Water Quality in Missouri: Complete Guide
Everything homeowners need to know about Missouri tap water - hardness, contaminants, treatment options, and costs.
Quick summary: Missouri has an average water hardness of 211 PPM across 15 cities. 100% of cities have hard water above 120 PPM. PFAS contamination is detected above EPA limits in at least one city. Most Missouri households will benefit from a water softener.
Water Hardness Across Missouri
Missouri's water hardness ranges from 140 PPM in Webster Groves to 299 PPM in Springfield, with a statewide average of 211 PPM. This makes Missouri one of the harder-water states in the country. The national average is approximately 120 PPM.
Most Missouri cities use surface water (rivers, lakes, reservoirs), which generally has lower mineral content than groundwater.
Contaminants of Concern in Missouri
PFAS: The average PFAS level across Missouri cities is 4.1 ppt. O'Fallon has the highest detected PFAS at 9.5 ppt, above the EPA maximum contaminant level of 4 ppt. Residents should consider a reverse osmosis or NSF P473-certified filter for drinking water.
Lead: Lead contamination comes from plumbing infrastructure, not the water source. Missouri homes built before 1986 are at higher risk due to lead solder. 1 cities show lead levels above 5 ppb.
Do You Need a Water Softener in Missouri?
In most of Missouri, yes. With 100% of cities having hard water above 120 PPM, the majority of households will see measurable benefits from a water softener - lower energy bills, less soap usage, and longer appliance life.
Impact of Hard Water in Missouri
At the state average of 211 PPM, untreated hard water causes measurable household impact: scale buildup that reduces water heater efficiency (DOE estimates up to 22%), increased soap and detergent use, premature appliance failure, and plumbing maintenance. A water softener ($600-$1,500 installed) eliminates these problems.