Ellicott City, Maryland

Environmental Quality Report Card

Ellicott City reports good air quality, with AQI levels better than the national average. Water tests indicate safe conditions across key measures. Facility compliance with environmental standards is below the national average.

Air Quality (Annual Overview)

Grade A
23.3 AQI

Yearly average AQI (2024): 23.3. National average: 41.4. 10 moderate days, 0 unhealthy days recorded.

Water Quality (Key Indicators)

Grade A
9.4 pH

Latest pH level (2024): 9.4. Ideal range: 6.5–8.5.

Facility Violations

Grade D
27 significant violations

Facilities like factories and treatment plants had 27 significant and 1139 total violations reported in 2024.

Water Quality (with EPA Standards)

Water quality measurements are provided by the Water Quality Portal , a collaboration between the USGS, EPA, and other agencies.

Characteristic Local Value Safe Range Grade Last Measured
pH 9.40 6.5 - 8.5 F 6/19/2024
Turbidity 2.80 NTU <5 A 6/19/2024

Water Quality (No EPA Standard)

These measurements do not have formal EPA standards but are still important indicators of local water quality.

Characteristic Local Value Unit Last Measured
Salinity 0.20 ppt 6/19/2024
Orthophosphate 0.00 mg/L 9/25/2024
Weather condition (WMO code 4501) (choice list) 1.00 None 6/19/2024
Temperature, water 26.80 deg C 6/19/2024
Dissolved oxygen (DO) 9.70 mg/L 6/19/2024
Ammonium 0.04 mg/L 9/25/2024
Chlorophyll a 2.49 ug/L 9/25/2024
Total Phosphorus, mixed forms 0.03 mg/L 9/25/2024
Specific conductance 354.00 uS/cm 6/19/2024
Nitrate + Nitrite 0.06 mg/L 9/25/2024
Wave height 0.09 m 6/19/2024
Total Nitrogen, mixed forms (NH3), (NH4), organic, (NO2) and (NO3) 0.45 mg/L 9/25/2024
Flow 0.43 cfs 6/19/2024
Cloud cover 5.00 % 6/19/2024
Phaeophytin - Periphyton (attached) 0.25 ug/L 9/25/2024
Temperature, air 28.00 deg C 6/19/2024
Depth, Secchi disk depth 1.00 m 6/19/2024
Depth of water column 1.10 m 6/19/2024
Wind velocity 6.00 knots 6/19/2024

Air Quality Details (2024–2025)

The Air Quality Index (AQI) measures how clean or polluted the air is. A lower AQI means cleaner air. Main pollutants include particulate matter like PM2.5, ozone, and others regulated by EPA standards.
Air quality data sourced from OpenAQ, aggregating official monitoring stations.

Yearly Average AQI National Average AQI Good Days Moderate Days Unhealthy Days Worst Day AQI Top Pollutant
23.3 41.4 342 10 0 57 (on 7/4/2024) PM2.5

Monthly AQI Trend

Monthly average AQI values over the past year. Lower values are better. Peaks may indicate pollution events.

Facility Compliance

Facility compliance and violation data come from the EPA's ECHO database.

1,814 monitored facilities

Total Violations: 1139

Significant Violations: 27

Total Penalties: $6,964,688

Despite 27 significant violations, Ellicott City reported 1,139 total violations across monitored facilities in 2024. This results in a compliance grade of D, reflecting below average adherence to environmental standards compared to national benchmarks.

About the Data

This report uses the latest publicly available environmental data:

  • Air Quality: Data sourced from the OpenAQ Platform, aggregating official air quality monitoring stations near Ellicott City.
  • Water Quality: Measurements from the Water Quality Portal, a collaboration between the USGS, EPA, and other agencies.
  • Facility Compliance: Sourced from the EPA's ECHO Database, detailing facility violations, penalties, and compliance rates.

All data is refreshed regularly and reflects the latest available figures for 2024.