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: BPR-RE 1385
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.]