Overview

The requirements for low total nitrogen (TN) and phosphorus (TP) under the Hawkesbury Nepean nutrient framework in Sydney are very low (< 0.35 mg/L TN and < 0.009 mg/L TP in some cases) to ensure the environmental health of the river system would be protected. To some extent, recycled water (for non-potable purposes or through potable recycled water (PRW)) can play a role in reducing loads to the river. However, there will need to be some ongoing discharge to the waterways, including for environmental reasons (to maintain flows in some areas). Sydney Water has a number of projects underway to upgrade existing plants or build new plants to provide treatment to achieve low TP and TN total nitrogen. This includes use of advanced biological nutrient removal, ultrafiltration and reverse osmosis, as well as considering impacts of the return centrate and more novel technologies.

Bondi Water Resource Recovery Facility (WRRF) is located in one of the most affluent suburbs in Sydney and is within walking distance from the world-famous Bondi Beach. The site treats wastewater to a Primary Treatment level, and discharges via an extended deep ocean outfall 2.2km into the sea. Bondi WRRF is especially unique due to the majority of the treatment assets being constructed within a cliff face around 40m below ground level, all inside underground caverns and tunnels with a single entry and exit point. This has over the years made it a site of unique complexity to operate, maintain and deliver projects. This presentation will discuss the deep ocean outfall sites in Sydney, how this site came to reside 40m below ground, as well as the day-to-day challenges in operating and maintaining the site, the challenges of delivering projects on site, and the planning and integration of major upgrades.

Western Treatment Plant (WTP) in Melbourne, Australia treats approximately 500ML/d of sewage. As part of a long-term augmentation strategy, Melbourne Water ran a demonstration-scale trial of short-cut nitrogen removal from 2017 to 2020 to test short-cut nitrogen removal for potential implementation in an upcoming major plant augmentation. Operating with limited carbon availability, the pilot plant (160 kL/d) observed improvements of 40% carbon reduction for nitrogen removal over baseline performance. The primary goal of demonstrating the feasibility of low carbon nitrogen removal was to enable Western Treatment Plant to meet its tighter treated water quality requirements and environmental obligations while maintaining carbon diversion to biogas production to supply the 16 MW power station on-site. The presentation will provide an overview of the demonstration plant design and trial results.

Speakers

Hannah Lockie, Technical Director, Sydney Water

Hannah is a Technical Director at Sydney Water. She previously worked in Design and Build and consulting roles as a process engineer. Since joining Sydney Water, she has been part of the overall lifecycle of projects covering regulation, planning, business cases, procurement and delivery. A significant part of her work involves the major projects associated with upgrades at the inland water resource recovery facilities to meet the new Hawkesbury Nepean Framework requirements.

Musaab Al-Saleem, Principal Process Engineer, Stantec

Musaab is a Principal Process Engineer with Stantec. Before joining Stantec Musaab worked in various roles with Sydney Water (Planning, Major projects interface, and Operations) as well as various design consultants and utilities in the UK both in client and consultant roles. Musaab’s varied and cross disciplinary background led him to be a proud “Specialist Generalist” with a focus on ensuring all jobs are done with the whole asset life cycle in mind.

Aprilia Vellacott, Technical Director, Jacobs

Aprilia is the Technical Director – Wastewater, ANZ for Jacobs. She has over 20 years experience in wastewater treatment plant design, review and optimisation, with a focus on energy and carbon efficient wastewater treatment. Aprilia has led two trial plants which have lead to significant energy and carbon savings for wastewater treatment, whilst producing higher quality effluent.

The material presented in this webinar has not been peer-reviewed. Any opinions are the presenters' own and do not necessarily represent those of IChemE or the Water Special Interest Group. The information is given in good faith but without any liability on the part of IChemE.

Webinar recording