RFI - Attachment F - Engineering Report

       refereed paper                                                           stormwater treatment


NUTRIENTS AND SOLIDS
REMOVAL BY AN ENGINEERED
TREATMENT TRAIN
Field evaluation of a gully pit insert
and cartridge media filter
M Wicks, N Vigar, M Hannah
Abstract                                       one-third of concentrations reported         Environment and Climate Change (DECC)
                                               in the literature as typical for urban       2007 recommends Suspended Solids (SS)
The performance claims for individual
                                               catchments in Australia.                     85%, Total Phosphorus (TP) 65%, and Total
stormwater treatment devices is often
                                                                                            Nitrogen (TN) 45%) and/or Event Mean
open to debate, as much of the data               One storm was also analysed
                                                                                            Concentrations (EMCs) in any stormwater
available has not been subjected to            for an expanded suite of nitrogen
                                                                                            discharged into natural ecosystems (e.g.
robust scrutiny and/or the claims are          analytes, which determined that more
                                                                                            ANZECC 2000 recommends turbidity
unable to be replicated. The following         than half the load was in soluble form.
article summarises the results from a field                                                 2-15 Nephelometric Turbidity Units (NTU),
                                               Furthermore, results from the field trial
trial of two such devices: an EnviroPod®                                                    TP 0.01 mg/L and TN 0.15 mg/L for river
                                               and research project indicated that this
and a StormFilter®, arranged in series                                                      systems in tropical Australia).
                                               treatment train system has the potential
(or a ‘treatment train’) treating runoff       to achieve meaningful load reductions           In general, each pollutant is removed
from a small road catchment on Streets         of Suspended Solids (up to 99%),             from the water column using a specific
Creek, Kuranda, west of Cairns                 Phosphorus (up to 70%) and Nitrogen          physical, chemical or biological process.
in Far North Queensland.                       (up to 45%) through the use of               Arranging these processes in sequence
                                               conventional screening, filtration and       provides a treatment train approach that
   This field trial complements an earlier
research project undertaken on the             ion-exchange removal technologies.           addresses and treats the whole pollutant
same system by James Cook University.                                                       load. There is, however, a paucity of
                                               Introduction                                 published peer-reviewed scientific
Data was collected from six storm
events, predominantly during the dry           Livingston and McCarron (1992) identified    information validating the removal
seasons of 2008 and 2009, and includes         that pollution loads (gross pollutants,      efficiency of each element or device used
simultaneous sampling of both the flow         sediment and nutrients) in stormwater        within a treatment train – let alone the
rate and water quality on the inflows          increase proportionally with the degree      performance of the treatment train itself.
to, and outflows from, the treatment           of urbanisation in the catchment. Most       The research referred to herein provides
train for a suite of particulate and           consent authorities in Australia have        information to validate the performance
soluble stormwater pollutants. Influent        established pollution removal efficiencies   claims of an EnviroPod® gully trap and a
concentrations for both Phosphorus             to be achieved prior to discharge from the   StormFilter ® cartridge arranged in series
and Nitrogen were found to be half to          urban catchment (eg, NSW Department of       as a treatment train.

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Figure 1. Location of the Kuranda Test Site.

                                                                                                         water    SEPTEMBER 2011 1