Air emissions associated with mining and preparation processes can include dust, emissions from combustion of fuels including vehicle exhaust, and release of naturally occurring gases from the geologic strata during the mining process.
Potential dust sources include vehicle traffic on unpaved mine roads, dumping and loading activities, material crushing, storage, and — at certain sites — blasting.
A variety of methods are used to prevent or limit the generation of fugitive and non-fugitive dust emissions. The primary means is to limit those activities that create the potential for generating airborne dust. These may include strategically positioning equipment and routing vehicle traffic patterns for shortened haul ways as well as surfacing long-term roads with stone.
A Perfect Compliance Rate
Our subsidiaries had a perfect compliance rate while operating around-the-clock and year-round.
While operations are underway, specific engineering controls are designed into the process equipment for the sole purpose of minimizing the generation of airborne particulates. Examples of these engineering controls include enclosures on coal and refuse conveyance devices, water sprays at material transfer points, the application of dust suppressants on road surfaces and coal storage piles, and the use of baghouse filter systems to capture particulates during material transfers of bulk loads of fine-grained process materials, to mention only a few. These engineering controls are designed and built into the permitted and approved designs of each of our operations.
While operations are underway, specific engineering controls are designed into the process equipment for the sole purpose of minimizing the generation of airborne particulates.
The teams at each operation understand and maintain compliance with the requirements of air quality permits and perform regular self-inspections to monitor for visible emissions and conduct performance tests on air quality control devices in order to ensure proper operation. Our fully compliant systems operations and their controls are inspected by state regulators on a regular basis.
Interaction with communities near or adjacent to our facilities led two Arch operations to deploy new initiatives in 2019 to control fugitive emissions from coal stockpiles. During high-wind events, excess coal dust can become airborne. To prevent the release of particulates, and to preserve valuable product, these mines — the Viper mine in Illinois and the West Elk mine in Colorado — developed efficient methods to apply a surface crusting agent to coal piles, using a combination of water cannons and dozer-mounted applicators, in order to solidify the surface of the pile. These crusting agents are applied in lieu of traditional water applications, which tend to have limited utility once the water evaporates. The crusting agents remain in place for as long as the pile remains undisturbed.
Our subsidiaries held a total of nine air permits in 2019, and had a perfect compliance rate while operating around-the-clock and year-round at most of their operations.