Alternative Mitigation of the Polk Tenant Site (7NC-F-111)Versar’s recent research into wells is telling us that they represent a very old and very conservative technology. The earliest wells that have been documented archaeologically are from Cyprus. These wells were dug about 10,000 years ago into hard, chalky sediment to reach deep, underground streams that flowed over bedrock. Early colonial period wells in parts of eastern North America such as Delaware were often shallow, tapping layers of water that were relatively close to the ground surface. Called aquifers, these layers were recharged by water directly from the contemporary ground surface and so were easily contaminated. Shallow wells with tainted water were often the source of fevers and more serious diseases. While the technology of wells is old, some aspects of their construction do not appear to have changed much. Wells in Eastern Germany dating to the Early Neolithic, about 7,500 years ago, contained some of the earliest recorded wooden architecture in the world in the form of notched and pegged wooden cribbing used to line the well shafts. Initial results of our survey of Delaware wells indicates that well shafts continued to be lined with wood—cribbing or sometimes barrels—while others used stone or brick. We are looking into patterns in the types of lining as well as geography, soil, and function.