Caldwell County, Texas
12 ZIP codes · Avg score 75/100 · Grade B · Updated 2026-06-03
Within Caldwell County, all 12 tracked ZIP codes show above-average drinking water safety — violations are infrequent and typically minor.
How Caldwell County Compares
How Caldwell County Compares
Caldwell County scores 7 points below the Texas state average (82/100) and 7 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Caldwell County, Texas
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 13.3 (asthma 9.6%, diabetes 14.2%)
Estimated additional annual cost per homeowner: $1,178, driven primarily by flood
Infrastructure: 0.312% avg pipe failure probability
42.5% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
→ Stable trendEPA violation counts by year across Caldwell County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 33 violations. Past 5 years: 97 total (97 health-based).
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $1,178
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
20,326 housing units in Caldwell County
Source: U.S. Census Bureau ACS B25034 (Year Structure Built).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Caldwell County
Remediation costs are relatively manageable for most homeowners in Caldwell County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for Caldwell County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in Caldwell County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Maxwell Special Utility District | 5,823 | 35 |
| 2 | TRI COMMUNITY WSC | 1,698 | 30 |
| 3 | Aqua Water Supply Corporation | 86,325 | 29 |
| 4 | CITY OF SAN MARCOS | 72,970 | 26 |
| 5 | Martindale Water Supply Corporation | 3,045 | 26 |
22 total water systems serve Caldwell County.
All ZIP Codes in Caldwell County
12 ZIP codes tracked in Caldwell County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 78616 | Dale | 91 | A | 5 (1 health) | $175K |
| 2 | 78644 | Lockhart | 88 | A | 1 | $243K |
| 3 | 78648 | Luling | 87 | A | 3 | $217K |
| 4 | 78655 | Martindale | 81 | B | 6 (1 health) | $223K |
| 5 | 78632 | Harwood | 73 | B | 0 | $184K |
| 6 | 78658 | Ottine | 73 | B | 0 | $446K |
| 7 | 78661 | Prairie Lea | 73 | B | 0 | $190K |
| 8 | 78670 | Staples | 73 | B | 0 | $233K |
| 9 | 78656 | Maxwell | 70 | B | 20 (16 health) | $195K |
| 10 | 78604 | Belmont | 66 | C | 0 | — |
| 11 | 78619 | Driftwood | 65 | C | 0 | $709K |
| 12 | 78638 | Kingsbury | 65 | C | 0 | $302K |
Recommended Buyer Guides for Caldwell County
Strictly editorial — no paid placements influence which guides appear; the selection draws on NSF certifications and EPA detection records for water systems serving this county.
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for Caldwell County, Texas
Overview
Caldwell County in Texas covers 12 ZIP codes with an average Home Safety Score of B (75/100).
5 of 12 ZIP codes have recorded EPA violations. 18 health-based violations have been documented.
← Back to Texas water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.