CBRM Wastewater: What We’re Doing Right

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Matt Viva

Matt Viva

As regular readers of the Spectator know, I have an affinity for document-based research — emails, letters, court records, consultants’ reports, council minutes, issue papers, doctoral theses — I am never happier than when up to my elbows in print.

But sometimes when you have an issue that you want very much to understand the best thing you can do is talk to someone who understands it.

That’s what I did this week on the issue of Canada’s Wastewater System Effluent Regulations (WSER) and the CBRM’s efforts to comply with them. Having read the regulations and received some further documentation from Environment Canada and listened to CBRM Council debate the issue last month, I found I still had questions, so I arranged to talk to Matt Viva, the head of wastewater operations in the CBRM.

I’m glad I did.

 

What’s WSER?

Here’s how I explained the WSER regulations back in August when I first wrote about them:

Introduced in 2012 under the Fisheries Act, the regulations apply to wastewater systems that deposit “a deleterious substance…in water.” In other words, to much of the wastewater the CBRM currently dumps into the Atlantic Ocean. Meeting the regulations will mean providing secondary wastewater treatment across the board. (Briefly, primary treatment involves “basic processes to remove suspended solid waste and reduce its biochemical oxygen demand” while secondary treatment “uses biological processes to catch the dissolved organic matter missed in primary treatment.” You can read more here.)

As I reported at the time, the regulations will have the biggest impact on coastal communities in British Columbia and the Atlantic Provinces. Viva explained that this is because, for hundreds of years, such communities looking to dispose of sewage could simply “daylight a pipe” to the coast and dump everything, untreated, into the ocean.

Inland communities disposing of sewage in water, he said, didn’t have this dubious “advantage.” Their waters are much more sensitive (imagine, for example, dumping raw sewage into Calgary’s Bow River) and as a result, most inland communities in Canada already provide secondary wastewater treatment.

Here in what is now the CBRM, we started treating sewage (in some communities) about 30 years ago. Currently, according to a March 2016 presentation to council by the head of Public Works, Wayne MacDonald, 80,000 people in the CBRM receive “municipal wastewater collection services” while 50,000 do not.

Viva says there are eight communities with untreated sewage in the CBRM. Two of these  — Glace Bay and Port Morien — are classified as “high risk” under WSER, which means the deadline for bringing them into compliance is 2020 (a deadline Viva had told me earlier they are unlikely to meet).

The communities that will be served by the recently green-lighted, $58 million West Sydney Harbour project (Coxheath, Westmount and part of Sydney River) are all classified as medium risk. The deadline for compliance in their case is 2030, which the CBRM will likely meet. The remaining communities (including Sydney, which is currently providing “enhanced” primary treatment at the Battery Point plant) must bring their systems into compliance by 2040.

 

Low-cost treatment

At the same time it approved the $58 million Sydney Harbour West Project, CBRM Council gave the go-ahead to a $1.4 million project to conduct environmental risk assessments (ERAs) to determine what will be necessary to make our remaining systems WSER compliant.

Viva says this work will be vital, because it will assess the needs in each community and determine the most appropriate wastewater treatment system to meet them.

If you’re like me, you’ve been cowering at the thought of that $425 million price tag for new or upgraded wastewater systems, but Viva says the figure is based on some pretty rough estimates, in terms of public infrastructure costs, and that once these ERAs are completed, we will have a much more accurate notion of the costs we’re facing.

And if you stop looking at the CBRM wastewater systems that don’t meet WSER standards for a moment and look, instead, at a couple that do, things start to appear a little less dire.

For example, the CBRM operates five wastewater lagoons (the Southwest Brook, Centerville, Meadowbrook and Tower Road lagoons plus the Birch Grove Constructed Wetland) and lagoons, according to the National Environmental Services Center (NESC) at West Virginia University, “use natural and energy-efficient processes to provide low-cost wastewater treatment” and are “one of the most cost-effective wastewater treatment options for many homes and communities.”

The big drawback with lagoons is that they require a lot of land, which is why they are used mostly to service small, rural communities. As for how they work, according to the NESC:

There are several different types and names for lagoons and many possible system designs. Lagoon systems include one or more pond-like bodies of water or basins designed to receive, hold, and treat wastewater for a predetermined period of time. Lagoons are constructed and lined with material, such as clay or an artificial liner, that will prevent leaks to the groundwater below. While in the lagoon, wastewater receives treatment through a combination of physical, biological, and chemical processes. Much of the treatment occurs naturally, but some systems are designed to also use aeration devices that increase the amount of oxygen in the wastewater. Aeration makes treatment more efficient, so that less land area is necessary, and aerators can be used to upgrade some existing systems to treat more wastewater.

Water leaving the CBRM’s lagoons must be disinfected. In four cases in the CBRM, that’s accomplished with chlorine, but in the fifth case (at Birch Grove), says Viva:

The effluent from this system is exceptional and disinfection occurs in a constructed wetland following the lagoon, i.e. no mechanical equipment required. This is the type of lagoon system that will be considered when investigating future treatment options.

 

Phenomenal effluent

Then there’s the Dominon and Bridgeport wastewater treatment plant. Unlike the Battery Point Plant in Sydney, which uses chemicals to treat wasteater, the Dominion and Bridgeport plant uses a biological process.

The plant was actually the setting for an After School Special produced by the CBRM in 2012.

Okay, I’m kidding, it’s not actually an After School Special. It does feature teenagers, but rather than coping with parental divorce or being pressured by their peers to drink, they’re touring their local sewage treatment plant. (Sample dialog: “Superman was once known as Clarke Kent, Pluto was once known as a planet, wastewater was once known as sewage.”)

I’m poking fun but the videos (there are two, the other is about the Battery Point plant) are actually really informative. You get to see the inner workings of both plants and if you’re interested in the subject at all (and you must be, you’re reading this) you really need to watch them. Go ahead, I’ll wait…

 

 

In a phrase only ever employed by wastewater management types, Viva described what leaves the Dominion plant as “phenomenal effluent” that “blows the federal requirements out of the water.”

To illustrate, he cited two WSER standards:

Carbonaceous biochemical oxygen demanding matter (CBOD) or carbonaceous matter (i.e. consisting of or containing carbon or its compounds) that consumes, by biochemical oxidation, oxygen dissolved in water.

TSS:  total suspended solids or non-filterable residue.

Viva says the limit for each, under WSER, is 25 mg per liter of water — in both cases, water leaving the Dominion plant contains 5-8 mg/L.

Viva says lower-cost yet efficacious systems like the Birch Grove lagoon and the chemical-free Dominion-Bridgeport plant will be the CBRM’s focus as it looks to upgrade wastewater treatment to meet WSER. Just what that expansion will look like (and how much it will cost) will become much clearer after those ERAs are completed.

I’m struggling for a nice pat ending to this story, but it’s evading me — probably because this story is far from over and I know I’ll be writing more about wastewater in future issues.

So I’ll end with a “to be continued…”

 

 

 

 

 

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