Water Quality in Waterloo, IA

Waterloo's water has very hard water (254 PPM). A water softener is recommended to protect plumbing and appliances. Read below for a full breakdown.

Waterloo Water Works · Source: Cedar River, wells · Serves 67,314 residents

254
Hardness (PPM)
348
TDS (PPM)
0.9
Chlorine (mg/L)
4
PFAS (ppt)
3
Lead (ppb)
254 PPM 0 400 Extremely Hard
CONTAMINANT LEVELS Hardness 254 PPM TDS 348 PPM PFAS 4 ppt Lead 3 ppb Chlorine 0.9 mg/L Nitrate 5 mg/L

Hardness Scale: Where Waterloo Falls

Soft 060120180250400+
Extremely hard water

Waterloo's Cedar River watershed produces very hard water from glacial geology.

What Waterloo's Water Means for Your Home

Waterloo residents deal with some of the hardest municipal water in the country. At 254 PPM (14.9 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 254 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 Waterloo homeowners discover this only after a water heater replacement or plumber visit.

Beyond hardness, Waterloo'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)254 PPM< 60 PPMNo federal limit⚠ Very Hard
Total Dissolved Solids348 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
Nitrate5 mg/L5 mg/L10 mg/L✓ OK

Recommendations for Waterloo Homes

🧂 Water Softener
At 254 PPM (14.9 GPG), Waterloo's water is extremely 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 Waterloo household of 2 to 4 people, a 48,000-grain softener is the right starting size.
Learn more about this solution →

About Waterloo's Water Supply

Water Utility: Waterloo Water Works

Water Source: Cedar River, wells

Population Served: 67,314

Hardness: 254 PPM (14.9 grains per gallon)

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

Des Moines

200 PPM · Very Hard

Cedar Rapids

284 PPM · Extremely Hard

Davenport

236 PPM · Very Hard

Iowa City

190 PPM · Very Hard

Council Bluffs

296 PPM · Extremely Hard

Ames

183 PPM · Very Hard

Frequently Asked Questions About Waterloo Water

Is Waterloo tap water safe to drink?
Waterloo'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 Waterloo?
Yes. At 254 PPM (14.9 GPG), Waterloo's water is extremely 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 Waterloo home with 2 to 4 residents, a 48,000-grain system is the most common starting size.
What water filter is best for Waterloo?
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 Waterloo's water come from?
Waterloo's drinking water is sourced from Cedar River, wells and treated by Waterloo Water Works. Waterloo's Cedar River watershed produces very hard water from glacial geology..
What is the hardness of Waterloo water in grains per gallon?
Waterloo's water hardness is 14.9 grains per gallon (GPG), which equals 254 parts per million (PPM). This is classified as extremely hard. Most water softener manufacturers recommend treatment above 7 GPG. To convert: 1 GPG = 17.1 PPM.
Does Waterloo water damage tankless water heaters?
Yes. Most tankless water heater manufacturers recommend water hardness below 7 to 11 GPG (120 to 188 PPM). At 14.9 GPG, Waterloo'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 Waterloo water safe for babies and infants?
Waterloo'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 Waterloo household per year?
At 254 PPM, hard water costs the average Waterloo 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 Waterloo 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 Waterloo Water Works Consumer Confidence Report. Hardness and contaminant levels represent typical average values and may vary by neighborhood and season. Last updated: 2026-02-12.