Freestone provided field and documentation support to Mission Support Alliance (MSA) during an inventory of underground injection control (UIC) wells across the Hanford Site in southeast Washington State. MSA is a Department of Energy prime contractor and is responsible for Hanford Site contractor integration, Hanford Site Wide permits, and infrastructure management. Hundreds of class V UIC wells were constructed during the construction and operation of the Hanford Site. The Washington State Department of Ecology defines a UIC well as a subsurface fluid distribution system designed to discharge fluids into the ground. A UIC well may consists of an assemblage of perforated pipes, drain tiles (or similar mechanisms), or a dug hole that is deeper than the largest surface dimension (WAC 173-218-030). Subsurface infiltration systems include drywells, pipe or French drains, drain fields, and other similar devices that are used to discharge stormwater directly into the ground.

Freestone reviewed historical records and recent inventory efforts to develop a comprehensive database of UIC wells on the Hanford Site. Freestone staff performed multiple field walk downs to assess the status of UIC wells discovered in historical records and updated records as appropriate. Staff coordinated with other Hanford Site prime contractors to collect information related to UIC well removal and closure and developed a GIS database and map package to assist other contractors in their inventory efforts. Finally, Freestone staff assisted MSA personnel with updating the Washington State Department of Ecology UIC well registration information for the Hanford Site.