Nitrate in San Antonio, TX Drinking Water
Nitrate data for San Antonio, Texas · 1,860,461 residents · 86 ZIP codes
Nitrate exposure in drinking water is tracked by EPA across the country; households in San Antonio, Texas are among those with confirmed detections in the public water record.
Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-06-04
Nitrate in San Antonio Tap Water
San Antonio, Texas has 36 EPA violations related to nitrate in drinking water.
This analysis covers 1,860,461 residents across 86 ZIP codes in San Antonio.
San Antonio's overall water quality grade is A (92/100).
Is Nitrate in San Antonio Water Safe?
If you live in an affected ZIP code, consider installing a reverse osmosis or ion exchange filter certified under NSF 53 / NSF 58 and testing your water independently.
EPA Violations for Nitrate in San Antonio
| Date | Violation Type | Status | ZIP Code |
|---|---|---|---|
| 2023-04-01 | Nitrate (Resolved) | Resolved | 78224 |
| 2023-04-01 | Nitrate (Resolved) | Resolved | 78245 |
| 2023-04-01 | Nitrate (Resolved) | Resolved | 78252 |
| 2023-04-01 | Nitrate (Resolved) | Resolved | 78264 |
| 2023-01-01 | Nitrate (Resolved) | Resolved | 78224 |
| 2023-01-01 | Nitrate (Resolved) | Resolved | 78245 |
| 2023-01-01 | Nitrate (Resolved) | Resolved | 78252 |
| 2023-01-01 | Nitrate (Resolved) | Resolved | 78264 |
| 2022-10-01 | Nitrate (Resolved) | Resolved | 78224 |
| 2022-10-01 | Nitrate (Resolved) | Resolved | 78245 |
| 2022-10-01 | Nitrate (Resolved) | Resolved | 78252 |
| 2022-10-01 | Nitrate (Resolved) | Resolved | 78264 |
| 2022-07-01 | Nitrate (Resolved) | Resolved | 78224 |
| 2022-07-01 | Nitrate (Resolved) | Resolved | 78245 |
| 2022-07-01 | Nitrate (Resolved) | Resolved | 78252 |
| 2022-07-01 | Nitrate (Resolved) | Resolved | 78264 |
| 2022-04-01 | Nitrate (Resolved) | Resolved | 78224 |
| 2022-04-01 | Nitrate (Resolved) | Resolved | 78245 |
| 2022-04-01 | Nitrate (Resolved) | Resolved | 78252 |
| 2022-04-01 | Nitrate (Resolved) | Resolved | 78264 |
| ... | 16 more violations |
Health Effects of Nitrate
- Methemoglobinemia ("blue baby syndrome") in infants under 6 months
- Increased risk of colorectal and bladder cancer (long-term)
- Thyroid disease from chronic exposure
- Possible reproductive effects
Health risk severity: High. Governed by the National Primary Drinking Water Regulations.
How Nitrate Gets Into Drinking Water
- Agricultural fertilizer runoff
- Animal feedlot operations and manure
- Septic system leachate
- Urban stormwater and wastewater discharge
What to Do About Nitrate in San Antonio Water
- Reverse osmosis is the most effective method for nitrate removal
- Ion exchange systems designed for nitrate can also work
- Standard carbon filters do NOT remove nitrate
- Boiling water increases nitrate concentration — never boil for nitrate
Look for filters certified under NSF 53 / NSF 58 for nitrate removal.