360 Environmental coordinated the site assessment and remediation of a contaminated site located in an inner-city location, Perth. Initial site investigations indicated a above-guideline levels of Total Petroleum Hydrocarbons (TPH), benzene, toluene, ethyl-benzene and xylenes (BTEX) and naphthalene in soil and groundwater.  A large hydrocarbon plume extending over 100m was found, contaminating a further two parcel of land adjacent to the site including a nursing home and a road reserve.

A complex remediation program was developed based on the site constraints preventing odours or noise releases, and restricting access to large areas of the plume during remediation. Remediation of soil entailed excavation of hydrocarbon-impacted soil and treatment at a bioremediation facility and backfilling with clean sands. Remediation of groundwater, both beneath the site and at two sites hydraulically downstream of the site, involved injection of an oxygen release compound into the superficial aquifer followed by monitored natural attenuation. Liaison with a Contaminated Sites Auditor was undertaken to ensure compliance with the Department of Environment and Conservation (DEC) (2001-2006) Contaminated Sites Management Series and the Contaminated Sites Act 2003.

 

The key components of the scope of work undertaken by 360 Environmental included:

  • Site assessments to determine the contamination status of the site.
  • Vapour monitoring beneath the site and a neighbouring nursing home where a hydrocarbon plume was found to occur.
  • Groundwater modelling.
  • Coordination of a health risk assessment to determine remediation objectives.
  • Formulation of a Remediation Action Plan (RAP).
  • Remediation of hydrocarbon impacted soil. Due to space constraints and sensitive neighbouring landuse soil was transported to a licensed bioremediation facility for treatment.
  • Community consultation.
  • Remediation of groundwater beneath the site and beneath two adjacent parcels of land including a large nursing home. Due to the sensitive land use of the sites requiring remediation, a passive approach was designed involving injection of an oxygen release compound and monitored natural attenuation.
  • Liaison with the Contamination Site Auditor.

Duration: 2006 - present

Client Referee: Jim Sweeney, CPD Group: 08 9472 9444