Hard water in Mercedes, TX

Tap water hardness
166mg/L
9.7gpg
HardReports range 166–226

Reported by North Alamo WSC · June 2022

TX typical
112 mg/L
EPA health violations since 2016
1
Softener for 3 people
24k grain
Data
Utility report

Mercedes water measures 166 mg/L (9.7 gpg) of hardness, hard by USGS standards. The number comes from North Alamo WSC, dated June 2022. Reports for this system disagree, with values from 166 to 226 mg/L.

Mercedes on the hardness scale, with nearby cities
060120180240300360+TX typical 112La Feria: 149 mg/LLa Feria 149Mila Doce: 161 mg/LMila Doce 161Olivarez: 161 mg/LOlivarez 161Elsa: 161 mg/LElsa 161San Juan: 162 mg/LSan Juan 162Weslaco: 164 mg/LWeslaco 164Alamo: 166 mg/LAlamo 166Progreso: 173 mg/LProgreso 173Donna: 216 mg/LDonna 216Harlingen: 228 mg/LHarlingen 228Mercedes 166mg/L as calcium carbonate060120180240300360+TX 112La Feria: 149 mg/LLa Feria 149Mila Doce: 161 mg/LMila Doce 161Olivarez: 161 mg/LOlivarez 161Weslaco: 164 mg/LWeslaco 164Progreso: 173 mg/LProgreso 173Donna: 216 mg/LDonna 216166 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Mercedes sits 54 mg/L above the typical Texas figure of 112. Of the 10 nearest cities we track, 6 have softer water and 3 have harder. The range nearby runs from 149 mg/L in La Feria to 228 in Harlingen.

What 166 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 166 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 Mercedes

3 people × 75 gallons a day × 9.7 gpg = 2,189 grains a day. A 24,000-grain unit regenerates about every 10 days.

Size it for your household

EPA record for Mercedes's water system

City of Mercedes · PWSID TX1080007

1 health-based violation since 2016

Serves about 16,258 people from surface water.

Health-based
1
Monitoring or reporting
4
Open now
0

EPA lists City of Mercedes as the system serving Mercedes. The hardness figure above comes from a different system's report, which TapWaterData uses for Mercedes.

20162017201820192020202120222023202420252026Lead and Copper Rule'16'18'20'22'24'26Lead and Copper Rule
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Lead and Copper Rulecorrosion control and lead sampling12024Resolved

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 Mercedes water hard?

Yes. It measures about 166 mg/L (9.7 grains per gallon), which the USGS classes as hard.

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

About 9.7 gpg. One grain per gallon equals 17.1 mg/L, so 166 mg/L divided by 17.1 gives 9.7.

What size water softener do I need in Mercedes?

For 3 people using 75 gallons each per day, 9.7 gpg works out to about 2,189 grains a day. A 24,000-grain softener covers that with a regeneration about every 10 days.

Has the Mercedes water system had EPA violations?

EPA records show 1 health-based violation for City of Mercedes since 2016, involving Lead and Copper Rule. There were also 4 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 342 cities in Texas

Hardness data: TapWaterData US Water Hardness (utility report, June 30, 2022), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.