Where is the Fattest Street in our Village?

Posted on July 16, 2008

It's not only the nation that is becoming fatter according to Anglian Water. The arteries beneath our streets - the sewers - are becoming furred and blocked. Why is this happening? Because more and more sinks and drains are being used as an invisible dustbin.

Fats and oils in the sewer can cause costly blockages, resulting in sewage flooding.

This can be very traumatic for anyone who experiences it, and can also be devastating for the environment and wildlife. Fats and oils in the sewer can attract rodents and slow down the flow of wastewater, increasing its scepticity and heightening the amount of odour experienced as a result, especially in hot, dry weather conditions.

The sewerage system plays one of the most important parts there is in protection of public health and is need of some protection itself. Do you know where your fattest street is?

Why are fats, oils and greases causing problems now?

• Fat production for cooking has trebled since the 1960s.
• We eat out more, use more takeaways and eat more convenience foods.
• As emphasis on recycling and tighter controls on waste collection have grown the temptation to throw more waste down the sink or drain has increased.
• The amount spent on jetting costs to clean sewers has trebled in five years, according to Water UK.

How do sewers become blocked?

• There is a view that you can pour hot fat down the sink or drain - don't! If you do it could cause a blockage resulting in sewage flooding in your home, your neighbour's or in the street - and if gets into a river or watercourses it can be devastating for wildlife.
• Hot fat quickly solidifies in the sewer and can become hard as rock taking specialist equipment to get rid of it.
• Cooking oil can mix with grit etc in the sewer.
• Abuse of sewers in this way can lead to increased rodents - in one trial that Anglian Water has carried out with WRC (Water Research Centre) in Chelmsford, the rodent population was significantly reduced when restaurants and takeaways took active steps to dispose of their fats, oils and grease responsibly - and there have been no cases of sewer blockages!

What should we do with our fats, oils and grease?

• Collect fat and oil in a container which can be used to mix with seeds and nuts to feed birds.
• Scrape food waste from plates into a bin - do not jet wash or rinse them under a tap.
• Use an organic fat trap to soak up fat - this can then be thrown in the bin.
• If you have a fat fryer lobby recycling centres to install containers for the collection of cooking oil - at the moment they only seem to recycle motor oil.

Restaurants and takeaways should have their oil collected for conversion into a biodiesel. They can also use a grease trap which is changed daily or use an enzyme product which should be used carefully. According to Water UK food outlets are one of the main sources or problems that are experienced in town and city centres. Have you smelt a bad whiff walking down your high street? It's more than likely caused by fat in the sewer beneath your feet. Make sure your favourite restaurant or takeaway is disposing of their fats, oils and greases responsibly!

Ten per cent of the capacity of our sewers is being lost to fats and oils. This amounts to 10,000 tonnes, which if converted could make 10 million litres of biodiesel, enough to run 8,000 average family cars for a year.

Jetting out sewers costs £5million a year in the Anglian Water region. It is money literally down the drain, because unless we change our habits, no sooner has the sewer been cleared than the fat starts building up again. We are also trying to reduce our use of energy in the face of climate change. Regular jetting also takes its toll on brick sewers as in the case of one street in St Ives where the sewer collapses because of the mortar that is blasted out of the brickwork when jetting takes place.

Biodiesel partnerships

The message is clear - help put sewers on a diet and don't sink your waste! Anglian Water is working with District Councils to combat the problem. Food outlets have been contacted by letter and have been asked to fill in a questionnaire outlining how they are disposing of their fats, oils and greases. They are being encouraged to have their oil taken away by reputable licensed operators. A reward scheme is also being launched in which those who are seen to have exemplary standards will be acknowledged through a sticker on the door and certificate so that customers and the local community can see that they are playing their part to protect the local environment.

Source: Focus, July 2008