What qualities are present in an endeavor that is sustainable?

A sustainable endeavor is one that allows future generations to carry it on at the same level of productivity that we do at present. Whatever natural capital is required will remain equally available in the future as it is now. The environmental effects of the enterprise will not damage, degrade, or deplete the systems with which it interfaces. Materials and energy will be used efficiently, wastes will be minimal and nontoxic, and the ecological footprint of the enterprise will remain unchanged or may diminish as better technology becomes available.