Description: | This historic 1936 diagram, which had been digitally enhanced and colorized, illustrated two possible plumbing configurations of a steam table depicting both a sanitary (lower diagram), and unsanitary (upper diagram) method of plumbing interconnectivity. 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. |