TapWaterGuide
Worldwide water safety reference
Safe Iowa, United States · Last reviewed:

Is Tap Water Safe to Drink in Des Moines?

Yes, tap water in Des Moines is safe to drink. Des Moines Water Works runs one of the world's largest nitrate removal facilities to counter farm runoff in its river sources, and finished water has stayed within EPA limits — even through the record nitrate surge of 2025.

Hardness
Moderate after lime softening
pH
8.5–9.5 (elevated by lime softening)
TDS
300–500 mg/L
EPA Status
Compliant
Soft
Moderate
Hard
Very Hard

Water Source

Des Moines Water Works (now part of Central Iowa Water Works) draws from the Raccoon and Des Moines Rivers plus shallow alluvial wells and an infiltration gallery, treating water at the Fleur Drive plant and two satellite plants.

EPA Compliance Status

Meets all federal Safe Drinking Water Act standards; nitrate removal treatment is used seasonally to maintain compliance.

Notable Contaminants & Context

  • Nitrate from agricultural runoff is the defining challenge — spring surges in the Raccoon and Des Moines Rivers regularly approach the 10 mg/L federal limit, managed by the utility's world-scale nitrate removal facility built in the 1990s
  • In summer 2025, record river nitrate forced central Iowa's first-ever lawn watering ban to keep treatment capacity ahead of demand; drinking water remained compliant throughout
  • Disinfection byproducts and seasonal algae taste/odor from river sources are monitored and managed

Water Quality Data

Key contaminants detected vs. regulatory limits. All values from the most recent published report — Source: Des Moines Water Works 2024 CCR.

Contaminant Detected Limit Status
Chlorine (total) 2.1 mg/L 4.0 mg/L
Fluoride 0.7 mg/L 4.0 mg/L
Lead (90th percentile) 3.4 µg/L 15.0 µg/L
Nitrate (as N) 4.2 mg/L 10.0 mg/L
TTHM (Total Trihalomethanes) 44.6 µg/L 80.0 µg/L
HAA5 (Haloacetic Acids) 33.2 µg/L 60.0 µg/L

✓ = below limit   ⚠ = above health goal   ✗ = exceeds guideline

How It Compares

Des Moines has been the national test case for farm-state drinking water: the utility even sued upstream drainage districts in 2015 over nitrate pollution. Treatment has kept tap water compliant, but at real and rising cost passed to ratepayers.

Tips

  • Tap water is safe for adults year-round; if you're mixing infant formula during a publicized nitrate peak, follow any utility guidance issued at the time
  • Reverse osmosis removes nitrate at home; standard carbon pitchers do not
  • Watch for seasonal conservation requests like the 2025 watering ban — they protect treatment capacity

Frequently Asked Questions

Sources & References

The safety rating and guidance on this page draw on the following sources. See our full methodology.