Control of Diesel Particulate Matter

Beginning in 2001 to present, Stillwater Mining Company has conducted extensive research of available diesel particulate matter (dpm) control technologies in an effort to comply with tightened underground air quality standards. Company research was expanded to include partnerships with various engine manufacturers, government agencies, trade associations and industry coalitions.

Having the ability to conduct isolated zone studies makes the Stillwater Mine a unique test ground for new dpm control technologies. The Stillwater Mine in partnership with the Mine Safety and Health Administration (MSHA), National Institute for Occupational Safety and Health (NIOSH) and the MARG Diesel Coalitions have conducted two extensive isolated zone studies to determine the effectiveness of individual dpm controls as well as controls used in combination. Once the effectiveness of these controls was determined in an isolated zone, a phase two study was undertaken to determine their effectiveness in an actual mining environment. A third study is scheduled for mid-2004 to research the potential for alternative fuels, fuel additives and ultra low sulfur fuels when used in combination with a variety of diesel particulate filters.

Both the Stillwater and East Boulder mines have completed extensive upgrades to improve mine ventilation systems. Ventilation improvements were initiated to increase the volume of air entering the mine, minimize the re-use of air by multiple work locations, increase intake to exhaust streams and create additional fresh air escape-ways.

Unfortunately, even with the extensive research and utilization of diesel particulate filters, low sulfur fuel and ventilation improvements, the mines continue to struggle to comply with the MSHA 400 microgram per cubic meter of air standard. While efforts continue to reduce dpm emissions, the company has implemented mandatory respiratory protection programs to reduce employee exposures to dpm and eliminate any potential health hazard.

Continued research of feasible control technologies will continue along with industry and agency partnerships until dpm issues can be remedied.

Compliance with MSHA Noise Standards

The Stillwater Mine and Mine Safety and Health Administration entered into a noise compliance agreement on July 9, 2003. This innovative approach to compliance is composed of two components. A settlement agreement that outlines enforcement procedures and a compliance action plan that clearly defines feasible engineering controls for equipment, a hearing conservation program, and exposure sampling strategy. This unique approach to enforcement is scheduled to expire in October of 2004. Stillwater Mining Company will request of MSHA that the agreement be extended at the Stillwater Mine and a similar agreement be created for the East Boulder Mine. It is believed this approach has improved relationships between the company and agency while creating opportunities for innovation and flexibility towards compliance.

It must be noted the hearing conservation program in place at both mines is highly effective. Hearing protectors are mandatory for all persons entering the mine. Annual audiometric testing confirms these protectors have prevented significant hearing loss among employees.