This year, the Kendall Bay sediment remediation project was recognised internationally, taking out silver for 'Sustainable Change for Good' at the 2021 Edison Awards™ .

The award was presented to our client, Jemena, for the design and delivery of the marine in-situ stabilisation (ISS) used in the remediation of Kendall Bay in New South Wales. Understood to be the world's first subaqueous in-situ stabilisation of contaminated sediment for environmental purposes, Ventia played a key role, leading advances in the use of ISS technology in underwater environments, and delivering a lasting environmental protection and enhancement solution.

Kendall Bay is a shallow marine environment characterised by intertidal mudflats, mangroves, outcropping sandstone rock, a sandstone seawall and a sandy beach. Approximately 10km west of Sydney's Central Business District on the south side of the Parramatta River, the Kendall Bay remediation project involved the remediation of legacy coal tar contamination, left behind by the former Mortlake Gasworks.

Keen to ensure the safety and protection of the local community and improve the marine ecosystem, our client Jemena briefed Ventia on the need for a lasting solution to treat acutely toxic contaminated sediments in the sensitive marine environment.

Over the next two years our team engineered and trialed long-term applications of in-situ sediment solidification. While ISS is a common and highly successful method used on land, there were previously only few, small-scale examples of use in a marine environment. The approach had never before been implemented in Australia and we had to ensure it was technically sound, environmentally justifiable and would meet Environment Protection Authority requirements.

In 2020 we deployed the first large-scale application of in-situ stabilisation in marine remediation anywhere in the world. ISS involved mixing marine cement with sediment underwater to form a stabilised raft-like structure to permanently contain the contaminated sediments. Once sediments were stabilised, clean sand and rock was installed to provide a suitable, rejuvenated environment for the recolonisation by microorganisms of the seabed and remediation areas adjacent to the former gasworks.

Ventia removed 7,500 tonnes of contaminated material, remediating an area with a total size of 11,800m2. The project methodology resulted in a significant reduction in virgin excavated natural material compared to a traditional 'excavate and replace' approach, and less truck haulage movements also reduced the impact of the works.

The Ventia Environmental Services team was honoured to be recognised by The Edison Awards™ in 2021, which celebrate the most innovative products and leaders in the world. Named after extraordinary inventor, Thomas Edison, this award is amongst the most prestigious accolades for excellence in new product and service development, marketing, design and innovation.

The Australasian Land and Groundwater Association (ALGA) also celebrated the success of the Kendall Bay remediation project recognising Ventia, Jemena, and partners Geosyntec Consultants and WSP with two 2021 ALGA Awards, winning in the 'Innovation that Advanced the Practice of Contaminated Site Remediation' and the 'Best Remedial Project >1M' categories. Ventia Engineering and Design Manager, Dr Sven Barthelme was also recognised for his outstanding talent and contribution to remediation, winning the 2021 'John Pym Excellence in Engineering' ALGA Award.