Cambridge tests show greywater systems work

A commercial development in Cambridge is testing greywater systems at scale, showing how buildings can reduce strain on municipal water and sewer infrastructure.

The 585 Kendall Square project uses a system that collects rainfall within the building’s footprint and repurposes it for non-potable uses like flushing toilets, irrigating landscaping, and cooling equipment. The setup prevents stormwater from overwhelming sewer lines, a problem worsened by heavier rainfall linked to climate change.

State and local officials, including legislators and plumbing industry leaders, toured the site last week. The visit was organized by a coalition that includes UA Plumbers Local 12, the Greater Boston Plumbing Contractors Association, and the International Association of Plumbing and Mechanical Officials. Their aim is to promote policies that encourage water reuse statewide.

“As climate change brings bigger storms to our region, I support projects like this that conserve water and strengthen our sewer systems,” said Senator Sal DiDomenico. He noted that local plumbers have played a central role in advancing the technology.

The system was installed by a contractor, with proper separation of greywater from drinking water, clearly labeled pipes, and strict adherence to safety codes.

The Kendall Square project functions as a live demonstration. The building’s design intercepts stormwater before it reaches sewer lines, lowering the risk of overflows during heavy rain. Such methods may become more widespread as cities address aging infrastructure and erratic weather patterns.

Water reuse has existed for years, but scaling it in commercial settings has been difficult. The Cambridge effort proves it can work without major changes to building design or operations. Its success may hinge as much on policy changes as on technical execution.

Tour participants acknowledged the system isn’t a complete solution. It won’t replace the need for pipe and treatment plant upgrades, but it could ease pressure by cutting demand.

The project won’t resolve every challenge, but it offers a practical example. If the system meets expectations, it could guide similar developments in Massachusetts and elsewhere. For now, it stands as a rare climate adaptation effort moving from theory to practice.