Hard water in Moorpark, CA

Tap water hardness
190mg/L
11.1gpg
Very hard

Reported by Ventura CWWD No. 1 - Moorpark · October 2025

CA typical
121 mg/L
EPA health violations since 2016
0
Softener for 3 people
24k grain
Data
Utility report

Tap water in Moorpark has about 190 mg/L of hardness, which is 11.1 grains per gallon. On the USGS scale that counts as very hard. The number comes from Ventura CWWD No. 1 - Moorpark, dated October 2025.

Moorpark on the hardness scale, with nearby cities
060120180240300360+CA typical 121Fillmore: 77 mg/LFillmore 77Calabasas: 77 mg/LCalabasas 77Westlake Village: 88 mg/LWestlake Village 88Agoura Hills: 88 mg/LAgoura Hills 88Thousand Oaks: 117 mg/LThousand Oaks 117Oak Park: 138 mg/LOak Park 138Simi Valley: 181 mg/LSimi Valley 181Camarillo: 218 mg/LCamarillo 218El Rio: 278 mg/LEl Rio 278Santa Paula: 383 mg/LSanta Paula 383Moorpark 190mg/L as calcium carbonate060120180240300360+CA 121Fillmore: 77 mg/LFillmore 77Westlake Village: 88 mg/LWestlake V. 88Thousand Oaks: 117 mg/LThousand O. 117Oak Park: 138 mg/LOak Park 138Simi Valley: 181 mg/LSimi Valley 181Camarillo: 218 mg/LCamarillo 218190 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Moorpark sits 69 mg/L above the typical California figure of 121. Of the 10 nearest cities we track, 7 have softer water and 3 have harder. The range nearby runs from 77 mg/L in Fillmore to 383 in Santa Paula.

What 190 mg/L means at home

Scale forms fast here. Kettles and coffee makers need regular descaling, and showerheads clog unless you clean them.

Tank water heaters collect mineral sediment that insulates the water from the burner, so flushing the tank matters more than usual.

Dishes and glass shower doors spot easily. Soap scum and a dull film on hair or laundry are common complaints.

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 190 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 Moorpark

3 people × 75 gallons a day × 11.1 gpg = 2,500 grains a day. A 24,000-grain unit regenerates about every 9 days.

Size it for your household

EPA record for Moorpark's water system

Ventura CWWD No. 1 - Moorpark · PWSID CA5610018

No health-based violations since 2016

Serves about 35,514 people from surface water.

Health-based
0
Monitoring or reporting
0
Open now
0

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 Moorpark water hard?

Yes. It measures about 190 mg/L (11.1 grains per gallon), which the USGS classes as very hard.

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

About 11.1 gpg. One grain per gallon equals 17.1 mg/L, so 190 mg/L divided by 17.1 gives 11.1.

What size water softener do I need in Moorpark?

For 3 people using 75 gallons each per day, 11.1 gpg works out to about 2,500 grains a day. A 24,000-grain softener covers that with a regeneration about every 9 days.

Has the Moorpark water system had EPA violations?

EPA records show no health-based violations for Ventura CWWD No. 1 - Moorpark since 2016.

Nearby cities

All 515 cities in California

Hardness data: TapWaterData US Water Hardness (utility report, October 6, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.