(4) Storm water quantity and quality standards for storm water management systems.

C. The owner or operator of a site designated as a significant existing source shall apply to the department for approval of a storm water management system.

D.__"Significant existing source" does not include:

(1)__Types of sources or activities described in subsection 7;

(2)__The developed area of a facility required to meet ongoing storm water management standards pursuant to a storm water general or individual permit issued pursuant to section 413; and

(3)__A municipal storm water conveyance system unless the storm water pollution originates with the conveyance system.

Sec. 8. Transition. Prior approval is required pursuant to the Maine Revised Statutes, Title 38, section 420-D if a person constructs, or causes to be constructed, a project that includes one acre or more of disturbed area on or after the effective date of this Act.

1. If a person has a project that required approval prior to the effective date of this Act, the project continues to require approval on and after the effective date of this Act.

2. If a person has a project that did not require approval prior to the effective date of this Act, and the person proposes to construct or cause to be constructed a project that includes one or more acres of disturbed area on or after the effective date of this Act, then approval is required. Only the construction on or after the effective date of this Act requires prior approval.

3. A disturbed area of less than one acre continues to be counted toward the one-acre permit threshold under this section following permanent stabilization to the extent it is considered developed area as defined in rules adopted by the Department of Environmental Protection.