A subcommittee on plumbing was appointed in 1921 under the Building Code Committee of the United States Department of Commerce. The purpose of this committee was to investigate the underlying principles of plumbing in order to recommend minimum requirements for plumbing codes and local ordinances. Most of the plumbing work of a dwelling is regulated by local ordinances or codes in communities where such exist, and is then passed upon by the local inspector. Many of these codes lack uniformity, some are obsolete, and there are unaccountable differences in regulation. There are at present a number of states that have enacted plumbing laws. These hold plumbing practice to certain main requirements. Several hundred cities also have adopted codes. Health is the basis on which such legislation is enacted.

The purpose of this subcommittee has been to prepare minimum requirements based on good plumbing principles and to draft a code based on these requirements. The relation of plumbing to health is discussed briefly in the following paragraphs of the subcommittee's report:1

The work of the committee has emphasized the necessity of considering the plumbing systems of buildings as intimately related to and forming an integral part of public water-supply and sewerage systems. The number and character of plumbing fixtures in a building are largely matters of individual choice, and owners have not sufficiently considered their relation to features of public service. Plumbing fixtures are the terminals of water-supply systems, and, to a large extent, control the quantity of water used. At the same time they are the beginnings of the sewerage system. The aggregate discharges from plumbing fixtures determine the flow in sewers and the volume of sewage reaching the outfall, this volume materially affecting the cost of any pumping or treatment of the sewage. It is evident, therefore, that the public interest may well justify a certain degree of governmental control over plumbing fixtures as affecting both the quantity of water available for public use and the economical operation of the sewerage system.

1 Recommended Minimum Requirements far Plumbing (U.S. Dept. of Commerce). Washington: Government Printing Office. 1929.

An important function of the house-drainage system is to carry away from plumbing fixtures human excreta and wastes which may contain disease-producing bacteria. Because of the possible presence of such organisms sewage may be dangerous and must be disposed of in such a manner that there will be no chance of disease transmission. Sanitarians to-day place great emphasis on the importance of sewage treatment and safe methods of ultimate sewage disposal.

The leakage of polluted water from the house-drainage system is insanitary and dangerous. Leakage within the house may pollute the habitation and permit food infection through the medium of insects. Leakage in the ground outside the house may pollute water supplies taken from neighboring wells or find its way into or under the building. The maintenance of water seals between fixtures and drains and the permanent tightness of plumbing systems are important not only because they prevent the passage of air, but because they prevent the access of insects to the interior of the drains and sewers. If cockroaches, water bugs, and other vermin can pass from drains to food, they may transport disease germs, and thus be a bacteriological menace to health. It is therefore important that the drainage system be tight and without danger of leakage.

L. 0. Howard, chief of the Bureau of Entomology of the United States Department of Agriculture, and C. W. Stiles, United States Public Health Service, in personal conversation with the late chairman of the committee, are authority for the statement that insects can and do pass from the interior of leaking drainage systems to living quarters. Several other observers also report such occurrences.

Another danger to be guarded against is the use of fixtures in which the water supply and waste connections are so arranged that polluted waste water from the fixtures may, under certain circumstances, return into the water-supply pipes.

The line where the safe water supply ends and sewage begins is sometimes very finely drawn. If faucets with open spouts discharge over plumbing fixtures and if there is a break between the water supply and the waste pipe, self-protection exists against possible pollution of the water-supply distributing system by the back flow of waste water into it. Plumbing fixtures such as water-closets, urinals, bidets, bathtubs, and lavatories with direct connections, secret wastes and overflows, and combination cocks offer possible sources of pollution.

The air in sewers and drains often contains gases resulting from the decomposition of excreta, soap, fats, and other wastes, together with gases from mineral oils which may come from garages, streets, and industrial establishments. Illuminating gas may also find its way into sewers through leakage. Among these gases may be found methane, sulphuretted hydrogen, and carbonic oxide. In large amounts those gases are poisonous to the human system, and there are physiological objections to breathing them even in small quantities. Hence, the air of sewers or drains should be kept from entering buildings intended for human habitation or occupancy by the use of proper plumbing installations and by suitable ventilation of the rooms or compartments in which the plumbing fixtures are located. The smell of these gases and other emanations from decomposing organic matter is naturally repugnant to human beings. It not only offends the sensibilities, but may produce shallow breathing, headache, and even nausea.

In addition to the above facts, it is important to consider the bacteriological aspects of sewer and drain air, a subject upon which there has been some misunderstanding. In recent years bacteriologists have made studies which have thrown light upon this subject. They have shown by experiment that while sewage often contains disease-producing bacteria derived from human excreta and body wastes these bacteria are rarely found in the air which escapes from sewers and drains. Hence, it has been argued by some that escaping sewer air has no influence on health. The committee does not agree with this conclusion. Health may be influenced by factors which do not cause specific diseases, for there are chemical and physiological as well as bacteriological factors involved. The investigations thus far made by bacteriologists should be considered to be merely a beginning of larger and more complete investigations which will doubtless be made as the science of bacteriology advances. The committee is of the opinion, therefore, that until further light on this somewhat obscure subject has been obtained the escape of sewer air from the house-drainage system, at frequent intervals or in considerable quantities, threatens the health of the building's occupants.

This whole matter has a quantitative as well as a qualitative aspect. The temporary losses of water seal in traps, which rarely occur and which are immediately replaced, do not involve any great danger to the health of the occupants, for in many cases the final drainage from the fixture will renew the seal within a short time, but where a loss of seal is likely to be of frequent occurrence and not readily replaced, or where breaks in the system admit sewer air continually to a building, the health of the occupants is subject to the dangers heretofore described.

For the above-mentioned reasons regulations governing the installation of plumbing have been established by law in many places. These regulations have been potent in improving living conditions throughout the country; in fact, they have even set the standards for those places where plumbing is not under public control. The knowledge now in possession of sanitarians in regard to the lessened bacteriological dangers of sewer air leads logically to some simplification in plumbing design, but it should not lead to an abandonment of practices necessary to protect buildings against the air of drains, which, in addition to its possible danger, is offensive to the smell.

The committee believes that good plumbing is a matter which concerns health. Government has the right to protect the people's health, but people also have rights, and plumbing regulations carried too far are unjust. Regulations which will not be supported by the courts fully and without question under a liberal interpretation of the police power may be regarded as unjust. Sanitary science, however, must be the guide to justice in this matter. The principles of science change as knowledge advances, and it is proper, therefore, that plumbing regulations be reviewed from time to time and, if necessary, revised.


The plumbing of a building includes the pipes for distributing the water supply, the fixtures for using water and drainage pipes for removing waste together with fittings and appurtenances. Plumbing means the installation of proper fixtures, and other apparatus for bringing in water supply and removing liquid and water-carried wastes. Good plumbing and plumbing fixtures usually result in a saving as they will require but a small expenditure for upkeep. Brass pipes are desirable for the distribution of the water supply in the home. If brass is too expensive for the entire water system, they should at least be used around the house heater and hot-water tank. Stops or valves should be installed. The automatic hot-water heater is one of the most desirable methods of heating water. Consider design, metal, and operating device in selecting faucets. The renewable feature of faucets should be considered as there is bound to be wear. Chromium plate is desirable as it requires little care. For kitchen sinks the swinging-spout type is desirable. The most desirable kitchen sink is the one with sink and drainboards cast in one piece.

City ordinances usually define the exact methods and materials used in the home for sewage disposal, outline the methods by which connections must be made, specify the installation of waste lines, and give definite rulings on the installation of traps and vents.

Considerable emphasis is placed by sanitarians on the importance of sewage treatment and safe methods of disposal. Regulations governing the installation of plumbing have been established in many places as many cities have plumbing codes or local ordinances governing plumbing. These regulations have been important in improving living conditions throughout the country and have been even instrumental in setting up standards where codes do not exist.


Babbitt, Harold E. Plumbing. New York: McGraw-Hill Book Co., Inc., 1928. Churchill, Allen, and Wickenden, Leonard. The House-Owner's Book.

New York: Funk & Wagnalls Co., 1928.

Water supply and plumbing (pp. 224-68).

House Beautiful Building Annual, I926. (Out of print.) Boston: Atlantic Monthly Co., 1926. Plumbing and plumbing fixtures (pp. 111-14).

Lescarboura, Austin C. Home-Owners' Handbook. New York: Scientific American Publishing Co., 1924. Plumbing and plumbing fixtures (pp. 343-68).

Starbuck, R. M. Modern Plumbing Illustrated. New York: Norman W. Henley Publishing Co., 1926. Excellent diagrams.

_______Standard Practical Plumbing. New York: Norman W. Henley Publishing Co., 1926. Plumbing for residences (pp. 208-15).

Tucker, Milton. Buying an Honest House. Boston: Little, Brown & Co., 1930. Equipment and fixtures (pp. 121-30).

U.S. Bureau of Public Roads. Farm Plumbing, by George M. Warren. U.S. Dept. of Agriculture, Farmers' Bull. 1426. Washington: Government Printing Office, 1924. Pp. 34.

_______Simple Plumbing Repairs in the Home, by George M. Warren. U.S.

Dept. of Agriculture, Farmers' Bull. 1460. Washington: Government Printing Office, 1925. Pp. 14.

U.S. Bureau of Standards. Recommended Minimum Requirements for Plumbing. Elimination of Waste Series, B.H. 13. Washington: Government Printing Office, 1929. Pp. 280.

Veiller, Lawrence. A Model Housing Law. New York: Russell Sage Foundation, 1920. Plumbing and sanitation practices (sees. 48, 49, 78, 124).

Walsh, Harold Vandervoort. The Construction of the Small House. New York: Charles Scribner's Sons, 1923. Essential features of good plumbing (pp. 94-108).