What’s happening in our watersheds?

What’s a Watershed?

A watershed is an area of land where all the water that is under it or drains off from other places goes. A watershed can be made up of a variety of habitats including wetlands, forests, creeks, rivers, etc. These wetlands help protect our water sources as they store, filter and discharge any runoff. They also control the amount of pollution in our water, prevent flooding, and help to protect biodiversity (“What is a Watershed?”, n.d.).

What’s the problem?

Despite all their helpful-ness, we still abuse them in many ways. A few activities that impact our watershed:

– Runoff from parking lots where pollutants such as car oil or gasoline, is carried off into streams and waterways.

-Acid rain, a phenomenon caused by many human activities including burning fossil fuels, falls into and acidifies waterways (“Protecting Water from Non-Point Source Pollution”, 2002).

-Pollutants from the drains (shampoos, soaps, etc) gets into the waterways and end up in the watershed.

-Usage of fertilizer releases and adds ions, such as nitrogen, into the watershed, when it otherwise wouldn’t be there.

-Urban development also blocks the natural flow of watersheds.

-Roadways can also cause trouble by giving water a “fast lane” to streams, leading to potential flooding (How Stuff Works, n.d.).


Water Treatment Process

Here’s how we get from raw lake water to drinkable tap water:

First, raw water is taken from Lake Ontario using large pipes in one of the four treatment plants in Ontario; The R.C Harris, the F.J Horgan, Island or R.L Clark Water Treatment Plants. Once the water enters the plant, screens are used to remove large objects and debris, and pre-chlorination happens; a process where chlorine is added to kill any micro-organisms (“Drinking water treatment,” 2015).

Alum, a chemical compound (Helmenstine, 2014), is also added at this point and causes small contaminates such as silt to clump together (“Drinking water treatment,” 2015). The chemicals are then mechanically mixed with the water and form larger groups of particles called “floc”. In a large tank, the heavy floc sinks to the bottom and is later on removed by being passed through several filters made of layers of gravel, fine sand and carbon or anthracite, a coal like mineral (“Drinking water treatment,” 2015). If there were any previous chemical, physical or biological impurities in the water, the filters would catch those, and the carbon layer has it’s own job of eliminating any taste or odour-producing chemicals as well.

   After being purified, the water will flow into holding basins before being distributed to North York citizens/ Torontonians. A safe level of chlorine is added to kill any micro-organisms left and excess chlorine is removed using sulphur dioxide. The City of Toronto also adds fluoride to water to help combat cavities (“Drinking water treatment”, 2015).

Finally, the plant adds ammonia to the water to stabilize any chlorine in the water and protect the water during it’s long journey from the plant to people’s taps (“Water treatment program,” 2014).

Here’s a graphic representation for any visual learners:

Screen shot 2015-01-12 at 6.53.56 PM

(“How is lake water turned into drinking water?”, 2014)

North York Water

The population of North York, along with other cities in Ontario, get their water from Lake Ontario (“Drinking water treatment,” 2015). Before any water can be consumed, it is first treated at water treatment plants spread throughout the city; plants include the R.C. Harris, F.J. Horgan, R.L. Clark, and Island, but the main water treatment plant that provides York Region’s population with clean and safe drinking water is the R.C. Harris water treatment plant. The R.C Harris plant can be found at the foot of Victoria Park Ave (Marsh, n.d.).

Here’s the R.C Harris plant:

Screen shot 2015-01-12 at 7.08.30 PM

(Flack, The r.c. harris water treatment plant)