Avoid blocking your sewer
First see the page Avoid blocking your drain (if you haven't already seen it), then come back to here.
The only difference between you blocking your drain and you blocking the sewer is that you don't arrange to fix it when it blocks. The Local Authority does it. Then they add whatever it cost them to the rates and you pay for it that way.
Yes - they add it to the rates. It's really an extra. If you and others didn't put the wrong things into the drains, then they would only be blocked by trees and subsidence. So it's extra added to the rates for fixing the problem that you created.
Why don't the Local Authority tell you about Household Sewer Pollution, and ask you to change? Well, they've been digging household rubbish out of the sewer for so long that they've got used to it. "That's the way it is. It happens like that all over the world. Nothing can be done about it."
But that's wrong. Why put up with blockages and pollution when you can stop them from happening? They are wasting our money.
How do you avoid blocking your sewer? -- Don't put the wrong things into it.