Andersen Air Force Base in Guam has been fined by the territory’s Environmental Protection Agency for using pool chlorination tabs that were classified as a pesticide to sanitize some of its drinking water.

Andersen said in a release Saturday that it had used Pool Time chlorination tabs to sanitize the water in a half-million gallon storage tank, which provided water to facilities on its Northwest Field.

But those chlorination tabs have been classified by the Guam EPA as a pesticide, Andersen said. The base said it stopped using those tabs as soon as it found out.

Andersen said that while the chlorination tab was improperly used, the water was safe to drink at all times.

“Both Guam EPA and Andersen AFB concluded that the use of the Pool Time chlorination tabs would not result in any adverse health effects,” Andersen said in the release. “Andersen AFB conducts routine analysis of its water supply and at no point was it deemed unsafe.”