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contechstormwater.com SingleStageDownSpoutStormFilterOperationandMaintenanceGuidelines
OperationandMaintenance
DownSpoutStormFilter
™
SingleStageUnits
Important:Theseguidelinesshouldbeused
asapartofyoursitestormwater
managementplan.
Overview
The singlestage DownSpout StormFilter™
(DSF) consists of a multichamber plastic
unit that can contain up to two StormFilter
cartridges. By configuring the StormFilter
cartridgeswithvariousfiltermedia,theDSF
is designed to remove pollutants such as
soluble zinc and other metals from rooftop
runoff.
The DSF is installed above ground,
occupying a small footprint (2.5’ x 5’), and
is easily integrated into most existing
downspoutconfigurations.Thesystemcan
be equipped with builtin ports for viewing
and sample collection to simplify
monitoring.Forhigherlevelsoftreatment,a
secondstagecanbeadded.
One singlestage, twocartridge DSF unit
can treat runoff from roof areas up to
14,000 square feet. The DSF is also
designed with aninternal high flowbypass
to minimize resuspension of trapped
pollutants in cases where extreme flows
exceedthewaterqualitydesignflow.
DesignOperation
TheDSFisinstalledastheprimaryreceiver
ofroofrunoff.Runoffisdirectlydischarged
to the DSF cartridge chamber by the
existing downspout system. Once in the
cartridge chamber, polluted water ponds
and percolates horizontally through the
mediainthefiltercartridges.Treatedwater
collectsineachcartridge’scentertubefrom
where it is directed by an underdrain
manifold to the outlet pipe on the
downstream side of the overflow weir and
discharged.
WhenflowsintotheDSFexceedthewater
quality design value, excess water spills
over the overflow weir, bypassing the
cartridge chamber, and discharges to the
outletpipe.
Applications
The DSF is an affordable, easily
maintained solution for treating rooftop
runofffromindustrialfacilities,warehouses,
andcommercialbuildings.Itsmodularand
changeable cartridges allow it to be
upgraded to meet changing removal
requirements without requiring purchase of
additionalequipment.
