Cincinnati has certainly come a long way since it was first settled in 1788. Back then, early settlers used hollowed-out logs to carry untreated water from the Ohio River to the main city center. Residents could pay 25 cents a week to have their water delivered by horse and oxen from the natural spring to their homes, and by 1805, Cincinnati had 1,700 residents taking advantage of this service.

As the city grew, so too did the innovations in Cincinnati drinking water. A steam engine from the riverboat Vesta replaced horses and oxen in 1824 and could pump as much as 1.2 million gallons of water a day. In 1828, Cincinnati started replacing hollowed logs with sturdier cast iron pipes that could withstand higher pressure and water flow.

By the 1890s, Cincinnati blossomed into the nation’s fifth-largest city and boasted one the country’s best water treatment systems. In 1928, the city pioneered the use of activated carbon filtration to improve taste and eliminate odor from chlorine treatment. The distribution system expanded in 1941, and again in the 1970s with the construction of The Charles M. Bolton Plant that produced water from the Great Miami Aquifer. Later, Cincinnati became the first utility in the nation to adopt the use of granular activated carbon in 1992.

Today, Greater Cincinnati Water Works supplies water from two sources: the Ohio River and the Great Miami Buried Valley Aquifer. The Richard Miller Treatment Plant treats surface water from the Ohio River, which supplies about 88% of Cincinnati drinking water. The Charles M. Bolton Treatment Plant treats groundwater from 13 wells and supplies about 12% of Cincinnati tap water.

Much of Cincinnati service lines still consist of the original cast iron pipes from the late 1800s. These pipes are prone to corrosion and biofilm contamination from chemical reactions, which create clusters of pipe deterioration and bacteria along the inside of the pipe, resulting in a “rotten egg” taste and smell. To combat the corrosion and biofilm contamination, many municipal water departments add high levels of chlorine, which further impacts the water’s taste and smell.

According to a recent water quality report, Cincinnati water quality meets or exceeds all state and federal health standards. However, samples of Cincinnati tap water may contain unregulated contaminants such as chloroform and sulfate.