Zachary Water Hardness & Quality Report (2026)

Zachary, Louisiana, in East Baton Rouge Parish — an East Baton Rouge Parish city adjacent to Baker and Slaughter north of Baton Rouge in south Louisiana — receives its municipal water from the Zachary Water Division, drawing from the Mississippi River through the Capital Region Water (Baton Rouge) system or the Zachary treatment plant.

The moderately hard 149 mg/L hardness and TDS of 374.7 mg/L are consistent with the Baton Rouge metro Mississippi River supply — similar to Baton Rouge itself and other East Baton Rouge Parish communities. The Mississippi River at Baton Rouge accumulates the combined drainage from the Missouri Ozarks (Ordovician Gasconade Dolomite), the Tennessee-Ohio carbonate plain, and the lower Mississippi calcareous Embayment, producing the moderately hard south Louisiana river supply.

At 149 mg/L, Zachary's water is moderately hard — scale builds in kettles and appliances over months, dishwashers benefit from rinse aid, and faucet aerators need periodic cleaning. Quarterly descaling is appropriate. The PFAS level of 12.9 ppt is very elevated and warrants a certified reverse osmosis drinking water filter — the East Baton Rouge Parish industrial corridor (ExxonMobil Baton Rouge Refinery, Dow Chemical Plaquemine, and the Mississippi River chemical complex), and the Mississippi River industrial PFAS loading from upstream manufacturing contribute to Zachary's very elevated readings.