Tour of Upgrades at the Bolivar Wastewater Treatment Plant
Twenty-five enthusiastic water professionals met at the Bolivar Wastewater Treatment Plant (WWTP) on World Water Day (22 March) to learn about recent infrastructure upgrades at the plant. The theme for this year’s World Water Day was ‘Water and Jobs’ so this tour provided an opportunity to hear from each of the main contractors involved in the delivery of the upgrades. Many of the participants had not been to Bolivar WWTP before and this tour provided a real opportunity to not only learn about the upgrades but also to see a large municipal WWTP in action.
We met up at the site administration building where background presentations were given by SA Water, the main contractors and Allwater. Following these, the group then split into three and were given tours of each portion of the upgrade works which were led by each contractor.
The group first heard from Olaf Richter and Paul MacKeddie from SA Water’s Asset Management team. Paul and Olaf provided an excellent overview of the key strategic objectives for the Bolivar WWTP upgrades including funding opportunities and constraints. The group also learned about a range of future projects at the plant including enhanced midge fly management, provision of more recycled water to the Northern Adelaide Plains to assist in State growth and jobs, implementation of co-digestion, and the interface between Bolivar WWTP land and the new Norther Connector road way.
Paul MacKeddie provides an overview of Bolivar WWTP
Iain Wood, Operations Manager at Guidera O’Connor provided an entertaining presentation of the upgrade of the Bolivar pump station. The group learned of the significance of this pump station in the Bolivar network in that it pumps approximately 60% of Adelaide’s sewage and it must be online continuously to avoid major overflow and significant environmental impact. The group learned of the challenges of replacing 6 pumps and installing an additional pump in a very confined space including maintaining continuous operation of the pump station during the two-year project. In addition to the pumps the project team replaced all of the mechanical and electrical equipment in the building, undertook major repairs of the building, including replacement of the roof, and at the same time kept the original architectural style of the building, a personal touch from Iain.
Inside the Bolivar Pump Station
Clarke Energy representatives, Vincent Kain and Michael Jones provided the group with an overview of the installation of new gas engines that utilise biogas generated from the WWTP and also natural gas when required. The group learned that the new gas engines provide approximately 80% of the electricity for the plant and at times generate excess electricity that is returned to the grid. Returning electricity to the grid is not only determined by the availability of excess electricity generated but also the price of grid energy on the ‘spot market’. Excess heat from the gas engines is captured and used to regulate the temperatures in the WWTP digesters.
Bolivar Electricity Generation Control Room
York Civil as lead contractor was responsible for the Bolivar WWTP Concrete Rehabilitation Works Package. Marc Doyle, Project Manager at York Civil, explained that the work involved the construction of two new grit vortex chambers to divert screened sewage through the new grit removal system and into the existing primary sedimentation tanks. Concrete remediation was performed to existing structures, which included the distribution channel, primary sedimentation tanks, launders and outlet channel. There were a number of work, health and safety risks associated with the project and the group was given an overview of some innovative ways of managing those risks. These include: 1. a float alarm that gives warning to workers to evacuate should the channel in which they were working begin to flood; 2. ensuring stretcher access was available to those working in the primary sedimentation tanks; 3. having special hygienically rated water bottles available for workers; and 4. hand sanitizer attached to a lanyard for on the spot use at the WWTP.
Bolivar Sedimentation Tank
Ben Parcell, M&E Maintenance Delivery Manager at Allwater, described the challenges that these significant upgrades had on the day to day operations of the plant. These included having pump and treatment capacity reduced for extended periods of time. These challenges were successfully managed through effective collaboration and interface between the contractor parties and Allwater. With the completion of these major upgrades a new chapter is now open for Allwater to operate Bolivar WWTP and its pump station with greater capacity, reliability, flexibility and overall less risk.
Participants enjoying the tour
Following the presentations and tour, the group enjoyed a gourmet style BBQ and spent quality time networking amongst themselves and the contractors. Thanks to Guidera O’Connor, Clarke Energy and York Civil for sponsoring the event. It was much enjoyed by all!
Enjoying the gourmet BBQ