The Environment Protection Authority (EPA) and Glenorchy City Council are continuing to investigate a pollution incident that occurred last week in the River Derwent at Prince of Wales Bay, when a significant amount of diesel fuel was found to have been released from an unknown land source via the stormwater into the bay.
Delegate for the EPA Director, John Mollison explained that a member of the public first reported the incident to the EPA on Thursday 17 September, when an orange discharge appeared in waters in the southern end of Prince of Wales Bay adjacent to a large stormwater drain.
"Officers from the EPA, Glenorchy City Council and Tasmania Fire Service (TFS) attended the site to investigate the report," he said.
"They observed very strong fuel-like fumes and initially managed the situation as a hazardous materials incident, with TFS testing air quality at stormwater manholes upstream of the discharge site.
"The installation of a collection boom around the mouth of the stormwater pipe was considered, but the site was too shallow for effective use of solid flotation boom and weather conditions were not suitable for absorbent booms or pads. High wind and wave action in fact assisted with dispersion of the material.
"Fresh water was flushed through the stormwater pipe in an attempt to clear the pipework, and the Council took samples of the discharged material which was subsequently confirmed to be diesel.
"Further reports of diesel in Prince of Wales Bay were reported to the EPA on Friday 18 September and we observed fresh and weathered diesel throughout much of the bay on Friday 18 and Saturday 19 September.
"We also received several reports of potentially affected seabirds and are liaising with the Wildlife Management Branch of the Department of Primary Industries, Parks, Water and Environment.
"The EPA and Council have monitored the site daily since the initial report and observed yesterday that only a small amount of diesel remained in the bay," said Mr Mollison.
"We will continue with our investigation into the source of the diesel and are keen to receive any further reports from the public in relation to the incident, including of potentially affected wildlife," he said.
Mr Mollison said that the EPA was grateful to have received the timely pollution report, enabling the relevant authorities to coordinate their response. He urged the public to report pollution incidents by contacting the EPA by phone on 1800 005171 or by emailing firstname.lastname@example.org. This includes reports of potentially affected wildlife which would be passed on to officers in DPIPWE for follow-up with specialist wildlife advice.