Kleinfelder has completed sediment stabilisation treatment trials to identify potential amendments to remediate / ameliorate contaminant impacts found in sediments within a client’s site. The sediment is known to contain specific contaminants, and the trials aimed to encapsulate these and improve the sediment’s geotechnical suitability to prepare the site for future commercial / industrial use.

Site Description

The site contained several ponds covering an area of around 60,000m2, each capturing stormwater, sewerage and wastewater, including a mix of contaminants such as metals, PFAS, fluoride, acid sulfate soil, Total recoverable hydrocarbons (TRH) and non-aqueous phase liquids (NAPLs). The geotechnical conditions of the sediment from each pond also varied significantly.

Testing

Kleinfelder presented a preliminary conceptual site model and potentially applicable environmental guidelines for groundwater and soil to provide context with respect to the environmental setting of the site and the requirement for future treatment.

The trials included baseline study on groundwater samples surrounding the site, geotechnical and environmental samples, and vapour samples collected from control reaction vessels. Twelve different treatment applications were added to 36 reaction vessels, maintaining three as untreated control vessels. Subsequent vapour sampling was conducted at 2-24 hours post-treatment, followed by further vapour sampling at 48 hours, 7 days, and 34 days post-treatment; geotechnical samples were also collected from each reaction vessel at 34 days post-treatment.

Project Results

Kleinfelder worked to identify a sustainable remediation approach to reduce the leachability of identified contaminants and geotechnically stabilise the sediment using a combination of geotechnical and chemical additives, and onsite demolition debris.

The trials conducted by Kleinfelder were able to demonstrate the effectiveness of an in-situ approach, and that the addition of demolition debris did not affect the contaminant profile of the material. The trials work has received Australian Land and Groundwater Association recognition.

Project Details

Location:
Queensland

Owner:
Confidential Client