ID#: 8637
This historic 1919 diagram, which had been digitally enhanced, depicted a properly constructed manhole cover, intended to cover an underground reservoir. As one of a series of instructional drawings, this image was used by the Minnesota Board of Health to train its state public health workers. The focus of this image, was on protecting potable water supplies from bacterial contamination, due to incorrect disposal of waste, including sewage that might foul ground water, lakes, rivers, and streams.
High Resolution: Click here for hi-resolution image (15.85 MB)
Content Provider(s): CDC/ Minnesota Department of Health, R.N. Barr Library; Librarians Melissa Rethlefsen and Marie Jones
Creation Date: 1919
Photo Credit:
Links: Minnesota Health Department
Minnesota Health Department; R.N. Barr Library
CDC Organization
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Copyright Restrictions: None - This image is in the public domain and thus free of any copyright restrictions.