Gretna Water Hardness & Quality Report (2026)

Gretna, Louisiana, in Jefferson Parish — a Jefferson Parish city adjacent to Harvey and Terrytown on the west bank of the Mississippi River opposite New Orleans in the Greater New Orleans metro — receives its municipal water from Jefferson Parish Water or Veolia Water Jefferson, drawing from the Mississippi River at the Jefferson Parish west bank intake.

The extremely soft 36.5 mg/L hardness and very low TDS of 55.3 mg/L are among the softest river water supplies in the USA — significantly softer than the Baton Rouge Mississippi River reading (136 mg/L). The Mississippi River at the New Orleans metro has been filtered through hundreds of miles of Mississippi River Alluvial Plain meanders and sediment traps downstream of Baton Rouge, dramatically reducing total dissolved solids. The Jefferson Parish water treatment also removes significant mineral content. The result is some of the softest municipal water in the continental US.

At 36.5 mg/L, Gretna's water is essentially distilled — no scale ever forms, soap lathers maximally, and appliances achieve theoretical maximum lifespan. No descaling is needed. The PFAS level of 5.4 ppt warrants a certified drinking water filter — the Greater New Orleans industrial corridor (Cancer Alley petrochemical complex — one of the largest PFAS sources in the USA), the Naval Air Station Joint Reserve Base New Orleans (AFFF), and the Mississippi River-Louisiana industrial PFAS legacy contribute to Gretna's readings.