Fighting Fat in the Blocked Arteries of London


Next month sees the launch of Unblocktober, an initiative that aims to increase public awareness of the problems in sewers caused by flushing plastic wipes and pouring fat down drains. Above ground, it’s hard to miss litter on the streets of London, and a recent campaign to reduce single use plastic offered opportunities for people to see for themselves how the plastic crisis is growing. In contrast, the 75,000 sewer blockages cleared by Thames Water every year are out sight and easier to ignore until they become a hazard.

The discovery of a 130 ton fatberg in the sewers of Whitechapel two years ago brought the problem of fat build up to everyone’s attention. However, much more needs to be done, not only to improve the sewer system, but also to change the way it is used.

Upgrading Pipes and Sewer Systems

The combined sewers of London were originally built to serve two and a half million residents and now have to cope with waste from almost five times as many inhabitants. They take away the wastewater from sinks, toilets and other appliances, but today they are also being fed with household wipes and the fat runoff from businesses that serve food.

To deal with this surge in use and misuse of the system, construction of a new super sewer is underway and expected to be completed by 2023. Its aim is to reduce the amount of sewage and water pumped into the Thames by 94%. On a smaller scale, upgrades to aging Victorian pipework are constantly ongoing in order to keep up with demand.

Pipes and fittings made from modern materials such as medium density polyethylene (MDPE) are tough and flexible and, in addition, are resistant to algae and bacteria, making them suitable for water systems. In addition, fittings seen here meet the demands of urban infrastructure including longevity and performance under pressure.

Minimising the Build Up of Fatbergs

Creating new channels and fitting replacement pipework to extend and upgrade sewer systems will alleviate problems. However, without more care being taken over what is placed in the system in the first place, fatbergs will just keep growing in size and number. Fats, oils and grease must be responsibly disposed of by businesses, and water companies are taking steps to enforce the use of filters and grease traps by restaurants and other traders that serve food.

Thames Water clear a blockage caused by fat every twenty minutes and so also urge residents to bin cooled fat in containers instead of pouring it straight down the drain.

Although fit for purpose when it was first constructed, London’s sewer system is now struggling to cope not only with drastically increased general water usage but also with the problems caused by contamination. Restorations, upgrades and new systems help to ease the flow, but without more awareness of the damage caused by flushing indissoluble items, the risk of increasingly large fatbergs forming will not diminish.