Eurobodalla Integrated Water Cycle Management Strategy

154
Eurobodalla Integrated Water Cycle Management Strategy
There is a need to sustainably manage the use of the Broulee aquifer for continued
use by both the environment and the water users.
Water Infrastructure Performance Issues
Water Supply
Analysis indicates that the existing local reservoir capacity meets Council’s service level for
current and future demands. Council has advised that under current demand conditions the
system also meets Council’s service level for mains pressure and fire fighting requirements.
Some residents use groundwater for garden watering. Based on past water quality data, the
practice poses a minor risk to the users however over-use of this resource poses a threat to
the environment. Measures should be taken to ensure this source is sustainably managed
for continued use by the environment and the householders.
Sewage
The nominal design capacity of the plant will be exceeded by around 2015, however the
reactor and the clarifier has been assessed to have a treatment capability in excess of
3.7 ML/d or 15 000 EP. This means the plant has the capacity to process loads for the next
30+ years, provided the pipeline linking the various treatment process units is adequate.
However, the plant needs some rehabilitation works to meet current OH&S legislation.
It is important to note that if the option to transfer sewage from the southern catchment of
Batemans Bay to Tomakin STP is implemented, the Tomakin STP would require increased
capacity to be implemented in 2-3 years time, rather than 15 years as indicated earlier.
The sewer network servicing Tomakin and the surrounding area is extensive and has been
grouped into three distinct catchments, the southern catchment serving the Broulee area,
the central catchment covering the Mossy Point area, and the northern catchment covering
the Tomakin area. There are six pumping stations in Broulee located along the bay
foreshore that transfer the sewage towards the treatment plant. There are three pumping
stations in Mossy Point and a major station that receives the sewage generated from both
the local and Broulee catchments. The sewage from the main pump station is transferred to
a main pumping station in the Tomakin catchment, which together with the local flows
transfers the sewage to the STP.
Due to its relative recent construction and the lower than anticipated load, the sewer
network has been performing satisfactorily during and after power failure and during rainy
periods. Due to the long transport network, high levels of hydrogen sulfide are generated
causing odours and impacting on the life of the assets. In view of the proximity of the main
transport link to the surrounding beaches, it is suggested Council undertake a
comprehensive risk analysis to identify potential failure modes and the critical facilities in
the network system. This analysis could then be used to develop critical control and
management response plans.
Although the EPA has assessed the performance of the outfall as being among the best in
NSW, in order to meet best practice standards Council should consider disinfecting the
wastewater prior to its discharge to the ocean environment. This, in addition to meeting best
practice standards, would also provide increased public health protection and improve the
aesthetic and environmental appeal of the area. Similar to the Batemans Bay system,
options available to enhance the discharge quality include wetland treatment, air flotation
and sand or membrane filtration. Reclaimed water reuse and recycling strategies are
discussed in Section 3.
Stormwater
The Barlings Beach sub-catchment encompasses vulnerable ecosystems and a significant
wetland that will need protection when development occurs. The main road that leads into