Eurobodalla Integrated Water Cycle Management Strategy

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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-27 Integrated Water Cycle Management Opportunities for Bodalla
Centralised management of effluent from onsite
facilities
Provision of
full reticulated
sewerage
system
Cost Estimate
Capital ($m) NPV @ 7% ($m)
2.57 2.85
Package Treatment Plant 2.66 2.93
Package Treatment Plant
with greywater reuse of
suitable systems 1
2.66 2.93
Package Treatment Plant
with greywater reuse of
suitable systems and
roofwater harvesting
utilising disinfected tanks 1
2.66 2.93
Note 1: As this is a strategy document, the saving s to Council for greywater reuse have not been costed. These
option will incur greater community costs
Centralised Management of Effluent from On-site Facilities
As an alternative to providing a full reticulated sewage system, the effluent from existing onsite
systems (e.g. septic tanks) could be collected and transported to a central treatment
facility. This type of system relies on smaller pipes than those required for a conventional
reticulated sewerage system. Pipes can be laid in the ground at a lesser gradient and at a
more shallow depth than that of conventional gravity sewerage, as the solids are captured
by the on-site system and the pipes only need to carry liquid effluent. This option has been
priced with a package treatment plant and opportunistic reuse
Reed beds are local treatment option that may be viable in Bodalla. Constructed Reed beds
use passive biological systems to treat a variety of wastes such as human, animal, plant
and industrial wastes. It is an extremely effective system with many environmental benefits
when compared with traditional treatment options.
Provision of Full Reticulated Sewerage System
An alternative to on-site treatment sewerage facilities is to transfer wastewater through a
Centralised sewer transport network to a treatment plant as described above. Unlike in the
previous opportunities the sewer transport pipes would be larger and possibly installed at
greater depths.
Provision of Full Reticulated Sewerage System with Grey Water Reuse
On-site systems that achieve a suitable level of treatment for greywater would be
maintained, and blackwater only would be transported to the STP using the reticulation
systems described above. The resulting greywater could then be utilised for a variety of
outdoor uses and for toilet flushing. Maintaining current aerated systems in Bodalla for
greywater reuse would reduce the volume of wastewater requiring treatment by 1.3 ML/a.
This in addition to reducing the volume of imported of reticulated water required for Bodalla,
would reduce the hydraulic load on the future Bodalla STP. With the implementation of
appropriate monitoring systems, long term environmental and water resource sustainability
and public health protection could be achieved.
Provision of Full Reticulated Sewerage System with Grey Water Reuse and Roofwater
Harvesting
This opportunity incorporates the components of the previous opportunity. In addition to the
elements described above, systems that are not suitable for greywater reuse (e.g. septic