Wastewater that recently swirled down a toilet bowl may be coming to your tap, in purified form, especially if you’re in a drought-stricken area where drinking water is increasingly scarce.

More municipal water systems in the West are considering water recycling, known in some places as “toilet-to-tap.” And Congress may begin supporting the idea as water systems scramble to find secure water supplies amid a decades-long drought driven by climate change, which may be the worst the region has experienced in more than a millennium.