Thornton, CO water quality
Thornton, CO is served by 9 public water systems, serving 233,214 people combined. Across those systems, we count 3 health-based violations in the last 5 years. The worst Tap Grade among them is C.
Water systems serving Thornton
THORNTON CITY OF
THORNTON, CO · 226,465 served
WOODLAND HILLS MHC
THORNTON, CO · 1,740 served
REDWOOD ESTATES
LAKEWOOD, CO · 1,500 served
THE GROVE AT ALTA RIDGE
THORNTON, CO · 1,300 served
FRIENDLY VILLAGE OF THE ROCKIES
THORNTON, CO · 1,046 served
AVILLA EASTLAKE
GREENWOOD VILLAGE, CO · 410 served
CHAPARRAL VILLAGE MHP
CENTENNIAL, CO · 303 served
THORNTON ESTATES
LAKEWOOD, CO · 300 served
HIDEAWAY STEAKHOUSE
THORNTON, CO · 150 served
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Is Thornton, CO tap water safe to drink?
9 public water systems serve Thornton, CO, with 3 health-based violations in the last 5 years across them. The worst Tap Grade among them is C. A Tap Grade summarizes public EPA compliance records; it is not a determination that water is safe or unsafe to drink.
Does Thornton's water have lead in it?
The most recent 90th-percentile lead sample is 3 ppb, versus the EPA action level of 15 ppb.
Has PFAS been detected in Thornton's water?
Yes — at least one water system serving Thornton has detected PFAS under UCMR5.
Other cities in Colorado
See all of Colorado →Source: EPA SDWIS/ECHO · Data as of 2026Q2
TapGraded presents public EPA data for information only — it is not health advice and not a determination that any water is safe or unsafe to drink. For health concerns, contact your water utility or local health department.