Barry’s Wastewater Treatment Tour


Have you ever wondered what happens to the
water that goes down drains and toilets? Hi, I’m Barry. Today I’m going to show you
how wastewater is treated. The journey begins here, in your community. When it rains, snows or when you wash your
car, the water run off is known as storm water. It goes to these storm drains that you see
on neighbourhood streets. Storm drains connect to streams and creeks,
and eventually, enters Lake Ontario. It’s not treated. But something different happens to the water
that we use inside the home. The water that goes down drains and toilets
is what we call wastewater. Because it’s mixed with food, soap, waste
and more, wastewater never goes straight to a river or a lake. It goes down the drain and then into a series
of pipes underground. In fact, if we lined up all the wastewater
pipes in Peel, they would stretch from Mississauga to Calgary – that’s over three thousand two
hundred kilometres. That’s 37 hours of driving! And when you flush the toilet or take a shower,
it can take a couple days for the wastewater to get to the wastewater treatment facility. So let’s skip ahead a couple days. All the wastewater from thousands of homes
and buildings in Brampton, Mississauga and parts of Caledon arrives here. It’s collected
in six big underground pipes right underneath me. Each pipe is 6 feet in diameter. Now let’s go see the first step in wastewater
treatment. The wastewater flows through these screens,
and look something like this. These trap all kinds of things that you should
never flush down the toilet. Things like rags, plastics, and dental floss. Everything the screens trap ends up on these
conveyor belts. The conveyors take all this garbage to big bins in the building next door. Trust me, this is the worst smelling place
here because of the wet garbage. When the bins are full, trucks take the garbage
away to landfill. Now let’s get some air and go see where wastewater
goes. After the screening, wastewater travels into
underground grit chambers. Each chamber is round and spins wastewater,
like swirling water in a cup. As it spins, sand and small rocks are separated, move to
the edges of the chambers and removed. Now that solid particles and garbage have
been removed from wastewater, it flows into a settling tank like this one. We call it a settling tank because wastewater
is given time to settle! At the top of the tank is where scum floats
and is made up of grease, fats and oils At the bottom of the tank is where sludge
sinks and is made up of solid material, mainly human waste. Over here we have an empty settling tank.
This tank is empty so you can see how deep it is. So now that we have sunken sludge and floating
scum. What happens next? See this big thing across the tank? We call
it the bridge, but it doesn’t stay in one place like a regular bridge. As the bridge moves it scrapes the sludge
along the bottom and skims the scum along the top. It takes 30 minutes for the bridge to move
all the way across the tank. Watch, I’ll show you! time lapse of bridge moving The scum is pushed to the end, where it’s
collected. We can’t see the sludge underwater, but you can see the scum collecting here. This process is a continuous cycle. The bridge
will lift, go back to the far end and start over again. Now our journey splits into two. First, let’s
see where the sludge and scum goes. Then we’ll come back and find out where wastewater goes. The sludge and scum from the settling tanks
referred to as biosolids go into these machines called centrifuges. A centrifuge spins biosolids super fast, like
a dryer, to get rid of excess water. But getting rid of the biosolids? That�s
where things really heat up. This is a biosolids incinerator, which heats
up to over 840 degrees Celsius. Biosolids enter the incinerator with a consistency
that’s like cake batter, up to about this point. Points to area on incinerator And the biosolids end up as ash, just like
this. For every 100 tonnes of biosolids, we end
up with 10 tonnes of ash. Let’s go see where the ash ends up. This is a lagoon where ash is stored. It’s
red because of natural iron minerals. This is just a little ways from the incinerators
over there, so we add water to the ash so it’s easy to pump it here. And that’s how biosolids have turned to ash. Now let’s go back where our journey split
in two and find out what happens to the wastewater from the settling tanks. With the biosolids removed from wastewater,
something interesting happens. Wastewater flows into these aeration tanks.
Aeration is pumping oxygen into the water. See all those bubbles? That’s the oxygen. Aeration allows good bacteria to eat the sludge
that didn’t sink and the scum that didn’t float in the settling tanks. This process
is what makes wastewater clear. But it’s not quite clean yet. Here are clarifying tanks. Remember the good bacteria that ate everything
in the water to make it clear? They sink to the bottom of the tanks and are removed. The surface water is what we discharge to
Lake Ontario. Along the way, we add chlorine to it as a final disinfectant. The outfall is an underwater pipe that stretches
just over one kilometre out into Lake Ontario. Along the way, there are 35 holes in the pipe
that the treated wastewater is dechlorinated and discharged into the Lake. We do this to
spread and reduce the environmental impact of treated wastewater. The entire wastewater treatment process is
closely monitored from this control room. Operators monitor the machinery and make sure
that chemical levels are meeting the right environmental standards at all times. Lake Ontario is our most important body of
water. It’s home to a variety of fish and plants, the source of our drinking water,
and as we showed you today, where treated wastewater and storm water ends up. And even though wastewater goes through an
intense treatment process before it’s returned, it’s important that we limit our impact on
the environment. We can do this by keeping harmful chemicals , things like paint, expired
medicine and harsh cleaners out of sinks, drains and toilets. Let’s all do our part to keep Lake Ontario
clean and healthy.