Projects

Beenyup WA Asbestos Remediation (Environmental)

BACKGROUND

Lyon Environmental was commissioned by Programmed Facility Management to perform environmental supervision of the remediation of the proposed Beenyup Bus Depot located at the northern end of the Water Corporation Beenyup wastewater treatment facility, in Craigie Western Australia.

An Asbestos Management Plan (AMP) was prepared in response to the detection of asbestos in shallow soils found during a Detailed Site Investigation (DSI) completed at the site prior to remediation.

PROCESS

Remediation earthworks were performed by asbestos removal contractors Focus Demolition under the direction of the principal contractor West Force Construction. Initially remedial works involved the removal of filled ground in the western half of the site; this was however extended to include the eastern half of the site at the request of the Water Corporation.

In all, the entire 1.7 ha area of the site including 0.3 m beyond the site boundary was removed down to undisturbed ground.
Limestone base was applied to the ground surface to minimise contact with the impacted ground surface prior to removal by excavator and to prevent cross contamination between contaminated and clean soils.

A total of 14,789 tonnes of soil was disposed off-site to landfill at completion of remediation Clean quarry sand was imported to site and used to backfill and compact excavations performed across the entire site.

Following remediation, Lyon Environmental performed soil validation collecting in excess of 250 samples across the sitesite.
All validation samples were tested for ACM (asbestos containing material) by sieving with fines sent for laboratory analysis for any fibres.

All final validation samples were compliant with the remediation criteria of no detectable ACM fragments or asbestos fines/fibrous asbestos (AF/FA).

Air monitoring was undertaken daily during the remediation works.

OUTCOME

The remediation of the entire site was successful in removing all traces of ACM fragments or asbestos fines/fibrous asbestos with all suspect soils removed to landfill.

On completion of remedial works, the entire site was considered decontaminated and fit for any land use.

Port Hedland removal of Underground Storage Tanks

BACKGROUND

(UST) located at a disused car depot in Port Hedland. The underground petroleum storage tanks comprised of one 10KL diesel tank and one 5KL tank containing unleaded petrol.

A concrete hardstand island was also removed as a part of the decommissioning works that housed the two product dispensers situated between the underground storage tanks. Vents pipes and all other ancillary equipment associated with each tank were also removed as a part of decommissioning.

PROCESS

Local earthmoving contractors and petroleum fitters were engaged to remove each of the fuel bowsers, expose the underground fuel tanks and disconnect suction and vent pipework.

The tanks were then transported from site to an authorised and accredited contractor in Geraldton for degassing and decommissioning in accordance with regulatory guidelines.

OUTCOME

Following the removal of underground storage tanks and associated infrastructure, further excavation work was performed to remove as much of the impacted soil from the void as practicable.

Localised hydrocarbon impact at depth (>2 m) beneath each of the bowser locations was mostly removed on completion of work, increasing the overall depth of the excavation to 3.2 m.
Following remedial works, the residual hydrocarbon impact did not compromise the sites ongoing use for commercial purposes.

Stockpiled contaminated soils was transported offsite to local landfill. The excavation was backfilled and compacted and the surface cover re-instated in accordance with the clients request.

Mundijong Site Remediation

BACKGROUND

Lyon Environmental (LE) were engaged to direct soil remedial works associated with the removal of petroleum infrastructure and contaminated soils at a service station site located in Mundijong.

The primary objective of the remediation program was to remove as far as practicable any contaminated soil as a part of fuel infrastructure upgrades occurring at the site.

As a part of remediation works was the installation of a passive groundwater remediation system where suitable compounds could be introduced into the aquifer via purpose built PVC conduits should there be a future need for ongoing groundwater treatment.

PROCESS

The process included the following:
· Removal of underground fuel storage tanks and ancillary equipment and disposal from site
· Supervise and direct the removal of hydrocarbon impacted soils within the exposed tank pit voids using a 25t excavator.
· Manage offsite disposal of contaminated soils
· Sampling and analysis of soils from the walls and base of the excavation void to validate the condition of the ground post remediation.
· Assessment of soil analysis against applicable health and environmental guidelines.
· Install specifically designed conduits to enable compounds to be introduced into the aquifer to promote natural attenuation, should further treatment of the groundwater be required.

OUTCOME

Prior to the tank removal and associated remediation the site represented a potential health risk based primarily associated with hydrocarbon vapour emissions as benzene from the underlying soil and/or groundwater.

Excavation and disposal of most of the residual soil impact during the tank removal significantly reduced the mass of hydrocarbons and potential vapour emission and as a source for ongoing groundwater degradation.

Soil testing indicated the residual soils remaining at the site were suitable for an on-going commercial landuse with negligible potential for significant vapour emissions.

Although groundwater remained contaminated, removal of impacted soil at the source is expected to significantly assist with plume natural degradation.

Need Contaminated land Environmental Services?

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