The Defence National Storage and Distribution Centre (DNSDC) Refuelling Area Remediation project involved the deconstruction of existing superstructure such as buildings and canopy. It also entailed the removal of all existing Underground Petroleum Storage System (UPSS) infrastructure, including all bowser pumps, associated pipework, one 65,000 litre and five 55,000 litre storage tanks with associated fittings and supply lines. Associated with the deconstruction and UPSS removal was the removal of asbestos pipes and quantities of contaminated soils of hazardous solid (HSW) and general solid waste (GSW) in nature. A separate multi-phase vapour extraction (MPVE) program will also be carried out over 12 months to remove light non aqueous phase liquid (LNAPL) groundwater contamination.
OPEC provided its services to the client in a compressed time frame enabling site works to commence as soon as was practicable. Using specialist deconstruction company Liberty Industrial OPEC carried out the works requiring an unrestricted demolition licence (removal of underground storage tanks) in NSW and moved rapidly to excavate and stockpile potentially contaminated soils in conjunction with Defence’s Environmental Consultant GHD. OPEC had sourced a sustainable solution for the contaminated soils which were sent to a bio farm for processing.
The project involved the removal of 1500 tonnes of GSW to the sustainable land farm, 300 tonnes of GSW to landfill, 100tonnes of HSW to land farm, 800 tonnes of concrete to concrete recycling and some 30 tonnes of metal waste also recycled. Over 2500 tonnes of virgin excavated material (VENM) was imported into the site to backfill the waste material excavation. All this was carried out on a site of limited size (less than 1 hectare) of which more than half became open excavations varying in depth from 1 to 5 metres below ground surface (BGL). Tight control of materials handling and transport on and off site have been paramount to the project’s success and working in close corroboration with the client and their environmental consultant essential.
The client has expressed their satisfaction with the way OPEC is delivering this project from both the time frame and problem solving all with the OPEC “can do” attitude.