| PREVIOUS | NEXT | NEW SEARCH |
The Evolution of the Conservation Movement, 1850-1920
Conservation by sanitation; disposal of waste (including a laboratory guide for sanitary engineers) by Ellen H. RichardsSources of Water Supplies
Various conditions which cause contamination or pollution. Like air, water is in constant circulation, rising Meteorological.from the sea and from all vegetation and earth surfaces in the form of pure vapor; carried by winds to high altitudes, condensed by cold, and precipitated through the earth's dusty, gas-thick atmosphere in the form of rainGeological.or snow, in anything but a pure condition. This precipated rain soaks into the dirty soil and, by the great solvent power of water, dissolves whatever is soluble.
A larger part of the rainfall in temperate zones washes the leaves of trees, the fields of grain, the roofs of houses, the streets of cities, the farmyards, the fertilized fields, the dump heaps, and flows in channels to the large lakes and the sea to begin its course again.
Water for domestic use is drawn from either the ground circulation or the surface flow. In pioneer regions that ground-filtered and cooled water was searched for and camped by, which flowed in sparkling volume, as springs. Such water may have traveled miles and been in the earth layers dozens of years, and become charged with tons of mineral substances, but it was usually free from organic matter, and if it ever carried any "germs," time and cold had destroyed them. Hence in pioneer times in temperate and tropical areas such spring water was the ideal drinking water, clear, cold, sparkling, pleasant to the taste.
Page 90 { page image }
In contrast to the muddy, warm, "flat" water of streams which primitive and pioneer peoples have used only as laundry tubs and sewers, one has only to travel in uncivilized lands to understand the preference for "springs" and the early worship of these fountains of life.
The nineteenth century, with its inventions, changed the habits of the people to such an extent as to exert a marked influence on the character of such apparently permanent features.
Changes to Mechanical Processes.Families no longer gathered at streams to wash themselves and their apparel. They dug wells near by their permanent homes and allowed that surface water which soaked from barnyard, garden, and near-by-fields to collect. They were lucky if they tapped an underground source flowing from distant collecting grounds to dilute this supply. The quality of this water was dependent on the geological character of the rock and rock deébris, the kind of cultivation, and most of all on the habits of the occupants of the homestead.
If they took pains to carry the waste water some distance, it was well cleaned before it soaked back. It they allowed it to penetrate the ground near by, it was often only partly cleaned. Time and distance are factors to be reckoned with.
Then came the house tank for supply to bathroom and toilet, with the necessary concomitant, the leaching cesspool at twenty to fifty feet from the well. Trouble was thus invited by the very means which civilization had been most proud of, cleanliness of person and belongings.
As in every other advance of mankind, the knowledge or right and safe methods has been gained at the expense of human life and suffering. As more people living on an acre of land needed more water, supplies were sought for and brought from a distance, and carried away in drains after using. At first these were surface waters flowing by gravity, the people using the wells in their own back yards.
More cities grew up and polluted the source. Thickly settled countries allowed wastes to percolate through rock crevices in the
Page 91 { page image }
hills and valleys it is now a rare occurrence to find an uncontaminated water within two hundred miles of any town. By uncontaminated I mean a water which shows no evidence of past pollution.
The fouling of water supplies like the littering of streets is a result of selfish carelessness, which reacts on the doer.
It is mainly ignorance and a clinging to traditional half truths, like "the ground is the purifier," "out of sight, out of minds."
Clean Soil.Since all water (except cistern water) comes in contact with earth, flowing over it or through its interstices, dissolving, washing, wasting, leaching, and transporting, the character and condition of the soil are of the utmost importance as regards the purity of water.
Much if not most of the danger from impure water comes from habits of people as regards soil.
Theories of purification by earth were very crude until about 1880 and the discovery of the nitrifying organism.
Information about SGML version of this document.
| PREVIOUS | NEXT | NEW SEARCH |