In this chapter—
(1) Environs.—
The term “environs” means the territory surrounding the District of Columbia included in the National Capital region.
(2) National capital.—
The term “National Capital” means the District of Columbia and territory the Federal Government owns in the environs.
(4) Planning agency.—
The term “planning agency” means any city, county, bi-county, part-county, or regional planning agency authorized under state and local laws to make and adopt comprehensive plans.