The collection of interstitial water has become increasingly important in sediment quality monitoring and remediation programs. Moreover, interstitial water sampling has become especially important in regulatory programs because interstitial water toxicity tests yield additional information not currently provided by solid-phase, elutriate (i.e., separated by washing), or sediment extract tests (Carr and Chapman, 1992; SETAC, 2001). Additionally, interstitial water toxicity tests have proved to be useful in sediment toxicity identification evaluation (TIE) studies (Burgess, 1996; Burton et al., 2003; Carr, 1998) as test procedures and sample manipulation techniques are generally less expensive, faster, and easier to conduct than solid-phase tests (SETAC, 2001). Sediment types ranging from sandy to uncompacted silt-clays are most suitable for interstitial water sampling (Sarda and Burton, 1995; SETAC, 2001). Such sampling is not typically performed on sediments with coarse particle size (such as gravel) or on hard, compacted clays, as the potential for interstitial water contamination in these sediment types is relatively low.