States › Colorado › Douglas County

Douglas County, CO Water Quality

Water quality data for 16 public water systems serving Douglas County, Colorado — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 16 water systems · 21 cities
✅
Generally Safe — Most Systems Performing Well

The majority of water systems have no active violations and lead levels well below the federal action level.

B

Douglas County Earns a B

Douglas County: 21 communities across 16 water systems. 100.0% have no open violations.

  • Median lead where detected: 2.00 ppb
  • 13 communities with a lead detection, 8 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 14 with significant inspection deficiencies
  • 100.0% of communities have no open violations
2 ppb
Median Lead Level
County-wide, 90th percentile
16
Water Systems
Active CWS & NTNCWS
100%
Violation-Free
No active violations on record
How we grade counties: MyWaterIQ uses EPA SDWIS enforcement data — actual MCL violations and lead test results — not the aspirational MCLG targets used by some sites. A grade reflects real compliance history, not theoretical risk. Learn more →

Cities by Water Quality

⭐ Best Performing
⚠ Needs Attention
  • Westcreek
    2.10 ppb
    Copper above the 1,300 ppb action level
    C
  • Parker
    2.00 ppb
    Copper above the 1,300 ppb action level
    C
  • Sierra Ridge
    2.00 ppb
    Copper above the 1,300 ppb action level
    C
  • The Pinery
    Not detected
    Copper above the 1,300 ppb action level
    C
  • Highlands Ranch
    2.00 ppb
    3 significant inspection deficiencies
    B
County Lead Level — Median 2 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 2 ppb — 13.3% of the federal action level
Systems by Lead Level
Under 5 ppb
10
5 – 10 ppb
3
No Data
8

All Cities in Douglas County

Highlands Ranch 2.00 ppb B
Castle Rock 2.00 ppb B
Parker 2.00 ppb C
Lone Tree 9.00 ppb B
The Pinery Not detected C
Castle Pines Not detected B
Roxborough Park 5.00 ppb B
Stonegate 2.00 ppb A
Meridian Not detected A
Castle Pines Village 2.00 ppb A
Sierra Ridge 2.00 ppb C
Meridian Village Not detected A
Acres Green 9.00 ppb B
Stepping Stone Not detected A
Perry Park 1.00 ppb A
Sterling Ranch Not detected B
Louviers Not detected B
Larkspur 1.00 ppb B
Sedalia Not detected B
Westcreek 2.10 ppb C
Grand View Estates 2.00 ppb A
Showing 21 cities
No active violations Active violations

About Douglas County Drinking Water

Douglas County is served by 16 water systems covering 21 communities. No community here has an open violation on record.

Of the communities reporting lead results, 13 recorded a detection, with a median of 2.00 ppb — 13% of the federal action level. 8 reported none detected, which means below the laboratory limit rather than an absence of lead.

No community here has PFAS above the federal limit on record. State inspectors recorded significant deficiencies at 14 of them.

Frequently Asked Questions

Is Douglas County tap water safe to drink?▼
No community in Douglas County has an open violation on record. No community has PFAS above the federal limit on record.
What is the lead level in Douglas County?▼
Among communities with a detection the median is 2.00 ppb, 13% of the 15 ppb action level. 8 reported none detected and 0 reported no result.
How many water systems serve Douglas County?▼
16 community water systems serve 21 communities here.
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