Since WW is continually coming into the plant, more microorganisms are growing. Therefore it is necessary to occasionally remove some from the plant. That "wasted" sludge is rich in organic matter. It is also rich in pathogens. One application, besides landfilling the sludge, is land application. Land application can serve several purposes: it can serve to rejuvenate land that has been stripped of nutrients and it can be used as fertilizer for fields. Advanced treated wastewater can also have novel uses.

Tallahassee Southeast Farm:
http://www.eog.state.fl.us/citytlh/utilities/water/farm.html
http://www.epa.gov/OW/you/agric.html
http://www.state.fl.us/citytlh/utilities/water/sewer.html




Sources (There are sssooo many, do I have to list all?):
Davis and Cornwell. 1991, McGraw-Hill Series in Water resources and Environmental Engineering, Second Edition, McGraw Hill, New York, NY.

Grady, C.P.L. Jr. 1999, "Biodegradation: The role of microbial physiology and kinetics", Proceedings of the Water Environment Federation 72nd Annual Conference and Exposition, Published on CD-ROM, WEF, Alexandria, VA.

Grady, C.P.L. Jr., Daigger, G.T., and Lim, H.C. 1999, Biological Wastewater Treatment, Second Edition, Marcel Dekker, Inc., New York, NY.