75-5-312. Temporary water quality standards. (1) The department may, on its own accord or upon a petition for rulemaking, as provided in 2-4-315, by a person, including a permit applicant or permittee, temporarily modify a water quality standard for a specific water body or segment on a parameter-by-parameter basis in those instances in which substantive information indicates that the water body or segment is not supporting its designated uses. When the department adopts temporary standards, the goal is to improve water quality to the point at which all the beneficial uses designated for that water body or segment are supported.

(2) As a condition for establishing temporary water quality standards for a particular water body or segment, the department or the petitioner, as applicable, shall prepare a support document and a preliminary implementation plan for use by the department in determining whether to adopt the proposed temporary water quality standards. A person shall submit a support document and a preliminary implementation plan to the department for its review at least 60 days prior to filing a petition with the department requesting the adoption of temporary water quality standards.

(3) The support document prepared by the department or the petitioner, as applicable, must describe:

(a) the chemical, biological, and physical condition of the water body or segment;

(b) the specific water quality limiting factors affecting the water body or segment;

(c) the existing water quality standards that are not being achieved;

(d) the temporary modifications to the existing water quality standards being requested;

(e) existing beneficial uses; and

(f) the designated uses considered attainable in the absence of the water quality limiting factors.

(4) The preliminary implementation plan prepared by the department or the petitioner, as applicable, must contain:

(a) a description of the proposed actions that will eliminate the water quality limiting factors identified in subsection (3)(b) to the extent considered achievable; and

(b) a schedule for implementing the proposed actions that ensures that the existing water quality standards for the parameter or parameters at issue are met as soon as reasonably practicable.

(5) Within 30 days after the department's adoption of temporary water quality standards, the department or the petitioner, as applicable, shall:

(a) modify the preliminary implementation plan and schedule to reflect the requirements and timeframe adopted by the department for the temporary standards; and

(b) develop a detailed work plan describing the implementation activities that will be conducted during the first field season of the temporary standards. The work plan must be approved by the director of the department.

(6) By March 1 of each year that the temporary water quality standards are in effect, the department or the petitioner, as applicable, shall submit a detailed work plan describing the implementation activities that will be conducted during that season. The annual work plans must be approved by the director of the department. The department shall maintain copies of the implementation plan, schedule, and annual work plans and any modifications to those plans and schedule.

(7) Upon the department's adoption of a temporary water quality standard, the department shall ensure that reasonable conditions and limitations designed to achieve compliance with the implementation plan are established in appropriate discharge permits.

(8) (a) A temporary modification of a water quality standard may not result in adverse impacts to existing beneficial uses or be established for a total period longer than 20 years.

(b) During the period of the temporary modification, the department may not allow a discharge that will cause overall water quality to become worse than the overall quality of the water body or segment prior to the discharge.

(9) If a state water is designated as having temporary standards, the department shall report at least every 3 years regarding whether adequate efforts have been made to implement the plans submitted as the basis for the temporary standards.

(10) The department shall review the temporary standards and implementation plan at least every 3 years at a public hearing for which notice and an opportunity for comment have been provided. During this review, the department shall consider the progress made in restoring water quality to a level that achieves the goal of the temporary water quality standards. The department may terminate or modify the temporary standards based on information submitted at the time of review.

(11) The department shall terminate a temporary standard for a parameter if:

(a) values for the modified parameter or parameters improve to conditions that support all designated uses for that classification;

(b) the state water for which the temporary standard is adopted is reclassified as provided for in 75-5-302; or

(c) the plan submitted in support of the temporary water quality standard is not being implemented according to the plan's schedule or modifications to that plan or schedule made by the department.

(12) The department may modify the implementation plan if there is convincing evidence that the plan needs modification.

(13) If a temporary standard for a parameter in a particular state water is terminated because the plan submitted in support of the temporary water quality standard is not being implemented according to the plan's schedule or modifications to that schedule made by the department, a person may request a new temporary standard by submitting both a petition for rulemaking and an implementation plan that meet the requirements of subsection (4). However, the department may not adopt another temporary standard for the parameter in the state water that would cumulatively be in effect for a total period longer than 20 years for the parameter in the state water.