Request for Further Information - 010.2008.00001896.001 [As Published] · 142008.1896

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23.   Council officers are concerned that the wetland is not big enough and may cause scour.
      Therefore, provide a Hec-Ras, Mike 11 or full 2d flow model to demonstrate that flow short
      circuiting or scour will not occur.
24.   Council officers are concerned that the smooth configuration of the concrete spillay does not
      provide any dissipation to protect the receiving area from scour. Therefore provide details of
      any dissipation and rip rap proposed along the spillway/ at its outlet based on the maximum
      expected velocities of water discharge from the wetland.
25.   Provide comment whether scour protection is required at the stormwater outlets shown on
      drawing JO7-071-01 and at the proposed outlet of the concrete pipes from the sediment
      forebay spillway.
26.   Please provide engineers detail as referenced on drawing J07-071-02.
27.   Council is concerned that the wetland is proposed in proximity of the Council sewer main and
      sewer pump station. Include monitoring for faecal coliforms at an appropriate frequency
      during construction to ensure damage to the pump station does not occur.
28.   Indicate the location of the sewer pump station overflow path on Drawing J07-071-04.
29.   Please label the sections on J07-071-01.
30.   Drawing JO7-071-05 states that handrails will be installed to an unnamed standard. Specify
      the relevant standard on the drawing.
31.   Specify the minimum rock size requirements on drawing JO7-071-05, based on maximum
      expected velocities.
32.   Incorporate a safety device within the pipework to ensure humans do not enter or become
      stuck in the pipework.
33.   Council is concerned that the bathymetry of the wetland is not reflective of a natural
      environment. Furthermore, the grade of bathymetry may affect the mosquito breeding
      success. Please provide a revised longitudinal section and an ecologist comment on the
      suitability and diversity of habitat zones proposed.
34.   Council is concerned that the absence of a high flow bypass will compromise the viability of
      the microphyte zone in high flow situations. Please provide justification for the absence of the
      high flow bypass from the wetland design.


SEDIMENT AND EROSION CONTROL PLAN
35.   Show approximate location of site exit referred to on Drawing J07-071-03.
36.   The erosion and sediment control plan refers to the requirement for a dam upstream of the
      sediment forebay during construction. Please indicate the dimensions and depth of the
      required dam.
37.   The Erosion and Sediment control plan proposes a turbidity release limit of 140 NTU based on
      the correlation of suspended solids and turbidity at another site. Council understands the
      correlation was based on all data points including many values where TSS exceeded the limit
      of 50mg/L. Council will only consider the correlation based on compliant TSS values of less
      than or equal to 50mg TSS/L. In this respect, provide Council with the data detailing the stated
      correlation in excel format. In order for council to accept any correlation please confirm to
      Council that the soil types at the subject site is the same/ consistent in terms of TSS and NTU
      correlations to the soil at the site where the correlation was sourced from.
38.   All Sediment and Erosion Control plans must be signed by an RPEQ or CPESC.