6 tons of water for domestic use: unit price 1.80*6=10.8
1 ton of sewage from the above amount of water: sewage unit price 0.6*1=0.6
This 1 ton of sewage disposal fee: unit price 2.3*1=2.3
And then there's a sewage fee at the end of the bill: 4.2 (I don't understand how it came about)
7 tons of waste disposal: unit price 0.6*7=4.2
We have a sewage fee at the back. I don't understand how it came about)
7 tons of garbage disposal: unit price 0.6*7=4.2