A. Tests for methane concentration under this section shall be made by certified or qualified persons trained in the use of an approved detecting device which is properly maintained and calibrated. Tests shall be made at least twelve inches from the roof, face, ribs, and floor.

B. When one percent or more methane is present in a working place or an intake air course, including an air course in which a belt conveyor is located, or in an area where mining equipment is being installed or removed, work shall cease and electrical power shall be de-energized in the affected working place at the equipment except intrinsically safe atmospheric monitoring systems (AMS). Changes or adjustments shall be made to the ventilation system to reduce the concentration to below one percent. Only work to reduce the concentration of methane below one percent shall be permitted. This does not apply to other faces in the entry or slope in which work can be safely continued.

C. When one and one-half percent or more methane is present in a working place or an intake air course, including an air course in which a belt conveyor is located, or an area where mining equipment is being installed or removed, only work necessary to reduce the methane concentration to less than one and one-half percent will be permitted and all other personnel shall be withdrawn from the affected area. Electrically powered equipment in the affected area shall be de-energized and other mechanized equipment shall be shut off except for intrinsically safe atmospheric monitoring systems (AMS).

D. When one percent or more methane is present in a return or split between the last working place on a working section and where that split of air meets another split of air, or the location at which the split is used to ventilate seals or worked-out areas, changes or adjustments shall be made to the ventilation system to reduce the concentration of methane in the return air to less than one percent.

E. When one and one-half percent or more methane is present in a return air split between the last working place on a working section and where that split of air meets another split of air or the location where the split is used to ventilate seals or worked-out areas, everyone except those persons required to perform necessary work to correct the problem shall be withdrawn from the affected area. Other than intrinsically safe atmospheric monitoring systems (AMS), all equipment in the affected area shall be de-energized at the source. No other work shall be permitted in the affected area until the concentration of methane in the return air is less than one percent.

F. An alternative methane level up to one and one-half percent may be allowed in the return air split where the following precautions are met: (i) the quantity of air in the split ventilating the active workings is at least 27,000 cubic feet per minute in the last open crosscut; (ii) the methane content of the air in the split is continuously monitored during mining operations by an intrinsically safe atmospheric monitoring system (AMS) that gives a visual and audible signal on the working section when the methane in the return air reaches one and one-half percent; and (iii) rock dust is continuously applied with a mechanical duster to the return air course during coal production at a location in the air course immediately outby the most inby monitoring point or inby such point provided the mechanical duster is maintained in a permissible condition and does not adversely affect the AMS. When one and one-half percent or more methane is present where a return air alternative is applied, all persons shall be withdrawn, except those necessary to improve ventilation, and changes or adjustments shall be made to reduce the concentration of methane in the return air to below one and one-half percent as set forth in subsection E.

G. The concentration of methane in a bleeder split of air immediately before the air in the split joins another split of air, or in a return air course other than described in subsections D and E, shall not exceed two percent.

History

Code 1950, § 45-60.3; 1954, c. 191; 1966, c. 594, § 45.1-58; 1978, c. 120; 1994, c. 28; 1996, c. 774; 1999, c. 256.