Is Castine, ME Tap Water Safe to Drink?
Graded C+, with 16 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
67.3/100
waterverge.com Castine, ME — Water Quality Report
Castine's drinking water received a grade of C+ (67.3 out of 100), indicating fair water quality. The city's 2 water systems serve approximately 1,056 residents using ground water under influence.
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 250 violations on record, including 10 health-based violations. 16 remain unresolved.
What to know about Castine's water
Castine ranks #150 out of 168 cities in Maine for water quality, placing it among the lowest-rated in the state.
Castine 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, Castine may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 11 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Castine, ME water safe to drink?
Castine's drinking water has significant quality concerns based on EPA testing data. With a grade of C+ (67.3/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 1,056 residents using groundwater (wells).
Recent water quality updates for Castine
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Castine's water quality assessment. Grade: C+ (67.3/100).
Contaminants: TTHM, Total Haloacetic Acids (HAA5).
Contaminants: TTHM, Total Haloacetic Acids (HAA5).
Contaminants: Lead and Copper Rule.
Federal disaster declaration (FEMA DR-3598). Hurricane event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-1691). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Castine's water supply.
Well within EPA limits.
Violation history
Castine's water system has 250 total violations on record, including 10 health-based violations. 16 remain unresolved. 11 violations were issued in the last 5 years.
Flood & environmental risk
Hancock County has experienced 6 federally declared disasters since 1972. 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 Castine's water come from?
Castine's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 1,056 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Castine residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Castine'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.
Castine'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 Castine
Industrial polluters nearby
Reported releases to surface water by facilities near Castine, ranked by pounds discharged annually.
Total reported releases to surface water: 659 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
GAC CHEMICAL CORP SEARSPORT, ME04974 | Ammonia | 657 | 6.6 mi |
SPRAGUE SEARSPORT TERMINAL SEARSPORT, ME04974 | Naphthalene | 2 | 6.4 mi |
IRVING OIL TERMINALS INC. SEARSPORT, ME04974 | — | — | 6.5 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites within 10 miles of Castine
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.
- CALLAHAN MINING CORP2.9 mi
Source: EPA Superfund National Priorities List
Drought conditions
D1 — moderate droughtHancock 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
Hancock County has experienced 6 federally declared disasters since 1972. 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 Castine compares by contaminant
Explore where Castine ranks among all Maine cities for specific contaminants.
Water source & infrastructure
Where Castine's water comes from
Castine'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 1,056 people through 2 water systems.
Water systems serving Castine
| System Name | PWSID | Population | Source |
|---|---|---|---|
| CASTINE WATER DEPARTMENT | ME0090330 | 983 | GU |
| HANCOCK VILLAGE MHP | ME0002527 | 73 | GW |
How Castine compares
Full Maine rankings →Castine's score of 67.3/100 is below the average of 82/100 among major Maine cities. It outscores 2 of 10 nearby cities. 8 of 10 nearby cities score higher.
Nearby cities
View Maine rankings →About Castine, ME
Learn more about your water
Guides and resources related to Castine's water quality findings.
Explore water quality across Hancock
Frequently asked questions
Is Castine, ME tap water safe to drink?
Castine's water quality earned a grade of C+ (67.3/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #150 out of 168 cities tested in Maine.
What contaminants are in Castine's water?
Lead was measured at 0.0 ppb (90th percentile). 250 violations are on record.
How is Castine'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 Castine?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Castine's water come from?
Castine's water is sourced from Ground water under influence. The city has 2 water systems serving approximately 1,056 residents.
What health violations has Castine's water system had?
Castine has 10 health-based violations on record. The most recent violation was recorded in May 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 16 violations remain unresolved.
Is Castine's groundwater at risk of contamination?
Castine 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 250 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 Castine's water compare to other cities?
Castine ranks #150 out of 168 cities in Maine (better than 11% of state cities) and #11256 out of 15744 cities nationally (29th percentile). The grade of C+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.