Greenlawn, NY water hardness

Tap water hardness
31mg/L
1.8gpg
Soft

Reported by Greenlawn WD · July 2025

NY typical
31 mg/L
EPA health violations since 2016
0
Data
Utility report

The water in Greenlawn carries roughly 31 mg/L of dissolved calcium and magnesium, or 1.8 grains per gallon. That is soft water. The number comes from Greenlawn WD, dated July 2025.

Greenlawn on the hardness scale, with nearby cities
060120180240300360+NY typical 31Huntington: 21 mg/LHuntington 21Dix Hills: 21 mg/LDix Hills 21Syosset: 24 mg/LSyosset 24Oyster Bay: 45 mg/LOyster Bay 45Kings Park: 46 mg/LKings Park 46Smithtown: 46 mg/LSmithtown 46Plainview: 54 mg/LPlainview 54Northport: 70 mg/LNorthport 70Fort Salonga: 70 mg/LFort Salonga 70Hauppauge: 85 mg/LHauppauge 85Greenlawn 31mg/L as calcium carbonate060120180240300360+NY 31Huntington: 21 mg/LHuntington 21Dix Hills: 21 mg/LDix Hills 21Kings Park: 46 mg/LKings Park 46Smithtown: 46 mg/LSmithtown 46Northport: 70 mg/LNorthport 70Fort Salonga: 70 mg/LFort Salon. 7031 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Greenlawn sits close to the typical New York figure of 31 mg/L. Of the 10 nearest cities we track, 3 have softer water and 7 have harder. The range nearby runs from 21 mg/L in Huntington to 85 in Hauppauge.

What 31 mg/L means at home

Soap and shampoo lather with very little product. Kettles and showerheads stay mostly free of white crust.

Some people notice that soap feels slow to rinse off in soft water. That slippery feel is normal and harmless.

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

Nothing, as far as hardness goes. At 31 mg/L a softener would have almost nothing to remove.

Carbon filter

If the water tastes of chlorine, a pitcher or faucet carbon filter takes care of that. It does not change hardness.

EPA record for Greenlawn's water system

Greenlawn Water District · PWSID NY5103271

No health-based violations since 2016

Serves about 42,000 people from groundwater.

Health-based
0
Monitoring or reporting
19
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 Greenlawn water hard?

No. It measures about 31 mg/L (1.8 grains per gallon), which the USGS classes as soft.

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

About 1.8 gpg. One grain per gallon equals 17.1 mg/L, so 31 mg/L divided by 17.1 gives 1.8.

Has the Greenlawn water system had EPA violations?

EPA records show no health-based violations for Greenlawn Water District since 2016. There were also 19 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 149 cities in New York

Hardness data: TapWaterData US Water Hardness (utility report, July 14, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.