Michigan Water Quality Rankings 2026: Best & Worst Cities

This page ranks the 3 Michigan cities whose water systems we have matched to EPA records. Every city starts at 100 points and loses points for health-based EPA violations in the last five years (SDWIS 2026Q2), its most recent Lead and Copper Rule 90th-percentile result, PFAS detected in EPA's 2023–2026 UCMR5 monitoring, and 2012–2019 compliance samples that averaged near or above a limit. Letters follow fixed bands (A ≥90, B ≥80, C ≥70, D ≥60, F below 60). Cities run from the highest score (Warren) down to the lowest (Grand Rapids); ties are ordered by population served. See the full scoring methodology for every deduction and the data vintages.

What your city's grade means

An A or B grade points to water that consistently tests within federal safety limits, while a C suggests moderate issues worth watching and a D or F flags contaminants or compliance problems serious enough to act on. These grades describe system-level water leaving the treatment plant — they can't account for your home's own plumbing, so older houses with lead service lines or fixtures can add contaminants after the water arrives. For a contaminant-by-contaminant view, see the Michigan contaminant breakdown or drill into the county-level rankings.

What Michigan residents should do

• Find your city in the ranking below and open its full report for its violation history, lead results and PFAS table.
• See how Michigan compares against the best-rated and worst-rated cities nationwide.
• Test your home's water if you have concerns — the most common issues involve lead, PFAS, and arsenic.
• Check whether your utility still has lead service lines in Michigan — EPA's inventory counts lead pipes by water system, a risk that plant-level grades cannot capture. Read the lead guide for testing and filter options.
• If treatment makes sense for your situation, compare certified water filters matched to the contaminants found in your area.

We track 3 cities in Michigan. 3 of them are matched to an active EPA-registered community water system (PWSID). Those 3 systems report serving 1,074,175 people in EPA's Safe Drinking Water Information System (SDWIS).

Of all 3 cities Michigan cities we can grade from EPA records, 3 cities (100%) grade B or better, 0 sit in the C range and 0 grade D or F. The average score is 98/100.

None of the 3 graded systems has a health-based EPA violation in the last five years; the 0 violations on file in that window are monitoring or reporting lapses.

3 cities have a Lead and Copper Rule 90th-percentile result from 2020 or later: 2 cities at 5 ppb or more.

EPA's UCMR5 PFAS monitoring (2023–2026) covers 3 cities: no PFAS was detected in any of them.

Warren scores highest (100) and Grand Rapids lowest (97), a 3-point spread.

Lead pipes are the part of tap-water risk a treatment-plant grade cannot see, so start with EPA's service line inventory (Q2 2026 snapshot). 2,775 Michigan systems inventoried 2,613,791 service lines: 199,943 confirmed lead plus 55,581 galvanized lines requiring replacement, spread across 228 systems. Another 301,508 lines (12%) are still of unknown material, which EPA counts as possible lead until verified.

Of the 3 city-linked Michigan utilities with an inventory on file, 3 report at least one lead or galvanized-requiring-replacement line. DETROIT CITY OF, which serves Detroit and 633,218 people, is the biggest and reports 80,595 lead lines and 120 galvanized requiring replacement.

Michigan's guide on this site singles out lead, PFAS, copper, and trihalomethanes. Lead (EPA action level 0.015 mg/L (15 ppb); health goal 0) harms brain development in children and raises blood pressure and kidney risk in adults; PFAS (EPA 2024 MCLs of 4.0 ppt for PFOA and PFOS) are linked to immune, developmental, liver and some cancer effects; Copper (EPA action level 1.3 mg/L) causes stomach upset short-term and liver or kidney damage with long exposure; Disinfection byproducts (regulated as TTHM (80 ppb) and HAA5 (60 ppb)) are associated with increased cancer risk over long exposure.

Where a system draws its water shapes which of these show up. Disinfection byproducts are a surface-water signature: chlorine reacts with organic matter in rivers and reservoirs, so byproducts tend to run higher where systems chlorinate surface water. Arsenic is naturally occurring and tends to show up in groundwater, leaching from bedrock into aquifers rather than arriving from pollution. PFAS are tied to specific sites — industrial discharges, firefighting-foam use at airports and bases — rather than to geology, so contamination is local and can affect either source type. Lead is different again: it enters after treatment from service lines and household plumbing, which is why the inventory figures above matter more than plant-level results. Your utility's Consumer Confidence Report names your source.

The best water quality in Michigan is found in Warren with a score of 100/100 and a grade of A. This puts Warren among the top-performing cities in the country for drinking water safety.

The most concerning water quality is in Grand Rapids scoring 97/100 with a grade of A. Residents may want to consider home water testing and filtration options.

The statewide average score is 98/100, which is 10 points above the national average of 88/100. A strong majority (100%) of Michigan cities exceed the national average, indicating generally good water infrastructure across the state.