using recycled water is really not such a new idea .
iguess it's not widely aadvertised yet , but it certainly is being done .
"...Although most water recycling projects have been developed to meet nonpotable water demands, a number of projects use recycled water indirectly1 for potable purposes. These projects include recharging ground water aquifers and augmenting surface water reservoirs with recycled water. In ground water recharge projects, recycled water can be spread or injected into ground water aquifers to augment ground water supplies, and to prevent salt water intrusion in coastal areas. For example, since 1976, the Water Factory 21 Direct Injection Project, located in Orange County, California, has been injecting highly treated recycled water into the aquifer to prevent salt water intrusion, while augmenting the potable ground water supply..."
from :
...EPA - WATER RECYCLING...