Ecological Evaluation Technical Guidance - State of New Jersey

N.J.A.C. 7:26E-4.8(c)1. The ERA may require the sampling of environmentaland biological media to underpin this evaluation.In addition, salinity regimes are dynamic in estuaries such that both freshwaterand marine species may be collocated in areas where potential exposure toCOPECs may occur. COPEC fate, transport, and toxicity may also be affected bythe salinity and need to be taken into consideration. Biological surveys may beneeded in those areas to provide more site-specific information on the variety ofecological receptors that may require more focused evaluation in the ERA.Ecological receptors in the estuary potentially exposed to COPECs includemigratory waterfowl and fish (freshwater and marine), benthicmacroinvertebrates, and submerged and emergent vegetation in the near-shoreareas. Salinity measurements should be taken to determine the appropriate ESCto apply and appropriate species to be used for toxicity testing. Given thatestuaries provide nursery and refugia, it may be appropriate to consider early lifestagetoxicity testing (ASTM, 2005b). Approaches to sampling these groups havebeen provided previously (Section 5.3.3.2).6.4.3 Urban AreasWhile ERAs can be conducted in urban areas, the increased anthropogenicdisturbance, some of which may be hundreds of years old, places special burdenson the process. The investigator is advised to place special focus on the problemformulation stage and in the selection of assessment and measurement endpoints.Of particular importance will be the selection of appropriate background arealocations as the potential ability to distinguish between site-related impactsassociated with a release, and the simple physical impacts from extended periodsof development.6.4.4 Hot SpotsHot spots are well-defined parts of a site or ESNRs where contaminant levels aresubstantially elevated above ESC or background contaminant levels in a highpercentage of the samples. The identification of hot spots will include theapplication of professional judgment. The area where the high frequency ofexceedances occurs may be relatively small (e.g., several square yards) or large(e.g., an acre or two), and found within the ESNR. Hot spots generally aredefined by (1) the frequency of detection above ESC or background contaminantlevels is elevated compared to surrounding site samples (e.g., 75%), and (2) themagnitude of the exceedance is substantial (e.g., more than 10 times the ESC orbackground contaminant levels). Where T&E species are present, a lowermultiplier should be considered. Statistical approaches (e.g., USEPA 2006a) thatidentify outliers at the upper tail of the data distribution can also be used toindicate localized source areas.Professional judgment will be needed in most cases to help determine whether ahot spot exists. Once identified, hot spots may be managed in a combination ofways, but typically through one of several actions: (1) collecting of morechemical or biological data to reduce uncertainty; (2) moving the areas forwardEcological Evaluation Technical Guidance Document 72Version 1.2 8/29/12