WRIA 62 WMP 032305 - Washington State Department of Ecology

March, 2005 -61- 023-1289-003.3040
4.2.4 WQUAL-3b Background and Rationale
Problem Statement: There is a need to participate in the TMDL processes and provide input
on TMDLs for the mainstem Pend Oreille River.
The Clean Water Act requires States and Tribes with water quality jurisdiction to develop a list of
waterbodies not meeting water quality standards. Development of Total Maximum Daily Loads
(TMDLs) is the process by which States and Tribes attempt to achieve water quality standards.
Washington State has jurisdiction over waterbodies within WRIA 62, with the exception of waters
within the exterior boundaries of the Kalispel Indian Reservation. The Kalispel Tribe has jurisdiction
over waterbodies on Kalispel Indian Reservation lands. Idaho State has jurisdiction over waterbodies
within Idaho. The role of the Environmental Protection Agency (EPA) is to review and approve
TMDLs and ensure that the TMDLs will work towards attaining applicable water quality standards
(i.e. State and Tribal water quality standards).
Information on the WRIA 62 303(d) listings and current TMDL activities are included in the Phase II,
Level 2 report (Golder, 2005). Development of the Pend Oreille River TMDLs will be completed by
the entities with water quality jurisdiction (i.e., Ecology in Washington, the Idaho Department of
Environmental Quality in Idaho and the Kalispel Tribe on reservation lands, with review and approval
by EPA).
Ecology is in the process of developing Total Dissolved Gas (TDG) and temperature TMDLs for the
mainstem of the Pend Oreille River (Figure 4-6). Details are available in Ecology’s Quality
Assurance Project Plans (QAPPs) for the Temperature and TDG Pend Oreille River Total Daily
Maximum Load Technical Studies (Ecology, 2004b; Ecology 2004c). The QAPPs and information
on TMDL timelines are available on Ecology’s web site
(http://www.ecy.wa.gov/programs/wq/tmdl/watershed/tmdl_info-ero.html). Ecology is considering
contracting with a specialist to review, expand and re-run an existing CE-QUAL-W2 temperature
model for the Pend Oreille River from the Idaho state line to Box Canyon Dam, and publish this
analysis in a Phase 1 report. Seattle City Light is planning to develop a CE-QUAL-W2 model for the
Boundary Dam reservoir, with technical support from Ecology. The final temperature TMDL will be
developed when the Idaho, Box Canyon, and Boundary models can be evaluated together. It is also
Ecology’s intent to coordinate with the Idaho Department of Environmental Quality to take the output
from a planned CE-QUAL-W2 temperature model of Lake Pend Oreille and the Pend Oreille River in
Idaho as input to the Washington model at the state line.
The following TMDLs are planned by the Idaho Department of Environmental Quality (IDEQ) in the
Priest River Basin in Idaho (Table 4-6 and Figure 4-6):
• Sediment, temperature and total dissolved gas for the Pend Oreille River (from Lake
Pend Oreille to the Washington – Idaho border).
The total dissolved gas (TDG) issues for the Clark Fork - Pend Oreille system in Idaho are primarily
being addressed, at the current time, through implementation of the Gas Supersaturation Control
Program for the Clark Fork Project (Avista 2004). This TDG program focuses on operations of the
Cabinet Gorge Hydroelectric Development, eight miles upstream of Pend Oreille Lake. In 2005,
Idaho DEQ will initiate a sub-basin assessment and TMDL effort for the Pend Oreille River. TDG
issues will be examined as they pertain to the Albeni Falls Hydroelectric Project and river conditions
between Albeni Falls and the Idaho - Washington state line.
WRIA 62 WMP 032305