Is Four Square Mile, CO tap water safe?
The short answer
None of the 3 utilities serving Four Square Mile has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and Colorado’s records.
Denver Water Board, which serves the most people here, has 3 results above the health goal. The worst: Lead at 3.6 ppb, above the health goal. Health goals are stricter than legal limits and are not enforced.
The water from Denver Water Board is moderately hard on average, 105 mg/L (6.1 grains per gallon), ranging from 55 to 124 mg/L. How Colorado’s water compares.
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 Four Square Mile’s ZIP codes, from EPA’s estimates.
- Open report
Denver Water Board
Colorado · serves 1.3 million people · about 11,400 in Four Square Mile
3 results above the health goal. The worst: Lead at 3.6 ppb, above the health goal. Hardness: moderately hard on average, 105 mg/L (6.1 grains per gallon), ranging from 55 to 124 mg/L.
No health-based violations since 2016
- Open report
Cherry Creek Valley WSD
Colorado · serves 22,000 people · about 7,700 in Four Square Mile
1 result above the health goal. The worst: Lead at 9.0 ppb, above the health goal.
No health-based violations since 2016
- Open report
City of Aurora
Colorado · serves 533,407 people · about 1,900 in Four Square Mile
3 results above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 21.4 ppb, above EPA’s health benchmark. Hardness: hard on average, 136 mg/L (8 grains per gallon), ranging from 87 to 198 mg/L.
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 Denver Water Board’s water, which serves the most people here. Another utility’s report names what handles its own results.
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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: Lead, Arsenic
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: Lead, Arsenic
Water testing near Four Square Mile
The 3 labs Colorado certifies closest to Four Square Mile, 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 2 miles
Certified for bacteria
SGS North America, Inc. - Denver
Denver, CO · about 8 miles
Certified for nitrate, lead and copper, metals, minerals and other inorganics
SGS North America, Inc. - Wheat Ridge
Wheat Ridge, CO · about 13 miles
Certified for nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, radioactivity
Which ZIP codes are in Four Square Mile: 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 Four Square Mile
Other towns in Arapahoe County with a page of their own.
What to do next
- Read Denver Water Board’s full reportEvery result with its dates, the violations, and the certification claim that handles each finding.Open the report
- Filters for LeadRanked by certification and what they cost over five years.The best water filters for lead, ranked
- On a private well?No utility tests a well. A certified lab test is the first step.How to test well water