B
70

US Water Score: B

Dillon, CO 80435

Summit County · Population served: 9,900 · Data updated July 2026

Service-area evidence: EPA service-area records associate the listed system with this ZIP. Boundaries may still overlap or change.

Water Systems Serving This Area

🌊
SNAKE RIVER WD
Groundwater · Pop. 9,900
PWSID: CO0159105
🏔
DILLON TOWN OF
Surface water · Pop. 3,254
PWSID: CO0159035
🏔
DILLON VALLEY DISTRICT
Surface water · Pop. 3,063
PWSID: CO0159040
🏔
EAST DILLON WD
Surface water · Pop. 2,501
PWSID: CO0159045
🌊
KEYSTONE RANCH
Groundwater · Pop. 670
PWSID: CO0159065

Contaminants Detected

ContaminantDetected LevelEPA MCLHealth GuidelineStatus
Lead
32.0
15 ppb 1 ppb
Copper
1720.0
1300 ppb 300 ppb

PFAS / Forever Chemicals

7 detected 3 above comparison value

UCMR5 occurrence results are screening information, not a finding of regulatory compliance or noncompliance. PFAS rules and compliance dates are evolving.

CompoundLevelEPA MCLHealth GuidelineStatus
PFOS22.0 ppt4 ppt4 pptAbove comparison value
PFHxS13.0 ppt10 ppt10 pptAbove comparison value
PFPeA8.0 pptNo standardNo federal MCL shown
PFBS6.6 ppt2000 ppt100 pptBelow comparison value
PFHxA6.3 pptNo standard400 pptNo federal MCL shown
PFOA5.8 ppt4 ppt4 pptAbove comparison value
PFHpA4.2 pptNo standardNo federal MCL shown

Violation History (Last 5 Years)

20Total (5yr)
1Health-Based
17Major

Water Quality Summary

Understanding Your Water in Dillon

Tap water quality in Dillon, Colorado (80435) receives an overall grade of B (Moderate-low record-based concern) with a score of 70 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is roughly in line with the Colorado state average of 68. The area is served by 6 water systems providing water to approximately 9,900 people, using groundwater and surface water sources. Notably, 3 PFAS compounds exceed the EPA final MCL value used for comparison — a significant concern given the persistent nature of these chemicals. Over the past 5 years, water systems here have accumulated 20 violations, including 1 health-based violations.

Your Score 70/100 B
vs State 2 pts above Colorado avg (68)
vs National 5 pts below national avg (75)

What a Grade B Means

A score of 70/100 means Dillon, CO performs well in the US Water Score model, with only minor system-level concerns. Residents should still review their utility's Consumer Confidence Report for official compliance information and household-specific context.

Groundwater: drawn from underground aquifers via wells
Surface water: sourced from rivers, lakes, or reservoirs

Health Information

What These Contaminants Mean for You

⚠️

Lead in Your Water

Lead is a toxic metal that can leach from aging pipes and plumbing fixtures.

Health Effects

Even low levels of lead exposure can cause developmental delays in children, kidney damage, and cardiovascular effects in adults. The EPA action level is 15 ppb, but health experts recommend no safe level of lead in drinking water.

Common Sources

Lead enters water primarily through corrosion of lead service lines, lead solder, and brass fixtures — especially in homes built before 1986.

What You Can Do

If lead is detected above 1 ppb, consider using a certified lead-removal filter (NSF/ANSI 53) for drinking and cooking water. Run cold water for 30 seconds before use if water has been sitting in pipes.

🔶

Copper in Your Water

Copper can leach into water from copper plumbing, especially in newer homes or when water is acidic.

Health Effects

Short-term exposure above 1,300 ppb can cause gastrointestinal distress. Long-term exposure may cause liver or kidney damage. People with Wilson's disease are especially vulnerable.

Common Sources

Copper pipes, fittings, and faucets are the most common source. Corrosive (low-pH) water accelerates copper leaching.

What You Can Do

If copper levels are elevated, flush pipes by running water for 15–30 seconds before use. Reverse osmosis and distillation systems effectively remove copper.

Common Questions

Frequently Asked Questions

Based on public water-system records, Dillon, Colorado receives an internal US Water Score grade of B (Moderate-low record-based concern) with a score of 70/100. This indicates relatively few system-level concerns in our model, but it is not an EPA safety rating and does not guarantee tap conditions inside individual homes.

ZIP code 80435 is served by 6 water systems using groundwater, surface water sources, providing water to approximately 9,900 people. Multiple source types mean your water may come from a blend of surface and underground sources.

Lead levels in the public-system record for Dillon, Colorado are 32.0 ppb, above the currently applicable EPA action level of 15 ppb. EPA's Lead and Copper Rule Improvements lower that action level to 10 ppb when the new requirements take effect. This system-level result does not measure an individual tap; consider a certified lead-removal filter and independent tap testing.

Yes — 7 PFAS compounds were detected in records associated with water serving Dillon, Colorado, and 3 results exceeded the numerical EPA MCL value used for comparison. UCMR5 occurrence results alone are not a regulatory compliance determination. PFAS rules and compliance timelines are evolving; verify current information with the utility and EPA.

Water systems serving Dillon, Colorado have received 20 violations in the last 5 years, including 1 health-based violation. Violations can range from paperwork issues (monitoring & reporting) to serious health-based violations where contaminant levels exceeded safe limits. Review the violation details above for specifics.

Based on detected contaminants (lead, PFAS, copper), residents in Dillon, Colorado should consider: Reverse osmosis (RO) system — most effective for PFAS, lead, and other contaminants. Always look for filters with NSF/ANSI certification for the specific contaminants you want to remove.

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