Oklahoma City's water is hard at 170 PPM. This level of hardness causes gradual scale accumulation on plumbing fixtures, inside water heaters, and on dishware. While not as aggressive as cities in the 200+ PPM range, homeowners who install a water softener or salt-free conditioner typically notice improved soap lathering, cleaner dishes, and longer appliance lifespans.
Beyond hardness, Oklahoma City's water quality is generally within EPA guidelines for regulated contaminants. Chlorine is present at 1.6 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.
Contaminant
Detected
Health Guideline
Legal Limit
Status
Hardness (as CaCO₃)
170 PPM
< 60 PPM
No federal limit
⚠ Hard
Total Dissolved Solids
250 PPM
< 300 PPM
500 PPM
✓ OK
PFAS (total)
3 ppt
4 ppt (EPA)
4 ppt (2024)
✓ OK
Lead
2 ppb
0 ppb (no safe level)
15 ppb (action level)
✓ Low
Chlorine / Chloramine
1.6 mg/L
Taste threshold ~1.0
4.0 mg/L
✓ Normal
Nitrate
3 mg/L
5 mg/L
10 mg/L
✓ OK
Recommendations for Oklahoma City Homes
💧Water Softener or Conditioner
At 170 PPM, Oklahoma City's water is hard. You will see gradual scale buildup on fixtures and inside water heaters. A salt-based softener removes hardness completely, while a salt-free conditioner prevents scale without removing the minerals. Your choice depends on whether you want soft-feeling water or just scale prevention.
Chlorine measured at 1.6 mg/L. While safe to drink, this level often causes noticeable taste, odor, and can dry skin and hair. A whole-house carbon filter removes chlorine from every faucet and shower.
Water quality can vary by neighborhood and season. The values above represent typical averages reported by OKC Utilities. 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.
Frequently Asked Questions About Oklahoma City Water
Is Oklahoma City tap water safe to drink?
Oklahoma 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 Oklahoma City?
It is worth considering. At 170 PPM, Oklahoma City's water is hard. You will notice gradual scale buildup in pipes and on fixtures over time. A salt-based softener extends appliance life and improves soap efficiency. A salt-free conditioner is a lower-maintenance alternative if you primarily want to prevent scale.
What water filter is best for Oklahoma City?
The best filter depends on which contaminants you want to address. For chlorine taste and odor, an activated carbon filter is effective and affordable, available as under-sink, countertop, or whole-house systems. See our softener vs. filter guide to understand the difference between these categories.
Where does Oklahoma City's water come from?
Oklahoma City's drinking water is sourced from Lakes + groundwater and treated by OKC Utilities.
What is the hardness of Oklahoma City water in grains per gallon?
Oklahoma City's water hardness is undefined grains per gallon (GPG), which equals 170 parts per million (PPM). This is classified as hard. To convert: 1 GPG = 17.1 PPM.
Does Oklahoma 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 undefined GPG, Oklahoma 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 Oklahoma City water safe for babies and infants?
Oklahoma 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 Oklahoma City household per year?
At 170 PPM, hard water costs the average Oklahoma 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 Oklahoma 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 OKC Utilities Consumer Confidence Report. Hardness and contaminant levels represent typical average values and may vary by neighborhood and season. Last updated: 2026-02-12.