Is Corunna, MI Tap Water Safe to Drink?
Graded A — but Chlorate was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
90.2/100
waterverge.com Corunna, MI — Water Quality Report
Corunna's drinking water received a grade of A (90.2 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 2,028 residents using purchased ground water.
Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 2 violations on record, including 0 health-based violations. 1 remains unresolved.
What to know about Corunna's water
Corunna ranks #112 out of 520 cities in Michigan for water quality, placing it above average in the state.
Corunna purchases its water from a regional wholesaler, meaning quality depends on both the supplier's treatment and the local distribution system's condition.
Hexavalent chromium (chromium-6) was detected at 0.35 µg/L in UCMR 3 testing. While below California's 10 µg/L limit and with no federal MCL set, residents sensitive to this contaminant may consider reverse osmosis filtration.
As a small community water system, Corunna may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Corunna, MI water safe to drink?
Corunna's tap water meets most EPA standards but has areas that warrant attention. With a grade of A (90.2/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 2,028 residents using groundwater (wells).
Recent water quality updates for Corunna
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Corunna's water quality assessment. Grade: A (90.2/100).
Contaminants: Total Haloacetic Acids (HAA5).
Federal disaster declaration (FEMA DR-3225). Hurricane event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-774). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Corunna's water supply.
Well within EPA limits.
Violation history
Corunna's water system has 2 total violations on record, including 0 health-based violations. 1 remain unresolved.
Flood & environmental risk
Shiawassee County has experienced 5 federally declared disasters since 1975. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Shiawassee River.
Where does Corunna's water come from?
Corunna's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 2,028 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Shiawassee River (river).
What Corunna residents can do
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Corunna's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Corunna
Industrial polluters nearby
Reported releases to surface water by facilities near Corunna, ranked by pounds discharged annually.
Total reported releases to surface water: 250 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
TOLEDO COMMUTATOR CO OWOSSO, MI48867 | Copper | 250 | 4.1 mi |
CIE NEWCOR MTG CORUNNA, MI48817 | — | — | 0.7 mi |
GENERAL SHALE BRICK INC. - PLANT 66 CORUNNA, MI48817 | — | — | 1.6 mi |
CIE NEWCOR MTG OWOSSO, MI48867 | — | — | 4.1 mi |
GREAT LAKES COMPOSITES LLC OWOSSO, MI48867 | — | — | 4.7 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Flood & disaster history
Shiawassee County has experienced 5 federally declared disasters since 1975. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 0.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Corunna compares by contaminant
Explore where Corunna ranks among all Michigan cities for specific contaminants.
Water source & infrastructure
Where Corunna's water comes from
Corunna purchases its water supply from a regional wholesale provider rather than treating raw water directly.
Water quality depends on both the wholesaler's treatment standards and the condition of Corunna's local distribution pipes and storage facilities.
Purchased water systems are common in suburban areas and smaller communities that lack the infrastructure for independent treatment.
The system is operated by local government ownership and serves approximately 2,028 people through 1 water system.
Water bodies near Corunna
Corunna is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Corunna
| System Name | PWSID | Population | Source |
|---|---|---|---|
| CORUNNA, CITY OF | MI0001640 | 2,028 | GWP |
How Corunna compares
Full Michigan rankings →Corunna's score of 90.2/100 is above the average of 70/100 among major Michigan cities. It outscores 8 of 10 nearby cities.
Nearby cities
View Michigan rankings →About Corunna, MI
Wikipedia →Corunna is a city in and the county seat of Shiawassee County in the U.S. state of Michigan. The population was 3,046 at the 2020 census. The city is surrounded by Caledonia Charter Township and is slightly east of the city of Owosso.
Learn more about your water
Guides and resources related to Corunna's water quality findings.
Explore water quality across Shiawassee
Frequently asked questions
Is Corunna, MI tap water safe to drink?
Corunna's water quality earned a grade of A (90.2/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #112 out of 520 cities tested in Michigan.
What contaminants are in Corunna's water?
Lead was measured at 0.0 ppb (90th percentile). 2 violations are on record.
How is Corunna's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Corunna?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Corunna's water come from?
Corunna's water is sourced from Purchased ground water. The city has 1 water system serving approximately 2,028 residents.
Is Corunna's groundwater at risk of contamination?
Corunna uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 2 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Corunna's water compare to other cities?
Corunna ranks #112 out of 520 cities in Michigan (better than 78% of state cities) and #2359 out of 15744 cities nationally (85th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Corunna's small water system affect quality?
Corunna's system serves approximately 2,028 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 2 violations on record.