It is a segment of the water based infrastructure serving the city of London. The modern London sewerage system was developed in the late nineteenth century. The system has been expanded to address the growing needs of the city as further investment in required for more expansion.
The stinking history of the London Sewerage system:
The River Thames had a bad reputation in the early nineteenth century. It was like an open sewer which distressed the public and made them vulnerable to many diseases. The health of the public had disastrous implications in the form of epidemics like cholera on the prowl.
Propositions to change and modernize the system of the sewers were realized in the year 1856 but were put on the back burner due to the inefficient funds. The Parliament understood the urgency of the issue due to the Great Stink in 1858. They vowed to resolve the issue as quickly as possible and develop a modern system of sewerage.
The interceptory sewers:
The responsibility of modernizing the London Sewerage System was given to renowned civil engineer Joseph Bazalgette who was made the Chief Engineer. He designed an extensive system of underground sewerage which diverted the waste to the Estuary of Thames. The Thames estuary was situated down stream of the centre of the main population.
The lost rivers:
The construction laid out and formed the main interceptory sewers which were six in number. These sewers put together could cover a distance of 160 km (100 miles). These channels of sewer even incorporated some of the stretches which were occupied by the lost rivers of London.
Three of the sewers were situated to the north of the Thames River. The sewer which was the southern most was a low level channel which was being constructed at the embankment of the Thames River. New roads were also constructed on the embankment to deduce the traffic congestions and public gardens were created.
The network of sewers:
The intercepting sewers were built from 1859 to 1865. Small and local sewers which ran for thirteen thousand miles conveyed their contents to the main sewers. The main sewers were 450 miles long and connected to the intercepting sewers. The interception sewer system was made up of three hundred and eighteen million bricks. Concrete of 670,000 cubic meters and excavated earth to the tune of 2.7 million cubic meters was used in the construction.
The sewage tends to flow eastwards due to gravity. In places such as Deptford, Chelsea and abbey Mills the pumping stations were created to raise the level of the water to garner sufficient flow. Sewers which lie to the north of the River Thames feed their volume of the London waste to the sewer of Northern Outfall. From here the sewage is sent to an important treatment works in Beckton. To the south of Thames the sewer of Southern Outfall reaches to a waste treatment facility situated at Crossness.
In the twentieth century crucial and important advancements were made to the system. Improvements were made to the treatment provision for the sewage in keeping with the environment friendly methods adopted. By this time the North Sea and Thames River were polluted to a substantial level. To reverse and maintain the pollution of the water bodies around London these changes were incorporated in the 20th century.
The modern developments in the sewerage system:
The old Victorian pipes which once made up the sewerage system in London now comprised less than a percent of the whole network of the sewerage pipes and channels in London.
The original sewerage system which was in place was made and designed to cope with 6.5 mm or one fourth of an inch of rainfall at the catchment areas. The original system of course was made for the needs of a much smaller population then that exists today in the area of London. The booming city and its rapid growth have only strained the sewerage system. The pressure on the networks capacity was being tested.
When storms struck London city the high rainfall levels in a small span of time would overwhelm the sewerage system. During this time the treatment works and the sewers were unable to deal with the huge volumes of the rainwater which passed through the system. The sewage and the rainwater mix together in the combined sewers and the excess of the mixed water is disposed off into the River Thames. If the excess water is not discharged as soon as possible flooding can affect the local area. It posed a massive health risk as the flooding could expose the many people with water that was mixed with sewage.
The capacity of the sewers has been a long debated subject. Increasing the sewerage capacity is on every one’s mind. A proposal has been conceptualized for the Thames Tideway. It is a transfer and storage tunnel which has a wide diameter. The diameter suggested for the tunnel is 7.2 m and 9m wide. The cost of the advancements will scoop out a major chunk of the tax payer’ money. The estimated cost is of tune pound 1.7 billion in the year 2004. And the decision to invest in such projects have been slow.
The modern advancements are a mega project which will construct a 22 mile long tunnel underneath the river bed of the River Thames which lies in between Corssness/Beckton in east and the Hammersmith in west. In the year 2007 the Mayor of the city of London announced that the modern changes will be complete by the year 2020.
The construction and the very design of the tunnel added to increase the capacity of the tunnel will take an expected fifteen years to complete. This will be a complete contrast to the old world structures of the huge steam engines. The four steam engines situated at Leicester are part of the treatment facility and were used to pump out the sewage. The run at special events which are organized some times during the year.