|Description:||This historic 1936 diagram, which had been digitally enhanced and colorized, illustrated in cross-connection, a water supply as it supplied a water closet equipped with a “flushometer” valve, as well as a drinking fountain. This was one of a series of instructional drawings used by the Minnesota Board of Health to train its state public health workers.|
The purpose of these images and the accompanying training was focused on protecting water supplies from bacterial contamination due to incorrect disposal of waste, such as sewage, in order to prevent water-borne diseases. The descriptive information accompanying this drawing referred to a governmental publication, which contained instructions describing how to correctly place and build such a device. The specific citation was, “Minnesota State Board of Health, Plumbing in Relation to Public Health, 1936, p. 31”.