OAR 340-041-0225
Basin-Specific Criteria (Mid Coast Basin): Water Quality Standards and Policies for this Basin
(1)
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: 6.5–8.5.(2)
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-0220: 100.0 mg/l.(3)
Nutrients in Clear Lake Watershed. In order to preserve the existing high quality water in Clear Lake north of Florence for use as a public water supply source requiring only minimal filtration, it is the policy of the Environmental Quality Commission to protect the Clear Lake watershed including both surface and groundwater, from existing and potential contamination sources with the following requirements:(a)
The total phosphorus maximum annual loading discharged into Clear Lake may not exceed 241 pounds per year from all sources.(b)
The total phosphorus maximum annual loading for the Clear Lake watershed may be deemed exceeded if the median concentration of total phosphorus from samples collected in the epilimnion between May 1 and September 30 exceed nine micrograms per liter during two consecutive years.(c)
Of the total phosphorus loading of 241 pounds per year specified in section (1) of this rule, 192 pounds per year will be considered current background and Department reserve and is not available to other sources.(d)
The total phosphorus maximum annual loading discharged into Collard Lake may not exceed 123 pounds per year.(e)
If water quality monitoring within the Clear Lake watershed indicates degradation, the Commission may require additional studies, corrective actions, or both, by rule. Such corrective actions may include but are not limited to the construction of sewage collection and off-site treatment and disposal facilities.(4)
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 20 mg/l of BOD and 20 mg/l of SS, or equivalent control;(b)
During the period of high stream flows (approximately November 1 to April 30) and for direct ocean discharges: 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.
Source:
Rule 340-041-0225 — Basin-Specific Criteria (Mid Coast Basin): Water Quality Standards and Policies for this Basin, https://secure.sos.state.or.us/oard/view.action?ruleNumber=340-041-0225.