Washington Water Hardness & Quality Report (2026)

The City of Washington Public Water System serves about 15,000 residents in Washington, Missouri, and nearby Franklin County areas. This utility relies on nine deep wells tapping into local groundwater aquifers, with no surface water sources involved. Managed by a sophisticated SCADA system, the water is treated at system facilities to meet all federal and state drinking water standards before reaching customers. The utility bills customers with a base charge of $7 monthly, plus tiered rates starting at $2.69 for every 1,000 gallons used up to 16,667 gallons.

The groundwater originates from the Ozark Plateaus region, specifically within the karst aquifer systems beneath Franklin County. The primary geological formations are Cambrian-Ordovician dolomites and limestones, including the Potosi Group, Eminence Formation, and Gasconade Dolomite. These soluble carbonate rocks are responsible for the water's characteristic hardness, as natural dissolution processes increase mineral content during the water's extended time within the aquifer. Recharge primarily comes from local precipitation infiltrating the plateau terrain.

This very hard water frequently causes scale buildup in household appliances, notably impacting water heaters, dishwashers, and washing machines by reducing their efficiency and lifespan. Homeowners often notice soap scum during cleaning and spotting on dishes and fixtures. Regular descaling with vinegar, installing sediment pre-filters, and annual flushing of water heaters are recommended maintenance practices. Given the water's hardness, installing a water softener is strongly advised to protect plumbing and extend appliance life, with reverse osmosis systems also an option for enhanced drinking water purity. The 2025 Annual Water Quality Report confirms compliance with EPA standards, including ongoing efforts to remove lead service lines.