ATLANTIC RBCA (Risk-Based Corrective Action) …

1 ATLANTIC RBCA (Risk- based Corrective action ) for Petroleum Impacted Sites in ATLANTIC Canada Version 3 User Guidance July 2012 ATLANTIC RBCA v 3 User Guidance updated July 2012 page i Notice to Document Users Considerable care has been exercised in preparing this publication. However, no party, including without limitation, ATLANTIC PIRI or its individual members, makes any representation or warranty regarding the accuracy, correctness, or completeness of the information contained herein, and no such party shall be liable for any direct, indirect, consequential, or incidental or other damages resulting from the use of this publication or the information contained herein. Information in this publication is subject to change without notice. ATLANTIC PIRI or its individual members, disclaims any responsibility or obligation to update the information contained herein.

2 Please refer to the ATLANTIC RBCA website for the most current version of this and supporting documents. Note: The blue text in this document indicates a link to another location within the document or to a website. ATLANTIC RBCA v 3 User Guidance updated July 2012 page ii Table of Contents INTRODUCTION .. 1 BACKGROUND .. 1 PURPOSE .. 2 SUPPORTING DOCUMENTATION .. 3 USE OF CANADA WIDE STANDARDS .. 6 PUBLIC SAFETY AND ENVIRONMENTAL EMERGENCIES INVOLVING PETROLEUM HYDROCARBON SPILLS .. 6 SITE CHARACTERIZATION .. 7 PROBLEM FORMULATION .. 7 DETAILED DATA COLLECTION .. 8 Environmental Site Assessment .. 8 Laboratory Reporting and Interpretation .. 8 Free Product Assessment .. 10 ECOLOGICAL SCREENING .. 11 REMEDIAL OPTIONS THE TIERED APPROACH .. 13 OVERVIEW .. 13 TOOL KIT PARAMETERS .. 15 TIER I RISK- based SCREENING LEVELS .. 15 Tier I Default Assumptions.

3 15 Mandatory Requirements at Tier I .. 16 Selecting Receptors .. 17 Selecting Groundwater Use .. 17 Selecting Soil Type .. 17 Modified TPH Interpretation .. 17 Modified TPH Guidelines .. 18 Consideration of Impacts Against Foundation Walls - Tier I .. 19 Soil Guidelines for the Protection of Potable Groundwater - Tier I .. 19 TIER II - SITE-SPECIFIC RISK ASSESSMENT .. 20 Pathway Specific Screening Levels (PSSLs) .. 20 Mandatory Requirements at Tier II .. 21 Developing Site-Specific Target Levels .. 21 SSTLs for Direct Soil Contact Exposures .. 21 Consideration of Impacts Against Foundation Walls - Tier II .. 22 Soil Guidelines for the Protection of Potable Groundwater - Tier II .. 22 TIER III SITE-SPECIFIC RISK ASSESSMENT .. 22 Guidance for Non-Petroleum Hydrocarbon Compounds .. 23 Soil Vapour Monitoring and Indoor Air Assessments .. 25 LIMITED REMEDIAL action .. 26 THE ATLANTIC RBCA VERSION 3 TOOL KIT.

4 27 SENSITIVE INPUT PARAMETERS .. 27 ATLANTIC RBCA v 3 User Guidance updated July 2012 page iii REPRESENTATIVE HYDROCARBON CONCENTRATIONS .. 29 CONSIDERATION OF HYDROCARBONS >C32 .. 30 ATLANTIC RBCA TOOL KIT LIMITATIONS .. 30 Earthen Floors .. 30 Inhalation Pathway - Heavy Hydrocarbon Fractions .. 30 Groundwater Transport Model .. 30 ADJUSTMENT FACTOR FOR THE INDOOR AIR PATHWAY .. 31 CUMULATIVE RISK .. 31 CONTROLS .. 32 REPORTING .. 32 List of Tables Table 1 Summary of Changes in RBCA Version 3 .. 4 Table 2 Comparison of PHC Analytical Methods .. 9 Table 3 Distribution of Carbon Fractions in Fresh Hydrocarbon Mixtures .. 18 Table 4a Tier I Risk based Screening Levels for Soil (mg/kg) .. Appendix 3 Table 4b Tier I Risk based Screening Levels for Groundwater (mg/L) .. Appendix 3 Table 5a Tier II Pathway Specific Screening Levels for Soil (mg/kg) .. Appendix 4 Table 5b Tier II Pathway Specific Screening Levels for Groundwater (mg/L).

5 Appendix 5 Table 6 Fresh Product Hydrocarbon Fraction Ratios .. Appendix 5 Table 7 ATLANTIC RBCA Default Exposure Factors and Target risks .. Appendix 5 Table 8 ATLANTIC RBCA Default Model Parameters .. Appendix 5 Table 9 Active Pathways Used in Calculation of Tier II PSSLs Ratios .. Appendix 5 List of Appendices Appendix 1 Best Management Practices for Environmental Assessment of Petroleum Impacted Sites In ATLANTIC Canada Appendix 2 Ecological Screening Protocol Appendix 3 ATLANTIC Canada Tier I Risk- based Screening Level Table Appendix 4 ATLANTIC Canada Tier II Pathway-Specific Screening Level Table Appendix 5 ATLANTIC RBCA Version 3 - Default Parameters Appendix 6 Site Assessment & Tier I/II Checklist Appendix 7 Site Closure Checklist Appendix 8 Acronyms and Definitions ATLANTIC RBCA v 3 User Guidance updated July 2012 page 1 INTRODUCTION BACKGROUND Risk- based Corrective action (known as RBCA or Rebecca ) has been used as the process for the development of Tier I and Tier II petroleum hydrocarbon assessment/remediation standards in ATLANTIC Canada since 1999.

6 ATLANTIC RBCA is a process developed to consider typical site conditions in ATLANTIC Canada for four common land uses (agricultural1, residential, commercial and industrial1). The ATLANTIC RBCA process is supported by two main components: 1) the regulatory endorsed philosophy of risk assessment, risk management and a tiered approach to remediation; and 2) a technical tool kit (composed of a software model, supporting technical guidance and applicable provincial legislation, regulations, and policy guidance). A Memorandum of Understanding (MOU) signed by the four ATLANTIC Deputy Ministers of Environment (originally in 1996 and most recently renewed in 2008) provides the mandate for a multi-stakeholder group, the ATLANTIC Partnership in RBCA Implementation (PIRI) to develop and promote the ATLANTIC RBCA process. ATLANTIC PIRI developed and released Version 1 of the ATLANTIC RBCA process, User Guidance and the RBCA Tool Kit for ATLANTIC Canada (referred to hereafter as the ATLANTIC RBCA Tool Kit) in 1999.

7 Version 1 of the ATLANTIC RBCA Tool Kit was based on the ASTM Standard E 1739-95, Standard Guide for Risk- based Corrective action Applied at Petroleum Release Sites. ATLANTIC RBCA was revised in 2003 to reflect changes recommended for harmonization with Canada Wide Standards for Petroleum Hydrocarbons (CWS PHC) developed by the Canadian Council of Ministers of the Environment (CCME) in 2001. ATLANTIC RBCA Version was subsequently updated to reflect the ASTM Standard E2081-00 and continues to be based on the carbon fractionation data published by the US TPH Criteria Working Group. (The model used to develop the updated ATLANTIC RBCA Tool Kit is marketed in the United States as the RBCA Tool Kit for Chemical Releases). The 2003 Tier I Risk- based Screening Levels (RBSLs) were developed using the ATLANTIC RBCA Tool Kit Version to facilitate assessment and planning for sites which meet specified default conditions.

8 The ATLANTIC RBCA Tool Kit also supports site-specific (Tier II) risk assessment and remediation planning and the software toolkit includes effective tools for more detailed Tier III assessments, if required. The entire ATLANTIC PIRI process is based on a philosophy of continuous improvement and defendable scientific knowledge. In January 2008, CCME completed their five year review of the CWS PHC for soil. Where each of the ATLANTIC Environment Ministers had signed the CCME Harmonization Agreements respecting environmental standards, they are each bound to ensure an equivalent level of environmental protection with CCME standards. As a result, ATLANTIC PIRI conducted an internal review of the 2008 CWS-PHC and supporting documents and recommended several changes to ATLANTIC RBCA Version The changes incorporated into ATLANTIC RBCA Version 3 primarily reflect a number of default modeling parameter values revised in the 2008 CWS PHC report.

9 1 Agricultural and Industrial Land Uses have been added in ATLANTIC RBCA Version 3. Descriptions of all four land uses provided in Section ATLANTIC RBCA v 3 User Guidance updated July 2012 page 2 ATLANTIC PIRI subsequently commissioned Groundwater Services Inc. (GSI) to complete the required changes to the ATLANTIC RBCA Tool Kit. The result is the revised ATLANTIC RBCA (Version 3) software Tool Kit for ATLANTIC Canada, this updated User Guidance document, and supporting documentation (Appendices 1-8). Provincial regulators may also update their policies and guidelines as required to support these changes. Revised Tier I Risk- based Screening Level (RBSL) Tables and Tier II Pathway-Specific Screening Level (PSSL) Tables have also been developed by ATLANTIC PIRI using the ATLANTIC RBCA Tool Kit Version 3.

10 Consistent with previous versions, upper concentration limits are included in the table for the purposes of practical limits for delineation at Tier I. The supporting documentation for this User Guidance Document (Appendices 1-8) may be updated from time to time. ATLANTIC RBCA users are advised to confirm on a regular basis that they are using the most recent version by checking and subscribing to the ATLANTIC RBCA website Version 3 of the ATLANTIC RBCA Toolkit also contains revisions to support future considerations for risk assessment of selected chlorinated volatile organic compounds which will expand the application of ATLANTIC RBCA. While these features are not currently approved for general use by Provincial regulators, supporting technical guidance is currently being developed and endorsement is anticipated. PURPOSE The purpose of this document is to provide assistance to the users of Version 3 of the ATLANTIC RBCA Tier I RBSL Tables, the ATLANTIC RBCA Tier II PSSL Tables and the ATLANTIC RBCA Tool Kit when assessing environmental risk, preparing and implementing a Remedial action Plan (RAP) and seeking regulatory site closure for petroleum hydrocarbon impacted sites.