Current through Register Vol. 60, No. 12, December 1, 2021
pH (hydrogen ion concentration). pH
values may not fall outside the following ranges:
(a) Marine waters: 7.0-8.5;
(b) Estuarine and fresh waters (except
Cascade lakes): 6.5-8.5;
Cascade lakes above 3,000 feet altitude: pH values may not fall outside the
range of 6.0 to 8.5.
Total 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 340-04l-0271: 500.0 mg/l.
Minimum Design Criteria for Treatment and
Control of Sewage Wastes:
(a) During periods
of low stream flows (approximately May 1 to October 31): Treatment resulting in
monthly average effluent concentrations not to exceed 10 mg/l of BOD and 10
mg/l of SS or equivalent control;
(b) During the period of high stream flows
(approximately November 1 to April 30): 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
Or. Admin. R.
DEQ 17-2003, f. & cert.
Stat. Auth.: ORS 468.020, 468B.030, 468B.035 &
Stats. Implemented: ORS 468B.030, 468B.035 &