Current through Register Vol. 60, No. 12, December 1, 2021
(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.
Dissolved Solids. Guide concentrations listed below may not be exceeded unless
otherwise specifically authorized by DEQ upon such conditions as it may deem
necessary to carry out the general intent of this plan and to protect the
beneficial uses set forth in OAR 340-041-0150: main stem Grande Ronde River --
Criteria for Treatment and Control of Sewage Wastes:
(a) During periods of low stream flows
(approximately June 1 to October 31): Treatment resulting in monthly average
effluent concentrations not to exceed 20 mg/l of BOD and 20 mg/l of suspended
solids or equivalent control;
During the period of high stream flows (approximately November 1 to May 31): A
minimum of secondary treatment or equivalent control and unless otherwise
specifically authorized by the Department, operation of all waste treatment and
control facilities at maximum practicable efficiency and effectiveness so as to
minimize waste discharges to public waters.
Or. Admin. R.
DEQ 17-2003, f. & cert.
Stat. Auth.: ORS 468.020, 468B.030, 468B.035 &
Stats. Implemented: ORS 468B.030, 468B.035 &