Castle Rock Municipal Water
EPA ID: WA5311800 · 4,367 people served · 2 ZIP codes
ZipCheckup's reading of EPA SDWIS for Castle Rock Municipal Water (WA5311800): 3 EPA violations in the last five years. 3 total violations across five years at Castle Rock Municipal Water - every finding closed, utility compliant today, 4,367 served.
Data: EPA SDWIS
Service Area Map
Coverage area for Castle Rock Municipal Water Source: EPA SDWIS service area boundaries.
Service area boundary - Grade A
Service Area Demographics
The Castle Rock Municipal Water serves a community with a median household income of $92,147 and an estimated 11,562 residents across its service area. Approximately 49% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: 46% of the population in this service area is classified as disadvantaged under EPA's EJScreen criteria. Communities with higher disadvantaged populations often face disproportionate environmental and health burdens, including aging water infrastructure and limited resources for remediation.
🌊 Where Does Your Water Come From?
Castle Rock Municipal Water's water is drawn from rivers, lakes, or reservoirs. Surface water sources are more exposed to agricultural runoff, stormwater, and upstream discharges, but they typically receive more intensive treatment before reaching your tap.
Infrastructure Risk
Detected Contaminants
How Castle Rock Municipal Water compares to EPA limits
What This Means For You
Haloacetic Acids (HAA5) at 1 mg/L exceeds the EPA maximum of 0.06 mg/L. Cancer risk; reproductive & developmental effects. Consider granular activated carbon (GAC) filtration.
Total Trihalomethanes (TTHM) at 1 mg/L exceeds the EPA maximum of 0.08 mg/L. Bladder & rectal cancer risk; reproductive concerns. Consider granular activated carbon (GAC) filtration.
E. coli at 1 Zero tolerance (any positive sample triggers immediate action) exceeds the EPA maximum of Zero tolerance (any positive sample triggers immediate action). Severe GI illness; potentially fatal kidney failure in children. Consider UV disinfection (99.99%) filtration.
Haloacetic Acids (HAA5) was detected in this water system. granular activated carbon (GAC) filtration can reduce exposure.
Find a certified water filter →Comparable Water Systems
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Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
Castle Rock Municipal Water (EPA ID: WA5311800) is a community water system in Washington that serves approximately 4,367 people from surface water sources.
This system provides water to 2 ZIP codes across 2 communities.
ZIP-Area Home Safety Context: A (98/100)
This is the average Home Safety Score for 1 of 2 service-area ZIP codes with all required score domains observed. It is not a grade for the water utility.
Model 4.0.0 uses SDWIS identity plus accepted ECHO SDWA lifecycle-based water compliance, the UCMR 5 PFAS MCL screen, EPA radon zone, and annual EPA AirData AQI across three equally weighted domains. Missing required evidence suppresses the score.
Violation History
Status breakdown for accepted records with record years 2021-2026: 3 resolved, 0 archived, 0 addressed, and 0 unaddressed. Under this source contract, current noncompliance is the sum of addressed and unaddressed records. Archived and resolved records are excluded from current noncompliance.
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| March 1, 2026 | E. coli | Non-health-based | Resolved |
| January 1, 2023 | Haloacetic Acids (HAA5) | Non-health-based | Resolved |
| January 1, 2023 | Total Trihalomethanes (TTHM) | Non-health-based | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 1 | No |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 1 | No |
| E. coli | Microbiological | 1 | No |
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| 0.005 mg/L | No | N/A |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 3 (Low Risk)
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by WA or modeled from parcel and building-footprint data.
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Castle Rock Municipal Water (WA5311800) on EPA.gov.
Frequently Asked Questions
Is Castle Rock Municipal Water water safe to drink?
The accepted 2026Q2 ECHO snapshot shows no current noncompliance for Castle Rock Municipal Water; its 3 accepted 2021-2026 records are resolved or archived. Historical compliance status does not establish conditions at a specific tap.
How many people does Castle Rock Municipal Water serve?
Castle Rock Municipal Water serves approximately 4,367 people across 2 ZIP codes in Washington.
Where does Castle Rock Municipal Water get its water?
The primary water source is surface water.
Federal UCMR5 PFAS Monitoring: Tested Clean
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). No PFAS compounds were detected.
Current MCL reflects the lowest state-enforceable limit (NYS 10 ppt for PFOA/PFOS, effective August 2020). The federal final MCL of 4 ppt for PFOA/PFOS (EPA April 2024 rule) is not enforceable until April 2029. Detections above 4 ppt but below 10 ppt are below current MCL but above the future federal limit.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Castle Rock Municipal Water (WA): 3 EPA Violations. https://zipcheckup.com/water-system/wa5311800/
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What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
Castle Rock Municipal Water (EPA ID: WA5311800) - request the latest Consumer Confidence Report or ask about specific contaminants.