C2. Eng Report

                                                        Proposed Service Station – 175 Eumundi Noosa Road, Noosaville
                                                                                     Ref: 20769 C R001 Rev 06 09.02.17
                                                                                                         February 2018

         Internal stormwater drainage shall be designed and constructed in accordance with AS3500.3 and
         all other relevant standards and guidelines.

9.5      Stormwater Quality Improvement Devices (SQIDs)
         A stormwater treatment train has been established to treat the runoff from the proposed
         development. The treatment train will enable a higher level of pollutant removal efficiency by using
         stormwater quality improvement devices (SQIDs). Maintenance of the SQIDs will be the
         responsibility of the owners of the development. The maintenance should be carried out in
         accordance with the manufacturer’s recommendations.

9.5.1    SPEL Puraceptor (High-Risk Area Only)

         The Service stations require a bunded area around fuel dispensing areas in order to capture fuel
         spills. The SPEL Puraceptor Class 1 is an integrated oil-spill capture and light liquid treatment
         separator that is commonly used to treat stormwater runoff from within this high-risk area. Water
         treated at the SPEL Puraceptor is then to be discharged to a secondary treatment device prior to
         discharge to the LPD. The Puraceptor will be maintained in accordance with the manufacturers
         maintenance manual. Refer to Appendix G for further information of the proposed SPEL Puraceptor.

9.5.2    StormSack (or approved equivalent)

         The SPEL StormSack is a mesh basket that is hung within inlet pits. The StormSack features a mesh
         made from woven polypropylene geotextile with US Mesh 20. The SPEL StormSack provides
         effective filtration of solid pollutants and debris typical of urban runoff.

9.5.3    Gross Pollutant Trap (GPT) (SPEL Ecoceptor or approved equivalent).

         This device is proposed to be installed immediately upstream of the detention tank in order to remove
         oils and grits commonly encountered on surfaces trafficked by motor vehicles, including roadways
         and carpark areas that cover a majority of the proposed development. The GPT will be required to
         remove potential contaminants to the satisfaction of the parameters. A SPEL Ecoceptor is to be
         installed or an appropriate GPT will be selected to adhere with Council’s specifications.

9.5.4    First Flush Device
         The initial runoff from the site’s roof area will be directed to landscaping via a first flush device/s. This
         will ensure that accumulated loose material collected in the initial roof runoff during a rainfall event
         is diverted to landscape areas before flows leave the site. A first flush device has a set limit on its
         capacity to convey flows. Once the initial runoff from a rainfall event meets this capacity the
         remainder of flows for the event are diverted to the Lawful Point of Discharge.

9.6      On-site Treatment Lifecycle Costs
         A lifecycle cost analysis is not a part of the scope of this report. All the recommended water quality
         treatment infrastructure lies within the development site and it shall be maintained and serviced by
         the owners of the development at no cost to Council.

9.7      Water Quality Monitoring
         No water quality monitoring is proposed for this development at this stage due to the nature of the
         development and the expected pollutant levels.

9.8      Maintenance
         Maintenance of the SQIDs will be the responsibility of the owners of the development. The
         maintenance should be carried out in accordance with the manufacturer’s recommendations.



BRISBANE / SYDNEY / MELBOURNE / GOLD COAST / SUNSHINE COAST / DARWIN / PERTH                                  Page 21