Is Calais, ME Tap Water Safe to Drink?
Graded A- — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
86/100
waterverge.com Calais, ME — Water Quality Report
Calais's drinking water received a grade of A- (86 out of 100), indicating good water quality. The city's 1 water system serves approximately 2,775 residents using groundwater.
Lead levels were measured at 2.4 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 8 violations on record, including 4 health-based violations. 3 remain unresolved.
What to know about Calais's water
Calais ranks #64 out of 168 cities in Maine for water quality, placing it mid-range in the state.
Calais 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, Calais may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Calais, ME water safe to drink?
Calais's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (86/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 2,775 residents using groundwater (wells).
Recent water quality updates for Calais
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Calais's water quality assessment. Grade: A- (86/100).
Federal disaster declaration (FEMA DR-3598). Hurricane event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4719). Flood event — may have impacted local water infrastructure.
1 health-based. Contaminants: TTHM.
Contaminants: Lead and Copper Rule.
Contaminants: Consumer Confidence Rule.
Key contaminant findings
Based on the most recent EPA sampling data for Calais'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
Calais's water system has 8 total violations on record, including 4 health-based violations. 3 remain unresolved. 1 violation was issued in the last 5 years.
Flood & environmental risk
Waldo County has experienced 10 federally declared disasters since 1974. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.
Where does Calais's water come from?
Calais's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 2,775 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Calais residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Calais'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.
Calais'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 Calais
Industrial polluters nearby
Reported releases to surface water by facilities near Calais, ranked by pounds discharged annually.
Total reported releases to surface water: 86,104 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
WOODLAND PULP LLC BAILEYVILLE, ME04694 | Nitrate compounds (water dissociable; reportable only when in aqueous solution) | 86,104 | 9.3 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites within 10 miles of Calais
Superfund sites nearby
Federally tracked hazardous-waste sites on the EPA National Priorities List. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.
- EASTERN SURPLUS9.9 mi
Source: EPA Superfund National Priorities List
Drought conditions
D1 — moderate droughtWashington 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
Waldo County has experienced 10 federally declared disasters since 1974. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Calais'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. | 2.4 | 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. | 5.49 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 5.490 mg/L (1993)
EPA action level: 1.3 mg/L
See how Calais compares by contaminant
Explore where Calais ranks among all Maine cities for specific contaminants.
Water source & infrastructure
Where Calais's water comes from
Calais'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 local government ownership and serves approximately 2,775 people through 1 water system.
Water systems serving Calais
| System Name | PWSID | Population | Source |
|---|---|---|---|
| CALAIS WATER DEPT | ME0090290 | 2,775 | GW |
How Calais compares
Full Maine rankings →Calais's score of 86/100 is on par with the average of 82/100 among major Maine cities. It outscores 5 of 10 nearby cities.
Nearby cities
View Maine rankings →About Calais, ME
Wikipedia →Winterport is a town in Waldo County, Maine, United States. The population was 3,817 at the 2020 census. It contains the census-designated place of the same name. The Winterport Historic District, extending several blocks along Main Street, was listed on the National Register of Historic Places in 1975.
Learn more about your water
Guides and resources related to Calais's water quality findings.
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Frequently asked questions
Is Calais, ME tap water safe to drink?
Calais's water quality earned a grade of A- (86/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #64 out of 168 cities tested in Maine.
What contaminants are in Calais's water?
Lead was measured at 2.4 ppb (90th percentile). 8 violations are on record.
How is Calais'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 Calais?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Calais's water come from?
Calais's water is sourced from Groundwater. The city has 1 water system serving approximately 2,775 residents.
What health violations has Calais's water system had?
Calais has 4 health-based violations on record. The most recent violation was recorded in January 2022. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 3 violations remain unresolved.
Is Calais's groundwater at risk of contamination?
Calais 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 8 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 Calais's water compare to other cities?
Calais ranks #64 out of 168 cities in Maine (better than 62% of state cities) and #4986 out of 15744 cities nationally (68th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Calais's small water system affect quality?
Calais's system serves approximately 2,775 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 8 violations on record.