Ferguson Water Hardness & Quality Report (2026)

Ferguson, Missouri, in Saint Louis County — a Saint Louis County inner-ring suburban city that gained national attention after the 2014 Michael Brown shooting and the subsequent Ferguson uprising and national criminal justice reform movement, a historically diverse working-class community in the north Saint Louis County corridor — receives its municipal water from Missouri American Water (MOAW), which draws from the Missouri River at the St. Louis metropolitan intake or from the Mississippi River through the St. Louis regional water distribution system. Ferguson is in the north Saint Louis County MOAW distribution zone.

The moderately hard 120 mg/L hardness and TDS of 207.7 mg/L reflect the Missouri-Mississippi blended supply's typical character at the St. Louis metropolitan distribution level — considerably softer than the pure Meramec (Ozark dolomite) supply (Arnold 250.5 mg/L) and consistent with the Missouri River-dominant North St. Louis County treatment zone. The Missouri River at St. Louis carries moderate hardness reflecting its long traverse through the Great Plains (Cretaceous chalk, Permian-Pennsylvanian calcareous formations, and Quaternary loess) but diluted by the larger flow compared to the smaller, harder Meramec. The finished Missouri-Mississippi blend at 120 mg/L is typical for the north St. Louis County MOAW distribution system.

At 120 mg/L, Ferguson'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 4.2 ppt is moderate for the Saint Louis metro — the Missouri River watershed's broad Plains agricultural and industrial drainage, the Mississippi River upstream industrial corridor, and the broader St. Louis metropolitan chemical and manufacturing complex contribute to Ferguson's PFAS background.