Franklin Square Water Hardness & Quality Report (2026)

Franklin Square, New York, in Nassau County — a major west Nassau County suburban community (Franklin Square is a significant Nassau County hamlet — a west Nassau County community in the Hempstead Town area adjacent to Valley Stream and Elmont; Franklin Square is a classic inner Long Island suburban community that developed primarily in the post-WWII era as part of the massive Long Island residential expansion (Nassau County was transformed from farmland to suburbs almost entirely between 1945 and 1965)), a diverse Nassau County community with a primarily Italian-American, Irish-American, and increasingly Hispanic-American and South Asian-American population (Franklin Square has seen significant demographic diversification in recent decades), adjacent to New Hyde Park and West Hempstead in the west Nassau County corridor, home of a significant retail and commercial corridor along Hempstead Turnpike, and a community with a strong working-class Long Island suburban character — draws its municipal water supply via the Nassau County Department of Public Works. Water hardness in Franklin Square measures 143 mg/L — classified as moderately hard.

Franklin Square's moderate hardness reflects the west Nassau County Long Island groundwater aquifer's calcareous-moderate character. The Nassau County aquifer at Franklin Square draws from the Cretaceous Magothy Aquifer (calcareous-moderate coastal plain sand). Nassau County DPW applies limited softening, producing the moderate 143 mg/L.

At 143 mg/L, Franklin Square residents encounter moderate scale accumulation. Monthly cleaning is recommended. Nassau County Department of Public Works consistently delivers water meeting all New York State DEC and EPA Safe Drinking Water Act requirements.