|This article is about a/an group of villains in Power Rangers Zeo, the second installment in the Zordon Era.|
The Hydro Contaminators were a group of aliens who attacked Aquitar by dumping poison into its waters. One came to Earth by following Cestro and planned to contaminate Earth's water supply. That Hydro Contaminator was destroyed by the Zeo Blaster.
The Aquitians and the Hydro Contaminators later settled their differences.
Apparently, the Hydro Contaminators had never heard of the Machine Empire (and possibly, the United Alliance of Evil). As the one who followed Cestro was surprised by the sudden appearance of the Cogs backing him up.