Standard Guide for Developing Representative Background Concentrations at Sediment Sites—Data Evaluation and Development Methodologies

Importancia y uso:

4.1 Intended Use: 

4.1.1 This guide may be used by various parties involved in sediment corrective action programs, including regulatory agencies, project sponsors, environmental consultants, toxicologists, risk assessors, site remediation professionals, environmental contractors, and other stakeholders.

4.2 Importance of the CSM: 

4.2.1 The CSM should be updated as needed and refined to describe the physical properties, chemical composition and occurrence, biologic features, and environmental conditions of the sediment corrective action project (Guide E1689).

4.3 Reference Material: 

4.3.1 This guide should be used in conjunction with other ASTM guides listed in 2.1 (especially Guides E3344 and E3382); this guide should also be used in conjunction with the material in the References at the end of this guide (including (1)). Utilizing these reference materials will direct the user in developing representative background concentrations for sediment at a sediment site.

4.4 Flexible Site-Specific Implementation: 

4.4.1 This guide provides a systematic, but flexible, framework to accommodate variations in approaches by regulatory agencies and by the user based on project objectives, site complexity, unique site features, regulatory requirements, newly developed guidance, newly published scientific research, changes in regulatory criteria, advances in scientific knowledge and technical capability, and unforeseen circumstances.

4.5 Regulatory Frameworks: 

4.5.1 This guide is intended to be applicable to a broad range of local, state, tribal, federal, or international jurisdictions, each with its own unique regulatory framework. As such, this guide does not provide a detailed discussion of the requirements or guidance associated with any of these regulatory frameworks, nor is it intended to supplant applicable regulations and guidance. The user of this guide will need to be aware of the regulatory requirements and guidance in the jurisdiction where the work is being performed.

4.6 Systematic Project Planning and Scoping Process: 

4.6.1 When applying this guide, the user should undertake a systematic project planning and scoping process to collect information to assist in making site-specific, user-defined decisions for a particular project, including assembling an experienced team of project professionals. These practitioners should have the appropriate expertise to scope, plan, and execute a sediment data acquisition and analysis program. This team may include, but is not limited to, project sponsors, environmental consultants, toxicologists, site remediation professionals, analytical chemists, geochemists, and statisticians.

4.7 Use of Representative Background Concentrations for Sediment to Set a Boundary: 

4.7.1 Representative background concentrations for sediments can be used to delineate a sediment corrective action, establishing the boundary of the sediment corrective action area by distinguishing site-related impacts from representative background concentrations for sediment. This application requires the development of a BTV for the representative background data set.

4.8 Use of Representative Background Concentrations for Sediment to Establish Cleanup Levels: 

4.8.1 Representative background concentrations for sediments can be used to establish cleanup levels for use in sediment corrective actions. In cases where risk-based sediment cleanup levels are below representative background concentrations for sediment, background concentrations are typically used as the cleanup level (3). This ensures that the cleanup levels are sustainable. Any recontamination from ongoing sources will eventually result in surface sediment concentrations greater than the risk-based cleanup level, but the surface sediment should still meet a cleanup level based on representative background concentrations for sediment, even following recontamination.

4.9 Use of Representative Background Concentrations for Sediment in Risk Assessments: 

4.9.1 Representative background concentrations for sediment can be used in the risk assessment process (including human and ecological risk assessments) to understand risks posed by background levels of contaminants to human health and the environment, and the incremental risks posed by site-related releases or activities (or both) that result in sediment concentrations that exceed representative background concentrations for sediment. Conversely, they can be used to estimate the risk reduction for various contaminants, if sediment is remediated from existing COC concentrations to lower values (that is, the representative background concentrations for sediment).

4.10 Use of Representative Background Concentrations for Sediment in Post-Remedy Monitoring Programs: 

4.10.1 Post-remedy monitoring programs can also use representative background concentrations for sediment either as a corrective action target or to understand how post-remedy concentrations for sediment compare to the sources not attributable to current or historical site-related releases or activities. Typically, source control actions taken to ensure that site-related releases are controlled and will not recontaminate the post-corrective action sediments must be developed based on an understanding of ongoing contributions from representative background. Ongoing sources unrelated to current or historical site-related releases or activities (that may or may not be subject to source control actions) must be considered in this evaluation.

4.11 Other Considerations: 

4.11.1 This guide does not cover all components of a program to develop representative background concentrations for sediment. It is meant to be used in conjunction with other guides (such as Guides E3163, E3164, E3240, E3344, and E3382) to do so.

4.11.2 The overarching process to develop representative background concentrations for sediment (including CSM considerations) is not covered in detail in this guide but is discussed in more depth in Guide E3382.

4.11.3 The selection of a background reference area(s) for the sediment site is not covered in detail in this guide but is extensively described in Guide E3344.

4.11.4 Sediment sampling and laboratory analyses are not covered in this guide. Guides E3163 and E3164 contain extensive information concerning sediment sampling and laboratory analyses.

4.11.5 Data quality objectives are not covered in this guide. Data quality objectives are described in (4).

4.11.6 Background study design considerations are not covered in this guide but are described in other references, including Guides E3163 and E3164, as well as (5, 6).

4.11.7 Geospatial analysis considerations are not thoroughly discussed in this guidance but are discussed in more depth relative to environmental evaluations in (7), which focuses on quality assurance concerns relative to geospatial analyses.

4.11.8 In this guide, “sediment” (3.1.19) is defined as a matrix being found at the bottom of a water body. Upland soils of sedimentary origin are excluded from consideration as sediment in this guide.

4.11.9 In this guide, only the concentrations of COCs are considered to be in scope. Residual background radioactivity is out of scope.

4.12 Structure and Components of This Guide: 

4.12.1 The user of this guide should review the overall structure and components of this guide before proceeding with use, including:

Section 1

Scope

Section 2

Referenced Documents

Section 3

Terminology

Section 4

Significance and Use

Section 5

Overview of Representative Background Concentration for Sediment Development Framework

Section 6

Development of Candidate Background Data Sets

Section 7

Evaluation of Candidate Background Data Sets to Obtain Representative Background Data Sets—Summary

Section 8

Visualization of Candidate Background Data Sets

Section 9

Evaluation of High Nondetect Data Points

Section 10

Evaluation of Outlying Data Points

Section 11

Forensic Chemistry Evaluation of Organic Contaminants

Section 12

Geochemical Evaluation of Trace Elements

Section 13

Methodology Application to Develop a Representative Background Data Set from a Candidate Background Data Set

Section 14

Development of Representative Background Concentrations for Sediment

Section 15

Comparison of Sediment Site and Representative Background Data Sets Using Statistical Two-Sample Testing

Section 16

Keywords

Appendix X1

Organic and Inorganic Chemistry Overview

Appendix X2

Illustrative Case Studies from One Example Sediment Site

Appendix X3

Summaries for Outlier Testing and Two-Sample Statistical Testing

References

 

Subcomité:

E50.04

Referida por:

E2020-22, E2081-22, E3382-24, E2205_E2205M-22, E3344-24, E3447-24, E3163-24, E3164-23

Volúmen:

11.05

Número ICS:

13.020.30 (Environmental impact assessment), 13.080.99 (Other standards related to soil quality)

Palabras clave:

anthropogenic background; background; geochemical evaluation; geochemistry; natural background; outliers; representative; sediment; statistics;