Is San Antonio, TX Tap Water Safe to Drink?
Yes, San Antonio tap water is safe to drink. No contaminants exceed health guidelines. However, San Antonio has very hard water at 240 PPM, which will cause scale buildup in plumbing and appliances over time. A water softener is worth considering.
Hardness Scale: Where San Antonio Falls
0Slightly
60Moderate
120Hard
180Very Hard
250Extreme
400+
How San Antonio Compares
San Antonio's water is 74% harder than the national average of 138 PPM. It ranks #208 out of 1000 cities in our database (harder than 79% of US cities we track). Within Texas, it ranks #24 of 76 cities (27% above the state average of 189 PPM). Among major US cities (500k+), San Antonio ranks #18 of 100 for hardness. At this hardness level, water heaters run an estimated 44% less efficiently due to scale insulation, and major water-using appliances typically last 3 years less than the national average lifespan.
What San Antonio's Water Means for Your Home
Hardness: 240 PPM - Treatment Recommended
San Antonio has some seriously hard water. At 240 PPM (14 grains per gallon), your tap is loaded with mineral content carried in from the watershed geology. Here's the thing: it's perfectly safe to drink. The minerals won't hurt you. But they will hurt your wallet. That adds up. Hard water at 240 PPM increases household costs through scale-coated water heaters that use more energy, extra soap and detergent, and appliances that wear out faster. Most San Antonio homeowners don't realize it until the plumber shows up. That's 27% harder than the Texas average.
Contaminants & Safety
Disinfection byproducts are the notable finding here. San Antonio's water has TTHMs at 22.9 ppb and HAA5 at 5.76 ppb — both within legal limits, but the EWG health guidelines are far stricter. These byproducts form when chlorine reacts with organic matter during treatment. A whole-house activated carbon filter reduces both chlorine and its byproducts. Want the full picture? Request your utility's annual Consumer Confidence Report.
What's in the Treatment Process
San Antonio's surface water supply requires heavy chlorination to stay safe — but that creates a tradeoff. The treatment process generates disinfection byproducts: TTHMs at 22.9 ppb (29% of the legal limit, but 152x the EWG guideline) and HAA5 at 5.76 ppb (10% of the legal limit, but 58x the EWG guideline). These are within legal limits, but the EWG sets much tighter thresholds based on cancer-risk research. A whole-house activated carbon filter reduces both chlorine and byproducts.
Chromium-6 was detected at 0.136 ppb, which is 6.8x the EWG health guideline. There's no separate federal limit for chromium-6, only total chromium. A reverse osmosis system is the most effective removal method. All measurements are within federal legal limits. The EWG guidelines represent a more conservative, health-based standard.
How Hard Water Affects Your Home
At 240 PPM, untreated hard water has measurable effects on household costs and appliance life:
- Water heater inefficiency: Scale insulation forces the heater to work harder (DOE estimates up to 22% more energy for heavily scaled units)
- Soap and detergent: Hard water reduces lathering, requiring significantly more product
- Appliance replacement: Water heaters, dishwashers, and washing machines fail 2-4 years earlier due to scale buildup
- Plumbing maintenance: Scale buildup in pipes reduces flow and requires more frequent service
Note: Impact varies by household size, water usage, and local energy costs. A home water test provides the most accurate assessment for your specific situation.
| Contaminant | Detected | Health Guideline | Legal Limit | Status |
|---|---|---|---|---|
| Hardness (as CaCO₃) | 240 PPM | < 60 PPM | No federal limit | ⚠ Very Hard |
| Total Dissolved Solids | 380 PPM | < 300 PPM | 500 PPM | ⚠ Elevated |
| PFAS (total) | 14.45 ppt | — | No total limit | Detected |
| ↳ PFOA | 0 ppt | 0 ppt | 4 ppt (2024) | ✓ OK |
| ↳ PFOS | 0 ppt | 0 ppt | 4 ppt (2024) | ✓ OK |
| Lead | 1.6 ppb | 0 ppb (no safe level) | 15 ppb (10 ppb in 2027) | ✓ Low |
| Chlorine / Chloramine | 1.5 mg/L | Taste threshold ~1.0 | 4.0 mg/L | ✓ Normal |
| Nitrate | 1.42 mg/L | 5 mg/L | 10 mg/L | ✓ OK |
Recommendations for San Antonio Homes
Our Top Picks for San Antonio (240 PPM)
Hard water at 240 PPM causes scale buildup, increased energy use, and premature appliance failure. A softener protects your plumbing and appliances.
Quick Fix for Chlorine: Shower Filter
At 1.5 mg/L chlorine, many San Antonio residents notice dry skin, brittle hair, and that "pool smell" in the shower. A shower filter installs in 5 minutes, no tools needed.
How to Test Your Water in San Antonio
With 240 PPM hardness, a quick test strip confirms whether your specific tap matches San Antonio's average before you invest in a softener. Hardness can vary within the same system.
Free option: Request SAWS's annual Consumer Confidence Report for official city-level data.
📊 Already Tested Your Water?
City averages miss neighborhood-level variation. Share your results to help your neighbors get better data.
We review every submission before publishing. Your ZIP is shown; your identity is not.
About San Antonio's Water Supply
Water Utility: SAWS
Water Source: Edwards Aquifer (Surface Water)
Population Served: 2,113,151
Hardness: 240 PPM (14 grains per gallon)
San Antonio's drinking water comes from surface sources — Edwards Aquifer. Surface water requires more extensive treatment than groundwater, including coagulation, filtration, and disinfection. This heavier chlorination is why disinfection byproducts tend to be higher in surface-supplied systems. Despite the treatment process, mineral hardness from the watershed carries through. The system serves 2.1 million residents.
Water quality can vary by neighborhood and season. For your exact numbers, request SAWS's Consumer Confidence Report (CCR) or test your own tap.
ZIP Codes Covered by This Report
This water quality data applies to all areas served by SAWS in San Antonio, TX, including ZIP codes:
78004, 78006, 78008, 78015, 78062, 78074, 78075, 78112, 78145, 78201, 78202, 78203, 78204, 78205, 78206, 78207, 78208, 78209, 78210, 78211, 78212, 78213, 78214, 78215, 78216, 78217, 78218, 78219, 78220, 78221, 78222, 78223, 78224, 78225, 78226, 78227, 78228, 78229, 78230, 78231, 78232, 78233, 78234, 78235, 78236, 78237, 78238, 78239, 78240, 78241, 78242, 78243, 78244, 78245, 78246, 78247, 78248, 78249, 78250, 78251, 78252, 78253, 78254, 78255, 78256, 78257, 78258, 78259, 78260, 78261, 78263, 78264, 78265, 78266, 78268, 78269, 78270, 78278, 78279, 78280, 78283, 78284, 78285, 78288, 78289, 78291, 78292, 78293, 78294, 78295, 78296, 78297, 78298, 78299, 78624
If your ZIP code is listed above, this report covers your water supply. Water quality may vary slightly by neighborhood.
Water Softener Sizing for San Antonio
At 240 PPM (14 GPG), here is how to size a softener for your San Antonio home. Multiply hardness in GPG (14) by daily water usage (roughly 50 gallons per person). A family of four uses about 200 gallons/day: 14 GPG × 200 gal = 2800 grains/day. Over a 7-day regeneration cycle, that is 19,600 grains - a 32,000-grain softener is the right fit for most San Antonio households.
Compare San Antonio to Other Texas Cities
Frequently Asked Questions About San Antonio Water
Is San Antonio tap water safe to drink?
Where does San Antonio's water come from?
Do I need a water softener in San Antonio?
Does San Antonio water damage tankless water heaters?
How much does hard water cost a San Antonio household per year?
What is the hardness of San Antonio water in grains per gallon?
What size water softener do I need for San Antonio?
Salt-based softener or salt-free conditioner for San Antonio?
Data sources: Lead and copper data from EPA Safe Drinking Water Act LCR reporting. Contaminant data from utility-reported testing results. PFAS data from EPA UCMR5 (2023–2025). Hardness from USGS and municipal reports. Data reflects system-level testing results and may not match your specific tap due to neighborhood plumbing, season, or recent utility changes. For your utility's latest results, request their Consumer Confidence Report (CCR). Our methodology. Last updated: 2026-02-24.
What San Antonio Homeowners Actually Buy
Common purchases for homes with 240 PPM water.
Affiliate disclosure: we may earn a commission. Selection based on San Antonio's water data.