We first met the folks at Sanima (formerly, x-runner) at the end of 2016. In the vast informal settlements around the mega-city, Lima, Peru, there is no water and sanitation infrastructure. Sanima provides solid waste disposal to these communities and as part of an EPA student grant invited us to help them develop a solution for liquid waste, greywater, and urine.

Because there is no water infrastructure, all household water needs to be delivered by truck, and all greywater and urine leaving the home runs directly into the environment untreated.

We believed that for this project to be successful we needed to design collaboratively with community members. With the help of Sanima, we hosted a number of codesign workshops with local community members to better understand their history, their current needs, and their dreams and aspirations for the future.

Throughout this process we heard a narrative of self-reliance, resilience, and community pride. And we heard an overwhelming preference for green space and vegetation. Potted plants populated the door steps of anyone that could afford them. In a city that gets only 6mm of rain each year, a little green goes a long way.

As we were exploring the use of plants to treat greywater and urine before it entered the environment, local community members understood the potential of the system and asked if we could design it so that it could treat household wastewater for reuse in their homes, so that we were not simply treating and discarding precious water, but actually recycling it.

Combining concepts from constructed wetlands, hydroponics, and biosand filters, we used modular containerized gardens that function as customizable public green space while filtering wastewater for reuse in bathing, laundry, and dishwashing.

This living, plant-based system would provide multiple social, environmental, and economic impacts when scaled throughout a community. Access to green space improves physical and mental health — reducing rates of allergies, asthma, and depression while improving recovery from illness and stress. Access to green space has even been shown to reduce crime. Furthermore, the plants and green spaces provide habitat and much needed shade. And the food, building materials, and other plant-based materials that can be grown in the system can be used by families or sold to provide extra income.

The modular aspect of our system was also important, allowing it to fit into irregularly shaped and leftover fragments of open space, which in Lima, we tended to find along stairwells.

We had an elegant, multiple-impact solution. We had an excited and engaged community ready to implement it. But before we were able to finish the project in Lima, COVID hit. We were forced to evacuate and put the project on hold. Now, with two years of NSF-funded R&D behind us, we are ready to get back to Peru.