Is Castroville, TX Tap Water Safe to Drink?
Graded C+, with 43 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
69.8/100
waterverge.com Castroville, TX — Water Quality Report
Castroville's drinking water received a grade of C+ (69.8 out of 100), indicating fair water quality. The city's 7 water systems serve approximately 7,418 residents using groundwater.
Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 109 violations on record, including 3 health-based violations. 43 remain unresolved.
What to know about Castroville's water
Castroville ranks #579 out of 1067 cities in Texas for water quality, placing it below average in the state.
Castroville relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
The system has seen 7 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Castroville, TX water safe to drink?
Castroville's drinking water has significant quality concerns based on EPA testing data. With a grade of C+ (69.8/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 7 water systems serve approximately 7,418 residents using groundwater (wells).
Recent water quality updates for Castroville
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Castroville's water quality assessment. Grade: C+ (69.8/100).
Contaminants: Consumer Confidence Rule.
Contaminants: Lead and Copper Rule.
1 health-based. Contaminants: Revised Total Coliform Rule.
Federal disaster declaration (FEMA DR-3313). Hurricane event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-1606). Hurricane event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Castroville's water supply.
Well within EPA limits.
Violation history
Castroville's water system has 109 total violations on record, including 3 health-based violations. 43 remain unresolved. 7 violations were issued in the last 5 years.
Flood & environmental risk
Medina County has experienced 2 federally declared disasters since 2005. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Medina Rv At La Coste.
Where does Castroville's water come from?
Castroville's drinking water comes from groundwater (wells), supplied by 7 water systems serving approximately 7,418 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Medina Rv At La Coste (river).
What Castroville residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Castroville's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Castroville
Industrial polluters nearby
Reported releases to surface water by facilities near Castroville, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
OLDCASTLE INFRASTRUCTURE - CASTROVILLE CASTROVILLE, TX78009 | — | — | 3.5 mi |
READY MIX #10 SAN ANTONIO, TX78245 | — | — | 9.8 mi |
MONTGOMERY ROAD READYMIX SAN ANTONIO, TX78252 | — | — | 7.0 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Drought conditions
D3 — extreme droughtMedina County is currently in D3 (extreme drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Medina County has experienced 2 federally declared disasters since 2005. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 0.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Castroville compares by contaminant
Explore where Castroville ranks among all Texas cities for specific contaminants.
Water source & infrastructure
Where Castroville's water comes from
Castroville's drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by local government ownership and serves approximately 7,418 people through 7 water systems.
Water bodies near Castroville
Castroville is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Castroville
| System Name | PWSID | Population | Source |
|---|---|---|---|
| CITY OF CASTROVILLE | TX1630005 | 3,913 | GW |
| OLD HWY 90 WATER SERVICE | TX1630035 | 1,215 | GW |
| MEDINA RIVER WEST WSC | TX1630028 | 1,158 | GW |
| HIGHWAY 90 RANCH WSC | TX1630014 | 412 | GW |
| MEDINA VALLEY WATER SUPPLY CO | TX1630036 | 255 | GW |
| OLD HWY 90 N RIDGE W SYSTEM | TX1630041 | 246 | GW |
| VALLEY MOBILE HOME PROPERTIES | TX1630011 | 219 | GW |
How Castroville compares
Full Texas rankings →Castroville's score of 69.8/100 is above the average of 46/100 among major Texas cities. It outscores 8 of 10 nearby cities.
Nearby cities
View Texas rankings →About Castroville, TX
Wikipedia →Castroville is a city in Medina County, Texas, United States. Its population was 2,954 at the 2020 census, up from 2,680 at the 2010 census. It is part of the San Antonio–New Braunfels, Texas Metropolitan Statistical Area. Castroville was founded by Alsatian-Texans, who came to Texas during the German emigration period of the mid-1800s. Most Alsatians who came to Castroville spoke Alsatian. The Alsatian culture and language are still kept alive by the residents of Castroville. Prior to 1893, Castroville was the first county seat of Medina County.
Learn more about your water
Guides and resources related to Castroville's water quality findings.
Explore water quality across Medina
Frequently asked questions
Is Castroville, TX tap water safe to drink?
Castroville's water quality earned a grade of C+ (69.8/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #579 out of 1067 cities tested in Texas.
What contaminants are in Castroville's water?
Lead was measured at 0.0 ppb (90th percentile). 109 violations are on record.
How is Castroville's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Castroville?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Castroville's water come from?
Castroville's water is sourced from Groundwater. The city has 7 water systems serving approximately 7,418 residents.
What health violations has Castroville's water system had?
Castroville has 3 health-based violations on record. The most recent violation was recorded in July 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 43 violations remain unresolved.
Is Castroville's groundwater at risk of contamination?
Castroville uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 109 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Castroville's water compare to other cities?
Castroville ranks #579 out of 1067 cities in Texas (better than 46% of state cities) and #10849 out of 15744 cities nationally (31th percentile). The grade of C+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.