San Antonio Water Quality Report 2026 — Is SAWS Water Safe?

San Antonio Water System (SAWS) serves 1.5 million residents from the Edwards Aquifer — a limestone aquifer under the Texas Hill Country. The source water is generally safe by EPA standards, but it comes with a specific set of concerns: extreme hardness, naturally occurring radium, detected PFAS, and elevated sodium. Here's what the 2024 data shows and what to do about it.

For the scored breakdown with letter grade, contaminant levels, and filter picks, see our San Antonio water quality report.

San Antonio Water Quality Overview (2024 Data)

What's in San Antonio Tap Water

Based on the SAWS 2025 Consumer Confidence Report (covering 2024 test data) and EPA UCMR5 monitoring:

• Water hardness: 272 mg/L — classified as "very hard." One of the highest readings of any major US city. Causes scale on pipes, appliances, and fixtures.
• PFAS: PFBA detected at 15 ppt in EPA UCMR5 monitoring. Below the EPA's new 4 ppt MCL for PFOA/PFOS, but above EWG's 1 ppt health guideline. Only RO and NSF P473-certified filters remove PFAS.
• Radium (combined): 3.4 pCi/L — naturally occurring from limestone geology. Below the EPA limit of 5 pCi/L but elevated vs national averages. Removed by reverse osmosis.
• Arsenic: 3.8 ppb — below the EPA limit of 10 ppb but above EWG's 0.004 ppb health guideline. Long-term exposure is linked to bladder and lung cancer.
• Sodium: 92 mg/L — elevated due to aquifer mineral content. Relevant for residents on low-sodium diets or with heart conditions. RO reduces sodium significantly.
• Disinfection byproducts: TTHMs at 32 ppb and HAA5 at 18 ppb — both below EPA limits of 80 ppb and 60 ppb respectively. SAWS has logged DBP violations in past reporting periods.
• Lead: 2.2 ppb (90th percentile) — well below the EPA action level of 15 ppb. Lead risk in SA comes from old home plumbing, not the distribution system.
• E. coli: None detected. SAWS sampled 390 sites monthly in 2024 with zero positives.

Where San Antonio Water Comes From

SAWS draws primarily from the Edwards Aquifer, fed by rainfall percolating through Texas Hill Country limestone. This geology is the direct cause of SA's hardness, radium, and arsenic — the water dissolves minerals from the rock as it travels underground.

SAWS also draws supplementally from the Carrizo Aquifer (via the Vista Ridge Pipeline) and surface sources during peak demand. Water quality can vary slightly by neighborhood and season depending on source blend.

The Hard Water Problem in San Antonio

The standard solution for whole-home hard water is a salt-based water softener. For drinking water specifically, a reverse osmosis system removes hardness minerals at the tap along with PFAS, radium, and arsenic. Most SA homeowners who fully address their water use both.

San Antonio Water Contamination: PFAS

PFAS ("forever chemicals") have been detected in SAWS water in EPA's UCMR5 national monitoring program (2023–2025). The compound found was PFBA at 15 ppt. This is below the EPA's new Maximum Contaminant Level for the six regulated PFAS, but above the EWG health guideline of 1 ppt.

PFAS are not removed by standard pitcher filters (Brita, PUR) or boiling. The only reliable options are NSF 58-certified reverse osmosis or NSF P473-certified carbon filters. See our full PFAS removal filter guide.

Is San Antonio Tap Water Safe to Drink?

By EPA standards: yes. SAWS has no open violations and the water meets all federal legal limits. But "meets EPA standards" and "contaminant-free" are not the same thing. PFAS, radium, and arsenic are all present at levels that exceed independent health guidelines, even if they're below legal limits.

Best Water Filters for San Antonio

Given SA's specific profile — PFAS, radium, arsenic, extreme hardness, and elevated sodium — reverse osmosis is the most comprehensive solution. It addresses all of SA's primary contaminants at the drinking tap. See the San Antonio water report for filter picks ranked for this specific water profile.

Frequently Asked Questions

Is San Antonio tap water safe to drink in 2026?

SAWS meets all EPA legal standards with no open violations. However, PFAS, radium, and arsenic are present above independent health guidelines. For healthy adults, SA tap water poses low acute risk. For children, pregnant women, or immunocompromised individuals, a certified RO filter is strongly recommended.

Why does San Antonio water taste different?

The Edwards Aquifer water has naturally high mineral content — calcium, magnesium, and sodium — which gives it a distinctive taste. The hardness (272 mg/L) is one of the highest of any major US city. An RO filter removes these minerals and significantly improves taste.

Why is San Antonio water so hard?

Rainwater percolates through Texas Hill Country limestone before reaching the Edwards Aquifer. As it travels through porous rock, it dissolves calcium and magnesium — the minerals that cause hardness. At 272 mg/L, SA water is classified as "very hard."

Does San Antonio water have PFAS contamination?

Yes. EPA UCMR5 monitoring detected PFBA at 15 ppt in SAWS water. This is below the EPA's new 4 ppt MCL for PFOA/PFOS but above EWG's 1 ppt health guideline. Only reverse osmosis or NSF P473-certified filters reliably remove PFAS.

What is the best water filter for San Antonio water?

For San Antonio's full contaminant profile (PFAS, radium, arsenic, hardness), a reverse osmosis system is the gold standard. For whole-home hard water, pair it with a salt-based softener. Renters can use the Clearly Filtered pitcher — certified to remove PFAS, radium, and arsenic without installation.