Police said Ryan Langsdorf, 28, and Ashley Moyer, 23, were cited for trespassing after officers caught them skinny dipping in the Mount Tabor Reservoir during the weekend, The (Portland) Oregonian reported Tuesday.

However, the city Water Bureau said Reservoir 6 is split into two sections and the pool where the incident occurred was not being used at the time. Officials said the city would have shut down the system and dumped millions of gallons of water if the in-use supply had been tainted.

The Water Bureau said it plans to have the pair prosecuted to the fullest extent of the law. They face a maximum penalty of a fine and community service.