Cullendulla Sewer Rising Main Realignment
Project: Realignment of the existing sewer rising main from Long Beach to Surfside
Cost: $3.178 million (awarded contract price) included in our 2018-19 Capital Program
Timeframe: September 2018 to February 2019
The project involves installing a sewer rising main beneath Cullendulla Creek Nature Reserve from Long Beach to Surfside.
The pipeline will replace the existing sewer pipe that has become exposed on Cullendulla Beach due to encroaching seas.
The new pipe will be located inland, safely away from the shoreline, and pass deep beneath Cullendulla Creek.
The route will extend from the existing depot at the east end of Myamba Parade, Surfide, 1.2 kilometers to near the existing pump station at Nuyen Place, Long Beach.
The HDPE pipe will have an internal diameter of 300mm and an external diameter of 450mm and be installed using horizontal directional drilling technology. This method will prevent any disturbance to Cullendulla Creek Nature Reserve and Cullendulla Creek.
The contract has been awarded to Dunstans Construction Group Pty Ltd and the works will be overseen by Public Works Advisory on our behalf.
Drilling works to install the pipe will begin in September and be complete by the summer holidays.
The old sewer pipe will be removed in February 2019.
Works will be carried out between 7am and 6pm, Monday to Friday.
Access to Cullendulla Creek Nature Reserve will not be affected and all walking tracks will remain open during works.
- Drilling works have resumed in Surfside to connect the bore hole to the Long Beach side.
- Once connected, the hole will be reamed out to a diameter of 660mm in preparation for pulling the strings of pipe through.
- After significant delays, the Maxi HDD rig arrived at the Surfside site and started drilling a 311mm diameter hole following the hole previously bored by the smaller drill rig.
- The delivery delay has caused disruption to the contractor’s schedule of works. In order to install the 1.2km pipe as soon as possible, drilling works continued over the weekends in December.
- The contractor has requested to resume work after the Christmas break, on 7 January, working Monday to Friday only.
- Over on the Long Beach side, the short lengths of pipe are being welded together to create three 400m strings.
- Each string of pipe will undergo pressure testing before it is installed.
- Once the drill head reaches Long Beach the pipe will be connected and pulled back through the bore hole to Surfside.
- Due to the proximity of the entry and exit points to the creek and nature reserve a 762mm diameter steel casing is being utilised to minimise the impact on the environment.
- The casing will significantly reduce the risks associated with any drill fluid release into the creek or reserve.
- An air hammer has been used to install approximately 30m of casing at the Surfside end and 50m at the Long Beach end penetrating into the harder formation below the alluvial layer.
- The drill rig has been moved to Long Beach and has drilled and reamed the 250m pilot hole from the eastern end.
- A larger drill rig will take on the massive task of connecting the two pilot holes.
- The head of the drill will be connected to the drill rig by numerous steel rods and carefully steered from aboveground by a trained operator.
- The new HDPE pipes lengths are being butt welded together to form three 400m lengths. The pipe welder is powered by a diesel generator which is causing considerable noise in the Long Beach area. We anticipate the contractors will finish the welding work in early December.
- Compounds have been established at either end of the new sewer rising main in Surfside and Long Beach.
- Drilling works are well underway with a relatively small diameter pilot hole drilled 250m horizontally 30m underground from the Surfside end heading toward Long Beach.
- The hole was then reamed to a larger diameter of 355mm.
- The new HDPE pipe has been delivered to Long Beach.
For more information about the project, please contact our Water & Sewer Senior Technical Officer, Richard Dixon:
- T: 4474 1000
- E: Council