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Review government records associated with Lone Tree, Colorado.
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Check your water bill for your utility name and confirm the reporting year. See EPA’s guide to finding your annual water quality report.
Public water-system records for Lone Tree, CO from EPA SDWIS.
Castle Rock Town of
Active monitoring or reporting issue detected in EPA SDWIS.
Reviewed: active/open records as of Q1 2026
City-area ZIP code · Serves 106,822 people
Englewood City of
Active monitoring or reporting issue detected in EPA SDWIS.
Reviewed: active/open records as of Q1 2026
City-area ZIP code · Serves 57,332 people
Aurora City of
PFAS detected below the official threshold used by this report.
Reviewed: active/open records as of Q1 2026
City-area ZIP code · Serves 533,407 people
Data from EPA SDWIS
PFAS screening separates EPA UCMR5 drinking-water monitoring from nearby DoD PFAS investigation-site records; EPA samples shown are from Apr 2023 to Apr 2025.
Drinking Water PFAS Monitoring
EPA UCMR5 samples public water systems. These results are separate from nearby PFAS cleanup or investigation-site records.
PFAS detections below EPA limits.
Nearby PFAS Investigation Sites
DoD records are nearby site investigations, not Lone Tree drinking-water detections. Record names come from the source database and can be broad.
No DoD PFAS investigation records shown for this report.
No health-relevant impairment records shown among the assessment records in this report.
Reviewed: source records as of 2026
NPDES permits regulate pollutant discharges into U.S. waterways. Facilities must report compliance quarterly.
Violation records
Last inspected: Dec 2025
Data from EPA ECHO
To investigate water contamination, check the sampling locations, dates and results below. For tap water records, see Drinking water quality above.
Reviewed: source records as of 2026
Review historical EPA air pollution records, including monitoring and facility emissions where available. For current conditions, check local air quality on AirNow.
Douglas County
Assessment year: 2020
According to EPA, a cancer risk of 20-in-1-million means that for every 1 million people continuously exposed to these air toxics over a 70-year lifetime, an estimated 20 may develop cancer from that exposure. This is in addition to cancer risk from all other causes.
Top modeled source groups
Data from EPA AirToxScreen
EPA designates an area as nonattainment when air quality does not meet federal health-based standards (NAAQS) for a specific pollutant.
Denver Metro/North Front Range: Ozone
NonattainmentSerious8-Hour Ozone (2015 Standard)
Health effects (EPA): Respiratory inflammation, aggravation of asthma, reduced lung function (EPA)
Denver-Boulder-Greeley-Ft. Collins-Loveland: Ozone
NonattainmentSevere 158-Hour Ozone (2008 Standard)
Original designation: Jul 2012
Health effects (EPA): Respiratory inflammation, aggravation of asthma, reduced lung function (EPA)
Maintenance areas
Previously nonattainment; currently meeting the standard and monitored under an EPA maintenance plan.
Adams, Denver, and Boulder Counties; Denver Metropolitan Area
PM10 · PM-10 (1987 Standard)
Classification: Moderate
Original designation: Nov 1990
Data from EPA Green Book
EPA annual monitor summaries describe past measurements. For current air quality, see AirNow.
Arapahoe Community College — Littleton, Colorado
Annual mean: 4.8 Micrograms/cubic meter (LC)
Observation year: 2025
Aurora East
Annual mean: 0.050 Parts per million
EPA primary exceedance count: 2 (Ozone 8-hour 2015)
Observation year: 2025
Birch Street — Commerce City, Colorado
Annual mean: 35.3 Micrograms/cubic meter (25 C)
Observation year: 2025
Data from EPA AQS
Reviewed: source records as of Q4 2025
Reviewed: source query run Nov 2026
Reviewed: source query run Nov 2026
Facilities with hazardous-waste handler records under RCRA in the reviewed 5-mile city-center search area. Active handler status is separate from air, water, or other ECHO compliance violations, which are shown in their own sections.
Active RCRA handler records in the reviewed city search area
No release reports shown in this group.
Reviewed: active/open records as of 2018
Data from EPA UST Finder
No MSHA mine or extraction site records shown for this report.
Douglas County, CO
EPA Radon Zone Map (June 2024 release)
Douglas County is EPA Radon Zone 1 (highest potential). EPA defines Zone 1 counties as having predicted average indoor screening levels above 4 pCi/L.
Radon levels can vary from home to home, so EPA recommends testing the property to know its indoor level.
FEMA flood zones describe mapped flood hazards. Look up a specific address with FEMA.
Minimal flood hazard — outside the 1% and 0.2% annual chance floodplains.
Results use an earlier stored RMP inventory. Current EPA ECHO location coverage is unverified.
EPA ECHO lists facilities linked to the Risk Management Program. Results include facilities with locations that can be matched. Records may be historical. Current operations, chemical inventories, and recent accident history are unverified.
Reviewed: 2000-present
Health outcomes from County Health Rankings. Values shown alongside state and national averages.
Douglas County, ColoradoPop. 375,988
County Health Rankings edition: 2024
Premature Death
Poor or Fair Health
Poor Physical Health Days
Poor Mental Health Days
Adult Smoking
Adult Obesity
Air Pollution - Particulate Matter
Drinking water violation indicator
Diabetes Prevalence
Life Expectancy
| Indicator | County | State | National |
|---|---|---|---|
| Premature Death | 3,973 | 6,994 | 7,972 |
| Poor or Fair Health | 8.7% | 12.8% | 14.2% |
| Poor Physical Health Days | 2.7 | 3.1 | 3.3 |
| Poor Mental Health Days | 4.1 | 4.8 | 4.8 |
| Adult Smoking | 8.9% | 12.1% | 15.0% |
| Adult Obesity | 23.0% | 25.1% | 34.0% |
| Air Pollution - Particulate Matter | 6.2 | 4.5 | 7.3 |
| Drinking water violation indicator | Yes | N/A | N/A |
| Diabetes Prevalence | 5.6% | 6.5% | 9.6% |
| Life Expectancy | 82.8 | 79.0 | 77.6 |
EPA testing found PFAS in water samples from the Town of Castle Rock. Results dated Aug 28, 2023 to Feb 21, 2024 include PFBA at 0.0051 micrograms per liter and PFPeA at 0.003 to 0.0047 micrograms per liter.
EPA testing found PFAS in water samples from the City of Englewood. Results dated Oct 7, 2024 to Apr 22, 2025 include PFBA at 0.0064 micrograms per liter and PFBS at 0.0035 to 0.0058 micrograms per liter.
EPA testing found PFAS in water samples from the City of Aurora. Results dated Apr 11, 2023 include PFBA at 0.0078 micrograms per liter and PFPeA at 0.0072 micrograms per liter.
Check with the utility that serves your address for its testing results.
EPA drinking water records on this page list 12 violations for the Town of Castle Rock.
EPA drinking water records on this page list 9 violations for the City of Englewood.
EPA drinking water records on this page list 2 violations for the City of Aurora.
Check your water bill to identify the utility serving your address. Ask that utility about current drinking water advisories.
Nearby EPA monitoring stations provide annual air quality measurements for Lone Tree.
The monitoring station at Arapahoe Community College, Littleton, Colorado recorded an annual average of 4.8 Micrograms/cubic meter (LC) for fine particles (PM2.5) in 2025.
The monitoring station at Aurora East recorded an annual average of 0.05 Parts per million for ozone in 2025.
The monitoring station at Birch Street, Commerce City, Colorado recorded an annual average of 35.3 Micrograms/cubic meter (25 C) for particles (PM10) in 2025.
Download 2025 EPA annual monitor dataCurrent air quality on AirNow
The radon data for Lone Tree covers Douglas County. EPA places this area in Zone 1, with a predicted average indoor radon screening level above 4 picocuries per liter.
No Superfund or brownfield sites were returned for this city report.
The county data for Lone Tree reports a life expectancy of 82.8 years in Douglas County, Colorado.
The figure is from the 2024 edition of County Health Rankings, a University of Wisconsin program that publishes county health statistics.
The county data for Lone Tree reports 3,973 years of life lost to deaths before age 75 per 100,000 residents in Douglas County, Colorado. This measure adds up the years lost to early deaths and adjusts for differences in population age.
The figure is from the 2024 edition of County Health Rankings, a University of Wisconsin program that publishes county health statistics.
The county data for Lone Tree lists fine-particle pollution (PM2.5) at 6.2 micrograms per cubic meter in Douglas County, Colorado.
The figure is from the 2024 edition of County Health Rankings, a University of Wisconsin program that publishes county health statistics.