Gulfport Water Hardness & Quality Report (2026)

Gulfport, Mississippi, the Harrison County seat on the Mississippi Gulf Coast — the second-largest city in Mississippi and a major Gulf Coast port and casino hub — draws its municipal water supply from the Mississippi Coastal Aquifer System via the City of Gulfport Water Division, pumping from Harrison County wells accessing the Miocene–Pliocene Citronelle Formation (the principal shallow coastal aquifer in coastal Mississippi) and potentially the Eocene Sparta Sand (a deeper, more confined Gulf Coast aquifer). Water hardness in Gulfport measures 113 mg/L — classified as moderately hard.

Gulfport's moderate hardness reflects the Mississippi Gulf Coast's Cenozoic aquifer geology. The Citronelle Formation (Pliocene–Miocene — coarse fluvial and coastal plain sand and gravel) is the primary aquifer in coastal Harrison County — a siliceous sand-dominated formation with some calcareous shell fragments and carbonate cement in parts of the formation. The Sparta Sand (Eocene) is a deeper artesian aquifer in the Gulf Coastal Plain sequence. The moderate 113 mg/L reflects siliceous Cenozoic sandy aquifers with some calcareous content — far less reactive than the carbonate-dominated Florida Floridan Aquifer system to the east (Pensacola: 237.5 mg/L) but more calcareous than the purely siliceous Cretaceous formations of northern Mississippi.

At 113 mg/L, Gulfport residents encounter moderate scale accumulation. Faucet aerators and showerheads develop deposits after several months — monthly cleaning with citric acid solution is practical maintenance. City of Gulfport Water Division consistently delivers water meeting all Mississippi MDEQ and EPA Safe Drinking Water Act requirements.