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Join us for a fascinating tour of Ashbridges Bay Treatment Plant, one of Toronto's oldest and largest water treatment facilities. Get a behind-the-scenes look at the complete wastewater treatment process, from screening to biosolids management. Explore the primary and secondary treatment areas, learn about the innovative technologies used, and witness the final effluent treatment before it's discharged. Experience the unique operations of this vital facility and gain insight into sustainable wastewater management practices. Uncover the hidden world of wastewater treatment with our expert guide, Colin, as he navigates you through this essential yet often overlooked aspect of urban infrastructure. Dive deep into the science and engineering behind keeping our waterways clean and healthy. Discover how this plant plays a crucial role in protecting public health and the environment. Don't miss this exclusive opportunity to explore the inner workings of a critical municipal facility!
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ASHBRIDGES BAY WASTEWATER TREATMENT PLANT VISIT Fun times at the funkiest (smelling) place in Toronto!
ASHBRIDGES BAY TREATMENT PLANT …is one of four water treatment plants operated by the City of Toronto. Built in 1910, it is one of Canada’s oldest and greatest—covering 40.5 hectares and servicing a population of 1.5M people. The plant is rates for 818 megalitres per day, and provides complete wastewater treatment, including removal of suspended solids, dissolved organics and phosphorous. Major treatments include screening and grit removal, primary treatment, secondary treatment, phosphorous removal, effluent disinfection, waste activates sludge thickening, anaerobic digestion, biosolids de-watering, and biosolids management. The plant employs ~150 staff and operates 24/7.
Colin was our guide and the general manager of the wastewater treatment plant.
Talking about areas that were built in 1910! Some areas they wish could have been better situated, but the place is evolving ever so slowly.
One of the valves that have to be monitored during storm events…because sometimes they leak.
Tissue papers and everything else you flushed ended up here. These mechanical screening machines remove large debris from the wastewater and are hauled to a sanitary landfill site.
This is an “open tank” and is part of the primary treatment. This primary clarifier allows heavier solids to settle to the bottom. This is also where seagulls like to drink their afternoon wastewater tea and bathe at the same time. Do you see that bridge-looking thing in the background?
The bridge close-up is actually a scraper moving very slowly towards the water flow, scraping all that grease floating. There’s also the same scraper underwater.
This Toblerone-looking waterfall is the first effluent. It's got a higher pathogen level than the second effluent AND--under certain storm conditions, we treat it with chlorine and dump it in the lake. No choice, it's either that or the whole place floods and ruin everything.
This place is called a BiosolidsPelletizer owned by a private company who takes our biosolid waste and make them into pellets that are applied as fertilizer on our farms. It is a drying facility via a multiple hearth incinerator with layers of oil heating plates that pretty much takes out all the water.
A place that doesn't smell. A safe haven for the olfactory nerves.
This is the waste activated sludge where most the microbial metabolism of waste is occurring. All natural. No funky lab strains. This is part of the secondary treatment.
This is called the "Chain of Flight". Each bar is a flight" that scrapes all the very fine gunk ever so slowly. This is part of the secondary treatment process called the “final clarifier”
MORE DETAILS ABOUT SECONDARY TREATMENT In the activated sludge process, effluent from the primary clarifiers is mixed with return activated sludge from the final clarifiers and aerated. The mixed “liquor” from the aeration tanks end up here to the large quiescent “final clarifiers” where activated sludge is allowed to settle. Some of it goes back to the aeration tanks to repeat the process, and the excess is removed and directed back to either the primary clarifier again, or the digestion tanks for anaerobic breakdown.
This is the weir, the final part of the secondary treatment where the final effluent goes to the main disinfection; it is usually chlorine but sometimes they use the back-up sodium hypochlorite (10-12% solution).
This is the sodium hypochlorite back-up they were using today.
Out-of-commision chemical scrubber. Colin says this was a giant pain in the ass to use. Finicky with the pH and temperature, and used sodium peroxide.
This looks like a pretty low-tech biofilter, but it works wonders. The white pipes contain odorous air, which they bring underneath this pile of compost. When the air comes up, it's clean. No chemicals. Uses just air and takes about 45 seconds for the air to come up. They just have to make sure the compost doesn't settle too much, otherwise decomposers make the place smelly.
Almost a fertilizer! This is 9% biosolids. They bake them so they will dehydrate up to 27% and that’s what they use for the biosolidspelletizer.
A really gigantic centrifuge used for dewatering. These guys are heavily regulated and are not very flexible. They won't run if processes downstream have failed.
SCADA is the brain of the entire operation. It gives and stores data of all the information going on in the plant. Sometimes, it automatically makes decisions when things go wrong and notifies personnel of the event.
The centrate is how they know things are going smoothly at the plant. Clear=good separation of water and gunk. Black=bad news bears
Chemicals used are:- polymers for thickening and for separation of water from biosolids-ferrous chloride for nutrient removal-chlorine for disinfection-sodium hypochlorite for disinfection and air handling
Today’s attendees: the Ryerson WEAO TEAM 2012-2013weao@ryerson.ca
