COUNTY REPORT CO

Jefferson County, Colorado

34 ZIP codes · Avg score 62/100 · Grade C · Updated

ZipCheckup grade for Jefferson County: C.

A mixed picture - some signals here are worth your attention.

While Jefferson County avoids the worst tiers, a portion of its 34 ZIP codes have logged violations.

How Jefferson County Compares

Jefferson County62/100
Colorado avg59/100
National avg73/100

How Jefferson County Compares

C
County Grade
62/100
Avg Safety Score
34
ZIP Codes
36
Water Systems

Jefferson County scores 3 points above the Colorado state average (59/100) and 11 points below the national average (73/100).

Data: ZipCheckup Home Safety Score model 4.0.0; EPA SDWIS, UCMR 5, EPA radon zones, EPA AirData Last verified:

C
County Grade
62
Avg Safety Score
34
ZIP Codes
Best ZIP: 80128 (67/100)
Lowest ZIP: 80465 (50/100)
$580K
Median Home Value
$2,326
Avg Remediation (40% of home value)

ZIP Code Risk Map

Water Quality Map: Jefferson County, Colorado

Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.

A B C D F

Key Risk Factors

Health risk index: 10.1 (asthma 11.2%, diabetes 8.3%)

Estimated additional annual cost per homeowner: $1,572, driven primarily by flood

61.9% of homes built before 1978 (lead paint era)

Violation History (2021–2024)

↑ Worsening trend

EPA violation counts by year across Jefferson County water systems. Health-based shown in red, total in blue.

2021
9 (9 health)
2022
16 (16 health)
2023
27 (27 health)
2024
18 (18 health)

Peak year: 2023 with 27 violations. Past 5 years: 70 total (70 health-based). Health-based violations are rising versus the prior 2-year window - worth closer monitoring.

Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.

County Health Indicators vs National Average

Asthma 11.2% (national: 8.9%)
Diabetes 8.3% (national: 10.5%)
Obesity 23.1% (national: 32.4%)

Black markers indicate national averages. Source: CDC PLACES, Census ACS.

Infrastructure Overview

1978
Median Build Year
61.9%
Pre-1978 Housing
42/100
Infrastructure Stress Indicator
58%
ZIPs with High Infrastructure Stress
Low
Lead Pipe Risk

Modeled area-level indicator, not a failure probability. Sources: Census ACS housing age, EPA DWINS infrastructure needs, EPA SDWIS violations, and EPA lead indicators.

Compound Risk Breakdown

Estimated additional annual cost per homeowner: $1,572

Flood $754/yr
Energy Code Gap $426/yr
Wildfire $300/yr

Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).

Housing Age Distribution

252,605 housing units in Jefferson County

Pre-1940 3%
1940–1959 11%
1960–1979 38%
1980–1999 29%
2000+ 19%

Source: U.S. Census Bureau ACS B25034 (Year Structure Built).

Water Safety Affordability

How much it costs to fix water issues relative to home values in Jefferson County

$580K
Median Home Value
$2,326
Est. Remediation Cost
0.4%
of Home Value
Remediation as % of home value low burden

Remediation costs are relatively manageable for most homeowners in Jefferson County, representing a small fraction of property value.

Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.

Health Outcomes vs National Average

CDC PLACES data for Jefferson County residents

Asthma 11.2% (US avg: 8.9%)
Diabetes 8.3% (US avg: 11%)
Obesity 23.1% (US avg: 32.4%)

Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.

Water systems serving Jefferson County

8 community water systems serving Jefferson County.

Show all 8 water systems

36 total water systems serve Jefferson County.

Systems with the most violations in Jefferson County

5 water systems with recorded EPA violations.

All ZIP Codes in Jefferson County

34 ZIP codes tracked in Jefferson County.

# ZIP Code City Safety Score Grade Violations Home Value
1 80128 Littleton 67 C 0 $554K
2 80215 Denver 67 C 0 $616K
3 80419 Golden 67 C 0
4 80214 Denver 66 C 34 $520K
5 80235 Denver 66 C 34 $544K
6 80002 Arvada 65 C 6 $539K
7 80004 Arvada 65 C 6 $591K
8 80033 Wheat Ridge 65 C 4 $569K
9 80226 Denver 65 C 35 $547K
10 80227 Denver 65 C 35 $535K
11 80228 Denver 65 C 4 (1 health) $607K
12 80232 Denver 65 C 35 $487K
13 80403 Golden 65 C 6 $797K
14 80003 Arvada 64 C 7 $487K
15 80005 Arvada 64 C 7 $620K
16 80007 Arvada 64 C 9 $818K
17 80021 Broomfield 63 C 9 (1 health) $530K
18 80127 Littleton 53 D 33 (11 health) $664K
19 80401 Golden 50 D 49 (12 health) $749K
20 80439 Evergreen 50 D 113 (25 health) $838K
21 80465 Morrison 50 D 55 (12 health) $629K
22 80001 Arvada
23 80006 Arvada
24 80034 Wheat Ridge
25 80162 Littleton
26 80225 Denver
27 80402 Golden
28 80425 Buffalo Creek $509K
29 80433 Conifer 37 (14 health) $698K
30 80437 Evergreen
31 80453 Idledale $450K
32 80454 Indian Hills 18 $757K
33 80457 Kittredge $386K
34 80470 Pine 6 (3 health) $631K

Recommended Buyer Guides for Jefferson County

Filtered against federal data, fitted to local risks.

Overview

Jefferson County in Colorado covers 34 tracked ZIP records with an average Home Safety Score of C (62/100) across 21 scored records.

21 of 24 ZIP codes with a reported violation count in the available EPA record have recorded EPA violations. 30 health-based violations appear in the available health breakdown.

← Back to Colorado Home Safety Profile

Data Sources

Reporting periods vary by source. Missing data is shown as unavailable, not as zero.

Frequently Asked Questions

Is water safe in Jefferson County?
Jefferson County receives a grade of C. Some ZIP codes have recorded violations and residents in affected areas may want to test their water.
How many water systems serve Jefferson County?
Jefferson County is served by 36 public water systems that supply drinking water to residents across 34 ZIP codes.
What is the biggest environmental risk in Jefferson County?
The primary environmental risk factor in Jefferson County is flood. This contributes to an estimated additional annual cost of $1,572 per homeowner.
How old are homes in Jefferson County?
The median home build year in Jefferson County is 1978. 61.9% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does Jefferson County compare to Colorado?
Jefferson County has an average Home Safety Score of 62/100 under model 4.0.0, which is above the Colorado state average of 59/100.

How to cite this page

APA ZipCheckup. (2026). Jefferson County, CO: HSS 62/100; PFAS Found in Water. https://zipcheckup.com/county/colorado/jefferson/
BibTeX
@misc{zipcheckup-county-colorado-jefferson,
  author = {{ZipCheckup}},
  title  = {{Jefferson County, CO: HSS 62/100; PFAS Found in Water}},
  year   = {2026},
  url    = {https://zipcheckup.com/county/colorado/jefferson/}
}

Page version: August 2026.

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