Commack Water Hardness & Quality Report (2026)

Commack, New York, a hamlet in the Town of Smithtown in Suffolk County — a major west central Suffolk County Long Island community (Commack is one of the larger Long Island communities in the Highway 25A–Northern State Parkway corridor), a primarily residential community with one of Long Island's major community parks (Hoyt Farm Park and Commack Motor Inn historic sites), a diverse Suffolk County community with a significant Jewish-American, Italian-American, and South Asian-American population, and adjacent to Hauppauge and Brentwood in the central Long Island suburban corridor — draws its municipal water supply from the Long Island aquifer system via the Suffolk County Water Authority (SCWA). Water hardness in Commack measures 174 mg/L — classified as hard.

Commack's hard supply reflects the west central Suffolk County aquifer geology. The Suffolk County Water Authority at Commack draws from: the Upper Glacial Aquifer (Pleistocene glacial outwash in the Harbor Hill and Ronkonkoma moraine zone — the west central Suffolk moraine deposits have more calcareous character than east Suffolk); the Cretaceous Magothy Formation (calcareous-moderate quartz sand — primary Long Island deep aquifer); and the Harbor Hill Moraine calcareous glacial deposits (calcareous Pleistocene till with limestone clasts). The west central Suffolk County SCWA supply produces the hard 174 mg/L.

At 174 mg/L, Commack residents face regular hard water challenges. Monthly descaling with citric acid solution is recommended. SCWA consistently delivers water meeting all New York State DEC and EPA Safe Drinking Water Act requirements.