1998-02-12 – Use of Soil Cleanup Criteria in 40 CFR Part 192 as Remediation Goals for CERCLA Sites

This memorandum addresses the use of the soil cleanup criteria in 40 CFR Part 192 when setting remediation... View Document

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1997-08-22 – Establishment of Cleanup Levels for CERCLA Sites with Radioactive Contamination

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
Signed by Steve Luftig & Larry Weinstock on August 22, 1997
OFFICE OF SOLID WASTE AND EMERGENCY RESPONSE
OSWER No. 9200.4-18
MEMORANDUM
SUBJECT: Establishment of Cleanup Levels for CERCLA Sites with Radioactive
Contamination
FROM: Stephen D. Luftig, Director s/Stephen D. Luftig
Office of Emergency and Remedial Response
Larry Weinstock, Acting Director s/Larry Weinstock
Office of Radiation and Indoor Air
TO: Addressees
PURPOSE

This memorandum presents clarifying guidance for establishing protective cleanup levels1 for radioactive contamination at Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) sites. The policies stated in this memorandum are inclusive of all radioactive contaminants of concern at a site including radon.2 The directive is limited to providing guidance regarding the
1This directive provides guidance on cleanup levels expressed as a risk, exposure, or dose level and not as a soil concentration level. The concentration level for various media, such as soil, that corresponds to a given risk level should be determined on a site-specific basis, based on factors such as the assumed land use and the physical characteristics (e.g., important surface features, soils, geology, hydro geology, meteorology, and ecology) at the site. This guidance does not alter the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) expectations regarding treatment of
principal threat waste and the use of containment and institutional controls for low level threat waste.
2Since radon is not covered in some Federal radiation regulations it is important to note that the cleanup guidance clarifications in this memorandum include radon. Attachment A is a listing of standards for radionuclides (including radon) that may be applicable or relevant and appropriate requirements (ARARs) for Superfund sites.
protection of human health and does not address levels necessary to protect ecological receptors.
This document provides guidance to EPA staff. It also provides guidance to the public and to the regulated community on how EPA intends that the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) be implemented. The guidance is designed to describe EPA’s national policy on these issues. The document does not, however, substitute for EPA’s statutes or regulations, nor is it a regulation itself. Thus, it cannot impose legally-binding requirements on EPA, States, or the regulated community, and may not apply to a particular situation based upon the circumstances. EPA may change this guidance in the future, as appropriate.
BACKGROUND
All remedial actions at CERCLA sites must be protective of human health and the environment and comply with Applicable or Relevant and Appropriate Requirements (ARARs) unless a waiver is justified. Cleanup levels for response actions under CERCLA are developed based on site-specific risk assessments, ARARs, and/or to-be-considered material3 (TBCs).
A listing is attached of radiation standards that are likely to be used as ARARs to establish cleanup levels or to conduct remedial actions. Cleanup standards have been under development by EPA under the Atomic Energy Act (AEA) and will be ARARs under certain circumstances if issued.
ARARs are often the determining factor in establishing cleanup levels at CERCLA sites. However, where ARARs are not available or are not sufficiently protective, EPA generally sets site-specific remediation levels for: 1) carcinogens at a level that represents an excess upper bound lifetime cancer risk to an individual of between 10-4 to 10-6; and for 2) non-carcinogens such that the cumulative risks from exposure will not result in adverse effects to human populations (including sensitive sub.populations) that may be exposed during a lifetime or part of a lifetime, incorporating an adequate margin of safety. (See 40 CFR 300.430(e)(2)(i)(A)(2).) Since all radionuclides are carcinogens, this guidance addresses carcinogenic risk. If non.carcinogenic risks are posed by specific radionuclides, those risks should be taken into account in establishing cleanup levels or suitable remedial actions. The site-specific level of cleanup is determined using the nine criteria specified in Section 300.430(e)(9)(iii) of the NCP.
It is important to note that a new potential ARAR was recently promulgated :
3To-be-considered material (TBCs) are non-promulgated advisories or guidance issued by Federal or State governments that are not legally binding and do not have the status of potential ARARs. However, TBCs will be considered along with ARARs as part of the site risk assessment and may be used in determining the necessary level of cleanup for protection of health and the environment.
– 2 .
NRC’s Radiological Criteria for License Termination (See 62 FR 39058, July 21, 1997). We expect that NRC’s implementation of the rule for License Termination (decommissioning rule) will result in cleanups within the Superfund risk range at the vast majority of NRC sites. However, EPA has determined that the dose limits established in this rule as promulgated generally will not provide a protective basis for establishing preliminary remediation goals (PRGs) under CERCLA.4 The NRC rule set an allowable cleanup level of 25 millirem per year (equivalent to approximately 5 x 10-4 increased lifetime risk) as the primary standard with exemptions allowing dose limits of up to 100 millirem per year (equivalent to approximately 2 x 10-3 increased lifetime risk). Accordingly, while the NRC rule standard must be met (or waived) at sites where it is applicable or relevant and appropriate, cleanups at these sites will typically have to be more stringent than required by the NRC dose limits in order to meet the CERCLA and NCP requirement to be protective.5 Guidance that provides for cleanups outside the risk range (in general, cleanup levels exceeding 15 millirem per year which equates to approximately 3 x 10-4 increased lifetime risk) is similarly not protective under CERCLA and generally should not be used to establish cleanup levels.
The lack of a protective comprehensive set of regulatory cleanup levels for radiation, together with the possibility of confusion as to the status of other Federal Agency regulations and guidance as ARARs or TBCs, may cause uncertainty as to the cleanup levels deemed protective under CERCLA. Until a protective comprehensive radiation cleanup rule is available, this guidance clarifies the Agency’s position on CERCLA cleanup levels for radiation.

OBJECTIVE
This guidance clarifies that cleanups of radionuclides are governed by the risk range for all carcinogens established in the NCP when ARARs are not available or are not sufficiently protective. This is to say, such cleanups should generally achieve risk levels in the 10-4 to 10-6 range. EPA has a consistent methodology for assessing cancer risks and determining PRGs at CERCLA sites no matter the type of contamination.6 Cancer risks for radionuclides should generally be estimated using the slope factor approach identified in this methodology. Slope factors were developed by EPA for more than 300 radionuclides in the Health Effects Assessment Summary Tables
4See letter, Carol Browner, Administrator, EPA, to Shirley Jackson, Chairman, Nuclear Regulatory Commission, February 7, 1997.
5See attachment B for a detailed discussion of the basis for the conclusion that the dose limits in the NRC rule are not adequately protective.
6U.S. EPA, “Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (Part A) Interim Final,” EPA//540/1-89/002, December 1989. U.S. EPA, “Risk Assessment Guidance for Superfund: Volume I – Human Health Evaluation Manual (Part B, Development of Risk-based Preliminary Remediation Goals”, EPA/540/R-92/003, December 1991.
– 3 .
(HEAST).7 Cleanup levels for radioactive contamination at CERCLA sites should be established as they would for any chemical that poses an unacceptable risk and the risks should be characterized in standard Agency risk language consistent with CERCLA guidance.
Historically, radiation exposure and cleanup levels have often been expressed in units unique to radiation (e.g., millirem or picoCuries). It is important for the purposes of clarity that a consistent set of existing risk-based units (i.e., # x10-#) for cleanups generally be used. This will also allow for ease and clarity of presenting cumulative risk for all contaminants, an objective consistent with EPA’s policy on risk characterization.8
Cancer risk from both radiological and non-radiological contaminants should be summed to provide risk estimates for persons exposed to both types of carcinogenic contaminants. Although these risks initially may be tabulated separately, risk estimates contained in proposed and final site decision documents (e.g., proposed plans, Record of Decisions (RODs), Action Memos, ROD Amendments, Explanation of Significant Differences (ESDs)) should be summed to provide an estimate of the combined risk to individuals presented by all carcinogenic contaminants.

IMPLEMENTATION
The approach in this guidance should be considered at current and future CERCLA sites for which response decisions have not been made.

Overall Exposure Limit:
Cleanup should generally achieve a level of risk within the 10-4 to 10-6 carcinogenic risk range based on the reasonable maximum exposure for an individual. The cleanup levels to be specified include exposures from all potential pathways, and through all media (e.g., soil, ground water, surface water, sediment, air, structures, biota). As noted in previous policy, “the upper boundary of the risk range is not a discrete line at 1 x 10-4, although EPA generally uses 1 x 10-4 in making risk management decisions. A specific risk estimate around 10-4 may be considered acceptable if justified based on site-specific conditions”.9
7U.S. EPA, “Health Effects Assessment Summary Tables FY-1995 Annual,” EPA/540/R-95/036, May 1995; and U.S. EPA, “Health Effects Assessment Summary Tables FY-1995 Supplement,” EPA/540/R-95/142, Nov. 1995.
8For further discussion of EPA’s policy, see memorandum from EPA Administrator Carol Browner entitled: “EPA Risk Characterization Program,” March 21, 1995.
9Memo from Assistant Administrator Don Clay to the Regions; “Role of the Baseline Risk Assessment in Superfund Remedy Selection Decisions’” OSWER Directive 9355.0-30; April 22, 1991.
– 4 .
If a dose assessment is conducted at the site10 then 15 millirem per year (mrem/yr) effective dose equivalent (EDE) should generally be the maximum dose limit for humans. This level equates to approximately 3 x 10-4 increased lifetime risk and is consistent with levels generally considered protective in other governmental actions, particularly regulations and guidance developed by EPA in other radiation control programs.11

Background Contamination:
Background radiation levels will generally be determined as background levels are determined for other contaminants, on a site-specific basis. In some cases, the same constituents are found in on-site samples as well as in background samples. The levels of each constituent are compared to background to determine its impact, if any, on site-related activities. Background is generally measured only for those radionuclides that are contaminants of concern and is compared on a contaminant specific basis to cleanup level. For example, background levels for radium-226 and radon-222 would generally not be evaluated at a site if those radionuclides were not site-related contaminants.
In certain situations background levels of a site-related contaminant may equal or exceed PRGs established for a site. In these situations background and site-related levels of radiation will be addressed as they are for other contaminants at CERCLA sites.12
10Cleanup levels not based on ARARs should be expressed as risk, although levels may at the same time be expressed in millirem.
11Further discussion and analysis of the basis for this recommendation is contained in the materials in the docket for the AEA standard under development by EPA, which is available at the following address: U.S. EPA, 401 M Street, S.W., Room M1500, Air Docket No. A-93-27, Washington D.C. 20460. The material is also available via computer modem through the Cleanup Regulation Electronic Bulletin Board (800-700-7837 outside the Washington area and 703-790-0825 locally), or on-line through the Radiation Site Cleanup Regulation HomePage (http://www.epa.gov/radiation/cleanup/). Cleanup levels based on some older ARARs that use a 25/75/25 mrem/yr standard (i.e., 25 mrem/yr to the whole body, 75 mrem/yr to the thyroid, and 25 mrem/yr to any other critical organ) may appear to permit greater risk than those based on 15 mrem EDE but on average correspond to approximately 10 mrem/yr EDE, using current risk methodologies. Similarly, ARARs based on a 25/75 mrem/yr standard used as an ARAR (i.e., 25 mrem/yr to whole body and 75 mrem/yr to any critical organ) would on average correspond to those cleanups based on 15 mrem/yr EDE. (See also “Comparison of Critical Organ and EDE Radiation Dose Rate Limits for Situations Involving Contaminated Land;” Office of Radiation and Indoor Air; April 1997.) See also Attachment B.
12For further information regarding EPA’s approach for addressing background at CERCLA sites see: National Oil and Hazardous Substances Pollution Contingency Plan, 55 FR 8717-8718, March 8, 1990; U.S. EPA “Guidance on Remedial Actions for Contaminated Ground Water at Superfund Sites,” EPA/540/G-88/003, December 1988, pg. 4-9;
U.S. EPA “Soil Screening Guidance: User’s Guide,” EPA/540/R-96/018, April 1996, pg. 8; and U.S. EPA “Risk
Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (Part A),” EPA/540/1-89/02, December 1989, pp. 4-5 to 4-10 and 5-18 to 5-19. It should be noted that certain ARARs specifically address how to factor background into cleanup levels. For example, some radiation ARAR levels are established as increments above background concentrations. (See attached chart for a listing of radiation standards that are likely to be used as ARARs.) In these circumstances, rather then follow the general guidance cited above, background should be addressed in the manner
– 5 .

Land Use and Institutional Controls:
The concentration levels for various media that correspond to the acceptable risk level established for cleanup will depend in part on land use at the site. Land uses that will be available following completion of a response action are determined as part of the remedy selection process considering the reasonably anticipated land use or uses along with other factors.13 Institutional controls (ICs) generally should be included as a component of cleanup alternatives that would require restricted land use in order to ensure the response will be protective over time. The institutional controls should prevent an unanticipated change in land use that could result in unacceptable exposures to residual contamination, or at a minimum, alert future users to the residual risks and monitor for any changes in use.

Future Changes in Land Use:
Where waste is left on-site at levels that would require limited use and restricted exposure to ensure protectiveness, EPA will conduct reviews at least once every five years to monitor the site for any changes including changes in land use. Such reviews should analyze the implementation and effectiveness of any ICs with the same degree of care as other parts of the remedy. Should land use change in spite of land use restrictions, it will be necessary to evaluate the implications of that change for the selected remedy, and whether the remedy remains protective (e.g., a greater volume of soil may need to be removed or managed to achieve an acceptable level of risk for a less restrictive land use).

Ground Water Levels:
Consistent with CERCLA and the NCP, response actions for contaminated ground water at radiation sites must attain (or waive as appropriate) the Maximum Contaminant Levels (MCLs) or non-zero Maximum Contaminant Level Goals (MCLGs) established under the Safe Drinking Water Act, where the MCLs or MCLGs are relevant and appropriate for the site. This will typically be the case where ground waters are a current or potential source of drinking water.14 The ARARs should generally be attained throughout the plume (i.e., in the aquifer).
prescribed by the ARAR ARARs, such as 40 CFR 192, are available to establish cleanup levels for those naturally occurring radionuclides that pose the most risk (such as radium-226 or Thorium in soil, and indoor radon) when those radionuclides are site related contaminants.
13In developing Land use assumptions, decision makers should consult the guidance provided in the memorandum from Elliott Laws A.A., OSWER entitled: “Land Use in the CERCLA Remedy Selection Process” (OSWER Directive No. 9355.7-04), May 25, 1995.
14In making decisions on ground water protection, decision makers should consult the guidance provided in “Presumptive Response Strategy and Ex-Situ Treatment Technologies for Contaminated Ground Water at CERCLA Sites” (OSWER Directive No. 9355.7-04) October 1996.
– 6 .

Modeling Assessment of Future Exposures:
Risk levels, ground water cleanup, and dose limits should be predicted using appropriate models to examine the estimated future threats posed by residual radioactive material following the completion of the response action.15 The modeling assessment should: (1) assume that the current physical characteristics (e.g., important surface features, soils, geology, hydrogeology, meteorology, and ecology) will continue to exist at the site; (2) take into account for each particular radionuclide that is a site-related contaminant, the following factors:

radioactive decay and the ingrowth of radioactive decay products when assessing risk levels;


the year of peak concentration in the ground water when assessing protection (e.g., remediating previous contamination and preventing future contamination) of ground water, and;


the year of peak dose when assessing dose limits; and,

(3) model the expected movement of radioactive material at the site both within media(i.e., soil, ground water, surface water, sediment, structures, air, biota) and to other media.

FURTHER INFORMATION
The subject matter specialists for this directive are Jeffrey Phillips of OERR and John Karhnak of ORIA. General questions about this directive, should be directed to 1-800-424-9346.
Attachments
Addressees National Superfund Policy Managers Superfund Branch Chiefs (Regions I-X) Superfund Branch Chiefs, Office of Regional Counsel (Regions I-X) Radiation Program Managers (Regions I, IV, V, VI, VII, X) Radiation Branch Chief (Region II) Residential Domain Section Chief (Region III) Radiation and Indoor Air Program Branch Chief (Region VIII) Radiation and Indoor Office Director (Region IX) Federal Facilities Leadership Council OERR Center Directors
15For further information regarding the basis for this recommendation, see U.S. EPA, “Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (Part A) Interim Final,” EPA//540/1-89/002, December 1989, pp. 10-22 and 10-24.
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OSWER Directive 9200.4-18 Attachment A

Likely Federal Radiation Applicable or Relevant and Appropriate Requirements (ARARs)
The attached draft table of Federal standards is a listing of Federal radiation regulations that may be “Applicable or Relevant and Appropriate Requirements” (ARARs) for Superfund response actions. This list is not a comprehensive list of Federal radiation standards. It must also be cautioned that the selection of ARARs is site-specific and those site-specific determinations may differ from
the attached analysis for some of the following ARARs.

Likely Federal Radiation (AEA, UMTRCA, CAA, CWA, SDWA) ARARs
When is standard
Standard Citation Applicable (Conduct/Operation or Level of Cleanup1) When is standard potentially a Relevant and Appropriate Requirement
Maximum contaminant levels (MCLs). Drinking 40 CFR 141 Rarely: At the tap where Where ground or surface water
water regulations designed to protect human water will be provided is considered a potential or
health from the potential adverse effects of directly to 25 or more current source of drinking
drinking water contaminants. people or will be supplied water
to 15 or more service
connections.
Concentration limits for liquid effluents from 40 CFR 440 Very Unlikely: Applies to Discharges to surface waters
facilities that extract and process uranium, Subpart C surface water discharges of some kinds of radioactive
radium, and vanadium ores. from certain kinds of waste.
mines and mills

– 1 .

Likely Federal Radiation (AEA, UMTRCA, CAA, CWA, SDWA) ARARs
When is standard
Standard Citation Applicable (Conduct/Operation or Level of
Cleanup1)
Federal Water Quality Criteria (FWQC) and State Water Quality Standards (WQS). Criteria/standards for protection of aquatic life and/or human health depending upon the designated water use. Water Quality Criteria; Report of the National Technical Advisory Committee to the Discharge from a CERCLA site to surface water. (C/O)
Secretary of the Interior; April 1, 1968.
Concentration limits for cleanup of radium-226, radium-228, and thorium in soil at inactive uranium processing sites designated for remedial action.2 40 CFR 192.12(a), 192.32(b)(2), and 192.41 Never: Standards are applicable only to UMTRCA sites that are exempt from CERCLA

When is standard potentially a Relevant and Appropriate Requirement
Restoration of contaminated surface water. (LC)
Sites with soil contaminated with radium-226, radium-228, and/or thorium
2For further information, see OSWER directive entitled “Use of Soil Cleanup Criteria in Subpart B of 40 CFR Part 192 as Remediation Goals for CERCLA sites.”
– 2 .

Likely Federal Radiation (AEA, UMTRCA, CAA, CWA, SDWA) ARARs
When is standard
Applicable
Standard Citation (Conduct/Operation
or Level of
Cleanup1)
Combined exposure limits for cleanup of radon 40 CFR Never: Standards are
decay products in buildings at inactive uranium 192.12(b)(1) and applicable only to
processing sites designated for remedial action 192.41(b) UMTRCA sites that are
exempt from CERCLA
Concentration limits for cleanup of gamma 40 CFR Never: Standards are
radiation in buildings at inactive uranium 192.12(b)(2) applicable only to
processing sites designated for remedial action UMTRCA sites that are
exempt from CERCLA
Design requirements for remedial actions that 40 CFR 192.02 Never: Standards are
involve disposal for controlling combined releases applicable only to
of radon-220 and radon-222 to the atmosphere at UMTRCA sites that are
inactive uranium processing sites designated for exempt from CERCLA
remedial action

When is standard potentially a Relevant and Appropriate Requirement
Sites with radioactive contamination that is currently, or may potentially, result in radon that is caused by site related contamination migrating from the soil into buildings
Sites with radioactive contamination that is currently, or may potentially, emit gamma radiation
Sites with radon-220 or radon.222 as contaminants which will be disposed of on-site.
– 3 .

Likely Federal Radiation (AEA, UMTRCA, CAA, CWA, SDWA) ARARs
When is standard
Applicable
Standard Citation (Conduct/Operation
or Level of
Cleanup1)
Performance objectives for the land disposal of 10 CFR 61.41 Unlikely: Existing
low level radioactive waste (LLW). licensed LLW disposal
sites at the time of license
renewal. (LC)
Unlikely that this would
occur.
National Emission Standards for Hazardous Air 40 CFR 61 Airborne emissions during
Pollutants (NESHAPs) under the Clean Air Act, Subparts H and I the cleanup of Federal
that apply to radionuclides. Facilities and licensed
NRC facilities. (CO)
Radiological criteria for license termination. 10 CFR 20 Existing licensed sites at
Subpart E the time of license
termination. (LC)

When is standard potentially a Relevant and Appropriate Requirement
Previously closed sites containing LLW if the waste will be permanently left on site.
Cleanup of other sites with radioactive contamination.
Previously closed sites.
1.Conduct/operation (C/O) refers to those standards which are typically ARARs for the conduct or operation of the remedial action. Level of Cleanup (L/C) refers to those standards which are typically ARARs for determining the final level of cleanup.
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OSWER Directive 9200.4-18 Attachment B

Analysis of what Radiation Dose Limit is Protective of Human Health at CERCLA Sites (Including Review of Dose Limits in NRC Decommissioning Rule)
Introduction
The Nuclear Regulatory Commission (“NRC”) has finalized a rule titled “Radiological Criteria for License Termination” (see 62 FR 39058, July 21, 1997). EPA has determined that the dose limits established in this rule generally will not provide a protective basis for establishing preliminary remediation goals (“PRGs”)under the Comprehensive Environmental Response, Compensation and Liability Act (“CERCLA”).1 The NRC rule sets an allowable cleanup level of 25 millirem per year effective dose equivalent (EDE) (equivalent to approximately 5 x 10-4 lifetime cancer risk) as the primary standard with exemptions allowing cleanup levels of up to 100 millirem per year (mrem/yr) EDE (equivalent to approximately 2 x 10-3 lifetime risk).2 While the NRC standards must be met (or waived) at sites where it is applicable or relevant and appropriate, cleanups at these sites will typically have to be more protective than required by the NRC rule dose limits in order to meet the requirement to be protective established in CERCLA and the 1990 revisions to the National Oil and Hazardous Substances Pollution Contingency Plan (“NCP”).3
Protectiveness for carcinogens under CERCLA is generally determined with reference to a cancer risk range of 10-4 to 10-6 deemed acceptable by EPA. Consistent with this risk range, EPA has considered cancer risk from radiation in a number of different contexts, and has consistently concluded that levels of 15 mrem/yr EDE (which
1See letter, Carol Browner, Administrator, EPA, to Shirley Jackson, Chairman, Nuclear Regulatory Commission, February 7, 1997.
2 Throughout this analysis risk estimates for dose levels were derived using a risk assessment methodology consistent with CERCLA guidance for assessing risks.
3Similarly, guidance that provides for radiation cleanups outside the risk range is generally not protective and should not be used to establish preliminary remediation goals .
– 1 .equate to approximately a 3 x 10-4 cancer risk) or less are protective and achievable.4 EPA has explicitly rejected levels above 15 mrem/yr EDE as being not sufficiently protective.
The dose levels established in the NRC Decommissioning rule, however, are not based on this risk range or on an analysis of other achievable protective cleanup levels used for radiation and other carcinogenic standards. Rather, they are based on a different framework for risk management recommended by the International Commission on Radiation Protection (ICRP) and the National Council on Radiation Protection and Measurements (NCRP). NRC’s application of this framework starts with the premise that exposure to radiation from all man-made sources, excluding medical and natural background exposures, of up to 100 mrem/yr., which equates to a cancer risk of 2 x 10-3, is acceptable. Based on that premise, it concludes that exposure from decommissioned facilities of 25 mrem/yr, which equates to a cancer risk of approximately 5 x 10-4, is acceptable, and allows the granting of exceptions in certain instances permitting exposure up to the full dosage of 100 mrem/yr from these facilities. EPA has carefully reviewed the basis for the NRC dose levels and does not believe they are generally protective within the framework of CERCLA and the NCP. Simply put, NRC has provided, and EPA is aware of, no technical, policy, or legal rationale for treating radiation risks differently from other risks addressed under CERCLA and for allowing radiation risks so far beyond the bounds of the CERCLA risk range.

1. Rationale for 15 mrem/yr as Minimally Acceptable Dose Limit
To determine an acceptable residual level of risk from residual radioactive materials following a response action that would be protective of human health, EPA examined the precedents established by EPA for acceptable exposures to radiation in regulations and site-specific cleanup decisions in light of the CERCLA risk range for carcinogens. EPA’s conclusion is that to be considered protective under CERCLA, remedial actions should generally attain dose levels of no more than 15 mrem/yr EDE for those sites at which a dose assessment is conducted. This dose level corresponds to an excess lifetime cancer risk of approximately 3 x 10-4.
1.1 The CERCLA risk range
Under CERCLA, all remedies are required to attain cleanup levels that “at a minimum. . . assure protection of human health and the environment.” CERCLA
4It should be noted that 15 mrem/yr is a dose level, not a media remediation level. Accordingly, this level could be achieved at CERCLA sites through appropriate site-specific combinations of active remediation and land-use restrictions to ensure no unacceptable exposures.
– 2 .§121(d)(1). The NCP provides that, for carcinogens, preliminary remediation goals should generally be set at levels that represent an upper-bound lifetime cancer risk to an individual of between 10-4 and 10-6. 40 CFR § 300.430(e)(2)(I)(A)(1). This regulatory level was set based on EPA’s conclusion that the CERCLA protectiveness mandate is complied with “when the amount of exposure is reduced so that the risk posed by contaminants is very small, i.e., at an acceptable level. EPA’s risk range of 10-4 to 10-6 represents EPA’s opinion on what are generally acceptable levels.” 55 Fed. Reg. at 8716 (March 8, 1990). EPA’s adoption of this risk range was sustained in judicial review of the NCP. State of Ohio v. EPA, 997 F.2d 1520, 1533 (D.C. Cir. 1993).
Under appropriate circumstances, risks of greater than 1 x 10-4 may be acceptable. CERCLA guidance states that “the upper boundary of the risk range is not a discrete line at 1 x 10-4, although EPA generally uses 1 x 10-4 in making risk management decisions. A specific risk estimate around 10-4 may be considered acceptable if justified based on site-specific conditions.”5 Other EPA regulatory programs have developed a similar approach to determining acceptable levels of cancer risk. For example, in a Clean Air Act rulemaking establishing NESHAPs for NRC licensees, Department of Energy facilities, and many other kinds of sites, EPA concluded that a risk level of “3 x 10-4 is essentially equivalent to the presumptively safe level of 1 x 10-4.” 54 Fed. Reg. at 51677 and 51682 (December 15, 1989). EPA explicitly rejected a risk level of 5.7 x 10-4 as not being equivalent to the presumptively safe level of 1 x 10-4 (in the case of elemental phosphorus plants) in this rulemaking. 54 Fed. Reg. at 51670.

1.2 Prior rulemaking decisions
EPA has examined the protectiveness of various radiation levels on a number of occasions. In each case, EPA’s determination of what constitutes an adequate level of protection was reached in a manner consistent with EPA’s regulation of other carcinogens. The conclusions from these efforts support the determination that 15 mrem/yr EDE should generally be the maximum dose level allowed at CERCLA sites. For example, EPA’s Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (“High-Level Waste Rule,” 40 CFR Part 191) sets a dose limit of 15 mrem/yr EDE for all pathways.
In addition, EPA set an effective dose equivalent of 10 mrem/yr EDE (excluding radon-222) for air emissions of radionuclides from federal facilities, NRC licensees, and uranium fuel cycle facilities under the National Emissions Standards for Hazardous Air
5″Role of the Baseline Risk Assessment in Superfund Remedy Selection Decisions” from EPA Assistant Administrator Don
R. Clay, April 22, 1991.
– 3 .Pollutants (NESHAP, 40 CFR Part 61). This lower limit included all air pathways, but excluded releases to surface and ground waters.
Not all EPA rules apply the current dose methodology of effective dose equivalent (EDE). A dose limit of 15 mrem/yr EDE is also consistent with the dose levels allowed under older multi-media standards that were based on the critical organ approach to dose limitation. Critical organ standards developed by EPA and NRC consist of a combination of whole body and critical organ dose limits. Three of these critical organ standards (EPA’s uranium fuel cycle rule, 40 CFR 190.10(a), developed for NRC licensees; NRC’s low level waste rule, 10 CFR 61.41; and EPA’s management and storage of high level waste by NRC and agreement states rule, 40 CFR 191.03(a)), referred to here as ‘25/75/25 mrem/yr’ dose limits, are expressed as 25 mrem/yr to the whole body, 75 mrem/yr to the thyroid, and 25 mrem/yr to any critical organ other than the thyroid. One standard (EPA’s management and storage of high level waste by DOE rule, 40 CFR 191.03(b)), referred to here as a “25/75 mrem/yr” dose limit, is expressed as 25 mrem/yr to the whole body and 75 mrem/yr to any critical organ (including the thyroid). To compare the dose level allowed under standards expressed in terms of EDE with the dose levels allowed under the critical organ approach to dose limitation, EPA has analyzed the estimated effective dose equivalent levels that would result if sites were cleaned up to the numerical dose limits used in these standards.6 The analysis indicates that if sites were cleaned up under a 25/75/25 mrem/yr dose limit, the residual contamination would correspond to approximately 10 mrem/yr EDE. For sites cleaned up under a 25/75 mrem/yr dose limit, the residual contamination would correspond to approximately 15 mrem/yr EDE. These findings are similar to those mentioned in the preamble to the high-level waste rule (40 CFR Part 191; December 20, 1993; 58 FR 66402). In that rulemaking, EPA noted that the dose limit of 25 mrem/yr to the whole body or 75 mrem/yr to any critical organ, which was used in a previous high-level waste rule (September 19, 1985; 50 FR 38066) corresponds to the same level of risk as that associated with a 15 mrem/yr EDE. A cleanup level of 15 mrem/yr EDE is thus generally consistent with all of these other standards, although there are minor differences.
Finally, standards for the cleanup of certain radioactively contaminated sites have been issued under the Uranium Mill Tailings Radiation Control Act (UMTRCA), P.L. 95.604. Those standards are codified at 40 CFR Part 192. Among other provisions, the UMTRCA standards limit the concentration of radium-226, radium-228, thorium-230 and thorium-232, within 15 centimeters (cm) of the surface to no more than 5 picoCuries per gram (pCi/g) over background. They also limit the concentration of these radionuclides below the surface to no more than 15 pCi/g over background. Since these standards were
6″Comparison of Critical Organ and EDE Radiation Dose Rate Limits for Situations Involving Contaminated Land” Office of Radiation and Indoor Air; April 1997.
– 4 .developed for the specific conditions found at the mill sites to which they apply (for example, all mill sites are required by law to remain in federal control), correlating these concentrations to dose requires a site-specific determination considering both the distribution and nature of contaminants at the site and the selected land use. Therefore, those standards are less relevant for determining if 15 mrem/yr EDE is consistent. However, analysis indicates that the cleanup of UMTRCA sites is consistent with the minimally acceptable dose limit of 15 mrem/yr EDE under a residential exposure scenario for radium-226, radium-228, and thorium-232, and is much more stringent for thorium-230.7 For land uses other than residential (e.g., commercial/industrial, recreational) the UMTRCA cleanup standards are more stringent for all four radionuclides.8

1.3 Site-Specific Decisions
EPA has examined the cleanup decisions made under Superfund to address sites contaminated with radioactive wastes. Many of these cleanup actions used the UMTRCA cleanup standard (40 CFR Part 192) as an ARAR. Some of the sites used State regulations as ARARs. For a number of major DOE cleanup actions such as those at the Hanford reservation and Rocky Flats, a 15 mrem/yr EDE cleanup level has been decided upon or proposed. In other cases of CERCLA radiation cleanup actions that are not based on ARARs, cleanup levels between 1 x 10-5 and 1 x 10-6 have been selected (Bomark, NJ; Fernald, OH; Charleston Naval Shipyard, SC; and Mare Island Naval Shipyard, CA). Overall EPA finds that a 15 mrem/yr EDE level (with a risk of 3 x 10-4) is at the upper end of remediation levels that have generally been selected at radioactively contaminated CERCLA sites.

2.0 Dose Limits in NRC’s Rule are not Protective
EPA reviewed the dose limits that are contained in NRC’s Radiological Criteria for License Termination (see 62 FR 39058, July 21, 1997). The NRC rule allows a cleanup level of 25 mrem/yr EDE (equivalent to approximately 5 x 10-4 lifetime risk) with exemptions allowing cleanup levels of up to 100 mrem/yr EDE (equivalent to approximately 2 x 10-3 lifetime risk). These limits are beyond the upper bound of the risk
7Reassessment of Radium and Thorium Soil Concentrations and Annual Dose Rates . Office of Radiation and Indoor Air, July 22, 1996.
8A level of 15 mrem/yr is also supported by EPA’s draft Federal Radiation Protection Guidance for Exposure of the General Public (59 FR 66414, December 23, 1994). The draft guidance recommends that the maximum dose to individuals from specific sources or categories of sources be established as small fractions of a 100 mrem/yr upper bound on doses from all current and potential future sources combined, and cites the regulations that are discussed in Section 1.2 of this paper as appropriate implementation of this recommendation. All of the regulatory examples cited support the selection of cleanup levels at 15 mrem/yr or less. However, because this guidance is in draft form and is subject to continued review within EPA prior to finalization, it should not be used as a basis for establishing acceptable cleanup levels.
– 5 .range generally considered protective under CERCLA. In addition, they present risks that are higher than levels EPA has found to be protective for carcinogens in general and for radiation, in particular, in other contexts. EPA has no technical or policy basis to conclude that these levels are protective under CERCLA.
The risk levels corresponding to the 25 to 100 mrem/yr EDE range allowed by the NRC rule (5 x 10-4 to 2 x 10-3) are unacceptably high relative to 1 x 10-4, which is the risk level generally used as the upper boundary of the CERCLA risk range for making risk management decisions at CERCLA sites. This determination is consistent with EPA’s explicit rejection of a risk level of 5.7 x 10-4 for elemental phosphorus plants in the preamble for a NESHAP rulemaking (54 FR 51670). In the same preamble, EPA stated that a risk level of “3 x 10-4 is essentially equivalent to the presumptively safe level of 1 x 10-4″ (54 FR 51677). It was during this same NESHAP rulemaking that NCRP first recommended to EPA its regulatory scheme (a dose limit of 25 mrem/yr EDE for a single source that if met would not require analyzing other sources, otherwise a dose limit of 100 mrem/yr EDE from all sources combined) that NRC cites as a source for the regulatory approach taken in its decommissioning rule.9 EPA rejected NCRP’s recommended regulatory scheme, and promulgated dose limits of no more than 10 mrem/yr EDE in its NESHAP rulemaking for radionuclides, while concluding that “individual dose levels greater than 10 mrem/y ede are inconsistent with the requirements of section 112” of the Clean Air Act. 54 Fed. Reg. at 51686.
The documentation and analysis supporting the NRC rule dose levels provide no basis for such a significant departure from the CERCLA risk range. Indeed, as discussed above, EPA’s past analyses and experience have demonstrated that exposures of 15 mrem/yr EDE or less are attainable and that such a departure is unwarranted. A dose limit of 25 mrem/yr EDE represents almost a doubling of the allowable risk from previous radiation rulemakings; the risk represented by a dose limit of 100 mrem/yr EDE is seven times as high as previously allowed. As note in Section 1.2, a dose limit of 25 mrem/yr effective dose equivalent is inconsistent with the dose levels allowed under older standards using a previous dose methodology (multi-media standards that were based on the critical organ approach to dose limitation). If these older dose standards were to be applied to the cleanup of contaminated sites, the average dose level would correspond to approximately 10 or 15 mrem/yr EDE on average.10 Also, analysis indicates that the cleanup of UMTRCA sites using the 5 pCi/g and 15 pCi/g soil standards under 40 CFR 192 is consistent with an upper bound of 15 mrem/yr EDE under a rural residential exposure
9″Control of Air Emissions of Radionuclides” NCRP Position Statement No. 6. The report cited by NRC, NCRP No. 116, merely references this previous NCRP position statement.
10″Comparison of Critical Organ and EDE Radiation Dose Rate Limits for Situations Involving Contaminated Land” Office of Radiation and Indoor Air; April 1997.
– 6 .scenario for radium-226, radium-228, and thorium-232, and is much more stringent for thorium-230.11 For land uses other than residential (e.g., commercial/industrial, recreational) the UMTRCA cleanup standards are more stringent for all four radionuclides.
11Reassessmen t of Radium and Thorium Soil Concentrations and Annual Dose Rates . Office of Radiation and Indoor Air, July 22, 1996.
– 7 .

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
Signed by Timothy Fields on August 22, 1997
OFFICE OF SOLID WASTE AND EMERGENCY RESPONSE
OSWER No. 9200.4-23
MEMORANDUM
SUBJECT: Clarification of the Role of Applicable, or Relevant and Appropriate
Requirements in Establishing Preliminary Remediation Goals under
CERCLA
FROM: Timothy J. Fields, Jr., Acting s/Timothy Fields, Jr.
Assistant Administrator
TO: Addressees
PURPOSE

This memorandum clarifies the relationship between the two key remedy selection mandates of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) as amended by the Superfund Amendments and Reauthorization Act of 1986 (SARA): 1) the requirement to protect human health and the environment; and 2) the requirement to attain, or waive if justified based on site-specific circumstances, applicable or relevant and appropriate requirements (ARARs). Specifically, this memorandum clarifies that, in rare instances, the Agency may establish preliminary remediation goals (PRGs) at levels more protective than required by ARARs, even at sites that do not involve multiple contaminants or pathways of exposure.
This document provides guidance to Regional staff, in dealing with the public and the regulated community, regarding how EPA intends to implement the National Oil and Hazardous Substances Pollution Contingency Plan (NCP). It describes national policy. This document is not a substitute for EPA’s statutes or regulations, nor is it a regulation itself. Thus, it cannot impose legally-binding requirements on EPA, States, or the regulated community, and may not apply to a particular situation based upon the circumstances.
2

BACKGROUND
In administering the CERCLA program since the promulgation of the 1990 revisions to the NCP, questions have periodically arisen over the relationship between the statutory mandates to: 1) protect human health and the environment; and, 2) attain, or waive if justified based on site-specific circumstances, ARARs. Specifically, questions have arisen over the circumstances under which it is appropriate to establish PRGs that are more protective than ARARs. It has been EPA’s policy that “compliance with a chemical-specific ARAR generally will be considered protective even if it is outside the [cancer] risk range (unless there are extenuating circumstances such as exposures to multiple contaminants or pathways of exposure).”1

FURTHER EXPLANATION OF POLICY
It remains EPA’s policy that ARARs will generally be considered protective absent multiple contaminants or pathways of exposure. However, this Directive clarifies that, in rare situations, EPA Regional offices should establish PRGs at levels more protective than required by a given ARAR, even absent multiple pathways or contaminants, where application of the ARAR would not be protective of human health or the environment. This judgment should be made based on a review of the level of risk associated with application of the ARAR; the soundness of the technical basis for the ARAR; and other factors relating to the ARAR or to its application at an individual site.
This balanced approach most fully implements the requirements of the NCP and the CERCLA. On one hand, it was clearly EPA’s intention in promulgating the NCP that PRGs would generally be based on ARARs in the absence of multiple contaminants or pathways. (See 40 CFR 300.430(e)(2)(I)(D); 55 Fed. Reg. at 8712.) This approach is sound; the protectiveness of health-based regulatory levels should not routinely be re.evaluated in individual CERCLA remedy selection decisions.
On the other hand, ARARs cannot be an absolute upper bound on cleanup levels in every case in the absence of multiple pathways or contaminants. CERCLA and the NCP establish separate requirements to be protective and meet ARARs. (CERCLA § 121(d)(1), (2); 40 CFR § 300.430(f)(1)(I)(A).) Indeed, protecting human health and the environment is the paramount objective of the Superfund program. (See 55 Fed. Reg.
1OSWER Directive 9355.0-30, “Role of the Baseline Risk Assessment in Superfund Remedy Selection Decisions” (April 22, 1991). This policy is consistent with the NCP. ( See 40 CFR 300.430(e)(2)(I)(D) (authorizing consideration of the cancer risk range where attainment of ARARs will result in cumulative cancer risk of greater than 10 -4 due to multiple pathways or contaminants). See also 1990 NCP Preamble, 55 Fed. Reg. at 8712 (“[w]hen health-based ARARs are not available or are not sufficiently protective due to multiple exposures or multiple contaminants, EPA sets remediation goals” based on site-specific risk-based factors, such as the cancer risk range).)
3

8700 (the NCP remedy selection process “is founded on CERCLA’s overarching mandate to protect human health and the environment”).) Furthermore, CERCLA requires that remedial actions attain ARARs “at a minimum,” clearly contemplating that remedial actions may be more protective than required by ARARs when circumstances so require. (CERCLA § 121(d)(2)(A).)
EPA’s policy of generally establishing PRGs based on ARARs, in the absence of multiple pathways or contaminants, is based on the assumption that individual ARARs will be protective. For example, the NCP expressly authorizes consideration of the cancer risk range in setting PRGs where attainment of ARARs would result in a cumulative risk in excess of 10-4 due to multiple contaminants or pathways. (40 CFR 300.430(e)(2)(I)(D).) The assumption underlying this provision is plainly that individual ARARs would achieve a risk of 10-4 or less. Similarly, the NCP preamble explains that EPA will modify PRGs to be protective where cumulative risks “make ARARs nonprotective” (55 Fed. Reg. at 8713); again, the assumption is that individual ARARs would be protective absent these cumulative risks. In cases where, based on available information, this assumption is not accurate, PRGs should be set at levels more protective than required by the ARAR in order to ensure protection of human health and the environment.

IMPLEMENTATION
In the rare circumstances where, based on available information, application of an ARAR would not be protective of human health or the environment, EPA should establish PRGs at levels that are more protective than required by the ARAR even absent multiple pathways or contaminants. As noted above, in deciding whether a PRG should be established at a level more protective than required by an ARAR, consideration should be given to the level of risk associated with application of the ARAR; the soundness of the technical basis for the ARAR; and other factors relating to the ARAR or to its application at an individual site.
Before making a site-specific determination that an ARAR at a given site is not protective of human health and the environment and should not be used as the basis for establishing PRGs, the site decision maker should consult with Headquarters, unless a prior determination has been made by Headquarters that a particular ARAR should not generally be used to establish PRGs at CERCLA sites.2 The subject matter specialist for this guidance is Robin Anderson of OERR and Brian Grant of OGC. General questions about this guidance should be directed to 1-800-424-9346.
Addressees National Superfund Policy Managers
2For an example of a Headquarters determination that the numerical limits established by a particular ARAR should not generally be used as the basis to establish PRGs at CERCLA sites, see the memorandum from Stephen D. Luftig titled: “Establishment of cleanup levels for CERCLA sites with radioactive contamination” (OSWER Directive 9200.4-18), August 1997, p. 3.
4
Superfund Branch Chiefs (Regions I-X)
Superfund Branch Chiefs, Office of Regional Counsel (Regions I-X)
Radiation Program Managers (Regions I, IV, V, VI, VII, X)
Radiation Branch Chief (Region II)
Residential Domain Section Chief (Region III)
Radiation and Indoor Air Program Branch Chief (Region VIII)
Radiation and Indoor Office Director (Region IX)
Federal Facilities Leadership Council
OERR Center Directors

Post

1995-03-09 – NRC – EPA – West Lake Landfill – Policy Issue – Deferral of Regulatory oversight to EPA

RECEIVED
2 2 1995
‘***
March 9, 1995
FOR:
FROM:
SUBJECT:
POLICY ISSUE
(Notation Vote) SECY-95-056
The Commissioners
James M. Taylor
Executive Director for Operations **
DEFERRAL OF REGULATORY OVERSIGHT TO THE U.S.
ENVIRONMENTAL PROTECTION AGENCY FOR TWO
SITES WITH RADIOACTIVE CONTAMINATION AND
LANDFILL DISPOSAL OF LICENSED MATERIAL FROM
REMEDIATION OF A THIRD SITE
PURPOSE:
To obtain the Commission’s approval for the staff to defer to the U.S.
Environmental Protection Agency (EPA) for the oversight of remediation
activities involving radioactive contamination at two sites and for staff’s
intent to allow disposal of licensed radioactive material in a hazardous waste
landfill.
SUMMARY:
The Nuclear Regulatory Commission and EPA conduct regulatory programs for site
remediation under the Atomic Energy Act (AEA) and the Resource Conservation
and Recovery Act (RCRA), and the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA), respectively. Under certain
conditions, NRC staff believes it would be appropriate for NRC to defer to
EPA, or an authorized State environmental protection program, for the
oversight of remediation of radioactively contaminated sites under NRC
Contact: Heather M. Astwood, NMSS
415-5819
NOTE: TO BE MADE PUBLICLY AVAILABLE WHEN THE FINAL SRM IS MADE AVAILABLE.
Enclosure
The Commissioners – 2 –
jurisdiction. The staff is proposing to defer, to ERA and an authorized State
environmental program, regulation of remediation of two unlicensed sites:
E.I. DuPont, Newport, DE; and West Lake Landfill, Bridgeton, MO. In addition,
the staff intends to authorize disposal of licensed material generated from
remediating Dow Chemical sites in Midland and Bay City, MI, in a hazardous
waste landfill regulated by the Michigan Department of Natural Resources under
the EPA-authorized RCRA program. Remediation activities at these sites are at
various stages of completion. Based on reviews to date, the staff believes
that the remedial actions and disposal required by ERA, or the authorized
State program, will be sufficient to protect the public and the environment
from the risks associated with the radioactive contamination at these sites.
Deferral would conserve Federal and licensee resources, streamline the
remediation process by eliminating duplicative agency reviews, and simplify
the review process by consolidating regulatory oversight within a single
agency. If the Commission approves deferral and disposal, the staff would:
continue to provide limited technical assistance to ERA or State agencies, on
request, for all sites (licensed and non-licensed); monitor remediation
activities; and review all relevant documents developed by the licensee and
ERA or State for each site with an NRC license.
BACKGROUND:
As part of NRC’s decommissioning program for nuclear facilities under the AEA,
some contaminated facilities pose special problems because of the presence of
both non-radiological and radiological hazards, limited technical and
financial viability of licensees, and concurrent regulatory jurisdiction over
various aspects of decommissioning. Some of the sites are being, or w i l l be,
remediated under EPA’s Superfund Program, in accordance with CERCLA and the
National Contingency Plan in 40 CFR Part 300. Other sites involve assessment
and disposal of hazardous waste under EPA’s RCRA Program. Similar interfaces
exist between NRC and State regulatory programs, in which EPA’s authority
under CERCLA and RCRA has been delegated to States. ERA actively promotes
delegation of the RCRA program to authorized States and tends to defer to
States that are w i l l i n g to oversee preparation of the Remedial
Investigation/Feasibility Studies (RI/FS) for individual sites.
Although the RCRA and CERCLA Programs both address hazards to the environment,
CERCLA is the more comprehensive statute because it addresses both operating
and inactive facilities and includes hazardous materials, as well as source,
special nuclear, and byproduct material as defined in the AEA. The staff
previously discussed EPA’s RCRA and CERCLA Programs in SECYs 93-235 and
93-322. RCRA uses a general regulatory program to manage hazardous waste from
generation to ultimate disposal. CERCLA provides authority to respond
whenever there is a release or potential release of hazardous material. The
facility owner or operator implements RCRA corrective action, whereas CERCLA
responses may be implemented by a number of different parties, including
private or public responsible parties, States, or Federal authorities. CERCLA
“hazardous substances” include RCRA “hazardous wastes,” as well as toxic
pollutants under the Clean Water Act (CWA), Clean Air Act (CAA), and Toxic
Substances Control Act (TSCA). Although source, special nuclear, and
byproduct materials are excluded from regulation under CWA, TSCA, and RCRA,
they are included under the CAA, so they are included within the scope of
CERCLA. Consequently, ERA can require remediation of both non-radiological
The Commissioners – 3 –
and radiological contamination, including source, special nuclear, and
byproduct material, in accordance with CERCLA.1
As a general policy, ERA has declined listing NRC-licensed sites for
remediation on the National Priorities List (NPL), in deference to NRC
regulation under the AEA, provided that remediation is progressing under an
NRC license. However, ERA has required remediation under RCRA or CERCLA at
sites that exhibited non-radiological contamination (e.g., chromium
contamination at the Shieldalloy facility in Newfield, NJ) or that were
licensed by Agreement States (e.g., Homestake uranium mill in Milan, NM).
Based on the most recent version of the NPL (February 1994), the total number
of sites listed on the NPL is 1191. The Superfund Program is wellestablished,
and has defined remediation procedures and criteria, including
those that address radioactive materials. Although the remediation process
and criteria are not identical to NRC’s, they are parallel in scope and
purpose, and in the staff’s judgment, are generally adequate for the
protection of the public and the environment. A detailed explanation of the
Superfund site remediation and closure process is given in Enclosure 1 of
SECY-93-235.
The Commission has previously considered staff recommendations to establish
procedures for transferring sites from NRC to EPA, for remediation under the
Superfund Program. In a staff requirements memorandum (SRM) concerning
SECY-89-224, dated August 22, 1989, the Commission stated that it w i l l decide
whether to pursue the transfer of sites, to EPA, for remediation, on a
case-by-case basis, or through a memorandum of understanding (MOD). The
March 16, 1992, general MOD between EPA and NRC explicitly excludes matters
arising under CERCLA and RCRA. Since the general MOU was signed, NRC staff
has negotiated site-specific cooperative agreements for remediation of the
Homestake uranium m i l l , under CERCLA, and the Sequoyah Fuels and Engelhard
Corporation facilities, under RCRA. The staff is also currently discussing
cooperative agreements with State agencies in Ohio and Pennsylvania.
In another SRM dated December 21, 1989, the Commission rejected the staff’s
recommendation to develop a protocol with EPA to govern the application of
Superfund to contaminated sites. Instead of developing a protocol, the
Commission directed the staff to provide, for each site the staff proposes to
defer to EPA or a State agency, under Superfund, analyses of: (1) the cleanup
standard that would apply under Superfund, and the differences between that
standard and the AEA standard; (2) the rights and authorities the State would
have if Superfund were extended to the site; and (3) the rights and
authorities that private citizens would have to sue the Federal Government or
the licensee(s), using the citizen-suit provisions of Superfund.
More recently, the staff proposed to the Commission, in SECY 93-235, to
communicate with EPA about transferring the Safety Light Corporation (SLC)
site at Bloomsburg, PA, to EPA, to supervise site remediation under Superfund.
The rationale for the transfer was to accelerate the remediation of the site
1 CERCLA does not cover releases that are subject to NRC required
financial protection pursuant to Section 170 of the AE Act (i.e., Price
Anderson), nor releases from a processing site under Title I of the Uranium
Mill Tailing Radiation Control Act of 1978.
The Commissioners – 4 –
and limit the Federal resources devoted to the litigation to compel SLC to
remediate the site. The paper explained that during the first half of 1993,
the staff and the licensee tried unsuccessfully to settle the litigation and
the staff believed, as of the date of the paper, that further negotiations
would be futile and litigation would resume shortly. While the Commission was
considering SECY-93-235, the parties resumed negotiations; and in an SRM dated
November 2, 1993, the Commission returned SECY-93-235 to the staff,
“…pending the outcome of the negotiations,” and instructed the staff to
“…keep the Commission informed of further developments and, based on the
outcome of the negotiations, submit recommendations for further action to the
Commission, should that be necessary.” The staff recently completed
negotiations with SLC and successfully concluded a settlement agreement that
governs characterization and remediation planning for the Bloomsburg site.
In a related matter, SECY-93-136 presented the Commission with an analysis of
the State of Utah decision to allow Envirocare of Utah to use only
institutional controls as a means of reducing the risk to the public health
and safety after closure, without government land ownership. ERA regulations
do not always require government land ownership of sites such as these. The
Commission determined that this approach was adequate for protection of the
public health and safety in this particular case, and in a Director’s Decision
under 10 CFR 2.206 issued by the Office of State Programs on January 26, 1995,
the Commission did not revoke Utah’s Agreement State status.
DISCUSSION:
At sites where radioactive and non-radioactive materials are located in
distinct and separate areas, NRC and ERA oversight and regulation of remedial
actions can proceed effectively and efficiently. Although the effectiveness
of the government’s response and oversight can be strengthened through
interagency cooperation, each area can be remediated independently in
accordance with each agency’s requirements and administrative process.
However, independent regulation of remedial activities is not always possible.
There are some sites that contain commingled radioactive and non-radioactive
contamination. At other sites, the contamination is not commingled, but
remediation of one type of contamination would affect the responsible party’s
ability or approach to characterization and remediation of the other type of
contamination. In other cases, although the predominant hazard may be
associated with one type of contamination, the licensee or property owner is
not capable, technically or financially, to remediate either type of
contamination, thus preventing timely and effective completion of necessary
decommissioning or remedial actions. In yet other cases, the responsible
party desires a coordinated government response to reduce overall costs,
improve efficiency, and promote a compatible solution for both types of
contamination.
Under certain circumstances, the staff believes it would be appropriate for
NRC to defer to ERA or authorized State oversight of remediation efforts,
under CERCLA, RCRA, or State statutes. Deferral at these sites would reduce
the amount of duplicative effort by both agencies and by the site owners. For
example, the types of analyses performed by ERA as part of the development of
the RI/FS, under CERCLA (40 CFR 300.430), are very similar to the analyses
The Commissioners – 5 –
conducted by NRC in developing an Environmental Impact Statement (EIS) under
the National Environmental Policy Act of 1969 (NEPA) and 10 CFR Part 51. Both
agencies require submission of fairly extensive information on the
environmental characteristics of the contaminated sites and the nature and
extent of contamination. In addition, the agencies require preparation and
submission of a plan for implementing remedial measures found necessary to
remove or contain contamination in accordance with applicable remediation
criteria. EPA’s plan is called a Remedial Design; NRC calls this a
decommissioning plan.
Without cooperation between the agencies, therefore, it is conceivable that
site owners could be required by the government to develop separate reports
for each agency on site characterization, assessment of remediation
alternatives, projected environmental impacts, plans for remedial measures,
and documentation that the remedial measures were appropriately implemented.
Such an approach could result in an unnecessarily duplicative and burdensome
effort by the site owners and by the agencies.
At worst, the requirements of one agency could explicitly conflict with those
of the other agency, thus frustrating the government’s overall intent to
ensure protection of the public and the environment from residual
contamination. If, for example, EPA decided to allow hazardous waste to
remain onsite, to avoid excessive worker exposure and cost, and NRC decided
that commingled radioactive waste would have to be exhumed and disposed of
offsite, it would be difficult and burdensome, if not impossible, for the site
owner to simultaneously comply with-the requirements of both agencies. The
conflict would be especially significant if one action preceded the other
(e.g., EPA requires a cover to be placed over the waste; NRC later determines
that the radioactive waste needs to be removed for off-site disposal).
The staff believes that it is appropriate to rely on EPA’s environmental
remediation programs to ensure protection of the public and environment at the
DuPont and Westlake Landfill sites. Both cases may rely, at least in part, on
institutional controls to ensure long-term protection. As discussed
previously and in the attachments, such reliance on institutional controls is
somewhat inconsistent with NRC’s established policies for low-level
radioactive waste disposal (cf. State or Federal land ownership requirement
for low level waste disposal in 10 CFR 61.59(a)). However, the staff believes
that EPA remediation will be sufficient to provide adequate protection under
the Atomic Energy Act.
In addition, deferral to EPA provides numerous savings in terms of reducing
the administrative and regulatory burden on responsible parties conducting the
remediation and in conserving NRC staff resources. The staff estimates that
deferral of each site should save between 0.25 and 0.5 FTE per year in direct
staff resources required to oversee remediation at the sites. These resources
would partially duplicate the oversight functions that EPA staff will provide
in overseeing the safe and protective execution of the planned remedial
actions. In addition, deferral should save NRC an additional 0.5 FTE per year
and S600K in program support that could be necessary at each site to prepare
an Environmental Impact Statement (EIS) to support consideration of exemptions
from NRC’s existing requirements for decommissioning for unrestricted use.
The Commissioners – 6 –
Since November 1993, the staff has initiated several EISs to consider
exemption requests as appropriate considering the requirements in 10 CFR Part
51. Deferral should also improve the timeliness of remediation by avoiding
the potential delay that could be associated with administration of
independent and complementary regulatory approval processes for remediation.
Remediation could be further delayed by opportunities for legal challenges to
NRC approval of remedial actions.
Allowing disposal of the Dow wastes in the hazardous waste landfill cells in
Midland may also allow a small increase in the long-term risk to the public
and environment due to some reliance on institutional controls. As previously
described for the Westlake and DuPont site remediation projects, however, NRC
staff believes that such disposal would provide adequate protection of the
public, and any small increase in the associated risk is counterbalanced by
the improvements in efficiency, reduction in regulatory and administrative
burden, and savings of NRC and responsible party resources.
The staff does not consider, however, that these cases would necessarily
establish a precedent for resolution of other waste disposal and
decommissioning cases or establishment of general requirements in these areas.
The decisions on deferral and on approving waste disposal are specific to
these cases. In the cases of DuPont and Westlake Landfill, the radioactive
components appear to be intimately mixed with non-radiological contaminants
and wastes that are not subject to the Commission’s jurisdiction. In fact, at
least for some of the wastes, the dominant risks to the public and environment
may be attributable to the non-radiological contaminants. In addition, both
sites are already listed on the National Priorities List for remediation under
CERCLA, and the basis for listing and selection of the remedies included
consideration of the radiological contaminants.
In the Dow case, the staff has considered the merits of disposing of the
specific wastes present at the Dow sites and under the specified conditions
for disposal as proposed by the licensee and the State. Staff has already
approved other disposals of radioactive waste in or adjacent to hazardous
waste landfill cells in accordance with the provisions of 10 CFR 20.302 and
20.2002. Each of these disposals has been based on a site-specific review by
the NRC staff to ensure adequate protection of the public and that potential
radiological doses do not exceed NRC’s limits in 10 CFR Part 20. In most
cases, the staff has assured that the potential doses do not exceed a small
fraction of the public dose l i m i t . The Dow case is especially significant,
however, because it involves the disposal of a relatively large volume of
radioactive waste that will be generated in decommissioning an SDMP site and
that intrusion into the waste, if it were to occur, could result in doses that
may exceed the public dose limit (e.g., if the intruder were to live on top of
exposed waste for an extended period). The staff believes that the likelihood
of such intrusion is remote in the Dow case because of the design of the
disposal cells and the use of the general area for disposal of hazardous
waste. It is likely that an intruder into the waste would recognize that a
waste disposal cell had been breached and could suffer risk from the nonradiological
contaminants in adjacent cells even if the NRC did not authorize
disposal of the radioactive waste.
The staff would be prepared to entertain similar requests to the Dow request
from licensees to dispose of licensed material in hazardous waste landfills or
The Commissioners – 7 –
other suitable disposal facilities (e.g., monofills, sanitary landfills) in
accordance with the requirements of 10 CFR 20.2002. In such cases, as with
the Dow case, the burden would rest with the licensee to demonstrate that the
requirements of 10 CFR Part 20 will be satisfied, specifically that the
potential doses will be consistent with the Part 20 limits and are as low as
is reasonably achievable. Credit for institutional controls, such as those
that accompany Dow’s proposal, would also be considered on a site-specific
basi s.
For these reasons, the staff believes that NRC should defer to EPA or State
oversight regulatory programs for specific aspects of the remediation of two
contaminated sites: E.I. DuPont, Newport, DE; Cotter Corporation (West Lake
Landfill), Bridgeton, MO; and allow disposal of radioactive waste from
remediation in a RCRA permitted landfill for Dow Chemical, Midland and Bay
City (Salzburg Landfill), MI. By deferral, the staff means a variety of
approaches depending on the specific status of the contaminated sites.
For the DuPont site, the staff proposes to recognize EPA’s approved remedial
measures under CERCLA as being sufficiently protective of the public and
environment. The site is not currently licensed by NRC; NRC licensing and
oversight of the remediation of a small quantity of thorium waste in a
landfill would not be necessary, nor required, under the AEA. No further
action would be taken by the NRC staff, unless specifically requested by EPA.
For the West Lake Landfill site, EPA has already agreed to assume lead
responsibility for the site. The West Lake Landfill is listed in NRC’s Site
Decommissioning Management Plan (SDMP). The NRC staff is proposing to defer
to EPA oversight of remedial measures under CERCLA. EPA’s remediation of the
site already considers both radioactive and non-radioactive materials. The
site is not currently licensed by NRC; the staff would take no further action
at the site after deferral, unless specifically requested by EPA. NRC would
remove the site from the SDMP after EPA completes remedial measures at the
site.
Regarding the Dow Chemical sites in Midland and Bay City, Michigan, the staff
proposes to allow the licensee to dispose of thorium-contaminated waste in a
licensee-owned and permitted hazardous waste landfill designed and operated in
accordance with the RCRA requirements administered by EPA and the State of
Michigan. The staff would authorize disposal in accordance with NRC
requirements in 10 CFR 20.2002 and support the decision with an Environmental
Assessment that would presume the effectiveness of RCRA controls in ensuring
protection of the public and environment. Regulatory responsibility for the
management and long-term control of the thorium in the disposal site would, in
theory rest with NRC. However, in terminating the license, NRC would
recognize that controls for the hazardous waste, developed under RCRA, while
relying on land use restrictions which are not dependant on State or EPA
regulatory power, w i l l be adequate for the thorium as well. In allowing
disposal in the Salzburg Landfill, NRC would be recognizing that disposal of
thorium-contaminated wastes in a hazardous waste landfill may be acceptable
under the AEA, instead of requiring offsite disposal at a licensed radioactive
waste disposal facility. The Dow storage sites are listed in the SDMP and are
being remediated under an NRC license. NRC staff would continue to license
and regulate the remedial measures directed at removing the thorium waste from
its present locations. At such time as all waste has been satisfactorily
The Commissioners – 8 –
disposed of in the hazardous waste landfill and residual radioactivity has
been reduced in accordance with existing criteria, the staff would terminate
Dow’s license for the Midland and Bay City sites and no further action would
be taken by the NRC staff.
Background information for the DuPont, Westlake Landfill, and Dow sites is
provided in Attachments 1 to 3, respectively. The potential advantages and
disadvantages of deferral for each site are summarized in Attachment 4.
Requested Analysis:
In accordance with the Commission’s previous direction on information to
support deferral decisions, the staff provides the following analyses of:
(1) the cleanup standard that would apply under Superfund and the differences
between that standard and the AEA standard; (2) the rights and authorities the
State would have if Superfund were extended to the site; and (3) the rights
and authorities that private citizens would have to sue the Federal Government
or the licensee(s), using the citizen-suit provisions of Superfund. The
following analyses are presented in generic terms that would apply to all
three sites. The discussion about remediation criteria is only pertinent at
this time to the West Lake Landfill site; ERA has already decided to stabilize
the thorium waste in place at the Dupont site, and the thorium waste from Dow
would be disposed of in an RCRA-regulated landfill cell. To compare specific
EPA and NRC remediation standards for the West Lake Landfill, more information
would be needed on the remediation criteria EPA intends to implement at that
site. EPA will determine these criteria through the RI/FS and Record of
Decision (ROD) process, as described below.
(1) Remediation Standard
As previously stated, both NRC and EPA have been granted the authority
to regulate radioactive materials, in certain situations. To determine
what remediation standards would govern the remedial actions at a
specific site, EPA would perform a Feasibility Study (FS). This study
is the basis for the development of a ROD that establishes remediation
standards and remedial actions for each site. EPA would prepare the FS
after the site had been scored and entered on the NPL, as explained in
Enclosure 1 of SECY-93-235.
EPA’s requirements for FSs in 40 CFR 300.430(e)(2)(i) require that the
lead agency establish remedial action alternatives, including
remediation objectives and goals. The remediation goals establish
acceptable exposure levels to protect human health and the environment
and are developed considering: applicable or relevant and appropriate
requirements (ARARs) under Federal or State environmental laws,
drinking-water standards and goals, water-quality criteria, and other
factors. For known or suspected carcinogens (including ionizing
radiation), acceptable exposure levels are generally concentration
levels that represent an excess upper-bound lifetime cancer probability,
for an individual, of about 10″A and a cancer probability of 10″6 for as
many in the population as practical. The 10″6 probability is used as
the point of departure for determining remediation goals when ARARs are
not available or are not sufficiently protective, because of the
presence of multiple contaminants or multiple pathways.
The Commissioners – 9 –
These risk goals do not necessarily take into account human intrusion in
the future. If human intrusion were to be considered in the dose
pathway analysis, the calculated dose for thorium contaminated sites
could be in excess of 100 mrem/yr assuming standard exposure scenarios
(e.g., resident farmer scenario). Therefore, sites with significantly
elevated thorium concentrations would not necessarily meet the
provisions of the proposed NRC rule on radiological criteria for
decommissioning (proposed amendments to 10 CFR Part 20; 59 FR 43200).
The statement of considerations for the proposed rule acknowledges that
some sites could not meet the limits proposed in the rule. Deferral to
the Federal Superfund/RCRA approach is a possible way to address these
cases.
NRC risk analyses differ from ERA risk analyses in several ways. ERA
calculates risk based on the chance of developing cancer. NRC relates
risk to both the chance of developing cancer and the chance of a
fatality as a result of cancer. NRC staff calculated the risk to a
maximally exposed member of the public who at some time in the future,
could reside on top of the site. By using a general risk estimate of
5xlO”2 fatal cancers per sievert (5xlO~4 per rem) of received dose
developed for exposure of a large population, NRC can estimate a
potential risk, to an individual, produced by a specific exposure.
Nevertheless, were an actual measured exposure to occur, the staff
recognizes that it would be more appropriate to estimate the risk to
that individual using the cancer risk tables developed by the National
Cancer Institute.
In general, NRC has not relied on institutional controls as a means for
protecting the public or the environment for decommissioning purposes.
However, ERA and DOE have relied on institutional controls to prevent or
reduce the likelihood for human intrusion and otherwise protect the
public (e.g., restrictions on groundwater use). Staff compared
regulatory considerations of institutional controls in SECY-93-322,
dated November 26, 1993. Reliance on institutional controls directly
affects projected risks to exposed humans.
Based on information provided by the ERA staff, NRC has reviewed 19 RODs
for sites that include some radiological contamination. Most cases
involved contamination by radium-226 and its decay products and other
naturally-occurring radionuclides. In most of the RODs, ERA selected
ARARs based on EPA’s standard, for remedial action, at uranium mill
tailings sites in 40 CFR Part 192. In many cases, ERA also identified
NRC guidance in Regulatory Guide 1.86 “Termination of Operating Licenses
for Nuclear Reactors,” as an ARAR for surface contamination on buildings
and equipment. Other sources of ARARs for radiological contamination
include: NRC’s air concentration limits in 10 CFR Part 20, Appendix B;
State guidance on acceptable surface contamination; DOE orders for
acceptable public and worker doses; Federal and State water quality
standards; and Federal and State air-emission limits.
The Commissioners – 10 –
(2) State Authority under Superfund
For facilities covered by CERCLA, 42 USC 9605, et sec?., the States are
encouraged to enter into cooperative agreements to enable them to
undertake certain actions, under the National Contingency Plan (NCR), as
the lead agencies. State and local response organizations are expected
to initiate measures necessary to protect the public health and safety,
consistent with the containment and cleanup requirements in the NCR.
The RI/FS required under 40 CFR 300.430(d) and (e) are to be performed
by a lead agency, in coordination with any support agencies. Under
40 CFR 300.5, the State may be designated as the lead agency to plan and
implement a response, if it is operating pursuant to a contract or
cooperative agreement, under Section 104(d)(l) of CERCLA, or designated
as the lead agency in a Superfund Memorandum of Agreement (SMOA) or
other agreement. In addition, even if the State does not serve as lead
agency, the lead agency is required to consult with the local officials
and community representatives before commencing field work for the
remedial investigation. Under 40 CFR 300.430(c), support agencies are
afforded an opportunity to identify their own ARARs, under 40 CFR
300.430(d)(3). Support agencies are to be notified, by the lead agency,
of the alternatives that will be evaluated in detail, to facilitate the
identification of ARARs and any appropriate guidance to be considered,
under 40 CFR 300.430(e)(8).
In addition to the above, 40 CFR 300.430(e)(9)(iii)(H) requires that the
State’s concerns be assessed, including its views on the preferred and
other alternatives for remedial action and the ARARs or proposed use of
waivers.
Further, 40 CFR 300.430(f)(1)(i)(C) provides that the lead agency must
consult with the State, and that State and community acceptance are
modifying criteria that are to be considered in the remedy selection.
Section 300.430(f)(4)(i) provides that the State’s views are to be
considered by the lead agency in its final remedy selection from among
the various alternatives.
(3) The Rights of Private Citizens under Superfund
As discussed above, ERA is to solicit community participation in the
identification of ARARs and other aspects of the RI/FS process. In
addition, private citizens are authorized under CERCLA to undertake a
response action to eliminate a release of a hazardous substance,
pollutant, or contaminant, subject to the citizens’ compliance with the
provisions of 40 CFR 300.700. Various mechanisms are provided in CERCLA
for a private citizen to recover the cost of such response action.
These mechanisms are summarized in 40 CFR 300.700, and include:
(a) recovery of the response cost, plus interest, from the
parties found to be liable; and (b) recovery from Superfund of the
private citizen’s reasonable costs, plus interest.
In addition, “citizens suits” are authorized under Section 310 of
CERCLA. Private citizens are authorized to commence a civil action, on
The Commissioners – 11 –
their own behalf, against: (a) any person who is alleged to be in
violation of any standard, regulation, condition, requirement, or order
under CERCLA; and (b) any Federal official who is alleged to have failed
to perform a required duty, under CERCLA. Judicial relief, in such
actions, may consist of an order to enforce and/or correct the violation
or an order imposing any civil penalty provided for the violation; and
the court may award the prevailing party his costs of litigation,
including reasonable attorney and expert witness fees.
RECOMMENDATIONS:
That the Commission:
1. Approve deferral to EPA’s CERCLA program for the remediation of the
thorium waste located on the E. I. DuPont Superfund site in Newport, DE.
2. Approve deferral to EPA’s Superfund program for remediation of the West
Lake Landfi11/Cotter Corporation site in Bridgeton, MO.
3. Approve staff’s plans to pursue a request submitted by Dow
Chemical Company for an exemption from the unrestricted release
provisions of 10 CFR 40.42(f)(3) and to authorize disposal of
thorium waste from remediation in a landfill in accordance with
10 CFR 20.2002. The landfill would be regulated under Michigan
hazardous waste regulations that implement the RCRA program for
long term control of the waste in the Salzburg Landfill cells,
including reliance on institutional and State control and longterm
monitoring of the Salzburg Landfill site in Midland, MI.
4. Note:
a. That although EPA is authorized to regulate byproduct, source, and
special nuclear material under CERCLA and CAA, the State agencies, if
they are not NRC Agreement States, are not authorized except under CAA.
That even though NRC is allowing disposal under the RCRA program
administered by EPA and Michigan Department of Natural Resources, NRC
staff will continue to regulate remediation of the Dow Chemical storage
sites in Michigan, which are currently licensed by NRC. With respect to
the disposal in the Salzburg landfill, the staff will continue to review
pertinent documents to ensure Michigan is not applying significantly
less stringent waste disposal requirements than NRC.
b. That reliance on institutional controls over the long term may not
provide as high a level of protection for the public health and
environment as that attained if there were no reliance on institutional
controls. This lower level of assurance results from the lack of a
guarantee that there will always be a responsible party to maintain the
controls.
The Commissioners – 12 –
COORDINATION:
The Office of the General Counsel has reviewed this paper and has no legal
objection. NRC staff consulted with ERA and the States of Delaware, Missouri,
and Michigan in preparing this paper. Neither ERA nor the States objected to
the staff’s proposed approach.
~2^1/L~
x , „„ /A- -^*yl^-^
/J^mes M. Ta/lor
(ecutive Director
for Operations
Attachments:
1. Bkgd Info for E.I. DuPont
2. Bkgd Info for Cotter Corporation
West Lake Landfill
3. Bkgd Info for Dow Chemical
4. Adv/Disadv of Prop Options by Site
Commissioners’ comments or consent should be provided directly to the Office
of the Secretary by COB Friday, March 24, 1995.
Commission Staff Office comments, if any, should be submitted to the Commissioners
NLT March 17, 1995, with an information copy to the Office of the Secretary.
If the paper is of such a nature that it requires additional review and comment,
the Commissioners and the Secretariat should be apprised of when comments may
be expected.
Distribution:
Commissioners
OGC
OCAA
DIG
OPA
OCA
ACNW
Region I
Region III
EDO
SECY
BACKGROUND INFORMATION FOR THE
E.I. DUPONT NEWPORT, DELAWARE, SITE
The E.I. DuPont site is located in Newport, Delaware, near 1-95, 1-495, and
the Christina River. The entire site is approximately 485,600 m2 (120 acres)
and contains a paint pigment production facility, a chromium dioxide
production facility, and two industrial landfills (North and South) which are
closed.
DuPont was licensed by the U.S. Atomic Energy Commission (AEC) and began using
radioactive materials at this site in 1961, for the processing of thorium into
metal alloys. The alloys consisted mostly of nickel, some chromium and
molybdenum, and thorium (approximately 2 to 5 percent by weight thorium-232).
Waste materials from this process were buried in the North Landfill,
reportedly, in accordance with 10 CFR 20.304 regulations that were in effect
at the time. According to DuPont, the thorium waste was placed in glass jars
that were subsequently placed in 55-gallon barrels together with disposable
protective clothing and debris from the waste-handling operations. The
barrels were then buried in a specific, although uncertain, section of the
North Landfill and covered with 3 m (10 feet) of soil. The area where the
thorium was buried is estimated to be 40 m by 10 m (130 ft by 35 ft) and
contains approximately 20 tons of thorium metal, which were placed in the
North Landfill over a 7 year period.
DuPont believes most of the thorium in the North Landfill consists of thorium
oxide, a relatively insoluble form of thorium. However, DuPont’s records, as
well as information in the Nuclear Regulatory Commission’s docket files,
indicate that thorium nitrate, a more soluble form of thorium, and other salts
could also have been disposed of in the North Landfill. Long-term releases
from these other forms of the thorium waste could be greater than from the
thorium oxide. They could also pose a greater threat to shallow groundwater
beneath the North Landfill site, because of leaching and subsequent transport.
The thorium burials comprised a small portion of the North Landfill area. The
remaining portion of the North Landfill was used for the disposal of
lithophone wastes (an inorganic paint pigment based on zinc and barium),
organic pigment wastes, chromium wastes, and other miscellaneous wastes,
including the off-specification thoriated nickel and other thorium wastes.
The Environmental Protection Agency (EPA) initiated the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA) Program for
remediation of the site in the 1980s and proposed the site for inclusion on
the National Priorities List (NPL) in 1987. EPA proposed the site for
remediation under CERCLA because of extensive non-radiological contamination.
DuPont used historical records and interviews with retired employees to
estimate the quantity of thorium that was buried in the l a n d f i l l . However,
the records are not complete and the exact quantity and form of the thorium
are not known. Although the entire DuPont site is currently undergoing
remediation, remediation of the North Landfill is of the most concern to NRC
because of the thorium buried in the landfill. The North Landfill is only a
small section of the entire 120-acre site.
Attachment 1
-2-
Based on available records of the burials, NRC staff believes that at least
some of the thorium wastes in the North Landfill exceeds the concentration
criteria in Options 1 and 2 of the 1981 Branch Technical Position (BTP)
entitled: “Disposal or Onsite Storage of Thorium or Uranium Wastes from Past
Operations” (46 FR 52061). NRC identified these criteria as the pertinent
release criteria in the Site Decommissioning Management Plan (SDMP) Action
Plan of April 16, 1992 (57 FR 13389) coupled with the principle that residual
radiation be reduced to as low as is reasonably achievable (ALARA). Because
thorium concentrations are expected to exceed these criteria in some areas by
a substantial margin (e.g., 10,000 pCi/g thorium-232), the NRC staff would
generally not consider onsite disposal as a viable disposal action.
In addition, as described above, it is possible that there are soluble forms
of thorium in the landfill, which could become mobile and enter the
groundwater beneath the site or the river adjacent to the site. DuPont has
not attempted to characterize the thorium waste in the landfill for the
following reasons: (1) the exact location of the thorium in the landfill is
not known; (2) intrusive and extrusive sampling may be necessary because the
waste is very heterogeneous, which would make accurate sampling through a
limited number of boreholes difficult; and (3) exposure to the hazardous
material in the landfill would cause risks to workers during the
characterization and sampling process.
Monitoring well sampling found slightly elevated levels of radium-226 and
radium-228 in the groundwater adjacent to the landfill. DuPont believes the
elevated levels are representative of background. Elevated levels of radium
were not found in surrounding wells or in wells located between the landfill
and the well containing the elevated readings.
EPA w i l l require DuPont to place a low-permeability cover system over the
landfill, capable of reducing infiltration by over 99 percent, to minimize
groundwater contamination below the site. In addition, DuPont is required to
construct a physical barrier wall extending from the top on the landfill,
along the river bank and down to the base of the Columbia aquifer. This wall
w i l l cause mounding of the groundwater in the landfill. Groundwater
extraction wells w i l l be installed to control this mounding. The recovered
groundwater shall be treated. This wall will prevent the contaminated
groundwater from entering the river. Monitoring will be needed to ensure
there will not be erosion of the river bank and the potential for erosion from
the river into the landfill itself.
The potential risks produced by the thorium contamination are small compared
with the risks posed by the other hazardous waste in the North Landfill, as
well as the materials on the remaining portions of the site. EPA’s risk
assessment supporting the ROD concluded that non-radiological risks
predominate over radiological risks associated with the thorium waste buried
in the landfill. EPA requires in the ROD that DuPont: monitor groundwater to
detect any potential migration of thorium or its decay products; apply
institutional controls to restrict public access to the waste and to
groundwater beneath and adjacent to the site; and assess the existence of
radiological contamination at other locations onsite. The remedial action
identified in the ROD was developed through a public process that involved
DuPont, State of Delaware, local community officials, members of the public,
and other interested parties.
The NRC staff believes that the remedial action required by EPA, under CERCLA,
-3-
would be sufficient to protect the public and the environment from the risks
associated with the thorium waste. Although NRC and ERA staffs suspect that a
majority of the thorium is in the relatively insoluble oxide form, there is a
possibility that some more soluble thorium compounds exist in the landfill.
However, with the cap, wall along the river bank, groundwater monitoring,
institutional controls, and groundwater use restrictions, the staff believes
that any significant contamination of the groundwater by thorium is unlikely
to occur. However, if it does, the staff believes the contamination would be
accompanied by other contaminants, promptly detected, and mitigated before
causing any significant health or environmental hazards.
Since the site is not currently licensed by NRC, the staff would not undertake
any other activities directly related to remediation of the site, including:
performing reviews of licensing (Superfund-required) documents; undertaking
site visits or inspections; monitoring ERA progress on the remediation; and
examining the completion of cleanup activities.
BACKGROUND INFORMATION FOR THE
WEST LAKE LANDFILL/COTTER CORPORATION
BRIDGETON, MISSOURI SITE
The West Lake Landfill is a 809,000 m2 (200-acre) tract located in St. Louis
County, Missouri, approximately 16 miles northwest of downtown St. Louis.
Beginning in 1962, portions of the property were used as an unregulated dump
for solid and liquid industrial wastes, municipal refuse, and construction
debris. In 1973, Cotter Corporation, a Nuclear Regulatory Commission
licensee, disposed of over 39,000 metric tons of uranium ore processing
residues and contaminated soil in two areas covering about 64,750 m2 (16
acres) of the site. This is a relatively small portion of the larger
809,000 m2 (200-acre) site. In 1976, the unregulated landfill was closed, and
in following years, the Missouri Department of Natural Resources issued
several permits for various portions of the 809,000 m2 site. Efforts to
remediate the site included NRC survey and site characterization work in the
1980s. In 1990, the Environmental Protection Agency (ERA) listed West Lake
Landfill as a Superfund site by adding it to the National Priorities List.
Under Superfund, EPA is now regulating remediation of the site for both
radiological and other hazardous wastes.
The radioactive wastes in the two soil areas are mostly covered by other
landfill materials. The site poses no immediate radiological threat to the
public. Radioactive wastes, in concentrations greater than the current NRC
standards for unrestricted release, are found in two soil piles and include
uranium-238, thorium-230, and radium-226. Elevated levels of radioactivity
(gross alpha particle contamination) have been detected in groundwater
monitoring wells onsite, indicating slight contamination above background.
The NRC staff proposes to defer to EPA’s Superfund Program for the remediation
of uranium contamination. NRC staff has already acknowledged that EPA’s
Superfund Program is responsible for the remediation of the radioactive waste
on this site. A letter dated May 1991 states that “. . . EPA is taking the
lead for site remediation activities . . . .” NRC staff has performed limited
reviews of EPA-required documents, including the Remedial Investigation/
Feasibility Study for the site, that included considerations of both
radiological and non-radiological material onsite. The NRC staff believes the
remedial actions that would be required by EPA, under the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA), would be
sufficient to protect the public and the environment from the risks associated
with the uranium contamination.
Under this deferral scenario, NRC staff would continue to provide certain
technical support to EPA, at the specific request of EPA. In addition, NRC
would retain a copy of the Record of Decision in the permanent files for the
site. The staff would take no further action at the site after deferral to
EPA, since the site is not currently licensed by the NRC.
Attachment 2
BACKGROUND INFORMATION FOR THE DOW CHEMICAL COMPANY
BAY CITY AND MIDLAND, MICHIGAN, SITES
Dow Chemical Company possesses thorium-contaminated waste under a Nuclear
Regulatory Commission license at two sites in Michigan: Bay City and Midland.
The Bay City site is located 1 mile south of Saginaw Bay and is 20 miles east
of Midland, Michigan. The thorium-contaminated waste at this site is stored
in a fenced-in area owned by Dow Chemical Company. Approximately 30,500 m3
(40,000 yd3) of thorium-contaminated waste is estimated to be stored at the
Bay City site. This waste has an average concentration of 188 pCi/g thorium-
232, with a range of from 2 to 7000 pCi/g thorium-232. Dow estimates that
there are about 9.2 Ci of thorium-232 and an equivalent amount of thorium-228
at the Bay City location.
The estimated volume of the thorium-contaminated waste at the Midland site is
over 9000 m3 (12,000 yd3). The area where the waste is stored at the Midland
site measures 50 m by 90 m (160 ft by 300 ft) and is roped off. The waste is
covered by a clay cover that is approximately 1-meter thick. The thoriumcontaminated
waste storage area is located within a larger industrial complex
that Dow owns and controls access to. The radioactivity in the waste varies
substantially and ranges up to 2000 pCi/g, with an average of 29 pCi/g
thorium-232 and an equivalent activity concentration of thorium-228. Dow
estimates that there is approximately 0.46 Ci of thorium-232 in the waste at
this site.
In 1956, the U.S. Atomic Energy Commission gave Dow Chemical Company a license
to use thorium metal and compounds to produce thorium-magnesium alloys. The
alloying process produced a thorium-contaminated waste. In 1973, the license
was amended to authorize storage only at Dow’s Bay City and Midland sites in
Michigan, and at the Madison site in Illinois. The Madison site is now under
the regulatory authority of the Illinois Department of Nuclear Safety.
Thorium-contaminated waste and associated contaminated soil are currently
being stored at both sites. Dow proposes to dispose of its thoriumcontaminated
waste in two dedicated disposal cells at the Dow-owned and
operated Salzburg Landfill in Midland. The Salzburg Landfill is permitted by
the Michigan Department of Natural Resources and the Environmental Protection
Agency (ERA), for the disposal of hazardous and non-hazardous solid wastes.
The Salzburg Landfill, is relatively large [615,100 m2 (152 acres)], and is
located 1.5 miles from the Midland site and 20 miles from the Bay City site.
The proposed disposal cell design, for the thorium-contaminated waste, would
be comprised of, from the bottom, a 6 meter clay underliner with a hydraulic
conductivity of less than 10″6 cm/s; 1 meter of recompacted clay with
hydraulic conductivity of less than 10″7 cm/s; a synthetic liner with a leak
detection and removal system consisting of a 0.33-meter sand drainage layer;
1.5 meters of clay; a geosynthetic liner; and a 0.33-meter sand leachate
drainage layer. This liner would underlie the thorium-contaminated waste
which would be covered by 1 meter of clay; a 100-mil HOPE synthetic liner;
0.33 meters of drainage medium; almost a meter (91 cm) of a frost protection
layer; and 0.66 meters of top soil. No liquid wastes are allowed to be
disposed of at the Salzburg Landfill. The approximate design area for one of
the proposed thorium-contaminated waste disposal cells is 61 m (200 ft) long
by 40 m (125 ft) wide, and the other is 221 m (725 ft) long by 23 m (75 ft)
Attachment 3
-2-
wide. Both disposal cells will be covered by a unified cover. There are 16
shallow monitoring wells around the proposed disposal cells. These monitoring
wells are required under Resource Conservation and Recovery Act (RCRA) and
State of Michigan hazardous waste requirements. Groundwater monitoring wells
and domestic wells in the area are sampled as part of the Salzburg Landfill
monitoring program.
The NRC staff proposes to allow Dow Chemical Company to dispose of licensed
material in EPA-approved RCRA designed cells in accordance with 10 CFR 20.2002
and thereby be exempt from NRC’s unrestricted release criteria of 10 CFR
40.42(j)(3) [Although the amended rule does not refer to unrestricted release,
but to release in accordance with NRC requirements, the criteria of the SDMP
Action Plan apply. These are essentially unrestricted release criteria.] Dow
has requested to bury thorium-contaminated waste in the Salzburg landfill, per
10 CFR 20.2002, at concentrations above NRC’s SDMP Action Plan criteria for
unrestricted release.
There is a parallel between what is being proposed by Dow and the burial of
low-level waste under 10 CFR Part 61. The performance objectives for the
disposal of low-level radioactive waste, as stated in 10 CFR Part 61 and the
Final Environmental Impact Statement for Part 61 (NUREG-0945), are to: 1)
protect public health and safety (and the environment) over the long term; 2)
protect the inadvertent intruder; 3) protect workers and the public during the
short-term operational phase; and 4) provide long-term stability, to eliminate
the need for active long-term maintenance after operations cease. The staff
believes that disposal of the thorium waste in the landfill would be generally
consistent with these objectives, although the staff has not completed the
kind of detailed review that would be required for a license application under
10 CFR Part 61.
For thorium contamination of the type presently stored by Dow under its
license, the dominant exposure pathway is direct exposure from human
intrusion. Thorium-232 has an extremely long half-life (in excess of 14
b i l l i o n years). Thus, the potential hazard will continue to exist whether the
material is excavated and shipped to a licensed disposal site (at an estimated
cost of about $28 million if disposed at Envirocare or significantly more if
disposed at a licensed low-level waste disposal facility) or excavated and
shipped to the Salzburg Landfill (at a cost of about $5 million). The primary
safety issue then becomes how to minimize the potential for human intrusion
over the long term under either disposal alternative. Dilution of the
contamination was not considered due to the significant increases in waste
volume that would be required to substantially reduce thorium concentrations
down to levels approaching natural background for soils in the Midland area.
As a regulated hazardous waste disposal facility, institutional controls would
be required to be maintained over the Salzburg Landfill under hazardous and
solid waste regulations. Dow states that, even though the concentration of
thorium in the waste exceeds NRC’s criteria for unrestricted release, the colocation
of the thorium waste disposal cells with the hazardous and solid
waste disposal cells would offer sufficient institutional control to deter
intrusion over the long term. The institutional controls offered by hazardous
and solid waste regulations involve environmental monitoring and reporting,
maintenance and release control, and controls on the post-closure use of the
land (i.e., no disturbance of the waste or any components of the disposal
unit). There are additional requirements for post-closure financial assurance
and a schedule for closure. Dow estimates that the pre-closure operational
-3-
period for the Salzburg Landfill will extend until approximately the year
2045. The post-closure institutional control period generally lasts 30 years
and can be extended by the ERA Regional Administrator or State agency. The
Salzburg Landfill is not a remote site, but because of the existence of the
hazardous waste already buried there, the land can never be used productively
again for farming and other non-industrial applications without extensive
remediation. Dow has already imposed restrictive covenants in the Salzburg
Landfill deed, in accordance with ERA requirements for hazardous waste
landfills. If the thorium wastes are buried in the Salzburg Landfill, Dow
proposes a requirement (to be inserted into the deed) to notify NRC (or its
successor) before disturbing the landfill.
On balance, the staff believes that disposing of the thorium wastes at the
Salzburg Landfill constitutes an as low as reasonably achievable (ALARA)
approach to remediation of the Bay City and Midland sites, and that the
conditions and restrictions placed on the landfill, combined with the RCRA
regulatory and cell design provisions, provide a comparable level of
protection of human health and the environment, as is provided at other
licensed low-level waste disposal sites. In the Office of the General
Counsel’s opinion, Dow’s proposed restrictive covenants appear adequate to
support an exemption. With one exception, the restrictive covenants, and the
co-location of the thorium-contaminated waste disposal cells with hazardous
and solid waste disposal cells, appear to achieve the same effect as if this
thorium-contaminated waste were buried at a location where State or Federal
control alone is considered sufficient to guarantee institutional care.
Inadvertent intrusion into the thorium waste disposal cells would be
controlled by the restrictive covenants on the deed as proposed by Dow in its
exemption request. The one exception is that, as with the Envirocare facility
in Utah, there is no assurance that, for the very long term, there will be a
responsible party with the obligation to take additional remedial action
should this become necessary.
Therefore, NRC staff proposes to allow disposal of licensed radioactive
material in the landfill operated by Dow and regulated by ERA and the State of
Michigan. This decision would be supported by an appropriate Environmental
Assessment, which would presume the adequacy of the cell design and
institutional controls (including ERA and Michigan regulation) in protecting
humans and the environment. NRC staff would notice in the Federal Register
its intent to issue a license amendment to allow the disposal of the waste in
the Salzburg Landfill, including the exemption. Pursuant to Subpart L of 10
CFR Part 2, the notice will offer an opportunity for an informal hearing. The
hearing would include approval of the decommissioning plan and the transfer
and disposal under 20.2002 at the Salzburg l a n d f i l l . Following completion of
the necessary safety and environmental reviews, NRC staff anticipates issuing
the amendment, provided the safety and environmental reviews are favorable.
Because the Dow storage sites are currently licensed by the NRC, the staff
would monitor the remedial activities being performed by Dow to ensure that
NRC requirements are satisfied. The staff would review all pertinent
documents and would terminate the license after disposal of the radioactive
material currently in storage at the Bay City and Midland sites and the
storage sites are cleaned up to unrestricted use standards.
ADVANTAGES AND DISADVANTAGES OF
PROPOSED OPTIONS FOR EACH SITE
Attachment 4
E. I. DUPONT CORPORATION
Administrative Alternatives for the
Remediation of the Newport, Delaware, Site
Deferral to EPA Superfund NRC Maintains Responsibility
Advantages
• Allows DuPont to continue remediation activities
in a timely and effective manner.
• Reduces delays and expense produced from
duplicative regulation.
• Ensures consistency in remediation decision for
both radiological and non-radiological waste.
• Avoids need for an NRC license.
• Promotes interagency cooperation and consistency
in selection of remedial actions.
Advantages
Remediation of the thorium contamination down to
Option 1 or 2 levels2 would reduce risk to
inadvertent intruders.
Provides higher level of assurance that remediation
is conducted in a satisfactory manner, from NRC’s
perspective.
2 Option 1 or 2 of the 1981 Branch Technical Position “Disposal or Onsite Storage
of Thorium or Uranium Wastes from Past Operations.”
-2-
Disadvantages
Relies on institutional controls for protection
of the public.
Could require removal at some point in the
future, if the thorium contaminates the
groundwater.
Reduces assurance of satisfactory remediation
from NRC’s perspective.
Disadvantages
May ultimately find that current proposed
remediation is acceptable and preferable, after
additional expense and time.
If exhumation would be required, could result in
increased risk to workers from exposure to nonradiological
and radiological wastes in the landfill
and extended storage of waste pending access to
disposal facilities.
Increases costs for DuPont, ERA, and NRC.
May require additional effort to establish location
of thorium waste in landfill.
Could require NRC license.
Could delay or impair remedial actions for the other
wastes onsite, pending resolution of the thorium
waste disposal issue._____________________
-3-
WEST LAKE LANDFILL/COTTER CORPORATION
Administrative Alternatives for the
Remediation of the Bridgeton, Missouri, Site
Deferral to ERA Superfund NRC Maintains Responsibility
Advantages
• Continues established lead responsibilities
between NRC and ERA (ERA lead).
• Reduces costs and delays produced from duplicative
regulat ion.
• Avoids need for an NRC license.
• Promotes consistency in NRC and ERA remedial
deci sions.
Advantages
• Maintains NRC control of the remediation under Atomic
Energy Act.
• May result in lower risk to public and environment if
site is remediated to Option 1 or 2 levels.
• Avoids reliance on institutional controls.
Disadvantages
• Reduces assurance that NRC w i l l find the remedial
action satisfactory because ERA has not yet
selected remedial action for the uranium
contamination.
• Introduces possibility that additional remediation
may be necessary in the future.
• Places remediation outside of NRC control; no
assurance when remedial actions w i l l occur.
Disadvantages
• Increases costs and duplicative effort for regulating
agencies and Cotter Corporation.
• May delay the remediation of the non-radioactive
materials onsite.
• May produce conflicts for Cotter if NRC and ERA
approve inconsistent remedial actions.
• May require imposition of a license through order, if
Cotter objects to license and one is required.
DON CHEMICAL COMPANY
Administrative Alternatives for the
Remediation of the Midland and Bay City, Michigan, Sites
Approve Site Disposal Request Removal & Offsite Disposal
Advantages Advantages
Reduces costs and delays from duplicative
regulation.
Allows timely completion of remediation and
termination of NRC licenses for the Midland and
Bay City sites.
Could reduce public and worker risks
from near site disposal as compared to
transporting waste across country.
Promotes consistency between NRC and ERA in terms
of remediation decisions.
Maintains NRC control of the disposal of the
radioactive waste.
May reduce long-term risks if wastes were disposed
of at a licensed disposal facility for radioactive
waste that does not rely on institutional controls.
Reduces by one the number of radioactive waste
disposal sites in the country.
Disadvantages
Additional remediation under NRC control may be
necessary at the Salzburg Landfill at some point
in the future, if warranted.
Establishes precedent for disposal of radioactive
wastes in hazardous waste landfill and for
reliance on institutional controls.
Disadvantages
• Relies on limited disposal capacity for radioactive
waste.
• Increases costs for regulating agencies and Dow
Chemical.
• May delay remediation of the Midland and Bay City
sites, pending resolution of waste disposal
location.
-5-

Post

2015-10-19 – EPA – West Lake Landfill – Mark Hague notes for call with Mathy Stanislaus

To:
From:
Stoy, Alyse[[email protected]]; Peterson, Mary[[email protected]]
Juett, Lynn
Sent:
Subject:
Mon 10/19/2015 3:50:03 PM
Notes for Mark’s Call with Mathy
Upcoming Activities
• October 23, 2016 – Bridgeton Landfill’s Expert Reports Due Date
• October 26, 2015 – CAG Meeting in St Louis
• October 26, 2015 Week- Congressional and Community Outreach by Acting RA
• November 13, 2015- Goal for completing negotiations on Addition Work and AOC
Modifications -which will provide an enforceable schedule for Final Feasibility
Study
• December 3, 2015- Goal for Announcement of Isolation Barrier Decision
Recent Community Concerns
Relocation: Over the past year, Lois Gibbs, Center for Health and Environmental
Justice, and Just Moms StLouis have asked EPA in writing to relocate residents within
a two-mile radius of the Site, payment of “property assurance” presumably to
compensate for loss of property value within a five-mile radius and establishment of a
health clinic. Initially these concerns were directed at potential exposure to RIM and
movement of the SSE. Then in early 2015, Bridgeton Landfill discovered potential
excessive S02 emissions from one of its landfill gas flares, which added to the
community’s concerns regarding their health. EPA has performed environmental
sampling at the West Lake Landfill site over the years, including air monitoring within the
community this past year, all of which have not shown evidence of releases from the
site that could pose an unacceptable risk to the community. EPA has informed the
community that we have determined that the conditions at the Site do not warrant
consideration of temporary or permanent relocation as a CERCLA response action at
this time.
‘–“–”–”–”–”–‘RIM- All data collected and reviewed by EPA supports the conclusion that
WLLFOIA4312- 001 – 0056383
RIM has not migrated off-site in soils or via air. (Further groundwater investigation is
being planned, but the nearby communities are all hooked up to public drinking water
supplies)
c__jc__jl_jc__jc__jc__j SSE – Based on the available scientific data evaluated to date by our experts,
the data do not conclusively support a scenario where the SSE will encounter the
RIM. To date, reviews of the data have not indicated advancement of the SSE beyond
the neck area of the Bridgeton Landfill. The radiological waste at West Lake Landfill is not
capable under any circumstance of producing a sustained chain reaction (fission or fusion) that is capable
of producing a nuclear reaction or “meltdown” as seen at the Chemobyl and more recently Fukushima
power plants. In the unlikely event the SSE should come into contact with the RIM, EPA
does not believe that the RIM will become explosive in the presence of heat. We do
anticipate an localized increases of radon gas escaping into the atmosphere.
State of Emergency: On September 4, the Attorney General released reports from its
experts who will testify in the upcoming hearing (currently scheduled for March 2016) in
the AG’s lawsuit against Bridgeton Landfill. These reports and the accompanying press
release made the following statements. Based upon the information and conclusions
contained in these reports, the community has repeated its requests for relocation as
well as circulated a petition for the governor to declare a state of emergency.
o RIM has migrated off-site through groundwater and airborne particulate matter
(based on their phytoforensics testing),
o The SSE is moving towards the RIM and could make contact in a matter of 3 – 5
months, and
o Groundwater is contaminated.
EPA has publically stated that we strongly disagree with these conclusions. Also, on
October 16, 2015, Republic Services released an excerpt from their deposition of one of
the AG’s landfill experts. Based on what was posted, the landfill expert stated he does
not believe the SSE has moved past the neck nor is currently moving towards the RIM.
St. Louis County Emergency Plan: Following the release of the AG expert reports,
postings in social media showed an increased public interest in emergency planning.
About two weeks ago, an October 2014 West Lake Landfill Shelter in Place/Evacuation
Plan was obtained and released by the press. In response to that release, four local
school districts sent letters to parents of school children regarding their implementation
plans. While the news of an emergency evacuation plan may be new information for
many people, the plan has existed and been publicly known for more than a year. The
plan was developed in 2014 in consultation with multiple emergency response
organizations including the EPA. In July 2014, Director of St. Louis County Office of
Emergency Management, Michael Smiley discussed the plan with the West Lake
Landfill Community Advisory Group. In April 2015, Local Emergency Planning
Committee Chairman and Director of the St. Louis County Police Department
Emergency Manager Mark Diedrich made a public presentation about the updated plan
WLLFOIA4312- 001 – 0056384
to the West Lake Landfill Community Advisory Group.
Local Elected Officials: Following the release of the AG expert reports, several local
officials are becoming increasingly involved and one has recently called for a
congressional oversight hearing into West Lake Landfill and a declaration of a state of
emergency. She will also be holding a series of nine town hall meetings in early
November claiming that radioactive waste will become airborne in 2-5 months.
FUSRAP: There are continued community and even congressional written requests for
DOE to reconsider its prior evaluation of the Site for the FUSRAP program. Many in the
community believe that if the site were turned over to FUSRAP, the USAGE would
excavate the RIM and dispose of it off-site, as they have done for much but not all of the
radioactively contaminated soils at FUSRAP sites in St. Louis. On September 10, 2015,
DOE responded to the congressional delegation’s recent request for reconsideration by
saying that they have no new information that would justify transfer of the site into the
FUSRAP program.
WLLFOIA4312- 001 – 0056385

Post

1997-08-22 – EPA – Establishment of Cleanup Levels for CERCLA Sites with Radioactive Cotamination.pdf

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
Signed by Steve Luftig & Larry Weinstock on August 22, 1997
OFFICE OF SOLID WASTE AND EMERGENCY RESPONSE
OSWER No. 9200.4-18
MEMORANDUM
SUBJECT:
Establishment of Cleanup Levels for CERCLA Sites with Radioactive
Contamination
FROM:
Stephen D. Luftig, Director s/Stephen D. Luftig
Office of Emergency and Remedial Response
Larry Weinstock, Acting Director s/Larry Weinstock
Office of Radiation and Indoor Air
TO:
Addressees
PURPOSE
This memorandum presents clarifying guidance for establishing protective cleanup levels1 for radioactive contamination at Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) sites. The policies stated in this memorandum are inclusive of all radioactive contaminants of concern at a site including radon.2 The directive is limited to providing guidance regarding the
1This directive provides guidance on cleanup levels expressed as a risk, exposure, or dose level and not as a soil concentration level. The concentration level for various media, such as soil, that corresponds to a given risk level should be determined on a site-specific basis, based on factors such as the assumed land use and the physical characteristics (e.g., important surface features, soils, geology, hydro geology, meteorology, and ecology) at the site. This guidance does not alter the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) expectations regarding treatment of
principal threat waste and the use of containment and institutional controls for low level threat waste.
2Since radon is not covered in some Federal radiation regulations it is important to note that the cleanup guidance clarifications in this memorandum include radon. Attachment A is a listing of standards for radionuclides (including radon) that may be applicable or relevant and appropriate requirements (ARARs) for Superfund sites.
protection of human health and does not address levels necessary to protect ecological receptors.
This document provides guidance to EPA staff. It also provides guidance to the public and to the regulated community on how EPA intends that the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) be implemented. The guidance is designed to describe EPA’s national policy on these issues. The document does not, however, substitute for EPA’s statutes or regulations, nor is it a regulation itself. Thus, it cannot impose legally-binding requirements on EPA, States, or the regulated community, and may not apply to a particular situation based upon the circumstances. EPA may change this guidance in the future, as appropriate.
BACKGROUND
All remedial actions at CERCLA sites must be protective of human health and the environment and comply with Applicable or Relevant and Appropriate Requirements (ARARs) unless a waiver is justified. Cleanup levels for response actions under CERCLA are developed based on site-specific risk assessments, ARARs, and/or to-be-considered material3 (TBCs).
A listing is attached of radiation standards that are likely to be used as ARARs to establish cleanup levels or to conduct remedial actions. Cleanup standards have been under development by EPA under the Atomic Energy Act (AEA) and will be ARARs under certain circumstances if issued.
ARARs are often the determining factor in establishing cleanup levels at CERCLA sites. However, where ARARs are not available or are not sufficiently protective, EPA generally sets site-specific remediation levels for: 1) carcinogens at a level that represents an excess upper bound lifetime cancer risk to an individual of between 10-4 to 10-6; and for 2) non-carcinogens such that the cumulative risks from exposure will not result in adverse effects to human populations (including sensitive subpopulations) that may be exposed during a lifetime or part of a lifetime, incorporating an adequate margin of safety. (See 40 CFR 300.430(e)(2)(i)(A)(2).) Since all radionuclides are carcinogens, this guidance addresses carcinogenic risk. If noncarcinogenic risks are posed by specific radionuclides, those risks should be taken into account in establishing cleanup levels or suitable remedial actions. The site-specific level of cleanup is determined using the nine criteria specified in Section 300.430(e)(9)(iii) of the NCP.
It is important to note that a new potential ARAR was recently promulgated :
3To-be-considered material (TBCs) are non-promulgated advisories or guidance issued by Federal or State governments that are not legally binding and do not have the status of potential ARARs. However, TBCs will be considered along with ARARs as part of the site risk assessment and may be used in determining the necessary level of cleanup for protection of health and the environment.
– 2 NRC’s
Radiological Criteria for License Termination (See 62 FR 39058, July 21, 1997). We expect that NRC’s implementation of the rule for License Termination (decommissioning rule) will result in cleanups within the Superfund risk range at the vast majority of NRC sites. However, EPA has determined that the dose limits established in this rule as promulgated generally will not provide a protective basis for establishing preliminary remediation goals (PRGs) under CERCLA.4 The NRC rule set an allowable cleanup level of 25 millirem per year (equivalent to approximately 5 x 10-4 increased lifetime risk) as the primary standard with exemptions allowing dose limits of up to 100 millirem per year (equivalent to approximately 2 x 10-3 increased lifetime risk). Accordingly, while the NRC rule standard must be met (or waived) at sites where it is applicable or relevant and appropriate, cleanups at these sites will typically have to be more stringent than required by the NRC dose limits in order to meet the CERCLA and NCP requirement to be protective.5 Guidance that provides for cleanups outside the risk range (in general, cleanup levels exceeding 15 millirem per year which equates to approximately 3 x 10-4 increased lifetime risk) is similarly not protective under CERCLA and generally should not be used to establish cleanup levels.
The lack of a protective comprehensive set of regulatory cleanup levels for radiation, together with the possibility of confusion as to the status of other Federal Agency regulations and guidance as ARARs or TBCs, may cause uncertainty as to the cleanup levels deemed protective under CERCLA. Until a protective comprehensive radiation cleanup rule is available, this guidance clarifies the Agency’s position on CERCLA cleanup levels for radiation.
OBJECTIVE
This guidance clarifies that cleanups of radionuclides are governed by the risk range for all carcinogens established in the NCP when ARARs are not available or are not sufficiently protective. This is to say, such cleanups should generally achieve risk levels in the 10-4 to 10-6 range. EPA has a consistent methodology for assessing cancer risks and determining PRGs at CERCLA sites no matter the type of contamination.6 Cancer risks for radionuclides should generally be estimated using the slope factor approach identified in this methodology. Slope factors were developed by EPA for more than 300 radionuclides in the Health Effects Assessment Summary Tables
4See letter, Carol Browner, Administrator, EPA, to Shirley Jackson, Chairman, Nuclear Regulatory Commission, February 7, 1997.
5See attachment B for a detailed discussion of the basis for the conclusion that the dose limits in the NRC rule are not adequately protective.
6U.S. EPA, “Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (Part A) Interim Final,” EPA//540/1-89/002, December 1989. U.S. EPA, “Risk Assessment Guidance for Superfund: Volume I – Human Health Evaluation Manual (Part B, Development of Risk-based Preliminary Remediation Goals”, EPA/540/R-92/003, December 1991.
– 3 (
HEAST).7 Cleanup levels for radioactive contamination at CERCLA sites should be established as they would for any chemical that poses an unacceptable risk and the risks should be characterized in standard Agency risk language consistent with CERCLA guidance.
Historically, radiation exposure and cleanup levels have often been expressed in units unique to radiation (e.g., millirem or picoCuries). It is important for the purposes of clarity that a consistent set of existing risk-based units (i.e., # x10-#) for cleanups generally be used. This will also allow for ease and clarity of presenting cumulative risk for all contaminants, an objective consistent with EPA’s policy on risk characterization.8
Cancer risk from both radiological and non-radiological contaminants should be summed to provide risk estimates for persons exposed to both types of carcinogenic contaminants. Although these risks initially may be tabulated separately, risk estimates contained in proposed and final site decision documents (e.g., proposed plans, Record of Decisions (RODs), Action Memos, ROD Amendments, Explanation of Significant Differences (ESDs)) should be summed to provide an estimate of the combined risk to individuals presented by all carcinogenic contaminants.
IMPLEMENTATION
The approach in this guidance should be considered at current and future CERCLA sites for which response decisions have not been made.
Overall Exposure Limit:
Cleanup should generally achieve a level of risk within the 10-4 to 10-6 carcinogenic risk range based on the reasonable maximum exposure for an individual. The cleanup levels to be specified include exposures from all potential pathways, and through all media (e.g., soil, ground water, surface water, sediment, air, structures, biota). As noted in previous policy, “the upper boundary of the risk range is not a discrete line at 1 x 10-4, although EPA generally uses 1 x 10-4 in making risk management decisions. A specific risk estimate around 10-4 may be considered acceptable if justified based on site-specific conditions”.9
7U.S. EPA, “Health Effects Assessment Summary Tables FY-1995 Annual,” EPA/540/R-95/036, May 1995; and U.S. EPA, “Health Effects Assessment Summary Tables FY-1995 Supplement,” EPA/540/R-95/142, Nov. 1995.
8For further discussion of EPA’s policy, see memorandum from EPA Administrator Carol Browner entitled: “EPA Risk Characterization Program,” March 21, 1995.
9Memo from Assistant Administrator Don Clay to the Regions; “Role of the Baseline Risk Assessment in Superfund Remedy Selection Decisions’” OSWER Directive 9355.0-30; April 22, 1991.
– 4 If
a dose assessment is conducted at the site10 then 15 millirem per year (mrem/yr) effective dose equivalent (EDE) should generally be the maximum dose limit for humans. This level equates to approximately 3 x 10-4 increased lifetime risk and is consistent with levels generally considered protective in other governmental actions, particularly regulations and guidance developed by EPA in other radiation control programs.11
Background Contamination:
Background radiation levels will generally be determined as background levels are determined for other contaminants, on a site-specific basis. In some cases, the same constituents are found in on-site samples as well as in background samples. The levels of each constituent are compared to background to determine its impact, if any, on site-related activities. Background is generally measured only for those radionuclides that are contaminants of concern and is compared on a contaminant specific basis to cleanup level. For example, background levels for radium-226 and radon-222 would generally not be evaluated at a site if those radionuclides were not site-related contaminants.
In certain situations background levels of a site-related contaminant may equal or exceed PRGs established for a site. In these situations background and site-related levels of radiation will be addressed as they are for other contaminants at CERCLA sites.12
10Cleanup levels not based on ARARs should be expressed as risk, although levels may at the same time be expressed in millirem.
11Further discussion and analysis of the basis for this recommendation is contained in the materials in the docket for the AEA standard under development by EPA, which is available at the following address: U.S. EPA, 401 M Street, S.W., Room M1500, Air Docket No. A-93-27, Washington D.C. 20460. The material is also available via computer modem through the Cleanup Regulation Electronic Bulletin Board (800-700-7837 outside the Washington area and 703-790-0825 locally), or on-line through the Radiation Site Cleanup Regulation HomePage (http://www.epa.gov/radiation/cleanup/). Cleanup levels based on some older ARARs that use a 25/75/25 mrem/yr standard (i.e., 25 mrem/yr to the whole body, 75 mrem/yr to the thyroid, and 25 mrem/yr to any other critical organ) may appear to permit greater risk than those based on 15 mrem EDE but on average correspond to approximately 10 mrem/yr EDE, using current risk methodologies. Similarly, ARARs based on a 25/75 mrem/yr standard used as an ARAR (i.e., 25 mrem/yr to whole body and 75 mrem/yr to any critical organ) would on average correspond to those cleanups based on 15 mrem/yr EDE. (See also “Comparison of Critical Organ and EDE Radiation Dose Rate Limits for Situations Involving Contaminated Land;” Office of Radiation and Indoor Air; April 1997.) See also Attachment B.
12For further information regarding EPA’s approach for addressing background at CERCLA sites see: National Oil and Hazardous Substances Pollution Contingency Plan, 55 FR 8717-8718, March 8, 1990; U.S. EPA “Guidance on Remedial Actions for Contaminated Ground Water at Superfund Sites,” EPA/540/G-88/003, December 1988, pg. 4-9;
U.S. EPA “Soil Screening Guidance: User’s Guide,” EPA/540/R-96/018, April 1996, pg. 8; and U.S. EPA “Risk
Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (Part A),” EPA/540/1-89/02, December 1989, pp. 4-5 to 4-10 and 5-18 to 5-19. It should be noted that certain ARARs specifically address how to factor background into cleanup levels. For example, some radiation ARAR levels are established as increments above background concentrations. (See attached chart for a listing of radiation standards that are likely to be used as ARARs.) In these circumstances, rather then follow the general guidance cited above, background should be addressed in the manner
– 5 Land
Use and Institutional Controls:
The concentration levels for various media that correspond to the acceptable risk level established for cleanup will depend in part on land use at the site. Land uses that will be available following completion of a response action are determined as part of the remedy selection process considering the reasonably anticipated land use or uses along with other factors.13 Institutional controls (ICs) generally should be included as a component of cleanup alternatives that would require restricted land use in order to ensure the response will be protective over time. The institutional controls should prevent an unanticipated change in land use that could result in unacceptable exposures to residual contamination, or at a minimum, alert future users to the residual risks and monitor for any changes in use.
Future Changes in Land Use:
Where waste is left on-site at levels that would require limited use and restricted exposure to ensure protectiveness, EPA will conduct reviews at least once every five years to monitor the site for any changes including changes in land use. Such reviews should analyze the implementation and effectiveness of any ICs with the same degree of care as other parts of the remedy. Should land use change in spite of land use restrictions, it will be necessary to evaluate the implications of that change for the selected remedy, and whether the remedy remains protective (e.g., a greater volume of soil may need to be removed or managed to achieve an acceptable level of risk for a less restrictive land use).
Ground Water Levels:
Consistent with CERCLA and the NCP, response actions for contaminated ground water at radiation sites must attain (or waive as appropriate) the Maximum Contaminant Levels (MCLs) or non-zero Maximum Contaminant Level Goals (MCLGs) established under the Safe Drinking Water Act, where the MCLs or MCLGs are relevant and appropriate for the site. This will typically be the case where ground waters are a current or potential source of drinking water.14 The ARARs should generally be attained throughout the plume (i.e., in the aquifer).
prescribed by the ARAR ARARs, such as 40 CFR 192, are available to establish cleanup levels for those naturally occurring radionuclides that pose the most risk (such as radium-226 or Thorium in soil, and indoor radon) when those radionuclides are site related contaminants.
13In developing Land use assumptions, decision makers should consult the guidance provided in the memorandum from Elliott Laws A.A., OSWER entitled: “Land Use in the CERCLA Remedy Selection Process” (OSWER Directive No. 9355.7-04), May 25, 1995.
14In making decisions on ground water protection, decision makers should consult the guidance provided in “Presumptive Response Strategy and Ex-Situ Treatment Technologies for Contaminated Ground Water at CERCLA Sites” (OSWER Directive No. 9355.7-04) October 1996.
– 6 Modeling
Assessment of Future Exposures:
Risk levels, ground water cleanup, and dose limits should be predicted using appropriate models to examine the estimated future threats posed by residual radioactive material following the completion of the response action.15 The modeling assessment should: (1) assume that the current physical characteristics (e.g., important surface features, soils, geology, hydrogeology, meteorology, and ecology) will continue to exist at the site; (2) take into account for each particular radionuclide that is a site-related contaminant, the following factors:

radioactive decay and the ingrowth of radioactive decay products when assessing risk levels;

the year of peak concentration in the ground water when assessing protection (e.g., remediating previous contamination and preventing future contamination) of ground water, and;

the year of peak dose when assessing dose limits; and,
(3) model the expected movement of radioactive material at the site both within media(i.e., soil, ground water, surface water, sediment, structures, air, biota) and to other media.
FURTHER INFORMATION
The subject matter specialists for this directive are Jeffrey Phillips of OERR and John Karhnak of ORIA. General questions about this directive, should be directed to 1-800-424-9346.
Attachments
Addressees National Superfund Policy Managers Superfund Branch Chiefs (Regions I-X) Superfund Branch Chiefs, Office of Regional Counsel (Regions I-X) Radiation Program Managers (Regions I, IV, V, VI, VII, X) Radiation Branch Chief (Region II) Residential Domain Section Chief (Region III) Radiation and Indoor Air Program Branch Chief (Region VIII) Radiation and Indoor Office Director (Region IX) Federal Facilities Leadership Council OERR Center Directors
15For further information regarding the basis for this recommendation, see U.S. EPA, “Risk Assessment Guidance for Superfund Volume I Human Health Evaluation Manual (Part A) Interim Final,” EPA//540/1-89/002, December 1989, pp. 10-22 and 10-24.
– 7 OSWER
Directive 9200.4-18 Attachment A
Likely Federal Radiation Applicable or Relevant and Appropriate Requirements (ARARs)
The attached draft table of Federal standards is a listing of Federal radiation regulations that may be “Applicable or Relevant and Appropriate Requirements” (ARARs) for Superfund response actions. This list is not a comprehensive list of Federal radiation standards. It must also be cautioned that the selection of ARARs is site-specific and those site-specific determinations may differ from
the attached analysis for some of the following ARARs.
Likely Federal Radiation (AEA, UMTRCA, CAA, CWA, SDWA) ARARs
When is standard
Standard
Citation
Applicable (Conduct/Operation or Level of Cleanup1)
When is standard potentially a Relevant and Appropriate Requirement
Maximum contaminant levels (MCLs). Drinking
40 CFR 141
Rarely: At the tap where
Where ground or surface water
water regulations designed to protect human
water will be provided
is considered a potential or
health from the potential adverse effects of
directly to 25 or more
current source of drinking
drinking water contaminants.
people or will be supplied
water
to 15 or more service
connections.
Concentration limits for liquid effluents from
40 CFR 440
Very Unlikely: Applies to
Discharges to surface waters
facilities that extract and process uranium,
Subpart C
surface water discharges
of some kinds of radioactive
radium, and vanadium ores.
from certain kinds of
waste.
mines and mills
– 1 Likely
Federal Radiation (AEA, UMTRCA, CAA, CWA, SDWA) ARARs
When is standard
Standard
Citation
Applicable (Conduct/Operation or Level of
Cleanup1)
Federal Water Quality Criteria (FWQC) and State Water Quality Standards (WQS). Criteria/standards for protection of aquatic life and/or human health depending upon the designated water use.
Water Quality Criteria; Report of the National Technical Advisory Committee to the
Discharge from a CERCLA site to surface water. (C/O)
Secretary of the Interior; April 1, 1968.
Concentration limits for cleanup of radium-226, radium-228, and thorium in soil at inactive uranium processing sites designated for remedial action.2
40 CFR 192.12(a), 192.32(b)(2), and 192.41
Never: Standards are applicable only to UMTRCA sites that are exempt from CERCLA
When is standard potentially a Relevant and Appropriate Requirement
Restoration of contaminated surface water. (LC)
Sites with soil contaminated with radium-226, radium-228, and/or thorium
2For further information, see OSWER directive entitled “Use of Soil Cleanup Criteria in Subpart B of 40 CFR Part 192 as Remediation Goals for CERCLA sites.”
– 2 Likely
Federal Radiation (AEA, UMTRCA, CAA, CWA, SDWA) ARARs
When is standard
Applicable
Standard
Citation
(Conduct/Operation
or Level of
Cleanup1)
Combined exposure limits for cleanup of radon
40 CFR
Never: Standards are
decay products in buildings at inactive uranium
192.12(b)(1) and
applicable only to
processing sites designated for remedial action
192.41(b)
UMTRCA sites that are
exempt from CERCLA
Concentration limits for cleanup of gamma
40 CFR
Never: Standards are
radiation in buildings at inactive uranium
192.12(b)(2)
applicable only to
processing sites designated for remedial action
UMTRCA sites that are
exempt from CERCLA
Design requirements for remedial actions that
40 CFR 192.02
Never: Standards are
involve disposal for controlling combined releases
applicable only to
of radon-220 and radon-222 to the atmosphere at
UMTRCA sites that are
inactive uranium processing sites designated for
exempt from CERCLA
remedial action
When is standard potentially a Relevant and Appropriate Requirement
Sites with radioactive contamination that is currently, or may potentially, result in radon that is caused by site related contamination migrating from the soil into buildings
Sites with radioactive contamination that is currently, or may potentially, emit gamma radiation
Sites with radon-220 or radon222 as contaminants which will be disposed of on-site.
– 3 Likely
Federal Radiation (AEA, UMTRCA, CAA, CWA, SDWA) ARARs
When is standard
Applicable
Standard
Citation
(Conduct/Operation
or Level of
Cleanup1)
Performance objectives for the land disposal of
10 CFR 61.41
Unlikely: Existing
low level radioactive waste (LLW).
licensed LLW disposal
sites at the time of license
renewal. (LC)
Unlikely that this would
occur.
National Emission Standards for Hazardous Air
40 CFR 61
Airborne emissions during
Pollutants (NESHAPs) under the Clean Air Act,
Subparts H and I
the cleanup of Federal
that apply to radionuclides.
Facilities and licensed
NRC facilities. (CO)
Radiological criteria for license termination.
10 CFR 20
Existing licensed sites at
Subpart E
the time of license
termination. (LC)
When is standard potentially a Relevant and Appropriate Requirement
Previously closed sites containing LLW if the waste will be permanently left on site.
Cleanup of other sites with radioactive contamination.
Previously closed sites.
1.Conduct/operation (C/O) refers to those standards which are typically ARARs for the conduct or operation of the remedial action. Level of Cleanup (L/C) refers to those standards which are typically ARARs for determining the final level of cleanup.
– 4 August
20, 1997
OSWER Directive 9200.4-18 Attachment B
Analysis of what Radiation Dose Limit is Protective of Human Health at CERCLA Sites (Including Review of Dose Limits in NRC Decommissioning Rule)
Introduction
The Nuclear Regulatory Commission (“NRC”) has finalized a rule titled “Radiological Criteria for License Termination” (see 62 FR 39058, July 21, 1997). EPA has determined that the dose limits established in this rule generally will not provide a protective basis for establishing preliminary remediation goals (“PRGs”)under the Comprehensive Environmental Response, Compensation and Liability Act (“CERCLA”).1 The NRC rule sets an allowable cleanup level of 25 millirem per year effective dose equivalent (EDE) (equivalent to approximately 5 x 10-4 lifetime cancer risk) as the primary standard with exemptions allowing cleanup levels of up to 100 millirem per year (mrem/yr) EDE (equivalent to approximately 2 x 10-3 lifetime risk).2 While the NRC standards must be met (or waived) at sites where it is applicable or relevant and appropriate, cleanups at these sites will typically have to be more protective than required by the NRC rule dose limits in order to meet the requirement to be protective established in CERCLA and the 1990 revisions to the National Oil and Hazardous Substances Pollution Contingency Plan (“NCP”).3
Protectiveness for carcinogens under CERCLA is generally determined with reference to a cancer risk range of 10-4 to 10-6 deemed acceptable by EPA. Consistent with this risk range, EPA has considered cancer risk from radiation in a number of different contexts, and has consistently concluded that levels of 15 mrem/yr EDE (which
1See letter, Carol Browner, Administrator, EPA, to Shirley Jackson, Chairman, Nuclear Regulatory Commission, February 7, 1997.
2 Throughout this analysis risk estimates for dose levels were derived using a risk assessment methodology consistent with CERCLA guidance for assessing risks.
3Similarly, guidance that provides for radiation cleanups outside the risk range is generally not protective and should not be used to establish preliminary remediation goals .
– 1 August
20, 1997
equate to approximately a 3 x 10-4 cancer risk) or less are protective and achievable.4 EPA has explicitly rejected levels above 15 mrem/yr EDE as being not sufficiently protective.
The dose levels established in the NRC Decommissioning rule, however, are not based on this risk range or on an analysis of other achievable protective cleanup levels used for radiation and other carcinogenic standards. Rather, they are based on a different framework for risk management recommended by the International Commission on Radiation Protection (ICRP) and the National Council on Radiation Protection and Measurements (NCRP). NRC’s application of this framework starts with the premise that exposure to radiation from all man-made sources, excluding medical and natural background exposures, of up to 100 mrem/yr., which equates to a cancer risk of 2 x 10-3, is acceptable. Based on that premise, it concludes that exposure from decommissioned facilities of 25 mrem/yr, which equates to a cancer risk of approximately 5 x 10-4, is acceptable, and allows the granting of exceptions in certain instances permitting exposure up to the full dosage of 100 mrem/yr from these facilities. EPA has carefully reviewed the basis for the NRC dose levels and does not believe they are generally protective within the framework of CERCLA and the NCP. Simply put, NRC has provided, and EPA is aware of, no technical, policy, or legal rationale for treating radiation risks differently from other risks addressed under CERCLA and for allowing radiation risks so far beyond the bounds of the CERCLA risk range.
1. Rationale for 15 mrem/yr as Minimally Acceptable Dose Limit
To determine an acceptable residual level of risk from residual radioactive materials following a response action that would be protective of human health, EPA examined the precedents established by EPA for acceptable exposures to radiation in regulations and site-specific cleanup decisions in light of the CERCLA risk range for carcinogens. EPA’s conclusion is that to be considered protective under CERCLA, remedial actions should generally attain dose levels of no more than 15 mrem/yr EDE for those sites at which a dose assessment is conducted. This dose level corresponds to an excess lifetime cancer risk of approximately 3 x 10-4.
1.1 The CERCLA risk range
Under CERCLA, all remedies are required to attain cleanup levels that “at a minimum. . . assure protection of human health and the environment.” CERCLA
4It should be noted that 15 mrem/yr is a dose level, not a media remediation level. Accordingly, this level could be achieved at CERCLA sites through appropriate site-specific combinations of active remediation and land-use restrictions to ensure no unacceptable exposures.
– 2 August
20, 1997
§121(d)(1). The NCP provides that, for carcinogens, preliminary remediation goals should generally be set at levels that represent an upper-bound lifetime cancer risk to an individual of between 10-4 and 10-6. 40 CFR § 300.430(e)(2)(I)(A)(1). This regulatory level was set based on EPA’s conclusion that the CERCLA protectiveness mandate is complied with “when the amount of exposure is reduced so that the risk posed by contaminants is very small, i.e., at an acceptable level. EPA’s risk range of 10-4 to 10-6 represents EPA’s opinion on what are generally acceptable levels.” 55 Fed. Reg. at 8716 (March 8, 1990). EPA’s adoption of this risk range was sustained in judicial review of the NCP. State of Ohio v. EPA, 997 F.2d 1520, 1533 (D.C. Cir. 1993).
Under appropriate circumstances, risks of greater than 1 x 10-4 may be acceptable. CERCLA guidance states that “the upper boundary of the risk range is not a discrete line at 1 x 10-4, although EPA generally uses 1 x 10-4 in making risk management decisions. A specific risk estimate around 10-4 may be considered acceptable if justified based on site-specific conditions.”5 Other EPA regulatory programs have developed a similar approach to determining acceptable levels of cancer risk. For example, in a Clean Air Act rulemaking establishing NESHAPs for NRC licensees, Department of Energy facilities, and many other kinds of sites, EPA concluded that a risk level of “3 x 10-4 is essentially equivalent to the presumptively safe level of 1 x 10-4.” 54 Fed. Reg. at 51677 and 51682 (December 15, 1989). EPA explicitly rejected a risk level of 5.7 x 10-4 as not being equivalent to the presumptively safe level of 1 x 10-4 (in the case of elemental phosphorus plants) in this rulemaking. 54 Fed. Reg. at 51670.
1.2 Prior rulemaking decisions
EPA has examined the protectiveness of various radiation levels on a number of occasions. In each case, EPA’s determination of what constitutes an adequate level of protection was reached in a manner consistent with EPA’s regulation of other carcinogens. The conclusions from these efforts support the determination that 15 mrem/yr EDE should generally be the maximum dose level allowed at CERCLA sites. For example, EPA’s Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (“High-Level Waste Rule,” 40 CFR Part 191) sets a dose limit of 15 mrem/yr EDE for all pathways.
In addition, EPA set an effective dose equivalent of 10 mrem/yr EDE (excluding radon-222) for air emissions of radionuclides from federal facilities, NRC licensees, and uranium fuel cycle facilities under the National Emissions Standards for Hazardous Air
5″Role of the Baseline Risk Assessment in Superfund Remedy Selection Decisions” from EPA Assistant Administrator Don
R. Clay, April 22, 1991.
– 3 August
20, 1997
Pollutants (NESHAP, 40 CFR Part 61). This lower limit included all air pathways, but excluded releases to surface and ground waters.
Not all EPA rules apply the current dose methodology of effective dose equivalent (EDE). A dose limit of 15 mrem/yr EDE is also consistent with the dose levels allowed under older multi-media standards that were based on the critical organ approach to dose limitation. Critical organ standards developed by EPA and NRC consist of a combination of whole body and critical organ dose limits. Three of these critical organ standards (EPA’s uranium fuel cycle rule, 40 CFR 190.10(a), developed for NRC licensees; NRC’s low level waste rule, 10 CFR 61.41; and EPA’s management and storage of high level waste by NRC and agreement states rule, 40 CFR 191.03(a)), referred to here as ‘25/75/25 mrem/yr’ dose limits, are expressed as 25 mrem/yr to the whole body, 75 mrem/yr to the thyroid, and 25 mrem/yr to any critical organ other than the thyroid. One standard (EPA’s management and storage of high level waste by DOE rule, 40 CFR 191.03(b)), referred to here as a “25/75 mrem/yr” dose limit, is expressed as 25 mrem/yr to the whole body and 75 mrem/yr to any critical organ (including the thyroid). To compare the dose level allowed under standards expressed in terms of EDE with the dose levels allowed under the critical organ approach to dose limitation, EPA has analyzed the estimated effective dose equivalent levels that would result if sites were cleaned up to the numerical dose limits used in these standards.6 The analysis indicates that if sites were cleaned up under a 25/75/25 mrem/yr dose limit, the residual contamination would correspond to approximately 10 mrem/yr EDE. For sites cleaned up under a 25/75 mrem/yr dose limit, the residual contamination would correspond to approximately 15 mrem/yr EDE. These findings are similar to those mentioned in the preamble to the high-level waste rule (40 CFR Part 191; December 20, 1993; 58 FR 66402). In that rulemaking, EPA noted that the dose limit of 25 mrem/yr to the whole body or 75 mrem/yr to any critical organ, which was used in a previous high-level waste rule (September 19, 1985; 50 FR 38066) corresponds to the same level of risk as that associated with a 15 mrem/yr EDE. A cleanup level of 15 mrem/yr EDE is thus generally consistent with all of these other standards, although there are minor differences.
Finally, standards for the cleanup of certain radioactively contaminated sites have been issued under the Uranium Mill Tailings Radiation Control Act (UMTRCA), P.L. 95604. Those standards are codified at 40 CFR Part 192. Among other provisions, the UMTRCA standards limit the concentration of radium-226, radium-228, thorium-230 and thorium-232, within 15 centimeters (cm) of the surface to no more than 5 picoCuries per gram (pCi/g) over background. They also limit the concentration of these radionuclides below the surface to no more than 15 pCi/g over background. Since these standards were
6″Comparison of Critical Organ and EDE Radiation Dose Rate Limits for Situations Involving Contaminated Land” Office of Radiation and Indoor Air; April 1997.
– 4 August
20, 1997
developed for the specific conditions found at the mill sites to which they apply (for example, all mill sites are required by law to remain in federal control), correlating these concentrations to dose requires a site-specific determination considering both the distribution and nature of contaminants at the site and the selected land use. Therefore, those standards are less relevant for determining if 15 mrem/yr EDE is consistent. However, analysis indicates that the cleanup of UMTRCA sites is consistent with the minimally acceptable dose limit of 15 mrem/yr EDE under a residential exposure scenario for radium-226, radium-228, and thorium-232, and is much more stringent for thorium-230.7 For land uses other than residential (e.g., commercial/industrial, recreational) the UMTRCA cleanup standards are more stringent for all four radionuclides.8
1.3 Site-Specific Decisions
EPA has examined the cleanup decisions made under Superfund to address sites contaminated with radioactive wastes. Many of these cleanup actions used the UMTRCA cleanup standard (40 CFR Part 192) as an ARAR. Some of the sites used State regulations as ARARs. For a number of major DOE cleanup actions such as those at the Hanford reservation and Rocky Flats, a 15 mrem/yr EDE cleanup level has been decided upon or proposed. In other cases of CERCLA radiation cleanup actions that are not based on ARARs, cleanup levels between 1 x 10-5 and 1 x 10-6 have been selected (Bomark, NJ; Fernald, OH; Charleston Naval Shipyard, SC; and Mare Island Naval Shipyard, CA). Overall EPA finds that a 15 mrem/yr EDE level (with a risk of 3 x 10-4) is at the upper end of remediation levels that have generally been selected at radioactively contaminated CERCLA sites.
2.0 Dose Limits in NRC’s Rule are not Protective
EPA reviewed the dose limits that are contained in NRC’s Radiological Criteria for License Termination (see 62 FR 39058, July 21, 1997). The NRC rule allows a cleanup level of 25 mrem/yr EDE (equivalent to approximately 5 x 10-4 lifetime risk) with exemptions allowing cleanup levels of up to 100 mrem/yr EDE (equivalent to approximately 2 x 10-3 lifetime risk). These limits are beyond the upper bound of the risk
7Reassessment of Radium and Thorium Soil Concentrations and Annual Dose Rates . Office of Radiation and Indoor Air, July 22, 1996.
8A level of 15 mrem/yr is also supported by EPA’s draft Federal Radiation Protection Guidance for Exposure of the General Public (59 FR 66414, December 23, 1994). The draft guidance recommends that the maximum dose to individuals from specific sources or categories of sources be established as small fractions of a 100 mrem/yr upper bound on doses from all current and potential future sources combined, and cites the regulations that are discussed in Section 1.2 of this paper as appropriate implementation of this recommendation. All of the regulatory examples cited support the selection of cleanup levels at 15 mrem/yr or less. However, because this guidance is in draft form and is subject to continued review within EPA prior to finalization, it should not be used as a basis for establishing acceptable cleanup levels.
– 5 August
20, 1997
range generally considered protective under CERCLA. In addition, they present risks that are higher than levels EPA has found to be protective for carcinogens in general and for radiation, in particular, in other contexts. EPA has no technical or policy basis to conclude that these levels are protective under CERCLA.
The risk levels corresponding to the 25 to 100 mrem/yr EDE range allowed by the NRC rule (5 x 10-4 to 2 x 10-3) are unacceptably high relative to 1 x 10-4, which is the risk level generally used as the upper boundary of the CERCLA risk range for making risk management decisions at CERCLA sites. This determination is consistent with EPA’s explicit rejection of a risk level of 5.7 x 10-4 for elemental phosphorus plants in the preamble for a NESHAP rulemaking (54 FR 51670). In the same preamble, EPA stated that a risk level of “3 x 10-4 is essentially equivalent to the presumptively safe level of 1 x 10-4″ (54 FR 51677). It was during this same NESHAP rulemaking that NCRP first recommended to EPA its regulatory scheme (a dose limit of 25 mrem/yr EDE for a single source that if met would not require analyzing other sources, otherwise a dose limit of 100 mrem/yr EDE from all sources combined) that NRC cites as a source for the regulatory approach taken in its decommissioning rule.9 EPA rejected NCRP’s recommended regulatory scheme, and promulgated dose limits of no more than 10 mrem/yr EDE in its NESHAP rulemaking for radionuclides, while concluding that “individual dose levels greater than 10 mrem/y ede are inconsistent with the requirements of section 112” of the Clean Air Act. 54 Fed. Reg. at 51686.
The documentation and analysis supporting the NRC rule dose levels provide no basis for such a significant departure from the CERCLA risk range. Indeed, as discussed above, EPA’s past analyses and experience have demonstrated that exposures of 15 mrem/yr EDE or less are attainable and that such a departure is unwarranted. A dose limit of 25 mrem/yr EDE represents almost a doubling of the allowable risk from previous radiation rulemakings; the risk represented by a dose limit of 100 mrem/yr EDE is seven times as high as previously allowed. As note in Section 1.2, a dose limit of 25 mrem/yr effective dose equivalent is inconsistent with the dose levels allowed under older standards using a previous dose methodology (multi-media standards that were based on the critical organ approach to dose limitation). If these older dose standards were to be applied to the cleanup of contaminated sites, the average dose level would correspond to approximately 10 or 15 mrem/yr EDE on average.10 Also, analysis indicates that the cleanup of UMTRCA sites using the 5 pCi/g and 15 pCi/g soil standards under 40 CFR 192 is consistent with an upper bound of 15 mrem/yr EDE under a rural residential exposure
9″Control of Air Emissions of Radionuclides” NCRP Position Statement No. 6. The report cited by NRC, NCRP No. 116, merely references this previous NCRP position statement.
10″Comparison of Critical Organ and EDE Radiation Dose Rate Limits for Situations Involving Contaminated Land” Office of Radiation and Indoor Air; April 1997.
– 6 August
20, 1997
scenario for radium-226, radium-228, and thorium-232, and is much more stringent for thorium-230.11 For land uses other than residential (e.g., commercial/industrial, recreational) the UMTRCA cleanup standards are more stringent for all four radionuclides.
11Reassessmen t of Radium and Thorium Soil Concentrations and Annual Dose Rates . Office of Radiation and Indoor Air, July 22, 1996.
– 7 UNITED
STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
Signed by Timothy Fields on August 22, 1997
OFFICE OF SOLID WASTE AND EMERGENCY RESPONSE
OSWER No. 9200.4-23
MEMORANDUM
SUBJECT:
Clarification of the Role of Applicable, or Relevant and Appropriate
Requirements in Establishing Preliminary Remediation Goals under
CERCLA
FROM:
Timothy J. Fields, Jr., Acting s/Timothy Fields, Jr.
Assistant Administrator
TO:
Addressees
PURPOSE
This memorandum clarifies the relationship between the two key remedy selection mandates of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) as amended by the Superfund Amendments and Reauthorization Act of 1986 (SARA): 1) the requirement to protect human health and the environment; and 2) the requirement to attain, or waive if justified based on site-specific circumstances, applicable or relevant and appropriate requirements (ARARs). Specifically, this memorandum clarifies that, in rare instances, the Agency may establish preliminary remediation goals (PRGs) at levels more protective than required by ARARs, even at sites that do not involve multiple contaminants or pathways of exposure.
This document provides guidance to Regional staff, in dealing with the public and the regulated community, regarding how EPA intends to implement the National Oil and Hazardous Substances Pollution Contingency Plan (NCP). It describes national policy. This document is not a substitute for EPA’s statutes or regulations, nor is it a regulation itself. Thus, it cannot impose legally-binding requirements on EPA, States, or the regulated community, and may not apply to a particular situation based upon the circumstances.
2
BACKGROUND
In administering the CERCLA program since the promulgation of the 1990 revisions to the NCP, questions have periodically arisen over the relationship between the statutory mandates to: 1) protect human health and the environment; and, 2) attain, or waive if justified based on site-specific circumstances, ARARs. Specifically, questions have arisen over the circumstances under which it is appropriate to establish PRGs that are more protective than ARARs. It has been EPA’s policy that “compliance with a chemical-specific ARAR generally will be considered protective even if it is outside the [cancer] risk range (unless there are extenuating circumstances such as exposures to multiple contaminants or pathways of exposure).”1
FURTHER EXPLANATION OF POLICY
It remains EPA’s policy that ARARs will generally be considered protective absent multiple contaminants or pathways of exposure. However, this Directive clarifies that, in rare situations, EPA Regional offices should establish PRGs at levels more protective than required by a given ARAR, even absent multiple pathways or contaminants, where application of the ARAR would not be protective of human health or the environment. This judgment should be made based on a review of the level of risk associated with application of the ARAR; the soundness of the technical basis for the ARAR; and other factors relating to the ARAR or to its application at an individual site.
This balanced approach most fully implements the requirements of the NCP and the CERCLA. On one hand, it was clearly EPA’s intention in promulgating the NCP that PRGs would generally be based on ARARs in the absence of multiple contaminants or pathways. (See 40 CFR 300.430(e)(2)(I)(D); 55 Fed. Reg. at 8712.) This approach is sound; the protectiveness of health-based regulatory levels should not routinely be reevaluated in individual CERCLA remedy selection decisions.
On the other hand, ARARs cannot be an absolute upper bound on cleanup levels in every case in the absence of multiple pathways or contaminants. CERCLA and the NCP establish separate requirements to be protective and meet ARARs. (CERCLA § 121(d)(1), (2); 40 CFR § 300.430(f)(1)(I)(A).) Indeed, protecting human health and the environment is the paramount objective of the Superfund program. (See 55 Fed. Reg.
1OSWER Directive 9355.0-30, “Role of the Baseline Risk Assessment in Superfund Remedy Selection Decisions” (April 22, 1991). This policy is consistent with the NCP. ( See 40 CFR 300.430(e)(2)(I)(D) (authorizing consideration of the cancer risk range where attainment of ARARs will result in cumulative cancer risk of greater than 10 -4 due to multiple pathways or contaminants). See also 1990 NCP Preamble, 55 Fed. Reg. at 8712 (“[w]hen health-based ARARs are not available or are not sufficiently protective due to multiple exposures or multiple contaminants, EPA sets remediation goals” based on site-specific risk-based factors, such as the cancer risk range).)
3
8700 (the NCP remedy selection process “is founded on CERCLA’s overarching mandate to protect human health and the environment”).) Furthermore, CERCLA requires that remedial actions attain ARARs “at a minimum,” clearly contemplating that remedial actions may be more protective than required by ARARs when circumstances so require. (CERCLA § 121(d)(2)(A).)
EPA’s policy of generally establishing PRGs based on ARARs, in the absence of multiple pathways or contaminants, is based on the assumption that individual ARARs will be protective. For example, the NCP expressly authorizes consideration of the cancer risk range in setting PRGs where attainment of ARARs would result in a cumulative risk in excess of 10-4 due to multiple contaminants or pathways. (40 CFR 300.430(e)(2)(I)(D).) The assumption underlying this provision is plainly that individual ARARs would achieve a risk of 10-4 or less. Similarly, the NCP preamble explains that EPA will modify PRGs to be protective where cumulative risks “make ARARs nonprotective” (55 Fed. Reg. at 8713); again, the assumption is that individual ARARs would be protective absent these cumulative risks. In cases where, based on available information, this assumption is not accurate, PRGs should be set at levels more protective than required by the ARAR in order to ensure protection of human health and the environment.
IMPLEMENTATION
In the rare circumstances where, based on available information, application of an ARAR would not be protective of human health or the environment, EPA should establish PRGs at levels that are more protective than required by the ARAR even absent multiple pathways or contaminants. As noted above, in deciding whether a PRG should be established at a level more protective than required by an ARAR, consideration should be given to the level of risk associated with application of the ARAR; the soundness of the technical basis for the ARAR; and other factors relating to the ARAR or to its application at an individual site.
Before making a site-specific determination that an ARAR at a given site is not protective of human health and the environment and should not be used as the basis for establishing PRGs, the site decision maker should consult with Headquarters, unless a prior determination has been made by Headquarters that a particular ARAR should not generally be used to establish PRGs at CERCLA sites.2 The subject matter specialist for this guidance is Robin Anderson of OERR and Brian Grant of OGC. General questions about this guidance should be directed to 1-800-424-9346.
Addressees National Superfund Policy Managers
2For an example of a Headquarters determination that the numerical limits established by a particular ARAR should not generally be used as the basis to establish PRGs at CERCLA sites, see the memorandum from Stephen D. Luftig titled: “Establishment of cleanup levels for CERCLA sites with radioactive contamination” (OSWER Directive 9200.4-18), August 1997, p. 3.
4
Superfund Branch Chiefs (Regions I-X)
Superfund Branch Chiefs, Office of Regional Counsel (Regions I-X)
Radiation Program Managers (Regions I, IV, V, VI, VII, X)
Radiation Branch Chief (Region II)
Residential Domain Section Chief (Region III)
Radiation and Indoor Air Program Branch Chief (Region VIII)
Radiation and Indoor Office Director (Region IX)
Federal Facilities Leadership Council
OERR Center Directors

Post

1991-10-04 – ATSDR – West Lake Landfill – Preliminary Health Assessment for West Lake Landfill

PRELIMINARY
Health
Assessment
for RECElrEIJ
OCT 0 7 i9St
– turc~u of
t:nvfronmer.t2f Epi~cmlalogy
WEST LAKE LANDFILL
BRIDGETON, ST. LOUIS COUNTY, MISSOURI
CERCLIS NO . MOD079900932
OCTOBER 4, 1991
U.S. DEPAI~rfl\1ENT OF HEAL1″‘H AND IIUMAN SERVICES
PUBLIC HEALTH SERVICE
Agency for Toxic Substances and Disease Registry
THE ATSDR HEALTII ASSESSMENT: A NOTE OF EXPLANATION
Section 104 (i) (7) (A) of the Comprehensive Environmental Response, Compensalion, and Liabilily Act of 1980
(CERCLA), as amended. st.ates ” … the term ‘health assessment’ shall include preliminary assessments of potential risks to
human health posed by individual sites and facilities, based on such factors as the nature and extent of contamination, the
existence of potential pathways of human exposure (including ground or surface water contamination, air emissions, and
food chain contamination), the size and potential susceptibility of the community wiLhin the likely pathways of exposure,
the comparison of expected human exposure levels to the short-Lenn and long-term health effects associated with
identified hazardous substances and any available recommended exposure or tolerance limits for such hazardous
substances, and the comparison of existing morbidity and mortality data on diseases that may be associated with the
observed levels of exposure. The Administrator of ATSDR shall use appropriate data, risks assessments, risk evaluations
and studies available from the Administrator of EPA.”
In accordance with the CERCLA section cited, ATSDR has conducted this preliminary health assessment on the data in
the site summary form. Additional health assessments may be conducted for this site as more information becomes
available to ATSDR.
The conclusion and recommendations presented in this Rea.Ith Assessment are the result of site specific analyses and are
nOL to be cited or quoted for other evalumions or Health Assessments.
Use of Lrade names is for identification only and does not constilutc endorsement by the Public Health Service or the
U.S. Department of Health and Human Services.
-. ..
PRELIMINARY HEALTH ASSESSMENT
WEST LAKE LANDFILL
BRIDGETON, ST. LOUIS COUNTY, MISSOURI
CERCLIS NO. MOD079900932
Prepared by
Missouri Department of Health
Under Cooperative Agreement with the
Agency for Toxic Substances and Disease Registry
——————– — —
SUMMARY
The West Lake Landfill, located in the City of Bridgeton, St. Louis County,
Missouri, was proposed for the National Priorities List (NPL) in October 1989.
Soil contaminated with radioactive waste from decontamination efforts at the
Cotter Corporation’s Latty Avenue plant in Hazelwood, Missouri, was dumped at
the landfill in 1973. The radioactive soil was used as cover over refuse and
in later years the radioactive soil itself was covered with additional soil
and debris. The area around the landfill consists mostly of industrial
buildings and business offices with small residential communities to the south
and east. Agricultural river bottom land borders to the west, but it is fast
being encroached upon by Earth City which is being developed for commercial
purposes. The site presents no apparent public health hazard because the
available data indicate human health is not currently being affected.
Exposures of concern could occur if ground water contamination increases and
spreads, exposed radioactive materials on the northwestern edges of the
landfill move off site, or on-site worker exposure increases. Continued
monitoring is recommended until additional environmental data is available to
assess the on-site and off-site contamination and help predict future
activity.
BACKGROUND
A. Site Description and History
The West Lake Landfill is a 200 acre tract located in the City of Bridgeton,
St. Louis County, Missouri (Fig. 1). The tract borders St. Charles Rock Road
on the northeast side and Old St. Charles Rock Road on the southwest. It is
northwest of Interstate 270 and about 4 miles west of the Lambert-St. Louis
International Airport. The tract was owned in its entirety by West Lake
Properties from 1939 to 1988. In 1988, most of the tract was sold to Laidlaw
Industries; however, West Lake Properties retained the two radioactively
contaminated areas through a subsidiary named Rock Road Industries. Laidlaw
Industries operates the landfill under a Missouri Department of Natural
Resources (MDNR) permit.
From 1939 to 1987, limestone was quarried at the site. In 1962, landfill
operations commenced using old quarry pits to receive municipal refuse,
industrial waste, and construction debris. Also located on the property is an
active industrial complex producing concrete ingredients and aggregates.
The landfill is located on the historical edge of the Missouri River alluvial
valley, with about 75 percent of the site being located in the floodplain.
Soils at the demarcation line vary from Missouri River alluvium to upland
loessal soil. The present channel of the Missouri River lies just under 2
miles west of the landfill. The floodplain area and new businesses/industries
being constructed there are protected by a flood control levee. The ground
water level in the Missouri River floodplain is generally within 10 feet of
the surface. The reported flow is to the northwest from the site toward the
Missouri River.
In 1973, approximately 43,000 tons of soil contaminated with barium sulfate
residues containing about 7 tons of uranium and its radioactive decay products
were placed in the landfill. The radioactive material consists primarily of
uranium (U-238), thorium (Th-230), and radium (Ra-226). The soil came from
decontamination efforts at the Cotter Corporation’s Latty Avenue plant in
Hazelwood where the material had been stored. In 1980-81, The Radiation
Management Corporation (RMC), under contract to the Nuclear Regulatory
Commission (NRC), conducted a detailed radiological survey of the West Lake
Landfill. Material was found to have been dumped in two areas (Fig. 2). Area
1 is located near the landfill main office and covers approximately 3 acres.
It contains about 20,000 cubic yards of radioactive contaminated soil buried
about 3 to 5 feet deep. It is located over a former quarry pit which was
previously filled with debris. Area 2 covers about 13 acres and lies above 16
to 20 feet of debris. The radioactive contaminated soil forms a layer from 2
to 15 feet thick consisting of approximately 130,000 cubic yards. Some of
this contaminated soil is at or near the surface, particularly along the face
of the northwestern berm.
In 1983-1984, the University of Missouri-Columbia (UMC) Department of Civil
Engineering, under contract to the NRC, further characterized the site and
evaluated potential remedial measures. In 1986, Oak Ridge Associated
Universities (ORAU) sampled well water on and close to the landfill to
determine if radioactive material had migrated into the ground water. Based
2
on the reports of these studies, the site was proposed for inclusion on the
National Priorities List (NPL) in 1989.
B. Site Visit
On March 21, 1990, representatives of the Missouri Department of Health (DOH),
the Agency for Toxic Substances and Disease Registry (ATSDR), Environmental
Protection Agency (EPA), and MDNR visited the West Lake Landfill site. The
president of West Lake Properties led a tour of the area. He showed the group
the two areas with radioactive contamination and reviewed the history and
current operations at the site.
It was noted during the site visit that the entire facility is now fenced, a
security project completed in 1989. Before the fencing, employees present
during working hours and security guards present after working hours helped
prevent unauthorized access. The two areas of radioactive contamination were
not readily identifiable or marked. Area 2 did have a temporary row of
barrels to indicate the approximate eastern boundary. The only persons having
regular access to the area are the site’s work force.
During the time of the visit, the weather was clear and it had not rained for
a few days. Area 1 had a few small puddles of standing water and good
vegetative ground cover with no obvious erosion problems. Area 2 had no
vegetative ground cover, but had a variety of soil and crushed limestone
cover. Drainage was good with the ground being dry except in the northernmost
end where some water had pooled. Some recent dumping of apparent construction
debris was being used to fill in the low area where the water was standing.
Physical hazards at the site consisted of discarded construction equipment and
miscellaneous construction debris. After the NPL site visit, a driving tour
was conducted of the surrounding off-site area to determine possible routes of
exposure, demographics of the area, land use, and the possible population at
risk.
C. Demographics, Land Use, and Natural Resource Use
The West Lake Landfill is located in the northwestern portion of the City of
Bridgeton, in St. Louis County, Missouri. Earth City Industrial Park is
located on the floodplain approximately 1 mile west of the landfill.
Population density on the floodplain is generally less than 26 persons per
square mile; the daytime population (including factory workers) is much
greater than the number of full-time residents.
Major highways in the area include Interstate 70 (I-70) and Interstate 270
(I-270), which meet south of the landfill. The Earth City Expressway and St.
Charles Rock Road lie, respectively, west and east of the landfill. The
Norfolk and Western Railroad passes about 1/2 mile from the northern portion
of the landfill. Lambert-St. Louis International Airport is located
approximately 4 miles east of the West Lake Landfill.
In addition to business/industries at Earth City, plants are operated by
Ralston-Purina and Hussman Refrigeration across St. Charles Rock Road. The
3
employees of these two plants probably comprise the largest group of
individuals in close proximity to the contaminated areas for significant
periods of time. Considering that land in this area is relatively inexpensive
and that much of it is zoned for manufacturing, industrial development on the
floodplain will likely increase in the future.
Two small residential communities are present near the West Lake Landfill.
Spanish Lake Village consists of about 90 homes and is located about 1 mile
south of the landfill, and a small trailer court lies across St. Charles Rock
Road, 1 mile southeast of the site. Subdivisions are presently being
developed 2 miles east and southeast of the landfill in hills above the
floodplain. Ten or more houses lie east of the landfill scattered along
Taussig Road. The City of St. Charles is located on the west bank of the
Missouri River about 2 miles from the landfill.
Areas south of the West Lake Landfill are zoned residential; areas on the
other sides are zoned for manufacturing and business. Most of the landfill is
zoned for light manufacturing (M-1). However, some of the northern portion of
the landfill is zoned for residential use; this includes the contaminated area
around the former Butler-type building site in Area 2. The field northwest of
the landfill between Old St. Charles Rock Road and St. Charles Rock Road is
under cultivation. Trends indicate that the population of this area will
increase, but the land will probably be used primarily for business/industrial
facilities.
No public water supplies are drawn from the alluvial aquifer near the West
Lake Landfill. It is believed that only one private well in the vicinity of
the landfill is used as a drinking water supply. In 1981, analysis showed
water in this well to be fairly hard (natural origins), but otherwise of good
quality.
Water supplies are drawn from the Missouri River at mile 29 for the City of
St. Charles, and the intake is located on the north bank of the river.
Another intake at mile 20.5 is for the St. Louis Water Company’s North County
plant.
The City of St. Louis takes water from the Mississippi River, which joins the
Missouri River downstream from the landfill. In this segment of the river,
the two streams have not completely mixed and the water derived from the
Missouri River is still flowing as a stream along the west bank of the
Mississippi River channel. Reportedly, the intake structures for St. Louis
are on the west bank of the river so that the water drawn may or may not be
mixed, depending on conditions.
D. State and Local Health Data
The Missouri Department of Health, State Center for Health Statistics,
analyzes and consults on health related information collected from several
sources. The Center’s Bureau of Health Data Analysis has available
statistical information, hospital discharge data, and the Multi-Source Birth
Defect Registry. The Multi-Source Birth Defect Registry consists of birth
outcome data from the following data sources: birth, death, hospital
4
—- ——–
discharge, Crippled Children’s Services, and Neonatal Intensive Care Unit
records.
For health assessments, cancer mortality rates by age, sex, and cancer site
are calculated to determine whether there is a significant difference between
the area of concern and the rest of the State. Birth data include fetal
deaths, low birth weight births, and frequency of malformations in the area of
concern with comparison to the State rate.
For most of the State, the smallest geographic area that can be studied is
defined by a zip code. In the St. Louis metropolitan area, census tract
information is available that allows further refinement of the potentially
exposed population. However, that may still represent a larger area than is
actually affected by a site such as West Lake Landfill and the additional
people in the study group may well dilute and obscure any adverse health
outcomes, if present.
COMMUNITY HEALTH CONCERNS
Community concern around the area seems to be minimal. The Missouri
Department of Health (DOH) has had contact with area residents through the DOH
private well water monitoring program. The residents have expressed interest
in the results of the water sampling., but have expressed no particular health
concerns. Newspaper articles have been published about the site and its
possible hazards and public concern about this site may increase in the future
because of its link to three radioactive waste sites near the St. Louis
airport. The three sites – Futura Coating Company, Hazelwood Interim Storage,
and St. Louis Airport – have been consolidated and listed on the NPL as the
St. Louis Airport/HIS/Futura Coating Site. These sites have generated
considerable interest and debate including involvement of a local
environmental group. Their interest may extend to West Lake as the
radioactive waste there came from the St. Louis sites.
A. Public Comment Response
In order to solicit public comment on the West Lake Landfill Preliminary
Health Assessment, the document was made available to the public as required
under the Missouri Department of Health cooperative agreement with ATSDR.
The Health Assessment was placed at four readily accessible repository sites
(City of Bridgeton, City Hall; Bridgeton Trails Branch, St. Louis County
Library; Murphy Health Center; and the St. Louis County Department of
Community Health and Medical Care) for a period of 30 days (April 29 –
May 29, 1991).
Notification of the availability of the Preliminary Health Assessment was in
the form of a news release on April 23, 1991, followed by two public notices
in the Sunday St. Louis Post Dispatch on May 5, 1991, and May 19, 1991. No
comments were received during the public comment period for the West Lake
Landfill Preliminary Health Assessment.
5
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS
A. On-Site Contamination
In 1980-81, a radiological survey of the West Lake Landfill was conducted by
the Radiation Management Corporation (RMC) of Chicago, Illinois. External
(gamma) radiation levels in microrems per hour (-R/Hr) were measured 1 meter
above the ground surface. This survey showed the radioactive contaminants to
be located in two areas of the landfill (Fig. 2). Both areas had places that
exceeded 100 -R/Hr with a maximum level as high as 3,000 to 4,000 -R/Hr
detected in Area 2. The total areas exceeding 20 -R/Hr were about 2 acres in
Area 1 and 9 acres in Area 2. Levels were again measured in May (Fig. 2) and
in July of 1981 and found to be significantly lower than the November 1980
sampling, especially in Area 1 where approximately 4 feet of sanitary fill had
been added. An equal amount of construction fill was added to most of Area 2.
As a result, only a few hundred square meters of Area 1 exceeded 20 -R/Hr and
the amount of Area 2 exceeding 20 -R/hr had decreased by about 10 percent with
a maximum reading of about 1600 -R/hr. The 20 -R/hr criterion was derived
from the NRC’s Branch Technical Position, 46 CFR 52061, October 23, 1981,
which aims at exposure rates less than 10 -R/hr above background levels.
Background radiation in the area is about 10 -R/hr.
Surface Soil Analysis
Surface soil samples were gathered and analyzed (1980-81) on site for gamma
activity. In all 61 surface soil samples, only uranium and/or thorium decay
chain nuclides and K-40 (potassium 40) were detected. On-site samples ranged
from about 1-21,000 picocurie per gram (pCi/gram) for Radium 226 (Ra-226) and
from less than 10 to 2,100 pCi/gram Uranium 238 (U-238). Off-site background
samples were on the order of 2 pCi/gram for Ra-226. In general, surface
activity was limited to Area 2, with only two small regions in Area 1 showing
surface contamination.
Subsurface Soil
Subsurface soil was measured by the drilling of 43 holes, with holes being
drilled in known contaminated areas and then additional holes being drilled at
intervals in all directions until no further contamination was detected.
Concentrations of Ra-226 ranged from less than 1 pCi/gram to 22,000 pCi/gram.
Ground water
In the fall of 1980, and the spring and summer of 1981, a total of 37 water
samples were taken and analyzed by RMC. One sample taken of standing water
near the Butler building in Area 2 equaled the EPA drinking water standard for
gross-alpha.
In 1981, MDNR collected 41 water samples that RMC analyzed for radioactivity,
but only 10 were shallow ground water standing in bore holes. Of these 10
samples, only one equaled the EPA gross alpha activity standard for drinking
water of 15 picocuries per liter (pCi/L). Four of the 10 shallow ground water
samples exceeded 30 pCi/L gross beta activity, ~ith most of the beta activity
6
coming from naturally occurring K-40 as determined from subsequent isotopic
analysis. Background activity is estimated as 1.5 pCi/L gross alpha activity
and 30 pCi/L gross beta activity.
In 1983, and again in 1984, eleven perimeter wells were sampled for gross
alpha and gross beta. In two years of sampling, only 1 well each year
exceeded the 15 pCi/L drinking water standard for gross alpha (18.2 pCi/L in
1983 NE boundary, and 20.5 pCi/L in 1984 W boundary). Only one well in 1983
exceeded 30 pCi/L gross beta activity level at 33.1 pCi/L gross beta.
In 1986 Oak Ridge Associated Universities (ORAU) personnel took water samples
from 44 perimeter wells. Only one well (17 pCi/L of gross alpha activity)
exceeded the drinking water standard. This well also contained 47 pCi/L gross
beta activity. This well, and another at 46 pCi/L were the only ones to
exceed the 30 pCi/L background gross beta activity level. These wells are
close to one another on the west boundary of the landfill.
Vegetative
No elevated radioactivity was found by RMC in vegetation consisting of on-site
weed samples and farm crop samples (winter wheat) located near the northwest
boundary of the landfill. This crop location was chosen for sampling because
water could run off from the fill onto the farm field.
Air
Concentrating on measuring radon and its daughters in the air, both gaseous
and particulate airborne radioactivity were sampled and analyzed between May
and August of 1981. These were sampled because of the known materials that
consisted partially or totally of uranium ore residues. A total of 111
samples from 32 locations were sampled and radon flux levels ranged from 0.2
pico curie per square meter-second (pCi/m2-sec)in low background areas to 865
pCi/m2-sec in areas of surface contamination. A set of air particulate
samples was taken to assess radon daughter concentration. Radon daughter
concentration is commonly reported in terms of working level (WL), a unit of
measurement originally developed for occupational exposure but also relevant
and appropriate for environmental exposure. The highest levels (0.031 WL)
were detected in November 1980, near and inside the Butler-type building, that
has since been removed. Off-site samples were taken for background at Earth
City, Taussig Road, and Old St. Charles Rock Road sites. The levels measured
were reported at 0.0011, 0.005, and 0.0017, respectively.
Other Contaminants
The site has been a landfill since 1962. Prior to regulation by the MDNR, it
is believed that the landfill may have accepted such materials as organics and
inorganics, heavy metals, solvents, pesticides, paints and pigments, acids,
bases, sewage sludge, as well as small quantities of unknown hazardous waste.
This is based on notification as required by the Comprehensive Environmental
Response, Compensation and Liability Act of 1980 (CERCLA) and may not be an
accurate representation of what was actually dumped in the landfill. (A
portion of CERCLA 103(c) requires owners and operators of facilities which had
7
stored, treated, or disposed of hazardous substance to notify the
Administrator of EPA of the existence of such facilities not later than
June 11, 1981. This requirement effectively obligated all owners and
operators of such facilities to report the existence of facilities that they
knew to have used at any time in the past for the storage, treatment or
disposal of hazardous waste.) (10)
The sampling data available for the site have not demonstrated significant
contamination of the ground water. Burns and McDonnell, in a 1986 report on
the hydrogeology of the site, reported to have found only methylene chloride,
bis (2-ethylhexyl) phthalate, and phenol in identifiable quantities in 2
rounds of sampling (December 1985 and May 1986). They also reported that the
general distribution of the organic constituents was scattered and irregular.
In round 2 of the sampling, the presence of methylene chloride was attributed
to the laboratory process rather than to any contaminant in the ground water.
In general, the detection of organics and heavy metals was scattered and
irregular, leaving inconclusive evidence as to the contamination of the
landfill by these materials.
B. Off-Site Contamination
Off-Site contamination from the West Lake NPL site has not been shown. The
Missouri Department of Health sampled private wells in the area most likely to
be contaminated. Four wells were sampled in 1988 and 1989 and no gross alpha
activity above the EPA drinking water standard of 15 pCi/l was found. The
samples were also tested for the presence of common pesticides. None were
detected in any of the samples.
The possibility exists that during the transportation of the radioactively
contaminated soil to the West Lake Landfill, some soil could have blown or
spilled from the transportation trucks. This is being investigated in
conjunction with the St. Louis Airport/HIS/Future Coating NPL site by a
contractor for the U.S. Department of Energy.
Research of the EPA Toxic Chemical Release Inventory (TRI) was conducted to
determine other chemical releases in the area of West Lake Landfill. Three
industries in the vicinity reported releases in the years 1987 and 1988, two
of which are within a mile of the site, while the third is just over a mile.
Releases of reported chemicals had no correlation with the West Lake Landfill
contamination.
C. Quality Assurance and Quality Control
Various organizations and laboratories have been involved in the sampling and
analysis with varying degrees of Quality Assurance and Quality Control
information available. In preparing this Preliminary Health Assessment,
DOH/ATSDR have, to an extent, relied on the information provided in the
referenced documents and assume adequate quality assurance and quality control
measures were followed with regard to chain-of-custody, laboratory procedures,
and data reporting. The validity of the analysis and therefore the
conclusions drawn for this health assessment are predicated on this reliance.
,
8
D. Physical and Other Hazards
Physical hazards at the site consist of discarded construction equipment and
miscellaneous waste construction debris around Area 2. The area is fenced and
only workers at the site would be expected to be exposed to possible hazards.
PATHWAYS ANALYSES
As discussed in the Site Description and History Subsection, the dumping of
approximately 43,000 tons of soil contaminated with barium sulfate residues
containing approximately 7 tons of uranium and its radioactive decay products
has polluted the West Lake Landfill.
A. Environmental Pathways (Fate and Transport)
Radioactive contaminated soil was used to cover debris and municipal waste at
the West Lake Landfill. The contaminated soil has since been covered over
with clean soil and remains exposed only in an area on the northwestern berm.
Erosion of this soil by surface water run-off would spread radioactive
contamination to the farm field west of the site and/or to the Creve Coeur
Creek. The creek has no known recreational purposes and is not expected to be
used for a water source. Approximately two miles downstream, the creek enters
the Missouri River. Water supplies for the City of St. Charles are drawn from
the opposite (north) bank of the river. The next known water intake is the
St. Louis Water Company North County Plant, which is approximately 8.5 miles
further downstream.
Wind erosion of dust from the berm is not expected to be a pathway of concern
except in very dry conditions or during disturbance. The landfill is located
on the historical edge of the Missouri River alluvial valley with about 75
percent of the site being located in the floodplain. There are two aquifiers
at the site consisting of the Missouri River alluvium and the shallow
limestone bedrock. Below the s~allow limestone is the relatively impermeable
Warsaw shale that acts as a barrier, making contamination of the deeper
limestone aquifer unlikely. The shale layer has been reached by quarrying
operations but has not been disturbed.
Ground water flow direction in the river floodplain varies somewhat, depending
on the water level. It generally tends to flow northwest toward the river.
Under high river conditions, the flow is more northerly. The ground water
level is generally within 10 feet of the floodplain surface. No public water
supplies are drawn from the alluvial aquifer near the West Lake Landfill. Any
leachate would be significantly diluted upon reaching the alluvial ground
water and further diluted once it reached the river.
The air above the contaminated soil provides a path for the dissemination of
radon gas. The gas and its alpha-particle emitting daughters then become
available for inhalation.
9
The high ratio of Th-230 to Ra-226 radioactivity indicates that decay of
Th-230 will increase the concentration of its product, Ra-226, until the two
radionuclides are in equilibrium. It is estimated that the Ra-226 activity
will increase by a factor of nine 200 years from now, and by a factor of
thirty-five 1,000 years from now. All radionuclides in the decay chain after
Ra-226 (and the Ra-222 gas flux) will be increased by similar multiples. (12)
B. Human Exposure Pathways
With the landfill being fenced, direct exposure to the contaminated soil on
the northwest berm to the public is not considered a viable route of exposure.
If the soil was eroded from the site by either wind or water, exposure to
radioactive materials could take place. Ground water in the area is not used
for municipal purposes, but a few private wells in the area are used for
domestic purposes and irrigation.
Surface water from the Missouri River used as a municipal supply for the City
of St. Charles is not expected to be affected by the landfill. The city draws
its water from the west bank where mixing has not occurred yet. The City of
St. Louis Water Company North County Plant takes its water from the Missouri
River at mile 20.5 where significant dilution of any possible contaminants
from the landfill has already occurred.
Radon exposure to the public is not expected to be a problem since the area is
fenced and there is no public access. Air levels off site would be typically
much lower than on site. The possibility does exist that, in the future,
increased levels of radon will be present as the material seeks equilibrium.
Ingestion of radioactive contaminants taken up by crops is not expected to be
a pathway of exposure. No elevated radioactivity was detected in on-site
weeds or in wheat grown near the site.
Fish from the Missouri River are not expected to be affected by the West take
Landfill primarily due to dilution. Fish in ponds along Creve Coeur Creek
west of the site may represent a potential exposure route; however, it is not
known if the ponds are used for fishing. The relatively low radioactivity in
the ground water in on-site monitoring wells would indicate that low activity
would be likely in any connected surface waters.
PUBLIC HEALTH IMPLICATIONS
No exposure is known to be occurring to residents around the site. The few
private wells in the vicinity have not shown any contamination from the West
Lake Landfill; however, on-site monitoring well sampling has revealed some
migration of uranium and its radioactive decay products into the ground water.
The majority of the area is served by a public water system with no source
wells in the area. Direct exposure of the public to ionizing radiation on
site is not expected because of restricted access. Exposure to on-site
workers is expected to be of small concern because the time spent in
10
contaminated areas is likely to be brief and can be monitored and controlled
to minimize cumulative exposure.
The possibility does exist that during the unloading and disposal of the
contaminated soil at West Lake, the unprotected workers could have been
exposed. Information on radioactive level, worker protection, conditions
during the process, times per day and the duration of the project would be
needed to determine if significant exposure had occurred.
A. Toxicological Implications
Contaminants present at the landfill are Uranium-238 (U-238), Thorium-230
(Th-230), Radium-226 (Ra-226), and Radon-222 (Rn-222) with half-lives of
approximately 4.5 X 109 years, 80,000 years, 1,600 years, and 3.8 days,
respectively. These radionuclides, members of the uranium decay chain, emit
alpha particles and gamma rays. At this site, the uranium, thorium and radium
are nearly completely covered with clean fill so as to not present a
significant direct dust inhalation or ingestion potential. Therefore, the
exposures of most interest would be inhalation of radon and its daughters and
ingestion of radioactively contaminated ground water. Radon gas, produced by
the decay of radium, diffuses up through the soil cover and mixes with the air
above it where it may be breathed. Rain falling on the soil cover percolates
down into and through the contaminated layers, picks up radioactive particles,
and delivers them to the ground water where they may eventually reach drinking
water wells. Additionally, rain may erode contaminated soil from the
northwest berm area and deposit it in the adjacent field where crop uptake is
possible.
Rn-222 has been shown to be carcinogenic, producing lung cancers when inhaled,
based principally on studies of uranium miners. Although radon gas itself is
inert, some will be absorbed into the blood from the lungs and transported
throughout the body; the rest will be exhaled. The radon decay products
(daughters) are charged particles. When inhaled, either directly or attached
to other airborne particulate mateer, they deposit on lung surfaces and lodge
in the mucosa. As the radon daughters decay, they emit alpha particles, the
major health hazard associated with radon gas exposure. The alpha particles
are potent ionizers, but do not travel far in tissue due to their relatively
large size. (S,8)
The principal health effect of this ionizing radiation in humans is cancer
induction and the most important target tissue is the bronchial epithelium.
Due to their short half-life, inhaled radon daughters emit their alpha
particles in the lung before they move on to other organs. Radon exposed
smokers are at greatly increased risk of respiratory tract cancer due to the
multiplicative interaction of the dual exposure. (8)
By convention, radon exposure is measured in terms of working levels (WL) and
cumulative exposures over time are measured in working level months (WLM).
One WL is defined as any combination of the short-lived radon daughters in 1
liter of air that results in the ultimate release of 1.3 x 105 MeV (million
electron volts) of alpha particle energy. This is approximately the amount of
11
alpha energy emitted by the short-half-life daughters in equilibrium with 100
pCi of radon. (8)
Given that the highest level detected on site was 0.031 WL, and that this
level is very close to the Nuclear Regulatory Commission (NRC) alternate
concentration limit of one-thirtieth (0.033) WL for unrestricted areas (3), it
does not appear that unacceptably high exposure is occurring at present.
Additionally, the population at risk, on-site workers, would not experience
continuous exposure at the highest level. Rather, their actual cumulative
exposure would be to the weighted average of their work location levels. This
average would be well below the NRC concentration limit. There is
insufficient information available on the actual exposure of workers to
further characterize the risk.
Since the radioactive material at the site is not a natural undisturbed
deposit, the radionuclides are not in equilibrium with each other. Therefore,
it is quite possible that the concentration of radon gas will increase
significantly in the future. This increases the potential for future exposure.
When ingested, soluble forms of U-238 are chemically toxic to the kidney,
producing tissue damage in the proximal tubules and consequent functional
impairment. The tissue will regenerate and function will return if exposure
ceases. This chemical toxicity is of much greater significance than the
potential for ionizing radiation effects since the soluble forms are excreted
from the body rather quickly. Conversely, insoluble forms may be retained in
the body for a long time and the radiation effects become paramount. Target
organs are principally the bone marrow and lymphatics. Exposure may result in
radiation-induced cancer. (1,4)
Thorium is relatively inactive chemically and, therefore, is of concern only
as a chronic radiation hazard. Little of an ingested dose of thorium is
retained in the body; however, once deposited, it remains for a long time.
The bones, lungs, and lymphatics are the primary depositories.
Highly radiotoxic, radium is metabolically handled the same as calcium. It is
deposited in the skeleton where it serves as a source of alpha radiation in
the bones and adjacent tissues. Studies of radium dial painters have clearly
demonstrated excess bone cancer in heavily exposed groups. However, low
exposures have shown relatively much less risk of bone cancer than would be
predicted from a simple straight line extrapolation from the high exposure
data. (4)
B. Health Outcome Data Evaluation
Missouri State Health Outcome Data were researched for the West Lake Landfill
site in order to determine if there was an indication of common health
problems associated with the area. Although little public health concern was
present to warrant the research, it was useful to explore every available
avenue in determining public health effects that could be present around the
site. If an indicator of common health problems was found, and the problems
could not be related to the site, a follow-up health study would be considered
to investigate the cause.
12
The DOH, State Center for Health Statistics, studied cancer deaths and
natality data for the years 1981-1988 for the census tracts most likely to be
affected by the West Lake NPL site (Fig. 3). Using statewide cancer death
rates, the expected number of deaths was calculated for the West Lake area.
This number was then compared to the actual (observed) number of deaths and a
test of statistical significance performed. “Statistical significance” means
that any noted difference between the two numbers is probably not due just to
chance. Cancer deaths were looked at by type of cancer for various age
groups, for all types combined for age groups, and for total cancer deaths for
all age groups combined. Cancer of the kidney in the 45-64 age group was the
only comparison that achieved statistical significance. There were 3 observed
deaths in this group when less than 1 would have been expected. Small numbers
like this, however, may not allow meaningful analysis and it is unknown if
these persons actually experienced any exposure.
Fetal deaths and low birth weight weights (less than 2,500 grams) were studied
for years 1981-1988. The observed number of fetal deaths was not significant
compared to the expected value. The number of observed low birth weight
weights for the site area was significantly lower than expected.
Based on the State rate, a study of 1981-1986 births did not reveal an
observed number of anomalies significantly different from those expected.
This study was based upon aggregated birth and death certificates, hospital
discharge, Crippled Children’s Service, and neonatal intensive care unit data.
These studies neither confirm nor deny a health threat to the population
potentially at risk from the West Lake Landfill. The census tracts located
between the Missouri River and Highway 270 in north St. Louis County, (the
smallest definable area for these studies), include a much larger geographical
area and larger population than would actually be affected by this site;
therefore, any adverse health effects might be obscured.
CONCLUSIONS
From the information reviewed, the West Lake Landfill is presently judged to
be of no apparent public health hazard. No exposures above applicable levels
of concern are known to be presently occurring or to have occurred in the
past. The only suspected exposure at a level of concern would have been to
unprotected workers during past disposal of radioactively contaminated soil at
the site.
The relatively low levels of radioactive contamination in the ground water
suggest that the radionuclides present in the landfill are not very soluble.
Thus, they may not migrate significantly from the soil into the water.
Although radiation has been detected in some perimeter monitoring wells, the
results have been inconsistant from the various sampling rounds and additional
sampling is required to confirm the presence and magnitude of any
contamination. Off-site ground water samples have not shown alpha or beta
activity above the National Interim Primary Drinking Water Regulations
(NIPDWR) levels of 15 pCi/l and 50 pCi/l, respectively.
13
Sampling for priority pollutants, including heavy metals and organics, showed
no consistent pattern of on-site ground water contamination that could be
contributed to the landfill. DOH off-site sampling and analysis of private
well water revealed no detectable levels of pesticides, but the analysis did
not include volatile organic compounds (VOC’s) or metals.
Radioactive material at or near the surface of the west berm apparently has
not eroded from the site because no material was detected off-site or in
vegetation in 1981 data.
Radon gas is diffusing into the air above the contaminated areas, with maximum
levels (1981 data) approximately equal to the NRC alternate concentration
levels allowable for unrestricted areas. Current levels are unknown and
levels are expected to increase in the future as the material seeks
equilibrium. The potentially exposed population consists of the site work
force whose presence in contaminated areas is believed to be brief and
intermittent, reducing the cumulative exposure. No warning placards were
present in the March 1990 site visit to indicate the radioactive contaminated
area and to prevent inadvertent exposure. Earlier off-site sampling for radon
did not reveal levels indicating any increased air concentration.
The health outcome data evaluation was inconclusive. The study population was
much larger than those expected to be affected by the site. Community concern
seems minimal, and is being adequately addressed by the DOH well water
sampling and analysis program. Current sampling data is needed to better
evaluate the levels of contamination in the ground water, soil, and air.
Appropriate surveys need to be done both on and off-site so present pathways,
potential exposure, and health effects can be determined.
RECOMMENDATIONS
It is recommended that at the earliest possible date a comprehensive Remedial
Investigation/Feasible Study (RI/FS) be completed for the ‘West Lake Landfill.
It should include at least:
a. On- and off-site ground water monitoring for radiation
and other contaminants;
b. On- and off-site soil sampling (surface and sub-surface)
and determination of air radiation levels;
c. A complete survey of area wells and monitoring for
landfill contaminants;
d. Proposal and implementation of a remedial action to
prevent present and future exposure to workers and the
public, if deemed necessary by the RI/FS.
During the community interview phase of the Remedial Investigation,
information should also be gathered on former workers who were involved with
the site during the transport, dumping, and spreading of radioactively
14
——– ———– ——
contaminated soil. The workers could then be encouraged to talk to public
health officials at public meetings or availability sessions, or be personally
interviewed at their homes in order to determine their past exposures, site
related common health problems, and environmental circumstances during that
time. The DOH will work with the EPA and MDNR to address this issue.
At the earliest possible date, a placard system identifying the radioactive
areas must be installed in order to prevent inadvertent exposure. It is also
recommended that DOH continue to expand its monitoring of area wells in order
to include metals and VOC’s associated with the landfill.
When additional data, i.e., the RI/FS, become available, such material will
form the basis for further assessment by DOH/ATSDR at a later date.
FOLLOW-UP STATEMENT
In accordance with the Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA) of 1980, as amended, the West Lake Landfill NPL site
has been evaluated for follow-up health activities. There are no indications
that the surrounding community is or has been exposed to site contaminants.
Although worker exposure to site contaminants may have occurred in the past
during the period of contaminated soil dumping, spreading and covering
operations, it is believed that the exposure most likely did not occur at
levels deserving of public health concern. Considering the available
information, the site is not being considered for follow-up health activities
at this time. Should the Remedial Investigation discover new evidence
indicating actual or potential exposure of the public to site contaminants,
DOH/ATSDR will reevaluate this site for follow-up health activities.
15
PREPARERS OF THE REPORT
Arthur Busch
Environmental Specialist
Missouri Department of Health
Stephen L. Meek
Toxicologist
Missouri Department of Health
ATSDR Regional Representative
Dan Harper, R.S.
Senior Regional Representative
Region VII
ATSDR Technical Project Officer
Burt J. Cooper
Environmental Health Scientist
Division of Health Assessment and
Consultation, Remedial Programs Branch
16
CERTIFICATION
This health assessment was prepared by the Missouri Department of Health under
a cooperative agreement with the Agency for Toxic Substances and Disease
Registry (ATSDR). It is in accordance with approved methodology and
procedures existing at the time the health assessment was initiated.
The Division of Health Assessment and Consultation, ATSDR, has reviewed this
health assessment and concurs with its findings.
17
.. C’
REFERENCES
1. Berlin, M. and Rudell, B.; “Uranium” in Handbook on the Toxicology of
Metals, edited by L. Friberg et al. Elsevier/North-Holland Biomedical
Press, 1979
2. Burns & McDonnell. Hydrogeologic Investigation, West Lake Landfill
Primary Phase Report. Kansas City, MO. October 1986. Project No.
84-075-4-004.
3. 10 CFR Part 20, App. B Concentrations in Air and Water Above
Natural Background
4. Casarett and Doull’s Toxicology: The Basic Science of Poisons. 3rd Ed.
edited by Curtis D. Klaassen, Mary 0. Amdur, and John Doull, Macmillan,
NY, NY, 1986
5. Harley, N .H.; “Environmental Lung Cancer Risk From Radon Daughter
Exposure” in The Risk Assessment of Environmental and Human Health
Hazards: A Textbook of Case Studies, Dennis J. Paustenbach, ed., John
Wiley & Sons, NY, NY, 1989
6. Missouri Department of Health. Cancer Registry and Natality Data
Analysis. West Lake Landfill,, Bridgeton, Missouri. 1990.
7. Missouri Department of Health.
Landfill, Bridgeton, Missouri.
Private Well Sampling Data, West Lake
1989.
8. National Research Council, Committee on the Biological Effects of
Ionizing Radiation (BEIR). 1988. Health Risks of RADON and Other
Internally Deposited Alpha-Emitters. Washington, DC: National
Academy Press.
9. Review of copies of EPA Form 8900-1, Notification of Hazardous Waste
Site, required by CERCLA 103(c). Missouri Department of Natural
Resources Site file, 1990.
10. Schroff, C. and Steinberg, R.E.; RCRA and Superfund – A Practice Guide
with Forms. Garland Law Publishing, New York, New York. 1989.
11. U.S. Nuclear Regulatory Commission. Office of Nuclear Material Safety
and Safeguards. Site Characterization and Remedial Action Concepts for
the West Lake Landfill. Docket No. 40-8801. July 1989.
12. U.S. Nuclear Regulatory Commission. Office of Nuclear Material Safety
and Safeguards. Radioactive Material in the West Lake Landfill.
NUREG-1308 Rev. 1 June 1988
13. U.S. Nuclear Regulatory Commission. Office of Nuclear Material Safety
and Safeguards. Radiological Survey of the West Lake Landfill. St.
Louis County, Missouri. NUREG/CR-2722. May 1982.
18
Figure 1.
Figure 2.
Figure 3.
” r
APPENDIX
West Lake Landfill Area Map and Site Location
West Lake Landfill External Gamma Radiation Levels Map
May, 1981.
Missouri Health Outcome Data Census Tract Location Map
19
N
0
SCALE 1:24 000
1000 0 1000 2000 3000 4000 5000 6000 7000 FEET
s:::s:;a
I 5 0 I KILOMETER
– ..:E::3:::: E3 ~,__:…..,
CONTOUR INTERVAL 10 FEET
NATIONAL GEODETIC VERTICAL DATUM OF 1929
SOURCE: USGS
WEST LAKE LANDFILL
FIGURE 1
AREA MAP AND
SITE LOCATION
‘ ..
St.CHARLES ROCK ROAD
AREA 1
AREA 2 t
~ … 20 .. R/hr
Figure 2 External gi.lnvna radiation levels, May, 1981
SOURCE: NRC, Radiological Survey of the Westlake Landfill, St. Louis Co., MJ 1982
N
N
fl’
V!
Tollto. U.S.67
Census tracts area
West Lake Landfill
ID.
ST. LOUIS
FIG. 3
CENSUS TRACT LOCATION
FOR
MISSOURI HEALTH OUTCOME DATA
+ :

Post

2015-04-02 – EPA – West Lake Landfill – Bridgeton Missouri CERCLA History

West Lake Landfill site, Bridgeton Missouri
CERCLA History
April2, 2015
• National Priority Listing (NPL) for West Lake
o West Lake Landfill was listed on the NPL in 1990 (See 55 FR 35502-25512, Aug.
30, 1990).
o The NPL listing package was primarily based on radioactive contamination;
however, the narrative summary mentions that there are other chemical
contaminants in the landfill.
o NPL listings are based on data of a sufficient nature to list the site but are not
inclusive of all contaminants that may present an unacceptable risk and do not
define the areal of extent of contamination.
• As noted in a 2012 HRS listing: The HRS does not require scoring all
pathways if scoring those pathways does not change the listing decision. The
HRS is a screening model that uses limited resources to determine whether a site
should be placed on the NPLfor evaluation and possible Superfund response. A
subsequent stage of the Superfund process, the remedial investigation (RI),
characterizes conditions and hazards at the site more comprehensively.
• For the West Lake site, Operable Unit (OU) 1 deals with landfills that contain RIM (and
other chemicals) and OU2 deals with the other non-RIM landfills at the NPL site.
• OUI had a Record of Decision (ROD) signed in 2008. Subsequent to the signature of the
ROD, concerns were raised by the Missouri Coalition for the Environment and others
regarding EPA’s decision to cap the Site and leave RIM in place. As a result, the Agency
chose to more thoroughly explore other potential alternate remedies, including full and
partial excavation. That has been the primary focus of work over the last few years,
including the NRRB consultation and ongoing work supported by OSRTI, ORD, and
others.
• OU2 (non-RIM landfills) had a separate ROD signed in 2008 for the non-radiation
portion of the site.
o The ROD for OU2 (non-RIM landfills) states: “For areas operated under state
permit, i.e., the Former Active Sanitary Landfill and the Closed Demolition
Landfill, the terms of their respective permits dictate the appropriate closure and
post-closure care requirements. Successful completion of these requirements
would eliminate the need for further CERCLA action at these units. Consistent
with EPA’s policy on coordination between the Resource Conservation and
Recovery Act and CERCLA actions, these regulated units are deferred to the state
regulatory program.”
o The OU2 ROD indicates that the Former Active Sanitary Landfill, also known as
the Bridgeton Landfill, is part of the OU2 area The OU2 ROD requirements
include:
• Installation of landfill cover meeting state sanitary landfill requirements
WLLFOIA4312- 001 – 0057929
• Groundwater monitoring consistent with requirements for sanitary
landfills
• Surface water runoff control
• Gas monitoring and control consistent with sanitary landfill requirements
• Institutional Controls
• Surveillance and maintenance of the remedy
o Because of the deferral, all of the activities and issues related to the Bridgeton
Landfill have been lead and managed by the State. This includes management of
the off-gassing, which has been an issue of significant community interest.
• The following maps are attached (please note the “North” arrows as the orientation can
vary from one map to the next):
o West Lake Landfill OU-2 map
• Shows the the overall boundaries and state permit coverages
o West Lake Site Layout for OU-1, which shows Radiological Areas 1 and 2
o West Lake Site vicinity map
• There also has been some recent discussion regarding a recent flyover.
o Based on discussions with the Region, in February 2015, a local fire department
official conducted a flyover using an infrared camera that supposedly indicated
that the North Quarry of the Bridgeton Landfill may have elevated temperatures.
Immediately north of the North Quarry is where RIM was found during 2014
sampling associated with locating an isolation barrier between the RIM and the
SSE. This could have led to the conclusion that the subsurface smoldering event
may have migrated to the radiation contamination areas.
o However, it appears that the State and the Region have determined that the data
from that flyover are not credible, due to concerns with the overall process,
equipment, etc.
o Thus, the Region and the State are no longer addressing the flyover. The Region
continues coordination with the state on review of the data from the temperature
probes and gas extraction wells to evaluate the possible movement of the SSE.
WLLFOIA4312- 001 – 0057930

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