Current through Register Vol. XLI, No. 19, May 10, 2024
Section 56-23-7 - Exhaust Gas Monitoring and Control7.1. In monitoring and controlling exhaust gases, the ambient concentration of exhaust gases in the mine atmosphere shall not exceed 35 ppm ceiling for carbon monoxide (CO), 25 ppm ceiling for nitric oxide (NO) and 3 ppm ceiling for nitrogen dioxide (NO2). The concentration of these exhaust gases shall be measured at the equipment operator's or equipment attendant's position and in by the last piece of diesel-powered equipment operating in the same split of air. Measurements shall be made weekly or more often if necessary by a qualified person and shall be conducted pursuant to the requirements of this section.7.2. Measurement of exhaust gases shall be made with a sampling instrument no less precise than detector tubes.7.3. If the concentration of any of the gases listed in section 7.1 is seventy-five percent or more of its exposure limit, changes to the use of the diesel equipment, the mine ventilation or other modifications to the mining process shall be made.7.4. If the concentration of any of the gases listed in section 7.1 exceeds the exposure limit, the diesel equipment operating in that split shall be removed from service immediately and corrective action taken. After corrective action has been taken by the mine operator, the diesel equipment may be returned to service in its regular operating mode for emissions testing purposes only, and emissions testing shall be conducted immediately to assure that the concentration does not exceed seventy-five per cent of the exposure limit. Corrective action must be taken until the concentration does not exceed seventy-five percent of the exposure limit before the diesel equipment can be returned to full operation.7.5. In addition to the other maintenance requirements set forth in this rule, the mine operator shall comply with the following requirements: 7.5.1. Repair or adjustment of the fuel injection system, engine timing or exhaust omissions control and conditioning systems shall only be performed by qualified mechanics authorized by the engine manufacturer or ASE certified diesel mechanics.7.5.2. Complete testing of the emissions system in accordance with section 20 of this rule shall be conducted prior to any piece of diesel-powered equipment being put into service, after any repair or adjustment to the fuel delivery system, engine timing or exhaust emissions control and conditioning system.7.5.3. Service and maintenance of the intake air filter exhaust particulate filter and the exhaust system shall be performed at specific time intervals based on the component manufacturer's recommendation, compliance with the engine or emissions control operation specifications and, as needed, based on the on-board diagnostics and/or emissions test results. Accurate records shall be maintained of all such service and maintenance.