Sec. 1. 38 MRSA §420, sub-§1-A, ¶¶A and B, as enacted by PL 1999, c. 500, §2, are amended to read:

A. After October 1, 2001 2003, a person, firm, corporation or other legal entity may not discharge mercury or any compound containing mercury, whether organic or inorganic, in any concentration that increases the natural concentration of mercury in the receiving waters.

B. Until October 1, 2001 2003, a person, firm, corporation or other legal entity may not discharge mercury or any compound containing mercury in a concentration greater than the concentration discharged as of the effective date of this paragraph interim discharge limits established by the department.

The department shall establish interim discharge limits, based on procedures specified in rule, for each facility licensed under section 413 and subject to this paragraph. The discharge limits may not be less stringent statistically than the facility's discharge levels as of the effective date of this paragraph, except that the department shall take into account factors such as reduction in flow due to implementation of a wastewater conservation plan, seasonal variations and changes in levels of production. When the department has established an interim discharge limit for a facility, that limit is deemed to be the concentration discharged as of the effective date of this paragraph, and a facility shall comply with that interim discharge limit.

When considering an enforcement action in response to a violation of this paragraph before the department establishes an interim discharge limit for the facility, the commissioner shall consider factors such as reduction in flow due to implementation of a wastewater conservation plan, seasonal variations and changes in levels of production.

A person, firm, corporation or other legal entity that discharges mercury shall implement a mercury pollution prevention plan consistent with model plans developed by the department. The facility shall provide information concerning the status of implementation of the mercury pollution prevention plan to the department by December 15, 1999 and December 15, 2000 September 1st of each year. A mercury pollution prevention plan must include monitoring for mercury as required by the department, and the monitoring information must be provided to the department.