Colorado Water Quality Ratings

TapWaterSafety has rated 27 public water systems in Colorado, serving a combined 6,183,574 residents. The statewide average grade is D.

Data sources: EPA SDWIS EPA ECHO EWG Tap Water Database Utility CCRs ⓘ How did we get these ratings?
State average grade
D
63/100
Total utilities rated 27
Population served 6,183,574
Most recent test 2024

Top water quality concerns in Colorado

  • Haloacetic acids (HAA9) significantly above health guideline
  • Total trihalomethanes (TTHMs) significantly above health guideline
  • Haloacetic acids (HAA5) significantly above health guideline
  • PFAS contamination
  • Perfluorohexane sulfonate (PFHXS) significantly above health guideline

Grade distribution

A
0 (0%)
B
2 (7%)
C
15 (56%)
D
6 (22%)
F
4 (15%)

All rated utilities in Colorado

Sorted by score, highest first. Click any utility to see the full grade card.

Rank Utility City Population Score Grade
#1 PUEBLO BOARD OF WW PUEBLO 114,070 81 B
#2 Colorado Springs Water Utilities Colorado Springs 478,000 78 B
#3 Aurora Water Utilities Aurora 374,000 69 C
#4 WESTMINSTER CITY OF WESTMINSTER 202,078 67 C
#5 SOUTHGATE WSD CENTENNIAL 55,000 67 C
#6 BOULDER CITY OF BOULDER 166,080 67 C
#7 BROOMFIELD CITY AND COUNTY OF BROOMFIELD 106,153 67 C
#8 LONGMONT CITY OF LONGMONT 102,866 67 C
#9 DENVER WATER BOARD DENVER 1,287,000 67 C
#10 CASTLE ROCK TOWN OF CASTLE ROCK 106,822 67 C
#11 COLORADO SPRINGS UTILITIES COLORADO SPRINGS 464,111 67 C
#12 ARVADA CITY OF ARVADA 171,610 67 C
#13 FT COLLINS LOVELAND WD FORT COLLINS 63,532 67 C
#14 LOVELAND CITY OF LOVELAND 95,471 67 C
#15 UTE WCD GRAND JUNCTION 92,580 67 C
#16 Denver Municipal Water System Denver 716,000 66 C
#17 GREELEY CITY OF GREELEY 132,310 65 C
#18 SOUTH ADAMS COUNTY WSD COMMERCE CITY 75,559 62 D
#19 HIGHLANDS RANCH WSD HIGHLANDS RANCH 103,444 62 D
#20 FT COLLINS CITY OF FORT COLLINS 179,901 61 D
#21 AURORA CITY OF AURORA 533,407 55 D
#22 PARKER WSD PARKER 75,949 55 D
#23 CONSOLIDATED MUTUAL MAPLE GROVE LAKEWOOD 81,400 55 D
#24 ENGLEWOOD CITY OF ENGLEWOOD 57,332 50 F
#25 BRIGHTON CITY OF BRIGHTON 56,304 48 F
#26 THORNTON CITY OF THORNTON 226,465 47 F
#27 EAST CHERRY CREEK VALLEY WSD AURORA 66,130 47 F