
Drinking Water Quality in Kansas
Kansas drinks from wells and surface water in nearly equal measure. Enter your ZIP below to see which community water system EPA lists for your county, what the federal record shows for it, and where its official annual water quality report lives. Every number on this page is EPA's, from the April to June 2026 extract, and none of it is a safety verdict in either direction.
854 community water systems serve 2.9 million people in Kansas, split 74 to 26 between surface and ground waterWhich water system serves your Kansas address?
EPA SDWA extract, April to June 2026Kansas divides at roughly the 98th meridian: east of it, reservoir systems like Water District 1 of Johnson County, the largest in the state at 490,000 people, and west of it, towns pumping the declining High Plains aquifer. Its 854 community systems spread across 105 counties, and rural water districts carry much of the map.
Kansas water systems by County
EPA's federal file lists active community water systems in 105 counties of Kansas. The table below is that record, sorted by reported population served. It is an inventory, not a ranking: a county with more listed violations is often just a county whose systems and state program report more completely.
Loading the county table from the committed EPA snapshot…

Kansas splits its drinking water down the middle
By reported population served, 74 percent of community system customers in Kansas are on surface water and 26 percent on ground water. Nationally about 72 percent of the served population is on surface water, so an even split like this one is rarer than it sounds. 364 of the state's systems buy some or all of their water wholesale from another system, so the system on your bill is not always the system running the treatment plant.
Water District 1 of Johnson Co
people served, on surface water, serving Johnson county. PWSID KS2009110.
EPA listed inventoryWichita, City of
people served, on surface water, serving Sedgwick county. PWSID KS2017308.
EPA listed inventoryKansas City Board of Public Utilities
people served, on ground water under the influence of surface water, serving Wyandotte county. PWSID KS2020906.
EPA listed inventoryOlathe, City of
people served, on surface water, serving Johnson county. PWSID KS2009115.
EPA listed inventoryPopulation served is self reported by each system to its regulator, and a wholesaler and the systems buying from it can both count the same household. Summed across Kansas that overlap inflates the total, so read the 2.9 million figure as the sum of what systems report, not as a census of people.
Our summary of information published by EPA SDWA quarterly download (SDWIS federal data)
Violations in the federal record for Kansas
As of the April to June 2026 extract, EPA's files list at least one health based violation that began in the five years to 2026-06-30 for 149 of Kansas's 854 community systems, which is 17.4 percent. 367 systems currently carry a violation EPA's status field marks Unaddressed. Health based is EPA's own dividing line, and it matters more than any total:
US EPA ECHO, SDWA Data Download Summary (health based violations)“These violations fall into three categories: Exceedances of the maximum contaminant levels (MCLs), which specify the highest allowable contaminant concentrations in drinking water; Exceedances of the maximum residual disinfectant levels (MRDLs), which specify the highest concentrations of disinfectants allowed in drinking water; and Treatment technique requirements, which specify certain processes intended to reduce the level of a contaminant.”
Everything else in the record is mostly monitoring and reporting: a required test or report that did not happen on schedule. Those are the bulk of all listed violations nationally, and they say nothing about what was in the water, only that nobody checked when the rules said to. Two more of EPA's own definitions worth knowing when you read a system's record: a violation is Unaddressed when, in EPA's words, "The violation is not Resolved or Archived, and has not been addressed by formal enforcement." and Archived when it is more than five years past its end date.
US EPA ECHO, SDWA Data Download Summary (violation status: Archived)“The violation is not Resolved, but is more than five years past its noncompliance period end date. In keeping with the Enforcement Response Policy, the violation no longer contributes to the public water system’s overall compliance status.”
And the caveat that binds this whole page, in the agency's words rather than ours:
US EPA ECHO, Drinking Water (SDWA) FAQs“Compliance statistics are based on violations reported by states to the EPA Safe Drinking Water Information System (SDWIS). EPA is aware of inaccuracies and underreporting of some data in this system. We are working with the states to improve the quality of the data.”
US EPA ECHO, Drinking Water (SDWA) FAQs“Due to the known incompleteness of the data reported by states and regions, we are careful to refer to systems as having reported violations or no reported violations.”
This is why Kansas's percentages cannot be compared against another state's as if they measured the water. A state whose program reports quickly and completely will show more listed violations than one that lags, for the same pipes and the same rivers. We publish EPA's counts with EPA's caveats and rank nobody.
Our summary of information published by EPA ECHO Drinking Water FAQs

Where Kansas's real water quality answers live
This page shows the compliance record. The actual test results, what was measured in the water and at what concentration, live in each system's annual Consumer Confidence Report, and federal law puts one in your hands every year:
US EPA, CCR Information for Consumers“EPA requires community water systems to deliver a Consumer Confidence Report, also known as an annual drinking water quality report, to their customers. These reports provide Americans information about their local drinking water quality.”
US EPA, CCR Information for Consumers“Reports must be sent by your water supplier each year by July 1.”
Find yours through EPA Consumer Confidence Report search or on your utility's website. Day to day regulation belongs to Kansas Department of Health and Environment, the state's primacy agency, whose records for any single system run deeper and fresher than the federal extract this page reads. Health questions about your tap water belong to your water system, your county health department and CDC Drinking Water, not to this page.
If you are on a private well, none of the above applies to you, and that is worth saying plainly:
US EPA, Private Drinking Water Wells“The quality and safety of drinking water from private domestic wells are not regulated by the Federal Government under the Safe Drinking Water Act nor by most state governments and laws.”
Testing a private well is the owner's job. Kansas Department of Health and Environment and county health departments publish what to test for locally, and EPA's private wells pages cover the basics.
Kansas drinking water FAQ
The rest of Kansas's water picture
Drinking water in nearby states
Inventory and violation counts are EPA's, from the April to June 2026 SDWA quarterly extract (published July 2026), active community water systems only. ZIP to county resolution uses the Census Bureau's ZCTA relationship file. Live checks read EPA Envirofacts. All are US Government works in the public domain. National picture: drinking water in every state