Hays Water Hardness & Quality Report (2026)

Hays, Kansas, in Ellis County — the Ellis County seat in the western Kansas High Plains, home of Fort Hays State University, the Sternberg Museum of Natural History (one of the premier fossil museums in North America — located in the heart of the Smoky Hills Chalk), and a western Kansas agricultural and energy industry hub — receives its municipal water from the Hays Water Department, which draws from Big Creek (a tributary of the Smoky Hill River) through the Hays Water Filtration Plant, supplemented by groundwater from the Ogallala Aquifer in the High Plains beneath Ellis County.

The moderately hard 175.5 mg/L hardness and elevated TDS of 420.8 mg/L reflect the western Kansas High Plains hydrology. Big Creek in Ellis County drains the Smoky Hills — the distinctive chalky escarpment of western Kansas underlain by the Cretaceous Niobrara Chalk Formation and the Cretaceous Greenhorn Limestone (the source of the world-famous Niobrara Chalk marine fossils at the Sternberg Museum — mosasaurs, pterosaurs, fish). The Cretaceous chalk and limestone contribute dissolved calcium and bicarbonate to both surface water and the Ogallala Aquifer recharge zone. The High Plains Ogallala aquifer, the deepest water table in the western Great Plains, similarly contacts calcareous Pliocene and Miocene alluvial sediments overlying the Cretaceous carbonates.

At 175.5 mg/L, Hays' water is moderately hard — scale builds in kettles and appliances over months, dishwashers benefit from rinse aid, and bathroom fixtures develop calcium deposits. Quarterly descaling is the standard schedule. The PFAS level of 2.9 ppt is very good for western Kansas — Hays' limited military presence (Fort Hays State military heritage is historical — the actual Fort Hays was decommissioned in 1889) and the predominantly agricultural Ellis County character produce a minimal PFAS background, reflecting the western High Plains' distance from active military and industrial PFAS sources.