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San Marcos, Texas: Is the Tap Water Safe to Drink?

2026 EPA water quality data for 13 community water systems serving 139,356+ residents. See violations, PFAS results, lead test results, and safety grades — free.

Is San Marcos Tap Water Safe to Drink?

San Marcos has 13 community water systems. 12 of 13 graded systems meet all EPA standards (grade A or B), while 1 has recorded violations. No active health-based violations are currently open. Check individual system reports below for specifics.

San Marcos Water Quality Overview

San Marcos, Texas is served by 13 community water systems providing water to approximately 139,356 residents. These systems draw from groundwater (9), groundwater purchased (2), surface water (1), surface water purchased (1) sources. San Marcos water systems have recorded 101 health-based violations in their history, though none are currently active. Including monitoring and reporting violations, there are 276 total violations on record.

13
Water Systems
101
Health Violations
12/13
Rated A or B
2
PFAS Tested
💧 Filter Guide📖 Violations Explained📄 Read Your CCR⚠ PFAS Guide

Find Your Water System

Search by ZIP code to find your exact water provider and see its full EPA report.

All 13 water systems in San Marcos

CITY OF SAN MARCOS B
SAN MARCOS, TX · 72,970 people · Surface Water 1 health violation in past 5 yrs
TEXAS STATE UNIVERSITY - SAN MARCOS A
SAN MARCOS, TX · 43,552 people · Groundwater ✓ No recent health violations
CRYSTAL CLEAR SUD A
SAN MARCOS, TX · 20,766 people · Surface Water Purchased ✓ No recent health violations
PROMISELAND CHURCH SAN MARCOS C
SAN MARCOS, TX · 625 people · Groundwater 3 health violations in past 5 yrs
SAN MARCOS BAPTIST ACADEMY A
SAN MARCOS, TX · 450 people · Groundwater ✓ No recent health violations
MCCOYS BUILDING SUPPLY 118 A
SAN MARCOS, TX · 325 people · Groundwater ✓ No recent health violations
ST MARKS EPISCOPAL CHURCH A
SAN MARCOS, TX · 225 people · Groundwater ✓ No recent health violations
WONDERLAND SCHOOL WATER SYSTEM A
SAN MARCOS, TX · 206 people · Groundwater ✓ No recent health violations
TEXAS STATE UNIVERSITY - FREEMAN CENTER A
SAN MARCOS, TX · 150 people · Groundwater ✓ No recent health violations
ROUGHHOUSE BREWERY A
SAN MARCOS, TX · 50 people · Groundwater ✓ No recent health violations
MIDDLETON BREWING A
SAN MARCOS, TX · 37 people · Groundwater ✓ No recent health violations
ALLIANCE REGIONAL WATER AUTHORITY 1B A
SAN MARCOS, TX · Groundwater Purchased ✓ No recent health violations
ALLIANCE REGIONAL WATER AUTHORITY A
SAN MARCOS, TX · Groundwater Purchased ✓ No recent health violations

Looking for water quality data across the whole state? See our full Texas tap water safety report covering Texas’s EPA-regulated water systems.

San Marcos Drinking Water: Frequently Asked Questions

Is San Marcos, Texas tap water safe to drink?

San Marcos has 13 community water systems. 12 of 13 graded systems meet all EPA standards (grade A or B), while 1 has recorded violations. No active health-based violations are currently open. Check individual system reports below for specifics.

How many water utilities serve San Marcos, Texas?

13 community water systems serve San Marcos, Texas, providing water to approximately 139,356 people. Different neighborhoods may be served by different utilities. Enter your ZIP code at the top to find your specific provider.

Does San Marcos tap water have lead?

Lead in drinking water typically enters from old pipes and fixtures inside homes and buildings, not from the treatment plant. The EPA requires water systems to monitor for lead under the Lead and Copper Rule. Click any water system above to see its most recent 90th-percentile lead test results. Homes built before 1986 are most likely to have lead plumbing components.

What contaminants have been found in San Marcos drinking water?

EPA violation records for San Marcos water systems are listed on each utility's report page. Common regulated contaminants include disinfection byproducts (TTHMs, HAA5), coliform bacteria, nitrates, and lead. Click any utility above to see its full violation history going back 10 years.

How do I find out which water company serves my address in San Marcos?

Enter your San Marcos ZIP code in the search box at the top of this page. ClearWater will identify the specific water system serving your area and show you its EPA violation history, lead test results, and an overall safety grade. You can also check your water bill or your utility's annual Consumer Confidence Report (CCR).