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Time until redirection:

The challenge former service stations pose

The site included an old service station with underground fuel storage tanks and other fuelling infrastructure still present; one of the tanks was filled with a liquid. In one workshop bay, the in-ground remains of a hydraulic hoist were still present. Waste liquid storage, old parts storage (including lead acid batteries) and parts cleaning areas were present within the service station area as well. An old timber house (still occupied) was present in another part of the site. Site limitations included a church and primary school, which adjoined two boundaries of the site, therefore consideration had to be given to noise and dust generation.

The preliminary site investigation determined that one tank was full of contaminated water, hydrocarbon contamination existed in the subsurface soil in the vicinity of the fuelling infrastructure, the hoist remains were found to be highly contaminated from hydraulic oil leakage, metals had leached into the soil from the old parts storage area and lead paint flakes from the outside of the house were leaching lead into the soil. A hidden waste disposal pit was uncovered during demolition works. The entire site was underlain by fractured rock at shallow depth.

Results from the preliminary site investigation

The preliminary site investigation determined that one tank was full of contaminated water, hydrocarbon contamination existed in the subsurface soil in the vicinity of the fuelling infrastructure, the hoist remains were found to be highly contaminated from hydraulic oil leakage, metals had leached into the soil from the old parts storage area and lead paint flakes from the outside of the house were leaching lead into the soil. A hidden waste disposal pit was uncovered during demolition works. The entire site was underlain by fractured rock at shallow depth.

Checking petroleum levels
Checking the liquid in the tank. Red indicates petroleum product, Clear is water.

Moving forward with a strong solution

A site remediation plan was developed to remove and validate the fuelling infrastructure and remediate all impacts. We worked closely with the appointed Auditor and the client’s demolition/earthmoving contractors and integrated our field works into the contractors demolition schedule. The school holiday break provided the opportunity to carry out the bulk of the remedial works without the risk of exposure to the students. We carried out the remediation of the soil around the house using our Niton XRF to field screen the soil for lead concentrations, which then enabled us to excavate all the lead impacted soil in a single round. Validation of the site and a risk assessment approach enabled the removal of the site from the EMR.

water separator at former service station in Keppera
A bund containing an oily water separator, waste oil tank and hydraulic oil tank.

The Results

The site, including the additional contamination discovered during the validation works program, was remediated, validated and removed from the EMR, the redevelopment of the site proceeded.

Excavator at former service station remediation
Excavator fitted with lifting chains removing a tank.