During delivery of home heating oil at an oil depot, the driver of a transport company vehicle did not fill the right tank and some 6,000 litres of product spilled via the tank duct, despite the presence of a flow limiter valve. The heating oil could be contained, for the most part, in the retention basin, though a small quantity was still able to reach the floor. Since the retention shut-off valve had not been tightly closed, a portion of product also made its way into the hydrocarbon separation system.

The next day, a specialist company was called in to clean the hydrocarbon separator and pump the heating oil that had entered the retention basin. Given the heavy rainfall during the night, a total of 19 tonnes of water/hydrocarbon mix were recovered and transferred to a waste processing centre.

The driver-deliverer did not stop in at the office to identify which tanks needed to be filled prior to the transfer operation, as stipulated in the official procedure. The flow limiter valve was inoperable, from signs showing that it had to be manually forced. Moreover, the opening and closing directions on the retention valve were not clearly legible.

Subsequent to the accident, the site operator fenced in the site and planned on informing the transport company in writing of the procedure that all drivers, whose responsibilities include onsite delivery, must respect. A specialised firm repaired the limiter valve and the retention valve was upgraded. The operator notified the Classified Facilities Inspection authorities of this incident following another case of water pollution occurring on February 21, 2008 (ARIA 34476).