Macksville Sewage Overflow Reduction

Rainfall events experienced during 2022 and to date this year have adversely impacted Council’s sewerage system in Macksville and caused a number of overflows to the Nambucca River.  This has impacted the oyster industry and resulted in the EPA issuing Council with a Pollution Reduction Program to take action to reduce the number of overflows in order to maintain river health.

Council’s monitoring of the sewerage system indicates that stormwater inflow into the system during wet weather events is a significant contributing factor to cause the overflows.  Council is now working with the EPA and other government stakeholders to undertake the following activities aimed at addressing the issue;

• Dye testing to identify any sources of illegal cross connection between the stormwater drainage and sewerage systems
• Investigation to identify points of stormwater ingress into the sewer system
• Repairs and upgrade works to prevent stormwater ingress into the sewer system
• Community education program
• Sewer relining and patching to prevent stormwater infiltration into the sewer system.

Council commenced dye testing in two major Macksville catchments in late 2022.  These were Catchment 7, roughly bounded by Boundary Street, Wallace Street, East Street and Nambucca Street and Catchment 3 which is essentially Kings Point.

The majority of dye testing has been completed and notices have been issued to properties with non – compliant plumbing instructing them to engage plumbers to address the issue.  Four properties were found with illegal cross connections and these have been or are in the process of being rectified.  Council has to revisit some 40 properties to redo the dye testing to ensure conformance.

Council has also identified a number of locations where its sewer system is subject to stormwater ingress with major sources in the Macksville CBD and Nambucca Street.  The pool was also identified as a major issue as it often discharges water to the sewer during rainfall events placing significant additional pressure on the capacity of an already stressed system. Council has rectified the problem behind Nambucca Street and has installed a bypass and dechlorination arrangement to discharge water from the pool to the stormwater system when this is required during rainfall events.  Council is also working with property owners in the Macksville CBD to eliminate the ingress of stormwater into the sewer system

CCTV inspections have also identified a number of locations where cracked or displaced pipes allow stormwater to infiltrate the sewer system.  Council has engaged a specialist contractor to reline and patch the identified pipes to prevent any further stormwater entry.  This work commenced on the 22 June and has now been completed

Council expects the work completed to date to significantly reduce the volume of stormwater entering the sewerage system thus reducing the frequency of overflows.  However, Council encourages all residents to be mindful of ensuring they are doing what they can to ensure that they are not contributing to the problems impacting the sewerage system.  This includes doing the following:

• Checking that overflow relief gullies are located above finished surface level and do not act as drains for surface water.
• Checking that there is no cross connection between roof downpipes or rainwater tank overflows and the sewer system.
• Not flushing wet wipes down the toilet and rather disposing of them in the waste bin.