&EPA
DIRECTIVE NUMBER:
TITLE:
APPROVAL DATE: OCTOBER*,
EFFECTIVE DATE: OCTOBER 9, 198*
ORIGINATING OFFICE: OFFICE cr -^.TIT
Q FINAL
D DRAFT
LEVEL OF DRAFT
DA Signed by AA or DAA /
D B Signed by Office Director
DC Review & Comment
REFERENCE (other document*):
, .
SCRA Facility
,>.-«4,~^^__~*
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DIRECTIVE
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» I
OS'A'ER POUCY DIRECTIVE NO.
9502.00-5 -
.P.I- :
c/EPA
vVasningipn uC 20460
OSWER Directive Initiation Request
9b02.00-5
qinator informa;
Nam* of Contact Person
David Faaan
Mail Code - Branch
WH-563
T'elecrtone'ftumoer
3S2-4740
Lead Office
D OERR
(3 osw
D OUST
LJ
D
AoO'Ov«d tor Rev
Signature o» O'«'Ce Director
AA-OSW6R
Oate
RCRA Facility Assessment Guidance
Summary of Directive
Transmits RCRA Facility Assessment Guidance to Regions and discusses definition
of a solid waste management unit
Key Words:
RCRA Facility Assessment, RFA, Solid Waste Management Unit
o' Directive
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POliCV C/RECTJVE W0.
^
# \ 9502.
UNITED STATE? ENVIRONMENTAL PROTECTION AGENCY
I
WASHINGTON D C 20460
?- ?°licv Directi'/e
9502.10-5 '
L!EMQRA:,'DUM
OF^iCi 3 =
sou D .VAS'S AND =ME*Gc
SUBJECT: RCRA Facility Assessment Guidance
FROM: J. Vvinston Porter, Assistant Administrator
Office of Solid Waste and Emergency Response
""0: Addressees
Attached you will find guidance on conducting RCRA Facility
Assessments (RFAs). This document replaces the draft guidance
(then called "PA/SI" guidance) which was distributed in August,
1985. The guidance in this final document does not fundamentally
alter the scope or approach to conducting RFAs that was outlined
in the draft document. Most revisions have been made to clarify
or strengthen certain features of the guidance to reflect v
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-2-
CSi:ER Policv Directive
9502.00-5
cannot be located without substantial samplina or other invest-
igations. Likewise, releases or areas of facilities which are
not solid waste management units, but which are nevertheless
potentially subject to corrective action under RCRA [e.g., §3008(h)]
or other authorities, should also be considered to be of relatively
lower priority in conducting RFAs. A discussion of these other
types of releases, and how they may be addressed, is presented
below.
Some Questions have been raised regarding the definition of
the term "solid waste management unit", which is relevant to
determining which units at a facility should be assessed in an
RFA. The Final Codification Rule (July 15, 1985) identified the
types of discernible units which are considered solid waste
management units to include landfills, surface impoundments,
waste piles, land treatment units, incinerators, tanks, container
storage units, injection wells and other physical, chemical and
biological treatment units. In addition, the Agency has inter-
preted the term to apply to areas associated with production
processes at facilities which have become contaminated as a
result of routine, systematic and deliberate releases of wastes
or constituents (a product may become a waste if it is discarded
or abandoned). An example of this type of solid waste management
unit would be a wood preservative "kickback" area/ where drippag^
of preservative fluids onto soils from pressure-treated wood ?
is allowed to occur over time. , . -
- * " .
Several Regions have requested clarification regarding the
application of the concept of "solid waste management unit" to
other contaminated areas at facilities, such as one-time spills,
leakage from product storage, and releases from production areas
that are not routine, systematic and deliberate. Such releases
are not considered to be solid waste management units. As explained
in the Final Codification Rule, spills of wastes or constituents
are considered subject to §3004(u) corrective action only if the
spill occurred from a solid waste management unit. A spill which
did not occur from a discernible solid waste management unit is
not of itself a solid waste management unit. Likewise, leakage
from product storage and other types of releases associated
with production processes would not be considered solid waste
management units, unless those releases were routine, systematic
and deliberate.
Although of relatively lower priority in conducting RFAs,
certain releases at facilities which are not related to solid waste
management units can be addres>sed using §3008(h) or other enforce-
ment authorities. In situations where an enforcement action has
been initiated at a facility to address releases that are not
related to solid waste management units, and where a permit is
subsequently issued to the facility, those actions can be continued
under the permit, under the authority of RCRA §3005(c)(3).
Likewise, at some facilities, investigators may have reason to
believe that an area that is not a solid waste management unit
is likely to be causing or have caused serious environmental
problems. In such cases, compliance schedules may be written in
permits (under §3005(c)(3) authority) or orders to provide for
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'-m Fqlicv Directive
~~ 9502.00-5
preliminary RFA-type investigations by owner/operators to address
such areas. If releases are subsequently identified which require
further investigation or action, the permit or order can be modified
to provide for necessary owner/operator actions.
If you have any questions or comments regarding the RFA
guidance, or other RFA-related issues, please contact Dave Fagan
at FTS 382-4740.
Addressees:
Hazardous Waste Division Directors, Regions I-X
RCRA Branch Chiefs, Regions I-X
RCRA Permit Section Chiefs, Regions I-X
RCRA Enforcement Section Chiefs, Regions I-X
State RCRA Permit and Enforcement Contacts
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Environmental Protection
Agency
Solid Waste
Washington DC 20460
l\\j;
Solid Waste
RCRA
Facility Assessment
Guidance
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OSVO POLICY DIKtUivt
9502.00-5
RCRA FACILITY ASSESSMENT GUIDANCE
Permits -and'State Programs Division
Offi ce of Sol id Waste
U.S. Environmental Protection Agency
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ACKNOWLEDGEMENTS
The document was prepared by the joint efforts of the following
individuals: Clem Rastatter (currently at EPA-OERR), Dave Pagan
and Oarsi Foss, OSW - Permits and State Programs Division; Mark
Gilbertson and Howard Wilson, Office of Waste Programs Enforce-
ment; Tina Kaneen, Office of General Counsel; Betsy Marcotte and
Ton Gherlein, Sobotka ft Company, Inc.
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TABLE OF CONTENTS 9 50 2. GO'S
Page
CHAPTER ONE - INTRODUCTION
I. OBJECTIVES AND SCOPE OF THE RCRA CORRECTIVE
ACTION PROGRAM 1-1
II . PURPOSE OF THE RFA 1-2
III. SCOPE OF THE RFA 1-3
IV. TECHNICAL APPROACH 1-5
V. ORGANIZATION OF THIS DOCUMENT 1-9
CHAPTER TMO - CONDUCTING A PRELIMINARY REVIEW
I. INTRODUCTION 2-1
A. Purpose 2-1
B. Scope 2-1
C. Product 2-2
It. GATHERING PR .1 NFORMATION 2-2
A. Written I nf ormat i on ' and Documents 2-3'
B. MeetingwithRe'levant Individuals 2-5
C. Collecting Additional Information 2-6
III. EVALUATING PR INFORMATION 2-6
A. Investigating Facility Waste Generation
Processes 2-6
8. Identifying SWMUs and Other Potential
Releases of Concern 2-7
C. Evaluating the Facility's Release Potential 2-8
IV. COMPLETING THE PRELIMINARY REVIEW 2-11
A. Identify ing Significant Data Gaps 2-12
B. Focusing the Visual Site Inspection and
Sampling Visit 2-12
C. Document ing the Preliminary Review 2-13
CHAPTER THREE - CONDUCTING A VISUAL SITE INSPECTION
U INTRODUCTION 3-1
A. Purpose 3-1
B. Scope & 3-1
C. Product > 3-1
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VWnl.lt I \JLIUI
9502. 00r5 3 '
" Page
II. PLANNING THE VISUAL SITE INSPECTION 3-2
III. CONDUCTING THE FIELD ACTIVITES DURING THE VSI 3-2
A. Obtaining Visual Evidence of Unit
Characteristics 3-4
8. Obtaining Visual Evidence of Waste
Character! sti cs 3-4
C. Obtaining Visual Evidence of Pollutant
Migration Pathways 3-4
0. Obtaining Visual Evidence of Release 3-5
E. Obtaining Visual Evidence of Exposure'
Potential 3-5
IV. DETERMINING THE NEED FOR FURTHER ACTION
DURING THE RFA 3-5
A. Determining the Need for a Sampling Visit 3-6
3 . Determining the Need for Interim Measures 3-7
C . Determining the Need for a Remedial
Investigation 3-7
CHAPTER FOUR - CONDUCTING THE SAMPLING VISIT
I. INTRODUCTION 4-1
A . Purpose " 4-1 '
8. Scope 4-1
C. Product 4-2
II. DEVELOPING A SAMPLING VISIT PLAN 4-2
A. Determining the Need for Sampling at Facilities 4-2
B. DevelopingaSamplingPlan 4-4
III. PREPARING- FOR THE SAMPLING VISIT 4-8
A. Gaining Facility Access 4-9
B. Community Relations 4-10
C. Preparing a Safety Plan 4-10
D. EPA Oversight of Owner/Operator Sampling
Acti vi ti es 4-11
IV. CONDUCTING THE SAMPLING VISIT 4-11
A. Preliminary Site Activities 4-11
B. Sampling Procedures 4-12
C. Photography 4-12
D. Logbook 4-13
E. Sample Shi pment /Sample Analysis 4-14
F. Decontamination/Demobilization 4-14
-iii-
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V. FINAL RFA RECOMMENDATIONS FOR FURTHER ACTION
A. Making RFA Release Determinations
8. Making Recommendations for Each SWMU or
Group of SWMUs
VI. FINAL RFA PRODUCT
CHAPTER FIVE - GROUND WATER
I. INTRODUCTION 5-1
A. Purpose 5-1
R. Scope 5-1
II. CONDUCTING A PRELIMINARY REVIEW AND VISUAL SITE
INSPECTION OF GROUND-WATER RELEASE POTENTIAL 5-2
A. Unit Character!sties 5-2
3 . Waste Characteristics 5-7
C. Pollutant Migration Pathways 5-3
0. EvidenceofRelease 5-9
E. Exposure Potential 5-10
F. Determining the Need for Additional
Samp!ing Information 5-11
III. COLLECTING ADD IT-I ONAL" S AMPL I NG I NFORMA'T I ON
IN THE SV 5-14
A. Sampling of Existing Ground-Water
Monitoring Wells 5 - ] 4
3. Soi1 Samp!ing 5-17
C. SoilGasMonitoring 5-17
D. Electromagnetic Conductivity Mapping 5-19
E. Sampling of Domestic Wells 5-20
F. Installation Of New Monitoring Wells 5-20
IV. MAKING GROUND-WATER RELEASE DETERMINATIONS 5-21
CHAPTER SIX - SURFACE WATER
I. INTRODUCTION 6-1
A.Purpose 6-1
B. Scope 6-1
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9502.00-5 ^ D
Page
II. CONDUCTING A PRELIMINARY REVIEW AND VISUAL SITE t
INSPECTION OF RELEASES TO SURFACE WATER 6-2
A. Unit Character!'sties 6-2
B. Waste Characteristics 6-5
C. Pollutant Migration Pathways 6-6
0. Evidence of Release 6-8
E. Exposure Potential 6-9
F. Determining the Need for Additional Sampling 6-10
III. COLLECTING ADDITIONAL SAMPLING INFORMATION IN THE SV 6-12
A. Surface Water Sampling 6-13
R. Sludge and Sediment Sampling 6-14
C. Soi1 Smapli ng 6-14
T. Run-Off Sanpling 5-14
IV. MAKING SURFACE WATER RELEASE DETERMINATIONS 6-15
CHAJTER SEVEN - AIR
I. INTRODUCTION * 7-1
A.Purpose 7-1
II. CONDUCTING A PRELIMINARY REVIEW AND VISUAL
' SITE INSPECTION OF AIR RELEASE POTENTIAL . 7-2
*
A._ Unit Characteristics "7-2
R. Waste Characteristics 7-6
C. Pollutant Migration Pathway 7-13
D. Evidence of Release 7-13
E. Exposure Potential 7-14
F. Determining the Need for Additional
Sampling Information 7-15
III. OBTAINING ADDITIONAL SAMPLING INFORMATION '7-16
IV. MAKING RELEASE DETERMINATIONS 7-18
CHAPTER EIGHT - SUBSURFACE GAS
I. INTRODUCTION 8-1
A. Purpose 8-1
R. Scope 8-1
II. CONDUCTING A PRELIMINARY REVIEW AND VISUAL SITE
INSPECTION OF SUBSURFACE GAS RELEASE POTENTIAL 8-2
A. Unit Characteristics 8-2
B. Waste Characteristics ' 8-5
C. Pollutant Migration Pathways 8-9
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Page
D. Evidence of Release 8-10
E. Exposure Potential 8-10
F. Determining the Need for Additional
Sampling in the SV 8-11
III. COLLECTING ADDITIONAL INFORMATION IN THE SV 8-12
IV. MAKING SUBSURFACE GAS RELEASE DETERMINATIONS 8-14
CHAPTER NINE - SOILS
I. INTRODUCTION 9-1
A. Purpose 9-1
8. Scope 9-1
II. CONDUCTING A PRELIMINARY REVIEW AND VISUAL
SITE INSPECTION OF RELEASES TO SOILS 9-2
A. Unit Characteristics 9-2
3. Waste Characteristics 9-5
C. Pollutant Migration Pathways 9-6
0. Evidence of a Release 9-7
E. Exposure Potential 9-7
F. Determining the Need for Additional Sampling 9-8
III. COLLECTING ADDITIONAL SAMPLING INFORMATION
IN THE SV 9-10
A. General Information on Selecting Sampling
Locati ons 9-10
B. Sampling Methodology and Evaluation of Results 9-11
IV. MAKING A RELEASE DETERMINATION 9-12
APPENDIX A - SAMPLE RFA REPORT OUTLINE
APPENDIX B - RFA INFORMATION SOURCES
APPENDIX C - SAMPLE LETTER OF REQUEST FOR OWNER/OPERATOR
INFORMATION
APPENDIX D - GAINING FACILITY ACCESS WHEN DENIED
APPENDIX E - PHYSICAL AND CHEMICAL PARAMETERS FOR
CONSTITUENTS OF CONCERN
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9 5U 2 . 00- 5 -« *
LIST OF EXHIBITS
Exhibit Page
1-1 Major Factors to Consider in Conducting RFAs 1-7
1-2 Types of Information Evaluated During the
Three Steps of the RFA 1-8
5-1 Ranking of Unit Potential for Ground Water
Releases and Mechanisms of Release 5-4
5-2 Monitoring Well Location 5-16
5-3 Checklist for Ground Water Releases 5-22
5-1 Ranking of Unit Potential for Surface Water
Release and Mechanisms of Release 6-4
5-2 Checklist for Surface Water Release 6-17
7-1 Unit Potential for Air Releases and
Mechanisms of Release 7-4
7-2 Parameters and Measures for Use in Evaluating
Potential Air Releases of Hazardous Waste
Consti tuents . 7-7
7-3 Hazardous Constituents of Concern as Vapor
Releases 7-8
7-4 Hazardous Constituents of Concern as
Particulate Releases 7-10
7-5 Checklist for Air Releases 7-20
8-1 Unit Potential for Subsurface Gas Releases
and Mechanisms of Release 8-4
8-2 Subsurface Gas Generation/Migration in a
Landfill 8-6
8-3 Subsurface Gas Generation/Migration from
Units Closed as Landfills 8-7
8-4 Checklist for Subsurface Gas Releases 8-15
9-1 Ranking of Unit Potential for Soil Release
and Mechanisms of Release 9-3
9-2 Checklist for Releases to Soils 9-14
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CHAPTER ONE
INTRODUCTION
OSWER POLICY DIRECTIVE NO,
9502.00-5 -
I. OBJECTIVES AND SCOPE OF THE RCRA CORRECTIVE ACTION PROGRAM
The primary objective of the RCRA corrective action program
is to clean up releases of hazardous waste or hazardous constit-
uents that threaten human health or the environment. The program
applies to all operating, closed or closing RCRA facilities.
The 1984 Hazardous and Solid Waste Amendments (HSWA) estab-
lished broad new authorities in t h e R C R A program to assist EPA in
accomplishing these objectives. These new authorities are:
o §3004(u) - Corrective Action for.Continuing Releases
Requires that any permit issued after November 8, 1984,
require corrective action for all releases from solid
waste management units at the facility. The provision
also requires t h * t owner/operators demonstrate financial
assurance for any required corrective action, and allows
schedules of compliance to be used in permits where the
corrective action cannot be completed prior to permit
i ssuance .
» ** ,
§3008(h) - Interim Status Corrective Action Orders .'
Provides authority to issue enforcement orders to compel
corrective action or other response measures at interim
status facilities, and to take civil action against
facilities for appropriate relief.
§30Q4(v) - Corrective Action Beyond the Facility Boundary
Directs EPA to issue regulations requiring corrective
action beyond the facility boundary where necessary to
protect human health and the environment, unless the
owner/operator can demonstrate that he is unable to
obtain the necessary permission, despite his best efforts
Until such regulations are promulgated, corrective action
orders can be issued to require the necessary corrective
action.
These authorities change the focus of the RCRA corrective
action program from detecting and correcting future releases from
regulated units to cleaning up problems resulting from past waste
management practices at RCRA facilities. Prior to passage of the
HSWA, EPA''s authority to require corrective action for releases
of hazardous constituents under RCRA was limited to ground water
releases from units that were covered by RCRA permits. Part 264,
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Subpart F provided the vehicle for requiring corrective action at
these "regulated units". The post-HSWA program extends RCRA
authority to releases to all media and all units at RCRA facili-
ties and encourages the use of other authorities, as needed or
appropriate, to help achieve corrective action objectives at
these facilities.
The RCRA corrective action program consists of three phases:
1. The RCRA Facility Assessment (RFA) to identify releases
or potential releases requiring further investigation.
2. The RCRA Facility Investigation (RFI) to fully charac-
terize the extent of releases.
3. Corrective Measures (CM) to determine the need for and
extent of remedial measures. This step includes the
selection and implementation of appropriate remedies
for all problems identified.
This guidance document describes the first phase of this
process and outlines procedures and criteria EPA and State
personnel snould follow in conducting RFAs at RCRA facilities.
II. PURPOSE OF THE RFA
The -RCRA'Faci 1 i ty Assessment is a three-stag"e process for:
o Identifying and gathering information on releases at
RCRA facilities;
o Evaluating solid waste management units (SWMUs) and other
areas of concern for releases to all media and regulated
units for releases to media other than ground water;
o Making preliminary determinations regarding releases of
concern and the need for further actions and interim
measures at the facility; and
o Screening from further investigation those SWMUs which
do not pose a threat to human health or the environment.
During the RFA, EPA or State investigators will gather information
on SWMUs and .-other areas of concern at RCRA facilities. They will
evaluate this information to determine whether there are releases
that warrant further investigatior or other action at these
facilities. Upon completion of the RFA, Agency personnel should
have sufficient information to determine the need to proceed to
the second phase (RFI) of the process.
All three steps of the RFA require the collection and analy-
sis of data to support initial release determinations:
1-2
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OSWER POLICY DIRECTIVE NO,
950 2 . 00-5 **
o The prel imi-nary review (PR) focuses primarily on eval-
uating existing information, such as inspection reports,
permit applications, historical monitoring data, and
interviews with State personnel who are familiar with
the faci11ty .
o The visual site inspection (VSI) entails the on-site
collection of visual information to obtain additional
evi dence of release .
o The sampling visit (SV) fills data gaps that remain upon
completion of the PR and VSI by obtaining sampling and
field data .
III. SCOPE OF THE RFA
This section addresses:
o Releases covered in the RFA;
o Relation of the RFA to the CERCLA PA/SI;
o The extent and role of sampling in the RFA; and
o Roles and_ responsibilities.
i . ,
Releases 'Covered in the RFA
The RFA should identify all areas of potential release at
RCRA facilities and include the investigation of releases to all
nedia: air, surface water, ground water, and soils. However,
ground water releases from regulated units are not addressed in
the RFA. EPA and/or State investigators should use the full com-
plement of RCRA authorities to secure appropriate action. These
include §3004(u), §3008(h), §3004(v), §3013 and §7003. If these
authorities are not sufficient to compel the desired action,
Agency investigators may wish to use other authorities, such as
CERCLA §106 or TSCA §7 authorities and should consult with EPA or
State offices responsible for administering these programs.
The HSWA §3004(u) provision focuses on investigating releases
from SWMUs at RCRA facilities. Solid waste management units are
defined as:
o Any discernible waste management unit at a RCRA facility
from which hazardous constituents might migrate, irre-
spective of whether the unit was intended for the manage-
ment of solid and/or hazardous waste.
The SWMU definition includes:
o Containers, tanks, surface impoundments, waste piles,
land treatment units, landfills, incinerators, and
1-3
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underground injection wells, including those units defined
a_s_ "regulated units" under RCRA.
o Recycling units, wastewater treatment units and other
units which EPA has generally exempted from standards
applicable to hazardous waste management units.
o Areas contaminated by "routine, systematic, and deliber-
ate discharges" from process areas.
The definition does not include accidental spills from production
areas and units in which wastes have not been managed (e.g.,
product storage areas).
The RFA will not routinely address releases that are per-
mitted or required to be permitted under other environmental
programs or contamination resulting from permitted discharges.
Where such discharges are of concern, RCRA personnel should refer
the case to the original permitting authority. If that authority
does not take appropriate action, EPA can exercise its authority
under §3004(>j), §3004(v), §3008(h) or §3013. Where the RFA
identifies contamination requiring further investigation, RCRA
staff should work on a case-by-case basis with the Regions and
other EPA permit programs to develop a solution to the contami-
nation problem .
The RFA does address releases from SWMUs to media other
than the' one covered by the unit's discharge permit. For example,
EPA can use §3004(u) or §3008(h) to control the release of volatile
organic compounds from NPDES-permitted wastewater treatment units
where there is cause for concern.
Relation of the RFA to the CERCLA PA/SI
The CERCLA PA/SI and the RFA differ in two important respects.
First, the CERCLA PA/SI focuses on the potential for offsite
exposures from releases, while the RFA focuses on identifying
specific releases at RCRA facilities and considers the potential
for offsite exposures primarily in determining whether to require
interim corrective measures.
Second, the CERCLA PA/SI was developed primarily as a method
for scoring facilities to determine whether they should be on the
CERCLA National Priority List (NPL). The RFA does not formally
rank or prioritize facilities. The RCRA program may use the
facility management planning (FMP) process to establish State and
Regional priorities at and among RCRA facilities. The FMPs
provide a framework for determining specific permitting and
enforcement actions that should be taken at a facility and which
facilities EPA should a-ddress first. Information on potential
releases at a facility is an important input into this process.
However, it is evaluated along with other information on the
facility's compliance and permitting status to establish overall
prog ram priorities .
1-4
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QS'sVER POUCV DiRECTIVt
9502 .00-5
Extent and Role of Sampling
EPA purposely designed the RFA to be limited in scope.
This guidance establishes a framework to assist EPA investigators
in making preliminary release determinations that are largely
based on existing information and best professional judgment. The
framework emphasizes the need to--focus data collection and analysis
efforts (i.e., sampling data) on those data that are required to
support specific permit or enforcement order conditions. In
general, the stronger the case that the investigator must make
to compel an owner/operator to conduct an RFI or to convince the
public that a SWMU does not pose a threat, the greater the amount
of information he/she will need to collect in the SV.
The Agency recognizes that sampling needs will differ on a
case-by-case basis. The extent of sampling will depend on the
amount and quality of information gathered in the PR and VSI, the
investigator's professional judgment regarding the amount of in-
formation necessary to support an initial release determination,
and the degree of owner/operator cooperation.
Responsibility for Conducting the RFA
As the program is currently set up, EPA and/or the States
are responsible for conducting RFAs. Because of the s.ubjective
nature of these investigations,- the Agency believes that it is
appropriate for a regulatory agency to conduct'the RFAs. These
initial release determinations will provide the- basis for requiring
a number of potential follow-on activities ranging in scope from
no further action to a full corrective action program. EPA and
the States may use contractors to assist them in conducting these
investigations, but the regulatory agency retains overall respon-
sibility for the RFA decisions.
In some instances, it may be appropriate for the facility
owner/operator to perform certain sampling activities. EPA
and/or the State should make such determinations on a case-by-case
basis and should carefully review and approve plans developed by
owner/operators and oversee field activities conducted by the
owner/operator.
IV. TECHNICAL APPROACH
All three steps of the RFA require the investigator to ex-
amine extensive data on the facility and specific units at the
facility. These data can generally be divided into five categories
o Unit characteristics;
o Waste characteristics;
o Pollutant migration pathways;
1-5
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o Evidence of release; and
o Exposure potential.
s
Exhibit 1-1 provides a matrix of these categories and the specific
factors that investigators need to consider in each category.
The investigator will need to apply his/her best professional
judgment in examining these factors, how they interact, and their
effects on the likelihood of a release and its significance.
Exhibit 1-2 outlines the types of information in each cate-
gory that investigators are likely to obtain during each of the
three steps in the RFA. In general, during the PR, the investi-
gator will examine documents and other written materials to
obtain information on the facility's location, potential environ-
mental receptors, characteristics of the waste handled at the
facility as a whole and managed in SWMUs, the design and operating
features of the SWMUs themselves, and evidence of past releases.
This information will assist the investigator in determining
which media and migration pathways are of concern and why. The
investigator will supplement this information with additional
evidence gathered during the VSI and samples taken during the SV.
Specific factors in each category that must be considered
will vary- depending on which medium is of concern. For example,
land-based units are more likely to have ground-water releases
than aboveground units; surface impoundments are more likely to
have air releases than landfills. Certain wastes tend to vola-
tilize and cause air releases, while other wastes are soluble in
water and tend to migrate via surface or ground water. A facil-
ity's location will determine which media are of concern. Surface
water releases should not be a concern for facilities that are
not located near surface water. Types of evidence and potential
receptors will also vary by media.
Each of the media-specific chapters describes the factors in
each of the five categories that investigators should examine for
the media of concern. Each chapter is organized to follow the
three steps of the RFA and is designed to assist the investigator
in identifying releases for each of the media of concern.
The RFA is completed when the investigator has sufficient
information to make a determination regarding releases or likely
releases at the facility and the need for further investigations.
Sometimes it.will be possible to make this determination after
completing the first two steps (the PR and VSI), and a SV will
not be necessary. In other cases, even upon -.ompletion of the
SV, the investigator may need to perform additional follow-up
inspections or collect further sampling or other information from
the owner/operator before making this determination.
In general, when the RFA is completed, the investigator
will have:
1-6
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^502.00-5
o Identified all potential releases of concern;
o Identified all SWMUs;
o Determined which areas need further investigation and
and collected sufficient information to focus these
investigations;
o Determined which areas require interim measures;
o Screened out releases that do not require any further
investigation; and
o Referred permitted releases to other authorities,
as appropriate.
Upon completion of the RFA, the investigator prepares a
report summarizing his/her findings. The report should integrate
the findings from all three steps in the RFA and include a de-
scription of the facility and its waste management practices,
release information for all SWMUs or groups of SWMUs and other
areas of concern, sampling plan and results, and final release
determinations and recommendations. This report should clearly
indicate those areas of the facility that require further inves-
tigation in a 3FI and should contain information to focus these
investigations. A sample outline of an RFA report is presented
.in Appendix A .
Conducting an RFA can present an opportunity to gather
information on a facility which may be useful for purposes other
than making RFA determinations. Regions or States may choose,
for example, to collect certain data on facility characteristics
and other site-specific environmental data as a means of estab-
lishing programmatic priorities for corrective action. Appendix
F provides a listing of some example data elements which could be
used for such purposes.
V. ORGANIZATION OF THIS DOCUMENT
This document contains nine chapters. The second chapter
describes the PR process, the third chapter describes the VSI,
and the fourth chapter explains the SV. In addition, there are
five technical chapters that apply the technical approach out-
lined in chapters two, three and four to the various media of
concern: ground water, surface water, air, subsurface gas and
soil.
1-9
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05WER POLICY DIRECTIVE NO,
CHAPTER TWO 9502- OQ- 5 ~*
CONDUCTING A PRELIMINARY REVIEW
I. INTRODUCTION
A. Purpose
This chapter describes how to conduct a preliminary review
(PR), the first step in the RCRA Facility Assessment (RFA) pro-
cess for identifying releases or potential releases at RCRA
facilities under the RCRA corrective action requirements. The
DR serves two primary purposes:
(1) To gather and evaluate existing information on facili-
ties in order to identify and characterize potential
releases; and
(2) To focus the activities to be conducted in the second
and third steps of the RFA, the visual site inspection
(V SI ) and the sampling visit (SV).
3. Scooe
During the PR--, EPA personnel will evaluate existing docu-
ments and speak with relevant individuals (e.g., RCRA inspectors,
Stater and Federal permitting staff, etc.) in order to identify
areas at a facility which may be releasing hazardous wastes o'r
hazardous constituents posing a potential threat to human health
and the environment. The PR will consider information on the
entire facility, and will not be limited to collecting and eval-
uating information covering the RCRA-regulated areas at the
facility. In particular, the investigator will identify and
gather information on SWMUs and other areas where wastes have
been managed at the facility.
While the scope of the PR will focus on identifying and
evaluating releases resulting from waste management activities,
the investigator should consider documents he/she finds which
provide information on releases at the facility which may be
beyond the scope of the RCRA corrective action authorities.
These could include releases subject to investigation andremedi-
ation under CERCLA or TSCA authorities.
The scdpe of the PR includes investigating release potential
to all environmental media at the facility (with the exception
of ground-water releases from regulated units):
o Ground water;
o Surface water;
o Air;
» i i i i j
o Soils; and
o Subsurfac-e (gas)
-------
At complex facilities with many SWMUs, it may be more
practical to evaluate groups of similarly located or designed
SWMUs rather than characterizing each unit separately. Addi-
tionally, investigators should not focus solely on releases
from SWMUs, but should examine the full facility for evidence
of spills and/or other releases resulting from waste management
activities which may not fit the definition of a SWMU release
(see definition of a SWMU on page 1-4).
This chapter describes how to conduct a PR at RCRA facili-
ties by:
(1) Collecting PR information;
(2) Evaluating PR information; and
(3) Completi ng the PR.
C. Product
At the end of the PR, the investigator will summarize the
findings of the PR. He/she should document the information
sources evaluated, describe the potential releases of concern
identified at the facility (especially all SWMUs), and make
recommendations that will focus subsequent activities in the
VSI and th-e SV. The results of the PR will serve as the founda-
tion of the RFA report, which will be revised at the end of the
VSI and finalized following the SV. A samp.le putllne^for an RFA..
report is 'included as Appendix A.
II. GATHERING PR INFORMATION
The first step in the PR involves collecting information on
a facility that will provide evidence of its potential for release
The success of the PR will depend to a great extent on the inves-
tigator's ability to collect relevant information. A PR may pro-
vide misleading results when significant sources of information
are not considered (e.g., enforcement documents describing known
releases, relevant sampling or monitoring data-,- etc .) EPA
should plan each PR to ensure that all relevant sources of infor-
mation pertaining to a facility are examined. Gathering data in
the PR will usually involve:
(1) Collecting documents and other written reports;
(2) Meeting with relevant individuals; and
(3) Collecting additional information from the
owner/ope rator.
The PR focuses on evaluating information in the five basic
categories presented in the RFA information matrix (Exhibit 1-1).
2-2
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9 5 0 2 . 0 0 - £
The matrix illustrates the types of information in each category
(unit characteristics, waste characteristics, pollutant migra-
tion pathways, evidence of release, and exposure potential) which
should be evaluated during the PR, It should be noted, however,
that it is difficult to obtain complete data for any of the five
categories during the PR, and that the VSI and SV will provide
additional opportunities to collect information during the RFA.
A. Written Information and Documents
This section briefly summarizes those data sources which
have been found to be most useful in conducting PRs to date. A
detailed discussion of all potentially relevant data sources is
included as Appendix B to this document.
Four basic RCRA file sources and several additional RCRA
documents typically contain the most useful information during
the PR:
(1) RCRA permit applications;
'2) Facility SWMU response (RSI #3);
' 3 ) RCRA inspection reports;
(4) RCRA exposure information reports; and
(5). Additional RCRA sources.
Brief discussions on each of these sources follow.
1 Permit Applications
Part A and 8 permit applications or closure plans are avail-
able for all facilities in the permit pipeline and addressed
under the corrective action program.^/ Although owner/operators
develop these applications to support permitting or closure of
regulated units, they will usually contain information on other
areas of the facility relevant to the RFA.
Part A permit applications provide information on the wastes
being treated, stored, and/or disposed in the regulated units at
a facility. These forms can be useful in identifying the wastes
of concern at the facility, although it should be noted that the
wastes disposed in old SWMUs may have different characteristics
than those currently disposed in regulated units, due to changes
in facility production processes or changes of ownership. The
Part A will often provide a scale drawing showing the location of
all past treatment, storage, and disposal areas (§270.13(h ) ) ,
which can be useful in identifying SWMUs and other areas of
concern.
The proposed Codification Rule of March 28, 1986 incorpor-
ates RSI 43 information (described above) into permit application
requirements. ';
2-3
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A land disposal Part B permit application provides extensive
hydrogeologic information related to the surficial aquifer at a
facility, including a description of the facility's ground-water
monitoring system. This information is useful for identifying
ground-water pollutant migration pathways and prior releases from
SWMUs at land disposal facilities. However, this information is
not likely to be available for storage and treatment facilities.
2. SWMU Response (RSI #3 Submission)
The Reauthorization Statutory Interpretation (RSI #3) issued
by EPA Headquarters required the EPA Regional Offices to request
owner/operators of RCRA facilities to submit data on each SWMU at
their facilities. The data owner/operators submitted in response
to this request is usually helpful for identifying SWMUs at a
facility. However, many submissions have been found deficient,
and RCRA investigators should not assume that these submissions
accurately identify all of a facility's SWMUs. Other sources,
such as compliance inspection reports and the VSI should be used
to verify and augment the information contained in the SWMU
response.
3 . Compliance Inspection Reports/Information
from Enforcment Orders
RCRA inspection reports will often provide extensive infor-
mation on facility waste generation and handling practices, old
and new waste management units, and prior releases at the facility
They may-also describe migration pathways and exposure points.
4. . Exposure Information Report
Only facilities seeking permits for landfills and surface
impoundments are required to submit exposure information. These
submissions provide information on all five categories in the RFA
information matrix (Exhibit 1-1). These reports can be useful in
identifying pollutant migration pathways from the facility to
potential exposure points, and may also discuss the likelihood of
human exposure to hazardous constituents.
5. Additional RCRA Sources
o Biennial Report (§265.75) -- The biennial report, prepared
by the owner/operator and submitted to the Regional
Administrator, provides a description and the quantities
of each hazardous waste received during the previous year,
and'the method of treatment, storage, or disposal for
each waste.
o Operating Log (§265.73) -- The facility operating log
provides* map displaying the location and quantities of
wastes disposed throughout the facility. It also provides
reports of all incidents that required implementation of
the Facility Contingency Plan.
2-4
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9502*00-5 s
o RCRA Waste Manifest (§265.71) -- The manifest will provide
details on all wastes received at the facility after
November 18, 1980. Facilities are only required however,
to retain manifest for three years.
o Notice to Local Authority (§265,14) -- The owner/operator,
within 90 days after closure of a disposal unit, must
submit to the local land authority and the Region records
of the locations and quantities of wastes within a closed
unit. The owner/operator must also provide descriptions
of the types, locations, and quantities of wastes in
units closed before promulgation of the Part 265 regula-
t i ons .
6 . Other Sources
Many other sources can provide useful information for evalu-
ating the likelihood of releases at a facility. After the RCRA
sources outlined above, these are likely to contain the most
valuable information:
o NPDES and CAA permits and permit applications;
o CERCLA PA/SI Reports;
o Installation Restoration Program (IRP) Reports;
o HRS Documentation;
o CERCLA RI/FS Studies;
o. CERCLA 103(c.) Notifications;
o Aerial Photographs'; ' .
o Other Federal/.State Agencies; and
o TSCA/OSHA/NPDES Inspections.
A nunber of other sources nay also provide some useful informa-
tion, although they will be needed less often:
o GEMS (Graphical Exposure Modeling System);
o State/Local Well Permit Offices;
o Municipal/County/City Public Health Agencies;
o Local Well Drillers;
o State/County Road Commissions;
o Utilities;
o Local Airports/Weather Bureaus;
o Naturalists/Environmental Organizations;
o Facility Employees;
o Colleges/Universities; and
o Interviews with Local Residents.
It will not be necessary to look at each of these sources in all
situations, but they can be examined as appropriate to help fill
information gaps. All the data sources listed above are described
more fully in Appendix B.
8. Meeting with Relevant Individuals
It will be useful to meet with personnel from State agencies
and other EPA program offices,(e.g., NPDES permitting program) in
2-5
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the Initial stages of the PR. Other EPA permitting programs may
have considerable historical knowledge of a facility, including
information on SWMU releases, instances of non-compliance, facility
waste generation practices, and inspection reports. Early contact
with these groups can help ensure that all relevant information
is considered during the PR.
C. Collecting Additional Information
In situations where the investigator does not find sufficient
information concerning the location or characteristics of a
facility's SWMUs to complete a PR, it may be necessary to request
additional information from the owner/operator. Such requests
should be in the form of a letter in which EPA requests additional
information from the facility in order to comply with the HSWA
corrective action requirements. Where necessary, EPA should cite
its §3007 information gathering authority to obtain this infor-
nation. These letters should be as specific as possible to ensure
that the requested information is submitted in a timely manner.
A sample letter is included as Appendix C.
III. EVALUATING PR INFORMATION
The PR focuses on evaluating the information gathered during
its initial stages. This section presents a framework for eval-
uating PR information in order to gajn an understand!ng,of the
facility's re!-ease potential.. This will involve three basic
steps :.
(1) Investigating the facility's waste generation processes;
(2) Identifying SWMUs and other potential releases of
concern ; and
(3) Evaluating the facility's release potential.
A. Investigating Facility Waste Generation Processes
It will be important to understand the facility's overall
waste generation and management activities, both past and present,
when evaluating how SWMUs and other areas of the facility have
been used to handle wastes and how they relate to the facility's
overall waste management system. Whenever possible, the investi-
gator should determine what types of waste have been managed at
the facility- since it began operation in order to identify poten-
tial constituents of concern.
As discussed in Section II of this chapter, RCRA compliance
inspection reports may provide a useful source of information on
manufacturing processes, as will some NPOES permit applications.
In some cases, inspection reports may also discuss where wastes
from previous manufacturing processes have been disposed at a
facility or may i.nelude information on past releases.
2-6
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y 5 0 2 . 0 0 -
The following example illustrates the benefits of investiga-
ting a facility's waste generation processes. A secondary lead
smelting facility closed several surface impoundments that were
orginally part of an NPOES wastewater treatment process. The
impoundments were clean closed by excavating to a depth determined
by the concentration of lead in the soil. The facility stated
that lead was the only constituent of concern in these units.
During the PR, EPA investigated the facility's production
processes and found that several other metals such as cadmium,
nickel, antimony, and barium might be mixed with the lead
wastes. Based on this information, EPA took soil samples for
each of these other constituents of concern.
B. Identifying SWMUs and Other Potential Releases of Concern
Once the investigator has gained an understanding of the
facility's overall waste generation and management activities,
he/she should locate all areas with potential releases of concern
on a map of the facility. The map should include all SWMUs iden-
tified in the RSI #3 SWMU response, SWMUs described in other
document?, and other potential releases of concern, e.g., spills
of Hazardous waste or constituents from waste management activi-
ties. In addition, the investigator should locate on the facility
iap other potential releases of concern which may be beyond the
scope of the RCRA authorities.
The facility map will be an extremely useful document
throughout the R FA, .especially., when conducting the VSI and the
SV. In addition to" locating SWMUs, it will often" be possible
to identify relevant migration pathways and potential exposure
points (e.g., rivers and nearby housing) on this map. Additional-
releases of concern can be added to the map when identified at
later stages in the RFA, particularly the VSI.
As discussed in the Introduction, the definition of a SWMU
includes recycling units, wastewater treatment units (such as
those regulated under NPOES), and other units which EPA has
generally exempted from RCRA permitting standards. Each of
these units identified at a facility should be located on the
facility map as a SWMU. Regulated land disposal units are also
treated as SWMUs, since they will be investigated for releases
to media other than ground water in the RFA.
Several information sources will be especially useful when
identifying SWMUs and other releases of concern in addition to
the RSI #3 submission. Historical aerial photographs, such as
those available from EMSL or EPIC, may reveal the presence of
past waste management areas which have become overgrown or
otherwise hidden. In some cases, closed landfills and surface
impoundments cannot be distinguished from ordinary open fields
and historical aerial photographs can help identify these units.
Appendix 8 provides a more detailed discussion on obtaining and
evaluating aerial photographs.
2-7
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C. E v a 1u a t i n g the Facility's Release Potential
Once the Investigator has identified potential releases of
concern at the facility, he/she should determine the likelihood
of release at each location by evaluating information gathered
in the initial steps of the PR. It will seldom be possible to
determine from one document that a SWMU has released hazardous
wastes or constituents. In most cases, the investigator will
have to deduce the likelihood that a release of concern has
occurred by evaluating information from numerous sources covering
the five categories of information presented in Exhibit 1-1: unit
characteristics, waste characteristics, pollutant migration path-
ways, evidence of release, and exposure potential.
The evaluation requires the investigator to seek evidence
that a unit has released or is likely to have released. The
investigator should make deductions based on various amounts of
information on the wastes contained within a unit, the design/
operating characteristics of the unit, and the presence of con-
taminants in any of the pollutant migration pathways associated
with the unit.
In some cases, the investigator may have actual evidence
that a unit released to a particular medium. In other situations,
it ^ay be necessary to draw connections between a constituent
identified in a unit, the likelihood that this constituent could
have been released from the unit, and sampling data showing the
presence of the constituent in a migration pathway. While this
deduction may not prov.e unequivocally that the constituent identi-
fied" in the environment originated in-the suspected unit, such
deductions' will usually be sufficient to identify a release of
concern intheRFA.
The investigator's ability to make deductions on the likeli-
hood of release will depend on the extent of information he/she
collects pertaining to the first four items in the RFA informa-
tion matrix: unit characteristics, waste characteristics, pollu-
tant migration pathways, and evidence of release. Information on
exposure potential is not needed to determine the likelihood of
release, but is important in determining the need for interim
corrective measures due to immediate exposure risks. The kinds
of information to be considered in each of these five categories
are described below.
1. Unit Characteristics
The design and operating characteristics of a SWMU will
determine to a great extent its potential f.or release. Many
treatment, storage, and disposal units are designed to prevent
releases to the environment. The investigator should evaluate
the physical characteristics of each SWMU or group of SWMUs to
determine how they affect the potential for releases.
The media-specific chapters in thisguidance provide detailed
discussions of how the design and operating characteristics of
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950 2.00-5 ~
various types of SWMUs affect their potential for releasing to
each medium. For example, surface impoundments with well-designed,
intact berms for controlling overtopping do not exhibit a high
potential for surface water releases. EPA assumes, however, that
unlined surface impoundments have a high potential for releasing
constituents to ground water. Surface impoundments which contain
volatile organic compounds also exhibit a high potential for air
releases. The investigator should examine the characteristics of
each SWMU based upon the discussions presented in Chapters Five
through Nine in order to consider the likelihood of release to
each of the environmental media: ground water, surface water,
air, soils, and subsurface (gas). Investigators will often find
situations where unit design characteristics suggest that a SWMU
poses little or no threat to the environment from releases (e.g.,
intact above-ground storage tanks).
2 . Haste Characteristics
In evaluating a SWMU's release potential, the investigator
should identify the wastes originally or currently contained in
the unit in order to link constituents observed in the environ-
ment with those present in the contaminant source. The investi-
gator can usually deduce that a release has occurred when he/she
jatermines that a SWMU contained a constituent that has been
observed in a pollutant migration pathway associated with that
unit.
The information gathered while investigating the waste
generation processes at a facility will- provide the'basis for
t'his part of the PR. In many cases, a facility will indicate how
it managed many of its waste streams, e.g., off-site shipment,
disposal in a specific surface impoundment, or storage in a waste
pile. When a particular waste stream can be traced to a particular
unit, the investigator can generally assume all of the constituents
present in that waste stream are also present in the unit.
The information gathered on facility waste generation
processes may often be useful in identifying constituents other
than listed constituents of concern to RCRA. For example, rapidly
decomposable refuse may produce methane when placed in landfills
under certain conditions.
The investigator should identify all of the hazardous con-
stituents which may be present in each SWMU or other areas of
concern. Some constituents will have a greater potential for
release from one kind of SWMU than another. For example, the air
chapter discusses the likelihood that volatile organic constituents
will be released from wastewater treatment units. The media-
specific chapters discuss the ways in which constituent properties
can affect the likelihood of releases to various media.
3. Pol 1utant Migration Pathway
The investigator should evaluate existing information con-
cerning the likely pollutant migration pathways associated with
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each SWMU or release of concern. In cases involving environmental
data, the investigator will have to demonstrate that it is reason-
able to deduce that a constituent observed in the environnent
originated at a specific SWMU or location, based upon knowledge
of the pollutant migration pathway.
While some pollutant migration pathways are largely facility-
wide (e.g., ground water), the investigator should evaluate the
importance of all pollutant migration pathways (i.e., ground
water, surface water, air, soils, and subsurface gas) that could
be associated with each SWMU and then evaluate information on
their characteristics. SWMUs which contain the same wastes and
are adjacent to each other may be grouped together during the RFA.
It will often be possible to eliminate certain pathways from con-
sideration for various SWMUs at this point in the PR.
Different types of SWMUs will exhibit different potentials
for releasing constituents to specific migration pathways. The
investigator should determine which SWMUs are likely to impact
which pollutant migration pathways at the facility, and gather
specific information that will aid in determining the charac-
teristics of thesa pathways. This part of the analysis also
pro/ides a critical role in identifying potential exposure points
along various migration pathways, which is important in evaluating
exposure potential for interim measures at the facility.
The media-specific chapters provide information to aid the
investigator in evaluating the physical characteristics of each
migration pathway of interest.. The investigator should consider:
o. Potential routes of pollutant transport;
o Physical factors within the pathway that could affect
the migration of constituents (e.g., organic content of
soil for releases to soil and ground water, or prevailing
wind patterns for air releases); and
o Other factors which could affect the fate of constituents
present in a migration pathway.
4« Evidence of Release
The investigator should examine available sources of informa-
tion to identify any evidence that constituents have been released
at a facility. The investigator may have access to direct and
indirect evidence of release, both of which may help in making
determinations of release at a facility.
Direct evidence of release includes official reports of
prior release incidents (which may be found in RCRA enforcement
or permtttfn-g documents, other Federal, State, or local government
documents, facility records, RSI #3 responses, etc.), visual
evidence clearly showing a release incident, or sampling data
that clearly identifies a releasing SWMU (e.g., surface water
samples for a specific constituent in a clear run-off pathway).
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OSVJEK ruuv,i uin ---
950 2.00-5
Indirect evidence of release includes sampling data taken along
relevant migration pathways which, when linked together with waste
composition data, can support a deduction concerning the
likelihood of release from a specific unit at the facility.
The VSI, which is described in Chapter Three, is generally
an excellent source of both direct and indirect evidence on
releases. Stained soils in a well-defined drainage pathway below
a unit can provide direct evidence of release; stressed vegeta-
tion may provide indirect evidence of release.
The media-specific chapters describe the types of evidence
that are important for releases to each of the environmental
media. For example, visual sightings of seepage along a stream
bank provide evidence of both a ground-water release and a sur-
face water release. The investigator should refer to the section
on evidence of release in each of the media-specific chapters.
In all cases, the investigator should use best professional judg-
ment in assessing the strength of any information source in
providing evidence of release.
5. Exoos'jre Potential
The investigator should evaluate available information on
the location, number, and characteristics of receptors that could
be affected by continuing releases at the facility. These recep-
tors include human populations, animal populations (particularly
any endangered or -protected species')', and sensitive environments.
This information will be most useful in helping the investigator
determine the need for interim corrective measures at the facility
to alleviate especially high risks of exposure. The investigator
should refer to the RCRA §3008(h) Corrective Action Orders Interim
Measures Guidance for details on when and how to implement interim
measu res .
The media-specific chapters provide information on what
receptors are likely to be affected by releases to each of the
medi a.
IV. COMPLETING THE PRELIMINARY REVIEW
The investigator's ability to determine that a release may
pose a threat to human health or the environment will increase
with the quantity and quality of information gathered in the
RFA. By the end of the PR, the investigator will usually have
identified many of the potential releases of concern at the
facility, and will have made a preliminary evaluation concerning
the likelihood that a release of concern has occurred at each
SWMU, group of SWMUs, or other potential areas of concern.
The next phase of the RFA, the VSI, provides additional
evidence to help the investigator determine which units or
areas of concern.require: additional investigation in a sampling
visit, interim measures, further investigation in an RFI, or no
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further action. The investigator will usually consider the
following factors before proceeding with the VSI: 1) identi-
fying significant data gaps, 2) focusing the next two steps of
the RFA, and 3) beginning the RFA report.
A. Identifying Significant Data Gaps
Depending upon the quality of information gathered during
the PR, the investigator may have a strong idea concerning the
-likelihood of releases from SWMUs or other areas of concern
identified in the PR. In many cases, however, the investigator
will be missing important information on a potential release or
unit of concern (e.g., information on the wastes handled
within the unit).
In such cases, it may be necessary to make a formal request
for additional information from the owner/operator. As stated
earlier, investigators may need to cite the RCRA §3007 informa-
tion authority when making this request. The letter should be
extremely specific in order to ensure that the owner/operator
clearly understands what information has been requested (see
Append! < C ) .
3. Focusing the Visual Site Inspection and Sampling Visit
One of the primary purposes of the PR is to provide the
investigator with an understanding of the waste management
activities at the f aci 1 i ty, 'enabl i ng him/her to focus subs-equent.
observations in the VSI and the SV to the greatest extent
possible. Because all facilities will undergo a PR and a VSI,
emphasis will be placed on the quality of the information
gathered in these two stages. If the conclusions drawn from a
PR and VSI are not based upon sufficient information, it is
likely that owner/operators or the public will challenge permit
conditions or enforcement orders developed to compel further
actions at the facility.
The investigator should evaluate the information gathered in
the PR on each SWMU or potential release of concern, and deter-
mine whether: 1) it is likely that the unit has released, 2) it
is unlikely that the unit has released, 3) there is insuffi-
cient evidence at this stage to assess the likelihood of release,
or 4) a release could threaten human health or the environment.
The VSI will provide more useful information if the investigator
conducts it with these preliminary determinations in mind.
While it is.too early to draw conclusions at the end of the PR,
-t will often be possible to screen out units from further con-
sideration at the end of the VSI. During the PR, the investigator
may identify units that are not likely to have releases of concern
These units should be inspected carefully in the VSI before deter-
mining that they need no further investigation or action.
The investigator can also make preliminary recommendations
concerning the need for collecting additional sampling data in
an SV. It will often be possible to identify units or locations
where sampling data can help in making determinations of release.
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950 2 . 00-5 -
Recommendations on sampling locations made in the PR should be
checked for appropriateness during the VSI. In general, the VSI
and SV should provide the additional information needed to fill
data gaps identified during the PR.
C. Documenting the Preliminary Review
The investigator should document the findings of the PR by
beginning the RFA report, which will summarize the complete RFA
process. The investigator will incorporate the results of each
step of the RFA into this report, resulting in a complete docu-
ment providing recommendations concerning: 1) the need for an RFI
-" "u- facility, 2) the need for interim measures at the facility,
the need for no further action at the unit/facility at
at the
or 3
this t i me.
At the end of the PR, the report should document information
sources, identify SVIM'Js and other areas of potential release on a
facility map, and contain preliminary evaluations of the likelihood
of release at each locations. This information will be used
throughout both the VSI and the SV.
1 sample outline of an RFA report is included as Appendix A.
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950 2 . 00-5
CHAPTER THREE
CONDUCTING A VISUAL SITE INSPECTION
I. INTRODUCTION
A. Purpose
The visual site inspection (VSI) is the second step of the
three-step RFA process for identifying releases at RCRA facilities
in the corrective action program. The VSI will focus on identify-
ing SWMUs and collecting visual evidence of release at facilities
to assist EPA in recommending further steps in the corrective
action process. The major purposes of the VSI include:
(1) Visually inspecting the entire facility for evidence
that releases of hazardous wastes or constituents have
occurred and identifying additional areas of concern;
(2) Ensuring that all SWMUs and areas of concern have been
identified;
(3) Filling data gaps identified in the PR; and
(4) Focusing recommendations concerning the need for a
sampling visit, interim measures, an RFI, or no further
actionatafacility.
By the end of the VSI, the investigator will be able to
determine at which locations it will be necessary to collect
additional environmental samples in a sampling visit (SV). In
some cases, it will be possible to screen a unit from further
investigation or to recommend further investigation in an RFI
without conducting additional sampling, thus completing the RFA.
B. Scope
The VSI will include the entire RCRA facility and can extend
beyond the property boundary in certain cases. The VSI should
focus on inspecting the discernible SWMUs at the facility. How-
ever, the investigator may inspect areas outside the facility
boundary to determine if a release has migrated offsite. The VSI
will generally be limited to collecting visual evidence of poten-
tial releases (i.e., photographic documentation), although it may
be appropriate in some cases to conduct air monitoring for safety
pu rposes i n the VSI .
C. Product
-Visual evidence gath-er-ed during the VSI will support the
initial information gathered during the PR on the likelihood of
release at specific locations in the facility. This information
should be evaluated along with the original information collected
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during the PR and integrated into the draft RFA report. Initial
determinations on the likelihood of release at the facility
should be revised accordingly. Typical VSIs will result in
substantial documentation of facility characteristics, which
should be integrated into the RFA report.
II. PLANNING THE VISUAL SITE INSPECTION
The VSI is a relatively simple procedure and should not
require a great deal of time to plan and execute. In general, the
site inspection activities can be completed in one day, although
there may be some extremely large facilities which will require
more ti me.
The PR provides most of the information needed to prepare
for conducting the VSI. During the PR, the investigator will
identify potential areas of release on a facility map, and make
preliminary evaluations of the likelihood of release at each loca-
tion. The investigator should rely upon this map when conducting
the VSI, documenting any unusual observations on the map and in a
1 o g b o o k .
The VSI will usually be the investigator's first visit to
the facility during the corrective action process. Therefore,
the investigator should develop a site safety plan prior to
conducting the VSI which outlines the need for personal safety
devi ces. ( e..g. , respirators, protective clothing, etc.) while
conducting the field activities. The exact content of each
safety plan will vary by site, depending on the complexity of the
site and on the investigator's planned activities. EPA personnel
should participate in an Agency-sponsored safety course prior to
conducting a VSI. Safety preparation is discussed further in
Chapter Four (see "Preparing for the Sampling Visit") and Appen-
dix E .
The VSI will probably be the owner/operator's first experience
with the new RCRA corrective action program as well. The investi-
gator should contact the owner/operator to schedule a date for
the VSI. At this time, he/she should also request a meeting with
representatives from the facility prior to conducting the field
activities. This meeting will provide the investigator with an
opportunity to explain the various steps of the corrective action
process to the owner/operator, and to answer any of the owner/
operator's questions about the RFA or the corrective action
program. During this meeting, the investigator should discuss
with the owner/operator the proposed safety plan and incorporate
his/her recommendations in the safety plan prior to conducting
the VSI .
III. CONDUCTING FIELD ACTIVITIES DURING THE VSI
Once the investigator has made the arrangements for conductin
the VSI and has completed the PR, he/she should conduct the field
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OSWER POLICY DIRECTIVE NO.
9502 oo->
activities. The owner/operator will usually accompany the inves-
tigator around the facility.
During the VSI, the investigator should:
o make visual observations of SWMUs and other areas of
concern at the facility;
o identify on a facility map all areas of concern;
o document all observations in a field logbook;
o take photographs of all SWMUs, potential releases, and
other locations of interest; and
o monitor for vapor emissions where appropriate to protect
the investigator's safety.
One of the primary purposes of the RFA will be to allow the
investigator to identify potential releases of concern not identi-
* i e d during the PR. The VSI also provides the investigator with
an opportunity to inspect the entire facility for potential
"aliases of concern and to gain insight into facility management
practices.
The investigator will focus in the VSI on identifying and
characterizing SWMUs, as defined in the Introduction. The §3004(u)
corrective action permitting authority requires that corrective
action be addressed at all SWMUs. In some, cases, however, he/she
will identify spills or other releases from waste management
activities which may require corrective action. These should
also be inspected fully in the VSI.
Finally, there may be situations where releases of concern
from manufacturing processes or product storage areas may be
observed during the VSI. The investigator should document and
photograph the presence of these releases. It may be necessary
in some cases to use CERCLA or TSCA investigative or enforcement
authorities to address these releases.
Field activities should be photographed carefuly to document
all visual observations. This will be especially important at
facilities where the VSI represents the last step in the RFA.
For additional discussion of photographic documentation proce-
dures, refer to Chapter 4, Section III.C.
The investigator should obtain information on each poten-
tial release based upon the five categories of information shown
in the RFA Information Matrix (Exhibit 1-1): unit characteristics,
waste characteristics, pollutant migration pathways, evidence of
relea-se* and exposure- p.otential. The fallowing sections briefly
describe some of the types of information that may be found in
eachofthesecategories.
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A. Obtaining Visual Evidence of Unit Characteristics
The VSI can provide useful information on unit character-
istics at RCRA facilities. Observations concerning the integrity,
location, and design of a unit can provide a great deal of infor-
mation on the likelihood that it has released. For example,
above-ground tanks can be inspected for the integrity of seams and
for the presence of adequate secondary containment. The investi-
gator may be able to screen from further investigation an above-
ground tank where these factors, in conjunction with the other four
categories, appear to be adequate to determine that no release of
hazardous wastes or constituents has occurred or is occurring.
Surface impoundments should be inspected for the adequacy of
berms, overtopping controls, and devices for the control of vola-
tile emissions. Landfills should be inspected for the presence
of runoff controls, erosion around the unit, and the potential
for particulate releases posing concern. In general, it will not
be possible to visually assess these units for ground-water releases
during the VSI. However, the investigator should note any signif-
icant visible deterioration of containment liners.
1 . Obtaining Visual Evidence of Waste Characteristics
In general, it will not be possible to obtain a great deal
of information during the VSI on waste characteristics. In cases
where the types of waste handled in a unit are not known, it will
seldom be possible-to determine their characteristics through '
visual observation. These will be determined primarily during
the sampling visit (SV). There wijl be some unusual cases,
however, where the investigator may find tanks or drums with
labels indicating that they contain hazardous wastes or consti-
tuents. These locations should be documented carefully during
the VSI .
C. Obtaining Visual Evidence of Pollutant Migration Pathways
The VSI will provide useful information on potential
pollutant migration pathways at the facility. Facility charac-
teristics that can facilitate the movement of releases from the
immediate area around a unit but have not been identified pre-
viously on the facility map will often be apparent during the
VSI. For example, erosion gullies at the base of landfills or
surface i mpoundments~"wi 11 provide direct pathways for surface
water and soil releases from these units. These pathways will be
especially visible after a recent precipitation event; whenever
possible, VSIs should be conducted soon after such events to help
identify these runoff pathways.
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9502.00-5 -*
The investigator should locate all potential migration path-
ways of concern on the facility map. These will be important
areas for sampling should it be necessary to conduct a SV at
these units. In addition, the investigator should correlate
photographs of these pathways and their documentation on the map
whenever possible.
D. Obtaining Visual Evidence of Release
The investigator should inspect the entire facility for
visual evidence of release. While it will not always be possible
to determine conclusively that a release has occurred based on
visual evidence, such evidence can provide a strong indication
that one has occurred. Visual evidence of release, coupled with
information indicating that a unit contained hazardous consti-
tuents, will often be sufficient to compel further investigation
in an RF I .
The investigator should look for obvious signs of release,
such as: discolored soils, dead vegetation or animals, etc. The
media-specific chapters describe in detail the types of visual
2 / i d e n c e that may be apparent at various types of waste management
in i t 3 .
- Obtaining Visual Evidence of Exposure Potential
The VSI will provide only limited information on exposure
potential -at the facility. The. VSI should include an investiga-
tion of the area "around 'the fa.ci 1 i ty to determine if there are
potential off-site releases and documenting evidence of such-
releases. In most cases, the PR will have identified whether
there are nearby residences, streams, and lakes. At a minimum,
the VSI should note any locations not identified in the PR where
the public could be exposed to releases.
IV. DETERMINING THE NEED FOR FURTHER ACTION DURING THE RFA
The results of the VSI should be incorporated into the draft
RFA report begun upon completing the PR. The results of the PR
and the VSI together will provide sufficient evidence for each
potential release of concern to determine either: 1) the need for
a sampling visit (SV) in the RFA, 2) the need for interim measures,
3) the need for further investigation in an RFI, or 4) the need
for no further action. It is crucial that the investigator document
the results' of the VSI in a concise and thorough manner in the
RFA report. These data, together with information obtained during
the PR, must be sufficient to support decisions regarding the
necessity of additional action at the facility, and are like'y
to b.e closely scrutinized or possibly challenged. As stated
previously, the R'FA report will be the primary legal document
supporting the Agency's initial corrective action activities at
the facility. Incomplete, contradictory, or obscure information
in the RFA report may jeopardize the Agency's position.
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The following sections discuss each of the possible recommen-
dations that can be made after completing the PR and. the VSI.
A. Determining the Need for a Sampling Visit
By the end of the VSI, the investigator will have collected
information on each potential release of concern and will have
made a preliminary evaluation concerning the likelihood of release
at each location. He/she will also have identified important
data gaps that interfer with the ability to make an enforceable
determination of release potential. In many cases, the investi-
gator will recommend the collection of new environmental samples
from the facility during the RFA to support his/her recommenda-
tions for further action during the RCRA corrective action process
The need for sampling at specific units will depend upon
several important factors, including: the complexity of the unit
and environmental setting, the quantity and quality of information
gathered during the PR and VSI, the preliminary recommendations
for further action at the facility, and the cooperativeness of
the owner/operator. The investigator must consider these factors
and r-ely upon his/her professional judgment in determining when
and where it will be useful to collect samples in the SV.
The preliminary recommendations for further action at a
facility can play an important role in determining the need for
and extent of sampling in the SV. If the investigator believes
that a SWMU may have a release he/she may want to collect samples
in" the. SV, to support the decision to. require further i nvest i-gat i-on
Sampl-ing conducted during a SV can be an important supplement to
information gathered during the PR and VSI, and provide the docu-
mentation necessary for developing enforceable permit conditions.
On the other hand, if the investigator believes it is unlikely
that a SWMU has released or that other areas actually present
problems, he/she may make a preliminary recommendation that the
unit will not need investigation in an RFI. It will often be
useful to support this recommendation with appropriate environ-
mental samples at the unit which will demonstrate that there is no
evidence that a release of concern is present. This will provide
valuable evidence to support the investigator's recommendation
should it be contested in a public hearing. It is likely to be
just as important to sample at units which will not require an
RFI as at those where one will be required.
There will be situations where the investigator makes a pre-
liminary recommendation that a unit should be investigated in an
RFI without actual sampling data demonstrating a release. In some
cases, it may be possible to make this recommendation without
taking additional samples in a SV. More typically, however, the
i nve-sti gator wtl 1 take samples at these units in order to demon-
strate that a release has occurred. More enforceable permit
conditions or enforcement orders can be developed when supported
by sampling evidence.
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950 2 . 00-5 -*
Taking environmental samples will be especially important
when the investigator believes the owner/operator will be unlikely
to cooperate in conducting an RFI at the facility. When the
owner/operator's cooperativeness is questionable, the investigator
should usually take samples to support recommendations for further
steps in the corrective action process, in case these recommenda-
tions are contested in an administrative hearing. Even the most
cooperative owner/operator, however, can challenge permit condi-
tions which are not supported by strong evidence.
8. Determining the Need for Interim Measures
The investigator can recommend implementation of interim
measures at any time during the RFA, although he/she may not
have sufficient information prior to the VSI to make this recom-
mendation. Interim measures should be conducted at the facility
whenever there nay be a significant risk of immediate exposure
resulting from releases at the facility. Interim measures typically
include such actions as repacking damaged drums, requiring safety
precautions for workers at the facility, or fencing off areas of
concern near the facility.
0 e *: 3ils on planning and implementing interim measures can be
" o u n d in the RCRA §30Q8(h) Corrective Action Orders Interim*Meas-
j r e s Guidance (Draft)"The investigator should consult this
document when determining the need for such immediate actions at
a facility. Interim measures are applicable to a facility whether
it i s-cooduc-ti ng corrective action under §3008(h), §3004(u), or
§3004(v). - - _ . .".
C. Determining the Need for a Remedial Investigation
Releases and likely releases that are identified during the
RFA as requiring further investigation will be fully character-
ized during the remedial investigation phase of the RCRA correc-
tive action process. The RFI will be conducted by the owner/
operator and may be an extremely resource intensive activity.
For this reason, it will be necessary to ensure that recommenda-
tions for RFIs at facilities are supported by sufficient evidence
collected during the PR, the VSI, and the SV. In most situations,
the investigator will choose to collect samples at questionable
units in order to support recommendations at the end of the RFA.
There will be cases, however, where the investigator will
recommend an RFI for particular units without collecting additional
samples in an SV. This will usually take place at facilities
where it rf a s possible to evaluate a large amount of high quality
evidence of release during the PR and VSI. In these cases, the
existing evidence of release must be sufficient to stand alone,
without supplemental sampling, in justifying an RFI. EPA should
collect add-ttronal sampling data whenever necessary, to develop
strong enforceable permit conditions.
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950 2.00^5
CHAPTER FOUR
CONDUCTING THE SAMPLING VISIT
I. INTRODUCTION
A. Purpose
The sampling visit (SV) is the third step of the three-step
RFA process designed to identify releases at RCRA facilities.
The SV focuses on collecting additional sampling information to
fill data gaps that remain upon completion of the PR and VSI to
enable the investigator to make release determinations^ in the RFA
8y the end of the SV, the investigator will have completed
the first phase of the RCRA corrective action process, and should
have identified all releases or potential releases requiring
further investigation at a facility.
8. Scope
Tie scope of the SV is limited. It is EPA's objective to
focus the collection and analysis of new sampling data in making
preliminary release determinations, and rely upon existing infor-
mation sources identified in the PR and technical judgments as
much as possible. By identifying specific areas where new infor-
mation.--is needed during the PR and VSI, -it'should be possible to
conduct focused, limited SVs'tKat will enable the' investigator
'to identify releases. EPA will defer major new data gathering
efforts to the RCRA Facility Investigation (RFI) phase of the con
rective action process.
As discussed previously, the RFA should examine each SWMU or
group of SWMUs at a facility. It will seldom be necessary to
investigate each SWMU in a SV, as the PR and VSI will often pro-
vide sufficient information to make release determinations.
The extent of the SV at a facility will vary on a case-by-
case basis, and will depend upon the amount and quality of infor-
mation gathered in the PR and VSI. The investigator's professional
judgment regarding the amount of information necessary to make an
initial release determination will influence the extent of the
SV. These determinations should consider a number of factors
including the degree of owner/operator cooperation and the
regulatory action planned for requiring further action. While
investigators are encouraged to minimize the amount of sampling
conducted during the SV, certain situations may require extensive
sampling.
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As discussed in Chapter One, Regions may rely under special
circumstances upon facility owner/operators to develop a sampling
plan and to conduct sampling and analysis activities during the
SV. In these cases, the Regions should review and approve the
owner/operator activities to ensure the quality of the new data.
This chapter describes these oversight responsibilities.
This chapter provides guidance to the investigator on the
following aspects of an SV:
(1) Developing a sampling plan;
(2) Preparing for the sampling visit;
(3) Conducting the sampling visit; and
(4) Making final RFA recommendations for further action.
C. Prod'uct
The results of the SV should be incorporated into the draft
RFA report begun after the PR and VSI activities. Because the
objectives of the SV are to fill data gaps identified previously
and to assist the investigator in making final recommendations at
the facility, it should be a straightforward matter to integrate
the SV findings into the RFA report.
II. DEVELOPING A SAMPLING PLAN' '
One of the major purposes of the PR and VSI is to make a-
preliminary assessment of the need for further investigation at
locations of concern throughout the facility and to focus the SV.
This section describes the major factors in developing a sampling
plan:
(1) How to determine the need for collecting sampling
information during-an SV; and
(2) How to develop a sampling plan for thre facility where
appropri ate.
A. Determining the Need for Sampling at Facilities
The need for additional sampling of potential releases of
concern wilt vary on a case-by-case basis, and the investigator
should rely upon best professional judgment in determining when
it will be appropriate. The investigator may choose to sample in
these situations:
o to collect additional information to suppport a determina
tion that a unit or facility does not need an RFI;
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o to collect additional information when the investigator
is unsure whether a release has occurred; and
o to collect additional information to confirm a determina-
tion of release and to compel an owner/operator to begin
an RFI (or some other further action).
In some cases, the information gathered in the PR and VSI
may provide sufficient evidence to indicate the need for an RFI at
a facility, or conversely, that no further action is necessary at
a facility. For example, if previous ground-water monitoring
results clearly indicate that an old, closed landfill has released
hazardous constituents to a surficial aquifer, the investigator
will have sufficient evidence to compel the owner/operator to
conduct an RFI at the unit, and it will not be necessary to conduct
additional sampling. Facility records reviewed during the PR may
indicate that an old, closed surface impoundment never contained
hazardous constituents, and ground-water monitoring data indicate
that the SWMU has not released. In this case, also, it would not
he necessary to take samples to support a determination that no
farther action is necessary at this time.
In nany cases, the '^formation gathered in the PR and VSI
iv il1 not be sufficient to enable the investigator to determine
conclusively that a SWMU has or has not released. For example, a
facility may have clean closed a surface impoundment several
years ago that once contained sludges analyzed to be marginally
E? toxic for ,a heavy' metal. It may not be clear whether or not
the impoundment released" constituents to the' ground water "in the
past, or whether any contaminated soil remains which could leach
contaminants to the ground water. It may be necessary to sample
the soils around the closed unit or to sample the ground water
(from existing wells) downgradient from the unit in order to
i denti fy a release .
Sampling may also be necessary at SWMUs where records do not
indicate what wastes were disposed in them. Old landfills and
surface impoundments without information on prior wastes may
require sampling; however, due to the danger involved when coring
or drilling into old waste, this is best left for an RFI.
In cases such as the previous one, the investigator may
determine, based upon best professional judgment, that a release
is likely to have occurred at a unit. At facilities with coopera-
tive owner/operators, it may be possible to move directly to an
RFI withoutcol 1ecting new sampling information, even though the
evidence does not conclusively indicate that a release has oc-
curred. However, at some facilities, it may be necessary to
conduct sampling in the SV in order to confirm or deny the pres-
ence of a. release before moving further in the corrective action
process. ''
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B. Developing a Sampling Plan
The sampling plan will be the primary document directing the
collection of additional information in the SV. When the inves-
tigator determines that sampling is necessary at a facility, it
will be important to clearly specify the data that are required
and the reasons for obtaining it. Investigators should remain
focused on the objectives of collecting additional information at
each unit, because the choice and extent of sampling locations,
methods, and parameters will be critical to their ability to make
meaningful release determinations.
The sampling plan should be developed to collect evidence
the investigator needs to make a release determination at a SWMU,
group of SWMUs, or other locations of concern. This may involve
collecting direct evidence (e.g., air samples from above or
around a surface impoundment) or indirect evidence (e,g, ground-
water sampling at a well downgradient from the SWMU) of a release.
In most cases, the investigator will collect samples from the
waste source and/or from an environmental medium, and based upon
knowledge of the pollutant migration pathway, deduce the likelihood
Via' the constituent originated in the SWMU.
~ h 3 sanpling plan may be developed by EPA, a contractor, the
o^ner/ operator, or a combination of these, depending upon the
situation. In all cases, EPA should review and approve the
es.
mpor-
s
.intended objectives. Due to the cost and time involved in an SV,
it may be necessary to revise sampling plans several times through
an iterative process before finally beginning work.
situation. In all cases, EPA should review and approve the
sampling plan carefully before initiating sampling activiti
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9502. 00- 5
Because of the time and personnel required to conduct sampling,
the information collected should be as concise and focused--as
possible.
The extent of sampling required in the SV will vary on a
case-by-case basis, and will depend upon the investigator's best
professional judgment concerning the need for new information.
Several factors will play a role in determining the extent of
sampling at the facility:
o The extent of information gathered during the PR and VSI;
o The cooperativeness of the owner/operator; and
o The complexity of the unit and the potential environmental
media of concern.
The following guideline should be followed when determining
how much sampling is required: The stronger the case that needs
to be made to compel an owner/operator to conduct an RFI, or to
convince the public that a SWMU does not pose a threat, the more
information that should be collected in the SV.
In general, the investigator should seek evidence that a
constituent identified in a SWMU.-has migrated to one of the
environmental media. In such cases, one positive sample confirm-
ing the presence-of. the constituent of concern in a well-defined
migration pathway may be sufficient to compel the owner/operator
to conduct an RFI. However, it may be necessary to take samples
at several different points around a unit to ensure that all of
the potential migration pathways have been sampled.
Detailed information on pollutant migration pathways in each
of the environmental media is presented in Chapters Five through
Nine. The investigator should identify the potential migration
pathways of concern for each SWMU during the PR and VSI. The
location and number of samples necessary to identify a release
will vary by unit type and by the migration pathway being inves-
tigated. For example, one groundwater monitoring well may be
insufficient to identify a release from a closed landfill due to
the complexities of the ground-water pathway. However, it may
only be necessary to take one hNU reading from above or around
a wastewater treatment unit in order to identify an air release
Each of the media-specific chapters contains specific details
determining.the extent and location of sampling.
on
When the investigator has reason to believe that an owner/
operator is likely to contest EPA's determination that a SWMU
should be investigated in an RFI, the investigator should be sure
to.gather suf f i ci eat- s.ajnpli ng information to support his/her
judgment on the likelihood of release. Should it be necessary to
compel the owner/operator to conduct an RFI through an enforcement
order and administrative hearing, the outcome will depend greatly
on the quality and conclusiveness of the data. Similarly the
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Agency will require strong data when defending its actions in a
public hearing.
2. Choosing Sampling Methods and Parameters
The investigator should choose appropriate sampling methods
and parameters during the SV in order to obtain meaningful sam-
pling results. The sampling plan should specify what methods and
parameters will be used at each sampling location at the facility.
It should also specify the number of samples to be taken at each
sampling point (sampling SOPs and QA/QC guidelines are discussed
later in this chapter). The media-specific chapters describe
many of the sampling methods which will be most valuable during
the SV and the criteria for choosing them.
In general, it will be possible to choose sampling techniques
and parameters which provide information on the unit ranging from
general indications of a release to precise, quantitative evidence
of a release. In some cases, it may be appropriate to take
screening level measurements (e.g., a VOC measurement with an hNU
photoionizer), while in other cases it may be necessary to sample
for specific organic or inorganic compounds. As stated previously,
sanpling for specific compounds will generally provide the most
jsefjl results during the SV. This will aid in developing a
>nore defensible Remedial Investigation Plan.
"
Sampling for indicator parameters such as total organic
.halogens (TOX'), conduct i yi'ty, or pH may be useful when the - .
investigator has little or no idea what wastes may have been
released to a medium. However, these parameters can give only
limited information and will not provide sufficient evidence of
release in most cases. Whenever possible, it will be advantageous
to identify the constituents of concern at each SMWU and sample
for those specific parameters.
The investigator should choose those sampling methods that
will provide the most usable results. In some cases, there may
only be one method appropriate for sampling a specific medium
(e.g., the presence of methane is normally monitored with a
combustible gas meter). However, there will be cases where
several methods may provide evidence of release.
For example, when investigating ground-water releases from
old landfills where existing monitoring wells are present, the
investigator should sample the ground water in order to identify
releases. However, existing monitoring wells may not always be
located sufficiently close to SWMUs to provide meaningful data on
releases. In these cases, it may be necessary to take a number
of soil samples around the unit and/or in the unsaturated zone
beneath the landfill in order to identify evidence of releases.
ATternatively, there rrray be tnstances where electromagnetic
conductivity (EM) testing or soil gas testing will provide useful
screening level information on prior releases at such units.
Finally, there ma.y be unusual si tuat i ons 'where the investigator
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03,,£!< PQUUT UIKtUIVt NU.
will need to drill new ground-water monitoring wi?l^r fri oi'dM r" Oo *"*
obtain information on ground-water contamination. The investigator
should be familiar with each of the potentially appropriate
sampling techniques and choose the best ones for each situation.
The media-specific chapters provide details on how to choose
appropriate sampling techniques.
3. Format for Sampling Plan
The sampling plan should be clear and understandable and
present logical actions for meeting the sampling objectives
at each SWMU, group of SWMUs , or other locations of concern. The
investigator should organize the sampling plan to identify the
actions to be taken at the facility. Depending upon the facility
characteristics, it may be appropriate to organize it by location
or by sampling technique. For example, there could be sections
for each SWMU that describe all of the sampling activities asso-
ciated with it; alternatively, there would be a section on soil
sampling that identifies all of the locations and methodologies
for sampling the soil throughout the facility.
Th.3 sampling plan should include information on each of the
D 11 o >/ i n g factors:
o Field operation
The sampling plan should discuss the sequence for conducting
the field activities.
o Sampling locations/rationale
As precisely as possible, the sampling plan should iden-
tify the location of each sample. A site map should be
prepared to guide the investigator to the appropriate
locations. Specific sampling methods, the number of
samples, the parameters being sampled, and a description
of the objectives for each sampling activity should be
included in the sampling plan.
o Analytical requirements
The sampling plan should discuss the technique and level
of detection that will be used to analyze each sample.
o Sample handling
Sample preservation and other handling practices should
be descri bed.
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0 Quality assurance/quality control
The plan should identify the number and type of quality
assurance samples, specifically the number of blanks,
duplicates, or spikes that will be taken. The specific
QA/QC guidelines to be followed in this program are to
be stipulated by each Region.
o Equipment decontamination
The sampling plan should identify the reagents and any
special procedures associated with equipment decontamina-
tion.
o Chain of custody
All samples collected (including blanks and spikes) must
be maintained under chain-of-custody procedures. Chain-
of-custody minimizes the potential for damaging or losing
samples before they are analyzed. Chain-of-custody tracks
the possession of a sample from the time of collection,
through all transfers of custody, to when it is received
in the laboratory, where internal laboratory chain-of-
custody procedures take over. Investigators should gen-
erally follow regional protocols for chain-of-custody
procedures.
4. .Reviewing a S.ampl i ng P 1 an
Ttie investigator should review the sampling 'plan carefully
to ensure that it meets EPA's objectives at each unit being
sampled. The investigator should be sure that appropriate sampling
methods and locations are selected, and that the extent of sam-
pling is appropriate for the determinations that are made at each
sampling location. This will be especially important when the
owner/operator or an EPA contractor develops the sampling plan;
however,, even when the EPA investigator develops the sampling
plan, it will be useful to review the plan in order to ensure its
completeness.
The sampling plan also describes the level of effort required
to conduct the proposed sampling strategy. This information
is usually presented in terms of person/hours for each sampling
technique or SWMU investigated, and may also include an estimate
of the elapsed time and the total costs.
III. PREPARING FOR THE. SAMPLING VISIT
The investigator should plan a number of activities prior to
initiating the SV activities at a site. Once the sampling plan
has been completed, reviewed, and finalized, the investigator can
make plans to begin the on-site activities. These plans will
i nclude :
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(1) Gaining facility access; 9502.00*5
(2) Handling community relations (if appropriate);
(3) Preparing a safety plan; and
(4) Specifying EPA oversight of owner/operator sampling
acti vi ti es .
A. Gaining Facility Access
Prior to conducting the field work, the investigator should
contact the owner/operator to schedule a time for the SV team
to enter the site and perform the necessary field activities.
Although EPA staff may already be coordinating activities for the
RFA with the owner/operator , the appropriate regional person
should contact the owner/operator to verify dates and describe the
nature of the field activities sample collection, photographic
documentation, facility inspection, and/or instrument monitoring.
If the owner/operater is responsible for collecting and
analyzing the samples, then the EPA official should contact the
owner/operator to schedule a date to oversee the field activities.
T 'i e agency should send the sampling plan and procedures for
perforning the sample collection to the owner/operator suffi-
ciently ahead of time for him to obtain the appropriate support.
If EPA is collecting and analyzing the samples, EPA should offer
the owner/operator a split of all samples collected. If the
owner/operator wishes to have splits,. EPA should instruct h'im to
provide analytical sample bottles for the spl'its.
After completing these arrangements, EPA should send a
letter to the owner/operator confirming the dates and field
activities. If access is denied, Appendix D provides guidance
on how to obtain access to a facility.
In some cases it may be necessary to access adjacent or
nearby properties in order to conduct a visual inspection or
collect samples. EPA should provide verbal as well as written
notification of the dates and nature of the work to owners of
these properties.
Although the RCRA investigator is authorized to inspect a
facility and collect samples and photographs, the owner/operator
can require the investigator to conduct the inspection and sample
collection activities to protect his legitimate rights. The
admissibi1ity of data in court may later be challenged if data
ara collected in violation of the owner/operator's constitu-
tional rights. The owner/operator can observe inspection activi-
ties, unless he interferes with the safe, or technically sound,
conduct at the sampling visit.
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The owner/operator has the right to request confidential
treatment of Confidential Business Information (C8I). Ordinarily,
environmental monitoring data are not confidential. If data
deemed confidential by the owner/operator are needed to properly
evaluate the facility, then the investigator should include a
precise description of the confidential data in the field log
book. The investigator should instruct the owner/operator to
follow up with a letter identifying the confidential data and(
explaining the reason why the data are business confidential.'
EPA regulations governing treatment and handling of confidential
data are delineated in 40 CFR Part 2, Subpart B, Sections 2.201
through 2.309.
B. Community Relations
If it is necessary to conduct field activities in or near
residential or non-industrial business areas, then the agency
should contact the appropriate local officials ahead of time.
It is difficult to remain unobtrusive while conducting site
inspections, particularly if field workers are wearing protective
clothing. Moreover, the presence of "official" people collecting
samples can cause alarm. In some cases, it will be difficult to
prevent this but prior, well-handled community contact can minimize
t ne alarm.
The Office of Solid Waste is preparing guidance on community
relations that will be available later this year. This document
will provide specific .guidance on when and how to implement a
community rel-ations program at RCRA facilities.
C. Preparing a Safety Plan'
Agency personnel should prepare a safety plan for each sam-
pling visit in accordance with appropriate EPA guidance. The
safety plan is usually prepared last and is tailored to the
specific SV activities. For some SVs, the safety plan will be
very simple and require few protective measures. Other, more
problematic sites, may require use of higher levels of protection.
For example, if the SV involves sampling lagoons, then the safety
requirements will be more involved than for one involving simple
visual reconnaissance. In developing the safety plan, the owner/
operator should be asked about potential hazards in advance of
field work, and should consult the Facility Contingency Plan.
Appendix E contains Chapter 9 from EPA's Standard Operating
Safety Guide.s, 1982 (SOSG) that explains how to develop a proper
site safety plan. The SOSGs were prepared in accordance with EPA
and other Federal health and safety guidelines, regulations and
orders. This appendix discusses the steps involved in developing
a safety plan and elaborates on the contents of each section of
the plan.
A brief outline of the contents of the safety plan is provided
below. /
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950 2.00-5
o Describe Known Hazards and Risks
o List Key Personnel and Alternates
o Identify Levels of Protection to be Uorn
o Identify Work Areas
o Identify Access Control Procedures-
o Describe Decontamination Procedures
o Describe Site Monitoring Program
o Identify Special Training Required
o Describe Weather-Related Precautions
EPA personnel should participate in an Agency-sponsored
safety course before visiting a site
0.
S _ - -. _ _ _._ .._._ ^ _. _.___
EPA Oversight of Owner/Operator Sampling Activities
The sampling visit plan should include provisions for EPA
oversight when the owner/operator conducts the sampling activities.
The level of EPA involvement will depend upon the extent of
sampling, the complexity of the site, and the cooperativeness of
the owner/operator. In some cases, EPA may believe that the
owner/operator can be counted on to provide reliable results. In
such situations, EPA oversight of the sampling activities may be
1 i TM t 9 d to presence at the facility during one day of the sampling
only. In other cases, it may be necessary to provide EPA presence
at the facility at all times during the sampling activities. The
investigator should take splits of all samples collected by the
owner/operator.
IV. CONDUCTING THE SAMPLING VISIT
The investigator may begin the site activities once he/she
has completed all of the preliminary activities. The sampling
visit involves gaining access to the site, performing the sampling
activities, taking photographs of all activities, keeping the SV
portion of the logbook, preparing samples for shipment and analysis
and, finally, decontamination/demobilization.
A . P r e 1 i m i n a r y Site Activities
The investigator should meet with the owner/operator prior
to entering the facility to conduct sampling. The investigator
will already have conducted a VSI; therefore, the owner/operator
should have some understanding of the corrective action process
from the initial meeting with the investigator(s). However, the
investigator should be prepared to answer questions concerning
his/her plans for sampling. In cases where the owner/operator
will conduct the sampling, the investigator can make the arrange-
ments to accompany him/her at this time. In addition, the inves-
tigator should offer to provide the owner/operator with duplicate
samp!es.
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8 Sampli ng Procedures
The investigator should follow the sampling plan once he/she
has gained access to the facility. The sampling plan should
describe all of the sampling locations, methods, and procedures
to be followed. If, for any reason, it is necessary to diverge
from the sampling plan, changes should be documented carefully.
Regardless of who performs the sample collection, continuous
monitoring for vapor emissions is needed to detect air releases
from sampling activities. If the owner/operator is collecting
the samples, EPA/State investigators should document precisely the
sequence of sampling activities, the procedures and instruments
used, and describe the samples (including location, depth,
appearance , etc . ) .
The EPA Regional offices have developed SOPs for most SV
sampling tasks under the CERCLA PA/SI program. In addition, EPA's
Office of Waste Programs Envorcement (OWPE) has developed the
RCRA Ground Water Monitoring Technical Enforcement Guidance Docu-
m e r\t ( T E G D ) t~oprovide guidance on wel 1 install atTi on and samp! i ng
procedures; EPA/SW-34S also provides sampling and analysis proce-
du"es for media relevant to the SV. For the most part, these
SOPs ara applicable to RCRA field activities. If the SOPs are
not applicable or appropriate for the particular field activity,
then a new SOP should be developed. Where modifications to
existing SOPs are made, they should be noted in the field logbook.
C. Photography
Investigators should use regular 35mm cameras for taking
photographs. They should not use filters, as they tend to dis-
color the picture and may unfairly bias the result by making
leachate seeps or lagoons look different from real life. The
investigator should identify and record in the fieldbook the
exact type of camera (including i.d. number), film (i.e., Fuji,
ASA 200), and the lens used. Photographs taken with unusual
lenses (e.g., wide-angle) are not admissible in court.
Photographs should be taken to document the conditions of
the facility and procedures used in inspection activities.
Particular emphasis should be placed on matters identified in
the work plan. Types of pictures that should be taken include:
o Representative overall picture(s) of facility;
o Posted signs identifying ownership of facility;
o Evidence of releases--1eachate seeps, pools, discolored
water, ^r strained soils;
o Individual units--la goons , drums, landfills, etc.;
o Visual evidence of poor facility maintenance;
o Adjacent land use; and
o Area that unauthorized persons can easily access.
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uirvt^nvc n\j.
, K 95° 2 00-5
0. Logbook ^
The logbook is perhaps the most important document produced
during the SV. It serves as a basis for integrating the SV
results into the RFA report, most importantly, supporting the
work done and results obtained in any future legal proceedings
under RCRA or CERCLA.
A unique logbook should be developed for each site and each
visit to the site. Logbooks should be bound and each page sequen-
tially numbered. Entries into the logbook should be chronological
-- a time notation should introduce each entry. The logbooks
should be maintained with indelible ink.
The following types of entries should be made in the logbook:
o All personnel oh site during each phase of the on site
work ;
o All instruments used during the field work with unique
identification numbers;
: Description of film used;
o Description of the weather and changes in the weather;
o Material observations related to items identified in the
work plan;
o Results' of field measurements--distances, instrument
readings, well measurements, locations;
o Factual descriptions of structures and features--we!Is
and well construction, units, containment structures,
buildings, roads, topographic and geomorphic features,
locations;
o Signs of contamination--oily discharges, discolored sur-
faces, dead or stressed vegetation;
o Sketches of facility layout, structured features and
points of contamination;
o Map of facility showing point and direction of photo-
graphs ;
,o Location and time of each sample; and
o Any other relevant items.
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E. Sample Shipment/Sample Analysis
Upon completion of the onslte work EPA or the owner/operator
should deliver all samples to the laboratory for analysis. SOPs
covering sample shipping are available in each of the regional
offices or in EPA safety training manuals. The time involved in
analyzing samples can vary from 40 days to three to four months.
F. Decontamination/Demobilization
Decontamination of persons and equipment occurs not only at
the completion of all field work but each time persons exit the
site, including rest breaks.
In many cases, decontamination may be very simple, e.g.,
removing disposable coveralls and washing field boots. Decon-
tamination after sampling activities will usually include decon-
tamination of field persons, and sampling and field equipment.
\]] clothing and support materials that will not be reused
should he containerized either for transport and eventual off-site
disposal or for on-site disposal.
V. FINAL RFA RECOMMENDATIONS FOR FURTHER ACTION
The final task in the RFA process is to make recommendations
concerning the need for furth.er a.ctipns at the facility. -These
recommendations include: (1) taking'no further action; (2) con-
ducting an RFI to identify the rate and extent of releases from
SVIMUs, groups of SWMUs, or other releases of concern; (3) planning
and implementing interim measures at the facility; or (4) referring
the further investigation and control of permitted SWMU releases
or other unusual releases to other environmental program offices.
The investigator will have completed the RFA only after recommen-
dations have been made which cover all potential releases of
concern investigated in the RFA.
In order to make these recommendations, the investigator
may make determinations concerning the likelihood of release
for some SWMUs after completing the PR and VSI. In other cases,
it will not be possible to make determinations until sampling
results from the SV have been evaluated. We discuss below how to
make final release determinations at the end of the RFA and how
to make recommendations for further action.
A. Making RFA Release Determinations
1. Evaluating Sampling Results from SV Activities
The first step in making an RFA release determination will
require the investigator to use best professional judgment in
evaluating the sampling results from the SV. This evaluation
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9502.00s5 ?
should be straightforward as long as the sampling plan was devel-
oped correctly, e.g., sampling points were selected to provide
enough additional evidence to support this determination.
After the laboratory completes its analysis, the investigator
can evaluate the validity of the analytical results from the
sampling activities. When EPA conducts the sampling, preliminary
review of analytical data involves ensuring that all deliverables
required by the CLP are included in the data package, checking
that all forms are completed within the requirements of the
contract, and identifying the key quality assurance items in the
data package. The EPA Regional Environmental Services Divisions
(ESDs) will perform a qualitative analysis of the data after this
preliminary data review, and determine if the data results are
valid. When the sampling is conducted by the owner/operator,
the investigator should rely upon best professional judgment in
evaluating the validity of the lab results.
2. Integrating Data Collected During the PR, VSI, and SV
Once the investigator has evaluated the validity of the
sanpling results, he/she should incorporate this additional data
with the information collected previously on each release location.
3 y this point in the process, the investigator should have all
additional information that was requested of the owner/operator
to facilitate determining the likelihood of a release.
3. .Determining the Likelihood of Release
The investigator should rely upon his/her best professional
judgment at the end of the RFA process to determine the likeli-
hood of release to all environmental media for all SWMUs and
other areas of concern. The VSI chapter described how the investi-
gator should make initial determinations of release at each SWMU,
group of SWMUs, or other potential areas of concern. The inves-
tigator will use the same basic judgment at the end of the SV;
the primary difference will be that there should be additional
information to support a determination after conducting the SV.
The investigator should determine the likelihood that a SWMU
has released by evaluating evidence collected in the RFA. In
some cases, the investigator will have direct evidence of a
release, which will provide the strongest support for a determi-
nation. In most cases, the investigator will be required to make
deductions from indirect evidence about the likelihood of release.
As stated previously, the strength of these deductions will
depend upon the quality of the waste information, the extent to
which the pollutant migration pathways have been characterized,
and the quality of the environmental sampling results and visual
observat ions.
The level of evidence needed to support a determination will
vary on a case-by-case basis, depending upon the cooperativeness
of the owner/operator, the EPA objectives- at the facility, and
the complexity of the facility. In general, it will be sufficient
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to identify one constituent that is present in both a SMWU and in
the migration pathway to support a release determination.
The investigator does not need to demonstrate with statistical
confidence that the SWMU has released during the RFA.
B. Making Recommendations for Each SWMU or Group of SWMUs
The final step in the RFA will entail making recommendations
concerning the need for further investigations under the corrective
action authority, based upon the release determinations described
above. This section describes each of the four possible recommen-
dations below: no further investigation, investigate further in
an RFI, plan and implement interim corrective measures, and refer
the control of a permitted release to another environmental
program office.
1. No Further Investigation
Investigators may conclude that a SWMU, a grouping of SWMUs,
3>~ an entire facility does not require further investigation
based on the information available from the PR and a visual in-
spection. In some cases it will be advisable to collect some
5 a "i p 1 i n g and analytical data to confirm that a unit or area has
not created a release that poses a threat to human health and the
environment. For many SWMUs, the determination that no furth-er
investigation is necessary will be relatively simple and straight-
f o r w'a r d .
Some units will have design and operating characteristics
which will effectively prevent releases to the environment. For
example, a wastewater treatment unit may have a cover to prevent
the release of VOCs to the air; such a unit would not require
further investigation for air releases.
SWMUs which never contained constituents of concern will
not require further investigation.
It is also appropriate to eliminate certain units from
further study on the basis that they clearly have not released
hazardous wastes or constituents into the environment. Examples
of such units include elevated tanks and, in some cases, surface
level storage tanks. In the case of aboveground tanks, unit
design and operation, plus the inspector's direct knowledge of
the facility, can provide sound evidence that the unit has not
caused a significant release. It will rarely be possible to make
such determinations for landfills and surface impoundments. More
explicit information as to making a "no further action" determina-
tion is presented in the media-specific chapters.
4-16
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d6<>2.005
2. Investigate Releases Further in
a RCRA Remedial Investi gati on
The investigator should recommend that a SWMU or other
release be investigated further in an RFI when he/she identifies
a SWMU with a likelihood (or documented evidence) of a release
which may pose a potential threat to human health and the environ-
ment. He/she should describe each SMWU and the relevant environ-
mental media which should be investigated in the RFI. It will be
important in focusing the RFI to determine which media are of
concern for each SWMU or potential release.
There are situations where the facility as a whole poses a
problem and where it is difficult to distinguish between individ-
ual SWMUs as sources of contamination. In these cases, it may be
more efficient to refer the entire facility to the RFI and require
the owner/operator to investigate the facility as a whole.
3. Adopt Interim Measures
The RFA should result in a recommendation to adopt interim
HP asures at the facility when the investigator believes immediate
action should he taken to protect human health or the environment
c r o n releases. The investigator should evaluate the severity of
the release and the proximity of potential receptors when assessing
the need for interim corrective measures.
.'Temporary corrective measures may be appropriate in situa-
tions where there is a release of hazardous wastes or constituents
into the environment that is currently affecting or.will affect
target populations or sensitive environments and the release may
be temporarily or permanently arrested by some type of interim
solution.
The RCRA §3008(h) Corrective Action Orders Interim Measures
Gui dance (draft) provides details on appropriate actions to take
in situations where immediate action is needed. Examples of
interim measures include: fencing a facility in order to prevent
direct contact with wastes; or stabilizing weak dikes to prevent
further surface water releases from impoundments. It is important
that these units should be investigated further in an RFI in order
to determine the adequacy of the interim measure and/or to design
a permanent solution.
4. Refer Permitted Release to Other Program Offices
Permitted releases which may either directly or indirectly
be posing a threat to human health or the environment should be
referred to the State or Federal program office that issued the
permit. EPA has not developed guide-lines on such referrals, thus
they should be conducted as necessary on a case-by-case basis.
Uhen the other program office cannot or will not investigate or
control the release, the investigator may recommend that the
units be investigated in an RFI and/or that interim measures be
initiated.
4-17
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When the RFA identifies contamination resulting from permit-
ted discharges or discharges requiring permits that require
further investigation in an RFI, EPA will work on a case-by-case
basis with the Regions and other EPA permit programs to develop a
solution to the contamination resulting from the discharges. For
example, when frequent violations of NPOES permits in the past
have resulted in an accumulation of hazardous materials in stream
sediments, the RCRA investigator should work with the NPDES auth-
ority to develop a solution to the contamination.
VI. FINAL RFA PRODUCT
The final RFA report will document the activities undertaken
in the PR, VSI, and SV. Many documents will be generated during
the SV, including a sampling plan, safety plan, sampling results,
an evaluation of the sampling results, and release determinations
aid recommendations for each unit. All of this information
should be compiled into the RFA report for future reference
during further phases of the corrective action program. Appen-
1ix A provides a sample outline for the RFA report.
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,.-_:< I" lil.iv. i -
CHAPTER FIVE 9502.00"5
GROUND WATER
I. INTRODUCTION
A. Purpose
This chapter provides technical information to support the
investigation of releases to ground water, with the exception of
releases from regulated units, during the RFA. While Chapters Two
through Four provide general guidance on conducting an RFA, this
chapter focuses on specific factors unique to the ground-water
medium that should be considered by the investigator.
q Icope
The scope of the RFA, discussed in Chapter One, extends to
all operating, closed, or closing RCRA facilities. The investi-
gator should evaluate the likelihood that a facility may have
releases to the ground water, with the exception of "regulated
units" (land disposal units that received wastes after July 26,
1932). Releases to ground water from regulated units should be
addressed in permits according to the requirements of Subpart F
of Part 264 (or corresponding State regulations), rather than
through §3004(u). The investigation of ground-water contamina-
tion from regulated un i t s wi-1 1 not be part of the RFA.
It is not the purpose of the RFA to install Subpart F mon-
toring wells in order to detect conclusively the presence of a
release. It will usually be sufficient to demonstrate that there
is a likelihood of release from a specific unit to the ground
water in order to require further investigations. The investi-
gator should rely upon best professional judgment when estab-
lishing evidence of release to ground water.
This chapter is organized to reflect the separate phases of
the RFA process. The first section describes the technical
factors that should be considered during the PR and VSI. The
second section describes the technical approach to obtaining
additional sampling information in the SV for ground water, and
should be consulted along with Chapter Three on conducting a
sampling visit. The final section discusses factors to consider
when making release determinations for ground water at the end of
the RFA. This section also presents options for further investi-
gation of ground-water releases to be evaluated at the end of the
RFA.
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II. CONDUCTING A PRELIMINARY REVIEW AND VISUAL SITE
INSPECTION OF GROUND-WATER RELEASE POTENTIAL
This section presents technical information related specif-
ically to the ground-water pathway to be considered when conduct-
ing the preliminary review and visual site inspection. Accordingly,
this section is organized to reflect the primary goals of the PR
and VSI described in Chapters Two and Three:
o Identifying and describing potential threats to ground
water at RCRA facilities; and
o Making a preliminary assessment of the need for further
investigations at these facilities.
This section reflects the importance of the five categories
of information to consider in conducting RFAs presented in Exhibit
1-1. It presents technical information specific to the ground-
water pathway covering the five areas and technical information
to help the investigator determine when additional sampling will
^e necessary in an SV to identify ground-water releases. The
section discusses each area separately:
' 1 ) Unit characteristics;
(2) Waste characteristics;
(3) Pol 1utant .migration pathways;
(4) Evidence of release;
(5) Exposure potential; and
(6) Determining the need for additional sampling information
This information will be relevant to the evaluation of
written documents in the PR and information gathered in a VSI.
Consult Chapters Two and Three for general guidance on how to
conduct PRs and VSIs.
A. Unit Characteristics
The design and operating characteristics of a unit will
determine to a great extent its potential for releasing hazardous
constituents to ground water. Many treatment, storage, and
disposal units are designed to prevent releases to the environ-
ment. The investigator should evaluate the unit characteristics
of ench SMWU or group of SWMUs at a facility to determine its
potential for releasing hazardous constituents to ground water.
The: general potential for ground water contamination from
any unit depends, to a great extent, upon its nature and function.
This concept is reflected in RCRA hazardous waste regulations.
For example, ground water monitoring is not a requirement for
5-2
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DIRECTIVE NO.
container storage units, while monitoring is required ToV
based units. Therefore, in evaluating the likelihood of ground-
water releases from a unit, the investigator should assess each
unit based upon:
o An understanding of the overall potential of the unit
to cause ground water releases;
o An understanding of the primary mechanisms by which
releases may occur from the unit; and
o An assessment of unit-specific factors which, singularly
or in combination, indicate the relative likelihood of
ground water releases from the unit.
The investigator should first consider the relative potential
of the unit to release. Exhibit 5-1 presents a generalized rank-
ing, in rough descending order, of different types of units and
their overall potential for causing ground-water contamination.
It lists the most common mechanisms by which ground-water releases
can occur from each unit type.
Exhibit 5-1 provides only a very theoretical sense of the
potential for units to cause ground water releases.
/net he r
cul ar
unit
relative potential ror units to cause ground water release1
Unit-specific factors should be evaluated in determining wl
further ground water investigations are needed for a parti*
The fol-lowing unit-specific factors should .be evaluated in,.
assessing a SWMU for ground water release's:
(1) Unit design;
(2) Operational history; and
(3) Physical integrity of the unit.
In making a unit assessment, the investigator should consider
ways in which the above factors may combine to suggest whether or
not releases have occurred. For example, examination of an above-
ground tank may reveal evidence of soil contamination adjacent to
the unit. However, the operational history of the unit reveals
that the tank has been in operation for only six months, the tank
is in good condition, and records indicate that the contamination
occurred as a single, relatively small overflow event. Considera-
tion of all of these factors indicates that, despite the evidence
of soil contamination, likelihood of a release to ground water is
very remote,1 and further remedial investigations for ground water
may not be necessary. The factors listed above are discussed in
more detail below.
5-3
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EXHIBIT 5-1
RANKING OF UNIT POTENTIAL FOR GROUND WATER
RELEASES AND MECHANISMS OF RELEASE
Unit Type
Release Mechanism
Class IV Injection
Wei 1
Surface Impoundment
Land Treatment Unit
Underground Tank
Waste Pile
Class I Injection
Wei 1
Spillage or other releases from waste
handling operations at the well head
Escape of wastes from well casing
Wastes are injected directly into the
subsu rface
Migration of wastes/constituents through
liners (if present) and soils
Damage to liners
Overflow events and other spillage outside
the impoundment
Seepage through dikes to surface and/or
subsurface
Migration of leachate through liners
(i f present) and soi1s
Precipitation runoff to surrounding
surface and subsurface
Spills and other releases outside the
containment area from 1 oadi ng/u'nl oadi ng
operat ions
Migration of constituents through the
unsaturated zone
Precipitation runoff to surrounding
surface and subsurface
o Tank she!1 failure
o Leaks from piping and ancillary equipment
o Spillage from coupling/uncoupling
operations
o Overf1ow
o Leachate migration through liner
(i f present) and soils
o Precipitation runoff to surface/subsurface
o Spillage or other releases fron waste
handling operations at the well he?d
o Escape of wastes frcm well casingi
o Migration of wastes from the injection zone
through- confining geologic strata to upper
aquifers
5-4
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ruuuT uIRKTIVE NO.
EXHIBIT 5-1 (Continued) 9 50 2 . 00- 5
RANKING OF UNIT POTENTIAL FOR GROUND WATER
RELEASES AND MECHANISMS OF RELEASE
Unit Type
Release Mechanism
In-ground Tanks
Container Storage
Unit
Above Ground Tank
Inci nerator
o Overflow
o Tank wall failure
o Leaks from ancillary equipment
o Spillage from coupling/uncoupling operations
o Spills from containers/container failure
subsequent migration through liner or base
(i f any) and soils
o Precipitation runoff from storage areas
o 0ve rf1ow
o Shell failure/corrosion
o Leaks from ancillary equipment
o Coupling/uncoupling operations
o Spillage or other releases from waste
handling or preparation activities
o Spills due to mechanical failure
5-5
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1. Unit Design
Evaluation of the unit's design should focus on the following
areas:
o The unit's capacity and dimensions;
o Materials, design, and construction of a unit;
o Any engineered features designed to prevent
releases to ground water; and
o The adequacy of such features.
The capacity and dimensions of a unit affect the potential
for a release in several ways depending upon the unit type. A
large volume, shallow surface impoundment is more likely to have
a release than a smaller capacity unit. The shallow depth with
the large volume indicates that there is a large surface area on
the bottom of the impoundment. Most releases occur through the
bottom by exfiltration through a clay liner or through leaks in a
synthetic liner. The larger the bottom surface, the greater the
1 i < 5 1 i h o o d that bottom leaks or exfiltration will occur.
Some units have engineered features that will reduce the
potential for a release to ground water. Landfills with double
liners and a leachate collection system will be much less likely
to have a release to ground water than do either land-based units
without liners' or with single clay li-ners. Some features in--
stalled to prevent 'ground water releases have different abilities
to do so effectively. For example, single clay liners do. not
prevent releases, but they delay the movement of leachate through
the less permeable clay layers.
2 . Operational History
During the PR, the investigator should evaluate the unit's
operational history for information that indicates a release to
ground water may have occurred. Operational factors that may
influence the likelihood of ground water releases include:
o Service life of the unit. Units that have been managing
wastes for long periods of time usually have a greater
likelihood of releases than units that have been opera-
ting for short periods of time. For example, an under-
ground tank that has been in service for six months will
have a much smaller likelihood of leakage due to corrosion
than will a twenty-year old underground tank.
o Operational status. In some cases, the operational
status of a- storage unit (e.g.,. closed, inactive, decom-
missioned) may have an effect on the relative likelihood
of a ground water release.
5-6
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UO..UT rUUUT UIKtUIVt INU.
a Operating procedures. Proper mai ntenanc*! p re^ul aQOifis-T>ec-
tions, and procedures for ensuring waste compatibility
with the unit may indicate that a unit is unlikely to have
released (this is particularly true for storage units
such as tanks and container storage areas). Evidence of
good operational practices may be available from owner/
operator records, and/or visual observation or historical
inspection reports. Conversely, poor operating practices
(e.g., underground tanks that are never leak tested or
inspected internally, storage of open containers of
wastes) may indicate relatively greater potential for
ground water releases.
3. Physical Integrity of Unit
During the VSI, the investigator should examine the physical
condition of the unit for indications of releases that may contami-
nate ground water. Deterioration of above-ground tanks should
reveal obvious signs of rust, corrosion and spills. Records of
recent leak inspections may also be available for both above and
below ground tanks, and these should be reviewed as part of the
r-\ f-j
It is likely to be difficult to evaluate the physical integ-
rity of many land-based units. However, dikes around surface
impoundments may show signs such as crumbling, slumping, and
infiltration around the toe, suggesting that the integrity of the
impoundment is questionable. In general, the investigator can
assume that most unlined landfills and surface impoundments have"
leaked to ground water.
8 . Waste Characteristics
The investigator should attempt to identify the wastes
handled at a facility and originally contained within a SWMU or
group of SWMUs during the PR. In the PR, the investigator will
try to connect information on waste types, hydrogeologic charac-
teristics, and ground-water contamination to determine whether
or not a SWMU, or group of SWMUs, or other areas of concern at
RCRA facilities have released constituents to "the ground water.
This section describes technical factors to consider when identi-
fying waste characteristics relevant to ground-water releases.
It also discusses physical/chemical properties that will affect
the release potential of wastes and their subsequent transport in
ground water.
The tendency for different hazardous constituents to migrate
from a given unit or area, through the unsaturated zone, and into
the ground water, will depend upon: the amount of waste present,
its.physical state.(i.e., liquid or solid), and the physical and
chemical properties of the constituents and the geologic materials.
Many of the constituents in Appendix VIII are essentially insol-
uble in water (at neutral pH) and/or bind tightly to soil par-
ticles, reducing" their tendency to migrate in ground water. The
5-7
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investigator should consider the potential mobility of the wastes
in a, unit, in combination with previously described unit-specific
factors, when assessing the likelihood of release.
The mobility of organic constituents can be expressed quan-
titatively by the sorption equilibrium coefficient (K
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S502.00-5 -
judgment and standard geologic and hydrogeologic principles,
consulting the information sources discussed in Chapter Two on
the subsurface characteristics of the site.
In cases where the investigator finds little direct evidence
that a particular unit had a release to ground water (e.g.,
documented evidence of a substantial tank leak), he/she may have
to deduce the likelihood of release from a facility by linking in-
formation on wastes, units comprising the facility characteristics
of the pollutant migration pathway, and evidence of ground-water
contamination located in this migration pathway. This demonstra-
tion will depend primarily upon an adequate characterization of the
direction and rate of ground-water flow at the facility.
The investigator may choose to recommend more detailed or
immediate investigations at the end of the RFA for facilities
with particularly vulnerable ground water (e.g., shallow sand and
gravel a q u i f a r s ) . More definitive guidance on evaluating the
vulnerability of ground water is contained in the criteria for
determining ground water vulnerability which OSW released in July
1986, [Interim Final, July 31, 1986 "Criteria for Identifying
^ r e a s of Vulnerable Hydrogeology."] This guidance may be helpful
in situations where a more complete understanding of ground water
vulnerability would assist in making the necessary determinations
in the RFA for a faci1i ty.
The ground water regime of the facility should be evaluated
for other potent i a.l -mi grat i on paths.. For example, ground water
often recharges surface water.bodies. Locating ground-water
discharge points may be important when identifying the potential
for surface water releases resulting from contaminated ground water,
Evaluation of the ground-water pollutant migration pathway
may also include evaluating any existing ground-water monitoring
systems at the facility which may be capable of detecting releases.
If it appears that an existing monitoring system may provide
information on continuing releases at the facility, it may be
necessary to evaluate its technical adequacy. Procedures for
examining the technical adequacy of existing monitoring wells are
described in Section III of this chapter.
When the investigator determines that an existing ground-
water monitoring system and the sampling and analysis program are
adequate to detect releases to ground water, and analytical data
(e.g., within the past year) indicate that there is no release,
it may not be necessary to investigate the unit or facility
f u rt her .
0. Evidence of Release
' * ".,-'
The investigator should examine any available sources of
information to identify evidence that constituents have been
released to the ground water at a facility. The investigator
should evaluate b'oth direct and indirect evidence of release
5-9
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during the PR and VSI. General considerations on how to look for
evidence of release are discussed in Chapters Two and Three.
Direct evidence of release to ground water may include
official reports of prior release incidents, such as a major tank
car spill to the ground or documentation that a surface impoundment
has released to ground water (e.g., some states used to permit
releases to ground water through their NPOES permitting process).
Indirect evidence of a release from the facility or a specific
unit at the facility will usually entail information on general
ground-water contamination. When the investigator identifies
indirect evidence of a SWMU release of this type, it may be
necessary to determine which SWMUs are likely to have released
the relevant constituents by evaluating the pollutant migration
pathways (hydrogeologic characteristics) and the waste character-
istics at the facility, as discussed previously.
VSIs may detect releases to other media, particularly soils,
that may indicate a high probability that contaminants have
migrated to the ground water. Evidence of soil contamination,
either through visual or sampling data, can provide an indication
that a release to ground water has occurred.
At some facilities, ground-water sampling data may be
available from wells at the facility, off-site wells, or from a
spring near the faci-lity. Other facilities may have no ground-
water monitoring information relevant to the overall facility.
At these -faci.l i t i es , the investigator should consi der. avai 1 ab.l e .
data on soil contamination or results of soil gas monitoring.
Electromagnetic conductivity surveys may provide evidence of
release for ionic species.
At facilities with ground-water monitoring data, these data
may indicate that hazardous constituents could have migrated from
the facility. However, the investigator will still need to eval-
uate the facility's units, waste, and migration pathway charac-
teristics, in order to support the possibility that the consti-
tuents originated from SWMUs at the facility.
E. Exposure Potential
The investigator should evaluate available information on
the location, number, and characteristics of potential receptors
that could be affected by ground-water releases at the facility.
These receptors include human populations, animal populations
(particularly any endangered or protected species), and sensitive
envi ronments .
Exposure potential information will be used primarily in
helping the i nvestfgartor determi rte th-e need for in-terint corrective
measures at the facility in order to address instances of ground-
water contamination posing especially high risks of exposure.
Types of exposure, information of concern include:
5-10
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w i *y
9502. 00-'"
o The proximity of the unit/facility to downgradient <-*
drinking water and irrigation wells;
o The potential for use of the aquifer as a drinking water
source; and
o The potential effect of aquifer discharges to nearby
surface water.
F . Determining the Need for Additional Sampling Information
The investigator may not be able to determine whether a
ground-water release from a unit/facility has occurred or is
likely to have occurred based upon existing data and the factors
described previously. In these situations, he/she should consider
whether conducting a sampling visit to obtain additional evidence
and fill data gaps will be needed in making a determination. In
this section, we present:
1) General information on factors to consider in determining
the need for additional sampling information;
?.} Factors to consider in selecting sampling parameters; and
3) An example to illustrate this discussion.
1. General Information on Determining the Need for Sampling
. At some facilities existing monitoring wells may be present
which could detect contamination from SWMUs at the facility.
Existing analytical data from such wells may, however, be inadequate
or unreliable. In such situations, new analytical data may be
useful in making release determinations. The following list
presents situations where additional sampling data could be
helpful in determining if a release has occurred:
o Available data are outdated, generally when data are
over one year old;
o The analytical methods used were inappropriate,
particularly if methods with very high detection levels
that may obscure significant releases were used;
o QA/QC was of unknown levels or non-existent;
o QA/QC information available (e.g. contaminated field/
trip blanks) suggests that available data may be invalid;
o The parameters monitored do not correspond to the waste
constituents suspected from the release, due to factors
such as quantity and mobility. For example, GC/MS
priority pollutant scans are available to detect a
'release of those chemicals, however, the waste contains
metal 1ic-cyanides and there is no data on either metals
or cyanide in the available sampling data;
5-11
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The available data are not of a rigorous QA/QC level or
may be questioned for other reasons, and it is anticipated
that the facility will challenge any permit condition or
enforcement order requiring an RFI; and
The available data are based on samples taken from
wells which were not adequately oriented to detect a
release from a specific unit and better wells have
since been installed or located but not sampled. It is
not routine to require that wells be installed during
an RFA.
2. Selection of Sampling Parameters
Knowledge of the wastes that may be potentially released
from a unit is the starting point when identifying sampling
parameters. However, many facilities have incomplete or no data
on the wastes deposited over time. When little is known of the
wastes managed in the unit, gas chromotography/mass spectrometry
(GC/MS) scans of various constituent groups (e.g., volatiles) are
often a good starting point. Investigators should select the
parameters to be analyzed for based on the facility-specific
^formation available and on the investigator's professional
jjdg-nent.
When a waste source is hazardous due to EP Toxicity, the
metals of concern are: arsenic, barium, cadmium, chromium, lead,
mercury, selenium, and silver.
The volatile GC/MS scan identifies chemicals that are charac-
teristic of solvents and lighter petroleum products (e.g., gasoline
Many of these compounds are readily found in the environment from
releases from various waste sources. Because they are very vola-
tile, older wastes may no longer contain these constituents since
they may have been released by evaporation into the air. The
indicator parameter, TOX, identifies the presence of halogenated
organics. If TOX levels have been identified, a volatile scan
should be helpful in identifying the specific compound released.
Acid extractable compounds may be present in heavier petro-
leam feedstocks, and certain industrial processes (e.g., penta-
chlorophenol from wood preserving). Some compounds (e.g., phenol,
pentach1orophenol , 2-chlorophenol) are commonly found from many
waste sources including organic waste treatment sludges. Phenol
and the mono halogenated phenols biodegrade readily in most soil
and surface.water environments.
Base/neutral compound" can often be found in wastes from
industries such as organic chemicals, plastics, and synthetic
fibers manufacturers. The pesticide scan identifies pesticides
that are found specifically in pesticide wastes and products from
the agrichemical industry.
5-12
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OSWER POLICY DIRECTIVE NO.
3. Example $502*00-5
An illustration of a situation in which sampling would be
called for is as follows: An unlined surface impoundment, con-
structed twenty years ago from naturally occurring site material,
is located at a facility close to homes withdrawing water from
domestic wells. The onsite soils are toigh in clay content,
although they also contain abundant cobbles which would interfere
with adequate compaction.
The investigator determines that the impoundment has not
received any wastes in the last five years; however, the pre-
viously deposited waste material has never been removed. The
wastes are identified as unspecified waste oils from unknown
sources and wastes containing lead and cadmium. While monitoring
wells have been installed, the monitoring data collected from
them only measure indicator parameters (e.g., pH, conductivity,
TOX and TOC). On.ly one parameter (TOC) showed an increase over
background. In addition, State sampling data from off-site
domestic wells detected significantly elevated levels of lead and
copper. However, the sampling protocol collected samples directly
" r o Ti the resident's tap, making it possible that the contamination
DM'ginated in the domestic plumbing system.
Because of the unit's design, construction method, and age,
the investigator may strongly suspect that a release has occurred.
While monitoring data exist, indicator parameters are not ade-
quate to identify potential releases of heavy metals. The one
elevated parameter, TOC, suggests that organics may have been
released from the oily wastes. However, 'elevated TOC values do
not conclusively indicate contamination from man-made sources,
and may result from natural sources.
In this scenario, the investigator should probably call for
additional ground-water sampling from existing wells to find
constituent-specific evidence of release not provided by the
indicator parameters. He/she would probably sample both on-site
and off-site wells for lead, cadmium, acid extractables, and the
base/neutral priority pollutants.
The acid extractables and base/neutral priority pollutant
scans would be appropriate since they can identify many of the
constituents commonly found in petroleum oil based wastes
(especially since the composition of the wastes was largely
unknown). While it might be possible to identify other constit-
uents at the site (e.g., VOCs), the investigator would probably
limit the sampling parameters to those most likely to be present.
Because of the high cost and delay associated with analyzing
sampling results, the investigator should attempt to limit the
selection of sampling parameters to those most likely to result
in- an fdent'i'fTeati'on of a release from.
5-13
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III. COLLECTING ADDITIONAL SAMPLING INFORMATION IN THE SV
This section presents technical information related specific-
ally to the ground-water pathway to be considered when collecting
additional sampling information in the SV. The information
presented here should be used to help the investigator meet one
of the primary goals of the SV:
o To collect additional sampling information to fill data
gaps identified in the PR and VSI leading towards a
release determination.
For each sampling method discussed, this section describes:
1) the general kinds of situations in which it will be appropriate
to employ a specific technique, 2) technical information on how
to conduct the sampling, and 3) specific details to be considered
when evaluating the sampling results. We do not provide the
actual SOPs on the sampling techniques here, although we do
reference the relevant manuals.
The choice of appropriate sampling methods will have a large
inoact on the cost and usefulness of the SV. The investigator
should be confident when developing and reviewing the sampling
plan that the procedures chosen will meet the needs of the RFA,
while not resulting in the collection of unnecessary data. We
discuss the following five sampling methods which may be of use
when investigating ground-water releases in the RFA:
(1)' Sampling of existing ground-water monitoring wells.;
( 2 ) Soi1 sampli ng;
(3) Soil gas monitoring;
(4) Electromagnetic conductivity mapping;
(5) Sampling of domestic wells; and
(6) Installation and sampling of new ground-water
moni tori ng welIs.
A. Sampling of Existing Ground-Water Monitoring Wells
The investigator should sample existing ground-water moni-
toring wells when they may provide useful data on contamination
resulting from facility-wide releases. As discussed in the
previous section, the investigator may decide to sample wells
when the most recent data are outdated, when the laborat.ry
analysis procedures are unknown or questionable, or when the
sampling parameters were inadequate. The investigator may also
choose to sample existing weTTs to provide EPA with data of its
own when the only available data was collected by the owner/
operator.
5-14
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OSWER POLICY DIRECTIVE NO.
^J 2 .00-5 1
The procedures for sampling monitoring wells have been de-
scribed extensively in many available documents. The investigator
should rely upon his/her best professional judgment when collecting
samples at existing wells. Well configurations at SWMUs should
be adequate to detect releases from these units. Before collecting
additional information, the investigator should ascertain the
adequacy of an existing monitoring system. He/she should evaluate
the locations of wells in relation to the specific SWMUs or other
areas of concern. In many cases, a facility's monitoring wells
will have been installed to detect contamination resulting from
regulated units, and will not pick up releases from other units
or areas of concern. Exhibit 5-2 depicts three examples of moni-
toring well systems, one that would be adequate for detecting
SWMU releases and two that would be inadequate.
After assessing the adequacy of well locations, the investi-
gator should evaluate data on well construction and design in
order to determine its adequacy. While data from properly con-
structed wells nay be of higher quality, it will not be necessary
to ensure that existing wells meet the stringent requirements
discussed in the RCRA Ground-water Monitoring Enforcement Guidance:
?C9A G round-wate r Mo n i t o r in g Technical Enforcement Gui dance
document (TEGO).The investigator should use best professional
judgment in evaluating sampling data based upon the quality of
the existing wel1s.
Sampling of ground-water monitoring wells in the RFA should
be conducted by trained pe r'so-nn-el . EPA h'as developed numerous
guidance manuals on appropriate sampling procedures. These
manuals may be consulted for specific field procedures:
o Ground Water Technical Enforcement Guidance Document
Draft, August 1985
o RCRA Draft Permit Writer's Manual; Ground-Water
Protection, October 1983
o Manual for Ground-Water Qua!ity Sampling Procedures,
1981
o Revised Draft Protocol for Ground-Water Inspections
at Hazardous Waste Treatment, Storage and Disposal
Faci1iti es , October 1985
The investigator should refer to Chapter Four for specific
recommendations on QA/QC, chain-of-custody, safety, and
decontamination procedures to be followed in the field. In
general, the OA/QC and sampling procedures followed by the
investigator should be appropriate to the intended use of the
data. For example, if the investigator anticipates that the
owner/operator may contest EPArs sampling results in court, it
would be advisable to use more stringent procedures.
5-15
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vfc.,cx ruUCY DIRECTIVE NO.
950 2 . 00- «=» -
The investigator should use best professional judgment rn **
evaluating sampling results collected in the SV, based upon
sound geologic and hydrogeologic principles. General guidance
on evaluting sampling results is presented in Chapter Four.
B. Soil Sampling
The investigator may choose to sample soils at the facility
in order to gain an understanding of the likelihood of a release
to ground water. Many constituents, when released to soils, will
further migrate into the surficial aquifer. The potential for
migration to the ground water will depend upon the properties of
the relevant constituents and the site geology (this is discussed
in greater detail in Section II of this chapter). Soil sampling
will be especially useful in situations where a facility lacks
ground-water monitoring data or the ground water is deep.
Sampling locations should be chosen to provide the most useful
information. For example, the investigator may want to determine
whether constituents have migrated from a closed surface impoundment.
Stratified sampling around the unit, and where possible, underneath
1 'n e unit, may be helpful in detecting constituent concentration
gradients indicative of migration. In other cases, the investigator
may simply wish to confirm that a release incident occurred, such
as a spill, by sampling the location where the suspected incident
took place. Technical details on how to sample soils is provided
in Chapter Eight of this guidance.
C. Soil Gas Monitoring " *
Soil gas m'oni tori ng' can be used .to detect the presence of
volatile organic compounds (VOC's) in ground water and will be
especially useful in cases where existing ground-water monitoring
systems are inadequate to detect these contaminants. This tech-
nique, developed and used extensively by EPA's Environmental
Response Team (ERT), detects the presence of VOC's in the unsat-
urated zone and provides a good indication of subsurface soil
and/or groundwater contamination. In -addition, this method can
provide same-day results during a field investigation and will
cost substantially less per sample than well drilling and GC/MS
analysi s .
Soil gas monitoring should be performed by trained personnel.
The following document describes in detail standard procedures
for conducting soil gas monitoring at waste sites:
Lappala, E and G. Thompson, "Detection of Ground-Water Con-
tamination by Shallow Soil Gas Sampling in the Vadose Zone
Theory and Applications." Proceedings of the Fifth National
Conference on Management of Uncontrolled Hazardous Waste
Sites-, Washington, D.C.,
5-17
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The following description of soil gas monitoring procedures
is intended to assist the permit writer in recognizing those
situations where its use would be appropriate, and to enable
him/her to oversee its implementation by a contractor or the
owner/operator.
When ground water or soils have been contaminated by VOC's,
gaseous components of these compounds will be present in the
interstitial pore spaces of the soil matrix, and are known as
soil gas. By sampling the gas in this interstitial space and
analyzing it for VOC's with a portable gas chromatograph in the
field or in the laboratory with a GC/MS, the presence of soil
and/or ground-water contaminants can be indicated.
First, the investigator must make a vertical hole in the
soil through which the gas samples can be drawn. A hole can be
made to a depth of five feet with a solid spring steel single
piston slarn bar (1.75m x 16.7 mm diameter). Threaded four foot
sections can be added to the slam bar when holes deeper than five
feet are desired.
After the hole has been made, the slam bar should be removed
carefully to prevent the walls of the hole from collapsing. The
investigator should then insert a stainless steel sampling tube
into the hole. In order to prevent soil from clogging the sam-
pling tube, a Teflon tube, slightly longer than the sampling
tube, should be inserted into the sampling tube. The.Tef1 on"tube
sho.uld be just wide enough to hold a small nail in its end, so
that the nail head is wide enough to cover the end of the'stain-
less steel sampling tube.
The sampling tube should be inserted into the hole, nail end
first; when the sampling tube has been inserted to the desired
depth, the Teflon tube can be removed, causing the nail to drop
to the bottom of the hole. The sampling tube should then be
removed 6 to 12 inches to ensure that soil gases will enter
freely. Finally, top dirt should be packed around the tube to
minimize iniltration of ambient air from the surface.
Soil gas will be pulled from the sample hole using a Gilian
pump. ERT recommends evacuating five to seven gas volumes prior
to sampling the hole. For a 1/4" hole about 10' deep and a
pumping rate of three 1iters/minute, this evacuation should take
about 15 seconds.
The gas in the well can be collected and sampled using three
different methods. The simplest involves attaching a portable
photoionization detector (e.g., Hnll) to the stainless steel tube,
using a short piece of Teflon tubing. The HnU provides indica-
tions of the total organic vapor concentration within the hole
calibrated to a benrene'' standard. This method does not provide
the investigator with information on individual compounds present
in the soil, but may provide a sufficient indication of contami-
nation to suggest the likehood of a release.
5-18
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The Hntl should be calibrated properly prior Yo
ground reading of 1 to 2 ppm (as benzene) may result from soil
moisture. Once the HnU reading has stabilized, usually after 45
to 60 seconds, the reading should be recorded.
Tedlar bags can also be used to collect soil gas for field
analysis with a portable photoionization gas chromatograph (e.g.,
Photovac) or laboratory analysis with a cryogenic trapping capil-
lary column gas chromatograph/mass spectrometer. The Tedlar bag
should be filled with about 200-700 ml of vapor from the borehole,
and analyzed within no more than 48 hours. This technique has
the advantage that individual compounds may be detected, provid-
ing more detailed sampling data during the SV. One disadvantage
involves uncertainties concerning the- interaction of the Tedlar
bag and the gas being collected. However, the quality of the
data will be higher than that obtained using an HnU.
The most accurate technique for sampling and analysis will
involve the use of sorbent tubes (e.g., Tenax, Chromosorb, etc.)
to collect gas samples for laboratory analysis by GC/MS. Because
contaminants collected on sorbent tubes maintain their integrity
for a longer period (14 days) than those collected with Tedlar
bags, i: ^ay be advantageous under some circumstances to use them
to collect soil gas samples. The chief disadvantage of this tech-
nique involves the necessity of analyzing the samples in a labora-
tory, adding time and expense to the monitoring procedure.
Soil gas monitoring can be effective in detecting VOC' s in
soil gas which have a vapor pressure ^greater th-an xylene (5 mm
Hg). Vapor pressures of anumber of constituents of concern-are
listed in Appendix E for further reference. This monitoring
technique does not provide a direct indication of the concentra-
tion of contaminants in ground water or soil. The relationship
between soil and ground-water concentrations and soil gas concen-
trations will depend greatly upon the organic content of the soil
and the octanol-water partition coefficient of the constituent of
concern. The technique will provide the investigator with evidence
of subsurface contamination, which will usually be sufficient to
indicate the need for an RFI at the locations of concern.
D . Electromagnetic Conductivity Mapping
Geophysical techniques have gained acceptability in the last
five years for the identification of waste releases to both ground
water and soils, as well as for the sensing of buried wastes.
This section briefly discusses one of these techniques, electro-
magnetic conductivity mapping (EM), which may be useful during
the RFA.
EM surveys can provide an indication of ground-water contam-
ination at sites with relatively simple, well-defined hydro-
geologies (e.g., shallow, relatively uniform sand and gravel
aquifers). This technique measures changes in the conductivity
of the subsurface materials at a site, which may depend upon the
5-19
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composition of the subsurface soils, and/or the presence of
dissolved contaminants in the ground water.
EM surveys provide iso-conductivity contours at a site,
indicating the movement of contaminants from a source. While
this technique does not provide information on either the types
of constituents present, or their concentrations, it can provide
indirect evidence of a release. However, it will primarily
indicate only the presence of ionic constitutents in ground water.
Conducting EM surveys requires qualified personnel and
expensive equipment, although it will be a relatively inexpensive
method when using experienced contractors in the SV. This section
does not provide technical information on how to perform an EM
survey.
The investigator should be cautious when evaluating the re-
sults of an EM survey, due to the potential for interference from
unusual geologic conditions at the site. Different geologic
materials have different conductivities (e.g., moist clays have a
higher conductivity than do dry sands). At facilities with
complex hydrogeologic characteristics, the results of EM surveys
could provide a false indication of contamination where non-homo-
geneities in the subsurface media reveal differences in conduc-
tivity. The difficulties associated with analyzing these data
represent the major drawback to using this technique.
'- -Sampling of Domestic Hells
In certain unusual cases, the investigator may choose to
sample domestic wells in order to identify releases from the
facility. This will be especially important when the investigator
believes that a contaminant plume originating at the facility
could pose an imminent threat to human health or the environment
near the facility. Sampling data taken from domestic wells could
provide sufficient evidence to suggest the need for immediate
interim corrective measures at a facility (e.g., such as counter-
pumping, or provision of an alternate drinking water supply).
Sampling residential water supplies could alarm affected
residents. Because of this potential for community reaction,
domestic wells should only be sampled when the investigator has
strong evidence to suggest the presence of a threat.
When sampling domestic wells, it is important to run the
water to remove any standing water within the distribution system.
It is also important to take the samples prior to any in line
treatment sys .ems (e.g., water softeners).
F . Installation Of New Monitoring Wells
In unusual situations, EPA may find that new monitoring
wells should be installed during the RFA in order to obtain
useful ground-water data. While this should not be necessary at
5-20
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DIRECTIVE MO.
9502.00-
most facilities* it may be appropriate where ground-water data
are wholly inadequate, where other sampling techniques do not
provide sufficient information on the site, or if the owner/operator
is recalcitrant and the investigator suspects that a release has
occurred .
In most cases such as that presented above, the investigator
should rely upon information collected during the RFA to demon-
strate that a release may have occurred, and recommend that the
facility conduct an RFI. However, this may not be possible when
dealing with recalcitrant owner/operators. As a last resort,
the investigator can recommend that new wells be installed.
Procedures for installing new wells should be based upon
accepted hydrogeol ogi c principles and best professional judgment.
New wells should conform to standards described in the TEGO or
Subpart F. Their locations should be chosen based on knowledge
of site hydrogeology a^d best professional judgment.
IV. MAKING GROUND-WATER RELEASE DETERMINATIONS
The final task in the RFA process is to make determinations
of release potential throughout the facility and to make recommen-
dations for further action to address these potential releases.
In making release determinations, investigators should evaluate
the relevant information on unit characteristics, waste charac-
teristics, site hydrogeology, and any evi dence' avai 1 abl e from
sampling and analytical data. Potential for exposure of receptors-
to contaminated ground water may also be a consideration in making
conclusions for further action. If on the basis of the information
and evidence available to the investigator, and his/her best pro-
fessional judgment, it can be reasonably determined that there
is, or is likely to be, a release of wastes or hazardous constituents
to ground water which merits further investigation/characterization,
or an immediate interim remedy, the owner/operator should be
required in the RFI to conduct these necessary actions. It should
often be possible, from the information gathered in the RFA, to
be able to specify in some detail the nature of the investigations
to be conducted; i.e., the area to be given further subsurface
investigation, the constituents to be monitored for, the general
area to be monitored for, and other elements of the ground water
characterization program.
It should be understood that it is not necessary to prove in
an RFA that ground-water contamination has occurred from SWMUs at
a facility. Confirming the presence of a release will often be
the initial phase of a follow -on RFI investigation.
Exhibit 5-3 is. a checklist that should help the investigator
evaluate specific factors to identify ground water releases and
determine the relative effect on human health and the environment.
In identifying releases, the investigator should consider the
types of inform a't ion presented in Exhibit 1-1, which are high-
lighted in this checklist.
5-21
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Exhibit 5-3
Checklist for Ground Water Releases
Identifying Releases
1. Potential for Ground Water Releases
o Unit type and design
Does the unit type (e.g., land-based) indicate the
potential for release?
Does the unit have engineered structures (e.g.,
liners, leachate collection systems, proper
construction materials) designed to prevent
releases to ground water?
o Unit operation
Does the unit's age (e.g., old unit) or
operating status (e.g., inactive, active)
indicate the potential for release?
Does the unit have poor operating procedures
that increase the potential for release?
noes the unit have compliance problems that
. indicate the potential for a-release to
ground water?
o Physical condition
Ooes the unit's physical condition indicate the
potential for release (e.g., lack of structural
integrity, deteriorating liners, etc.)?
o Locational characteristics
Is the facility located on permeable soil
so the release could migrate through the
unsaturated soil zone?
Is the facility located in an arid area with less
infiltration of rainwater and therefore with less
potential for downward migration of any release?
Does the distance from a unit or area to the upper-
most aquifer indicate the potential for release
(e.g., the waste lies within the aquifier)?
Does the rate of ground water flow greatly
inhibit the migration of a release from the
facility?
Is the facility located in an area that recharges
surface water?
5-22
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Exhibit 5-3 (continued) OSWER POLICY DIHECTiYE MO.
Checklist for Ground Water Releases 950 2 . 00" 5
o Waste characteristics
Does the waste exhibit high or moderate character-
istics of mobility (e.g., tendency not to sorb to
soil particles or organic matter in the unsaturated
zone) ?
Does the waste exhibit high or moderate levels of
toxi ci ty?
Does the waste exhibit hazardous characteristics
(e.g., lower high p H ) ?
2. Evidence of Ground Water Releases
o Existing ground-water monitoring systems
Is there an existing system?
Is the system adequate? *
Are there recent analytical data that
i ndi cate a release?
o Other evidence of ground water releases.
Is there evidence of contamination around
the unit (e.g., discolored soils, lack of or
stressed vegetation) that indicates the
potential for a release to ground water?
Does local well water or spring water sampling
data indicate a release from a facility?
Determining the Relative Effect of the Release on Human
Health and the Environment
1. Exposure Potential
o Conditions that indicate potential exposure
Are there drinking water well(s) located near
the faci1i ty?
Does the direction of ground water flow
indicate the potential for hazardous consti-
tuents to migrate to drinking water wells?
Does the ground water discharge to a surface
water body with recreational use or that supports
fish or any endangered species?
5-23
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OSWER POLICY DIRECTIVE KO.
CHAPTER six 9502.00-5
SURFACE WATER
I. INTRODUCTION
A. Purpose
This chapter provides technical information to support the
investigation of SWMU and other releases to surface water during
the RFA. While Chapters Two, Three, and Four provide general
guidance on conducting RFAs, this chapter focuses on specific
factors unique to the surface water media that should be con-
sidered by the investigator.
This chapter has been organized to reflect the separate
phases of the RFA process:
o Conducting a preliminary review of existing information
related to releases to surface water;
o Inspecting the facility to obtain evidence of release;
o Collecting additional sampling information in the SV; and
o Making final release determinations.
The first section describes the technical factors that' should
be considered during the PR and VSI. The second section describes
the technical approach to obtaining additional sampli.ng information
in the SV for surface water, and should be consulted along with
Chapter Four on conducting a SV. The final section discusses
factors to consider when making release determinations to surface
water at the end of the RFA. This section also discusses the
options for further investigation to be evaluated at the end of
the RFA for surface water releases.
B. Scope
The investigator should evaluate all RCRA facilities for
releases to surface water that pose an actual or potential threat
to human helath and the environment. These releases may include
surface water discharges permitted or required to be permitted
under the NPDES program. In these cases, the investigator should
attempt to make an initial characterization of the potential
problem. However, he/she should usually refer the further inves-
tigation and control of these discharges to the NPDES permitting
authority, rather than addressing them through RCRA authorities
[§3008(h), §3004(u), or §3004(v)J. EPA is developing more specific
guidance'on how-to nrake these referrals.
-------
In most cases surface water investigations will relate to
run-off from specific SWMUs. However, there may be situations
where general facility run-off may be impacting human health and
the environment. The 3Q08(h) corrective action authority allows
the investigator to address these situations.
II. CONDUCTING A PRELIMINARY REVIEW AND VISUAL SITE
INSPECTION OF RELEASES TO SURFACE WATER
This section presents technical information related specifi-
cally to the surface water pathway to be considered when conduct-
ing the PR and VSI. Accordingly, this section has been organized
to reflect the primary goals of these steps as described in
Chapters Two and Three:
o Identifying and describing potential threats to surface
water at RCRA facilities; and
o Making a preliminary assessment of the need for a SV or
other actions at these facilities.
This section reflects the importance of the RFA information
matrix (Exhibit 1.1) for evaluating the likelihood of releases to
surface water in the PR. It describes each of the five types of
.information described in this matrix as it applies to the surface
,water pathway. In addition, this section provides technical
information to help the investigator determine when additional
sampling will be necessary in a SV to identi-fy surface water
releases. The factors discussed are as follows:
(1) Unit characteristics;
(2) Waste characteristics;
(3) Pollutant migration pathways;
(4) Evidence of release;
(5) Exposure potential; and
(6) Determining the need for additional sampling information
This information will be relevant to the evaluation of
written documents in the PR and information gathered during the
VSI. Consult Chapters Two and Three for general guidance on
conducting PAs and VSIs.
A. Unit Characteristics
The design and operating characteristics of a SMWU will
determine to a great extent its potential for releasing hazardous
constituents to surface water. Many treatment, storage, and
disposal units are designed to prevent releases to the environment
6-2
-------
^502.00-5
The investigator should evaluate the unit characteristics of each
SMWU or group of SWMUs at a facility to determine their potential
for releasing hazardous constituents to surf-ace water.
As with the other media, the likelihood that a SWMU has con-
taminated surface water or a surface water drainage pathway is
largely dependent on the nature and function of the unit. For
example, open units that contain liquids (e.g., surface impound-
ments) have a greater potential for release than closed landfill
cells that have been properly capped.
Exhibit 6-1 loosely ranks commonly observed SWMUs in a de-
scending order on the basis of their potential for having releases
that may cause surface water contamination. It is intended to
.provide a general sense of the relative potential for units to
cause these types of releases. The investigator will also need
to evaluate unit-specific factors in determining the potential
for release from a particular unit.
The major unit-specific factors the investigator should
evaluate are discussed below.
- Unit design
The investigator should determine whether the unit has
engineered features (e.g., run-off control systems) that are
designed to prevent releases from the unit. If such features
are jn place, the investigator should evaluate whether they are
adequate (in terms of capaci-ty, engineering, etc.) to prevent .
releases. A landfill, for example, may have berms to control
run-off, but the berms may not be adequate to contain run-off
dj^ing periods of peak rainfall. In addition, a surface impound-
ment or open tank with insufficient freeboard may not be able to
prevent overtopping that could occur because of wave action
during storm events.
2. Operational history
During the PR and VSI, the investigator should examine the
unit's operating history to obtain i nf ormat i orr -that indicates
releases have taken place. There are several operational factors
that influence the likelihood of release.
o Operating life of the unit. Units that have been operat-
ing for long periods of time are generally more likely to
have releases than new units.
o Operating status of the unit. In some cases, the operat-
ing status of a unit (e.g., closed, inactive, etc.) may
have an effect on the relative likelihood of release.
6-3
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EXHIBII 6-1
RANKING OF UNIT POTENTIAL FOR SURFACE WATER RELEASE
AND MECHANISMS OF RELEASE
Unit Type
Surface Impoundment
Landfi11
' J a s t e Pile
Land Treatment Unit
Container Storage
Area
Above-ground Tank
I n-ground Tank
I nci nerator
Class I and IV
Inject ion Well
Release Mechani sm*
o Releases from overtopping
o Seepage
o Migration of run-off outside the unit's
run-off collection and containment system
o Migration of spills and other releases
outside the containment area from
loading and unloading operations
o Seepage through dikes to surrounding
areas (e.g., soils, pavement, etc.)
o Migration of run-off outside the unit's
run-off collection and containment system
o Migration of spills and other releases
outside the containment area from
loading and unloading operations
o Migration of run-off outside the
containment area
o Migration of run-off outside the
containment area
o Releases from overflow
o Leaks through tank shell
o Spills from coupling/uncoupling
operations
o Releases from overflow
o Spills from coupling/uncoupling
operations
o Spills or other releases from waste
handling/preparation activities
o Spills due to mechanical failure
o Spills from waste handling opera-
ti ons at the we!1 head
* The two remaining solid waste management units; waste transfer
stations, and -waste recycling operations generally have mechanis!
of release similar to tanks. All units may release to ground
water when the surface water at the facility is hydrogeologica11y
connected to it.
6-4
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9502 00-^
o Operating procedures. Maintenance and inspection records
should 1ndlcate whether a unit is likely to have released.
Units that are inspected regularly and properly maintained
are less likely to have releases than units that have
been poorly maintained.
3. Physical condition of the unit
During the VSI, the investigator should examine the units
for evidence of releases or characteristics that could cause
releases. For example, when inspecting a surface impoundment,
the investigator should determine whether the earthen dikes are
structurally sound to prevent releases. Cracks, slumping or
seeps around the toe in these dikes may cause releases to the
surface water drainage pathway.
8. Waste Characteristics
The investigator should attempt to identify the wastes
originally contained within a SWMU or group of SWMUs during the
PR. In the PR, the investigator will try to connect information
on waste types, the surface water drainage pathway, and evidence
of surface water, sediment, or soil contamination to demonstrate
the likelihood that specific SWMUs, groups of SWMUs, or other
areas have released constituents to the surface water. This
section describes technical factors to consider when identifying
waste characteristics relevant to surface water releases. It
also discusses physical./chemical properties .that will affect the
release potential of wastes and their subsequent transport in'the
surface wat-er drainage pathway. '
Information on constituents and their properties can aid the
investigator in identifying migration pathways of concern and
sampling locations in environmental media. For example, knowing
that the waste primarily contains heavy metals, which have a ten-
dency to precipitate and settle, the investigator can look for
evidence of a release in the sediments around the point of dis-
charge into a river and plan on taking samples of the bottom
sedi ment.
Constituents, depending on their properties, will tend to
migrate in different forms and at different rates in the pathway.
Some constituents, which are highly soluble, will dissolve in
water and be transported within the water column. Insoluble
constituents can be transported into surface water by suspension
from turbulent run-on/run-off. Other generally insoluble waste
constituents are lighter than water and will be transported on
the surface, forming oily sheens. Hazardous metals and inor-
ganics (e.g., arsenic and cyanides) may be relatively mobile in
water, depending upon the pH of the wastes and the surface water,
the oxidation-reduction potential of the surface water (this
will be most important in the lower layers of deeper lakes), and
the ligands present for complex formation. Hard surface water,
6-5
-------
due to the presence of higher concentrations of carbonate ions,
will support the formation of relatively immobile metal complexes.
These metal complexes form precipitates, which will settle out
with sediment.
The tendency of organic constituents to adsorb to soils can
be expressed quantitatively by the sorption equilibrium coeffi-
cient (K(j). The value of K
-------
9502 . 00-5
deductions on the likelihood of release by linking information
on waste characteristics, the pollutant migration pathway, and
indirect evidence of release (e.g., environmental sampling data
showing contamination of surface water, soils in drainage pathways,
or stream sediments). It will be easier to demonstrate that a
contaminant originated at a particular SWMU when the investigator
can show that, based on the characteristics of the surface water
drainage pathway, a release from the particular SWMU would be
likely to result in the observed contamination.
In characterizing surface water release pathways, the invest-
igator should identify any drainage pathway(s) leading from
the unit of concern to surface water. Topographic maps provide
information on the slope of the intervening terrain between the
units of concern and downgradient surface water, which is helpful
in determining the route run-off follows to surface water. These
maps may also help in locating surface water bodies.
Upon entering surface water, the transport of the constituents
in the surface water pathway is highly dependent on the type of
surface water body. The three major classifications of surface
water are: rivers and streams, impoundments (e.g., lakes, bays,
etc.) and estuaries (including wetlands).
Contaminants entering rivers and streams will tend to be
transported downstream. However, as discussed earlier, heavy
metals.are likely to settle out with sediment. Also, VOCs entering
a turbulen-t stream may volatilize into the air.
Constituents entering impoundments or estuarine systems will
tend to pol-lute areas near their discharge points because these
water bodies are relatively slow moving and are not likely to
transport the constituents significant distances.
The investigator also should look for any effect that permit-
ted discharges (e.g., NPDES, dredge or fill) may have on environ-
mental pathways. For example, a NPDES discharge may be releasing
RCRA constituents not covered by the permit, causing downstream
contamination. In addition, the investigator should consider the
possibility that waste in NPDES units or in other permitted
discharges may be releasing to ground water or air.
Finally, the investigator should consider possible intermedia
transfers to surface water. He/she should consider the potential
for releases, from soil and/or ground water (ground water discharge)
to affect the surface water pathway.
In sum, the investigator should use his/her knowledge of the
constituents in the waste, the drainage patterns leading from the
unit to surface water, and the effect of different surface water
bodies on the transport of various constituents, to identify areas
to look for evidence of release. He/she should also use this
knowledge to specify appropriate sampling points.
6-7
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D. Evidence of Release
The investigator should examine any available sources of
information to identify evidence that constituents have been
released to the.surface water at a facility. The investigator
should evaluate both direct and indirect evidence of release
collected during the PR. General considerations on how to look
for evidence of release are discussed in Chapters Two and Three.
Direct evidence of release to surface water may include
official reports of prior release incidents, such as a major tank
car spill to the ground or documentation that a surface impound-
ment has released to surface water. Indirect evidence will
usually entail information from surface water quality monitoring
data, including visual observations of aquatic stress (e.g., fish
kills) from water contamination. When the investigator identifies
indirect evidence of this type, it may be necessary to determine
its source at the facility by evaluating the pollutant migration
pathways and the waste characteristics at the facility.
The investigator should examine available sources of infor-
mation and use recent visual observations obtained during a
site inspection to identify any evidence that hazardous constit-
uents have released from SWMUs at the facility to surface water.
NPDES files are particularly useful in identifying historical
releases to surface water or determining the likelihood of current
releases.. NPDES personnel that, are familiar 'with the facility can
often obtain information on past releases. Other key sources
of information include: RCRA inspection reports, CERCLA reports
(e;g., PA/SI), and discussions with the State agency responsible
for fisheries and wildlife management.
Due to the intermittent nature of many surface water releases,
the VSI is particularly important. The investigator should
examine the site and nearby surface water for physical evidence
of release and focus on trying to obtain evidence of releases in
areas between the unit and the closest surface water body. The
investigator should look for visible evidence of uncontrolled
run-off. If releases have occurred or are occurring at a unit,
there is likely to be evidence around the unit that indicates a
release is taking place. In addition, if the facility is located
adjacent to surface water, the investigator should examine the
surface water for evidence of releases. During the VSI, the
investigator should look for:
o Observable contaminated run-off or leachate seeps;
o Drainage patterns that indicate possible run-off from
units at the facility;
o Evidence of wash-outs or floods, such as highly eroded
soil, damaged trees, etc.;
6-8
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.CK POUCY D'srcrvs
950 2 . 00- S
o Discolored soil, standing water, or dead vegetation "
along drainage patterns leading from the unit;
o Discolored surface water, sediment or dead aquatic
vegetation ;
o Evidence of fish kills;
o Unpermitted point source discharges;
o Units (including old fill material that is now considered
hazardous waste) discharging in surface water; and
o Permitted discharges that are of concern, e.g., downstream
contamination resulting from permitted discharges;
release of RCRA constituents to surface water; NPDES
units/discharges causing contamination problems in other
media (e.g., air, ground water).
E . Exposure Potential
The investigator should evaluate available information on
the location, number, and characteristics of potential receptors
that could be affected by surface water releases at the facility.
These receptors include human populations, animal populations
(particularly any endangered or protected species), and sensitive
environments.
Potential receptor information will be used primarily in
helping the investigator determine the need for interim corrective
measures at the facility in order to address instances of surface
water contamination posing especially high risks of exposure.
The investigator should evaluate the likelihood for receptors
to be exposed to hazardous constituents through releases to
surface water in order to assess the severity of release. If
receptors are currently being exposed to a release or have a high
potential for being exposed, then the investigator should consider
recommending immediate corrective measures (e.g., run-off control
measures) to limit or eliminate exposure to the release.
The types of information that are useful in evaluating the
potential for human and environmental receptors to be exposed to
surface water releases are discussed below.
1 . Human receptors
Human receptors can be exposed to the release via their
use of surface water. The investigator should determine the use(s)
of the surface water body of concern (e.g., no use, commercial or
industrial, irrigation, fisheries, commercial food preparation,
recreation, or drinking). A release is more likely to signifi-
cantly impact human health if the surface water is being used as
a source of contact recreation (e.g., swimming) rather than being
6-9
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used for Industrial or a commercial purposes. Information on the
location of any drinking or irrigation water intakes is usually
listed in public records, which may be obtained from the local
health department.
2. Environmental receptors
Constituents in a release to surface water may contact sen-
sitive habitats (e.g., a highly productive biological community,
or a habitat of rare or endangered plants or animals). The
investigator should locate any sensitive habitats in the surface
water pathway. This information can generally be obtained by
talking with State Fish and Wildlife Management Agencies and
local environmental groups. In some cases, reports such as
environmental impact studies have been prepared for the area.
F. Determining the Need for Additional Sampling
In the surface water medium, investigators may often find
that existing data on a release from a unit is unavailable or
insufficient. In cases where historical information and visual
observations are not adequate to determine if a surface water
release from a unit has occurred or is likely to have occurred,
he/she should consider whether additional sampling and analysis
would help in making a determination. In this section, we
present:
o 'General information- on factors .to consider in deter- -
mining the need for additional sampling information;
o Factors to consider in selecting sampling parameters;
and
o An example to illustrate this discussion.
1. General Information on Determining The Need for Sampling
The following are example situations where additional analy-
tical data would be helpful in determining if a release has
occurred:
o During visual inspections, indirect evidence of a
release (e.g., oil slicks, foam) have been observed,
and chemical analysis may identify the unit causing
the release; and
o Existing surface ^ater monitoring data or available
information suggest a release, anc1 more data will
either confirm the release and/or identify the unit
of concern.
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950 2.00-5
2. Selection of Sampling Parameters
Knowledge of the wastes that may be potentially released
from a unit 1s the starting point when identifying sampling
parameters. However, many SWMUs have incomplete or no data on the
wastes deposited over time. When little is known of the wastes
managed in the unit, gas chromotography/mass spectrometry (GC/MS)
scans such as acid extractables or base/neutral extractables be-
come a good starting point when selecting parameters for analysis
in surface water and sediments.
When a waste source is hazardous due to EP Toxicity, the
metals of concern are arsenic, barium, cadmium, chromium, lead,
mercury, selenium, and silver. The following metals precipitate
readily under many naturally occurring conditions and can be
found in sediment analysis: cadmium, lead, nickel, and zinc.
The volatile GC/MS scan identifies chemicals that are charar-
teristic of solvents and lighter petroleum products (e.g., gaso-
line). Many of these compounds are readily found in the environ-
ment from releases from various waste sources. Because they are
very volatile, and surface water bodies (particularly rivers and
streams) have the capacity to release these constituents via
evaporation into the air, evidence of these chemicals may be very
difficult to obtain. It is not recommended to analyze surface
water bodies for these constituents unless a release is current
or on-going. Leachate samples and run-off,..if available, are
more ammenable to retaining evidence of volatile constituent
releases. ' . . _ .
Acid extractable compounds may be present in heavier petro-
leum feedstocks, and certain industrial processes (e.g., penta-
chlorophenol from wood preserving). Some of those compounds
(e.g., phenol, pentachlorophenol , 2-chlorophenol) are present in
common waste sources, including POTW discharges. Phenol and the
mono-halogenated phenols biodegrade readily in most soil and
surface water environments.
Base/neutral compounds can often be found in wastes from
industries such as plastics and synthetic fibers manufacturers.
The pesticide scan identifies pesticides that are found specif-
ically in pesticide wastes and products from the agrichemical
i ndustry.
When collecting surface water and sediment samples, it may
be valuable'to sample an up-stream site for the same chemical
parameters that will be analysed in the area of the suspected
release. There will often be a high potential for other waste
sources (e.g., POTWs, industrial NPDES discharges) to contaminate
surface waters with the same constituents under investigation in
the RFA.
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3. Example
An illustration of a situation in which sampling would be
called for is as follows: A waste pile of thickened and filtered
wastewater treatment sludges from an electroplating operation has
been stockpiled on a cement pad for almost ten years. Visual
inspection of the waste pile shows that there are no on-site
controls to prevent run-on and run-off. In fact, channels are
observed leading downgradient from the pile, reaching a medium
s'ized stream about 200 yards away.
The waste pile contains both copper and nickel from the
electroplating process. The sludge was formed by the treatment
of wastewaters containing copper cyanide and nickel cyanide by
the addition of lime to form insoluble precipitates. Analysis
of current sludge samples shows significant levels of cyanide.
There is no data on the cyanide levels in the ten year old
waste pile. There is no water quality data from the stream
on the parameters of interest (e.g., copper, nickel, or cyanide).
Fish kills were reported on the stream eight or more years ago.
There have been no recently documented fish kills.
In this scenario, the investigator should probably call
for sampling to find constituent-specific evidence of a release
to surface water. Cyanide, being mobile in water, is anticipated
to be leached out of the waste pile and dispersed down stream
during storm events. Any evidence 'of a release must be preserved
in the soil.and sediment.. Therefore, the sampling program centers
around copper and nick'eT analysis in the' soils and sediments.
Soil sampling is recommended for the low spots in the drainage
where run-off may have formed puddles.
The investigator should take sediment samples of the stream
bottom, and analyze them for copper, nickel, and cyanide.
Because cyanide is soluble and degradable in small quantities in
the sediments and soils, it may not be found in the sediments or
remain in the water. Because of the high cost and delay asso-
ciated with analyzing sampling results, the investigator may
attempt to limit the selection of sampling parameters to those
most likely to result in an identification of a release.
III. COLLECTING ADDITIONAL SAMPLING INFORMATION IN THE SV
This section presents technical information related specifi-
cally to the surface water pathway to be considered when collect-
ing additional sampling information in the SV. Accordingly, the
information presented here should be used to help the investigator
meet oie of the primary goals of the SV:
o To collect additional sampling information to fill data
gaps identified in the PR and SVI.
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uo..cn
950 2 . 00-5
For each sampling method discussed, this section describes:
1) the general kinds of situations in which it will be appropriate
to employ a specific technique, 2) technical information on how
to conduct the sampling, and 3) specific details to be considered
when evaluating the sampling results. This section does not pro-
vide the actual SOPs on sampling techniques, but references
relevant manuals.
The choice of appropriate sampling methods will have a large
impact on the cost and usefulness of the SV. The investigator
should be confident when developing and reviewing the sampling
plan that the procedures chosen will meet the needs of the RFA,
while not resulting in the collection of unnecessary data. This
section discusses the following four sampling methods which may
be of use:
(1) Surface water sampling;
(2) Sediment sampling;
( 3 ) Soi 1 sampl ing; and
( 4 ) Run-off sampl i ng.
A. Surface Water Sampling
It is important to select sampling locations for surface
waters prior to actu.al sample collection since location will
often affect the choice of sampling equipment. Selection of
sampling location depends 'on surface water body type (e.g., pond
or stream), flow rate, depth, and width. In practice, safety and
physical access limitations will often affect sample locations.
Surface water samples can be collected directly by submerg-
ing the sample bottle. However, it is preferable to use a sample
collection container (e.g., beaker), properly cleaned and of
appropriate material, to avoid contaminating the outside of the
bottle used to transport the sample back to the laboratory.
It is often necessary to collect samples away from the
shore. If a plume is visible, samples should be taken within the
plume. A telescoping aluminum pole with an adjustable beaker
clamp attached to the end is the easiest device to use to reach
sampling locations several feet off-shore. The collection vessel
or the sampl.e bottle is held by the clamp. Samples can be trans-
ferred to appropriate bottles for shipment back to the laboratory.
Surface water samples should be preserved and cooled to 4°C. prior
to shipment to the laboratory. The laboratory may provide the
preservatives within the bottles. These cannot be used for
direct sampling.
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B. Sludge and Sediment Sampling
Sediment or sludge can usually be sampled by using a
stainless steel scoop or trier. Where sediment has a shallow
liquid layer above it, it may be scooped by a pond sampler or
preferably with a thin-tube sampler. This device is preferred
because it causes less sample disturbance and will also collect
an aliquot of the overlying liquid, thus preventing drying or
excessive sample oxidation before analysis.
If the sludge layer is shallow, less than 30 centimeters,
corer penetration may damage the container liner or bottom. In
this case, a Ponar or Eckman portable dredge can be used since
these samplers can generally only penetrate a few centimeters.
Of the two samplers, Ponar grab samplers can be applied to a
wider range of sediments and sludges. They penetrate deeper and
seal better than the spring-activated Eckman dredges, especially
in granular substrates.
When sampling, the investigator should consider a number of
additional factors. For instance, because streams, lakes, and
impoundments generally demonstrate significant variation in
sediment composition resulting from distance from inflows, dis-
charges, or other disturbances, the investigator should document
exact sampling locations by means of triangulation with stable
references on the banks of the stream or lake. In addition, the
investigator may have to modify or not use some devices described
above if rocks, debris and organic material in the sediment
complicate s-ampl i n.g'.- .
EPA's publication, Character!' zati on of Hazardous
Waste Si tes-A Methods Manual; Volume 11. 7Tv a11 a b 1 e Samp ling
Methods , Second E d i t i o n , pages 2-8 to^-18, describe these
sampling techniques in greater detail.
C. Soi1 Sampli ng
If run-off or leachate samples cannot be obtained directly
(e.g., lack of precipitation), soil samples can be taken within
gullies or other run-off channels to identify contamination.
Results showing contaminated soil in a run-off pathway will indi-
cate the potential for a surface water release. Constituents
found in drainage pathways may confirm the presence of contaminated
run-off. The identification of a release to soils and the appro-
priate sampling protocol is covered in Chapter Seven, Soils.
D. Run-off Sampli ng
Sampling of run-off and leachate seepage involves several
technical difficulties and will be less common in the RFA. The
major criteria used to determine how and where to sample include:
obtaining a representative sample, safety of the personnel con-
ducting the sampling, and the timing of sample collection with
the high precipitation necessary to create run-off or infiltration
6-14
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9502.00-5
and seepage. Lack of precipitation during the sampling program is
the major obstacle to obtaining run-off samples.
Due to the differences in run-off patterns between facilities,
no one sampling method is considered reliable for obtaining a
representative sample at every location. The investigator will
need to use professional judgment when designing site-specific
sampling plans. When sampling sheet run-off or small leachate
streams, a weir may be used to enable the liquid to spring free
of the surface to provide a sufficient volume for the parameter
analysis. These samples should be collected as grabs and all
parameters should be taken within a short period of time (i.e.,
1 ess than 15 mi nutes).
The best method for manually collecting samples is to use
the actual sample container that will be used to transport the
sample to the laboratory. This will prevent the contamination of
samples by the use of a collection device. The collection
container should be properly cleaned.
Samples for oil and grease analysis should be collected dir-
ectly from the run-off. The investigator should avoid using
collection vessels when transferring oil and grease samples since
oil residue will adhere to the vessel and may not be transferred
with the sample to the container.
Care should be taken to avoid collecting leaves and debris in
the vessel. "The sample can then be transferred-to-the appropriate
container. Some laboratories will add the preservatives directly
to the sample containers and other laboratories will have the
sampling team preserve the samples. The investigator should
use appropriate methods to preserve run-off samples. Leachate
samples, which are generally considered to be hazardous samples
rather than environmental samples, should not be preserved. SW
846, Test Methods for Evaluating Solid Waste - Physical Chemical
Methods is the best reference for hazardous samples. Methods for
Chemical Analysis of Water and Wastes 1s a good reference for
preservation techniques for run-off samples.
In evaluating results, it is very Important to determine if
representative samples were obtained and appropriate sampling
methods were used to collect parameters. QA/QC protocol for
sampling is described in Chapter Four.
IV. MAKING SURFACE WATER RELEASE DETERMINATIONS
This section summarizes information that the investigator
should consider when making release determinations in the surface
water pathway.
6-15
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Chapter Four presents the general procedure to be followed
when making release determinations in the RFA. This involves:
o Evaluating sampling results from the SV;
o Integrating facility information gathered in the PR,
VSI , and the SV;
o Determining the likelihood of release at the facility; and
o Making recommendations concerning the need for further
i nvesti gations .
The investigator should rely upon information available and
his/her best professional judgment when making release determina-
tions in the surface water pathway. As stated in Chapter Four,
it will often be necessary to make deductions on the likely
origins of surface water contamination in the RFA when there is
evidence of such contamination. In order to do this, the inves-
tigator should be able to demonstrate that: 1) the constituents
identified in the surface water or sediments were present in the
specific unit or group of units; and 2) the pollutant migration
pathways at the site support a determination that a constituent
leaking from a specific unit or group of units would be likely to
migrate to the surface water of concern. The investigator should
rely upon best professional judgment in making this determination.
Further investigations to establish the presence of, and
character of, surface water (and/or s-ediment) contamination
problems, and the sources of such contamination,- should be required
of the owner/operator when information.or evidence indicates that
there is or is likely to be releases from the facility to the
surface water body which poses an actual or potential threat to.
human health or the environment.
Exhibit 6-2 is a checklist that should help the investigator
evaluate specific factors to identify surface water releases
and determine the relative effect on human health and the en-
vironment. In identifying releases, the investigator should
consider the types of information presented in Exhibit 1-1
which are highlighted in this checklist.
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EXHIBIT 6-2
Checklist for Surface Water Releases
0' ' '£;>. POLICY DIRECTIVE NO.
9 50 2 00-5 *2
o Unit Design and Physical Condition
Are engineered features (e.g., run-off control systems)
designed to prevent releases from the unit)?
- Does the operational history of the unit indicate that a
release has taken place (e.g., old, closed or inactive unit,
not inspected regularly, improperly maintained)?
Does the physical condition of the unit indicate that re-
leases may have occurred ( e.g., cracks or stress fractures
in tanks or erosion of earthen dikes of surface impound-
ments ) ?
o .Release Migration Potential
Does the slope of the facility and intervening terrain
indicate potential for release?
Could surface run-off from the unit reach the nearest
downgradient surface water body?
Is the intervening terrain characterized by soils and
vegetation that allow overland migration ( e.g., clayey
soils, and sparse vegetation)?
Does data on one-year 24-hour rainfall indicate the poten^
tial for area storms to cause surface water or surface
drainage contamination as a result of run-off?
6-17
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EXHIBIT 6-2 (cont.)
Checklist for Surface Water Releases
o Waste Characteristics
Is the volume of discharge high relative to the size and
flow rate of the surface water body?
Do constituents in the discharge tend to sorb to sediments
(e.g., metals)?
Do constituents in the discharge tend to be transported
downstream?
Do waste constituents exhibit moderate or high characteristics
of persistence (e.g., PCBs, dioxins, etc.)?
Do waste constituents exhibit .moderate or high characteristics
of toxi city' (e.g. , metal s ,. chl ori nated pest-icides, etc.)?
o Evidence of Release
Is there direct evidence (e.g., sampling data; observed
contaminated run-off)?
Is there indirect evidence (e.g., discolored soil, dead
vegetation )?
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CHAPTER SEVEN 9502«00»5
AIR
I. INTRODUCTION
A. Purpose
This chapter provides technical information to support the
investigation of air releases during the RFA. While Chapters Two
Three, and Four provide general guidance on conducting an RFA,
this chapter focuses on specific factors unique to the air medium
that should be considered by the investigator.
In investigating the potential for air releases during the
RFA, the investigator should focus his/her attention on operating
units. Operating waste management units have the greatest poten-
tial for air releases because they actively expose wastes to the
air on a continuous basis. In investigating air releases, EPA
personnel should take safety precautions in order to reduce their
exposure to on-site emissions. Safety precautions are discussed
in Chapter Four.
Wastewater treatment units, such as those in treatment
trains regulated by NPOES, can cause significant volatile air
emissions. The investigator should address potential air releases
from these units in the RFA.
This chapter is organized to reflect the separate phases of
the RFA process:
o Conducting a preliminary review of existing information;
o Conducting a visual site inspection;
o Collecting additional sampling information in a SV; and
o Making release determi nat i o'ns .
The first section describes the technical factors that should
be considered during the PR and VSI. The second section describes
the technical approach to obtaining additional -sampling information
in the SV for air, and should be consulted along with Chapter
Four on conducting a SV. The final section discusses factors to
consider when making air release determinations at the end of the
RFA. This section also presents options for further investigation
of air releases to be evaluated at the end of the RFA.
-------
II. CONDUCTING A PRELIMINARY REVIEW AND VISUAL
SITE INSPECTION OF AIR RELEASE POTENTIAL
This section presents technical information related specifi-
cally to the air pathway to be considered when conducting the PR
and VSI. Accordingly, this section has been organized to reflect
the primary goals of these phases of the RFA described in Chapters
Two and Three:
o Identifying and describing potential threats to air at
RCRA facilities; and
o Making a preliminary assessment of the need for a SV or
other actions at these facilities.
This section presents technical information specific to the
air pathway covering the five types of information described in
Exhibit 1-1, and technical information to help the investigator
determine when additional sampling will be necessary in a SV to
identify air releases. We will discuss these six types of infor-
mat i on separately:
(1) Unit characteristics;
(2) Waste characteristics;
(3) Pollutant migration pathways;
(4) Evidence of release; " ' -
(5) Exposure potential; and
(6) Determining the need for additional sampling information.
This information is relevant to the evaluation of written documents
in the PR and information gathered in the VSI.
A. Unit Characteristics
The design and operating characteristics ~o~f a SWMU will
determine to a great extent their potential for releasing hazardous
constituents to air. While the investigator should evaluate all
SWMUs for air releases, including NPDES units, the investigation
should focus on operating units. As previously mentioned, opera-
ting units have the greatest potential for air releases because
they actively expose wastes to the air on a continuous basis.
Wastes in closed, inactive units will have a lower potential to
cause air releases. There may be some exposure to the air if a
cover has eroded or broken down, but air releases resulting from
these situations are likely to be negligible (i.e., undetectaule).
When assessing the potential for releases, the key factors
to examine include:
7-2
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3502.00-5
0 Unit size. The size of a unit determines the mass of
potential contaminants available for release. Volatil-
ization rates are likely to be larger from open units
(e.g., surface impoundments and open tanks) with large
surface areas.
o Purpose of the unit (treatment, storage , or disposal ).
In general, units in which active treatmentis occurring
have the greatest potential for air releases. In many
cases, treatment is designed to promote volatilization of
constituents. In other cases, this is not the main
purpose of the treatment method in use. However, the
resultant mixing and movement of wastes leads to high
volatilization rates.
o Design of the unit. Units in which wastes are in direct
contact with the atmosphere have a higher potential for
releases than closed or covered units.
o Current operational status. The nature of air releases
is such that the majority of the mass available for
release will be released shortly after the waste is
placed in the unit. Thus, as mentioned, operating units
are of greater concern than closed units. This is par-
ticularly true for unit types and wastes for which vola-
tilization is important. Units with potential particulate
releases may continue to release contaminants well after
cl osure , ' especi al ly if the unit has been poorly maintained..
o Unit specific factors. There are specific design and oper-
ational factors associated with each unit type which are
useful in evaluating the potential for release. These
factors are summarized in Exhibit 7-1.
In addition' to considering the individual unit sizes, the investi-
gator should be aware of the toita1 area used for solid waste
management at a facility. Although individual units may have
undetectable releases, the total release from a facility can be
significant. Exhibit 7-1 lists specific considerations for par-
ticularly important unit types.
In assessing a unit's potential for air release, the inves-
tigator should be aware of the importance of interactions between
the various unit characteristics listed above and the character-
istics of the wastes placed in the unit. It is important to
examine how-these two factors combine to result in an air release.
For example, a facility may have several large operating surface
impoundments, suggesting a potential for large air releases.
However, if the facility is a steel manufacturer treating only
spent pickle liquor in these ponds, it is unlikely any air
release will occur because the hazardous constituents in the
waste are non-volatile, soluble metals.
7-3
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EXHIBIT 7-1
UNIT POTENTIAL FOR AIR RELEASES
AND MECHANISMS OF RELEASE
Unit Type
Characteristics and Mechanisms of Release
Operating Surface
Impoundments
Wastes directly exposed to atmosphere
promotes vapor phase emissions
Large surface areas and shallow depths
promote increased volatilization
Mechanical treatment methods (such as
aeration) increase volatilization
Open Roofed Tanks
Wastes directly exposed to atmosphere
(promotes vapor phase emissions)
Mechanical treatment or frequent mixing
will increase volatilization
tandfil 1s
Volatilization of vapor phase constituents
through the sub-surface and daily/permanent
cover
Poor or no daily cover increases volatili-
zation , . j^
Open trench fill operations allow direct^P
exposure of waste to atmosphere
Volatile gases transported by convection
of biogenic gases released via routine
landfill venting (particularly important
in sanitary/hazardous mixed fills)
Particulate releases generated by machinery
during filling operations
Particulate releases due to wind erosion of
cover and/or exposed wastes
Land Treatment Units
Wastes normally in direct contact with
atmosphere
Application techniques which maximize waste
contact with atmosphere, such as surface
spreading or spray irrigation promote
increased volatilization
Particulate releases due to wind erosion
7-4
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EXHIBIT 7-1 (Continued)
UNIT POTENTIAL FOR AIR RELEASES
AND MECHANISMS OF RELEASE
0502,00-5
Unit type
Waste Piles
Characteristics and Mechanisms of Release
Participate emissions from uncovered
waste piles
Location of waste pile in open area with
no erosion protection promotes particulate
generati on
Waste handling activities on and around
pile increase emissions
Volatile emissions are likely to be rare,
but can occur based on waste composition
Drum Sto rage Areas
Vaporization from drums frequently left
open to atmosphere or from poorly sealed
drums
Vapor emissions from areas containing
leaking drums
C'overed Tanks
o Volatile releases from pressure vesting,
poorly sealed access ports, or improperly
operated and maintained valves and seals.
Inci nerators
o Stack emissions of particulates
o Stack emissions of volatile constituents
High temperatures may cause volatilization
of low vapor pressure organics and metals
o Volatile releases via malfunctioning valves
during incinerator charging
Non-RCRA Wastewater
Treatment Ponds and
Tanks
Low concentration wastes may volatilize
due to large surface area and active waste
treatment. Releases can be significant
due to generally large treatment
capaci ti es
Other Design and
Operating Practices
Inadequate spill collection systems promote
intermittent air releases
Lack of vapor collection systems for use
during container/tank cleaning operations
Absence of dust suppression or particulate
control measures
7-5
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The following section discusses the waste and constituent-
specific factors the investigator should consider in assessing a
waste's potential to release airborne constituents.
B. Waste Characteristics
Only certain hazardous constituents have a significant
potential for air releases. This section identifies these con-
stituents and the factors that affect their release. The physical
form of the waste contained in a solid waste management unit will
determine to a great extent the potential for air releases from
the unit. Wastes may be solid, dilute aqueous solutions, dilute
organic solutions, or concentrated solutions.
Air releases from solid wastes, such as those placed in
landfills or waste piles, will be governed by different principles
than govern releases from liquid wastes. The two types of
emissions of greatest concern are:
(1) volati1es ; and
(2) particulates.
We discuss below the characteristics that affect the potential
for each type of emission. These characteristics are summarized
in Exhibit 7-2, which outlines the likely unit types and appro-
priate . parameters to consider when evaluating airborae releases
from d-ifferent types of waste'streams (e.g., whether the release
will be volatile or particulate). The investigator may find it
useful to consider these factors if he/she is uncertain about the
potential for constituents to release, based solely on unit charac'
teristics and the lists of constituents of concern for vapor-phase
and particulate emissions provided in Exhibits 7-3 and 7-4. A
potential use of this information on the factors that effect the
potential for air releases would be to use it to help support the
investigator in determining that certain units will not have air
releases.
1 Volatile Emissions
Volatile constituents of concern for air releases include
organic vapors and volatile metals (e.g., arsenic and mercury).
Exhibit 7-3 lists a select number of hazardous chemical compounds
which EPA's Office of Air Quality Planning and Standards (OAQPS)
considers to be of prime concern with respect to vapor phase air
releases. The table also lists the RCRA waste codes for waste
streams that contain these constituents to aid in their iden-i-
fication. While these wastes are of primary concern, many other
wastes have the potential co volatilize. Therefore, where there
is a large quantity of waste, the investigator should address
both total volatile organic compounds (VOC) emissions as well as
emissions of the specific compounds listed in Exhibit 7-3.
The concentration of specific constituents in each unit is
another factor governing the potential for air releases. The
7-6
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EXHIBIT 7-2
8502.00-? 2
PARAMETERS AND MEASURES FOR USE IN EVALUATING.
POTENTIAL AIR RELEASES OF HAZARDOUS WASTE CONSTITUENTS
Emission and Waste Type
A. Vapor Phase Emissions
-- Dilute Aqueous Solution^/
Units or Concern1/
Surface Imp.,
Tanks, Containers
-- Cone. Aqueous Solution^/ Tanks, Containers,
"~ Surface Imp.
Immiscible Liquid
-- Solid
Containers, Tanks
Landfills, Waste
Piles, Land Trt.
8. Particulate Emissions
Solid
Landfills, Waste
Piles, Land Trt.
Useful Parameters
and Measures
Solubility,
Vapor Pressure,
Partial Pressure,^/
Henry's Law
Solubility,
Vapor Pressure,
Partial Pressure,
Raoults Law
Vapor Pressure,
Partial Pressure
Vapor Pressure,
Partial Pressure,
Octanol/Water
Partition Coeff.
Particle Size
Distribution,
Site Activities,
Management Methods
V Incinerators are not specifically listed on this table be-
cause of the unique issues concerning air emissions from these
units. Incinerators can burn all the forms of waste listed in this
table. The potential for release from these units is primarily a
function of incinerator operating conditions and emission controls,
rather than waste characteristics.
£/ Although the octanol/water partition coefficient of a con-
stituent is usually not an important characteristic in these waste
streams, there are conditions where it can be critical. Specific-
ally, in waste containing high concentrations of organic particu-
lates, constituents with high octanol/water partition coefficients
will adsorb to the particulates. They will become part of the sludge
or sediment matrix, rather than volatilizing from the unit.
2/ Applicable to mixtures of volatile components.
7-7
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EXHIBIT 7-3
HAZARDOUS CONSTITUENTS OF'CONCERN AS VAPOR RELEASES
Hazardous Constituent
Acet aldehyde
Acrolein
Acrylonitrile
Al lylchloride
Benzene
Benzyl chloride
Carbon Tetrachloride
Chlorobenzene
Chloroform
Chloroprene
Creosols
Cumene (isopropylbenzene)
1,4-dichlorobenzene
1,2-dichloroethane
Oichloromethane
Dioxin
Epichlorohydrin
Ethyl benzene ,
Ethylene oxide
Formaldehyde
Hexachlorobutadiene
Hexachlorocyclopentadiene
Hydrogen cyanide
RCRA Waste Codes
K001,11001
K012
K011,K012,K013,U009
F024,F025
F024,F025,K001,K014,K019,K083,K085,K103,K105
K015,K085,P028
FOQ1,F024,F025,KQ16,K016,K020,K021,K073,U211
F001 ,F002,F024,F025,K015,K016,K085,K105
F002,F024,F025,K009,K010,K016,K019,K020,K073,
K021.K029.U044 .
F024,F025
F004tU052
U055
F002,F024,F025,K016,K085,K105,U072
K018,K019,K020,K029,K030,K096,F024,F025,U077
F001,F002,F024,F025,K009,K010,K021,U080
F020,F021,F022,F023,F028
K017,K019,K020,U041
F003
U115
K009,K010,K038,K040,U122
F024tF025,K040,K016,K018,K030,U128
F024,F025,K032,K033,K034,U130
F007,F009,F010,K013,K060
7-8
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vo,,La ruLILT O'i.XcCTIVE NO,
EXHIBIT 7-3 (cont.) 950 2 . 00- 5 -
HAZARDOUS CONSTITUENTS OF CONCERN AS VAPOR RELEASES
Hazardous Constituent
Hydrogen flouride
Hydrogen sulfide
Maleic anhydride
Methyl acetate
N-Dimethylnitrosamine
Naphthalene
Nitrobenzene
Ni trosomorpholine
Phenol
Phosgene
Phthalic anhydride
Polychlorinated biphenyls
Aroclor 1242
Aroclor 1248
Aroclor 1254
Aroclor 1260
Propylene oxide
1,1,2,2-tetrachloroethane
Tetrachloroethylene
Toluene
1,1,1-trichloroethane
Trichloroethylene
Vinylchloride
Vinylidenechloride
Xylenes
RCRA Waste Codes
K023.K093.U147
U100
F024 ,F025,K001,K035.K060.K087,U165
F004,K025,K083,K103,U169
K001,K022,K087,U188
P095
K016,K023,K024,K093,K094,U190
K085
F024,F025,K016,K019,K020,K021,K030,K095,K096,U209
F001,F002,F024,F025,K016,K018,K109,K020,K021,U210
F005 ,F024,F025,K015,K036,K037,U220
F001,F002,F024,F025,K019,K020,K028,K029,K073,K095,
K096.U226
F001,F002,F024,F025,K016,K018,K019,K020,U228
K019 ,K020,K023,K029,K028,F024,F025,U043
F003,F025,K019,K020,F024,K029,U078
F020.U239
7-9
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EXHIBIT 7-4
HAZARDOUS CONSTITUENTS OF CONCERN AS PARTICULATE RELEASES
Hazardous Constituent
Arsen ic
RCRA Waste Codes
0000,0004, K060,K021,K084,P010,
P011.P012
Asbestos
U013
Beryllium
0000,0006,P015
Cadmi urn
0000,0006, F006,F007,F008,F009,
F061.F062, F064,F065,F067,F068,F069
Chromi urn
0000,0007, F006,F007,F008,F009;F002,
F064,F069,F086,
Lead
DOOO,D008,F006,F009,K003,K044,K048,
K052,K061,K062,K064,K069 K086.P110
Mercury
0008.K071.K106
Nickel
F006,F007,F008,F009
7-10
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1 "- nv.
higher the concentration of a particular constitireftrpesd- 5
in a unit, the greater is its potential for air release. However,
the intrinsic potential for a constituent to volatilize depends
on chemical and physical properties that vary greatly between
different constituents. Accordingly, a highly concentrated
solution of one constituent may result in a lower release potential
than a dilute concentration of another constituent.
Constituent-specific physical and chemical parameters are
yery important indicators of the potential for a vapor-phase
release. The parameters most important when assessing the vola-
tilization of a constituent include the following:
o Water solubility. The solubility in water indicates the
maximum concentration at which a constituent can dissolve
in water at a given temperature. This value can help
the investigator estimate the distribution of a constituent
between the dissolved aqueous phase in the unit and the
undissolved solid or immiscible liquid phase. Considered
in combination with the constituent's vapor pressure, it
can provide a relative assessment of the potential magni-
tude of volatilization of a constituent from an aqueous
env1ronment.
o Vapor pressure. Vapor pressure measures the pressure of
vapor in equilibrium with a pure liquid. It is best used
in .a relative sense; constituents with high vapor pres-
sures are more likely to have releases than those with
. low vapor pressures, depending on 'other, factors such as
relative solubility and concentrations (i.e. at high
concentrations releases can occur even though a
-constituent's vapor pressure is relatively low).
o Octanol/water partition coefficient. The octanol/water
partition coefficient indicates the tendency of an organic
constituent to sorb to organic constituents in the soil
or waste matrices of a unit. Vapors with high octanol/
water partition coefficients will adsorb readily to organic
carbon, rather than volatilizing to the atmosphere. This
is particularly important in landfills and land treatment
units, where high organic carbon contents in soils or
cover material can significantly reduce the release
potential vapor phase constituents.
o Partial pressure. For constituents in a mixture, particu-
larly i n a solid matrix, the partial pressure of a consti-
tuent will be more significant than the pure vapor pressure
In general, the greater the partial pressure, the greater
the potential for release. Partial pressures will be
difficult to obtain. However, when waste characterization
data is available partial pressures can be estimated
using methods commonly found in engineering and environ-
mental science handbooks.
7-11
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o Henry's Law constant. Henry's law constant is the ratio
of the vapor pressure of a constituent and its aqueous
solubility (at equilibrium). It can be used to assess
the relative ease with which the compound may be removed
from the aqueous phase via vaporization. It is accurate
only when used concerning low concentration wastes in
aqueous solution. Thus it will be most useful when the
unit being assessed is a surface impoundment or tank con-
taining dilute wastewaters. Generally, when the value of
Henry's Law constant is less than 10E-7 atm-nH the consti-
tuent will not volatilize from water. As the value in-
creases the potential for significant vaporization increas-
es, and when it is greater than 10E-3 rapid volatilization
wil1 occur.
o R a o u 11's Law - Raoult's Law can be used to predict re-
leases from concentrated aqueous solutions (i.e. solutions
over 10% solute). This will be most useful when the unit
of concern entails container storage, tank storage, or
treatment of concentrated waste streams.
For solid wastes, imiscible liquids, and wastes disposed of
in landfills, land treatment, or waste piles, there are no simple
measures that can be used to assess the potential for volatiliza-
tion of a constituent. The investigator will need to consider the
appropriate chemical, physical, and unit parameters, and then use
his/her best judgment in determining the potential for release.
2- Particulate Emissions ' .
Exhibit 7-4 lists hazardous constituents that are of special
concern for particulate air releases. Particulate emissions from
solid waste management units can contain organic material, heavy
metals, or both. The heavy metals shown in Exhibit 7-4 are pre-
dominantly associated with particulate releases, although both
arsenic and mercury may be present as vapor phase releases due to
their relatively high vapor pressures. Similarly, the organic
compounds shown in Exhibit 7-3 may also be found adsorbed or bound
to soil and/or other particulate matter releases.
In general, there will be fewer facilities with particulate
emissions. However, at some facilities particulate emissions may
be very significant (e.g., discharges from a lead smelter) and
threaten the safety of on-site workers and EPA personnel during a
site visit..
The likelihood of particulate releases at hazardous waste
management facilities is generally associated with landfills,
land treatment units and/or waste piles. The potential for
particulate releases is governed by different parameters than
those that affect vapor-phase releases.
For particulate releases, the size distribution of the
particles in the'release plays an important role in both
dispersion and actual exposure. Large particles will settle out
7-12
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9502.00-5
of the air more rapidly than small particles, thus they will not
travel as far off-site or be diluted as much by dispersion. Very
small particles (i.e., those that are less than 5 microns in
diameter), are considered to be respirable and thus present a
greater health hazard than larger particles. The investigator
should examine the source of the particulate emissions to obtain
information on particle size.
The primary mechanism for generating particulate releases at
hazardous waste facilities is wind erosion. In general, the
unit's location will affect the potential for the wind to erode
wastes in the unit. The unit's location and orientation with
respect to the prevailing winds and large structures on-site will
determine the unit's vulnerability to wind erosion and the poten-
tial for particulate releases. Agency personnel should determine
the location of SWMUs of concern with respect to prevailing winds
and the use of wind screens (both natural and man-made) and daily
covers to determine the unit's vulnerability to wind erosion.
C . P_ol 1 utant _Mi g_rati on Pathway
The investigator should identify the migration route(s) for
potential air releases in order to identify:
o The locations along the route where target populations
may be exposed to the release; and
o Locations to-sample for. evidence of release (e.g., south
or north'edge of the unit), where no evidence of release
exists, but the irivestigator believes, based on unit an'd
waste characteristics, that releases may occur.
In identifying air pollutant migration pathways, the investi-
gator should determine the direction of the prevailing winds
around the facility, and characterize the geography (e.g., narrow
valleys and urban areas containing large buildings, or artificial
canyons) along the wind pathway. Using this information, he/she
should be able to identify upwind and downwind sampling locations
and target populations that may be exposed to air releases along
their migration route.
The investigator may be able to obtain some of this information
from local weather data bases as part of the PR. Most of this
information, however, will probably be collected during the VSI.
D. Evidence of Release
The investigator should examine any available sources of
information to identify evidence that constituents have been
released to the air at a facility in a proportion that poses an
actual or potential threat to human health and the environment.
General considerations on how to look for evidence of release are
discussed in Chapters Two and Three.
7-13
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Direct evidence of air releases will include the following:
o Air sampling/monitoring data associated with a particular
unit (e.g., samples taken from above a NPOES unit; moni-
toring data required under a Clean Air Act permit);
o Visual evidence of particulate releases from a unit;
Indirect evidence of release includes the following:
o Evidence of contamination around the facility that may have
resulted from an air release (e.g., accumulated particulate
emissions from a smoke stack or 1andfi11/waste pile);
o On-site air monitoring data gathered under the OSHA program;
o Records of citizen complaints associated with the facility
concerning odors, headaches, nausea, or observed particulate
releases.
During the viusal site inspection, the investigator should
identify any evidence that hazardous constituents have released
or are continuing to release from SWMUs at the facility to the
air. During the visual site inspection he/she should confirm the
presence of units of concern and look for evidence of particulate
emissions from units. Although the investigator may occasionally
smell vapor-phase relea-ses, in most cases, these releases will be
difficult to identify without samples. Procedures for col 1ecting
additional sampling information are discussed in Section III.
E. Exposu re Potenti a 1
The investigator should evaluate available information on
the location, number, and characteristics of potential receptors
that could be affected by air releases at the facility. Human
receptors are of primary concern for air releases. Potential
receptor information will be used primarily in helping the inves-
tigator determine the need for interim corrective measures at the
facility in order to address instances of air contamination
posing especially high risks of exposure.
Population density and distance from the source are the pri-
mary factors in determining the significance of a potential
exposure. Distance should be measured from the unit(s) containing
the waste rather than from the facility boundary, although total
facility emissions from all SWMUs should also be kept in mind.
Most importantly, the investigator should consider the density of
the population residing near the site, as well as transients such
as workers in factories, offices, restaurants, models, or students
The most significant exposure potential will occur in situa-
tions when there is a high population density very close to the
site. However, because concentrations can be quite high, even
low density populations in such close proximity to the site are
7-14
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of concern. Dispersion can significantly reduce concentrations
as distance from a site increases. Thus, the significance of
high population density at larger distances from the site is
reduced.
The investigator needs to consider the relationship between
distance, concentration, and population density in evaluating the
significance of an exposure potential. An additional factor to
consider is the population located along the line of the most
predominant wind direction at a site. Because the RFA is pri-
marily concerned with continuous releases, populations located
along this line downwind of the site are more likely to receive
significant exposures than populations located along other vectors.
If the investigator determines that units at a facility are
releasing large volumes of unsaturated hydrocarbons, he/she may
need to consider population density over a much larger area.
These constituents contribute to the formation of photochemical
smog and ozone, which, in combination with other regional pollu-
tant releases, can cause significant exposures over a wide
geograph i c area .
F. Determining the Need for Additional Samp!ing Information
If the investigator determines, based on his inspection of
the unit, that there is a significant potential for the unit to
be releasing substantial quantities of .volatile constituents and
in consideration of the proximity of receptors, he/she may choose
to sample to determine conclusively whether an air release is
occurring which merits further investigation. We discuss in this
section:
(1) General information on factors to consider in determining
the need for additional sampling information; and
(2) Factors to consider in selecting sampling parameters.
1. General Information on Determining the Need for Sampling
The investigator should use his/her best professional judgment
in determining when a unit may be releasing hazardous constituents
to the air. In some situations, a unit may exhibit a strong poten-
tial for air releases, based upon unit and waste characteristics,
but the investigator wants to confirm this with additional data.
This may be necessary in situations where the owner/operator has
not cooperated with EPA, and he/she may contest an EPA request to
conduct further investigations by denying the presence of air
releases.
7-15
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2. Selection of Sampling Parameters
In selecting sampling parameters, the investigator should
consider those constituents he/she believes to be of concern at
the facility. These constituents are discussed in detail earlier
in this chapter. In general, the investigator will be able to
confirm a release when one constituent has been shown to release,
and therefore, the number of parameters considered should be as
limited as possible.
In many cases, the investigator will be able to confirm or
deny the presence of an air release by sampling for VOCs with an
indicator device. However, these devices can miss episodic re-
leases. These devices (e.g., OVA and HNU) measure the concentra-
tion of volatile organics in the air, and thus provide a screening
level technique for identifying releases. These sampling methods
are discussed further in Section III.
III. OBTAINING ADDITIONAL SAMPLING INFORMATION
This section presents technical information related specifically
to air releases to be considered when collecting additional
sampling information in the SV. The information presented here
should be used to help the investigator meet one of the primary
goalsoftheSV:
o To collect.additional sampling information to fill data
gaps identified in the RR and VSI, leading towards final
release determinations.
For each sampling method discussed, this section describes:
1) the general kinds of situations in which it will be appropriate
to employ a specific technique, 2) technical information on how
to conduct the sampling, and 3) specific details to be considered
when evaluating the sampling results. This section does not
provide the actual SOPs on sampling techniques here, although it
does reference the relevant manuals where possible.
The choice of appropriate sampling methods will have a large
impact on the cost and usefulness of the SV. The investigator
should be confident when developing and reviewing the sampling
plan that the procedures chosen will meet the needs of the RFA,
while not resulting in the collection of unnecessary data.
We describe several sampling techniques that will be appro-
priate for identifying air releases during the RFA:
(1) Indicator techniques (OVA and HNU);
(2) Draeger tubes; and
(3) Monitoring stations with Tenax tubes.
7-16
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1. Indicator Techniques (OVA and HNU)
*w-tn ruLlOT UIKtCTlVt N
9502,0(H5
The most common air sampling technique will Involve the use
of portable air monitoring instruments which measure total organic
constituents present in the air at the sampling point. The two
most commonly used devices are the organic vapor analyzer (OVA),
and the HNU photoionization detector. The OVA detects the pres-
ence of organic compounds in air with a flame ionization detector,
while the HNU detects organic compounds with a photoionization
detector. While these units provide somewhat different results,
this discussion will be limited to the HNU; most of the discussion
will be applicable to use of the OVA.
The HNU provides the investigator with a quick and simple
method for determining the presence of organic compounds in the
air, and for providing a general indication of their magnitude.
When evaluating the likelihood of releases at wastewater treatment
tanks, the investigator should hold the HNU as close as possible
to the unit and wait for the meter to equilibrate. The instrument
provides a reading of organic vapor concentration in terms of
parts per million.
The investigator should be aware that both of these instruments
are calibrated to measure accurately only one volatile constituent:
the HNU is calibrated for benzene, while the OVA is calibrated
for methane. Thus, when encountering other organic constituents,
the meter may indicate either higher or lower concentrations of
that constituent than are actually present. The investigator
should consider' that these instruments provide general indications
on the presence of volatile organics, not quantitative evidence.
However, an HNU indication of organic vapors at a site may be
sufficient to compel further investigations at that unit.
2. Draeger Tubes
When the investigator seeks more detailed information on the
presence of organic constituents in the air, Oraeger tubes can be
useful for measuring specific constituents.' This sampling tech-
nique shares the advantage of the HNU and OVA in that Oraeger
tubes are a portable, field technique, which does not require
laboratory analysis.
Oraeger tubes contain a sorbent material encased in a small
glass tube, through which an air sample is pulled with a hand-
held pump. The sorbent material has been chemically-treated
to turn a co-lor when the specific constituent of concern is
present in the air. The length of the stained material indicates
the concentration of the constituent in the air; the tube contains
a calibrated scale for reading concentration in parts per million
directly off of the tube.
7-17
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Draeger tubes have several advantages over the indicator
techniques discuss-ed above. Because they are constituent-specific,
they provide a better indication of the toxicity posed by an air
release. They also will provide a more accurate measurement of
the constituents of concern, since there is no problem based upon
the calibration to one constituent. However, Draeger tubes are
not available for all volatile constituents of concern. They are
also slightly more difficult to use, in that the investigator
should carry around Draeger tubes for each of the potential
constituents or vapor classes of concern at the site. Still,
they should be considered extremely portable.
3. Monitoring Stations with Tenax Tubes
In some situations, the investigator may find it necessary
to install a stationary monitoring station for making more quan-
titative determinations of air releases at a site. This air
monitoring will involve the use of Tenax tubes to collect organic
constituents, and subsequent laboratory analysis of these
constituents with a GC/MS. This sampling technique will seldom
be necessary during the RFA, primarily due to its technical
difficulty, and because the simpler techniques described here
will generally provide sufficiently useful results.
The investigator should consult with qualified professionals
familiar with the use of air monitoring devices, when he/she
believes that more quantitative evidence of a release will be
necessary in the RFA. '
IV. MAKING RELEASE DETERMINATIONS
The final task in the RFA process is to make determinations
of release potential throughout the facility and to make recommen-
dations for further action to address these potential releases.
This section summarizes information that the investigator should
consider when making release determinations in the air pathway.
Chapter Four presents the general procedure to be followed
when making release determinations during the RFA. This involves:
o Evaluating sampling results from the SV;
o Integrating facility information gathered in the PR and
the ,VSI;
o Determining the likelihood of release at the facility; and
o Making recommendations concerning the need for further
i nvesti gati ons .
7-18
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9502.00-5 -
The investigator should rely upon his/her best professional *
judgment when making release determinations in the air pathway.
In order to make a release determination, the investigator will
probably have to demonstrate that a unit of concern contains
constituents that have a potential for vapor-phase or particulate
release. In most cases, this information on constituent release
potential along with some indirect evidence of release (e.g.,
odors, observed particulate releases, facility-wide sampling
data) will prove sufficient to make an adequate release determin-
ation. However, in certain cases, it will be necessary to obtain
existing or new direct evidence of release that links constituents
identified through sampling with constituents in the unit.
Exhibit 7-5 is a checklist that should help the investigator
evaluate specific factors to identify air releases. In identifying
releases, the investigator should consider types of information
presented in Exhibit 1-1, which are highlighted in the checklist.
7-19
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EXHIBIT 7-5
CHECKLIST FOR AIR RELEASES
o Unit Characteristics
Is the unit operating and does it expose wastes to the
atmosphere?
Does the surface area of the unit create create a potential
for air release?
o Does the unit contain waste that exhibits a potential for
vapor phase release?
Does the unit contain hazardous constituents of concern as
vapor releases?
o Does the unit contain waste and exhibit site conditions that
suggest a potential for particulate release?
Does the unit contain hazardous constituents of concern as
particulate releases? ' .-
Do constituents of concern as particulate releases {e.g.,
smaller, inhalable particulates) have potential for release
via wind erosion, reentrainment by moving vehicles, or
operational activities?
o Evidence of Air Release
Is there direct evidence of release from the unit (e.g.,
air sampling data; observed particulate releases)?
Is there indirect evidence of release from the unit (e.g.,
evidence of contamination around the facility that may have
resulted from an air release; OSHA monitoring data; citizen
compliants regarding health problems, odors, or observed
particulate releases)?
7-20
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y 5u 2. oo- s 2*
CHAPTER EIGHT
SUBSURFACE GAS
I. INTRODUCTION
A. Purpose
This chapter provides technical information to support the
investigation of releases of subsurface gas during the RFA.
While Chapters Two, Three, and Four provide general guidance on
conducting RFAs, this chapter focuses on specific factors unique
to subsurface gas releases that should be considerd by the inves-
ti gator.
B. Scope
In the RFA, investigators should determine whether releases
of subsurface gas have occurred at a facility. In general, EPA's
primary concern is to determine whether there are gas releases
that could reach explosive levels in on-site or off-site buildings.
Therefore, the primary constituent of concern in the subsurface
gas investigation is methane, due to its explosive properties and
frequency of detection in subsurface gas.
As with other media, the investigations that may be required
'in an RFI to determine the nature and extent of subsurface gas
releases will be very resource intensive .for both the owner/operator"
and for the Agency. Therefore, the investigator should also
identify in the RFA those units/facilities that do not require
further investigation for subsurface gas releases.
This chapter has been organized to reflect the separate
phases of the RFA process:
o Making a preliminary assessment of subsurface gas
releases in the PR ;
o Obtaining evidence in a VSI;
o Collecting additional sampling information in a SV; and
o Making release determinations.
The first section describes the technical factors that should
be considered during the PR and VSI. The second section describes
the technical approach to obtaining additional sampling information
in the SV for subsurface gas releases, and should be consulted
along with Chapter Four on general guidance to be followed in
conducting a SV. The final section discusses factors to consider
when making release determinations of subsurface gas releases.
This section also presents options for further investigation of
subsurface gas releases to be evaluated at the end of the RFA.
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II. CONDUCTING A PRELIMINARY REVIEW AND VISUAL SITE
INSPECTION OF SUBSURFACE GAS RELEASE POTENTIAL
This section presents technical information related specif-
ically to subsurface gas releases to be considered when conduct-
ing the PR and VSI. Accordingly, this section has been organized
to reflect the primary goals of these steps in the RFA:
o Identifying and describing potential threats from
subsurface gas at RCRA facilities; and
o Making a preliminary assessment of the need for and
extent of sampling required.
This section presents technical information specific to this
pathway covering the five types of information described in
Exhibit 1-1, and technical information to help the investigator
determine when additional sampling will be necessary in a SV to
identify subsurface gas releases. The section discusses these
six types of information separately:
(1) Unit characteristics;
(2) Waste characteristics;
(3) Pollutant migration pathways;
(4) Evidence of release; '.-
(5) Potential receptors; and
(6) Determining the need for additional sampling
i nformati on .
This information will be relevant to the evaluation of
written documents in the PR and information gathered in a VSI.
A. Unit Characteristics
The design and operating characteristics of a unit will
determine to a great extent its potential for releasing methane.
The investigates should evaluate the unit characteristics of each
SWMU or group of SWMUs at a facility to determine their potential
for contributing to the generation and release of methane in
subsurface gases.
The general potential for subsurface gas release* from a
SWMU depends, to a great extent, upon the nature and function of
the unit. The investigator should assess each unit based upon:
o An understanding of the overall potential of the unit
to cause subsurface gas releases;
8-2
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9502.<00i5 -
o An understanding of the primary mechanisms by which
releases may occur from the unit; and
o An assessment of unit-specific factors which, singularly
or in combination with each other, indicate the relative
likelihood of subsurface gas releases from the unit.
The investigator should first consider the relative potential
of the unit to release. Exhibit 8-1 presents a generalized rank-
ing, in rough descending order, of the different types of SWMUs and
their overall potential for causing subsurface gas releases, and
a listing of the most common mechanisms by which these releases
can occur from each unit type.
It should be understood that Exhibit 8-1 provides only a
theoretical sense of the relative potential of these units to cause
releases. Unit-specific factors should be evaluated in determining
whether further investigations are needed for a particular unit.
Only two types of solid waste management units are of
concern in the subsurface gas investigation due to their poten-
tial for generating methane or other subsurface gases of concern.
These units include active and closed landfills and units that
have been closed as landfills. Each is described more fully
below:
0 Landf111s. Landfills are the most likely SWMUs to
.generate subsurface gases resulti-ng in a rel.ease. Th«
underground deposition of decomposable refuse with or
without hazardous c-onsti tuents provides a large source
of gas and a driving force that can carry other gases
venting to the atmosphere and/or migrating horizontally
as a subsurface gas. Closing landfills with impermeable
caps without venting systems retards the release of these
landfill gases as surface emissions. In these instances,
a large percentage of those gases migrate laterally
through soils along confining barriers such as ground
water tables, clay layers, synthetic liners, and compacted
covers. This migration could cause significant accumula-
tions of potentially explosive gas in facility structures
or in buildings off-site.
o Units closed as 1andfn.1_s. Inactive SWMUs that have been
closedas landfills maygenerate subsurface gases. These
sites include closed surface impoundments or waste piles
containing decomposable or volatile wastes with in-place
impermeable covers. Similar to landfills, gases generated
in sites closed as landfills may migrate laterally, pos-
sibly causing significant accumulations. However, closed
surface impoundments and waste piles generally contain
small quantities of decomposable and volatile wastes and
are at shallow depths. Thus, significant gas migration
and subsequent subsurface gas releases are less likely
for these'units than for landfills.
8-3
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EXHIBIT 8-1
UNIT POTENTIAL FOR SUBSURFACE GAS
RELEASES AND MECHANISMS OF RELEASE
Unij Type
Closed Landfills
o Lateral migration of methane beneath
landfill cap to on-site or off-site
structures .
o Migration of methane through conduits
to on-site or off-site structures.
Active Landfills
o Lateral migration of methane beneath
landfill cap to on-site or off-site
structures
Closed Water Piles
o Lateral migration of methane beneath
landfill cap to on-site or off-site
structures .
Closed Surface
Impoundments
o Lateral migration of methane beneath
landfill cap to on-site or off-site
structures.
8-4
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Other SWMUs are unlikely to have subsurface gas releases
because gases generated in the units are more likely to vent to
the atmosphere than to concentrate in the unsaturated soil.
Barriers (e.g., paving, compaction, or installation of covers for
closure), can permit some lateral migration to occur from these
units. Generally, however, this lateral migration will be limited
to the extent of the barrier. Shallow SWMUs will also have a
lower potential for releasing methane, since availability of
oxygen will interfere with the anaerobic conditions supporting
methane generation.
Although depth is one of several considerations for deter-
mining the potential for releases, the type of SWMU establishes
potential migration pathways and the waste characteristics create
the driving force for subsurface gas movement. Exhibits 8-2 and
8-3 illustrate some potential pathways from a few types of SWMUs.
The investigator should consider the characteristics presented
here when evaluating the likelihood of a SWMU to release methane.
B. Waste Characteristics
The investigator should attempt to identify the wastes
originally contained within a SWMU or group of SWMUs during the
PR, in order to determine their potential for generating methane.
The investigation for methane is different than investigations
for releases to the other media discussed in this guidance, in
that the constituent of concern in this chapter is generated in
the un,it, rather than merely a waste present from a treatment,
storage, or disposal activity. Therefore, the investigator
sh'ould determine whether wastes conducive to the generation of
methane are present in SWMUs at the facility.
Anaerobic decomposition of organic wastes generates large
volumes of methane gas under the proper conditions. When methane
is generated in SWMUs, the potential exists for it to accumulate
under pressure and to migrate from the unit, thereby posing a
significant risk of explosion. The methane may also be mixed
with other volatile hazardous constituents present in the unit,
and may increase the potential hazard associated with the accumu-
1ated gas.
Conventional solid waste refuse and biological sludges
are the primary waste type of concern for generating methane gas.
The volume of gas produced in the unit depends upon both the
quantity and types of refuse present. Units may either contain
primarily refuse or a mixture of refuse and hazardous wastes.
Units where refuse has been codisposed with hazardous wastes may
pose the most serious threat, because of the potential for other
volatile hazardous wastes to be mixed with the methane.
Higher volumes of methane will be generated at units con-
taining larger quantities of refuse. The volume of gas generated
.4lso depends upon the age of the unit and how long the waste has
xeen in the unit. Methane generation will increase slowly after
waste emplacement to a maximum generation rate which will slowly
decline as the waste decomposes. The active lifetime for methane
8-5
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8-6
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generation from units closed as landfills depends primarily upon
the amount of precipitation infiltrating into the waste. Land-
fills in the arid Southwest will generally produce methane for
20-30 years, while landfills in the humid Southeast may only
generate methane for 4-5 years after waste emplacement. Landfills
with higher moisture content provide a more suitable environment
for bacterial degradation.
The temperature of waste at the time of emplacement can also
affect the methane generation rate. Wastes placed in landfills
in the winter at temperatures below 10° C may not generate methane
for up to 5 years, even in climates with warm summers, due to the
insulating properties of the waste. The waste can remain at tem-
peratures low enough to effectively inhibit bacterial decomposition
for several years. The types of refuse disposed in the unit can
also affect the rate of methane generation. Descriptions of the
two types of refuse that can generate methane and a brief discus-
sion of other wastes that may mix with methane follow:
o Rapid Decomposable Refuse. Rapid decomposable wastes
will produce methane at high rates under the proper
conditions. These wastes include organic sludges from
wastewater treatment facilities, food wates, garden
wastes, and other vegetable matter (e.g., grass clippings,
tree trimmings, etc.). The high concentration of readily ,
degradable organic-compounds in these wast'es provides an
ideal energy source for the anaerobic organisms that
produce methane.
o Slow Decomposable Refuse. Slow decomposables will not
produce the immediate high volumes of methane possible
with the rapid decomposables. However, they will produce
methane at lower rates in the unit over a longer period
of time, and thus also pose a substantial threat. Slow
decomposables include paper, cardboard, wood, leather,
some textiles, and several other assorted organic ma-
terials. Slow decomposables are commonly a large percen-
tage of municipal refuse, and should be present in large
quantities if the SWMUs contain municipal refuse.
o Other Wastes of Concern. Volatile organic wastes disposed
in the unit of concern for subsurface gas releases may
volatilize into the pockets of methane gas produced by
refuse decomposition and increase the hazard associated
with the gas. This situation could occur where lie;; ids
such as solvents have been disposed of in landfills or
waste piles in high concentrations. These compounds are
not likely to migrate from the unic unless methane is
present to act as a carrier. However, certain volatile
compounds would be likely to form mixtures with methane
where wastes are codisposed. The volatile wastes and
waste constituents of concern for subsurface gases are
the same as those that have the potential for air
releases. These are listed in Exhibit 7-2.
8-8
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C. Pollutant Migration Pathways
The investigator should evaluate any available information
pertaining to the hydrogeologic characteristics of a facility
in order to determine the pollutant migration pathways associated
with subsurface gas releases during the PR. As stated previously,
methane can accumulate under pressure within certain types of
units, and then migrate from that unit through the subsurface due
to the force of this pressure.
Certain natural conditions and engineered structures can act
as barriers that impede the migration or conduits that promote
the migration of subsurface gas. For example, venting systems
can prevent subsurface gas migration, while underground utility
lines can promote migration. We describe below several factors
that can affect the migration of subsurface gas:
(1) Natural barriers and conduits; and
(2) Engineered barriers and conduits.
1. Natural Barriers and Conduits
Gas migration can be impeded by various geologic barriers.
A soil's effective porosity and permeability are perhaps the most
important natural barriers to gas migration. Porosity is a
function of soil type, moisture .content, and weathering. Permea-
bility is determined by soil type. Tight, uniform soild such as
clays, at least to the depth of the unit, are good barriers.
Sandy soil will likely encourage venting of gas to the atmosphere,
thus preventing horizontal migration. Climatic conditions such
as precipitation or freezing can also affect gas migration. Both
factors tend to reduce the porosity of surface soils preventing
upward gas migration.
Gas migration can also be impeded or prevented by hydrologic
barriers such as surface water, ground water, and saturated soils.
Subsurface gas does not penetrate ground water and surface water.
Thus, if there is a lake or perennial stream between the unit and
any structure, migration is unlikely. A high ground water table
will restrict migration to the shallow unsaturated zone. High
water tables also allow for the use of trenches as gas control
devices.
Subsurfa-ce gases that come in contact with these barriers
will tend to migrate towards the pathway of least resistance,
either man-made or natural conduits. For example, sand and
gravel lenses below a less permeable soil layer are excellent
conduits for subsurface gas migration. As an uncommon example,
if a landfill or site closed as a landfill was surrounded (along
all sidewalls and bottom) by water, gas migration beyond the
confining barrier would not be expected. In most cases, however,
ground water and saturated soils only partially surround a unit
(usually along the bottom). Thus, lateral or vertical migration
can occur through this natural conduit.
8-9
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2. Engineered Barriers and Conduits
Some facilities may have engineered structures which either
intentionally or unintentionally impede the migration of subsurface
gas. Engineered barriers include:
o Synthetic liners that effectively contain wastes;
o Slurry walls that border landfill units; and
o Gas control or venting systems.
The investigator should review documents on the design and opera-
tion of these systems and inspect the systems to confirm that
they are functioning properly. Subsurface gas control systems
are almost exclusively associated with disposal sites for
municipal-type waste rather than for hazardous waste. These
systems are probably only present afe hazardous waste facilities
where municipal waste is codisposed with hazardous waste or where
a sanitary landfill is operating at the same site.
Gas migration from SWMUs may be facilitated by man-made
structures located within the facility or near the property
boundary. Examples of engineered structures which may act as
condui ts i nclude :
o Underground power transmission lines;
o Sewer and drainage pipes; and
o Und-erground telephone cables.
Gases migrating from a SWMU may enter the gravel-backfi11ed
trenches surrounding these structures and travel great distances
to buildings or other engineered structures, resulting in a
potential hazard. It may be useful to inspect the facility blue-
prints and check with utilities to the extent that these tasks
were not completed" during the PR or VSI in order to ensure that
no structures are present that could increase the likelihood of
gas migration to on- and off-site receptors.
D. Evidence of Release
The investigator should examine any available sources of
information to identify evidence that subsurface gas has migrated
from a facility. Most evidence of subsurface gas releases will
usually be limited to official reports of explosions at or near
the facility. In some cases, there may be sampling information
taken from ve'nts placed near the units indicating the presence of
methane in a unit, linger most ci rcumstarces, the investigator
should assume that units containing metKane will pose a threat
for migration and potential explosion.
E. Exposure Potential
The Investigator should evaluate available information on
the location, number, and characteristics, of buildings that
could be affected by subsurface gas releases at the facility. As
stated at the beginning of this chapter, the RFA will focus
8-10
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9502. 00-s
primarily on the potential for methane to migrate to on-site ana
off-site buildings. Typically, methane can migrate up to 1000
feet from its source, although it could travel further under ideal
condi tions.
Potential receptor information will be used primarily to
help the investigator determine the need for immediate corrective
measures at the facility in order to alleviate potentially high
risks of explosion attributable to methane migration. In general,
immediate actions may be necessary when the investigator encounters
buildings with explosimeter readings above 25% of the LEL (lower
explosive limit). The investigator should identify those structures
that may be located close enough to a source of methane to warrant
further investigation, and in some cases, sampling.
F. Determining the Need for Additional Sampling in the SV
If the investigator determines, based on his inspection of
the unit, that there is a significant potential for the unit to
generate methane, and that the site geologic and hydrogeologic
conditions may promote migration , he/she may choose to sample to
determine conclusively whether methane has been released. We
discuss in this section:
(1) General information on factors to consider in determining
the need for additional sampling information;
(2) Factors to' consider in selecting sampling parameters; and
(3) An example to illustrate this discussion.
1. General Information on Determining the Need for Sampling
The following list presents several situations in which the
investigator may find it useful to obtain additional sampling
information during a SV:
o To identify explosive levels of methane in structures; to
identify the need for emergency action;,,
o To confirm adequate operation of a landfill gas venting
system;
o To identify the presence of refuse in units with unknown
waste composition; and
o To confirm the presence of toxic constituents mixed with
subsurface gas.
The investigator should use best professional judgment in
determining when a SWMU may be a source of subsurface gases.
When he/she believes that a unit contained decomposable wastes,
and believes that the site conditions could facilitate methane
8-11
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migration, it may be appropriate to sample for methane at appro
priate locations. These are described in detail in Section
III of this chapter.
2. Selection of Sampling Parameters
As stated previously, methane will be the primary constituent
of concern for investigations of subsurface gas releases. There-
fore, the investigator will usually sample for methane when
identifying releases.
However, under certain unusual situations (e.g., units where
large quantities of refuse were codisposed with hazardous wastes),
it may be necessary to identify the presence of other potentially
hazardous constituents in subsurface gas. In these cases, the
potential constituents of concern will the same as those identi-
fied as potential constituents of concern for air releases-. The
investigator should refer to Chapter Seven of this document for
guidance on identifying and sampling these constituents of concern,
3. Example
An illustration of a situation in which sampling would be
called for follows: An electroplating facility previously dis-
posed some of its electroplating sludges along with refuse gen-
erated at the facility in a medium-sized landfill (2 acres). The
company closed the landfill five years before the RCRA investi-
gator began 'conducting the RFA. They closed the landfill by
installing a clay cap with a vegetative cover.
The investigator found records of the past use of the land-
fill during the PR, and recognized a potential methane generation
problem. After requesting a facility diagram from the owner/oper-
ator, the investigator discovered a telephone line running from
off the facility boundary, underneath and adjacent to the landfill
towards one of the facility structures. The investigator recog-
nized the underground telephone line to be a potential conduit
for any methane migrating from the closed landfill.
Because the telephone line entered a facility structure, the
investigator would decide to take explosimeter readings within
the structure of concern. However, because the absence of methane
in the facility structure does not necessarily prove the absence
of methane, the investigator also decides to take several soil
gas measurements around the perimeter of the landfill, in order
to identify the presence of methane at the unit boundary.
III. COLLECTING ADDITIONAL INFORMATION IN THE SV
This section presents technical information related specific-
ally to subsurface gas releases to be considered when collecting
additional sampling information in the SV. The information
presented here should be used to help the investigator meet one
of the primary goals of the SV:
8-12
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'2-00-5
o To collect additional sampling information to fill data
gaps identified in the PA, leading towards final, release
determinati ons.
For each sampling method discussed, this section describes:
1) the general kinds of situations in which it will be appropriate
to employ a specific technique, 2) technical information on how
to conduct the sampling, and 3) specific details to be considered
when evaluating the sampling results. This section does not
provide the actual SOPs on the sampling techniques here. However,
it references the relevant manuals.
The choice of appropriate sampling methods will have a large
impact on the cost and usefulness of the SV. The investigator
should be confident when developing and reviewing the sampling
plan that the procedures chosen will meet the needs of the RFA,
while not resulting in the collection of unnecessary data.
One example of a sampling technique that will be appropriate
for identifying subsurface gas releases during the RFA is the
combustible gas meter (explosimeter) measurement. Considerations
on how to use this device and on evaluating its results follow
below.
1. Combustible Gas Meter
Methane field monitoring can be performed with combustible gas
meters in buildings, sewers, or fn the s,oil. A combustible gas
meter will provide a reliable determ-i nation of combustible gas
concentrations. It will not indicate whether or not the combust-
ible gas detected is actually methane gas, although, if the waste
in the unit could generate methane, it is likely that the meter
is detecting methane. Any significant gas reading (whether it is
methane or not) is of concern.
Combustible gas meters usually indicate the percentage of
the lower explosive limit (LEL) of the atmosphere being monitored.
The LEL indicates the lowest concentration of methane in air
which could result in combustion, or in severe cases, an explosion.
EPA guidelines under CERCLA consider 25% of the LEL to be an
action threshold; the investigator should evacuate immediately
when readings higher than 25% of the LEL are obtained.
Reported experience indicates 0 to 100 percent of the lower
explosive limit detection to be accurate with hotwire catalytic
combustion principal instruments. However, many users prefer
instruments with the capability of determining both the 0 to 100
percent LEL and the percent methane present when the concentra-
tion exceeds 100 percent LEL (i.e., 5 percent methane). Dual
scale instruments are available for this application. Typically,
the 0 to 100 percent gas scale uses a thermal conductivity sensor.
The carbon di.oxide in 1 andfi 11-generated gas is reported to
interfere with the thermal conductivity sensor, so the investigator
should not assume that readings above 100 percent LEL are accurate.
8-13
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Some of the single scale 0 to 100 percent LEL instruments can
also be fitted with air dilution tubes or valves- to allow readings
of the percent gas when the concentration is above the LEL.
Instructions on the use and calibration of these instruments
should be obtained from the manufacturer.
Monitoring in a facility structure (e.g., buildings, sewers,
existing monitoring wells, gas vents) should normally be done
after the building has been closed overnight or for a weekend,
and when the soil surface has been wet or frozen for several
days. Monitoring or sampling should be done in confined areas
where gas may accumulate, such as basements, crawl spaces, near
floor cracks, attics, around subsurface utility connections, and
in u.ntrapped drain lines.
Soil gas monitoring can be performed to identify the potential
for methane releases at a unit. The investigator will normally
drill shallow wells of a minimal diameter (2") and insert the
monitoring device in the hole. There will be some time delay
due to the slow movement of gas through the soils and into the
wel 1 .
IV. MAKING SUBSURFACE GAS RELEASE DETERMINATIONS
The final task in the RFA is to make release determinations
and recommendations concerning the need for further investigation
(e.g., an RFI). While subsurface gas p-robl ems'may not occur at
a large number of facilities", where they ar'e encountered, they
may pose extremely high risks to the investigator and facility
employees.
Exhibit 8-4 is a checklist that should help the investigator
evaluate specific factors to identify subsurface gas releases, or
to identify sites that have a high potential for gas release and
gas migration to on-site or off-site buildings. In identifying
releases, the investigator should consider the series of factors
described in the chapter and highlighted in the checklist to
determine the potential for release. The primary factors include:
whether or not the unit contains waste that generates methane, and
the potential for migration through the subsurface.
8-14
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^502.00-5 3
Exhibit 8-4
Checklist for Subsurface Gas Releases
1. Potential for Subsurface Gas Releases
o Does the unit contain waste that generates methane or
generates volatile constituents that may be carried by
methane (e.g., decomposable refuse/volati1e organic wastes)?
o Is the unit an active or closed landfill or a unit closed
as a landfill (e.g., surface impoundments and waste piles)?
2. Migration of Subsurface Gas to On-site or Off-site Buildings
o Are on-site or off-site buildings close to the unit?
o Do natural or engineered barriers prevent gas migration
from the unit to on-site or off-site buildings (e.g., low
soil permeability and-porosity hydrogeologic barriers/liners,
slurry walls, gas control systems)? .
o Do natural site characteristics or man-made structures
(e.g., underground power transmission lines, sewer pipes/
sand and gravel lenses) facilitate gas migration from the
unit to buildings?
3. Evidence of Release
o Does sampling data indicate a release of concern?
8-15
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950 2 00-5
CHAPTER NINE
SOILS
I. INTRODUCTION
A. Purpose
This chapter provides technical information to support the
investigation of releases to soils during the RFA. While
Chapters Two, Three, and Four provide general guidance on conduc-
ting RFAs, this chapter focuses on specific factors unique to the
soil medium that should be considered by the investigator.
This chapter has been organized to reflect the separate
phases of the RFA process:
o Conducting a preliminary review of information on soil
releases;
o Conducting a visual inspection of the facility;
o Collecting additional sampling information in the SV; and
o Making release determinations.
The first section describes the technical factors that
should be considered during the PR and VSI. The second section
describes the technical approach to obtaining additional .sampling
information in the SV-for soils, and should be consulted along
with Chapter Four on conducting a SV. The final section discusses
factors to consider when, making final release determinations to
soils at the end of the RFA.
It should be understood that it is not the objective of an
RFA to identify all areas of contaminated soil at a facility, and
to require further investigaiton for all contaminated soil areas.
Investigators should focus on identifying soil contamination
which, through direct contact of humans or other potential
receptors, or by leaching or otherwise migrating to other media
such as ground water or surface water, poses a threat to human
health and the environment. Not all soil contamination poses
such risks; investigators should only focus on areas of soil
contamination which clearly have the potential for causing serious
environmental problems.
B. Scope
During the RFA, the investigator should evaluate the likeli-
hood that the facility has releases to soils which pose a threat
to human health and the environment. While in most cases this
will relate to contamination from specific units, there may be
situations where other sources of soil contamination may be
impacting human health and the environment.
-------
II. CONDUCTING A PRELIMINARY REVIEW AND VISUAL
SITE INSPECTION OF RELEASES TO SOILS
This section presents technical information related specifi-
cally to the soil medium to be considered when conducting the PR
and VSI. Accordingly, this section has been organized to reflect
the primary goals of these processes described in Chapters Two
and Three:
o Identifying and describing potential releases to soils at
RCRA faci1i ties; and
o Making a preliminary assessment of the need for and ex-
tent of sampling required.
This section presents technical details on each of the five
types of information described in Exhibit 1-1:
(1) Unit characteristics;
(2) Waste characteristics;
(3) Pollutant migration pathways;
(4) Evidenceof_ release; and
(5) Expo-sure potential.
In addition, technical information is provided to help the inves-
tigator determine when additional sampling will be necessary in a
SV to identify soil releases. Each area is discussed separately.
A. Unit Characteristics
A unit's design and operating characteristics of a SMWU will
determine to a great extent its potential for releasing hazardous
constituents to soils. Many treatment, storage, and disposal
units are designed to prevent releases to the environment. The
investigator should evaluate the characteristics of each SWMU or
group of SWMUs at a facility to determine their potential for
releasing hazardous constituents to soils.
As with.other media, the likelihood that a SWMU has contam-
inated soils is largely dependent on the nature and function of
the unit, iherefore, each SWMU or grouping of similar units
should be evaluated for its potential to release constituents
that may contaminate surrounding soils. The unit evaluation
should be based upon:
o An understanding of the inherent design characteristics
and features that might cause the unit to have a release
to surrounding soils;
9-2
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tAn IB i i
RANKING OF UNIT POTENTIAL FOR SOIL RELEASE
AND MECHANISMS OF RELEASE
Unit Type
Surface Impoundment
Landfill
Waste Pile
Land Treatment Unit
Contai ner Storage
Area
Above-ground Tank
In-ground Tank
Inci nerator
Class I and IV
Injection Well
Release Mech an i sm
o Releases from overtopping
o Seepage
o Migration of run-off outside the unit's
run-off collection and containment system
o Migration of spills and other releases
outside the containment area from
loading and unloading operations
o Seepage through dikes to surrounding
soils
o Migration of run-off outside the unit's
run-off collection and containment system
o Migration of spills and other releases
outside the containment area from
loading and unloading operations
o Migration of run-off outside the
containment area
o Migration of run-off o'utside the
containment area
o Releases from overflow
o Leaks through tank shell
o Spills from coupling/uncoupling
operations
o Releases from overflow
o Spills from coupling/uncoupling
operations
o Spills or other releases from waste
handling/preparation activities
o Spills due to mechanical failure
o Spills from waste handling opera-
tions at the well head
* The two remaining solid waste management units; waste transfer
stations, and waste recycling operations generally have mechanisms
of release similar to tanks.
9-3
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o An understanding of the primary mechanisms by which the
releases may occur from the unit and the potential for
thi s release .
When assessing the likelihood of releases to soils from a
unit, the investigator should initially consider the relative
potential of the unit for a release. For example, an above-ground
tank located directly on soil has a greater potential for a
release than does the same tank raised two feet above a cement
pad with adequate curbing. Exhibit 9-1 presents a generalized
ranking of the different types of SWMUs and their potential for
having releases that contaminate surrounding soils. Exhibit 9-1
also lists the mechanism for release associated with each unit
type.
The major unit-specific factors the investigator should
evaluate are discussed below.
1. Unit design
The design factors of the unit, including its capacity and
dimensions, can indicate the potential for a soil release. For
example, an undersized above-ground tank will be more susceptible
to overtopping than an adequately sized unit.
Features designed to reduce or eliminate release should also
be considered. Some features are better able to eliminate releases
than others.. A triple-lined landfill with a leachate collection
system will be less prone to subsurface releases than a single
clay-lined surface impoundment.
2. Operational history
The investigator should evaluate the unit's operational
history for information which indicates that a release may have
occurred. Operational factors that may influence the potential
for a release include:
o The length of service life of the unit. Older units will
have a greater potential for a release, particularly due
to failure of liners or control equipment than newer units
o Operational status (Active, inactive, closed)
o Operational procedures such as proper maintenance, regular
inspections and records. A well maintained unit has less
likelihood of leaks, spills or enuipment failure.
3. Physical Condition of Unit
During the VSI, investigctor should examine the units for
evidence of releases or characteristics that could cause releases.
For example, when examining a surface impoundment, he/she should
determine whether'the earthen dikes are structurally sound and
capable of preventing releases. Cracks, slumping, or seeps
9-4
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950 2 , 00- -'
' -j
around the toe in the dike may show evidence that the unit's
condition may cause releases to the surrounding soils.
B. Waste Characteristics
The investigator should attempt to identify the wastes
originally contained within a SWMU or group of SWMUS during the
PR. In the RFA, the investigator should try to connect informa-
tion on waste types, unit characteristics, and evidence of soil
contamination to demonstrate the likelihood that specific SWMUs
or groups of SWMUs have released constituents to the soils. This
section describes technical factors to consider when identifying
waste characteristics relevant to soil releases. It also discusses
physical/chemical properties that affect the release potential
of wastes and their subsequent transport in soils.
Information on wastes is usually available in Part A permit
applications, inspection reports, and facility operating records
reviewed during the PR. The investigator should compile specific
information on waste characteristics in order to assess not only
the potential for a release to soils, but also to identify the
chemical form that the hazardous constituent might take in the
soil environment, and to determine if a contaminant found in a
soil release can be expected to migrate to other media.
Constituents tend to migrate in different forms an,d at dif-
ferent rates in the soil medium, depending upon their properties.
Some Appendix VIII consti tuents are insolu.bl.e-in water and bind
tightly* to soil particles, thus minimizing their migration poten-
tial. Therefore, it is important to evaluate a waste's mobility
in order to determine its potential for dispersion in soils and
its tendency for transfer to other media. Releases of organics
may behave very differently than metals in the soil environment.
Hazardous metals and inorganics (e.g., arsenic and cyanide)
may be relatively mobile. Other inorganics and metals (e.g.,
lead) are less mobile depending upon the pH of the wastes, and
the ligands available in soil for complex formation.
The mobility of organic constituents can be expressed
quantitatively by the sorption equilibrium constant (Kd). The
value of K,.) depends upon the organic content of the soil and the
constituent-specific soil adsorption coefficient (KQC).
The investigator will seldom have access to information on
organic content of soils at a facility; instead it will be more
useful to estimate the relative mobility of a constituent as
expressed by Koc. Koc values have been calculated for only a
small set of hazardous constituents; however, the octanol-water
coefficient as expressed by (Kow), can be used as an indicator of
Kd. Appendix E presents Koc and log(Kow) values for most consti-
tuents of concern. Because these values are log values, chemicals
with KpW values of more than two can be considered relatively
immobile. Values less than one are considered to be mobile.
9-5
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The volatility and biodegradabi1ity of constituents can also
be important in identifying whether contaminated soil can act as
a transfer medium. For example, highly volatile components of a
past release may no longer be present for detection in a sampling
program. Readily biodegradable components also may not be present
although certain degradation products may indicate that a release
has occurred.
C . Pollutant Migration Pathways
The investigator should evaluate during the PR available
information pertaining to potential soil migration pathways at a
facility. Contaminated soils can transfer chemicals to ground
water by leaching, to surface water by contaminating run-off, and
to air by the suspension of contaminated particulates. This
information will play a major role in identifying the potential
for intermedia transfer of releases during the PR.
The identification of migration pathways associated with
soil releases will be most important when the soil is being
evaluated as a transfer medium. Basic to any evaluation of
pathways for soils is the assessment of site geology, soil type,
and climate. This evaluation relies on standard information
usually available during the PR for each site. The primary
climatic effect that should be determined is the annual rainfall.
Sites located in regions with high annual or seasonal precipitation
will h.ave a greater potential for releases to spread through the
soil or to the other aqueous media.. -Conversely,, very arid regions
may be susceptible to 'wind-borne distribution of contaminated
soi1 particulates.
The investigator should evaluate the site's topography and
look for low lying areas where spills may collect. He/she should
also estimate the proximity of the unit in question to surface
water, particularly locations within flood plains.
The underlying geology of a site should be determined in
order to evaluate the potential of soils to transfer contaminants
to that medium. Soil characteristics that are to be evaluated
are dependent upon underlying geology.
The determination of site-specific soil characteristics will
be useful when determining the impact of a potential soil release.
Soils are characterized by particle size, ranging from large sand
particles, te silt, to the small clay colloids. Loams are soils
where these particles are found in various percentages. Releases
will be distributed through sandy soils more readily than through
clays. Clays usually have an associated attraction for certain
chemicals since they are weakly ionized.
The organic content of soils will also affect their ability
to bind or biodegrade certain chemical releases. This informa-
tion is avai1able.for most sites from USGS or State Soil Conserv-
ation Service soil maps. Interpretive data are usually available
9-6
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9502.00*5
along with the map. General information will often be included
on the depth of a soil layer.
D. Evidence of a Release
During the PR, the investigator should examine available
sources of information to identify evidence that constituents
have been released to soils at a facility. The investigator
should evaluate both direct and indirect evidence of release
during the PR. Chapter Two outlines general considerations on
looking for evidence of releases.
The VSI is particularly useful for identifying releases to
soils. Stressed vegetation can indicate the likelihood of a soil
release. Direct evidence of soil releases includes:
o Evidence of oiliness or slick on soils; and
o Discoloration from background soil color.
Direct evidence of a release may also include official
reports of prior release incidents, such as a major tank leak
onto the ground. Indirect evidence of a release to soils may be
provided by ground-water monitoring data that show contamination.
When the investigator identifies indirect evidence of this type,
it may be possible to determine the source of the release by
evaluating the pollutant/soil migration pathways and the waste
characteristics at the facility. Soil sampling data may exist at
some facilities, although th'i s will 'not-be likely", since there
are no requirements for soil monitoring.
There are likely to be instances of soil contamination that
cannot be linked directly to units at a facility. Areas that
were used to handle wastes in the past but are now unused may
have contaminated soil.
E. Exposure Potential
The investigator should evaluate available information on
the location, number, and characteristics of potential receptors
that could be affected by releases to soils at the facility.
These receptors include human populations, animal populations
(particularly any endangered or protected species), and sensitive
envi ronments .
While it is not within the scope of the RFA to estimate the
risk associated with a release to soils, it is important to iden-
tify any potential for direct exposure to the release. Informa-
tion on the potential for direct exposure include:
o The security of the facility. Is access to the site
prevented by adequate fencing or barriers?
9-7
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o The proximity of the unit/facility to children, specifi-
cally to schools and play grounds.
If the migration of chemicals from soil releases to other
media has been identified, the sections in th is Guidance on
releases to those media should be refered to in order to determine
exposure potential to constituents released and transfered to
other media.
The investigator should evaluate the severity of the release
to soils along with the potential for direct exposure. If recep-
tors are currently being exposed to highly contaminated soils or
have a high potential for being exposed, the investigator should
consider recommending immediate corrective measures to limit
access and direct exposure.
F. Determining the Need for Additional Sampling
The investigator may not be able to determine whether a
release to soils from the unit has occurred, since existing data
may be unavailable or insufficient. In cases where historical
information and visual observations are not adequate to determine
if a release from a unit to soil has occurred or is likely to
have occurred, he/she should consider whether additional sampling
and analysis would help make a determination. In this section,
we present:
(1) General information' oh factors to consider in deter-
mining the need for additional sampling information;
(2) Factors to consider in selecting sampling parameters;
(3) An example to illustrate this discussion.
1. General Information on Determining the Need for Sampling
Soil sampling during the SV will generally be confined to
surface soils or to shallow coring using hand equipment. Because
of the relative ease in obtaining soil samples, in some cases,
soil sampling may be used to obtain information on releases to
ground water where existing wells may not be adequate and new
well placement is beyond the scope of the RFA.
The following are situations where soil sampling data could
be useful :
o Visual examination reveals an area at a facility where
unspecified wastes were applied in liquid form for several
years. Facility is situated on sandy soils with rapidly
moving ground water, with nearby drinking water wells
located apparently downgradient. Sampling data would
reveal presence of and types of constituents in the soil,
which if positive could trigger additional ground water
investigations.
9-8
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9502,0';^,
o Ground-water data downgradient from an above-ground tank
indicates contamination from its wastes. No record of
a spill exists and the unit appears structurally sound,
however, the observed contamination should have migrated
to the ground-water through the soils.
o Drainage patterns show that runoff from a landfill tends
to collect in a low lying area. Constituents expected to
be released sorb to soils and contamination of the run-
off can be veri fi ed .
2. Selection of Sampling Parameters
Knowledge of the wastes that may be potentially released from
a unit is the starting point when identifying sampling parameters.
However, many SWMUs have incomplete or no data on the wastes
deposited over time. When little is known of the wastes managed
in the unit, GC/MS scans for volatiles, acid extractables or
base/neutrals become a good starting point when selecting param-
eters for analysis in soils.
Metals are also of concern under RCRA. If a waste source is
hazardous due to EP Toxicity, the metals of concern are a smaller
subset: arsenic, barium, cadmium, lead, mercury, selenium, and
silver. The following metals precipitate readily under many
naturally occurring conditions and may be detected in soil anal-
ysis: cadmium, lead, nickel and zinc.
The volatile GC/MS scan identifies chemicals that are -charac-
teristic of solvents and lighter petroleum products. Beca.use
they are volatile, they can evaporate from soil releases into the
air. Evidence of these chemicals may be difficult to obtain in
older releases.
The acid extractables (i.e., phenols) may be present in
heavier petroleum feed stocks and certain industrial processes
(e.g. pentachlorophenol from wood preserving). Phenol and the
mono-halogenated phenols biodegrade in a soil environment.
Pentachlorophenol is very persistent.
Base/neutral compounds can often be found in wastes from
industries such as the plastics and synthetic fibers manufacturers
The pesticide scan identifies pesticides that are found in pesti-
cide wastes and products from the agrichemical industry.
All monitoring data should be coordinated with the unit
specific information available on the potential for constituents
to be released to soils and the investigator's professional
judgment.
9-9
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III. COLLECTING ADDITIONAL SAMPLING INFORMATION IN THE SV
This section presents technical information related specifi-
cally to the soils medium to be considered when collecting addi-
tional sampling information in the SV. Accordingly, the informa-
tion presented here should be used to help the investigator meet
one of the primary goals of the SV:
o To collect additional sampling information to fill data
gaps identified in the PR and VSI.
For each sampling method discussed, this section describes:
1) general situations where it is appropriate to employ a specific
technique, 2) technical information on how to conduct the sampling,
and 3) specific details to be considered when evaluating the
sampling results. This section does not provide the actual SOPs
on the sampling techniques. However, it references relevant
manuals .
The choice of appropriate sampling methods will have a large
impact on the cost and usefulness of the SV. The investigator
should be confident when developing and reviewing the sampling
plan that the procedures chosen will meet the objectives of the
RFA, while not resulting in the collection of unnecessary data.
We discuss soil sampling at surface, shallow depths, and special
cases where deep samples are warranted.
A. Gen'eral Information on Selecting Sampling Locatidns ' .
The investigator should use best professional judgment in
determining appropriate locations for soil sampling. During the
visual site inspection, pertinent topographic features should be
located. These features include drainage patterns, fill areas,
erosional and depositionals areas. Any surface run off, seeps,
springs and the proximity to surface water and wet areas should
also be noted. Releases from a unit will seek the lowest area.
Such low spots may be depositional areas for any released chemicals
and would be the best location to start any subsequent sampling.
Topographic maps are helpful. Strategically locating the sampling
areas should minimize the number of samples necessary and the
effort for their collection.
After identifying the areas designated for soil sampling,
the exact location of the sample area and the specific sample
location should be recorded on a site map. Soil sampling will be
generally completed by using surface samples and hand equipment.
Surface soil sampling should be conducted in depositional areas
since these areas tend to have higher concentrations of released
constituents. This is valuable for the screening function of the
RFA, but these levels are not indicative of the overall area
conditions. The extent of a release will be determined under the
RFI. j
9-10
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oavrs POLICY DIRECTIVE w.
*502.00.5
ne foot below
The depth of the sample (e.g., surface, o
surface) should be recorded in a field log book. When identify-
ing metal constituents from a release, it may be important to
consider soil type since many have natural background levels of
certain heavy metals.
8. Sampling Methodology and Evaluation of Results
Soil sampling will usually be done using hand equipment such
as stainless steel spoons, scoops, shovels, hand auger and small
diameter push tubes. This equipment is available for sampling at
shallow depths; however, when soil is difficult to penetrate,
even shallow sampling may require power equipment such as augers.
Shelby sampling tubes or thin wall push tubes can be used by both
hand and power equipment. Stainless steel components are recom-
mended for these tubes. Soil samples are extruded from the tubes
for logging and for selective sampling. The tubes can also be
capped and sent directly to the laboratory for analysis.
Surface sampling of soils can be done with a stainless steel
spoon or scoop. Grass, leaves and other debris should be scraped
off the surface prior to sampling. Shallow samples can be col-
lected by digging a hole with a shovel or post hole digger, then
removing all loose soil from the hole and sampling with a stain-
less steel spoon at the desired depth. For densely packed soils
or deeper soil samples, a soil auger may be used. The sample is
extruded and 100 to 200 grams of the sample is transfered to a
250 ml''co-ntai ner. A label is attached with required informatian
and the depth of the sample, and its location is recorded in the
field 1ogbook .
Soil samples are collected in wide-mouth glass jars equipped
with Teflon-lined screw caps. These samples require no preserva-
tion or refrigeration. Tape the lid securely and mark with
collector's initials. Carefully pack the samples with the appro-
priate chain-of-custody forms. Chapters six and seven of the
"Revised Draft Protocol for Ground-Water Inspections at Hazardous
Waste Treatment, Storage and Disposal Facilities" October 1985,
are a good reference for these soil sampling techniques. Charac-
ter ization of Hazardous Waste Si tes - A^ Methods Manual, Volume
11 . Ayai1able Sampli ng Methods is also a good reference for more
d e t aTT on soil sampli ng techni qu e s .
If it is necessary to sample soils at depths greater than 18
inches, sampling with power equipment can be done. It may be
important to sample at lower depths when the release is very
mobile and not of recent occurrence. The investigator may suspect
that the release has moved several feet below the surface and
that surface sampling may no longer show evidence of the release.
Split barrels or piston-type samplers will be most useful in
these situations. These methods are based on ASTM 01586-67(1974),
"Method for Penetration Test and Split Barrel Sampling of Soils",
and ASTM D1587-74, Thin Walled Tube Sampling of Soils.
9-11
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The sampling of soils at depths greater than 4 feet can be
accomplished by the use of test pits and trenches. The size of
the pits and trenches will vary, but should be large enough to
permit the entry of personnel, under strict safety requirements.
The excavation of the pits is performed most commonly by a back-
hoe. Because of the equipment involved, sampling from a pit will
seldom be appropriate in the RFA, although this method may be
applied in certain circumstances when it is valuable to make a
visual in situ inspection. This technique may be applied in
situations where the investigator suspects that the release may
be in pockets distributed both horizontally and vertically through-
out the soils, and may not be detected readily by sample borings.
Once the pit or trench has been opened, it should be stabil-
ized by sloping the walls or by the use of shoring material.
Sampling then occurs at designated spots by using scoops, shovels
or hand augers. All pertinent information on pit location and
sample location within the pit should be recorded in the field
logbook. Photographs are a valuable aid when identifying the
exact location of a sample within a pit or other subsurface
visual evidence of contamination.
The exact depth and construction of a test pit should be
designed by a field geologist or soils scientist. Sufficient
space on site should be maintained for placement of removed
material. After sampling, backfill material should be returned
to the pit under the direction of the f i el d . geol ogi st or soi-ls
scientist.
IV. MAKING A RELEASE DETERMINATION
The final task in the RFA is to make determinations of release
potential throughout the facility and to make recommendations for
further action to address potential releases. This section
summarizes information that the investigator should consider when
making release determinations for the soils media.
Chapter Four presents the general procedure to be followed
when making release determinations at the end fo the RFA. This
i nvolves :
o Evaluating sampling results from the SV;
o Integrating facility information gathered in the PR,
VSI, and SV to determine the likelihood of release at the
facility; and
o Making final recommendations concerning the need for
further investigations.
The investigator should rely upon his/her best professional
judgment and available information when making determinations as
to whether or not contaminated soils pose a potential or actual
9-12
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QSWER POLICY DIRECTIVE NO.
threat to human health and the environment. Furrier iTfvesrVgalHons
should be required if it is determined that exposure of receptors
is occurring or is likely to occur through direct contact with
contaminated soils, or if there is a likelihood that contaminated
soils are causing contamination of ground water or other human
health or environmental problems.
Exhibit 9-2 is a checklist that should help the investigator
evaluate specific factors to identify releases to soils and to
determine the effect on human health and the environment. When
identifying releases, the investigator should consider the series
of characteristics described in the chapter and highlighted in
the check list that determine the potential for releases to soil
from units of concern. These characteristics include: the unit
type (e.g., above ground tank), the unit's containment systems
(e.g., liners), and the unit's design capacity. Also, factors
such as the unit's age, condition, the quality of its operating
procedures, and whether or not the unit has a record of compliance
problems may indicate the potential for a release.
9-13
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EXHIBIT 9-2
CHECKLIST FOR RELEASES TO SOILS
Identifying Releases
Potential for Soil Releases from the Unit
o Unit type and design
- Does the unit type (e.g., landbased) indicate the potential
for release?
- Does the unit have engineered structures (e.g., liners,
proper construction material) designed to prevent releases?
o Unit operation
- Does the unit's age (e.g., old unit) or operating status
(e.g., inactive) indicate the potential for release?
- Does the unit have poor operating procedures that increase
the potential for a release?
o Physical condition
- Does the unit's physical condition indicate the potential
for release (e.g., lack of structural integrity)?
o Site characteristics that affect the ability for soil to act
as a transfer media
- Is the soil particle size large (e.g., sand) such that the
migration of releases through the soil can readily occur?
- Is the soil high in organic material that may either bind or
biodegrade certain chemical releases?
- Is the soil layer shallow (e.g., less than six feet)?
- Is high annual rainfall characteristic of this climate?
Is the unit located near a body of water (e.g., in flood
plain)?
Is runon and runoff from the unit controlled?
9-14
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APPENDIX A
SAMPLE RFA REPORT OUTLINE
OSWER POLICY DIRECT^
9502v 00= 5
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0- . -. JCV DiREC c NO.
950 2 . 00- 5 5.
APPENDIX A
SAMPLE RFA REPORT OUTLINE
I. Conducting the Preliminary Review
A. Facility Waste Generation and Manufacturing Process Description
B. General Background on Environmental Setting
C. Locations and Characteristics of SWMUs and Other Potential
Areas of Concern
1. Facility Map Identifying SWMUs and Potential Areas of Concern
2. SWMU Information (for each SWMU or location of concern)
a. Unit Characteristics
b. Waste Characteristics
c. Pollutant Migration Pathways
d. Evidence of Release
e. Exposure Potential
D. Identifying Data Gaps and the Need for Additional Owner/Operator
Information
II. Conducting the Visual Site Inspection
A. Description of VSI Activities and Observations
B. Update SWMU Information Based Upon VSI Results
C. Conclusions and Recommendations for Further Action at Each
SWMU/Location - '
1. No Further Action
2. Conducting a Sampling Visit
3. Conducting a RCRA Facility Investigation
A. Implementing Interim Measures
III. Conducting the Sampling Visit
A. General Description of Sampling Objectives
B. Sampling Plan for SV
C. Results of Sampling Visit
D. Conclusions and Final RFA Recommendations for Further Action at
Each SWMU/Location
APPENDICES
A. Visual Site Inspection Logbook
B. Phot.ographic Documentation of VSI
C Sampling Visit Logbook
D. Photographic Documentation of SV
E. Sampling Visit Safety Plan
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9502-00-5
APPENDIX B
INFORMATION SOURCES
-------
RFA INFORMATION SOURCES 9502
This appendix provides details on the many sources of information whcih may be
useful during the RFA, particularly the preliminary review. Most of these sources
will b« readily available to Regional/State staff. This section provides a brief
description of the contents of each source and information on how to obtain them.
I. RCRA Sources B-l
1. Permit Applications B-l
2. RSI 13 Submission (SWMU Response) B-l
3. Compliance Inspection Reports/Information from
Enforcement Orders B-2
4. Exposure Information Report..* B-2
5. Other RCRA Sources. B-2
II. CERCLA Sources B-2
1. CERCLA PA/SI Reports B-2
2. HRS Documentation B-3
3. CERCLA RI/FS Studies B-4
4. CERCLA 103(C) Notifications , B-4
III. Other Federal Environmental Program, Sources B-4
1. NPDES Permits and Permit Applications B-4
2. Clean Air Act Permits and Permit Applications B-4
3. TSCA/OSHA Inspections B-5
4. Department of Defense Installation Restoration
Program (IRP) Reports B-5
IV. Other Miscellaneous Sources B-5
1. Aerial Photography. B-5
2. State/Local Well Permits B-6
3. U.S. Geological Survey and State Hydrogeologic Maps B-6
4. U.S. Soil Conservation Service Soil Maps B-7
5. GEMS (Graphical Exposure Modeling System) B-7
6. Municipal/County/City Public Health Agencies B-7
7. State/County Road Commissions B-7
8. Utilities B-8
9. Local Airports/Weather Bureaus B-8
10. Naturalists/Environmental Organizations B-8
11. Employees B-8
12. Colleges /Universities B-8
13. Interviews With Local Residents B-8
14. Standard Reference Texts B-9
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RFA INFORMATION SOURCES A tr A O H A - "
«/ OU & U v ~ D
I. RCRA Sources
1. Permit Applications
Part A notifications and Part B applications for permits contain a sizable
amount of information on the facility design and physical characteristics of the
surrounding area. This information will sometimes apply to both unregulated
releases from regulated units and releases from unregulated ("old") units, and
should prove invaluable at many facilities in assessing the potential for old
units to contaminate ground water. If the facility is seeking only an above-
ground storage facility permit, however, the permit application data may not
provide much information useful in evaluating an "old" landfill.
Part B applications may not characterize the lower aquifers if they are not
connected to the uppermost aquifer. If the application data are inadequate to
properly assess the impacts to ground water, the information may need to be
developed through other sources discussed later.
In addition to relevant data on the facility as a whole, the permit applica-
tion also provides information that can be used to evaluate the potential for
unregulated releases from regulated units, specifically surface water and air
releases. Most of the pertinent data relate to the design and maintenance of the
unit will be contained in the application. Part B permit applications for land
disposal facilities will also provide information on whether actual releases
have occurred.
It is Important to evaluate well placement when reviewing ground water
monitoring data for regulated units. In some cases the location of existing
monitoring wells may make it difficult to determine if contamination results
from the regulated unit, an unregulated unit, or both. Review of the analytical
data must be coupled with data on well location and ground water flow to posi-
tively identify the source of the observed release.
The Regional offices and/or the State offices will have copies of the
permit applications for the facilities within their jursidiction.
2. RSI 13 Submission (SWMU Response)
The data submitted in response to the Reauthorization Statutory Interpreta-
tion (RSI *3), dated February 5, 1985 from Jack W. McGraw, should provide infor-
mation on the type and location of SWMUs, and information on the quantities and
types of wastes disposed in the SWMUs. These submissions, however, may be incom-
plete or inaccurate, and should not be relied upon solely to Identify and charac-
terize SWMUs. In many cases, the owner/operator was unclear which units to
consider SWMUs, and the historical information on wastes disposed in them may not
have been readily available to the owner/operator.
The SWMU response will be available to Regional RCRA personnel.
B-l
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3. Compliance Inspection Reports/Information from Enforcement Orders
Compliance Inspection Reports are available for most RCRA facilities.
These reports contain useful information on site management practices, monitor-
ing data, and unit conditions and should help in identifying problem units and
releases for possible sampling. Comprehensive monitoring evaluations (CME'a),
which evaluate ground water monitoring systems at the facility, may provide an
indication of whether prior releases have occurred at the facility. Frequent
violations of operating standards may indicate prior releases. Some RCRA in-
spection reports will contain detailed information on the management practices
at the facility, suggesting the wastes most likely to be found on site.
Enforcement actions at facilities may result in enforcement orders. Re-
ports of these actions may provide useful information on releases at a site.
In many cases, the investigator may be able to obtain information on unregulated
units from results of investigations required in enforcement actions.
These reports will usually be kept on file in Regional and State offices
with jurisdiction over the facility.
4. Exposure Information Report
The 1984 Hazardous and Solid Waste Amendments require owner/operators to
submit an exposure information report (EIR) to describe the likelihood of expo-
sure resulting from waste disposal activities. Only facilities seeking operat-
ing permits for landfills and surface Impoundments are required to submit EIRs.
EIRs will be available at Regional/State 'offices for facilities within
jurisdiction.
5. Other RCRA Sources
Several additional RCRA sources may provide useful information during the
RFA. These sources will all be on file at the Region/State office for facili-
ties within their jurisdiction.
o Biennial report
o Operating log
o RCRA waste manifest
o Notice to local authority
o ACL requests
II. CERCLA Sources
1. CERCLA PA/SI Reports
Almost 15 percent of the facilities seeking RCTIA Part B permits have re-
ceived CERCLA inspections. The site inspection reports for these facilities
can provide a considerable amount of information on facility and unit design
and management, waste characterization, and pollutant dispersal pathways,
particularly for SWMUs and inactive units* They may also have limited informa-
tion about target populations. The exact amount of information provided in
each report will depend on the amount of information available at the time the
report was completed.
B-2
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The CERCLA SI report ia likely to provide some information fQ(£VttfePflW£J(<&*£CiW£ ?i!
ing categories:
o Facility design/management practices 950 2 00-£>
Listing of SWMU operations, facility layout;
Discussion of conditions of Identified SWMUs; and
Design specifications for SWMUs (when available).
o Waste characteristics
Type and quantity of waste received to the extent known
o Pollutant dispersal pathways
Analytical data on "observed releases" from the facility;
Geology, topography, hydrogeology, climate of the area (if unit could
be releasing to ground water);
Climatic data (e.g. precipitation, wind data); and
Facility topography as it relates to surface drainage patterns.
o Receptor characteristics
Size and characteristics of nearby populations and sensitive environ-
ments potentially exposed through air, surface water, and ground
water routes.
In addition to reviewing the final SI report, the person conducting the RCRA
preliminary assessment should also examine the CERCLA site file. These files
contain supplementary information used to evaluate the site under CERCLA. These
files include such items as:
o Field log book for the SI, ...
d Trip reports for the SI '
o Records of communication
o Miscellaneous historical data/reports
Except for the first item, the exact contents of the file will vary depend-
ing upon the type of information available and the data collection procedures
used at the time of the CERCLA SI.
The CERCLA PA/SI reports will be on file in the Superfund division of
Regional/State offices with jurisdiction over the facility.
2. HRS Documentation
Some subset of the sites that have undergone CERCLA PA/SIs have been scored
using the Hazard Ranking System (HRS). Information on target populations and
sensitive environments should be available for each of the routes scored. The
most frequently scored routes are surface water and ground water. This document
may identify potential locations of concern for the RFA, though it may not
be comprehensive.
The Regional CERCLA program offices have copies of all CERCLA HRS reports
and files.
B-3
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3. CERCLA RI/FS Studies
Again, some subset of the sites that have been given an HRS score will have
been subject to a remedial investigation/feasibility study (RI/FS). If so, these
reports will characterize in great detail: air, surface water, ground water and
soil contamination, as well as populations actually or potentially affected by
these releases.
The Regional CERCLA program offices have copies of all CERCLA RI/FS reports
and files.
4. CERCLA 103(c) Notifications
Some sites may have information available on wastes disposed of at the
facility from a CERCLA 103(c) notification, which provides information on all
reportable quantities. In the early stages of the CERCLA program, owners or
operators of waste management facilities and transporters were required to
notify EPA of places where CERCLA hazardous substances had been disposed. EPA
reviewed approximately 9000 notifications representing approximately 2000
sites, after accounting for redundant reporting. If the facility filed a CERCLA
103(c) notification, and no other source of information is available, this
source may provide a record of past disposal operations, such as information on
types, locations and volumes of waste disposed.
The reviewer should contact the Regional CERCLA coordinator to see if a
CERCLA I03(c) notification exists for the facility.
III. Other Federal Environmental Program Sources
1. NPDES Permits and Permit Applications
The National Pollutant Discharge Elimination Program (NPDES) regulates the
discharge of all pollutants into the waters of the United States. Many RCRA
facilities also have NPDES permits for their wastewater discharges, and will
have submitted permit applications and usually received permits. These permit
applications may provide a large amount of detail on the types of waste generated
at the facility, and some historical dats on how these wastes were disposed in
the past.
The investigator should contact the Regional or State NPDES office in order
to obtain copies of pertinent permits and/or permit applications.
2. Clean Air Act Permits and Permit Applications
Some RCRA' facilities will have air emissions requiring stationary source
controls under the Clean Air Act. These permits and permit applications may
provide useful information on waste generation at the facility. The baghot ;e
emission control dusts from some facilities (e.g., secondary lead smelting
facilities) are listed hazardous wastes and must be disposed in accordance with
RCRA. The Clean Air Act permits and permit applications should be consulted at
the appropriate facilities.
The investigate"* should contact the Regional/State air permitting office
for information on permitting at these facilities.
B-4
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OSWER POLICY DIRECTIVE NO.
3. TSCA/OSHA Inspections
$502.00-5
The Toxic Substances Control Act (TSCA) regulates the disposal of PCBs and
PCB equipment. In some cases the responsibility for conducting TSCA inspections
is merged with the RCRA inspection program. In other cases, these inspections
are conducted by a different unit within EPA. TSCA inspection files may have
useful data on how much and where disposal and storage of PCBs has taken place
at a particular facility.
The Occupational Safety and Health Administration (OSHA) inspection reports
may identify the types of materials handled by a facility and may also establish
whether the owner or operator has a history of violations. Violation histories
can indicate a facility's propensity for releases that might be subject to cor-
rective action.
For information on TSCA activities at a facility, the investigator should
contact the Regional toxic substances office. For information on OSHA inspec-
tions, the investigator should contact:
Occupational Safety and Health Administration, Federal Agency Programs
202-523-6027
4. Department of Defense Installation Restoration Program (IRP) Reports
The Department of Defense has been conducting a corrective action program
at its facilities, entitled the Installation Restoration Program (IRP), for
approximately ten years. This program was developed to characterize and remed-
iate contamination at DOD facilities, and is similar to the Superfund program.
The IRP program is organized into four phases: Phase I, which is similar to
the' RFA; Phase II, which is similar to a CERCLA Remedial Investigation; Phase
III, which is similar to a CERCLA Feasibility Study; and Phase IV, which is the
design/construct phase of the program.
All DOD facilities should have a completed Phase I report, which will be
very useful during the RFA at these facilities. Many of the facilities will
also have a completed Phase II report, which will also be of great use during
the RFA. Each branch of the armed forces has a separate office coordinating
their IRP work. The Investigator should contact the following offices in order
to obtain copies of IRP reports:
o U.S. Air Force: Occupational and Environmental Health Laboratory (OEHL)
o U.S. Army: U.S. Army Toxic and Hazardous Materials Agency (USATHMA)
o U.S. Navy: Naval Facilities Engineering Command (NavFEC)
IV. Other Miscellaneous Sources
1. Aerial Photography
Aerial photography, especially historical aerial photography, can be a
valuable tool in a prelimary assessment. Historical aerial photography can
provide the following types of information:
o The location of past disposal units;
o The location of releases;
B-5
-------
o Evidence of existing or past vegetation stress;
o Potential routes for contamination migration;
o Location and numbers of target populations; and
o Land use in the area. ^^
A number of RCRA sites that were evaluated under CERCLA have had both
historical and recent aerial survey analysis. The RCRA reviewer should contact
his/her regional coordinator for aerial photography. These coordinators have
access through ORD/EMSL/LV to an index of sites that have had aerial photo-
graphic analyses.
If an historical analysis and current overflight do not exist, they can be
requested through the regional coordinator. EMSL has a computerized system
which accesses the major sources of extensive aerial photography including
libraries, archives, and the U.S. Geologic Survey. EMSL can use this to order
copies of the photographs, analyze the photographs for relevant features and
prepare a bound copy of the analysis. In most cases, historical aerial photo-
graphy will suffice for the purposes of the RCRA RFA.
The usefulness of current aerial photographs is more limited. They may be
able to identify vestiges of old disposal practices, current vegetation damage,
and surface drainage patterns. Infrared photographs may be useful in identify-
ing areas of strained vegetation. They can also accurately locate target
populations. However, much of this information may be readily ascertainable
from a visual inspection of the facility. Accordingly, requests for overflights
should be requested only when there are no other sources of the data.
*-
2. State/local well permits
Most states require well drillers to obtain we'll installation permits.
This source, if available, can provide the most reliable information on the
number of households using well water in a particular area. These offices can
often identify the aquifer from which individual wells draw and the construction
of individual wells, Including diameter. This Information can also help in
identifying the closest downgradient wells that have the appropriate well
construction characteristics for sampling.
This information is usually kept on file in state environmental program
offices, or may be found at county public works departments.
3. U.S. Geologic Survey and State Hydrogeologic Maps
The U.S. Geologic Survey (USGS) and state geologic surveys may have detailed
maps characterizing the hydrogeology at locations of RCRA facilities. Many of
these maps will supplement the ground-water characterization found in Part B
applications, and for storage and treatment facilities, may provide the most
available source of hydrogeologic information.
The USGS also hat a series of geological atlases providing data on geology
and soils. These maps can cover areas as small as one quadrangle (a 7.5 minute
map), which is approximately 6 by 8 miles. These maps can also provide data on
soils and rock types underlying facilities which may be helpful if data provided
by the applicant are incomplete or unavailable. This may be especially useful
for evaluating larger facilities.
B-6
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JOIiLn ( uuiui UIIIL.UIIII. ii
USGS hydrological map3 provide Information on ground water y^eld, soil
transmissivity and location of USGS wells (for monitoring water levels). This
type of nap may assist the reviewer in understanding the relationship between
land based units and depth to ground water, location of ground water recharge
areas, prevailing regional flow, and ground water discontinuities (if the owner
or operator has not already provided this type of information). These maps are
also available for areas as small as 7-1/2'.
These maps can be obtained by contacting the local USGS office, or in the
case of state maps, the local state survey office.
4. U.S. Soil Conservation Service Soil Maps
U.S. Department of Agriculture Soil Conservation Service (SCS) offices map
soil types and permeabilities at a resolution extending down to 2 acres in somes
cases. These maps typically characterize soil type to a depth of six feet, and
the backup information used to develop these maps may evaluate soils to greater
depths. This backup information is also available through the local SCS.
5. GEMS (Graphical Exposure Modeling System)
EPA has access, through each of the regional offices, to a computerized
system with the capability to identify the number of individuals within a
specific radius of a facility. This system is readily available and can provide
reliable information on populations potentially at risk from air releases.
When coupled with data on ground use patterns, it can also quantify target
populations drinking ground water.
6. Municipal/County/City. Public Health Agencies
Municipal/county/city public health agencies or departments can provide a
wealth of information on the types of units located at a particular facility
and the wastes routinely received at the site. Fire marshalls can provide
information on the nature of any fires or explosions that have occurred at the
facility. Information on Incidents and site management practices can assist in
determining if any release's have occurred or are likely to occur as a result of
poor facility management. These agencies maintain their records and files for
a number of years and often provide the only other source of Information on
"old" units.
Even if these files contain little information, employees who have worked
with the local agency or fire department for a number of years, often know a
lot about the site or where to obtain additional information.
7. State/County Road Commissions
Core samples of soils and rocks underlying a proposed road are often
analyzed during the engineering and planning stages of road construction.
Records of these analyses are usually retained and available through most
State/County road commissions. This information can provide useful data, where
none or little are otherwise available, to evaluate the potential for contami-
nants to migrate through soils and ground water, and possibly to determine
where to sample. This source will not be used routinely during the RFA.
B-7
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8. Utilities
Utilities may be able to provide extremely reliable and up-to-date popula-
tion data. They can identify the number of households using public water sup-
plies, both ground water and surface water. They can also identify the locatio
of public water wells and Intakes. This information is necessary not only to
determine the affected population but may also help identify possible locations
for sampling. It will not usually be necessary to use this source during the UFA.
9. Local Airports/Weather Bureaus
2 These organizations maintain accurate historical records of the local cli-
mate. This information is essential in evaluating the potential and direction
that contaminants could migrate through the air and the rate that contaminants
could migrate through the ground water and surface water routes. Contaminants
can be expected to migrate faster through the ground water in areas with higher
precipitation. Wind directlon(s) is essential in identifying downwind targets
for air releases. Temperature is essential to evaluate the propensity for
materials to volatilize. The amount of rainfall, especially during peak periods,
can also indicate the likelihood that contaminants will migrate overland to
surface water.
10. Naturalists/Environmental Organizations
Local environmental groups can provide information on the presence and
location of wildlife and endangered species. They often have access to indi-
viduals or Information which can identify the nesting grounds for animals.
They can also identify any other sensitive environments.
11. Employees
Employees at the facility, both current and former, may be able to provide
information on facility design and management as well as information on the
types of wastes received at the facility. It may be difficult to obtain owner
or operator permission to interview current employees. For former employees,
it may be difficult to identify a knowledgable and reliable individual. When
interviewing former and current employees, the Investigator should be sure to
understand the employee's motivation for providing the information and should
find out why former employees no longer work at the facility.
12. Colleges/Universities
The biology departments of local colleges and universities may have informa-
tion on the location of sensitive environments. In some cases, graduate student
reports and publications have carefully mapped the location of nesting grounds
and migratory pathways. Such studies can be valuable in identifying the impact
of releases on target environments. The geology or agriculture departments of
local colleges and universities may have information characterizing the local
geology and hydrogeology. This can include maps of the area and studies evalu-
ating the permeabilities of soils.
13. Interviews with Local Residents
As a last resort, local residents can be a source of information on a
facility. Sometimes, long-term residents know a. considerable amount about the
B-8
-------
kind of operations conducted at a facility and the type and amount of waste
received at a facility. In general, this source of iaformatioa Ahgqldjse
avoided to prevent any undue or premature alarm. OSWtR FOliCY D'RECTiV'E
14. Standard Reference Texts
Chemical Fate and Transport Information
1. U.S. EPA, Water-Related Environmental Fate of 129 Priority Pollutants.
EPA-440/4-79-029a&b, 1979.
2. U.S. EPA, Aquatic Pate Process Data for Organic Priority Pollutants,
EPA-440/4-81-014, December 1982.
3. Weast, R.C., ed. , CRC Handbook of Chemistry and Physics. 61st ed.,
CRC Press, 1981.
4. IGF, Inc., Draft, Superfund Public Health Evaluation Manual, Prepared
for U.S. EPA, Office of Emnergency and Remedial Response, December 18,
1985.
Ground-Water Hydrology and Monitoring Well Construction
1. Freeze, R. Allan, and John Cherry, Groundwater. Prentice-Hall, 1979.
2. U.S. EPA, Office of Waste Programs Enforcement, RCRA Ground -Water
Monitoring Technical Enforcement Guidance Document, Draft. August, 1985.
3. Johnson Division, Groundwater and Wells, 2nd ed., 1986. ' .
Hazardous Waste Site Characterization, Sampling, and Analysis
1. U.S. EPA, Environmental Monitoring Systems Laboratory, Characterization
of Hazardous Waste Sites-A Methods Manual, Volume I-Site Investigations,
Volume II, Available Sampling Methods, and Volume III. Available Laboratory
Analytical Methods. EPA/600/4-84/075, April 1985.
2. U.S. EPA, Office of Emergency and Remedial Response, Guidance on
Remedial Investigations Under CERCLA, May 1985.
3. U.S. EPA, Test Methods for Evaluating Solid Waste. Physical /Chemical
Methods. EPA SW-846, July 1982.
4. Standard Methods for the Examination of Water and Wastewater, 16th
Ed., American Public Health Association, 1985.
Personal Safety
1. American Conference of Governmental Industrial Hygienists, Threshold
limit Values and Biological Exposure Indices for 1985-86. 1985.
B-9
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2. National Institute of Occupational Safety and Health/Occupational
Safety and Health Administration, NIOSH/OSHA Pocket Guide to Chemical
Hazards, U.S. Government Printing Office.
3. U.S. EPA, Office of Emergency and Remedial Response, Standard Operating
Safety Guides, Edison, NJ, 1984.
lexicological Properties of Chemicals
1. Sax, Irving, ed., Dangerous Properties of Industrial Materials, 6th ed.,
Van Nostrand Reinhold, 1984.
2. National Institute of Occupational Safety and Health, Registry of Toxic
Effects of Chemical Substances, U.S. Government Printing Office, (annual).
3. Clayton, G.D. and P.E. Clayton, Patty's Industrial Hygiene and Toxicology,
3rd ed.,Vols. 1-3, Wiley Interscience, 1979.
4. ICF, Inc., Draft, Superfund Public Health Evaluation Manual, Prepared for
U.S. EPA, Office of Emergency and Remedial Response, December 18, 1985.
B-10
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00* ^
APPENDIX C
SAMPLE LETTER OF REQUEST FOR
OWNER/OPERATOR INFORMATION
-------
QSWEH FSJCf :.?^r-"VE
9502.00^5
Dear Sirs:
As we have discussed in our recent telephone conversations, the
f
Plant has been selected by EPA as a subject for testing EPA's draft guidance,
RCRA Facility Assessment Guidance. The preliminary assessment (PA) is the
first phase in the process of determining whether solid waste management units
(SWMU's) are releasing hazardous constituents to the environment and require
corrective action.
After reviewing EPA files on the Plant, a list of questions
regarding additional information has been developed. It is anticipated that
the requested information exists in your files. An attempt was made to keep
the requested information to a minimum in order to avoid impacting your effort
in preparing the Part B application.
The following information Is requested:
1. Provide elevations of all SWMU units and/or identify the 100-year floodplain
for the entire facility property.
2. Provide any available information (dates, quantities, materials, locations)
on past spills in the production area.
3. -Spill tanks are shown on Figure B-I of submittal, but are not
mentioned in the text. Explain the purpose of the tanks and provide chemical
information on the material stored in the tanks. If this unit does not fit
the definition of a solid waste management unit, explain why.
4. For the New Trash Incinerator (Unit I.A.), indicate whether a permit has
been issued by the Air Pollution Control Board. Provide a
copy of the permit if it has been issued.
5. For the Waste Treatment Sludge Incinerator (Unit I.C.), provide the start-
up date and planned closure date. Describe plans for treating or disposing
of sludge after closure of the incinerator.
6. For the Waste Treatment unit (Unit 3), provide the following:
i) A description of the modifications In plan operations which, when
combined with amendments to the hazardous waste regulations,
have,rendered the wastewater non-hazardous since November 1, 1983.
11) The start-up date for the original wastewater treatment unit (the
"pre 7/82" unit), and any available description of wastewaster treat-
ment and sludge disposal prior to the start-up of this unit.
ill) Any available data concerning the hazardous constituents present in
the sludge from the wastewater treatment plant unit prior to November
1, 1983.
C-l
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7. For the Waste Recycling Operations (Unit 4), provide the following:
i) A. map showing the location of each recycling unit and associated
storage tank and piping. The map should be on a scale of one-inch
equal to not more than 200 feet.
ii) An explanation of disposal and/or treatment of residues for each
recycling unit.
8. Provide the exact locations of the land farm areas and delineate boundaries
where possible. Clarify how many land farm areas have been used in the past.
9. Provide any available information on the chemical composition of the sludge
that has been applied to the land farms in the past.
10. For the Storage Tanks (Unit 8), provide the following:
i) A may showing the location of each tank and associated piping. The
map should be on a scale of one-inch equal to not more than 200 feet.
A map combining the Waste Recycling Operations (Unit 4), as requested
above, with the storage tanks is acceptable.
ii) For each tank, indicate if any secondary containment exists. A "yes"
or "no" response will suffice.
iii) Describe the leak test performed, frequency and date of last test for
each tank.
iv) For each tank identified as having been found to leak, provide any
available information describing the approximate period of leakage
and estimated volume of leaked wastes.
v) For the tanks identified which may have been used in the past for
solid waste storage, indicate which tanks are underground, elevated
or at surface level.
11. Clarify how many landfills exist or have existed at the facility. Delineate
boundaries of each landfill (where possible). If any other landfills are
identified, describe what materials were disposed of in these landfills.
12. Provide any available Information (dates, quantities, materials, locations)
on past spills at the facility that were reported to the National Response
Center (or the Department of Health) as required under CERCLA.
t
C-2
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oswta POLICY DIRECTIVE NO.
.00-5
f
APPENDIX D
GUIDANCE ON OBTAINING ACCESS TO
A. RCRA FACILITY IF ACCESS FOR
A SITE INVESTIGATION IS DENIED
[SOURCE MATERIAL FROM: U.S.E.P.A. HAZARDOUS WASTE GROUND
WATER TASK FORCE, "REVISED DRAFT PROTOCOL FOR GROUND-WATER
INSPECTIONS AT HAZARDOUS WASTE TREATMENT, STORAGE AND
DISPOSAL FACILITIES", JUNE 1985]
-------
f
FOR A SITS INVESTIGATION IF ACCESS IS DENIED
If an Investigator is denied access to a facility to
the following procedural steps oust be followed.
9502.00^5 .
Upon Denial of Access
I. Upon denial of access, thoroughly document the event, noting time,
date, and facility personnel encountered. *
2. Ask for reason of denial of access to facility.
3. If the problem is beyond the investigator's authority, suggest that the
owner/operator contact an attorney to obtain legal advice regarding
his/her responsibility for providing facility access under Section 3007
of RCRA.
4. If entry is still denied, exit from the premises and document
any observations made pertaining to the denial, particular!/ any
suspicions of violations being covered up.
5. Report all aspects of denial of entry to the U.S. EPA Office of
Regional Counsel for appropriate action, which may include help
tn obtaining a search warrant. **
Search Warrant Inspections
Conducting a site investigaton under a search warrant will differ from a noraal
inspection. The following procedures should be complied with in these
situations:
Development of a Search Warrant
I. An EPA Office of Regional Counsel attorney will assist the investigator
in the preparation of the documents necessary to obtain a search warrant
and will arrange for a meeting with him/her and a U.S. Attorney. The
investigator should bring a. copy of the appropriate draft warrant and
affadavits to the meeting.
2. The U.S. EPA Office of Regional Counsel attorney will inform the
appropriate Headquarters Enforcement attorney of any denials of
entry and send a copy of all papers filed to EPA Headquarters.
3. The attorney will then secure the warrant and forward it to the
U.S. Marshall who will issue it to the owner/operator.
* Under no circumstances discuss potential penalties or do anything
which may be construed as threatening.
** It should be stressed that it is the policy of U.S. EPA to obtain a warrant
only when all other efforts to gain lawful entry have been exhausted.
D-l
-------
Use of a Warrant Co Gain Entry
I. The Investigator should never attempt to make any forceful entry of the
facility.
2. If there is a high probability that entry will be refused even with a *
warrant or where there are threats of violence, the investigator should
be accompanied be a U.S. Marshall.
3. If entry is refused to an investigator holding a warrant but not
accompanied by a U.S. Marshall, the investigator should leave the
facility and in fora the U.S. EPA Office of Regional Counsel.
Use of a Warrant to Conduct the Investigation
I. The investigation oust be conducted strictly in accordance wich the
warrant. If the warrant restricts the investigation to certain areas
of the premises or to certain records, those restrictions muse be
followed.
2. If sampling is authorized, all standard procedures oust be carefully
followed including presentation of receipts for all samples taken. The
facility should also be informed of its right to retain a portion of
the samples obtained by the investigator (split samples).
3. If records or property are authorized to be taken, the Investigator must
provide receipts to the owner/operator and maintain an inventory of all
itans removed from the premises.
. > 4. In accordance with the warrant, the. investigator should take
of all areas where violations are suspected. Photographs should also
be taken at each sampling location as a quality control procedure.
For further guidance regarding denial of facility access consult the National
Enforcement Investigation Center. (303) 236-5100
D-2
-------
9502.00*5
APPENDIX E
PHYSICAL AND CHEMICAL
PARAMETERS FOR CONSTITUENTS
OF CONCERN
[THE ATTACHED WAS PREPARED BY ICF, INC., FOR THE
OFFICE OF EMERGENCY AND REMEDIAL RESPONSE, EPA,
AND FOUND IN "DRAFT SUPERFUND HEALTH ASSESSMENT
MANUAL", MAY 1985]
-------
CSWER Dire
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OSfl& POLICY DIRECTIVE NO.
aoo-5
APPENDIX F
EXAMPLE DATA ELEMENTS FOR FACILITY PR IORITIZAT ION
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09ER POLICY DIRECTIVE NO.
APPENDIX F 950 2 . 00" 5
EXAMPLE DATA ELEMENTS FOR FACILITY PRIORITIZATION
1. What is the net recharge of the facility area?
2. What is the distance from the unit to the aquifer below the
unit? If actual depth is unknown, circle closest approxima-
tion of depth from ranges given below:
Feet; 0-5 5-10 10-30 30-50 50-75 75-100 100+
3. What is the slope of the surface topography within the
facility boundary? Circle closest approximation of slope
from ranges given below:
% Slope; 0-2 2-6 6-12 12-18 18+
4. How deep is the soil layer beneath the facility?
(Use soil references cited in RFI guidance.)
5. Is there a surface water body downgradient that is within
t w'o m i 1 e s -o f t h e u n i t ?
If yes, what is the distance betwen the surface water body
and the unit?
6. For land disposal facilities (that should have information
on hydraulic conductivity, hydraulic gradient, and effective
porosity included in their Part B permit applications),
calculate the time of travel (TOT) to the facility boundary
and the nearest drinking water well downgradient. Refer to:
Criteria for Identifying Areas of Vulnerable Hydrogeology -
Interim Final, June 1985;the time of travel calculation
was developed by the UTS'. EPA Office of Solid Waste as a
tool to be used in assessing the vulnerability of ground
water in different hydrogeologic settings.
The foflowing steps should be completed when calculating TOT:
a) What is the calculated or average velocity (V) of ground-
water flow below the facility? (Refer to criteria cited
above.)
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b) What is the distance to:
1) facility boundary?
2) nearest downgradient drinking water well(s)?
What is the TOT for:
1) time to facility boundary?
2) time to nearest downgradient drinking water well(s)?
(Refer to Criteria cited above.)
7. For facilities other than land disposal facilities, facilities
located on karst terrain or fractured bedrock:
If a rapid ground water velocity is suspected, collect data
on hydraulic gradient, hydraulic conductivity, and effective
porosity in order to calculate TOT from the unit to 1)
facility boundary and 2) nearest drinking water well.
8. What is/are the waste constituent(s) of concern? If unknown,
provide available information on the following aspects of
the waste to allow reasonable inferences to be drawn on what
constituents are present.
a) Suspected classes of compounds (e.g., organic solvents,
inorganics, etc.);.
b) Waste streams (e.g., pickle liquor);
c) Manufacturing process(es) which produced waste.
9. Are there any active production wells near the unit or
faci1ity? If yes:
a) What is the distance between the unit and the production
well(s)?
b) What is the production capacity of the well(s)?
c) How old is the unit(s)?
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