No dry toilet, septic tank, cesspool, insanitary cow lot, horse lot, hog pen or any collection of filth, garbage or other offensive or filthy thing or substance shall be permitted within 200 feet of any well; provided, that if it is evident that pollution is reaching the well from a source farther away than the distance mentioned above, the source of the pollution shall be eliminated.
(1964 Code, § 19-437)