What is a reasonable daily domestic consumption? The answer to this question necessarily depends upon the character of the building and the habits and occupation of its inmates. It is a universal experience that as soon as water is introduced it is used more lavishly, but also more recklessly and regardless of waste. For personal use, from twenty to twenty-five gallons per person should prove to be ample per day: this comprises water for drinking and cooking, for washing clothes, house and kitchen utensils, personal ablutions, and bathing; but, taking into account other requirements on the farm or of country houses, we require at least sixty gallons per capita per diem. To provide water for the horses, cows, sheep, for carriage washing, for the garden, for irrigation of the lawn, for fountains, etc., and keep a suitable reserve in case of fire, the supply should be not less than 150 gallons per person per day.
A Good Pressure Required
The third essential requirement is a good water pressure. Where a suitable source of water is found, it pays to make it conveniently available, so as to avoid carrying water by hand, which is troublesome and not conducive to cleanliness. A sufficient pressure is attained by either storing water at, or lifting it to, a suitable elevation above the point of consumption. In this respect many farm and country houses are found to be but very imperfectly supplied. Often the tank is placed only slightly higher than the second story of the house. As a result, the water flows sluggishly at the bathroom faucets, and, in case of fire, no effective fire stream can be thrown. Where a reservoir is suitably located above the house, the pressure is sometimes lost by laying pipes too small in diameter to furnish an ample stream. Elevated tanks should always be placed so high as to afford a good working pressure in the entire system of pipes. Where a tower of the required height is objectionable, either on account of the cost or on account of appearance, pressure tanks may be installed which have many advantages.
In selecting a source of water supply, the following points should be borne in mind for guidance: first, the wholesomeness of the water; next, the cost required to collect, store, and distribute the water; finally, where a gravity supply is unavailable, the probable operating expenses of the water system, cost of pumping, etc.
Collection of Rain Water
The collection of rain water near extensive manufacturing establishments is not advisable, except where arrangements are provided for either filtering or distilling the water. In the country, rain water is pure and good, if the precaution is observed to allow the first wash from roofs to run to waste. The rain may be either caught on the roofs, which must always have a clean surface and clean gutters, or else on artificially prepared catchment areas. As an example, I quote: "All about the Bermuda Islands one sees great white scars on the hill slopes. These are dished spaces, where the soil has been scraped off and the coral rock exposed and glazed with hard whitewash. Some of these are a quarter acre in size. They catch and carry the rainfall to reservoirs, for the wells are few and poor, and there are no natural springs and no brooks." (Mark Twain, "Some Rambling Notes of an Idle Excursion.")
After the close of the Boer War the English sent about 7,000 Boer prisoners of war to Bermuda, where they were encamped on some of the smaller islands of the group, and the entire water supply for the encampment was obtained by building artificial catchment areas as described in the above quotation.
Sometimes, instead of building underground cisterns, rain water is caught and stored in barrels above ground; if so, these should always be well covered, not only to avoid pollution, but to prevent the barrels from becoming mosquito breeders. Cisterns should always be built with care and made water-tight and impervious. The walls should be lined with cemented brickwork. In soil consisting of hard pan, cisterns in some parts of the country are built without brick walls, the walls of the excavation being simply cemented. I do not approve of such cheap construction, particularly where the cistern is located near a privy or cesspool. Pollution of cistern water is often due to the cracking of the cement lining. Overflows of cisterns should never be connected with a drain, sewer, or cesspool. Run the overflow into some surface ditch and provide the mouth with a fine wire screen, to exclude small animals. It is not recommended to build cisterns in cellars of houses.
Quality of Water Obtained from Lakes
Lakes yield, as a rule, a supply of clear, bright, and soft water. This is particularly the case with mountain lakes, because they are at a distance from sources of contamination. The character of the water depends upon whether the lake is fed by brooks, that is, by the rain falling upon the watershed, or also by springs. In one case the water is surface water exclusively; in the other, it is surface and underground water mixed. The purity also depends upon the depth of the lake and upon the character of its bottom.