MONTANA’S TMDL DEVELOPMENT SCHEDULE
Total Maximum Daily Loads (TMDLs) are developed for waterbodies that have pollutant causes of impairment. DEQ has developed more than 600 TMDLs (see Final TMDL Documents and identified more than 1,400 impaired waterbody – pollutant combinations that still require TMDL development within Montana, all of which are identified on the state’s 303(d) list. When developing TMDLs, DEQ uses a watershed scale approach that involves concurrently addressing multiple TMDLs within a project area.* DEQ maintains an updated map of the TMDL project area boundaries. This map identifies those project areas where TMDLs have been completed and where TMDL development activity is scheduled through 2014. A list of active projects and project contacts is located on the TMDLs Under Development webpage.
The majority of all impairment causes requiring TMDL development in Montana fall within one of the following pollutant groups: sediment, nutrients, metals, temperature, pathogens, or salinity. TMDL planning is focused on each applicable pollutant group for a given project area since each pollutant group normally has unique water quality standards, sources, assessment methods, sampling protocols, corrective measures, and impacts to designated beneficial uses. TMDLs are then developed within a project area for each waterbody impaired by the same pollutant group independent of when a waterbody is first put on the 303(d) list. This approach, referred to as a “list neutral” approach, allows for greater efficiency, results in a better understanding of impairment causes across the watershed, and improves on the ability to implement water quality improvement efforts at a more holistic watershed scale.
Implementing this more efficient “list neutral” approach is the basis for a recent amended judgement to a TMDL lawsuit originally filed in 1999. Until recently, the lawsuit required completing TMDLs only for waterbody - pollutant combinations from the 1996 303(d) List by December 31, 2012. Because the 1996 303(d) List represents about 50% of all identified impairment conditions throughout the state, meeting the original conditions of the lawsuit meant that a TMDL project for any pollutant group would only address about 50% of the problems within the project watershed, on average. DEQ would then need to repeat much of the TMDL project work at a later date, after satisfying the lawsuit, to address TMDL development needs for the other 50% of the impairment causes within a watershed or project area. The amended judgment requires TMDL development for 664 specific waterbody - pollutant combinations from Montana’s 2010 303(d) List by 2014 via implementation of the “list neutral” approach for TMDL development projects.
The 664 waterbody - pollutant combinations are included within Attachment A of the amended judgment. Per this judgment, if DEQ determines that any waterbody - pollutant combination from the list of 664 is not impaired and a TMDL is therefore not required, then a replacement TMDL must be developed for a different waterbody – pollutant combination, not originally identified within Attachment A. The amended judgment also requires TMDL related assessment work for an additional 12 waterbody - pollutant combinations located within the Flathead watershed. These are identified within Attachment B of the amended judgment.
The 664 waterbody - pollutant combinations scheduled for completion by 2014 represent a continued focus on DEQ’s TMDL development prioritization approach. This prioritization approach integrates stakeholder interests; areas with increased development; availability of data and other relevant information; completion of TMDLs in areas where TMDL work has begun; consideration of recreation, economics and aesthetics; and protection and restoration of native fishes, particularly bull trout and cutthroat trout. The result is a significant focus on completing TMDLs within watersheds in Montana’s Columbia and Upper Missouri river basins. The prioritization approach also justifies continued TMDL assessment and other TMDL support work, such as water quality standards development, in the Tongue and Powder project areas, as noted within the TMDL schedule map, even though these areas are not part of the amended judgment requirements.
* Note: Initially, DEQ organized TMDL development around TMDL Planning Areas (TPAs). The project area boundaries normally coincide with TMDL planning area (TPA) boundaries, but occasionally a project area involves multiple TPAs and/or portions of TPAs as a way to increase TMDL program efficiency.
