What San Antonio Residents Should Know
San Antonio residents benefit from one of the cleanest natural water sources in the country, with most of the city's water coming from the Edwards Aquifer. The limestone aquifer naturally filters the water and provides excellent protection against many common contaminants.
The San Antonio Water System (SAWS) maintains high standards for water quality and consistently meets or exceeds all federal and state drinking water requirements. However, the city's water is naturally very hard, containing high levels of calcium and magnesium that can cause scale buildup on fixtures and appliances.
While lead contamination is not a widespread issue in San Antonio, some older neighborhoods with pre-1986 homes may have lead service lines or plumbing components. Additionally, concerns about aquifer protection persist as urban development expands over sensitive recharge zones.
Key Contaminants Found
These substances have been detected in San Antonio's water supply, though most are at levels well below regulatory limits.
Hard Water Minerals
Not a Health ConcernSource: Natural limestone deposits in the Edwards Aquifer
Health Effects: No direct health concerns, but can cause dry skin, hair issues, and appliance/plumbing damage
San Antonio Levels: 18.2 grains per gallon (311 mg/L), considered "extremely hard"
EPA Limit: Not regulated (aesthetic concern only)
Lead
Below LimitSource: Lead service lines, lead solder in plumbing, and older fixtures in pre-1986 buildings
Health Effects: Developmental delays in children, learning disabilities, reduced IQ, kidney problems, high blood pressure
San Antonio Levels: Average 2.6 ppb (90th percentile), with less than 2% of samples exceeding the EPA action level
EPA Limit: Action level 15 ppb, but no safe level exists
Nitrates
Below Limit, But PresentSource: Agricultural fertilizers, septic systems, and natural deposits
Health Effects: High levels can reduce oxygen in blood (methemoglobinemia), particularly dangerous for infants
San Antonio Levels: 1.2-2.7 ppm, higher in areas near agricultural activity
EPA Limit: 10 ppm
Trihalomethanes (TTHMs)
Below LimitSource: Byproducts formed when chlorine used to disinfect water reacts with organic matter
Health Effects: Potential increased risk of cancer with long-term exposure, liver, kidney problems
San Antonio Levels: 25-35 ppb, varying by season and location
EPA Limit: 80 ppb
Neighborhood Variations
Water quality in San Antonio is generally consistent across the city, but some variations exist by neighborhood and water source.
Water Quality by Area
| Neighborhood/Area | Risk Level | Primary Water Source | Buildings Pre-1986 | Notable Concerns |
|---|---|---|---|---|
| Downtown/King William | Medium | Edwards Aquifer | 75% | Aging Infrastructure, Lead |
| Alamo Heights | Medium | Edwards Aquifer | 68% | Lead, Hard Water |
| South Side | Medium | Edwards & Trinity Aquifers | 55% | Nitrates, Hard Water |
| Northwest Side | Low | Edwards Aquifer | 32% | Hard Water Only |
| North Central | Low | Edwards Aquifer | 29% | Hard Water Only |
| Far West/Culebra | Low | Edwards & Trinity Mix | 15% | Hard Water Only |
Data based on San Antonio Water System (SAWS) sampling and U.S. Census housing statistics.
Recommended Action Steps
While San Antonio's water is generally safe, these steps can help address common concerns and improve your water quality experience.
Address Hard Water Issues
Consider installing a water softener to reduce the effects of San Antonio's extremely hard water. This will protect appliances, improve soap efficiency, reduce scale buildup on fixtures, and prevent dry skin and hair problems.
Test Your Water If in an Older Home
If your home was built before 1986, request a water quality test from SAWS or use a certified laboratory to check for lead and other potential contaminants from older plumbing materials.
SAWS Water Testing InfoRun Cold Water Before Use
For homes in older neighborhoods, run cold water for 30-60 seconds before using it for drinking or cooking, especially first thing in the morning or after being away from home for several hours.
Consider a Multi-Stage Filter
While not essential for health concerns, a multi-stage filter can improve taste, reduce chlorine odor, and address any remaining concerns about trace contaminants. Look for NSF-certified filters appropriate for your specific needs.
Maintain Water Efficiency
Help protect the Edwards Aquifer by practicing water conservation, especially during drought periods. Install low-flow fixtures, fix leaks promptly, and follow SAWS watering guidelines for outdoor irrigation.
Water Conservation TipsStay Informed About Water Quality
Review the annual Consumer Confidence Report from SAWS to stay informed about water quality testing results and any emerging concerns for your specific area of San Antonio.
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