“Construction” means any:
1. Preliminary planning to determine the feasibility of treatment works or pollution control projects;
2. Engineering, architectural, legal, fiscal or economic investigations or studies, surveys, designs, plans, working drawings, specifications or procedures which comply with the requirements adopted pursuant to 33 U.S.C. §§ 1381 et seq.; or
3. Other necessary actions including the erection, building, acquisition, alteration, remodeling, improvement or extension of treatment works or pollution control projects, or the inspection or supervision of any item set forth in this section.