[Illustration: Fig. 2.--The rickety, uncomfortable, unspeakably foul, dangerous ground privy. Neglected by the owner, shunned by the hired man, avoided by the guest, who, in preference, goes to near-by fields or woods, polluter of wells, meeting place of house flies and disease germs, privies of this character abide only because of man's indifference] Sewage or impure drainage water should never be discharged into or upon ground draining toward a well, spring, or other source of water supply. Neither should such wastes be discharged into openings in rock, an abandoned well, nor a hole, cesspool, vault, or tank so located that pollution can escape into water-bearing earth or rock. Whatever the system of sewage disposal, it should be entirely and widely separated from the water supply. Further information on locating and constructing wells is given in Farmers' Bulletin 1448-F, Farmstead Water Supply, copies of which may be had upon request to the Division of Publications, Department of Agriculture. Enough has been said to bring home to the reader these vital points: 1. Never allow the farm sewage or excrements, even in minutest quantity, to reach the food or water of man or livestock. 2. Never expose such wastes so that they can be visited by flies or other carriers of disease germs. 3. Never use such wastes to fertilize or irrigate vegetable gardens. 4. Never discharge or throw such wastes into a stream, pond, or abandoned well, nor into a gutter, ditch, or tile drainage system, which naturally must have outlet in some watercourse. [Illustration: Fig. 3.--How an apparently good well may draw foul drainage. Arrows show direction of ground water movement. _A-A_, Usual water table (surface of free water in the ground); _B-B_, water table lowered by drought and pumping from well _D_; _C-C_, water table further lowered by drought and heavy pumping; _E-F_, level line from surface of sewage in cesspool. Well _D_ is safe until the water table is lowered to _E_; further lowering draws drainage from the cesspool and, with the water table at _C-C_, from the barn. The location of well _G_ renders it unsafe always] [Illustration: Fig. 4.--An insanitary, poorly drained barnyard. (Board of Health, Milwaukee.) Liquid manure or other foul drainage is sure to leach into wells situated in or near barnyards of this character] HOW SEWAGE DECOMPOSES