Is Castle Rock, CO tap water safe?
The short answer
1 of the 7 utilities serving Castle Rock has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and Colorado’s records: Beverly Hills Mutual WC.
Town of Castle Rock, which serves the most people here, has 3 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 25 ppb, above EPA’s health benchmark. Health goals are stricter than legal limits and are not enforced.
A town can be served by more than one utility, and some homes are on private wells. The name on your water bill tells you which is yours, and your ZIP code narrows it down. They are listed by how many people each serves in Castle Rock’s ZIP codes, from EPA’s estimates.
- Open report
Town of Castle Rock
Colorado · serves 110,298 people · about 22,200 in Castle Rock
3 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 25 ppb, above EPA’s health benchmark.
No health-based violations since 2016
- Open report
Castle Pines North MD
Colorado · serves 12,800 people · about 2,400 in Castle Rock
1 result above EPA’s health benchmark. The worst: Lithium at 24 ppb, above EPA’s health benchmark.
No health-based violations since 2016
- Open report
Castle Pines Village MD
Colorado · serves 5,656 people · about 940 in Castle Rock
2 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 30.9 ppb, above EPA’s health benchmark.
No health-based violations since 2016
- Open report
Silver Heights WSD
Colorado · serves 301 people · about 210 in Castle Rock
1 result above the health goal. The worst: Lead at 1.0 ppb, above the health goal.
No health-based violations since 2016
- Open report
Consolidated Bell Mtn Ranch MD
Colorado · serves 1,162 people · under 100 in Castle Rock
Nothing in its records is above a health goal.
No health-based violations since 2016
- Open report
Beverly Hills Mutual WC
Colorado · serves 325 people · under 100 in Castle Rock
2 results above the health goal. The worst: Lead at 3.0 ppb, above the health goal.
1 health-based violation since 2016
- Open report
Solitude MD
Colorado · serves 40 people · based in Castle Rock
Nothing in its records is above a health goal.
No health-based violations since 2016
What handles it
Each of these is certified, on a certifier’s listing, for a result above a line in Town of Castle Rock’s water, which serves the most people here. Another utility’s report names what handles its own results.
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Aquasana SmartFlow Reverse Osmosis (AQ-SFRO2)
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Lead, Arsenic
Brondell Capella RC250 Reverse Osmosis System
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Lead, Arsenic
Water testing near Castle Rock
The 3 labs Colorado certifies closest to Castle Rock, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Colorado Department of Health & Environment
Denver, CO · about 24 miles
Certified for bacteria
SGS North America, Inc. - Denver
Denver, CO · about 29 miles
Certified for nitrate, lead and copper, metals, minerals and other inorganics
SGS North America, Inc. - Wheat Ridge
Wheat Ridge, CO · about 31 miles
Certified for nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, radioactivity
Which ZIP codes are in Castle Rock: Census 2020 relationship files. Which utilities serve them, and how many people: EPA SDWIS and EPA’s service area map. Each utility’s results: EPA UCMR 5, EPA SDWIS, and EPA’s and the state’s compliance monitoring, as its report lists them. How they are measured: methodology. Certified labs: CDPHE certified drinking water laboratories; distances from the Census 2020 ZIP code tabulation area gazetteer.
Near Castle Rock
Other towns in Douglas County with a page of their own.
What to do next
- Read Town of Castle Rock’s full reportEvery result with its dates, the violations, and the certification claim that handles each finding.Open the report
- About LithiumWhat it does to health, where it comes from, and the certification claim that addresses it.About Lithium
- On a private well?No utility tests a well. A certified lab test is the first step.How to test well water