Approved replicable methodology (ARM) means part 71 permit terms that:
(1) Specify a protocol which is consistent with and implements an applicable requirement, or requirement of this part, such that the protocol is based on sound scientific and/or mathematical principles and provides reproducible results using the same inputs; and
(2) Require the results of that protocol to be recorded and used for assuring compliance with such applicable requirement, any other applicable requirement implicated by implementation of the ARM, or requirement of this part, including where an ARM is used for determining applicability of a specific requirement to a particular change.
40 CFR § 71.2
The following definitions apply to part 71. Except as specifically provided in this section, terms used in this part retain the meaning accorded them under the applicable requirements of the Act.