It’s been four years since the Riverhead sewage treatment plant came online, but some pollution levels are still on the rise in St. John’s harbour.
Coliform bacteria testing done by the city of St. John’s shows that, on average, levels have dropped by more than 90 per cent between 2008 and 2012.
Levels of ammonia in the water, on the other hand, have gone up by 70 per cent over the same time period, and there’s been no decrease in nitrogen or phosphorus in the water. Ph levels — a measure of acidity — have stayed the same, too, and testing shows that the water has become cloudier.
St. John’s Deputy Mayor Shannie Duff, who chairs the regional waste water committee, said the bottom line is that nobody expected the Riverhead facility to be a perfect solution.
“A lot of the visible floatable lumps of you-know-what are gone. Still, I wouldn’t swim in it, but we didn’t ever expect to,” she said. “From a public health issue, it's OK right now, and we are moving to a situation where it will be much more OK, but it’s not a cheap solution.”
Altogether, the harbour cleanup project has cost more than
$171 million; the Riverhead treatment plant on Southside Road cost $83 million alone to build, and on top of all the capital costs, it’s $3.7 million a year to operate the facility.
Moreover, as it stands right now, the city is still dumping 30-40 per cent of its sewage into the harbour untreated at the Temperance Street outfall.
There have been ongoing issues with the liners at the Riverhead digester tanks; the city is waiting until those problems are fixed — hopefully early next year — before flipping the switch and sending the Temperance Street sewage over to Riverhead.
But even when all of that is squared away, it won’t really do anything to help the nitrogen and ammonia levels in the water.
The Riverhead plant is only a primary treatment facility, which means it filters out the physical grit and chunks of stuff, but it doesn’t do anything to eliminate chemicals that are dissolved in the water.
“Secondary treatment is more of a biological, chemical process where you actually remove things that are dissolved in the water. That’s when you start to treat for ammonia and phosphorus,” said Deanne Kincade, manager of the Riverhead plant.
“Right now we don’t do that, and we can’t expect to remove ammonia as part of a secondary process.”
Kincade said in the grand scheme of things, the levels of nitrogen in the harbour are fairly low. They do regular testing of the treatment plant effluent to meet federal regulations, and the measure of nitrogen that they focus on is well below the levels that would kill fish.
“The good thing about Newfoundland’s wastewater is that it’s very dilute and we don’t have a lot of industry, so we’re not getting a lot of things like metals or ammonia compared to (other cities in Canada).” she said.
The Northeast Avalon Atlantic Coastal Action Program (NAACAP) — formerly known as St. John’s Harbour ACAP — spent a long time lobbying for efforts to clean up the harbour.
Phoebe Metcalfe, environmental technologist with NAACAP, said things are getting better, but people can’t be satisfied with how far things have come yet.
“I would like to think that it is better. It is a first step in making it better with the primary treatment plant down there, but there still is, like I said, lots to be done,” she said. “A lot of people think this plant is here, everything is wonderful, it does it all. Some people don’t realize that it is only primary treatment or that there is still an outfall that’s going in (the harbour.)”
One way or another, eventually the city is going to have to do even more to clean up the harbour.
Federal regulations are forcing all municipalities to install secondary treatment. Duff said depending on how much nitrogen, organic content, chlorine and suspended solids are in the wastewater effluent, municipalities will have to have secondary treatment in place by 2020 or 2030.
Duff said the city’s waste water is “just on the cusp” of being clean enough that we can put it off to 2030, which buys more time and hopefully makes secondary treatment cheaper for local taxpayers.
“We could, as soon as 2020, be forced into a secondary treatment option with huge expense,” she said. “Our immediate issue is to try to get our levels down below the mark that forces us to do this by 2020 not 2030.”