Household Sewer Pollution
Every day, the country's sewers and sewage treatment works are inundated with items they are not
supposed to deal with.
They are designed to handle human waste, toilet paper, and little else.
Careless disposal of sanitary items, nappies, etc. into the sewers will cause problems including the flooding of your home or someone else's.
Household waste pipes are normally 100mm (4 inches) in diameter the same size as a margarine tub and even street sewer pipes are usually only 150mm (6 inches). The pipe from the sink to the drain is 40mm. The pipe from the toilet to the drain is 80mm.
No surprise then that blockages happen when the wrong things go down. Clogging caused by Fat, Oil and Grease ("FOG") reduces the size of the pipes, so increasing the risk of a blockage. Blockages means backed-up sewage flowing out of the system via a manhole, a gully trap or a toilet.
Most of the fat, oil and grease put down the drain is liquid. The walls of the underground pipe are cold, so the fat and oil soon cool and stick to the walls of the pipe. Flushing hot water down does not stop this. The underground pipe soon cools it again. It just sticks further along, still in your drain.
The fat and oil builds up inside the pipe, with all sorts of "no-no" objects stuck in it. Eventually it gets scraped away. If the "build up" is faster than the "scrape away" then the drain or sewer blocks.
Your home is constantly under threat of flooding if drains receive personal items such as nappies, sanitary towels, and condoms, mixed with a good helping of used fat and oil.
Sewage flooding is a big health risk to humans and it's not a "good look". When it flows on into waterways it endangers river-life and everything in the sea that might come in contact with it.
There are two kinds of Household Sewer Pollution:
- The Fat, Oil and Grease (FOG) that you pour down the kitchen sink.
- The "Unnatural Human Waste" things that you put or pour down the toilet or gully trap.
See The Life-cycle of FOG and The Life-cycle of Sewer Litter for more details.
The sewers can be thought of as being like a beaver stream in North America. The FOG and "Unnatural Human Waste" items are the mud and sticks of the beaver's dam. If there was no mud then the pile of sticks would be unstable and would also wash away. If there were no sticks, the beaver's dam wouldn't be durable and the mud would just wash away. And of course, if the beaver didn't have any mud or sticks there would be no dam at all.