STP22-0347 DA Engineering Report RFI Response Rev C

                                                                                                             STP CONSULTANTS



9.1      POLLUTANTS OF CONCERN
         The South-East Queensland Stormwater Quality Guidelines provide guidance on the types of pollutants likely to be
         generated from different developments. The Water Quality Objectives for Noosa are listed in Table 9.2. The
         pollutants most likely to be of concern for Residential and Commercial developments are identified in Table 9.1
         below.

                                                                                     Development Phase
                                        Pollutant
                                                                                Construction      Operation

            Litter                                                                                      

            Sediment                                                                              unlikely

            Hydrocarbons (including oil and grease)                                                     

            Toxic materials (e.g. cement slurry, asphalt primer, solvents)                        unlikely

            pH altering substances (e.g. cement slurry and wash waters)                           unlikely

            Oxygen demanding substances (organic and chemical matter)             possibly         unlikely

            Nutrients (nitrogen and phosphorus)                                                         

            Pathogens / Faecal coliforms (bacteria and viruses)                   possibly         unlikely

            Heavy metals (often associated with fine sediment                     unlikely         unlikely

            Surfactants (e.g. detergents from car washing)                        unlikely         possibly

            Thermal pollution (heat)                                              unlikely         unlikely

            Table 9.1 – Pollutants Likely to be of Most Concern


9.2      DESIGN OBJECTIVES FOR WATER MANAGEMENT
         The Environmental Protection (Water) Policy 1997 provides a framework for identifying environmental values and
         associated water quality objectives; this framework is consistent with the efficient use of resources and best
         practice environmental management and involves the community through consultation and consideration of
         economic and social impact assessment. Environmental Values (EV) are a reflection of the qualities of a
         catchment that the community believes to be important. As such, environmental values are established through
         community consultation rather than through a scientific process. Once EV are established for a catchment, Water
         Quality Objectives (WQO) can be defined, which are meant to protect these values.

         While load based reduction targets focus on performance of a stormwater quality management system within the
         urban footprint, concentration based WQO’s are concerned with median flow concentrations as they enter
         downstream receiving water.




Civil Engineering Report & Site Based Stormwater Management Plan | STP22-0347                                             21