Authorities want to find out who tipped the “industrial amount” of concrete into the sewer system. (Supplied: Thames Water)
A “concreteberg” estimated to be at least 100 metres long has blocked three sewers in London and will take months and hundreds-of-thousands of pounds to remove.
- The concreteberg has set to the brickwork of three Victorian-era sewers
- Tankers will pump waste from the blocked sewers to prevent sewage flooding homes and businesses
- Cleaning fatbergs and blockages from sewers costs about $32.7 million annually
At least eight weeks of disruption are expected around Islington as crews use jackhammers, drills and high-pressure water jets to break apart at what Thames Water has described as the biggest concrete blockage the company has had to deal with.
“The subterranean blockage is thought to be at least 100 metres long and weigh 105 tonnes — as heavy as a blue whale,” Thames Water said in a statement.
Tankers will pump waste from the jammed sewers around the clock to help protect nearby properties from being flooded with sewage.
“Normally blockages are caused by fat, oil and wet wipes building up in the sewer but unfortunately, in this case, it’s rock-hard concrete,” Thames Water operations manager Alex Saunders said.
“It’s in there and set to the Victorian brickwork, so we need to chip away at it to get it removed.”
Throughout the next five years, about 200,000 monitors will be installed across London’s sewers as Thames Water tries to cut down what it calls “the mindless abuse” of the system.
Authorities are investigating how the “industrial amount” of concrete ended up in the sewer and will move to recover the cost of the clean-up if they find those responsible.
Cleaning sewage blockages cost Thames Water $32.7 million annually.
Monster toxic fatberg displayed in museum
While the latest concreteberg has set the record for that particular type of sewer blockage, it is less than half the size of a “monster fatberg” that was found in a Whitechapel sewer in 2017.
That 130-tonne, 250-metre-long melange of sewage, fat, grease, nappies and condoms grew over a period of several months and took more than two months to be extracted.
Samples of the still-hazardous remnants were air-dried, locked inside specially sealed units and placed on temporary display at the Museum of London.
Most of the monster fatberg was melted and converted to biofuel that could be used to power vehicles such as London’s buses.
The problem is worse in winter when pipes are colder and fat solidifies much faster.
Authorities recommend sanitary products and cooking fats be disposed of with other household rubbish, rather than flushed into the sewage system.