Is Mendon, MA Tap Water Safe to Drink?
Graded A-, with 16 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
87.3/100
waterverge.com Mendon, MA — Water Quality Report
Mendon's drinking water received a grade of A- (87.3 out of 100), indicating good water quality. The city's 2 water systems serve approximately 501 residents using gup.
Lead levels were measured at 1.0 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 90 violations on record, including 4 health-based violations. 16 remain unresolved.
What to know about Mendon's water
Mendon ranks #74 out of 280 cities in Massachusetts for water quality, placing it mid-range in the state.
As a small community water system, Mendon may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Mendon, MA water safe to drink?
Mendon's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (87.3/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 501 residents using gup.
Recent water quality updates for Mendon
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Mendon's water quality assessment. Grade: A- (87.3/100).
Federal disaster declaration (FEMA DR-4780). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-3599). Hurricane event — may have impacted local water infrastructure.
Contaminants: Lead and Copper Rule.
Contaminants: Revised Total Coliform Rule.
Contaminants: Lead and Copper Rule.
Key contaminant findings
Based on the most recent EPA sampling data for Mendon's water supply.
Well within EPA limits.
Violation history
Mendon's water system has 90 total violations on record, including 4 health-based violations. 16 remain unresolved.
Flood & environmental risk
Worcester County has experienced 10 federally declared disasters since 1991. 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 Blackstone River, West River Below West Hill Dam, Nr Uxbridge, Blackstone River, Rt 122 Bridge, Nipmuc River, Branch River.
Where does Mendon's water come from?
Mendon's drinking water comes from gup, supplied by 2 water systems serving approximately 501 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Blackstone River (river), West River Below West Hill Dam, Nr Uxbridge (river), Blackstone River, Rt 122 Bridge (river), Nipmuc River (river), Branch River (river).
What Mendon residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Mendon's water.
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.
Mendon'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
Drought conditions
D1 — moderate droughtWorcester County is currently in D1 (moderate drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Worcester County has experienced 10 federally declared disasters since 1991. 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. | 1.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Mendon compares by contaminant
Explore where Mendon ranks among all Massachusetts cities for specific contaminants.
Water source & infrastructure
Where Mendon's water comes from
Mendon's water comes from groundwater under the direct influence of surface water, a designation that requires the same treatment rigor as surface water systems.
This source type is vulnerable to both surface contamination pathways and naturally occurring underground contaminants.
The system is operated by local government ownership and serves approximately 501 people through 2 water systems.
Water bodies near Mendon
Mendon is located near 5 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Mendon
| System Name | PWSID | Population | Source |
|---|---|---|---|
| MENDON WATER DEPARTMENT | MA2179000 | 470 | GUP |
| MENDON HOUSING AUTHORITY | MA2179001 | 31 | GW |
How Mendon compares
Full Massachusetts rankings →Mendon's score of 87.3/100 is above the average of 80/100 among major Massachusetts cities. It outscores 8 of 10 nearby cities.
Nearby cities
View Massachusetts rankings →About Mendon, MA
Wikipedia →Mendon is a town in Worcester County, Massachusetts, United States. The population was 6,228 at the 2020 census. Mendon is part of the Blackstone River Valley National Heritage Corridor, an early center of the industrial revolution in the United States. Mendon celebrated its 350th anniversary on May 15, 2017.
Learn more about your water
Guides and resources related to Mendon's water quality findings.
Explore water quality across Worcester
Frequently asked questions
Is Mendon, MA tap water safe to drink?
Mendon's water quality earned a grade of A- (87.3/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #74 out of 280 cities tested in Massachusetts.
What contaminants are in Mendon's water?
Lead was measured at 1.0 ppb (90th percentile). 90 violations are on record.
How is Mendon'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 Mendon?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Mendon's water come from?
Mendon's water is sourced from GUP. The city has 2 water systems serving approximately 501 residents.
What health violations has Mendon's water system had?
Mendon has 4 health-based violations on record. The most recent violation was recorded in December 2020. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 16 violations remain unresolved.
How does Mendon's water compare to other cities?
Mendon ranks #74 out of 280 cities in Massachusetts (better than 74% of state cities) and #4167 out of 15744 cities nationally (74th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.