Hydrogeology of the Hanford Site in South-Central Washington State

The Hanford Site is situated within the Pasco Basin of south-central Washington and occupies an area of approximately 1450 Km² (Figure 1). The Pasco Basin is one of a number of topographic depressions located within the Columbia Plateau Physiographic Province (Figure 2), a broad basin located between the Cascade Range and the Rocky Mountains. The Columbia River flows through the northern edge of the Site and forms part of the eastern boundary. Activities over the past 45 years at the Hanford Site include the siting of nuclear reactors, characterization activities for the Basalt Waste Isolation Project (BWIP), and waste management activities. The purpose of this paper is to discuss the hydrogeology of the Hanford Site and the general extent of contamination due to past activities at the Site.