Castle Rock, Colorado: Is the Tap Water Safe to Drink?
2026 EPA water quality data for 29 community water systems serving 120,053+ residents. See violations, PFAS results, lead test results, and safety grades — free.
Is Castle Rock Tap Water Safe to Drink?
28 of 29 tested water systems in Castle Rock meet federal drinking water standards with no active violations. 1 system has 2 active health-based violations — check individual reports below for details. 1 system has been tested for PFAS (forever chemicals).
Castle Rock Water Quality Overview
Castle Rock, Colorado is served by 29 community water systems providing water to approximately 120,053 residents. These systems draw from groundwater (27), surface water (1), gwudi (1) sources. 2 active health-based violations across Castle Rock water systems require attention. Including monitoring and reporting violations, there are 547 total violations on record.
Find Your Water System
Search by ZIP code to find your exact water provider and see its full EPA report.
All 29 water systems in Castle Rock
Looking for water quality data across the whole state? See our full Colorado tap water safety report covering Colorado’s EPA-regulated water systems.
Castle Rock Drinking Water: Frequently Asked Questions
Is Castle Rock, Colorado tap water safe to drink?
28 of 29 tested water systems in Castle Rock meet federal drinking water standards with no active violations. 1 system has 2 active health-based violations — check individual reports below for details. 1 system has been tested for PFAS (forever chemicals).
How many water utilities serve Castle Rock, Colorado?
29 community water systems serve Castle Rock, Colorado, providing water to approximately 120,053 people. Different neighborhoods may be served by different utilities. Enter your ZIP code at the top to find your specific provider.
Does Castle Rock tap water have lead?
Lead in drinking water typically enters from old pipes and fixtures inside homes and buildings, not from the treatment plant. The EPA requires water systems to monitor for lead under the Lead and Copper Rule. Click any water system above to see its most recent 90th-percentile lead test results. Homes built before 1986 are most likely to have lead plumbing components.
What contaminants have been found in Castle Rock drinking water?
EPA violation records for Castle Rock water systems are listed on each utility's report page. Common regulated contaminants include disinfection byproducts (TTHMs, HAA5), coliform bacteria, nitrates, and lead. Click any utility above to see its full violation history going back 10 years.
How do I find out which water company serves my address in Castle Rock?
Enter your Castle Rock ZIP code in the search box at the top of this page. ClearWater will identify the specific water system serving your area and show you its EPA violation history, lead test results, and an overall safety grade. You can also check your water bill or your utility's annual Consumer Confidence Report (CCR).