Medford Water Hardness & Quality Report (2026)

Medford, New York, in Suffolk County in the Town of Brookhaven in central Long Island, receives its municipal water from the Suffolk County Water Authority (SCWA), which draws from the Long Island Glacial Aquifer through production wells across central Suffolk County. The SCWA operates the largest water utility in New York State outside of New York City, supplying over 1.2 million people from the Long Island glacial aquifer system — primarily the Magothy Aquifer and the shallower Upper Glacial Aquifer beneath Suffolk's central plain.

The moderately soft 68 mg/L hardness and low TDS of 104.6 mg/L reflect the Long Island Glacial Aquifer's characteristic mineralogy. The Magothy Formation is a deep Cretaceous coastal plain deposit — a sequence of clean quartz sands and gravels laid down as river delta and shallow marine environments during the Cretaceous Period — geologically dominated by quartz and feldspar derived from Precambrian shield basement rocks of New England and New York with virtually no calcium carbonate. The overlying Upper Glacial Aquifer consists of Pleistocene glacial outwash from the same crystalline upland terrain. Both produce naturally soft water with very low dissolved mineral content throughout Suffolk County.

At 68 mg/L, Medford's water is pleasantly soft — comfortable for all household uses. Soap lathers well, appliances scale very slowly, and the dishwasher produces spotless glassware with minimal rinse aid. Annual or semi-annual descaling of kettles and coffee machines is typically sufficient. The very low PFAS level of 3.3 ppt is among the cleanest in the Long Island dataset — central Suffolk County's agricultural and residential land use contributes minimal PFAS compared to western Long Island communities near military airfields and industrial sites.