Table 1a and Table 1b lists the SQGs that were applied and those used to develop them. The DaS program contains four LAL values, for Cd, Hg, tPAH and tPCB (CEPA, 1999). For other contaminants of interest, the DaS program may look to the CCME Interim Sediment Quality Guideline (ISQG) list (CCME, Epacadostat molecular weight 2002), and then to SQGs from other jurisdictions. The metal values in the ISQG list are based upon the threshold effects levels (TELs) and probable effects levels (PELs) from MacDonald et al. (1996), but

without the inclusion of Ni for which no ISQG was available. As many other dredging programs include Ni in their lists, the TEL and PEL values, including Ni, are also applied in test protocols. However, the DaS and ISQG lists do not address all of the

other organics (e.g. pesticides, TBT) that were evaluated in this study and some of the ‘other’ organic SQG values used come from sources other than the GSK J4 molecular weight CCME. To compare sediment data to a full list of SQGs in this study, a range of dredging program LAL and UAL values (IMO, 2009), as well as non-dredging sediment threshold and probable effects values (Buchman, 2008), were collected (Table 1a and Table 1b). A “Consensus” set of LAL and UAL values was generated by calculating the geometric mean of all dredging LAL values for a given parameter. If no dredging values were available, or, if the only dredging-value was the CCME value (which is largely based on the non-dredging TEL and PEL values), then the geometric mean of the relevant non-dredging threshold or probable effects SQGs was used. It is not suggested that these values should be taken up as regulatory values. SQGs from different countries are developed based upon different sediment size fractions, and different analytical methods. As most (but not all) sediment contaminants tend to associate with the fine-grained Dichloromethane dehalogenase sediment fraction, these differences could result in different analytical results and pass/fail interpretations in various countries. However, it has been noted that overall sediment pass/fail outcomes using different SQG sets with the same narrative intent (e.g., LAL, UAL) do not differ

nearly as much as outcomes using different analyte sets and decision rules (Apitz et al., 2007, Apitz, 2008, Apitz, 2011 and Wenning et al., 2005). The “Consensus” LAL and UAL values developed for this paper provide a consistent set of hypothetical SQGs for the full suite of contaminants in this study. There are countless potential analyte and SQG lists that could be tested; in this paper we present a subset of plausible values to provide insight into how a range of choices affects potential regulatory outcomes. As various analyte and action level lists are selected by Environment Canada in future, the implications of these specific choices could be tested using the database. As noted above, the DaS PCB LAL is based upon aroclor, rather than congener values.