The U.S. Surface Transportation Board (“STB”) on December 1, 2009 instituted a formal proceeding to examine tariff rules established by the BNSF Railway Company (“BNSF”) that limit the amount of coal dust that can be emitted by trains transporting coal over certain railroad lines leaving the Powder River Basin (“PRB”). The STB’s decision comes in response to a petition filed by Arkansas Electric Cooperative Corporation (“AECC”), which challenged BNSF’s tariff rules as violating the railroad’s common carrier obligation under federal law. Before the decision, BNSF disputed AECC’s allegations and asked the STB to declare that its dust emission limits are reasonable and lawful. The STB will examine (1) whether the tariff rules are unreasonable; (2) whether BNSF may implement rules to control dust; and, (3) what actions BNSF may take to enforce compliance with its rules.
 Because of industry-wide interest in this matter, the STB decided to solicit broad public participation. Thus, the proceeding is not limited to shippers and carriers of PRB coal. Rather, any member of the public may participate. However, in order to participate, an interested person must notify the STB in writing of its intent to participate no later than December 11, 2009.
 The proceeding will be governed by procedures and a schedule established in the decision. In particular, the STB decided to allow discovery to take place because of the fact-intensive nature of the issues. Participants may take discovery of BNSF, AECC, and any other shipper or shipper organization potentially affected by BNSF’s tariff rules. Discovery closes on February 1, 2010. Under the procedural schedule, opening evidence is due March 16, 2010; reply evidence is due April 30, 2010; and, rebuttal evidence is due May 17, 2010. In order to protect sensitive and confidential business information, the proceeding will be subject to a protective order issued in conjunction with the decision.