Is Chilmark, MA Tap Water Safe to Drink?
Graded D+ — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
54.1/100
waterverge.com Chilmark, MA — Water Quality Report
Chilmark's drinking water received a grade of D+ (54.1 out of 100), indicating poor water quality. The city's 2 water systems serve approximately 930 residents using groundwater.
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 146 violations on record, including 10 health-based violations. 27 remain unresolved.
What to know about Chilmark's water
Chilmark ranks #264 out of 280 cities in Massachusetts for water quality, placing it among the lowest-rated in the state.
Chilmark relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
As a small community water system, Chilmark may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 28 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Chilmark, MA water safe to drink?
Chilmark's drinking water has significant quality concerns based on EPA testing data. With a grade of D+ (54.1/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 930 residents using groundwater (wells).
Recent water quality updates for Chilmark
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Chilmark's water quality assessment. Grade: D+ (54.1/100).
Contaminants: Nitrate.
Contaminants: Nitrate, Nitrite.
Contaminants: Revised Total Coliform Rule.
Federal disaster declaration (FEMA DR-3599). Hurricane event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4097). Hurricane event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Chilmark's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Violation history
Chilmark's water system has 146 total violations on record, including 10 health-based violations. 27 remain unresolved. 28 violations were issued in the last 5 years.
Flood & environmental risk
Dukes 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 Tiasquam River, Mill Brook, Blackwater Brook.
Where does Chilmark's water come from?
Chilmark's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 930 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Tiasquam River (river), Mill Brook (river), Blackwater Brook (river).
What Chilmark residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Chilmark'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.
Chilmark'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 droughtDukes 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
Dukes 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.
Recommended water filters
Based on contaminants detected in Chilmark's water supply, we recommend the following filter types.
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 |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 4.53 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Chilmark compares by contaminant
Explore where Chilmark ranks among all Massachusetts cities for specific contaminants.
Water source & infrastructure
Where Chilmark's water comes from
Chilmark's drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by private ownership and serves approximately 930 people through 2 water systems.
Water bodies near Chilmark
Chilmark is located near 3 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Chilmark
| System Name | PWSID | Population | Source |
|---|---|---|---|
| MENEMSHA WATER COMPANY | MA4062000 | 841 | GW |
| Aquinnah Wampanoag | 010307001 | 89 | GW |
How Chilmark compares
Full Massachusetts rankings →Chilmark's score of 54.1/100 is below the average of 80/100 among major Massachusetts cities. It outscores 1 of 10 nearby cities. 9 of 10 nearby cities score higher.
Nearby cities
View Massachusetts rankings →ZIP codes served by Chilmark
The water systems serving Chilmark cover 1 ZIP code. Select any ZIP to see which water systems serve that area.
About Chilmark, MA
Wikipedia →Chilmark is a town on Martha's Vineyard in Massachusetts. The population was 1,212 at the 2020 census. The fishing village of Menemsha is located on the western side of the town along its border with the town of Aquinnah. Chilmark had the highest median home sale price of any town or city in Massachusetts in 2013.
Learn more about your water
Guides and resources related to Chilmark's water quality findings.
Explore water quality across Dukes
Frequently asked questions
Is Chilmark, MA tap water safe to drink?
Chilmark's water quality earned a grade of D+ (54.1/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #264 out of 280 cities tested in Massachusetts.
What contaminants are in Chilmark's water?
Lead was measured at 1.0 ppb (90th percentile). 146 violations are on record.
How is Chilmark'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 Chilmark?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Chilmark's water come from?
Chilmark's water is sourced from Groundwater. The city has 2 water systems serving approximately 930 residents.
What health violations has Chilmark's water system had?
Chilmark has 10 health-based violations on record. The most recent violation was recorded in October 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 27 violations remain unresolved.
Is Chilmark's groundwater at risk of contamination?
Chilmark 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 146 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 Chilmark's water compare to other cities?
Chilmark ranks #264 out of 280 cities in Massachusetts (better than 6% of state cities) and #12634 out of 15744 cities nationally (20th percentile). The grade of D+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.