Enviropacific developed a sustainable and cost-effective solution for the remediation of the drain on Todd Road, noting the complexity surrounding environmental, occupational and delivery risk. This project has prevented future contamination of the surrounding community.
History of the Site
The lower reaches of the Yarra River, known as Fishermans Bend, was occupied by fishermen of European descent since the 1850s. In the early to mid-1900s, an industrial expansion made way for significant manufacturing facilities including GM Holden (GMH), Boeing and the Commonwealth Aircraft Corporation.
Since 2012, the area has been designated as a major urban renewal area, with plans for 80,000 residents by 2050 across four residential suburbs. The legacy of industrial use of this land has resulted in ongoing groundwater contamination, including volatile organic compounds.
As a result of an investigation into historical chemical usage activities associated with the manufacturing at the former GMH facility, Poly Chlorinated Biphenyl (PCB) impacts were identified in stormwater sediment both on-site and off-site. Subsequent to the contamination being identified, GMH entered into a voluntary site contamination audit which included stormwater drains exiting the property, including the off-site drains on Todd Road.
Todd Road dissects the precinct, bordered to the east by the former GMH engine manufacturing facility and Defence Science and Technology Organisation (DSTO). A service station, shooting range, go-carting complex, and the Westgate Freeway is located to the south, with the road heading north towards the Yarra River.
There is an 1800mm diameter stormwater drain that flows parallel to Todd Road and discharges into the Yarra River. Investigative works had found that PCB impacted foundry sand was the cause of contamination within the drains.
To satisfy the obligations of the audit and the EPA notifiable chemical order applicable to PCB’s, the contamination required removal, with successful remediation of the drain defined as the removal of all solid and liquid content, followed by CCTV validation inspections.
Remediation Challenges and Design
Enviropacific developed a bespoke solution for the remediation of the drain on Todd Road, noting the complexity surrounding environmental risk, occupational risk, and delivery risk. The overall effect of which would be to prevent contamination from entering the Yarra River. The original tender scope of works stipulated the removal of sediment and liquid with off-site disposal from the site to a licensed treatment facility.
The Enviropacific solution presented a more sustainable and cost-effective pathway, with the initial onsite treatment of all solids and liquids. This allowed reuse of treated water, and/or disposal to stormwater, as well as dewatering of sediment to concentrate the key waste stream for off-site treatment.
The removal and disposal of waste as per the original scope would have resulted in excess of 80 combo truckloads of waste leaving the site. The Enviropacific solution required only 20 loads of concentrated waste, with almost 900kL of treated water disposed locally through the stormwater network under a legal point of discharge, removing a significant number of trucks from Melbourne’s roads.
Dewatering Storm Drains – Challenges and Solutions
Contamination Challenges and Solutions
Removal of Sediment – Challenges and Solutions
Stakeholders – Challenges and Solutions
Outcomes
This project not only included the development of a remediation strategy that prevents environmental harm while solving legacy issues but also provided the client with a solution that went above scope and added value by diverting contaminated waste from landfills. Key outcomes of the project:
- The extraction and transfer of 1M litres of sediment and water to an on-site treatment and sediment dewatering plant.
- The treatment, testing and discharge of 891,185 litres of impacted water. The water was treated and discharged to local stormwater under ANZECC 2000 Marine Water 95% Species Protection.
- The treatment, testing and discharge of 104.26 tonnes of PCB free category C contaminated solids and 123,680 litres of PCB free category C contaminated sludge.
- Separation of sediment, offsite disposal of scheduled PCB impacted sediment to EPA licensed facility. Non-scheduled PCB impacted solids of 124.62 tonnes were also taken care of.
- Validation of drains and sign off of audit.
- Prevention of contamination to the Yarra River
- A clean drain returned to the City of Melbourne
The post Remediation, Preventing Future Contamination at Fishermans Bend appeared first on Enviropacific.