(a) Comparison to an established standard. Success
of revegetation shall be judged on the effectiveness of the vegetation
for the approved postmining land use, the extent of cover compared
to the cover occurring in natural vegetation of the area, and the
general requirements of §12.555 and §12.556 of this title
(relating to Revegetation: General Requirements; and Revegetation:
Use of Introduced Species).
  (1) Standards for success and statistically valid sampling
techniques for measuring success shall be selected by the Commission.
  (2) Standards for success shall include criteria representative
of unmined lands in the area being reclaimed to evaluate the appropriate
vegetation parameters of ground cover, production, or stocking. Ground
cover, production, or stocking shall be considered equal to the approved
success standard when they are not less than 90% of the success standard.
The sampling techniques for measuring success shall use a 90% statistical
confidence interval (i.e., one-sided test with a 0.10 alpha error).