Rain Water catchment systems:
Portland receives an average of 36 inches of rain/year. Each of the 4 homes has a 400 sq. ft footprint, and the rain it captures gives it inhabitants around 12 gal/day/person. It requires a total of 16,000 gallon tank or four, 4,000 gallon tank for rainwater storage. To meet the water use conditions, there are several ideas that have been suggested, including recycling showers, foot pumped water flow to sinks, no flow (composting) toilets, etc.
Gray Water Systems
Gray water is planned to be used for watering gardens. This means that this water will need to be kept for several months for the summer months where little rain falls. 24,000 gallons need to be stored to meet the irrigation needs. This can be done in four 6,000 gal tanks. Both tanks can fit in a basement, with additional room for compost collection. There is a suggestion to use silver nano impregnated cloth to kill bacteria and sterilize water-promising, but needs further investigation. Alternative approaches to meet DEQ’s new Gray Water codes would be the use of filtering systems. Care needs to be used in all filtering/sanitizing systems in order to fall within the power available to sanitize potable water without chemicals.
Black and Yellow water systems
Waste composting urine separation systems and nutrient recovery systems. Composting toilets and urine diversion systems are used to turn human wastes into viable plant fertilizers and soil amendments.