43 CFR §3510.15

1. (a)The lands are contiguous to your existing Federal lease or to non-Federal lands you own or control;
2. (b)The new fringe lease does not exceed the maximum size allowed in a lease, as specified in § 3503.37 of this part;
3. (c)The acreage of the modified lease, including additional lands, is not in excess of the maximum size allowed for a lease, as specified in § 3503.37 of this part;
4. (d)The mineral deposit is not in an area of competitive interest to holders of other active mining units in the area;
5. (e)The lands for which you applied for a fringe acreage lease lack sufficient reserves of the mineral resource to warrant independent development;
6. (f)
   1. (1)The lands for which you applied for a lease modification contain known deposits of the same mineral deposit that can be mined only as part of the mining operations on the original Federal lease; or
   2. (2)
      1. (i)The acreage to be added does not contain known deposits of the same mineral; and
      2. (ii)The acreage to be added will be used for surface activities that are necessary for the recovery of the mineral deposit on the original Federal lease; and
      3. (iii)Had the acreage added by the modification been included in the original Federal lease at the time of that lease's issuance, the original Federal lease would have been reasonably compact.
7. (g)Leasing the lands will conserve natural resources and will provide for economical and efficient recovery as part of a mining unit; and
8. (h)You meet the qualification requirements for holding a lease described in subpart 3502 of this chapter and the new or modified lease will not cause you to exceed the acreage limitations described in § 3503.37.