RISC - RISC/RISC4_Manual.pdf · PDF fileRISC Manual Version 4.0 ii • RISC allows for pathway, compound and receptor additivity • The fate and transport models in RISC can be used

RISC4Users Manual

Lynn R. SpenceSpence Engineering

Pleasanton, California

Terry WaldenBP Oil International

Sunbury, UK

Developers:

October, 2001

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FORWARD

BACKGROUND

In 1993, BP made a business decision in the U.S. to develop a standardized approach

for conducting soil and groundwater risk assessments across all downstream

activities (service stations through refineries). The rationale was that the company

needed to ensure that the latest thinking on fate and transport, exposure, statistical

analyses and toxicological criteria were adopted and applied uniformly its businesses.

It would also help ensure that BP spoke with a consistent voice when approaching

regulators and the community on this vital issue.

Eventually it became clear that a software package containing embedded fate and

transport models with intuitive user inputs offered the most convenient and flexible

means of implementing this objective. This would enable the process to be readily

standardized, communicated and transferred, while still allowing a risk application to

be individually tailored to the regulatory regime of the particular business or country.

By developing the code in-house, BP would also be able to rapidly adopt new

algorithms or approaches (e.g. indoor air models), thus keeping the process evergreen.

Versions 1.0 and 2.0 of the code were released in January, 1994 and August, 1995,

respectively, with the former pre-dating the publication of the ASTM standard Risk-

Based Corrective Action Applied at Petroleum Release Sites, commonly known as

RBCA. Version 3.0, released in September, 1997, was a major upgrade that allowed

back-calculations to be performed, i.e. soil and groundwater clean-up targets to be

calculated for an input value of acceptable risk.

While similar to the RBCA Toolkit marketed by Groundwater Services Inc., RISC is

more functional, flexible and user-friendly. The major differences are:

RISC has a more intuitive graphical interface

RISC Manual Version 4.0

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RISC allows for pathway, compound and receptor additivity

The fate and transport models in RISC can be used in the presence of phase-separated product

There is a vadose zone model in RISC

The groundwater models are transient

Probabilistic (Monte Carlo) exposure capabilities are provided in RISC

RISC includes a critical pathway - indoor showering - missing in the Toolkit

VERSION 4.0 NEW FEATURES

Version 4.0 of RISC has new features that give it even greater flexibility in assessing

risk for the following scenarios:

Irrigation pathways, i.e. water used for gardening but not for indoor usage

Vegetables grown in contaminated soil

Two new vapor models , where the vapors are allowed to biodegrade duringtransport through the unsaturated zone

Models for surface water and sediment contamination from impactedgroundwater and direct comparison with relevant national standards for thesemedia

The use of groundwater MCLs (maximum concentration levels) and surfacewater concentrations in addition to acceptable risk levels as the criteria forback-calculating clean-up targets

The ability to calculate a site-specific target level (SSTL) for a TPH mixtureusing the site-specific measured concentrations of the TPH fractions detectedin the soil

It is felt that Version 4.0 provides the latest and most complete package for calculating

risk to human health and surface water. This version has been peer-reviewed by

Arcadis, Geraghty and Miller in Cambridge, UK. Their review is included in

Appendix R.

Forward

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RISC DISTRIBUTION AND HELP DESK

BP is distributing the software and manual to all its U.S. and international affiliates

who, in turn, are free to transfer it without charge to their regulators and risk

consultants. The software is not proprietary however, and can be purchased and

downloaded by third parties over the Internet at the web site,

www.groundwatersoftware.com, for $450 (USD). Additional charges will apply if

the recipient wants the Internet provider to supply a hard copy of the manual.

All recipients of the software should periodically check the web site,

www.bprisc.com, to download upgrades related to bug fixes or minor improvements

to the code. The downloads on this web site are functional only to existing software

users.

Finally, any problems with the manual or software, including questionable output or

data interpretation issues, should be directed to the software developer, Lynn Spence.

Her details are as follows:

Phone: 925-462-3124

Fax: 925-846-3152

E-mail: lynnspence@bprisc.com

Address: Lynn Spence

239 Main Street, Suite E

Pleasanton, CA 94566

USA

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Table of Contents

FORWARD

BACKGROUND

VERSION 4.0 NEW FEATURES

RISC DISTRIBUTION AND HELP DESK

1.0OVERVIEW AND GETTING STARTED

1.1 INTRODUCTION1.1.1 Background

1.1.2 Uses of this Software

1.1.3 Overview of Features

1.1.4 Organization and Scope of this Report

1.2 GETTING STARTED1.2.1 Hardware and Software Requirements

1.2.2 Installation Instructions

1.2.3 General Instructions (How to Use RISC)

2.0DATA AND ANALYSIS TOOLS

2.1 RBCA TIER 1 SPREADSHEET2.1.1 Tier 1 Applications

2.1.2 Tier 2 Applications

2.1.3 How to Use

2.2 SURFACE WATER QUALITY CRITERIA

3.0CHOOSE CHEMICALS OF CONCERN

3.1 CHOOSE CHEMICALS

3.2 VIEW CHEMICAL PROPERTIES

3.3 ADD NEW CHEMICAL TO DATABASE

3.4 REMOVE CHEMICAL FROM DATABASE

3.5 RESTORING THE ORIGINAL CHEMICAL DATABASE

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4.0CHOOSE EXPOSURE PATHWAYS

4.1 HUMAN HEALTH EXPOSURE PATHWAYS4.1.1 Select Contaminated Media and Fate and Transport Models

4.1.2 Select Exposure Pathways

4.2 ECOLOGICAL/WATER QUALITY

5.0DETERMINE RECEPTOR POINT CONCENTRATIONS

5.1 USER-SPECIFIED CONCENTRATIONS5.1.1 Single Value

5.1.2 Monte Carlo Distributions

5.1.3 Sample Data Base

5.2 FATE AND TRANSPORT MODELS

6.0DESCRIBE THE RECEPTORS

6.1 HUMAN HEALTH6.1.1 Step 4a: Choose Receptor and Analysis Type

6.1.2 Step4b: Enter Exposure Data

6.2 ECOLOGICAL/WATER QUALITY

7.0CALCULATE RISK

7.1 DESCRIPTION OF EACH INTAKE ROUTE7.1.1 Ingestion of Soil

7.1.2 Dermal Contact with Soil

7.1.3 Ingestion of Groundwater

7.1.4 Dermal Intake in the Shower

7.1.5 Inhalation in the Shower

7.1.6 Inhalation of Outdoor Air

7.1.7 Inhalation of Indoor Air

7.1.8 Ingestion of Surface Water

7.1.9 Dermal Contact With Surface Water

7.1.10 Ingestion of Home-Grown Vegetables Grown in Contaminated Soil

7.1.11 Ingestion of Home-Grown Vegetables Irrigated With Groundwater

7.1.12 Ingestion of Irrigation Water

7.1.13 Dermal Intake with Irrigation Water

7.1.14 Inhalation of Irrigation Water Spray

7.2 CALCULATION OF CARCINOGENIC RISK

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7.3 CALCULATION OF HAZARD INDEX

8.0CALCULATE CLEAN-UP LEVELS

8.1 SET-UP THE SIMULATION

8.2 "RULES" USED IN THE BACK-CALCULATION

8.3 DESCRIPTION OF METHOD USED TO CALCULATE CLEAN-UP LEVELS8.3.1 Direct Pathways

8.3.2 Pathways Using Fate and Transport Models

8.3.3 Equations Used to Calculate Target Receptor Point Concentrations

8.4 RESULTS OF THE CLEAN-UP LEVEL CALCULATION

9.0 RESULTS

9.1 DETERMINISTIC OUTPUT

9.2 MONTE CARLO OUTPUT9.2.1 Monte Carlo Tables

9.2.2 Monte Carlo Charts

9.3 TRANSFERRING TABLES AND CHARTS TO OTHER APPLICATIONS

10.0 EXAMPLE RISK ASSESSMENT SCENARIOS

10.1 EXAMPLE 1: FORMER GAS STATION REDEVELOPED WITH SINGLEFAMILY HOUSING

10.2 EXAMPLE 2: IRRIGATION AND VOLITILIZATION FROMGROUNDWATER

10.3 EXAMPLE 3: SURFACE WATER ECOLOGICAL RISK

11.0 CHEMICAL DATABASE

11.1 PHYSICAL/CHEMICAL PROPERTIES11.1.1 Density

11.1.2 Vapor Pressure (saturated)

11.1.3 Solubility

11.1.4 Henrys Law Coefficient

11.1.5 Log Octanol/Water Partition Coefficient (log Kow)

11.1.6 Organic Carbon Partition Coefficient (Koc)

11.1.7 Inorganic Partition Coefficient (Kd)

11.1.8 Diffusion Coefficients in Air and Water

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11.1.9 Degradation Rates

11.1.10 Vegetable Uptake Factor

11.2 TOXICOLOGICAL PROPERTIES11.2.1 USEPA Carcinogenic Classification

11.2.2 Toxicity Parameters

11.2.3 Inhalation Conversion Factors

11.2.4 Absorption Adjustment Factors (AAFs)

11.2.5 Skin Permeability Coefficient

11.3 TECHNICAL DETAILS OF THE CHEMICAL DATABASE11.3.1 Chemical Database Format

11.3.2 Restoring the Original Chemical Database

12.0 REFERENCES

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LIST OF TABLES

Table 2-1. Summary of the Sheets in the Tier 1 Spreadsheet

Table 4-1. Exposure Pathways Associated With Receptor Media

Table 5-1. Soil Properties Database

Table 5-2. List of Fate and Transport Models and Source Terms Required for Each Model

Table 6-1. Default Receptor Types and Exposure Routes

Table 6-2. Intake Parameters for Adult Residents (page 1 of 2)

Table 6-2. Intake Parameters for Adult Residents (page 2 of 2)

Table 6-3. Intake Parameters for Child Residents (page 1 of 2)

Table 6-3. Intake Parameters for Child Residents (page 2 of 2)

Table 6-4. Intake Parameters for Wo