The Six Different Stages of the Water Treatmemt Plant

)n Thrusday, the 5th of November we 6th Graders went on a field trip to the Aetra Water Treatment Plant. It was about an hour and a half away drive from school. When we reached we went straight away to the Plant. There were six important stages that water from the river has to pass through before it is sent to the city.

The first stage is to separate the big pieces of garbage by a gate with holes then the smaller pieces of garbage are separated by another gate with smaller holes. This is very similar to the process of filtration. The second part of the first stage is that the water needs to be oxidized(aerate)

The second stage is to add alum to the water so the dirt particles clump to one another to form one big dirt particle, called floc. The process of this is called coagulation.

The third stage is when the larger floc particles settle to the bottom. At the Aetra Water Treatment Plant the water is stored in large tanks for the floc particles to settle at the bottom. This is known as sedimentation.

The fourth stage is the water goes through a series of filters. At the Aetra Water Treatment Plant, they use layers of sand,coal and gravel to filter the water. The process of water going through a series of filters is called filtration. While the water flows through the filters the other dirt particles including the floc particles are left outside while the water flows through. Think of it as a strainer instead of wanting spaghetti you want the water that boiled the spaghetti.

The fifth stage is called disinfection. Disinfection is when a disinfectant,such as chlorine or bleach is added to the water which kills any remaining germs,bacteria and harmful chemicals which cannot be seen.

And the last stage is when the water goes through inspection to see if all the machines are working to keep our water clean! In the lab they take water samples from the start of the week till the end of the week, so they can make comparisons from the water that they purified today and with another day.

Now you may think that it will take over an hour just to purify a liter of water, but let me tell you this the Aetra Water Treatment Plant produces over about 5,000 liters of treated water per second, 24 hours a day, 7 days a week. Think, how much litres of treated water would the Aetra Water Treatment plant produce in a day, if they produced about 5,000 litres per second?