The agriculture committee of Chile's lower house has voted in favor of a motion that seeks to ensure the return of unused treated water to rivers for agricultural use.
The motion was introduced in April by lawmakers Denise Pascal and Adriana Muñoz, from opposition parties PS and PPD respectively, and was approved unanimously by the committee, a press release from congress reads.
Muñoz said the motion makes it clear that unused water can't be used by utilities for commercial purposes, and must be returned to rivers.
According to national water utility association Andess president Guillermo Pickering, the motion is unconstitutional as utilities own the water that they treat.
The motion now goes to the lower house for discussion.
Earlier this year, press reports surfaced claiming that some utilities planned to sell treated water to mining companies instead of returning it to rivers for agricultural use.
The issue ignited a debate over water rights, with irrigation groups and national agriculture association SNA finding political support for its position that utilities do not own treated water.
In June, national sanitation service authority SISS announced that it lacked jurisdiction to determine whether utilities become owners of the wastewater they treat, reversing its previous decision allowing utility Aguas Andinas to sell treated wastewater.
SISS's new position was backed by the supreme court, which in May ruled in favor of the authority in a suit that claimed the authority had erroneously interpreted Chilean law.
Article 61 of Chile's general sanitation services law states that water companies must discharge wastewater in the natural or artificial water table under terms specified in concessions.