Current through Register Vol. 63, No. 3, March 1, 2024
(1) pH
(hydrogen ion concentration). pH values may not fall outside the following
range: main stem Columbia River (mouth to river mile 309): 7.0 - 8.5.
(2) Total Dissolved Solids. Guide
concentrations listed below must 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-0101:
(a) Main stem Columbia
River (river miles 120 to 147 and 218-309) -- 200.0 mg/l;
(b) All other river miles of main stem
Columbia River -- 500.0 mg/l.
(3) Total Dissolved Gas. The Commission may
modify the total dissolved gas criteria in the Columbia River for the purpose
of allowing increased spill for salmonid migration. The Commission must find
that:
(a) Failure to act would result in
greater harm to salmonid stock survival through in-river migration than would
occur by increased spill;
(b) The
modified total dissolved gas criteria associated with the increased spill
provides a reasonable balance of the risk of impairment due to elevated total
dissolved gas to both resident biological communities and other migrating fish
and to migrating adult and juvenile salmonids when compared to other options
for in-river migration of salmon;
(c) Adequate data will exist to determine
compliance with the standards; and
(d) Biological monitoring is occurring to
document that the migratory salmonid and resident biological communities are
being protected.
(e) The Commission
will give public notice and notify all known interested parties and will make
provision for opportunity to be heard and comment on the evidence presented by
others, except that the Director may modify the total dissolved gas criteria
for emergencies for a period not exceeding 48 hours;
(f) The Commission may, at its discretion,
consider alternative modes of migration.
(4) Minimum Design Criteria for Treatment and
Control of Sewage Wastes:
(a) During periods
of low stream flows (see paragraphs 4(a)(A) and 4(a) (B) of this rule):
Treatment resulting in monthly average effluent concentrations not to exceed 20
mg/l of BOD and 20 mg/l of SS or equivalent control. Periods of low stream flow
vary throughout the main stem Columbia River. Low stream flow periods, by river
mile, are:
(A) River miles 120 to 147:
Approximately July 1 to January 31;
(B) River miles 147 to 218: Approximately May
1 to October 31.
(b)
During periods of high stream flows (see paragraphs 4(b)(A) and 4(b)(B) below):
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.
(A) River miles 120 to 147: Approximately
February 1 to June 30;
(B) River
miles 147 to 218: Approximately November 1 to April 30.
Stat. Auth.: ORS 468.020, 468B.030, 468B.035 &
468B.048
Stats. Implemented: ORS 468B.030, 468B.035 &
468B.048
