Maryland · drinking water · SDWIS through latest publish

Patuxent Naval Air Station (Navfac-Wash) Water Quality — Patuxent River, Maryland

PWSID MD0180022 · GroundwaterFederal

22,000 people served. No health-based SDWIS violations recorded in the past 5 years. 32 remain unresolved. Last cited 3 years ago.

ALL SDWIS VIOLATIONS · 20202026 (annual count)
Bar chart of annual values from 2020 to 2026, in violations. Most recent year (2026): 0 violations.31 violations'20'21'22'23'24'25'260 violations
Anomaly engine

Active signals

UNRESOLVED VIOLATION · SDWIS VIOLATION

Total Trihalomethanes (TTHM)

Unresolved Total Trihalomethanes Rule violation cited in 2023 (total trihalomethanes (tthm)).

EPA SDWIS record

UNRESOLVED VIOLATION · SDWIS VIOLATION

Beryllium

Unresolved Phase I/II/V Inorganic Chemical Rules violation cited in 2022 (beryllium).

EPA SDWIS record

UNRESOLVED VIOLATION · SDWIS VIOLATION

Beryllium

Unresolved Phase I/II/V Inorganic Chemical Rules violation cited in 2022 (beryllium).

EPA SDWIS record

UNRESOLVED VIOLATION · SDWIS VIOLATION

Barium

Unresolved Phase I/II/V Inorganic Chemical Rules violation cited in 2020 (barium).

EPA SDWIS record

Most-cited contaminants

What This Utility Gets Cited For

  • Beryllium4 citations
  • Mercury (inorganic)4 citations
  • Total Trihalomethanes (TTHM)3 citations
  • Barium3 citations
  • Cadmium3 citations
  • Chromium3 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 · TOTAL TRIHALOMETHANES (TTHM)

2023 · Total Trihalomethanes (TTHM) · Total Trihalomethanes Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2950

MONITORING · TOTAL TRIHALOMETHANES (TTHM)

2023 · Total Trihalomethanes (TTHM) · Total Trihalomethanes Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2950

MONITORING · TOTAL TRIHALOMETHANES (TTHM)UNRESOLVED

2023 · Total Trihalomethanes (TTHM) · Total Trihalomethanes Rule

Failure to monitor as scheduled

CONTAMINANT CODE 2950

MONITORING · BERYLLIUM

2022 · Beryllium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 1040

MONITORING · BERYLLIUMUNRESOLVED

2022 · Beryllium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1040

MONITORING · BERYLLIUMUNRESOLVED

2022 · Beryllium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1040

MONITORING · BERYLLIUM

2022 · Beryllium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 1040

MONITORING · CONTAMINANT 5000

2022 · Contaminant 5000 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 5000

MONITORING · CONTAMINANT 5000

2022 · Contaminant 5000 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 5000

MONITORING · BARIUMUNRESOLVED

2020 · Barium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1010

MONITORING · BARIUMUNRESOLVED

2020 · Barium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1010

MONITORING · BARIUMUNRESOLVED

2020 · Barium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1010

MONITORING · CADMIUMUNRESOLVED

2020 · Cadmium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1015

MONITORING · CADMIUMUNRESOLVED

2020 · Cadmium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1015

MONITORING · CADMIUMUNRESOLVED

2020 · Cadmium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1015

MONITORING · CHROMIUMUNRESOLVED

2020 · Chromium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1020

MONITORING · CHROMIUMUNRESOLVED

2020 · Chromium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1020

MONITORING · CHROMIUMUNRESOLVED

2020 · Chromium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1020

MONITORING · SELENIUMUNRESOLVED

2020 · Selenium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1035

MONITORING · SELENIUMUNRESOLVED

2020 · Selenium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1035

MONITORING · SELENIUMUNRESOLVED

2020 · Selenium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1035

MONITORING · CONTAMINANT 1036UNRESOLVED

2020 · Contaminant 1036 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1036

MONITORING · CONTAMINANT 1036UNRESOLVED

2020 · Contaminant 1036 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1036

MONITORING · CONTAMINANT 1036UNRESOLVED

2020 · Contaminant 1036 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1036

MONITORING · CONTAMINANT 1074UNRESOLVED

2020 · Contaminant 1074 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1074

MONITORING · CONTAMINANT 1074UNRESOLVED

2020 · Contaminant 1074 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1074

MONITORING · CONTAMINANT 1074UNRESOLVED

2020 · Contaminant 1074 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1074

MONITORING · CONTAMINANT 1075UNRESOLVED

2020 · Contaminant 1075 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1075

MONITORING · CONTAMINANT 1075UNRESOLVED

2020 · Contaminant 1075 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1075

MONITORING · CONTAMINANT 1075UNRESOLVED

2020 · Contaminant 1075 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1075

MONITORING · CONTAMINANT 1085UNRESOLVED

2020 · Contaminant 1085 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1085

MONITORING · CONTAMINANT 1085UNRESOLVED

2020 · Contaminant 1085 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1085

MONITORING · CONTAMINANT 1085UNRESOLVED

2020 · Contaminant 1085 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1085

MONITORING · ASBESTOSUNRESOLVED

2020 · Asbestos · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1045

MONITORING · ASBESTOSUNRESOLVED

2020 · Asbestos · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1045

MONITORING · ASBESTOSUNRESOLVED

2020 · Asbestos · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1045

MONITORING · MERCURY (INORGANIC)

2020 · Mercury (inorganic) · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 1025

MONITORING · MERCURY (INORGANIC)UNRESOLVED

2020 · Mercury (inorganic) · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1025

MONITORING · MERCURY (INORGANIC)UNRESOLVED

2020 · Mercury (inorganic) · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 1025

MONITORING · MERCURY (INORGANIC)

2020 · Mercury (inorganic) · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 1025

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

Who Drinks This Water

St. Mary's County, Maryland (utility's served county per SDWIS GEOGRAPHIC_AREA — city-level not yet matched): a service population of 113,814. Local disparity score for pm2.5 (fine particulate) sits well below the reference (4). Why we surface this →

POPULATION SHARE
7.6%

Low-income

POPULATION SHARE
28.2%

People of color

POPULATION SHARE
6.9%

Under age 5

POPULATION SHARE
13.3%

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.4below the national median
  • OzoneHealth riskGround-level ozone (smog) inflames the airways. Even short exposures trigger asthma attacks and worsen chronic lung and heart disease.20below 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.5below 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.19below 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.11below 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.13below 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.43near 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.80above 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.28below 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.34below 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.45near 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.68above 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.77above the national median
EJ disparity scores · service-area block groups (100 = national reference; higher = greater disparate burden)
IndicatorDisparity scoreReading
PM2.5 (fine particulate)4well below the reference
Ozone31well below the reference
Nitrogen dioxide (NO₂)6well below the reference
Diesel particulate18well below the reference
Toxic releases (RSEI)9well below the reference
Traffic proximity13well below the reference
Lead-paint risk (pre-1960 housing)25well below the reference
Superfund site proximity47well below the reference
RMP-facility proximity0well below the reference
Hazardous-waste site proximity30well below the reference
Underground storage tanks36well below the reference
NPDES wastewater proximity53below the reference
Drinking-water non-compliance7well 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.