Development Application part 7 of 10 Stormwater Management Report - MCU13/0092

                                                   SECTION 1




1.1      DESCRIPTION


5tormFilter is a  passive, flow-through stormwater filtration system. It consists of vaults that house
rechargeable cartridges filled with a variety of filter media. The filter systems are installed in-line with storm
drains. The 5tormFilter works by passing stormwater through media-filled cartridges, which
                                                                                                 trap particulates
and adsorb materials such as dissolved metals and hydrocarbons. After being filtered through the media, the
treated stormwater flows into a collection pipe or discharges into an open channel drainage
                                                                                                 way. 5tormFilter
is offered in three different configurations:
                                           cast-in-place, precast and linear. The precast and linear models
utilize pre-manufactured vaults. The cast-in-place units are customized for larger flows and
                                                                                             may be either
covered or uncovered underground units.



1.2     OPERATION


1.2.1   Purpose

The 5tormFilter is a passive stormwater filtration system designed to improve the
                                                                                     quality of stormwater runoff
from the urban environment before it enters receiving waterways.


Through independent third party studies, it has been demonstrated that the 5tormFilter is highly effective for
treatment of first flush flows and flow-paced flows during the latter part of a storm. In
                                                                                          general, 5tormFilter’s
efficiency is highest when pollutant concentrations are highest. The primary target pollutants for removal are:
sediments (T55),soluble metals, soluble phosphorus, nitrates, and oil and grease.



1.2.2   Sizing

The 5tormFilter@ is typically sized to treat the peak flow of a water quality design storm as it
                                                                                                 passes through
the filter. The peak flow is determined by calculations based on the contributing watershed
                                                                                                  hydrology and
using a design storm magnitude. The design storm is usually based on the regulatory requirements set by the
local stormwater management agency. The particular size of a 5tormFilter is determined by the number of
filter cartridges (see Figure 4) required to treat the peak stormwater flow. Each cartridge is designed to treat a
peak flow of 1 Litre/second. For example: a peak design stormwater flow rate of lOLls would require that 10
cartridges be used in the treatment vault.

Because of the highly porous nature of the granular filter media, the flow through a newly installed cartridge is
restricted to ll/s, using a restrict or disc, to ensure adequate pollutant-media contact time.



1.2.3   Basic Function


The 5tormFilter is designed to siphon stormwater runoff through a filter cartridge containing media.          The
variety of media available can be designed to act as a mechanical filter to remove sediments, as an ion
exchanger to remove dissolved heavy metals, and as an absorber to remove oils and greases.




@2011 Stormwater360