Wilmington Island Water Hardness & Quality Report (2026)

Wilmington Island, Georgia, in Chatham County — an unincorporated Chatham County community adjacent to Savannah and Thunderbolt on the Wilmington River barrier island near Tybee Island in southeast Georgia — receives its water from the Savannah Water Division, drawing from the Savannah River (Chatham County) through the southeast Georgia distribution.

The moderately soft 86.5 mg/L hardness and TDS of 141.1 mg/L reflect the southeast Georgia Savannah River supply's moderate Piedmont crystalline character — consistent with Savannah proper (~85 mg/L). The Savannah River at Chatham County drains the Georgia Piedmont — Precambrian Elberton Granite (insoluble), Precambrian Carolina Slate Belt metasedimentary (slightly calcareous), and Cretaceous coastal plain alluvial input (slightly calcareous) as the Savannah crosses the Coastal Plain fall line above Chatham County. The predominantly insoluble Piedmont granite with minor coastal plain contribution produces the moderately soft southeast Georgia supply.

At 86.5 mg/L, Wilmington Island's water is moderately soft — light scale forms slowly in appliances, dishwashers remain efficient, and bathroom fixtures need occasional cleaning. Semi-annual descaling is appropriate. The PFAS level of 4.2 ppt warrants a certified drinking water filter — Hunter Army Airfield (Chatham County — AFFF, directly at Savannah) and the Savannah River PFAS background from the Savannah-Augusta industrial corridor contribute to Wilmington Island's readings.