Castle Rock, WA: 1 Violation — 85/100 (2026)
1 ZIP code · 4 water systems · Updated 2026-06-03
Castle Rock, WA: reliable drinking water, above-average safety record, few violations.
How Castle Rock Compares
Data: EPA SDWIS Last verified: 2026-06-03
Castle Rock Water: The Quick Version
- Your city's water systems recorded 1 violation in the past 5 years.
- Average lead level: 0.005 mg/L.
- Homes built before 1986: 53% — older plumbing may contain lead solder.
- Estimated remediation: $1,800 per household.
- CDC health risk index: 13.81 — above typical levels.
Water Systems Serving Castle Rock
Across Castle Rock, WA, 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 4 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 1 ZIP code in Castle Rock, Washington (population ~9,367), covering 4 community water systems serving approximately 65,506 people region-wide.
1 of 1 ZIP code (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Castle Rock: A (85/100)
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
Castle Rock water systems draw from: Groundwater, Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0050 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)
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 98611 | A | 1 | 0 | Castle Rock Municipal Water |
All ZIP Codes in Castle Rock
- 98611 [A] — 1 violation
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.
CDC Health Data for Castle Rock
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
Key Contaminants Detected in Castle Rock
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
How Old Is Castle Rock's Housing Stock?
With 53% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
Housing age is one of the most reliable proxies for plumbing-era lead risk, because two federal milestones — the widespread use of lead pipes before 1970 and the continued use of lead solder until 1986 — define the highest-risk tiers of the residential housing stock. With a median build year of 1987, Castle Rock falls squarely within the older range — meaning a large fraction of the housing was built under the plumbing standards of those earlier eras. The distribution above captures where that risk concentrates, and why older neighborhoods warrant particular attention from residents concerned about tap water quality.
Over half of homes in Castle Rock were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.
Source: U.S. Census Bureau ACS B25034.
Castle Rock: Remediation Cost in Perspective
In Castle Rock, property wealth outpaces what documented remediation typically demands — the equity burden lands well within the low tier.
Remediation costs in Castle Rock are relatively low compared to home values. The $1,200–$2,500 estimated range is a small fraction of median property value. Home values are 18% below the Washington average.
Protecting Children from Lead in Castle Rock
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.
In recent monitoring under the Lead and Copper Rule, citywide samples for Castle Rock have approached or crossed the regulatory action level on multiple occasions. Combined with 53% of stock dating from the pre-rule era, the picture supports baseline single-tap reads as a standard household-level step.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Castle Rock
170 FEMA flood insurance claims are on file for Castle Rock, and 100% of local ZIP codes fall within federally designated flood zones — enough to put flood exposure on the planning radar, though short of the concentrated-risk threshold where treatment-system vulnerability becomes a primary consideration.
Castle Rock has a moderate flood history with 170 FEMA claims averaging $26,613 per payout. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
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>$1,800</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 Castle Rock, WA