BALTIMORE — Baltimore officials said this week that a confluence of problems with aging infrastructure contributed to an E. coli contamination of the city water system in early September.

The Washington Post reports the problems reduced chlorine levels, which led to three positive tests for E. coli. A city spokeswoman tells the newspaper no one was sickened.

According to The Baltimore Sun, the contamination led to a boil water advisory for a wide swath of the city and into Baltimore County.