Duluth Water Hardness & Quality Report (2026)

Duluth, Georgia, in Gwinnett County — a major northeast Georgia Atlanta suburban community (Duluth is a significant Gwinnett County city — a northeast Atlanta suburban community in the rapidly growing Gwinnett County I-85 corridor; Duluth has become one of the most significant Korean-American communities in Georgia — the Duluth–Suwanee–Johns Creek corridor along I-85 in Gwinnett County has the highest concentration of Korean-American residents, businesses, churches, and restaurants in the Southeast United States; the 'Koreatown' of the Atlanta suburbs is centered on the Duluth–Suwanee–Norcross corridor), a diverse Gwinnett County community with a significant Korean-American, Chinese-American, Indian-American, and Latino-American population, adjacent to Johns Creek and Suwanee in the northeast Gwinnett County corridor, home of Infinite Energy Center (the largest convention and arena complex in the greater Atlanta area outside the city itself), and one of the most ethnically diverse suburban communities in the South — draws its municipal water supply via Gwinnett County Department of Water Resources. Water hardness in Duluth measures 147.5 mg/L — classified as moderately hard.

Duluth's moderate hardness reflects the northeast Georgia Gwinnett County Chattahoochee Piedmont watershed's calcareous-poor geology with distribution variation. The Chattahoochee River watershed at Duluth–Gwinnett County drains the Precambrian Georgia Piedmont gneiss (calcareous-poor). Gwinnett County Water Resources treatment produces the moderate 147.5 mg/L.

At 147.5 mg/L, Duluth residents encounter moderate scale accumulation. Monthly cleaning is recommended. Gwinnett County Water Resources consistently delivers water meeting all Georgia EPD and EPA Safe Drinking Water Act requirements.