August 23, 1911: Municipal Journal article. Water Tanks Cause of Impure Water “Chicago, Ill.-Flat dwellers who patronize Lake Michigan for drinking purposes can get a certificate of quality from the City Health Department. Health Commissioner Young declared that any samples brought to the department drawn from faucets in apartment houses will be tested, and if found to be impure orders will be given to the owners of the buildings to cleanse the tanks on the roofs from which the supply is drawn. Much of the danger from drinking water comes from the neglect of the owners of apartment houses to keep these tanks properly cleaned. The regulations of the Health Department require that these tanks be covered and sufficiently protected to keep cats or other animals from wandering into them. In many of them, however, moss and other vegetable matter accumulates. In practically all buildings more than two stories in height tanks are necessary in order to supply water to the upper floors.”
Commentary: In Chicago during this period, algae growing in elevated water tanks was the least of a resident’s problems. It was not until the year of this article (1911) that Chicago began installing chlorination stations on the pumping facilities from Lake Michigan. Prior to this, death from severe typhoid fever epidemics killed many tens of thousands over the decades of the city serving contaminated water. Filtration was not installed until 1947.