In the seventeenth century the first experiments were made with cast — iron pipe but it was not until the middle of the eighteenth century that these pipes were cheap enough for wide use. The durability of cast iron and its freedom from breaks and leakages soon made its use almost universal, although steel and other materials were also used. This advance, together with improved pumping methods, made it economically possible for all but the smallest villages to obtain water supplies and to deliver the water into the homes of the citizens.
Although some cities were able to collect safe water from uninhabited regions and thereby reduce waterborne disease to a low level, many others found that their supplies were dangerously polluted and that the danger was increasing as population increased upon watersheds. Accordingly, treatment methods were developed that, when properly applied, reduced the hazard. Coagulants have been used in water treatment since at least B.
The application of various treatment techniques in the early part of the twentieth century resulted in the marked decrease in waterborne disease. An immediate reduction in typhoid fever followed over a period of 7 years. Outbreaks of waterborne disease still occur in the United States and other countries with generally modern treatment systems.
The average number of such incidents in the United States in the period to was 25 per year. Most of these outbreaks were associated with obvious deficiencies in treatment or distribution systems. Remains of sanitary sewers are to be found in the ruins of the ancient cities of Crete and Assyria, Rome also had sewers, but they were primarily, drains to carry away storm water.
It was the practice to deposit all sorts of refuse in the streets, and accordingly the storm sewers also carried much organic matter at times. Sewerage was practically unknown during the Middle Ages, and construction of sewers was not resumed until modern times. At first, these were storm sewers not intended to carry domestic sewage. As late as , the discharge of household wastes into the sewers of London was forbidden.
The water courses in or near towns apparently were used as convenient places of refuse disposal, for many Writers comment upon the offensive condition of the London brooks, with their burden of dead dogs and filthy of all sorts. In the course of time it was recognized that sanitation would best be served by permitting the use of sewers to convey human excreta away from dwellings as promptly as possible, and the original storm drains became combined sewers which carried both stormwater runoff and the liquid wastes from occupied buildings.
The development of water supplies, of course, played a large part in the greater use of plumbing Systems with water — flush toilets. The commonly used vault toilets, which frequently overflowed and always Produced odours, were soon legislated out of existence in the larger cities in favour of the water — carried system. Web icon An illustration of a computer application window Wayback Machine Texts icon An illustration of an open book.
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