San Marcos, TX: 2 Violations — 83/100 (2026)
2 ZIP codes · 12 water systems · Updated 2026-06-03
Unlike many cities its size in TX, San Marcos keeps health-based violation rates low — systems here score at or above the state average for tap water safety, with no systemic concerns flagged in the current data set.
How San Marcos Compares
Data: EPA SDWIS Last verified: 2026-06-03
Key Facts for San Marcos Residents
- Your city's water systems recorded 2 violations in the past 5 years.
- Average lead level: 0.0016 mg/L.
- Estimated remediation: $2,000 per household.
- CDC health risk index: 10.83.
San Marcos's Water Providers
Across San Marcos, TX, residential water comes from 3 primary utilities rather than a single consolidated provider. Each system operates independently — managing its own distribution infrastructure, rate schedules, and EPA compliance filings. Federal records track 12 water systems in the area, with these top providers accounting for the majority of residential connections.
Overview
We track water quality and home safety data for 2 ZIP codes in San Marcos, Texas (population ~87,775), covering 12 community water systems serving approximately 356,186 people region-wide.
2 of 2 ZIP codes (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for San Marcos: B (83/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
San Marcos water systems draw from: Groundwater, Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0016 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 3 (Low Risk)
- Zone 1 (High): 0 ZIP codes
- Zone 2 (Moderate): 0 ZIP codes
- Zone 3 (Low): 2 ZIP codes
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Contaminant 1009 | Other | 3 | 2 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 78666 | B | 1 | 0 | City of San Marcos |
| 78667 | A | 1 | 0 | City of San Marcos |
All ZIP Codes in San Marcos
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Updated daily.
San Marcos Community Health Snapshot
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
What's in San Marcos's Water?
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
How Remediation Costs Compare in San Marcos
Given current San Marcos valuations, the remediation-to-property-value ratio is low — most homeowners are looking at a proportionally modest share that fits within routine financial planning.
Remediation costs in San Marcos are relatively low compared to home values. The $1,300–$2,950 estimated range is a small fraction of median property value. Home values are 19% above the Texas average.
San Marcos: Lead Risk & Vulnerable Populations
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 Marcos 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.
San Marcos: Flood History & Water Damage Risk
Substantially more flood exposure than most communities appears in San Marcos's NFIP record — 869 documented claims and 100% of ZIP codes in FEMA flood zones. That exposure level makes the water-quality implications of flooding an active planning consideration rather than a background one.
San Marcos has a significant flood history with 869 FEMA flood insurance claims on record, averaging $20,630 per claim. With 100% of ZIP codes in FEMA-designated flood zones, flood risk is a major concern for homeowners and water quality.
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. Flood damage can add significantly to the estimated <strong>$2,000</strong> remediation cost per household.
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.
Deep Dive Reports
Detailed analysis for San Marcos, TX