Water Quality Report · Updated May 12, 2026

ROCHESTER HILLS

Serving 74,000 residents in ROCHESTER HILLS, Michigan .

National rank 95th percentile
Michigan rank 58th percentile
Data confidence Medium
Quick answer

ROCHESTER HILLS delivers tap water graded B (79/100) by TapWaterSafety.org. The utility serves approximately 74,000 residents in ROCHESTER HILLS, Michigan using surface water (purchased). 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. For questions, the utility can be reached at 248-656-4640.

Data sources for this grade: utilities.csv EWG Tap Water Database ⓘ How did we get this rating?
74,000
People served
1
City served
7
Contaminants detected
5
Above health guidelines
0
EPA violations (5 yr)

Is ROCHESTER HILLS tap water safe to drink?

ROCHESTER HILLS delivers tap water that earns a grade of B (79/100) from TapWaterSafety.org — a good rating, with only minor concerns relative to health-based guidelines.

The utility serves 74,000 residents in ROCHESTER HILLS, drawing from surface water (purchased).

Public testing data identifies 5 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Haloacetic acids (HAA5), Chromium (hexavalent), 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.

Top concerns in this water

Based on the most recent EPA and EWG data, these are the most significant water quality issues for ROCHESTER HILLS.

Haloacetic acids (HAA9) significantly above health guideline

Moderate concern

Haloacetic acids (HAA9) detected at 24.2 ppb, 403x above the EWG health guideline of 0.06 ppb.

Total trihalomethanes (TTHMs) significantly above health guideline

Moderate concern

Total trihalomethanes (TTHMs) detected at 36.7 ppb, 244x above the EWG health guideline of 0.15 ppb.

Haloacetic acids (HAA5) significantly above health guideline

Moderate concern

Haloacetic acids (HAA5) detected at 16.6 ppb, 166x above the EWG health guideline of 0.1 ppb.

Contact ROCHESTER HILLS

Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.

Recommended water filters for ROCHESTER HILLS

Filters matched to the specific contaminants in this water supply.

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 79/100 breaks down across five weighted components. Read the full methodology →

Health Guideline Performance
22 / 40
Legal Compliance
20 / 20
High-Risk Contaminants
20 / 20
Compliance History
10 / 10
Source Water Vulnerability
7 / 10

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
24.2 ppb 0.06 403× over
Total trihalomethanes (TTHMs)
Disinfection byproduct
36.7 ppb 0.15 80.0 100 244× over
Haloacetic acids (HAA5)
Disinfection byproduct
16.6 ppb 0.1 60.0 60 166× over
Chromium (hexavalent)
Heavy metal
0.104 ppb 0.02 5.2× over
Nitrate*
Inorganic
0.4 ppm 0.14 10.0 11.3 11.3 10 2.9× over
Strontium
Radiological
0.0976 ppb 1500.0 Below guideline
Fluoride*
Inorganic
0.677 ppm 4.0 1.5 1.5 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.

ROCHESTER HILLS service area

This water system serves 1 community in Oakland County, Michigan. Click any city for its dedicated tap water quality page.

About this water system

Public Water System ID
MI0000325
Owner type
Local government
Source water
Surface water (purchased)
Service connections
24,105
Service area
ROCHESTER HILLS, Oakland County, Michigan