The New Mexico Environment Department (NMED) plans to issue by Feb. 22 a final air permit for BHP Billiton’s San Juan Coal mining operations that for the first time considers greenhouse gas emissions from mining operations.
This mining facility is located approximately 16 miles west of Farmington, and 4.6 miles northeast of Waterflow, in San Juan County. It includes a surface mine and a longwall-equipped deep mine that supply captive coal to the nearby San Juan power plant operated by Public Service Co. of New Mexico.
A recent NMED permit notice said that coal combustion by-products (CCBs) consisting of fly ash and gypsum are transported by haul trucks from the power plant and taken to reclamation areas where bulldozers add it to piles of overburden for the mine’s ongoing reclamation of prior surface mining areas. The coal processing and transporting, as well as the reclamation activities, are a source of particulate matter emissions.
Particulate matter emissions from the coal prep plant are based on the maximum coal production capacity of 13 million tons per year. Particulate matter emissions from haul truck traffic are based on transport rates of: 8,200,000 tons per year of coal; 1,840,000 tons per year of fly ash; and 390,000 tons per year of gypsum.
This coal mining operation also releases methane from underground coal seams and surrounding rock strata, with that methane vented to the atmosphere using ventilation and degasification systems.
This is a first-time Title V Operating Permit for this mine and is required under state code. New Mexico’s Title V definition of “major source” has been amended to include a stationary source that emits or has the potential to emit greenhouse gas (GHG) emissions in amounts of 100,000 tpy or more CO2e, and 100 tpy or more GHG mass emissions. That definition became effective for existing stationary sources on July 1, 2011. The mine is now considered a “major source” for Title V purposes.
The NMED has made a preliminary determination that this facility will comply with the requirements of New Mexico Administrative Code and the New Mexico Air Quality Control Act. Therefore, the preliminary intent of NMED is to issue the air quality operating permit on or before Feb. 22, 2014.