Hard water in Piedmont, OK

Tap water hardness

123mg/L

7.2gpg

Hard

Reported by Deer Creek Rural Water Corp · October 2025

OK typical: 152 mg/L
EPA health violations since 2016: 8
Softener for 3 people: 24k grain
Data: Utility report

The water in Piedmont carries roughly 123 mg/L of dissolved calcium and magnesium, or 7.2 grains per gallon. That is hard water. The number comes from Deer Creek Rural Water Corp, dated October 2025.

Piedmont on the hardness scale, with nearby cities

Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 123 mg/L, Piedmont is 29 mg/L below the typical Oklahoma figure of 152. Of the 10 nearest cities we track, 1 has softer water and 9 have harder. The range nearby runs from 94 mg/L in Moore to 463 in El Reno.

What 123 mg/L means at home

Expect white crust on faucets and showerheads, plus spots on dishes that come out of the dishwasher.

Kettles collect scale quickly. Water heaters build up sediment at the bottom of the tank, which makes them work harder over time.

Soap and detergent need a little more to lather, and soap scum shows up in the tub.

Hardness is not a health problem, and EPA sets no limit for it. It is a matter of scale and soap.

What to do about it

At 123 mg/L most of the trouble is scale, and only a few things deal with it.

Ion-exchange water softener

The standard whole-house fix. It swaps calcium and magnesium for sodium or potassium and needs salt plus a drain. Size it with the calculator below.

Salt-free conditioner

No salt and no drain line. It changes how minerals form scale instead of removing them, so water still tests hard.

Reverse osmosis or carbon filter

Under-sink reverse osmosis removes minerals from drinking water only. Plain carbon filters improve taste but do not soften.

Softener size for Piedmont

3 people × 75 gallons a day × 7.2 gpg = 1,618 grains a day. A 24,000-grain unit regenerates about every 14 days.

Size it for your household

EPA record for Piedmont's water system

Piedmont Municipal Authority · PWSID OK2000909

8 health-based violations since 2016

Serves about 7,542 people from surface water.

Health-based: 8
Monitoring or reporting: 39
Open now: 2

EPA lists Piedmont Municipal Authority as the system serving Piedmont. The hardness figure above comes from a different system's report, which TapWaterData uses for Piedmont.

Each dot is one health-based violation, placed at the start of its compliance period.

Contaminant or rule	Violations	Period	Status
Lead and Copper Rulecorrosion control and lead sampling	1	2024	Resolved
Gross alpha radioactivitynaturally occurring radioactivity	5	2016–2024	Resolved
Uraniumnaturally occurring radioactivity	2	2016	Resolved

Health-based means a contaminant above its legal limit or a missed treatment step. Monitoring and reporting violations are late or missing tests and notices. Source: EPA ECHO, 2026Q3 export, violations with periods starting 2016 or later. Full EPA record.

Questions

Is Piedmont water hard?

Yes. It measures about 123 mg/L (7.2 grains per gallon), which the USGS classes as hard.

What is the water hardness in Piedmont in grains per gallon?

About 7.2 gpg. One grain per gallon equals 17.1 mg/L, so 123 mg/L divided by 17.1 gives 7.2.

What size water softener do I need in Piedmont?

For 3 people using 75 gallons each per day, 7.2 gpg works out to about 1,618 grains a day. A 24,000-grain softener covers that with a regeneration about every 14 days.

Has the Piedmont water system had EPA violations?

EPA records show 8 health-based violations for Piedmont Municipal Authority since 2016, involving Lead and Copper Rule, Gross alpha radioactivity, Uranium. There were also 39 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 34 cities in Oklahoma

Hardness data: TapWaterData US Water Hardness (utility report, October 21, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.