How hard is the water in Monsey, NY?

Tap water hardness
106mg/L
6.2gpg
Moderately hardCounty estimate

County estimate from 43 water samples in Rockland County · July 2026

NY typical
31 mg/L
Softener for 3 people
24k grain
Data
County estimate

Water samples from around Monsey put hardness at about 106 mg/L (6.2 gpg), which would be moderately hard on the USGS scale. Treat this as a rough guide: it is the median of 43 samples taken across Rockland County, mostly wells and streams, not a test of Monsey's treated tap water.

Monsey on the hardness scale, with nearby cities
060120180240300360+NY typical 31Irvington: 6 mg/LIrvington 6Elmsford: 17 mg/LElmsford 17Tarrytown: 19 mg/LTarrytown 19Sleepy Hollow: 22 mg/LSleepy Hollow 22Briarcliff Manor: 30 mg/LBriarcliff Manor 30Peekskill: 100 mg/LPeekskill 100Ossining: 103 mg/LOssining 103Spring Valley: 106 mg/LSpring Valley 106New City: 106 mg/LNew City 106Croton-on-Hudson: 107 mg/LCroton-on-Hudson 107Monsey 106mg/L as calcium carbonate060120180240300360+NY 31Tarrytown: 19 mg/LTarrytown 19Sleepy Hollow: 22 mg/LSleepy Hol. 22Ossining: 103 mg/LOssining 103Spring Valley: 106 mg/LSpring Val. 106New City: 106 mg/LNew City 106Croton-on-Hudson: 107 mg/LCroton-on-. 107106 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Monsey sits 75 mg/L above the typical New York figure of 31. Of the 10 nearest cities we track, 7 have softer water and 1 has harder. The range nearby runs from 6 mg/L in Irvington to 107 in Croton-on-Hudson.

What 106 mg/L means at home

You may see faint white spots on glasses and shower doors after the water dries.

Scale builds up slowly. A kettle or coffee maker needs descaling now and then, maybe every few months.

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

Optional. Plenty of households at this level live with it and descale the kettle now and then.

Water softener

Worth a look if spots on glass bother you, or if your tankless water heater manual asks for softer water.

Carbon filter

Improves taste and removes chlorine. It leaves calcium and magnesium in place.

Softener size for Monsey

3 people × 75 gallons a day × 6.2 gpg = 1,395 grains a day. A 24,000-grain unit regenerates about every 17 days.

Size it for your household

EPA record for Monsey's water system

We could not match Monsey to a community water system in EPA's records. Your water bill or the yearly Consumer Confidence Report names the system and its ID.

Questions

Is Monsey water hard?

Somewhat. It measures about 106 mg/L (6.2 grains per gallon), which the USGS classes as moderately hard.

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

About 6.2 gpg. One grain per gallon equals 17.1 mg/L, so 106 mg/L divided by 17.1 gives 6.2.

What size water softener do I need in Monsey?

For 3 people using 75 gallons each per day, 6.2 gpg works out to about 1,395 grains a day. A 24,000-grain softener covers that with a regeneration about every 17 days.

Nearby cities

All 149 cities in New York

Hardness data: TapWaterData US Water Hardness (county estimate, July 4, 2026), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.