View Full Version : Can someone explain the science of how this works?

07-15-2010, 09:50 PM
Walls of fat' removed from London's sewers

Enough fat to fill nine double-decker buses is being removed from sewers under London's Leicester Square.

A team of "flushers" equipped with full breathing apparatus has been drafted in with shovels to dig out an estimated 1,000 tonnes of putrid fat.

And powerful jets are being used to break it down.

The operation, which began in the early hours of this morning, is claimed to be the largest-ever sewer clean-up of its kind.

The build-up is the result of years of "sewer abuse" - when anything other than water, human waste and toilet paper is put down drains - according to Thames Water.

Source (http://www.independent.co.uk/news/uk/home-news/walls-of-fat-removed-from-londons-sewers-2025528.html)

How does anything other than water, waste, and TP turn into FAT?

Chris P
07-15-2010, 09:55 PM
Soaps, shampoos, fabric softeners, and laundry detergents are full of fatty stuff. In addition, people sending bacon grease, fry oil, etc., adds to the problem. I know this first-hand; I had to have my main drain snaked about a year ago, and watched through the manhole cover down the street as nasty, nasty fist-sized chunks of grease washed out. One house clogged a 4-inch pipe, imagine what an entire city would do.

07-30-2010, 11:01 PM
I can confirm the same with me. Greasy buildups over a period of 13 years clogged the 4” drain pipe that runs the length of my house. I can’t imagine how bad that might get with an entire city. Note also that because we use a septic system, we do not flush/drain animal fat or laundry detergent down into the system because the fatty buildup eventually clogs the tanks. Even with that, the system still clogged with fist sized chunks of blackened, rock hard greasy material.

07-30-2010, 11:11 PM
There's a lot of restaurants in London, and a lot of them pour liquid fat down the drain

07-31-2010, 05:30 PM
*Insert English diet joke*

08-01-2010, 08:16 AM
Judging by defyalllogic's initial question, it may be she was only considering waste material from toilets as opposed to waste from kitchen sinks, baths, road run-off and all the other splendid things that lead to the sewers. However, even if only toilet waste is considered, there is plenty of fat and grease that comes through the digestive system!