Matthew visited the original Abbey Mills Pumping Station in East London to take part in a sewer tour and discuss Thames Water’s plans to construct a new ‘super sewer’. The 20-mile (32km) Thames Tunnel would run from west to east London, broadly following the route of the river, collecting sewage discharge triggered by rainfall.
Entering the sewage system down a ladder at Wick Lane, Matthew saw for himself the five parallel chambers of the Northern Outfall from where the waste of north London collects on its way for treatment at Beckton. But it is not just sewage waste that washes through the sewers, it is also ‘grey water’ from washing machines, baths and showers and outdoor drains. The amount of water keeps the sewers flowing but sometimes they become blocked by the accumulation of cooking fat that is poured down millions of sinks. This is removed by a team of 39 ‘flushers’ who physically remove fat, waste and debris from the tunnels underneath the streets of the capital.
Concerns have been raised about the cost of the Thames Tunnel to water customers as well as the long-term environmental gain. The original Victorian system, rarely seen by the average Londoner, was controversial because of its cost when it was first built but it has lasted almost 150 years. However it has now become inadequate for the capital’s current needs. At times of high rainfall, waste water and sewage is pumped directly into the Thames – about 32 million cubic metres of diluted sewage into the river each year, enough to fill the O2 arena 15 times. Hence the need for the ‘super sewer’.
Matthew said: “I remain concerned about the cost of the new sewer but if Thames Water puts off the project it will cost more in the longer term. Bazalgette’s original construction of the sewer was opposed on the basis of cost but his decision to double the original capacity ensured its continuing use today. We have to think in the same way and start this project.”