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Air Resource Management Program - Monitoring Pollutants in the Air

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Ozone

A person on a forest hillside conducting ozone testing from an outdoor ozone monitoring station. There are small patches of snow on the ground.
John Korfmacher, physical scientist, conducting ozone monitoring at Pike-San Isabel National Forest, Colorado. (USDA Forest Service photo)

Surface ozone is a pollutant, regulated by the Environmental Protection Agency. Unlike stratospheric ozone (the “ozone layer”), surface ozone can cause damage to foliage and growth inhibition in a range of tree and understory species. The Forest Service Rocky Mountain Research Station began surface ozone data collection in 2006 on the White River National Forest in western Colorado in response to concerns about impacts of oil and gas development on air quality in remote, high-elevation areas, especially designated federal wilderness. The network expanded in the following years to a total of 25 small stand-alone, solar-powered stations. Besides Colorado, stations are located in Nebraska, Wyoming, New Mexico, Arizona, Utah, and Nevada.

The network’s mission, monitoring surface ozone levels at sites adjacent to wilderness areas, supports assessments of forest and grassland conditions across parts of three Forest Service regions. Six sites collect data year-round, while the remaining 19 are operated seasonally, usually April through September. Data collected from these 25 sites are part of the larger Air Quality System. The Rocky Mountain Research Station also publishes an annual report detailing ozone trends and hazards across the network’s area.

A map of active ozone air quality monitors across the Continental United States of America.
Active ozone air quality monitors in the continental United States. There are also monitors in Puerto Rico, Hawaii, and Alaska. (Image from the AirData Air Quality Monitors interactive map by the Environmental Protection Agency)

Follow these steps to replicate the map of monitors managed by the Forest Service and download annual and daily data.

  1. Navigate to the Interactive Map of Air Quality Monitors page and launch the map app.

  2. Turn on the layer called “Ozone – Active”.

  3. Click on the three dots on the layer and click “View in Attribute Table”.

  4. In the Attribute Table that appears, click on “Options” on the left side, then “Filter”.

  5. Click on “Add expression” with the following statement: Reporting Agency (string) is US Forest Service.

  6. Change the basemap in the upper right toolbar to “Topographic”.

Resources:

Methane

The Forest Service is part of the multi-agency effort to remediate orphaned wells. Orphaned wells on Forest Service-managed lands are primarily concentrated on four national forests: the national forests and grasslands in Texas, the Allegheny National Forest, the Daniel Boone National Forest, and the Wayne National Forest. Crew members approach this work by identifying the locations of orphaned wells, determining if the wells are leaking methane, then planning their protocol depending on the specific circumstances of each wellsite.

The exact number of orphaned wells in the United States is not known for a few different reasons according to the Department of the Interior: the number can change, inventories are collected by different entities, and inventories are often comprised of both “documented wells” and “undocumented wells.” The estimated number of undocumented orphaned wells in the United States is between 310,000 and 800,000, but the true number may be much higher. Scientists may use historical land use records, maps, discussions with nearby residents, and technological devices, such as satellites or drones, to assist with locating orphaned wells.

The team uses many technological devices and scientific instruments to first assess whether there is a leak, then to locate and test for multiple types of methane leaks from orphaned wells. This is important since the leaks may occur at different locations of the wellsite. For example, a gas rover can be used to scan the well and nearby infrastructure. This handheld sensor searches for locations with elevated methane concentrations that indicate a leak. A Forward Looking InfraRed instrument can also be used to detect and locate any potential leaks, which are helpful for scanning hard-to-reach areas as they offer thermal imaging and infrared for gas detection.

Federal agencies provide quantitative estimates (flow rates) of methane leaks at orphaned wells. Once a well is selected and funded for plugging, a variety of methane flow rate measurement tools are available depending on the specifics of each well.

The team must be able to adapt to real-world challenges that arise from measuring flow rates at orphaned wells, the various types of wells they may encounter, and how to adjust techniques to obtain valid measurements given these conditions. Some technical field challenges include locating undocumented wells, navigating varying conditions of well sites, and considering endangered species and their protections.

Conditions of orphaned wells and their surroundings can differ drastically. For wells that are determined to be leaking methane, scientists may or may not be able to measure the emissions depending on the specific circumstance. Some wells can be easily covered by a portable chamber to obtain flow rate. Others cannot have flow rate measurements or estimates conducted due to safety or inaccessibility, so the emissions remain unknown or unknowable.

Two people wearing hard hats testing for methane leaks from an old well head in a grass covered forest clearing.
District staff learning how to use a handheld methene sensor. The orphaned well is in a basin with several feet of standing water. (USDA Forest Service photo by Jacob Deal)
An old, rust coverd well head surrounded by lush green vegetation in a forest.
An orphaned well separator tank. (USDA Forest Service photo by Jeff Sorkin)
Part of a large old pump jack on an orphaned well, hidden in the thick vegetation.
A large old pump jack on an orphaned well, hidden in the thick vegetation. (USDA Forest Service photo by Jacob Deal)
4. An old pump jack on an orphaned well. The storage tank is in the background.
An old pump jack on an orphaned well. The storage tank is in the background. (USDA Forest Service photo by Jeff Sorkin)
5. A Forward-Looking Infrared (FLIR) camera showing that the well is not leaking methane.
A Forward-Looking Infrared (FLIR) camera showing that the well is not leaking methane. (USDA Forest Service photo by Jacob Deal)

Resources:

Visibility

A covered air quality monitoring station with equipment under a covered structure and monitoring equipment on poles attached to the roof.
An IMPROVE site. (USDA Forest Service photo)
A map of the continental United States displaying Forest Service IMPROVE sites, National Park Service IMPROVE sites representing Forest Service wilderness, and Forest Service Class I wilderness areas.
Forest Service IMPROVE Network Sites, 2024. (USDA Forest Service infographic by Scott Copeland)

The Forest Service conducts visibility monitoring as a member of the Interagency Monitoring of Protected Visual Environments (IMPROVE) program. The program monitoring network measures particulate air pollution that causes haze. Particulates are collected on filters at each site. Samples are then analyzed at a central lab to determine the amount of haze present and which pollutants contribute to the haze. The data collected can be used to determine trends in air quality and progress towards the national visibility goal of no human caused visibility impairment in class I areas.

The Forest Service also monitors some wilderness areas using webcams to provide near real-time online images to interested viewers.

Resources

Smoke

A person standing next to a smoke monitoring station, with left hand hold open a panel door while looking at the camera.
Rick Graw, regional air program manager, standing next to a smoke monitoring station. (USDA Forest Service photo)

Air quality specialists use weather, smoke models, and air quality monitoring data to inform fire management staff of potential smoke impacts. Fire managers use this information to implement prescribed burning techniques that will reduce smoke impacts on air quality. Air quality monitoring provides state and local health departments, as well as the public, with real-time air quality information. This data is critical during wildfire season when smoke levels are often at unhealthy levels.

Here are a few examples of how Forest Service staff across the nation approach smoke monitoring and management.

  • Northern Region: Staff maintain a few E-Sampler portable particulate monitors that assess particulate levels resulting from wildland fire smoke. These monitors are equipped with satellite uplink capabilities so the concentrations can be monitored in near real time over the internet.

  • Southwestern Region: Staff worked to enhance real-time, daily wildfire smoke coordination with air quality partners at the local, state, and federal level in New Mexico. They also contributed to Air Quality Alerts, that were made available to the public, media, and other local, state, and Federal partners throughout the state.

  • Pacific Southwest Region: Staff collaborated with National Park Service and Bureau of Land Management to increase joint emergency smoke monitoring, such as during wildland fire incidents. Incident smoke monitoring has become much more seamless and efficient between agencies and prescribed fire monitoring has become more of an interagency effort. Staff have also directly supported the Sequoia, Kings Canyon, and Yosemite National Parks with smoke monitoring.

  • Southern Region: Staff engaged with Air Resource Advisors, highly trained air specialists tasked with providing technical, on-the-ground support during wildfires, to train them to support prescribed fire activities, including deployment of smoke monitors for measuring community pollution levels.

Resources