Is Highlands Ranch, CO tap water safe?
The short answer
Neither of the 2 utilities serving Highlands Ranch has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and Colorado’s records.
Highlands Ranch WSD, which serves the most people here, has 3 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 35.2 ppb, above EPA’s health benchmark. Health goals are stricter than legal limits and are not enforced.
A town can be served by more than one utility, and some homes are on private wells. The name on your water bill tells you which is yours, and your ZIP code narrows it down. They are listed by how many people each serves in Highlands Ranch’s ZIP codes, from EPA’s estimates.
- Open report
Highlands Ranch WSD
Colorado · serves 103,444 people · about 90,700 in Highlands Ranch
3 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 35.2 ppb, above EPA’s health benchmark.
No health-based violations since 2016
- Open report
Northern Douglas County WSD
Colorado · serves 6,160 people · about 1,000 in Highlands Ranch
1 result above EPA’s health benchmark. The worst: Lithium at 32 ppb, above EPA’s health benchmark.
No health-based violations since 2016
What handles it
Each of these is certified, on a certifier’s listing, for a result above a line in Highlands Ranch WSD’s water, which serves the most people here. Another utility’s report names what handles its own results.
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Countertop reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 4, 2026
Certified for: Arsenic, Lead
Aquasana SmartFlow Reverse Osmosis (AQ-SFRO2)
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Arsenic, Lead
Brondell Capella RC250 Reverse Osmosis System
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Arsenic, Lead
Water testing near Highlands Ranch
The 3 labs Colorado certifies closest to Highlands Ranch, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Colorado Department of Health & Environment
Denver, CO · about 13 miles
Certified for bacteria
SGS North America, Inc. - Wheat Ridge
Wheat Ridge, CO · about 18 miles
Certified for nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, radioactivity
SGS North America, Inc. - Denver
Denver, CO · about 18 miles
Certified for nitrate, lead and copper, metals, minerals and other inorganics
Which ZIP codes are in Highlands Ranch: Census 2020 relationship files. Which utilities serve them, and how many people: EPA SDWIS and EPA’s service area map. Each utility’s results: EPA UCMR 5, EPA SDWIS, and EPA’s and the state’s compliance monitoring, as its report lists them. How they are measured: methodology. Certified labs: CDPHE certified drinking water laboratories; distances from the Census 2020 ZIP code tabulation area gazetteer.
Near Highlands Ranch
Other towns in Douglas County with a page of their own.
What to do next
- Read Highlands Ranch WSD’s full reportEvery result with its dates, the violations, and the certification claim that handles each finding.Open the report
- About LithiumWhat it does to health, where it comes from, and the certification claim that addresses it.About Lithium
- On a private well?No utility tests a well. A certified lab test is the first step.How to test well water