What is Cheyenne water hardness in grains per gallon?

Cheyenne's water hardness is undefined grains per gallon (GPG), equivalent to 190 parts per million (PPM). 1 GPG = 17.1 PPM.

Water Quality in Cheyenne, WY

Cheyenne's water has very hard water (190 PPM) and PFAS above EPA limits (7 ppt). A water softener is recommended to protect plumbing and appliances. An activated carbon filter can reduce PFAS levels. Read below for a full breakdown.

BOPU · Source: Granite Springs + Crystal Reservoir · Serves 64,235 residents

190

Hardness (PPM)

290

TDS (PPM)

0.8

Chlorine (mg/L)

PFAS (ppt)

Lead (ppb)

Hardness Scale: Where Cheyenne Falls

Soft 060120180250400+

Hard waterPFAS from F.E. Warren AFB

What Cheyenne's Water Means for Your Home

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

PFAS contamination is a significant concern in Cheyenne. At 7 parts per trillion, levels exceed the EPA's 2024 maximum contaminant level of 4 ppt. PFAS are synthetic chemicals that do not break down in the environment or the human body, which is why they are called "forever chemicals." Long-term exposure has been associated with increased cancer risk, thyroid disruption, and immune system effects. A whole-house activated carbon filter or point-of-use reverse osmosis system can reduce PFAS to safe levels. Look for NSF P473 certification when comparing products.

Contaminant	Detected	Health Guideline	Legal Limit	Status
Hardness (as CaCO₃)	190 PPM	< 60 PPM	No federal limit	⚠ Very Hard
Total Dissolved Solids	290 PPM	< 300 PPM	500 PPM	✓ OK
PFAS (total)	7 ppt	4 ppt (EPA)	4 ppt (2024)	⚠ Above limit
Lead	2 ppb	0 ppb (no safe level)	15 ppb (action level)	✓ Low
Chlorine / Chloramine	0.8 mg/L	Taste threshold ~1.0	4.0 mg/L	✓ Normal
Nitrate	2 mg/L	5 mg/L	10 mg/L	✓ OK

Recommendations for Cheyenne Homes

🧂 Water Softener

At 190 PPM (undefined GPG), Cheyenne's water is 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 Cheyenne household of 2 to 4 people, a 48,000-grain softener is the right starting size.

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🔬 Activated Carbon Filter for PFAS

PFAS detected at 7 ppt, above the EPA maximum contaminant level of 4 ppt. PFAS are linked to cancer, thyroid disease, and immune system effects with long-term exposure. A whole-house granular activated carbon (GAC) filter or a point-of-use reverse osmosis system can reduce PFAS. Look for NSF P473 certification, which specifically tests for PFAS removal.

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About Cheyenne's Water Supply

Water Utility: BOPU

Water Source: Granite Springs + Crystal Reservoir

Population Served: 64,235

Hardness: 190 PPM (undefined grains per gallon)

Water quality can vary by neighborhood and season. The values above represent typical averages reported by BOPU. 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 Cheyenne to Other Wyoming Cities

Laramie

66 PPM · Moderately Hard

Casper

196 PPM · Very Hard

Frequently Asked Questions About Cheyenne Water

Is Cheyenne tap water safe to drink?

Cheyenne's water meets EPA legal standards for drinking water safety. However, legal limits and health-optimal levels are different things. PFAS levels exceed the 2024 EPA health standard, which is a concern for long-term exposure. 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 Cheyenne?

Yes. At 190 PPM (undefined GPG), Cheyenne's water is 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 Cheyenne home with 2 to 4 residents, a 48,000-grain system is the most common starting size.

What water filter is best for Cheyenne?

The best filter depends on which contaminants you want to address. For PFAS, look for a filter with NSF P473 certification. Granular activated carbon (GAC) and reverse osmosis systems are both effective. Standard carbon pitcher filters may not remove PFAS adequately. See our softener vs. filter guide to understand the difference between these categories.

Where does Cheyenne's water come from?

Cheyenne's drinking water is sourced from Granite Springs + Crystal Reservoir and treated by BOPU.

What is the hardness of Cheyenne water in grains per gallon?

Cheyenne's water hardness is undefined grains per gallon (GPG), which equals 190 parts per million (PPM). This is classified as hard. Most water softener manufacturers recommend treatment above 7 GPG. To convert: 1 GPG = 17.1 PPM.

Does Cheyenne 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, Cheyenne'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 Cheyenne water safe for babies and infants?

Cheyenne'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 Cheyenne household per year?

At 190 PPM, hard water costs the average Cheyenne 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 Cheyenne 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 BOPU Consumer Confidence Report. Hardness and contaminant levels represent typical average values and may vary by neighborhood and season. Last updated: 2026-02-12.