2023 Idaho Code › Title 39 - HEALTH AND SAFETY › Chapter 36 - WATER QUALITY › Section 39-3611 - DEVELOPMENT AND IMPLEMENTATION OF TOTAL MAXIMUM DAILY LOAD OR EQUIVALENT PROCESSES.

39-3611. DEVELOPMENT AND IMPLEMENTATION OF TOTAL MAXIMUM DAILY LOAD OR EQUIVALENT PROCESSES. (1) For water bodies described in section 39-3609, Idaho Code, the director shall, in accordance with the priorities set forth in section 39-3610, Idaho Code, and in accordance with sections 39-3614 through 39-3616, Idaho Code, and as required by the federal clean water act, prepare a subbasin assessment and develop a total maximum daily load to allocate pollutant loads to point source and nonpoint sources that discharge pollutants to the water body.
(2) Upon the completion of a total maximum daily load, the director shall publish notice of the final decision on the TMDL in the Idaho administrative bulletin and provide written notice to members of the applicable watershed advisory group. The director’s final decision shall be based upon a record that provides the basis for the total maximum daily load. The rulemaking provisions in sections 67-5220 through 67-5231, Idaho Code, shall not apply to TMDLs. The director’s final decision regarding a TMDL may be appealed to the board of environmental quality in accordance with section 39-107(5), Idaho Code, and the rules governing such appeals. The time for appeal to the board shall commence upon publication in the administrative bulletin. The board’s final decision is subject to judicial review under section 39-107(6), Idaho Code. The provisions of this subsection shall apply to all total maximum daily loads developed by the director after January 1, 1995. Provided however, that the rulemaking provisions in sections 67-5220 through 67-5231, Idaho Code, shall apply to TMDLs for metals in the Coeur d’Alene River Basin, upstream from the head of the Spokane River. Provided further, that nothing herein shall modify the requirement that water quality standards be promulgated as rules of the department pursuant to title 67, chapter 52, Idaho Code.
(3) For water bodies where an applicable water quality standard has not been attained due to impacts that occurred prior to 1972, no further restrictions under a total maximum daily load process shall be placed on a point source discharge unless the point source contribution of a pollutant exceeds twenty-five percent (25%) of the total load for that pollutant. Existing uses shall be maintained on all such water bodies.
(4) Subbasin assessments and total maximum daily load processes developed pursuant to this section shall include, but not be limited to:
(a) Identification of pollutant(s) impacting the water body;
(b) An inventory of all point and nonpoint sources of the identified pollutant(s), if practical, or an analysis of the land types, land uses and geographical features within the watershed that may be contributing identified pollutants to the water body;
(c) An analysis of why current control strategies are not effective in assuring full support of designated beneficial uses;
(d) A plan to monitor and evaluate progress toward meeting water quality standards;
(e) Pollution control strategies for both point sources and nonpoint sources;
(f) Identification of the period of time necessary to achieve full support of designated beneficial uses through implementation of pollution control strategies, which takes into account any expected changes to applicable water quality standards; and
(g) An adequate margin of safety to account for uncertainty.
(5) Point source discharges for which a national pollutant discharge elimination system permit is approved after January 1, 1995, shall be deemed to have met the requirements of this section.
(6) No instream target for a pollutant shall be set as part of a TMDL process unless the data and analysis in the subbasin assessment demonstrate that the pollutant is causing or contributing to a violation of a water quality standard in the stream for which the TMDL is being developed. If a pollutant load is allocated to a tributary inflow as part of a downstream TMDL, the director shall develop a plan to meet such allocation in consultation with the tributary watershed advisory group as provided in subsection (8) of this section.
(7) The director shall review and reevaluate each TMDL, supporting subbasin assessment, implementation plan(s) and all available data periodically at intervals of no greater than five (5) years. Such reviews shall include the assessments required by section 39-3607, Idaho Code, and an evaluation of the water quality criteria, instream targets, pollutant allocations, assumptions and analyses upon which the TMDL and subbasin assessment were based. If the members of the watershed advisory group, with the concurrence of the basin advisory group, advise the director that the water quality standards, the subbasin assessment, or the implementation plan(s) are not attainable or are inappropriate based upon supporting data, the director shall initiate the process or processes to determine whether to make recommended modifications. The director shall report to the legislature annually the results of such reviews.
(8) Each TMDL and any supporting subbasin assessment shall be developed and periodically reviewed and modified in consultation with the watershed advisory group for the watershed in which the water bodies are located. Consultation shall include, but not be limited to:
(a) Upon request, providing the watershed advisory group with all available information in the possession of the department concerning applicable water quality standards, water quality data, monitoring, assessments, reports, procedures and schedules for developing and submitting the TMDL and any supporting subbasin assessment to the United States environmental protection agency;
(b) Utilizing the knowledge, expertise, experience and information of the watershed advisory group in assessing the status, attainability or appropriateness of water quality standards, and in developing a TMDL and any supporting subbasin assessment; and
(c) Providing the watershed advisory group with an adequate opportunity to participate in drafting the documents for the TMDL and any supporting subbasin assessment and to suggest changes to the documents.
(9) No TMDL shall be published for public comment or submitted for approval to the United States environmental protection agency until consultation, as herein provided, has occurred. If, after consultation, the watershed advisory group disagrees with the TMDL or any supporting subbasin assessment, or has determined that applicable water quality standards should be reevaluated or revised, such position and the basis therefor shall be documented in the public notice of availability to the TMDL and any supporting subbasin assessment for review, and in any submission of the same to the United States environmental protection agency. The director shall respond to the points raised by the watershed advisory group and shall document the response in the final decision.
(10) Nothing in this section shall be interpreted as requiring best management practices for agricultural nonpoint source activities which are not adopted on a voluntary basis, nor shall this section be interpreted to relieve any person from the responsibility to comply with the Idaho forest practices act.
History:
[39-3611, added 1995, ch. 352, sec. 1, p. 1173; am. 1997, ch. 279, sec. 6, p. 834; am. 2003, ch. 351, sec. 1, p. 938; am. 2005, ch. 334, sec. 2, p. 1049.]