Water in Missouri.
Missouri's lead mining belt in the southeast has groundwater lead concerns separate from infrastructure-related lead exposure. St. Louis and Kansas City both have aging service-line inventories.
How Missouri regulates drinking water.
Federal SDWA primacy. No state MCLs stricter than federal. Lead-mining-belt monitoring is a state priority.
Missouri Department of Natural Resources — Public Drinking Water Branch
Missouri's water history, in order.
The contamination events, regulatory shifts, and major settlements that define how this state thinks about drinking water today.
- 2017
St. Louis identifies 60,000+ lead service lines requiring replacement.
- 2020
Statewide PFAS sampling expanded under federal UCMR 5.
The actual water you drink.
The physical rivers, aquifers, lakes, and reservoirs that feed Missouri's public water systems. Source quality is the foundation of tap quality — and where the long-term protection fights happen.
- riverMissouri River
Kansas City metro.
- riverMississippi River
St. Louis metro.
- aquiferOzark Plateau Aquifer
Southern MO.
- lakeLake of the Ozarks
Source-water mix
~55% surface water, ~45% groundwater
Major cities served
Kansas City · St. Louis · Springfield · Columbia · Independence
Who actually serves the water.
The largest public water systems in Missouri by population served. Click your ZIP after to see the full live EWG report for your specific utility.
- Kansas City WaterKansas City460Kserved
- St. Louis Water DivisionSt. Louis300Kserved
- Missouri American WaterMulti-region1,500Kserved
Where the contamination comes from.
Every state has a different industrial fingerprint. The industries below are the dominant historical and active contamination sources in Missouri's drinking water systems.
Southeast MO lead-mining belt drives geologic-source lead exposure separate from infrastructure lead. St. Louis radiological legacy (West Lake Landfill, Mallinckrodt sites) affects groundwater. Agricultural runoff in northwest MO drives nitrate.
What state data flags most consistently.
Drawn from EPA SDWIS sampling records, EWG state summaries, and regional regulatory action over the past five years. Read the full deep dive on each.
Lead
A neurotoxic metal that leaches from old pipes and solder. No safe level for children.
Trihalomethanes (TTHMs)
Byproducts of chlorinating water. Linked to bladder cancer at chronic exposure.
Nitrate
Fertilizer and animal waste runoff. Acutely dangerous for infants under 6 months.
PFAS (Forever Chemicals)
A class of ~15,000 synthetic chemicals that don't break down. Now regulated for the first time.
Risk isn't evenly distributed.
St. Louis and Kansas City pre-1986 housing residents face the highest infrastructure-lead exposure. Lead-mining-belt residents face geologic lead.
~15% on private wells, concentrated in southern Missouri Ozarks and lead belt.
What's coming for Missouri's water.
Missouri River flooding intensity affects KC and St. Louis treatment plants. Ozark groundwater karst contamination risk increases with extreme weather. Lake of the Ozarks algal bloom advisories increasing.
Limited program
MO DNR provides voluntary technical assistance; some districts (especially St. Louis area) have conducted voluntary testing.
Five questions for your next Consumer Confidence Report.
Your utility is required to send you a Consumer Confidence Report annually. Most are dense and procedural. These are the questions worth following up on for Missouri specifically.
- 1
If I'm in southeast MO, is my well in the lead-mining-belt geologic exposure zone?
- 2
Has my St. Louis-area system been impacted by Coldwater Creek radiological contamination?
- 3
When was my private well last tested?
Most state regulators allow public records requests for the underlying lab reports behind your CCR — your utility should be able to provide them on request.
NSF/ANSI 53 carbon block for lead. Reverse osmosis for lead-mining-belt private wells.
We don't recommend brands — the NSF/ANSI certification number matters more than the name on the box.
This is the state. Your address is the answer.
State-level patterns don't tell you about your specific tap. Run your ZIP for the live EWG contaminant report on your utility — or build a personalized Water File for your household.
Source-water mix, utility counts, lead-service-line estimates, and private-well shares are approximate, drawn from EPA SDWIS public data and state primacy-agency summaries. Contaminant rankings reflect EWG state-level monitoring data and regional regulatory action — they are not exhaustive. Timeline events are publicly documented. See methodology for the full sourcing. Search EPA SDWIS for Missouri