Environment Southland (ES) is urging Southern boaties to check they’re not inadvertently pumping fuel from their bilge or when taking on fuel after intermittent reports of oil leakages in Bluff Harbour.

ES deputy harbourmaster Zak Smith said maritime and compliance teams had drawn a blank in searching for the source of the oil reported at various times and locations in the harbour in the past months.

Consented bulk fuel store and fuel suppliers have been ruled out as the source after audits of tanks and pressure testing of their lines.

The tidal nature of the harbour means oil could travel a distance from the source before it was seen and reported.

“It’s very much a process of elimination unless, or until, we can catch the leak as it happens, and that’s where boaties and the public can help.” 

It is possible the source could be a boat, either one that’s operational or on moorings.

Bilge is the lowest part of the vessel where water, fuel, oil, debris and other substances collect.

While clean bilge water can be discharged to the sea, when it contains contaminants, it is considered waste, Smith said.

Bilge waste can be emptied using absorbents, or a vacuum system to pump into containers, which can then be disposed of appropriately onshore.

Smith urged the public to immediately contact Environment Southland’s Pollution Hotline on 0800 76 88 45 if they spot oil.

“The Pollution Hotline is monitored 24/7. If we are going to succeed in tracking this to source we will need immediate notification,” he said.

The chance of investigators finding the source in the harbour environment diminished with every minute that passed.