Gas Supersaturation Monitoring Report for Spill Below Bonnevielle Dam, March 10-13, 2001

摘要

The US Fish & Wildlife Service (USFWS) requested a total dissolved gas (TDG) waiver from the Oregon Department of Environmental Quality and an adjusted dissolved gas standard from the Washington Department of Ecology (WDOE) for spill at Bonneville Dam for a ten day period in March, 2001. These requests were made to allow for TDG saturation up to 115% as measured at the Camas/Washougal monitoring station (river mile 122) and 120% in the Bonneville Dam tailrace, as measured at the Skamania and Warrendale monitoring stations (at river mile (RM)141 on the Washington and Oregon shores, respectively). The Oregon Environmental Quality Commission approved this request at its November 30, 2001 meeting. The WDOE provided the adjusted TDG standard previously on March 8, 1999. The adjusted TDG standard expires in the year 2003. One of the conditions of the approved waiver and adjusted TDG standard was that the USFWS conduct biological and physical monitoring downstream of Bonneville Dam during the spill period and to provide reports of this monitoring. The USFWS Columbia River Fisheries Program Office (CRFPO) monitored water conditions and examined fish collected below Bonneville Dam for signs of Gas Bubble Trauma (GBT) during the March 2001 spill period. This report summarizes the results of this monitoring program.