The Air Quality e-Notification system provides information as a public service and is not intended as a warning or alert. The measurements taken at Longmont’s air monitoring stations are part of a contract with Boulder Atmosphere Innovation Research (Boulder AIR) to analyze and report atmospheric emissions and possible pollutants from oil and gas operations near the city as well as reporting measurements of greenhouse gases and other emissions from non-oil and gas well sources, such as motor vehicles.

On Monday, November 29, 2021 at approximately 4:15 pm, the Union Reservoir air monitoring station recorded a sudden increase in methane and other VOCs (volatile organic compounds). The increase lasted for approximately 15 minutes before levels returned to normal. Methane levels were significantly elevated and the chemical signatures indicate that the source was likely natural gas. Benzene and toluene were also elevated; however, these compounds were not recorded at levels above the State’s health guidance values.

Despite being a short-term event, data collection during events such as this plays an important role in the air quality study being carried out by Longmont’s contractor Boulder AIR. The information will also be part of the larger data set shared with the scientific and governmental groups that have expressed interest in our data, and will be provided in upcoming regulatory hearings when relevant.

The wind direction at the time of the event suggests that the source is located east/southeast of Union Reservoir. Longmont’s air quality monitoring stations are not designed to identify specific sources of air pollution. Additionally, the oil and gas surface operations east of Union Reservoir are located outside Longmont City boundaries and are outside the City’s legal jurisdiction. Oil and gas operators working directly east of Longmont will be notified of the event and complaints will be filed with the Colorado Oil and Gas Conservation Commission (COGCC) and Colorado Department of Public Health and the Environment (CDPHE).

As always, preliminary data from this study can be viewed online at http://www.bouldair.com/longmont.htm.  Boulder AIR’s preliminary data are averaged to allow near-real-time reporting.  Please note that data displayed on the 3-day graphs may differ slightly from data displayed on 30-day graphs because 3-day graphs show 5-minute averages and 30-day graphs show 15-minute averages.   

About the Air Quality Study: As directed by City Council, and in accordance with the objectives of the Sustainability Plan, an air quality monitoring program has been developed to monitor oil and gas emissions, and the overall air quality in the City of Longmont. Air monitoring instruments are located at Union Reservoir and next to Lykins Gulch. Air monitors track the presence of compounds such as carbon dioxide, ozone, nitrogen oxides, methane, benzene, and particulate matter. Visit bouldair.com/longmont to see Longmont’s preliminary air quality data in near real-time.