Code of Maine Rules
06 - DEPARTMENT OF ENVIRONMENTAL PROTECTION
096 - DEPARTMENT OF ENVIRONMENTAL PROTECTION - GENERAL
Chapter 579 - CLASSIFICATION ATTAINMENT EVALUATION USING BIOLOGICAL CRITERIA FOR RIVERS AND STREAMS
Section 096-579-5 - Application of decision results

A. Attainment of statutory classification. A waterbody shall be determined to be in attainment of the designated aquatic life uses and characteristics of its assigned water classification, if the association value, as determined according to Sections 3 and 4 of this chapter, following methods outlined in "Methods for Biological Sampling and Analysis of Maine's Rivers and Streams" (DE P LW 0387 -B2002), is shown to be equal to or greater than 0.6 for that class or any higher class, or where the provisions for professional judgement determine that the water should be determined to be in attainment of its assigned water classification or any higher classification; and where other standards and criteria pertinent to protecting the aquatic life uses of the classification are determined to be attained (including, but not limited to, support of indigenous fish or other aquatic species, as required in the water quality classification law).

B. Reporting. Results of classification attainment evaluation must be reported in the department's biennial water quality assessment report and Section 305(b) of Federal Clean Water Act. Waters that are determined not to attain their statutory classification are listed in the state's list of impaired waters as required in Section 303(d) of the Federal Clean Water Act.

C. Antidegradation. Waters that attain the aquatic life use standards of a higher classification must be protected in accordance with the applicable statutory provisions for antidegradation. For the purposes of antidegradation, attainment of aquatic life use standards of a higher classification shall be based on classification attainment evaluations of 2 or more consecutive sampling outcomes, from different sampling years, that attain a higher class, and taking into account critical water quality conditions including, but not limited to, conditions of low flow, high water temperature, maximum loading from point source and nonpoint source discharges, and conditions of acute and chronic effluent toxicity.

D. Licensing, permitting and water quality certification activities. An activity regulated by the Department may be approved when a classification attainment evaluation finds that the standards of classification of the water body are met and will continue to be met, notwithstanding the approved activity. An activity regulated by the Department may be approved when a classification attainment evaluation finds that the standards of classification of the water body are not met if it can be shown that the activity does not, or a new activity will not, cause or contribute to non-attainment of designated aquatic life uses and other standards of the assigned water classification.

If the classification attainment evaluation shows that the standards of classification of the water body are not met, and the applicant is unable to show that the activity does not, or a new activity will not cause or contribute to non-attainment, then a license, permit or water quality certification may only be issued when it can be demonstrated that modifications to the proposed activity, as required by the new license, permit or certification, will provide attainment conditions. If two or more activities can be shown to cause or contribute to non-attainment of the assigned water classification, then a license, permit or water quality certification may only be issued when it can be demonstrated that modifications to the activity, as required in the license, permit or certification, in conjunction with modifications to other sources in the watershed that contribute to the non-attainment, including modifications that are a part of a Department approved total maximum daily load, will provide attainment. The department may require additional monitoring of the affected waters following issuance of any license, permit or water quality certificate.