Wastewater Treatment in Barrie
By Martina Rowley
You turn on the shower. Clean, hot water rushes out in fine streams, like strings of shiny little beads. The water hits your body with comforting splashes, bounces off you, and forms foamy channels on the shower floor. It swirls around the drain a few times and then down it goes. Gone. But where does it actually go? And how does it go from being foamy to being clean enough to swim in and even re-use?
Introducing: Barrie’s very own wastewater treatment plant. In 1988, this state-of-the-art Water Pollution Control Centre up-grade was completed at its current location at 249 Bradford Street, in Barrie. Occupying an area of 25.5 acres, it treats the city’s residential, commercial, institutional and industrial sewage and can process a daily average influent (incoming wastewater) of 57,000m3. That is the equivalent of 114 filled swimming pools of 25×10 metres in size and 2 metres depth. The maximum daily peak capacity is more than twice that, 136,000m3, to accommodate peak influent flows.
The centre is a so-called tertiary treatment plant, meaning wastewater is processed to the greatest degree by: 1) removing coarse solids, sand and grit; 2) a chemical and biological process using pure oxygen and live bacteria; and, 3) nitrification to convert ammonia and organic nitrogen into nitrates. An additional final treatment removes any remaining, i.e. suspended, solids and then disinfects the water by using ultra-violet light instead of chlorine.
All processes are fully automated and continually monitored, requiring a staff of only around 20. Ed Blom, who works at the Plant as a Maintenance Operator Class 4, says: “The amount of technology here is amazing. My work is different every day and it’s a constant learning experience.” He is excited about the diversity of his work, dealing with electronics, mechanics, and computers. “I never get bored – it’s really great. Even when you consider what [product] you’re dealing with,” he adds laughing.
For the curious-minded public there are free tours. When I visited the treatment plant on a hot day in July, I didn’t even notice any overly strong smells. In fact, I was surprised at how clean the site and all the areas around the various tanks were. Current construction work will further reduce “smelly work” during the process of removing untreatable items coming in with the wastewater. New grinders will be able to break down and remove objects like small rocks, plastics, rags and large chunks of wood. This will eliminate the need for manually taking out and disposing of these items caught by bar screens.
Handling this large amount of wastewater are huge aerated tanks, settling tanks, and digestors, to name but a few. Pipes transport the influent from one treatment to the next, separating the sludge from an ever-thinning and clean liquid. Smaller and smaller “bits” get removed and oxygen and bacteria are used to perform the organic treatment component of the process. The sludge is withdrawn to the digestion process, where it is stabilized in an anaerobic state (without oxygen). The whole process from start to finish can take from four to eight hours, depending on the quantity and therefore strength of the inflow. By the time the water reaches its final stage of disinfection through ultra-violet light, it already looks like “normal” water and has no malodour.
To ensure compliance with stringent guidelines by the Ministry of the Environment, scientists on-site regularly check the levels of ammonia and phosphorus permitted to go into the lake. In the end, 98% of the original intake of wastewater is discharged into Lake Simcoe as a clean and odourless effluent. A pipe takes the water approximately 300 metres out and discharges it gradually through a staged-outlet, i.e. a pipe that narrows and has many exit holes.
If you look from the water fountain at Centennial Park out towards the lake, you can tell the area by the flock of gulls that often swim or hover above. That is because the discharged water is generally warmer than the lake water. Depending on the time of year, it can be between 12-20C°. The Plant has no existing data on how this may affect the ecology of Kempenfelt Bay but we all know that it keeps the ice thinner in the winter when the lake freezes over.
A by-product of the bacterial (anaerobic) digestion is methane gas. It is burned and the resulting energy is recycled within the plant, providing 30% of its electrical requirements. If you’ve ever driven or walked along Lakeshore Drive and wondered about the clear orange flame you saw across the road, that’s excess gas being burnt. [Currently, this process is off-line for installation of a new gas pre-treatment system, which will be completed and running again in May 2004.] In the event of an electrical blackout, the plant’s diesel generator kicks in after two minutes to provide emergency power, which allows the whole plant to keep operating.
“The Plant is very future-oriented,” Ed tells me with a certain pride. “We really stay at the forefront of technology.”
Biosolids undergoes further treatment to reduce volume and are then stored at the Bio-Solids Storage Facility during the winter in closed tanks or open lagoons and eventually used by farmers as agricultural fertilizer and soil conditioner. By the time it ends up on the fields it has been tested at least twice: once before it leaves the wastewater treatment plant, and again before it leaves the storage facility. Barrie’s wastewater treatment therefore generates three products: clean effluent (water), energy, and fertilizer.
In order to assure strict controls, the City of Barrie maintains a sewer use by-law, which regulates the discharge from industry into the sanitary sewer system. It also has a spill response in place for any hazardous waste spills and responds to spill complaints 24-hours a day, 7 days a week. Funding for all these services comes from the City, as well as our sewer rates, and is calculated on the volume of water used. And as the Sustainable Water and Sewage Systems Act, 2002, states:
“The Sustainable Water and Sewage Systems Act, 2002, helps ensure clean, safe drinking water for Ontario residents by making it mandatory for municipalities to assess and cost-recover the full amount of water and sewer services. The provision of waste water services to the public includes any source protection measure related to the provision of waste water services and collecting, treating and discharging waste water.”
Essential aids in assuring good practices are consumer education and environmental legislation. Part of the Ontario Building Code introduced in 1997 requires low-flow toilets to be installed in all new homes, and offers a $60-75 rebate to homeowners replacing their older model toilets. This, together with an increased awareness of water conservation, has lowered Barrie’s water consumption by over 20%. In 1997, an average of 450 litres wastewater were produced per person/per day. By 2002, this had decreased to 403 litres per person/per day. Water conservation remains an important issue, as our city grows at a rapid pace. Today, the wastewater plant is able to cope with a population of up to 132,000. A plant expansion is already in the pipeline: an Environmental Assessment is in progress and pre-design planning should be completed by the end of 2004.
If you would like to find out more and see for yourself, phone the Water Pollution Control Centre to arrange a free tour at 705-739-4221 between Monday and Friday, 08:00 a.m. to 4:30 p.m., or request their pamphlet Water Pollution Control Centre for detailed information.
Acknowledgements:
Thank you to Ed Blom and Ralph Deschevy, Plant Manager, for their contribution.