HOUSE DRAINAGE AND SANITARY PLUMBING. BY WM. PAUL GERHARD, CIVIL AND SANITARY ENGineer, Newport, R. I. The State Board of Health and the writer desire to express their sincere thanks to the following gentlemen, who kindly loaned electrotypes for this report: To Mr. Edw. S. Philbrick, Civil and Sanitary Engineer, Boston, for Figs. 3, 3a, 9, 26, 28, 29, 29a, 30, 31, 32, 33, 37, 41, 45, 46, 49, 51, 52, 57, 58, 61, 62, taken from his book, American Sanitary Engineering." To Messrs James R. Osgood & Co. (Publishers Ameritan Architect and Building News), Boston, for Figs. 59 and 60, taken from articles on "Modern Plumbing," by Prof. T. M. Clark, in the American Architect for 1878. To Messrs. Henry C. Meyer & Co., New York, for illustrations of many of their sanitary goods; see Figs. 63, 64, 65, 66, 67. To the J. L. Mott Iron Works, New York, for illustrations of many of their sanitary manufactures; see Figs 20, 21, 43, 50, 50a, 53, 59a 82, 82a. To A. G. Meyers, Sanitary Depot, New York, for illustrations of their sanitary appliances, Figs. 47a, 68, 69, 78, 79. To the Sanitary Engineer," New York, for Figs. 10-18, 38, 39, 40, 42, 44, 47, 48, 49a, 85, from articles that appeared in its columns. HOUSE DRAINAGE AND SANITARY PLUMBING. Many erroneous ideas still prevail about sewer gas and its danger to health which arises, by having so-called "modern conveniences" in our dwellings. It is the purpose of this paper, without in any way adding to the "plumbing scare", clearly to define wherein the danger consists, but at the same time to establish rules for the proper drainage and plumbing of houses, which, if carefully observed, will secure to the anxious house owner, work of superior quality and of a positively safe character. Plumbing fixtures, which were considered a luxury years ago, are now believed to be necessary, not only for comfort and convenience, but also, and even more so, for health and for cleanliness. Even a small house is nowadays generally provided with a kitchen sink, a water-closet, and sometimes a bath-tub, while in a costly modern residence, arranged with an elaborate system of plumbing, we find kitchen, pantry and scullery sinks, slop sinks, laundry tubs, stationary wash-basins in closets near bed-rooms, a great number of bath or dressing rooms, with water-closets, urinals, bath- and foot-tubs, bidets and other fixtures. The suggestions and recommendations of this report apply with equal force to the drainage and plumbing of tenements, small houses, costly residences, villas, apartment houses, hotels, factories, schoolhouses or public buildings. As every plumbing fixture is not only an outlet for the waste-water to the drain, but possibly may become an inlet for drain air, the danger increases with the number of fixtures. It is, therefore, of the utmost importance to arrange the plumbing and drainage of a building so as entirely to exclude any possibility of the escape of sewer gas into it. I shall, first, briefly consider what is meant by the term "sewer gas." This term, as Prof. W. Ripley Nichols has truly said,* is "an unfortunate one, and gives rise to a quite widespread but very erroneous idea. Many seem to suppose the "sewer gas" to be a distinct gaseous substance, which is possessed of marked distinguishing characteristics, which fills the ordinary sewers and connecting drains, and which, as a tangible something, finds its way through any opening made by chance or by intention, and then, and only then, mixes with the atmospheric air." Sewer gas is a mechanical mixture of a number of well-known gases, having their origin in the decomposition of animal or vegetable matter, with atmospheric air. This mixture is continually varying, according to the more or less advanced stage of putrefaction of the foul matters, which form a sediment and a slimy coating of the inner surfaces in drains and pipes. It is also variable with the character of this sediment or deposit, and with the physical conditions (moisture, heat, etc.) under which the decomposition takes place. The principal gases found in sewers and drains are oxygen, nitrogen, carbonic dioxide, carbonic oxide, ammonia, carbonate of ammonia, sulphide of ammonium, sulphuretted hydrogen and marsh gas. The three first named gases are the principal constituents of the atmosphere, surrounding the globe, and are found present in the following average proportion, viz.: 20.9 vols. oxygen in 100 vols. of air, together with 2 to 5 vols. carbonic dioxide in 10,000 vols of air. According to R. Angus Smith the amount of oxygen is: in the average, 20.96 vols. in 100 vols. of air. in pure mountain air, 20.98 vols. in 100 vols. of air. at the sea shore, 20.999 vols. in 100 vols. of air. in streets of populous cities, 20.87 to 20.90 vols. in 100 vols. of air. The air in sewers and drains contains much less oxygen, as some of it combines with the carbon of putrefying organic matter forming carbonic dioxide. The amount of nitrogen in the air of sewers is little different from that in the atmosphere which we breathe; but the amount of carbonic dioxide present is greatly increased. The lowest amount of oxygen in sewer air is recorded to be 17.4 vols. in 100 vols. of air; the amount of carbonic dioxide is in the average 2.3 vols. in 100 vols. Sulphuretted hydrogen varies greatly, but the quantity is generally so small as not to be easily determined. Still more difficult is it to find by chemical analysis the proportion of other gases of decay. *See Prof. W. Ripley Nichols' report upon chemical examination of the air of the Berkeley street sewer, in Boston, Mass., 1878. In well ventilated and well flushed sewers, Dr. Russell, of Glasgow, found the following ratio: 20.70 vols. of oxygen in 100 vols. of air. 78.79 vols. of nitrogen in 100 vols. of air. 0.51 vols. of carbonic dioxide in 100 vols. of air. No sulphuretted hydrogen in 100 vols. of air. Traces of ammonia in 100 vols. of air. Carbonic oxide is present only in excessively minute quantities, and even then it may have entered the sewer or drain through leakage of illuminating gas from gas mains. In the absence of more satisfactory methods of analysis, it is usual with chemists to determine the amount of pollution of the air, or the organic matter in it, by determining the amount of carbonic dioxide. present, assuming that there is a certain fixed proportion between the amount of carbonic dioxide and the organic matter.* Thus, Prof. W. Ripley Nichols records as the average of many carefully conducted experiments in Boston, the amount of carbonic dioxide in a sewer in that city as follows: The average of 31 determinations in January, 1878, was 8.7 vols. of CO2 in 10,000 vols. of air. He remarks: "It appears from these examinations that in such a sewer as the one in Berkeley street, which, being of necessity tidelocked, is an example of the worst type of construction, the air does not differ from the normal standard as much as many, no doubt, suppose. In a general way, as we have seen, there is a larger amount of variation from normal air during the warmer season of the year; but even when the amount of carbonic acid was largest, it was only extremely seldom that sulphuretted hydrogen could be detected." "I think it should be said that the soil-pipes and housedrains are much more likely causes of discomfort and danger than the sewers." *Such is strictly true only for air fouled by respiration, while it may not give accurate results in other cases. In regard to this interesting question I must refer to the Report of Prof. Ira Remsen on the subject of organic matter in the air, published in the National Board of Health Bulletin, vol. 2, No 11. |