Response to Information Request - MCU12/0184

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                                                                             Callaghan & Toth


         TABLE 3.2:         COMPARISON OF LOAD REDUCTIONS


             Parameter                               MUSIC       POLLUTANT
                                                 REDUCTION         LOAD
                                                     RESULT      REDUCTION
                                                                 TARGETS
             Flow                                     34%
             Total Suspended Solids                   78%          80%
             Total Phosphorous                        59%          60%
             Total Nitrogen                           53%          45%
             Gross Pollutants                         54%


3.3.2 Assessment of Results


The developed site has been modelled as a series of commercial sub-catchments, which
incorporate Water Sensitive Urban Design (WSUD)treatment trains. Plan No’s 1209-02 to
1209-05 shows the proposed locations of the rainwater tanks, bio-retention swales, basins,
swales and buffers. The reductions listed in Section 3.3.1 above do not comply for Total
Suspended Solids and Total Phosphorus targets. The TSS reduction of the proposed
treatment train is 78% which is within an 2.5% error of reaching the 80% target. Given that
the location of the chicken sheds is on the ridges of the property and treated stormwater
runoff exiting the treatment train still has to travel through vegetated areas (in the order of
100m to 500m) prior to reaching surface waters, i.e. onsite dams, Blackfellow Creek, etc, the
remaining suspended solids will be removed while travelling over the vegetated existing farm
land.


The Total Phosphorus result is a 59% reduction with the proposed treatment train and the
target is 60%,which is within an 2% error of reaching the 60% target. Again as the treated
stormwater runoff is travelling over 1 00m-500m through vegetated farm areas to reach
surface waters it is considered the small amount of phosphorus not removed in the treatment
devices will be treated in the onsite vegetated areas before entering local waterways.


Therefore, it is considered that the proposed stormwater treatment system is currently
sufficient to reduce the pollutants prior to exiting the site.




                                                                                         15
1209 Animal Husbandry   Top Forestry Rd, Ridgewood
                        -
                                                                                 SWQMP
April 2013