Tacoma South Sewerage Upgrade

You are already connected to Council’s sewerage system. However, properties within the Tacoma South scheme boundary are required to changeover to the upgraded system, as the existing vacuum system will be decommissioned.

The vacuum system was installed in 1989 and is nearing the end of its lifespan. The system has been underperforming and requires an increasing need for maintenance, with no corresponding improvement in performance.

The problems are difficult to identify, and when a single vacuum component malfunctions, or the system becomes water logged, this impacts the service to all 104 dwellings.

The current system is inappropriate for flood prone areas and fails to operate correctly during periods of flooding and the proposed alternative technology will perform better in a flood situation. 

PSS’s are particularly suited to areas which have an existing community, that are flat and have a high-water table. Because the network consists of sealed pressurised pipes and pressure sewer units (PSUs) with grinder pumps, inflow and infiltration is minimised.

These pipes are not constrained by maintaining constant grade. They are installed using shallow trenching and trenchless technology, reducing the disruption to vegetation and existing ground surfaces.

A PSS has the ability to monitor individual pump performance, ensuring efficient response and resolution to issues, and for remote isolation of properties that are more susceptible to flooding while allowing the rest of the network to remain in service. The recovery time with this system after flooding will also be faster. 

Once installed the only visible parts of the pressure sewer system on your property will be the tank lid, control panel and boundary kit. Your property will be reinstated as close as practicable to its pre-existing condition as part of Central Coast Council’s (CCC) installation works.

The pressure sewer mains (network) will be located in the road reserve and public land. Council may need to remove obstacles such as trees. However, as part of this process we will liaise with you to ensure minimal disruption or impact to your property. You will be consulted prior to any works happening on your property.

Pressure Sewer Unit (PSU)

The PSU is a collection tank, similar in size to the existing vacuum pod, a grinder pump unit and a control panel. There will be a PSU located on each property generally near the current vacuum pod. Your existing house sewer will be redirected to discharge into the PSU and the vacuum pod will be decommissioned.

The lid of the PSU will be approximately 120 millimetres above the ground surface. The pump has a grinder that breaks down solids prior to discharge into the reticulation system.

Control Panel

A control panel, which automatically operates the pump, will generally be located adjacent to, and at the same level as, your main switch board on the side of your house.

Boundary Kit

The property discharge line from the PSU connects to the boundary kit, which contains a set of valves, and is located just inside your property boundary.

Generally, installation and ongoing maintenance of the new system is expected to have minimal impact on the local environment and residents.

Council will continue to provide regular updates via letter to keep residents informed throughout the delivery and construction process.

We have visited every property, and met with property owner’s personally, to review and discuss property design plans.

Residents will have another opportunity to discuss the planned upgrade works, including property design, re-assess the electrical equipment for any changes, ask questions and discuss any potential changes before works commence.

Experience from similar installations on the Central Coast has shown that noise and odour levels associated with the pump unit are negligible.

Regarding noise, the ground surrounding the buried unit absorbs the majority of noise levels.

As for odours, some minor odours may be noticed for a short period following a holiday house being left vacant for long periods, however this is similar to a conventional gravity system. 

You will be contacted prior to construction, to arrange a meeting to review your property plan, document any changes if required, approve locations of the equipment, review electrical requirements and plan for installation.

If you have not already, you will also be asked to sign a CCC User Agreement, which outlines CCC and the property owner’s roles, responsibilities, and ownership of the new system; in particular CCC’s ongoing operation and maintenance and the electricity supply offset arrangement.

This meeting will be a great opportunity for you to discuss any concerns you may have and understand the benefits for you and your community. 

The property plan shows the location of the PSU and the associated equipment such as control panel, electrical cable and boundary kit. The plan was produced in early 2015, but as things may have changed since then, they will be reviewed and finalised as part of the detailed design finalisation prior to construction. 

Property owners will be required to meet the costs of supplying electricity to operate the pump, generally around $25-30 per year, which will be offset by a reduced annual sewer charge for Tacoma South to account for these electricity costs. 

Council awarded a contract in March 2023 with construction commencement in May 2023 weather permitting. 

Installation on your property will generally take 2-3 days per property, allowing for the installation of the PSU, grinder pumps, control panel and transfer from the old vacuum system. Alternative servicing arrangements, if required, will be made with residents during this period.

General construction traffic will exist within Tacoma South for the duration of the construction phase (approximately 8-10 weeks).

Council is responsible for the installation, operation and maintenance of the PSS. This includes the boundary kit, discharge pipeline, pumping unit and cabling between the pumping unit and control panel. Council will install a new circuit breaker in your switchboard and power cabling from your switchboard to the new control panel. However, this cabling becomes the responsibility of the property owner (as it normally extends through roofs or under houses). If the tank were to overflow under normal use, Council would be responsible for clean-up, refer to the Home Owner’s Manual.

The unit has in-built storage that will allow for the restricted use of wastewater facilities during a power outage.

Should something go wrong with the unit or the collection system, the water level in the unit will reach an alert trigger, setting off an alarm through a remote device to Council, or light and alarm on the control panel. Refer to your Home Owner’s Manual. Council will then attend your property to check the problem.

The unit and the control panel are secured against unauthorised access. Central Coast Council Water and Sewer maintenance and operational staff and contractors will be the only people authorised for access.

As all the solids in the wastewater would be ground to a slurry, there is a very low likelihood of a blockage beyond the unit. The likelihood of a blockage in the household plumbing would remain the same as your existing system.

The unit is fully sealed against storm, ground or floodwater ingress. The only potential for overflow is misuse by the occupants during periods of long power outages or if they connect their roof drains, swimming pools or spas directly to the sewer.

As a pool or spa owner, you should be aware that backwashing or draining your pool or spa can cause the existing vacuum system and the proposed PSS to overflow or set off an inbuilt alarm.

There are options available to minimise this risk and these will be discussed at your property design appointment to discuss specific site requirements.

If you are already connected to the sewer, the pool/spa discharge will connect into the pressure sewer system. The backwash water could enter the pressure sewer pumping unit faster than the system can pump it to sewer. This will cause the high water alarm to sound, and may also cause an overflow.

In this case, a retention/buffer tank will need to be installed on your property to slow down the flow into the pressure sewer pumping unit. The retention/buffer tank will temporarily store any backwash (or other cycle) and progressively release water into the sewer at a rate of less than 0.5 L/s. This will avoid nuisance alarms and unnecessary Council call outs to the property. Alternatively, you can replace your sand filter with a cartridge filter that does not require backwashing.

You cannot discharge chlorinated backwash water from the pool to the stormwater system, but you can discharge it to land – as long as it doesn’t cause environmental harm or encroach on your neighbour’s property.

If you are proposing to install a new swimming pool or large spa, you should consider installing a carbon cartridge filter so that backwashing is not required. If you wish to install a sand filter, the discharge will need to be connected to the sewer. If you are connected to the pressure sewer system, you will need to install a retention tank so that the discharge flowrate into the pressure sewer pumping unit is less than 0.5 L/s.

The agreed format of discharge will be covered by a condition of consent for the dwelling or pool. The cost for any additional equipment/work required to be installed to accommodate large sudden discharges from spas or swimming pools will be met by the property owner.