UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, O.C. 20460
x. «/» SOL'O
SEP 7,IW
OSWER Directive #9355.4-02
MEMORANDUM
SUBJECT: Interim Guidance on Establishing Soil Lead Cleanup
Levels at Superfund Sites.
FROM: Henry L. Longest II, Director
Office of Emergency and Remedia
Bruce Diamond, Director"
Office of Waste Programs Enforcement
TO: Directors, Waste Management Division, Regions I, II,
IV, V, VII and VIII
Director, Emergency and Remedial Response Division,
Region II
Directors, Hazardous Waste Management Division,
Regions III and VI
Director, Toxic Waste Management Division,
Region IX
Director, Hazardous Waste Division, Region X
PURPOSE
The purpose of this directive is to set forth an interim soil
cleanup level for total lead, at 500 to 1000 ppm, which the Office
of Emergency and Remedial Response and the Office of Waste Programs
Enforcement consider protective for direct contact at residential
settings. JM* range is to be used at both Fund-lead and
Enforcement-lead CERCLA sites. Further guidance will be developed
after the Agency has developed a verified Cancer Potency Factor
and/or a Reference Dose for lead.
BACKGROUND
Lead is commonly found at hazardous waste sites and is a
contaminant of concern at approximately one-third of the sites on
the National Priorities List (NPL). Applicable or relevant and
appropriate requirements (ARARs) are available to provide cleanup
levels for lead in air and water but not in soil. The current
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National Ambient Air Quality standard for lead is 1.5 ug/m3.
While th« exist ing Maximum Contaminant Level (MCL) for lead is
50 ppb, the Agency has proposed lowering the MCL for lead to 10 ppb
at the tap and to 5 ppb at the treatment plant f1). A Maximum
Contaminant Level Goal (MCLG) for lead of zero was proposed in
1988 (2). At the present time, there are no Agency-verified
toxicological values (Reference Dose and Cancer Potency Factor,
ie., slope factor), that can be used to perform a risk assessment
and to develop protective soil cleanup levels for lead.
Efforts are underway by the Agency to develop a Cancer
Potency Factor (CPF) and Reference Dose (Rf D) , (or similar
approach) , for lead. Recently, the Science Advisory Board
strongly suggested that the Human Health Assessment Group (HHAG)
of the Office of Research and Development (ORD) develop a CPF for
lead, which was designated by the Agency as a B2 carcinogen in
1988. The HHAG is in the process of selecting studies to derive
such a level. The level and documentation package will then be
sent to the Agency's Carcinogen Risk Assessment Verification
Exercise (CRAVE) workgroup for verification. It is expected that
the documentation package will be sent to CRAVE by the end of
1989. The Office of Emergency and Remedial Response, the Office*
of Waste Programs Enforcement and other Agency programs are
working with ORD in conjunction with the Office of Air Quality
Planning and Standards (OAQPS) to develop an RfD, (or similar
approach), for lead. The Office of. Research and Development and
OAQPS will develop a level to protect the most sensitive
populations, namely young children and pregnant women, and submit.
a documentation package to the Reference Dose workgroup for
verification. It is anticipated that the documentation package
will be available for review by the fall of 1989.
The following guidance is to be implemented for remedial
actions until further guidance can be developed based on an Agency
verified Cancer Potency Factor and/or Reference Dose for lead.
Guidance
This guidance adopts the recommendation contained in the 1985
Centers few Disease Control (CDC) statement on childhood lead
poisoning v^) and is to be followed when the current or predicted
land use im residential . The CDC recommendation states that
"...lead in soil and dust appears to be responsible for blood
levels in children increasing above background levels when the
concentration in the soil or dust exceeds 500 to 1000 ppm".
Site-specific conditions may warrant the use of soil cleanup
levels below the 500 ppm level or somewhat above the 1000 ppm
level. The administrative record should include background
documents on the toxicology of lead and information related to
site-specific conditions.
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The rtnge of 500 to 1000 ppm refers to levels for total lead,
as measured by protocols developed by the Superfund Contract
Laboratory Program. Issues have been raised concerning the role'
that the bioavailability of lead in various chemical forms and
particle sizes should play in assessing the health risks posed by
exposure to lead in soil. At this time, the Agency has not
developed a position regarding the bioavailability issue and
believes that additional information is needed to develop a
position. This guidance may be revised as additional information
becomes available regarding the bioavailability of lead in soil.
Blood-lead testing should not be used as the sole criterion
for evaluating the need for long-term remedial action at sites that
do not already have an extensive, long-term blood-lead data
EFFECTIVE DATE OF THIS GUIDANCE
This interim guidance shall take effect immediately. The
guidance does not require that cleanup levels already entered into
Records of Decisions, prior to this date, be revised to conform *
with this guidance.
1 In one case, a biokinetic uptake model developed by the Office
of Air Quality Planning and Standards was used for a site-
specific risk assessment. This approach was reviewed and
approved by Headquarters for use at the site, based on the
adequacy of data (due to continuing CDC studies conducted over
many years). These data included all children's blood-lead
levels collected over a period of several years, as well as
family socio-economic status, dietary conditions, conditions of
homes and extensive environmental lead data, also collected over
several years. This amount of data allowed the Agency to use the
model without a need for extensive default values. Use of the
model tbuc allowed a more precise calculation of the level of
cleanup needed to reduce risk to children based on the amount of
contamination from all other sources, and the effect of
contamination levels on blood-lead levels of children.
REFERENCES
1. 53 FR 31516, August 18, 1988.
2. 53 FR 31521, August 18, 1988.
3. Preventing Lead Poisoning in Young Children, January
U.S. Department of Health and Human Services, Center'
Disease Control, 99-2230.
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D.C. 20460 „
J* 26 090
• . . OFFICE OF
_. " . . SOLID WASTE AND EMERGENCY RESPONSE
OSWBR Directive t 9355.4-02A
MEMORANDUM
SUBJECT: Supplement to InterIB Guidance on Establishing Soil
Lead Cleanup Levels at Superfund .Sites
FROM: Henry L. Longest II, Director ^
Office of Emergency and Reaedia^, Response
Bruce M. Diamond, Directoi _^
Office of Waste Programs Enforcement
TO: Directors, Waste Management Division, Regions I,
IV, V, VII, and VIII
Director, Emergency and Remedial Response Division,
Region II
Directors, Hazardous Waste Management Division,
Regions III and VI
Director, Toxic Waste Management Division,
Region IX
Director, Hazardous Waste Division, Region X
The purpose of this directive is to reiterate that OSWBR
Directive f9355.4-02, titled "Interim Guidance on Establishing
Soil Lead Cleanup Levels at Superfund Sites" and dated September
7, 1989, is a guidance document and not a regulation. As is the
case with other guidance documents, this guidance should not be
used as a regulation.
The lead level range provided in the directive is to be
considered by a Regional Administrator in arriving at cleanup
levels to be entered into Records of Decisions for individual
Superfund sites, the directive is not binding in formulating
individual cleanup levels.* The directive is clear on its face
» The "Effective Date" provision of the directive should
not be read to suggest that the directive has regulatory impact.
The provision simply clarifies that the directive does not
require or contemplate that Agency decision makers will re-open
Records of Decisions already entered into in order to consider
the data provided in the directive.
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that it provides only "interim guidance," that BPA is continuing
to evaluate studies on the toxici'ty .of. lead, and that the
guidance may be revised as additional-information becomes
available with respect to the bioavailability of lead in soil.
Moreover, the directive plainly states that site-specific
conditions and data may be taken into account in setting soil
cleanup levels for individual sites, which may be above, or below
the levels set forth in the directive, and that the
administrative record for any particular site should include
site-specific information as well as background documents on the
toxicology of lead.
In summary, the cleanup levels for a particular response
action must be based on the entire administrative record for that
response action, of which the guidance will typically be only a
part.
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