Section 690-404 - Ventilation(a) Minimum quantities.--Minimum quantities of ventilating air where diesel-powered equipment is operated shall be maintained pursuant to this section.(b) Approvals.-- Each specific model of diesel-powered equipment shall be approved by the department before it is taken underground. The department shall require that an approval plate be attached to each piece of the diesel-powered equipment. The approval plate shall specify the minimum ventilating air quantity for the specific piece of diesel-powered equipment. The minimum ventilating air quantity shall be determined by the bureau based on the amount of air necessary at all times to maintain the exhaust emissions at levels not exceeding the exposure limits established under section 419. (c) Minimum air quantities.--The minimum quantities of air in any split where any individual unit of diesel-powered equipment is being operated shall be at least that specified on the approval plate for that equipment. Air quantity measurements to determine compliance with this requirement shall be made at the individual unit of diesel-powered equipment.(d) Multiple units in operation.-- Where multiple units are operated, the minimum quantity shall be at least the total of 100% of MSHA's Part 7 approval plate ventilation rate for each unit operating in that split. Air quantity measurements to determine compliance with this requirement shall be made at the most downwind unit of diesel-powered equipment that is being operated in that air split. If MSHA promulgates new regulations that change the MSHA Part 7 approval plate ventilation rate, the minimum quantity where multiple units are operated shall be revised on a direct ratio basis upon recommendation of the technical advisory committee in accordance with section 424. (e) Minimum quantities of air in certain splits.--The minimum quantities of air in any split where any diesel-powered equipment is operated shall be in accordance with the minimum air quantities required in subsections (a), (b) and (c) and shall be specified in the mine diesel ventilation plan.2008, July 7, P.L. 654, No. 55, §404, effective in 180 days [ 1/5/2009].