Missoula, Montana

Environmental Quality Report Card

Missoula reports good air quality, with AQI levels better than the national average. Water tests indicate concerning conditions across key measures. Facility compliance with environmental standards is above the national average.

Air Quality (Annual Overview)

Grade A
31 AQI

Yearly average AQI (2024): 31.0. National average: 41.4. 52 moderate days, 3 unhealthy days recorded.

Water Quality (Key Indicators)

Grade N/A
7.86 pH

Latest pH level (2024): 7.86. Ideal range: 6.5–8.5.

Facility Violations

Grade B
5 significant violations

Facilities like factories and treatment plants had 5 significant and 635 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 7.86 6.5 - 8.5 A 10/21/2024
Turbidity 0.75 NTU <5 A 10/21/2024
Ammonia 0.02 mg/L <0.5 A 7/14/2024
Copper 0.00 mg/L <1.3 A 4/14/2025

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
Chloride 1.87 mg/L 4/14/2025
Total Nitrogen, mixed forms 0.18 mg/L 10/21/2024
Total Phosphorus, mixed forms 0.01 mg/L 10/21/2024
Total dissolved solids 115.00 mg/L 10/21/2024
Nitrate + Nitrite 0.04 mg/L 10/21/2024
Temperature, water 9.90 deg C 10/21/2024
Total suspended solids 14.00 mg/L 4/14/2025
Orthophosphate 0.00 mg/L 10/21/2024
Dissolved oxygen saturation 103.30 % 10/21/2024
Dissolved oxygen (DO) 10.55 mg/L 10/21/2024
Specific conductance 177.40 uS/cm 10/21/2024
Calcium 16.00 mg/L 4/14/2025
Sulfate 7.90 mg/L 4/14/2025
Aluminum 0.28 mg/L 4/14/2025
Alkalinity, total 48.00 mg/L 4/14/2025
Organic carbon 2.50 mg/L 4/14/2025
Bicarbonate 58.00 mg/L 4/14/2025
Potassium 1.00 mg/L 4/14/2025
Magnesium 4.00 mg/L 4/14/2025
Hardness, Ca, Mg 58.00 mg/L 4/14/2025
Sodium 4.00 mg/L 4/14/2025
Selenium 0.00 mg/L 4/14/2025

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
31 41.4 303 52 3 152 (on 9/8/2024) 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.

2,420 monitored facilities

Total Violations: 635

Significant Violations: 5

Total Penalties: $7,100,000

Despite 5 significant violations, Missoula reported 635 total violations across monitored facilities in 2024. This results in a compliance grade of B, reflecting strong 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 Missoula.
  • 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.