4. Water is supplied to Kağıthane Drinking Water Treatment Plants established on the back of Kağıthane district being one of the historical regions of İstanbul from Terkos Lake and Alibeyköy Dams. Aeration Unit The first unit that raw water taken from the dam and lake enters to the plants is the Aeration Unit. Pre-Ozonization Unit Microorganisms in the water in Pre-Ozonization Unit are eliminated and taste and odor in water are corrected. Raw Water Inlet Construction Water is taken to Raw Water Inlet Construction of the plant via steel water pipelines of 2200 mm. Following pre- chlorination here water is passed through water energy break wall.

5. Fast Mixing Unit Slow mixing Unit Setting Unit Colloidal substances loads of which are neutralized in fast mixer with the effect of Aluminum Sulphate are taken to mixing unit to become ball. Water is mixed slowly and colloidal substances are met each other. Setting unit is the section where colloidal materials being flock in slow mixing unit and being in the raw water is seperated from water. Sulphate

6. The water coming from setting is conveyed to filter unit after being chlorinated in four seperate channels. The purpose of chlorination is to provide manganese oxidation and to prevent chlorine by products formation. There are 20 fast sand filters each one of which consists of two divisions and being 108 m 2 surface areas. There is sand with 1 m height and 0,8- 1,25 mm diameter performing filtration process. The system suspending the sand is porous concrete obtained from the gravel and cement mixture. Filters blocked are subjected to backwash operation by applying air and water from the lower part. Engine Filtration Unit

7. Clean Water Tank The purified water coming from the Filter Unit is taken to 15000 m 3 and 30000 m 3 clean water reservoirs after being subject to final chlorination NETWORK After clarified water in Kağıthane Drinking Water Treatment Plants is collected in reservoirs, it is supplied to the supply network. And, this is the last of the adventure of water up to our school. Clean water reservoir Our School

8. We got Ka ğ ıthane Water Treatment Plants’ water quality reports. The reports prove that the result is healthy and drinkable water. The healthy and drinkable water travels a long way to come to our school from Ka ğ ıthane Water Treatment Plants. So how can we be stil sure of the drinking quality of water, coming from the taps in our school. We searched and learned that the pipes in İ stanbul were changed into polyethylene 2002. The pipes in the location of our school and inside the school were changed into polyethylene in 2006. But our school’s conctruction is very old and therefore there are some iron pipes that couldn’t be changed. We don’t drink water from the taps and the school pay money for spring water stored in carboys. Are these carboys healthy ? We won’t be able to test every carboy, so our aim is to obtain healthy drinkable tap water in our school.

9. In our research trip to İ SK İ Water Treatment Plants, we are thankful to environmental engineer Nazlı Sezin Korkut and machine technician Yavuz Karaca’ for their interest to our project and the help for the information.