( Originally Published 1917 )
Community Health Work.—Most of the problems so far discussed in this book have been problems of individual conduct. We can all of us do much to keep our bodies in vigorous health and to protect them against disease germs coming from outside. But there are other things necessary for good health that are beyond the control of the individual, particularly in the case of those who live crowded together in cities and towns.
You must have pure water to drink; but in a place where many people live and where the soil is necessarily more or less polluted, you cannot get safe water by digging a well for yourself. You ought not to drink impure milk; but your father could hardly go every morning to the dairy to make sure that everything is clean and right. If your neighbor has scarlet fever, the members of the family should not be allowed to carry the disease to others, but you alone could hardly force your neighbor to take the proper precautions. This is where the community, the city, or the town steps in and does collectively the things which individuals could not do for themselves.
Problems of Municipal Sanitation.—The special work of the Board of Health in controlling communicable disease, supervising food supplies, and educating the public in the principles of healthy living will be discussed in the next chapter. There is a group of health problems, however, which have to do with engineering rather than with medicine, and which are often grouped under the head of Municipal Sanitation, though they must receive attention not only in cities but also in towns and in thickly settled villages. These are the problems of public water supply, sewage disposal, refuse disposal, and street cleaning.
The Public Water Supply.—An ample supply of pure water is one of the first needs of any community, and in a large city the problem of obtaining such a supply is by no means a simple one.
The amount of water used by American cities is enormous, much larger than it need be, because a great deal is wasted. A large part of this waste comes from taps which are left running, or from taps or flush tanks which are in bad repair so that they trickle all the time. The good citizen will see that this does not happen in his house, for all the water wasted costs the taxpayer money.
Various Kinds of Water Supply.—All of our water supply comes first of all from the clouds, in the form of rain. Individual houses may collect rain directly as it falls on the roof and carry it by gutters to a cistern—a good arrangement if the cistern is kept clean.
When the rain falls to the earth, part of it runs over the surface of the ground into small brooks, and thence into larger streams or ponds. Many cities get their drinking water from these streams and ponds, which are called surface supplies. Sometimes, if the stream or pond is high up in the hills, the water will flow down to the city by gravity (the attraction of the earth which causes water to flow from a higher to a lower level). All that need then be done is to build a large pipe or aqueduct which branches out into .smaller and smaller pipes in the city streets, and finally into individual pipes running into each house. Where this kind of gravity supply cannot be obtained, surface water may be pumped up from a neighboring stream into the city pipes by great steam pumps.
While much of the rain water runs off from the surface of the ground, some of it trickles down into the earth and becomes ground water. If men dig down far enough into the earth anywhere, they will finally come to this ground water trickling along through the soil toward the ocean or the bed of some river or lake. In low places, the ground water is at the surface or very near the surface, while in other places it may be necessary to go down thousands of feet before striking water.
If a hole is dug or a pipe is driven down to a point below the ground water level, the ground water will flow into the hole or pipe and make a well. Cities may get their supply of water by driving a series of such wells and pumping the water up from them. This forms what is called a ground water supply.
Purification of Public Water Supplies.—The raindrop, as it first forms in the clouds, is pure water. In falling through the air, it picks up dust particles floating there and washes the air so as to give us the bright, clear days we have after a heavy rain. There are, however, practically no disease germs in the upper air, so that in this respect the rain water is still pure when it reaches the earth.
As soon as the raindrop touches the ground, its pollution begins. You may have seen the swollen brooks just after a heavy rain, muddy, with the dirt which the rain had washed from the surface of the earth. Along with the rest of the dirt, it is quite likely that human excretions have been washed into the brook. Many of the larger streams and ponds also receive a direct discharge from house drains and sewers.
The danger from water supplies polluted in these ways has been pointed out in Chapter XXII. There is now no excuse for running any such risks, since we have simple and cheap methods of making water safe to drink.
There are three principal ways of purifying polluted waters: by storage, filtration, and disinfection.
Storage Reservoirs.—If the water of a polluted stream flows into a large lake or reservoir and passes very slowly through it, taking several weeks to go from one end to the other, practically all the disease germs will die out. This is called purification by storage. It is often an effective way of getting a good water supply. There is danger, however, that floods after a heavy rain or surface currents caused by the wind may, at times, carry water quickly across such a reservoir, so that the expected purification will not be secured.
Filtering the Water Supply.—A more certain way of getting a safe public water supply is by filtration. A city water filter does its work more thoroughly than the little filters on the tap in the house, which take out sticks and large particles of dirt, but not bacteria. The city filters are great beds of sand, each bed sometimes an acre in area. As the water slowly trickles through these sand beds, the bacteria are caught on the surfaces of the sand grains. Such a filter will make even polluted river water clean, pure, and safe to drink. In some filters, chemicals are added to the water; they make a deposit on the surface of the sand which helps to strain out the bacteria.
Disinfecting the Water Supply.—Water supplies may also be purified by disinfection with certain chemicals, particularly chlorine. Very minute amounts of these chemicals will destroy the disease germs and most of the other germs in water, without harming it in any way. This is such a cheap way of making water safe that any city can afford it.
Hard and Soft Waters.—Water which contains a large amount of certain mineral matters in solution is called hard water. A great deal of soap must be used to get a lather with hard water, and the mineral matter in such waters collects on the walls of steam boilers and injures them. The taste is also unpleasant unless one is used to it.
In many parts of the country where hard waters are found, the city softens the water or takes out the sub-stances that cause hardness by special chemical treatment.
Sewerage.—Some of the difficulties in disposing of wastes - from houses in the country have been mentioned in Chap-ter XXII. In a thickly settled community, it is necessary to provide in some special way for the removal of such materials. Just as clean water is brought to each house in the water pipes, so the soiled water from toilet, bath, and kitchen sink is carried away by another system of pipes, the sewers. It is a great advantage to have sewers under the streets to carry off all the liquid wastes from the houses. A sewerage system brings up a new problem for the city, however, for at the end of the big sewer, into which the little sewers empty, there is a river of sewage that must somehow be disposed of.
Sewage Disposal.—The simplest thing to do with sewage is to discharge it into the nearest stream, lake, or harbor. If there are no bathing beaches or oyster beds near at hand, and if the stream or lake is large and the amount of sewage small, the sewage will disappear in the water without causing any trouble. The sewage matter in such a case is destroyed and changed to an odorless liquid form by the action of certain bacteria which live upon it. These bacteria need oxygen to carry on the work, and there must be plenty of oxygen in the water, in order that this kind of sewage disposal may succeed. If a large amount of sewage is put into a small stream or pond, the oxygen dissolved in the water may all be used up; and then another kind of bacteria, which live where there is no oxygen, begin to grow. These bacteria cause a different kind of change in the sewage, the change we call putrefaction, which produces foul odors. A body of water which has too much sewage discharged into it becomes ill-smelling and a nuisance to the whole neighborhood.
In order to avoid this condition, cities that are not situated on very large bodies of water usually have to purify their sewage before they discharge it. Sometimes all that is necessary is to strain out the solid matter by passing the sewage through fine screens, or to let the solids
settle in tanks. Sometimes it is necessary to go farther and to purify the sewage by passing it through filters of sand or stone.
These sewage filters are not intended to strain out bacteria (like the water filters described above) but to secure chemical changes in the organic matter of the sewage, so that it will not decay and produce bad smells. The filters in this case are really places where the useful kind of bacteria that destroy sewage matter can live and get a good chance to do their work. Such bacteria grow on the stones or sand grains of the filter in a jellylike mass. Plenty of air is supplied for their use, either by letting the sewage run on to the filter in small quantities at a time, or by making the filter so open that air can get freely through it. For in-stance, the filter shown in Fig. 129 is a bed of rough stones about two inches in diameter. The,sewage is sprayed up into the air from little fountains all over the bed, and as it trickles down through the bed, the bacteria on the surface of the stones feed upon it and purify it.
Disposal of Garbage and Refuse.—Besides the liquid wastes of the city which flow away in the sewers, there are solid wastes which must somehow be disposed of. There is the garbage or kitchen waste, the ash from fires of all sorts, and the rubbish, such as waste paper, sticks, tin cans, and bottles. The employees of the city, or of some private contractor engaged by the city, should come at regular and frequent intervals to carry these things away. Garbage, especially, decays and becomes offensive, if it is not promptly removed.
The carts in which garbage is carried through the streets should be of metal so that they can be kept clean, and should have tight-fitting covers so that they may not be offensive as they pass. The ash and rubbish carts should be covered sufficiently to keep the ashes and papers from blowing about.
In small communities, the refuse may be dumped into some low open place, and the garbage may be taken to farms and fed to pigs. Refuse dumps are always likely, however, to be a nuisance. They smell bad and breed flies; dust blows from them, and they are often the sources of dangerous fires.
In large cities, there must generally be some definite way of disposing of refuse. The clean ashes may be used for filling low areas. The rubbish may be sorted, and the papers and cans sold to manufacturers. The garbage may be treated in a so-called reduction plant, where the grease and fertilizing substance which it contains are extracted and sold. Another way is to burn all the solid wastes together in a special kind of furnace called an incinerator.
Keeping the City Clean.—Dirty streets and dirty back-yards are unsightly, and contribute indirectly to ill-health. Accumulations of organic filth breed flies, and flies may carry disease. We.judge people largely by the conditions of their home; if the house is dirty and untidy, we think that it is not a pleasant place to be in, and that the family is slovenly. It is just so with a town; and we all want our town or city to be one that we may be proud of.
A good citizen will help the city government to keep the streets clean, by never scattering papers, banana skins, or other refuse. In many places, the young people of the town have formed themselves into a civic militia, and as Boy Scouts or School Sanitary Squads have done splendid service in keeping their neighborhoods clean and orderly.
There is one man of whom we always like to think, in. connection with this problem of municipal cleanness, Colonel George E. Waring (1833-1898). The election of 1894 in New York City turned very largely on the dirty condition into which the city government had allowed the streets to fall. The new administration asked Colonel Waring to reform the whole business of street cleaning. His men were called Waring's White Wings, because they were dressed in white washable suits; and they did their work so thoroughly, under the system he worked out, that his reputation became world-wide as "the man who cleaned New York." When the United States took possession of Cuba in 1898, Colonel Waring was sent to clean up Havana, and he did it with the same success.
QUESTIONS FOR DISCUSSION AND REVIEW
1. Which do you think is more important in a community, the water supply or the sewerage system?
2. Show by an example why it is necessary to have general laws of sanitation in a community rather than to trust to the hygienic habits of single families.
3. Where does water come from primarily? Trace the history of the glass of water that you drank at breakfast, from its source to your glass.
4. What are surface supplies? Ground water supplies?
Under which head would you class a lake? A river? A well?
5. By what different means is water forced into our houses?
6. How may water become polluted?
7. What three ways have engineers and chemists found to purify water? Explain each of the three.
8. If you live in `a city or town where there is a public water supply, find out where the supply comes from and what steps are taken to make it safe. If you live in the country, where water is supplied by wells, study the well at home or on the school property, its location with reference to the closet or cesspool and other sources of pollution, and the means taken for protecting it from surface wash.
9. Why is there nowadays often more danger from water in the country than in the city?
10. Why is hard water considered undesirable? How is it sometimes changed?
11. What dangers are there in emptying sewers into a river or lake?
12. Cite an instance in which typhoid fever was carried to several towns through discharge of sewage into a river.
13. Under what conditions may sewage be emptied into a river or lake with safety?
14. What happens when sewage is discharged into a large body of water? Into a small one?
15. Explain the method of sewage filtration.
16. What advantages are there in having a clean city? Which do you think is better, to clean up a little every day or to have periodical Clean-up Days?
17. How are household wastes and refuse disposed of in your town?
18. How can boys and girls help the paid street cleaner? Have you cans for waste papers on the street corners in your town? Do you use them?
19. Who was Colonel Waring and what did he do?