UntttA^an*
EnvirarwTNmai Pro wet ion
A^incv
WW
Offic* of
M*t*r enforcanwm tnd
WMflin«
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D C. 20460
OCT 5 1987
office of
WATER
MEMORANDUM
SUBJECT: Guidance on the Conduct of RCRA Facility
Assessments at POTWs
FROM:
J Director
o Enforcement and
Permits (EN-335)
TO:
Water Management Division Directors
Regions I-X
Attached is a copy of our final guidance document for
conducting RCRA facility assessments at POTWs. This document
applies to POTWs that receive hazardous waste by truck, rail, or
dedicated pipe. The document will assist you in implementing the
RCRA corrective action requirements at POTWs.
The attached guidance should be used in conjunction with the
"Guidance for Implementing RCRA Permit-by-Rule Requirements at
POTWs" that I mailed to you on July 21, 1987. The previous
guidance explains the procedures for issuing a permit-by-rule to
a POTW. Corrective action is a major requirement of the permit-
by-rule, and today's guidance will assist you in completing the
first phase of corrective action - the RCRA Pacility Assessment.
For those Regions with POTWs that receive hazardous waste by
truck, rail, or dedicated pipe, (to date we have identified 26
such POTWs), we anticipate that the permits-by-rule will be issued
during FY88. The major task of these permits is preparing a
schedule for corrective action. The attached guidance will assist
you in preparing these schedules.
For more information about the guidance, have your staff
contact Paul Connor of the Permits Division at FTS-475-771B. I
hope you find the guidance document useful.
Attachment
cc: Permits Branch Chiefs, Regions I-X
Hazardous Waste Coordinators, Regions I-X
-------
GUIDANCE ON THE CONDUCT OF RCRA
FACILITY ASSESSMENT AT POTVs
October 1987
U.S. Environmental Protection Agency
401 N Street, S.V.
Washington, DC 20460
-------
DISCLAIMER
This guidance is intended to assist Regional and State
personnel in exercising their discretion in implementing RCRA
Facility Assessment requirements at POTWs. EPA vill not in all
cases undertake actions that comport with the guidance set forth
herein. This document is not a regulation (i.e., it does not
establish a standard of conduct which has the force of lav) and
should not be used as such. Regional and State personnel must
exercise their discretion in using this document as well as other
relevant information in applying the RCRA Facility Assessment
requirements to POTVs.
-------
ACKNOWLEDGEMENT
This document was prepared under the direction of EPA
Headquarters, Office of Water Enforcement and Permits (OWEP), by
Science Applications International Corporation (SAIC), EPA
Contract Number 68-01-7043, Work Assignment Number Pl-23. In
preparing certain portions of this document (especially Chapter
2), OWEP and SAIC relied extensively on guidance previously
prepared by the Office of Solid Waste. Special appreciation is
extended to the following individuals for their participation in
the document's preparation: Paul Connor, Attorney-Advisor and EPA
Work Assignment Manager; James Taft, Environmental Engineer; and
Frank Sweeney and Robert Linett of SAIC.
-------
TABLE OF CONTENTS
PAGE
1. INTRODUCTION 1-1
1.1 OVERVIEW OF RCRA PERMIT-BY-RULE PROVISIONS
AND CORRECTIVE ACTION PROGRAM 1-1
1.1.1 Overview of RCRA Permit-by-Rule Provisions 1-1
1.1.2 Overview of RCRA Corrective Action Program 1-5
1.1.3 Overview of the RFA 1-7
1.2 PURPOSE AND SCOPE OF THE GUIDANCE DOCUMENT 1-11
1.3 ORGANIZATION OF THE GUIDANCE DOCUMENT 1-12
2. CONDUCT OF THE RCRA FACILITY ASSESSMENT 2-1
2.1 TECHNICAL APPROACH FOR THE RCRA FACILITY ASSESSMENT... 2-1
2.2 CONDUCTING THE PRELIMINARY REVIEV 2-5
2.2.1 Purpose and Scope of PR 2-5
2.2.2 Gathering PR Information 2-6
2.2.3 Evaluating PR Information 2-12
2.2.4 Completing the PR 2-18
2.3 CONDUCTING THE VISUAL SITE INSPECTION (VSI) 2-19
2.3.1 Purpose, Scope, and Vork Product of the VSI.... 2-19
2.3.2 Planning the VSI 2-20
2.3.3 Conducting Field Activities During the VSI 2-22
2.3.A Determining the Need for Further Action During
the RFA 2-25
2.4 CONDUCT OF THE SAMPLING VISIT 2-28
2.4.1 Purpose and Scope 2-28
2.4.2 Developing a Sampling Plan 2-29
2.4.3 Preparing for the SV 2-33
2.4.4 Conducting the SV.... 2-36
2.4.5 Final RFA Recommendations for Further Action... 2-37
2.4.6 Pinal RFA Product 2-42
3. EVALUATION OF VASTE AND UNIT CHARACTERISTICS AT POTVS 3-1
3.1 POTW UNIT CHARACTERISTICS 3-1
3.1.1 Description of Typical POTV Treatment
Processes 3-1
3.1.2 RCRA Terminology as Applied to POTV
Treatment Units/Processes 3-6
3.1.3 Typical POTV Configurations 3-7
3.1.4 Pollutant Fate Processes and Release
Mechanisms within POTVs 3-10
3.1.5 Impacts of POTV Treatment System Configuration
on Pollutant Releases 3-15
i i
-------
3.1.6 Fate of Specific Pollutants within POTVs
3-17
3.2 POTV WASTE CHARACTERISTICS 3-17
3.2.1 Data Source for POTV Waste Characterization.... 3-18
3.2.2 Potential Sources and Types of Hazardous
Wastes and Constituents Discharged to POTVs.... 3-24
3.2.3 Physcial/Chemical Properties of Selected
Hazardous Waste Constituents 3-29
4. ASSESSMENT OF RELEASES TO GROUND WATER AND SOIL, AND BY
SUBSURFACE GAS 4-1
4.1 UNIT CHARACTERISTICS AFFECTING POTENTIAL FOR
RELEASES TO GROUND VATER AND/OR SOILS 4-1
4.1.1 Unit Characteristics Influencing Potential
for Soil Contamination Through Surface Runoff.. 4-3
4.1.2 Unit Characteristics Influencing Potential for
Ground Water or Soil Contamination Through
Subsurface Leachate 4-9
4.1.3 Data Required to Assess Unit Characteristics
Affecting Potential for Releases to Ground
Water and Soil 4-17
4.2 WASTE CHARACTERISTICS AFFECTING POTENTIAL FOR
RELEASES TO GROUND VATER AND SOIL 4-18
4.2.1 Waste/Constituent Properties Influencing
Movement Through Soil and Ground Water 4-18
4.2.2 Data Requirements for Assessments of
Waste Characteristics 4-22
4.3 ASSESSMENT OF MIGRATION POTENTIAL OF RELEASE TO
GROUND WATER OR SOIL 4-22
4.3.1 Soil Characteristics 4-22
4.3.2 Hydrogeologic Characteristics 4-25
4.3.3 Existing Soil and Ground-Vater Monitoring
Data 4-28
4.3*4 Data Requirements for Assessment of Migration
Pathways for Releases to Ground Vater or Soil.. 4-30
4.4 SAMPLING TECHNIQUES FOR GROUND VATER AND SOIL 4-30
4.4.1 Assessment of the Need for Sampling 4-30
4.4.2 Selection of Sampling Parameters 4-31
4.4.3 Selection of Sampling Locations 4-32
4.4.4 Appropriate Procedures for Ground-Vater
and Soil Sampling 4-33
4.5 ASSESSMENT OF POTENTIAL EXPOSURE DUE TO RELEASES TO
GROUND VATER OR SOIL 4-34
iii
-------
4.5.1 Potential Effects on Human Health 6-35
4.5.2 Potential Effects on the Environment 4-37
4.5.3 Data Required for Assessment o£ Potential
Exposures Due to Releases to Ground Water
and Soils 4-37
4.6 ASSESSMENT OF SUBSURFACE GAS RELEASES 4-38
4.6.1 Unit Design and Operation 4-39
4.6.2 Waste Characteristics 4-40
4.6.3 Gas Generation Mechanisms 4-41
4.6.4 Gas Migration Barriers * 4-42
4.6.5 Assessment of Releases 4-43
5. ASSESSMENT OF POTV RELEASES TO SURFACE WATERS
AND SEDIMENTS 5-1
5.1 APPLICABILITY OF CORRECTIVE ACTION REQUIREMENTS TO
RELEASES TO SURFACE WATERS AND SEDIMENTS 5-1
5.2 UNIT CHARACTERISTICS AFFECTING POTENTIAL FOR
RELEASES TO SURFACE UTTERS 5-2
5.2.1 Unit Characteristics Influencing Pass Through
to Receiving Waters .5-2
5.2.2 Unit Characteristics Influencing Movement
Through Surface Runoff 5-5
5.3 WASTE/CONSTITUENT CHARACTERISTICS AFFECTING POTENTIAL
FOR RELEASE TO SURFACE WATERS OR SEDIMENTS 5-7
5.3.1 Waste/Constituent Properties Affecting Pass
Through to Receiving Waters 5-7
5.3.2 Waste/Constituent Properties Affecting
Migration Through Surface Runoff 5-7
5.3.3 Waste/Constituent Properties Affecting
Accumulation in Sediments and Aquatic Species.. 5-8
5.3.4 Data Required on Waste Characteristics for
Assessing Potential for Releases to Surface
Waters and Sediments 5-8
5.4 ASSESSMENT OP MIGRATION POTENTIAL OF RELEASES TO
SURFACE WATERS AND SEDIMENTS 5-10
5.4.1 Migration Potential of Releases to Soils 5-10
5.4.2 Migration Potential of Constituents in
Surface Waters and Sediments 5-12
5.4.3 Data Required for Assessment of Migration
Pathways for Releases to Surface Vaters
and Sediments 3-17
5.5 SAMPLING TECHNIQUES FOR SURFACE WATERS AND SEDIMENTS.. 5-18
5.5.1 Assessing the Need for Additional Sampling 5-18
5.5.2 Selection of Sampling Parameters 5-18
iv
-------
5.5.3 Selection of Sampling Locations 5-19
5.5.4 Sampling Techniques for Surface Waters and
Sediments 5-21
5.6 ASSESSMENT OF POTENTIAL EXPOSURE DUE TO RELEASES TO
SURFACE WATERS AND SEDIMENTS 5-24
5.6.1 Potential Effects on Human Health 5-24
5.6.2 Potential Effects on the Environment 5-25
5.6.3 Data Required for Assessment of Potential
Exposures Due to Releases to Surface Waters
and Sediments 5-26
6. ASSESSMENT OF RELEASES TO AIR 6-1
6.1 APPLICABILITY OF CORRECTIVE ACTION REQUIREMENTS
TO RELEASES TO AIR 6-1
6.2 UNIT CHARACTERISTICS AFFECTING POTENTIAL FOR
RELEASES TO AIR 6-1
6.2.1 Unit Characteristics Influencing Volatilization
from Wastewater and Sludge Treatment Units 6-2
6.2.2 Unit Characteristics Influencing Emissions
from Incinerators to Air 6-3
6.2.3 Unit Characteristics Influencing Fugitive
Particulate Emissions 6-4
6.2.4 Data Required for Assessment of Unit
Characteristics Affecting Potential for
Releases to Air 6-5
6.3 WASTE CHARACTERISTICS AFFECTING POTENTIAL FOR
RELEASE TO AIR 6-8
6.3.1 Waste/Constituent Properties Influencing
Volatilization to Air 6-8
6.3.2 Waste/Constituent Properties Influencing
Emissions During Sludge Incineration 6-10
6.3.3 Waste/Constituents Properties Influencing
Adsorption to Solids 6-10
6.3.4 Data Required Cor Assessment of Waste/
Constituent Properties Affecting Potential
for Release to Air 6-10
6.4 ASSESSMENT OP MIGRATION POTENTIAL OF RELEASES TO AIR.. 6-11
6.5 SAMPLING TECHNIQUES 6-12
6.5.1 Assessment of the Need for Sampling 6-12
6.5.2 Selection of Sampling Parameters 6-13
6.5.3 Selection of Sampling Locations 6-13
6.5.4 Appropriate Sampling Procedures for Air 6-13
6.6 ASSESSMENT OF POTENTIAL HUMAN HEALTH AND
ENVIRONMENTAL EFFECTS DUE TO RELEASES TO AIR 6-15
V
-------
6.6.1 Potential Effects on Human Health 6-15
6.6.2 Potential Effects on the Environment 6-17
6.6.3 Data Required for Assessment of Potential
Human Health and Environmental Effects Due
to Releases to Air 6-18
APPENDIX A - PROFILE OF POLLUTANT FATE IN ACCLIMATED AND UNACCLIMATED
SECONDARY POTU
APPENDIX B - HAZARDOUS WASTE CONSTITUENTS POTENTIALLY GENERATED AND DISCHARGED
BY SELECTED INDUSTRIES
APPENDIX C - DATA ON PHYSICAL AND CHEMICAL PROPERTIES FOR SELECTED
CONSTITUENTS
vi
-------
1. INTRODUCTION
This document provides guidance for the conduct of RCRA Facility
Assessments (RFA), the initial phase of corrective action under the Resource
Conservation and Recovery Act (RCRA), at POTV facilities. This introductory
chapter provides an overview of RCRA permit-by-rule provisions and corrective
action programs, discusses the purpose and scope of the guidance document, and
summarizes the organization of the document.
1.1 OVERVIEW OF RCRA PERMIT-BY-RULE PROVISIONS AND CORRECTIVE ACTION PROGRAM
1.1.1 Overview of RCRA Permit-by-Rule Provisions
The goal of the RCRA program is to require "cradle-to-grave" management
of hazardous wastes. Management requirements are Initially triggered by a
determination that a waste is hazardous as defined in RCRA hazardous waste
identification and listing regulations (40 CFR Part 261). Any party handling
a hazardous waste must provide notification to EPA and obtain an EPA identifi-
cation number. The generation, transportation, treatment, storage, or
disposal of the wastes is subject to waste tracking requirements (i.e.,
manifesting requirements) and numerous other management requirements under
RCRA.
Any party which treats, stores or disposes of a hazardous waste
(typically referred to as treatment, storage and disposal facilities (TSDF)),
is subject to extensive RCRA regulations pertaining to the management of these
wastes. Vhere a hazardous waste is transported offsite from a generator's
property, the transporter is also regulated by the hazardous waste management
system, and oust comply with manifesting requirements to ensure delivery of
the hazardous vaste to an approved TSDF.
Host hazardous wastes which are received by a Publicly Owned Treatment
Works (POTV) for treatment are exempt from RCRA requirements under the
Domestic Sewage Exclusion (DSE). As defined at 40 CFR (261.4(a), the DSE
operates to exclude "any mixture of domestic sewage and other wastes that pass
through a sewer system to a publicly owned treatment works for treatment" from
1-1
-------
being defined as a solid vaste, and therefore cannot be a hazardous waste
under RCRA. Based on Congressional intent that the DSE apply to wastes which
are controlled under the construction grants and pretreatment program pursuant
to the Clean Vater Act, the DSE exempts industrial discharges that mix vith
domestic vastes in the sever system from most RCRA requirements. Accordingly,
if a POTW accepts industrial vastes that are mixed vith domestic vastes in the
sever system prior to reaching the POTW property boundary, the industrial
vastes vill not be regulated as a hazardous vaste under RCRA.
Note, however, that the domestic sewage exemption does not apply until
after the waste enters the sever system and mixes vith domestic sevage prior
to reaching the POTW property boundary. Thus, the generator of such waste is
subject to RCRA generator requirements (40 CFR Part 262), and any treatment or
storage of such vaste by the generator prior to the vaste entering the sever
system vould require the generator to have a RCRA permit (unless otherwise
exempt). Likevise, transportation of such vaste prior to the vaste entering
the sever system vould subject the transporter to RCRA transportation
requirements (AO CFR Part 263), including manifest requirements.
One of the generator requirements is §262.20 vhich requires generators of
hazardous vaste to transport vaste only to a "designated facility," vhich is
defined as a facility vith a RCRA permit or interim status. (RCRA interim
status is a statutorily recognized grandfather clause for facilities existing
at the time RCRA first applied to their operations. POTVs receiving a
hazardous vaste influent do not have interim status). In addition, trans-
porters are required to transport hazardous vaste only to designated
facilities, or another designated transporter of the vaste to a designated
facility.
The dunping of hazardous waste down a manhole outside of the POTV
facility is thus a violation of RCRA hazardous vaste generator and transporter
requirements: the generator and transporter could both be liable. Even if
the POTW is covered by a RCRA permit by rule, hazardous vaste cannot be
trucked to and dumped dovn a manhole outside of the POTV property boundary;
1-2
-------
the manhole is not part of the permitted facility. Likewise, collection
systems or pumping stations outside of the POTV property boundary cannot be
used by POTVs for the receipt of trucked hazardous waste.
On the other hand, POTVs which accept any hazardous wastes by truck, rail
or dedicated pipeline at the POTV facility are considered TSDFs under RCRA.
Since these POTVs are already subject to environmental controls, including
permitting requirements, under the CVA NPDES and pretreatment programs, these
facilities are not required to obtain full-fledged RCRA permits, but are
instead eligible for a RCRA permit by rule provided certain requirements are
satisfied.* These requirements are specified in 40 CFR 270.60(c), and are
discussed below. Vith the exception of the new corrective action provisions,
these permit-by-rule requirements have dual purposes: (1) to "close the loop"
of the waste tracking system by requiring a POTV to comply with manifesting
and reporting requirements; and (2) to ensure that wastes delivered to a POTV
by truck, rail, or dedicated pipeline are controlled under the CVA.
Under 40 CFR 270.60(c) of the RCRA regulations, a POTV accepting
hazardous waste by truck, rail, or dedicated pipeline may receive a RCRA
permit by rule if the facility:
• Has a NPDES permit, and
t Complies with the conditions of the NPDES permit.
*Note, however» that RCRA also applies to POTVs which treat, store or dispose
of hazardous waste sludge generated onsite. Since the current status of
these facilities present some regulatory complexities, State and Federal
water management programs should coordinate implementation of RCRA
requirements for such treatment works vith their respective enforcement and
solid waste counterparts* In the case of EPA, specifically, Regions should
coordinate with the Office of Vater Enforcement and Permits and the Office of
Solid Vaste.
1-3
-------
• Complies with the following regulations:
- AO CFR 266.11, identification number;
- 60 CFR 266.71, use of manifest system;
60 CFR 266.72, manifest discrepancies;
- 60 CFR 266.73(a) and (b)(1), operating record;
- 60 CFR 266.75, biennial report;
- 60 CFR 266.76, unmanifested waste report; and
- For NPDE5 permits issued after November 8, 1986, 40 CFR 266.101,
corrective action.
• Accepts only hazardous waste vhich meets Federal, State, and local
pretreatment requirements vhich would apply if the waste were dis-
charged to the P0TV through a sewer, pipeline or similar conveyance.
(Emphasis added).
The corrective action requirement highlighted above was added to the permit-
by-rule provisions as part of the Codification Rule amending the RCRA regula-
tions in response to the 1986 Hazardous and Solid Waste Amendments (HSVA) to
RCRA (50 FR 28752, July 15, 1985).
Under permit-by-rule provisions, EPA will require compliance with
corrective action requirements by POTVs vhich:
• Have an NP0ES permit;
• Have received hazardous waste by truck, rail or dedicated pipe and are
currently treating, storing or disposing of hazardous waste;* and
• Have been covered by a permit-by-rule prior to November 8, 1986 and
the FOTV's NFDES permit has been reissued since such date or are being
covered for the first tine by the permit-by-rule after November 8,
1984.
*Note that if a P0TU received hazardous waste by truck, rail, or pipe at any
time, it may be difficult for the POTW to shov that it no longer treats,
stores, or disposes of hazardous waste.
1-4
-------
Corrective action requirements will be implemented through the issuance of
mini-RCRA permits, referred to as RCRA Individual Determination of Explicit
Requirements ("RIDER") permits, to POTVs in conjunction vith the NPDES
permitting process.
1.1.2 Overview of RCRA Corrective Action Program
The primary objective of the RCRA corrective action program is to
identify and clean up releases of hazardous waste or hazardous constituents
that threaten human health or the environment. The 1986 HSVA established
broad new authorities in the RCRA program to assist EPA in accomplishing these
objectives. These new authorities include:
• Section 300&(u) - Corrective Action for Continuing Releases:
Requires that any permit issued after November B, 1984, require
corrective action for all releases of hazardous waste or hazardous
constituents from solid waste management units at the facility. The
provision also requires that 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 issuance.
• Section 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.
• Section 3004(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.
Other significant RCRA authorities which may be utilized to address corrective
action include Section 3008(a), the Section 7003 enforcement authority, the
Section 3013 information-gathering authority, and the Section 3007 inspection
authority. Moreover, CERCLA authorities may be invoked where appropriate.
1-5
-------
These nev corrective action authorities contained in the 1984 HSVA
amendments change the focus of the RCRA corrective action program from
detecting and correcting releases from regulated units to cleaning up problems
resulting from a broad range of waste management practices at RCRA facilities.
Prior to passage of HSVA, EPA authority under RCRA to require corrective
action for releases of hazardous constituents vas limited to ground-water
releases from units covered by RCRA permits. The HSVA program extends RCRA
authority to all solid waste management units at RCRA facilities and all
environmental media, and encourages the use of other legal authorities to help
achieve corrective action objectives at these facilities.
Because RCRA permit-by-rule facilities are treated as RCRA permitted
facilities for the purposes of corrective action, Sections 3004(u) and (v)
vill typically be the corrective action provisions most relevant to the
conduct of corrective action at POTV permit-by-rule facilities. The Section
3008(h) authority vill apply only in those rare cases vhere a POTV has interim
status under RCRA. This distinction is significant since the corrective
action authorities differ somewhat in scope. For example, the Section 3004(u)
corrective action authority is restricted to releases from solid vaste
management units (SVMUs) at a facility, while the Section 3008(h) authority
applies more broadly to any releases associated with hazardous waste manage-
ment activity at a facility. Section 3004(u) corrective action is imposed
through permit conditions, while Section 3008(h) imposes corrective action
through enforcement orders.
The RCRA corrective action program consists of three phases:
• RCRA Facility Assessment (RFA) - to identify releases or potential
releases requiring further investigation;
• RCRA Facility Investigation (RFI) - to fully characterize the nature
and extent of releases; and
• Corrective Measures (CM) - to determine the need for and extent of
remedial measures. This step includes the selection and implementa-
tion of appropriate remedies for all problems identified.
1-6
-------
This guidance document addresses only the first phase of this process and
outlines procedures and criteria for the conduct of RFAs by EPA, State, and
POTV personnel at POTV permit-by-rule facilities.
1.1.3 Overview of the RFA
The RCRA Facility Assessment is a three-stage process for:
• Identifying and gathering information on releases at RCRA facilities;
• Evaluating solid vaste management units (SVHUs)* for releases to all
media and evaluating regulated units for releases to media other than
ground vater; and
• Making preliminary determinations regarding releases of concern and
the need for further actions at the facility.
During the RFA, investigators will gather information on SVHUs and other areas
of concern at RCRA facilities. They vill evaluate this Information to
determine vhether there are releases that warrant further investigation or
other action at these facilities. Upon completion of the RFA, Agency- per-
sonnel 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 analysis of data to
support Initial release determinations:
0 Preliminary revlev (PR) - focuses primarily on evaluating existing
information, such as inspection reports, permit applications, his-
torical monitoring data, and interviews with State personnel who are
familiar with the facility;
• Visual site inspection (VSI) - entails a site inspection for the
collection of visual information to obtain additional evidence of
rel««st; and
• Saapling visit (SV) - fills data gaps that remain upon completion of
th« PR and VSI.
~See page 1-8 for definition of SVMU.
1-7
-------
The RFA should include the investigation of releases to all environmental
media, including air, surface water, sediments, ground water, soils, and
subsurface gas. The RFA may address releases that are subject to permitting
requirements under the NPDES program and other environmental programs. Uhere
permitted discharges or contamination resulting from permitted discharges are
problematical, investigators should refer the case to the original permitting
authorities. If necessary, EPA may exercise its RCRA corrective action
authorities to remedy the environmental problem. The RFA also addresses
releases from SVMUs to media other than the one covered-by the unit's dis-
charge permit. For example, EPA may use its corrective action authorities to
control the release of volatile organic compounds (VOCs) from NPDES-permitted
wastewater treatment units where there is cause for concern. EPA and State
investigators should use the full complement of RCRA and CVA authorities to
secure appropriate action. Alternatively, Agency investigators may wish to
use other authorities such as CERCLA or State authorities, and should consult
with EPA or State offices responsible for administering these programs.
The HSVA Section 3004(u) provision focuses on addressing releases from
SVMUs at RCRA facilities. For the purposes of conducting corrective action at
POTVs, the facility is defined as: The portion of the POTV which is designed
to provide treatment, storage, or disposal of municipal or industrial waste
and contiguous property owned or operated by the municipality. The definition
includes sewers, pipes, and other conveyances which transport wastewater to
the POTV plant only to the extent these conveyances are located upon or under
the property described above. The definition excludes contiguous property in
which the legal rights of the municipality are restricted to the trans-
portation of waste on or through the property (e.g., easements).
By this definition, a facility will include property containing tradi-
tional vasttvatcr and sludge treatment units (e.g., headwords, wastewater
treatment tanks and basins, sludge processing units, sludge incinerators,
etc.), as veil as any adjacent areas of the municipal property used for
treatment, storage, or disposal of any solid or hazardous waste. Accordingly,
a facility may include units, such as adjacent municipal landfills or
municipal refuse incinerators, which handle wastes other than wastewaters or
sewage sludges. On the other hand, the facility definition operates to
1-8
-------
exclude POTV operations, particularly those involving sevage sludge use or
disposal (e.g., landfilling, land application, incineration, etc.) which occur
at noncontiguous, offsite properties owned or operated by the municipality.
An offsite, noncontiguous operation is a separate facility, and may even be a
RCRA TSDF if the vaste managed at the site is hazardous.
The definition also precludes consideration of possible releases of
hazardous vastes or constituents occurring outside the property boundaries.
As a result, releases from POTV collection systems (e.g., exfiltration,
volatilization, combined sewer overflows/bypasses) outside the contiguous
property of the POTV should not be evaluated in the conduct of RFA at the
POTV. Under HSVA Section 3004(v), however, EPA may, under certain conditions,
require corrective action for a release within the facility but which extends
beyond a facility boundary where necessary to protect human health and the
environment.
Solid vaste management unit (SVMU) is defined to include any discernible
waste management unit at a RCRA facility from which hazardous waste or
constituents might migrate, regardless of whether the unit was intended for
the management of solid or hazardous vaste. The SVMU definition includes:
• Containers, tanks, surface impoundments, waste piles, land treatment
units, landfills, incinerators, and underground injection wells,
including those units defined as "regulated units" under RCRA;
• Recycling units, vastevater treatment units, and other units which CPA
has generally exempted from standards applicable to hazardous vaste
management units; and
• Areas contaminated by "routine and systematic discharges'1 from process
areas.
The definition does not include one-time accidental spills from production
areas or units in vhich vastes have not been managed (e.g., product storage
areas). One-time spills containing hazardous materials vhich are not cleaned
up may be subject to RCRA Sections 3008(a) or 7003, or CERCLA enforcement
authorities. The scope of the SVMU definition should be considered in
evaluating areas of the POTV facility (e.g., chemical handling operations)
vhich resemble production areas at a typical RCRA facility.
1-9
-------
In accordance vith the SVMU definition, conduct of RFA at a POTV should
focus on plant units used to manage hazardous or solid vaste. These units may
include:
• Any vaste management units downstream from the point of discharge to
the treatment plant of wastes (e.g., hazardous wastes, septage wastes,
Landfill leachate, etc..) delivered to the POTV by truck, rail, or
dedicated pipeline. Vastes delivered to a POTV treatment plant by
truck, rail, or dedicated pipeline are not covered by the DSE, and
should therefore be considered solid wastes.
• Any waste management units which generate oc handle a treatment
residual (e.g., grit, primary sludge, waste activated sludge, etc.)
which is regulated as a solid waste under RCRA.
• Any waste management units which handle other materials (e.g.,
municipal refuse, spent solvents, etc.) regulated as solid wastes
under RCRA.
In effect', the definition applies to all vaste management units at a POTV
facility except those which handle only wastewaters which are exempt under the
DSE. As a result, the SVMU definition will encompass most units typically
found at POTVs including sedimentation tanks, aeration tanks, wastewater
treatment ponds, trickling filters, aeration basins, sludge holding basins and
other units used for the treatment, storage or disposal of wastewaters or
sludges•
Once a release of hazardous wastes or constituents is identified at a
SVMU, corrective action vill apply to the vaste or constituent regardless of
its origin within the POTV. A release from a POTV SVMU may result from the
presence of materials and substances contributed in DSE vastes, non-DSE solid
vastes (e.g., truck, rail, or dedicated pipeline vastes, sewage sludge, etc.),
or some combination of these tvo vaste types. Moreover, complete mixture of
wastes in POTV vaste management units vill often make it difficult or impos-
sible to determine vhether hazardous vastes or constituents contributing to a
release are derived from DSE or non-DSE vastes. Accordingly, in order to
assess vastes and constituents managed at and potentially released from POTV
units, the RFA investigator should fully characterize vastes and constituents
1-10
-------
contained in both DSE and non-DSE vastes discharged to a POTV. The investi-
gator should also characterize vastes discharged in the past to the POTV,
including DSE and non-DSE vastes discharged prior to enactment of the 1984
HSVA corrective action amendments.
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 framevork 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.
The Agency recognizes that sampling needs vill differ on a case-by-case
basis. The extent of sampling vill depend on the amount and quality of
information gathered in the PR and VSI, the investigator's professional
judgment regarding the amount of information necessary to support an initial
release determination, and the degree of owner/operator cooperation.
1.2 PURPOSE AND SCOPE OF THE GUIDANCE DOCUMENT
The EPA Office of Solid Waste (OSV) has prepared guidance for the
performance of RFA at RCRA facilities, (NTIS #PB 87-107 769, OSV Publication
#530-SV-86-053, October, 1986). In contrast to the OSV guidance, however,
this guidance applies only to the conduct of RFA at POTVs that must obtain a
RCRA permit by rule. Prepared by the EPA Office of Water (0V) in consultation
vith EPA/OSV, this document is intended to supplement existing RCRA guidance
in providing specific guidance for the conduct of RFA at POTVs subject to RCRA
permit-by-rule facilities. This guidance adapts basic RCRA procedures and
methodologies for use in the assessment of hazardous releases from POTVs
receiving hazardous vastes by truck, rail, or dedicated pipeline. This
document is also intended to provide EPA and State water program officials and
POTV operators vith essential background information on RCRA authorities and
procedures, especially those pertaining to corrective action.
The guidance document vill highlight technical areas in vhich conduct of
RFA at POTVs can be expected to differ markedly from the conduct of RFA at
traditional RCRA TSDFs. Distinctive aspects of POTV RFA relate to the
following considerations:
1-11
-------
• Relative similarity of waste management units and treatment system
configurations across POTVs compared vith traditional RCRA TSDFs;
• Potential diversity and variability over time of wastes and con-
stituents received by POTVs, and limitations in POTV knowledge
concerning types of wastes and constituents entering the plant; and
• Lack of traditional RCRA data sources (e.g., Part B permit appli-
cations, ground-water monitoring data, etc.) for use in the conduct of
RFA at POTVs.
These technical concerns are given special consideration in this document.
In other technical areas where POTV characteristics resemble those of tradi-
tional RCRA TSDFs for purposes of the RFA, this guidance document relies
heavily on guidance contained in the EPA/OSV RFA guidance document.
To provide maximum usefulness to the investigator, this document contains
most of the information and guidance necessary to support conduct of a POTV
RFA. Still, in certain technical areas involving detail and complexity (e.g.,
ground-water monitoring), the investigator will be referred to other guidance
documents prepared by the EPA hazardous waste and water programs. Also, the
investigator should be familiar vith the companion EPA/OSV guidance document
for the conduct of RFA at RCRA interim status and permitted facilities.
~ 1.3 ORGANIZATION OF THE GUIDANCE DOCUMENT
This document contains six chapters. The second chapter details the RFA
process as it applies to POTV facilities. The third chapter provides an
overview of vastes and vaste management units typically found at POTVs. The
last three chapters outline procedures for the assessment of releases to
specific environmental media, including releases to ground vater, soil and
subsurface gas (Chapter 4), releases to surface vater and sediments (Chapter
5), and releases to air (Chapter 6).
1-12
-------
2. CONDUCT OF THE RCRA FACILITY ASSESSMENT
This chapter provides a methodology for conducting RCRA Facility
Assessments (RFAs) at POTVs. Section 2.1 outlines the overall technical ap-
proach for performance of the RFA. Sections 2.2 to 2.4 provide detailed guid-
ance for each of the three RFA stages, which are:
• Preliminary Review (PR);
• Visual Site Inspection (VSI); and
• Sampling Visit (SV).
The general RFA procedures outlined below are supplemented by information
in Chapter 3, which describes how the RFA may be adapted to consider wastes
and waste management units typically found at POTVs. Chapters 4, 5, and 6
explain how the RFA may be adapted to consider technical factors relating to
specific environmental media.
2.1 TECHNICAL APPROACH FOR THE RCRA FACILITY ASSESSMENT
All three RFA steps require the investigator to examine data on the POTV
as a whole and on specific units at the facility. Types of facility data can
generally be divided into five categories:
t Unit characteristics;
• Vaste characteristics;
• Pollutant migration pathways;
• Evidence of release; and
• Exposure potential.
Figure 2-1 provides a matrix of these categories, and identifies types of
factors an investigator should consider within each category. In conducting
an RFA, the investigator will utilize best professional judgment to evaluate
these factors and their related significance in determining the likelihood of
a release at the facility.
2-1
-------
PICURE 2-1. MAJOR PACTORS TO CONSIDER IN CONDUCTING RPAs
Unit Waste Migration Evidence of Exposure
Characteristics Characteristics Pathways Release Potential
Type of unit
Type of waste
Topographic
Prior inspec-
Proximity to
placed in the
characterise ics
tion reports
affected pop
Design features
uni t
Geologic setting
Ci t izen
ula tion
Operating prac-
Migration and
complaints
Proximity to
tices (past and
dispersal char-
Hydrogeologic
sens i t i ve
present)
acteristics of
setting
Moni toring data
environments
the waste
Period of
Hydrologic setting
Visual evidence
Likelihood o
operat ion
Toxicological
e.g., discolored
migration to
characteristics
Atoospheric
soil, seepage,
potent ial
Age of unit
condi t ions
discolored
recep tors
Physical and
surface water or
Location of
chenical
runoff.
uni t
characteristics
Other physical
General physical
evidence, e.g.,
condi t ions
fish kills,
worker illness,
Method used to
odors
close the unit
RFA sampling
data
-------
Figure 2-2 outlines the types of information in each category that an
investigator should obtain and evaluate during the RFA. During the pre-
liminary review, the investigator should examine documents and other written
materials to obtain information on the characteristics of wastes managed at
the POTV facility as a whole and in specific SVMUs, the design and operating
features of the SWMUs, facility location and setting, evidence of past and
ongoing releases, and potential environmental receptors. This information
will assist the investigator in identifying migration pathways and environ-
mental media which represent significant concerns for the RFA. The inves-
tigator should supplement this information with evidence gathered during the
visual site inspection and sampling data collected during the sampling visit.
Evaluation of technical factors within each category should reflect con-
cerns relating to specific environmental media. For example, in evaluating
unit characteristics at a facility, the investigator should recognize that
inground units are more likely to cause ground-water releases than above
ground units, and that open wastewater treatment tanks are more likely to
cause air releases than closed landfills. Similarly, in revieving waste
characteristics, an investigator should recognize that certain wastes tend to
volatilize and be released to air, while other wastes are soluble in water and
tend to migrate to surface or ground water. The environmental media that
should receive the greatest attention will also depend on facility location
and setting. For example, ground-water releases will generally not be a
significant concern at facilities located on relatively impermeable, thick
soils. Types of evidence and potential receptors will also vary by medium.
The RFA is completed vhen the investigator has sufficient information to
make a preliminary determination regarding the presence of releases or poten-
tial releases at the POTV facility and the need for further investigation.
Sometimes, it vill be possible to make this determination after completing the
first two RFA stages (i.e., PR and VSI). In these instances, a SV vill not be
necessary. In other cases, even vhen the SV is completed, the investigator
may need to collect additional information, conduct follov-up inspections, or
perform additional sampling before making a determination.
2-3
-------
raie 2-2. types op momokm evaukud duu*c he rfa
REA SIS'
LKTT
awMnstisncs
WASTE
CHARACTERISTICS
HICRATICN
PAIHUAYS
EVIDENCE OF
release
EXPOSURE
POTENTIAL
PRELIMINARY
REVIEW
Evaluate informa-
tion on design,
liners, age, con-
struction, loca-
tion, aethod of
closure.
Review historical
inforation on
types, volumes,
characteristics
of wastes
handled.
Review site hydro-
geology, surface
water nroff path-
ways, prevailing
winds, locations
of rivers, etc.
Review historical
sanpling data,
reports of release,
citizen cxnplaints,
etc.
Locate drinking
water wells, uses
of nearby surface
water, potential
for subsurface gas
migration, etc.
VISUAL SITE
INSHDLTIUN
Review general
wit conditions.
Luck for evidence
of uiit failure,
problenatic oper-
ating practices,
subsidence and/or
ponding at closed
wits.
Review waste
nanagemait
practices.
Observe erosion
indicating nroff,
likely pathways
of release to
each mod inn from
wits, etc.
Obtain visual evi-
dence of releases,
e.g., seeps, dead
vegetation, dis-
colored soils and
sedunents, etc.
Collect visual
evidence on poten-
tial receptors, e.g.,
hunans and sensitive
environments.
SAMPLING
VISIT
Hay observe addi-
tional evidence.
Characterize
waste through
sailing and
analysis.
Sample pathways
for additional
evidence of
release.
Saople pathways/
wastes for
specific con-
stituents.
Sanple for hazard-
ous constituents
in yelLs, concentra-
tions of volatile
organics in air.
-------
In general, when the RFA is completed, the investigator should have per-
formed the following:
• Identified all SVMUs;
• Identified all potential releases of concern;
• Determined which areas of the facility require further investigation
and collected sufficient information to focus these investigations;
• Screened out releases not requiring further investigation;
• Referred permitted releases to other authorities, as appropriate; and
• Determined which releases require interim corrective measures.
Upon completion of the RFA, the investigator should prepare a report
that describes these six activities and summarizes the findings of the RFA.
2.2 CONDUCTING THE PRELIMINARY REVIEW
2.2.1 Purpose and Scope of the Preliminary Review
This section of the chapter describes procedures for conducting a prelim-
inary review (PR), the first RFA stage. The PR serves three primary purposes:
• To identify SVMUs at the facility;
• To collect and evaluate existing information on the facility in order
to identify and characterize potential releases from the SVMUs; and
• To focus the activities to be conducted in the second and third stages
of the RFA, the visual site inspection (VSI) and the sampling visit
(SV).
After careful evaluation of existing information, the investigator should
structure subsequent RFA information collection, inspection and sampling
activities to focus on closing data gaps that may hinder or preclude accurate
determinations on the presence of releases or potential releases from SVMUs at
the facility.
During the PR, the investigator should reviev existing documents on the
entire POTV facility and interview individuals to identify SVMUs that may have
2-5
-------
released or be releasing hazardous vastes or constituents. The PR should not
be limited to those portions of the facilities used to manage hazardous waste
delivered to the POTV by truck, rail or dedicated pipeline. Rather, in
keeping with the scope of RCRA Section 3004(u) corrective action, the investi-
gator should gather information relating to all known SVMUs and other waste
management areas. At large, complex POTVs with many SUMUs, it may be more
practical to characterize groups of similarly designed SVMUs or those in the
same area rather than individual units. The investigator should also consider
information on releases that may be beyond the scope of^RCRA corrective action
authorities. Some releases may be subject to investigation and remediation
under statutory authorities other than RCRA. Any release of hazardous
constituents, as defined in RCRA, is subject to these requirements.
The scope of the PR includes investigating release potential to all
environmental media, including:
• Ground water, soils, and subsurface gas;
• Surface water and sediments; and
• Air.
The PR should also collect and evaluate information on releases that are per-
mitted or subject to permitting requirements under NPDES or other environ-
mental programs. As a result, a PR conducted at a POTV should include
hazardous vastes or constituents released through a NPDES-permitted outfall or
as emissions from sewage sludge incinerators. In addition, the PR should
consider information on releases to environmental media other than the medium
for which the release is permitted. For example, the PR should evaluate the
potential for releases of hazardous vastes and constituents to air from plant
headvorks, primary clarifiers, secondary vastevater treatment units and other
SVMUs.
2.2.2 Gathering Information
In the first stage of the PR, the investigator vill gather information
and documents providing evidence of the potential for releases from SVMUs and
the POTV facility. The success of the PR will depend to a great extent on the
2-6
-------
investigator's ability to collect all relevant information. Data gathering
for the PR should typically entail:
• Collection of written information and documents;
• Interviews with individuals familiar with the facility; and
• Requests for additional information from the facility owner/operator.
Each of these steps is discussed belov.
Collecting Written Information and Documents on the POTV Facility
Because POTUs have been controlled under the CVA, traditional RCRA data
sources, such as Part A permit applications, Part B permit applications, RCRA
inspection reports and RCRA exposure information reports, vill not be
available. Similarly, because CERCLA authorities have rarely been applied to
POTVs, data sources such as CERCLA preliminary assessment/site investigation
reports, CERCLA remedial investigation/feasibility study reports, hazard rank-
ing system documentation and CERCLA Section 103(c) notifications, vill prob-
ably contribute little useful information to the RFA. Instead, the investi-
gator will have to rely extensively on data sources relating to the NPDES,
pre treatment, construction grants and other water programs administered under
the CVA. In addition, the investigator may use facility records and other
site-specific materials to assess unit characteristics, waste characteristics,
and the environmental setting.
The folloving six types o£ data sources may provide useful information
for conducting PR for a POTV:
• NPDES prograa records;
• Pretreatment program records (e.g., manifests);
• RCRA program records;
• Facility design, construction and operating records;
• Records pertaining to land disposal of sludges, ash and effluent; and
• Site-specific materials for assessing the environmental setting of the
facility.
2-7
-------
NPDES program records. NPDES program records may contain significant
information on the potential for releases of hazardous wastes and constituents
to surface waters and sediment. Possible NPDES data sources include:
• NPDES permits;
• Permit applications - including Form 2C testing data (may not be
available if the POTV completed a Standard Form A for domestic
vastevater discharges), general facility information (e.g.,
topographic maps, wastewater flov diagram);
• Permit records - including draft permits, statements of basis for
permit conditions, fact sheets;
• Discharge monitoring reports (DMRs) - containing self-monitoring data
for permit parameters;
• Noncompliance reports - including written reports of upsets, bypasses
and certain effluent limit violations;
• Inspection reports - including reports from compliance evaluation
inspections, compliance sampling inspections, performance audit in-
spections, compliance biomonitoring inspections, toxics .sampling in-
spections, diagnostic inspections, reconnaissance Inspections and
legal support inspections; and
• Enforcement documents - including administrative orders, consent
decrees.
These documents should be available either in EPA Regional or State water
office files or in POTV records.
Pretreatment program records. Pretreatment program records may contain
useful data on the types of hazardous wastes and constituents discharged to
the POTV by industries. In particular, pretreatment data sources may provide
information on hazardous constituents contained in DSE wastes treated at the
POTV. Possible pretreatment data sources include:
• POTV pretreatment program submissions;
• Industrial vaste surveys - including a list of significant industrial
dischargers to POTV system;
• POTV influent/effluent/sludge sampling data - identifying hazardous
constituents, especially CVA priority pollutants, present in POTV
influent, effluent, and sludge vastestreams;
2-8
-------
0 Pretreatment audit reports and pretreatment compliance inspections;
• Annual POTV pretreatment reports - summarizing POTV pretreatment
activities for a given year;
• Industrial baseline monitoring reports;
• Industrial discharge permits - containing legal conditions for indus-
trial discharges to POTV;
• Industrial self-monitoring reports - containing industrial monitoring
data for regulated parameters; and
• Industrial inspection reports and compliance monitoring data - con-
taining data from inspections and monitoring visits conducted by POTVs
ac industries.
These documents should be contained in POTV records and may also be available
from EPA Regional or State water office files.
RCRA program records. As discussed above, most of the data sources
typically available for RCRA treatment, storage, and disposal facilities
(e.g., Part B permit applications, RCRA inspection reports, RCRA exposure
information reports) will not be available for POTV facilities. Still, vhere
a POTV has received hazardous vastes by truck, rail, or dedicated pipeline,
and is therefore regulated as a permit-by-rule facility, certain RCRA data
sources should be available. These records may include hazardous vaste
notification forms, manifest records, operating records and biennial reports.
At a minimum, these data sources should provide information on types and
quantities of non-DSE hazardous vastes managed at the POTV facility. Once the
vaste type has been Identified, the investigator may refer to hazardous vaste
identification regulations [40 CFR Part 261] or RCRA listing documents for
additional information on vaste characteristics and constituents. RCRA pro-
gram records nay be obtained from EPA Regional or State hazardous vaste files
or POTV records.
Facility design, construction, and operating records. Facility design,
construction, and operating records provide essential information on unit
characteristics and environmental setting of the POTV facility. For example,
foundation testing and site preparation records may contain useful information
about the geologic and hydrogeologic setting. Facility data sources may
include:
2-9
-------
• "As built" engineering drawings;
• Construction grants facility plans and applications;
• Site maps and surveys;
• Foundation testing/site preparation records, including boring logs,
soil tests, measurements on depth to water table, etc.;
• Plant operations and maintenance (0 & M) manuals;
• Equipment supply manuals;
• Daily operating logs;
• Annual and monthly operating records;
• Reports describing emergency conditions at POTV (e.g., spills, upsets,
bypasses, explosions); and
• Records of citizen complaints, (e.g., odors, fish kills, ground-water
contamination).
Facility records vill provide technical data necessary to determine whether
POTV unit characteristics and the environmental setting contribute sig-
nificantly to the potential for a release to any environmental medium.
Records on land disposal of effluent, sludges, or ash. Some POTVs oper-
ate onsite land disposal units (i.e., landfills, underground injection,
application, waste piles or surface impoundments) for the management of efflu-
ent, sludges, or ash residuals. The investigator should collect and review
records pertaining to the operation of any of these units. Possible data
sources include:
• Effluent, sludge, and ash sampling data, including EP toxicity testing
data for solid vaste residuals;
• Permits for land disposal, such as Subtitle 0 land disposal permits,
NPDES permits for spray irrigation operations, or UIC permits for
underground injection of effluent; and
• Engineering records related to the design, construction, or operation
of POTV land disposal units.
These records can generally be obtained from either State solid vaste or water
program files or POTV records.
2-10
-------
Site-specific materials for assessment of a facility's environmental
set ting. In those instances vhere site-specific environmental information is
lacking, the data necessary to assess the environmental setting of a POTV will
have to be assembled from a variety of non-POTV data sources. Examples of
these data sources include:
• Topographic, surface geologic, hydrogeologic, hydrologic, and other
maps maintained by the U.S. Geological Survey and State geological
agencies;
• Soil survey maps maintained by the U.S. Department of Agriculture;
• Maps and surveys maintained by other Federal/State agencies;
• Aerial photographs;
• State/local veil permit offices;
• Local public health agencies;
• Local veil drillers;
• Local airports/veather bureaus;
• Colleges/universities;
• Environmental organizations; and
t Facility records for nearby RCRA TSO facilities or CERCLA sites
Technical data collected from these and other sources will be used for the
assessment of potential migration pathways and environmental receptors of any
releases from the POTV facility.
Interviewing Individuals Familiar With the Facility
POTV operators and employees will have the most information about a
facility and should be consulted during the visual site inspection. As part
of the PR, the investigator should interview personnel from EPA Regional and
State environmental program offices who are familiar with the POTV. Because
POTVs have historically been regulated primarily under the CVA, staff from
Federal and State NPDES, pretreatment, and construction grants offices are
likely to have information on the POTV. Vhen POTVs operate units such as
2-11
-------
landfills or incinerators that are controlled under other environmental pro-
grams, officials from the corresponding program offices should also be con-
sulted. Early contact vith these program officials can help to ensure that
all relevant information is considered during the PR. Vhere possible, Che
investigator should also contact local colleges and universities and public
interest groups that may be familiar vith the POTV facility.
Requesting Additional Information From the Facility Owner/Operator
In situations where the investigator does not find sufficient information
to complete the PR, it may be necessary to request additional information from
the POTV ovner/operator. Such requests should be in the form of a letter in
vhich EPA requests additional information from the facility to comply vith
RCRA corrective action requirements. Vhere necessary, the investigator should
cite EPA information-gathering authorities under RCRA Section 3013 or CVA
Section 3.08, as veil as RCRA corrective action provisions (i.e., RCRA Sections
3004(u) and (v)), to obtain this information. These letters should be as spe-
cific as possible to ensure that the requested data are submitted in a timely
manner.
2.2.3 Evaluating PR Information
The investigator should evaluate all information collected during the PR
to determine the release potential of the POTV facility. Evaluation of
available information involves three basic steps:
• Characterizing hazardous vastes and constituents managed at the POTV
facili ty;
t Identifying SVMUs at the facility; and
• Evaluating the potential for releases from the SVMUs.
Each step is discussed below.
Characterizing Hazardous Wastes and Constituents Managed at the POTV
Characterization of hazardous vastes and constituents managed at a POTV
may be more difficult than at a typical RCRA TSD facilities. Because POTVs
2-12
-------
may serve a large, diverse and changing industrial community, wastes and
constituents entering the treatment plant may vary over time. Also, because
wastes managed at a POTV originate offsite and are mixed vith other wastes in
a POTV collection system, a POTV may have limited information on types of
wastes and constituents entering the treatment plant. In spite of these
difficulties, it is essential for the investigator to identify to the greatest
extent possible the types of hazardous wastes and constituents that may be
present at the POTV.
Since corrective action requirements apply to releases of RCRA hazardous
wastes or constituents contained in either DSE or non-DSE wastes, the
investigator should gather information on both waste types. To assess DSC
wastes, the investigator should use pretreatment data sources to characterize
the industrial community served by the POTV and identify specific wastes and
hazardous constituents discharged by industries to the POTV collection system.
Also, influent, effluent, and sludge toxics sampling data collected for NPDES
and pretreatment programs should be carefully reviewed. RCRA program data
sources, such as hazardous waste notifications, manifesting records or
operating records, should be revieved if available to identify hazardous
wastes delivered to the POTV facility by truck, rail, or dedicated pipeline.
The investigator should also characterize wastes discharged in the past to the
POTV facilities, including wastes discharged prior to enactment of the 1984
RCRA corrective action amendments. Chapter 3 of this document provides more
detailed guidance on the types of vastes and constituents managed at POTVs.
Identifying SVHUs at the POTV
In this step, the investigator should identify all SVHUs at the POTV and
mark these units on a facility map. The map should designate all knovn SVMUs,
any waste management areas vhich may meet the definition of a SVMU (see
Chapter 1 for the definition of a SVMU), and other potential releases of con-
cern that may be beyond the scope of RCRA corrective action authorities. The
facility map will be a useful document throughout the RFA, particularly during
the VSI and SV stages o£ the RFA. Besides shoving facility layout and
possible SVHUs, the map vill often contain information on relevant migration
pathways and potential exposure points. Additional SVHUs may be added to the
map as they are identified in subsequent stages of the RFA.
2-13
-------
Most data necessary to identify SVMUs at a POTV facility should be read-
ily accessible from facility design, construction and operating records.
Generally, as a result of the extensive documentation for these public facili-
ties and frequent use of offsite disposal for treatment residuals, an investi-
gator will confront fever of the difficulties associated vith the identifica-
tion of abandoned waste management units at RCRA TSD facilities. Also, while
RCRA TSD facilities often use numerous independent treatment and disposal
systems for the management of residuals, POTV plants typically employ a single
connected wastewater and sludge treatment system. Accordingly, an investi-
gator performing a PR for a POTV facility may not have to resort to more
unusual data sources such as aerial photographs to identify and characterize
historical waste management practices at the POTV. On the other hand, a PR
will be more complicated where a POTV operates or has operated onsite land
disposal units for wastewater treatment residuals or offsite waste materials
such as municipal refuse. In these cases, an investigator should exercise
special caution in identifying unit and waste characteristics for these waste
management practices.
Evaluating the POTV Facility's Release Potential
During this phase of the PR, the investigator should determine the
likelihood of releases from each SVMU at the POTV. The investigator's ability
to draw conclusions on the likelihood of release will depend on the extent of
available information on unit characteristics, waste characteristics, pol-
lutant migration pathways, and evidence of releases. Information on exposure
potential is not needed to determine the likelihood of releases, but is
important in determining the need for interim corrective measures because of
immediate exposure risks. Types of information which should be considered in
these five categories are described belov.
Unit characteristics. The design and operating characteristics of a SVHU
will determine, to a significant extent, its potential for release to one or
more envlronnental media. As a result, the investigator should carefully
evaluate the physical characteristics of each SVMU or group of SVMUs to
determine how they affect the potential for releases. Major technical factors
which should be considered in the evaluation of unit characteristics include
2-14
-------
type of unit, design features, operating practices, period of operation, age
of unit, location of unit, general physical condition, and unit closure
me thod.
Chapter 3 provides an overview of waste management units commonly found
at POTU facilities and their potential for releases to the environment. Also,
the media-specific chapters (Chapters 4, 5, and 6) of this guidance document
discuss how design and operating characteristics of various types of SVMUs
affect their potential for release to each environmental medium. For example,
in evaluating a POTV facility for possible ground-water impacts, unlined
surface impoundments such as aerobic or facultative wastewater lagoons can be
assumed to have a high potential for releasing constituents to ground water.
Similarly, open wastewater treatment tanks and impoundments, especially units
with aeration processes, will exhibit a high potential for air releases.
Vaste characteristics. The investigator should identify wastes or
constituents entering the POTV and determine the probable fate of these wastes
and constituents within various POTU treatment units. Chapter 3 provides a
methodology for the identification of likely constituents in POTV wastestreams
based on a review of the industrial community served by the POTV. Chapter 3
also contains a brief discussion on the fate of many hazardous constituents
within a typical POTV facility.
In evaluating the release potential for POTV SVMUs, the investigator
should identify wastes and constituents present in the POTV and in the
specific SVMU in order to correlate constituents present in the environment
with those present in the contaminant source. The investigator can usually
deduce that a release has occurred if the POTV facility and/or a specific unit
contain a constituent observed in a pollutant migration pathway. Information
gathered on facility vaste generation processes may also be useful in
identifying constituents other than RCRA listed constituents. For example,
refuse that decomposes rapidly may produce methane when placed in landfills.
The evaluation of POTV wastes should consider the type of vaste treated
in the unit, migration and dispersion characteristics of the vaste, and
toxicological, physical, and chemical characteristics. The release potential
2-15
-------
for specific wastes and constituents will vary depending on unit type. For
example, volatile organic compounds are more likely to be released from
wastewater treatment tanks, such as activated sludge treatment basins, while
toxic metals will tend to concentrate in POTV sludges and may be released to
surface waters from sludge lagoons and waste piles. Chapters 4, 5, and 6
discuss the ways in which constituent properties affect the likelihood of
releases to a specific environmental medium.
Pollutant migration pathways. The investigator should evaluate existing
information concerning the likely pollutant migration pathways associated with
each SVMU. Major factors to be considered in this evaluation are hydrologic
setting, geologic setting, hydrogeologic setting, atmospheric conditions, and
topographic characteristics. This information will be critical when the
investigator attempts to demonstrate that constituents observed in the
environment originated at a specific SVMU.
Different types of SVMUs will exhibit varying potential for the release
of constituents to specific migration pathways. As a result, the investigator
should identify the pollutant migration pathways that are most likely to be
affected and gather information necessary to assess the characteristics of
these pathways. Chapters 4, 5, and 6 provide information to assist the
investigator in evaluating the physical characteristics of each migration
pathway of interest. This part of the analysis also plays a critical role in
evaluating the need for interim measures at the facility by identifying
potential exposure points along the various migration pathways.
Evidence of release. The investigator should examine available informa-
tion to identify any evidence that hazardous wastes or constituents have been
released at the POTV facility. The investigator may have access to direct and
indirect doeuMntary evidence of releases. Direct documentary evidence of a
release may include official reports of prior release incidents (e.g., CVA
noncompliance reports, CVA enforcement documents), or sampling data that
clearly identifies a release. In other cases, it may be necessary to use
indirect evidence to drav connections between a constituent identified in a
unit, the likelihood that this constituent could have been released from the
unit, and existing sampling data showing the presence of the constituent in
2-16
-------
the migration pathway. While this connection may not establish unequivocally
that the constituent identified in the environment originated in the suspected
unit, this evidence will usually be sufficient to trigger further study. In
all cases, the investigator should use best professional judgment to assess
the strength of any information source providing evidence of a release.
Exposure potential. The investigator should evaluate available infor-
mation on the location, number, and characteristics of receptors potentially
affected by past and continuing releases at the POTV facility. These recep-
tors may include human populations, animal populations, and sensitive environ-
ments. The exposure evaluation should consider proximity to affected popula-
tion, proximity to sensitive environments, and likelihood of migration to
potential receptors. Chapters 4, 5, and 6 provide information on the types of
receptors which are likely to be affected by releases to the various
environmental media.
2.2.4 Completing the PR
The ability to determine the presence and significance of a release will,
increase vith the quantity and quality of information evaluated during the
RFA. By the PR's end, the investigator vlll usually have identified potential
releases at the facility, and will have performed a preliminary evaluation
concerning the likelihood that releases have occurred at specific SVMUs or
groups of SVMUs. Before proceeding with the next phase of the RFA, the VSI,
the investigator should achieve the folloving three objectives:
• Identify significant data gaps;
• Focus activities to be performed during VSI and SV; and
• Document the PR.
Each objective is described briefly belov.
Identifying Significant Data Gaps
Depending on the quality of information gathered and reviewed during the
PR, the investigator may achieve significant progress in identifying potential
releases from SVMUs at the facility. In many cases, however, the investigator
2-17
-------
will still lack important information on vaste characteristics, unit char-
acteristics or other aspects of the facility or environmental setting.
Problems associated vith data gaps may be particularly severe since the
extensive data normally contained in records for fully-regulated RCRA TSD
facilities are not available for POTV facilities. Accordingly, basic informa-
tion must be assembled from a variety of non-RCRA data sources. In cases
where an investigator determines that important information is missing and
cannot reasonably be gathered as part of VSI or SV activities, the investi-
gator should formally request additional information from the POTV owner/
operator.
Focusing Activities to be Performed During the VSI and SV
One of the PR's primary purposes is to provide the investigator with an
understanding of waste management activities at the facility, thereby enabling
the investigator to focus subsequent activities conducted during the VSI and
SV. Because all facilities will undergo a PR and VSI, emphasis should be
placed on the quality of information gathered in these tvo stages. If the
conclusions drawn from the PR and VSI are not based on sufficient information,
it is likely that facility ovners/operators or the public will challenge per-
mit conditions or enforcement orders intended to compel further action at the
facility.
The investigator should evaluate the information gathered in the PR on
each SVMU and potential release, and determine whether: (1) it is likely that
the unit has a release; (2) it is unlikely that the unit has a release; (3)
there is insufficient evidence at this stage to assess the likelihood of a
release; or (4) a release could threaten human health or the environment.
While it is premature to draw conclusions regarding specific units at the
completion of the PR, it vlll often be possible to screen units from further
consideration at the conpletion of the second RFA stage, the VSI. As a
result, where the investigator identifies units during the PR that are not
likely to have releases of concern, the investigator should inspect these
units carefully in the VSI before determining that the units need no further
investigation or action.
2-18
-------
During the PR, the investigator may also make preliminary recommendations
on the need to collect samples. It will often be possible to identify units
or locations where sampling data can assist in making release determinations.
Sampling recommendations should be checked for appropriateness during the VSI.
In general, the VSI and SV should provide additional information necessary to
fill data gaps identified during the PR.
Documenting the PR
At the PR's completion, the investigator should prepare a report that
documents information sources, identifies SVMUs, and presents preliminary
evaluations of the likelihood of release at each location. This information
vill be used throughout the VSI and SV, and will provide a foundation for
preparation of the final report summarizing the findings of the entire RFA
process.
2.3 CONDUCTING THE VISUAL SITE INSPECTION (VSI)
2.3.1 Purpose, Scope, and Vork Product of the VSI
The visual site inspection is the second step of the three-step RFA
process for identifying releases at RCRA facilities under the corrective
action program. Hajor purposes of the VSI include:
• Visually inspecting the entire facility for evidence that releases of
hazardous wastes or constituents from POTV SVMUs have occurred, and
identifying additional areas of concern;
• Ensuring that all POTV SVMUs have been identified;
t Filling data gaps identified in the PR; and
• Formulating Initial recommendations concerning the need for a sampling
visit, interim measures, a remedial facility investigation (RFI), or
no further action at a facility.
By the end of the VSI, the investigator also vill have determined appropriate
locations for environmental sampling to be performed during a subsequent
sampling visit. In some rare cases, it vill be possible to complete the RFA
2-19
-------
after the VSI is concluded, where all POTV SVMUs can either be screened from
or recommended for further investigation in an RFI without the conduct of
additional sampling during an SV.
The VSI will include the entire POTV facility and may need to extend
beyond the property boundary in cases where an investigator needs to determine
whether a release from a POTV SVMU has migrated offsite. For off-site
property, permission to conduct any walk through inspection should be obtained
beforehand. As discussed previously, however, corrective action at POTV
facilities will not apply to releases from POTV collection systems offsite.
The VSI will generally be limited to collection of visual evidence of poten-
tial releases (i.e., photographic documentation), although it may be appropri-
ate in some cases to conduct air monitoring using portable direct read
instruments.
2.3.2 Planning the VSI
The VSI 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
some large POTV facilities that may require more time. The PR provides much
of the information needed to prepare for the VSI. In conducting the VSI, the
investigator should use the facility map prepared during the PR, identifying
SVMUs and potential releases at the facility.
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 that outlines the need for personal safety devices
(e.g., respirators, protective clothing). The content of the safety plan will
vary by site, depending on the site's complexity and the investigator's
planned activities. All personnel vho will go on-site should participate in a
safety course that meets OSHA requirements prior to conducting a VSI.
Following a review of materials collected during the PR, the investigator
should contact the owner/operator to schedule a date for the VSI. The
investigator should arrange to meet with facility representatives before
conducting field activities. This meeting will provide the investigator with
2-20
-------
an opportunity to explain the various steps of the corrective action process
to the owner/operator, and answer any of the ovner/operator's questions about
the RFA process or the corrective action program. During this meeting, the
investigator should discuss the proposed safety plan with the POTV ovner/
operator and incorporate his/her recommendations in the safety plan prior to
conducting the VSI.
Logbook
The logbook is perhaps the most important document produced from an RFA.
It provides a basis for integrating VSI and SV results into the RFA report,
and documents inspection and sampling activities in support of any future
legal proceedings under RCRA, CVA, or CERCLA. A new logbook should be
developed for each site and for each visit to the site. Logbooks should be
bound and pages numbered sequentially, and entries should be chronological and
preceded by a notation for time of the entry. A logbook should be maintained
vith indelible ink.
The following types of entries should be made in the logbook:
• Identities of all personnel onsite during each phase of a VSI or SV;
• Descriptions of instruments used during the field work, Including
instrument identification numbers;
• Description of film used;
• Description of the weather and changes in the weather;
• Observations relating to SVMUs and their potential for release;
• Results of field measurements, instrument readings, and well
measurements;
• Factual descriptions of site structures and features, including wells
and veil construction, units, containment structures, buildings,
roads, topographic, and geomorphic features;
• Signs of contamination such as oily discharges, discolored surfaces
dead or stressed vegetation;
• Sketches of facility layout, SVHU location structural features, points
of contamination, and release paths;
2-21
-------
• Facility map showing points and direction of photographs, SVMUs,
release paths, locations of visual evidence of releases, and potential
receptors; and
• Other relevant items.
Pho tography
Investigators should use regular 35mm cameras for taking photographs.
Filters should not be used since they tend to discolor images and may unfair ly
bias photographic results by altering the appearance of physical evidence such
as leachate seeps or lagoons. The investigator should identify and record in
the logbook the exact type of camera (i.e., including identification number),
film, and lens used. Photographs taken with unusual lenses (e.g., wide-angle)
can be challenged and may not be admissible in court. Photographs should be
taken to document the facility conditions, and procedures used in inspection
activities. Types of pictures may include:
• Representative picture(s) of entire faci lity;
• Posted signs identifying ownership of facility;
0 Evidence of releases—leachate seeps, pools, discolored water, or
strained soils;
• Individual SVMUs, including photographs from different angles and
direction;
• Visual evidence of poor facility maintenance that may contribute to
the likelihood of a release;
• Adjacent land use; and
• Areas accessible to unauthorized persons.
2.3.3 Conducting Field Activities During the VSI
Once arrangenents for the VSI have been made, the investigator should
proceed with field activities. The owner/operator or his designated repre-
sentative should accompany the investigator while field activities are
conducted at the facility.
2-22
-------
During the VSI, the investigator should:
• Walk through the entire facility;
• Identify all SVMUs and other areas of concern on a facility map;
• Document all observations in a field logbook;
• Take photographs of all SVMUs, potential releases, receptors, and
other locations of interest; and
• Monitor for vapor emissions as necessary to protect the investigator's
safety.
Conduct of the VSI will enable the investigator to inspect the entire POTV
facility for potential releases not previously identified and to gain further
insight into facility waste management practices.
During the VSI, the investigator vill focus primarily on identifying and
characterizing POTV SVMUs. The RCRA Section 3004(u) corrective action
authority requires that the need for corrective action be determined for all
SVMUs. Vhere the investigator identifies spills or other releases which may
not be regulated under RCRA Section 3004(u) corrective action (e.g., releases
beyond the facility boundary, accidental product spills) the investigator
should nonetheless inspect, document, and photograph these releases. It may
be necessary, in some cases, to use other statutory authorities in addressing
these releases (e.g., RCRA 7003).
Visual Evidence of Unit Characteristics
The VSI should provide substantial information on unit characteristics at
a POTV. Observations concerning the integrity, location, and design of a unit
can provide information indicating the likelihood that a release has occurred.
For examplef above-ground vastevater and sludge tanks can be inspected for the
integrity of scans and for the presence of adequate secondary containment.
Vastevater and sludge impoundments should be inspected for the adequacy of
berms, overtopping controls, and devices to control volatile emissions.
Sludge and ash landfills should be inspected for the presence of runoff
controls, erosion around the unit, and potential for the release of par-
ticulate constituents. In general, it will not be possible during the VSI to
2-23
-------
assess most POTV units for ground-water releases. IE possible, the investi-
gator should inspect containment (e.g., liners) for visible indications of
deterioration. Where units have a high potential for release to groundwater
and contain highly mobile wastes. sampling likely vill be needed to rule out a
release.
Visual Evidence of Waste Characteristics
Generally, it vill not be possible to obtain a great deal of information
during the VSI on POTV 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. Waste characteristics will
be investigated primarily during the preliminary review (PR) and sampling
visit (SV) phases of the RFA. Still, the investigator may use the VSI as an
opportunity to inspect additional onsite POTV records regarding types of
vastes and constituents that are managed at the POTV facility, and to confirm
data collected during the PR.
Visual Evidence of Pollutant Migration Pathways
The VSI should provide substantial information on potential pollutant
migration pathways at the POTV facility. Facility characteristics that can
facilitate the movement of releases from the immediate area around a unit, but
have not been identified previously on the facility map, vill often be
apparent during the VSI. For example, erosion gullies at the base of land-
fills or surface impoundments will provide direct pathvays for surface water
and soil releases from these units. The investigator should locate all
potential migration pathvays of concern on the facility map. These locations
will be important areas for sampling should it be necessary to conduct a SV or
RFI at the POTV. In addition, photographs of these pathvays should be corre-
lated with facility map locations whenever possible.
Visual Evidence of Releases
The investigator should inspect the entire facility and, if possible and
permission can be obtained, areas beyond facility boundaries for visual
evidence of releases. Vhile it vill not alvays be possible to determine
conclusively that a release has occurred based on visual evidence, such
2-24
-------
evidence can provide a strong indication of a release. Visual evidence
coupled with information indicating that a unit contained hazardous con-
stituents, will often be sufficient to compel further investigation under a
RFI, The investigator should look for obvious signs of release, such as
discolored soils, dead vegetation or animals, or unusual odors.
Visual Evidence of Exposure Potential
The VSI should provide information on exposure potential at the facility.
In most cases, the PR will already have identified whether there are nearby
residences or drinking water wells, but the location of previously identified
receptors should be confirmed during the VSI. At a minimum, the VSI should
identify any additional receptors, especially those near or in migration
paths.
2.3.4 Determining the Need for Further Action During the RFA
The results of the VSI should be incorporated into the draft RFA report,
which is begun on completion of the PR. The results of the PR and the VSI
together should provide sufficient evidence to make a determination of the
need for one of the following steps:
• Sampling visit;
• Interim measures*;
• Further investigation in an RFI; and
• No further action.
The investigator should document the results of the VSI concisely and
thoroughly in the draft RPA report. Together with information obtained during
the PR, the report must support decisions regarding the need for additional
action at the facility. The RFA report will be the primary legal document
supporting the Agency's initial corrective action activities at a POTV. The
report may be closely scrutinized and/or challenged. Incomplete, con-
tradictory, or confusing information in the RFA report may jeopardize the
Agency's position.
*See page 2-27 below for discussion of interim measures.
2-25
-------
The RFA report vill include recommendations for further action.
Information and evaluations presented in the report must be defensible and
must support recommendations. The following sections discuss each of the
possible recommendations that can be made after completing the first tvo
stages of the RFA.
Recommending a Sampling Visit (SV)
On completion of the VSI, the investigator should have collected infor-
mation on each potential release and completed a preliminary evaluation
concerning the likelihood of. releases from each SVMU and from the facility.
The investigator should also have identified important data gaps that may
interfere with his/her ability to make an enforceable determination of release
or release potential. To fill these gaps, the investigator may recommend
collecting environmental samples from the facility to support his/her
recommendations for further action under the RCRA corrective action process.
The need for sampling at specific units vill depend on several important
factors, including the complexity of the unit and its environmental setting,
the quantity and quality of information gathered during the PR and VSI,
preliminary recommendations for further action at the facility, the facility
compliance record, and the cooperativeness of the owner/operator. The
investigator must consider these factors, using his/her best professional
judgment, to determine vhen a sampling visit is appropriate.
The preliminary recommendations for further action at a facility play an
important role in determining the need for sampling. If the investigator
believes a release may have occurred, samples collected in the SV can support
a decision to require further assessment. On the other hand, if the investi-
gator believes a release is not likely, a preliminary recommendation that the
unit does not need further investigation can be made. Sampling can
demonstrate that no release has occurred.
There may be situations in vhich the investigator makes a preliminary
recommendation that a unit should be investigated in a RFI vithout actual
sampling data that demonstrates a release has occurred. For example, most
2-26
-------
determinations on ground-vater releases vill have to be made with little or no
ground-water monitoring data since few POTV facilities have installed ground-
vater monitoring wells. In these situations, the investigator may have to
rely on an assessment of waste characteristics, unit characteristics, migra-
tion pathways, and soil sampling data to make these determinations. Where
possible, samples should be taken at these units during the sampling visit to
demonstrate that a release has occurred.
Environmental sampling is especially important when the investigator
believes the POTV owner/operator will be unlikely to cooperate in conducting a
RFI at the facility. When the owner/operator's cooperativeness is ques-
tionable, the investigator should sample to support recommendations for
further steps in the corrective action process in case these recommendations
are contested in an administrative hearing. Even the most cooperative
owner/operator may ultimately challenge permit conditions that are not
supported by strong evidence.
Recommending Interim Measures
The investigator can recommend that interim measures be implemented at
any time during the RFA, although he/she may not have sufficient information
prior to the VSI to make this recommendation. Interim measures should be
recommended whenever there is a significant risk of immediate exposure
resulting from releases at the facility. Interim measures are applicable to
POTV facilities conducting corrective action under RCRA Section 3006(u) or
3004(v) authorities, and may be implemented through permit conditions
contained in RCRA RIDER permits issued to POTV permit-by-rule facilities*, or
through other appropriate enforcement authorities.
Recommending A Remedial Facility Investigation (RFI)
Releases identified during the RFA vill be fully characterized during the
remedial facility Investigation (RFI) phase of the RCRA corrective action
process. The RFI likely will be conducted by the POTV owner/operator and may
'Details on planning and implementing interim measures can be found in the
RCRA (3008(h)) Corrective Action Orders Interim Measures Guidance (Draft).
2-27
-------
be resource-intensive. Thus, recommendations for RFIs at facilities should be
supported by the evidence collected during all stages of the RFA. In most
situations, the investigator should collect samples at units to support
recommendations for a RFI.
There may be cases, however, where the investigator will recommend a RFI
for particular units without collecting additional samples. This situation is
most likely to occur at facilities where an investigator has been able to
obtain and evaluate evidence of releases during the PR-and VSI. In these
cases, existing evidence of release must be sufficient in the absence of
supplemental sampling to support the requirement for a RFI.
Recommending No Further Action
The RFA also serves to screen from consideration units that do not
threaten human health or the environment with releases of hazardous wastes or
constituents. In some cases, the investigator may choose to make this type of
determination after conducting the PR and VSI, rather than taking additional
samples in a SV. A decision to take no further action after the VSI should be
made knowing that the public may contest EPA's decision. In these situations,
it will be useful to collect additional sampling information in a SV.
2.4 CONDUCTING THE SAMPLING VISIT
2.4.1 Purpose and Scope
The sampling visit is the final stage of the RFA process. The SV has two
primary purposes:
• Fill data gaps identified in the PR and VSI by collecting new sampling
data.
• Mailt a final determination on the presence of releases or potential
releases requiring further investigation.
At the conclusion of the SV, the investigator will have completed the first
phase of the RCRA corrective action process.
2-28
-------
EPA intends to limit the collection and evaluation of new sampling data
in making preliminary release determinations, and rely as much as possible
upon existing information sources identified in the PR and VSI. Under this
approach, EPA vill defer major new data gathering efforts to the RCRA Facility
Investigation (RFI) phase of the corrective action process. As a result, the
investigator should use information sources developed in the PR and VSI to
identify sampling activities which are essential in making final release
determination for SVMUs or groups of SWMUs at the POTU facility.
The extent of sampling needed at a POTU will vary considerably depending
on the quality of information gathered in the PR and VSI. Other factors to
consider include the degree of owner/operator cooperation and type of
regulatory action necessary to require further action at the facility. While
EPA policy encourages the EPA Regions and States to minimize the amount of
sampling conducted during the SV, a lack of information on possible environ-
mental contamination at some POTVs may necessitate more extensive SVs at POTV
facilities than would be conducted at some RCRA TSDFs. EPA Regions may choose
to rely on facility owner/operators to develop a sampling plan and conduct
sampling activities. The Regions should be prepared to exercise oversight of
owner/operator sampling activities.
2.4.2 Developing a Sampling Plan
Because the need for additional sampling vill vary on a case-by-case
basis, the investigator must rely on best professional judgment in determining
when a SV is appropriate. The investigator may choose to sample in the
following cases:
• To collect additional information to support a preliminary determina-
tion that a unit has not released and does not require any further
actions
• To collect additional information to support a preliminary determina-
tion that a unit has released and should conduct a RFI, implement
interim measures, or take some other further action; and
• To collect additional information for determining whether a facility
has had a release of hazardous waste or constituents.
2-29
-------
In some cases, information gathered in the PR and VSI may provide suffi-
cient evidence to indicate that a RFI is necessary, or that no further action
is necessary. In other cases, the information gathered in the PR and VSI will
not be sufficient to enable the investigator to determine conclusively that
there has been a release. For example, a facility may have a surface impound-
ment that contains sevage sludges knovn to be contaminated with heavy metals.
Information collected during the PR and VSI may not clearly indicate whether
the impoundment has released constituents to ground water, or whether any
remaining contaminated soil can potentially leach contaminants to ground
vater. In this situation, it may be necessary to sample the soils around the
closed unit or sample the ground vater from existing veils located dovn-
gradient from the unit to identify a release.
The scope of sampling activities conducted during the SV will also depend
on the extent to which the investigator can obtain meaningful results from
vastestream and environmental sampling. The ability to obtain meaningful
sampling results will relate, in turn, to a number of technical, factors
including accessibility to appropriate sampling locations, likelihood of
environmental contamination from off-site sources, and type of sampling
equipment required. For example, because few, if any, POTVs have already
installed ground-water monitoring veils, the investigator will probably have
to rely on technical evaluation documents and other vritten information, and
soil sampling results to make determinations on the possibility of ground-
water releases. Similarly, an assessment of releases to surface vaters and
sediments may be hindered by the relative inaccessibility of appropriate
sampling locations in POTV receiving vaters and by the presence of possible
contamination from non-POTV sources discharging to the receiving vaters. In
these cases, the investigator may have to make final release determinations
based entirely on data collected in the PR and VSI.
The sampling plan vill be the primary document directing the collection
of additional data in the SV. This plan should be developed to support the
collection of evidence necessary to make a release determination for
individual SVMUs, or groups of SVHUs. The procedure may involve the col-
lection of direct evidence (e.g., air samples from a surface impoundment) or
indirect evidence (e.g., soil samples at a point dovngradient from the SWMU)
2-30
-------
of a release. In many cases, the investigator may collect samples from the
waste source and from an environmental medium, and based upon knowledge of the
pollutant migration pathvay, evaluate the likelihood that the constituent
originated in the SVMU.
The sampling plan may be developed by EPA, a contractor, and/or the
ovner/operator. In all cases, EPA should review the sampling plan carefully
before initiating activities to ensure that the plan can achieve the stated
objectives.
Determining the Extent and Locations of Sampling
The extent of sampling required in the SV will vary by site. Vhen the
investigator has reason to believe that an owner/operator is likely to contest
EPA's determination that a SWMU should be investigated in a RFI, the
investigator should be sure to gather sufficient sampling information to
support his/her judgment on the likelihood of releases. The Agency also will
need ample data when defending its actions in a public hearing.
In general, it is sufficient to determine that a constituent identified
in a SVMU has been released to one environmental medium. It may be necessary
to take samples at several different points around a unit to ensure that all
potential migration pathvays have been sampled. One positive sample con-
firming that the constituent of concern is present in a well-defined migration
pathvay will usually be sufficient to indicate the need for a RFI.
The location and number of samples necessary to identify a release will
vary by unit type and migration pathvay. Por example, samples from a single
ground-water monitoring veil may not be sufficient to identify a release from
a closed landfill because of the complexities of the ground-water pathvay.
However, one measurement using a direct-read instrument above or adjacent to a
wastewater treatment unit may suffice in identifying an air release. Each of
the media-specific chapters in this document contains specific guidance on
determining the extent and location of sampling.
2-31
-------
Choosing Sampling Methods and Parameters
The sampling plan should specify methods and parameters for each sampling
location at the facility. The plan should also specify the number of samples
to be taken at each sampling point. Generally, an investigator may choose
sampling techniques and parameters to provide either screening level measure-
ments (e.g., a general scan with an hNU photoionizer indicating the presence
of volatile organic compounds) or precise, quantitative measurements for
specific organic or inorganic compounds. As stated previously, sampling for
specific compounds vill generally provide the most useful results from the SV
and aid in developing defensible recommendations. Sampling for indicator
parameters such as total organic halogens (TOX), conductivity, or pH may be
useful vhere the investigator cannot identify wastes that may have been
released to a medium. However, indicator parameters offer limited information
and will generally not provide sufficient evidence of release. Chapters 4, 5,
and 6 describe sampling strategies for each environmental medium and provide
guidance on the selection of appropriate sampling methods and parameters.
Preparing the Sampling Plan
Vhile there is no established format for the sampling plan, it should
present clear and logical steps for meeting the sampling objectives at each
SVMU or group of SVMl/s. Depending on facility characteristics, it may be more
appropriate to organize the discussion in the plan by sampling location or by
sampling method. The sampling plan should contain information on each of the
following factors:
• Field activities - The plan should discuss the sequence and schedule
for conducting the field activities.
• Sampling locations/rationale - As precisely as possible, the sampling
plan should identify the location of each sample to be taken on a site
map. A description of the objectives for each sampling activity
should be included in the plan, along with a discussion of hov the
sampling activities vill result in data that vill achieve the
objectives. The plan should describe specific sampling methods,
number and locations of samples and parameters.
• Analytical requirements - The sampling plan should explain the
technique and level of detection used to analyze each sample.
2-32
-------
• Sample handling - Sample preservation and other handling practices
should be described. These can usually be described in an appendix to
the sampling plan, or where appropriate, a specific document may be
referenced.
• Quality assurance samples - The plan should identify the number and
type of quality assurance samples (blanks, duplicates, or spikes) to
be taken. Specific QA/QC guidelines are discussed later in this
chapter.
• Equipment decontamination - The sampling plan should identify reagents
and any special procedures associated with equipment decontamination.
Reviewing a Sampling Plan
The investigator should review the sampling plan carefully to ensure that
it meets EPA objectives for each unit being sampled. Careful evaluation of
the plan will ensure that appropriate sampling methods and locations are used,
and that the extent of sampling will be sufficient to support release determi-
nations made for each sampling location. Review of the plan will be
especially important in instances where the owner/operator or an EPA con-
tractor has developed the sampling plan.
2.4.3 Preparing for the SV
Once the sampling plan has been completed and reviewed, the investigator
may make plans to begin on-site activities. These plans should include:
• Gaining facility access;
• Handling community relations;
• Preparing a safety plan;
• Specifying the QA/QC and chain-of-custody requirements; and
• Specifying EPA oversight of ovner/operator sampling activities.
Gaining Facility Access
Prior to conducting field work, the investigator should contact the POTV
ovner/operator to schedule a time for the SV. The appropriate person (either
EPA or a designated contractor) should contact the owner/operator to verify
sampling dates and describe the nature of the field activities. If the
ovner/operator vill be responsible for collecting and analyzing the samples,
2-33
-------
then the ovner/operator should be contacted to verify the sampling dates and
arrange for the oversight of field activities. Where EPA or a contractor vill
conduct the sampling, the Agency should coordinate vith the POTV ovner/
operator before the SV, so that he or she can make necessary arrangements.
EPA should offer the ovner/operator a split of all samples collected. If the
ovner/operator vishes split samples, then he should provide sample bottles for
the splits. After completing ail arrangements, a letter or phone call to the
ovner/operator confirming the sampling dates and scope of field activities
should be made.
In some cases, it may be necessary to gain access to adjacent or nearby
properties in order to conduct a visual inspection or collect samples. EPA
should provide verbal as veil as vritten notification of the dates and nature
of the vork to ovners of these properties, and receive vritten notice granting
access for the proposed activities.
Community Relations
If it is necessary to conduct field activities in or near residential or
nonindustrial business areas, the appropriate local officials should be
contacted prior to the SV. It is difficult to remain unobtrusive in conduct-
ing site inspections, particularly if the investigators are vearing protective
clothing. Moreover, the presence of persons collecting samples may cause
undue alarm.
Preparing a Safety Plan
Agency personnel should prepare a safety plan for each SV in accordance
vith appropriate EPA guidance. The safety plan should be tailored to the
specific saapling activities. For some SVs, the safety plan vill be very
simple and require few protective measures. Other sites may require use of
higher levels of protection. In developing the safety plan, the POTV owner/
operator should be questioned closely about potential hazards at the facility.
2-34
-------
For detailed assistance in developing a safety plan, the investigator is
referred to EPA's Standard Operating Safety Guide, 1982 (SOSG) vhich explains
how to develop a proper site safety plan. The SOSG vas prepared in accordance
vith EPA and other Federal health and safety guidelines, regulations, and
orders. This reference discusses the steps involved in developing a safety
plan and describes the contents of each section of the plan. A site-specific
safety plan should describe:
• Known hazards and risks;
• Personnel and alternates;
• Levels of protection to be worn;
• Vork areas;
• Access control procedures;
• Decontamination procedures;
• Site monitoring program;
• Special training required; and
• Weather-related precautions.
Personnel should participate in an approved safety course before visiting a
site, as required by OSHA.
QA/QC and Chaln-of-Custody Requirements
All samples, including blanks and spikes, should be maintained under
chain-of-custody procedures to ensure the validity of analytical results for
any future legal proceedings. These procedures minimize the potential for
contaminating, damaging, or losing samples prior to their analysis by tracking
the possession of a sample from the time of collection through all transfers
of custody to receipt by the laboratory, vhere internal laboratory chain-of-
custody procedures take over. Investigators should review EPA regional
protocols for chain-of-custody procedures before the SV.
EPA Oversight of Owner/Operator Sampling Activities
The sampling plan should provide Eor EPA oversight vhere the owner/
operator conducts the sampling activities. The level of EPA involvement vill
depend on the extent of sampling, the complexity of the site, and the
2-35
-------
cooperativeness ot the ovner/operator. In some cases, EPA may believe chat
the owner/operator will provide reliable sampling results. In these cases,
EPA oversight can be limited to presence at the facility during some portion
of the SV. In other cases, it may be necessary to provide EPA oversight at
the facility during the entire SV.
2.4.4 Conducting the SV
Once all preliminary activities have been completed, the investigator may
begin the site activities. The sampling visit involves gaining access to the
site, performing sampling activities, photographing all activities, keeping
the SV portion of the logbook, preparing samples for shipment and analysis,
and finally decontamination and demobilization.
Preliminary Site Activities
The investigator should meet vith the owner/operator prior to entering
the facility to conduct sampling. Since the investigator will already have
conducted a VSI for the POTV facility, the POTV ovner/operator should have
some understanding of the corrective action process. During this meeting, the
investigator should be prepared to answer questions relating to the sampling
plan. In addition, the investigator should offer to provide the ovner/
operator vith duplicate samples. In cases vhere the ovner/operator vill
perform the sampling, the investigator should arrange for splitting samples
and discuss oversight activities at this time.
Sampling Procedures
The investigator should adhere to the sampling plan once sampling
activities begin. If it is necessary for any reason to diverge from the
sampling plan, changes and the need for modification should be carefully
documented. Continuous air monitoring for vapor emissions should be performed
to detect any air releases resulting from sampling activities. If the POTV
ovner/operator is collecting the samples, EPA or State investigators should
document precisely the sequence of sampling activities and the procedures and
instruments used, and characterize the sample by location, depth, appearance,
and other relevant attributes.
2-36
-------
The EPA Regional offices have developed standard operating procedures
(SOPs) for most SV sampling tasks under the CERCLA PA/SI program. These SOPs
are usually applicable to RCRA field activities as well. In instances where
the SOPs are not appropriate for a particular field activity, a new SOP should
be developed by the investigator. Modifications to existing SOPs should be
noted in the field logbook.
Sample Shipment/Sample Analysis
Upon completion of the on-site work, EPA or the POTV owner/operator
should deliver all samples to the laboratory for analysis. SOPs covering
sample shipment are available in each Regional office or in EPA safety
training manuals. Time required for analysis of samples may range from 40
days to 4 months.
Decontamination/Demobilization
Decontamination of persons and equipment should occur not only when all
field work is completed, but also each time a person leaves the site for any
reason, including rest breaks. Decontamination after sampling activities will
usually consist of removal of disposable clothing and decontamination of
sample bottles and sampling and field equipment. All materials that vill not
be reused should be containerized for transport and disposal. Decontamination
of persons and equipment vill be necessary vhere significant contact with
hazardous materials is likely (e.g., sampling). As a result, in conducting
VSI and SV at POTV facilities, the need for decontamination procedures should
be assessed on a site-specific basis.
2.4.5 Final RFA Recommendations For Further Action
The final task in the RFA process is to make recommendations concerning
the need for further actions at the facility. These recommendations include:
(1) taking no further action; (2) conducting a RFI to identify the rate and
extent of releases from SVMUs or groups of SVMUs; (3) planning and implement-
ing interim measures at the facility; or (4) referring the further investiga-
tion and control of permitted SVMU releases or other unusual releases to other
environmental program offices. The RFA is complete only after recommendations
have been made for all releases and potential releases investigated. The
2-37
-------
investigator may determine the likelihood of release for some SUMUs after
completing the PR and VSI. In other cases, it will not be possible to make
such determinations until sampling results from the SV have been evaluated.
Making RFA Release Determinations
After the laboratory completes i cs analysis, the investigator should
evaluate the validity of analytical results. When EPA conducts the sampling,
a preliminary review of the analytical data ensures that all required deliver-
ables are included in the data package, all forms meet contract requirements,
and key quality assurance items in the data package are identified. Regional
personnel may vish to perform a qualitative data analysis after this pre-
liminary data reviev, and determine if the data results are valid.
Once the investigator has evaluated the validity of sampling results,
sampling data should be added to information collected previously for each
SVMU and release location. At this point in the process, the investigator
should also have received any additional information requested from the POTV
owner/operator, and should take this into consideration.
The investigator must use best professional judgment to determine the
likelihood of release to any environmental medium for each SVMU or group of
SVMUs. The VSI section has already described hov an investigator may make
initial release determinations for these units. The investigator should use
the same procedures in evaluating additional information collected during the
SV.
In some cases, the investigator vill have direct evidence o£ a release.
In most cases, hovever, the investigator will be required to draw conclusions
from indirect evidence about the likelihood of release. As stated previously,
the strength of these deductions will depend upon the quality of the vaste
information, the extent to which the pollutant migration pathways have been
characterized, and the quality of the environmental sampling results and
visual observations.
2-38
-------
The level of evidence needed to support a determination vill 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 vill be sufficient to identify one constituent that is present in
both a SVMU and in the migration pathway to support a release determination.
The investigator does not need to demonstrate vith statistical confidence that
the SVMU had a release.
It may often be more difficult to demonstrate that'a unit does not have a
release. While this conclusion may be intuitively apparent to the investiga-
tor, the public may demand stronger supporting evidence. In situations where
the public has demonstrated significant concern, it may be necessary to
conduct a broader sampling program in attempting to confirm that a unit does
not have a release requiring further investigation.
Making Recommendations for Each SVMU or Group of SVMUs
The final step in a RFA entails making recommendations on the need for
further investigations. Four recommendations are possible:
• No further action;
• Investigate further in a RFI;
• Plan and implement interim corrective measures; and
• Refer the control of a permitted release to another environmental
program office.
No further action. No further investigation vill be necessary for SVMUs
vhich have not released hazardous vastes or constituents to the environment.
Vhere an investigator identifies a de minimis release from a SVMU that
requires no further action, the investigator should clearly document the
evidence and basis of this recommendation.
There are several general situations vhere it vill be possible to deter-
mine that a SVMU needs no further action. Some units vill have design and
operating characteristics that vill effectively prevent releases. The
investigator should be careful in determining that a unit poses no threat of
2-39
-------
release if the unit still contains wastes of concern or is located in a
vulnerable area. The investigator should always consider the age of the SWMU
and its potential for failure in evaluating the need for further action.
In some situations, it may be appropriate to eliminate certain units from
further study because they clearly have not released hazardous wastes or
constituents into the environment. Examples of such units include above
ground and, in some cases, surface level wastewater or sludge treatment tanks.
In the case of above ground tanks, a review of unit design and operation, as
well as the inspector's direct knowledge of the facility, may provide sub-
stantial evidence that the unit has never leaked. It will rarely be possible
to make similar determinations for landfills and surface impoundments.
Investigate releases further in a RCRA remedial facility investigation.
The investigator should recommend that a SWMU or other release be investigated
further in a RFI when he or she identifies a release or potential release from
a SWMU to an environmental medium. The investigator should describe each SWMU
and the relevant environmental media to be investigated in the RFI. In
focusing the RFI, it is important to determine media of concern for each SWMU
or group of SWMUs. There may be situations where the facility as a whole
poses a problem (i.e., releases have been confirmed over wide areas) and where
it is difficult to distinguish among individual SWMUs as sources of contamina-
tion. In these cases, it may be more effective to recommend a RFI that
requires the owner/operator to investigate routes of release for the entire
facili ty.
Adopt interim measures. Where evidence suggests that immediate action
should be taken to protect human health or the environment from releases, the
RFA should recommend interim measures at the facility. The investigator
should evaluate the severity of the release and the proximity of potential
receptors in assessing the need for interim corrective measures. Examples of
interim measures include fencing a facility to prevent direct contact with
wastes, or stabilizing weak dikes to prevent surface vater releases from
impoundments. It is important that these units be investigated further in a
RFI in order to determine the adequacy of the interim measure and design a
permanent remedy.
2-40
-------
Refer permitted releases to other program offices. Permitted releases
that may threaten human health or the environment should be referred to the
Federal or State program office that issued the permit. Since EPA has not
developed guidelines on such referrals, they should be addressed on a case-
by-case basis. The following four types of releases may be encountered:
• Permitted discharges from units- in compliance with their permits - As
a matter of policy, EPA will exercise discretionary authority in
investigating permitted releases in the RFA. In cases where dis-
charges from units in compliance with permits issued by EPA media
programs are cause for concern, EPA will initially refer the case to
the original permitting authority and request that they further
control the release through their permitting program. If the permit-
ting authority cannot or will not control this permitted discharge in
order to meet RCRA standards, EPA should, if necessary, exercise its
authority under RCRA Sections 3004(u), 3005(c)(3), 3008(h), or 7003 to
control the discharge. This situation should arise only rarely if at
all.
0 Permitted discharges from units not in compliance with permits - In
cases where discharges from units out of compliance witn permits
issued by EPA media programs are cause for concern, EPA will refer the
case to the original permitting authority and request that they bring
the discharge into compliance with permit conditions.
• Releases to other media from units with permitted discharges - EPA
will use its RCRA corrective action authorities to control releases to
media other than the one for which the discharge is permitted. For
example, EPA will use §3004(u) to control the release of VOCs from
NPDES-permitted wastewater treatment units where there is a potential
threat from air releases. These releases will not routinely be
referred to the other permitting authority, since this authority would
not have permitted a release to the other media.
• Contamination resulting from permitted discharges - Vhen the RFA
identifies contamination resulting from permitted discharges requiring
further investigation, EPA will work on a case-by-case basis with the
Regions and other EPA permit programs to develop a solution to the
contamination problem resulting from the discharges. For example,
when frequent violations of NPDES permits in the past have resulted in
an accumulation of hazardous materials in stream sediments, the RCRA
investigator should work vith the NPDES authority to develop a solu-
tion to the contamination problem.
2-41
-------
2.4.6 Final RFA Product
The final RFA report should document the activities undertaken in the PR.
VSI, and SV. Many documents vill be generated during the SV, such as the
sampling plan, safety plan, sampling results, evaluation of the sampling
results, release determinations, and recommendations for each unit. All of
this information should be compiled into the RFA report for future reference
during any subsequent phases of the corrective action program.
2-42
-------
3. EVALUATION OF WASTE AND UNIT CHARACTERISTICS AT POTVs
This chapter of the guidance document provides the investigator with an
overview of POTV unit and waste characteristics. The first section of this
chapter describes types of solid vaste management units typically found at
POTVs, and identifies potential release points for these units. The second
section of this chapter provides a methodology for the characterization of
wastes managed at POTV facilities.
3.1 POTV UNIT CHARACTERISTICS
For an investigator to assess potential pollutant release points at
POTVs, treatment operations and the units that typically constitute a POTV's
system must be understood. This section of the guidance presents typical POTV
treatment system configurations and characterizes the impacts of POTV con-
figuration on pollutant releases. Finally, it provides data that can be used
to characterize the fates of specific pollutants within POTVs.
3.1.1 Description of Typical POTV Treatment Processes
Although POTVs employ numerous treatment units and processes, the follow-
ing discussion focuses on those most commonly found.at POTVs, as veil as those
with the potential for significant releases to the environment. Common POTV
treatment units and processes include:
• Bar screens;
• Comminutors;
t Grit chambers;
• Primary clarifiers;
• Activated sludge units;
• Secondary clarifiers;
• Lagoons (facultative and aerated);
• Chlorination units;
• Anaerobic digesters;
• Aerobic digesters;
• Sludge drying beds;
• Incinerators;
3-1
-------
• Sludge lagoons and vaste piles;
• Land application of sludge;
• Landfill disposal of sludge;
• Land application of effluent; and
• Underground injection of effluent.
Each of these treatment units and processes is described below.
Bar Screens
Preliminary treatment of wastewater begins with removal of coarse solids.
The usual procedure is to pass the wastewater through racks or bar screens.
These screens may be cleaned mechanically or manually. Material retained on
the screens may be discharged to comminutors or removed by hauling to land-
fills. Bar screens are typically located upstream of the POTV's influent
pumps and hence are well below ground level. They are generally installed in
concrete conduits.
Comminutors
Comminutors grind material retained on the bar screen and return the
ground material to wastewater for removal in downstream treatment processes.
Coarse material is cut by teeth and shear bars on a revolving drum as the
solids are passed through a stationary comb. The small sheared particles pass
through the drum slots and are channeled back to the wastewater flow.
Comminutors are located adjacent to bar screens, typically well below ground
level, in concrete conduits.
Grit Chambers
Grit chaabers are basins designed to remove grit, consisting of sand,
gravel, clndtrs, or other heavy solid materials. The chambers are intended to
protect moving mechanical equipment from abrasion and accompanying abnormal
wear, to reduce formation of heavy deposits in pipelines, channels, and con-
duits, and to reduce the frequency of digester cleaning required as a result
of excessive accumulation of grit in such units. Accumulated grit from grit
chambers is most commonly disposed as fill. A grit chamber can consist of
either an above-ground or below-ground basin. They are typically made of
concrete and can be either aerated or nonaerated.
3-2
-------
Primary Clarifiers
In a primary clarifier (sometimes railed a sedimentation tank), the
•jastevater is held in a relatively quiescent state so that solids vith a
higher specific gravity than the wastewater will settle, and those with a
lower specific gravity will tend to rise. The objective of treatment by
sedimentation is to remove readily settleable solids and floating material and
thus to reduce the suspended solids content. The primary clarifier can be
either an above ground or below ground basin usually of concrete.
Activated Sludge
In the activated sludge process, domestic sewage is stabilized biologi-
cally in a reactor under aerobic conditions. The resulting biological mass is
separated from the liquid in a secondary settling tank. A portion of the
settled biological solids is recycled while the remaining mass is removed to
prevent overloading the system vith biomass. The conventional activated-
sludge process consists of an aeration tank, a secondary clarifier, and a
sludge recycling line.
Facultative Lagoons
Lagoons in which the stabilization results from a combination of aerobic,
anaerobic, and facultative bacteria are known as aerobic-anaerobic lagoons or
facultative lagoons. The floor of the lagoon is typically unlined clay.
Oxygen is maintained in the upper layer by the presence of algae or by the use
of surface aerators. The biological community in the upper layer consists of
aerobic bacteria while the microorganisms in the bottom layer are facultative
and anaerobic bacteria. A large portion of the solids settle on the bottom of
the lagoon. As the solids build up, a portion will undergo anaerobic decompo-
sition, which results in a highly stabilized effluent.
Aerobic Lagoons
Aerobic lagoons are typically unlined earthen basins. The contents of an
aerobic lagoon are completely mixed by aeration, and both the incoming solids
and biological solids produced from waste conversion do not settle out. In
effect, the essential function of this type of lagoon is waste conversion.
3-3
-------
Depending on the detention time, the effluent vill contain from one-third to
one-half the value of incoming BOD in the form of biological solids. Before
the effluent is discharged, solids are removed by settling.
Chlorinat ion
The most important use of chlorine, a strong oxidizing agent, is for
disinfection, although it has other uses such as odor control and BOD
reduction. Chlorine may be applied directly as a gas or in an aqueous
solution. The most widely used chlorinacors have vacuum-feed devices. The
chlorine contact chambers are typically above ground concrete basins.
Anaerobic Sludge Digestion
Anaerobic sludge digestion involves the biological decomposition of
sludges in the absence of oxygen. In the digestion process, anaerobic
bacteria convert organic matter to methane gas and carbon dioxide. As these
gases rise to the surface, the sludge particles and other materials, such as
grease, oils, and fats, ultimately form a layer of scum. Through digestion,
the sludge becomes more mineralized and thickens because of gravity. The
process itself can be a one-stage, tvo-stage, or high rate digestion process.
Anaerobic digesters typically are covered, above ground concrete basins.
Aerobic Sludge Digestion
In the aerobic sludge digestion process, sludge is aerated and biological
solids are oxidized to carbon dioxide, water, and nitrates. Aerobic digestion
is normally conducted in unheated basins similar to those used in the
activated sludge process. For the most part, these basins are above ground
and constructed of concrete.
Drying Beds
Sludge drying beds are used to devater digested sludge. Sludge is placed
on the beds in an 8-12 inch layer and alloved to dry. After drying, the
sludge is removed and disposed of in a landfill, or pulverized for use as a
fertilizer. Open beds are used vhere adequate isolated space is available.
Covered beds vith greenhouse type enclosures are used where it is necessary to
3-4
-------
devacer sludge continuously throughout the year despite adverse weather, and
where they cannot be sufficiently isolated. The beds are most commonly flush
with ground level and made of concrete.
Incineration
The incineration process converts the sludge into inert ash, which can be
easily disposed. With dewatering to approximately 30 percent solids, the
process is usually self-sustaining without the need for supplemental fuel,
except for initial warm-up and heat control. In the multiple hearth design,
heated air and products of combustion pass by finely pulverized sludge that is
continually raked to expose fresh surfaces. Products of combustion are
released to the atmosphere.
Sludge Lagoons and Vaste Piles
The sludge lagoon is essentially a large, unheated shallow digester.
Lagoons do not allow recovery of methane gas or the continuous removal of
digested sludge. Uhen the lagoon becomes filled with digested sludge, it must
be either abandoned, or drained and the digested sludge excavated. The lagoon
floor is usually unlined clay.
Land Application of Sludge
Vet digested sludge may be disposed of by spreading over farm land. The
humus in the sludge conditions the soil, improving its moisture retentiveness.
Landfill Disposal of Sludge
If a suitable site is convenient, a sanitary landfill can be used for
disposal of sludge, grease, and grit whether or not it is stabilized.
Disposal in a sanitary landfill method is most suitable if the landfill is
also used for disposal of the refuse and other solid wastes.
Land Application of Effluent
Spraying on irrigable land, wooded areas, and hillsides has been used to
dispose of POTV wastewater. The amount of wastewater that can be sprayed
depends on the climatic conditions, infiltration capacity of the soil, types
of crops or grasses grown, and the standards imposed on runoff.
3-5
-------
Underground Injection of Effluent
Ground-water recharge is a common method for combining water reuse and
effluent disposal. Recharge has been used to replenish ground-water supplies
in many areas. In New York, California, Florida, and other coastal areas,
treated effluent has been used to replenish ground water and stop saltwater
intrusion.
3.1.2 RCRA Terminology as Applied to POTV Treatment Units/Processes
Many POTV treatment units and processes can be evaluated in terms of
traditional RCRA hazardous waste treatment, storage, and disposal units. This
correspondence between POTV terminology and RCRA terminology is valuable to
investigators who may be relatively unfamiliar with key aspects of the RCRA
program. The use of traditional RCRA terminology will assist investigators in
identifying and understanding pollutant releases at POTVs.
Applicable RCRA terminology for various hazardous waste treatment,
storage or disposal units includes:
• Tank - A stationary device designed to contain an accumulation of
hazardous waste, which is constructed primarily of nonearthen
materials (e.g., wood, concrete, steel, plastic) that provide struc-
tural support.
• Surface Impoundment - A facility or part of a facility which is a
natural topographic depression, man-made excavation, or diked area
formed primarily of earthen materials (although it may be lined with
man-made materials), which is designed to hold an accumulation of
liquid wastes or wastes containing free liquids, and which is not an
injection well. Examples of surface impoundments are holding,
storage, settling, and aeration pits, ponds, and lagoons.
• Land Treatment - A facility or part of a facility vhere hazardous
waste is applied to or incorporated into the soil surface. Such
facilities are disposal facilities if the waste remains after closure.
• Landfill - A disposal facility or part of a facility where hazardous
waste is placed in or on land and which is not a land treatment
facility, a surface impoundment, or an injection well.
• Incinerator - Any enclosed device using controlled flame combustion
that neither meets the criteria for classification as a boiler or is
listed as an industrial furnace.
3-6
-------
• Underground Injection - The subsurface emplacement of fluids through a
boredT drilled, or driven veil, or through a dug veil, vhere the depth
of the dug veil is greater than the largest surface dimension.
t Vaste Pile - Any noncontainerized accumulation of solid, nonfloving
hazardous vaste that is used for treatment or storage.
Table 3-1 provides a list of RCRA classifications that apply to common POTV
units. It should be noted from Table 3-1 that no corresponding RCRA units are
provided for bar screens and comminutors. They are difficult to categorize as
RCRA units because they are devices rather than containment structures.
Many of the POTV units listed in Table 3-1 are categorized as RCRA tanks
or surface impoundments. The distinction between tank, and impoundment
pertains to the geometry of the individual unit as veil as how the unit is
situated. If the unit is self-supporting, regardless of its position relative
to the ground, the unit is classified as a tank. If the unit is not self-
supporting, it is classified as a surface impoundment. It is evident from
Table 3-1 that many POTV units can be constructed alternatively as tanks or
surface impoundments.
3.1.3 Typical POTV Configurations
As POTVs utilize many different treatment units/processes, POTVs also
possess different configurations. Figure 3-1 presents a diagram of the
treatment system configuration for a typical POTV. The POTV treatment units
and processes shovn in Figure 3-1 can include the following:
• Headwords
- Bar screens
- Coauainutors
- Grit chambers
• Priaary Tanks/Impoundments
- Primary clarifiers
• Secondary Tanks/Impoundments
- Activated sludge units
- Facultative lagoons
- Aerated lagoons
- Secondary clarifiers
3-7
-------
TABLE 3-1.
POTV UNIT
TRADITIONAL RCRA UNIT
Bar Screen
N/A*
Comminutor
N/A*
Grit Chamber
Tank/Surface Impoundment
Primary Clarifier
Tank/Surface Impoundment
Facultative Lagoon
Tank/Surface Impoundment
Aerated Lagoon
Tank/Surface Impoundment
Activated Sludge
Tank/Surface Impoundment
Secondary Clarifier
Tank/Surface Impoundment
Chlorination Contact Chamber
Tank/Surface Impoundment
Aerobic Digester
Tank/Surface Impoundment
Anaerobic Digester
Tank/Surface Impoundment
Drying Beds
Surface Impoundment/Vaste Pile/Tank
Incinerator
Incinerator
Sludge Lagoon
Surface Impoundment/Landfill
Landfill
Landfill
Land Application of Sludge
Land Treatment Unit
Underground Injection of Effluent
Underground Injection Well
Land Application of Effluent
Land Treatment Unit
* N/A - Not applicable.
3-8
-------
Influent
<«
Effluent Treatment
•nd Otscharge
Sludge
Processing
Units
SeconcUry
Tank/Iapoundaents
Prlasry
lank/Upountentt
HastciMtcr flow
Sludge flox
FIGURE 3-1. TYPICAL POTW CONFIGURATIONS
-------
• Effluent Treatment and Discharge
Chlorination
Land application
Underground injection
- Discharge to receiving waters
• Sludge Processing Units
- Aerobic digesters
- Anaerobic digesters
• Sludge Incinerator
Incinerators
• Sludge Storage
- Sludge lagoons
Sludge drying beds
• Sludge Disposal (includes ash disposal)
Landfill
Land application.
POTV treatment system configuration is important in assessing pollutant
releases from treatment units and processes, since the constituents in the
influent to a particular treatment unit are essentially determined by the
removal efficiencies of upstream units. This influence of upstream units on
pollutant releases is discussed in more detail in Section 3.2.5.
3.1.A Pollutant Fate Processes and Release Hechanisms Vithin POTVs
To identify and assess pollutant releases within POTVs, pollutant fate
vithin POTVs must be understood by the investigator. The principal fates of
pollutants in POTVs include:
• Biodtgr&dation,
• Volatilization,
• Adsorption to sludge,
• Chemical reaction,
• Combustion, amd
• Pass through.
3-10
-------
Table 3-2 presents a matrix of principal competing fate processes by POTV
treatment unit. The table does not, however, consider the influence of the
physical and chemical characteristics of specific pollutant fate processes.
For instance, volatilization has been designated as a competing fate process
in activated sludge units, indicating that aeration vill strip volatile
organics from vastewaters in activated sludge basins. On the other hand,
volatilization of certain semivolatiles in activated sludge basins may veil be
minimal•
Table 3-2 also indicates that biodegradation is most likely to occur in
those POTV units specifically designed for that purpose, including activated
sludge units, facultative and aerated lagoons, aerobic and anaerobic
digesters, and aerated grit chambers. Volatilization is expected in those
POTV units that are aerated, including grit chambers, activated sludge basins,
facultative and aerated lagoons, and aerobic digesters. Volatilization vill
also occur in anaerobic digesters vhere the gaseous products of sludge
digestion (methane and carbon dioxide) can effectively strip volatiles from
the sludge. Furthermore, volatilization vill occur in units such as sludge
drying beds and sludge lagoons, where evaporation is a method of treatment.
Finally, volatilization vill occur in sludge incinerators, vhich are
specifically designed to convert POTV sludges into gaseous products.
Table 3-2 shows that sludge adsorption is generally confined to POTV
sludge treatment operations, such as sludge digestion, drying, and settling
operations (primary and secondary clarifiers), and biological treatment units,
such as activated sludge units and vastevater lagoons, in vhich sludges are
brought into close contact with wastewaters. Other competing fate processes
cited in Table 3-2 are chemical reaction, vhich occurs in chlorinatlon units,
and combustion, which occurs in sludge incinerators.
Pollutants not removed by the fate processes just discussed vill
typically pass through a POTV unit untreated. POTV treatment units in vhich
pollutant pass through can occur are designated in Table 3-2. Ultimate
disposal options, such as landfill and application of sludge, land application
of effluent, and underground injection of effluent, by definition possess no
pass through potential and thus are not so designated in Table 3-2.
3-11
-------
TABLE 3-2. PRINCIPAL COMPETING POLLUTANT FATE PROCESSES
Unit Biodegradation Volatilization
Adsorption Chemical
to Sludge Oxidation Combustion Pass Through
or Ash in Effluent
Bar Screen
*
Comminuter
*
Grit Chaaber
*l
*
Priaary Clarifier
*
*
Activated Sludge
*
*
*
*
Facultative Lagoon
*
*
*
Aerated Lagoon
*
*
*
Secondary Clarifier
*
A
Chlorination
*
*
Aerobic Digester
*
*
*
Anaerobic Digester
*
*2
*
Sludge Drying Beds
*
Sludge Lagoon
*
Sludge Incinerator
*
*
Landfill
Land Application
of Sludge
Land Application
of Effluent
Underground Injection
of Effluent
1if aerated
Stripping by digester off-gases
through evaporation
^adsorption to incinerator ash
-------
Table 3-3 delineates the potential pollutant release mechanisms for each
POTV treatment unit and process. These pollutant release mechanisms are
defined as follovs:
• Stripping/Volatilization - aeration of wastewaters and sludges, which
causes volatiles to be stripped and subsequently emitted to the
atmosphere; also includes emission of volatiles through evaporation;
• Leaching - wastewaters entering the ground water from the bottom of
unlined basins;
• Pass Through and Discharge - untreated pollutants, not removed by POTV
treatment units or processes, discharged in the POTV effluent;
includes discharges to a receiving stream, land application, or
underground injection; and
« Overflow of Treatment Units - open basins within the POTV can overflow
onto POTV grounds, if improperly operated, overflows could seep through the soi
1 to ground water.
As shown in Table 3-3, aerated treatment processes, such as grit cham-
bers, activated sludge basins, and aerobic digesters can emit volatiles
through air stripping. Volatiles can also be emitted to the atmosphere
through evaporation in sludge incinerators, sludge drying beds, and from land
to which effluent has been applied. Pollutants can leach into ground water
from unlined basins such as sludge drying beds and lagoons, or from the land
following application of POTV sludges or effluent. In addition, pollutants
can pass through the POTV untreated and be discharged in effluent following a
POTV's final treatment step, usually a secondary clarifier or a chlorination
unit. Finally, Table 3-3 designates POTV treatment units and processes that
are open and consequently can release pollutants to the land by overflow.
Significant pollutant fate processes within the POTV for a given pollut-
ant will largely determine the location(s) and extent of the pollutant's
release froa the POTV. Accordingly, nonvolatile, biorefractory organics will
likely pass through the POTV and be discharged, whereas nonvolatile, biode-
gradable organics may be almost entirely broken dovn in an activated sludge
basin and not be significantly released by the POTV. Also, pollutant fate
processes operating in upstream treatment units/processes will affect the
extent of releases in downstream units. Thus, volatile organics may be
3-13
-------
TABLE 3-3. POTENTIAL POLLUTANT RELEASE MECHANISMS
Stripping/ Pass Through Overflow of
Unit Volatilization Leaching and Discharge Treatment Unit
Bar Screen
*
Comminuter
•k
Grit Chamber
•k
Primary Clarifier
*
Activated Sludge
if
ir
Facultative Lagoon
*L
*¦
*
Aerated Lagoon
k
¦k
~
Secondary Clarifier
~
~
Chlorinat ion
~
~
Aerobic Digester
*
~
Anaerobic Digester
**
Sludge Drying Beds
~
•k
Sludge Lagoon
~
Sludge Incinerator
Landfill
*
Land Application
of Sludge
~
Land Application
of Effluent
~
*
~
Underground Injection
of Effluent
~
~
1 if aerated
^stripped by digester off-gases
3-14
-------
partially stripped in an aerated grit chamber, thereby reducing volatile
emissions from downstream activated sludge units. The impact of the sequence
of POTV treatment units/processes on pollutant releases is discussed in more
detail in the next section of this report.
3.1.5 Impacts of POTV Treatment System Configuration on Pollutant Releases
As noted above, the POTV's configuration will determine the locations and
extent of releases within the POTV. As a result, removal efficiencies of
upstream treatment units/processes vill affect downstream loadings and the
extent of downstream releases. Table 3-4 indicates, by POTV treatment
unit/process, the impacts on downstream pollutant loadings caused by the
operation of POTV treatment units/processes immediately upstream.
Loadings of volatile and semivolatile organics to primary clarifiers can
be reduced by stripping/volatilization occurring in an upstream aerated grit
chamber. Stripping/volatilization in an upstream aerated grit chamber and
sludge adsorption in an upstream primary clarifier will account for reductions
in organics loadings to biological treatment units (i.e., activated sludge,
facultative lagoon, aerated lagoon). Stripping/volatilization, biodegrada-
tion, and sludge adsorption within biological treatment systems in turn, to
reduce pollutant loadings to the secondary clarifier. Metals loadings to the
secondary clarifier are reduced by upstream sludge adsorption in the primary
clarifier and upstream biological treatment systems.
Pollutant loadings to sludge processing units (aerobic, anaerobic
digesters) are determined by the extent of sludge adsorption in the primary
and secondary clarifiers. Stripping/volatilization of volatile organics will
occur in the digesters, reducing the loadings of these pollutants to addi-
tional dovnstreaa sludge processing. Similarly, biodegradation of semi-
volatile organics vithin digesters will reduce downstream loadings of these
pollutants. Finally, it should be noted that biodegradation of organic
pollutants, as veil as volatilization of organics through evaporation, will
occur in sludge drying beds and lagoons. These processes reduce pollutant
loadings in dried sludge taken from sludge drying beds/lagoons for
landfilling.
3-15
-------
TABLE 3-4. DfPACIS OF UPSTREAM INTS (H DOWSISEAM POLLUTANT LMUNGS
Treatment Unit/Process
Headvorks
Bar Screen
Corininutor
Grit Chamber
Influent Loadings of
Volatile Organics
Reduced by:
No upstream units
No upstream units
Influent Loadings of
Senivolatile Organics
Reduced by:
Not affected by upstream units
Influent Loadings of
Metals Reduced by:
->
->
Primary Tanks/Impoundments
Primary Clarifier
Stripping/volatilization
in aerated grit charter
Not affected
Not affected
Secondary Tanks/Impoundments
Activated Sludge
Facultative Lagoon
Aerated Lagoon
Secondary Clarifier
Stripping/volatilization
in aerated grit chamber
Stripping/volatilization
in biological treatment
Sludge adsorption in
primary clarifier
Biodegradaticn and
sludge adsorption in
biological treatment
Sludge adsorption
in primary
clarifier
Sludge adsorption
in biological
treatment
Sludge Processing Ihits
Aerobic Digester
Anaerobic Digester
Influent loadings are determined by sludge adsorption in primary/
secondary clarifier
Sludge Incineration and Sludge Storage
Sludge Incinerator
Sludge Lagoons
Sludge Drying Beds
Stripping/volatilization
in aerobic or anaerobic
digester
Biodegradaticn in
aerobic or anaerobic
digestor
Not affected
Sludge Disposal
Landfill
Landfill Application
Volatilization through
evaporation from sludge
lagoons/drying beds; also
stripping/volatilization
in aerobic or anaerobic
digestor
Effluent Treatment and Discharge
Biodegradaticn in
sludge drying beds/
lagoons; also in
aerobic or anaerobic
digestor
Not affected
Chlorination
Land Application
Underground Injection
Loadings determined by PCJTW removals affected through volatilization,
biodegradaticn, and/or sludge adsorption
3-16
-------
3.1.6 Fate of Specific Pollutants within POTVs
It has already been noted within this report that specific pollutants
have differing fates within POTVs. The EPA Report to Congress on the
Discharge of Hazardous Vastes to POTVs provides some data on the fate of
priority and nonpriority pollutants. Data on pollutant fate extracted from
this report are compiled in Appendix A. The table provides estimates of
typical POTV pass through rates (as a percent of POTV influent loading), air
emission rates, and sludge partitioning rates for acclimated and unacclimated
treatment plants.
3.2 POTV VASTE CHARACTERISTICS
A significant aspect of the RFA involves the characterization of the
wastes received by the POTV. Proper waste characterization will assist the
investigator in focusing further data collection efforts (i.e., visual site
inspections and sampling visits) and in determining the presence of releases
or potential releases at the hazardous waste management facility. Vaste
characterization at POTV facilities represents a significant challenge since
POTVs may receive a broad range of hazardous wastes and constituents generated
offsite by a diverse set of industrial users. In characterizing wastes
managed at a POTV, investigators should be aware that the discharge of
hazardous wastes and constituents to a POTV can occur in tvo ways:
• Vastes containing hazardous constituents can be discharged to a POTV
collection system and mixed vith domestic sevage (i.e., DSE vastes)
prior to arrival at the POTV treatment plant, and
• Hazardous wastes may be discharged directly to a POTV treatment plant
by truck, rail, and dedicated pipeline (non-DSE waste).
Consequently, a release from a POTV solid waste management unit (SVHU) may
result froa the presence of hazardous wastes and constituents contributed
by either DSB vastes or non-DSE vastes, or some combination of these vastes.
The investigator should attempt to characterize all hazardous vastes and
constituents managed by a POTV.
This section provides the RFA investigator with guidance on how to
collect the data necessary to characterize hazardous vastes and constituents
3-17
-------
managed at a POTV. The best data sources will generally consist of data
maintained by the POTV. These data sources are discussed in Section 3.2.1
belov. Section 3.2.2 discusses "default" data which can be used by the
investigator in instances where existing data sources do not provide
sufficient information on POTV wastes.
3.2.1 Data Sources for POTV Vaste Characterization
There are several data sources available to investigators performing
RFAs at POTVs. These data sources should be utilized by investigators to
characterize all hazardous wastes and constituents that may be present within
POTV treatment units. Accessibility of the data will depend in part, upon the
party responsible for conducting the RFA. If State personnel are responsible
for performing the RFA, requests to EPA and/or the POTV may be required to
obtain the data necessary for proper vaste characterization. If EPA personnel
will perform the RFA, data requests to the State and POTV may be needed to
supplement existing vaste characterization data for a POTV. The following
section provides descriptions of data sources vhich vill assist an
investigator in characterizing the hazardous vastes and constituents managed
at a POTV.
RCRA Program Data
Initially, the investigator may utilize records and reports required by
the RCRA program to characterize hazardous vastes and constituents managed at
a POTV. POTVs vhich accept hazardous wastes transported by truck, rail, or
dedicated pipeline are subject to RCRA permit by rule requirements. As such,
a POTV is required to comply with RCRA procedural provisions involving the
submission of reports to document knovn hazardous waste activities. These
provisions include the following:
• EPA Identification Number - facilities that treat, store, or dispose
of hazardous vastes are required to file a notification of activity
and receive an EPA identification number.
• Manifest System - Permit-by-rule conditions require POTVs to comply
vith the manifest regulations for TSDFs (40 CFR Part 264.71-264.72).
The manifest system is originated by the generator, continued by the
transporter, and completed by the POTV. The POTV must return a copy
3-18
-------
of the completed manifest to the generator, and retain a copy for its
records. The Uniform Hazardous Vaste Manifest requires specific
information regarding the hazardous vaste to be treated including:
- Manifest document number
- Name, address, telephone number, and EPA identification number of
the generator
- Name and identification number of each transporter
- Name, address, and EPA identification number of the POTV (including
the same information for an alternate TSDF)
- DOT shipping name, hazard class, and waste identification number
- Total quantity of each vaste by weight or volume
- Type and number of containers used in transpprting the waste
- Certification that the hazardous waste has been properly classi-
fied, described, packaged, marked and labeled, and is in proper
condition for transportation
- Waste minimization certification stating that the generator has a
program in place to reduce the volume and toxicity of the waste.
Operating Record - Permit-by-rule conditions require a POTV to main-
tain an operating record regarding hazardous waste practices. This
operating record must contain the folloving information as it becomes
available:
- Description of the type and quantity of each hazardous waste
received
- Method and dates of its treatment, storage, or disposal at the
facility, as per Appendix I of the RCRA regulations.
Biennial Report - A POTU subject to permit-by-rule must submit
biennial reports to EPA or appropriate State agency by March 1 of each
even-numbered year. This report details POTV treatment, storage, and
disposal activities in the previous odd-numbered year. The folloving
information is required:
- EPA identification number, name, and address of the facility
- Calendar year covered by the report
- EPA identification number for each generator from which hazardous
waste was received
- Description and quantity of each hazardous waste received during
the year, listed by the EPA identification number of the generator
- Certification signed by the ovner or operator of the facility or
his authorized representative
- Method of treatment, storage, or disposal for each hazardous waste.
Unmanifested Vaste Report - If an unmanifested hazardous vaste is
accepted by a POTV from an offsite source, the POTV is required to
file an unmanifested vaste report. This report must contain the
folloving:
3-19
-------
EPA identification number, name, and address of the facility
- Date the vaste was received
- EPA identification number, name, and address of the generator and
the transporter, if available
- Description and quantity of each unmanifested hazardous vaste
received
- Method of treatment, storage, and disposal for each waste
- Certification signed by the owner or operator of the POTV or his
authorized representative
- Brief explanation of why the waste was unmanifested, if known.
An investigator utilizing these data sources shouLd recognize that these
records and reports provide information on hazardous wastes and not hazardous
constituents. The investigator will need to refer to 40 CFR Part 261 of RCRA
regulations to identify the constituents which provide a basis for regulation
of these wastes as hazardous under RCRA. For example, if the investigator
determines that a POTV manages an F006 listed hazardous waste (i.e., electro-
plating wastewater treatment sludge), the investigator should accordingly
evaluate the potential for release of cadmium, hexavalent chromium, nickel,
and cyanide, which are the hazardous constituents associated with F006.
Generators of hazardous wastes are also required to notify EPA and obtain
an EPA identification number. Therefore, if an investigator wishes to
identify POTV users with the potential to discharge hazardous wastes and
constituents to the POTV under the DSE, a list of RCRA generators located in
the POTV service area should be obtained. This generator listing may be quite
large depending upon the size of the POTV service area. The investigator may
also wish to consider RCRA facilities which treat, store or dispose of
hazardous wastes. Hazardous waste treatment, storage, and disposal facilities
(TSDFs) are also required to notify EPA of their activities and submit
biennial reports which describe hazardous waste activities at the facility. A
TSDF listing within the POTV service area may also assist the investigator in
identifying industries with the potential to discharge hazardous wastes and
constituents to the POTV.
POTV Sampling Data
The investigator should also utilize POTV sampling data to characterize
POTV wastes. In particular, influent, effluent and sludge sampling data for
3-20
-------
the POTV treatment plant vill provide the investigator vith useful information
regarding the presence of hazardous wastes and constituents present at a POTV.
Nonetheless, POTV sampling data may be limited in tvo key respects. First,
many POTVs are not required to perform sampling for parameters that are not
regulated in their NPDES permit. Thus, in the absence of toxic limits in a
POTV NPDES permit, an investigator may not find sampling data for hazardous
constituents. Secondly, most sampling performed by POTVs is limited to metals
or a subset of EPA priority pollutants. As a result, POTV sampling data for
nonpriority hazardous constituents vill probably not be available.
NPDES Program Data
Data generated by POTVs for NPDES program reporting requirements may be
useful to an investigator attempting to characterize vastes and constituents
managed by a POTV. For example, NPDES permit applications submitted by POTVs
to EPA or the NPDES-delegated State should list the major industrial users of
these POTVs. Also, POTVs are required to submit monthly discharge monitoring
reports (DMR) to EPA or the NPDES-delegated State. These DHRs cpntain data
regarding POTV compliance with NPDES discharge standards and requirements.
Monitoring data for hazardous waste constituents may be available on these
DMRs where a POTV is subject to toxic pollutant standards, or is required to
monitor for toxic pollutants. However, in most cases, analyses for con-
stituents other than metals are rare. Finally, as part of EPA/delegated State
oversight of POTVs, various inspections are performed to determine the
compliance status of POTVs with NPDES program requirements. Inspection
reports may provide useful information on the presence of specific hazardous
constituents at a POTV.
Pretreatment Program Data
Many POTVs have bc«n required by EPA to develop pretreatment programs to
control the discharge of industrial wastes to their treatment systems. If an
investigator is performing an RFA at a POTV that administers a local pretreat-
ment prograa, the investigator may find substantial data useful in charac-
terizing POTV vastes. Pretreatment data that may assist in characterizing
POTV waste are discussed belov.
3-21
-------
Industrial Vaste Surveys. As part of the pretreatment program develop-
ment process, POTVs are required to identify and locate all possible indus-
trial users, and identify the volume and character of pollutants discharged by
these users. To gather this information, POTVs have typically surveyed all
industrial users located within their service area and collected the following
informal ion:
• Name of industry;
• Address of facility;
• Standard Industrial Classification (SIC codes);
• Wastewater flow;
• Types and concentrations (or mass) of pollutants contained in
discharge (Note: This may not provide information on many hazardous
consti tuents-);
• Major products manufactured or services supplied if pollutant
constituents in discharge are not known; and
• Description of existing onsite pretreatment facilities and practices.
A POTV industrial waste survey will provide a list of industrial users located
within the POTV service area, and information on the manufacturing processes
and waste generation practices of these industrial users. The original
completed survey information for each industrial user should be maintained in
POTV pretreatment program files.
POTV Industrial User Monitoring. As part of a POTV's implementation of
its pretreatment program, the POTV will monitor its industrial users to ensure
compliance with applicable pretreatment standards and requirements. This
monitoring includes Inspection and sampling of industrial users regulated by a
POTV. An investigator should review the data generated by these POTV monitor-
ing efforts for information on industry wastes.
A POTV will typically collect information necessary to maintain current
operations and waste data on its industrial users and to determine the user's
compliance status with pretreatment standards and requirements. POTV
inspection information should cover the following areas:
3-22
-------
• Manufacturing faci lity;
t Chemical storage areas;
• Hazardous waste generation;
• Spill prevention and control procedures;
• Pretreatment facilities;
• Industrial user sampling procedures;
• Lab procedures (if applicable);¦ and
• Self-monitoring records.
Findings from industrial user inspections can assist in the identification of
actual or potential discharges of hazardous wastes or constituents to a POTV.
Further, each pretreatment POTV is required to sample the wastewaters
from its regulated industrial users in order to ensure compliance with
discharge standards. An investigator should consider revieving sampling
results to determine if hazardous waste constituents are being discharged by
those industries of concern. It should be noted, however, that many POTWs
will only analyze for regulated pollutants or for pollutants khown or believed
to be present in the industrial user's discharge. Also, fev POTVs vill
conduct sampling for nonpriority pollutant parameters.
Industrial User Self-Monitoring. Industries covered by a Federal
categorical standard must comply with the baseline monitoring and compliance
status reporting requirements found in AO CFR Part 403.12 of the pretreatment
regulations. Information required in a baseline monitoring report, which is
submitted only once to the POTV (or Control Authority) Includes:
• Identifying information (i.e., name, address, operators and owners);
• List of environmental permits held by the facility;
• Description of operations (including average rate of production and
SIC code);
• Flow measurement of all regulated process wastestreams and all
nonprocess wastestreams if the combined vastestrean formula (40 CFR
403.6) is utilized;
• Measurement of pollutants regulated in process wastestreams;
3-23
-------
• Statement of certification of compliance; and
• Compliance schedule (if out of compliance).
Information required in compliance status reports, vhich are submitted
periodically to the POTV, includes:
• Nature and concentration of pollutants in regulated process
wastestreams;
• Flov measurement of all regulated process vastestreams, and all
nonprocess wastestreams if the combined vastestream formula (40 CFR
403.6) is utilized; and
• Statement of certification of compliance (only needed for the final
compliance report).
Beyond self-monitoring requirements contained in Federal Standards, POTVs may
require further self-monitoring reports for both categorical and non-
categorical industrial users. These local reporting requirements may include:
• Notification of slug loads discharged by an industrial user;
• Notification of in-plant changes vhich may effect discharged vaste
quality or quantity; and
• Monitoring requirements for applicable local limits.
3.2.2 Potential Sources and Types of Hazardous Wastes and Constituents
Discharged to POTVs
Where adequate vaste information is not available in POTV files, an
investigator vill have to rely upon professional judgment and outside data
sources to characterize hazardous vastes and constituents potentially managed
at a POTV. This section provides guidance for the investigator in determining
types of hazardous vastes and constituents vhich may be present at a POTV
based upon a review of the the types of industrial users served by the POTV.
Profile of Potential Large Quantity Generators
Appendix B provides a list of hazardous constituents potentially
discharged by an industrial user in any one of 15 selected industrial cate-
gories. Industrial users in these categories have the potential to generate
3-24
-------
and ultimately discharge to a POTV large quantities of hazardous wastes or
constituents. To use Appendix B, the investigator must first identify the
types of industries (i.e., organic chemical manufacturers, wood preservers)
discharging to the POTV. Section 3.1.1 discussed several sources of data
vhich may be utilized by the investigator to identify types of large quantity
generator (LOG) industries discharging to the POTV. Other data sources such
as local Chamber of Commerce lists, Durr and Bradstreet and telephone books can
also be consulted by the investigator. In many cases, industries are identi-
fied and described by their SIC codes. Table 3-5 provides a listing of the 15
selected LQG industries and SIC codes associated with these industry types.
Once the types of LQG industries are determined by an investigator,
Appendix B may be used to identify hazardous constituents potentially
generated and eventually discharged to a POTV by specific industries. As
shovn in Appendix B, there are several LQG industries that have the potential
to discharge a wide variety of hazardous constituents to a POTV. For example,
hazardous waste management facilities have the potential to discharge a broad
range of hazardous wastes and constituents. Further, investigators should be
aware that some industry types are common to many POTVs (i.e., metal
finishing/equipment manufacture), while other industry types may be concen-
trated in certain geographical areas (i.e., wood preserving in the southeast
and northwest).
Profile of Potential Small Quantity Generators
It is estimated that 630,000 facilities in the Nation generate less than
1,000 kilograms pec month of hazardous waste. Historically, these small
quantity generators (SQGs) have been subject to less stringent RCRA disposal
requirements than other generators. However, regulations recently promulgated
by EPA have significantly broadened S0G requirements. Recent studies of SQGs
by EPA have demonstrated that a significant proportion of all SQGs discharge
their hazardous wastes to POTVs. Because industries which qualify as SOGs are
common to most POTV service areas, an investigator should always consider
possible contributions of hazardous wastes and constituents by SQGs.
3-25
-------
TABLE 3-5. APPLICABLE SIC CODES P
GENERATORS OF CONCERN
Industry
Electrical and Electronic Components
Explosives Manufacture
Hazardous Vaste Management Facilities
Inorganic Chemicals Manufacture
Iron and Steel Manufacture
Metal Finishing/Equipment Manufacture
Nonferrous Metals Manufacture
Organic Chemicals Manufacture
Paint Manufacture
Pesticides Manufacture
Petroleum Refining
Pharmaceuticals Manufacture
Plastics/Rubb«r Manufacture
Utilities (Steaa Electric)
Wood Preserving
POTENTIAL LARGE QUANTITY
Applicable SIC Codes
3612, 3624,
3641,
3671
3672, 3673,
3674,
3677
3679, 3339
3482, 3483,
2892,
2899
1389, 2992,
3031,
3341
4212, 4953,
5085,
5093
2812, 2813,
2816,
2819
3312, 3313,
3315,
3316
3317, 3321,
3322,
3324
3325, 3462,
3493
all 34 SIC
codes
all 35 SIC
codes
all 36 SIC
codes
all 37 SIC
codes
all 38 SIC
codes
all 39 SIC
codes
3331, 3332,
3333,
3334
3339, 3341,
3350,
3354
3355, 3356,
3357,
3361
3362, 3369,
3399,
3463
3497
2865, 2869
2851
2869, 2879
2911
2831, 2833, 2834
2821, 2822, 2823, 2824
4911, 4931
2491
3-26
-------
To assist the investigator in evaluating the actual or potential dis-
charge of SQG wastes foe a given POTV, Table 3-6 identifies common types of
SQGs generating hazardous vastes, predominant types of hazardous wastes
generated by these SQGs (i.e., as percent of total vaste volume for the
industry), and hazardous constituents typically associated vith these
hazardous vastes. For example, if an investigator determines that several
industrial and commercial laundries are present in the POTV service area, then
tetrachloroethylene, vhich is a possible constituent of filtration residues
from dry cleaning, may be released from the POTV to the'environment.
Profile of Other Vastes Potentially Discharged to a POTV
There are several other types of wastes potentially discharged to a POTV
vhich may be hazardous or contain hazardous constituents. If accepted at a
POTV facility, these vastes should be carefully evaluated by the investigator.
Descriptions of these waste types are provided belov.
Septage Vastes. In considering septage wastes, an investigator should
identify their possible sources. Septage vastes derived exclusively from
household sources are not considered hazardous wastes and vill probably not
contain significant quantities of hazardous constituents. Nonetheless, where
septage vastes are derived vholly or in part from nonhousehold sources, such
as industrial septic tanks, the vastes are regulated as any other solid
vastes, and may be deemed hazardous if the septage has been contaminated with
listed or characteristic vastes. Septage vastes hauled from nonhousehold
sources can also be contaminated vith high levels of hazardous constituents.
Leachate, Contaminated Ground Water, and Impoundment Vastes. Facilities
that treat, store, or dispose of RCRA regulated hazardous vastes may generate
hazardous vwtl residuals as a result of normal operations or due to unusual
situations facility closure requireaents). Examples of such residuals
are leachate*; contaainated ground water, and surface impoundment vastes.
Where accepted at a POTV facility, these residual vastes should be carefully
evaluated for the presence of hazardous vastes or constituents.
3-27
-------
TA*L£ 3-4, SMALL gUAtfTITY CUUlATUC HATAiOOUS WASTft TfFftS AND TYPICAL lUZAUXMJS UASTO 0UHST1TUUTTS
1HUJSTKY
Construction lodu«try
CuMeilca MAOyUctvft
F«rilllicr Naouf«cCur«
loduiitilil And CiMMrclal UuAdrlo
Ubor«(o(Ufl «od Hotpllili
Mltceli«rt«oui ChealctK rorauLttori
Motor Vehicle Stivlctt
PcU(ld| 4 Publishing
StKviu fteiated loduitrl««
Sotp* tod D«ur|«o(« Haaufictyrt
Trao«po(t«tlM Service*
Wholesale t«uU Trade
Wood furniture ftetlnlshlng
HA2A&U0US WASTE TYft(S)
ACCOUNTING K0«
*H)l Of WASTE CEHt-mTfcl)
Igntuble Uaitca (90t)
Strong Acid or Alkaline Wastes (601)
Ignltable Waste* (301)
Strong Acid or Alkaline Wastes (1001)
Filtration Residue fro* Dry
Cleaning (991)
Spent Solvents (^0X)
Ignltable Waste* (201)
Strong Acid or Alk*llae Wastes (ibl)
Other SLeactive Ws*te* (1^1)
Strong Acid or Alkalia* Waste* (601)
Spent Solvent* (251)
Pesticide Washing and Biasing
Solution (101)
Spent Solvents (901)
Strong Acid or Alkaline Waste* (101)
Photographic Wastes (7il)
Strong Acid or Alkaline Wastes (IDX)
Spent Solvents (101)
Photographic Waste* OS1)
Waste For**ldehyd* tlW)
Solution or Sludge* with
Photo*liver (201)
Pesticide* W**hlog and tloslog
Solution (Ml)
Stroog Acid or Alkaline Waste# (4U1)
Spent Solvents (1001)
ignltable Paint Waste* (2)1)
Photographic Was Ice (201)
Spent Solvents (201)
Waatewatet Wood Preservative ()H)
Pesticide Waahlng and Rinsing
Solution (1*1)
Filtration fcealdue (ros Dry
Cleaning (bUt)
cpenl c~' :nl» "
TtMCAI. HAZARDOUS WAS ft: CONSTITUENTS
Naphtha, kerosene, turpentine, gasoline
dleeel tuel
Acetone, ethyl acetate
AssortU, phosphoric acid, bullurlc acid
Tetrachloroethylene, pet rut cue solvents
Acetone; *ethyl ethyl ketone; •elltyl
leobotyl ketone; benzene; toluene;
•ethylene chloride; Methanol;
hydrochloric, sulfuric, nilrlc, and
chroalc *cld*; caustic soda
Solvents (e.g., as listed for
"Laborator lee"), pest 1 elded , clieakd J
Interred late*/feedstocks (e.g . ,
chlorobentene, nitrobenzene, ani1IneJ
Gasoline, naphta, tetraethyl lead,
sulfuric acid
Silver, cyanide, chrosius, ketones,
alcohols, eater*, aromatic hydrocdrbons
Silver, cyanide* chro*lu«, toradldehyde
phenol, pesticides
Sadiii« hydroxide, potauslua hyJroilde,
phenol, cresol*
Cssallne, dlesel fuel, naphiha (froa
tank cleaning and hazardous wdo(e
hauling operations*, alaout any KCHA
waste la possible)
Cresols, toluene, sliver, cyanide,
chroalua, pesticide*, naphtha,
turpentine, aethyl ethyl ketone,
aelhyl isobutyl ketone, phlhalate
esters
Tel rd chloroethy I cue , Ii.mm, I , »«;4liyJ«-iu
cliiuilde, aelhyl ethyl V.a,-'1"1
ittub el Ol li J |, l i-1 n
-------
Superfund Vaste. Cleanup of Superfund sites by Federal, State, and
private parties frequently results in the generation of aqueous wastes such as
leachate, contaminated ground water, impoundment vastes, and other waste-
waters. Vhere delivered to a POTU by truck, rail, or dedicated pipeline, some
Superfund wastes may be hazardous as defined by RCRA. These wastes may
contain hazardous constituents frequently found at CERCLA sites (e.g.,
trichloroethylene, lead, toluene, benzene, PCBs, and chloroform).
Used Oil. As defined by RCRA statutory provisions, used oil is any oil
that has been refined from crude oil, used and, as a result of such use,
contaminated by physical or chemical impurities. Used oils include:
• Spent automotive lubricating oils (including car and truck engine
oil), transmission fluid, brake fluid, and off-road engine oil.
• Spent industrial oils, including compressor, turbine, and cleaning
oils, hydraulic oils, metal working oils, gear oils, electrical oils,
refrigerator oils, and railroad drainage.
• Spent industrial process oils.
Under current RCRA provisions, used oils are exempt from RCRA hazardous waste
regulat ions.
In reviewing used oils for possible regulation, EPA has noted the
frequent contamination of used oils vith metals (e.g., lead, arsenic, cadmium,
chromium) and solvents (e.g., trichloroethylene 1,1,1-trichloroethane,
tetrachloroethylene), as veil as the presence of hazardous constituents (e.g.,
naphthalene, toluene, phenol) that are naturally occurring in petroleum-
derived and synthetic oils.
3.2.3 Physical/Chemical Properties of Selected Hazardous Vaste Constituents
Once an investigator has sufficiently characterized the hazardous vastes
and/or constituents that are, or have the potential to be, discharged to a
POTV, the investigator should begin an initial assessment of the potential for
release of these hazardous vastes and/or constituents from the POTV to the
environment. In order to undertake this assessment, the physical/chemical
properties of the identified hazardous constituents should be considered.
3-29
-------
These physical/chemical properties will determine the fate of the hazardous
constituent within the POTV, and the fate of the hazardous constituent once
released to the environment. Selected physical/chemical properties to be
utilized in assessing the fate of selected hazardous waste constituents are
included in Appendix C.
Specific use of each of these physical/chemical properties in assessing
releases to the environment will be discussed in further detail in other
portions of this guidance, including:
• Chapter 4 .which discusses physical/chemical properties of constituents
to be considered in assessing releases to ground water, soil, and
subsurface gas.
• Chapter 5 which discusses physical/chemical properties of constituents
to be considered in assessing releases to surface waters and
sediments, and
• Chapter 6 which discusses physical/chemical properties of constituents
to be considered in assessing releases to air.
3-30
-------
4. ASSESSMENT OF RELEASES TO GROUND WATER AND SOIL,
AND BY SUBSURFACE GAS
This section contains guidance on identifying and evaluating releases to
ground water, soil, and subsurface gas from SVMUs at POTVs. The major diffi-
culty investigators will encounter when evaluating releases of hazardous con-
stituents to soils and ground water at a specific site will be the lack of
information on operating units, wastes managed, and hydrogeological
conditions. Investigators likely vill be required to make assumptions as to a
unit's potential for release based on design and operating records. Visual
evidence of upkeep and maintenance, and spills outside a unit's containment,
will indicate the likelihood of a release. However, sampling results
demonstrating hazardous constituents are present outside a unit's containment
probably vill be required to prove a release has occurred.
A unit's design and construction, and the POTVs operating practices,
vill control the potential for releases to occur; these are discussed in
Section 4.1. The extent of a release vill depend on the physical/chemical
behavior of specific constituents as they move through the environment; these
are discussed in Section 4.2. The migration path released constituents vill
follov is a function of the release mechanism, the method of transport, and
site-specific conditions; these are discussed in Section 4.3. Sampling may be
required to confirm releases or to identify hazardous constituents managed at
units; sampling procedures are discussed in Section 4.4. Finally, the
potential impacts of a release vill depend on the receptors along the migra-
tion path that vould be affected by released constituents; these are discussed
in Section 4.5. Releases to subsurface gas are discussed in Section 4.6.
4.1 UNIT CHARACTERISTICS AFFECTING POTENTIAL FOR RELEASES TO GROUND WATER
AND/OR SOILS
A unit's design, construction, and operation vill control the mechanisms
by vhich a unit may release hazardous constituents to soils and ground vaters.
Releases occur for the following reasons:
• Design assumptions are not correct, (e.g. surface water control
structures at a waste pile vere designed using incorrect storm
intensity data, or runoff/infiltration percentages, resulting in
surface runoff releases).
4-1
-------
• Construction is poor (e.g. the concrete base of an impoundment was
constructed of below-specification materials, or foundation prepara-
tion was not adequate, causing a cracked base resulting in wastewater
infiltration to ground water).
• Improper or poor operating practices cause releases (e.g. sludges are
placed outside containment areas, or foam overs are not controlled,
causing releases to soils and possibly ground waters).
In some cases, units are designed or operated to intermittently release haz-
ardous constituents. Although most units are intended to control or prevent
releases, any combination of improper design, construction, or operation may
cause releases.
Unit characteristics likely to cause releases are evaluated during the
preliminary review and visual site inspections. Design, construction, and
operating records may identify actual releases or obvious flaws that would
lead to releases. For example, EPA assumes that unlined, including clay- or
soil-lined, basins or impoundments will leak. Design records will indicate
the type of materials that provide containment at units. Similarly, a sludge
pile may be designed and constructed with a concrete pad but without surface
runoff controls. Design records and a visual inspection would identify this
deficiency. During the PR and VSI, inspectors should focus on identifying:
1. Design characteristics and features that would likely cause a unit to
release constituents to soils and/or ground water.
2. Primary release mechanisms and the likelihood of occurrence.
During the VSI, visual evidence of releases and the physical integrity of
the unit should be observed. Unit characteristics previously identified
should be confirmed. Evidence of actual releases or potential releases will
indicate migration paths, which will guide the selection of sampling locations
if a sampling visit is needed.
4-2
-------
4.1.1 Unit Characteristics Influencing Potential for Soil Contamination
Through Surface Runoff
Surface runoff releases occur for two reasons:
• Wastewaters or sludges have breached or overflowed containment, and
• Precipitation has contacted va&te, most often sludges, dissolved or
entrained constituents, and transported constituents outside
containment.
Releases of the first type usually occur at surface impoundments, tanks,
and basins. Releases of the second type usually occur at landfills, waste
piles, land treatment units, sludge processing units, and container storage
areas. Table 4-1 lists surface runoff release mechanisms for units found at
POTVs.
The potential for surface runoff releases is a function of the adequacy
of a units containment (e.g. tank vail, dike, or berra), and the operational
practices that cause or prevent overflows artd control runoff. Table 4-2 lists
design factors and operational practices that cause surface runoff-type re-
leases. Factors to consider vhen assessing the potential of specific units
for surface runoff releases to occur either by leaks and overflows, or by
contaminated runoff, are discussed below.
Leaks/Overflows From Tanks, Basins, and Impoundments
Leaks and overflows are caused by containment that is inadequate to con-
trol the volume or type of waste managed at a unit, or by operational prac-
tices that exceed the design standards of the units containment. For example,
an overflow from an open-topped tank or an impoundment can result if the
capacity of the unit Is not sufficient to manage peak flows or storm surges
(i.e., a design flaw), or if operators do not maintain sufficient freeboard
(i.e., an operations error). A leak In a tank wall or impoundment bank can
result if wastes managed at the unit are not compatible with the containment
(i.e., either an operator error or a design flaw). Design characteristics and
operational practices that could combine to cause an overflow or leak must be
anticipated vhen assessing release potential at basins, impoundments, and
tanks.
4-3
-------
TABLE 4-1. RELEASE MECHANISMS FOR SURFACE RUNOFF RELEASES
Unit type
Release Mechanism
Surface Impoundment
Releases from overtopping
Seepage through containment
Containment failure
Landfill
Migration of runoff outside the runoff collection
and containment system
Migration of spills and other releases outside
the containment area from loading and unloading
operations
Seepage through dikes to surrounding soils
Waste Pile
Migration of runoff outside the runoff collection
and containment system
Migration of spills and other releases outside
the containment area from loading and unloading
operations.
Land Treatment Unit
Migration of runoff outside the containment area
Container Storage Area
Migration of runoff outside the containment area
Above-Ground Tank
Releases from overflow
Leaks through tank shell
Spills during transfer operations
In-Ground Tank
Releases from overflov
Spills during transfer operations
Incinerator
Spills or other release error in waste
handling/preparation activities
Spills due to mechanical failure
Injection Wells
Spills from waste handling operations at the veil
head
4-4
-------
TABLE 4-2. CAUSES OF SURFACE RUNOFP TYPE RELEASES
Design and Operating Practices
Design Practices
Insufficient cover
Inadequate freeboard
(runon/runoff control)
Presence of liquids or waste
exposed to environment
Inadequate secondary containment
and runon/runoff control
Operating Practices
Operational failure, faulty piping
or other occurrences resulting in
leaks and spills
Cracks or structural failure in
dike walls or tanks
Lack of protection from dike wall
erosion or tank corrosion
Repair, installation or replacement
of any primary or secondary
containment system while the unit
contains waste
Applicable SVMUs
Surface impoundments, waste piles,
landfills
Surface impoundments
Surface impoundments, waste piles,
landfills, land treatment units
Waste piles, landfills, land treatment
units, container storage areas, tanks,
waste handling areas
Tanks, container storage areas,
waste handling areas
Surface impoundments, landfills,
container storage areas, tanks
Surface impoundments, landfills,
tanks, container storage areas
All SVMUs
Inadequate QA/QC procedures used All SVMUs
during operation of SVMU
4-5
-------
Unit containment is not adequate to prevent leaks and overflows if:
• The unit has insufficient capacity to manage possible vaste
quantities.
• The unit's containment is not compatible vith the types of vaste
managed.
• The unit's containment vas not properly constructed and is not veil
maintained.
Sufficient design capacity can be evaluated by examining design and
operation records. Maximum volumes managed by each unit should be readily
available in facility records or can be calculated using standard engineering
methods. These calculations can be performed either during the PR or the VSI.
Units vith inadequate design capacity vill have a high potential for
overflov unless automatic overtopping control mechanisms such as diversions to
emergency surge basins or vaste-feed cutoff devices are in-place. Units vith
adequate design capacity vill have a lov potential for overflov-type release
unless operational practices exceed design conditions. For example, a con-
taminated surface water control pond designed assuming a two or three-foot
freeboard may have inadequate containment capacity if operated vith a one-foot
freeboard. The combinations of design and operating factors that could result
in a release must be evaluated when assessing capacity.
Vaste/containment compatibility should not be a problem at most POTVs
because of the dilute concentrations likely to be encountered. However, units
where concentrated wastes are managed should be examined to determine compati-
bility. Highly acidic or corrosive wastes may adversely impact clay soils,
steel or synthetic tank materials, concrete, or synthetic liners. Available
EPA guidance documents should be consulted if highly concentrated wastes are
managed at a unit. A high release potential should be assigned those units
managing high concentration wastes which may not be compatible with
containment materials are managed.
The physical integrity of containment structures should be evaluated as a
final step in assuring the adequacy of containment and the likelihood of a
4-6
-------
leak or overflow. Initially, an investigator should consider age of the units
as a preliminary indication of its potential for release. Usually, construc-
tion quality control information will not be available to determine that
proper procedures were followed. Therefore, the apparent physical condition
of the containment will be the only measure of its integrity. Investigators
must visually inspect all containment structures such as tank vails, dikes,
and berm surfaces to identify obvious inadequacies. Rusting steel tanks,
popped seams, dents in tank vails, eroded embankments, cracked concrete vails,
etched or crumbling concrete, and overgrovn earthen embankments are examples
of visual evidence that upkeep and maintenance practices are not adequate to
maintain the design integrity of a containment system. Newly repaired con-
tainment at units vith poor operational histories also may indicate that
wastes have breached containment. In general, a high potential for overflows
or leaks should be assigned to units where maintenance of containment struc-
tures appears poor. A high potential should also be assigned when visual
evidence such as rusted tanks, spill stains, discolored soils, and erosion and
washouts at potential release points indicate releases have occurred.
In general, those units most likely to leak or overflow at POTVs are
tanks, basins, and impoundments that:
• Are constructed of materials which are not compatible vith wastes
managed.
• Are operated vith inadequate freeboard to maintain sufficient capacity
and do not have automatic overtopping controls.
• Are located at facilities that manage combined storm and sanitary
flows without adequate overtopping controls in-place.
Runoff from Sludge Processing or Dlposal Units
Runoff releases from sludge processing or disposal units such as land-
fills, landftras, impoundments, incinerators, and piles are caused because
containment is not present, is not sufficient to manage the volume of runoff
from major storms, or is not well maintained. Vaste/containment compatibility
is not a factor because concentrations of constituents in runoff vill be low.
4-7
-------
Units without containment to prevent surface runoff are assumed to have
released hazardous constituents to soils and possibly ground vater. At units
that have runoff containment, releases of contaminated runoff can still be
caused by combinations of design characteristics and operational practices.
For example, containment will be sufficient to manage the runoff from a waste
pile during a 25-year, 24-hour storm (i.e., RCRA Subtitle C regulatory
requirement for runoff control for waste piles, land treatment units, and
landfills) providing that less than a certain volume of waste is present with-
in containment. Containment will be insufficient if the- facility routinely
stores greater volumes of waste at the unit, reducing the runoff volume that
can be controlled. Factors which can combine to reduce the adequacy of con-
tainment must be evaluated when assessing the potential for release of con-
taminated runoff from sludge processing, use, or disposal units.
A unit's containment is not adequate to control contaminated runoff if:
• The unit has insufficient capacity to manage possible volumes of
runoff from a 25-year, 24-hour storm, and
• Containment was not properly constructed or is not veil maintained.
In general, units where containment is not sufficient to control the calcu-
lated volumes of runoff will likely have releases of contaminated runoff.
Even units with adequate design capacity may have a high potential for runoff
releases unless mechanisms are in-place to remove runoff and prevent overflow
of containment. Similarly, units with adequate design capacities may not have
sufficient available volume if waste is placed inside containment and reduces
the available volumes.
The physical integrity of any containment structures should be evaluated
as a final step in assessing the likelihood of a release of contaminated run-
off. Runoff containment structures usually will be earthen berms, ditches or
embankments, but sometimes may be asphalt or concrete. Erosion, washouts,
cracks, or overgrown vegetation are signs that upkeep and maintenance are not
adequate to maintain the integrity of the containment. A high potential for
releases of contaminated surface runoff should be attributed to units where
upkeep and maintenance are poor, or where visual signs of release are present.
4-8
-------
4.1.2 Unit Characteristics Influencing Potential For Ground Vater or Soil
Contamination Through Subsurface Leachate
Subsurface leachate refers to hazardous constituents dissolved in water
that move through the unsaturated zone and enter ground water. These releases
occur for tvo reasons:
• Hazardous constituents previously released by units to soils or
surface waters are transported by infiltrating precipitation or
surface waters through the unsaturated zone to ground vater; this is
referred to as an indirect release.
• Wastewaters or contaminated precipitation leak through inadequate or
nonexistent bottom containment (i.e., exftitration) and migrate
through the unsaturated zone to ground water; this is referred to as a
direct release.
Hazardous constituents in surface soils are assumed to migrate down
through the unsaturated zone and to ground water because most constituents are
soluble to some extent and most areas have a net downward movement of moisture
from land surface through the unsaturated zone to ground water. Indirect
releases to soils and possibly ground vater through subsurface leachate (#1
above) are assumed to occur whenever there is a release to surface soils. A
unit with characteristics that indicate a high potential for releasing con-
stituents to surface soils via surface runoff also will have a high potential
for an indirect release to subsurface soils and ground water (see Section
4.2.1).
Hazardous constituents released to surface waters may also migrate to and
affect subsurface soils and possibly ground water in areas where surface
waters recharge ground waters. Although most surface waters represent ground
water discharge areas (i.e., ground-water flows into the surface water body),
the reverse occurs naturally in some areas, and in other areas where pumping
has lowered the vater table. The potential for constituents in surface waters
to reach ground vater is a function of site-specific hydrogeologic conditions.
Therefore, because indirect releases to soils and ground vater might occur
whenever there is a release to surface vaters, the unit characteristics that
influence the potential for these indirect releases by infiltrating surface
vaters are also those that affect the potential for releases to surface waters
(see Chapter 5).
4-9
-------
Direct releases may occur at impoundments, basins, above and below grade
tanks, landfills, landfarms, piles, and any unit from which wastewaters or
contaminated runoff may infiltrate. Direct release potential is a function of
the adequacy of a unit's containment intended to prevent exfiltration of
waste from the unit. Table 4-3 lists mechanisms by which units release
hazardous constituents as subsurface leachate. Table 4-4 lists design and
operating factors which cause such direct ground-vater releases.
The potential for direct releases to occur is evaluated by examining
design, construction, and operating records to determine the likelihood of
exfiltration, and by visually inspecting the unit to observe evidence of
actual spills and degree of upkeep and maintenance. Available records will
indicate the type, extent, age, design, and construction method for contain-
ment structures. Visual inspection of the unit will confirm unit characteris-
tics, and also will indicate the care taken in operating and maintaining the
unit. Because direct releases to ground water and soils will not be observ-
able, data or observations of poor upkeep or spills along with.unit character-
istics which would increase the potential for a release to occur (e.g., older
liners are more likely to leak than new ones) must be used to evaluate the
likelihood of a direct release occurring.
The following trends can be used as general guidance vhen evaluating the
potential for direct releases via exfiltration of waste from a unit:
• Unlined basins, Impoundments, or sludge management areas are presumed
to leak and to have direct release to subsurface soils and ground
water.
• Older units require more upkeep and maintenance (e.g., periodic
draining to inspect, clean, and replace liners), and more extensive
containment (e.g., double liners versus single liners) to prevent
direct releases of hazardous constituents to soils and ground water.
In general, older units have a greater potential for leaking than
younger units.
• Cracks observed on the sides and walls of concrete units are presumed
to extend to below the vaste/vastewater level and are present on the
units bottom; these units are presumed to leak.
• Larger units at locations where extensive foundation preparation work
was required because of less than suitable soils will have a higher
potential for direct release because of a greater likelihood of
differential settling causing a bottom liner failure.
4-10
-------
TABLE 4-3. RELEASE MECHANISMS FOR GROUND-WATER RELEASES
Unit Type
Release Mechanism
Surface Impoundment
•
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
Landfill
•
Migration of leachate through liners (if present)
and soils
•
Precipitation runoff to surrounding surface and
subsurface
•
Spills and other releases outside the containment
area from loading/unloading operations
Land Treatment Unit
•
Migration of constituents through the unsaturated
zone
•
Precipitation runoff to surrounding surface and
subsurface
Underground Tank.*
•
Tank shell failure
•
Leaks from piping and ancillary equipment
•
Spillage from coupling/uncoupling operations
•
Overflow
Vaste Pile
•
Leachate migration through liner (if present) and
soils
•
Precipitation runoff to surface/subsurface
In-ground Tanks
•
Overflow
•
Tank wall failure
•
Leaks from ancillary equipment
•
Spillage from coupling/uncoupling operations
Container Storage
•
Spills from containers/container failure
Uni t
subsequent migration through liner or base (if any)
and soils
•
Precipitation runoff from storage areas
Above Ground Tank
•
Overflow
•
Shell failure/corrosion
•
Leaks from ancillary equipment
•
Coupling/uncoupling operations
Incinerator
•
Spillage or other releases from waste handling or
preparation activities
0
Spills due to mechanical failure
*In general, releases from underground storage tanks which store RCRA hazar-
dous wastes are subject to Subtitle C corrective action. Releases from
underground storage tanks which contain other "regulated substances" as
defined in Subtitle I of RCRA will be subject to a different set of correc-
tive action requirements which have not yet been promulgated.
4-11
-------
TABLB A-A. CAUSES OP DIRECT GROUND-VAT8R RELEASES*
Design Practices
Inadequate QA/QC procedures used during construction
Insufficient hydrogeologic investigations
Improper foundation preparation prior to liner system installation
Inadequate design of liner, leachate collection and leak detection systems
Operating Practices
Inadequate QA/QC procedures used during operation of SVMU
~Applicable to landfills, surface impoundments and waste piles.
/, - 1 t
-------
Factors to consider vhen assessing the potential for direct releases to
soils or ground water by subsurface leachate migration at particular types of
units are discussed below.
Leaks in Tanks and Basins
POTUs may contain above or below ground tanks or in-ground basins. Tanks
may be steel, fiberglass, or concrete. Basins are primarily steel or concrete
and are distinguished from tanks by RCRA Subtitle C definitions; tanks are
those units vhich do not depend on surrounding soils to provide structural
support. In other words, raised above ground, the unit would support its
weight plus that of the material it is designed to contain. The Subtitle C
program assumes that tanks, because of the added structural support inherent
in their design and construction, are less likely to leak. However, release
mechanisms are the same for tanks and basins.
There are two principal causes of steel tank/basin failure:
• Corrosion reduces the thickness of the steel and results in holes or
cracks.
• Improper construction or site preparation, open seams, or other flaws
result in a breach in the unit wall.
Because subsurface releases cannot be observed, release determinations
must be made based on evaluation of design, construction, and operating prac-
tices. Operating records vill Indicate if regular testing of tank integrity
or inspection of liners or vails is conducted at the facility. This
information will identify units that have had releases, the causes of
failures, and the frequency of failure.
Identified releases must be evaluated to determine the potential effects
and the need for further study or action. The causes of release and the fre-
quency of failure can be used to identify the potential for additional release
at that unit and other units. For example, if a concrete basin released
wastewater through cracks that developed in the base because of settling, or
if a steel tank corroded because the local soils had a high conductivity, then
other concrete basins and steel tanks are susceptible to release for these
4-13
-------
same reasons. Other facilities in the area, or local and state environmental
officials, also can be contacted for information regarding unit failure mech-
anisms and frequency. As is the case vith other units, the data reviev pro-
cess should focus on identifying actual releases or combinations of factors
vhich could combine to increase the potential for releases to occur.
In general, the following factors increase the potential for releases
from tanks or basins to occur:
• Single-walled steel tanks are more likely to release than are
double-valled steel units.
• Unprotected steel units are more likely to release than protected
ones.
• The frequency of below ground tank or basin failure increases with
age.
• The frequency of underground tank failure increases as conductivity of
the surrounding soils increases.
• Steel units in contact with ground water are more likely to release
than units above the water table.
• The frequency of leaks from concrete units increases with the size of
the unit.
• Poor operating and maintenance procedures increase the potential for
failure.
Leachate from Unllncd Impoundments, Ponds, and Lagoons
Unlined units are presumed to release constituents to the unsaturated
zone and possibly to ground water. Therefore, making a release determination
is a matter of identifying the presence and type of a base liner at a unit.
Design and construction records will identify materials used and specifica-
tions of any bottom liner. A visual inspection will confirm unit construction
information, and indicate the level of upkeep and maintenance given the unit.
In general, units excavated into native soils that are not prepared will have
a higher rate of exfiltration and an increased potential for affecting ground
water than will units vith compacted clay or soil bases.
4-14
-------
Some units may be constructed with engineered features that reduce or
eliminate the potential for release. These features act to remove leachate
and prevent release, and provide actual evidence a unit is not releasing con-
stituents. These features include:
• Leachate collection systems over a primary soil base.
• Leachate collection systems between a primary and secondary soil base.
• Leachate collection/leak, detection systems under soil bases.
The first system acts to remove liquids as they are generated and begin
to migrate through the soil liner. These units will be found primarily at
landfills or drying/dewatering beds. The second system serves as a detection
system yarning the operator that a primary base has failed, and acts to remove
the liquids as they accumulate and before they can move through the secondary
base. The final system acts as does the second system, but the lack of an
underlined to reduce the rate of infiltration reduces the effectiveness of the
system. The latter tvo systems are used at landfills and impoundments, ponds
and lagoons. In general, the potential for release is negligible at those
units where leachate is removed as it is generated, or where leak detection
systems provide evidence releases are not occurring. Investigators must
determine that these engineered features are properly designed and maintained
before assigning a unit a low release potential.
Leachate/Runoff from Sludge and Ash Processing or Disposal Units
Sludge and ash processing, use or disposal units Include tanks, piles,
lagoons, incinerators, and landfills. Previous discussions on releases from
tanks and basins should be referred to when these type units are being
evaluated. This section will discuss leachate/runoff releases from sludge/ash
piles and landfills.
The potential for release from these units depends on the quantity of
leachate generated and the adequacy of containment. Units that generate large
quantities of leachate are more likely to have releases through liners than
are units generating little leachate. Large quantities of leachate ponded at
the base of a unit can create large hydrostatic pressures that will result in
4-15
-------
a break-out unless containment is specifically designed to handle the pres-
sures. Units where daily cover, run-on diversion structures or caps are in
place to divert infiltration will generate less leachate by reducing the quan-
tity o£ water that will enter the unit and contact wastes. In general, land-
fills that manage ash exclusively will generate less leachate, and the primary
source of leachate will be incident precipitation. Sludge units, and mixed
ash and sludge units, will generate larger quantities of leachate because of
the increased liquid content of sludges.
The extent of containment at sludge/ash processing units will also affect
the potential for releases to occur. Unlined units are presumed to leak
unless engineered features that eliminate the potential for release are in
place (refer to Section 4.2.2.2). Synthetic liners and concrete bases, if
designed and constructed properly and assuming the unit is veil operated and
maintained, will have a low potential for release. However, the potential for
releases to occur, either because of seal splitting or liner rupture, or be-
cause of cracks developing in concrete, increases with age. Release potential
also increases with unit size, because the potential for improper site prep-
aration or liner or base construction increases.
In assessing a release from sludge processing units, design, construction
and operating records vill identify vaste types handled; containment design,
type, and construction; and operating practices. A visual inspection will
confirm unit construction and operation information, and vill indicate the
level of upkeep and maintenance for the unit. Evidence of leachate generation
such as ponded liquids vithin a fill area, or leachate seeps and breakouts
along the base and sides of the unit, also vill be collected during the VS1.
At active units, bases or liners usually vill not be visible during the VSI,
so design, construction and operating information must be used to estimate the
likelihood of liner or base failure.
In general, the following factors increase the potential for releases
from sludge/ash processing units:
4-16
-------
• Unlined units are presumed to release constituents via infiltration.
• The potential for releasing constituents through the liner increases
as the quantity of leachate generated increases; sludge units without
precipitation control/diversion structures will generate the largest
volumes of leachate.
• The potential for release of leachate increases vith unit age and
s ize.
• Units where leak detection systems have confirmed leaks through
primary or secondary units will have a higher potential for release
then will units where systems have not detected .a breakout.
• Poor operating and maintenance procedures increase the potential for
liner failure.
Leaks in Sever Pipes and Other Equipment
Underground pipeline leaks throughout the U.S. have been well documented.
However, obtaining information to determine the potential for underground
pipes or conduits to leak is difficult. In general, the potential for
exfiltration from sever pipes increases vith age. During an RFA, there is
little that can be done to evaluate pipeline leaks. Hovever, if ground-vater
contamination is confirmed at a POTV, than leakage from pipes and other
belov-ground conduits should be investigated as a potential source.
4.1.3 Data Required to Assess Unit Characteristics Affecting Potential for
Releases to Ground Vater and Soil
In summary, the design, construction, and operation of a unit controls
the potential for the unit to release hazardous constituents to ground vater
and soil. In assessing the potential for release, investigators should focus
on the type, extent, and upkeep of containment features that are intended to
prevent release. Unlined units or units vithout runoff/runon control or
containment features are presumed to leak. Units vhere there is documented or
visual evidence of a release also vill have a greater potential to release.
In other cases, the available unit information must be examined to identify
possible release mechanisms and the potential for release.
Unit data that should be evaluated vhen assessing the potential for re-
leases to ground vater or soils include:
4-17
-------
• Unit age and size.
• Design and construction records, including foundation/size preparation
data.
• Containment design and construction data, including materials, used,
extent, and calculations used in designing structures.
• Operational records and SOP manuals
• Maintenance and inspection schedules.
• Maintenance (both scheduled and nonscheduled) records.
• Release reports.
• Sampling results.
Specific unit information and its use in making release determinations depend-
ing on the possible release mechanisms and unit type are discussed in Sections
4.2.1 and 4.2.2.
4.2 VASTE CHARACTERISTICS AFFECTING POTENTIAL FOR RELEASE TO GROUND VATER AND
SOIL
Vaste constituent properties will affect the migration rates of constit-
uents once released, the potential for intermedia (e.g. from soils to ground
vater) migration to occur, and sometimes, the potential for a release. Waste
constituents managed at individual units will be identified during the prelim-
inary review or visual site inspection phases of the RFA.
4.2.1 Vaste/Constituent Properties Influencing Movement Through Soil and
Ground Water
Constituents migrate in different forms and at different rates in soil
and ground water, depending upon their properties. Releases of organic con-
stituents will behave differently than will releases of metals. Therefore, a
constituents nobility oust be evaluated to determine its potential for dis-
persion and its tendency for transfer to other media. Also, constituent
mobility and persistence will guide selection of sampling locations and para-
meters. Mobile, persistent constituents will migrate farther and remain in
4-18
-------
the environment longer than less mobile, easily degradable ones, and may be
more likely to impact receptors than less mobile, readily degraded
constituents.
Vaste or constituent properties affecting release potential or transport
through soils and ground vater include:
• Waste physical state
• Constituent concentration in vastes or soils
• Solubility
• Octanol/vater partition coefficient
• pH
t Persistence.
These properties are discussed belov.
Vaste Physical State
The physical state of a vaste (i.e., whether it is solid, liquid, gas, or
some solid-liquid mixture) influences the potential for constituent transport.
The physical form of a vaste affects the nobility of vaste constituents in the
environment and their potential to migrate betveen media. For example,
spilled sludge-like, insoluble vastes vill not move overland as quickly as
liquid vastevater. Therefore, insoluble constituents in sludge are more
likely to remain in the immediate vicinity of a unit, rather than percolating
dovnvard to ground vater or floving across the land surface to surface vater.
Constituents in liquid vastes are more likely to migrate to soil or ground
vater than are constituents in sludges.
Vaste Constituent Concentration
The concentration of constituents in a vaste usually does not influence
the release potential at a unit. However, if there has been a release or
there is potential for release based on a unit's physical characteristics
(e.g., a possible leaky liner) then a vaste vith high constituent levels vill
be of greater concern than a vaste containing lov concentrations both because
of the higher risk associated vith exposure to higher concentrations, and
4-19
-------
because higher concentrations vould migrate over larger distances. A waste
vith high levels of hazardous constituents released to soils will cause high
levels of the same constituents to occur in the recipient soils.
Solubili ty
Vater solubility is a chemical property that indicates the constituents
affinity for vater, and indicates the sorption of chemicals to soils. Highly
water-soluble compounds tend to move rapidly through soil because they dis-
solve and move vith vater rather than adsorbing to soil particles. Insoluble
compounds, therefore, will remain in the soil matrix and thus vill accumulate
in soils to a much greater extent than soluble compounds. Knowledge of chemi-
cal solubility can be very useful in determining the release and migration
potentials at a particular site. If a compound is highly soluble, ground
vater vill require further investigation.
Octanol/Vater Partition Coefficient
The sorption equilibrium coefficient (Kd) is a quantitative expression of
the mobility of organic constituents. Kd depends on the organic content of
soils and the constituent-specific soil adsorption coefficient (Kac)> During
the RFA, the inherent mobility of a constituent as measured by Koc vill be
more useful because site specific information on soil organic content likely
vill not be available. However, fev Koe values have been developed for
hazardous constituents. Instead, the octanol-vater partition coefficient
(Koh) can be used to approximate mobility. A large Ko- indicates that a
constituent is likely to be relatively immobile (i.e., vill not migrate far
through soils), while a small Kow indicates that a constituent is likely to be
mobile.
Most Katf values are expressed in log form. In general, constituents vith
a log Kow of sore than tvo should be considered relatively imaobile, and
likely vill not migrate far through soils. Kow values are provided in
Appendix C.
£§
The pH of a waste may affect contaainant release and migration in tvo
vays:
4-20
-------
• It can alter the chemical form of acids and bases, metal salts and
other metal complexes, thereby altering their water solubility and
soil sorption properties and making them more or less mobile.
• It may alter the soil's chemical or physical makeup, leading to
changes in sorptive capacity and permeability.
Therefore, obtaining data on the pH of unit-specific wastes can be very impor-
tant because of this property's effect on other vaste and soil characteris-
tics. For example, a compound's affinity for soil particles may be either
increased or decreased, thereby affecting the release and migration potential
in local soils. This situation, however, is probably unlikely at most POTVs
because the wastes handled are characteristically highly diluted, having rela-
tively neutral pH values between 8.0 and 6.0. Outside this range, investiga-
tors should consider the possible effects of high or low pH on constituent
mobility.
Persistence
The persistence of a compound in soils is an indirect function of its
biodegradability, which is a compound's capability of being broken down into
innocuous products by microorganisms. The greater a compound's biodegrad-
ability, the less persistent it is in the environment. Appendix C provides
data regarding the biodegradation rates for constituents within POTV treatment
systems. This data can be used as a general indicator of the rates compounds
will degrade in the environment; compounds that are not very persistent in the
POTV will tend not to be persistent in the environaent. As an alternative,
the Hazard Ranking Systea of the National Contingency Plan evaluates the per-
sistence of compounds based on biodegradability, and can be used to evaluate
the persistence of coapounds. Metals are usually a good Indicator of releases
to soils because of th«ir relatively lov mobility and high persistence.
Relatively persistent coapounds that are also insoluble in water will be
expected to reaain in the soil matrix for a auch longer period of time than
those compounds that biodegrade relatively rapidly. A release to soils of a
waste containing persistent coapounds is more likely to result in long term
soil contamination than a release involving nonpersistent coapounds.
4-21
-------
4.2.2 Data Requirements for Assessment of Vaste Characteristics
The assessment of vaste characteristics for units examined during a POTV
RFA requires certain types of data. These data are available from a number of
sources, most of vhich have already been discussed in Chapter 3. The initial
sources of information that should be examined are the facility files and
records. Facility records will indicate waste constituents managed at the
facility and waste analysis data, vhich will contain some data on waste char-
acteristics (i.e. waste physical state, constituent concentrations, and pH).
From the information available in facility files, data gaps can be identified
for which other sources of information can then be researched. Chapter 3
should be referred to for sources of data on the other vaste characteristics
affecting potential release and migration.
4.3 ASSESSMENT OF MIGRATION POTENTIAL OF RELEASE TO GROUND VATER OR SOIL
The rate of constituent movement across land surface, through the unsat-
urated zone, and in ground water vill determine the extent of the areas
affected by a release. Vater is the primary mechanism transporting constitu-
ents through the environment. Therefore, the flov rates and patterns of water
at a site must be examined during the RFA evaluation estimating the extent of
a release. Soil and hydrogeologic factors vhich usually can be evaluated
during a RFA and vhich affect the migration potential of releases to ground
water and soil are discussed belov.
4.3.1 Soil Characteristics
Hazardous constituents in vastevaters and sludges are released to soils
either as surface flovs (e.g., in spills of vastevaters and sludges, or in
sludges spread across land surface) or as Infiltration (e.g., in vastevaters
exfiltrating froa basins, or in contaainatlon precipitation percolating
through tha unsaturated zone). Assessing the extent of surficial releases is
relatively straightforvard. Surficial releases vill follov drainage patterns,
and any areas over vhich released wastes have moved vill be affected. Hov-
ever, the concentrations found in soils vill depend on the size of the release
and initial concentrations, absorptive capacity of the soils, drainage pat-
terns, distance from the release point, length of time since the release, and
4-22
-------
amount and type of degradation that has taken place. In general, site drain-
age patterns (i.e., topography) and size of the release control the extent of
surface soils affected by a release.
Assessing the extent of release to subsurface soils is more difficult
because the migration paths through the unsaturated zone cannot be directly
observed, and because a number of factors influence the migration of hazardous
constituents through the subsurface. Vater movement through the unsaturated
zone is very complicated. Vater applied at the land surface or released to
near-surface soils, as in the case of a leaking surface impoundment, will move
depending on the relative strength of forces which act to pull liquids back
towards land surface, bind water to soil particles, or drav vater dovn towards
the vater table. Evaporation and evapotranspiration remove vater from the
portion of the unsaturated zone nearest land surface. Capillary forces hold
vater to soil particles and slov or prevent vater movement. Gravity pulls
vater dovn through the unsaturated zone towards the vater table. These forces
act in varying strengths throughout the unsaturated zone, resulting in high
variability in moisture content and rate of vater movement throughout the
zone.
Assessing the exact effects of the various factors influencing the rate
of migration through the unsaturated zone is not required during an RFA.
Information that can be used to estimate the relative magnitude of these vari-
ous factors, thereby estimating the relative migration potential of a release
through the zone are described belov. In general, there is a net downward
movement of moisture in the unsaturated zone in all but the most arid areas.
Therefore, investigators should assume that releases to the unsaturated zone
have a high potential to migrate and enter ground vater. The factors
discussed btlov can be used to modify this assessment.
Topography
Topography controls the drainage patterns at a site, and also can be used
as a first order approximation of the configuration of the ground-water table.
Therefore, topography will control the migration path of a surficial release,
and also vill indicate the general direction of ground-water flow (i.e., from
4-23
-------
areas of higher to lover elevations). The migration path of a surficial re-
lease will identify the zones of likely surface and subsurface soil
contamination.
Published topographic maps shoving small scale topography are available
from the state or U.S. Geological surveys. In addition, design and construct-
ion records should include site-specific, larger scale maps shoving topography
before and after construction. In using topographic maps, the investigator
should note the publication or revision date on the map, and note any changes
made to the site since that date. These maps also can be used to identify
potential migration paths, ground-vater discharge areas (e.g., streams,
rivers, lakes, or ponds), other receptors, or other potential sources vhich
might affect sampling results or environmental quality.
Soil Classification and Surficial Geology
Soils at the site should already be classified according to the U.S.
Department of Agriculture Soils Classification System (SCS). This system
identifies soils based on physical and chemical properties of the soil
profile. From a SCS series name, soil scientists can derive information on
soil structure, climate, surface slope, and other factors relevant to
contaminant transport.
Many surficial geology maps will describe the thickness, depth and tex-
ture of subsurface materials, the presence of saturated zones, and possibly
other hydrogeologic features. Published surficial geology maps are available
from the State and Federal geological surveys. Hovever, soil boring informa-
tion gathered during foundation testing conducted prior to construction will
provide the beat information on subsurface conditions at a site. In many
instances, engineering test firms vill construct subsurface cross sections
from these borings, and these cross sections may indicate the depth to vater,
soil permeability, or other valuable information.
Hydraulic Conductivity
An essential physical property affecting contaminant mobility in soil is
the hydraulic conductivity, also called the coefficient of permeability. This
4-24
-------
property indicates the ease with which liquids vill flov through the soil, and
is dependent on the porosity o£ the soil, grain size, degree of consolidation
and cementation, and other soil factors, as veil as on the viscosity of the
liquid. Foundation testing records may indicate the permeability of soil
samples collected prior to construction. If grain si2e distribution tests
were conducted on cases, then permeability can be estimated using tables pro-
vided in many standard hydrogeology texts or reference books. If available
data limited to borehole records and drillers descriptions, an approximate
permeability can be determined again using tables in standard references.
Organic Carbon Content
The amount of natural organic material in a soil has a strong effect on
retention of organic pollutants. The greater the fraction, by weight, of
organic carbon (foe)» the greater the adsorption of organics. Soil foc's
range from under 1 percent for a clean sand to over 50 percent for a peat
soil. In general, the amount of natural organic material can be estimated
using soil classification descriptions and standard soil science references.
4.3.2 Hydrogeologic Characteristics
Assessing the extent of releases in ground water requires information on
ground-water flov rates and direction. In most cases, detailed hydrogeologic
information vill not be available at POTVs. Therefore, investigators vill
have to use available data and make assumptions to estimate the potential for
and extent of a release.
Estimating the direction of ground-vater flov at POTVs generally is
simplified because of nearby surface vater bodies such as streams or rivers.
Host perennial streass and rivers represent discharge zones for ground vater;
ground vater flows into and provides the base flov for the vater body. In
these cases, ground vater under the POTV is moving towards the vater body.
Hovever, during storas, the levels in streasa and rivers can Increase faster
than the vater table can rise, and vater vill flov into ground vater.
Eventually, the river levels vill recede and normal ground-vater flov condi-
tions vill return to normal. These scenarios are illustrated in Figure 4-1.
4-25
-------
LOCAL ANO REGIONAL GROUNO WATER
PLOW SYSTEMS IN MUMIO ENVIRONMENTS
TEMPORARY REVERSAL op GROUNO-WATJ¦ »(.OW out TO
PLOOOING OP A river OR JTRgAM
tyucal GROUND-WATER »lOW paths IN ARIO environments
I I llti.lirtttAt >Mlf f'QM |T|iaii«N
| I mt, 0< mi "•< '«cn M iiw
I t
' I
9
¦
FIGURE 4-1
4-26
-------
In arid regions, some vater bodies may recharge ground water. This
scenario also is illustrated on Figure 4-1. In these cases, identifying the
direction of ground-vater flov will be difficult and may require site-specific
data.
Estimating the rate of ground-vater flov requires site-specific data that
likely will not be available at POTVs. In general, a release to ground water
should be assumed to have flowed tovard, and entered, nearby surface water
bodies. Detailed discussions of ground-vater flov theory are available in any
hydrogeologic text as a reference. EPA's Guidance Document on Leachate Plume
Management (EPA/540/2-85/004, Nov. 1985) contains a brief discussion on
methods to assess the extent of a ground-vater release. Information useful in
assessing the rate and direction of ground-vater flov are described below.
Subsurface Stratigraphy
In order to characterize the hydrologic setting of a site, site geology
must be analyzed. Geologic site characterization consists of both a charac-
terization of subsurface stratigraphy, which includes soil and unconsolidated
sediment cover analysis. Bedrock features include features such as lithology
and structure, as veil as depositional information, indicating the sequence of
events which resulted in the present subsurface configuration. In general,
porous materials (e.g., sand, salt, and clay) vill be the materials most often
found at POTVs. Ground vater in these media flov towards nearby discharge
areas such as rivers and streans.
Direction of Plow
A thorough understanding of flov direction vill require site-specific
veil data. In unconsolidated materials likely to be found under POTVs, the
vater table vill approxiaate land surface topography; ground vater vill flov
generally ia the direction o£ decreasing topography and towards discharge
areas.
Hydraulic Gradient
The hydraulic gradient is defined as the change in static head per unit
distance in a given direction. The hydraulic gradient defines the direction
4-27
-------
of flov and may be expressed on naps of water level measurements taken around
the site. Ground-water velocity is a function of hydraulic gradient. The
hydraulic gradient can only be determined from veils located onsite.
Hydraulic Conductivity
A measure of the ability of an aquifer material to allov vater to flov is
the hydraulic conductivity (K). Hydraulic conductivity is the volume of vater
that will move per unit time under a unit hydraulic gradient through a unit
area measured at right angles to the direction of flov. K has the dimensions
of length divided by time (commonly expressed in feet/day or centimeters/
second). Table 4-5 lists ranges of values for K for various geologic mate-
rials. This table can be used as a relative indicator of the rate of ground-
water flov under a site. Water can flov faster through materials vith higher
hydraulic conductivities.
Depth to Ground Water
The depth to ground vater is the distance from land surface to the vater
table. In general, the deeper the ground vater, the longer contaminants will
require to move through the unsaturated zone to ground vater. Depth to vater
can be measured by veils located onsite. The potential for ground-vater con-
tamination increases as depth to ground vater decreases.
4.3.3 Existing Soil and Ground-Water Monitoring Data
Soil and ground-vater monitoring data likely will not be available for a
POTV. However, other, nearby facilities required to monitor soils and ground
vater may provide information on soil and ground-vater quality, and hydroto-
logic conditions. These sources include subtitle C land treatment, storage or
disposal facilities; aunicipal vater utilities operating veil fields; subtitle
D landfills) and CERCLA sites. If soil or ground-vater monitoring data is
essential in completing an RFA, onsite borings or monitoring veils will be
required. EPA's Technical Enforcement Guidance Document describes monitoring
veil installation and sampling procedures that should be followed.
4-28
-------
TABLE 4-5. RANGE OP HYDRAULIC CONDUCTIVITY VALUES FOR VARIOUS
GEOLOGIC MEDIA (After Freeze and Cherry, 1979)
Geologic
Material
Gravel
Sand, veil sorted
Silty sand
Silt
Clay, unveathered
Glacial till
Carbonate rocks
Sandstones
Shales
Crystalline rocks
Highly fractured
Relative unfractured
1 gal/day/sq.ft. ¦ 1.74 x 10~s ft/day
1 gal/day/sq.ft. * 4.72 x 10~5 cm/sec
Hydraulic Conductivity
cm/sec gal/day/sq.f t.
10*
- io7
10
- 10s
1
- 104
10"2
- 10*
10"5
1
1—»
o
1
Kl
1
O
o
1
1
o
rH
- 105
H
o
1
o
rH
1
10" 6
1
o
1
1
o
H
1
o
Ui
10"7
n
1
o
1
10"1 - 102
10"4 - 1
10"5 - 10"1
10"7 - 10"3
10"10 - 10"7
10'10 - 10*4
10"7 - 1
10"8 - 10"4
10"11 - 10"7
10"S - 1
10"lJ - 10*1
4-29
-------
4.3.4 Data Requirements for Assessment of Migration Pathways for Releases to
Ground Water or Soil
In general, the best information will be provided by site foundation soil
borings, and nearby facilities or sources required to monitor ground-water
quality. Local, State, and Federal sources will provide general area infor-
mation, but probably will not supply necessary site-specific information.
4.4 SAMPLING TECHNIQUES FOR GROUND VATER AND SOIL
The following section discusses assessment oE the need for sampling and
the selection of sampling parameters, sampling locations, and appropriate
sampling procedures for ground water, soil, and wastes.
4.4.1 Assessment of the Need for Sampling
An investigator likely will need sampling data in the following
ins tances:
• Releases are suspected as probable at a unit, but the constituents
managed in the unit are not known.
• Releases are suspected as possible, but the presence of constituents
in the environment is not confirmed.
• Releases are observed or confirmed, but the constituents released or
remaining are not known.
At a POTV, the investigator should assunc that hazardous constituents entering
the facility are present in all units. However, concentrations of constit-
uents will vary fron unit to unit.
Samples froe possible migration paths may identify constituents and con-
firm that releases have occurred. This evidence usually will be sufficient to
require a facility to conduct an RFI. These saaples can also Identify con-
stituents regaining in soils from past releases, and indicate if the release
is a potential problem. Pinally, media samples will indicate the relative
threat posed to other media and receptors. The decision on the need for sam-
pling depends on site-specific conditions and the amount of information an
investigator believes is necessary to confirm or deny a release has occurred
and may be a possible hazard.
4-30
-------
A.A.2 Selection of Sampling Parameters
The selection of sampling parameters will be based on the media to be
sampled and the purpose of the sampling. In cases where a waste requires
further characterization, an extensive array of parameters may be selected
{i.e., Appendix VIII of 40 CFR Part 261). In other situations, a subset of
the Appendix VIII parameters may be more appropriate. Analytical parameters
selected for ground water and soil sampling vill be based on the composition
of wastes known to be managed in the unit under investigation, or known or
suspected to have been released at the site. Depending upon hov much informa-
tion is available on the waste and/or release characteristics, sample param-
eters may include nonhazardous constituents which may indicate the presence of
hazardous constituents, (i.e., indicator parameters) or specific hazardous
constituents. Nonspecific indicator parameters include: pH, total organic
carbon (TOC), total organic halogens (TOX), and specific conductance. Spe-
cific hazardous constituents may include any chemical constituent, including
constituents such as toluene, benzene, or heavy metals.
Indicator parameters are used most often in cases where the composition
of the wastes is unknown or sufficient detail on their constituents is un-
available. These types of parameters will simply indicate whether there has
probably been a release. Indicator parameter values must be compared to back-
ground sample values in order to determine if there is a significant differ-
ence between background and the suspected release location. Indicators alone
may not be sufficient to characterize a release, since the natural background
variability of indicator parameters can be quite high.
Analyses for specific hazardous constituents should be used whenever
possible because they are direct confirmation of a release. The selected
parameters should be waste-specific subsets of hazardous constituents from 40
CFR Part 261 Appendix VIII. In developing a list of saapling parameters, the
following factors should be considered:
• The nature of vastes to identify mobile and persistent constituents.
• The detection limits of parameters.
4-31
-------
• The effects of soil and unsaturated zone (if present) characteristics
on the mobility, stability, and persistence of the waste constituents.
Selected sampling parameters should be representative of constituents at least
as mobile as the most hazardous constituent reasonably expected to be derived
from a unit's vaste. In addition, the constituents selected should include
those persistent in the media being sampled.
4.4.3 Selection of Sampling Locations
The selection of sampling locations vill be based on the location and
accessibility of vater veils at the facility, the location of ground-vater
seeps/springs, the visible extent of a release (i.e., soil staining; dead
vegetation), and potential migration paths. In cases where constituents
present in wastes must be identified, samples vill be collected from specific
vaste management units at locations where high concentrations are expected.
Most POTVs do not have ground-vater monitoring veils in place, and new
veils usually vill not be installed during an RFA. Therefore, the locations
of veil sampling points vill depend on where drinking vater and other produc-
tion veils are located at and around the facility. If there has been either a
confirmed release or there is reason to suspect there has been a release at a
unit that may affect ground vater, veils located dovngradient from the point
of release should be sampled. In addition, saaples should be collected from
locations upgradient from the suspected release point to obtain background
ground-vater quality data. The background data can then be used for compari-
son purposes. If veils are not available for saapling, then ground-vater
seeps or small springs, if available, can be saapled.
Soil saapling likely vill be conducted much aore frequently at POTV
facilities than ground-vater saapling. Location of soil saaple collection
points vill be based on the unit location, the knovn or suspected extent of
the release, the topography at the site, (i.e., where surface runoff drains)
and the visible signs of release such as stained soil and lack of vegetation.
The number of soil saaples taken around a specific unit vill depend on the
size of the unit, the suspected voluae of released substance, and the mobility
of the hazardous constituents. The more extensive the release is believed to
be, the more points should be sampled.
4-32
-------
In addition, background soil samples should always be collected. A back-
ground area should be selected based on its similarity to the study area in
terms of soil type, drainage, stratigraphic location, and other physical char-
acteristics. Background soil samples should be taken from areas that are not
near a suspected source of contamination. Selection and sampling of approp-
riate background areas is very important because confirmation of a release
vill be based on the comparison of the study area soil results and the back-
ground levels. Most often a single background sample is sufficient for one
facility unless there is information available that indicates that background
soil quality varies across the facility property. In these cases, multiple
background samples may be necessary.
4.A.4 Appropriate Procedures for Ground-Water and Soil Sampling
Ground-vater sampling vill probably not be conducted at most POTV facili-
ties. Therefore, a detailed discussion on ground-vater sampling procedures is
not provided here. The investigator is instead referred to procedures that
are set forth for ground-vater sampling in Test Methods for Evaluating Solid
tfaste-Physlcal Chemical Methods (SV-846), and the RCRA Ground-Water Monitoring
Technical Guidance Document (0SVBR-9950.1). The appropriate methods and tech-
niques for ground-vater sample collection, preservation, and handling during a
POTV SV are presented in these two documents.
There are tvo basic types of soil sanpling techniques that can be used in
collecting soil and vaste samples as part of a POTV saapling visit. A grab
sample is defined as a single representative sample of a specific location at
a given point in tiae. Vhen a source is known to vary vith location or dis-
tance from the sourct, grab samples collected at suitable locations and ana-
lyzed separately can indicate the extent of these variations. Coaposite saa-
ples are combinations of sore than one sample collected at various saapling
locations and/or different points in tiae. Primarily, analysis of composites
yield average values and can, in certain instances, be used as an alternative
to analyzing a number of individual grab samples and calculating an average
value. It should be noted, hovever, that compositing can mask problems by
diluting isolated concentrations of some hazardous constituents to belov
detection limits, or to belov Halts of concern.
4-33
-------
Surface samples or shallow subsurface methods will often be used during a
RFA. Deep drilling or coring usually will not be required during an RFA.
Sampling in the upper soil zone can be accomplished with a variety of simple
tools, including shovels, spatulas and soil punches. Contaminants that have
moved downvards in the soil profile require tools such as tube samplers and
augers. Depending on soil conditions manually operated tools are useful to 20
feet below land surface. Below this, hydraulically or mechanically driven
equipment is needed. The RCRA Ground-tfater Monitoring Technical Guidance
Document (OSWER-9950.1) or the Test Methods for Evaluating Solid Vaste-
Physical Chemical Methods (SV-846) provide detailed descriptions of soil
sampling procedures.
4.5 ASSESSMENT OF POTENTIAL EXPOSURE DUE TO RELEASES TO GROUND WATER OR SOIL
Many hazardous constituents have been identified or listed as hazardous
due to their adverse effects in humans, other organisms, and/or the environ-
ment. These effects can be acute, chronic, or subchronic, depending on the
level of exposure. Many substances also affect reproduction, or are suspected
of being carcinogens. Constituents can also enter the food chain through
plant uptake or ingestion by organisms. In various concentrations, constitu-
ents can kill vegetation and aquatic organisms, or poison a soil so that
plants or crops will not grow. The type of effects and the concentration
level that causes the effects depend on the specific constituent and the
target receptor; similar organisms can have widely different reactions to the
same compound.
Determining the risk to the target population of a given set of constitu-
ents requires a very coaplex, specialized study and should not be conducted
during an RFA. Instead, an investigator should assuae that there will be an
adverse impact to any receptor exposed to a hazardous constituent released
from a unit. In conducting the RFA, the inspector should focus on identifying
the potential receptors along possible release paths, and assuae they will be
at some risk if exposed to the hazardous constituent. Suggestions for identi-
fying potential receptors and possible effects are provided below.
4-34
-------
4.5.1 Potential Effects on Human Health
The primary risk to human health from releases to soils and ground vater
is posed by ingestion of contaminated drinking water and contaminated crops
and organisms. For the RFA, an investigator need only determine the potent ial
for a release to reach drinking vater supplies or enter the food chain. This
potential depends primarily on the location of possible receptors. A greater
potential for adverse effects exists when receptors are located near release
points.
Drinking vater veils likely will not be located dovngradient of units at
POTVs located along streams or rivers because, in most cases, the direction of
ground-vater flov is towards the surface vater and the only activities likely
to be conducted betveen units and the river are related to the POTV. However,
contaminated ground vater is more likely to discharge to and affect surface
waters. As a result, investigators should assess the potential impacts of
contaminated ground vater discharged to surface waters (see Section 5.6).
In assessing the potential for a release to ground water to enter drink-
ing water systems, an investigator first must determine the locations of vater
supply wells near the POTV. Veils dovngradient of the POTV obviously are at
risk, with those closest to the units at greatest risk. Veils that are close
to the POTV but apparently upgradient (e.g., the POTV is located betveen the
well and a river towards which ground vater is flowing) also may be at some
risk because:
• During floods or periods of high flov, the level of the river rises
and can locally change vater table elevations close to the river so
that vater flovs avay Eros the river; wells upgradient of the site nay
be at risk during these periods (refer to Section 4.5.2).
• Largv veils or vellflelds can locally alter ground-vater flov con-
ditions so that vater is flowing from the surface vater tovards the
veil.
A third class of veils possibly at risk are those located downstream from a
POTV that is releasing constituents to surface water either directly or in
contaminated ground vater. Many wells alongside rivers drav significant
quantities of vater fro# the river. The locations of drinking vater veils
4-35
-------
around the POTVs, including veils upgradient, dovngradient, and downstream,
should be identified during the PR.
In assessing risk, investigators should assume that the nearest dovn-
gradient veils will be affected by a release to ground vater, unless suffi-
cient hydrogeological information is available to calculate flow rates and
determine flow directions. The assumption that dilution and degradation vill
reduce the concentrations of released constituents to acceptable levels should
not be made during the RFA. Dilution may not be a significant process affect-
ing leachate plumes resulting from a continuous release (e.g., exfiltration
from an impoundment) and while degradation may reduce concentrations, even low
levels of certain compounds are hazardous. Dovngradient veils located vithin
a mile of a POTV that has potentially released hazardous constituents to
ground vater should be considered at risk. Their presence indicates that a
high potential for a release affecting drinking vater exists at the site.
Human health can also be affected if constituents enter the food chain.
Direct application to farmlands of sludge containing hazardous constituents
presents an immediate risk and may trigger an immediate response. Any surface
release has the potential for entering the food chain and affecting human
health. However, most human exposure routes other than by crop uptake are
based on constituents first entering surface vater or ground vater. The
potential for human health impacts caused by contamination of food supplies by
constituents in surface waters are discussed in Section 5.6.1.
In general, the following scenarios pose a high potential for human
health to be affected by releases to soil and ground vater:
• Direct application of sludge to croplands or areas topographically
upgradient from croplands.
• Drinking vater veils are located vithin one-mile dovngradient of
units.
• Drinking vater veils are located betveen POTVs and streams or rivers.
e Drinking vater veils are located upgradient of a POTV but topography
across the entire area is relatively flat, increasing the possibility
of gradient reversal during high surface vater flov conditions.
A-36
-------
• Large vellfields are located near POTVs (NOTE: the owners of large
wells or vellfields will have hydrogeologic test results available
which usually will identify the zone from which the well draws water,
which will indicate if the veil draws water from under the POTV).
• Large wellfields are located alongside rivers and downstream of a POTV
suspected of releasing constituents to ground water.
4.5.2 Potential Effects on the Environment
The potential effects of releases to soils or ground waters generally are
caused by direct toxicity or accumulation of hazardous materials. High con-
centrations of constituents can have immediate and lasting effects on plants
and animals, while low-levels can accumulate or be concentrated in the en-
vironment, or can slovly have an effect on populations. Populations most at
risk are those generally recognized as particularly sensitive.
Wetlands generally are regarded as the most sensitive habitat. Contami-
nants released to soils can migrate in runoff and enter wetlands. Vetland9
also can represent a recharge area for ground waters. Constituents entering a
wetland, either in surface runoff or ground water, can accumulate in plants
and animals that are a food source for birds. Documented losses of large
predatory species (e.g., hawks, eagles) are examples of the type of effect an
exposure to hazardous constituents can have.
In assessing potential effects of releases, investigators should identify
dovngradient receptor population areas such a9 wildlife refuges, sanctuaries,
and parks which may be affected by a release.
4.5.3 Data Required for Assessment of Potential Exposures Due to Releases to
Ground Water and Soils
The pretence of possible receptors along migration paths controls the
potential for exposure because of releases to ground water and soils. Migra-
tion paths are determined based on a number of factors as discussed in Section
4.3. The locations of the following receptors should be identified during the
PR and VSI:
• Public drinking water supply wells.
4-37
-------
• Private supply veils, including irrigation veils.
• Wetlands, protected environments, and parks.
• Farmlands.
Public health authorities can provide the locations of major vater supply
veils. The operators of the veils vill be able to provide hydrogeologic data
on the veils, indicate the recharge zone for the veil, and also indicate the
supply area served by the veil. Houses and businesses in areas not supplied
by municipal or public vater supply systems should be assumed to have private
veils. Local veil drillers vill also be able to indicate the area vhere pri-
vate veils are located, although they may not be able to provide specific
sites. Some counties and states have files (hard copy and computerized) that
list the locations of knovn supply veils. However, these registries usually
do not provide data on veils installed prior to the start of the registry, and
should not be considered comprehensive.
State resource agencies and environmental protection departments vill be
able to provide the locations of vetlands, protected areas, and parks. Many
of these areas are designated on topographic maps, and these maps also vill
indicate nondesignated receptor areas such as vetlands. Topographic maps vill
identify orchards, special farm areas and nondeveloped areas that could be
used for farming. Hovever, observations during the VSI vill likely suffice in
identifying farmlands possibly at risk from a release to soils. In areas of
extensive irrigation, investigators should assume that irrigation is provided
by ground vater.
4.6 ASSESSMENT OF SUBSURFACE GAS RELEASES
Subsurface gas generation and migration froa a waste management unit can
result in human health and environaental hazards, particularly if gaseous
materials, such as methane, go undetected for long periods of time and build
up to levels that may result in an explosion and/or fire. The most common gas
releases consist of oethana and carbon monoxide, which are most often produced
through the anaerobic decomposition of organics in landfills. Methane is of
particular concern due to its explosive/flammable properties. Other hazardous
4-38
-------
gases of concern are dependent upon the types o£ wastes managed, the volatil-
ity of the vaste constituents, temperature, and possible chemical interactions
among wastes.
The potential for a subsurface gas release to occur at a POTV facility
depends upon unit design and operation, vaste characteristics, gas generation
mechanisms, and gas migration barriers. Factors influencing the potential for
the release of subsurface gases are discussed in the following subsections.
4.6.1 Unit Design and Operation
Waste management units with a high potential for the release of subsur-
face gas are those that are partially or entirely belov grade, and receive
sludges. Units that pose the greatest potential for subsurface gas migration
include landfills, sites closed as landfills (e.g., surface impoundments or
waste piles vith impermeable covers), and underground storage tanks. Land-
fills and surface impoundments are the two types of units that may release
gases at POTVs.
Gas generated in landfills can vent vertically to the atmosphere and/or
migrate laterally through permeable soil. Closure of the landfill or periodic
covering of cells vith impermeable caps will impede the vertical movement of
the gases, forcing them to migrate laterally froa the unit. Gas migration
laterally through the subsurface (e.g., through underground utility lines or
sand lenses) may accumulate in structures on or off the site property. There-
fore, it is important that the investigator knov the type and design of each
unit of concern including the presence of liners, the vaste constituents
placed in the unit and their gas generation potential, and subsurface condi-
tions surrounding the unit prior to initiating a sampling program.
Gas generation and subsequent migration are likely to occur at units
closed as landfills. Although units such as surface iapoundaents and vaste
piles may be closed as landfills, they generally produce less gas than land-
fills because they contain saall quantities of decoaposable and volatile
wastes and are located at shallow depths. Closure of units using impermeable
covers will increase the potential for lateral gas aoveaant and accuaulation
in onsite and offsite structures.
4-39
-------
4.6.2 Waste Characteristics
In assessing the potential for gas release at a unit, the investigator
should determine whether wastes that can generate methane are present.
Anaerobic decomposition of organic wastes generates large volumes of methane
gas under the proper conditions. Vhen methane is generated at a unit that is
below grade and capped, there is high potential that the gas will accumulate
under pressure and migrate from the unit, thereby posing a significant risk of
explosion. Methane may also be mixed with other volatile hazardous constitu-
ents present in the unit depending on existing wastes, and may increase the
potential hazard associated with the accumulating gas.
Biological sludges are the primary waste type of concern for methane gas
generation. The volume of gas produced in a unit depends on the quantity and
types of refuse present. Higher volumes of methane will be generated at units
containing larger quantities of refuse. The volume of gas generated also
depends upon the age of the unit and hov long the waste has been 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 generation from units closed as landfills depends pri-
marily 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 nay 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 tim« of emplacement can also affect the
methane generation rate. Vastes placed in landfills in the winter at tem-
peratures balov 10*C may not generate methane for up to 5 years, even in
climates with vara summers, due to the Insulating properties of the waste.
The waste can remain at temperatures lov enough to effectively inhibit bac-
terial decomposition for several years.
The types of wastes disposed in a unit vill also affect the rate of
methane generation. Rapid decomposable vastes vill produce aethane at high
rates under the proper conditions. These vastes include those that vould be
4-40
-------
found in landfills and surface impoundments of POTVs (i.e., organic sludges
from wastewater treatment facilities). The high concentration of readily
degradable organic compounds in this type of vaste provides an ideal energy
source for the anaerobic organisms that produce methane.
4.6.3 Gas Generation Mechanisms
There are three potential gas generation mechanisms: biological decom-
position, chemical decomposition, and physical decomposition. The mechanism
that will play a role at any particular vaste management unit vill depend upon
the type of unit in question and the types of wastes managed in that unit.
Vlth regard to POTV facilities, biological decomposition vill probably be most
significant because the units in question vill generally include landfills and
surface impoundments containing organic vastes (e.g., sevage sludges).
Biological decomposition is significant in most landfills and units
closed as landfills due to anaerobic microbial degradation of organic vastes
such as sevage and treatment plant sludges. Generally, the anount of gas
generated in a unit is directly proportional to the anount of organic matter
present. Organic vastes such as sewage sludges decompose rapidly resulting in
gas generation shortly after burial with high initial yields. Much slower
decomposing organic vastes include paper, cardboard, vood, leather, some tex-
tiles, and several other organic components. Inorganic and inert materials
such as plastics, man-made textiles, glass, ceranics, metals, ash and rock do
not contribute to biological gas production. However, these types of vastes
are not typically nonaged at POTV facilities.
Vaste characteristics can increase or decrease the rate of biological
decomposition. Pactors that enhance anaerobic decomposition include: high
moisture cootant, adequate buffer capacity and neutral pH, sufficient nutri-
ents (nitrogan and phosphorus) and moderate temperatures. Characteristics
that generally decrease biological deco>position include: the presence of
acidic or basic pfl, sulfur, soluble aetals and other aicrobial toxicants. The
investigator should review the vaste characteristic information to estimate
the rate of biological decomposition and subsequent gas generation.
4-41
-------
Under anaerobic conditions organic vastes are primarily converted by
microbial action into carbon dioxide and methane. Trace amounts of hydrogen,
ammonia, aromatic hydrocarbons, halogenated organics and hydrogen sulfide are
also present. With respect to subsurface migration, the gases of concern are
methane (because of its explosive properties) and other volatile organics that
may be present in amounts hazardous to human health or the environment.
4.6.4 Gas Migration Barriers
There are two types of gas migration barriers: natural barriers and
engineered barriers. Natural barriers include surface water, ground vater,
and geologic formations. Engineered barriers include walls, onsite struc-
tures, and underground structures, caps, and liners.
Natural Barriers
Surface water, ground water, and saturated soils can slow down or prevent
subsurface gas migration. Gases encountering these barriers will follow the
pathway of least resistance, usually through unsaturated porous soil. Geo-
logic barriers can also slow down or prevent subsurface gas migration. Soil
permeability is perhaps the most important natural barrier to gas migration.
„ Gravels and sands allow gas to migrate freely, while clayey gravels and sandy
and organic clays impede its movement. The location of natural barriers
should be used to establish the location of air monitoring and/or sampling
points.
Engineered Barriers
Landfills and units closed as landfills may use caps and liners to pre-
vent moisture infiltration and leachate percolation to ground water. Caps
also can contribute to lateral gas movement when upvard migration to the sur-
face is restricted. Liners tend to impede lateral migration into the sur-
rounding unsaturated soils. The ovner/operator should evaluate cap/liner
systems (type, age, location, etc.) to determine if gas migration could occur.
Similar to liners, slurry walls are used to border landfill units and can
contain lateral gas movement. Vith respect to underground tanks, caps and
liners are not typically used. These tanks are often placed into soils with
backfill during installation, followed by paving on the surface. Thus, any
4-42
-------
escaping gases from a leaking underground tank may migrate laterally along the
path of least resistance adjacent to the units.
4.6.5 Assessment of Releases
During a sampling visit at a POTV facility, the investigator should ex-
amine available sources of information' to identify evidence that subsurface
gas has migrated from a unit. Host evidence of subsurface gas releases vill
usually be limited to reports of explosions at or near a unit. In some cases,
there may be sampling information taken from vents placed near the units
indicating the presence of methane in a unit. Under most circumstances, the
investigator should assume that units generating methane have a high potential
for gas migration and possible explosion.
4-43
-------
5. ASSESSMENT OF POTV RELEASES TO SURFACE WATERS AND SEDIMENTS
This chapter covers the assessment of releases of hazardous constituents
from a POTV to surface vaters and sediments. Releases can occur by two
pathways: direct discharge to surface vaters through an outfall structure
(pass through releases) and surface runoff from effluent and sludge management
practices. The following sections of this chapter summarize:
• The attributes of treatment units that relate to pass through and
surface releases to soils.
• The characteristics of constituents that affect potential for
releases.
• Soil and topographic features that determine the potential for surface
migration of releases to soils.
• Characteristics of water bodies affecting the fate and effects of
released constituents.
• Sampling methods for surface vaters and sediments.
• Humans and environmental risks posed by releases to surface waters and
sediments.
5.1 APPLICABILITY OF CORRECTIVE ACTION REQUIREMENTS TO RELEASES TO SURFACE
VATERS AND SEDIMENTS
EPA will exercise discretionary authorities in investigating releases to
surface vaters and sediments. Corrective action may apply to the folloving
types of releases:
• NPDES permitted releases - including releases of treated or untreated
POTV effluent discharged to surface vaters or sediments.
• Nonpermitted offsite releases - including surface runoff of overflows,
spills and leaks from POTV units to surface vaters or sediments.
• Nonprnitted onsite releases - including releases to soils which pose
a threat of release to surface vaters and sediments.
Vhere releases are identified, they vill be addressed, to the extent possible,
by EPA or State vater permitting officials.
5-1
-------
5.2 UNIT CHARACTERISTICS AFFECTING POTENTIAL FOR RELEASES TO SURFACE VATERS
There are several potential sources of releases that may migrate to
surface waters. These sources are listed in Table 5-1. The major charac-
teristics of various treatment units leading to possible contamination of
surface vaters are discussed in the following subsections.
5.2.1 Unit Characteristics Influencing Pass Through to Receiving Vaters
There are several characteristics of POTVs that can be used to assess
whether releases to surface water or sediments have occurred or are occurring.
Included in these characteristics are the type and level of treatment at a
plant, the scope of constituents regulated by an NPDES permit, the record of
compliance with a permit, the history of spills or upsets at the plant, and
possible long term cumulative effects of discharges.
Type and Level of Treatment
The type and level of treatment at a plant strongly influences the
possibility of pass through releases to a receiving water body. Primary
treatment, which allows little opportunity for biodegradation or volatili-
zation of influent constituents, will eliminate only the larger solids in a
wastestream and allow pass through releases of many soluble, biodegradable, or
volatile constituents that would normally be removed by other treatment.
Insoluble constituents that are less dense than water may also pass through.
If records of industrial discharges to the plant indicate the presence of
significant loading of these constituents to a primary treatment plan, this
fact should be considered when determining what further action is required.
Secondary or tertiary treatment of a POTV vill significantly reduce the
potential for release of all chemicals to surface vaters. However, it should
be remembered that even efficient POTVs usually pass through a few percent of
many constituents, and large influent loads may still result in significant
releases to receiving vaters.
In evaluating the potential for release by pass through, the lack of
strong aeration in secondary and tertiary units will lead to increases in
volatile constituents in the effluent. Normally, 10 percent or less of
5-2
-------
TABLE 5-1. RELEASE MECHANISMS FOR
SURFACE VATER RELEASES
Unit Type
POTV
Surface Impoundment
Release Mechanism
Landfill
Vaste Pile
Land Treatment Unit
Above-ground Tank
In-ground Tank
Incinerator
• Pass through releases at discharge point
• Releases from overtopping
• Seepage
t Migration of runoff outside the unit's runoff
collection and containment system
e Migration of spills and other releases outside the
containment area from loading and unloading
operations
• Seepage through dikes to surrounding areas (e.g.,
soils, pavement, etc.)
• Migration of runoff outside the unit's runoff
collection and containment system
• Migration of spills and other releases outside the
containment area from loading and unloading
operations
• Migration of runoff outside the containment area
• Releases from overflow
• Leaks through tank shell
• Spills from coupling/uncoupling operations
• Releases from overflow
• Spills from coupling/uncoupling operations
• Spills or other releases from waste
handling/preparation activities
• Spills due to mechnical failure
*The two remaining solid waste management units; waste transfer stations, and
waste recycling operations generally have mechanisms of release similar to
tanks.
5-3
-------
volatile organic chemicals in the influent will be found in the effluent, but
without aeration, this level can increase to 20 or 30 percent, a substantial
increase in pass through loadings.
Scope cf Parameters Regulated in NPDES Permits
NPDES permits normally cover only a small percentage of the constituents
likely to be released by POTVs. The extent to which individual constituents
not specifically listed in a permit are released to surface waters and
sediments can be estimated by (1) identifying those industries discharging to
the POTV by dedicated pipeline, truck, rail or sewers and developing a list of
constituents and their loadings from industry data, or (2) developing a list
of constituents and their loadings from influent records. Estimation of
loadings reductions due to treatment will then produce estimated effluent
loadings.
Record of Compliance with NPDES Permit
NPDES monitoring records are used for evaluating the operating
performance of the POTV. A comparison of measured effluent loadings with
permitted loadings indicates the level of compliance achieved by normal plant
operations. Frequent or substantial noncompliance with permit conditions
implies poor operating standards that usually result in high levels of
releases of constituents both listed and not listed in the permit.
Spills/Upsets at the POTV
A history of spills or upsets at the POTV indicates influent slug loads
that are either too large in volume to be handled by the treatment units or
have much higher concentrations of toxic materials than normal. In the first
case, releases to surface waters by surface runoff or releases to ground water
may have occurred. Since the treatment process will have been by-passed for
these releases, the level of hazard of the releases will be high. In the
second case, the level of treatment will be significantly reduced for the
period of the upset, allowing probable releases greater than the permitted
level. Occasional small spills or upsets are not usually significant;
frequent spills or upsets are a basis for concern.
5-4
-------
Pre-NPDES or Nonpermitted Discharges
Historical records of industries sending effluents to the POTV may
indicate that industries once discharging to the plant are not now doing so.
If the discharges ceased prior to issuance of an NPDES permit, permits and
monitoring records will fail to indicate the possibility of significant past
releases. It is thus necessary to estimate the POTV effluent loadings based
on inputs from such industries to determine if there vere significant dis-
charges of constituents that have accumulated in sediments or biota. If
significant discharges vere probable, further action may be required.
Characteristics of SVMUs Leading to Runoff
Movement by surface runoff will be potentially significant if land
application of effluent or sludge is common practice at the POTV. Under both
circumstances, special attention should be given to possible releases unless
investigation of the land application area indicates that it is not possible
for the effluent or runoff from the sludge to enter adjacent waters. Land
application areas at a lover topographic level than nearby surface waters, or
elevated land between the land application area and surface waters both
preclude runoff.
- Long Term, Cumulative Effects of Discharges
POTV removal efficiencies are high for many constituents -- between 80
and 95 percent. However, even when 5 to 20 percent of a constituent passes
through a POTV to the discharge point, significant accumulation of con-
stituents can occur in sediments and biota over several years of discharge.
Constituents with low aqueous solubility and high particle affinity (high Kow)
are of particular concern. If constituents with these characteristics appear
in the effluent, it Is desirable to obtain further information on the ultimate
fate of these constituents.
5.2.2 Unit Characteristics Influencing Movement Through Surface Runoff
The major potential source of surface runoff releases will be through
direct runoff of land applied effluent, overflow of basins or tanks, runoff
from sludge storage, leaks from above ground tanks or basins, or faulty
5-5
-------
temporary connections betveen treatment or storage units. Except for runoff
from sludge storage facilities, releases near the influent end of the treat-
ment process are likely to have greater adverse effects than releases from the
effluent end. Treatment vill reduce the level of hazardous constituents as
the vastestream passes through the POTV. Emphasis in the RFA should therefore
be placed on potential for releases at the influent end and around sludge
storage locations.
Rainfall runoff from sludge storage facilities is ^ major source of
nonpass through release to surface vaters and is particularly important vhen
above ground uncontained storage is used. While a bed liner may protect
ground vater, it is not likely to protect surface vaters. Stains leading away
from sludge storage or drying units give strong indication of releases from
these units and is a basis for further investigation.
Major Characteristics of SWMUs Leading to Overflows
The propensity for overflow of tanks and basins is related to the ability
of the POTV to regulate flow through the treatment process. Inadequate
storage volumes in primary clarifiers combined with a lack of facilities to
re-route influents during peak flows will increase the likelihood of a
release. Combined sewage and storm water influent will also raise the
magnitude of peak flows, increasing the probability of occurrence of
overflows.
Evidence of previous overflows and the evaluation of the possibility of
overflows is obtained by visual inspection of treatment units and their
surroundings. High water levels in the units during periods of lov influent
volumes may indicate a high potential for overflow. Similarly, water marks on
the tanks or basins close to the top of a unit indicate prior near overflow
conditions. Scour channels adjacent to tanks, or stains or watermarks on the
outside of tanks, basins or the surrounding area are prima facie evidence of
previous overflows. Given a high probability of overflow or evidence of
actual overflows, it is necessary to estimate the extent and effect of the
release.
5-6
-------
Characteristics of SVMUs Leading to Leakage or Spills
In contrast to overflows, leaks are not likely to give rise to
significant releases of constituents to surface vaters. Leaks normally imply
small volumes of waste, and often will have greater impact on ground water
than on surface water. Nonetheless, above ground tanks or treatment units
should be inspected for cracks, particularly cracks associated with stains or
water marks on the tank or the ground surrounding the tank. Spills arise
through loose or worn fitting between transporting vehicles and storage tanks,
if any. In addition, valves used for rerouting waste streams may be worn and
cause spillage in certain position.
5.3 VASTE/CONSTITUENT CHARACTERISTICS AFFECTING POTENTIAL FOR RELEASE TO
SURFACE WATERS OR SEDIMENTS
Certain characteristics of constituents will increase the probability
that a material will reach or be found in surface vaters or sediments and thus
require assessment in an RFA. One group of chemicals is likely to pass
through the treatment process unchanged and be released through discharge- A
second group is likely to be released by surface runoff after rainfall or in
the event of spills or leaks. A third group will be accumulated within sedi-
ments or biota so that substantial concentrations can be attained over time,
_ even with small rates of release.
5.3.1 Vaste/Constituent Properties Affecting Pass Through to Receiving Vaters
The first group of constituents are those that tend to pass through the
POTV in significant quantities. These chemicals may appear at high concentra-
tions in POTV effluent where removal rates due to volatilization, adsorption
to sludge and biodegradation within POTV treatment units are limited.
Chapter 3 provides a compilation of overall removal rates and principal fate
pathways for selected Appendix VIII constituents treated at POTV facilities.
5.3.2 Vaste/Constltuent Properties Affecting Migration Through Surface Runoff
Compounds that pass through a POTV are also likely to be found in
releases through surface runoff. However, since overflows or leaks can occur
at any stage of the treatment process, biodegradability is less important in
5-7
-------
determining the likelihood of release. Similarly, volatility is less
important because the short time required for a leak or overflow to reach
surface waters will result in little constituent loss through volatilization.
High solubility and low particle affinity increase the passage of constituents
from the source of a leak or overflow to the receiving waters.
Constituents that normally become part of the sludge stream usually
attach readily to particles and are not very soluble in water. Therefore,
runoff from sludge units will contain a relatively high proportion of
chemicals that would not normally be found in surface runoff.
5.3.3 Waste/Constituent Properties Affecting Accumulation in Sediments and
Aquatic Species
Constituents that accumulate in sediments and aquatic biota have very
different characteristics from the previous tvo groups. These constituents
have high affinities and low solubility in water, and thus are likely to occur
in sludge in much higher concentrations than in effluents. However, even
though the effluent load of these constituents is generally only a few percent
of the influent load, their behavior in the receiving water will cause their
concentrations in sediments and biota to increase over time and thus become a
source of environmental concern after several years of discharge.
5.3.4 Data Required on Waste Characteristics for Assessing Potential for
Releases to Surface Waters and Sediments
The major characteristics of waste water constituents that determine
their propensity for releases to surface waters and their partitioning between
surface waters and sediments are solubility, lipophilicity, particle affinity,
volatility, biodegradability, and density. Chapter 3 provides a compilation
of numerical values for these properties for many hazardous constituents. The
nature of each characteristic is described in the following paragraphs.
Solubili ty
Aqueous solubility of constituents indicates the amount of chemical that
will dissolve in a given volume of water. The higher the value, the higher
the probability that surface runoff of the constituent will be significant.
5-8
-------
Lipophilici ty
The tendency of a constituent to dissolve in a lipid-like material more
than water. In a mixture of equal amounts of octanol and vater, lipophilicity
(K„v) is the ratio of the concentration of the constituent in octanol to the
concentration of the constituent in vater at equilibrium. High values mean
that the constituent is much more soluble in octanol than in water, indicating
a greater particle affinity and a higher potential for bioaccumulation in
aquatic organisms. High octanol/vater partition coefficients are also
generally associated with low water solubility.
Volatili ty
The tendency of a chemical to vaporize rather than remain in an aqueous
phase. This tendency is measured by the partial pressure of the constituent
in air divided by its solubility in vater (Henry's law constant). The higher
the value, the greater the amount of chemical that will "dissolve" in air --
the greater the volatility. Highly volatile compounds will generally be
released to air, not to surface waters or sediments.
Biodegradabillty
The tendency of a chemical to be "destroyed" or modified by biological
action. However, there are no chemical or physical properties of a con-
stituent that can be measured to determine or predict biodegradabillty. While
biodegradability can be measured in laboratory studies, fev data are available
for the range of compounds normally of concern. Appendix A presents data on
POTV removal efficiencies for "acclimated" and "unacclimated" treatment
systems. The difference in removal efficiency between these two system types
is a measure of the biodegradability of the waste.
Densi ty
The density of a constituent is significant when it has low solubility in
water. Density will then determine whether a chemical will tend to float on
the water's surface or sink to the bottom. Density is defined as the mass of
5-9
-------
a specific volume of material divided by the mass of the same volume of water.
Values less than 1.0 indicate that the constituent vill float on water; values
greater than 1.0 indicate that the constituent will sink.
5.4 ASSESSMENT OF MIGRATION POTENTIAL OF RELEASES TO SURFACE WATERS AND
SEDIMENTS
Constituents that are released onsite to the ground surface may reach
surface waters directly through surface runoff or indirectly through ground
water. This section covers only direct releases — ground-water releases are
considered in Chapter 4. However, once constituents reach surface waters, by
pass through, surface runoff, or ground water, their fate will be determined
by the type of water body. This section summarizes the factors affecting the
potential of releases to the ground surface reaching surface waters and their
fate in the receiving waters.
5.4.1 Migration Potential of Releases to Soils
If spills or overflow have occurred at the POTV, the migration pathvay
for the release will need to be determined. As already indicated, large
volumes of releases through overflows are more likely to reach receiving
waters than small volume leaks or spills. However, several factors vill
determine the likelihood of larger volumes of releases in affecting surface
waters. These include general topography, the presence of containment dikes,
soil types, and location of the POTV within a floodplain.
Continuous Dovnslope Gradient
Spills, leaks or overflow to the ground surface result in migration to
one of three receptors — to surface waters, to ground water or to the
atmosphere. A continuous dovnslope gradient between a potential overflow or
leak and rectiving waters is the most significant indication that there is a
potential for release to surface waters. The steeper the slope of the
gradient, the more likely the release. However, if there is a light upslope
gradient at any point betveen the point of release and receiving waters, only
larger overflows are likely to reach surface waters.
5-10
-------
Containment Structures
The presence and condition of containment dikes or berms vill have a
large impact on the potential for releases to the ground surface in reaching
surface waters. Well designed and veil maintained dikes vill ensure minimal
opportunity for release. Erosion around dikes, evidence of collapse caused by
vater contact, or large imperfections in the dike surface are evidence of both
significant overflow, spillage or leakage as veil as probable release to
surface vaters.
Soil Permeability
The permeability of soils determines the potential for migration to
surface vaters if a continuous dovnslope gradient exists. Highly permeable
sandy soils vill encourage migration to ground water, vhile relatively
impermeable clays or paved surfaces vill encourage migration to surface
waters. Without a continuous dovnslope, impermeable soils or paved areas vill
encourage atmospheric releases of volatile organic compounds, vhile con-
stituents vith low vapor pressures vill build up on the ground surface.
Vegetation
The presence of vegetation, particularly grasses and other densely
distributed plants, vill reduce the flov rate down any dovnslope gradient by
increasing the frictional resistance to vater flov. Plants may also
accumulate hazardous materials as veil as take up some of the vater. The
reduction in flov increases the probability of releases to ground vater and
the atmosphere, vhile vater and hazardous material uptake reduces the
potential for surface runoff. The absence of vegetation, particularly in
natural channels, thus Increases the probability of migration to surface
vaters.
POTV Elevation
The elevation of a POTV above the stage level of a rarely occurring flood
vill also affect the potential of migration of hazardous materials to surface
waters. Obviously, if treatment units are belov the flood stage level, there
is significant risk of flooding of the entire POTV. Vith flooding, no other
physical factors have any real significance. If flooding is not likely to
5-11
-------
occur because the POTV is located above the flood stage, the height of the
POTV above a flood stage will be related to the depth to the water table. A
small depth to water table will indicate that migration to ground water is
unlikely because soils will be saturated, and that even if releases do reach
ground water, they will also probably end up in surface waters (see Chapter
4).
5.4.2 Migration Potential of Constituents in Surface Vaters and Sediments
The nature of the receiving water for pass through and surface runoff
releases will determine the fate and potential effects of those releases.
Each of the three major receiving water types, including lakes and impound-
ments, rivers and streams, and estuaries, have unique characteristics that
influence the amount of dilution of the release, the distance that hazardous
constituents will be carried avay from the release point, and the location of
any sedimentation of materials from pass through releases.
Lakes and Impoundments
Lakes and impoundments are typically quiescent bodies of water, with lov
current velocities determined primarily by wind strength and direction. As a
result, movement of a discharge plume will depend on the direction and
velocity of winds over the previous day or two. Onshore winds will tend to
concentrate a plume along the shore, while alongshore or offshore winds will
move the plume avay from the discharge point, thus effectively diluting it.
Sedimentation of particulates and precipitation of insoluble constituents
will generally occur in the immediate vicinity of any outfall structures.
Greatest sediment concentrations are likely to be a short distance avay from
the discharge point in the opposite direction from the prevailing winds.
In deep lakes, temperature stratification (see Figure 5-1) will usually
develop in spring or early summer. Discharge above this stratification (i.e.,
thermocline) may affect the extent of dispersion of settled particles. Lover
density particles, mostly organic materials may settle to the thermocline and
5-12
-------
Olifofropbic
to»»
f TO ff 2C*
'• 1 • /1
L«kc Constance *
*
~
_ X
/
a
O
^ rr zo'C
~ . 1—n—
Brcitcr Lucin !
Eutrophie
7T
Gi. Plontr Sm* Tt
iOi-
25r-
/
Likt G«nr»«
,"~~T
\
,L
±0i
+1^
FIGURE 5.1. TYPICAL TEI«RATUR£ STRATIFICATION
IN LAKES. (Source: RI Guidance)
5-13
-------
be more dispersed than more dense particles. In addition, the rate of supply
of oxygen to vaters belov the thermocline is very much reduced so that oxygen
levels belov the thermocline approach low levels, particularly in warmer
climates, as summer progresses. Lou oxygen levels may cause the
remobilization of some heavy metals from the sediments, appreciably raising
their concentrations in deeper vaters.
Mixing of discharges with lake waters is generally poor unless aided by
outfall diffusers. Location of the diffusers in deeper-, colder water vill
cause the generally warmer, less dense effluent water to rise to the surface,
increasing mixing and thus effectively diluting the effluent plume.
Rivers and Streams
Rivers and streams are generally characterized by water flowing dovn a
topographic gradient. Since the rate of sedimentation is inversely propor-
tional to the velocity of water flov, the rate of vater flov vill determine
where sediments will accumulate. The steepness of the topographic gradient
determines the velocity of vater flov. Typically, hovever, gradients vary
considerably in hilly areas, giving rise to sections that are fast flowing and
sections that are slov. Coastal rivers and streams tend to be of more uniform
gradients and have a more even distribution of current velocities. Such
streams or rivers are often characterized by oxbovs, vhich are isolated
waters, caused by the sealing off of a previous bend in the river, and
meanders where a river curves back and forth on itself, rather than a
relatively straight course.
Effluent plumes and surface runoff usually mix veil in rivers, although
vith large rivers, a distinct plume may form along the nearshore bank and
perhaps be United to the surface portion of the river. Surface plumes are
typical vhen the effluent temperature is much higher than the temperature of
the river. Vithin a few miles, plume distinctness usually disappears.
Hovever, hazardous constituents in the plume may be carried tens of miles
downstream vithin one or tvo days, even if the plume cannot be distinguished
from the rest of the river.
Because of the turbulence in most rivers and streams, sedimentation and
precipitation of materials from pass through releases are likely to occur
5-U
-------
downstream from the discharge in areas vhere current velocities decrease.
Generally, sedimentation vill occur in locations where the river suddenly
deepens or at the inside edge of a sharp bend. In deep, slow moving rivers,
sedimentation vill begin immediately, vith greatest sediment concentrations
several hundred yards downstream. During floods, however, the increased
volumes of water flowing through the river channel may be sufficient to scour
previously deposited sediments, in some cases relocating these sediments
several miles downstream.
Estuaries
Estuaries are similar to rivers in their behavior, with two exceptions:
currents may flow both upstream and downstream based on tidal forces, and
higher salinity bottom waters may affect the location of deposited materials.
All estuaries have net downstream flow towards the ocean. The magnitude
of the net flow is the same as the magnitude of the upstream freshwater input
to the estuary. However, depending on the topographic gradient, size of the
channel, freshwater flow, the size of the connection with the sea, and the
magnitude of local tides, there may be small or large current reversals during
a tidal cycle. These current reversals vill affect the distribution of
discharge plumes and the location of sedimentary particles. This also vill
affect the choice of sampling locations, especially vhere "upstream" and
"downstream" sampling is desired.
Additionally, a vertical salinity gradient (i.e., halocline, see Figure
5-2) may exist within an estuary. The more saline, dense water vill be
overlaid by fresher water. The deeper water will tend to have a larger
upstream current component than the shallower, fresher components. Direct
discharge into the deeper water may cause the plume to have greater movement
upstream than anticipated from an examination of surface currents. As well,
because of higher salinity, insoluble constituents, particularly metals, will
settle out much more rapidly than is the case in fresh waters. Counteracting
these effects vill be the tendency for the discharge, usually less saline and
warmer than the estuary, to rise through the more dense, saline vaters, mixing
with it. Under certain circumstances, the resulting plume may not reach the
5-15
-------
SURFACE
9aM«222e
BOTTOM
J VELOCITY J
SALINITY
BOTTOM
Ktttri corrfseonfl to crosi itcttont
FI6URE 5.2. TYPICAL SALIHITY PROFILES IN A STRATIFIED ESTUARY.
(Source: TetraTech, 1982)
5-16
-------
surface, but may be transported as part of the mid-depth water. This results
in lower net downstream transport than would be expected by examination of
surface currents.
Floods are less likely to move deposited sediments in estuaries than in
rivers. However, if salinities in bottom waters are the same as those in the
surface waters during a flood, it may be assumed that some relocation of
sediments has occurred.
5.4.3 Data Required for Assessment of Migration Pathways for Releases to
Surface Waters and Sediments
Data for assessing the potential of releases to the ground surface to
migrate to surface waters can be obtained from several sources. U.S.
Geological Survey topographic maps will indicate general elevations of the
POTV above nearby surface waters, and may have sufficient detail to determine
natural channels from the POTV. However, plans of the POTV are more likely to
be accurate for this purpose. POTV plans will also indicate the presence of
any containment structures.
During construction, surveys of the POTV site will have been carried out.
These surveys may have included soil types, depths to ground water and vegeta-
tion, all of which are useful in predicting the potential for runoff to sur-
face waters. It should be remembered, however, that vegetation maps prior to
construction may no longer be appropriate. In addition, the POTV may have
been built on fill with materials substantially different from those listed in
the survey.
U.S. Geological Survey stream flov records are sometimes useful for
estimating volumes of vater passing the POTV. If gauging stations are too far
away for meaningful use, however, the linear rate of water movement can be
determined by vertical gradients on topographic sheets. Pools and slower
flowing sections of rivers can usually be identified on these maps.
For navigable lakes and estuaries there are often navigation charts that
plot water depths. These charts can be used to estimate water flow by
5-17
-------
multiplying the cross sectional area of the channel as shown by the chart by
the linear flow rate of the estuary. Areas of sediment deposition around
tributary mouths can also be identified from these charts. Tributary deltas
may be appropriate locations for sampling sediments.
5.5 SAMPLING TECHNIQUES FOR SURFACE WATERS AND SEDIMENTS
5.5.1 Assessing the Need for Additional Sampling
In the previous sections of this Chapter, guidelines have been given on
when a RFI will be required. Additional sampling will not normally be
required if those guidelines indicate a clear case for initiating RFI. On the
other hand, if there is no clear evidence that a RFI is necessary or if the
decision is likely to be controversial, additional sampling is advisable.
The purpose of sampling must be clear for the results to be meaningful,
however. If access to desirable sampling locations is denied by safety or
other reasons, using less desirable locations may yield equivocal results. In
this case, sampling will serve no useful purpose. Only with careful selection
of sampling parameters and locations will the resulting data assist in
determining if a RFI is necessary.
5.5.2 Selection of Sampling Parameters
The great majority of samples to be taken during an RFA will be for
chemical analysis. Biological analyses, when required, will usually be
limited to species presence-absence comparisons of a rudimentary nature. The
following paragraphs outline what constituents should be analyzed and where
samples should be taken.
In making the selection of analytes, the investigator may wish to
restrict costs by limiting sample analysis to a few indicator constituents
most likely to be released. Usually, however, the cost of analyzing a few
chemicals is not appreciably different from analyzing several — the major
cost is in sample preparation. Therefore, stringent limitation of parameters
to be determined is not always cost effective. On the other hand, inorganic
5-18
-------
samples (e.g., metals such as lead or copper) require very different sample
preparation from organic samples. Care should be taken if both are likely
constituents of concern. Each group vill have a different likelihood of being
found at particular locations. Selection of the most likely parameters will
save analytical costs, as long as inorganic and organic analyses are not mixed
unless required for a single sample location.
In vater samples, emphasis should be placed on soluble constituents,
especially those that are nonvolatile and nonbiodegradable. Appreciable loads
of these constituents in influent streams vill probably -be found in effluent
s treams.
For soil, sediment and biota samples, metals and lipophilic organic
compounds are good choices. These are the constituents that are likely to
attach to particles and be accumulated by biota. Sizeable influent loads of
any of these constituents vill maximize the chances of these constituents
being found.
Samples of biota should usually be limited to obtaining specimens for
chemical analysis (i.e., bioaccumulation in lipid tissues). Any biological
analyses requiring taxonomic identification should be left to the RFI.
However, the absence of species belov discharges or a large reduction in the
abundance of plants or animals belov a suspected surface runoff or pass
through release could indicate deleterious effects and may be sufficient cause
for requiring further investigation.
5.5.3 Selection of Sampling Locations
Data on constituent concentrations may be required in one or more of the
folloving: effluent, receiving vater, soils, sediments, or biota. The appro-
priate choice of the sample analyte and location vill maximize the utility of
information returned for the sampling effort. The discussion that follovs
outlines locations vhere each of these media should be sampled.
The effluent can be sampled at any point in the treatment process.
Chosen locations should coincide vith points of suspected release. If any
effluent is sampled, sampling locations should include POTV effluent
5-19
-------
immediately prior to discharge to the receiving vaters. The effluent should
be sampled for:
• Hazardous constituents knovn or suspected to be in the effluent but
not covered by an NPDES permit.
• Hazardous constituents that have been discharged at levels in viola-
tion of applicable NPDES permit.
• Any soluble, nonbiodegradable, nonvolatile hazardous constituents
present in the influent in significant quantities.
Areas where surface runoff enters receiving water are also areas where
soils, sediments or plants are likely to have accumulated lipophilic compounds
with releases. A comparison of constituent levels in soils or plants in the
runoff channel with those in similar materials on nearby higher ground may
provide evidence that runoff releases have occurred. A comparison of
constituent levels in sediments a few meters downstream from the intersection
vith those upstream may provide similar evidence. However, allowance must be
made in lakes and estuaries for uncertainties about upstream and downstream
locations of samples. Often only a transect above and belov the point of
suspected release will provide adequate "proof" that a release has occurred.
However, high concentrations near the intersection may be sufficient to
warrant further investigation for lakes and estuaries where upstream-
downstream comparisons are often difficult to interpret.
Sampling locations in receiving waters should be at or downstream of a
discharge point. For water column samples in particular, it will be necessary
to sample in the discharge plume. While one or two samples in the plume will
not be adequate for comparing the effluent concentrations and the receiving
water concentrations to determine dilution accurately, a rough estimate is
useful for assessing potential impacts.
Locations for sampling sediments are downstream of a release point. The
distance downstream will depend on the rate of flow of water and the depth of
the water course. In deep lakes or impoundments, for example, sediments
immediately adjacent to discharges are likely to have elevated levels of
5-20
-------
constituents. Fast flowing rivers -- 4 or 5 miles an hour or greater -- will
keep most sedimentary material in suspension until a deeper, slower flowing
section is reached. Because materials will settle or precipitate at the
slower flowing section, samples should be taken at these locations. If a
slower flowing section is not nearby, samples may be taken on the inside of a
sharp bend in the river, also an area of reduced current speed.
When taking sediment samples, it is important to obtain samples of fine-
grained material. Coarse material, sand or gravel, is usually well washed and
provides feu places for the attachment of chemicals with high particle
affinity. Silts and clays provide proportionately more sites, and thus are
likely to have much higher concentrations of the chemicals of concern. If
samples yield only coarser materials, the investigator should attempt to find
locations where finer sediments occur. Absence of constituents in these
materials provides almost conclusive proof that past releases have not been
significant.
When sampling biota for chemical constituents, a similar rationale
applies. Animals living in finer sediments are exposed to higher levels of
chemicals of concern, and also are more likely to feed primarily on materials
in the sediments. These factors combine to increase bioaccumulation in
species inhabiting fine sediments. Absence of significant concentrations of
chemicals in these animals can be taken as evidence that previous high
releases did not occur.
The sampling of biota for taxonomic identification is not usually
recommended as part of an RFA. Under certain circumstances, however, the
collection of plants and animals above and below a known or suspected release
point can provide valuable information. If water depths are shallow, and
there are not other obvious differences above and below the point of suspected
release, differences in the abundance and kinds of bottom dwelling plants and
animals can point to effects not easily documented in any other way.
5.5.4 Sampling Techniques for Surface Waters and Sediments
Vhen sampling is necessary, it will take one of three forms: sampling of
waters or effluents, sampling of sediments and biota, and sampling of soils.
5-21
-------
Soil sampling is covered in Chapter A on ground vater. The following
paragraphs outline sampling in waters and sediments, each of which requires
different techniques.
For all techniques, certain specific information must be recorded: the
location of the sample, the date and time the sample was taken, the medium
sampled (i.e., water, soil, sediment), the number of the sample container, and
by whom the sample was taken. For water bodies, additional information is
required on the depth of the sample, and other observations that may influence
the interpretation of the data. Veather conditions, estimated rate of stream
flow, and location in relation to a thermocline may be useful observations to
record, depending on the type of water body.
Determination of sampling locations for later documentation is required.
This can -be accomplished by one of several methods, each of which is somewhat
inaccurate. Triangulation on known landmarks is the easiest, and is carried
out by measuring the compass direction from the sampling location to two known
landmarks. This allows subsequent plotting of the intersection of the two
lines on USGS topographic sheets, appropriate for many lakes, streams and
rivers, or nautical charts for estuaries. Nautical charts are generally
available from boating stores for most near-sea locations.
Vater samples may be taken at the surface or at depth. Water at the
surface is usually sampled by means of a sampling beaker dipped into the
water, and subsequently emptied into a clean sample bottle. Care must be
taken to prevent contamination of samples, especially if some samples are
taken in the effluent and others are taken in the receiving water. It is
usually good practice to vork from the most dilute location to the most con-
centrated. It is also good practice to clean the sampling beaker between
samples. Vhan working with concentrated waste streams, using a beaker holder
or wearing disposable plastic gloves vill minimize the chances of being
exposed to hazardous constituents. Receiving water samples are taken by a
Kemmerer sampler, a device that can be lowered into the water to the desired
depth and then closed by means of a brass weight (messenger) sliding down the
attached wire. Less care need be taken to prevent contamination with the
Kemmerer sampler, as it vill usually be used only in receiving waters.
5-22
-------
Sediment samples for chemical analysis should be taken by a drop core, a
hollov tube that is dropped from the surface into the sediments, or pushed
into sediments in shallov locations. In fine sediments, 4 or 5 cm of sediment
will be sufficient to seal the core, and it can be retrieved. The cored
material can be laid out on an impermeable surface, and the top 1 to 2 cm can
be cut off and placed in a container for later analysis. Samples should be
frozen.
In shallov waters, biota can be sampled with a dip net run through
sediments. Large amounts of sediments can be vashed out of the net by
continuous dipping. Animals remaining can be identified by general type
(worms, larvae, clams, etc.) and compared with animals from similar materials
at other locations. Large differences are noteworthy, and should be part of
the evidence that releases have occurred. If biota are being sampled for
chemical analysis, the sample should be placed in a container and immediately
refrigerated or frozen.
In deep waters, benthic animals will be sampled most effectively by a
Peterson grab. This device is lowered into the water, and after it reaches
bottom, it is retrieved. The process of bringing the grab back to the surface
closes the javs, entrapping the sample. On the surface, sediments need to be
sieved through geological screens or their equivalent. Fine sediments are
washed out, leaving larger sediments and biota. As with the dip net sampler,
animals are placed in a container and refrigerated or frozen as soon as
possible.
For deep water stations, a boat must be used since sampling from the
shoreline will not be meaningful with discharges as little as 20 meters off
shore. In rare circumstances, a bridge will be located where samples are
appropriate, but this cannot be relied on. If the investigator does not have
experience with boats, particularly under the conditions required for
sampling, the investigator should not attempt sampling without experienced
help.
Details on the use of the various samplers described above should be
obtained from Characterization of Hazardous Waste Sites — A Methods Manual,
5-23
-------
Volume II, Available Sampling Methods (EPA/600/4-84-076) before attempting
their use in the field.
5.6 ASSESSMENT OF POTENTIAL EXPOSURE DUE TO RELEASES TO SURFACE WATERS AND
SEDIMENTS
Potential exposures due-to releases to surface waters and sediments are
based on the transport of constituents of concern once they have reached the
surface vater body. In streams, rivers and estuaries, the transport logically
follows vater flov, vith the distance traveled being dependent on the physical
characteristics of the constituent. Soluble chemicals and those that are less
dense than vater vill tend to travel at the same rate as the vater. Insolu-
ble, dense chemicals vill tend to travel at much slower rates. In lakes and
impoundments, the direction and velocity of transport vill be much more
variable, and may require a RFI to determine whether potential exposure
exists.
5.6.1 Potential Effects on Human Health
The primary risks to human health from releases to surface waters are the
contamination of drinking vater supplies, the consumption of contaminated
fish, and accidental ingestion of surface vaters during water-based
recreational activity. During an RFA, detailed analysis of these risks vill
not be possible — it is only necessary to demonstrate that the potential for
a significant risk exists. This potential is determined through an
examination of the possibilities of releases reaching sensitive areas, thereby
causing human impact.
The location of drinking vater intakes in relation to POTW pass through
releases is critical. Vater can travel several miles in a day, and constitu-
ents in the receiving vaters can have a long term, low level effect on humans
if these constituents pass into drinking vaters. The likelihood of signifi-
cant effects is related to the amount of dilution of constituents in the
effluent stream. A small effluent volume in relation to the volume of vater
passing the discharge structure indicates high dilution. Similarly, the input
of additional tributaries below the discharge point will further increase
dilution. In lakes and impoundments, additional complications arise in that
the direction and velocity of currents are often poorly understood. Vhile
5-24
-------
effluent plumes may not always be visible more than a fev hundred yards from
the discharge point, constituents in the water can be elevated over a very
large area. Proximity of the water intake to the discharge point will be
significant factor in increasing the potential for human health effects.
A second significant source of potential health hazards are created by
the consumption of fish or shellfish contaminated with hazardous materials.
Shellfish contamination is likely to occur in the immediate vicinity of the
outfall, but fish, particularly migratory fish, can attain high concentrations
of accumulated materials and pose risks to humans several miles distant.
Appreciable accumulations of lipophilic compounds in sediments will increase
the possibility of fish and shellfish contamination.
A third, relatively minor source of potential health hazards is exposure
during primary contact recreation. Accidental ingestion of hazardous mate-
rials while swimming, water skiing or diving is the main exposure pathway, but
skin exposure may be significant under unusual circumstances. Both of these
potential hazards are likely to be minor, however, since primary contact
recreation is generally avoided in areas of obvious pollution.
5.6.2 Potential Effects on the Environment
The potential environmental effects of releases to surface waters are
generally caused by direct toxicity or accumulation of hazardous materials.
High levels of exposure may lead to immediate and long-lasting changes to
various species of plants or animals, and lov levels of exposure can lead to a
slow change to communities through accumulation. Since in many cases it will
be difficult to obtain information on the changes to a particular environment
over time, it is best to focus on specific target environments that are
recognized as sensitive or unique in the general location of the POTV.
The moat sensitive habitat is wetlands. Periodic flooding, or entrapment
of waters containing hazardous materials leads to accumulation of constituents
in the myriad small plants and animals that serve as a food source for birds,
the unique fauna of most marshes and swamplands.
5-25
-------
Other environments may be just as sensitive. Habitats of rare or
endangered species of aquatic or terrestrial life that are exposed to
hazardous materials will pose an additional threat to those species.
Similarly, sensitive ecological habitats may be affected by releases to
surface vaters.
5.6.3 Data Required for Assessment of Potential Exposures Due to Releases to
Surface Vaters and Sediments " —
Local public health authorities will be able to provide the location of
drinking vater intakes. Additional information on problems experienced vith
contamination of water supplies will be available from the same source. A
comparison between likely pass through releases from the POTU and the
chemicals posing problems in the water supply may provide strong evidence that
the POTV is a source of the constituents of concern.
Bans on fishing and shellfishing may have been placed on waters at or
near the POTV. State resource agencies or local public health authorities are
generally responsible for imposing these bans. It should be determined
whether restrictions on taking fish or shellfish appear to be related to
releases from the POTV.
Interviews vith people living in the area of the POTV may lead to
discovery of human health problems that have not been brought to the attention
of public health authorities, or for which they may not have Jurisdiction.
Illnesses caused by contact vith the vater or through eating fish are
indicators most likely to be related to surface vater releases. Any strong
indications that problems uncovered may be related to releases warrant further
investigation. Similarly, local inhabitants vill be avare of spills or major
upsets at the POTV that may not be documented.
State resource agencies vill be able to provide a variety of information
required to assess the environmental effects of surface water releases. In
particular, they vill generally be avare of local vetlands, endangered species
habitats, and bird and wildlife sanctuaries. In addition, any significant
5-26
-------
changes in populations of birds and fish, or declines in fish catches vill
probably be available from this source. If records are extensive enough, a
case might be developed relating these changes to construction or operation
the POTV, and thus a direct link between releases and environmental effects
In the absence of information on suspected direct impacts, the inves-
tigator may still make a case sufficient to warrant a RFI. If estimates of
pass through releases, after dilution in the receiving waters, appear to be
sufficient magnitude to be transported and have an effect on any aspect of
human health or the environment, further investigation vill be necessary to
determine the nature and extent of these effects.
5-27
-------
6. ASSESSMENT OF RELEASES TO AIR
This chapter of the guidance document is designed to provide practical
information for determining whether a release of hazardous constituents to air
has occurred or is occurring at a POTV. Waste, unit, and environmental
characteristics that may influence the potential for air releases are
described in this section, as are possible information sources. This chapter
also describes air sampling techniques and methods for assessing potential
human exposures and environmental effects.
6.1 APPLICABILITY OF CORRECTIVE ACTION REQUIREMENTS TO RELEASES TO AIR
EPA will exercise discretionary authorities in investigating releases
from POTV units to ambient air. Corrective action may apply to the following
types of releases:
• Releases permitted under Clean Air Act (CAA) provisions - including
emissions from sewage sludge incinerators regulated under CAA provi-
sions, such as Section 111 New Source Performance Standards (NSPSs),
Section 112 National Emission Standards for Hazardous Air Pollutants
(NESHAPs), or State Implementation Plans (SIPs) designed to ensure
compliance with National Ambient Air Quality Standards (NAAQSs).
• Nonpermitted releases - including volatilization of organic compounds
from POTV unit processes or fugitive particulate emissions from POTV
sludge handling operations.
Identified releases vill be addressed, to the extent possible, by EPA or State
air permitting officials.
6.2 UNIT CHARACTERISTICS AFFECTING POTENTIAL FOR RELEASES TO AIR
This section describes some of the POTV processes and practices that may
influence the potential for releases to air. The discussion of volatilization
concentrates on unit processes where most volatilization is thought to occur.
The section on particulates discusses incinerator operation and control
technology and sludge management practices.
6-1
-------
6.2.1 Unit Characteristics Influencing Volatilization from Wastewater and
Sludge Treatment Units
The design and operation of a POTV can significantly influence the
volatilization that occurs at the plant. A major consideration is whether
POTV unit processes (e.g., headworks, aeration basins) are open to the ambient
air, because direct contact with the atmosphere promotes air releases. If
processes are open to weather and the POTV receives significant quantities of
VOCs in wastewater, some volatilization will certainly occur. To the extent
that units are covered, volatilization is probably reduced. In some cases,
however, covering unit processes may increase hazardous exposures for POTV
workers by concentrating vapors inside buildings or structures.
Volatilization may be increased by natural forces such as temperature and
wind. It may also be increased by POTV processes that generate aerosols
(e.g., trickling filters) or agitate wastewater (e.g., screens, grit
chambers). In both cases, the processes create physical conditions that
increase volatilization. Aeration basins are probably the greatest source of
volatilization. In aeration basins, air is blovn up through the wastewater to
support activated sludge treatment. For less volatile compounds, aeration
helps achieve biodegradation for chemicals with longer residence times in the
POTV. For volatile compounds, however, aeration results in movement of
bubbles to the surface of the basin where organics are released to the ambient
air.
Vhen visiting the POTV site, the investigator should attempt to identify
POTV processes that facilitate volatilization, especially those that involve
mixing or moving wastewater. For instance, the influent flow rate may
influence the degree of volatilization. Generally, the higher the flow rate
of the influent, the greater the degree of volatilization brought about by
wastewater turbulence.
The surface area of process units can also influence pollutant behavior.
The larger the surface area of ponds, lagoons, or basins, the greater the
opportunity for volatilization. Also, organics are more likely to volatilize
from shallow basins than from deep basins. Certain sludge processing
practices may also result in volatilization of organics. For example, heating
6-2
-------
sludge prior to incineration facilitates combustion, but may drive off
organics that are not tightly bound to the sludge. The investigator should be
alert for these situations in conducting the site investigation.
6.2.2 Unit Characteristics Influencing Emissions from Incinerators to Air
Most sevage sludge incinerators are either multiple-hearth or fluidized-
bed incinerators. Each type of system reaches and maintains temperatures of
1,300 to 1,800° Fahrenheit to destroy organic constituents in sludge. Organic
compounds are not destroyed completely vhen operating conditions are not
optimal, such as during incinerator startup and shutdown. Under these
conditions, emissions can contain toxic organics or intermediate products that
may be more toxic than the original compounds. Also, material that is not
combusted in the incinerator vill contain inorganics, including heavy metals.
Emissions of inorganics from sevage sludge incinerators are influenced by
the combustion temperature of the incinerator, and for fluidized-bed units,
the air flov velocity through the bed. Test data indicate that emissions of
some metals increase along vith combustion temperature. This is particularly
problematic for chromium. At high incineration temperatures, chromium, which
is usually present in sevage sludge in its trivalent state, can be oxidized to
hexavalent chromium, the more toxic valence state for that metal (Locating and
Estimating Air Emissions from Chromium, EPA-450/4-84-007g, July 1984)). In
addition, for chemicals vith relatively lov vapor pressures, such as arsenic
and mercury, combustion at normal Incinerator temperatures vill cause them to
volatilize. The challenge for incinerator operators is to operate at a
temperature high enough to destroy the organics, but lov enough to avoid
volatilization of metals.
For fluidized-bed units, the velocity of air blown through the bed is
used to control the method by vhich remaining inorganic sludge material is
removed froa the incinerator. At lover air velocities, the sludge adheres to
the bed materials (usually sand), and they are removed from the bottom of the
incinerator. Using higher velocities of air, the inorganic sludge material
can be forced out along vith exhaust gases. This practice, of course,
increases particulate emissions.
6-3
-------
A final physical characteristic affecting the potential for environmental
release is the emission control technology system used on an incinerator.
Typically, incinerators possess particulate control devices that range from
vet scrubbers to very efficient electrostatic precipitators. Depending on the
control technology used and the actual emissions of an incinerator, particu-
late emissions can be reduced by from 80 to 95 percent. Unfortunately, parti-
culate control devices will not collect' emissions of volatile organics that
escape destruction in the incinerator, nor vill they trap emissions of metals
that have volatilized.
It should be noted that these same characteristics generally apply to
co-incineration units that burn sludge and municipal refuse. Combustion
temperature and chemical composition of the waste being incinerated are
important to both sludge incinerators and co-incineration units in determining
the likelihood and magnitude of potential air releases. In addition, the
control technologies for both types of incinerators are the same.
6.2.3 Unit Characteristics Influencing Fugitive Particulate Emissions
This section describes conditions at a POTV that may lead to windblown
particulate emissions. Particulates may be released because of simple
erosion, or they may be emitted from sludge piles and sludge handling
machinery operation as discussed below.
Wind Erosion
If dried sludge piles are located in an exposed area some wind erosion
vill occur. The geographic location of the piles, the meteorology"of the
surrounding area, (i.e., predominant wind direction and speed), and the
presence or absence of nanmade or natural obstacles that block the wind can
each influence the potential volume of erosion.
Operational Activities
Operational activities associated with handling sludge include the
methods by which sludge is moved from a POTV's solids processing facility to
the sludge pile, the manner in which the waste is applied to the pile, and the
6-4
-------
methods used to remove the sludge from the pile for incineration or for off-
site disposal. Each of these activities can influence the quantity of
fugitive emissions. Emissions will be reduced if dust suppression or
particulate control techniques are being used at the POTV.
A major factor that will influence emission rates is the moisture content
of the sludge. If sludge is removed from the POTV site and incinerated or
trucked to a landfill while moist, fev fugitive emissions are likely to occur.
Only sludge that is allowed to become relatively dry or% that is dried in a
POTV process poses a significant risk of fugitive emissions. Many use heat to
drive off vater before incineration. This may volatilize organic compounds
and also increase the likelihood of fugitive windblown emissions.
6.2.4 Data Required for Assessment of Unit Characteristics Affecting
Potential for Releases to Air
In gathering information about the POTV, the investigator should be alert
for direct or indirect evidence that a release to air has tjaken place or is
still occurring. Potential sources of information include:
• Air monitoring data collected by the POTV or an air pollution control
agency, which may have been obtained under the requirements of an air
quality permit.
• Visible emissions from the POTV.
• Nearby indications of air emissions, (e.g., evidence of particulate
emissions).
• Air monitoring data collected under worker health and safety programs.
• Citizen complaints about releases that may Include odors or observable
pollutant releases, or complaints about headaches and nausea.
Sources of thvsc data may include the POTV, State and local air pollution
agencies, State and local Boards of Health, and Regional EPA offices.
During the site visit, the investigator should examine the area for
visible signs of current emissions or evidence of past releases. The inves-
tigator should also be alert for unusual odors, particularly chemical smells,
-------
that may indicate air releases of volatile compounds. The following sections
describe techniques for assessing unit characteristics and their likelihood
for air releases.
Volatilization
Assessment of POTV processes that may cause volatilization should begin
with a reviev of plant diagrams, The physical layout and processes of the
plant should be carefully noted. One factor to assess is vhether units are
exposed to the atmosphere or covered. If processes are^open, the likelihood
of volatilization increases. Other factors that should be assessed include
prevailing temperature and wind speed. Data can be checked for accuracy
during a site visit.
Those processes that mix or agitate wastewater or sludge should be
identified. A priority is to determine whether the POTV has aeration units,
since they provide suitable conditions for volatilization. The investigator
should also note the influent velocity at the headworks, which also presents
favorable conditions for volatilization. If the POTV heats sludge, this
practice should be identified since it is likely to drive off volatile
organics. Finally, the surface area and depth of water bodies used to treat
waste should be determined. Generally, the larger the surface area and more
shallow the body of water, the greater the chance for volatilization to occur.
Incineration
The investigator should be careful to examine sludge monitoring data to
determine concentrations of arsenic and mercury. These inorganics can be very
difficult to control because of their tendency to volatilize during incinera-
tion. During the site visit, the investigator should be alert for visible
signs of emissions froo the incinerator.
A very important information source is the incinerator's air quality
operating permit, which should contain information useful in assessing the
potential for releases. Depending on the age of the incinerator and local air
quality conditions, it may have to comply with Federal NSPS and NESHAPS, and
6-6
-------
State or local regulations designed to comply with National Ambient Air
Quality Standards. An incinerator's operating permit may contain all of these
requirements.
A typical operating permit will provide some or all of the following
information: (1) a detailed description of the incinerator, including
destruction efficiency, control technology in use, and the technology's
control efficiency; (2) regulatory requirements including emission limits for
one or more pollutants and monitoring and recordkeeping requirements; and (3)
physical operating requirements (e.g., combustion temperature, waste residence
time in the incinerator). All of this information can be valuable in
assessing the potential for a release.
The source's air quality file may contain summaries of enforcement
visits. The relevant air pollution control agency should also have a com-
pliance record for the incinerator. The investigator should examine this
information to assess the unit's past performance in controlling emissions.
In some cases, monitoring data for the incinerator may be available.
These data are particularly valuable, and can be used to determine whether
emissions are occurring from the facility. Finally, for fluidi2ed-bed
incinerators, the investigator should determine hov the inorganic materials
are removed from the unit. If they they are not removed as solid waste, they
are removed as air emissions along with exhaust gases.
Fugitive Particulate Emissions
The vulnerability of the POTV to wind erosion can be assessed by deter-
mining typical wind speed and direction, the extent to which the POTV is
exposed to the wind, and the location and surroundings of the sludge piles.
The nearest airport or National Veather Service Station may be able to provide
local meteorological information, or the investigator can consult a climato-
logical atlas. Again, the investigator should be alert for signs of visible
particulate emissions.
6-7
-------
Vehicular traffic within site boundaries should be observed. The volume
and duration of traffic should be noted, as veil as any reentrainment of dust
that may be caused by movement of vehicles. Sludge handling operations within
the facility should be observed to determine if these activities may be
causing particulate emissions. The sludge itself should be examined to
determine uhether it is dry enough to release windblown particulates.
6.3 VASTE CHARACTERISTICS AFFECTING POTENTIAL FOR RELEASE TO AIR
The operation of POTVs presents two major opportunities for release of
hazardous materials to the air. First, organic compounds can volatilize from
POTV unit processes. Second, particulates and volatile metals can be emitted
from sewage sludge disposal and management activities. The following sections
discuss the characteristics of waste and constituents that affect whether
there will be releases to air from volatilization or particulate emissions.
6.3.1 Vaste/Constituent Properties Influencing Volatilization to Air
The three main factors influencing volatilization to air are the organic
compounds present in wastewater, the concentration of volatile compounds in
wastewater, and each compound's physical and chemical characteristics. The
higher the concentration of a volatile chemical in wastewater, the greater the
potential for an air release. As discussed in Chapter 3 of this guidance
document, the POTV may have influent monitoring data that provide
concentrations of individual compounds.
A given compound's physical and chemical properties have the greatest
influence on a compound's tendency to volatilize. As a result, less volatile
compounds that are present in high concentrations in wastewater may present a
lower potential for release than compounds with higher volatility that are
present in lover concentrations. The most important of these physical and
chemical properties are described below.
Vater Solubility
A compound's solubility in water is the maximum concentration at which
that compound can dissolve in water at a given temperature. This value can be
used to estimate the relative quantity of a compound that is dissolved in
6-8
-------
vater and that vhich is undissolved or immiscible. In general, the higher the
vater solubility of a given compound, the lower the potential for volatiliza-
tion to air. Also, compounds vith higher solubility are generally more bio-
degradable in biological treatment systems. Lov solubility may be associated
vith greater environmental persistence. Along vith vapor pressure, solubility
is used to estimate a compound's Henry's Lav Constant (discussed belov), a
measure commonly used to describe a compound's tendency to volatilize.
Vapor Pressure
Vapor pressure is the pressure exerted by a compound as a vapor in
equilibrium vith its pure liquid state. In general, compounds vith higher
vapor pressures are more likely to volatilize than compounds vith lover vapor
pressures. It should be noted, hovever, that releases can occur even though
the pollutant's vapor pressure is relatively lov, particularly if vastevater
is aerated.
Henry's Lav Constant
The Henry's Lav Constant for a given compound represents the equilibrium
distribution of that compound between air and vater at a constant temperature.
Henry's Lav Constant is used as a measure of the relative ease in vhich the
compound may volatilize from aqueous solution.
Chemicals vith high Henry's Lav Constants are most likely to volatilize.
In general, vhen a compound's Henry's Lav Constant is less than 10~7
atm-m3/mole, the compound vill tend not to volatilize from water. As Henry's
Lav Constant values Increase, the potential for volatilization increases.
Compounds vith values greater than 10"3, on the other hand, are likely to
volatilize from POTV treatment units. Henry's Lav Constants for selected
compounds are presented in Appendix C.
An important note is the effect of temperature on a compound's tendency
to volatilize. In general, the greater the temperature, the higher a
compound's vapor pressure. Investigators should consider this association in
making plans for conducting site investigations.
6-9
-------
6.3.2 Waste/Constituent Properties Influencing Emissions During Sludge
Incineration
The vaste characteristics discussed below, the concentration of metals
and toxic organics in sewage sludge, are important because of their strong
influence on the environmental significance of particulate matter emissions.
These characteristics do not influence the likelihood of release, but rather
the environmental threat or significance of a given release. Another waste
characteristic, the particle size distribution of a release, will strongly
affect both the dispersion and environmental consequence of a particulate
matter release. This will be discussed more fully in Section 6.4 of this
chapter.
Vaste/constituent properties do not have a major influence on emissions
from sludge incinerators. Rather, incinerator design, operation, and emission
control systems determine the type and amount of constituents that will be
released during incineration; these factors have been discussed in Section
6.2.2. Vaste/constituent properties do determine the fate and distribution of
constituents once they are released, and these factors are discussed in
Section 6.4.
6.3.3 Vaste/Constituent Properties Influencing Adsorption to Solids
Octanol/Vater Partition Coefficient
The octanol/vater partition coefficient measures the tendency of an
organic compound to sorb to organic material in sevage sludge. Compounds vlth
high coefficients are more likely to adsorb to solids in sevage sludge and are
therefore less likely to volatilize compounds vhich absorb to sludge, however,
are more likely to be release in incinerator emissions or fugitive particulate
emissions froa other sludge handling practices. Coefficients for selected
compounds art presented in Appendix C.
6.3.4 Data Required for Assessment of Vaste/Constituent Properties Affecting
Potential for Release to Air
The most important data requirement is information on the quantities and
chemical composition of the wastes that are received by the POTU. For
6-10
-------
volatile organic compounds or VOCs, a very important source of information is
the data on industrial user discharges maintained by the POTV. These data may
have been collected under an industrial user survey, or may have been obtained
as a result of compliance monitoring. This information should help identify
those organic compounds that are being discharged to the POTV, and their
amounts. The POTV may also have influent monitoring data on organic
compounds.
Once the investigator has examined the data on discharges to the POTV,
the next step is to assess the physical/chemical characteristics of the
chemicals discharged to the POTV. Appendix C provides Henry's Lav Constants
for a number of selected compounds. Using Henry's Lav Constant values as a
screening tool, the investigator may determine the likelihood of a compound
volatilizing from the POTV into the ambient air.
A second major data source is sludge monitoring data. The sludge concen-
trations of metals and adsorbed organics are crucial in assessing the environ-
mental significance of emissions of particulate matter. Elevated concentra-
tions of toxic metals (e.g., chromium, cadmium, arsenic) in sludge warrant
concern about potential human health risks, unless incinerator emissions are
very well-controlled.
6.4 ASSESSMENT OF MIGRATION POTENTIAL OF RELEASES TO AIR
As mentioned earlier, environmental factors such as temperature and uind
speed can influence the rate of volatilization. The rate at which compounds
volatilize generally increases with temperature. Also, as solid wastes become
warmer and drier and water evaporates, the likelihood of particulate emissions
increases. In wastewater containing organics, the evaporation of water tends
to increase the concentration of organics, which makes volatilization more
likely. Higher wind speeds across the surface of a body of water tend to
induce turbulence and therefore promote releases to the air. Finally,
higher wind speed increases particulate matter entrainment.
6-11
-------
The investigator is also interested in the pathway that a given release
to air might take after leaving the POTU. The factors that influence the dis-
persion and destination of air releases are local meteorology, terrain, and
che characteristics and spacing of nearby buildings and vegetation. The
investigator should identify the prevailing wind direction and observe the
local geography, (e.g., hills, tall buildings) as veil as other factors that
are likely to help determine the direction of movement of an air release.
Once the investigator has identified the likely pathway, human populations
living along that route can be identified, along vith candidate sites for
collecting upvind and downwind ambient samples. If citizens living in these
areas have filed odor complaints or citizen suits about POTV releases, this
may indicate that air releases have occurred in the past. The monitoring
sites should be chosen where available information suggests that releases will
occur.
For particulates, the particle size distribution of the release plays a
major role in influencing dispersion. Large particles will not travel as far
as smaller particles, and will tend to settle out of the release plume
earlier. In addition, the smaller particles tend to be those causing greater
risk to human health, because they penetrate the human lung. Larger particles
are also less likely to be emitted as fugitive emissions. Particle size
information may be available in a sludge incinerator's air quality permit.
6.5 SAMPLING TECHNIQUES
6.5.1 Assessment of the Need for Sampling
An investigator may choose to collect ambient sanples after determining
that there is a significant potential for air releases from a POTU. In some
cases, sampling nay not be feasible because of accessibility or problems in
obtaining oaaningful data. Monitoring data are not necessary to conclude that
a release has occurred, but are desirable in those situations vhere monitoring
is feasible.
6-12
-------
6.5.2 Selection of Sampling Parameters
The investigator must first determine the pollutant or set of pollutants
that appears to be of concern at the POTV. The number of pollutants chosen
should be very limited, since it is necessary to demonstrate only that one
pollutant is being released from the POTV. The investigator must also attempt
to identify the points vithin the POTV that are most likely to be sources of
air emissions. This information vill be used to help determine the best
sampling points.
6.5.3 Selection of Sampling Locations
After identifying the pollutants of concern and their emission source,
the investigator must then determine the best location for collecting ambient
samples. If emissions from the aeration basins appear to be most significant,
then the location of the aeration basins should be vhere ambient samples are
collected.
Sampling points vill be selected based on unit type and location. To
determine vhether a release is occurring, the investigator should use simple
upvind/dovnvind sampling. Samples should be collected upvind of the source,
directly above the source, and dovnvind of the source. If more data are
desired on vhether the release is headed offsite, a fourth sampling site
dovnvind of the site perimeter is necessary. Samples should be collected from
about three to six feet above the ground.
6.5.4 Appropriate Sampling Procedures for Air
Air sampling techniques that are relevant to conducting RFAs are those
that can quickly and econoaically indicate that VOCs or particulates are being
released. If the vaste constituent of concern is a VOC, portable organic
vapor screening devices can be used to detect most organics in the air at the
point vhere the sample is taken. The instruments do not detect some
hydrocarbons* such as pesticides, polynuclear aroisatics, and polychlorinated
biphenyls. These compounds are typically present at very low concentrations,
vhich inhibits their detection by such instruments.
6-13
-------
Portable devices are useful to confirm the presence of gaseous or vapor
phase organic compounds. They cannot yield accurate data on the specific
compounds that may be present, nor their ambient concentration. They directly
measure a total concentration for all organic compounds that register. The
two most common screening devices are flame ionization detectors, such as the
Century Organic Vapor Analyzer (OVA) 100 series and the AID Model 550, and
photoionization detectors, such as the HNU Model PI-101 and the Photovac
10A10. These relatively simple instruments can quickly provide a rough
measurement of the organic vapor concentration at a given point down to a few
parts per million. If lower detection limits are desired, an onsite gas
chromatograph can lover detection limits dovn to parts per billion.
Investigators should remember that photoionization detectors are
typically calibrated only for benzene, and OVAs for methane. As a result,
photoionization detectors are very sensitive in picking up low molecular
weight aromatics such as benzene and toluene. For other organic compounds or
mixtures of compounds, these instruments do not yield accurate measurements of
ambient concentrations, but instead provide a general indication of the
presence of volatile organics. The readings of these instruments can point to
a need for further investigation.
Another disadvantage of these systems is their relative insensitivity.
They can detect compounds in the parts per million range, vhen ambient
concentrations in the parts per billion may be of concern for some compounds.
Given this fact, these instruments are primarily useful in situations where
high VOC concentrations are expected. They can be used to determine if a
release is actually occurring at the headvorks or aeration basins by sampling
directly above them. They may be used to assess the relative release rates
from different POTV processes. They may also be used to identify the most
advantageou* locations for siting more elaborate and expensive monitors.
However, because of their high detection limits, these instruments cannot be
used to demonstrate that a release is not occurring. The concentration of the
constituents being released may simply be below the instrument's detection
limit.
6-14
-------
An alternative to these portable instruments is the use of detector
tubes. These tubes are portable, do not require laboratory analysis, and
measure specific compounds. They are small glass cubes that contain a sorbent
material that has been treated to change color when a specific organic
compound is present in the air. A hand-held pump dravs the air sample into
the tubes. The length of the color change indicates the concentration of the
compound in the air sample, and can be read in parts per million using the
scale on the tube.
Detector tubes yield a more accurate measurement of a specific compound,
since the calibration problem of the portable instruments does not apply.
Unfortunately, tubes are not available for all compounds, and they are
relatively bulky since separate tubes must be carried for each of the com-
pounds that may be of concern. In addition, their limit of detection is also
in the parts per million range. For situations where one or tvo compounds are
discharged to the plant in high concentrations and volatilization is expected,
detector tubes may be the best choice. They also may be the best choice if
the investigator needs to determine that a specific compound is being
released.
For particulate matter, personal dust monitors are available. Similar to
the screening instruments used for organics, they cannot identify specific
compounds but can be used to assess vhether particulates are being released.
6.6 ASSESSMENT OF POTENTIAL HUMAN HEALTH AND ENVIRONMENTAL EFFECTS DUE TO
RELEASES TO AIR
There are tvo major categories of environmental effects of air releases
from a POTV: 1) potential risk to human health, which includes both POTV
workers and people living in surrounding neighborhoods; and 2) potential risk
to the environaent. The following sections contain guidance on assessing the
potential effects of air releases.
6.6.1 Potential Effects on Human Health
Persons that may be exposed to an air release includes POTV workers,
residents living in neighborhoods near the POTV, and individuals that might be
6-15
-------
in che vicinity of the POTV during the day (e.g., people working or going to
school nearby). If hazardous releases occur, POTU workers are likely to be
exposed to the highest concentrations. The investigator should identify the
number of workers on the POTV site and their general location at the plant
during a typical work day.
The investigator should also identify the location and number of persons
living and working in residences and businesses nearest the POTV. The
investigator should pay special attention to structures^ that are located along
the migratory pathvay that air releases are like to follow, based on
predominant vind direction and the presence of natural or artificial vind
barriers. Individuals living or working in these areas are most likely to be
exposed to an air release. In identifying households or businesses that lie
along the release pathway, the investigator should be sure to identify
neighborhoods that could be exposed to both particulate emissions from sludge
piles, sludge handling, and sewage sludge incineration and volatile emissions
from various POTV processes.
Population density and distance from the source are the two factors that
have the greatest effect pn potential exposures. The highest potential for
exposure occurs where a densely populated neighborhood is located immediately
adjacent to a POTV. Situations where only a few individuals live very close
to a POTV are still important, because concentrations near the POTV can be
significant even though the number of people exposed may be relatively small.
The health effects for different potential exposure groups fall into two
basic categories. The first includes the acute, threshold health effects on
POTV workers and people living or working in the immediate neighborhood.
These effects may be caused by brief exposures to toxic substances and are
unlikely to affect communities located further away. Chronic health effects
from continuous, long-term exposure to lower concentrations of toxic sub-
stances are an important concern for the individuals mentioned above and
others who live or work in areas within the release pathway.
6-16
-------
6.6.2 Potential Effects on the Environment
As mentioned earlier, the same emissions of particulates and VOCs that
present risks to human health also threaten the environment. The environ-
mental effects of air releases can include vater quality degradation, buildup
of pollutant levels in soils, materials damage, and damage to vegetation,
including crops and forests. Aesthetic effects of air pollution can include
visibility impairment and odor problems.
Surface vater and soil contamination resulting from air pollution occurs
because of atmospheric deposition. Pollutants are emitted to the ambient air
and dispersion takes place. Many of these pollutants are subsequently
deposited onto surface vater or land. In assessing the potential for such
effects, the investigator should identify nearby bodies of surface water that
may be sites for atmospheric deposition, as veil as land areas where soil
contamination would be of concern, such as school playgrounds, garden plots,
or pasture areas for livestock. Other sensitive environmental areas, such as
wetlands or endangered species habitats, that are near the POTV should also be
identified.
Many organic compounds also serve as precursors to the criteria pollutant
ozone. Ozone causes damage to trees, crops, and decorative vegetation. The
proximity of the POTV to crops, forests, and public parks should be noted.
This information will give the investigator an indication of the potential
threat to nearby vegetation.
6-17
-------
APPENDIX A
PROFILE OF POLLUTANT PATE IN ACCLIMATED SECONDARY POTW*
Pollutant
Total
Removal
Rate (X)
Air
Emissions
Rate (Z)
Sludge
Parti tion
Rate (X)
Biodegradation
Rate (X)
Pass
Through
Rate (*)
Acenaphthylene
95
19
8.55
67.45
5
Acetaldehyde
95
0.47
9.5
85.02
5
Acetone
95
0.47
9.5
85.02
5
Acetonecyanohydrin
90
0
9
81
10
Acetophenone
80
0.4
3
71.6
20
Acetyl Chloride
95
0.47
9.5
85.02
5
Acrolein
95
0.47
9.5
85.02
5
Acrylamide
90
0
9
81
10
Acrylic Acid
90
0
9
81
10
Acryloni trile
90
0.45
9
80.55
10
Aldicarb
90
0
9
81
10
Aldrin
90
0
33.3
56.7
10
Aniline
95
0
9.5
85.5
5
Anthracene
95
0
52.25
42.75
5
Antimony
60
0
60
0
40
Antu
90
0
9
81
10
Arsenic
50
0
50
0
50
Atrazine
90
0
7.2
82.8
10
Barium
90
0
90
0
10
Benzal Chloride
90
0
7.2
82.8
10
Benzene
95
23.75
1.9
69.35
5
p-Benzoquinone
95
0
7.6
87.4
5
Benzotrichloride
90
18
7.2
64.8
10
Benzyl Chloride
90
22.5
7.2
60.3
10
Bis-2-Chloroethoxy H«thane
10
0
1
9
90
Bis-2-Chloroethyl Ether
90
0.45
9
80.55
10
Bis-2-Ethylhexyl Phthalate
90
0
65.7
24.3
10
Bromacil
90
0
9
81
10
Bromomethane
95
85.5
0
9.5
5
N-Butyl Alcohol
95
0
9.5
85.5
5
-------
APPENDIX A
PROFILE OF
POLLUTANT PATE IN
ACCLIMATED
SECONDARY POTW* (Continued)
Pollutant
Total
Removal
Rate (X)
Air
Emissions
Rate (X)
Sludge
Partition
Rate (X)
Biodegradation
Rate (X)
Pass
Through
Rate (v~
Butyl Benzyl Phthalate
95
0
42.75
52.25
5
Cadmium
2?
0
27
0
73
Captan
90
0
7.2-
82.8
10
CarboEuran
90
0
9
81
10
Carbon Disulfide
95
76
0.95
18.05
5
Carbon Tetrachloride
90
72
11.7
6.3
10
Chlordane
90
9
33.3
47.7
10
Chlorobenzene
90
27
13.5
49.5
10
Chlorobenzilate
90
9
7.2
73.8
10
p-Chloro-m-Cresol
95
0
7.6
87.4
5
Chloroethane
95
76
0.95
18.05
5
Chloroform
90
63
1.8
25.2
10
Chloromethane
95
85.5
0.95
8.55
5
2-Chloronaphthalene
95
0.47
35.15
59.37
5
2-Chlarophenol
95
0
7.6
87.4
5
Chromium
70
0
70
0
30
Cresols
95
0
7.6
87.4
5
Curaene
95
38
3.8
53.2
5
Cyanide
60
0.3
57
2.7
40
Cyclohexane
95
9.5
3.8
81.7
5
Cyclohexanone
85
0
8.5 .
76.5
15
Diazinon
90
0
7.2
82.8
10
Dibromomethane
85
42.5
12.75
29.75
15
Di-N-Butyl Phthalat*
90
0
19.8
70.2
10
1,2-Dichlorobenzene
90
45
31.5
13.5
10
1,3-Dichlorobenzene
90
45
2.7
42.3
10
1,4-Dichlorobenzene
90
45
22.5
22.5
10
Dichlorodifluoromethane
95
90.25
0
4.75
5
1,1-Dichloroethane
90
63
0
27
10
1,2-Dichloroethane
90
45
4.5
40.5
10
A-2
-------
APPENDIX A
PROFILE OF POLLUTANT PATE IN ACCLIMATED SECONDARY POTW* (Continued)
Pollutant
Total
Removal
Rate (X)
Air
Emissions
Rate (Z)
Sludge
Parti tion
Rate (X)
Biodegradation
Rate (Z)
Pass
Through
Rate (Z)
1,1-Dichloroethylene
95
76
0
19
5
2,4-0
90
0
7.2
82.a
10
2,4-DB
90
0
7.2
82.8
10
2,4-Dichlorophenol
95
0
7.6
87.4
5
1,2-Dichloropropane
90
45
0
45
10
Dichloropropanol
90
9
9
72
10
Dichlorvos
90
0
9
81
10
Dlcofol
90
45
8.1
36.9
10
Diethyl Phthalate
90
0
0.9
89.1
10
3,3-Dimethoxy Benzidine
60
0
8
72
20
Dimethylamine
95
0.47
9.5
85.02
5
2,4-Dimethyl Phenol
95
0
6
87.4
5
Dimethyl Phthalate
95
0
95
5
2,4-Dinitrophenol
90
0
81
10
Di-N-Octyl Phthalate
90
0
2
82.8
10
Dinoseb
90
0
2
82.8
10
1,4-Dioxane
90
0
81
10
Diphenanid
95
0
6
87.4
5
Diphenyl Amine
90
0
2
82.8
10
Disulfolton
90
0
2
82.8
10
Diuron
95
0
6
87.4
5
Endrin
95
0
15
59.85
5
Epichlorohydrin
87
0
7
78.3
13
Ethyl Acetate
95
0.47
9.5
85.02
5
Ethyl Benzene
95
23.75
5.7
65.55
5
Ethylene Oxide
90
0.45
9
80.55
10
Ethylene Thiourea
85
0
5
76.5
15
Ethyl Ether
95
9.5
5
/6
5
Fenthion
80
0
4
73.6
20
Ferbam
90
0
2
82.8
10
A-3
-------
APPENDIX A
PROFILE OF
POLLUTANT PATB IN
ACCLIMATED
SECONDARY POTS* (Continued)
Pollutant
Total
Removal
Rate (X)
Air
Emissions
Rate (X)
Sludge
Parti tion
Rate (X)
Biodegradation
Rate (X)
Pass
Through
Rate (X)
Folex
90
0
2
82.8
10
Formaldehyde
85
0.42
8.5
76.07
15
Formic Acid
90
0.45
9
80.55
10
Furan
90
0.45
12.6
76.95
10
Furfural
90
0.45
9
80.55
10
Hexachloro-1,3-Butadiene
95
0.47
8.55
85.97
5
Hexachlo roet hane
95
0.47
8.55
85.97
5
Hydrazine
95
0.47
9.5
85.02
5
Isobutanol
95
0
9.5
85.5
5
Lead
70
0
70
0
30
Haleic Hydrazide
90
0
9
81
10
Mercury
50
0.25
47.5
2.25
50
Methanethiol
95
38
9.5
47.5
5
Methanol
100
0.5
10
89.5
0
Methoxychlor
90
54
8.1
27.9
10
MCPA
95
0
7.6
87.4
5
Methyl Ethyl Ketone
95
0.47
9.5
85.02
5
Methyl Isobutyl Ketone
90
0
9
81
10
Methylene Chloride
95
38
13.3
43.7
5
Mevinphos
90
0
9
81
10
Naled
80
0
8
72
20
Napthalam
90
0
9
81
10
Naphthalene
95
0.47
26.6
67.92
5
Nickel
35
0
35
0
65
p-Nitroaniline
90
0
9
81
10
Nitrobenzene
90
0
9
81
10
2-Nitropropane
95
85.5
0.95
8.55
5
N-Nitrosodimethyl Amine
90
0
9
81
10
Oxamyl
90
0
9
81
10
Parathion
0
0
0
0
100
-------
APPENDIX A
PROFILE OF POLLUTANT FATE IN ACCLIMATED SECONDARY POTV* (Continued)
Pollutant
Total
Removal
Rate (X)
Air
Emissions
Rate (X)
Sludge
Partition
Rate (X)
Biodegradation
Rate (X)
Pass
Through
Rate (Z)
Parathion Methyl
90
0
7.2
82.8
10
Pentachloroethane
95
57
14.25
23.75
5
Pentachlorophenol
95
0
17.1
77.9
5
Phenol
95
0
14.25
80.75
5
Phenylene Diamine
90
0
9
81
10
Phorate
90
0
7.2
82.8
10
Phosgene
100
0.5
10
89.5
0
Phthalic Anhydride
90
0
9
81
10
2-Picoline
80
0.4
8
71.6
20
PCB
92
9.2
22.08
60.72
8
Pyrethrins
80
0
6.4
73.6
20
Pyridine
15
0.07
1.5
13.42
85
Resorcinol
95
0
9.5
85.5
5
Selenium
50
0
50
0
50
Silver
90
0
90
0
10
Sodium Fluoroacetate
95
0
9.5
85.5
5
Stirofos
85
0
6.8
78.2
15
Styrene
90
22.5
13.5
54
10
Te t rachlorobenzene
90
27
33.3
29.7
10
1,1,1,2-Tetrachloroethane
95
47.5
3.8
43.7
5
1,1,2,2-Tetrachloroethane
90
36
3.6
50.4
10
Tetrachloroethylene
90
45
2.7
42.3
10
Tetrahydrofuran
95
28.5
9.5
57
5
Thiourea
90
0
9
81
10
Thiran
90
0
9
81
10
Toluene
95
23.75
26.6
44.65
5
Toluene Diamine
90
0
9
81
10
Toxaphene
95
57
3.8
34.2
5
Trans-1,2-Dichloroethylene
90
63
27
0
10
Tribromonethane
65
35.75
5.2
24.05
35
-------
APPENDIX A
PROFILE OP
POLLUTANT PATE IN
ACCLIMATED
SECONDARY POTV* (Continued)
Total
Air
Sludge
Pass
Removal
emissions
Partition
Biodegradation
Through
Pollutant
Rate (X)
Rate (X)
Rate (X)
Rate (X)
Rate (X)
1,2,4-Trichlorobenzene
85
42.5
7.65
34.85
15
1,1,1-Trichloroethane
95
76
0.95
18.05
5
1,1,2-Trichloroethane
80
40
0
40
20
Trichloroethylene
95
66.5
5.7
22.8
5
Trichlorofluororaethane
95
76
0
19
5
2,4,6-Trichlorophenol
95
0
7.6
87.4
5
2,4,5-T
90
0
7.2
82.8
10
1,2,3-Trichloropropane
75
30
6
39
25
1,1,2-TC 1,2,2-TF Ethane
90
63
3.6
23.4
10
Trifluralin
90
0
33.3
56.7
10
Vanadium Pentoxide
25
0
2.5
22.5
75
Vinyl Chloride
95
85.5
1.9
7.6
5
Xylenes
95
23.75
14.25
57
5
*Estimates derived from Report to Congress on the Discharge of Hazardous Wastes to Publicy
Ovned Treatment Works, U.S. Environmental Protection Agency, February 6, 1986.
A-6
-------
APPENDIX A
PROFILE OP POLLUTANT FATE IN UNACCLIMATED SECONDARY POTV*
Total Air Sludge Pass
Pollutant
Removal
Rate (X)
Emissions
Rate (X)
Parti tion
Rate (X)
Biodegradation
Rate (X)
Through
Rate (X)
Acenaphthylene
90
54
8.1
27.9
10
Acetaldehyde
95
4.75
9.5
80.75
5
Acetone
50
2.5
5
42.5
50
Acetonecyanohydrin
50
0
5
45
50
Acetophenone
50
2.5
5
42.5
50
Acetyl Chloride
50
2.5
5
42.5
50
Acrolein
95
4.75
9.5
80.75
5
Acrylamide
62
0
6.2
55.8
38
Acrylic Acid
85
0
8.5
76.5
15
Acrylonitrile
75
3.75
7.5
63.75
25
Alachlor
50
0
4
46
50
Aldicarb
50
0
5
45
50
Aldrin
90
0
33.3
56.7
10
Aniline
85
0
8.5
76.5
15
Anthracene
90
0
49.5
40.5
10
Antimony
60
0
60
0
40
Antu
50
0
5
45
50
Arsenic
50
0
50
0
50
Atrazine
35
0
2.8
32.2
65
Barium
90
0
90
0
10
Benzal Chloride
55
16.5
4.4
34.1
45
Benzene
90
72
1.8
16.2
10
p-Benzoquinone
50
0
4
46
50
Benzotrichloride
45
13.5
3.6
27.9
55
Benzyl Chloride
90
45
7.2
37.8
10
Bis-2-Chloroethoxy Methane
10
0
1
9
90
Bis-2-Chloroethyl Ether
50
2.5
5
42.5
50
Bis-2-Ethylhexyl Phthalate
90
0
65.7
24.3
10
Bromacil
50
0
5
45
50
Br omoraethane
95
90.25
0
4.75
5
A-7
-------
APPENDIX A
PROFILB OP POLLUTANT
FATE IN
UNACCLIMATED
SECONDARY POTW* (Continued)
Pollutant
Total
Removal
Rate (X)
Air
Emissions
Rate (X)
Sludge
Parti tion
Rate (*)
Biodegradation
Rate (Z)
Pass
Througn
Rate (v
N-Butyl Alcohol
90
0
9
81
10
Butyl Benzyl Phthalate
90
0
40.5
49.5
10
Cadmium
27
0
27 ..
0
73
Cap tan
50
0
4
46
50
Carbofuran
50
0
5
45
50
Carbon Disulfide
85
76.5
0.85
7.65
15
Carbon Tetrachloride
85
76.5
8.5
0
15
Chlordane
90
9
33.3
47.7
10
Chlorobenzene
90
45
13.5
31.5
10
Chlorobenzilate
60
6
4.8
49.2
40
p-Chloro-m-Cresol
50
0
4
46
50
Chloroethane
90
81
0.9
8.1
10
Chloroform
80
72
1.6
6.4
20
Chlororaethane
90
85.5
0.9
3.6
10
2-Chloronaphthalene
80
4
29.6
46.4
20
2-Chlorophenol
65
0
5.2
59.8
35
Chromium
70
0
70
0
30
Cresols
50
0
4
46
50
Cumene
95
57
3.8
34.2
5
Cyanide
60
3
57
0
40
Cyclohexane
95
85.5
3.8
5.7
5
Cyclohexanone
50
0
5
45
50
Diazinon
60
0
4.8
55.2
40
Dibromomethane
80
64
12
4
20
Di-N-Butyl Phthalat*
90
0
19.8
70.2
10
1,2-Dichlorobenzene
87
78.3
8.7
0
13
1,3-Dichlorobenzene
87
78.3
2.61
6.09
13
1,4-Dlchlorobenzene
87
78.3
8.7
0
13
Dichlorodifluoromethane
95
90.25
0
4.75
5
1,1-Dichloroethane
80
72
0
8
20
A-8
-------
APPENDIX A
PROFILE OF
POLLUTANT PATB IN
UNACCLI MATED
SECONDARY POTV* (Continued)
Pollutant
Total
Removal
Rate (2)
Air
Emissions
Rate (X)
Sludge
Partition
Rate (X)
Biodegradation
Rate (Z)
Pass
Through
Rate (?)
1,2-Dichloroethane
50
45
2.5
2.5
50
1,1-Dichloroethylene
90
81
0
9
10
2,4-D
60
0
4.8
55.2
40
2,4-DB
60
0
4.8
55.2
40
2,4-Dichlorophenol
55
0
4.4
50.6
45
1,2-Dichloropropane
70
63
0
7
30
Dichloropropanol
50
25
5
20
50
Dichlorvos
50
0
5
45
50
Dicofol
90
45
8.1
36.9
10
Diethyl Phthalate
75
0
0.75
74.25
25
3,3-Dimethoxy benzidine
30
0
3
' 27
70
Dimethylamine
90
4.5
9
76.5
10
2,4-0ia
-------
APPENDIX A
PROFILE OP POLLUTANT
PATE IN
UNACCLIMATED
SECONDARY POTV* (Continued)
Pollutant
Total
Removal
Rate (X)
Air
Emissions
Rate (X)
Sludge
Partition
Rate {X)
Biodegradation
Rate {%)
Pass
Through
Rate (21
Ferbam
55
0
4.4
50.6
45
Folex
60
0
4.8
55.2
40
Formaldehyde
85
4.25
8.5-
72.25
15
Formic Acid
90
4.5
9
76.5
10
Furan
70
3.5
9.8
56.7
30
Furfural
60
3
6
51
40
Hexachloro-1,3-Butadiene
90
4.5
8.1
77.4
10
Hexachloroe thane
90
4.5
8.1
77.4
10
Hydrazine
85
4.25
8.5
72.25
15
Isobutanol
90
0
9
81
10
Lead
70
0
70
0
30
Haleic Hydrazide
75
0
7.5
67.5
25
Mercury
50
2.5
47.5
0
50
Methanethiol
77
46.2
7.7
23.1
23
Methanol
95
4.75
9.5
80.75
5
Methoxychlor
90
54
8.1
27.9
10
MCPA
50
0
4
46
50
Methyl Ethyl Ketone
50
2.5
5
42.5
50
Methyl Isobutyl Ketone
50
0
5
45
50
Methylene Chloride
87
52.2
12.18
22.62
13
Mevinphos
50
0
5
45
50
Naled
50
0
5
45
50
Napthalam
40
0
4
36
60
Naphthalene
75
3.75
21
50.25
25
Nickel
35
0
35
0
65
p-Nitroaniline
69
0
6.9
62.1
31
Nitrobenzene
25
0
2.5
22.5
75
2-Ni tropropane
95
90.25
0.95
3.8
5
N-Nitrosodimethyl Amine
75
0
7.5
67.5
25
Oxamyl
50
0 .
5
45
50
A-10
-------
APPENDIX A
PROFILE OP POLLUTANT FATE IN UNACCLIHATED SECONDARY POTV* (Continued)
Pollutant
Total
Removal
Rate (7)
Air
Emissions
Rate (X)
Sludge
Partition
Rate (X)
Biodegradation
Rate (2)
Pass
Through
Rate (X)
Parathion
55
0
4.4
50.6
45
Parathion Methyl
55
0
4.4
50.6
45
Pentachloroethane
75
45
11.25
18.75
25
Pentachlorophenol
25
0
4.5
20.5
75
Phenol
83
0
12.75
72.25
15
Phenylene Diamine
75
0
7.5
67.5
25
Phorate
60
0
4.8
55.2
40
Phosgene
100
5
10
85
0
Phthalic Anhydride
90
0
9
81
10
2-Picoline
15
0.75
1.5
12.75
85
PCB
92
9.2
22.08
60.72
8
Pyrethrins
60
0
4.8
55.2
40
Pyridine
15
0.75
1.5
12.75
85
Resorcinol
75
0
7.5
67.5
25
Selenium
50
0
50
0
50
Silver
90
0
90
0
10
Sodium Fluoroacetate
50
0
5
45
50
Stirofos
60
0
4.8
55.2
40
Styrene
90
72
13.5
4.5
10
Te t rachlorobenzene
90
27
33.3
29.7
10
1,1,1,2-Tetrachloroethane
90
63
3.6
23.4
10
1,1,2,2-Te trachloroethane
25
15
1
9
75
Te trachloroethylen*
85
68
2.55
14.45
15
Tetrahydrofuran
75
52.5
7.5
15
25
Thiourea
75
0
7.5
67.5
25
Thiram
75
0
7.5
67.5
25
Toluene
90
72
18
0
10
Toluene Diamine
75
0
7.5
67.5
25
Toxaphene
90
72
3.6
14.4
10
Trans-l,2-Dichloroethylene
80
72
8
0
20
A-ll
-------
APPENDIX A
PROFILE OP POLLUTANT FATE D) UNACCLIMATED SECONDARY POTV* (Continued)
Total Air Sludge Pass
Removal Emissions Partition Biodegradation Through
Pollutant Rate (X) Rate (X) Rate (2) Rate (Z) Rate (2"
Tribromomethane 35 21 2.8 11.2 65
1.2.4-Trichlorobenzene 85 51 7.65 26.35 15
1.1.1-Trichloroethan e 90 81 0^ 8_11 10
1.1.2-Trichloroethane 25 20 0 5 75
Trichloroethylene 87 69.6 5.22 12.18 13
Trichlorofluoromethane 90 81 0 9 10
2,4,6-Trichlorophenol 55 0 4.4 50.6 45
2.4.5-T 50 0 4 46 50
1.2.3-Trichloropropan e 25 17.5 2 fL_5 75
1,1,2-TC 1,2,2-TP Ethane 85 68 3.4 13.6 15
Trifluralin 90 0 33.3 56.7 10
Vanadium Pentoxlde 25 0 2_J5 22.5 75
Vinyl Chloride 95 90.25 1.9 2.85 5
Xylenes 87 69.6 13.05 4.35 13
~Estimates derived from Report to Congress on the Discharge of Hazardous Wastes to Publlcy
Ovned Treatment Works, U.S. Environmental Protection Agency, February 6, 1986.
A-12
-------
AFPUDlI I
HAXABIKWIS WASTS OONSTITUUTTS POTENT IA1XT CSNUATBD
AND DISCHARGED OT SKLSCTBD IMMJSTKIKS
Electrical
and
Electronic Explosives
Coaponenta Manufacture
Hazardous
Waste
Management
Facilities
Iron Metal
Inorganic and Finishing/
CheatcaIs Steel Equipment
Manufacture Manufacture Manufacture
Nonferrous
Met a 1s
Manufacture
Organic
Cheatca Is
Manufacture
Acenaphthylene
X
X X
X
X
Acetaldehyde
X
X
Acetone
X
X
X
X
AceConecyanohydr1n
X
X
Acetophenone
X
X
Acetyl Chloride
X
X
Acrolein
X
X
Acrylaalde
X
X
Acrylic Acid
X
K
Acrylonltrlle
X
X
Alachlor
X
Aldlcarb
X
Aldrln
X
Aniline
X
K
Anthracene
X
X
X X
K
X
Antlaony
X X
X
XXX
Antu
X
Araenlc
X
X
XXX
Atraxlne
X
Barlua
X
X
XXX
Bensal Chloride
X
X
¦eocene
X
X
X X
X
X
p-Bensoqulnone
X
X
Benzotrlchloride
X
X
Benzyl Chloride
X
X
X
X
Bls-2-Chloroethoxy Methane
X
X
Bls-2-Chloroethyl Ether
X
X
Bls-2-ethylhexyl Phthalate
X
X
X
broucl 1
X
-------
AfPKMOlX |
m/iBIXMIS IUSTI COMSTITOKNTS POnUTTULLV CBNUATKD AID D1SOUBCK0 BY SKLSCTUt 1HDUSTV1BS (Continued)
Electrical
Hazardous
1 ron
Hetd 1
and
Waste
Inorganic
and
Finishing/
Honferrous
Organic
Elect ronlc
tuples Ives
Manageaent
Chealcals
Steel
tquIpaent
Het j1 a
ChealcaJa
Coaponenta
Manufacture
Facilities
Manufacture
Hanufacture
Hanufacture
Hanuf acturt
Manufacture
Broaoaethane
X
X
N-Butyl Alcohol
11
X
X
X
Butyl Benzyl Phthalate
X
X
X
Cadalua
X
X
X
X
X
X
Captan
Carbofuran
Carbon Disulfide
X
X
Carbon Tetrachloride
X
X
X
X
Jhlordane
X
:hlorobenzene
X
X
X
X
:tiiorobenzl late
X
i-Chloro-a-Cresol
X
X
:hloroechane
X
X
hlorofora
X
X
X
X
:hloroaelhane
X
X
X
X
-Chloronaphthalene
X
X
-Chlocophenol
X
X
hroalua
X
X
X
X
X
X
raaola
X
X
X
X
uaene
X
X
X
X
X
«
e
m
>
X
X
X
X
X
X
ydoheiane
X
X
K
X
X
pclohexanone
X
X
X
X
tazlnon
X
I broaoaethane
X
X
l-N-Butyl Phthalate
X
X
X
. 2-Ulchlorobenzene
X
X
X
X
, 3-Dlchlorob«uzene
. 4-Dichlorobenzene
-------
APPENDIX 5
UUIMUS UASTB CDKSTITOXIITS
Electrical
and
Electronic
Components
potent laixt
Explosives
Manufacture
GBMEUTU AND
Hazardous
Waste
Manageaent
Facllltlea
DtSCIUSSKD BT
Inorganic
Chealcals
Manufacture
SBLBCreD 1NDQSTVIBS (Continued)
Iron Metal
and Finishing/ Nonferrous
Steel Equipment Metala
Manufacture Manufacture Manufacture
Organic
Chealcals
Manufacture
01ch1orod1fIuoroae thane
X
X
1,l-Dlchloroethane
X
X
1.2-Dlchloroethana
X
X
K
X
1,l-Dlchloroethylene
X
X
2.4-D
X
2.4-DB
X
2,4-Dlchlorophenol
X
X
1,2-Dlchloropropane
X
X
Olchlorapropanol
X
X
Dichlorvos
X
Dlcofol
X
Diethyl Phthalate
X
X
X
3,3-Dlaethoiy benzidine
X
X
Dlaechylaalne
X
X
2.4-Dlaethyl Phenol
X
XXX
Ulaethyl Phthalate
X
X
X
2,4-Dlnltrophenol
X
XXX
X
Dl-N-Octyl Phthalate
X
X
X
Dinoeeb
X
1,4-Dloxane
X
X
Diphenaald
X
Diphenyl Aalne
X
X
Dlaulfoion
X
Uluron
X
tudrtn
X
Eplchlorohydrlu
X
X
fcthvl Acetate
X
X
X
X
Ethyl Benzene
X
X
XXX
X
hthylene l)*lde
X
K
-------
APPENDIX ¦
WimiKinS HASTE OOKSTlTUKirrS POrarTLALLY G8MUAT8D AMD DISCHABCKD BT SELECTED UtDUSTtlBS (Cootl»utd)
Electrical
and
electronic Explosives
Coaponenta Manufacture
Ethylene Thiourea
Ethyl Ether
Penthlon
Hazardous
Waste
Hanageaent
Pact!1tles
X
X
X
Iron Hetal
Inorganic and Finishing/ Nunierrous
Chealcala Steel Equtpaent MeLals
Manufacture Manufacture Manufacture Manufacture
Urgentc
Chealcala
Hanuf actu re
X
X
Perbaa
Folex
Formaldehyde
Foralc Acid
Puran
Furfural
X
Hexachloro-1,3-Butadiene
X
Hexachloroethane
X
Hydrazine
X
Isobutanol
X
X
X
Lead
X
X
X
X
X
X
Halelc Hydrailde
X
Mercury
X
X
X
Methanethlol
X
X
X
Methanol
X
X
X
Hethoxychlor
MCPA
Methyl Ethyl Ketone
X
X
X
Methyl Isobutyl Ketone
X
X
X
Methylene Chloride
X
X
X
ievlnphos
Haled
Napthalaa
Naphthalene
X
X
X
X
X
K
Ml eke 1
X
X
X
X
X
1>-N11 roanl 11 ne
-------
Aprmoii ¦
¦mabdobs vasts coMSTi-nwrrs
porrmriAU-t a
UKKATVD AMD
PlflfBAICHP BY
SELECTED 1MDUSTBIKS (Continued)
Electrical
Hazardous
iron Hetal
and
Waste
tnorganlc
and Finishing/ Nonferrous
Organic
Electronic
Exploalves
Manageaent
Cheatcala
Steel Equipaent Hetals
Chealcala
Components
Manufacture
Facilities
Manufacture
Manufacture Manufacture Manufacture
Manufacture
Nitrobenzene
X
2-N1tropropane
X
X
N-HItrosodlaethyl Aalne
X
X
X
Oxaayi
X
Parathlon
X
Parathlon Methyl
Pentachloroethane
X
X
Pcntachlorophenol
X
X
Phenol
X
X
XX X
X
Phenylene Dlaalne
X
X
Pborate
X
Phoa&ene
X
X
Phthallc Anhydride
X
X
2-Plcollne
X
PC#
X
X
XX X
X
Pyrethrlna
X
Pyridine
X
X
teaorctnol
X
X
Selenlua
X
X
X
X X
Sliver
X
X
X X
Sodtua Fluoroacetate
X
Stlrofoa
X
Styrene
X
XX X
X
Tetrachlorobenzene
X
X
1,1,1,2-Tetrachloroethane
X
X
1 ,1,2,2-Tet rachloroethane
X
X
Tetrachloroethylene
X
X
X
X
Telrahydrofuran
X
X
X
X
Thiourea
X
X
-------
APPEKDU I
HAZARDOUS UASTI COHSTITUEHTS POTKITT LALLT QKJIUATKD AMD DISCUAUXD BY SBL£CTCD UtDUSTVIKS (Continued)
Chlraa
Toluene
Toluene Diamine
Electrical
and
Electronic
Components
Explosives
Manufacture
Hazardous
Waste
Manageaent
Facl11tlea
X
X
X
Inorganic
Chenlcala
Manufacture
1 ron
and
Steel
Manufacture
Metal
Finishing/
Equipment
Manufacture
Nonferrous
Met a Ib
Ma nut aclure
Organ 1 c
Cheat ca1u
Hanufacture
"onaphene
"rana-1,2-Dlchloroethylene
ribroaoaethane
,2,4-Trlchlorobantene
, I, l-Tr tchLoroeltiane
rlchloroethylene
rlchlorofIuorone thane
.4.6-Trlchlorophenol
,4,5-T
,2,3-Trlchloropropane
,1.2-TC 1.2.2-TF Ethane
rlfluralln
anadlun Pentoxlde
Inyl Chloride
ylenea
-------
APPDDII I
HAT ABIWOS WA3TB C0MST1TUBHTS
rarwuuxT c
HKU1BD AMD OlSOUiaO BV SELECTED 1MD0STB1BS
Paint
Manufacture
Peatlcldes
Manufacture
Plastics/ Utilities
Petroleua Pharnaceutlcala Rubber (Steaa Wood
Refining Manufacture Manufacture Klectrlc) Preserving
Acenaphthylene
X
X X
Acetaldehyde
X
X X
Acetone
X
X
X X
Acetonecyanohydrln
Acetophenone
X X
Acetyl Chloride
Acroleln
X
X
Aery 1aside
Acrylic Acid
X
X
Aerylonltrlle
X X
Alachlor
X
Aldlc«rb
X
Aldrln
X
Ant line
X
X XX
Anthracene
X
X x
Antlaony
X
X
Antu
X
Araenlc
X
X
X x
Atraclne
X
Barlua
X
X
X x
Benial Chloride
Bantene
X
X
XXX X
p-Bencoqu1none
Bensotrlchloride
Bensyl Chloride
X
X
Bla-2-Chloroethoiy Methane
Bla-2-Chloroethyl Ether
Blo-2-EthyIhexy1 Phthalate
X
X
Bruaacl1
X
Broooaelltaoe
-------
AFraMDlX ¦
HAZARDOUS
WASTE OONSTITUKirrS POTBJfTLAU.* GXNBSATVD AMD DISTHABGKI) BY SELECTED
IKDUSniKS (Coat lnaed)
Paint
Manufacture
Pesticides
Manufacture
Petroleua Pharmaceuticals
Refining Manufacture
Plastics/ Utilities
i Rubber (Steaa
Manufacture Electric)
Wood
Preserving
N-Butyt Alcohol
X
X
X
X
Butyl Benzyl Phthalace
X
Cadilu*
X
X
X
Captan
X
X
Carbofuran
X
Carbon Disulfide
X
X
X
Carbon Tetrachloride
X
X
K
Chlardane
X
Chlorobenzene
X
X
X
X
Chioroberullate
X
p-Chloro-a-Cresol
X
Chloroethane
X
Chloroform
X
X
X
X
Chloroaethane
X
X
X
X
2-£hloronaphthalene
2-Chlorophenol
X
X
Chroalua
X
X
X
X X
X
Cretola
X
X
X X
X
Cuaene
X
X
X X
X
X
Cyanide
X
X X
X
Cvclohexane
X
X
X X
X
X
Cyclohexanone
X
X
X
Olazlnon
X
Dlbroaoaethane
X
01-N-BuCyt Phthalace
X
1,2-Dlchlorobenzene
X
X
X
1 .1-Dlchlorobenxene
1 ,4-lHchlorobemene
X
01chlorod1f1uuroaechane
X
1 l-Ulchloroethane
X
X
-------
APPKBDIX B
Paint
Manufacture
(T1ALLV OHUT
PestIcldea
Manufacture
ED AMD DISCBAKCSD IT SELECTED INDUSTRIES (Cootlowed)
Plastics/ Utilities
Petroleum Pharmaceuticals Rubber (Stean
Reflnlnit Manufacture Manufacture electric)
Uood
Preserving
1,2-Dlchlnroethane
(
X
K
1,1-Dlchloroethylene
X
2,4-0
X
2,«-DB
X
2,4-Dlchlorophenol
X
X
1.2-Dlchloropropane
Dlchloropropanol
Dlctilorvoa
X
Dlcolol
X
Diethyl Phthalate
X
3,3-DlBethosy benzldin
•
Dlaethylaalne
X
X
2,4-Dlaethyl Phenol
X
X
X
DiaeChyl Phthalate
X
2,4-Dlnltrophenol
X
X
Dl-H-Octyl Phthalate
X
Dlnoseb
X
1,4-Dloun«
X
x x
Dlphenasld
X
Dlphenyl Aalne
X X
Dlaulfoton
X
Dluron
X
Bndrln
X
Eplchlorohydrln
X
ethyl Acetate
X
X
X
Ethyl Bentene
X
X
X XX
X
ethylene Oxide
X X
ethylene Thiourea
tthyl tther
X
X
X
Fenthlon
X
-------
APPENDIX >
mwnoilg MAST! COMSTITUKJfTS POTBIfTLALLy CSIUATKD AMD DISCBAKC8D BT SKLBCTKO LMDUSTO1BS (Continued)
Plautlcs/ Utilities
Paint Pesticides
Petroleua
Pharaaceutlcals
Rubber
(Stean
Wood
Manufacture Manufacture
KefInlng
Manufacture
Manufacture
Elect r1c )
Hreuerv 1 n«
Perban
X
Poles
X
Poraaldehyde
X
Poralc Acid
X
Puran
X
Furfural
X
X
X
Hexachloro-1,3-Butadlene
X
Hexachloroethane
X
Hydrazine
X
Iaobutanol
X
X
X
Lead
X X
X
X
Halelc Hydraride
Mercury
X X
X
Hethanethlol
X
X
X
Methanol
X X
X
X
Methoaychlor
X
MCPA
X
Methyl Ethyl Ketone
X X
X
X
X
Methyl laobutyl Ketone
X
X
X
X
Methylene Chloride
X X
X
X
Mevlnphoa
Naled
X
Napthalaa
X
Naphthalene
X X
X
X
X
Nickel
X X
X
p-Nltroant1lne
X
X
X
Nit rubenzene
X
X
Z-Nliropropaiie X X
N-N11robojIneIhy1 Anlne
Oxanyl X
-------
Arruoii •
hhwiwii tujm oonsrinwrrs rerunlaixy cuobaw mb oisoukcbo bi shuctco ikdustmks (continued)
Plasties/ Utilities
Paint
Manufacture
Pestlcldea
Manufacture
Petroleua
Refining
PharaaceutIcaia
Manufacture
flubbe r
Manufacture
(Stem
Elect r1c )
Wood
Preserving
Parathion
Parathion Methyl
Pentachloroethane
X
X
Pentachiorophenol
Phenol
Phenylene Dlaaine
*
X
X
X
X
X
X
X
K
X
Phorate
Phoagene
Phthallc Anhydride
X
X
X
2-Plcoline
PCB
Pyrethrlns
X
X
X
Pyridine
taaorclnol
Selenlua
X
X
X
X
X
X
Silver
Sodlua Pluoroacetate
Stlrofoa
X
X
X
X
Stytene
Tecrachlorobencene
I.I.I. 2-Tetrad)loraetbane
X
X
X
K
X
1,1,2,2-Tetrachloroethane
Tetrachloroathylene
Tetrahydrofuran
X
X
X
X
X
X
X
X
X
Thiourea
Thlraa
Toluene
X
X
X
X
X
X
Toluene Dlaaine
Toxaphene
Trans-I cMoroetliylene
-------
tfranu »
uAMinrws
IUSTI OOMSTITllBirrS rOTIUfTUUXT OUUUtAnO AMD DISOUROtfl IT SHLKCTED
UDUSniBS (Continued)
Paint
Manufacture
Pesticides Petroleua Phanaaceutteals
Manufacture Refining Manufacture
Plasties/ Utilities
Rubber (Stcao
Manufacture Electric)
Wood
Preuervlnx
Trlbroaoaethane
X
1,2,4-Trlchlorobenzene
X
1.1. I-Trichlocoethane
X
X X
1,1,2-Trlchloroethane
X
X X
X
Tr lchloroethylene
X
X X
Trlchlorofluoroaethane
X X
2,4,6-Trlchlorophenol
X
X
2,4,5-T
X
X
1.2.3-Trlchloropropane
1,1,2-TC 1,2,2-Tf Ethane
X
X
Trlfiuralin
X
Vanadiua Pentoxlde
Vinyl Chloride
X
Xy lenes
X
XX X
X
X
-------
APPENDIX C
DATA ON PHYSICAL AND CHEMICAL PROPERTIES FOR SELECTED CONSTITUENTS
Consti tuent
Vater
Solubility (mg/1)
Henry's Lav
Constant
atm-m /nol
Octanol/Vater
Parti tion
Coefficient (K ;
Acenaphthylene
4.0
1.45 x 10"3
1.17 x 104
Acetaldehyde
-
7.4 x 10"5
2.7
Acetone
1.0 x 10*
6.8 x 10-6
.57
Acetonecyanohydrin
-
Lov
0.4
Acetophenone
-
Low
38.9
Acetyl Chloride
-
Low
0.67
Acrolein
-
6.79 x 10"5
0.8
Acrylamide
-
3.0 x 10~l°
1.55
Acrylic Acid
1.0 x 10s
Lov
0.59
Acryloni trile
7.9 x 104
9.2 x 10"s
1.78
Alachlor
-
Lov
210
Aldicarb
-
2.1 x 10"*
' 11
Aldrin
0.18
1.6 x 10"5
4.7 x 104
Aniline
-
1.1 x 10"S
9.5
Anthracene
0.045
8.6 x 10"5
2.8 x 104
Antimony
-
-
-
Antu
-
Lov
130
Arsenic
-
-
-
Atrazine
-
2.6 x 10"9
478
Barium
-
-
-
Benzal Chloride
-
1.7 x 10"4
645
Benzene
1.78 x 10J
5.5 x 10"J
126
p-Benzoquinon«
-
5.0 x 10"7
1.6
Benzotrichlorld*
-
1.1 x 10"4
831
Benzyl Chlorid*
3.3 x 103
5.1 x 10"1
200
Bis-2-Chloroethoxy Methane
8.1 x 104
2.7 x 10"7
18.2
Bis-2-Chloroethyl Ether
1.02 x 104
1.3 x 10"s
29.0
Bis-2-Ethylhexyl Phthalate
0.4
3.0 x 10"7
5 x 108
Bromacil
-
Lov
72
Bromomethane
900
1.06 x 10"1
12.6
C-l
-------
APPENDIX C
DATA ON PHYSICAL AND CHEMICAL PROPERTIES FOR SELECTED CONSTITUENTS (Continued)
Consti tuent
Water
Solubility (mg/1)
Henry's Law
Cons tant
atm-m /mol
Oc tanol/Vater
Parti tion
Coefficient (K...
N-Butyl Alcohol
-
7 x 10"s
No data (lov k )
v o w '
Butyl Benzyl Phthalate
2.9
1.0 x 10"s
6.3 x 104
Cadmium
-
-
N/A
Captan
0.5
Low
224
Carbofuran
-
8.3 x 10"9
40
Carbon Disulfide
3.0 x 103
1.2 x 10"2
No data (lou K...
Carbon Tetrachloride
7.5 x 102
2.3 x 10"2
436
Chlordane
0.056
9.4 x 10"5
2.1 x 104
Chlorobenzene
488
3.5 x 10"3
690
Chlorobenzilate
22
5.2 x 10-s
4000
p-Chloro-m-Cresol
3.85 x 103
2.5 x 10"6
1300
Chloroethane
5.74 x 103
1.48 x 10"2'
34.7
Chloroform
1.0 x 104
2.88 x 10"3
93
Chloromethane
6.45 x 103
3.8 x 10"1
8.1
2-Chloronaphthalene
-
3.15 x 10'4
1.3 x 104
2-Chlorophenol
2.85 x 104
4.7 x 10"S
148
Chromium
-
-
N/A
Cresols
3.0 x 104
2.5 x 10"s
1360
Cumene
-
1.4 x 10"2
4500
Cyanide
-
-
-
Cyclohexane
-
0.18
2700
Cyclohexanone
-
2.5 x 10"5
6.46
Diazinon
-
1.4 x 10"6
570
Dibromomethan®
-
Moderate
Lov
Di-N-Butyl Phthalat*
-
2.8 x lO'7
1.58 x 10*
1,2-Dlchlorobenzene
100
3.6 x 10"3
2400
1,3-Dichlorobenzene
123
2.63 x 10"1
3600
1,4-Dichlorobenzene
79
2.37 x 10"3
3600
Dichlorodifluoromethane
280
1.5
145
1,1-Dichloroethane
5.5 x 103
4.26 x 10"3
63
C-2
-------
APPENDIX C
DATA ON PHYSICAL AND CHEMICAL PROPERTIES FOR SELECTED CONSTITUENTS (Continued)
Consti tuent
Water
Solubility (mg/1)
Henry's Lav
Constant
atm-m /mol
Octanol/Ua ter
Partition
Coefficient (K_.
1,2-Dichloroethane
8.5 x 103
9.14 x 10"'
34
1,l-Dichloroethylene
2.3 x 103
1.5 x 10"J
134
2,4-D
610
2.0 .x 10'10
645
2,4-DB
-
Low
530
2,4-Dichlorophenol
4.6 x 103
2.0 x 103
2000
1,2-Dichloropropane
2.7 x 103
2.8 x 10"3
87
Dichloropropanol
-
4.0 x 10~4
0.34
Dichlorvos
-
3.5 x 10~7
28
Dicofol
-
4.7 x 10"3
4.5 x 104
Diethyl Phthalate
896
4.75 x 10"S
1600
3,3-Dimethoxy benzidine
-
1.0 x 10"11
28.8
Dimethylamine
1.0 x 10s
5.9 x 10"'
0.5
2,4-Dimethyl Phenol
-
1.8 x 10"5
316
Dimethyl Phthalate
5.0 x 103
2.1 x 10"7
131
2,4-Dini trophenol
5.6 x 103
6.45 x 10"10
34.7
Di-N-Octyl Phthalate
-
3.0 x 10~7
1.58 x 10s
Dinoseb
45
Lov
124
1,4-Dioxane
4.3 x 10!
7.0 x 10"7
0.38
Diphenamid
-
Lov
210
Diphenyl Amine
58
Low
3160
Disulfoton
-
2.6 x 10"5
1800
Diuron
-
Lov
400
Endrin
0.25
4.0 x 10"7
3.4 x 104
Epichlorohydrin
6.0 x 104
3.13 x 10"5
0.42
Ethyl Acetate
-
1.2 x 10"4
5.37
Ethyl Benzene
152
6.44 x 10"J
1412
Ethylene Oxide
1.0 x 10*
3.63 x 10"s
0.5
Ethylene Thiourea
2.0 x 103
Lov
0.14
Ethyl Ether
-
8.69 x 10"4
5.88
Fenthion
C-3
2.0 x 10"7
480
-------
APPENDIX C
DATA ON PHYSICAL AND CHEMICAL PROPERTIES FOR SELECTED CONSTITUENTS (ConHmiPd)
Consti tuent
Water
Solubility (mg/1)
Henry's Law
Constant
atm-m /mol
Octanol/Vater
Parti tion
Coefficient (K...;
Ferbam
-
Low
300
Folex
-
Low
Moderate
Formaldehyde
4.0 x 105
5.1 x 10"4
0.13
Formic Acid
1.0 x 107
4.4 x 10'7
0.8
Furan
-
5.7 x 10"3
21.8
Furfural
-
3.6 x 10"6
7.2
Hexachloro-1,3-Butadiene
0.15
1.03 x 10"2
6.0 x 104
Hexachloroe thane
50
9.85 x 10"3
4.2 x 104
Hydrazine
3.4 x 10*
Low
0.06
Isobu tanol
9.5 x 104
1.03 x 10"s
4.07
Lead
-
-
N/A
Maleic Hydrazide
-
Low
5.0 x 10"4
Mercury
-
-
N/A
Methanethiol
-
4.0 x 10"3
4.57
Methanol
-
1.1 x 10"6
.23
Methoxychlor
-
Moderate
8.0 x 104
MCPA
-
Low
110
Methyl Ethyl Ketone
3.53 x 10"5
5.8 x 10"5
-
Methyl Isobutyl Ketone
-
-
-
Methylene Chloride
2.0 x 104
2.03 x 10"3
18
Mevinphos
-
Low
3.5
Naled
-
Low
24
Napthalam
-
Low
4
Naphthalene
31.7
4.8 x 10"4
2200
Nickel
-
-
-
p-Nitroaniline
-
1.0 x 10"s
24.6
Nitrobenzene
1.9 x 103
1.3 x 10"5
72
2-Nitropropane
-
.12
Low
N-Nitrosodimethyl Amine
-
Low
0.27
Oxamyl
-
2.4 x 10"10
4
C-4
-------
APPENDIX C
DATA ON PHYSICAL AND CHEMICAL PROPERTIES FOR SELECTED CONSTITUENTS (Continued)
Constituent
Vater
Solubility (mg/1)
Henry's Lav
Constant
atm-m /mol
Octanol/Vater
Parti tion
Coefficient (K_
Parathion
-
5.8 x 10"7
141
Parathion Methyl
-
5.6 x 10"8
110
Pentachloroethane
-
2.17 x 10"3
4700
Pentachlorophenol
14
2.8 x 10~S
1.1 x 105
Phenol
9.3 x 104
4.54 x 10"7
30
Phenylene Diamine
-
Lov
(o-) 25.7
(m-) 12.6
Phorate
-
5.7 x 10"s
3.2 x 10"5
Phosgene
-
Hydolyzes
Hydrolyzes
Phthalic Anhydride
-
1.0 x 10"lc
0.48
2-Picoline
-
2.4 x 10"5
15.85
PCB
0-400
lo^-io*5
104-107
Pyrothrins
-
Lov
Moderate
Pyridine
1.0 x 10s
7 x 10"9
0.02
Resorcinol
-
1.0 x 10"13
6.3
Selenium
-
_
N/A
Silver
-
-
N/A
Sodium Fluoroacetate
-
Low
Low
Stirofos
_
3.3 x 10"6
2100
Styrene
280
9.7 x 10"J
891
Tetrachlorobenzene
6.0
1.0 x 10"4
4.7 x 104
1,1,1,2-Tetrachloroethane
2.9 x 103
l.l x 10~J
1100
1,1,2,2-Tetrachloro«thane
2.9 x 103
3.8 x 10~4
363.08
Te t rachloroethylana
200
1.53 x 10"J
759
Tetrahydrofuran
-
1.08 x 10~4
5.4
Thiourea
1.7 x 10s
Lov
.016
Thirara
-
Lov
Lov
Toluene
534.8
6.7 x 10"3
620
Toluene Diamine
-
2.3 x 10"'
0.81
Toxaphene
0.5
4.3 x 10"1
2000
Trans-1,2-Dichloroethylene
6.3 x 103
C-5
6.6 x 10"3
34
-------
APPENDIX C
DATA ON PHYSICAL AND CHEMICAL PROPERTIES FOR SELECTED CONSTITUENTS (Continued)
Cons t i tuent
Vater
Solubility (mg/1)
Henry's Lav
Constant
atm-m /mol
Oc canol/Va ter
Partition
Coefficient (K...
Tribromomethane
3.0 x 103
5.82 x 10"1
200
1,2,4-Trichlorobenzene
30
2.3 x 10"3
1.9 x 104
1,1,1-Trichloroe thane
720
3.0 * 10"J
310
1,1,2-Tricoloroethane
4.5 x 103
7.42 x 10"4
117
Trichloroethylene
1.1 x 103
9.1 x 10"3
263
Trichlorofluororaethane
1.1 x 103
5.8 x 10"2
339
2,4,6-Trichlorophenol
800
4.0 x 10"*
4100
2,4,5-T
-
2.2 x 10"4
5248
1,2,3-Trichloropropane
-
-
102
1,1,2-TC 1,2,2-TF Ethane
10.0
High
2000
Irifluralin
-
-
-
Vanadium Pentoxide
-
-
_
Vinyl Chloride
2.7 x 101
1.99 x 10"1
17
Xylenes
1.98 x 10J
5.1 x 10"3
(o-) 1585
(m-) 589
(P-) 1412
C-6
------- |