The typical American home uses 270,000 gallons of water per year - equal to about 5 swimming pools. Water costs about $1.50 for 1000 gallons, so the average annual expense is $405. Consider rain water cisterns for landscaping or greywater systems to save money. Greywater is wastewater from bathtub, shower drain, sinks, washing machines, and dishwashers that can be treated and recycled for irrigation, toilets, and exterior washing, resulting in water conservation and savings.
Small scale systems are just a few hundred dollars, but if you go with a larger system that has subsurface drip irrigation for your lawn. Cost goes up to $1,500-$5,000. A typical residential grey water system that will save $5-$20 worth of freshwater a month.
The ROI Calculation is based on the lower end of the cost range and the low end of the savings range. However, if you are on septic, the economics are more favorable since it takes partial load off of the septic tank.
For Greywater regulations in your State: Click Here
For a Directory by State of 'Green' Builders, Utility/Sponsors, and Lenders: Click Here