It has been asserted that certain diseases, not necessarily causing death, are caused by hard water, as calculus, cancer, goiter, and cretinism; but, as already pointed out in Chapter II, no satisfactory proof has ever been established. One must conclude that within reasonable limits there is little to choose between a hard and soft water for drinking purposes, although a change from a soft water to a hard, or vice versa, usually produces temporary derangements.
Loss of soap.
For washing purposes the value of a soft water is more marked. When a hard water is used, a certain amount of soap is required to neutralize the hardness before the soap is effective, and this takes place at the rate of about 2 ounces of soap to 100 gallons of water for each part of calcium carbonate per gallon, or about 3 ounces of soap to 10,000 gallons for each part per million increase in hardness.
The village of Canisteo, New York, has a hard spring water, the hardness being recorded by the State Department of Health as 162.8 parts calcium carbonate in a million parts of water. Clifton Springs water has a hardness of 208. Catskill, New York, which gets its water from a stream running down from the hillside, has a hardness of 22.1 or 140.7 parts less than Canisteo. Mr. G. C. Whipple says ("Value of Pure Water") he has found that 1 pound of soap is needed to soften 167 gallons of water when that water has a hardness of 20 parts per million, and that each additional part requires 200 pounds of soap to soften a million gallons. If Clifton Springs and Catskill should each use 100,000 gallons per day, the additional cost of the hard water, at five cents a pound for soap, would be 20 × 140.7 × 0.05 = $140.70, provided all the village water were neutralized with soap. Probably not over one fiftieth part of the water is so neutralized, so that the added cost of soap is actually about $2.80 a day. Whipple expresses this cost as H/100 = D, where H is the hardness in parts per million and D is the cost in cents for every 1000 gallons used for all purposes. Thus Canisteo water costs 162.8/100 = 1.6 cents per 1000 gallons used, while Catskill costs only 22.1/100 or 0.2 cent on account of soap.
This discussion is intended to suggest a comparison between a well of hard water and a surface supply of soft water, when both are available. It should arouse an interest in securing a soft water as well as a clear water, and the advantages of the softer water, in so far as soap consumption alone is concerned, are seen to be not inconsiderable.
Vegetable pollution.
The vegetable and animal matter is organic in its origin and nature, and their effect on water may be taken up together.
Vegetable pollution is generally the result of decayed leaves, roots, bark, and such other vegetable tissue as would be likely to be found where the water-supply flows through a swamp or accumulates in hollows and depressions. This sort of water is likely to have a brownish or yellowish brown color, to have a slightly sweetish taste, and to be soft, that is, free from mineral solids. Usually such water can be used for drinking purposes without serious consequences. Æsthetically, it is objectionable because of its color, and the city of Boston has expended many thousands dollars in building channels around swamps and in providing artificial outlets for swamps, so that the color of the water collected on the watershed shall not show the color induced thereby. Water from the Dismal Swamp of Virginia is so discolored as to look like coffee, and yet, in the vicinity, it is much prized for drinking, and formerly great pains were taken to fill casks with this water when in preparation for a long sea voyage.
Such matter always has a marked influence on a chemical analysis of the water, shows large amounts of nitrogenous matter, and apparently indicates a polluted supply; but, if the reason for this apparent pollution lies in the presence of a swamp, no danger to health therefrom is to be apprehended. Such water also is less subject to decay or putrefaction, and if a water-supply for a house is to be taken from a small pond, a gathering ground containing swamps is likely to furnish a more satisfactory water, color alone excepted, than one free from such swamps.
Pollution of water by animals.