IMPURE WATER.

Patea Mail, Volume VIII, Issue 142, 27 November 1895, Page 3

IMPURE WATER.

The dangers of using impure water as a* drink, or for domestic purposes, are ■ greater and as direct as the risks arising from breathing impure air. Water entirely and chemically pure is only to bo obtained by the chemical process of dis- I filiation ; so that the word pure applied to water is only used relatively. Drinking ' water to be pure must be free from con- j lamination due to animal and vegetable ! decay, and the quantity of dissolved minerals must be below a certain amount, j Water direct from a river is never very ( pure, because the rainfall washes manure j off the land on the banks of tbe rivers. Rain water is only pure when collected in I the open country, because all the rain j which falls in towns passes through air ' contaminated with the effluvia of living 1 beings, and with sulphur and many other | impurities coming from the burning of I coal, coke and gas, and the various I manufactories. Water obtained from j shallow wells, dug in close proximity to , houses and closets, is often unhealthy, I because impurities sink into the earth and trickle down the sides of shallow wells which have no concrete walling. The most pure water is obtained from natural springs on hillsides and from deep wells which have been dug at considerable distance from any possible surface pollution. In such cases the only objection to such water is that it may contain too much lime, and be too hard for use. When a town has to be supplied, it is usual for the water company to procure a supply from all those sources, and to combine the several waters and pass them through large filter beds of fine sand, and so equalise the peculiar characters of the several sources of supply. The filtration through sand tends further to purify and aerate the water, which latter pi’ocess renders water much more agreeable to drink. Impure water, when consumed, may lead to a state of general debility and blood poisoning, or it may convey the germs of special diseases, such as typhoid fever and diphtheria. When waters contain impurity duo to decaying animal and vegetable refuse, it may set up diarrhoea and sickness. In many cases the water from shallow wells has been tbe means of spreading an epidemic. There was a notable instance of this in the case of a public pump used in St. Giles Parish, London. It was found that cholera occurred in all the houses supplied from this well. This was in 1854, when 400 persons were attacked in five days, and all had consumed water from this particular source. It was shown that dirty water had dripped into the well after soaking through the ground around.