Current through Register Vol. 60, No. 12, December 1, 2021
Effluent filters used in onsite systems must meet the following
(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.
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.
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
when the filter is removed.
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.
Effluent filter units external to the tank must be