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The
Status of the TMDLEcology began working on a Dissolved Oxygen Water Quality Improvement Project (TMDL) in 1998. In the fall of 2000, Ecology contracted with the U.S. Army Corps of Engineers (USACE) to apply the CE-QUAL-W2 model to the Spokane River and Lake Spokane system. The USACE collaborated with Portland State University. A report (Cusimano, 2004) on the water quality study and modeling effort was completed in 2004 (see Technical Information page for a link to the report).
In October 2004, Ecology released a draft TMDL for public comment. Prior to the release, entities that discharge to the Spokane River (the Dischargers) developed a Use Attainability Analysis and submitted a petition for rule making to revise the dissolved oxygen water quality criteria for the Spokane River and Lake Spokane. Shortly thereafter, Ecology and the Dischargers agreed to withdraw the petition, put the draft TMDL on hold and develop an implementation plan for the TMDL. This led to the creation of the Spokane River TMDL Collaboration (Collaboration).
The Collaboration included Ecology, the Dischargers, local governments, Idaho Department of Environmental Quality (IDEQ), the U.S. Environmental Protection Agency (EPA), the Spokane Tribe of Indians, environmental groups, and power companies. The Collaboration developed the Foundational Concepts for the Spokane River TMDL Managed Implementation Plan. The Collaboration agreed that the TMDL’s Managed Implementation Plan will be consistent with the principles described in the Foundational Concepts. The agreement was formalized through a Memorandum of Agreement signed on March 7, 2007.
During 2007, Ecology worked with Portland State University to run some additional model scenarios to incorporate modifications to the modeling approach as a result of the Collaboration. The dissolved oxygen TMDL has been revised to reflect the Foundational Concepts and the new modeling. The draft report, Spokane River and Lake Spokane Dissolved Oxygen Total Maximum Daily Load, Water Quality Improvement Report was distributed for a 45-day public comment period in September 2007.
As a result of the concerns and issues raised by the comments, Ecology has modified the report and is providing an additional 30-day public comment period on the revised draft. The comment period is from May 20 - June 24, 2008. Ecology will consider all comments but focus on those that address the following changes:
| Topic | Changes in current Revision |
| Avista Dams | Additional language to describe the 401 certification requirements for the hydroelectric dams on pages 4 and 5. |
| Spokane Tribe of Indians Water Quality Standards | Spokane Tribe water quality standards are recognized and discussed on pages 7, 10, and 33 through 34. |
| Modeling | New language and updates to Table 3 on page 15 to
describe how net groundwater phosphorus values are derived for Lake
Spokane and the Spokane River. Additional bullets to describe modeling runs for ammonia in 2007 and the use of corrected flows for Hangman Creek on page 19. |
| Implementation Timeframe for TMDL, Permits and Ten Year Assessment | A new table (Table 8) and additional language to
describe the schedule sequence for the TMDL, NPDES permits, and
associated target pursuit actions and wasteload allocations on pages
46 and 47. Language has been added on page 35 to clarify that to the extent the Foundational Concepts document suggested no enforceable limits during the first ten years, the NPDES permits will contain enforceable limits in their ten-year compliance schedules. Language has been added to page 48 to specify how final wasteload allocations may change (but still be protective of water quality) based on data collected in advance of the ten-year assessment. Language has also been added on pages 48 and 50 to clarify that monitoring will be conducted on a biennial basis and will be assessed in advance of ten years in order to determine compliance with the NPDES permits and whether dissolved oxygen is being improved in Lake Spokane for the ten-year assessment. |
| Load and Wasteload Allocations | Revised wasteload allocations for Table 5 on page
29. Ammonia values have also been revised following the 2007
modeling (see fourth bullet above). The 10 µg/L target remains in
the Managed Implementation Plan per the Foundational Concepts and as
described with new language on page 46. An equation to convert concentrations to lbs/day on page 30 in place of Table 6 in the previous draft (tables are re-numbered after 5). The lbs/day wasteload allocations are provided in Table 9 in the Managed Implementation Plan on page 49, based on the 10 µg/L concentration. |
| Language Changes | Clarifying language to describe the water quality
standards on pages 9 through 11. Additional language and a graph (Figure 5) have been added to describe loading capacity in Lake Spokane on pages 24 through 26. Additional language to clarify that nonpoint source reductions can be made to the mainstem of the Spokane River or the tributaries on pages 27 and 40. The language describes how only tributary nonpoint loads are identified and assigned load allocations but that the Dischargers can and should pursue actions to reduce nonpoint pollution to the mainstem in order to improve dissolved oxygen in Lake Spokane. Additional language to clarify the interim , technology-based, and final wasteload allocations (page 39) and the activities of the ten year assessment (pages 49-51) in the Managed Implementation Plan. Additional bullet points in the Reasonable Assurances section on pages 31 through 34 including the Coeur d’ Alene Lake Management Plan, the Liberty phosphorus fertilizer no-use policy, and the Spokane County phosphate dishwasher detergent ban. Groundwater monitoring has been added as an activity to the Managed Implementation Plan on page 51. |
| New Sections | New section on stormwater discharges on pages 42
through 44. A responsiveness summary is included as Appendix G which describes Ecology’s approach to issues such as background water quality, implementation timeframe, and other issues in more detail. A November 2004 modelers agreement has been added as Appendix H. |
Ecology appreciates the effort made by all the individuals and organizations that provided comments to address the critical issues in the previous draft plan. Use this link to get an electronic copy of the draft.
Paper copies of the draft report will be available by May 27, 2008 from Ecology’s Eastern Regional Office at the address below.
Please direct any questions or comments to:
David Moore Water Quality Program - Eastern Regional Office Washington State Department of Ecology 4601 N. Monroe Street Spokane, WA 99205-1295 Phone: (509) 329-3514 Email: dmoo461@ecy.wa.gov
Next: Technical Information about the TMDL
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