Approval Standards for Onsite Sewage Treatment and
Disposal Systems Outlet Filter Devices
Approval Standards for On-Site Sewage
Treatment and Disposal Systems
Outlet Filter
Devices
Paul Booher, PE
Bureau of Water and OnSite
Sewage Programs
DESIGN AND PERFORMANCE CRITERIA
--Specify total filter surface area, in
square feet, (filter solid area plus filter void area)
FLOW AREA--Specify filter open area, in square feet,
(filter void area only)
FILTRATION METHODS--Filters shall prevent solid
particles larger than a nominal 1/8" diamter sphere from passing
through the opening.
CLOGGED FILTER BY-PASS PROTECTION--there shall be no
bypass capability designed into the filter which will allow
waste to be discharged.
FILTER DESIGN--Filter orifices shall be formed by
casting, molding, or developed by penetration or sawcut.
Openings developed by penetration, sawcut or equivalent shall
ensure the complete removal of the filter material to
prevent the openings from reclosing during the lifteime of the
filter. The designed opening shall be process controlled and the
material must be removed. Mold flash and penetration burrs shall
be completely removed.
The filter shall be secured to the outlet device rooutlet opening
such that inadvertent movement does not take place during
operation. the dimensions of the filtering components shall be
consistent throughout. For example, the distance from the filter
mesh to the outlet device inside wall shall not very outside of
process control limits.
STRUCTURAL INTEGRITY--the filter shall be designed
such that thefiltering medium maintains structural integrity
throughout the useful life of the device. The filter medium
shall not tear or otherwise distort so as to make the filter
inoperable during normal operations of the septic tank.
OPERATIONAL VERIFICATION--The manufacturer shall
provide results of field testing for their product(s) being
considered for approval.
DRAWINGS--Manufacturer shall provide drawings to
the Department with the written request for product approval
submittal. Drawings shall show all dimensions.
FREQUENCY OF MAINTENANCE--Manufacturer shall
provide data and information reflecting actual operational
experience related to the frequency of necessary unit maintenance
to keep the unit functional and shall specify the recommended
method and frequency of maintenance.
INSTALLATION INSTRUCTIONS--Manufacturer shall
provide installation instructions to installer.
MATERIALS OF CONSTRUCTION--the filter shall be
constructed of proven corrosion resistant material for use in
wastewater environments.
MAINTENANCE ACCESSIBILITY--64E-6.013(3)(b),FAC
requires accessibility to the inlet and outlet devices. When
outlet filter devices are used, this rule shall include
convenient accessibility to the filter for maintenance through
servece manholes or equivalent.
CERTIFICATIONTO DEPARTMENT OF HEALTH, ONSITE SEWAGE
PROGRAMS--The manufacturer shall certify to the
Department that the filter(s) meet the requirements of this
standard.
FILTER APPLICATION--Filters shall be sized in
accordance with the manufacturers' recommendations for the
service intended.
Please address any questions to Dr. David Lindbo.
This page
(http://www.ces.ncsu.edu/plymouth/septic/98booher.html)
created by
Vera MacConnell,
Research Technician, I
on February 1, 1999.
Last Updated on June 3, 1999.