COUNTY REPORT CO

Jefferson County, Colorado

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

ZipCheckup grade for Jefferson County: C.

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

For Jefferson County, the grade is neither top-tier nor bottom-tier; it summarizes data for 34 ZIP codes rather than measuring water at any home, and because it blends several sources, a middle result can come from very different mixes of strengths and weaknesses.

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

C
County Grade
62
Avg Safety Score
34
ZIP Codes
Best ZIP: 80128 (67/100)
Lowest ZIP: 80465 (50/100)
$580K
Median Home Value
$689
Avg Remediation (0.12% 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%)

Modeled additional annual cost estimate per homeowner: $1,289, largest modeled factor: Flood

52% of homes built before 1980 (lead paint was banned for residential use in 1978)

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
52%
Pre-1980 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 DWINSA infrastructure needs, EPA SDWIS violations, and EPA lead indicators.

Compound Risk Breakdown

Estimated additional annual cost per homeowner: $1,289

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
$689
Est. Remediation Cost
0.1%
of Home Value
Remediation as % of home value low burden

Modeled remediation costs in Jefferson County can be compared with the median property value; actual costs vary by property.

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 mapped to Jefferson County ZIP codes

8 community water systems mapped to Jefferson County ZIP codes; EPA may list more systems serving the county.

Show all 8 water systems

36 water systems mapped to Jefferson County ZIP codes in our data; EPA may list more systems serving the county.

Systems with the most violations in Jefferson County

5 water systems with violations in EPA records.

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

Which guides appear depends on what the county data show.

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?
We map 36 public water systems to 34 ZIP codes in our data for Jefferson County. EPA may list more systems serving the county, so this is not a full count.
What is the biggest environmental risk in Jefferson County?
In ZipCheckup's cost model, the factor with the largest estimated average annual cost in Jefferson County is flood. Across all modeled risk factors, the estimated average additional annual cost is $1,289 per homeowner; actual costs vary by home.
How old are homes in Jefferson County?
The median home build year in Jefferson County is 1978. 52% of homes were built before 1980; homes built before 1978 may contain lead-based paint, and older homes may have 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 at or 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: October 2026.

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