Massachusetts · drinking water · SDWIS through latest publish

Hanover Water Dept Water Quality — Hanover, Massachusetts

PWSID MA4122000 · Mixed sourcesMunicipal

14,984 people served. 3 health-based SDWIS violations recorded in the past 5 years. 47 remain unresolved. Last cited 1 year ago.

ALL SDWIS VIOLATIONS · 20202026 (annual count)
Bar chart of annual values from 2020 to 2026, in violations. Most recent year (2026): 0 violations.30 violations'20'21'22'23'24'25'260 violations
Anomaly engine

Active signals

UNRESOLVED VIOLATION · SDWIS VIOLATION

Mercury (inorganic)

Unresolved Phase I/II/V Inorganic Chemical Rules violation cited in 2025 (mercury (inorganic)).

EPA SDWIS record

UNRESOLVED VIOLATION · SDWIS VIOLATION

Arsenic

Unresolved Phase I/II/V Inorganic Chemical Rules violation cited in 2025 (arsenic).

EPA SDWIS record

UNRESOLVED VIOLATION · SDWIS VIOLATION

Selenium

Unresolved Phase I/II/V Inorganic Chemical Rules violation cited in 2025 (selenium).

EPA SDWIS record

UNRESOLVED VIOLATION · SDWIS VIOLATION

Asbestos

Unresolved Phase I/II/V Inorganic Chemical Rules violation cited in 2025 (asbestos).

EPA SDWIS record

Most-cited contaminants

What This Utility Gets Cited For

  • Mercury (inorganic)3 citations
  • Arsenic3 citations
  • Selenium3 citations
  • Asbestos3 citations
  • Barium3 citations
  • Cadmium3 citations
Violation history

What's On The SDWIS Record

Health-based violations exceed an MCL or treatment-technique standard. Monitoring violations are reporting failures with no measured exceedance — they tell you the system isn't fully transparent, not that the water is unsafe today.

MONITORING · MERCURY (INORGANIC)UNRESOLVED

2025 · Mercury (inorganic) · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1025

MONITORING · ARSENICUNRESOLVED

2025 · Arsenic · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1005

MONITORING · SELENIUMUNRESOLVED

2025 · Selenium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1035

MONITORING · ASBESTOSUNRESOLVED

2025 · Asbestos · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1045

MONITORING · BARIUMUNRESOLVED

2025 · Barium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1010

MONITORING · CADMIUMUNRESOLVED

2025 · Cadmium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1015

MONITORING · CHROMIUMUNRESOLVED

2025 · Chromium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1020

MONITORING · CONTAMINANT 1052UNRESOLVED

2025 · Contaminant 1052 · Lead and Copper Rule

Failure to monitor as scheduled

CONTAMINANT CODE 1052

MONITORING · CONTAMINANT 1074UNRESOLVED

2025 · Contaminant 1074 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1074

MONITORING · CONTAMINANT 1075UNRESOLVED

2025 · Contaminant 1075 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1075

MONITORING · CONTAMINANT 1036UNRESOLVED

2025 · Contaminant 1036 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1036

MONITORING · CONTAMINANT 1085UNRESOLVED

2025 · Contaminant 1085 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1085

MONITORING · FLUORIDEUNRESOLVED

2025 · Fluoride · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1024

MONITORING · LEADUNRESOLVED

2025 · Lead · Lead and Copper Rule

Failure to monitor as scheduled

CONTAMINANT CODE 1030

MONITORING · MERCURY (INORGANIC)UNRESOLVED

2024 · Mercury (inorganic) · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1025

MONITORING · MERCURY (INORGANIC)UNRESOLVED

2024 · Mercury (inorganic) · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1025

MONITORING · ARSENICUNRESOLVED

2024 · Arsenic · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1005

MONITORING · ARSENICUNRESOLVED

2024 · Arsenic · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1005

MONITORING · SELENIUMUNRESOLVED

2024 · Selenium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1035

MONITORING · SELENIUMUNRESOLVED

2024 · Selenium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1035

MONITORING · ASBESTOSUNRESOLVED

2024 · Asbestos · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1045

MONITORING · ASBESTOSUNRESOLVED

2024 · Asbestos · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1045

MONITORING · BARIUMUNRESOLVED

2024 · Barium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1010

MONITORING · BARIUMUNRESOLVED

2024 · Barium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1010

MONITORING · CADMIUMUNRESOLVED

2024 · Cadmium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1015

MONITORING · CADMIUMUNRESOLVED

2024 · Cadmium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1015

MONITORING · CHROMIUMUNRESOLVED

2024 · Chromium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1020

MONITORING · CHROMIUMUNRESOLVED

2024 · Chromium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1020

MONITORING · CONTAMINANT 1052UNRESOLVED

2024 · Contaminant 1052 · Lead and Copper Rule

Failure to monitor as scheduled

CONTAMINANT CODE 1052

MONITORING · CONTAMINANT 1052UNRESOLVED

2024 · Contaminant 1052 · Lead and Copper Rule

Failure to monitor as scheduled

CONTAMINANT CODE 1052

MONITORING · CONTAMINANT 1074UNRESOLVED

2024 · Contaminant 1074 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1074

MONITORING · CONTAMINANT 1074UNRESOLVED

2024 · Contaminant 1074 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1074

MONITORING · CONTAMINANT 1075UNRESOLVED

2024 · Contaminant 1075 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1075

MONITORING · CONTAMINANT 1075UNRESOLVED

2024 · Contaminant 1075 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1075

MONITORING · CONTAMINANT 1036UNRESOLVED

2024 · Contaminant 1036 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1036

MONITORING · CONTAMINANT 1036UNRESOLVED

2024 · Contaminant 1036 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1036

MONITORING · CONTAMINANT 1085UNRESOLVED

2024 · Contaminant 1085 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1085

MONITORING · CONTAMINANT 1085UNRESOLVED

2024 · Contaminant 1085 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1085

MONITORING · FLUORIDEUNRESOLVED

2024 · Fluoride · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1024

MONITORING · FLUORIDEUNRESOLVED

2024 · Fluoride · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1024

MONITORING · LEADUNRESOLVED

2024 · Lead · Lead and Copper Rule

Failure to monitor as scheduled

CONTAMINANT CODE 1030

MONITORING · LEADUNRESOLVED

2024 · Lead · Lead and Copper Rule

Failure to monitor as scheduled

CONTAMINANT CODE 1030

MONITORING · CONTAMINANT 2987UNRESOLVED

2024 · Contaminant 2987 · Arsenic Rule

Failure to monitor as scheduled

CONTAMINANT CODE 2987

MONITORING · CONTAMINANT 2987UNRESOLVED

2024 · Contaminant 2987 · Arsenic Rule

Failure to monitor as scheduled

CONTAMINANT CODE 2987

HEALTH-BASED · TOTAL TRIHALOMETHANES (TTHM)UNRESOLVED

2020 · Total Trihalomethanes (TTHM) · Total Trihalomethanes Rule

Maximum contaminant level exceeded

CONTAMINANT CODE 2950

HEALTH-BASED · TOTAL TRIHALOMETHANES (TTHM)UNRESOLVED

2020 · Total Trihalomethanes (TTHM) · Total Trihalomethanes Rule

Maximum contaminant level exceeded

CONTAMINANT CODE 2950

HEALTH-BASED · TOTAL TRIHALOMETHANES (TTHM)UNRESOLVED

2020 · Total Trihalomethanes (TTHM) · Total Trihalomethanes Rule

Maximum contaminant level exceeded

CONTAMINANT CODE 2950

Equity context · ACS 2018-2022 · USEPA-clone EJ disparity

Who Drinks This Water

Plymouth County, Massachusetts (utility's served county per SDWIS GEOGRAPHIC_AREA — city-level not yet matched): a service population of 529,548. Local disparity score for pm2.5 (fine particulate) sits well below the reference (7). Why we surface this →

POPULATION SHARE
6.7%

Low-income

POPULATION SHARE
22.1%

People of color

POPULATION SHARE
5.7%

Under age 5

POPULATION SHARE
18.8%

Over age 64

NATIONAL PERCENTILE · vs all US block groups (population-weighted; ranked against the national EJScreen indicator distribution)

  • PM2.5 (fine particulate)Health riskFine inhalable particles 2.5 micrometers or smaller. They travel deep into the lungs and into the bloodstream — linked to asthma, heart disease, stroke, and premature death.7below the national median
  • OzoneHealth riskGround-level ozone (smog) inflames the airways. Even short exposures trigger asthma attacks and worsen chronic lung and heart disease.41near the national median
  • Nitrogen dioxide (NO₂)Health riskA tailpipe and combustion gas. Concentrates near busy roads and industrial sites; raises risk of airway inflammation, asthma, and lower respiratory infections in children.24below the national median
  • Diesel particulateHealth riskSoot from diesel engines (trucks, trains, ports, construction). EPA classifies it as a likely human carcinogen and a major driver of childhood asthma near freight corridors.30below the national median
  • Toxic releases (RSEI)Health riskEPA's Risk-Screening Environmental Indicators score — weights TRI chemical releases by toxicity, where they go, and how many people are nearby. Higher means greater modeled cancer and chronic-health risk.69above the national median
  • Traffic proximityHealth riskPopulation-weighted distance to high-volume roads. Living close to heavy traffic raises exposure to PM2.5, NO₂, and diesel exhaust — and the cardiovascular and asthma risks that follow.75above the national median
  • Lead-paint risk (pre-1960 housing)Health riskShare of housing built before 1960, when lead-based paint was common. Dust from deteriorating paint is the leading cause of childhood lead poisoning, which permanently impairs cognitive development.71above the national median
  • Superfund site proximityHealth riskPopulation-weighted distance to NPL Superfund sites — the most contaminated waste sites in the country. Nearby groundwater, soil, and air can carry industrial solvents, metals, and other long-lived contaminants.67above the national median
  • RMP-facility proximityHealth riskDistance to facilities holding chemicals at quantities large enough to require an EPA Risk Management Plan (refineries, fertilizer plants, etc.). These pose acute exposure risk during accidental releases.40near the national median
  • Hazardous-waste site proximityHealth riskDistance to RCRA hazardous-waste handlers (treatment, storage, disposal facilities). Indicates potential exposure to industrial chemicals in air, soil, and groundwater.68above the national median
  • Underground storage tanksHealth riskDensity of underground tanks (gasoline, heating oil, industrial fluids). Leaking tanks are a leading source of benzene and other volatile organic compounds in groundwater drinking-water supplies.62above the national median
  • NPDES wastewater proximityHealth riskDistance to permitted industrial wastewater dischargers. Closer proximity raises exposure to pollutants released into surface waters used for fishing, recreation, and downstream drinking-water intakes.71above the national median
  • Drinking-water non-complianceHealth riskEPA score for public water systems with health-based Safe Drinking Water Act violations. Higher means more residents on systems that recently exceeded safe limits for contaminants like lead, arsenic, or nitrate.89in the highest 20% nationally
EJ disparity scores · service-area block groups (100 = national reference; higher = greater disparate burden)
IndicatorDisparity scoreReading
PM2.5 (fine particulate)7well below the reference
Ozone25well below the reference
Nitrogen dioxide (NO₂)32well below the reference
Diesel particulate26well below the reference
Toxic releases (RSEI)52below the reference
Traffic proximity57below the reference
Lead-paint risk (pre-1960 housing)51below the reference
Superfund site proximity36well below the reference
RMP-facility proximity24well below the reference
Hazardous-waste site proximity52below the reference
Underground storage tanks42well below the reference
NPDES wastewater proximity41well below the reference
Drinking-water non-compliance16well below the reference

Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror).

Source. EPA Safe Drinking Water Information System · retrieved 2026-05-07. Reporting period 2020-01-012026-05-07.

What this is not. SDWIS records compliance against federal MCLs — not a direct readout of tap-water concentrations. Active health-based violations are not the same as a current crisis; we link to the EPA record so you can verify return-to-compliance status before forming a conclusion.