An Act relative to greywater recycling

HD 3157 requires new multifamily construction projects (using less than 3,000 gallons of water daily) in Massachusetts to incorporate greywater recycling systems. It defines greywater as wastewater from showers, sinks, and laundry (excluding toilet or kitchen sink waste), and establishes two system tiers: Tier 1 for single-family homes under 400 gallons per day (for toilet flushing or irrigation), and Tier 2 for other buildings. Key provisions mandate safe system design (avoiding human/pet contact, 24-hour storage limits, and diversion to sewer during backups), while requiring all systems to connect to existing public or on-site sewer systems. The law aims to promote water conservation through regulated reuse, applying to new multifamily projects and private residential systems meeting specific flow and safety standards.