Southglenn Water Hardness & Quality Report (2026)
Water Hardness
~120–179 mg/L
Hardestimated · not lab-verified
Source
reservoir
pH Level
7.7
neutral = 7.0
Lead
0.004 mg/L
✓ Below action level
TDS
202.2 mg/L
Est. Daily Cost
$0.40
energy & soap waste
Source: See methodology section below · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Southglenn, your appliances are currently losing 20% efficiency due to mineral buildup.
| Appliance | In Southglenn | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 6.8 yrs | 8.5 yrs | -20% |
| Washing Machine | 9.6 yrs | 12 yrs | -20% |
| Water Heater | 12 yrs | 15 yrs | -20% |
Regional Water Comparison
How Southglenn compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Southglenn, Colorado | ≈ 120–179 mg/L | 3.6 ppt | 🟠 Hard | reservoir |
| Greenwood Village, Colorado | ≈ 120–179 mg/L | 3.1 ppt | 🟠 Hard | reservoir |
| Highlands Ranch, Colorado | ≈ 120–179 mg/L | 49.6 ppt | 🟠 Hard | reservoir |
| Castlewood, Colorado | ≈ 60–120 mg/L | 3.4 ppt | 🟡 Moderately Hard | reservoir |
| Littleton, Colorado | ≈ 120–179 mg/L | 3.1 ppt | 🟠 Hard | reservoir |
National Benchmark
How Southglenn compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Southglenn | ≈ 120–179 mg/L | 🟠 Moderate |
| USA National Avg | 151 mg/L | 🟠 Moderate |
| Scarsdale Top Rated | 0.02 mg/L | 🟢 None |
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What Makes Southglenn's Water Unique?
Local geology and source profile
Southglenn, Colorado, is primarily served by the Highlands Ranch Metropolitan District (HRMD) and Denver Water through interlocal agreements, with additional supply from the Centennial Water and Sanitation District. Key sources include the South Platte River, treated at facilities including the Marston Treatment Plant and Northwater Treatment Plant operated by Denver Water. Groundwater is also drawn from confined alluvial aquifers in Douglas County via wells. The service area covers the Southglenn community in Arapahoe and Douglas Counties, south of Denver.
The watershed encompasses the South Platte River basin, originating in the Rocky Mountains and flowing through mineral-rich Front Range geology. Aquifers in the Denver Basin, such as the Arapahoe Formation (Cretaceous sandstone), overlie Laramie-Fox Hills units, leaching calcium and magnesium into the groundwater. This geology imparts a hard character to both surface and groundwater supplies, with seasonal variations from snowmelt dilution to higher mineralization during winter baseflow when aquifer contributions dominate.
Hard water in Southglenn leads to scale buildup in hot water heaters, dishwashers, washing machines, and pipes, reducing efficiency and lifespan. White deposits on fixtures and glassware are common, and additional detergent is required for effective cleaning. Regular maintenance such as deliming appliances every one to two years and installing drain screens is recommended. A water softener is advised for households to prevent scale and extend appliance life. Water quality meets EPA standards; pH is typically 7.5–8.5; treatment at Denver Water plants involves filtration, chlorination, and fluoridation.
Geology & Source: South Platte River watershed and Denver Basin alluvial aquifers; Cretaceous Arapahoe Formation sandstone and Laramie-Fox Hills units; calcium and magnesium leaching from mineralized Front Range geology yields hard supply
Other Colorado Water Reports
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Frequently Asked Questions
Is Southglenn's water safe to drink?
Do I need a water softener in Southglenn?
How does Southglenn compare to the USA average?
Data Sources & Methodology
Water quality data for Southglenn is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.
Water Hardness
Modelled estimate based on state-level USGS geological survey data for this region. No direct USGS Water Quality Portal measurement was matched to this city — the value reflects a statistical range calibrated to the state's dominant rock types and typical source water characteristics.
pH
Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.
TDS — Total Dissolved Solids
Estimated using a derived ratio from water hardness and regional conductance profiles. TDS in natural water correlates strongly with total mineral content including hardness ions.
PFAS — Perfluoroalkyl and Polyfluoroalkyl Substances
EPA UCMR5 (5th Unregulated Contaminant Monitoring Rule, 2023–2025) — sum of PFAS compounds detected at the public water system serving this city. A value of 0 indicates the system was sampled with no detection above reporting limits.
Lead
Modelled estimate based on the EPA Lead and Copper Rule 90th-percentile tap-sample methodology. No publicly available per-city lead dataset with sufficient national coverage exists. Values are a conservative baseline derived from city population tier and infrastructure age — all estimates are maintained below the EPA action level of 0.015 mg/L.
Appliance Lifespan
Calculated from water hardness using a linear degradation model. Baseline lifespans represent soft-water performance (kettle: 8.5 yrs, washing machine: 12.0 yrs, water heater: 15.0 yrs). Hard water mineral scale progressively reduces operational life in direct proportion to hardness concentration.