Longmont, Colorado
Environmental Quality Report Card
Longmont 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 AYearly average AQI (2024): 21.4. National average: 41.4. 18 moderate days, 0 unhealthy days recorded.
Water Quality (Key Indicators)
Grade BLatest pH level (2024): 7.71. Ideal range: 6.5–8.5.
Facility Violations
Grade CFacilities like factories and treatment plants had 41 significant and 1912 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 |
|---|---|---|---|---|
| Lead | 0.00 mg/L | <0.015 | A | 9/2/2024 |
| Arsenic | 0.33 mg/L | <0.01 | F | 11/4/2024 |
| Copper | 0.33 mg/L | <1.3 | A | 11/4/2024 |
| Zinc | 1.78 mg/L | <5 | A | 11/4/2024 |
| pH | 7.71 | 6.5 - 8.5 | A | 11/4/2024 |
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 |
|---|---|---|---|
| Aluminum | 12.10 | ug/L | 11/4/2024 |
| Uranium-238 | 10.60 | ug/L | 11/4/2024 |
| Sodium | 56.80 | mg/L | 11/4/2024 |
| Manganese | 35.50 | ug/L | 11/4/2024 |
| Iron | 54.60 | ug/L | 11/4/2024 |
| Specific conductance | 1224.60 | uS/cm | 11/4/2024 |
| Selenium | 0.78 | ug/L | 11/4/2024 |
| Alkalinity, total | 220.00 | mg/L | 11/4/2024 |
| Escherichia coli | 167.00 | #/100mL | 10/23/2024 |
| Dissolved oxygen (DO) | 8.76 | mg/L | 11/4/2024 |
| Nickel | 28.60 | ug/L | 11/4/2024 |
| Calcium | 125.00 | mg/L | 11/4/2024 |
| Sulfate | 473.00 | mg/L | 11/4/2024 |
| Total Nitrogen, mixed forms | 5.04 | mg/L | 11/4/2024 |
| Fluoride | 0.21 | mg/L | 11/4/2024 |
| Chloride | 17.10 | mg/L | 11/4/2024 |
| Temperature, water | 6.01 | deg C | 11/4/2024 |
| Potassium | 2.22 | mg/L | 11/4/2024 |
| Hardness, Ca, Mg | 601.00 | mg/L | 11/4/2024 |
| Magnesium | 61.10 | mg/L | 11/4/2024 |
| Organic carbon | 2.91 | mg/L | 11/4/2024 |
| Molybdenum | 1.65 | ug/L | 11/4/2024 |
| Chromium | 10.20 | ug/L | 10/8/2024 |
| Total Phosphorus, mixed forms | 0.01 | mg/L | 10/8/2024 |
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 |
|---|---|---|---|---|---|---|
| 21.4 | 41.4 | 337 | 18 | 0 | 88 (on 7/31/2024) | 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.
4,261 monitored facilities
Total Violations: 1912
Significant Violations: 41
Total Penalties: $13,880,625
Despite 41 significant violations, Longmont reported 1,912 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 Longmont.
- 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.