Joseph Bazalgette was born in 1810 in Enfield. He was trained as an engineer, in Ireland, and was famous for building the extensive sewerage system under London. He set up as a consulting engineer in London in 1842. Then he became caught up in railway mania and was involved in survey work. There was so much work that he had a kind of nervous breakdown and had to retire to the country to recuperate.
In 1849 he was appointed assistant engineer to the Metropolitan Commission of sewers. There had been a broad plan in place to build a sewerage system to carry sewage eastwards, but it was not detailed. In 1852 Bazalgette was appointed as engineer to the commission.
In 1848-49 there had been a cholera epidemic that killed 14,000 Londoners. And again in 1852 another 10,000 died. The theory at the time was that bad air or miasma caused the infection. But there were those that thought different. Dr John Snow advanced the theory of contaminated water. Bazalgette commissioned a study and it was discovered that cholera cases were related to the proximity to local water standpipes. This endorsed his unpopular theory, but suggested a good reason for clearing the sewage from the streets of London and cleaning up the Thames.
Bazalgette was appointed as engineer of the new Metropolitan Board of Works in 1856. He was tasked with building the massive sewerage system underneath London, it would eventually comprise of 1300 miles of street sewers and 82 miles of large intercepting sewers carrying the waste to the east of the city. There was the “great stink” of London in 1858, which prompted Parliament to legislate for the work and in 1859, work commenced and would take approximately 15 years.
The street sewers were built to flow into the intercepting sewers that were built along the banks of the Thames north and south. The sewage would flow on a natural self-cleansing gradient to outfall tanks at Becton and Crossness where it would be dumped into the Thames at high tide. There were pumping stations at Deptford and Crossness on the south side and at Chelsea and Abbey Mills on the north. There were pumps at the outfalls to bring the sewage up to ground level. In 1900 treatment tanks known as sewage farms were built for a better solution to the problem of dealing with the waste.
Bazalgette did not appear to be particularly ambitious, but he was very dedicated to his work. He calculated the diameter of the sewer, based on the amount of waste produced and the maximum population density. Then he doubled the diameter of the sewer design, as he did not want to have to rebuild the system later. This wisdom allowed the sewer system to still be functional today. Tower blocks in the sixties and seventies produced a greater population density and therefore a greater flow to the system. Without this foresight sewers would have overflowed onto London streets in the 1960’s.
It is also a testament to the skills of the London builders. Harsh and dangerous conditions did not prevent excellent work from tunnellers, bricklayers and other trades.
Another benefit of building the intercepting sewers was the creation of the embankments. The Chelsea, Victoria and Albert embankments sat above the main sewer flowing east. They tidied up the Thames, giving definite banks, facilitating an excellent roadway through central London, thus easing congestion. It also provided for over 50 acres of building land. There were many companies and organisations that used the river. Lengthy negotiations were needed before work could commence in 1864.
Bazalgette took personal responsibility for the joining of each connection with the local system. His capacity for hard work was admirable. The immediate result of the new system was a fall in the number of deaths by 12,000 a year between the early 1870’s and the late 1880’s.
Other projects included new bridges across the Thames. Battersea, Putney and Hammersmith were all his design. All are still being used today, with a much greater volume of heavy traffic. They are still standing, even Hammersmith just!
There are many in the construction industry of today that like to maximise profit or build monuments to themselves. But Joseph Bazalgette was clearly motivated in making London a safer, more attractive and better place. His legacy was that in his lifetime he could have rightly claimed to have saved so many lives because of his Civil Engineering skills hard work and dedication. He was a fine example of a man who had got his priorities right.