Water Quality in Castle Rock, CO: 27 Violations - Grade N/A
6 water systems · 3 directly mapped ZIP records
Available EPA records report 27 violations across 3 directly mapped ZIP records with known counts for Castle Rock. This is compliance evidence, not a property-level tap-water verdict.
Data: EPA Safe Drinking Water Information System (SDWIS)
Water Quality by ZIP Code in Castle Rock
This table shows typed EPA water evidence only. Missing violation counts are displayed as N/A, not zero.
| ZIP Code | Violations | Health | |
|---|---|---|---|
| 80108 | 26 | 0 | View report → |
| 80104 | 9 | 0 | View report → |
| 80109 | 9 | 0 | View report → |
Water Quality Overview
Castle Rock, Colorado has directly mapped EPA water-system data for 3 ZIP codes. This page reports typed compliance facts and does not relabel the multi-source Home Safety Score as a drinking-water grade.
The available EPA records report 27 violations (all classified as monitoring/reporting type in the available record) across 3 directly mapped ZIP records with reported counts.
Lead Levels
The average 90th percentile lead level across Castle Rock water systems is 0.0023 mg/L - within EPA limits. No exceedances appear among the 3 ZIP records with known lead status.
Water Systems Serving Castle Rock
Castle Rock is served by 6 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 99,741 people across 3 ZIP codes.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
The EPA has taken 29 enforcement actions against water systems serving Castle Rock. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Castle Rock
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels and violation history
Request your CCR - your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test - certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration - NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories - monitor your local utility website and local news for boil water advisories or system alerts
Contaminants Detected in Castle Rock Water Systems
The following contaminants have been detected or caused violations across Castle Rock's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| E. coli | Microbiological | N/A | 7 | 3 | No |
| Gross Alpha | Radionuclides | 15 pCi/L | 6 | 3 | No |
| Combined Radium | Radionuclides | 5 pCi/L | 6 | 3 | No |
| Gross Beta | Radionuclides | 50 pCi/L | 6 | 3 | No |
| Lead and Copper Rule | Treatment Technique | N/A | 5 | 3 | No |
| Surface Water Treatment Rule | Treatment Technique | N/A | 3 | 1 | No |
| Stage 1 DBP Rule | Treatment Technique | N/A | 2 | 1 | No |
| Revised Total Coliform Rule | Microbiological | N/A | 1 | 1 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 1 | 1 | No |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 0.06 mg/L | 1 | 1 | No |
| Total Coliform | Microbiological | N/A | 1 | 1 | No |
| Stage 2 DBP Rule | Treatment Technique | N/A | 1 | 1 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
EPA Enforcement History
The EPA and state regulators have taken 16 enforcement actions against water systems serving Castle Rock. Recent actions:
| Date | Action Type |
|---|---|
| 2025-11-26 | State Informal Action |
| 2025-11-26 | State Order Extension |
| 2025-11-12 | State Order Extension |
| 2025-08-20 | State Informal Action |
| 2025-08-20 | State Informal Enforcement |
| 2025-08-07 | State Order Extension |
| 2025-07-18 | State Informal Action |
| 2025-07-18 | State Informal Enforcement |
| 2025-07-16 | State Informal Action |
| 2025-06-30 | State Informal Action |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-11-26.
Castle Rock vs. Nearby Colorado Cities
How Castle Rock's water quality compares to similar cities in Colorado:
| City | Direct EPA ZIPs | Violations | Systems | Population |
|---|---|---|---|---|
| Castle Rock | 3 | 27 | 6 | 99,741 |
| Brighton | 3 | 24 | 9 | 99,643 |
| Loveland | 2 | 86 | 8 | 93,688 |
| Grand Junction | 6 | 2 | 3 | 112,115 |
Recommended Water Filters for Castle Rock
Based on contaminants detected in Castle Rock's water supply, these filter types are recommended:
Reverse Osmosis (under-sink)
- Removes: Arsenic, Barium, Nitrate
- Effectiveness: 90-99%
- Cost range: $150–$500
- Certification: NSF/ANSI 58
- Recommended products:
- Waterdrop G3P800
- iSpring RCC7AK
- Crystal Quest Arsenic Filter
Water Quality by ZIP Code in Castle Rock
EPA coverage and recorded violations can differ across Castle Rock's ZIP codes. Missing counts are shown as unavailable, not zero:
Common Questions About Castle Rock Water
These are the most common questions residents search for about water quality in Castle Rock, Colorado:
Is Castle Rock water hard or soft? Water hardness varies by source. Castle Rock's 6 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Castle Rock tap water? City-level EPA records cannot determine safety at a specific tap. No health-based violations are recorded across 3 directly mapped ZIP records with known counts, but this is not a property-level safety guarantee.
What is the best water filter for Castle Rock? Based on detected contaminants, a reverse osmosis (under-sink) filter is most recommended. See our Water Filter Matcher for personalized recommendations.
Castle Rock vs. Colorado Average
Understanding how Castle Rock compares to the broader Colorado average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below - water quality can vary significantly even within Castle Rock.
ZIP Codes in Castle Rock
Castle Rock spans 3 ZIP codes. EPA water-system coverage is available for 3 directly mapped ZIP codes. Check each ZIP code for detailed contaminant data, violation history, and system information.
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
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Source reporting periods vary. See each cited source for its publication schedule.