Green Bay, Wisconsin

Environmental Quality Report Card

Green Bay 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
25.2 AQI

Yearly average AQI (2024): 25.2. National average: 41.4. 23 moderate days, 1 unhealthy days recorded.

Water Quality (Key Indicators)

Grade B
7.96 pH

Latest pH level (2024): 7.96. Ideal range: 6.5–8.5.

Facility Violations

Grade C
9 significant violations

Facilities like factories and treatment plants had 9 significant and 1530 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 7.96 6.5 - 8.5 A 5/18/2025
Ammonia 0.02 mg/L <0.5 A 4/20/2025
Turbidity 16.20 NTU <5 F 4/20/2025

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
Dissolved oxygen saturation 91.80 % 5/18/2025
Salinity 0.36 ppt 11/7/2024
Chlorophyll c 2.00 ug/L 9/23/2024
Transparency, tube with disk 55.00 cm 5/18/2025
Temperature, water 17.40 deg C 5/18/2025
Dissolved oxygen (DO) 8.80 mg/L 5/18/2025
Specific conductance 345.30 umho/cm 5/18/2025
Depth, Secchi disk depth 3.00 ft 9/23/2024
Phosphorus 0.23 mg/L 5/4/2025
Nitrate + Nitrite 0.77 mg/L 4/20/2025
Total suspended solids 42.90 mg/L 5/4/2025
Chlorophyll a 12.00 ug/L 9/23/2024
Escherichia coli 15.00 #/100mL 5/18/2025
Total Phosphorus, mixed forms 0.04 mg/L 9/23/2024
Pheophytin a 7.80 ug/L 9/23/2024
Chloride 28.00 mg/L 4/20/2025
Total Kjeldahl nitrogen (Organic N & NH3) 1.31 mg/L 4/20/2025
Cloud cover 90.00 % 5/18/2025
Chlorophyll b 0.09 ug/L 9/23/2024
Chlorophyll a, corrected for pheophytin 16.00 ug/L 9/23/2024
Sulfate 150.00 mg/L 8/25/2024
Chlorophyll a (probe relative fluorescence) 47.80 ug/L 4/20/2025
Temperature, air 7.22 deg C 4/20/2025
Flow 25.11 ft3/sec 5/4/2025
Calcium carbonate 172.00 mg/L 4/20/2025
Suspended Sediment Concentration (SSC) 23.60 mg/L 8/27/2024
Magnesium 23.90 mg/L 4/20/2025
Calcium 39.80 mg/L 4/20/2025
Organic carbon 8.59 ppm 7/16/2024

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
25.2 41.4 341 23 1 156 (on 6/3/2025) 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.

2,113 monitored facilities

Total Violations: 1530

Significant Violations: 9

Total Penalties: $10,868,880

Despite 9 significant violations, Green Bay reported 1,530 total violations across monitored facilities in 2024. This results in a compliance grade of C, reflecting 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 Green Bay.
  • 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.