Paul Wheaton and Kelly Ware read Art Ludwig's "Create an Oasis with Greywater." It is the world's most popular greywater book. Paul mentions the Wheaton Eco Scale, and how Art Ludwig is at Level 9. The book describes "how to choose, build, and use 20 types of residential greywater systems" in different contexts (urban to village). It explains how to put one together in an afternoon for under $40. The book shares how as a teenager, Art moved into the tackroom at his parents' house, with only a garden faucet. Art writes that every home should be surrounded by an oasis to thrive off the outgoing water and nutrients of the home. Paul talks about getting around having a septic system, and he and Kelly talk about the details of having one (such as the importance of not killing the bacteria in them with antibacterial soap or bleach if you don't want to have to empty them). Kelly talks about the legality of rainwater and greywater systems.
Creating an Oasis is the #1 landscaping book, and the #2 plumbing book (#1 is Art's other book: Water Storage). The bacteria in soil convert the greywater to water soluble plant food and the plants eat it to clean the water. Greywater is any wastewater generated in the home except from toilets (which is called blackwater) Paul likes the idea of keeping the organic material that goes into blackwater on his own land as well, and knows that cottonwoods and poplars love poop. Those trees the most composting and nutrient rich to use in a hugelkultur bed later. He is very cautious about contamination though, and likes how Art encourages people to use microscopes and measure the cleanliness of what they are doing. Paul is upset that his power bill is paying for coupons to pay for fluorescent lightbulbs. Paul lists off why to use greywater: reduced use of freshwater, less septic tank/treatement plant strain, more effective purification, feasibility for sites unsuitable for a septic tank, reduced use of energy and chemicals, groundwater recharge, plant growth, reclamation of nutrients, and an increased awareness of and sensitivity to natural cycles. Kelly shares about the "sunny john" and she and Paul talk about different outhouse designs.
Paul lists off when not to use greywater: insufficient space, inaccessible drainpipes, unsuitable soil/climate, legality concerns/permit hassles, poor cost-to-benefit ratio, lowered return flows, insufficient combined wastewater flow, inappropriate development, and health concerns (although greywater is incredible safe). Apparently, 7% of U.S. households re-use greywater. There is more information at oasisdesign.net.