Water Quality Report · Updated October 07, 2026
OLATHE, CITY OF
OLATHE, CITY OF delivers tap water graded B (78/100) by TapWaterSafety.org. The utility serves approximately 143,014 residents in OLATHE, Kansas using surface water. The most significant water quality concerns are: Haloacetic acids (HAA9) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline; Arsenic detected. For questions, the utility can be reached at 913-971-8350.
Is OLATHE tap water safe to drink?
OLATHE, CITY OF delivers tap water that earns a grade of B (78/100) from TapWaterSafety.org — a good rating, with only minor concerns relative to health-based guidelines.
The utility serves 143,014 residents in OLATHE, drawing from surface water.
Public testing data identifies 7 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Haloacetic acids (HAA5), Arsenic, Chromium (hexavalent), Chlorite, Nitrate. For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
EPA compliance record
Official U.S. EPA records for OLATHE, CITY OF (system ID KS2009115) for the last 3 years. Checked 2026-10-07.
| Rule | Type | Since | Status |
|---|---|---|---|
| Stage 1 Disinfectants and Disinfection Byproducts Rule | Missed testing or reporting | 03/01/2025 | Open |
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Quick actions for OLATHE residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for OLATHE, CITY OF.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 25.4 ppb, 423x above the EWG health guideline of 0.06 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 42.8 ppb, 286x above the EWG health guideline of 0.15 ppb.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 14.4 ppb, 144x above the EWG health guideline of 0.1 ppb.
Arsenic detected
Moderate concernArsenic detected at 0.333 ppb.
Contact OLATHE, CITY OF
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for OLATHE
Filters matched to the specific contaminants in this water supply.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.
Reverse osmosis certified for arsenic (NSF/ANSI 58)
$429-$599Reverse osmosis certified under NSF/ANSI 58 for arsenic is the most reliable home option.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
Score breakdown
This utility's overall score of 78/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Haloacetic acids (HAA9) Disinfection byproduct |
25.4 ppb | 0.06 | — | — | — | — | — | 423× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
42.8 ppb | 0.15 | 80.0 | 100 | — | — | — | 286× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
14.4 ppb | 0.1 | 60.0 | 60 | — | — | — | 144× over |
| Arsenic Heavy metal |
0.333 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 83× over |
| Chromium (hexavalent) Heavy metal |
1.25 ppb | 0.02 | — | — | — | — | — | 62× over |
| Chlorite Disinfection byproduct |
130.0 ppb | 50.0 | 1000.0 | — | — | — | — | 2.6× over |
| Nitrate Inorganic |
0.234 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 1.7× over |
| Bromochloromethane Other |
0.0225 ppb | 0.06 | — | — | — | — | — | Below guideline |
| Chlorate Disinfection byproduct |
68.8 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
2.79 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Barium Heavy metal |
77.0 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Molybdenum Other |
4.35 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Selenium Heavy metal |
2.1 ppb | 30.0 | 50.0 | 20 | 40 | 30 | — | Below guideline |
| Manganese Heavy metal |
1.14 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Strontium Radiological |
0.363 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Chromium (total) Heavy metal |
2.03 ppb | — | 100.0 | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.737 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Lithium Other |
19.2 ppb | — | — | — | — | — | — | Below guideline |
| Metolachlor Pesticide/Herbicide |
0.403 ppb | — | — | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
OLATHE, CITY OF service area
This water system serves 1 community in Johnson County, Kansas. Click any city for its dedicated tap water quality page.
Find the right filter for OLATHE water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.