Municipal engineering applicable to conditions existing in Bengal : six lectures delivered in February and March 1899 at the Civil Engineering College, Sibpur / by A.E. Silk.

  • Silk, A. E.
Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: Municipal engineering applicable to conditions existing in Bengal : six lectures delivered in February and March 1899 at the Civil Engineering College, Sibpur / by A.E. Silk. Source: Wellcome Collection.

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    into the springs, especially when rain falls after a long period of dry weather which has oaused small cracks possibly to open in the soil; then there is a much-frequented public road passing right through the collecting ground, and the droppings of horses, dogs and cattle passing along the road are liable to be washed into tlie springs ; lastly, there is a public latrine on the collecting area. In spite of all the chemical and bacteriological analyses that may be produced to show that the water from these springs is wholesome, I have no hesitation in condemning it as an unsuitable, and further as an absolutely dangerous source of supply for drinking water. In all hilly tracts and mountainous regions the only sources of water are land-springs during the dry weatber, and land-springs mixed with surface water during the rainy season. ]f the collecting grounds of these springs are reserved forests, as tbey are in Darjeeling, the water-supply will be very much purer during the dry season than during the rainy, for during the latter season the water must necessarily contain a large amount of decaying vegetable matter both in solution and in suspension; in fact, I have heard tbe water which is supplied to Darjeeling described as a strong infusion of jungle tea. It is quite probable, though, that slow filtration of this water through sand would yield a water of a very bigh standard of purity. If any one of you during his career is called on to devise a means of supplying water from a source such as I have just now described, above all things bear in mind the question of the possible pollution, not only of the collecting ground of the spring, but also of the stream formed by the spring along its course; it is of vital importance. Upon this point only depends whether you will have a fairly pure supply _ of water or an absolutely impure supply of the worst class. A terrible example of the result of supplying water from springs liable to pollution occurred towards the end of the year 1897 in the town of Maidstone in England. The following description of the springs is taken from the Local Government Board E,eport: The FarUigh Ragstone Springs.—These lie to the south-west of the town, ^ rise from the subsoil skirting the two banks of the Medway, and include the following:— Gallons per week. Ewell spring ... ... 1,-540,000 Tutsham-in-Orchard ... ... 105,000 Tutsham-in-Field ... ... 35,000 Big Church, South-Eastern Railway ... 106,000 Other South-Eastern Eailway springs ... 1,050^000 Total ... 3,080,000 _ All the springs are derived from more or less shalloiw sources m theHythe beds of the lower greensajxd, known locally as 'ragstone ' which is very liable to be fissured. The springs are not pi-oteoted m any way, and the gathering grounds of Bome of them are covered