Welcome back. In our journey to create a system of total resource recovery, we have successfully turned every liquid and organic stream from the home into clean water, energy, and rich soil. Now we face the final, and most stubborn, category of household waste: the inorganic materials from the kitchen, primarily plastics, glass, and metals used in packaging.

Welcome back. We have successfully closed the water and nutrient loops from the bathroom, turning human waste into clean water, energy, and fertilizer. Now, we turn our attention to the heart of the home: the kitchen. Every meal prepared generates organic "waste"—vegetable peels, coffee grounds, eggshells, and leftovers. In a linear world, this is trash destined for a landfill, where it rots and produces potent greenhouse gases. In our city, it is a valuable stream of energy and nutrients.

Welcome back. In our last article, we tackled the most challenging household waste stream: blackwater. By separating and processing it at the source, we turned a liability into fertilizer and energy. But what about the rest of the water? The water from our showers, sinks, and laundry, known as greywater, accounts for 60-75% of total household water use. To treat this slightly-soiled water with the same energy-intensive process as blackwater is an immense waste.

In our closed-loop city, we see greywater not as waste, but as a readily available resource. The key is to treat it intelligently, locally, and biologically.