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Comprehensive Consumer Confidence Report for San Antonio, Texas — served by the San Antonio Water System (SAWS)
Perfect compliance record — no recorded violations
View detailed city report →What to know about San Antonio's tap water
San Antonio water is notably hard — the Edwards Aquifer flows through limestone, so it picks up calcium and magnesium. This is an aesthetic issue (scale, spotting), not a health risk.
Because the supply is mostly clean groundwater with little organic matter, chlorination byproducts stay low compared with river-fed cities.
The Edwards Aquifer supply contains no lead; any lead comes from older household plumbing. SAWS treats water to control corrosion and keep levels low.
San Antonio's A+ grade reflects consistently low contaminant levels plus a perfect (100/100) EPA compliance history with no recorded violations.
San Antonio is one of the largest US cities supplied primarily by groundwater. Water from the Edwards Aquifer is naturally filtered as it moves through limestone, so it arrives clean and needs little treatment — a major reason for the city's A+ grade.
SAWS has deliberately diversified beyond the Edwards Aquifer (which is protected by state pumping limits) to keep the supply resilient through Texas droughts.
SAWS disinfects with chlorine (chloramine in the distribution system) to keep water safe from the aquifer to the tap.
Because Edwards Aquifer water is naturally filtered through limestone, it needs far less treatment than surface (river/lake) supplies before distribution.
Treatment is tuned to reduce corrosivity, limiting lead and copper that could otherwise leach from older household plumbing.
The H2Oaks Center uses reverse-osmosis desalination for brackish groundwater, and SAWS fluoridates the supply for dental health.
No Recorded Violations
The San Antonio Water System has a perfect 100/100 compliance score with no recorded EPA drinking water violations — a key reason San Antonio grades A+.
Call SAWS Customer Service at (210) 704-7297 to request a printed copy of the annual water quality report.
Water System: San Antonio Water System (SAWS)
Public Water System ID: TX0150016
Population served: ~1.8 million
Yes. San Antonio tap water earns an A+ (95/100) with a perfect compliance score and no recorded violations. The San Antonio Water System (SAWS) draws mostly from the naturally filtered Edwards Aquifer and meets all EPA drinking water standards. Some residents still filter for the hard-water mineral taste, especially in older homes with aging plumbing.
San Antonio is largely groundwater-supplied. Its historic primary source is the Edwards Aquifer, supplemented by the Carrizo-Wilcox Aquifer delivered through the Vista Ridge pipeline, the Trinity Aquifer, brackish groundwater desalination at the H2Oaks Center, and recycled water — one of the most diversified water supplies of any large US city.
The Edwards Aquifer flows through limestone, so the water dissolves calcium and magnesium along the way. That makes San Antonio's tap water noticeably hard — you may see scale on fixtures and spotting on glassware. Hardness affects taste and appearance, not safety.
It's optional — the water is already safe and high-scoring. Most San Antonio residents who filter do so for the hard-water mineral taste or a bit of extra chlorine and lead protection in older homes. A certified pitcher handles taste, chlorine, and lead with no installation; a good renter-friendly option is the Clearly Filtered pitcher, which is independently lab-tested to reduce lead, chlorine, and disinfection byproducts. Note a pitcher won't soften hard water — for scale you'd need a water softener.
The San Antonio Water System (SAWS) publishes its annual Consumer Confidence Report online at saws.org. Reports are also available by calling SAWS Customer Service at (210) 704-7297.