Ecological Evaluation Technical Guidance - State of New Jersey

specific measurements of receptor health, population indices, measurement ofexposure, or direct measures of ecotoxicological effects. Exposure measures the existence and movement of stressors in theenvironment and their co-occurrence with the assessment endpoints or itssurrogate such as chemical-specific concentrations in abiotic and bioticmedia that are directly based on media or on food intake.Effects measure changes in an attribute of an assessment endpoint or itssurrogate in response to a stressor to which it is exposed, such as directtoxicity.Ecosystem and receptor characteristics measure variables that influencethe behavior, life history, and distribution of populations or individuals ina community that may be adversely affected by contaminant exposure.Examples of measurable variables include population density, changes inspecies composition over time, or change in relative biomass.The tools used to evaluate the measurement endpoints are as varied as themedia present at an individual site and can include such activities as chemicalsampling, toxicity tests, bioaccumulation studies, biological inventories, andhabitat assessments. The determination of adverse ecological impacts isusually dependent on the comparison of the results of these measurements toeither baseline or reference conditions and comparison to known benchmarkconditions established as safe levels. Examples of Assessment andcorresponding Measurement Endpoints are presented in Table 6-1.6.1.1.2 Ecological Conceptual Site ModelAn ecological conceptual site model (ECSM) organizes the informationknown about a site into a clear overview that can be used to identify data gapsand needs, remedial strategies, and source control needs. The model can helpin developing decision criteria. Information that should be included in theECSM includes (1) how site-related COPECs enter a system, (2) howCOPECs move in that system (including fate and partitioning), and (3) themechanisms for exposure and uptake in ecological receptors.The model can be simple to very complex depending on the depth of existingknowledge about the site and the complexity of the ecological question beingasked. Often the ECSM evolves as the investigation proceeds from the EEthrough the ERA. At the EE stage of the process the ECSM provides anoverview of contaminated media, pathways, and exposure scenarios based onreasonable assumptions and uncertainties. In the ERA stage, this ECSM maybecome more refined as additional site-specific data are compiled and the siteis better understood.The ECSM is generally graphic, usually in the form of either a chart or othergraphic, but it can also be merely descriptive. Graphic ECSMs should besupported by a brief and concise text component. Two examples of ECSMsthat can be used to support the EE documentation are shown below (Figures6.1 and 6.2). The ECSM should be incorporated into the development of anEcological Evaluation Technical Guidance Document 34Version 1.2 8/29/12