Water Quality in Des Moines, IA

Des Moines's water has very hard water (200 PPM) and elevated nitrates (8 mg/L). A water softener is recommended to protect plumbing and appliances. Read below for a full breakdown.

DMWW · Source: Des Moines + Raccoon Rivers · Serves 214,237 residents

200
Hardness (PPM)
310
TDS (PPM)
0.9
Chlorine (mg/L)
4
PFAS (ppt)
3
Lead (ppb)
200 PPM 0 400 Very Hard
CONTAMINANT LEVELS Hardness 200 PPM TDS 310 PPM PFAS 4 ppt Lead 3 ppb Chlorine 0.9 mg/L Nitrate 8 mg/L

Hardness Scale: Where Des Moines Falls

Soft 060120180250400+
Very hard waterHigh nitrates (agricultural runoff)Seasonal spikes

What Des Moines's Water Means for Your Home

Des Moines residents deal with some of the hardest municipal water in the country. At 200 PPM (undefined grains per gallon), the water contains high concentrations of dissolved calcium and magnesium picked up from the regional geology as surface water is treated and distributed. This is not a safety issue. The minerals are safe to consume. But they create real, measurable costs for homeowners. Hard water at 200 PPM costs the average household $800 to $1,200 per year in hidden expenses, including higher energy bills from scale-insulated water heaters, increased soap and detergent usage, and premature appliance failure. Many Des Moines homeowners discover this only after a water heater replacement or plumber visit.

Beyond hardness, Des Moines's water quality is generally within EPA guidelines for regulated contaminants. Chlorine is present at 0.9 mg/L as a disinfectant residual, which is normal for municipal water systems. If you notice a pool-like taste or experience dry skin, a whole-house carbon filter is the most common and affordable solution. For homeowners who want to understand the full picture, requesting your utility's annual Consumer Confidence Report provides neighborhood-level data.

ContaminantDetectedHealth GuidelineLegal LimitStatus
Hardness (as CaCO₃)200 PPM< 60 PPMNo federal limit⚠ Very Hard
Total Dissolved Solids310 PPM< 300 PPM500 PPM⚠ Elevated
PFAS (total)4 ppt4 ppt (EPA)4 ppt (2024)✓ OK
Lead3 ppb0 ppb (no safe level)15 ppb (action level)✓ Low
Chlorine / Chloramine0.9 mg/LTaste threshold ~1.04.0 mg/L✓ Normal
Nitrate8 mg/L5 mg/L10 mg/L⚠ Elevated

Recommendations for Des Moines Homes

🧂 Water Softener
At 200 PPM (undefined GPG), Des Moines's water is very hard. Scale will accumulate in pipes, water heaters, and on fixtures. A salt-based ion exchange softener removes the calcium and magnesium causing the problem. For a typical Des Moines household of 2 to 4 people, a 48,000-grain softener is the right starting size.
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🍼 Reverse Osmosis for Drinking Water
Nitrate measured at 8 mg/L, above the health guideline of 5 mg/L. Nitrate is especially dangerous for infants under 6 months (blue baby syndrome). A point-of-use reverse osmosis system under your kitchen sink is the most effective nitrate removal method for drinking and cooking water.
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About Des Moines's Water Supply

Water Utility: DMWW

Water Source: Des Moines + Raccoon Rivers

Population Served: 214,237

Hardness: 200 PPM (undefined grains per gallon)

Water quality can vary by neighborhood and season. The values above represent typical averages reported by DMWW. To get exact numbers for your address, request a copy of the most recent Consumer Confidence Report (CCR) from your utility, or have your water independently tested.

Compare Des Moines to Other Iowa Cities

Cedar Rapids

284 PPM · Extremely Hard

Davenport

236 PPM · Very Hard

Iowa City

190 PPM · Very Hard

Waterloo

254 PPM · Extremely Hard

Council Bluffs

296 PPM · Extremely Hard

Ames

183 PPM · Very Hard

Frequently Asked Questions About Des Moines Water

Is Des Moines tap water safe to drink?
Des Moines's water meets EPA legal standards for drinking water safety. However, legal limits and health-optimal levels are different things. Review the contaminant table above for specific numbers and how they compare to both legal limits and health guidelines.
Do I need a water softener in Des Moines?
Yes. At 200 PPM (undefined GPG), Des Moines's water is very hard. Without a softener, expect visible scale buildup on faucets and shower heads, reduced water heater efficiency (15 to 25 percent higher energy costs), spotted dishes and glassware, and soap that does not lather well. A salt-based water softener is the standard solution. For a typical Des Moines home with 2 to 4 residents, a 48,000-grain system is the most common starting size.
What water filter is best for Des Moines?
The best filter depends on which contaminants you want to address. See our softener vs. filter guide to understand the difference between these categories.
Where does Des Moines's water come from?
Des Moines's drinking water is sourced from Des Moines + Raccoon Rivers and treated by DMWW.
What is the hardness of Des Moines water in grains per gallon?
Des Moines's water hardness is undefined grains per gallon (GPG), which equals 200 parts per million (PPM). This is classified as very hard. Most water softener manufacturers recommend treatment above 7 GPG. To convert: 1 GPG = 17.1 PPM.
Does Des Moines water damage tankless water heaters?
Yes. Most tankless water heater manufacturers recommend water hardness below 7 to 11 GPG (120 to 188 PPM). At undefined GPG, Des Moines's water exceeds this threshold. Scale buildup inside the heat exchanger reduces efficiency and can void the manufacturer's warranty. A water softener installed upstream of the tankless heater is the standard solution.
Is Des Moines water safe for babies and infants?
Caution is warranted. Nitrate levels in Des Moines are 8 mg/L, which is above the health guideline of 5 mg/L. Nitrate can cause methemoglobinemia (blue baby syndrome) in infants under 6 months. If you have an infant, use a reverse osmosis filter or bottled water for formula preparation until nitrate levels are confirmed below 5 mg/L.
How much does hard water cost a Des Moines household per year?
At 200 PPM, hard water costs the average Des Moines household an estimated $800 to $1,200 per year in hidden costs. This includes 15 to 25 percent higher water heating bills from scale insulation, 50 to 75 percent more soap and detergent usage, shorter appliance lifespans (water heaters, dishwashers, washing machines), and increased plumbing maintenance. A water softener typically costs $600 to $1,500 installed and $50 to $100 per year in salt, which means most Des Moines households see a return on investment within 1 to 2 years.

Data sources. Water quality data compiled from EPA SDWIS, EWG Tap Water Database, USGS water hardness studies, and the DMWW Consumer Confidence Report. Hardness and contaminant levels represent typical average values and may vary by neighborhood and season. Last updated: 2026-02-12.