(a) Within 180 days of October 18, 1989, the Mayor shall, pursuant to subchapter I of Chapter 5 of Title 2, issue proposed rules to implement the provisions of this subchapter, including rules that establish categorical exemptions for major actions that would have no significant impact on the environment. The proposed rules shall be submitted to the Council for a 45-day period of review, excluding Saturdays, Sundays, legal holidays, and days of Council recess. If the Council does not approve or disapprove the proposed rules, in whole or in part, by resolution within this 45-day review period, the proposed rules shall be deemed approved.
(b) The District Department of the Environment shall issue rules to assist District agencies in the review of an environmental impact screening form and in the preparation of an EIS, pursuant to subchapter I of Chapter 5 of Title 2.