Throughout San Antonio and across its water systems, EPA compliance data for TX shows above-average performance - violations are minimal, none of the tracked systems have recorded repeated MCL exceedances in recent cycles, and the safety picture has held steady across multiple reporting periods.

Data: EPA SDWIS, FEMA NFIP, Census ACS Last verified: 2026-07-19

Water Quality in San Antonio

We track water quality and home safety data for 86 ZIP codes in San Antonio, Texas, covering 19 community water systems serving approximately 1,860,461 people.

86 of 86 ZIP codes (100%) have recorded EPA violations - 172 total, including 86 health-based violations.

Average Home Safety Score: A (92/100)

Water sources: Groundwater, Surface water.

Top Contaminants

Lead Risk

• Average lead level (90th percentile): 0.0016 mg/L
• 49% of housing built before 1986 (when lead solder was banned)
• 12% of housing built before 1950 (when lead pipes were standard)
• Median year built: 1982
• Most common estimated pipe material: Copper
• Lead exposure risk score: 50/100
• Estimated lead service line probability: 16%
• 33 ZIP codes classified as high or very high lead risk

With 49% of homes built before the 1986 lead solder ban, San Antonio residents - especially those in older neighborhoods - should consider testing their tap water for lead. Homes built before 1950 are at the highest risk of having lead service lines.

Housing Age Distribution

733,729 total housing units across 86 ZIP codes:

Flood Risk

FEMA National Flood Insurance Program data for San Antonio:

• 2,152 flood insurance claims on record
• $30,788,603 total paid out
• $14,307 average claim payout
• Dominant FEMA flood zone: X (Low risk)
• 16 of 86 ZIP codes in high-risk flood zones (A/V)

Radon Risk

Dominant EPA radon zone: Zone 3 (Low Risk)

• Zone 1 (High): 0 ZIP codes
• Zone 2 (Moderate): 0 ZIP codes
• Zone 3 (Low): 86 ZIP codes

Neighborhoods by Safety Score

Safest Areas

Areas Needing Attention

What San Antonio Residents Can Do

Test Your Water

• Order a certified lab test - home test kits cost $20–50 and cover lead, bacteria, and common contaminants
• Request your utility's CCR (Consumer Confidence Report) - your water provider must publish this annually
• Check your ZIP code - each area in San Antonio has different water systems and risk levels

Filter Your Water

• NSF-certified pitcher filter removes chlorine taste and some contaminants ($20–40)
• NSF 53-certified filter for lead - recommended for homes built before 1986
• Reverse osmosis system removes 95%+ of contaminants including lead, PFAS, and nitrates ($150–400)

Stay Informed

• Visit your ZIP code report for detailed, address-level data
• Sign up for EPA water quality alerts
• Review the annual water quality report from your local utility

All ZIP Codes in San Antonio

• 78201 [B] - 2 violations ⚠
• 78202 [A] - 2 violations ⚠
• 78203 [A] - 2 violations ⚠
• 78204 [A] - 2 violations ⚠
• 78205 [A] - 2 violations ⚠
• 78206 [A] - 2 violations ⚠
• 78207 [A] - 2 violations ⚠
• 78208 [A] - 2 violations ⚠
• 78209 [B] - 2 violations ⚠
• 78210 [A] - 2 violations ⚠
• 78211 [A] - 2 violations ⚠
• 78212 [B] - 2 violations ⚠
• 78213 [B] - 2 violations ⚠
• 78214 [A] - 2 violations ⚠
• 78215 [A] - 2 violations ⚠
• 78216 [B] - 2 violations ⚠
• 78217 [B] - 2 violations ⚠
• 78218 [B] - 2 violations ⚠
• 78219 [A] - 2 violations ⚠
• 78220 [A] - 2 violations ⚠
• 78221 [A] - 2 violations ⚠
• 78222 [A] - 2 violations ⚠
• 78223 [A] - 2 violations ⚠
• 78224 [A] - 2 violations ⚠
• 78225 [A] - 2 violations ⚠
• 78226 [A] - 2 violations ⚠
• 78227 [B] - 2 violations ⚠
• 78228 [B] - 2 violations ⚠
• 78229 [A] - 2 violations ⚠
• 78230 [B] - 2 violations ⚠
• 78231 [A] - 2 violations ⚠
• 78232 [B] - 2 violations ⚠
• 78233 [A] - 2 violations ⚠
• 78234 [A] - 2 violations ⚠
• 78235 [A] - 2 violations ⚠
• 78237 [A] - 2 violations ⚠
• 78238 [B] - 2 violations ⚠
• 78239 [A] - 2 violations ⚠
• 78240 [A] - 2 violations ⚠
• 78241 [A] - 2 violations ⚠
• 78242 [A] - 2 violations ⚠
• 78243 [A] - 2 violations ⚠
• 78244 [A] - 2 violations ⚠
• 78245 [A] - 2 violations ⚠
• 78246 [A] - 2 violations ⚠
• 78247 [A] - 2 violations ⚠
• 78248 [A] - 2 violations ⚠
• 78249 [A] - 2 violations ⚠
• 78250 [A] - 2 violations ⚠
• 78251 [A] - 2 violations ⚠
• 78252 [A] - 2 violations ⚠
• 78253 [A] - 2 violations ⚠
• 78254 [A] - 2 violations ⚠
• 78255 [A] - 2 violations ⚠
• 78256 [A] - 2 violations ⚠
• 78257 [A] - 2 violations ⚠
• 78258 [A] - 2 violations ⚠
• 78259 [A] - 2 violations ⚠
• 78260 [A] - 2 violations ⚠
• 78261 [A] - 2 violations ⚠
• 78263 [A] - 2 violations ⚠
• 78264 [A] - 2 violations ⚠
• 78265 [A] - 2 violations ⚠
• 78266 [A] - 2 violations ⚠
• 78268 [A] - 2 violations ⚠
• 78269 [A] - 2 violations ⚠
• 78270 [A] - 2 violations ⚠
• 78278 [A] - 2 violations ⚠
• 78279 [A] - 2 violations ⚠
• 78280 [A] - 2 violations ⚠
• 78283 [A] - 2 violations ⚠
• 78284 [A] - 2 violations ⚠
• 78285 [A] - 2 violations ⚠
• 78286 [A] - 2 violations ⚠
• 78287 [A] - 2 violations ⚠
• 78288 [A] - 2 violations ⚠
• 78289 [A] - 2 violations ⚠
• 78291 [A] - 2 violations ⚠
• 78292 [A] - 2 violations ⚠
• 78293 [A] - 2 violations ⚠
• 78294 [A] - 2 violations ⚠
• 78295 [A] - 2 violations ⚠
• 78296 [A] - 2 violations ⚠
• 78297 [A] - 2 violations ⚠
• 78298 [A] - 2 violations ⚠
• 78299 [A] - 2 violations ⚠

Frequently Asked Questions

Is the tap water safe to drink in San Antonio, TX?

San Antonio has an average Home Safety Score of 92/100 (grade A) across 86 ZIP codes. There are 172 recorded EPA violations, 86 of which are health-based. Safety varies by neighborhood - check your specific ZIP code report for details.

Does San Antonio have lead in the water?

The average 90th-percentile lead level across San Antonio is 0.0016 mg/L, below the EPA action level of 0.015 mg/L. No ZIP codes currently exceed the EPA lead action level. About 49% of housing was built before 1986, when lead solder was banned.

Is San Antonio at risk for flooding?

FEMA data shows 2,152 flood insurance claims in San Antonio ZIP codes, with an average payout of $14,307. 16 of 86 ZIP codes are in high-risk FEMA flood zones (A or V).

Are there lead pipes in San Antonio homes?

49% of San Antonio housing was built before 1986, when lead solder was common in plumbing. 12% was built before 1950, when lead pipes were standard. The most common estimated pipe material is Copper. The estimated probability of lead service lines is 16%. We recommend testing your water if your home was built before 1986.

What contaminants have been found in San Antonio water?

The most common contaminants by violation count are Total Coliform, Stage 1 DBP Rule. Across 86 ZIP codes, 86 have recorded EPA violations. Check your ZIP code report for the specific contaminants in your area.

Data Sources

• Water quality: EPA Safe Drinking Water Information System (SDWIS)
• Lead/copper: EPA Lead and Copper Rule sampling data
• Housing age: U.S. Census Bureau American Community Survey
• Flood data: FEMA National Flood Insurance Program
• Lead exposure: Composite risk score based on housing age, water lead levels, and service line estimates
• Radon: EPA Map of Radon Zones

Updated daily.

Housing Age Profile

Cities with large shares of pre-1986 housing carry elevated aggregate risk from lead-soldered plumbing; San Antonio sits on the lower end of that spectrum. The median build year of 1982 reflects a housing stock in which post-ban construction is dominant - meaning lead-soldered copper joints are less prevalent across the city as a whole. Still, aggregate figures don't tell you what's happening inside a specific older home. Any structure built before 1986, and particularly those built before 1970 when lead pipes were commonly installed, can still present meaningful lead risk regardless of the city-wide picture.

1982

Median Year Built

0%

Pre-1986 (Lead Paint Risk)

0%

Pre-1970 (Lead Pipes Risk)

Most homes in San Antonio were built after 1986, reducing the risk of lead contamination from plumbing. Older homes should still be tested.

Source: U.S. Census Bureau ACS B25034.

Protecting Children from Lead in San Antonio

0.0016

mg/L Avg Lead (Limit: 0.015)

Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.

Lead risk in San Antonio appears low overall, but individual homes may differ. Testing is the only way to confirm your water's lead content.

Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.

Climate-Related Water Risk for San Antonio

A moderate NFIP record for San Antonio - 2152 insurance claims paired with 0% of ZIP codes in FEMA flood zones - points to a flood history where water-quality pathways have likely been periodically relevant.

2,152

Total FEMA Flood Claims

~108

Est. Claims/Year

San Antonio has a moderate flood history with 2,152 FEMA claims. Flood events can contaminate drinking water and overwhelm treatment systems.

How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure.

Residents in flood-prone areas should consider flood insurance even outside FEMA zones - over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.

Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.