Phase 2 Environmental Site Assessment

Phase 2 Environmental Site Assessment

Former Military Barracks, Central Bangkok, Thailand

SLP Environmental Consultants was appointed by the Australian Government to design, implement and report a Phase 2 Environmental Site Assessment (intrusive geo-environmental site investigation) for a large plot of prime real estate located in downtown Bangkok. SLP has previously conducted a Phase 1 Environmental Site Assessment of the subject property which confirmed that the target land had been host to several former potentially contaminative land uses over the last 60-70 years. The primary objective of the Phase 2 ESA was to determine the contamination status of the property. The assignment was conducted in accordance with practice presented in ASTM E1903—11, Standard Practice for Environmental Site Assessments: Phase II Environmental Site Assessment Process.

The site investigation locations were targeted to focus on areas of potential environmental concern that were identified during the preceding Phase 1 Environmental Site Assessment and the scope of works comprised of the rotary boring of several exploratory holes across the subject property to a depth of 5m below ground level (bgl) and the recovery of soil samples for laboratory analysis.

Groundwater monitoring wells were installed in several of the soil bores and these were developed and purged in accordance with industry best practice in order to obtain a representative sample from the shallow groundwater body. Field monitoring for parameters such as pH, conductivity and dissolved oxygen was then undertaken prior to groundwater samples being recovered for laboratory analysis. The recovered soil and groundwater samples were scheduled for environmental testing for a comprehensive range of parameters including heavy metals and volatile and semi-volatile organic compounds at an ISO 17025 accredited environmental laboratory. A coordinates and elevation survey was also undertaken at each borehole location in order to determine the hydraulic gradient in the shallow aquifer.

The soil and groundwater test results were compared with relevant Thai and Australian Guideline Values to assess if activities on the site had resulted in significant soil or groundwater contamination. The interpretative reporting included a qualitative risk assessment to assess whether the soil and groundwater conditions represented an unacceptable risk to future site occupants or local environmental receptors.