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Counties → Colorado

Jefferson County, Colorado

SDWIS compliance plate

Sheet CO059 · Jefferson County 113 sys · 5,182 viol · #122/3254

VIOL-SEVERE · HEALTH-LOW · RANK-TOP · PHOTO-FINISH · PFAS-MID · SRC-GW · SYS-MID · BOOK-FULL

  • VIOL-SEVERE 85.0% flagged
  • HEALTH-LOW 19.9% health
  • RANK-TOP #122/3254
  • PHOTO-FINISH ±0.3 pp
  • PFAS-MID 25.0% detect
  • SRC-GW GW lead 58%
  • SYS-MID 113 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Montrose County ( -0.3 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Jefferson County ranks #122 of 3,254 counties by people served, and #5 of 64 counties in Colorado. See methodology · corpus placement.

Jefferson County standing, lower-flagged corpus third

Flagged-system rate 85.0% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 19.9% is health-based share in the middle third (≤ 24.5%) . UCMR5 detect rate 25.0% is UCMR5 detect rate in the tested-pool middle third (≤ 33.3%) . Population served ranks #122 of 3,254 · #5 of 64 in Colorado.

Flagged-rate neighbourhood around Jefferson County

Lowest/highest poles plus in-state counties nearest Jefferson County on % of SDWIS systems with ≥1 violation. Full ladder: /counties.

0% 20% 40% 60% 80% 100% Broomfield · lowest Montrose · near Adams · near Kiowa · highest 66.7% 83.1% 84.6% 85% 86% 87.5% 100%

Source: EPA SDWIS (county aggregates) As of 2026-05-15

Water Systems

System Name Population Violations PFAS
Arvada City Of 171,610 18 Clean
Consolidated Mutual Maple Grove 81,400 18 Detected
Green Mountain WSD 49,400 6 -
Bancroft Clover WSD 44,000 0 -
Golden City Of 38,288 0 Clean
Bear Creek WSD 30,000 0 -
Wheat Ridge Water District 20,000 4 -
Evergreen MD 15,750 36 Clean
Ken Caryl WSD 12,000 0 -
Lakehurst WSD 12,000 0 -
Valley WD 10,000 0 -
North Table Mountain WSD 10,000 10 Clean
Morrison Town Of 9,887 276 Detected
Willowbrook WSD 9,348 0 -
Lakewood City Of 6,000 0 -
Edgewater City Of 5,300 13 -
High View WD 4,000 0 -
Genesee WSD 3,920 180 Clean
Meadowbrook WD 3,290 1 -
Molson Coors Beverage Company 2,725 23 -
South Sheridan Water and Sewer Dist 2,500 5 -
Alameda WSD 2,480 0 -
Conifer High School 2,350 48 -
Mountain WSD 1,941 221 -
Aspen Park MD 1,800 124 -
Ralston Valley WSD 1,610 2 -
Indian Hills WD 1,300 108 -
Bear Creek Lake Park 1,250 51 -
Tiny Town Historical Park 1,210 16 -
Staunton State Park 1,079 3 -
North Lincoln WSD 1,000 6 -
Homestead WC 1,000 244 -
Alta Convenience No 6152 1,000 19 -
Brook Forest WD 998 17 -
Marshdale Elem School 920 0 -
Golden Terrace West 825 22 Clean
Friends of Dinosaur Ridge 770 16 -
Mt Vernon Country Club 734 266 -
Elk Creek Elem School 600 37 -
Golden Terrace Village 580 22 -
Conifer WA 550 14 -
Conifer MD 525 518 -
Geneva Glen Camp 513 28 -
Granite Lake 506 16 -
Sheridan MHP 480 63 -
Mountainside Estates MHP 473 31 -
Golden Terrace South 425 25 -
Ramah in the Rockies 405 32 -
Forest Hills MD Riva Chase 400 190 -
Mother Cabrini Shrine 389 8 -

Compare beyond Colorado

Lower-flagged peers for Jefferson County

Cross-state counties nearest Jefferson County on flagged-system share (85.0%) and cumulative violation count (5,182). In-state neighbours stay on the compliance plate above.

Similar flagged-system rate

Nearest cross-state counties by % of SDWIS systems with at least one violation on record.

4 peers

Similar violation load

Nearest cross-state counties by cumulative SDWIS violation count (all systems in the county).

4 peers

Read our methodology · Check your water system - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This page draws directly on EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.