Response to Info Request - Attachment 4a - Engineering Report Part 1 MCU18-0015 & RAL18-0001 · MCU18/0015

8.0    SEWERAGE RETICULATION


Refer to the attached Engineering Drawing C5756/15/P23 for details of the proposed
sewer reticulation layout.


Proposed units 1-12 will be connected to reticulated sewer via an internal gravity sewer
network (Private) that will connect to the existing manhole SM2668739 in Picture Point
Crescent with an Invert level of 19.35m AHD (from UW records).


Proposed Lot 2 can readily connect to existing manhole SM2670601 located just outside
of north-east boundary.


It is proposed that Lot 4 be serviced by a privately owned pump station with macerator,
which will lift effluent to the existing manhole in Alma Way, SM2670588. Adjacent gravity
reticulation is approximately 3-5m above expected lot finished floor levels.


Due to the presence of sand foundations and steep gradients across the site, it is not
recommended      that     the   sewer   network    be   constructed    using   traditional
excavation/trenching.


It is proposed to construct the internal sewer network and provide connection to the
downstream network using Horizontal Directional Drilling (HDD). This will limit the zone
of disturbance and reduce the impacts of construction works on existing vegetation.


Refer to technical advice relating to HDD, prepared by Bamser Engineering and attached
as Appendix I.




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