We did science with Sally and we learned waste water,is toilet water,shower water,kitchen sink water, goes down to the sewer where some of the dirty stuff in the water gets cleaned like poo.
After that we had to got 2 plastic cups,we poured it half way then got 2 teaspoons of salt but the other cup with fresh water and dipped in then we got a dropper and it dropped inside. types of food colouring yellow and blue and red so i chose 3 three colours so then we mixed it with the tea spoon and then it turned it to this is my friend Vasiata we used this food colouring that blue then we had to put our thumb over it then cover it and it would have a drop the we carried on with 2 more food colouring and it ended up like that picture with me the blue t-shirt.