Nitrate in Douglas, AZ Drinking Water
Nitrate data for Douglas, Arizona · 19,568 residents · 4 ZIP codes
Water quality records for Douglas, Arizona show Nitrate detections on file — a finding that places it among the contaminants worth tracking for this area.
Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-05-14
Nitrate in Douglas Tap Water
Nitrate has been detected in Douglas, Arizona drinking water at a maximum level of 5.6 ppb — below the EPA MCL of 10 mg/L (as nitrogen).
This analysis covers 19,568 residents across 4 ZIP codes in Douglas.
Douglas's overall water quality grade is B (75/100).
Is Nitrate in Douglas Water Safe?
Nitrate was detected in Douglas water but currently falls within EPA limits. However, some health organizations argue the EPA MCL may not be protective enough.
If you are concerned, a reverse osmosis or ion exchange filter can reduce nitrate levels further.
Nitrate Levels by ZIP Code
| ZIP Code | Nitrate Level | EPA Limit | Status |
|---|---|---|---|
| 85607 | 5.6 ppm | 10 mg/L (as nitrogen) | OK |
| 85608 | 5.6 ppm | 10 mg/L (as nitrogen) | OK |
| 85655 | 5.6 ppm | 10 mg/L (as nitrogen) | OK |
| 86555 | 5.6 ppm | 10 mg/L (as nitrogen) | OK |
Average nitrate level across Douglas: 5.6 ppb
Health Effects of Nitrate
- Methemoglobinemia ("blue baby syndrome") in infants under 6 months
- Increased risk of colorectal and bladder cancer (long-term)
- Thyroid disease from chronic exposure
- Possible reproductive effects
Health risk severity: High. Governed by the National Primary Drinking Water Regulations.
How Nitrate Gets Into Drinking Water
- Agricultural fertilizer runoff
- Animal feedlot operations and manure
- Septic system leachate
- Urban stormwater and wastewater discharge
What to Do About Nitrate in Douglas Water
- Reverse osmosis is the most effective method for nitrate removal
- Ion exchange systems designed for nitrate can also work
- Standard carbon filters do NOT remove nitrate
- Boiling water increases nitrate concentration — never boil for nitrate
Look for filters certified under NSF 53 / NSF 58 for nitrate removal.