Case Study - LNAPL Recovery
Background
Red diesel contamination was identified within an ornamental pond at a large hotel and wedding venue from an unknown source. The diesel was identified to be present within groundwater below a car park area on site.
Initial product recovery work had been undertaken by another contractor who had installed a treatment system recovering approximately 700 litres of groundwater per day and who recovered approximately 645 litres of diesel. Initially free product thickness of up to 930 mm were recorded on site.
A total of approximately 110 cubic metres of diesel contaminated groundwater was recovered and processed over a period of 16 months by the initial contractor.
LNAPL Recovery
Oracle were instructed to increase pumping capacity at the site to prevent further migration to the pond and installed additional abstraction and monitoring boreholes.
Oracle installed a groundwater treatment system in November 2020 with a 3m3 per hour groundwater treatment capability and installed 8 pneumatic top loading pumps. Oracle deployed their Environment Agency mobile plant permit to ensure regulatory compliance.
Outcome
The system was maintained on a weekly basis by our WAMITAB qualified remediation engineers to ensure compliance with the permit and also the most effective operation of the system. The system was continually monitored by a telemetry system to ensure maximum operational time and value for the client.
Oracle operated the groundwater treatment system for a period of 15 months at the site and achieved an average daily system discharge of 7 m3. As of February 2022 all free phase diesel has been removed from the site with a total of over 940 litres recovered by Oracle at an average rate of 2.85 litres per day. A total of over 3,100 m3 of groundwater was processed by the system.