Pensar, a leading water infrastructure contractor, is spearheading a joint venture tasked with building Unitywater’s Wamuran Irrigation Scheme, a project that will provide recycled water to farmers year-round while sustainably managing wastewater from the Caboolture South Treatment Plant. To ensure the project’s 10 km of pipeline was constructed to the highest standards, Pensar engaged Pipe Tek to complete pigging and testing of the alignment before it becomes operational next year.
The Wamuran Irrigation Scheme Joint Venture (JV), made up of construction contractor Pensar and local growers Twin View Turf and Pinata Farms, was awarded the contract by Unitywater to design and construct the Wamuran Irrigation Scheme (WIS). Pensar has a proven reputation in the design and delivery of fit-for-purpose critical infrastructure solutions for a range of industry segments, providing a broad spectrum of technical capabilities to organisations such as government departments, regional and metropolitan councils, and the private sector.
Taking the pressure off
The WIS will take Class A recycled water from the Caboolture South Wastewater Treatment Plant to farms for irrigation, ensuring a sustainable future for the growing regional population while reducing the nutrient discharge into the Caboolture River, with 11 tonnes of nitrogen and 1.8 tonne of phosphorus being diverted away from the river in the first stage alone.
The WIS will help address forecast population growth in the Moreton Bay region that will increase wastewater through Unitywater’s treatment plants. Subsequently, the scheme will help provide a secure water supply for local agricultural businesses and growers as well as contribute to nutrient offsets at Caboolture River.
In addition, as more water becomes available from the treatment plant, the scheme will expand to service more local growers.
According to Moreton Bay Regional Council, the region’s agricultural industry is worth an estimated $846 million, with exports worth approximately $420 million to the local economy. This includes the largest strawberry producing area in Australia, more than 25 per cent of Australia’s pineapples and a burgeoning finger lime segment among others.
A design and feasibility assessment for the project kicked off in early 2020, with Unitywater assessing the scheme’s efficiency and design for current and future demand targets. The JV started construction of the WIS in early 2022 and the scheme is expected to be operational next year.
During this construction phase, Pipe Tek was engaged by Pensar for pigging and pressure testing on the 10 km pipeline being constructed as part of the project. Pipe Tek’s analysis will guarantee the integrity of the pipeline before it is brought online, avoiding any issues like leaks or sections coming apart once in use.
Pipe Tek Managing Director Myles Brannelly says the company was excited to be involved in such an important project, ensuring local farmers are able to maintain irrigation on their farms.
“Agriculture is the lifeblood of many parts of Australia, but especially in the Moreton Bay region, which produces so much fruit, vegetables and meat for consumption around the country and overseas,” he says.
“Water is such a precious resource in the area it was imperative that for this project the pipeline was analysed to the highest standards to ensure efficient operation once the WIS is completed.”
Pigging and testing
Once mobilised on site, Pipe Tek commenced pigging of the pipeline, with medium density foam pigs used on sections constructed using horizontal directional drilling & trenching to remove air and debris prior to testing. Some mainline sections couldn’t be pigged, leading Pipe Tek to use valves in order to bleed out air at all high points of each section.
After pigging had been completed, Pipe Tek pressurised the pipeline to the required test pressure, after which it needed to sit and relax for a minimum of 12 hours before the commencement of the pressure test. The test maintains the required pressure for the specified amount of time to ensure the structural integrity of the pipeline.
To complete the pigging and testing Pipe Tek used its custom built hydro testing trailer, equipped with an inbuilt air actuated hydro test pump. The trailer features calibrated pressure gauges and flow meters, and has a compact design to ensure manoeuvrability on testing sites with limited footprints, which Brannelly says was a key challenge on the project.
“The main challenge has been how tight the job has been with other stakeholders and contractors working closely together on site. It’s been a real test of maintaining strong communication and patience to ensure we get the job done right.”
Testing of the pipeline is ongoing but is expected to be be completed in May. Once finalised, the pipeline will be commissioned prior to going online, which is estimated to be in May 2024. In addition to pigging and testing, Pipe Tek has also been contracted to complete facility testing during this commissioning process.
Brannelly says the company is thrilled to have established a new relationship with an innovative infrastructure contractor in Pensar, and looks forward to partnering with the company again on future projects.
“It has been an absolute pleasure to work alongside Roy Jordan and the entire team over at Pensar,” he says.
“The engineers have been competent and easy to work with and have really highlighted why we do the work we do.”
Pipe Tek is one of the only pipeline contractors in Australia, New Zealand, Papua New Guinea and the Pacific which provides a full turnkey solution to its clients. The company’s services include non-destructive testing, pre-cleaning, gauging, filling, hydrostatic and pneumatic testing, dewatering, drying with either desiccant or refrigeration dryers, nitrogen purging, caliper pigging, inline inspection with dig ups and verification by phase array.
This article featured in the March edition of The Australian Pipeliner.