Castle Rock, CO
CASTLE ROCK TOWN OF · Serves 107K people · Surface Water
contaminants
detected
exceed
guidelines
PFAS
chemicals
Most concerning
Arsenic
475×health limit
TraceAlso detected: TOTAL HALOACETIC ACIDS (HAA5), Thallium, Trichloroacetic acid, Dichloroacetic acid, Bromoform, chlorate, Uranium, Chloroform, Nitrate, Lead, Fluoride, strontium… (+27 more contaminants)
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The truth about legal limits
Legal does not equal safe.
Meeting EPA legal limits does not mean your water is safe for drinking.
We benchmark against the strictest independent health-based guidelines.
All Contaminants
37Filter by health risk
Critical findings — every contaminant in your water that exceeds the EWG health limit by 10× or more. Start here.
Filtration Analysis
Viven
Multi-stage
Activated
Carbon filter
Reverse
Osmosis only
PFAS / Forever Chemicals
Viven
99.9%Carbon
PartialRO only
YesHeavy Metals
Viven
99.9%Carbon
LimitedRO only
YesRadionuclides
Viven
99.9%Carbon
NoRO only
YesMinerals re-added
Viven
YesCarbon
NoRO only
NoContaminants in your water that Viven removes
Reserve nowFrequently asked
Castle Rock water quality questions
- Is tap water in Castle Rock, CO (ZIP 80104) safe to drink?
- Tap water for ZIP 80104, served by CASTLE ROCK TOWN OF, has 20 contaminants detected above independent EWG health guidelines, including Arsenic at 475× the guideline. Meeting EPA legal limits does not necessarily mean water is safe — federal legal limits are often far higher than the latest health-based guidelines.
- What contaminants are in Castle Rock, CO tap water?
- EPA monitoring data for ZIP 80104 shows 37 contaminants detected, including Arsenic, HAA9, HAA6Br, Dibromoacetic Acid, Combined Radium, Chromium. Each detected level is compared against both EPA legal limits and the stricter EWG health guidelines.
- Does Castle Rock, CO tap water have PFAS ("forever chemicals")?
- Yes — 2 PFAS compounds were detected out of 30 tested for ZIP 80104. PFAS are persistent synthetic chemicals linked to cancer, immune effects, and developmental harm, with no safe level of exposure established.
- How can I remove these contaminants from my drinking water?
- A multi-stage filtration system that combines activated carbon, reverse osmosis, and remineralization removes PFAS, heavy metals, and disinfection byproducts while restoring beneficial minerals. The Viven faucet is engineered to remove 99.9% of the contaminants found in tap water.
- Where does this Castle Rock, CO water quality data come from?
- This report is built from U.S. EPA data: the Unregulated Contaminant Monitoring Rule (UCMR 3/4/5), the Six-Year Review (SYR4), the Lead and Copper Rule (LCR), and SDWIS violation records. Detected levels are compared against EPA legal limits and Environmental Working Group (EWG) health guidelines. Data last updated 2026-05-01.
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