API Publ 4700-2001 pdf free download

API Publ 4700-2001 pdf free download.PRIMER FOR EVALUATING ECOLOGICAL
RISK AT PETROLEUM RELEASE SITES.
As indicated in Figure 2, the site investigator—in consultation with risk assessment experts—can proceed with further tiered investigations if relevant receptors and habitats are present and if there is potential for complete exposure pathways. There is some debate over what screening-level methods should be used in a Tier 1 Screening Analysis for the Tiered Ecological Assessment Process. One possibility is to compare chemical levels in the environmental media of concern to ecological benchmarks, which are intended to be used as screening- level tools, not as cleanup levels. One method or a combination of other qualitative or quantitative requirements may be used. These methods are available at the Federal or state level to compare local biological and environmental conditions and to consider exposed habitat areas for ecological assessments. ASTM (2000) uses the term “relevant ecological screening criteria” to refer to comparisons that may be made during a Tier 1 ecological risk assessment. Relevant ecological screening criteria are “generic, non– site-specific ecological criteria or guidelines that are determined to be applicable to relevant ecological receptors and habitats, exposure pathways, and site conditions utilized during the Tier 1 evaluation” (ASTM, 2000). Higher tiers typically use more site-specific and/or quantitative methods to evaluate ecological risk. These methods may include fate and transport modeling, biological studies, and toxicity measurements. Such information on exposure and effects can be organized into a weight-of- evidence approach. These more sophisticated techniques require trained personnel with experience in ecological risk assessment. Further, an assessment’s acceptability depends to some degree on the regulatory setting, and is most successful when regulators have been brought into the assessment at an early phase. These early discussions are an important part of problem formulation in the EPA framework (Figure 1).
Environmental management decisions are based on several factors, including the evaluation of ecological risk. To conduct an ecological risk assessment, a tiered approach may be used. The site investigator begins by characterizing the petroleum release site as well as the nature and extent of subsequent petroleum contamination. Then, relevant receptors/habitats at or near the site are identified. Next, the investigator must determine if there are actual or potential complete exposure pathways of receptors or habitats to the source of petroleum contamination. Finally, the investigator reports the preliminary evaluation results, including a site conceptual model, to guide further tiered investigation or to facilitate site management decisions. Upon completion of the preliminary evaluation, management decisions can be made, based on the collected information about ecological risk plus other regulatory, financial, and political considerations.
An explicit expression of the environmental value that is to be protected and is operationally defined by one or more attributes of an ecological component. An example of an assessment endpoint is sustainability of warm water fish species in Lake Z, typical of those found in other recreational lakes. In this example, the attribute is sustainability (e.g., growth, development, and reproduction), and the ecological component is warm water fish species in Lake Z. Benchmark An ecological benchmark in a specific medium is the contaminant concentration considered protective of specified receptors and habitats. Benchmark levels are considered to be protective exposure levels, not cleanup levels. BTEX Benzene, toluene, ethylbenzene, and isomers of xylene. Other than ethers/alcohols, these are among the most soluble constituents of petroleum products.