A group of 27 GR12 learners investigated this challenge.
The girls were sent in pairs to count how many toilets there are in the school and calculated how much water is used when flushing the toilets. The results were as follows: we have 68 toilets in the school and out of 27 girls we have a total number of 46 flushes a day. There are 30 classes in the school so we multiplied 46x30 which totalled to 1 380 flushes per day. We added on 120 flushes for staff per day. So that equals 1500 flushes per day. We are working on an average of 10 litres per flush, so 1 500 x10 litres gives us 15 000 litres used per day.
We then did a survey in the class to find out how many times in the day the girls go to the toilet and the class calculated how many litres of water is used to flush the toilet. The results were as follows:
The class then did some research on water saving devices for bathrooms and find out about the following:
We also checked for leaks in the toilets and found a toilet with a malfunction and this was immediately reported.
Dual flush toilets cost about R1 000 each and there will be an instillation cost here too. The most cost effective way to save water would be to put 2 litre coke bottles into the toilets and we calculated that this will save this will save 3000 litres per day. Waterless toilets were also investigated, and we agreed they were a good idea, but would have to get past the yuk factor. It seems ridiculous that we use potable water to flush away our waste. Using grey water to flush away waste was also suggested as an option. Grey water systems range in price from a few thousand rand upwards, depending on the size and purity of the water produced.
This information was communicated to management who agreed to allow us to put 2 litre cooldrink bottles into our toilet cisterns – a very cost effective way to save water with each flush which cost the school nothing. The school was asked to bring 2litre cooldrink bottles to school. Also one of our jojo tanks was piped into our main bathroom to save water.