OVERVIEW:

To achieve an enclosed, regenerating life-support system, the Biospherians have had to recycle all human and animal wastes, maintain a healthy atmosphere, and retain and recycle salt and fresh water ecosystems as well as utility, rain, and potable water systems.

For a system to be self-sustaining over the 100-year period for which Biosphere was designed, it must retain and reuse every bit of nutrient that was in its soil and water on day one. In this sense, there are virtually no wastes inside Biosphere 2. Wastes become resources, as the end product of one system becomes a nutrient that feeds another system. Managing this process - moving nutrients around Biosphere's closed system - is challenging, because nutrients must be in the right place, in the right quantity, at the right time.

For two years, the Biosphere crew has recycled 100 percent of its wastes - something that has never before been achieved by inhabitants of a closed system.

Biosphere 2 uses a waste treatment system that puts ecology and biology to work, making use of aquatic plant and microbial activity. It shows the capacity of human-made wetlands to process waste products and isolate potential chemical pollutants.

Through this process, human wastes and domestic waste water have been re-introduced into a productive agricultural system.

A separate system condenses water from the atmosphere to supply drinking water. In addition, Biosphere 2 has a back-up sterilization system for potable water that uses ultraviolet light, and does not introduce chemicals into the water.

The marine salt water communities and fresh water streams and ponds have been maintained as separate recirculating ecosystems.

There has been no build-up of potentially harmful trace contaminants in the atmosphere.

"The same water that we brought with us in September 1991 is still with us two years later. This is an area in which Biosphere 2 can give something back to Earth. We don't have all the answers, but we can suggest ways to protect water from agricultural drain-off, or manage human waste so we're not dumping new chemicals into our water. "

Biospherian Gaie Alling

"The microbes (in the lagoon) not only clean up that water but also create a beautiful garden. We cut that garden and feed it to the animals. All of the left-over nutrients go back into our agriculture as milk, eggs and meat, and then go back through the system again as manure gets composted. "

Biospherian Mark Nelson