Marrero Water Hardness & Quality Report (2026)

Marrero, Louisiana, in Jefferson Parish — a major Jefferson Parish west bank suburban community (Marrero is the largest unincorporated community in Jefferson Parish and one of the larger communities on the west bank of the Mississippi River in the greater New Orleans metro — a primarily residential community in the Westbank area of Jefferson Parish, across the Mississippi from Kenner and Metairie), a diverse Jefferson Parish community with a significant Hispanic-American, African-American, and Vietnamese-American population, adjacent to Harvey and Gretna along the Jefferson Parish west bank corridor (the Westbank Expressway–US-90 corridor), and a major Jefferson Parish community in the New Orleans suburban fabric — draws its municipal water supply from the Mississippi River via the Jefferson Parish Water System. Water hardness in Marrero measures 83 mg/L — classified as moderately soft.

Marrero's moderate softness reflects the Mississippi River supply's naturally calcareous-low deltaic alluvium. The Mississippi River at Marrero–Jefferson Parish carries water draining the upper Mississippi River basin (primarily calcareous-poor to moderate geology in the upper watershed), and Jefferson Parish applies effective treatment producing the moderate 83 mg/L — similar to New Orleans itself.

With hardness at 83 mg/L, Marrero residents enjoy moderately soft water. Jefferson Parish Water System consistently delivers water meeting all Louisiana DEQ and EPA Safe Drinking Water Act requirements.