OAR 340-073-0056
Distribution Boxes, Drop Boxes, and Diversion Valves: Effluent Filters
(1)
Filters must be of durable, resilient, corrosion resistant, non-degradable materials resistant to deformation under normal operating conditions.(2)
Filters must be designed to prevent the escape of sludge or scum during normal operation and in the event of a malfunction, including filter clogging.(3)
The filter must retain all particles greater than 1⁄8 inch.(4)
The filter assembly must baffle the sludge and scum layers to prevent the escape of gross solids during sludge bulking or gas ebullition.(5)
Filters must be designed and positioned to allow for easy, trouble-free removal from and reinstallation to the screen apparatus from the assembly.(6)
The assembly must be capable of withstanding stresses placed upon it by installation, operation, and service.(7)
The assembly in the septic tank must perform as a conventional tank outlet that meets the requirements of OAR 340-073-0025 (Tank Construction)(6) when the filter is removed.(8)
The filter must be designed to handle the flow of the system it is to serve without excessive maintenance. For a single family dwelling, maintenance is considered “excessive” when the filter requires service or cleaning more than one time per year. Service must be performed each time the tank is pumped and in accordance with the manufacturer’s specifications.(9)
To obtain department approval, the manufacturer of an effluent filter must provide the department with the necessary technical data to show that the design and materials comply with this rule. The manufacturer must provide an operation and maintenance manual with each unit distributed.(10)
Effluent filter units external to the tank must be watertight.
Source:
Rule 340-073-0056 — Distribution Boxes, Drop Boxes, and Diversion Valves: Effluent Filters, https://secure.sos.state.or.us/oard/view.action?ruleNumber=340-073-0056.