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DCC Home

Welcome

Welcome to the EPA's "Dose Compliance Concentrations for Radionuclides at Superfund Sites" (DCC) Download and Calculator website for demonstrating compliance with dose-based Applicable or Relevant and Appropriate Requirements (ARARs). The recommended DCCs on this website are dose levels for contaminated soil, water, and air.

This tool presents recommended DCCs calculated using suggested default input parameters and the latest dose conversion factors. In addition, you may modify the input parameters to create site-specific DCCs to meet the needs of your site. To ensure proper application of the DCCs, please see further guidance for DCC use in the User's Guide, What's New, FAQ, and Download Area links. Below is a general description of DCC use. The EPA has prepared a fact sheet for the general public that describes DCC uses, DCC calculator operation, and land uses available for assessment. Additionally, this fact sheet describes the PRG and DCC calculators in greater detail for EPA staff. The OSWER Directive, Superfund Radiation Risk Assessment: A Community Toolkit was also developed by the EPA to help the public understand more about the risk assessment process used at Superfund sites with radioactive contamination.

The DCC calculator was largely developed based on the PRG calculator and benefited from its peer reviews, which may be seen here. The DCC calculator results were previously verified. The documentation from these may be seen on the Internal Verification and External Verification, which also benefits from the external verification review of the PRG calculator. Several other comparison reviews that focused on describing the default parameters in various models may be found here.

Introduction

The purpose of this database is to provide a DCC calculation tool to assist risk assessors, remedial project managers, and others involved with risk assessment and decision-making at CERCLA sites in developing DCCs.

The website was initially made available for use in a transmittal memo entitled "Distribution of OSWER Radionuclide ARAR Dose Compliance Concentrations (DCCs) for Superfund Electronic Calculator", January 28, 2004.

ARAR Dose Compliance Concentrations

Dose conversion factors (DCFs), or "dose coefficients", for a given radionuclide represent the dose equivalent per unit intake (i.e., ingestion or inhalation) or external exposure of that radionuclide. These DCFs are used to convert a radionuclide concentration in soil, air, water, or foodstuffs to a radiation dose. DCFs may be specified for specific body organs or tissues of interest or as a weighted sum of individual organ dose, termed the effective dose equivalent. These DCFs may be multiplied by the total activity of each radionuclide inhaled or ingested per year, or the external exposure concentration to which a receptor may be exposed, to estimate the dose equivalent to the receptor.

At this website, you will find DCCs calculated using the dose conversion factors from International Commission on Radiological Protection (ICRP) 30, ICRP 60, and ICRP 107. This website does not address the calculation of DCCs for ARARs based on ICRP 2 dose conversion factors (e.g., 40 CFR 141.66(d), 10 CFR 61.41).

CERCLA is NOT a Dose-Based Program

It is EPA's recommendation that dose assessments should only be conducted under CERCLA where necessary to demonstrate ARAR compliance. Further, dose recommendations in guidance should generally not be used as to-be-considered material. For more information on this issue, please see questions 33 and 36 on pages 27 to 29 of "Radiation Risk Assessment At CERCLA Sites: Q & A" (EPA 540-R-012-13, May 2014).

Also, EPA generally does not use ARARs greater than 12 mrem/yr to establish cleanup levels at CERCLA sites. Cleanup levels not based on an ARAR should be based on the carcinogenic risk range (generally 10-4 to 10-6, with 10-6 as the point of departure and 1 x 10-6 used for PRGs). For further guidance on this issue, refer to question 35 on page 28 of "Radiation Risk Assessment At CERCLA Sites: Q & A" (EPA 540-R-012-13, May 2014).

Related CERCLA Calculators and Guidance

It should also be noted that calculating a DCC does not address human cancer risk, noncancer toxicity, or potential ecological risk. Of the radionuclides generally found at CERCLA sites, only uranium has potentially significant noncancer toxicity. When assessing sites with uranium as a contaminant, it may also be necessary to consider the noncancer toxicity of uranium using other tools, such as EPA's Regional Screening Levels (RSLs) for Chemical Contaminants at Superfund Sites electronic calculator for uranium in soil, water, or air and the WTC for uranium inside buildings. EPA's SDCC Calculator should be used to assess radionuclide dose for hard outside surfaces, and the BDCC Calculator for radionuclide dose inside buildings. EPA's PRG Calculator should be used to assess radionuclide cancer risk for soil, water, and air; BPRG Calculator for radionuclide cancer risk inside buildings; and the SPRG Calculator for radionuclide cancer risk for hard outside surfaces. Similarly, some sites with radiological contaminants in sensitive ecological settings may also need to be evaluated for potential ecological risk. EPA's guidance "Ecological Risk Assessment Guidance for Superfund: Process for Designing and Conducting Ecological Risk Assessment" contains an eight step process for using benchmarks for ecological effects in the remedy selection process.