1209 SWQMP Report_3 2013

                                                                             Callaghan & Toth

         TABLE 3.3:        COMPARISON OF LOAD REDUCTIONS FOR BUNDED
                           COMPOSTING AREAS

             Parameter                             MUSIC       POLLUTANT
                                                 REDUCTION       LOAD
                                                  RESULT       REDUCTION
                                                                TARGETS
             Flow 3%
             Total Suspended Solids                   85%          80%
             Total Phosphorous                       58% 60%
             Total Nitrogen                           50%          45%
             Gross Pollutants                        100%


3.3.2 Assessment of Results

The developed site has been modelled as a series of “Commercial” and “Agricultural” sub-
catchments, which incorporate Water Sensitive Urban Design (WSUD) treatment trains. Plan
No’s 1209-02 to 1209-04 shows the proposed locations of the rainwater tanks, bio-retention
swales, bio-retention basins, grassed swales, and vegetated buffers.

The reductions listed in Table 3.2 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 a 2.5% error of reaching the 80% target. Given that the location of the Poultry 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 results for the sheds and roads (Table 3.2) and Bunded composting
areas (Table 3.3) is a 59% reduction and 58% reduction respectively. The target is 60%,
which means the treatment train results are within a 2% error of reaching the 60% target.
Again as the treated stormwater runoff is travelling over 100m-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.




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1209 Animal Husbandry – Top Forestry Rd, Ridgewood                         SWQMP_REV_3
September 2013