40 C.F.R. § 21.6
(a) Statements shall not be issued for applications in the following areas:
(4) Other non-water related pollution abatement additions, alterations, or methods of operation which are not integral to meeting the requirements of the Act, although they may be achieving the requirements of another Federal or State law or regulation.
Comment: An example would be where stack emission controls were required on equipment that operated the water pollution control facility. This emission control equipment as an integral part of the water pollution control systems would be approvable. However, emission control equipment for a general purpose incinerator that only incidentally burned sewage sludge would not be approvable. The general purpose incinerator might also receive loan assistance but under separate procedures than those set out for water pollution control.