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Resource Center for Risk-Based Methodologies

Risk Based Screening Level (RBSL) Spreadsheet for Upstream Sites Spreadsheet and User’s Guide

API Publication 4752
July 2008


Description
This spreadsheet simplifies calculations of Tier 1 and limited Tier 2 cleanup or action levels for compounds often  found at oil and gas exploration and production sites.

Based on the risk assessment methodologies developed by the U.S. EPA and the American Society of Testing and Materials (ASTM), the spreadsheet reflects the advances made by the Total Petroleum Hydrocarbons Criteria Working Group and the Petroleum Environmental Research Forum (PERF) Project 97-08.

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Risk-Based Methodologies for Evaluating Petroleum Hydrocarbon Impacts at Oil and Natural Gas E&P Sites
API Publication 4709

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File Size: 2.5 MB
Version Date: February 2001
License: Free

Ordering information for printed and bound copies
(Enter document number 4709 in form).
Description
"Risk-Based Methodologies for Evaluating Petroleum Hydrocarbon Impacts at Oil and Natural Gas E&P Sites" (API Publication 4709) explains the fundamentals of risk-based decision making in the context of today's E&P operations. The process of calculating human health risk-based screening levels for total petroleum hydrocarbons (TPH) is described in an easy-to-understand question and answer format. (Risk-based screening levels [RBSLs] are chemical-specific concentrations in environmental media that are considered protective of human health.)  Risk assessment concepts developed by EPA, and such research groups as the Petroleum Environmental Research Forum (PERF) and the Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG), are used to calculate RBSLs for TPH in crude oil and condensates obtained from around the world. These methodologies were also applied to polyaromatic hydrocarbons (PAHs), metals, and benzene in TPH.

Additional resources contained in this manual include a description of the physical and chemical characteristics of crude oil, condensate, and E&P wastes (contrasted with refined products), a summary of the federal regulatory status of E&P wastes, and a listing of key equations used for calculating RBSLs.

Risk-Based Decision-Making for Assessing Petroleum Impacts at Exploration and Production Sites.

Edited by McMillen, S.J., R.I. Magaw and R.L. Carovillano. Published by: US DOE, Tulsa, OK
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Description
This book presents the scientific background material necessary to support a risk-based decision-making (RBDM) approach for managing hydrocarbon-impacted soil at oil and natural gas industry exploration and production (E&P) sites. The general RBDM approach is largely based on guidance originally developed by the United States Environmental Protection Agency (USEPA). That framework was later refined by the American Society for Testing and Materials (ASTM) for evaluating individual chemicals and the Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG) and PERF for complex petroleum hydrocarbon mixtures. The information and approach described in this report have recently been used in the development of risk-based regulatory programs in several oil and natural gas producing states in the United States.

Detailed information about the composition of crude oils and gas condensates is summarized and the total petroleum hydrocarbon (TPH) fractions and individual chemicals of potential concern in these mixtures are identified. The fate, transport, and toxicity information necessary for estimating potential risks to human health is then described and used to generate risk-based screening levels (RBSLs) that can be used in a Tier 1, or screening level, risk evaluation. These RBSLs represent soil concentrations that are protective of human health and are calculated using exposure equations recognized by USEPA as providing conservative estimates (i.e., lower than necessary for the protection of human health) of acceptable concentrations in soil. The calculated Tier 1 RBSLs can be compared to regulatory criteria to determine whether the criteria are protective of human health, or in instances where there are no regulatory criteria, the RBSLs can be used as limiting concentrations for TPH or specific chemicals of concern in soil.

Table of Contents

Chapter 1 - An Overview of Risk-Based Decision-Making for Site Management

Chapter 2 - Technical Basis for Current Soil Management Levels of Total Petroleum Hydrocarbons

Chapter 3 - Composition of Crude Oils and Gas Condensates

Chapter 4 - Application of the Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG) Methodology to Crude Oils and Gas Condensates

Chapter 5 - Performance of TPHCWG Analytical Method for Crude Oils in Soils

Chapter 6 - Predicting the Fate and Transport of Hydrocarbons in Soil and Groundwater

Chapter 7 - Development of Reference Doses for Heavy Total Petroleum Hydrocarbon (TPH) Fractions

Chapter 8 - Developing Total Petroleum Hydrocarbon Risk-Based Screening Levels for Sites Impacted by Crude Oils and Gas Condensates

Chapter 9 - Hydrocarbon Transport From Oil and Soil to Groundwater

Chapter 10 - Risk-Based Soil Screening Levels for Crude Oil: The Role of Polyaromatic Hydrocarbons

Chapter 11 - An Evaluation of Benzene Risk

Chapter 12 - Risk Evaluation of Metals in Crude Oils

Chapter 13 - Application of Risk-Based Decision-Making for International Exploration and Production Site Management

Appendix - The Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG) Analytical Method: Characterization of C6 to C35 Petroleum Hydrocarbons in Environmental Samples.


Frequently Asked Questions About TPH Analytical Methods for Crude Oil

Trying to decide when to use a conventional total petroleum hydrocarbon (TPH) measure (e.g., Modified 418.1) or a fractionation method (such as the TPH Criteria Working Group Analytical Method) for analyzing crude oil or impacted soil?  “Frequently Asked Questions About TPH Analytical Methods for Crude Oil” answers these and other questions by explaining the use and limitations of the various available TPH approaches.

View/Download (Modified from API Publication 4709 September 2001)

Key References for Crude Oil TPH Fractionation Methods:


Texas Natural Resources Conservation Commission: Analytical Methods 1005 and 1006 for TPH Fractionation
Note: TX 1006 incorporates some of the recommendations from Douglas et al., 2001, such as using the wider bore fractionation column.

E&P Site Cleanup Levels Revisited: Opportunities for Risk-Based Decision Making

Presentations and Papers from the Sixth Annual International Petroleum Environmental Conference (IPEC).
November 16-18, 1999. Houston Texas.

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File Size: 45 MB
Version Date: November 1999
License: Free

(Scroll to page 456 to see the 4 papers noted below)
E&P Site Cleanup Levels Revisited: E&P Site Cleanup Levels Revisited: Opportunities for Risk-Based Decision Making
Technical Basis for Current Soil Management Levels of Total Petroleum Hydrocarbons
. George Deeley, Equilon Enterprises, LLC, Houston, TX; H. James Sewell and Wayne A. Hamilton, Shell Exploration & Production, Houston, TX;
A New Risk-Based Approach to Establish Cleanup Levels for TPH. Dave Nakles and Steve Geiger, ThermoReTec, Monroeville, PA; Sara McMillen, Chevron Research & Technology Company, Richmond, CA; Harley Hopkins, American Petroleum Institute, Washington, D.C.
A Risk Evaluation of Metals in Crude Oils. Renae Magaw, Sara McMillen, and William Gala, Chevron Research & Technology Co., Richmond, CA
Polyaromatic Hydrocarbon Content in Crude Oils Around the World. J.M. Kerr and H.R. Melton, Exxon Production Research Co., Houston, TX; S. J. McMillen and R.I. Magaw, Chevron Research & Technology Company, Richmond, CA; G. Naughton, Arthur D. Little Co., Cambridge, MA
An Evaluation of Benzene Risk at E&P Sites. Sara McMillen and Karen Synowiec, Chevron Research & Technology Co., Richmond, CA; George Deeley, Equilon Enterprises, LLC, Houston, TX

Description

This file contains several presentations and papers that were assembled as part of a technical session for the Sixth Annual International Petroleum Environmental Conference that was held in November 1999. These presentations were derived primarily from the work that had been done under the auspices of the Petroleum Environmental Research Forum (PERF) Project 97-08, Scientifically Sound Risk-Based Decision Tools for E&P Sites. This project developed a methodology to determine risk-based screening levels (RBSLs) for total petroleum hydrocarbons in soils at oil and gas exploration and production sites. The work was based on both non-cancer human health endpoints for total petroleum hydrocarbons (TPH) and the effects of carcinogenic compounds of interest (e.g., benzene and polyaromatic hydrocarbons) to determine risk based screening levels (RBSLs). However, it should be understood that the technical assessment of the effects of benzene on the RBSLs was not final at the time of the meeting. Hence, the benzene results that were presented in this technical session should be considered preliminary, in nature, and possibly subject to change in the future.