OAR 340-041-0265: Basin-Specific Criteria (Powder/Burnt): Water Quality Standards and Policies for this Basin

(1) pH (hydrogen ion concentration). pH values may not fall outside the following range: all Basin streams (other than main stem Snake River): 6.5–9.0. When greater than 25 percent of ambient measurements taken between June and September are greater than pH 8.7, and as resources are available according to priorities set by the Department, the Department will determine whether the values higher than 8.7 are anthropogenic or natural in origin. (2) Minimum Design Criteria for Treatment and Control of Sewage Wastes: a minimum of secondary treatment or equivalent control and unless otherwise specifically authorized by the Department, the operation of all waste treatment and control facilities at maximum practicable efficiency and effectiveness so as to minimize waste discharges to public waters.