August 11, 1909: Municipal Journal and Engineer article. Queen Lane Reservoir Water Treated Chemically. “Philadelphia, Pa.-Though residents of that section of the city lying south of Allegheny avenue and between Sedgley avenue, Twenty-seventh street and the Schuylkill River have for more than two months supposedly been drinking absolutely raw, unfiltered water from the Queen Lane reservoirs, it became known recently that they have been using water that has been chemically purified by the city. Without letting the public into the secret, Chief Dunlap of the Water Bureau has had the bacteriologists of the Water Department improvise a station at the Queen Lane Reservoir for the oxidization of water by a chemical process which has proved highly effective. A shed has been erected at the intake of the reservoir, and all the water that is pumped from the river to the reservoir is ozonated or oxidized by chemical process as it passes through the shed. By oxidization all the animal or vegetable life is destroyed in the water, and it goes into the reservoir free from harmful impurities. Of course Chief Dunlap says this process does not clarify the water, but this is accomplished to a very large extent by precipitation or sedimentation [in Queen Lane Reservoir].”
Commentary: It is highly unlikely that ozone was being used to disinfect the water supply in Philadelphia in 1909 (in a shed by the river). More likely, the use of the term ozone referred to the chlorination of water, which supposedly released “nascent oxygen” which was responsible for killing bacteria. The same argument (some might say subterfuge) was used in the second Jersey City trial, which was going on during the time that this article was published. No water utility wanted to admit that it was using chlorine during this period. After the New Jersey Supreme Court approved the use of chlorine for drinking water disinfection in 1910, the linguistic jujitsu exemplified in this article was not as widely used.