Saint John's habit of pumping raw sewage into the ocean is about to come to a formal end.  

The New Brunswick city will soon be celebrating the completion of its harbour cleanup, an infrastructure project that started nearly a decade ago and cost almost $100 million. City officials and researchers say the results are priceless.

Still, officials wouldn’t say what is exactly left to complete or how much longer it will take.

Twenty years ago, raw sewage poured into the harbour at a rate of six Olympic-size swimming pools every day.

“All the places you will be visiting today are contaminated with fecal coliform bacteria and every other human pathogen you can imagine,” said environmentalist Tim Vickers.

He used to give a so-called annual toilet tour of 50 open sewer pipes spilling into the waterways, where research showed the fish got so polluted they were unsafe to handle.

Now filtered water pumps into the ocean after a multi-stage process made possible by investments from all levels of government.

The cleaning begins by screening out the items that should not be flushed at the Eastern Wastewater Treatment Facility: baby wipes, feminine hygiene products and dental floss are all still going into toilets.

“We're trying to get the message out about the things that don't break down in the sewer system,” said Graham Huddleston, operations manager of Environmental Protection at the city.

“We have to pay to dispose them when they get here. This costs over $100 a ton to get rid of because it's contaminated.”

Grit and sand from storm drains are also removed. Then bacteria, flushed with oxygen, feed on the organic material. The solid waste, or sludge, is repeatedly skimmed out and redirected to composting.

The plant is maintained by five certified operators who say the machines are state of the art.

The last step is an ultraviolet light to neutralize the bacteria and other pathogens.

Next month, researchers will return to measure the contamination on the banks of Marsh Creek. They expect to find a significant improvement.