South Byron STP

CLIENTNSW Public Works/Byron Shire Council

The South Byron Treatment Plant Project involved the demolition of all above and below ground infrastructure, along with asbestos removal and the remediation of burial pits and sludge drying beds.

Asbestos removal works included the removal of bonded asbestos sheeting from buildings and mastic sealant from treatment plant infrastructure. In addition, a significant amount of asbestos pipework was removed from the bases of the two trickle filter tanks. All asbestos removal was validated by a certified hygienist.

Over 1,000m3 of river rock contained in the treatment plant’s trickling filter system was selectively removed, washed and stockpiled for reuse in future landscape and rehabilitation works.

Prior to the start of demolition works, residual sludge contained within the digester treatment tanks were treated and disposed off site to landfill. Over the 10 years the site had been closed, stormwater had occupied a number of tanks and pits on site. Following sampling and analyses, Liberty obtained approval for discharge into the adjacent lagoon and saved the client significant costs for off site disposal to a treatment facility.

The demolition involved breaking and crushing of all above ground concrete storage tanks, former office, storage buildings, below ground concrete tanks, digester tanks, trickle tank filters and all associated below and above ground infrastructure. A total of approximately 1500 tonnes of above and below ground concrete infrastructure was demolished, crushed, screened and stockpiled for reuse by Council.

Upon commencement of excavation works to one of the former sludge ponds it was identified that construction and demolition debris had been used to fill the area. Liberty Industrial undertook screening of this material to remove the sand material and reduced the associated volume of waste to landfill by over 80%. In total approximately 4,000m3 of impacted soil was remediated by screening to remove aesthetically unsuitable material.

The residual screened sand was validated as clean for reuse and backfilled within the excavation.

Liberty has excavated identified “hot spots” from the Remediation Action Plan and disposed to landfill up to 2,000 tonnes on asbestos impacted soils, including waste from the former “grit and rag” location.

The site was demolished, remediated, backfilled and regraded in a timeframe of 10 weeks enabling future redevelopment works to progress.