Tap Water Quality Report
Tap water quality in MCKINNEY, Texas
Tap water in MCKINNEY, Texas receives a grade of C (71/100) from TapWaterSafety.org. It's served by CITY OF MCKINNEY. The most significant water quality concerns are: Haloacetic acids (HAA9) significantly above health guideline; Bromochloroacetic acid significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in MCKINNEY's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving MCKINNEY.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 31.7 ppb, 528x above the EWG health guideline of 0.06 ppb.
Bromochloroacetic acid significantly above health guideline
Moderate concernBromochloroacetic acid detected at 6.91 ppb, 346x above the EWG health guideline of 0.02 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 31.3 ppb, 209x above the EWG health guideline of 0.15 ppb.
EPA compliance record
Official U.S. EPA records for CITY OF MCKINNEY (system ID TX0430039) for the last 3 years. Checked 2026-10-07.
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Recommended filters for MCKINNEY
Filters matched to the specific contaminants in MCKINNEY's 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.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
All contaminants detected in MCKINNEY's tap water
Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. 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 |
31.7 ppb | 0.06 | — | — | — | — | — | 528× over |
| Bromochloroacetic acid Disinfection byproduct |
6.91 ppb | 0.02 | — | — | — | — | — | 346× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
31.3 ppb | 0.15 | 80.0 | 100 | — | — | — | 209× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
19.0 ppb | 0.1 | 60.0 | 60 | — | — | — | 190× over |
| Bromodichloromethane Disinfection byproduct |
11.2 ppb | 0.06 | — | — | — | — | — | 186× over |
| Dibromoacetic acid Disinfection byproduct |
3.55 ppb | 0.03 | — | — | — | — | — | 118× over |
| Dibromochloromethane Disinfection byproduct |
8.43 ppb | 0.1 | — | — | — | — | — | 84× over |
| Dichloroacetic acid Disinfection byproduct |
10.2 ppb | 0.2 | — | — | — | — | — | 51× over |
| Trichloroacetic acid Disinfection byproduct |
2.76 ppb | 0.1 | — | — | — | — | — | 28× over |
| Chloroform Disinfection byproduct |
9.81 ppb | 0.4 | — | — | — | — | — | 25× over |
| Radium, combined (-226 and -228)* Radiological |
0.5 pCi/L | 0.05 | 5.0 | — | — | — | — | 10× over |
| Chromium (hexavalent) Heavy metal |
0.0803 ppb | 0.02 | — | — | — | — | — | 4.0× over |
| Bromoform Disinfection byproduct |
1.88 ppb | 0.5 | — | — | — | — | — | 3.8× over |
| Chlorate Disinfection byproduct |
738.8 ppb | 210.0 | — | — | — | — | — | 3.5× over |
| Nitrate Inorganic |
0.224 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 1.6× over |
| Atrazine* Pesticide/Herbicide |
0.148 ppb | 0.1 | 3.0 | 0.1 | 100 | 0.15 | — | Fails EU |
| Chlorite* Disinfection byproduct |
61.2 ppb | 50.0 | 1000.0 | — | — | — | — | 1.2× over |
| Bromate* Disinfection byproduct |
0.108 ppb | 0.1 | 10.0 | 10 | 10 | 0.1 | — | 1.1× over |
| Simazine* Pesticide/Herbicide |
0.0644 ppb | 0.1 | 4.0 | — | — | — | — | Below guideline |
| Barium* Heavy metal |
46.1 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
1.82 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Monobromoacetic acid Disinfection byproduct |
0.686 ppb | 25.0 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
0.275 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Perfluorobutanoic Acid (PFBA) PFAS |
6.4 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
0.474 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Strontium Radiological |
0.721 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Acetone* Other |
6.8 ppb | — | — | — | — | — | — | Below guideline |
| Cyanide* Inorganic |
47.8 ppb | — | 200.0 | 50 | 70 | 150 | — | Below guideline |
| Cyanogen chloride* Other |
0.7 ppb | — | — | — | — | — | — | Below guideline |
| Fluoride* Inorganic |
0.541 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Hexadecanoic acid* Other |
7.2 ppb | — | — | — | — | — | — | Below guideline |
| Methyl isobutyl ketone* Other |
0.0733 ppb | — | — | — | — | — | — | Below guideline |
| Metolachlor* Pesticide/Herbicide |
0.0333 ppb | — | — | — | — | — | — | Below guideline |
| Octadecanoic acid* Other |
21.0 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, California OEHHA PHGs, EWG Tap Water Database.
Treatment plant contact info
For service issues, water quality concerns, or to request a Consumer Confidence Report from CITY OF MCKINNEY.