Water Quality in Iowa City, IA

Iowa City's water has very hard water (190 PPM). A water softener is recommended to protect plumbing and appliances. Read below for a full breakdown.

Iowa City Water · Source: Iowa River wells · Serves 74,828 residents

190
Hardness (PPM)
301
TDS (PPM)
1.1
Chlorine (mg/L)
3
PFAS (ppt)
3
Lead (ppb)
190 PPM 0 400 Very Hard
CONTAMINANT LEVELS Hardness 190 PPM TDS 301 PPM PFAS 3 ppt Lead 3 ppb Chlorine 1.1 mg/L Nitrate 4 mg/L

Hardness Scale: Where Iowa City Falls

Soft 060120180250400+
Very hard water

Iowa City draws from alluvial wells along the Iowa River. Water is very hard from Midwest limestone and glacial deposits.

What Iowa City's Water Means for Your Home

Iowa City residents deal with some of the hardest municipal water in the country. At 190 PPM (11.1 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 190 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 Iowa City homeowners discover this only after a water heater replacement or plumber visit.

Beyond hardness, Iowa City's water quality is generally within EPA guidelines for regulated contaminants. Chlorine is present at 1.1 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)190 PPM< 60 PPMNo federal limit⚠ Very Hard
Total Dissolved Solids301 PPM< 300 PPM500 PPM⚠ Elevated
PFAS (total)3 ppt4 ppt (EPA)4 ppt (2024)✓ OK
Lead3 ppb0 ppb (no safe level)15 ppb (action level)✓ Low
Chlorine / Chloramine1.1 mg/LTaste threshold ~1.04.0 mg/L✓ Normal
Nitrate4 mg/L5 mg/L10 mg/L✓ OK

Recommendations for Iowa City Homes

🧂 Water Softener
At 190 PPM (11.1 GPG), Iowa City'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 Iowa City household of 2 to 4 people, a 48,000-grain softener is the right starting size.
Learn more about this solution →

About Iowa City's Water Supply

Water Utility: Iowa City Water

Water Source: Iowa River wells

Population Served: 74,828

Hardness: 190 PPM (11.1 grains per gallon)

Water quality can vary by neighborhood and season. The values above represent typical averages reported by Iowa City Water. 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 Iowa City to Other Iowa Cities

Des Moines

200 PPM · Very Hard

Cedar Rapids

284 PPM · Extremely Hard

Davenport

236 PPM · Very Hard

Waterloo

254 PPM · Extremely Hard

Council Bluffs

296 PPM · Extremely Hard

Ames

183 PPM · Very Hard

Frequently Asked Questions About Iowa City Water

Is Iowa City tap water safe to drink?
Iowa City'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 Iowa City?
Yes. At 190 PPM (11.1 GPG), Iowa City'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 Iowa City home with 2 to 4 residents, a 48,000-grain system is the most common starting size.
What water filter is best for Iowa City?
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 Iowa City's water come from?
Iowa City's drinking water is sourced from Iowa River wells and treated by Iowa City Water. Iowa City draws from alluvial wells along the Iowa River. Water is very hard from Midwest limestone and glacial deposits.
What is the hardness of Iowa City water in grains per gallon?
Iowa City's water hardness is 11.1 grains per gallon (GPG), which equals 190 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 Iowa City water damage tankless water heaters?
Yes. Most tankless water heater manufacturers recommend water hardness below 7 to 11 GPG (120 to 188 PPM). At 11.1 GPG, Iowa City'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 Iowa City water safe for babies and infants?
Iowa City's water meets all EPA safety standards and is generally considered safe for preparing infant formula. The hardness minerals (calcium and magnesium) are not harmful. If your home has older plumbing, running cold water for 30 seconds before use is a good precaution to flush any lead from pipes.
How much does hard water cost a Iowa City household per year?
At 190 PPM, hard water costs the average Iowa City 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 Iowa City 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 Iowa City Water Consumer Confidence Report. Hardness and contaminant levels represent typical average values and may vary by neighborhood and season. Last updated: 2026-02-12.