Ecological Evaluation Technical Guidance - State of New Jersey

esults are then evaluated using USEPA’s hydrocarbon narcosis model (USEPA, 2003).It has been documented that the ability of the SPME method to predict toxicity correlatewell with toxicity observed with standard sediment toxicity tests. This technique wasmore reliable at predicting PAH impacts than were those found through the use of bulkPAH concentrations and Equilibrium Partitioning (EqP) to estimate pore waterconcentrations (Moles et al., 2006; Hawthorne et al., 2007). The method recentlybecame standardized (USEPA SW-846 Method 8272/ASTM provisional standardD7363-07) and incorporated into USEPA’s document titled Evaluating Ecological Riskto Invertebrate Receptors from PAHs in Sediments at Hazardous Waste Sites (2009d).http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=214715• Polyethylene (PE) and polyoxymethylene (POM) samplers: These samplers are similarto SPMEs in their ability to sorb organic compounds from sediments. A principaladvantage of using these samplers is their ability to come into equilibrium faster thanSPMEs. Recent work has shown that uptake of PAH and PCBs by PE and POMsamplers correlate with benthic organism uptake (Tomasaewski and Luthy, 2008).Centrifugation:Centrifugation is another method used for the collection of pore water samples. Thismethod involves placing bulk sediments in a large-capacity centrifuge (e.g., a bucket-stylecentrifuge with one liter capacity per sample) and centrifuging them at low speed (e.g.,7,400 x gravitational force) for 15 to 30 minutes (ASTM, 2000; Environment Canada,1994). In some cases, subsequent high-speed centrifugation (e.g., 10,000 x gravitationalforce) may be necessary or desirable, particularly if the selected test species have lowtolerance to suspended particles. Centrifugation requires the collection of a large volumeof sediment to extract a sufficient amount of pore water suitable for analysis, oftencontributing to elevated method detection limits (MDLs).Additional Pore Water Sampling Devices:One additional pore water sampling device that is unique in that it measures threeparameters is the US Navy’s Trident probe. The Trident probe is a flexible, multi-sensor,water-sampling probe for screening and mapping groundwater plumes at the surface waterinterface. The probe has the ability to measure conductivity, temperature, and pore water,and is well-suited for spatially identifying where groundwater is discharging to surfacewater. Once the groundwater and surface water discharge is located, pore water samplescan be collected to chemically characterize the contamination.http://meso.spawar.navy.mil/Capabilities/Trident/index.htmlEcological Evaluation Technical Guidance Document 118Version 1.2 8/29/12