Untreated sewage flows into Darwin harbor

The government promised to have the pump and pipeline of the Larrakeyah sewage outfall, known locally as the ‘poo shooter’, closed by this month in favour of diverting about one billion litres of sewage a year to a treatment plant at Ludmilla.

Power and Water general manager Steve McKenzie says it is a complicated project. In this year’s Territory budget, $24m was earmarked as a direct investment into closing the Larrakeyah ocean outfall to divert sewerage to the Ludmilla Wastewater Treatment Plant and upgrade Ludmilla to a "secondary" system to improve treatment processes.

Advanced primary treatment at Ludmilla - grit removal, filtration and sedimentation - now removed "almost all" the physical contaminants.

McKenzie said, "There will be three more connections and, probably by the end of November, we think about 60% of the flow will be transferred. The last connections will occur in December. The sewage will then be partially treated at the Ludmilla plant before being pumped into the sea.”

Construction and upgrades at the Ludmilla plant are also six to eight months behind schedule because of excessive wet season rainfall this year and some raw sewage will flow into Darwin Harbour until May next year.