of Chapter 431 of the Texas Transportation Code.

Today SSLGC supplies the majority of Schertz's drinking water from the Carrizo-Wilcox Aquifer in northwest Gonzales County, roughly 40 miles from the city. The system operates 12 groundwater supply wells, a 35 million gallon per day treatment facility, and more than 40 miles of transmission pipeline. SSLGC also maintains 15.1 million gallons of water storage capacity and 15 high-service pumps to deliver treated water to Schertz and Seguin. The SSLGC general manager is based in Seguin; the corporation's operational background is documented at seguintexas.gov/510/SSLGC-Water-Corporation.

Schertz retains two Edwards Aquifer backup wells, designated Naco Well 1 and Naco Well 2. These wells are only activated when the primary SSLGC supply from Carrizo-Wilcox is limited or during peak demand periods. Under normal conditions, the water arriving at your Schertz tap is Carrizo-Wilcox groundwater treated and transported through the SSLGC system.

The Carrizo-Wilcox Aquifer is a major confined sandstone aquifer extending from the Rio Grande to the Louisiana border, covering roughly 11,227 square miles of outcrop and 25,491 square miles of subsurface, according to the Texas Water Development Board (twdb.texas.gov/groundwater/aquifer/majors/carrizo-wilcox.asp). Unlike the Edwards Aquifer limestone formation, the Carrizo-Wilcox is a sandstone aquifer. That geological difference affects water chemistry: Carrizo-Wilcox water typically carries elevated total dissolved solids and a different mineral profile than Edwards Aquifer supply, although both are moderately to very hard in the San Antonio northeast corridor.

For residents who want to confirm the current source for their specific address or review SSLGC treatment data, the City of Schertz water utility information is available at schertz.com/208/Water-Wastewater-Utility.

How hard is Schertz tap water?

Water hardness is measured in grains per gallon (gpg) or milligrams per liter of calcium carbonate (mg/L as CaCO3). The U.S. Geological Survey classifies water as soft below 1 gpg, moderately hard from 1 to 7 gpg, hard from 7 to 10 gpg, and very hard above 10 gpg (usgs.gov/special-topics/water-science-school/science/hardness-water).

Schertz water from the Carrizo-Wilcox Aquifer runs at approximately 12 grains per gallon based on regional estimates for this aquifer formation in the Guadalupe County area. That places it in the very hard tier by the USGS scale. Verify the current hardness specific to your address by requesting a reading from the City of Schertz at 210-619-1040, or schedule a free in-home water test with True H2O at (210) 726-6895. Hardness can vary between distribution zones and shifts with aquifer conditions over time.

At 12 gpg, Schertz homeowners experience the full range of hard water effects. Calcium carbonate scale builds on faucets, showerheads, and inside appliances. Dishwashers leave mineral spots on glasses and dishes. Soap and shampoo lather less efficiently because hard water ions interfere with soap chemistry. Water heaters accumulate scale internally, which forces the unit to work harder over time. The U.S. Department of Energy notes that scale buildup from hard water reduces water heater efficiency and shortens equipment service life (energy.gov/energysaver).

One distinction worth noting: Schertz water, at approximately 12 gpg, is softer than the Edwards Aquifer supply used in most of Bexar County, which typically reads 15 to 20 gpg according to the San Antonio Water System 2024 Consumer Confidence Report (saws.org/your-water/water-quality/water-quality-report/). Schertz homeowners relocating from central San Antonio may notice their water is somewhat softer, but it is still well above the softening threshold. The Carrizo-Wilcox supply also carries elevated total dissolved solids compared to Edwards Aquifer water, which affects taste and mineral content at the kitchen tap even after softening.

What does the 2024 Schertz Consumer Confidence Report show?

The City of Schertz 2024 Consumer Confidence Report (PWSID TX0940003) covers the reporting period January 1 through December 31, 2024. The report is available at schertz.com/217/Water-Quality-Report. The following figures come from the 2024 CCR as summarized by waterqualitylookup.com sourced from the official Schertz CCR document; verify all numbers against the primary report before making health decisions.

Disinfection byproducts: Total trihalomethanes (TTHM) registered a highest locational running annual average (LRAA) of 10.8 micrograms per liter, with individual samples ranging from 1.1 to 15.8 μg/L. The EPA maximum contaminant level for TTHM is 80 μg/L. Total haloacetic acids (HAA5) registered a highest LRAA of 1.8 μg/L, with individual samples ranging from 1.0 to 1.8 μg/L. The EPA MCL for HAA5 is 60 μg/L. Both readings are far below the legal limits and are notably lower than values typical of surface water utilities in the region. Groundwater sources like the Carrizo-Wilcox Aquifer contain less organic matter than surface water reservoirs, which means less precursor material available to form disinfection byproducts during chlorination.

Lead and copper: Lead was reported at 0 at the 90th percentile, with zero of the sampled sites above the EPA action level of 15 micrograms per liter. Copper measured 0.07 mg/L at the 90th percentile, well below the action level of 1.3 mg/L. Both readings indicate no lead or copper concern at the utility distribution level.

Disinfectant: The City of Schertz uses chlorine as its primary disinfectant. The 2024 report shows an average chlorine residual of 1.67 ppm, with a minimum of 0.81 ppm and a maximum of 2.19 ppm. The EPA maximum residual disinfectant level (MRDL) is 4.0 ppm. Schertz operates well within this standard.

Microbial: Total coliform bacteria testing showed zero positive monthly samples. No E. coli was detected.

PFAS: The City of Schertz has PFAS monitoring data on record under EPA UCMR5 monitoring requirements. No PFAS compounds are currently detected above EPA health-based guidelines, according to EPA SDWIS data sourced through tapwaterdata.com (as of October 2025). Ongoing PFAS monitoring will continue through 2029 under the EPA's 2024 PFAS National Primary Drinking Water Rule. Verify current PFAS status with the City of Schertz or the TCEQ drinking water viewer at tceq.texas.gov/drinkingwater/dwv.

The City of Schertz reported zero MCL violations for 2024. All regulated contaminants were within EPA and TCEQ legal limits for the reporting year.

Is Schertz tap water safe to drink in 2026?

Based on the 2024 Consumer Confidence Report and EPA records (PWSID TX0940003), Schertz tap water meets all federal Safe Drinking Water Act primary standards. The system reported no maximum contaminant level violations for 2024. PFAS compounds are not detected above EPA health-based guidelines. Lead and copper levels are far below their respective action levels. Total coliform testing found no positive monthly samples.

The Environmental Working Group (EWG), a nonprofit that publishes a tap water database using voluntary guidelines stricter than enforceable federal limits, notes contaminants in the City of Schertz water system that exceed EWG's precautionary thresholds. EWG guidelines are research-based targets set more conservatively than EPA MCLs; exceeding them does not constitute a legal violation. For the complete EWG dataset on the City of Schertz, see ewg.org/tapwater/system.php?pws=TX0940003.

For the majority of Schertz residents with healthy immune systems, the city's tap water is safe to drink as delivered under federal regulatory standards. Households with infants, pregnant individuals, or immunocompromised family members often choose to add point-of-use treatment for additional protection on drinking and cooking water. This is a personal choice based on risk tolerance and household composition, not a response to any regulatory violation.

For current water quality notices, compliance status, or questions about your specific service address, contact the City of Schertz water utility at 210-619-1040 or visit schertz.com/208/Water-Wastewater-Utility. The TCEQ drinking water viewer at tceq.texas.gov/drinkingwater/dwv is the authoritative Texas regulatory database for public water system compliance records.

Does Schertz need a water softener?

Water softening becomes practically beneficial above approximately 7 grains per gallon, the point where scale buildup in plumbing and appliances accelerates meaningfully. At approximately 12 gpg, Schertz water sits well above that threshold. The question for most Schertz homeowners is not whether to soften but which system suits their household's daily water use and plumbing configuration.

A whole-home ion exchange water softener removes calcium and magnesium ions by exchanging them for sodium ions as water passes through a resin tank. Softened water then flows to every tap, showerhead, appliance, and water heater in the home. This prevents scale from forming inside hot water supply lines, inside the water heater, in dishwasher spray arms, and in washing machine fill valves. Softened water also improves soap lather, reduces spotting on dishes and glassware, and leaves skin and hair feeling less dried out after bathing.

One consideration specific to Carrizo-Wilcox Aquifer supply is elevated total dissolved solids. Ion exchange softening removes hardness minerals but does not significantly reduce total dissolved solids or other non-hardness minerals that may be elevated in Carrizo-Wilcox water. Some Schertz residents notice a flat or minerally taste in their tap water that persists even after softening. For households concerned about drinking water taste or mineral content, pairing a softener with a point-of-use reverse osmosis system at the kitchen sink provides the most complete treatment approach.

The correct grain capacity for a softener is calculated based on incoming hardness and daily household water use. A licensed water treatment professional should measure your actual hardness before sizing any system. Oversized systems waste salt and water during regeneration cycles; undersized systems let hard water break through between cycles. True H2O offers free in-home water testing in Schertz and across the Guadalupe County service area to determine your water's actual hardness before recommending any system.

Does Schertz need a reverse osmosis system?

Reverse osmosis is particularly relevant for Schertz homeowners for two reasons: the elevated total dissolved solids naturally present in Carrizo-Wilcox Aquifer supply, and the value of comprehensive point-of-use filtration for drinking and cooking water.

The Carrizo-Wilcox Aquifer is a confined sandstone formation that produces water with naturally elevated TDS compared to limestone aquifer systems like the Edwards Aquifer. Total dissolved solids is not itself regulated by the EPA as a primary health-based contaminant, but elevated TDS water can taste flat, brackish, or minerally, and it leaves scale and mineral residue that a water softener alone does not address at the drinking tap. A reverse osmosis system pushes water through a semipermeable membrane under pressure, rejecting dissolved solids including calcium, magnesium, sodium, and most other dissolved minerals, and producing low-TDS drinking water.

An under-sink RO system certified to NSF/ANSI Standard 58 removes greater than 90 percent of a broad range of contaminants, including total dissolved solids, lead, certain PFAS compounds, and nitrates. NSF 58 is the specific standard covering residential drinking water treatment systems that use membrane filtration. NSF International maintains a publicly searchable certified product database at nsf.org where you can confirm that any system you consider has passed independent performance testing.

For Schertz households with children, or for anyone who wants assurance beyond what the municipal distribution system provides, an under-sink RO system paired with a whole-home water softener covers both the hard water problem throughout the house and the drinking water quality question at the kitchen tap. The softener handles the scale and appliance protection function for the entire plumbing system; the RO unit handles the final polishing and TDS reduction for water that will be consumed.

True H2O serves Schertz and the surrounding Guadalupe County area with free in-home water testing and professional installation of water softeners and reverse osmosis systems. Call (210) 726-6895 or visit the water testing page on this site to schedule.