Their completion enabled the Metropolitan Board to fill in the open sewers, which had so long polluted the atmosphere, and been such a fertile source of disease in the districts where they existed, and took away from the Vestries any excuse for delay in carrying out the construction and putting in order of the local sewers for which they were responsible. The central authority had thus brought into existence a gigantic system of sewerage by which the river near London ceased to be the main sewer of London, and the whole of the metropolis was relieved of many of the most powerful causes of fever, cholera, and other destructive diseases. It was a great work, admirably and expeditiously carried out, and it cleared the way for other sanitary reforms which were impossible without an effective general system of sewerage, yet which were essential if a satisfactory condition of the public health were ever to be attained. The central body also proved its great utility by securing uniformity in the sewerage and drainage works which fell to the duty of the local authorities to carry out. All plans by the Vestries had to be submitted to the Board so that the Board might see that they were consistent with the main system. Both main drainage and house drainage were thus steadily being extended and improved, but in many places things were still outrageously bad. Nor had the creation of fresh evils been effectually prevented, for from Bromley came the complaint that several new estates were rapidly being covered with small house property which drained into cesspools. And the Medical Officer of Health for Fulham wrote (1866):-- "The active operations of your Board have fortunately relieved the Fulham district to a large extent from that pregnant source of mischief--want of drainage; still there are large tracts of building land yet unprovided for, on much of which houses by dozens are being squatted without any regard to this great essential by the builders, save the horrid cesspool system. It is enough to have to counteract the evils of past imprudence without perpetuating them by such wilful recklessness...." The supply of water to the inhabitants of London was of equal importance to an efficient system of sewerage. The problem had by no means been solved by "The Metropolis Water Act" of 1852, which had enacted that within five years after the passing of the Act a constant supply should be given by the companies. Unfortunately, the supply was in the hands of various public companies over which the local governing authorities had practically little or no control, and, like all sanitary legislation of this period, the results were not commensurate with the intentions of the Legislature. An illustration of how insufficient the supply was, was detailed in a report of the Medical Officer of Health for Whitechapel in 1862:-- "A return has been made by the Inspector of 133 courts in the district.