§ 21.2 Definitions.

(a) Small business concern means a concern defined by section 2[3] of the Small Business Act, 15 U.S.C. 632, 13 CFR part 121, and regulations of the Small Business Administration promulgated thereunder.

(b) For purposes of paragraph 7(g)(2) of the Small Business Act, necessary and adequate refers to additions, alterations, or methods of operation in the absence of which a small business concern could not comply with one or more applicable standards. This can be determined with reference to design specifications provided by manufacturers, suppliers, or consulting engineers; including, without limitations, additions, alterations, or methods of operation the design specifications of which will provide a measure of treatment or abatement of pollution in excess of that required by the applicable standard.

(c) Applicable Standard means any requirement, not subject to an exception under § 21.6, relating to the quality of water containing or potentially containing pollutants, if such requirement is imposed by: