The UN projects a global population of 11.2 billion by the year 2100. Concurrent with the population increase, NASA projects increased temperatures globally, with disproportionate impacts on tropical and polar regions. With no studies suggesting a slow in population migration rates into cities, aspects of urban planning, and the organization of individual living spaces, will inevitably determine the continued existence of urban centers. NANOFLOUR is designed for buildings with localized wastewater treatment and rainwater collection systems. NANOFLOUR functions to optimize greywater purification, by eliminating the energy needed in the process. Nanotechnology is embedded within finely milled white powder, and purifies water upon contact. After the purification cycle, NANOFLOUR will aggregate, and change color to indicate water safety levels. The clumped powder may then be removed and placed into compost to increase the speed of biodegradation. NANOFLOUR may be used within central building wastewater tanks, and among other water containment structures.