1. (a) Any diesel engine introduced into an underground area of a mine covered by this part after July 5, 2001, other than an engine in an ambulance or fire fighting equipment which is utilized in accordance with mine fire fighting and evacuation plans, must either:

   1. (1) Have affixed a plate evidencing approval of the engine pursuant to subpart E of Part 7 of this title or pursuant to Part 36 of this title; or

   2. (2) Meet or exceed the applicable particulate matter emission requirements of the Environmental Protection Administration listed in Table 57.5067-1, as follows:

      Table 57.5067-1

      EPA requirement	EPA category	PM limit
      40 CFR 86.094-8(a)(1)(i)(A)(2)	light duty vehicle	0.1 g/mile.
      40 CFR 86.094-9(a)(1)(i)(A)(2)	light duty truck	0.1 g/mile.
      40 CFR 86.094-11(a)(1)(iv)(B)	heavy duty highway engine	0.1 g/bhp-hr.
      40 CFR 89.112(a)	nonroad (tier, power range)	varies by power range:
      	tier 1 kW<8 (hp<11)	1.0 g/kW-hr (0.75 g/bhp-hr).
      	tier 1 8≤kW<19 (11≤hp<25)	0.80 g/kW-hr (0.60 g/bhp-hr).
      	tier 1 19≤kW<37 (25≤hp<50)	0.80 g/kW-hr (0.60 g/bhp-hr).
      	tier 2 37≤kW<75 (50≤hp<100)	0.40 g/kW-hr (0.30 g/bhp-hr).
      	tier 2 75≤kW<130 (100≤hp<175)	0.30 g/kW-hr (0.22 g/bhp-hr).
      	tier 1 130≤kW<225 (175≤hp<300)	0.54 g/kW-hr (0.40 g/bhp-hr).
      	tier 1 225≤kW<450 (300≤hp<600)	0.54 g/kW-hr (0.40 g/bhp-hr).
      	tier 1 450≤kW<560 (600≤hp<750)	0.54 g/kW-hr (0.40 g/bhp-hr).
      	tier 1 kW≥560 (hp≥750)	0.54 g/kW-hr (0.40 g/bhp-hr).
      Notes:
      “g” means grams.
      “hp” means horsepower.
      “g/bhp-hr” means grams/brake horsepower-hour.
      “kW” means kilowatt.
      “g/kW-hr” means grams/kilowatt-hour.

2. (b) For purposes of paragraph (a):

   1. (1) The term “introduced” means any engine added to the underground inventory of engines of the mine in question, including:

      1. (i) An engine in newly purchased equipment;
      2. (ii) An engine in used equipment brought into the mine; and
      3. (iii) A replacement engine that has a different serial number than the engine it is replacing; but
   2. (2) The term “introduced” does not include engines that were previously part of the mine inventory and rebuilt.
   3. (3) The term introduced does not include the transfer of engines or equipment from the inventory of one underground mine to another underground mine operated by the same mine operator.

[66 FR 5907, Jan. 19, 2001, as amended at 66 FR 27864, May 21, 2001; 67 FR 9184, Feb. 27, 2002]