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                UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                           WASHINGTON, D.C. 20460
                                APR 13 1998
                                                         OFFICE OF

                                                     SOLID WASTE AND EMERGENCY RESPONSE
                                          OSWER Directive  9200.4-26
MEMORANDUM

SUBJECT:   Approach for Addressing Dioxin in  Soil at CERCLA and
          RCRA Sites

FROM:     Timothy Fields,  Jr. Acting Administrator /s/
          Office of Solid Waste and Emergency Response

TO:       Director, Office  of  Site Remediation  and  Restoration
           Region  I
          Director, Emergency  and Remedial Response Division
           Region  II
          Director, Division of Environmental  Planning  and
          Protection
           Region  II
          Director, Hazardous  Waste Management  Division
           Regions  IX
          Director, Waste Management Division
           Region  IV
          Director, Waste,  Pesticides, & Toxics  Division
           Region V
          Director, RCRA Multimedia Planning  &  Permitting
          Division
           Region V
          Director, Superfund  Division
           Regions  III,  V,  VI, VII
          Assistant Regional Administrator, office  of  Ecosystems
          Protection  and Remediation
           Region VIII
          Director, Hazardous  Waste Program
           Region VIII
          Director, Office  of  Environmental Cleanup
           Region X
          Director, Office  of  Waste and  Chemical Management
           Region X
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PURPOSE

     The purpose of this  Directive  is  to  recommend  preliminary
remediation goals  (PRGs) or starting points for setting cleanup
levels for dioxin in soil at Comprehensive Environmental Response,
Compensation and Liability Act  (CERCLA) and Resource Conservation and
Recovery Act (RCRA) corrective action  sites. These  recommended levels
are to be used pending the release of  the U.S. Environmental
Protection Agency  (EPA) comprehensive  dioxin reassessment report and
cross-program assessment of the impacts of the report. One ppb  (TEQs,
or toxicity equivalents) is to be generally used as a starting point
for setting cleanup levels for CERCLA  removal sites and as a PRG for
remedial sites for dioxin in surface soil involving a residential
exposure scenario.  For commercial/industrial exposure scenarios, a
soil level within the range of 5 ppb to 20 ppb (TEQs) should
generally be used as a starting point  for setting cleanup levels at
CERCLA removal sites and as a PRG for  remedial sites for dioxin in
surface soil. These levels are recommended unless extenuating
site-specific circumstances warrant a  different level.

     The dioxin levels  discussed  in this  Directive  are also
generally recommended for actions taken under RCRA  at corrective
action sites. The recommended levels of 1 ppb (TEQs) for residential
soils and within the range of 5 ppb to 20 ppb (TEQs) for
commercial/industrial soils should generally be used as starting
points in setting soil cleanup levels  at RCRA corrective action
sites.  These levels are generally consistent with soil cleanup levels
set at RCRA facilities throughout the  country where dioxin is a
principal contaminant of concern at the facility. However, because
states are the primary implementors of the RCRA Corrective Action
program, this Directive does not prescribe specific procedures for
implementation under RCRA.

     This Directive sets  forth  the  policy basis  for these
recommended levels and prescribes procedures for implementing these
recommendations.

BACKGROUND

     To date, EPA  has  generally selected  1 ppb as a cleanup  level
for dioxin in residential soils at Superfund and RCRA cleanup sites
where dioxin is a principal contaminant of concern  at the facility.
EPA has also, to date, generally selected a cleanup level for dioxin
within the range of 5 ppb to 20 ppb for commercial/industrial soils
at Superfund and RCRA cleanup sites where dioxin is a principal
contaminant of concern at the facility. The levels  that EPA has
selected at these sites are protective of human health and the
environment. Based on presently available information, and using
standard default assumptions for reasonable maximum exposure
scenarios,  the upper-
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bound lifetime excess cancer risk from residential exposure  to  a
concentration of 1 ppb dioxin is approximately  2.5 x  10~4,  which is
at the higher end of the range of excess cancer risks that are
generally acceptable at Superfund sites. The  calculated upper-bound
excess cancer risk associated with a lifetime commercial/industrial
exposure to 5 ppb, or the lower end of the range recommended for
commercial/industrial soils, is approximately 1.3 x 10~4, which  is
also within the CERCLA risk range. It should be noted that there is
more difficulty in generalizing about the cancer risk associated with
commercial/industrial cleanup levels than there is with residential
cleanup levels due to the greater variability in exposures associated
with commercial/industrial scenarios. Accordingly, the consultation
process for Superfund sites referenced in the implementation section
of this Directive should be used to ensure the  selection of
appropriate, protective dioxin levels at CERCLA commercial/industrial
sites. Similarly, for RCRA corrective action  sites, please refer to
the implementation section of this Directive.

      EPA  is presently  completing  work  on  a  comprehensive
reassessment of the toxicity of dioxin, to be embodied in  the
documents entitled "Health Assessment Document  for 2,3,7,8
tetrachlorodibenzo-p-dioxin  (TCDD) and Related  Compounds"  and
"Estimating Exposure to Dioxin-like Compounds." The reassessment
report, which is scheduled to be issued in 1998, will represent the
culmination of an Agency-wide effort to collect, analyze and
synthesize all of the available information about dioxin.  It has
undergone significant internal and external review and is  one of the
most comprehensive evaluations of toxicity of a chemical ever
performed by the Agency. Following release of the report,  the Office
of Solid Waste and Emergency Response  (OSWER) will participate  in a
cross-program review of the implications of the report for the
regulation and management of dioxin by EPA. We  anticipate  that  this
review will culminate in OSWER guidance addressing the management of
dioxin at CERCLA and RCRA sites.

      The  Office  of  Solid Waste  and  Emergency  Response does not
believe it is prudent to establish new, and possibly  varying,
precedents for Superfund or RCRA dioxin levels  just prior  to the
release of this reassessment report. As with  any other pollutant, it
is important that EPA ensure appropriate national consistency in
remediation efforts. The Agency has used 1 ppb  as a residential
cleanup level and between 5 ppb and 20 ppb as a commercial/industrial
cleanup level at CERCLA and RCRA cleanup sites  for dioxin  in soil in
the past; it is anticipated that OSWER will be  issuing guidance,
informed by the reassessment effort, that will  provide a basis  for
the selection of dioxin cleanup levels in the near future. In the
interim, for sites that require the establishment of  a final dioxin
soil cleanup level prior to the release of the  reassessment  report
and
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development of OSWER guidance,  EPA  should  generally  use  1  ppb  (TEQs)
as a starting point for  residential  soil cleanup  levels  for  CERCLA
non-time critical removal  sites  (time permitting,  for  emergency  and
time critical sites) and as  a  PRG for remedial  sites.  EPA  should
generally use a level within the range  of  5  ppb to 20  ppb  (TEQs)  as  a
starting point for cleanup levels at CERCLA  non-time critical  removal
sites  (time permitting,  for  emergency and  time  critical  sites) and as
a PRG  for remedial sites for commercial/industrial soil. These levels
should also be used as starting points  in  setting soil cleanup levels
at RCRA corrective action  sites.

      For  CERCLA  remedial sites,  consistent with 40 CFR §
300.430 (f) (5) (iii) (D) , EPA should commit to  reviewing  Records  of
Decision  (RODs)  (i.e., RODs  in which this  Directive  has  been used to
develop dioxin soil cleanup  levels)  promptly following the release
and analysis of the reassessment report and  OSWER guidance,  and,  if
necessary, to making changes to the  RODs and cleanup actions,  based
on the information contained in the  reassessment  report  and  in the
OSWER  guidance. Similarly, in  the case  of  non-time critical  removal
actions  (time permitting,  for  emergency and  time  critical  actions),
EPA should commit to reviewing Action Memoranda promptly following
the release and analysis of  the reassessment report  and  OSWER
guidance, and, if necessary, to making  changes  to the  Action
Memoranda and cleanup actions,  based on the  information  contained in
the reassessment report  and  the OSWER guidance. EPA  should similarly
commit to reviewing RCRA cleanup decisions  (i.e.,  decisions  for  which
this Directive has been  used)  promptly  following  the release and
analysis of the reassessment report  and OSWER guidance.

IMPLEMENTATION

      Regional management should consult with the  appropriate Office
of Emergency and Remedial  Response  (OERR)  Regional Centers on  all
proposed Fund and Potentially  Responsible  Party-lead site  decisions
under  CERCLA, including  other  Federal agency-lead and  state-lead site
decisions, involving the development of dioxin  soil  cleanup  levels
for non-time critical removal  sites  (time  permitting,  for  emergency
and time critical removal  sites) and remedial sites. Consultation
should be initiated at the risk assessment stage.  For  Federal
agency-lead sites, OERR  will,  in turn,  notify the Federal  Facilities
Restoration Reuse Office of  ongoing  consultations. The Office  of Site
Remediation Enforcement  will provide support if enforcement  issues
are identified. For consultation procedures,  refer to  the  OSWER
"Headquarters Consultation for Dioxin Sites", 9200.4-19, December 13,
1996,  plus the OSWER "Consolidated  Guide to  Consultation Procedures
for Superfund Response Decisions",  9200.1-18FS, May  1997.
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      In the  case  of  EPA-lead  RCRA  corrective  action  sites,  Regions
should provide the Office of Solid Waste Permits and State  Programs
Division  (OSW/PSPD) with proposed dioxin soil cleanup levels  (i.e.,
prior to notice and comment) in order to ensure appropriate
implementation of this Directive. For state-lead RCRA corrective
action sites, it is also recommended that states use the dioxin
levels recommended by this Directive as starting points in  setting
soil cleanup levels. States are encouraged to share their approaches
with the Regions in a manner consistent with established procedures
for EPA support and oversight of state RCRA Corrective Action
programs.

      The  levels in  this  Directive  are recommended  unless  extenuating
site-specific circumstances warrant different levels, a more
stringent state applicable or relevant and appropriate requirement
(ARAR) establishes a cleanup level at CERCLA sites, or a more
stringent state requirement applies at RCRA sites. We recommend that
levels other than 1 ppb  (TEQs) for residential soils and outside the
range of 5 ppb to 20 ppb  (TEQs)  for commercial/industrial soils be
used only where evidence exists that risks posed by the site differ
from risks estimated using standard national default guidance values.
These recommendations apply to RCRA corrective actions, CERCLA
non-time critical removal actions  (time permitting, for emergency and
time-critical actions) and CERCLA remedial actions where cleanup
levels are to be developed for dioxin in soil, regardless of whether
dioxin itself drives the decision-making process.

      The  recommended  levels found  in this Directive, generally
considered protective of human health and the environment,  apply to
surface soils. Please note that with respect to human health, these
levels are based on the direct contact exposure pathway. The
recommended levels in this Directive do not apply to other  exposure
pathways,  such as migration of soil contaminants to ground  water or
to agricultural products. While the focus of this Directive is on
soils, these recommended levels also apply to sediments in  the event
that this environmental medium is considered to be a direct exposure
pathway for human receptors.

      This document  provides guidance to EPA  staff. The  guidance  is
designed to communicate national policy on dioxin cleanups  for soil.
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.

      If you  have  any  questions concerning this Directive, please
contact either Marlene Berg at (703)603-8701 in Headquarters or Elmer
Akin of Region 4 at  (404)562-8634,  as Marlene and Elmer are
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co-chairs of the Superfund Dioxin Workgroup.  For the RCRA Corrective
Action program, please contact  Robert  Hall  of the Office of Solid
Waste Permits and State Programs Division at  (703)308-8484. Attached,
for your information, is a list of  Regional points of contact who are
serving on the dioxin workgroup.

Attachment:     Superfund Dioxin Workgroup: Regional Points of
                Contact

cc:  Mike Shapiro, OSWER
      Peter Grevatt,  OSWER
      Steve Luftig,  OERR
      Elaine  Davies,  OERR
      Larry Reed,  OERR
      Gershon Bergeisen, OERR
      David Bennett,  OERR
      Bruce Means,  OERR
      Betsy Shaw,  OERR
      Paul Nadeau,  OERR
      Tom Sheckells  OERR
      Murray  Newton,  OERR
      John Cunningham, OERR
      Dave Evans,  OERR
      Joe LaFornara,  OERR
      Mark Mjoness,  OERR
      Jim Woolford,  FFRRO
      Elizabeth Cotsworth, OSW
      Barry Breen,  OSRE
      Tudor Davies,  OW
      Craig Hooks,  FFEO
      Earl Salo, OGC
      Bill Sanders,  OPPT
      Bill Farland,  ORD
      Regional  Counsel, Regions  I-X
      Peggy Schwebke,  Region  5
      Superfund Dioxin Workgroup
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