The Five Billion Pound Super Sewer

Following workers across the capital for three years as they race to build an enormous super sewer on time and on budget... London's Victorian sewer network is at bursting point. Its tunnels are regularly pushed past their limit, and each week the equivalent of 300 Olympic swimming pools full of raw sewage is released into the Thames, totalling 39 million tonnes every year. Now a huge engineering project is underway to massively expand the capital's capacity to deal with its own waste. Twenty miles long and seven metres wide, the enormous tunnel will be created directly beneath the River Thames by an army of 4,000 workers, and will capture this waste before it enters the river. The supersewer is the biggest upgrade to the sewage system for more than 150 years, but built 90 metres under London, it is also the biggest engineering challenge for a generation. In this three-part series, cameras follow workers across the capital over three years as they race to build the enormous tunnel on time and on budget. (BBC)