Union Water Hardness & Quality Report (2026)

Union Public Water Supply draws its water from the Ozark Plateau aquifer system, serving the city of Union and surrounding areas in Franklin County, Missouri. This utility, identified by MO6010801, obtains its supply from groundwater sources, as detailed in its annual Consumer Confidence Report. The Ozark Plateau is characterized by ancient carbonate rock formations from the Ordovician and Cambrian periods. These include the Plattin and Joachim Dolomites, which are highly soluble. Groundwater percolating through these rocks dissolves significant amounts of calcium and magnesium, resulting in a very hard water supply.

The geology of the Ozark Plateau aquifer system is the primary driver of Union's water hardness. Composed mainly of Ordovician and Cambrian dolomite and limestone, formations like the Plattin and Joachim Dolomites are prone to dissolution. This process, accelerated by the region's karst topography and fractured bedrock, allows for rapid groundwater movement. Consequently, natural softening processes are limited, and the water emerges rich in dissolved minerals, giving it its characteristic very hard quality.

Homeowners in Union will likely notice scale buildup on fixtures, in pipes, and within appliances like water heaters and dishwashers, reducing their efficiency and lifespan. You’ll also find that soaps and detergents don't lather as readily, requiring more product for cleaning. Installing a water softener is highly recommended to combat the effects of this very hard water, protecting your plumbing and improving cleaning. The Missouri Department of Natural Resources also reports on lead monitoring, with Union Public Water Supply responsible for managing lead levels in its own pipes, and compliance data is available through the DNR Drinking Water Watch website.