A MASSIVE revamp East London’s sewage treatment gets under way soon to reduce river contamination before the ambitious 20-mile Thames riverbed tunnel is built. The go-ahead for a �200 million scheme announced today means Crossness treatment works handling half-as-much sewage than now

By Mike Brooke

A MASSIVE revamp East London's sewage treatment gets under way soon to reduce river contamination before the ambitious 20-mile Thames riverbed tunnel is built.

The go-ahead for a �200 million scheme announced today by Thames Water means Crossness treatment works being able to handle almost half-as-much sewage than it does now.

This would reduce storm water that pours into London's ageing Victorian sewers and overflows into the Thames during heavy rainfalls when the system gets overloaded.

The work is part of a �650m programme to bring London's five major sewage treatment works into the 21st century, such as Crossness and Beckton.

Another �600m is planned for the Lee sewage tunnel to 'drain off' 32 million tonnes of floodwaters from East London's Lower Lea Valley, between Hackney and Bromley-by-Bow.

"We inherited a Victorian sewerage system which is struggling to cope with the demands of 21st century London," explained Thames Water's operations chief Steve Shine.

"The population has doubled since then, with climate change also bringing heavier rainfall and many green spaces being concreted over, preventing natural drainage."

Construction on the four-mile Lee Tunnel between Stratford's Abbey Mills pumping station and Beckton sewage works starts in the spring. The tunnel will be as wide as three London buses and nearly 250ft deep in places.

But even more ambitious is the 20-mile Thames Tunnel planned under the riverbed from Chiswick following the winding river past the Houses of Parliament, Tower of London, Isle of Dogs and Greenwich to join the Lee Tunnel at Beckton (see map above).

This is to divert storm water from 34 overflow outlets along the Thames the Victorians built that pour into the river during downpours, which will now to be carried under the riverbed to Beckton.

But it won't come cheap. The Thames Tunnel alone is likely to cost around �1.5 billion.