9285.9-27
EPA 540/R-94-099
PB95-963212
October 1994
INTRODUCTORY PRELIMINARY ASSESSMENT
TRAINING MANUAL
Office of Emergency and Remedial Response
U.S. Environmental Protection Agency
Washington, DC
-------
-------
9285.9-27
EPA 540/R-94-099
PB95-963212
October 1994
INTRODUCTORY PRELIMINARY ASSESSMENT
TRAINING MANUAL
Office of Emergency and Remedial Response
U.S. Environmental Protection Agency
Washington, DC
-------
9285.9-27
EPA540-R-94-099
PB95-963212
FOREWORD
This manual is for reference use of students enrolled in scheduled training courses of the U.S.
Environmental Protection Agency (EPA). While it will be useful to anyone who needs information
on the subjects covered, it will have its greatest value as an adjunct to classroom presentations
involving discussions among the students and the instructional staff.
This manual has been developed with a goal of providing the best available current information;
however, individual instructors may provide additional material to cover special aspects of their
presentations.
Because of the limited availability of the manual, it should not be cited in bibliographies or other
publications.
References to products and manufacturers are for illustration only; they do not imply endorsement
by EPA.
Constructive suggestions for improvement of the content and format of the manual are welcome.
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INTRODUCTORY PRELIMINARY ASSESSMENT TRAINING
2 Days
This course provides participants with an introduction to the Superfund site assessment process and the
fundamentals of the preliminary assessment phase of this process. The site assessment process is used
to screen hazardous waste sites for inclusion on the U.S. Environmental Protection Agency's (EPA)
National Priorities List and to prioritize sites for further investigation and remediation. Participants will
receive the background necessary to perform preliminary assessments and to develop preliminary site
scores. The course is designed for individuals with little experience in the initial evaluation of hazardous
waste sites.
The course format is based on the EPA document entitled Guidance for Performing Preliminary
Assessments Under CERCLA. The focus is on implementing EPA preliminary assessment guidance rather
than on emphasizing the mechanics of scoring sites using the Hazard Ranking System.
Topics to be discussed include an overview of the site assessment process; the fundamentals of the Hazard
Ranking System; data collection strategies; site reconnaissance and documentation procedures; site,
source, and waste characterization techniques; groundwater, surface water, air, and soil exposure pathway
analyses; and preliminary assessment scoring methodology.
After completing this course, participants will be able to:
Describe how the outcome of the site assessment process affects the placement of a hazardous
waste site on the National Priorities List.
Define key phrases related to preliminary assessments.
Conduct a preliminary assessment data search and develop a site reconnaissance plan.
Perform preliminary assessment site scoring.
Note: Calculators are highly recommended.
Continuing Education Units: 1.2
111
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TABLE OF CONTENTS
Section
Section 1:
Section 2:
Section 3:
Section 4:
Section 5:
Section 6:
Section 7:
Section 8:
Section 9:
Title Page
Introduction
Lecture Notes 1-1
Conducting the Preliminary Assessment Investigation
Lecture Notes 2-1
Case Study 2-12
Site, Source, and Waste Characterization
Lecture Notes 3-1
Case Study 3-12
Ground Water Pathway
Lecture Notes 4-1
Case Study v 4-23
Surface Water Pathway
Lecture Notes 5-1
Case Study 5-21
Soil Exposure Pathway
Lecture Notes 6-1
Case Study 6-12
Air Pathway
Lecture Notes 7-1
Case Study 7-13
Completing the Preliminary Assessment Investigation
Lecture Notes 8-1
Appendixes
Appendix A - Fact Sheets
Appendix B - Acronym List and Glossary
Appendix C - Integrated Assessments
Appendix D - PA Data and Site Characteristics Form
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Section 1:
Introduction
-------
INTRODUCTION
What You Can Expect
This course...
Introduces the site assessment process and how preliminary
assessments (PAs) fit in
Provides practical advice on conducting PAs and completing PA
scoresheets
Focuses on existing guidance and how to use it
Introduces the concept of "integrated assessments"
This course does not..
Assume you have much background in Superfund site
assessment or with the Hazard Ranking System (MRS)
OH*1
PA Guidance Goals
Assist PA investigators in:
Conducting high-quality assessments
Making correct site screening or further action
recommendations
Achieving national consistency in performing PAs
PA Guidance, section 1.1 OH 2
Introduction 10/94
page 1-2
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INTRODUCTION
PA Guidance Structure
Section 1 Introduction
Section 2 Conducting the PA Investigation
Section 3 Site Evaluation and Scoring
Section 4 Reporting Requirements I
Section 5 Reviews
References
I
I
Glossary I
Appendixes
I
PA Guidance, section 1.1 OH 3
V
Legislative and Regulatory Background
Comprehensive Environmental Response, Compensation and
Liability Act of 1980 (CERCLA), section 105
Hazard Ranking System (MRS), 47 CFR 31180, July 16,1982
Superfund Amendments and Reauthorization Act of 1986 (SARA)
Revised MRS, 55 FR 51532, December 14,1990
PA Guidance, section 1.2 OH 4
10/94 Introduction
page 1-3
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INTRODUCTION
SARA Mandate
"...assess the relative degree of risk to human health and the
environment posed by sites."
PA Guidance, section 1.2 OH 5
V
Notes:
Introduction 10/94
page 1-4
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INTRODUCTION
Super-fund Tackles Hazardous Waste Emergencies
and the Nation's Most Serious Sites
Site Discovery and Study: Finding the Most Serious Sites
Long-Term Cleanup: Fixing the Most Serious Sites
National
Priorities
List
Rl/FS
Recc
Dec!
trdof
Iston
Remedial
Design
Rem
Act
edlal
ton
0AM
Deletion
OH* 6
10/94
Introduction
page 1-5
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INTRODUCTION
"Integrated Assessments"
Integrating removal and remedial site assessment
investigation to achieve increased efficiency and shorter
response times
One of many programs associated with the implementation of
the Superfund Accelerated Cleanup Model (SACM)
Site Assessment Goals
Screen
Determine the nation's priorities for remediation
Evaluate
OH«7
Identify and address sites posing immediate threats
Identify sites with lesser threats and refer to appropriate authorities
Identify sites for NPL
Document
Establish defensible documentation
PA Guidance, section 1.3
OH* 8
Introduction
page 1-6
10/94
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INTRODUCTION
CERCUS
Sites
PA
| Sites
SI/HRS
Sites
NPL
Sites
Site Assessment Screening Process
PA Guidance, section 1.3
A
OH* 9
J
^\
The Site Assessment Process:
Preliminary Assessment (PA)
First step to determine whether site warrants further CERCLA
action
Low-cost review of available information (120 hours)
States conduct PAs under cooperative agreements
EPA-led PAs performed by contractors
Results in a decision to proceed with process or NFRAP
Discovery » CERCUS »
PA *
HRS
SI .» HRS
^ Score
PA Guidance, sections 1.3 and 1.4
*~-~
» NPL
OH* 10
J
194 Introduction
page 1-7
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INTRODUCTION
The Site Assessment Process:
Site Inspection (SI)
Involves more detailed data collection
Generally involves chemical sampling for the first time
Intended to test hypotheses and assumptions made at PA
Results in a decision to recommend for HRS scoring or NFRAP
Discovery
*
CERCLIS
»
PA
*
HRS
8'
*
HRS
Score
*
NPL
PA Guidance, section 1.3
OH* 11
The Site Assessment Process:
Hazard Ranking System (HRS)
Tool to consistently screen and identify sites eligible for NPL
Uses information gathered at PA and SI
Assigns a score indicating "relative risk" of a site
Results in a decision to list site on NPL or NFRAP
PA
*
HRS
SI
*
HRS
Scorn
PA Guidance, section 1.3
OH* 12
Introduction
page 1-8
10/94
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INTRODUCTION
The Site Assessment Challenge
Evaluate many sites with limited resources
Make sound decisions from limited information
Protect public health without spending excess resources on sites
that pose little threat
PA Guidance, section 1.2 OH 13
V
The Four Site Assessment Questions
1. Have hazardous substances been deposited at the site?
If so, what and how much?
2. Have hazardous substances migrated from the site?
3. Who and what are likely to be impacted?
4. Must an emergency action be taken?
OH* 14
10/94 Introduction
page 1-9
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INTRODUCTION
Why These Questions?
These questions are the foundation of MRS
Evaluate:
Waste characteristics
Likelihood of release
Targets
OH* 18
MRS Factor Categories
Waste
Characteristics
Ukelihood
of Release
Targets
What are the
properties of the
hazardous
substances, and
how much is likely
to migrate?
What is the
likelihood that a
hazardous
substance has
been or will be
released
to the
environment?
Who or what is
threatened by the
hazardous
substances?
OH* 16
Introduction
page 1-10
10/94
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INTRODUCTION
MRS Pathways and Factor Categories
we
LR
T
Waste
Characteristics
Likelihood of
Release
Targets
Ground
Water
teal
Surface
Water
n
%rT
Air
Soil
Exposure
PA Guidance, section 1.5
OH* 17
Notes:
10/94
Introduction
page 1-11
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INTRODUCTION
MRS Pathways Mini Exercise
OH* 18
Introduction
page 1-12
10/94
-------
INTRODUCTION
Purpose of the PA
Differentiate sites that warrant further action from those that pose
little or no threat
Support emergency response and remedial activities
Gather information for the site assessment process
PA Guidance, section 1.4 OH 19
V
Scope of the PA*
Review existing information about the site
Conduct a site reconnaissance
Collect information about the site, especially target information
Reevaluate all information
Develop a preliminary site score
Prepare PA summary report
as defined in section 420 of the NCP (40 CFR Part 300)
PA Guidance, section 1.4
OH* 20
10/94 Introduction
page 1-13
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INTRODUCTION
PA Activities: The Big Picture
Data collection
Reporting
Reconnaissance
Scoring
Typical Ranoa
60-80 hours
20-30 hours
10-20 hours
5-15 hours
AVERAGE PA = 120 hours
PA Guidance, section 1.4, figure 1-2 (modified)
OH* 21
PA Structure
Follows MRS structure
Divided into four exposure routes (pathways)
Pathways divided into three factor categories
- Waste characteristics
- Likelihood of release
- Targets
Student note: Turn to PA Guidance, Table 1-1,
PA Factors by Pathway, page 9
PA Guidance, section 1.5
OH* 22
fnff
page 1-14
10/94
-------
INTRODUCTION
PA Strategy
Focus on critical factorsones that most impact PA score
Maintain nationally consistent evaluation process
MRS model provides all factors involved in decision-making
process
PA Guidance, sections 1.4 and 1.5
OH* 23
PA Critical Factor Example:
Ground Water Pathway
Likelihood of Release
OH* 24
10/94
Introduction
page 1-15
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INTRODUCTION
Targets
Who and what are likely to be impacted?
Targets are critical
- "Uncapped" factorsweigh heavily
- No target = no site
A comprehensive target survey is possible at PA stage
PA Guidance, section 1.5
OH* 26
PA Terminology
Sources
Suspected release vs. no suspected release
Primary targets vs. secondary targets
Yes
1
Primary
Targets
*
Suspected
Release?
1
Secondary
Targets
-
| No
Secondary I
Targets 1
PA Guidance, section 1.6
OH* 26
Introduction
page 1-16
10/94
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8
GROUND WATER PATHWAY SCORESHEET
Pathway Ch*r*c1»ri*ticM
Do you suspect a release (see Ground Water Pathway Criteria List, page 7)7
Is the site located in karst terrain?
Depth to aquifer:
Distance to the nearest drinking water well:
Yes
Yes
No
No
It
(t
LIKELIHOOD OF RELEASE
1. SUSPECTED RELEASE: II you suspect a release to ground water (see page 7),
assign a score of 550. Use only column A for this pathway.
2. NO SUSPECTED RELEASE: If you do not suspect a release to ground water, and
the site is in karst terrain or the depth to aquifer is 70 feet or less, assign a score
of 500; otherwise, assign a score of 340. Use only column B for this pathway.
TARGETS
3. PRIMARY TARGET POPULATION: Determine the number of people served by
drinking water wells that you suspect have been exposed to a hazardous
substance from the site (see Ground Water Pathway Criteria List, page 7).
people
4. SECONDARY TARGET POPULATION: Determine the number of people served by
drinking water wells that you do NOT suspect have been exposed to a hazardous
substance from the site, and assign the total population score from PA Table 2.
Are any wells part of a blended system? Yes No
If yes, attach a page to show apportionment calculations.
5. NEAREST WELL: If you have identified a primary target population for ground
water, assign a score of 50; otherwise, assign the Nearest Well score from
PA Table 2. If no drinking water wells exist within 4 miles, assign a score of zero.
6. WELLHEAD PROTECTION AREA (WHPA): If any source lies within or above a WHPA,
or if you have identified any primary target well within a WHPA, assign a score of 20;
assign 5 if neither condition holds but a WHPA is present within 4 miles; otherwise
assign zero.
7. RESOURCES
lto.ao.iM.o.1. a
H0.1M.I.1.1. -a
T -
WASTE CHARACTERISTICS
8. A. If you have identified any primary target for ground water, assign the waste
characteristics score calculated on page 4, or a score of 32, whichever is
GREATER; do not evaluate part B of this factor.
B. If you have NOT identified any primary target for ground water, assign the
waste characteristics score calculated on page 4,
M00J3. in
we -
GROUND WATER PATHWAY SCORE:
LR x T x WC
82,500
|tubf*ct to maximum of
1001
A-15
Introduction
page 1-17
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INTRODUCTION
PA Components
Narrative report
References
PA data and site characteristics form
PA scoresheets
Turn to PA Guidance, appendixes A, C, and D for examples
PA Guidance, appendixes A, C, and D OH 27
\
Notes:
Introduction 10/94
page 1-18
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Section 2:
Conducting the Preliminary
Assessment Investigation
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CONDUCTING THE PA INVESTIGATION
Preliminary Assessments
PA Activities
PA Guidance, section 1.4, figure 1-2 (modified)
Data collection
Reporting
Reconnaissance
Scoring
Typical Range
60-80 hours
20-30 hours
10-20 hours
5-15 hours
AVERAGE PA = 120 hours
OH-1
Conducting tfi« PA Investigation
page 2-2
4/94
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CONDUCTING THE PA INVESTIGATION
Data Collection: Strategies
Verify site name and location
Collect and review readily available general site information
Determine site eligibility
Conduct file searches
Obtain and review "desktop" information
Plan and conduct site reconnaissance
PA Guidance, section 2 OH 2
V
Data Collection: PA Information Needs
Specific information required to conduct a PA is contained in PA
Guidance, Figure 2-1, Checklist of PA Information Needs, page 14
Be familiar with this list before starting data collection activities
PA Guidance, section 2 OH 3
4/94 Conducting the PA Investigation
page 2-3
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Figure 2-1
Checklist of PA Information Needs
GENERAL SITE INFORMATION
Site Name and Location D Owner/Operator Information
CERCLIS ID Number D Operational History
Type of Facility D Environmental Setting
Type of Ownership D Approximate Size of Site
Site Status (active/inactive) D Latitude/Longitude
Years of Operation D Site Sketch
SOURCE AND WASTE CHARACTERISTICS
Source Types and Locations ' D Waste Types and Quantities
Size of Sources (dimensions) D Hazardous Substances Present
GROUND WATER USE AND CHARACTERISTICS
d! General Stratigraphy and Hydrogeology D Municipal Wells Within 4 Miles
D Presence of Karst Terrain (locations, populations served,
D Depth to Shallowest Aquifer blended systems)
D Private Wells Within 4 Miles D Distance to Nearest Drinking
(locations, populations served) Water Well
D Wellhead Protection Areas
SURFACE WATER USE AND CHARACTERISTICS
D Flood Frequency at Site
D Distance to Nearest Surface Water
D Surface Water Body Types Within 15 Downstream Miles
D Surface Water Flow Characteristics Within 15 Downstream Miles
D Drinking Water Intakes Within 16 Downstream Miles (locations, populations served, blended systems)
D Fisheries Within 15 Downstream Miles
O Sensitive Environments and Wetlands Within 15 Downstream Miles
SOIL EXPOSURE CHARACTERISTICS
D Number of People Living Within 200 Feet D Number of Workers at Facility
D Schools or Day Care Within 200 Feet (enrollment) D Locations of Terrestrial Sensitive Environments
O Populations Within 1 Mile
AIR PA THWA Y CHARACTERISTICS
D Populations Within 4 Miles D Locations of Sensitive Environments
D Distance to Nearest Individual Within 4 Miles
D Acreage of Wetlands Within 4 Miles
Conducting the PA Investigation
page 2-4
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CONDUCTING THE PA INVESTIGATION
Data Collection: PA Information Sources
Site Assessment Information Directory (EPA)
PA Guidelines, Appendix B, PA Information Sources
Go to PA Guidance, appendix B
PA Guidance, section 2
OH* 4
Data Collection: File Searches
Existing file information
EPA RCRA files
EPA CERCLA files, 103 forms, citizen complaints
State environmental department files
State/county health department files
In-house files
Tax offices
Historical property/ownership information
PA Guidance, section 2.3
OH* 5
4/94
Conducting the PA Investigation
page 2-5
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CONDUCTING THE PA INVESTIGATION
Data Collection: "Desktop" Information
Maps
Geological information
Data bases/geographic information systems
Aerial photography
Telephone inquiries
PA Guidance, section 2.4
OH-6
Site Reconnaissance and Documentation
PA Guidance, section 2.5
OH«7
Conducting the PA Investigation
page 2-6
4/94
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CONDUCTING THE PA INVESTIGATION
Site Reconnaissance: Objectives
Observe site conditions
Verify
- Site file data
- Population data
- Environmental data
Fill in data gaps identified after conducting file search
Develop documentation for reports, scores, and PA
conclusions
Evaluate need for removal action
PA Guidance, section 2.5 OH»8
Site Reconnaissance: Preparation
Review what is known about the site
Plan to collect data to help determine:
- Source location, size, and condition
- Likelihood of a release
waste types and containment
site security
- Targets most likely to be exposed
distance from source to targets
targets at greatest risk
Decide whether to conduct onsite or offsite reconnaissance
Prepare health and safety plan
Gather necessary equipment
PA Guidance, section 2.5.1 OH 9
4/94 Conducting ths PA Investigation
page 2-7
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CONDUCTING THE PA INVESTIGATION
Site Reconnaissance: Activities
Conduct perimeter survey
Identify emergency response conditions
Evaluate source types, sizes, and containment
Assess waste disposal practices
Estimate quantity
Assess areas of stained soil and impacted vegetation
PA Guidance, sections2.5.2and2.5.3 OH* 10
J
Site Reconnaissance: Activities
Determine drainage pathways
Verify nearby targets
Assess nearby land uses
Interview local authorities
PA Guidance, sections 2.5.2 and 2.5.3 OH 11
Conducting the PA Investigation 4/94
page 2-8
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CONDUCTING THE PA INVESTIGATION
Emergency Reponse Considerations
(Integrated Assessment and Response)
Site conditions that might lead to a removal assessment:
Threat of fire and/or explosion
Threat of direct contact with hazardous substances
Threat of continuing release of hazardous substances
Threat of drinking water contamination
Notify EPA when above conditions are observed
PA Guidance, section 2.6 OH 12
Documentation
Photodocumentation
Site sketch
Logbook
OH* 13
4/04 Conducting th9 PA Investigation
page 2-0
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CONDUCTING THE PA INVESTIGATION
Documentation: Logbook Entry Examples
Personnel present
Site location
Date and time of visit
Weather conditions
Visual observations
Photographic record
Site sketch
Conversations
Housecounts
See example, PA Guidance, page 30
PA Guidance, section 2.5.1 OH 14
V
Documentation: Logbook Requirements
Bound notebook
Waterproof paper
Waterproof ink
Pages numbered
Each page signed and dated
Unused space crossed out
Student Note: Turn to Logbook Mini-Exercise
PA Guidance, section 2.5.1 OH 15
Conducting too PA Investigation 4/94
page 2-10
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CONDUCTING THE PA INVESTIGATION
Example Logbook Entries
Good or bad?
1. 0800. Arrived at the site and began the perimeter survey. The
following potential sources were identified: drums, a debris pile, and
some contaminated soil. The site was over 10 acres in size. The
nearest house was between 150 and 250 feet away.
2. 0800. The following were observed in the southwest section of the
property:
A lagoon filled to within 6 inches from top of freeboard. The
area is estimated to be approximately 100 feet x 200 feet.
Depth is unkown.
A vertical aboveground storage tank, 1000-gallon size.
Written on tank side: "PENTA." Tank appears to be in good
condition; no indication of leakage.
3.1125. Followed site drainage from southeast comer of site to stream.
Drainage path was dry and had some orange discoloration. There
appeared to be some stressed vegetation along drainage (photo 13).
Stream was flowing.
4. 1420. Team members Hart and Jones met with Mr. Ralph Singer, chief
engineer, City of Springfield Water Department. He showed us a map
indicating the location of the water intake on Lake Springfield and the
distribution area served. He also provided the following information:
1,476 households are served by this intake, no other sources of water
exist within 15 miles downstream of the site, and the water from Lake
Springfield is not blended with other supplies.
5. 0745. Arrived on site and met with site owner, Ms. Frieda Gluck. We
toured the site and observed several drums and a debris pile. She
said that her husband, who had operated the site, was dead and that
she didn't have any money if EPA wanted to prosecute her.
4/94 Conducting the PA Investigation
page 2-11
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CONDUCTING THE PA INVESTIGATION
CASE STUDY: ABC VACUUM SERVICE
GENERAL INFORMATION
OBJECTIVE
Using background information, inspection reports, and site reconnaissance notes for the ABC
Vacuum Site, complete the "General Information" portion of the PA scoresheet.
METHOD
1. Review the background information, site reconnaissance logbook notes and map,
and the waste management inspection report.
2. Read the PA scoresheet general information instructions provided in this case study.
3. Complete the "Site Description and Operational History" and "Probable Substances
of Concern* portions of the PA scoresheet.
General Overview:
This 13-acre site is located in Atlas Parish, Louisiana. It is currently inactive.
The site was operated as a vacuum service and drilling fluids manufacturer from 1975
to 1985 (prior history is unknown).
- Wastewater was extracted from reserve pits created during petroleum exploration
and production activities.
- The facility is believed to have transported hazardous wastes that may have been
discharged into an onsite lagoon.
- The facility manufactured water- and oil-based drilling fluids.
The perimeter of the site is unfenced. Trespassing occurs infrequently.
Five homes in a small subdivision are situated between 100 and 200 feet to the
northwest of the site.
The mean annual precipitation is 57 inches.
Conducting ffio PA Investigation 4/94
page 2-12
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WASTE MANAGEMENT INSPECTION REPORT
DATE
10
FACILITT_
LOCATION
FXCILITT TYPE Vacuum.
.Q^«4 drllUcfc, £U/fti:S
or
^pWrgAf ^"V^A ^
RCSA WASTE COOES
Conducting the PA Investigation
page 2-13
-------
WASTE MANAGEMENT INSPECTION REPORT - PAGE 2
WXflTZ QUMTTITIES
A&>W/r> hng
cr
NOHCOMPLIAHCZ
COMMZMT8
. x*l i/
T8 A\UyW< M> W. /i«M^4g^ -Wa^OfrrWi 4p ^?«U g^d
"^g^Y^/^". L-QjC^*rs-f\ ^JMvVrSr./j^LO^^W^A. / > AA PV^/*^T\ hp g/*\ i)aft)rr\<»_
\..-
-------
I
-------
o>
2
31
I
. Volume LMKncavi.
JW.W
Sifc
am
-------
ID ta
fl^ Q»
(D«Q
7«- of s/Ve
aieffcJ. .
-------
;± S. Houses
ABC icuuM SERVICE
no-* -to sc°'e
TRACK
-------
APPENDIX A
OMB Approval Number: 2050-0095
Approved for Use Through: 1/92
PA Scoresheets
Site Name:
CERCLIS ID No.:
Street Address: _
City/State/Zip:
Investigator:
Agency/Organization:
Street Address:
City/State/Zip:
Date:
Conducting the PA Investigation
page 2-19
A-1
-------
INSTRUCTIONS FOR SCORESHEETS
Introduction
This scoresheets package functions as a self-contained workbook providing all of the basic tools to
apply collected data and calculate a PA score. Note that a computerized scoring tool, "PA-Score," is
also available from EPA (Office of Solid Waste and Emergency Response, Directive 9345.1-11). The
scoresheets provide space to:
Record information collected during the PA
Indicate references to support information
Select and assign values ("scores") for factors
Calculate pathway scores
Calculate the site score
Do not enter values or scores in shaded areas of the scoresheets. You are encouraged to write notes
on the scoresheets and especially on the Criteria Lists. On scoresheets with a reference column,
indicate a number corresponding to attached sources of information or pages containing rationale for
hypotheses; attach to the scoresheets a numbered list of these references. Evaluate all four pathways.
Complete all Criteria Lists, scoresheets, and tables. Show calculations, as appropriate. If scoresheets
are photocopy reproduced, copy and submit the numbered pages (right-side pages) only.
GENERAL INFORMATION
Site Description and Operational History: Briefly describe the site and its operating history. Provide
the site name, owner/operator, type of facility and operations, size of property, active or inactive
status, and years of waste generation. Summarize waste treatment, storage, or disposal activities that
have or may have occurred at the site; note also if these activities are documented or alleged. Identify
probable source types and prior spills. Summarize highlights of previous investigations.
Probable Substances of Concern: List hazardous substances that have or may have been stored,
handled, or disposed at the site, based on your knowledge of site operations. Identify the sources to
which the substances may be related. Summarize any existing analytical data concerning hazardous
substances detected onsite, in releases from the site, or at targets.
Conducting the PA Investigation
page 2-20 A.2
-------
GENERAL INFORMATION
Site Description and Operational History:
Probable Substances of Concern:
(Previous investigations, analytical data)
Conducting the PA Investigation
page 2-21
A-.1
-------
GENERAL INFORMATION (continued)
Site Sketch- Prepare-a sketch of the site (freehand is acceptable). Indicate all pertinent features of
the site and nearby environs, including: waste sources, buildings, residences, access roads, parking
areas drainage patterns/water bodies, vegetation, wells, sensitive env.ronments, etc.
Conducting the PA /nvest/gatfon
page 2-22 A-4
-------
GENERAL INFORMATION (continued)
Site Sketch:
(Show all pertinent features, indicate sources and closest targets, indicate north)
A-5
Conducting the PA Investigation
page 2-23
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CASE STUDY SUPPLEMENT: ABC VACUUM SERVICE
GENERAL INFORMATION
OBJECTIVE
Using available general site information for the ABC Vacuum Service site, identify data
gaps, develop a set of PA site reconnaissance objectives, address site access issues,
complete an equipment list, and determine the adequacy of a prepared site safety
plan.
METHOD
1. Review the site information found in the student manual. Working with
an assigned partner or group, complete the following activities and
record all answers on the worksheet provided with this exercise.
Identify any obvious data gaps in the available information.
» List at least eight (8) PA site reconnaissance objectives for the
ABC Vacuum site.
Outline the steps necessary to obtain access to this site.
2. Read the site safety plan prepared for the ABC Vacuum site. Determine
if this plan is adequate for the PA objectives outlined above. Make any
necessary adjustments to the plan.
3. Complete the attached equipment list for the site reconnaissance of the
ABC Vacuum site. Include only the equipment you will need to meet the
PA objectives.
Conducting the PA Investigation
page2a-1 11/94
-------
CASE STUDY SUPPLEMENT: ABC VACUUM SERVICE
WORKSHEET
Identify data gaps:
List at least eight PA site reconnaissance objectives:
1
2
3
4
5
6
7
8
Outline the steps necessary to obtain site access:
Conducting the PA Investigation
page2a-2 11/94
-------
SITE SAFETY PLAN
Site Name:
Site Address:
Site Contact:
Phone f:
Other Contacts:
Purpose of site visit:
Proposed investigation team:
Responsibility
Site Manager:
Site Surveillance Team Member:
Site Surveillance Team Member:
Personnel
Site status: active: inactive: unknown:
Hazard evaluation: (check all that apply)
waste types: liquid: solid: sludge: _
waste characteristics:
corrosive:
toxic:
ignitable:
reactive: .
Identification of expected hazards (chemical/physical):
Hazard assessment: low.
moderate
Work tasks to be performed:
vapor:
volatile: _
unknown:
reactive:
other: _
high
unknown
Protective equipment/clothing:
Respiratory Clothing Gloves Boots Modifications
(A,B,C,D)
-------
EQUIPMENT UST: SITE RECONNAISSANCE VISIT
(Check off those items that apply)
Expendable Protective Equipment
butyl rubber boots (M_, L_, XL_)
boot covers (S_, M_, L_, XL_)
hip boots (specify size)
other
Respiratory Protection
SCBA tanks (45 cu. ft. composite)
SCBA harness
Cascade system
50-foot airlines
full-face respirator (SCBA/APR)
respirator cartridges (specify type)
escape bottle
other
Gloves
cotton (work
gloves)
Viton
Butyl
Neoprene
Latex
leather
other
Recordkeeping Supplies
field notebook
waterproof pens/indelible markers
clipboard
ruler
Chemical Resistant Clothing
Tyvek (S_. M_, L
Saranex (S , M ,
fully encapsulating
_, XL_, XXL_)
L_, XL, XXL_)
suit (specify size)
other
Personal Protection/Safety Equipment
hard hat
safety goggles
splash shield
rain suit (S , M , L ,
life vest (S_, M_, L_,
XL_, XXL_)
XL_, XXL_)
ear plugs
first aid kit
other
, Air Monitoring Equipment
PID (HNU , Photovac , other )
organic vapor analyzer
oxygen meter/explosimeter
hydrogen sulfide meter
radiation meter/mini-rad
detector tubes
other (specify )
Meters
pH meter
conductivity meter
resistivity meter
metal detector
Conducting the PA Investigation
equip.list page 1
10/94
-------
EQUIPMENT UST: SITE RECONNAISSANCE VISIT
(Check off those items that apply)
Cameras/Film
SX70 Polaroid
35mm Pentax
Kodamatic
12/24/36 print film (rolls )
1 2/24/36 slide film (rolls )
other
Surveying Equipment
optical rangefinder
Brunton compass
compass
binoculars
300-foot steel tape
wooden stakes
Decontamination
Indian Tank
hand sprayer
eyewash bottles
scrub brushes
Alconox
buckets
paper towels
other
Hand Tools
hacksaw
bolt cutter
wire cutter
pliers
rake
shovel
trowel
other
Tape
clear plastic
duct tape
masking tape
strapping tape/fiber tape
flagging tape
other
Miscellaneous
mobile phone
radios
locks/keys
trash bags
plastic roll (10 feet by 25 feet)
vermiculite
Additional supplies:
Conducting the PA Investigation
equip.list page 2
10/94
-------
Section 3:
Site, Source, and Waste
Characterization
-------
SITE, SOURCE, AND WASTE CHARACTERIZATION
Site Assessment Question 1
Have hazardous substances been deposited at the site?
If so, what and how much?
Evaluate waste characteristics onceuse for all four pathways
PA Guidance, section 3.2 OH 1
How to Structure Your Data Search
Types of sources on file
Any impoundments? Are they full? Have they overflowed? Can
they? If empty, were they used at one time? Where did the
contents go?
Any drums? Are they corroding? How are they stored and
protected from weather? Can contents get out?
Waste quantity
How much?
What kinds?
Physical nature (solid or liquid)?
PA Guidance, section 3.2 OH 2
S/to, Source, and Waste Characterization 4/94
page 3-2
-------
SITE, SOURCE, AND WASTE CHARACTERIZATION
Source/Waste Information Sources
Files
Waste manifests
Prior inspection reports
Prior enforcement orders
Site reconnaissance observations
Source size/dimensions
Containment
Evidence for waste migration
Aerial photography
Current and historical source types and locations
Source size/dimensions
PA Guidance, section 3.2 OH 3
V
Site Definition
A site is an area consisting of the aggregation of sources and the
areas between sources
A site is independent of property boundaries
A site should be defined using all information, historical and
present day, regardless of current fences, boundaries, or
ownership
PA Guidance, section 3.2.1 OH 4
4/94 Stto, Source, and Waste Characterization
page 3-3
-------
SITE, SOURCE, AND WASTE CHARACTERIZATION
Mini Exercise: Defining the Site
New
Residential
Community
XYZ
Corporation
Current XYZ
property boundary
OH* 5
Srtg, Source, and Waste Characterization
page 3-4
4/94
-------
SITE, SOURCE, AND WASTE CHARACTERIZATION
Source Definition
Definition
Source: area where hazardous substances have been deposited,
stored, disposed of, or placed. Also, soil that may be
contaminated from hazardous substance migration.
Reminders
Evaluate present and former sources.
Generally, source information is limited. However, incomplete
information is still useful.
PA Guidance, section 3.2.1 OH 6
V
Types of Sources
Landfills
Surface impoundments
Drums
Containers or tanks
Waste piles
Landfarm/land treatment
Contaminated soil
Other
PA Guidance, section 3.2.1, table 3-1 OH 7
4/94 Site, Source, and Waste Characterization
page 3-5
-------
SITE, SOURCE, AND WASTE CHARACTERIZATION
MRS SOURCE TYPE DESCRIPTIONS
Active fire area: An area that is presently burning or smoldering and which, without
remedial action, will continue to do so intensely.
Buried/below-ground containers or tanks: A container or tank, the entire surface area
of which is situated completely below the surface and which is not visible; however, a
buried/below-ground tank may have a small fraction of its associated piping above the
surface.
Buried/backfilled surface impoundment: A surface impoundment that has been com-
pletely covered with soil after final deposition of waste materials.
Bum pit: An uncovered area on or under the land surface that was at one time used to
bum waste materials or was otherwise significantly inflamed but is not presently burning.
Containers or tanks: (1) Any stationary device designed to contain an accumulation of
waste, which is constructed primarily of nonearthen materials (e.g., wood, concrete, steel,
or plastic) which provides structural support. (2) Any portable device in which waste is
stored or otherwise handled.
Contaminated soil (excluding land treatment): (1) An area of soil that contains con-
centrations of a hazardous substance significantly above background. Evidence that the
substance detected is related to the site must be provided to substantiate use of this
descriptor. (2) An area on which available evidence demonstrates that hazardous sub-
stances were spilled. Note: somewhat similar to area of observed contamination but
without the requirement that the hazardous substance be located within 2 feet of the
surface.
Landfarm/land treatment: A method of waste management in which liquid waste or
sludges are spread over land and tilled. Also applies to the shallow injection of liquids.
The distinguishing characteristic is shallow injection or tilling of the soil.
Landfill: (1) A cleared area on the ground surface containing waste. (2) A man-made or
natural hole in the ground containing waste. The landfill may have been backfilled with
soil, either after or contemporary with the waste disposal, covering the wastes from view.
The landfill may have been formed either by excavating the hole or by forming earthen
walls around a cleared area. Due to weathering, erosion, and similar phenomena, how-
ever, once-buried wastes in a landfill may become exposed (e.g., partially buried drums).
The contents of a landfill may include nearly any or all types of wastes, including buried
drums.
S/fc, Source, and Wastg Characterization 4/94
page 3-6
-------
SITE, SOURCE, AND WASTE CHARACTERIZATION
Piles (by type):
Chemical waste pile: A pile consisting primarily of discarded chemical products
(whether marketable or not), by-products, or unused feedstocks.
Scrap metal or junk pile: A pile consisting primarily of scrap metal or discarded du-
rable goods (e.g., appliances, automobiles, auto parts, furniture).
Tailings pile: A pile consisting of primarily of any combination of overburden from a
mining operation and tailings from a mineral mining, beneficiation, or processing opera-
tion.
Trash pile: A pile consisting of primarily paper, garbage, refuse, or discarded non-
durable goods (e.g., food packaging).
Other A term reserved for use when a pile of indeterminate origin has accumulated and
is shown to contain certain hazardous substances, contaminants, pollutants, or radionu-
clides.
Surface Impoundment: A natural topographic depression, man-made excavation,
bermed, or diked area, primarily formed from earthen materials (lined or unlined) which
was designed to hold an accumulation of liquid wastes, wastes containing free liquids, or
sludges that were not backfilled or otherwise covered. The distinguishing characteristics
of a surface impoundment are the emphasis on liquid waste and the general lack of soil
cover. Two types of surface impoundments are distinguished: those at which the depos-
ited liquid has evaporated, volatilized, or leached (dry), and those with exposed liquid
(other). Synonymous terms include lagoon pond, aeration pit, settling pond, and tailings
pond.
4/94 SH9, Source, and Waste C/wvcteffzattofi
page 3-7
-------
SITE, SOURCE, AND WASTE CHARACTERIZATION
Waste Characterization
Evaluate each source at a site based on four tiers
Constituent quantity
Wastestream quantity
Source volume
Source area
For each source, evaluate as many tiers as you have information to
support.
Go to PA Guidance, appendix A,
PA table 1, page A-9
PA Guidance, section 3.2.2 (definitions on page 45) OH 8
V J
Waste Characterization (continued)
For constituent and wastestream tiers, all quantities are converted
to pounds so they can be added together
Use conversions on table 1 (page A-9)
Constituent and wastestream information is often unavailable at
PA stage
PA Guidance, section 3.2.2 OH 9
Site, Source, and Waste Characterization 4/94
page 3-8
-------
SITE, SOURCE, AND WASTE CHARACTERIZATION
Waste Characterization (continued)
Single source site
Three waste characterization (WC) values based on ranges of
waste quantity:
- 18
-32
- 100
Use Single Source column of table 1a; assign each evaluated tier
a WC score based on its waste quantity
Highest WC value is WC score for site
PA Guidance, section 3.2.2, page 47 OH 10
Notes:
4/94 Sits, Sourc9, and Waste Characterization
page 3-9
-------
SITE, SOURCE, AND WASTE CHARACTERIZATION
Mini Exercise:
Waste Characteristics Score: Single Source
Example: 500 gallons of a spent solvent mixture
disposed of in a landfill that is 600 feet
wide, 1,000 feet long, and 30 feet deep.
Directions: Using PA table 1 (page A-9 of PA
Guidance), determine the waste
characteristic (WC) score for all tiers.
AREA = 600 ft x 1,000 ft = 600,000 square feet
VOLUME = 600 ft x 1,000 ft x 30 ft = 18,000,000 cubic feet
WASTESTREAM QUANTITY = 500 gal x 10 Ibs/gal = 5,000 Ibs of
wastestream
CONSTITUENT QUANTITY = Unknown
OH* 11
Site, Source, and Waste Characterization
page 3-10
4/94
-------
SITE, SOURCE, AND WASTE CHARACTERIZATION
Waste Characterization (continued)
Multiple source site
Determine waste quantity for each applicable tier of each source
using divisors in Multiple Source column of table 1a
Select highest waste quantity for each source
Sum source highest waste quantity values to yield waste quantity
total
Apply waste total to table 1 b to determine WC score for site
PA Guidance, section 3.2.2, page 47 OH 12
V
Notes:
4/94 Site, Source, and Waste Characterization
page 3-11
-------
SITE, SOURCE, AND WASTE CHARACTERIZATION
CASE STUDY: ABC VACUUM SERVICE
SOURCE CHARACTERIZATION
OBJECTIVE
Using the site information from the site reconnaissance visit, general information from the
previous exercise, and the site map, determine the waste characteristic score for each source.
METHOD
1. Review the source information provided below.
2. Describe each source on the source evaluation worksheet.
3. Use PA Table 1, "Waste Characteristics (WC) Scores," and the source descriptions
to calculate the WC scores for each source. Record the calculations and the scores
on the source evaluation scoresheets.
Potential Sources:
Two hundred drums are situated on a small concrete pad north of the aboveground
mixing tanks.
A lagoon on the northwest comer of the site is bounded on the south and west by
drainage ditches. The estimated area of the lagoon is 3,000 square feet.
There is a 750-square-foot oxidation pond behind the warehouse. Unspecified debris
was observed in the pond during the site reconnaissance.
A 500-square-foot rubbish pile is located on the southeastern comer of the site.
Two 1,000-gallon mixing tanks are located on a concrete pad on the northeastern
comer of the site.
Some parts of the drainage ditches were seen overflowing during reconnaissance.
Three distinct areas of stained soil were observed; total estimated area, 1,000 square
feet.
S/te, Source, and Mfesto Characterization 4/94
page 3-12
-------
ABC Vacuum Service
Drainage ditches
Drainage direction
Warehouse complex road
Not to Scale
o> 3
-------
SOURCE EVALUATION
Number and name each source (e.g., 1. East Drum Storage Area, 2. Sludge Lagoon, 3. Battery Pile).
Identify source type according to the list below.
Describe the physical character o( each source (e.g., dimensions, .contents, waste types, containment,
operating history).
Show waste quantity (WQ) calculations (or each source for appropriate tiers. Refer to instructions opposite
page 5 and PA Tables 1 a and 1 b. Identify waste quantity tier and waste characteristics (WC) factor category
score (for a site with a single source, according to PA Table 1 a). Determine WC from PA Table 1 b for the sum
of source WQs for a multiple-source site.
Attach additional sheets if necessary.
Determine the site WC factor category score and record at the bottom of the page.
Source Type Descriptions
Landfill: an engineered (by excavation or construction) or natural hole in ihe ground into which wastes have been
disposed by backfilling, or by contemporaneous soil deposition with waste disposal, covering wastes from view.
Surface Impoundment: e topographic depression, excavation, or diked area, primarily formed from earthen
materials (lined or unlined) and designed to hold accumulated liquid wastes, wastes containing free liquids, or
sludges that were not backfilled or otherwise covered during periods of deposition; depression may be dry if
deposited liquid has evaporated, volatilized or leached, or wet with exposed liquid; structures that may be more
specifically described as lagoon pond, aeration pit, settling pond, tailings pond, sludge pit, etc.; also e surface
impoundment that has been covered with soil after the final deposition of waste materials (i.e., buried or
backfilled).
Drums: portable containers designed to hold a standard 55-gallon volume of wastes.
Tanks and Non-Drum Containers; any stationary device, designed to contain accumulated wastes, constructed
primarily of fabricated materials (such as wood, concrete, steel, or plastic) that provide structural support; any
portable or mobile device in which waste is stored or otherwise handled.
Contaminated Soil: soil onto which available evidence indicates that a hazardous substance was spilled, spread,
disposed, or deposited.
Plla: any non-containerized accumulation above the ground surface of solid, non-flowing wastes; includes open
dumps. Some types of piles are: Chemical Waste Pile - consists primarily of discarded chemical products, by-
products, radioactive wastes, or used or unused feedstocks; Scrap Metal or Junk Pile - consists primarily of
scrap metal or discarded durable goods such as appliances, automobiles, auto parts, or batteries, composed of
materials suspected to contain or have contained a hazardous substance; Tailings Pile - consists primarily of any
combination of overburden from a mining operation and tailings from a mineral mining, beneficiation, or processing
operation; Trash Pile -- consists primarily of paper, garbage, or discarded non-durable goods which are suspected
to contain or have contained a hazardous substance.
Land Treatmant: landfarming or other land treatment method of waste management in which liquid wastes or
sludges are spread over land and tilled, or liquids are injected at shallow depths into soils.
Other: a source that does not fit any of the descriptions above; examples include contaminated building, ground
water plume with no identifiable source, storm drain, dry well, and injection well.
Site, Source, and Waste Characterization
page 3-14
A-O
-------
SOURCE EVALUATION
Source
No.:
Source Name:
Source Description:
Source Waste Quantity (WQ) Calculations:
Source
No.:
Source Name:
Source Description:
Source Waste Quantity (WQ) Calculations:
Source
No.:
Source Name:
Source Description:
Source Waste Quantity (WQ) Calculations:
Site WC:
Site, Source, and Waste Characterization
page 3-15
A-7
-------
WASTE CHARACTERISTICS (WC) SCORES
WC, based on waste quantity, may be determined by one or all of four measures called "tiers'-
constituent quantity, wastestream quantity, source volume, and source area. PA Table 1a (page 5)
is divided into these four tiers. The amount and detail of infprmation available determine which tier(s)
to use for each source. For each source, evaluate waste quantity by as many of the tiers as you have
information to support, and select the result that gives you the highest WC score. If minimal,
incomplete, or no information is available regarding waste quantity, assign a WC score of 18
(minimum).
PA Table 1a has 6 columns: column 1 indicates the quantity tier; column 2 lists source types for the
four tiers; columns 3, 4, and 5 provide ranges of waste amount for sites with only one source, which
correspond to WC scores at the top of the columns (18, 32, or TOO); column 6 provides formulas to
obtain source waste quantity (WQ) values at sites with multiple sources.
To determine WC for aftej with only one source:
1. Identify source type (see descriptions opposite page 41.
2. Examine all waste quantity date available.
3. Estimate the mass and/or dimensions of the source.
4. Determine which quantity tiers to use based on available source information.
5. Convert source measurements to appropriate units for each tier you can evaluate for the source.
6. Identify the range into which the total quantity falls for each tier evaluated (PA Table Taj.
7. Determine the highest WC score obtained for any tier 118, 32. or TOO, at top of PA Table la columns 3, 4, and
5, respectively).
8. Use this WC score for a/I pathways. '
To determine WC for srtas with murtiple sources:
1. Identify each source type [see descriptions opposite page 41.
2. Examine all waste quantity data available for each source.
. 3. Estimate the mass and/or dimensions of each source.
4. Determine which quantity tiers to use for each source based on the available information.
5. Convert source measurements to appropriate units for- each tier you can evaluate for each source.
6. For each source, use the formulas in column 6 of PA Table la to determine the WQ value for each tier that can
be evaluated. The highest WQ value obtained for any tier is the WQ value for the source.
7. Sum the WQ values for ell sources to get the site WQ total.
8. Use the site WQ total from step 7 to assign the WC score from PA Table 1b.
9. Use this WC score for ell pathways. '
' The WC score is considered in all four pathways. However, if a primary target is identified for the ground
water, surface water, or air migration pathway, assign the determined WC or a score of 32, whichever is
greater, as the WC score for that pathway.
Site, Source, and Waste Characterization
page 3-16 A_8
-------
PA TABLE 1: WASTE CHARACTERISTICS (WC) SCORES
V
o
I
u
M
E
A
R
E
A
SOURCE TYPE
N/A
N/A
Landfill
Surface
impoundment
Drums
Tanks and non-
drum containers
Contaminated soil
Pile
Other
Landfill
Surface
impoundment
Contaminated soil
Pile"
Land treatment
PA Tabl* 1i: WC Scores for Single Source Situ and Formula!
for Multiple Source Site*
SINGLE SOURCE SITES (aulgned WC icoru)
WC - 18
S 1 OO Ib
i 500, OOO Ib
S6.75 million fr1
S250.OOO yd'
S6.750 tr3
S2SO yd3
3 l.CXX) dnjmt
S 50, OOO otMoni
i6.75 million h*
S250.0OO yd'
S6.750 ft*
S250 yd'
S6.750 fr1
S250 yd'
S340.OOO fr1
27.8 gent
S1.3OO fr1
SO.O29 «ci«.
S3. 4 million fr1
£78 >crti
S1.30O fr1
50.029 «cr.«
S27.000 h*
£0.02 «eni
WC - 32
> 100 10 10.000 Ib
> 5OO.OOO to SO million Ib
> 4.75 million 10 675 million ft3
> 250.0OO 10 25 million yd1
>6,750 \o 675. OOO fr"
>250 lo 25.000 yd1
> l.OOO lo 100. OOO dnjm»
> 50.0OO 10 5 million oalloni
>«.75 million lo 875 million fr1
> 250. OOO 10 25 million yd'
>0.750 lo 675. OOO ft1
>250 to 25, OOO yd'
>6.7SO to 675. OOO fr"
>250 to 25.000vd'
>34O.OOO to 3* million rr1
> 7.8 to 780 i
>1,30O lo 130. OOO FT1
>0.029 lo 2.9 icrti
>3.4 million to 340 million hr1
>78 lo 7. BOO >crn
> 1.3OO lo 130.0OO tr>
70.029 10 2.9 >cr27.OOO lo 2.7 million fr1
>0.92 lo 62 10, OOO Ib
> SO million Ib
>675 million fr1
>25 million yd'
>675,000 fr3
> 25.000 yd'
> 100, OOO dnjm«
> 5 million g'Hont
>675 million (T1
> 25 million yd'
>675.OOO fr"
> 25.000 yd'
> 675. OOO ft3
> 25.000 yd'
> 34 million fr1
> 780 >ci«i
> I3O.OOO rr1
> 2.S icrgi
>34O million fr1
>7.8OO tcni
> 130. OOO fr"
> 2.9 »erti
> 2.7 mtlllon fr1
> 62 »crti
MULTIPLE SOURCE
SITES
Formula lor
Anigning Source
WQ Valuei
Ib
Ib -- 5,000
tr3 H- 67,500
Y0 10 100
> 100 lo 10.0OO
> 10.0OO
WC Scan
18
32
100
Site, Source, and Waste Characterization
page 3-17
A-9
-------
Section 4:
Ground Water Pathway
Resources
Wellhead
protection
area
Nearest
well
\
Ground water
population
/\
AQUIFER
-------
GROUND WATER PATHWAY
Ground Water Pathway
Wellhead
protection
area
AQUIFER
OH*1
Data Search Questions
Aqurferfs)
What is local stratigraphy?
What aquifer(s) serves nearby areas?
How deep is the shallowest aquifer?
Wells (targets)
How many drinking water wells? Locations?
Any municipal systems? Private wells?
How many people are served?
Is water from different wells blended? Is ground
water blended with surface water?
Go to PA Guidance,
appendix A, page A-11, Ground Water Use Description
PA Guidance, section 3.3
OH* 2
Ground Water Pathway
page 4-2
4/94
-------
GROUND WATER PATHWAY
Aquifer Definition
Aquifer (as defined by PA Guidance)
Saturated subsurface zone from which drinking water is drawn
For site assessment purposes, ground water used for certain
resources, such as agriculture and recreation, is also evaluated
PA Guidance, section 3.3, page 52 OH 3
v
Ground Water Information Sources
U.S. Geological Survey (USGS)
Well logs
Water utility
Local offices
Site reconnaissance observations
Files for other, nearby sites
Data bases
PA Guidance, section 3.3 OH 4
4/94 Ground Water Pathway
page 4-3
-------
GROUND WATER PATHWAY
Site Assessment Questions for Ground Water
1.
Have hazardous
substances been
deposited at the
site? If so, what?
How much?
2. What is the likelihood
that hazardous
substances have been
released to ground
water?
WC x LR x T
82,500
3. Who and what are
likely to be impacted
by contaminated
ground water?
Ground
Water
Pathway
Score
OH* 6
Ground Water Pathway Evaluation
Waste characteristics (WC)
Determined during source characterization
Likelihood of re/ease (LR)
Suspected release
No suspected release
Targets (T)
Primary targets
Secondary targets
PA Guidance, section 3.3
OH* 6
Ground Wirier Pathway
page 4-4
4/94
-------
GROUND WATER PATHWAY
Ground Water Pathway Criteria List
Contains elements to consider when determining whether
suspected release exists
Contains issues to consider when determining whether any
drinking water wells are primary targets
Not a tally sheet
Consider other site-specific issues
Go to PA Guidance, appendix A,
pages A-12 and A-13, Ground Water Pathway Criteria List
PA Guidance, appendix A
OH«7
Special Considerations for Likelihood of Release:
Depth to Aquifer
Depth to Water
22 feet
Maximum Depth
of Wastes 5 feet
Depth to Aquifer
22 feet -5 feet = 17 feet
AQUIFER j
Depth to Aquifer = Depth to Ground Water from Surface
Minus Maximum Depth of Waste
Not to Scale
PA Guidance, section 3.3.1, page 56
OH* 8
4/94
Ground Water Pathway
page 4-5
-------
GROUND WATER PATHWAY
Special Considerations for Likelihood of Release:
Karst Terrain
Definition: Terrain with unique characteristics of relief and
drainage due to a high degree of rock solubility
Majority of karst conditions occur in limestone areas, but can also
occur in dolomite, gypsum, and salt deposits
Karst characteristics: Cavernous porosity, disappearing streams,
abundant springs, and very high transmissivity
PA Guidance, section 3.3.1, page 57 OH 9
Likelihood of Release
"Suspected Release" or "No Suspected Release"
Suspected release: high likelihood hazardous substance has
been released to ground water
No suspected release: low likelihood of release
Requires professional judgment based on site and pathway
conditions
PA Guidance, section 3.3.1, pages 59 and 60 OH 10
Ground Water Pathway 4/94
page 4-6
-------
GROUND WATER PATHWAY
Likelihood of Release
a) How likely are hazardous
substances to escape from
source?
b) Once substances have
escaped from source, how
likely are they to reach
ground water?
OH* 11
Example
Suspected Release or No Suspected Release
OH* 12
4/94
Ground Water Pathway
page 4-7
-------
GROUND WATER PATHWAY
Ground Water Targets
Drinking water supply wells located within 4 miles of the site
Ground water target = well
Ground water population = people served by well
Primary targets are determined by likelihood of exposure
Secondary targets are distance-weighted
PA Guidance, section 3.3.2 OH 13
V
Ground Water Targets
Multiple aquifers
Evaluate all ground water sources within 4 miles as targets,
regardless of aquifer from which they draw
PA Guidance, section 3.3.2 OH 14
Ground Water Pathway 4/94
page 4-8
-------
GROUND WATER PATHWAY
V
Ground Water Targets
At PA, conduct comprehensive target survey
Municipal wells
Community wells
Private wells
Need to know
Well locations
Number of people served
All targets must be plotted on a map
PA Guidance, section 3.3.2 OH 15
Ground Water Targets
Nearest drinking water well
PA considers proximity of nearest drinking water well
Consult local water authorities for municipal systems
Conduct "windshield" survey for private wells
PA Guidance, section 3.3.2 OH 16
4/94 Ground Water Pathway
page 4-9
-------
GROUND WATER PATHWAY
Ground Water Targets
Target distance categories
A series of concentric circles around the site with radii of % mile,
V& mile, 1 mile, 2 miles, 3 miles, and 4 miles is drawn on a
topographic map
Distance circles are used to evaluate secondary drinking water
target populations
Distance is measured from nearest source to well, not population
PA Guidance, section 3.3.2
OH* 17
Ground Water Targets
Target distance categories
(Not to scale)
A = people served
by well A
B = people served
by well B
OH* 18
Ground Wator Pathway
page 4-10
4/94
-------
GROUND WATER PATHWAY
Ground Water Targets
Blended municipal systems
Definition: entire system is interconnected by valves or
connecting lines so that water drawn from any supply well and/or
intake can reach any user of the system
For blended systems, assign a population to each well or water
intake
PA Guidance, section 3.3.2, pages 62-64 OH 19
V
Ground Water Targets
Blended municipal systems: apportionment of population
Apportionment is based on each well's contribution
Base apportionment on average annual production
Apportionment is not necessary if any well serving the system is a
primary target
Apportionment is not necessary if all system wells are in one
target distance category
PA Guidance, section 3.3.2 OH 20
4/94 Ground Water Pathway
page 4-11
-------
GROUND WATER PATHWAY
Ground Water Targets
Blended municipal systems: apportionment of population
The "40-Percent Rule"
If any supply well or intake in a blended system contributes 40
percent or more of the system's annual production, apportion
population to each well based on percent contribution
If all supply wells and/or intakes contribute less than 40 percent,
apportion population equally among all
PA Guidance, section 3.3.2, page 63 OH 21
V
Notes:
GroundWatarPtthwty 4/94
page 4-12
-------
GROUND WATER PATHWAY
Mini Exercise: Blended Municipal Well System
The 40-Percent Rule
DW-1
DW-2
-------
GROUND WATER PATHWAY
Ground Water Targets
Worker and student populations
Should be evaluated if they are served by ground water drawn
from within 1 mile of source
Generally, do not spend time collecting information about
populations outside of 1 mile because distance-weighting will
greatly reduce their significance
OH* 23
J
Ground Water Targets
Primary or secondary target wells
Primary targets: high likelihood drinking water wells in question
have been exposed to hazardous substances from site
Secondary targets: low likelihood of exposure
Requires professional judgment based on site, pathway, and
target characteristics
PA Guidance, section 3.3.2, page 65 OH 24
Ground Water Pathway 4/94
page 4-14
-------
GROUND WATER PATHWAY
Ground Water Targets
Primary target population
Definition: the human population served by drinking water from
primary target wells
Primary targets are possible only if a release is suspected
PA Guidance, section 3.3.2, pages 66-70 OH 25
J
Ground Water Targets
Ground water criteria list
Primary target well selection is based on:
- Characteristics of site and environs
- Sources, types, and quantities of wastes
- Proximity of well to source(s)
- Characteristics of the well
Primary target wells are identified using the Ground Water
Pathway Criteria List (PA Guidance, appendix A, page A-13)
PA Guidance, section 3.3.2, pages 66-70 OH 26
4/94 Ground Water Pathway
page 4-15
-------
GROUND WATER PATHWAY
Ground Water Targets
Secondary target population
Definition: the human population served by drinking water drawn
from secondary target wells
If no release is suspected, all targets are evaluated as secondary
targets
If a release is suspected, some targets may be evaluated as
primary targets and others as secondary targets
Populations are distance-weighted based on the distance
category in which wells are located
Populations served by wells located in inner rings carry more
"weight" because contaminants become diluted as they migrate
outward
PA Guidance, section 3.3.2, pages 71-72 OH 27
V _ . _
Ground Water Targets
Wellhead protection area (WHPA)
Definition: a state-designated area restricting certain land uses
and industrial practices around drinking water wells
Consider if any onsite sources or primary targets are located
within a designated WHPA
Also consider if neither of the above apply but any part of a
designated WHPA is located within 4 miles of the site
PA Guidance, section 3.3.2, page 74 OH 28
GroundWatarPathway 4/94
page 4-16
-------
GROUND WATER PATHWAY
Ground Water Targets
Resources
Definition: use of ground water for purposes other than drinking water
Irrigation of commercial crops
Watering of commercial livestock
Commercial food preparation
Recreation
Generally, do not expend significant effort evaluating resources
during PA
Usually assigned a default value of 5 points
PA Guidance, section 3.3.2, page 75 OH 29
Ground Water Pathway Scoresheet
PA Guidance, appendix A, pages A-14 through A-17
Directions found in PA Guidance, section 3.3.2, and in appendix A
Secondary target population values determined using PA Table 2,
Values For Secondary Ground Water Target Populations
Go to PA Guidance, appendix A,
Ground Water Pathway Score Sheet, page A-15
OH* 30
4/94 Ground Water Pathway
page 4-17
-------
8
GROUND WATER PATHWAY SCORESHEET
ftifiwty Cltmrtatnttict
Do you suspect a release (see Ground Water Pathway Criteria List, page 7)7
Is the site located in karst terrain?
Depth to aquifer:
Distance to the nearest drinking water well:
Yes No
Yes No
LIKELIHOOD OF RELEASE
1. SUSPECTED RELEASE: If you suspect a release to ground water (see page 7),
assign a score of 550. Use only column A for this pathway.
2. NO SUSPECTED RELEASE: If you do not suspect a release to ground water, and
the site is in karst terrain or the depth to aquifer is 70 feet or less, assign a score
of 500; otherwise, assign a score of 340. Use only column B (or this pathway.
LR -
TARGETS
3. PRIMARY TARGET POPULATION: Determine the number of people served by
drinking water wells that you suspect have been exposed to a hazardous
substance from the site (see Ground Water Pathway Criteria List, page 7).
_ people x
10
4. SECONDARY TARGET POPULATION: Determine the number of people served by
drinking water wells that you do NOT suspect have been exposed to a hazardous
substance from the site, and assign the total population score from PA Table 2.
Are any wells part of a blended system? Yes _ No _
If yes, attach a page to show apportionment calculations.
5. NEAREST WELL: If you have identified a primary target population for ground
water, assign a score of 50; otherwise, assign the Nearest Well score from
PA Table 2. If no drinking water wells exist within 4 miles, assign a score of zero.
6. WELLHEAD PROTECTION AREA (WHPA): If any source lies within or above a WHPA,
or if you have identified any primary target well within a WHPA, assign a score of 20:
assign 5 if neither condition holds but a WHPA is present within 4 miles; otherwise
assign zero.
7. RESOURCES
IN.ll.M.3.1. -
T -
WASTE CHARACTERISTICS
8. A. If you have identified any primary target for ground water, assign the waste
characteristics score calculated on page 4, or a score of 32, whichever is
GREATER; do not evaluate part B of this factor.
B. If you have NOT identified any primary target for ground water, assign the
waste characteristics score calculated on page 4.
WC
GROUND WATER PATHWAY SCORE:
LR x T x WC
82,500
(tub^ct to * nuiimum of
1001
Ground Water Pathway
page 4-18
A-15
-------
PA TABLE 2: VALUES FOR SECONDARY GROUND WATER TARGET POPULATIONS
PA Table 2a: Non-Karst Aquifers
Distance
from Sfte
0 to X. milo
> )4 to y, mile
> 54 to 1 milo
> 1 to 2 miles
>2 to 3 miles
> 3 to 4 miles
Population
Nearest Well =
Nearest
Well
fchoose
highest}
20
18
9
5
3
2
Population Served by Wells Within Distance Category
i
to
10
i
1
1
1
1
1
11
to
30
2
i
i
i
i
i
31
to
100
5
3
2
1
1
1
101
to
300
16
10
5
3
2
1
301
to
1.000
52
32
17
9
7
4
1.001
to
3.0OO
163
101
52
29
21
13
3.001
to
10.0OO
521
323
167
94
68
42
1O.OO1
to
30,000
1.633
1.012
522
294
212
131
f
30.O01
to
1OO.OOO
5.214
3,233
1.668
939
678
417
Qrwmtmr
thmn
1OO.OOO
16,325
10.121
5.224
2.938
2.122
1.306
Score =
Population
Value
PA Table 2b: Karst Aquifers
Distance
from Site
0 to X. mile
> X to K mile
> H to 1 mila
> 1 to 2 miloi
> 2 to 3 milei
> 3 to 4 miloi
Population
Nearest Well -
Nearest
Well
luse 20
for karstl
20
20
20
2O
20
20
Population Served by Wells Within Distance Category
i
to
70
1
1
1
1
1
1
11
10
30
2
1
1
1
, 1
1
31
to
100
5
3
3
3
3
3
101
to
3OO
16
10
8
a
8
8
301
to
1.OOO
52
32
26
26
26
26
1.001
to
3.OOO
163
101
82
82
82
82
3.001
to
1O.OOO
521
323
261
261
261
261
10.00 1
to
3O.OOO
1.633
1.012
816
816
816
816
*
30.0O1
to
1OO.OOO
5.214
3.233
2,607
2.607
2.607
2.6O7
Qrwmtmr
thmn
1OO.OOO
16.325
10.121
8.162
8.162
8.162
8.162
Score
Population
Value
Q.
sr
o «
OJ t)
(0 ft)
-------
GROUND WATER PATHWAY
Mini Exercise: Secondary Ground Water Target Population
,DW-1
1.8 miles from source;
serves 1,500 people
Town of Baker has 3 wells
of equal capacity serving
2,700 people
DW-2
0.8 miles from source;
serves 842 people
DW-5
5.2 miles from source;
serves town of Baker
SOURCE
DW-4
2.5 miles from source;
serves town of Baker
DW-3
0.4 miles from source;
serves town of Baker
OH* 31
Mini Exercise: Secondary Ground Water Target Population
Distance
Category (mi.)
0-1/4
1/4 -1/2
1/2-1
1-2
2-3
3-4
Number
Of People
Distance-Weighted
Population
OH* 32
Ground WtterPtthwty
page 4-20
4/94
-------
GROUND WATER PATHWAY
Mini Exercise: Ground Water Target Population
DW-3
2.4 miles from source;
serves 842 people
DW-1
0.3 miles Irom source;
serves 25 people
(Contaminant plume)
(Not to scale)
DW-2
1.3 miles Irom source;
serves 137 people
Well
DW-1
DW-2
DW-3
Primary or
Secondary
Distance Category
Population
Population Value
for Secondary Targets
OH* 33
4/94
Ground Water Pithway
page 4-21
-------
GROUND WATER PATHWAY
Ground Water Scoring
WC x LR
82,500
Ground
Water
Pathway
Score
OH* 34
Notes:
Ground Water Pathway
page 4-22
4/94
-------
GROUND WATER PATHWAY
CASE STUDY: ABC VACUUM SERVICE
GROUND WATER PATHWAY
OBJECTIVE
Using background information from file searches, site reconnaissance notes, reference materi-
als, maps, and phone conversation records, complete the "Ground Water Pathway" portion of
the PA scoresheets.
METHOD
1. Review the general ground water pathway information summary provided below and
the file information included with this exercise.
2. Using the information provided, complete the "Ground Water Use Description"
section of the PA scoresheets.
3. Read the instructions for the "Ground Water Pathway Criteria List" and complete the
"Suspected Release" and "Primary Targets" evaluations. Determine whether you
hypothesize a suspected release and identify whether there are any primary targets.
Summarize the rationale for these decisions in the space provided.
4. Using the existing site information and the scoresheet instructions, complete all the
portions of the "Ground Water Pathway Scoresheet." PA Table 2, Values for
Secondary Ground Water Target Populations, should be used to determine
population values for secondary targets if applicable. Remember to evaluate the
"Nearest Well" category.
5. Calculate and record the ground water pathway score.
Ground Water Pathway:
There are two aquifers of concern:
- A shallow, water-table aquifer (depth to water = 30 feet) that consists mainly of fine-
to coarse-grained sands
- A deeper aquifer (depth to water = 160 feet) that consists mainly of fine- to coarse-
grained sands and gravel
Five nearby residences use private wells that tap the shallow aquifer.
4/94 Ground Water Pathway
page 4-23
-------
GROUND WATER PATHWAY
No other private wells exist within 4 miles of the site.
A blended municipal well system is present within 1 mile of the site.
- The total population served is 8,900.
- The wells tap the deeper aquifer and are screened at approximately 195 feet.
Ground water is also used in commercial crawfish farms.
No wellhead protection area is located within 4 miles of the site.
The site is not located in an area of karst terrain.
Municipal Well System Apportionment:
WELL
IDENTIFICATION
Well A
WellB
WellC
DISTANCE
FROM SITE
2,800 feet
(0.45 miles)
4,000 feet
(0.76 miles)
4,000 feet
(0.76 miles)
PERCENT ANNUAL
PRODUCTION
30
35
35
Ground WttorPtthwty
page 4-24
4/94
-------
ABC Vacuum Service
iffiM
Stained
: ! i ! i ! i ! i ! i :: v: !: :: : t
Stained soil
1: .: -V "! ''. '' ''."'!: -*!: -*!: -0
Debrist:::K:0xidatton
Ii pads
Warehouse
Septic
tank
Private well
Property boundary
Standing :
rainwater
Rubbish
pile
Not to Scale
-------
ABC Vacuum Service
Residential
\15'
Ground Water Pathway
cage 4-26
\
-------
Geology Of Atlas Parish, Louisiana
By MARY CLARKE
U.S. GEOLOGICAL SURVEY
U.S. DEPARTMENT OF THE INTERIOR
UNITED STATES GOVERNMENT PRINTING OFFICE : 1989
Ground Water Pathway
page 4-27
-------
HYDROGEOLOGIC SETTING
Atlas Parish is situated in the subtropical zone along the borders of the Mississipi
River. Annual precipitation for this region averages 57 inches and is the major source of
recharge for the aquifers of the area.
GEOLOGIC FRAMEWORK
The Atlas Parish aquifer system consists of two aquifers of similar
composition. The shallow aquifer is composed of alluvial sediments, namely fine-to-coarse
grained sands, and has a depth to water of approximately 30 feet The deeper aquifer
consists mainly of fine-to-coarse grained sands and gravels with depth to water being
estimated at 160 feet As a result of these compositions, permeabilities for both aquifers
are high.
Ground Water Pathway
page 4-28
-------
PHONE CONVERSATION RECORD
Originator
Conversation with:
Name .
Company
C-A
Address ^r***4L
n C, Co -*, »< ~l^tj>«*
Phone.
Subject
3/Oh
Originator Placed Call
C Originator Received Call
w.o. NO.
er
NO«M:
G Tickle File.
I] Fdlow-Up By: _
G Copy/Route To:
Follow-Up-Action:.
Originator's Initials.
. Ground Water Pathway
page 4-29
-------
GROUND WATER PATHWAY
Ground Water Use Description: Provide information on ground water use in the vicinity. Present the general
stratigraphy, aquifers used, and distribution of private and municipal wells.
Calculations for Drinking Watar Populations Served by Ground Water: Provide populations from private wells
and municipal supply systems in each distance category. Show apportionment calculations lor blended supply
systems.
Ground Water Pathway
page 4-30 A'10
-------
GROUND WATER PATHWAY
GROUND WATER USE DESCRIPTION
Describe Ground Water Use Within 4-miles of the Site:
(Describe stratigraphy, information on aquifers, municipal and/or private wells)
Calculations for Drinking Water Populations Served by Ground Water:
Ground Water Pathway
page 4-31
A-11
-------
GROUND WATER PATHWAY CRITERIA LIST
This "Criteria List" helps guide the process of developing hypotheses concerning the occurrence of a
suspected release and the exposure of specific targets to a hazardous substance. The check-boxes
record your professional judgment in evaluating these factors. Answers to all of the listed questions
may not be available during the PA. Also, the list is not all-inclusive; if other criteria help shape your
hypotheses, list them at the bottom of the page or attach an additional page.
The "Suspected Release" section identifies several site, source, and pathway conditions that could
provide insight as to whether a release from the site is likely to have occurred. If a release is
suspected, use the "Primary Targets" section to evaluate conditions that may help identify targets
likely to be exposed to a hazardous substance. Record responses for the well that you feel has the
highest probability of being exposed to a hazardous substance. You may use this section of the chart
more than once, depending on the number of targets you feel may be considered "primary."
Check the boxes to indicate a "yes," "no," or "unknown" answer to each question. If you check the
"Suspected Release" box as "yes," make sure you assign a Likelihood of Release value of 550 for the
pathway.
Ground Water Pathway
page 4-32 A-12
-------
GROUND WATER PATHWAY CRITERIA LIST
SUSPECTED RELEASE
PRIMARY TARGETS
Y N U
a o n
s k
ODD
ODD
ODD
ODD
ODD
D D
ODD
ODD
ODD
ODD
D D
D D
Are sources poorly contained?
Is the source a type likely to contribute to
ground water contamination (e.g., wet
lagoon)?
Is waste quantity particularly large?
Is precipitation heavy?
Is the infiltration rate high?
Is the site loc.ited in an area of karst terrain?
Is the subsurface highly permeable or
conductive?
Is drinking water drawn from a shallow
aquifer?
Are suspected contaminants highly mobile in
ground water?
Does analytical or circumstantial evidence
suggest ground water contamination?
Other criteria?
SUSPECTED RELEASE?
Y N U
eon
s k
D D D
ODD
D D D
ODD
ODD
ODD
Is any drinking water well nearby?
Has any nearby drinking water well been
closed?
Has any nearby drinking water user reported
foul-tasting or foul-smelling water?
Does any nearby well have a large drawdown
or high production rate?
Is any drinking water well located between the
site and other wells that are suspected to be
exposed to a hazardous substance?
Does analytical or circumstantial evidence
suggest contamination at a drinking water
well?
D O O Does any drinking water well warrant
sampling?
D D
D 'D
Other-criteria?
PRIMARY TARGET(S) IDENTIFIED?
Summarize the rationale for Suspected Release (attach an
additional page if necessary):
Summarize the rationale for Primary Targets (attach an
additional page if necessary):
A-13
Ground Water Pathway
page 4-33
-------
GROUND WATER PATHWAY SCORESHEET
Pathway Characteristics
Answer the questions at the top of the page. Refer to the Ground Water Pathway Criteria List (page 7) to
hypothesize whether you suspect that a hazardous substance associated with the site has been released to
ground water. Record depth to aquifer (in feet): the difference between the deepest occurrence of a hazardous
substance and the depth of the top of the shallowest aquifer at lor as near as possible) to the site. Note
whether the site is in karst terrain (characterized by abrupt ridges, sink holes, caverns, springs, disappearing
streams). Record the distance (in feet) from any source to the nearest well used for drinking water.
Likelihood of Release (LR)
1. Suspected Release: Hypothesize based on professional judgment guided by the Ground Water Pathway
Criteria List (page 7). If you suspect a release to ground water, use only Column A for this pathway and do
not evaluate factor 2.
2. No Suspected Release: If you do not suspect a release, determine score based on depth to aquifer or
whether the site is in an area of karst terrain. If you do not suspect a release to ground water, use only Column
B to score this pathway.
Targets (T) .
This factor category evaluates the threat to populations obtaining drinking water from ground waiter. To
apportion populations served by blended drinking water supply systems, determine the percentage of population
served by each well based on its production.
3. Primary Target Population: Evaluate populations served by all drinking water wells that you suspect have
been exposed to a hazardous substance released from the site. Use professional judgment guided by the Ground
Water Pathway Criteria List (page 7) to make this determination. In the space provided, enter the population
served by any wells you suspect have been exposed to a hazardous substance from the site. If only the number
of residences is known, use the average county residents per household (rounded up to the next integer) to
determine population served. Multiply the population by 10 to determine the Primary Target Population score.
Note that if you do not suspect a release, there can be no primary target population.
4. Secondary Target Population: Evaluate populations served by all drinking water wells within 4 miles that
you do not suspect have been exposed to a hazardous substance. Use PA Table 2a or 2b (for wells drawing
from non-karst and karst aquifers, respectfully) (page 9). If only the number of residences is known, use the
average county residents per household (rounded to the nearest integer) to determine population served. Circle
the assigned value for the population in each distance category and enter it in the column on the far-right side
of the table. Sum the far-right column and enter the total as the Secondary Target Population factor score.
5. Nearest Well represents the threat posed to the drinking water well that is most likely to be exposed to a
hazardous substance. If you have identified a primary target population, enter 50. Otherwise, assign the score
from PA Table 2a or 2b for the closest distance category with a drinking water well population.
6. Wellhead Protection Area (WHPA): WHPAs are special areas designated by States for protection under
Section 1428 of the Safe Drinking Water Act. Local/State and EPA Regional water officials can provide
information regarding the location of WHPAs.
7. Resources: A score of 5 can generally be assigned as a default measure. Assign zero only if ground water
within 4 miles has no resource use.
Sum the target scores in Column A (Suspected Release) or Column B (No Suspected Release).
Waste Characteristics (WC)
8. Waste Characteristics: Score is assigned from page 4. However, if you have identified any primary targe:
for ground water, assign either the score calculat-ed on page 4 or a score of 32, whichever is greater.
Ground Water Pathway Score: Multiply the scores for LR, T, and WC. Divide the product by 82,500. Round
the result to the nearest integer. If the result is greater than TOO, assign TOO.
Ground Water Pathway
page 4-34 A-I 4
-------
8
GROUND WATER PATHWAY SCORESHEET
Ptthvtmy
Do you suspect a release (see Ground Water Pathway Criteria List, page 7)7
Is the site located in karst terrain?
Depth to aquifer:
Distance to the nearest drinking water well:
LIKELIHOOD OF RELEASE
1. SUSPECTED RELEASE: If you suspect a release to ground water (see page 7),
assign a score of 550. Use only column A for this pathway.
2. NO SUSPECTED RELEASE: If you do not suspect a release to ground water, and
the site is in karst terrain or the depth to aquifer is 70 feet or less, assign a score
of 500; otherwise, assign a score of 340. Use only column B for this pathway.
LR -
TARGETS
3.
4.
PRIMARY TARGET POPULATION: Determine the number of people served by
drinking water wells that you suspect have been exposed to a hazardous
substance from the site (see Ground Water Pathway Criteria List, page 7).
people x
10
SECONDARY TARGET POPULATION: Determine the number of people served by
drinking water wells that you do NOT suspect have been exposed to a hazardous
substance from the site, and assign the total population score from PA Table 2.
Are any wells part of a blended system? Yes No
If yes, attach a page to show apportionment calculations.
5. NEAREST WELL: If you have identified a primary target population for ground
water, assign a score of 50; otherwise, assign the Nearest Well score from
PA Table 2. If no drinking water wells exist within 4 miles, assign a score of zero.
6. WELLHEAD PROTECTION AREA (WHPA): If any source lies within or above a WHPA,
or if you have identified any primary target well within a WHPA, assign a score of 20;
assign 5 if neither condition holds but a WHPA is present within 4 miles; otherwise
assign zero.
7. RESOURCES
T -
WASTE CHARACTERISTICS
8. A. If you have identified any primary target for ground water, assign the waste
characteristics score calculated on page 4, or a score of 32, whichever is
GREATER; do not evaluate pan 8 of this factor.
B. If you have NOT identified any primary target for ground water, assign the
waste characteristics score calculated on page 4.
we -
GROUND WATER PATHWAY SCORE:
LR x T x WC
82,500
liubOct u
i maximum of 100)
A-15
Ground Water Pathway
page 4-35
-------
03
co
o
-0
I
PA TABLE 2: VALUES FOR SECONDARY GROUND WATER TARGET POPULATIONS
PA Table 2a: Non-Karst Aquifers
Distance
from Sit*
0 to K mile
> K to K mile
>)4 to 1 mile
> 1 to 2 miles
> 2 to 3 miles
> 3 to 4 miles
Population
Nearest Well =
Nearest
Well
(choose
highest)
20
18
9
5
3
2
Population Served by Wells Within Distance Category
i
to
10
1
1
1
1
1
1
11
to
30
2
1
1
1
1
1
31
to
100
5
3
2
1
1
1
10 1
to
30O
16
10
5
3
2
1
301
to
1.OOO
52
32
17
9
7
4
1.0O1
to
3.OOO
163
101
52
29
21
13
3,OO 7
fo
70.0OO
521
323
167
94
68
42
10.O01
to
30.000
1.633
1.012
522
294
212
131
*
30.001
to
100.0OO
5.214
3,233
1.668
939
678
417
Qnmtmr
thmn
100.000
16,325
10.121
5.224
2,938
2.122
1.306
Score =
Population
Value
PA Table 2b: Karst Aquifers
Distance
from Site
0 to K mile
> K to K mile
> H to 1 mile
> 1 to 2 mile*
> 2 to 3 mile*
> 3 to 4 mile*
Population
Nearest Well -
Nearest
Well
(use 20
for karstl
20
20
20
20
20
20
Population Served by Wells Within Distance Category
i
to
10
1
1
1
1
1
1
11
to
30
2
1
1
1
1
1
31
to
100
5
3
3
3
3
3
101
to
300
16
10
8
8
8
8
301
to
1.0OO
52
32
26
26
26
26
1.001
to
3.00O
163
101
82
82 .
82
82
3,007
to
10.000
521
323
261
261
261
261
70.001
to
30.000
1.633
1,012
816
816
816
816
/
3O.OO7
fo
100.OOO
5.214
3.233
2.607
2.6O7
2.6O7
2.6O7
Onmtor
thmn
10O.OOO
16,325
10.121
8.162
8.162
8.162
8,162
Score -
Population
Value
-------
Section 5:
Surface Water Pathway
latoor
-------
SURFACE WATER PATHWAY
Surface Water Definition
Surface water: naturally occurring, and some man made,
perennial water bodies
All surface water is eligible
Intermittently flowing water bodies qualify as surface water in
areas with less than 20 inches mean annual precipitation
Overland flow must reach surface within 2 miles to score pathway
See PA Guidance, glossary,
for detailed definitions of water body types
PA Guidance, section 3.4
OH*1
Notes:
Surface Water Pathway
page 5-2
11/94
-------
SURFACE WATER PATHWAY
Contaminants Can Reach Surface Water by:
Runoff
Overland flow
Flood
Ground water
discharge to surface
water
Runoff
Percolation
Flow
OH* 2
Site Assessment Questions for Surface Water
1. Have hazardous
substances been
deposited at site?
If so, what? How
much?
2. What is the
likelihood that
hazardous
substances have
been released to
surface water?
3. Who and what are
likely to be impacted
by contaminated
surface water?
WC x LR x T =
82,500
Surface
Water
Pathway
Score
PA Guidance, section 3.4
OHO
11/94
Surface Water Pathway
page 5-3
-------
SURFACE WATER PATHWAY
Surface Water Pathway Evaluation
Waste
Characteristics
PA Guidance, section 3.4
Drinking
Water Threat
H Likelihood of I
Release |
I
Human Food
Chain Threat
Environmental
Threat
OH* 4
Characterize the Surface Water Migration Path
Define overland segment
Define "in-water" segment
Determine flow(s) of the surface water body/bodies
to the 15-mile target distance limit
Locate targets for all threats
PA Guidance, section 3.4
OH* 5
Surftce Water Pathway
page 5-4
11/94
-------
SURFACE WATER PATHWAY
Surface Water Information Sources
USGS topographic maps, water resources reports
State water reports
Local water utility
Soil Conservation Service field office
U.S. and state fish and wildlife offices
National Weather Service
Site reconnaissance
PA Guidance, section3.4.1 OH*6
Data Search Questions:
Surface Water Pathway
Likelihood of Release
What is distance wastes must travel to surface water? Where
does site drainage enter surface water?
Is site subject to flooding? What is flood frequency?
Targets
Uses of surface water downstream from site? Drinking? Fishing?
Recreation?
Any wetlands or other sensitive environments downstream that
could be impacted?
PA Guidance, sections 3.4.1 and 3.4.2 OH 7
11/94 Surface Water Pathway
page 5-5
-------
SURFACE WATER PATHWAY
Likelihood of Release
Suspected Release
Criteria list consideration
Summarize rationale for suspected release
Record decision on likelihood of release in "Pathway
Characteristics" box on PA scoresheet
Go to PA Guidance, Criteria List for Suspected
Release to the Surface Water Pathway, pages 78-80
PA Guidance, section 3.4.1 and appendix A, pages A-20 and A-21
OH* 8
Notes:
Suifict Wafer Pathway
page 5-6
11/94
-------
SURFACE WATER PATHWAY CRITERIA LIST
SUSPECTED RELEASE
PRIMARY TARGETS
Y N U
eon
s k
ODD
D 0 D
ODD
ODD
D D D
ODD
D D D
ODD
D O D
ODD
ODD
ODD
D D O
D D
D D
Is surface water nearby?
Is waste quantity particularly large?
Is the drainage area large?
Is rainfall heavy?
Is the infiltration rate low?
Are sources poorly contained or prone to
runoff or flooding?
Is a runoff route well defined (e.g., ditch or
channel leading to surface water)?
Is vegetation stressed along the probable run-
off route?
Are sediments or water unnaturally discolored?
Is wildlife unnaturally absent?
Has deposition of waste into surface water
been observed?
Is ground water discharge to surface water
likely?
Does analytical or circumstantial evidence
suggest surface water contamination?
Other criteria?
Y N U
eon
s k
D D D Is any target nearby? If yes:
D Drinking water intake
D Fishery
O Sensitive environment
D D O Has any intake, fishery, or recreational area
been closed?
D D O Does analytical or circumstantial evidence
suggest surface water contamination at or
downstream of a target?
ODD Does any target warrant sampling? If yes:
O Drinking water intake
D Fishery
D Sensitive environment
D D
D.D
O D
D O
Other criteria?
PRIMARY INTAKE(S) IDENTIFIED?
PRIMARY FISHERYIIES) IDENTIFIED?
PRIMARY SENSITIVE ENVIRONMENTfS]
IDENTIFIED?
SUSPECTED RELEASE?
Summarize the rationale for Suspected Release (attach an
additional page if necessary):
Summarize the rationale for Primary Targets (attach an
additional page if necessary):
Surface Water Pathway
page 5-7
A-21
-------
SURFACE WATER PATHWAY
Likelihood of Release
No Suspected Release
Special considerations
- Distance to surface water
- Flood frequency
PA Guidance, section 3.4.1 OH 9
V J
Likelihood of Release:
Distance to Surface Water
Definition: shortest distance runoff would follow from a source to
surface water
Measured along shortest drainage route ("as the water flows")
Probable point of entry (PPE): point at which runoff from site
most likely enters surface water
Identify runoff route and PPE on site sketch in PA scoresheet
PA Guidance, section 3.4.1, pages 81 and 82 OH 10
Surface Water Pathway 11/94
page 5-8
-------
SURFACE WATER PATHWAY
Likelihood of Release:
Distance to Surface Water
OH»11
Likelihood of Release:
Flood Frequency
Locate site with respect to surface water floodplains
Use FEMA flood insurance rate maps
Record flood frequency in "Pathway Characteristics" box on PA
scoresheet
PA Guidance, section 3.4.1, page 83
OH* 12
11/04
Suffice Water Pathway
page 5-9
-------
SURFACE WATER PATHWAY
Evaluate Three Separate Target Threats
Drinking water threat
People drinking surface water; drinking water intakes;
resources
Human food chain threat
People eating fish taken from surface water; fisheries
Environmental threat
Impacts to sensitive environments (including wetlands,
critical habitats, and national parks) along the surface
water route
PA Guidance, section 3.4.2
OH* 13
1. Begin
measuring in-
water segment
at PPE and
continue
downstream
for 15 miles.
X
Runoff
route
Target Distance Limit
1SmNn
Downttraam
front PPE
Go to PA Guidance, section 3.4.2, pages 87 and 88,
for more examples
PA Guidance, section 3.4.2, page 86
2. If in-water
segment ends in
a lake, ocean, or
coastal waters,
measure within
that water body
an arc from
mouth of stream
to shores of
receiving water
body.
OH* 14
Surftca Wrtor Pathway
page 5-10
11/94
-------
SURFACE WATER PATHWAY
Targets:
Drinking Water Threat
Identify drinking water intakes
Identify nearest drinking water intake
Determine flow rates at intakes
Evaluate drinking water population
PA Guidance, section 3.4.2 OH 15
V
Notes:
OH* 16
11/94 Surface Water Pathway
page 5-11
-------
SURFACE WATER PATHWAY
Targets:
Drinking Water Threat
Determine flow at target intakes
- Obtain average flow rate in cubic feet per second (cfs)
- Estimate using water body type (PA table 4, page A-25)
Sources of information
- Local water authorities
- USGS water data reports
PA Guidance, section 3.4.2, page 89 OH 17
V
Targets:
Drinking Water Threat
Evaluate Drinking Water Population
Evaluate population served by each surface water intake
Estimate __ Number of Average number of
population "~ service X persons per
connections household
Apply rule of apportionment for "blended" systems
PA Guidance, section 3.4.2, page 90 OH 18
Surface Water Pathway 11/94
page 5-12
-------
SURFACE WATER PATHWAY
Targets:
Drinking Water Threat
Primary drinking water targets
Target = intake
Population = people served by intake
Primary target population identified using criteria list
(appendix A, page A-21)
Primary target intake implies a high likelihood that hazardous
substance has reached intake
PA Guidance, section 3.4.2, page 97 OH 19
Targets:
Drinking Water Threat
Secondary drinking water targets
Low likelihood that hazardous substance has reached intake
Secondary targets are dilution-weighted
Consider workers and students only when information is readily
available
Go to appendix A,
PA tables 3 and 4, page A-25
PA Guidance, section 3.4.2, page 99 OH 20
11/94 Surface Water Pathway
page 5-13
-------
SURFACE WATER PATHWAY
Primary vs. Secondary Targets
Municipal
intake
OH* 21
Targets:
Drinking Water Threat
Resources: use of surface water for purposes other than
drinking
Examples
- Irrigation of commercial food or forage crops (5-acre minimum)
- Watering of commercial livestock
- Ingredient in commercial food preparation
- Major or designated water recreation area
Generally, sufficient to assign value of 5 as default
PA Guidance, section 3.4.1, page 102
OH* 22
Surface Water Pathway
page 5-14
11/94
-------
SURFACE WATER PATHWAY
LIKELIHOOD OF RELEASE AND DRINKING WATER THREAT SCORESHEET
Do YOU suspect a release (see Surface Water Pathway Criteria List, page 11|?
Distance to surface water:
Flood frequency:
What is the downstream distance 10 ihe nearest drinking water intake?
Nearest fishery? miles Dearest sensitive environment?
Yes
No
miles
yrs
miles
LIKELIHOOD OF RELEASE
1. SUSPECTED RELEASE: If you suspect a release to surface water (see page 1 11.
assign a score of 550. Use only column A for this pathway.
2. NO SUSPECTED RELEASE: If you do not suspect a release to surface
water, use the table below to assign a score based on distance to surface
water and flood frequency. Use only column B lor this pathway.
Distance to surface water £ 2.500 feet
Distance to surface water > 2.500 feet, and
Site in annual or 10-year tloodplain
Site in 100-year floodplain
Site m 500-year Moodplain
Site outside 500-year lloodpiain
500
500
4OO
300
too
DRINKING WATER THREAT TARGETS
3. Record the water body type, flow |i( applicable), and number of people served
by each drinking water intake within the target distance limit. If (here is no
drinking water intake within the target distance limn, factors *. 5. and 6
each receive zero scores.
Intik* N*m*
Wttff SooV Tyf" Row ftofJt 5~v«y
els
cfs
els
PRIMARY TARGET POPULATION: If you suspect any drinking water intake listed
aoove has been exposed to a hazardous substance from the site (see Surface Water
Pathway Criteria List, page 1 1), list the intake name(s) and calculate the factor
score based on the total population served.
people x 10 =
5. SECONDARY TARGET POPULATION: Determine the number of people served by
drinking water intakes that you do NOT suspect have been exposed to a hazardous
substance from the site, and assign the total population score from PA Table 3.
Are any intakes pan of a blended system? Yes No
If yes. anach a page to show apportionment calculations.
6. NEAREST INTAKE: If you have identified a primary target population lor the
drinking water threat (factor 4), assign a score of 50: otherwise, assign the
Nearest Intake score from PA Table 3. If no drinking water intake exists within
me target distance limit, assign a score of zero.
7 RESOURCES
T -
A-23
Surface Water Pathway
page 5-15
-------
SURFACE WATER PATHWAY
Targets:
Human Food Chain Threat
Fishery: area of a surface water body from which food chain
organisms are taken, or could be taken, for human consumption
Includes both commercial and sport fishing
Identify all fisheries located between the PPE and the 15-mile
TDL
Identify by water body type or flow characteristics
PA Guidance, section 3.4.1, page 91 OH 23
Targets:
Human Food Chain Threat
Primary target fishery
It is highly likely that hazardous substances have reached the
fishery
Identified using the criteria list (appendix A, page 22)
Secondary target fishery
It is unlikely that hazardous substances have reached the fishery
Scored on the basis of flow rate
Evaluated only if a primary target is not identified
PA Guidance, section3.4.2,pages 103and 104 . OH*24
SufftcaWMar Pithwiy 11/94
page 5-16
-------
SURFACE WATER PATHWAY (continued)
HUMAN FOOD CHAIN THREAT SCORESHEET
LIKELIHOOD OF RELEASE
Enter Surlacc Water Likelihood of Release score from page 12. LR -
5u*^*crW
/?/*«
AT« 5Mj>*aT«4
firftirt
HUMAN FOOD CHAIN THREAT TARGETS
8. Record the water body type and Mow (il applicable! lor each fishery within
the target distance limit. II there is no fishery within the target
distance limit, assign a Targets score ol 0 at the bortom ol the page.
*./,~y /V.m. W.r~ »<«y >"H" flow
cts
cfs
cfs
cfs
cfs
9. PRIMARY FISHERIES: If you susoect any fishery listed above has been exposed
to a hazardous substance from the site Isee Surface Water Criteria List, page 1 1),
assign a score ol 300 and do not evaluate Factor 10. List the primary fisheries:
10. SECONDARY-FISHERIES
A. If you suspect a release to surface water and have identified a secondary fishery
but no primary fishery, assign a score ol 210.
B. If you do not susoect a release, assign a Secondary Fisheries score from (he table
below using the lowest How at any fishery within the target distance limit.
iowmmt Row
< 10 cfs
10 to 100 els
> 100 cts. coastal
tidal waters, oceans,
or Great Lakes
£*oo/>^«/y R*h*fi*e Soon
210
30
12
T -
A-27
Surface Water Pathway
page 5-17
-------
SURFACE WATER PATHWAY
Targets:
Environmental Threat
Sensitive environment
General definition: terrestrial or aquatic resource, fragile natural
setting, or other area with unique or highly valued environmental
or cultural features
Most common type of sensitive environment is wetland
Wetland
General definition: an area that is sufficiently inundated by
surface or ground water to support vegetation adapted for life in
saturated soil conditions
PA Guidance, section 3.4.2, pages 92 and 93 OH 25
V
Targets:
Environmental Threat
Identify all sensitive environments in or adjacent to in-water
segment
PA table 5 (page A-31) lists sensitive environment types and
assigned values
Measure wetland frontage along water body; see PA table 6
(page A-31) for assigned score
Identify primary targets using criteria list
Go to Appendix A,
tables 5 and 6, page A-31
PA Guidance, section 3.4.2, pages 92 and 93 OH 26
Surface Water Pathway 11/94
page 5-18
-------
SURFACE WATER PATHWAY (continued)
ENVIRONMENTAL THREAT SCORESHEET
LIKELIHOOD OF RELEASE
Enter Surface Water Likelihood of Release score Irom page 12. LR -
5uMpM«*^
flt^Uf
H* Sutffatf^
A at***.
IMM.400_» - IOQ
ENVIRONMENTAL THREAT TARGETS
11. Record the water body type and How (il applicable) lor each surface water
sensitive environment within the target distance limit (see PA Tables 4
and 51. I' there is no sensitive environment within the target distance
limit, assign a Targets score ol 0 at the bonom ot the page.
1 2. PRIMARY SENSITIVE ENVIRONMENTS: II you suspect any sensitive environ-
ment listed above has been exposed to a hazardous substance Irom the site (see
Surface Water Criteria List, page 1 1), assign a score ol 300 and do not evaluate
factor 13. List the primary sensitive environments:
13. SECONDARY SENSITIVE ENVIRONMENTS: II sensitive environments are
present, but none is a primary sensitive environment, evaluate Secondary
Sensitive. Environments based on flow.
A. For secondary sensitive environments on surface water bodies with flows of
100 els or less, assign scores as follows, and do not evaluate part B of
this factor:
flow
cfs
els
els
cts
cfs
Ofc/DO/i W«yAr
IP A T,l>J. /;
X
X
X
X
X
£/Tv*nwvrvOT< Trp« * 100 els, assign a score of 10.
T -
A-29
Surface Water Pathway
page 5-19
-------
SURFACE WATER PATHWAY
Surface Water Pathway
we x LR x
WC x LR x
WC x LR x
82,500
82,500 =
82,500
SURFACE WATER
PATHWAY THREAT
SCORES
Evaluate drinking water, human food chain, and
environmental threats (subject to noted maximums)
Sum scores for each threat to obtain overall pathway
score
PA Guidance, section 3.4.2, page 108
OH* 27
Notes:
Surface Water Pathway
page 5-20
11/94
-------
SURFACE WATER PATHWAY
CASE STUDY: ABC VACUUM SERVICE
SURFACE WATER PATHWAY
OBJECTIVE
Using background information from file searches, site reconnaissance notes, and maps, com-
plete the "Surface Water Pathway" portion of the PA scoresheets.
METHOD
1. Review the general surface water pathway information summary provided below and
the map included with the exercise.
2. Read the instructions for the surface water pathway criteria list and complete the
"Suspected Release" and "Primary Targets" evaluations. Determine whether you
hypothesize a suspected release and identify whether there are any primary targets.
Summarize the rationale for these decisions in the space provided.
3. Using the existing site information and the scoresheet instructions, complete all
portions of the "Surface Water Pathway Scoresheet." PA Table 3, "Values for
Secondary Surface Water Target Populations" and PA Table 4, "Surface Water
Type/Flow Characteristics With Dilution Weights for Secondary Surface Water
Sensitive Environments," should be used to determine population values for
secondary targets if applicable. Remember to evaluate the "Nearest Intake" factor.
4. Calculate and record the surface water pathway score.
Surface Water Pathway:
Runoff is channeled into intermittent drainage ditches along the perimeter of the
facility.
These drainage ditches flow 6,000 feet (1.1 miles) into the perennial ditch.
The perennial ditch reaches the bayou 3 miles from the site.
The bayou empties into a river 10 miles from the site.
11/94 Surface Water Pathway
page 5-21
-------
SURFACE WATER PATHWAY =
Estimated flow rates:
- Bayou = 15 cubic feet per second (cfs)
- River = 75 cfs
Both the bayou and the river are used for fishing and swimming.
There are no surface water intakes within the 15-mile target distance limit.
The following sensitive environments are present:
- A critical habitat for federally designated endangered species is located 14 miles
downriver from the site.
- A 5-acre wetland is located 12 miles downriver from the site. The wetland frontage
equals 0.4 miles.
The site lies within the 500-year floodplain.
The drainage basin covers an area of about 165 acres.
Surface Water Pathway
page 5-22
-------
Site
Perennial
Ditch
ABC Vacuum
Service
Surface Water Map
(not to scale)
Endangered
species
habitat
Wetland
15-Mile target
distance limit
Surface Water Pathway
page 5-23
-------
SURFACE WATER PATHWAY
Migration Route Sketch: Sketch the surface water migration pathway (freehand is acceptable)
illustrating the drainage route and identifying water bodies, probable point of entry, flows, and targets.
Surface Water Pathway
page 5-24 A'18
-------
10
SURFACE WATER PATHWAY
MIGRATION ROUTE SKETCH
Suface Water Migration Route Sketch:
(include runoff route, probable point of entry, 15-mile target distance limit, intakes, fisheries,
and sensitive environments)
A-19
Surface Water Pathway
page 5-25
-------
SURFACE WATER PATHWAY CRITERIA LIST
This "Criteria List" helps guide the process of developing hypotheses concerning the occurrence of a
suspected release and the exposure of specific targets to a hazardous substance. The check-boxes
record your professional judgment in evaluating these factors. Answers to all of the listed questions
may not be available during the PA. Also, the list is not all-inclusive; if other criteria help shape your
hypotheses, list them at the bottom of the page or attach an additional page.
The "Suspected Release" section identifies several site, source, and pathway conditions that could
provide insight as to whether a release from the site is likely to have occurred. If a release is
suspected, use the "Primary Targets" section to guide you through evaluation of some conditions that
may help identify targets likely to be exposed to a hazardous substance. Record responses for the
target that you feel has the highest probability of being exposed to a hazardous substance. You may
use this section of the chart more than once, depending on the number of targets you feel may be
considered "primary."
Check the boxes to indicate a "yes," "no," or "unknown" answer to each question. If you check the
"Suspected Release" box as "yes," make sure you assign a Likelihood of Release value of 550 for the
pathway.
If the distance to surface water is greater than 2 miles, do not evaluate the surface water migration
pathway. Document the source of information in the text boxes below the surface water criteria list.
Surface Water Pathway
page 5-26 A-20
-------
SURFACE WATER PATHWAY CRITERIA LIST
SUSPECTED RELEASE
PRIMARY TARGETS
Y N U
eon
s k
D O D
D a a
ODD
oo a
ODD
ODD
ODD
D D a
D D a
c D a
ODD
ODD
C D D
D G
a D
Is surface water nearby?
Is waste quantity particularly large?
Is the drainage area large?
Is rainfall heavy?
Is the infiltration rate low?
Are sources poorly contained or prone to
runoff or flooding?
Is a runoff route well defined (e.g., ditch or
channel leading to surface water)?
Is vegetation stressed along the probable run-
off route?
Are sediments or water unnaturally discolored?
Is wildlife unnaturally absent?
Has deposition of waste into surface water
been observed?
Is ground water discharge to surface water
likely?
Does analytical or circumstantial evidence
suggest surface water contamination?
Other criteria?
Y N U
eon
s k
D D D Is any target nearby? If yes:
D Drinking water intake
O Fishery
D Sensitive environment
O O O Has any intake, fishery, or recreational area
been closed?
D O O Does analytical or circumstantial evidence
suggest surface water contamination at or
downstream of a target?
ODD Does any target warrant sampling? If yes:
D Drinking water intake
D Fishery
O Sensitive environment
D D
O D
D D
D O
Other criteria?
PRIMARY INTAKE(S) IDENTIFIED?
PRIMARY FISHERYIIESI IDENTIFIED?
PRIMARY SENSITIVE ENVIRONMENT(S)
IDENTIFIED?
SUSPECTED RELEASE?
Summarize the rationale for Suspected Release (attach an
additional page if necessary):
Summarize the rationale for Primary Targets (attach en
additional page if necessary):
A-21
Surface Water Pathway
page 5-27
-------
SURFACE WATER PATHWAY LIKELIHOOD OF RELEASE AND DRINKING WATER THREAT SCORESHEET
Pathway Characteristics
The surface water pathway includes three threats: Drinking Wa,ter Threat, Human Food Cham Threat and
Environmental Threat. Answer the questions at the top of the page. Refer to the Surface Water Pathway Criteria
List (page 11) to hypothesize whether you suspect that a hazardous substance associated with the site has been
released to surface water. Record the distance to surface water (the shortest overland drainage distance from
a source to a surface water body). Record the flood frequency at the site (e.g., 100-yr, 200-yr). if the sue is
located in more than one floodplain, use the most frequent flooding event. Identify surface water use(s) along the
surface water migration path and their distance(s) from the site.
Likelihood of Release ILR)
1. Suspected Release: Hypothesize based on professional judgment guided by the Surface Water Pathway Criteria
List (page 11). If you suspect a release to surface water, use only Column A for this pathway and do not evaluate
factor 2.
2. No Suspected Release: If you do not suspect a release, determine score based on the shortest overland
drainage distance from a source to a surface water body. If distance to surface water is 2,500 feet or less, assign
a score of 500. If distance to surface water is greater than 2,500 feet, determine score based on flood frequency.
If you do not suspect a release to surface water, use only Column B to score this pathway.
Drinking Water Threat Targets (Tl
3. List all drinking water intakes on downstream surface water bodies along the surface water migration path.
Record the intake name, the type of water body on which the intake is located, the flow of the water body, and
the number of people served by the intake (apportion the population if part of a blended system).
4. Primary Target Population: Evaluate populations served by all drinking water intakes that you suspect have
been exposed to a hazardous substance released from the site. Use professional judgment guided by the Surface
Water Pathway Criteria List (page 11) to make this determination. In the space provided, enter the population
served by all intakes you suspect have been exposed to a hazardous substance from the site. If only the number
of residences is known, use the average county residents per household (rounded up to the next integer) to
determine population served. Multiply by 10 to determine the Primary Target Population score. Remember, if you
do not suspect a release, there can be no primary target population.
5. Secondary Target Population: Evaluate populations served by all drinking water intakes within the targe;
distance limit that you do not suspect have been exposed to a hazardous substance. Use PA Table 3 (page 1 3)
and enter the population served by intakes for each flow category. If only the number of residences is known,
use the average county residents per household (rounded to the nearest integer) to determine population served.
Circle the assigned value for the population in each flow category and enter it in the column on the far-right side
of the table. Sum the far-right column and enter the total as the Secondary Target Population factor score.
Gauging station data for many surface water bodies are available from USGS or other sources. In the absence
of gauging station data, estimate flow using the list of surface water body types and associated flow categories
in PA Table 4 (page 13). The flow for lakes is determined by the sum of flows of streams entering or leaving the
lake. Note that the flow category "mixing zone of quiet flowing rivers" is limited to 3 miles from the probable
point of entry.
6. Nearest Intake represents the threat posed to the drinking water intake that is most likely to be exposed to a
hazardous substance. If you have identified a primary target population, enter 50. Otherwise, assign the'score
from PA Table 3 (page 13) for the lowest-flowing water body on which there is an intake.
7. Resources: A score of 5 can generally be assigned as a default measure. Assign zero only if surface water
within tne target distance limit has no resource use.
Sum the target scores in Column A (Suspected Release) or Column B (No Suspected Release).
Surface Water Pathway
page 5-28
A-22
-------
12
SURFACE WATER PATHWAY
LIKELIHOOD OF RELEASE AND DRINKING WATER THREAT SCORESHEET
fiwty CflfffCtwOCM
Do you suspect J release (see Surface Water Pathway Criteria List, page 11)?
Distance to surface water:
Flood frequency:
What is the downstream distance 10 the nearest drinking water intake? miles
Nearest fishery? miles Nearest sensitive environment? miles
Yes
No
yrs
LIKELIHOOD OF RELEASE
1. SUSPECTED RELEASE: If you suspect a release 10 surface water (see page 1 11,
assign a score of 550. Use only column A for this pathway.
2. NO SUSPECTED RELEASE: If you do not suspect a release to surface
water, use the table below to assign a score based on distance to surface
water and flood frequency. Use only column B tor this pathway.
Distance to surface water £ 2.500 feel
Distance to surface water > 2. 500 feel, and
Sue in annual or 10-year lloodpiam
Site in 100-year lloodpiain
Site in 500-year tioooolam
Site outside 500-year floodpiam
500
500
4OO
300
too
LR -
DRINKING WATER THREAT TARGETS
Record the water body rype, flow |i< applicable), and number of people served
by each drinking water intake within tne target distance limit. If there is no
Ormking water intake within the target distance limit, factors *. 5. and 6
each receive zero scores.
Inlikt Htm*
W»r«v SoaY Tvp* flow />»>/>* 5«rv«y
cts
els
cfs
PRIMARY TARGET POPULATION: If you suspect any drinking water intake listed
aoove has been exposed to a hazardous substance from (he sue (see Surface Water
Pathway Criteria List, page 11), list the intake namelsl and calculate the factor
score based on the total population served.
people x 10 =
5. SECONDARY TARGET POPULATION: Determine the number of people served by
Ormking water intakes that you do NOT suspect nave been exposed to a hazardous
substance from the site, and assign the total population score from PA Table 3.
Are any intakes part of a blended system? Yes No
if yes, anach a page to snow apportionment calculations.
6. NEAREST INTAKE: if you have identified a o'imarv target population for the
onnking water threat (factor 4|, assign a score of 50: otherwise, assign me
Nearest intake score from PA Table 3. if no drinking water intake exists within
me target distance limn, assign 3 score of zero
7 RESOURCES
1*0 M to I t .a
IK 10 t t a
T -
A-23
Surface Water Pathway
page 5-29
-------
"2 *»
« §
°> 2-
en o
»
PA TABLE 3: VALUES FOR SECONDARY SURFACE WATER TARGET POPULATIONS
Surface Water
Body Flow
flee PA Table 4)
<10 cl.
10 to IOO cfi
>1OO to 1.OOO cli
> l.OOO to 10.0OO cli
> 10.OOO cfi or
Giaal Lakai
3 mil* Mixing Zon«
Population
Nearest Intake =
Nearest
Intake
f choose
highest)
20
2
1
0
0
10
Population Served by Intakes WHhln Flow Category
1
i»
30
2
1
0
0
0
1
j;
fa
too
s
1
0
0
0
3
10}
la
300
16
2
1
0
0
8
301
It
l.OOO
S2
S
1
0
0
26
1.OO1
if
3.000
163
16
2
1
0
62
3.001
l»
10.OOO
521
S2
S
1
0
261
10.0O1
i»
30.000
1.633
163
16
2
1
816
30.O01
l»
10O.OOO
5.214
521
52
5
1
2.607
f OO.oo I
I*
300.000
16.325
1.633
163
16
2
8.162
30O.O0 1
to
1.000.000
52.136
5.214
521
52
S
26.068
Qf9»tmf
MM
l.OOO. OOO
163.246
16.325
1.633
163
16
81.663
Score -
PopuUtkut
V*!k*
ro
en
PA TABLE 4: SURFACE WATER TYPE / FLOW CHARACTERISTICS
WITH DILUTION WEIGHTS FOR SECONDARY SURFACE WATER SENSITIVE ENVIRONMENTS
Typo of Surface
Water Body Type OR
minimal ilraam
mall lo modarata itraam
modarala lo larga ilraam
larga tlraam to rivar
larga rivar
3-mila mixing jone of
quiat (lowing ilraam* or riven
coatlal tidal water (haibori.
oundi, bays. ale.), ocaan.
or Graal Lakai
Water Body
Flow
< 10 cfi
10 lo lOOcd
> 100 to 1.000 el«
> 1.000 to 10.OOO cfi
> 10.0OO cfi
10 cfi or graatar
N/A
Dilution.
Weight
1
0.1
N/A
N/A
N/A
N/A
N/A
-------
SURFACE WATER PATHWAY HUMAN FOOD CHAIN THREAT SCORESHEET
Likelihood of Release (LR)
LR is the same for all surface water pathway threats. Ehter LR score from page 12.
Human Food Chain Threat Targets (T)
8. The only human food chain targets are fisheries. A fishery is an area of a surface water body from
which food chain organisms are taken or could be taken for human consumption on a subsistence,
sporting, or commercial basis. Food chain organisms include fish, shellfish, crustaceans, amphibians,
and amphibious reptiles. Fisheries are delineated by changes in surface water body type (i.e., streams
and rivers, lakes, coastal tidal waters, and oceans/Great Lakes) and whenever the flow characteristics
of a stream or river change.
In the space provided, identify all fisheries within the target distance limit. Indicate the surface water
body type and flow for each fishery. Gauging station flow data are available for many surface water
bodies from USGS or other sources. In the absence of gauging station data, estimate flow using the
list of surface water body types and associated flow categories in PA Table 4 (page 1 3). The flow for
lakes is determined by the sum of flows of streams entering or leaving the lake. Note that, if there are
no fisheries within the target distance limit, the Human Food Chain Threat Targets score is zero.
9. Primary fisheries are any fisheries within the target distance limit that you suspect have been
exposed to a hazardous substance released from the site. Use professional judgment guided by the
Surface Water Pathway Criteria List (page 1 1) to make this determination. If you identify any primary
fisheries, list them in the space provided, enter 300 as the Primary Fisheries factor score, and do not
evaluate Secondary Fisheries. Note that if you do not suspect a release, there can be no primary
fisheries.
10. Secondary fisheries are fisheries that you do not suspect have been exposed to a hazardous
substance. Evaluate this factor only if fisheries are present within the target distance limit, but none
is considered a primary fishery.
A. If you suspect a release to surface water and have identified a secondary fishery but no primary
fishery, assign a score of 210.
B. If you do not suspect a release, evaluate this factor based on flow. In the absence of gauging
station flow data, estimate flow using the list of surface water body types and associated flow
categories in PA Table 4 (page 13). Assign a Secondary Fisheries score from the table on the
scoresheet using the lowest flow at any fishery within the target distance limit. (Dilution weight
multiplier does not apply to PA evaluation of this factor.)
Sum the target scores in Column A (Suspected Release) or Column B (No Suspected Release).
A-26
Surface Water Pathway
page 5-31
-------
SURFACE WATER PATHWAY (continual
HUMAN FOOD CHAIN THREAT SCORESHEET
LIKELIHOOD OF RELEASE
Enter Surface Water Likelihood of Release score from page 12. LR -
^ZT
IMA
N* SMpMtW
*«*
1M0400JOO. IOI
Hmfmnnctt
HUMAN FOOD CHAIN THREAT TARGETS
Record the water body type and (low (if applicable! lor each fishery within
the target distance limit. If there is no fishery within the target
distance limit, assign a Targets score of 0 at the bottom of the page.
Ft,**, H.m. W.It, 100 cts. coastal
tidal waters, oceans.
or Great Lakes
Secondary Rmhmrit
M Scorm
210
30
12
T -
Surface Water Pathway
page 5-32
A-27
-------
SURFACE WATER PATHWAY ENVIRONMENTAL THREAT SCORESHEET
Likelihood of Release (LR)
LR is the same for all surface water pathway threats. En,ter LR score from page 12.
Environmental Threat Targets (T)
11. PA Table 5 (page 16) lists sensitive environments for the Surface Water Pathway Environmental
Threat. In the space provided, identify all sensitive environments located within the target distance
limit. Indicate the surface water body type and flow at each sensitive environment. Gauging station
flow data for many surface water bodies are available from USGS or other sources. In the absence
of gauging station data, estimate flow using the list of surface water body types and associated flow
categories in PA Table 4 (page 13). The flow for lakes is determined by the sum of flows of streams
entering or leaving the lake. Note that if there are no sensitive environments within the target distance
limit, the Environmental Threat Targets score is zero.
12. Primary sensitive environments are surface water sensitive environments within the target
distance limit that you suspect have been exposed to a hazardous substance released from the site.
Use professional judgment guided by the Surface Water Pathway Criteria List (page 11) to make this
determination. If you identify any primary sensitive environments, list them in the space provided,
enter 300 as the Primary Sensitive Environments factor score, and do not evaluate Secondary Sensitive
Environments. Note that if you do not suspect a release, there can be no primary sensitive
environments.
13. Secondary sensitive environments are surface water sensitive environments that you do not
suspect have been exposed to a hazardous substance. Evaluate this factor only if surface water
sensitive environments are present within the target distance limit, but none is considered a primary
sensitive environment. Evaluate secondary sensitive environments based on flow.
In the table provided, list all secondary sensitive environments on surface water bodies with flow
of lOOcfs or less.
1) Use PA Table 4 (page 13) to determine the appropriate dilution weight for each.
2) Use PA Tables 5 and 6 (page 16) to determine the appropriate value for each sensitive
environment type and for wetlands frontage.
3) For a sensitive environment that falls into more than one of the categories in PA Table 5, sum
the values for each type to determine the environment value (e.g., a wetland with 1.5 miles
frontage (value of 50) that is also a critical habitat for a Federally designated endangered
species (value of 100) would receive a total value of 150).
4) For each sensitive environment, multiply the dilution weight by the environment type (or length
of wetlands) value and record the product in the far-right column.
5) Sum the values in the far-right column and enter the total as the Secondary Sensitive
Environments score. Do not evaluate part B of this factor.
If all secondary sensitive environments are on surface water bodies with flows greater than 100
cfs, assign 10 as the Secondary Sensitive Environments score.
Sum the target scores in Column A (Suspected Release) or Column B (No Suspected Release).
Surface Water Pathway
A-28 PaSe 5"33
-------
SURFACE WATER PATHWAY (continued)
ENVIRONMENTAL THREAT SCORESHEET
LIKELIHOOD OF RELEASE
Enter Surface Water Likelihood of Release score from page 12. LR -
Su*f~a**
/t«w««
iMa
M. 5ui*«o>W
* 100 cfs. assign a score of 10.
T -
Surface Water Pathway
page 5-34
A-29
-------
PA TABLE 5: SURFACE WATER AND AIR PATHWAY SENSITIVE ENVIRONMENTS VALUES
Sensitive Environment
Criucal habitat lor Federally designated endangered or threatened species
Marine Sanctuary
National Park
Designated FedaraJ Wildefnaes Art*
Ecologically important nut identified under (ha Coaital Zone Wilderness Act
Stniitw« Areas id»nufi*d under tha Nauonal Estuary Program or Near Coastal Water Program of the Claan Water Act
Critical Araai Identified under tha Claan Lakee Program ol the Clean Water Act Isubareas in lakaa or entire small lakes)
National Monumant (air pathway only)
National Seashore Recreation Area
National Lakashora Recreation Area
Assigned Valum
100
Habitat known to be used by Federally designated or proposed endangered or threatened spaciaa
National Preserve
Nauonal or State Wildlife Refuge
Unit of Coastal Barrier Resources System
Federal land designated for tha protection of natural ecosystems
Administratively Proposed Federal Wilderness Aree
Spawning ereaa critical for tha maintenance of fish/shellfish species within a rivar system, bay, or estuary
Migratory pathwaye and feeding areas cntical for the mamtenencs of anadromous fish speciee in a rivar system
Terrestrial areas utilized for breeding by large or dense aggregations of vertebrate animals (air pathway) or
semi-aquatic foragara (surface water pathway)
National river reach designated as Recreational
75
Habitat known to be used by State designated endangered or threatened species
Habitat known to be used by a spaciee under review as to its Federal endangered or threatened starus
Coastal Sarnar (partially developed)
Federally designated Scenic or Wild Rivar
50
Stale land designated for wildlife or game management
State designated Scervc or Wild River
Slata designated Natural Area
Particular areas, relatively small in size, important to maintenance of unique biotic communities
25
State deaignaiad areas lor protection/maintenance of aquatic lila under the Clean Water Act
Wetlands
Sea PA Table 6 (Surlaca Water Pathway)
or
PA Table 9 (Air Pathway)
PA TABLE 6: SURFACE WATER PATHWAY
WETLANDS FRONTAGE VALUES
Total Length of Wetlands
Less than 0.1 mile
0.1 to 1 mile
Greater than 1 to 2 miles
Greater than 2 to 3 miles
Greater than 3 :o 4 miles
Greater than 4 to 8 milet
Greeter than 8 to 1 2 miles
Greater than 1 2 to 16 miles
Greater than 16 to 20 miles
Greater than 20 miles
Assigned Value
0
25
50
75
100
150
250
350
450
500
A-31
Surface Water Pathway
page 5-35
-------
SURFACE WATER PATHWAY WASTE CHARACTERISTICS. THREAT, AND PATHWAY SCORES
Waste Characteristics (WC)
14. Waste Characteristics: Score is assigned from page'4. However, if a primary target has been
identified for any surface water threat, assign either the score calculated on page 4 or a score of 32,
whichever is greater.
Surface Water Pathway Threat Scores
Fill in the matrix with the appropriate scores from the previous pages. To calculate the score for each
threat: multiply the scores for LR, T, and WC; divide the product by 82,500; and round the result to
the nearest integer. The Drinking Water Threat and Human Food Chain Threat are each subject to a
maximum of 100. The Environmental Threat is subject to a maximum of 60. Enter the rounded threat
scores in the far-right column.
Surface Water Pathway Score
Sum the individual threat scores to determine the Surface Water Pathway Score. If the sum is greater
than 100, assign 100.
Surface Water Pathway
page 5-36 A 32
-------
SURFACE WATER PATHWAY (concluded)
WASTE CHARACTERISTICS. THREAT, AND PATHWAY SCORE SUMMARY
WASTE CHARACTERISTICS
14. A. If YOU have identified any primary target for surface water (pages 12, 14,
or 15), assign the waste characteristics score calculated on page 4, or a score
of 32, whichever is GREATER; do not evaluate pan B of this factor.
8. If you have NOT identified any primary target for surface water, assign the
waste characteristics score calculated on page 4.
HOOJ7. . Ill
we -
SURFACE WATER PATHWAY THREAT SCORES
Threat
Drinking Water
Human Food Chain
Environmental
Ukttihood ot
RrnJ**** ILK) Scor*
tfrom pty* 121
Jirgtu fTI Soar*
tpta*, 12. 14, 151
Pithwty W*«»»
Cti*rtd»niDc* fWCl Soon
td»t*nnin»d tbovml
Thrift Soon
LR t T i WC
/ 82. 500
|M«VM ! I«^WW*I * IOOI
IM^IM ( t ' "" * '°°*
.
SURFACE WATER PATHWAY SCORE
(Drinking Water Threat + Human Food Chain Threat -t- Environmental Threat)
A-33
Surface Water Pathway
page 5-37
-------
Section 6:
Soil Exposure Pathway
Fence
, Breach
H M
200 «Mt
XYZ
Corporation
-------
SOIL EXPOSURE PATHWAY
Soil Exposure Threat
People or other targets coming into direct contact with
hazardous substances
Contaminated soil and accessible site wastes are evaluated
PA Guidance, section 3.5 OH 1
V J
Site Assessment Questions 2 and 3
for Soil Exposure
2. Is there suspected contamination?
3. Do people live, go to school, or work on or within 200
feet of suspected contamination? Are there terrestrial
sensitive environments?
OH* 2
So// Exposure Pathway 4/94
page 6-2
-------
SOIL EXPOSURE PATHWAY
Soil Exposure Pathway Evaluation
Waste
Characteristics
1
Likelihood
of Exposure
Nearby Target
Population
1
Resident Target
Population
Resource
Environmental
Human
OHO
Likelihood of Exposure and Targets
Fence
inftnc*
H H
200 tot
XYZ
Corporation
OH* 4
4/94
Soil Exposure Pathway
page 6-3
-------
SOIL EXPOSURE PATHWAY
Likelihood of Exposure
For most PAs, assume suspected surface
contamination
Need appropriate quality analytical data to assume no
suspected contamination
Score 550 for suspected contamination and score 0 for no
suspected contamination
Determine area(s) of suspected contamination
Consider mechanisms to transport contaminants to nearby
properties
PA Guidance, section 3.5.1, pages 110 and 111 OH 5
Likelihood of Exposure:
Suspected Contamination
Definition: Areas known or suspected to contain hazardous
substances not covered by an essentially
impenetrable cover or more than 2 feet of clean cover
material
(Not limited to soils-any accessible surface source is
considered)
PA Guidance, section 3.5.1 OH 6
Soil Exposun Pathway 4/94
page 6-4
-------
SOIL EXPOSURE PATHWAY
Likelihood of Exposure:
What is Area of Suspected Contamination?
Asphalt Paving
PA Guidance, section 3.5.1
OH* 7
Likelihood of Exposure
Evaluate all sources except:
Sources covered by at least 2 feet of clean material or
impenetrable cover
Sources not accessible by direct contact-
Examples:
- Wastes secured inside a building
- Ground water plume with no identifiable source
PA Guidance, section 3.5.1
OH* 8
4/94
Soil Exposure Pathway
page 6-5
-------
r
Soil Exposure Targets
Resident population threat
Residents and students
Workers
Terrestrial sensitive environments
Resources
Nearby population threat
Residents within 1 mile of contamination
PA Guidance, section 3.5.2
V
^
OH* 9
J
Soil Exposure Targets:
Resident Population Threat Target Evaluation
Resident population factor is defined as:
Person who resides on or within 200 feet of area of suspected
contamination
Person who attends school or daycare on or within 200 feet of
area of suspected contamination
R
C
PA Guidai
V
'esident population is identified using the Soil Exposure Pathway
Criteria List
Turn to appendix A, Soil Exposure Pathway
Criteria List, page A-35
nee, section 3.5.2
OH* 10
J
Soil Exposure Pathway 4/94
page 6-6
-------
SOIL EXPOSURE PATHWAY CRITERIA LIST
SUSPECTED CONTAMINATION
RESIDENT POPULATION
Y N U
eon
a k
DO n
Is any residence, school, or daycare facility on
or within 200 feel of an area of suspected
contamination?
Surficial contamination can generally be assumed.
O O O Is any residence, school, or daycare facility
located on adjacent land previously owned or
leased by the site owner/operator?
D D D Is there a migration route (hat might spread
hazardous substances near residences,
schools, or daycare facilities?
ODD Have onsite or adjacent residents or students
reported adverse health effects, exclusive of
apparent drinking water or air contamination
problems?
D D D Does any neighboring property warrant
sampling?
D D
D D
Other criteria?
RESIDENT POPULATION IDENTIFIED?
Summarize the rationale for Resident Population (attach an additional page if necessary):
Sell Exposure Pathway
page 6-7
A-35
-------
SOIL EXPOSURE PATHWAY
Soil Exposure Targets:
Resident Population Threat
School
Playground
OH«11
Soil Exposure Targets
Resident population threat also includes:
Workers on facility property or nearby property
Terrestrial sensitive environments on the area of suspected
contamination
Resources
Turn to appendix A, Table 7, Soil Exposure
Pathway Terrestrial Sensitive Environment Values
PA Guidance, section 3.5.2
OH* 12
Soil Exposure Pathway
page 6-8
4/94
-------
PA TABLE 7: SOIL EXPOSURE PATHWAY
TERRESTRIAL SENSITIVE ENVIRONMENT VALUES
Ttrrtstritl StnsHlv* fnyironmfrrt ' Assigned Vtlut
Terrestrial critical habitat lor Federally designated endangered or threatened species
National Par*
Designated Federal Wilderness Area
National Monument
Terrestrial habitat known to be used by Federally designaied or oroposeo threatened or enoangered species
National Preserve (terrestrial)
National or State terrestrial Wildlife Refuge
Federal land designated for protection of natural ecosystems
Administratively proposed Federal Wilderness Area
Terrestrial areas utilized by large or dense aggregations of animals (vertebrate speciesl for breeding
Terrestrial habitat used by State designated endangered or threatened species
Terrestrial habitat used by species under review for Federal designated endangered or threatened status
State lands designated for wildlife or game management
State designated Natural Areas
Panicular areas, relatively small in size, important to maintenance of unique biotic communities
100
75
50
25
Soil Exposure Pathway
A-39 Page 6-9
-------
SOIL EXPOSURE PATHWAY
Soil Exposure Targets
Nearby population threat
Population that does not qualify as resident population but may
come in contact with areas of contamination
Located within a 1-mile radius of site
Population Within
1 Mile
< 10,000
10,000-50,000
>50,000
Nearby Population
Threat Score
1
2
4
PA Guidance, section 3.5.4
OH* 13
Resident Population Threat Score
LE x T x WC
82,500
Note:
T does not include nearby
population threat score; it is
added to the above calculated
value
PA Guidance, section 3.5.4
OH* 14
Soil Exposure Pathway
page 6-10
4/94
-------
SOIL EXPOSURE PATHWAY SCORESHEET
Do any people live on 0' within 200 It o' areas of Suspected contamination?
Do any people anend school or daycare on or within 200 It ol areas
ol suspected contamination?
Is the facility active? Yes No II yes. estimate the number ol workers:
Yes .
Yes
No
No
LIKELIHOOD OF EXPOSURE
1. SUSPECTED CONTAMINATION: Surlicial contamination can generally be assumed.
and a score o< 550 assigned. Assign zero only il the absence ol surficial
contamination can be confidently demonstrated. LE -
RESIDENT POPULATION THREAT TARGETS
2. RESIDENT POPULATION: Determine the number of people occupying residences
or attending school or daycare on or within 200 feet of areas of suspected
contamination (see Soil Exposure Pathway Criteria List, page 18).
people x 10 -
3. RESIDENT INDIVIDUAL: If you have identified a resident population (factor 21,
assign a score of 50; otherwise, assign a score of 0.
4. WORKERS: Use the following table to assign a score based on the total number of
workers at the facility and nearoy facilities with suspected contamination:
Number ef Woi-tan
0
1 to 100
101 to 1,000
> 1 .000
5eorw
0
5
10
15
5. TERRESTRIAL SENSITIVE ENVIRONMENTS: Use PA Table 7 to assign a value
for each terrestrial sensitive environment on an area of suspected
contamination:
r«*r**l/)W ,$«*U/D'W £nvtn>nm**if Typ*
VtJts.
Sum -
6. RESOURCES
T -
WASTE CHARACTERISTICS
RESIDENT POPULATION THREAT SCORE:
NEARBY POPULATION THREAT SCORE:
SOIL EXPOSURE PATHWAY SCORE:
Resident Population Threat - Nearby Population Threat
LE X T X WC
82.500.
C0m4m//i«0on
JllC.U
Ul. to. t. a
7.
Assign the
waste characteristics score calculated on page 4.
WC -
noa. a. m
A-37
So// Exposure Pathway
page 6-11
-------
SOIL EXPOSURE PATHWAY
CASE STUDY: ABC VACUUM SERVICE
SOIL EXPOSURE PATHWAY
OBJECTIVE
Using background information from file searches, site reconnaissance notes, and maps, com-
plete the Soil Exposure Pathway portion of the PA scoresheets.
METHOD
1. Review the general soil exposure pathway information summary (provided below),
existing source information, and the maps included with the exercise.
2. Read the instructions for the soil exposure pathway criteria list and complete the
"Resident Population" evaluation. Determine whether you can identify a resident
population. Summarize the rationale for this decision in the space provided.
3. Using the existing site information and the scoresheet instructions, complete all
portions of the soil exposure pathway scoresheet. PA Table 7, Soil Exposure
Pathway Terrestrial Sensitive Environment Values, should be used to determine
values for terrestrial sensitive environments, if applicable. Remember to evaluate
the resident individual factor.
4. Calculate and record the soil exposure pathway score.
Soil Exposure Pathway:
Nineteen residents live within 200 feet of the site.
No schools or daycare facilities are within 200 feet of the site.
The site is inactive; therefore, no workers are present onsite.
Ten people are employed at the crayfish ponds.
One report indicated that the warehouse complex employed 65 people.
Soil Exposure Pathway 4/94
page 6-12
-------
ABC Vacuum Service
Warehouse
Shed on
:;: Standing ;:\ top of
;i; rainwater :V\ mixing
tanks
Drainage ditches
Drainage direction
Warehouse complex road
Not to Scale
-------
ABC Vacuum Service
Residential
Area
\15'
Soil Exposure Pathway
page 6-14
-------
SOIL EXPOSURE PATHWAY CRITERIA LIST
Areas of surficial contamination can generally be assumed. This "Criteria List" helps guide the process
of developing a hypothesis concerning the exposure of specific targets to a hazardous substance at
the site. Use the "Resident Population" section to evaluate site and source conditions that may help
identify targets likely to be exposed to a hazardous substance. The check-boxes record your
professional judgment. Answers to all of the listed questions may not be available during the PA.
Also, the list is not all-inclusive; if other criteria help shape your hypothesis, list them at the bottom
of the page or attach an additional page.
Check the boxes to indicate a "yes," "no," or "unknown" answer to each question.
Soil Exposure Pathway
A-34 page 6-15
-------
18
SOIL EXPOSURE PATHWAY CRITERIA LIST
SUSPECTED CONTAMINATION
RESIDENT POPULA TION
Y N
e o
Sufficial contamination can generally be assumed.
O D 3 Is any residence, school, or daycare facility on
or within 200 feet of an area of suspected
contamination?
O D LJ Is any residence, school, or daycare facility
located on adjacent land previously owned or
leased by the site owner/operator?
D D D Is there e migration route that might spread
hazardous substances near residences,
schools, or daycare facilities?
D D D Have onsite or adjacent residents or students
reported adverse health effects, exclusive of
apparent drinking water or air contamination
problems?
DOG Does any neighboring property warrant
sampling?
D D
D 0
Other criteria?
RESIDENT POPULATION IDENTIFIED?
Summarize the rationale for Resident Population (attach an additional page if necessary):
Soil Exposure Pathway
page 6-16
A-35
-------
SOIL EXPOSURE PATHWAY SCORESHEET
Pathway Characteristics
Answer the questions at the top of the page. Identify people who may be exposed to a hazardous substance
because they work at the facility, or reside or attend school or daycare on or within 200 feet of an area of
suspected contamination. If the site is active, estimate the number of full and part-time workers. Note that
evaluation of targets is based on current site conditions.
Likelihood of Exposure (LEI
1. Suspected Contamination: Areas of surficial contamination are present at most sites, and a score of 550 can
generally be assigned as a default measure. Assign zero, which effectively eliminates the pathway from further
consideration, only if there is no surficial contamination; reliable analytical data are generally necessary to make
this determination.
Resident Population Threat Targets IT)
2. Resident Population correspondsto "primary targets" for the migration pathways. Use professional judgment
guided by the Soil Exposure Pathway Criteria List (page 18) to determine if there are people living or attending
school or daycare on or within 200 feet of areas of suspected contamination. Record the number of people
identified as resident population and multiply by 10 to determine the Resident Population factor score.
3. Resident Individual: Assign 50 if you have identified a resident population; otherwise, assign zero.
4. Workers: Estimate the number of full and part-time workers at this facility and adjacent facilities where
contamination is also suspected. Assign a score for the Workers factor from the table.
5. Terrestrial Sensitive Environments: In the table provided, list each terrestrial sensitive environment located
on an area of suspected contamination. Use PA Table 7 (page 20) to assign a value for each. Sum the values
and assign the total as the factor score.
6. Resources: A score of 5 can generally be assigned as a default measure. Assign zero only if there is no land
resource use on an area of suspected contamination.
Sum the target scores.
Waste Characteristics (WC1
7. Enter the WC score determined on page 4.
Resident Population Threat Score: Multiply the scores for LE, T, and WC. Divide the product by 82,500.
Round the result to the nearest integer. If the result is greater than 100, assign 100.
Nearby Population Threat Score: Do not evaluate this threat if you gave a zero score to Likelihood of Exposure.
Otherwise, assign a score based on the population within a 1 -mile radius (use the same 1 -mile radius population
you evaluate for air pathway population targets):
Population Within One Mile Nearby Population Threat Score
< 10,000 1
10,000 to 50,000 2
> 50,000 4
Soil Exposure Pathway Score: Sum the Resident Population Threat score and the Nearby Population Threat
score, subject to a maximum of 100.
So/7 Exposure Pathway
A-36 Pfl9e 8'17
-------
SOIL EXPOSURE PATHWAY SCORESHEET
flOlvriy CA*/»cf«rbrfe«
Do any people live on or within 200 ft ol areas ol suspected contamination?
Do any people anend school or daycare on or within 200 ft ol areas
of suspected contamination?
Is the facility active? Yes No If yes, estimate the number of workers:
Yes
Yes
No
No
LIKELIHOOD OF EXPOSURE
1.
SUSPECTED CONTAMINATION: Surlicial contamination can generally be
and a score of 550 assigned. Assign zero only if the absence of surficial
contamination can be confidently demonstrated.
assumed.
LE -
Suip*C1*d
Conf tminttion
RESIDENT POPULATION THREAT TARGETS
2. RESIDENT POPULATION: Determine the number of people occupying residences
or attending school or daycare on or within 200 feet of areas of suspected
contamination (see Soil Exposure Pathway Criteria List, page 18).
people x 10 -
3. RESIDENT INDIVIDUAL: If you have identified a resident population (factor 2),
assign a score of 50; otherwise, assign a score of 0.
4. WORKERS: Use the following table to assign a score based on the total number of
workers at the faciliry and nearby facilities with suspected contamination:
Numbtf of Wort in
0
1 to 100
101 to 1.000
> 1 .000
Seor*
0
5
10
15
S. TERRESTRIAL SENSITIVE ENVIRONMENTS: Use PA Table 7 to assign a value
for each terrestrial sensitive environment on an area of suspected
contamination:
r«r»jr/TW 5«*u/o'yv £nvi>ojvn«m Typ*
VtJu*
Sum
6. RESOURCES
T -
WASTE CHARACTERISTICS
RESIDENT POPULATION THREAT SCORE:
NEARBY POPULATION THREAT SCORE:
SOIL EXPOSURE PATHWAY SCORE:
Resident Population Threat -t- Nearby Population Threat
LE X T X WC
82,500.
III. iu. ». a
7.
Assign the waste characteristics score calculated on page 4.
WC -
iioa. aa. - m
So// Exposure Pathway
page 6-18
A-37
-------
PA TABLE 7: SOIL EXPOSURE PATHWAY
TERRESTRIAL SENSITIVE ENVIRONMENT VALUES
Ttrrtstritl Stnsitlv* Environment ' Assigned Vtlui
Terrestrial critical habitat tor Federally designated endangered or threatened species
National Pare.
Designated federal Wilderness Area
National Monument
Terrestrial naoitat known to be used by Federally designated or oroposed threatened or endangered species
National Preserve (terrestrial)
National or State terrestrial Wildlife Refuge
Feoerai lano designated for protection of natural ecosystems
Administratively proposed Federal Wilderness Area
Terrestrial a:eas utilized by large or dense aggregations of animals (vertebrate species) for breeding
Terrestrial haoitat used by State designated endangered or threatened species
Terrestrial haoitat used by species under review for Federal designated endangered or threatened status
State iands Designated for wildlife or game management
State Designated Natural Areas
Particular areas, relatively small in size, important to maintenance of unique biotic communities
100
75
50
25
Soil Exposure Pathway
A'39 page 6-19
-------
Section 7:
Air Pathway
Threat
Potential aourcee
of a retoaee to air
Fire
Bum operation (odore,
JMM, pwticuMM)
Contaminant* may
aettfe on buldinga or
Mttto onto aofe
Swuitiv* Environment
(«.g-, twbtat. pvfc, or
Mine tailings
pile
DryanddtMty
condiUorw may
parttcutate* to ba
blown offttta
Waste water
lagoon **> "!
vapon/gaaea tnat ara
datacted by nearby
raaldanta/«vorkar«
Contaminated
soils
-------
AIR PATHWAY
ThTMt
PotentW oufcst
oftnliMitoilr
Fir*
Bum operation (odoni,
WastBwatef
lagoon
Air Pathway
Continiinmts may
Mttto on budding* or
Mtt* onto »oifc
. hat**. p*V or
Dry«nddu*y
condlbon* may CMJM
pwticuMM to b«
blown oflW*
ItayralMM
v«pora/gMM that ire
detected by nwrty
midcnta/worlw*
Contaminated
ote
OH*1
Air Pathway Evaluation
Waste
Characteristics
Likelihood
of Exposure
Human
Population
Targets
Sensitive
Environment
Targets
PA Guidance, section 3.6
OH* 2
AirPalhway
page 7-2
4/94
-------
AIR PATHWAY
Site Assessment Questions 2 and 3 for Air
2. What is the likelihood that hazardous substances are being
released to air and can be detected through sampling?
3. Who and what are likely to be affected?
PA Guidance, sections 3.6.1 and 3.6.2 OH
Likelihood of Release
Evaluated differently than other migration pathways
Based on likelihood of detecting airborne hazardous substances
during SI sampling
Scored on "suspected release" or "no suspected release"
Determined using the Criteria List for Suspected Release to Air
Pathway (appendix A, page A-41)
PA Guidance, section 3.6.1 OH 4
V .
4/94 AlrPtihway
page 7-3
-------
AIR PATHWAY CRITERIA LIST
SUSPECTED RELEASE
PRIMARY TARGETS
Y
e
s
D D Q Are odors currently reported?
D a
D D C
CDC
D D
C D
Has release of a hazardous substance lo the air
been directly observed?
Are there reports ol adverse health effects
(e.g., headaches, nausea, dizziness) potentially
resulting from migration of hazardous
substances through the air?
Does analytical or circumstantial evidence
suggest a release to the air?
Other criteria?
If you suspect a release to air, evaluate all populations and
sensitive environments within 1/4 mile (including those
onsite) as primary targets.
SUSPECTED RELEASE?
Summarize the rationale for Suspected Release (attach an additional page il necessary):
Air Pathway
page 7-4
A-41
-------
AIR PATHWAY
Air Targets
People living, going to school, or working within 4 miles of site
Sensitive environments (terrestrial and aquatic) within % mile
Resources
PA Guidance, section 3.6.2
OH*S
Air Targets:
Target Distance Categories
1
2
3
- % mile
- V* mile
- 1 mile
- 2 miles
- 3 miles
- 4 miles
(Not to scale)
PA Guidance, section 3.6.2
OH-6
4/94
Air Pathway
page 7-5
-------
AIR PATHWAY
Human Population Targets
Residential populations
Identify population onsite and in each of the six distance
categories
Can use data bases or housecounts depending on distance from
site
Worker and student populations
Identify those within % mile of site
Use readily available information
PA Guidance, section 3.6.2, pages 131 and 132 OH 7
V
Human Population Targets
Data Bases
Automated data bases based on U.S. Census population are very
useful
Graphical Exposure Modeling System (GEMS)
Other population data base resources:
- National Planning Data Corporation (NPDC)
- Local city/county planning offices
- Topographically Integrated Geographic Encoding and
Referencing (TIGER)
PA Guidance, section 3.6.2 OH 8
Air Pathway 4/94
page 7-6
-------
AIR PATHWAY
Data Bases
Limitations of automated
population data bases:
"Census tracts" based on
population density
(smaller in urban areas; larger in
rural areas)
Population is assigned to
centroid of tract
Result: underestimation or
overestimation of population for
small, close-in, distance
categories (% mile, Ya mile)
PA Guidance, section 3.6.2, page 131
OH* 9
Data Bases
Solution:
Verify close-in population with house counts from topographic
maps, aerial photos, reconnaissance windshield survey, or
combination of all three
Generally, automated population data bases are sufficiently
accurate beyond *A mile
PA Guidance, section 3.6.2, page 132
OH* 10
4/94
AlrPtthway
page 7-7
-------
AIR PATHWAY
Human Population Targets
Nearest individual
Defined as the closest person to any source at the site
Indicates the magnitude of threat to the person who is most likely
to be exposed
Represented by nearest regularly occupied building
Distance to nearest individual is noted on the pathway
characteristics box of the air pathway scoresheet
PA Guidance, section 3.6.2, page 137
OH* 11
Sensitive Environment Targets
Identify all sensitive environments
either onsite, within % mile of the
site, or within 1/& mile of the site
Include terrestrial and aquatic
environments
PA table 5 (appendix A, page A-31)
lists qualifying sensitive
environments
Wetlands are scored on acreage
totals within each distance ring
PA Guidance, section 3.6.2, pages 132-134
OH* 12
Air Pathway
page 7-8
4/94
-------
AIR PATHWAY
Primary and Secondary Targets
All populations and sensitive environments out to and including
the %-mile distance category are considered primary targets
Must have suspected release to identify primary targets
All targets beyond 1/4 mile are considered secondary targets
Secondary target population values are assigned using PA table 8
(appendix A, page A-45)
PA Guidance, section 3.6.2, pages 134-136 OH 13
V
Notes:
4/94 AirPrttway
page 7-9
-------
PA TABLE 8: VALUES FOR SECONDARY AIR TARGET POPULATIONS
Dlsttnct
from Sit»
Onaite
>0 to X. mile
> X. to X mil.
> H lo I mile
> 1 to 2 rrwlef
> 2 lo 3 milai
>3 lo 4 mil m
Population
Nearest Individual =
Nearest
Individual
(choose
highest)
20
20
2
\
0
0
0
Population Within Distance Category
1
i»
10
1
1
0
0
0
0
o
11
lo
30
2
1
0
0
0
0
0
31
la
too
S
1
1
0
0
0
0
tot
to
3OO
is
4
i
i
0
0
0
3O1
lo
1.OOO
52
13
3
1
1
1
0
1.001
lo
3.OOO
163
41
9
3
1
1
1
3.001
lo
10.OOO
521
130
28
8
3
1
1
10.OO1
If
3O.OOO
1.633
408
88
26
8
4
2
30.001
to
1OO.OOO
6.214
1.303
282
83
27
12
7
1 0O.OO1
to
300.000
18.325
4.081
882
2B1
83
38
23
3OO.OO 1
t*
I.OOO.OOO
52.136
13.034
2.815
834
268
120
73
Orfmtof
thflt
I.OOO.OOO
163.248
4O.811
8.815
2.812
833
378
229
Score -
Poputotiot
VtliM
>
en
PA TABLE 9: AIR PATHWAY VALUES
FOR WETLAND AREA
We tland Area A sslgrted Value
Le«i than 1 acre
1 lo SO «crei
Giantai than 50 lo 1OO acrai
Create' lhan 1OO to ISO aciai
Graalar lhan 150 to 2OO acfea
Creator lhan 2OO lo 30O scre«
Gi.aler thin 3OO lo 4OO aciaa
Greater lhan 4OO lo 5OO acial
Greater lhan 5OO acre*
0
25
75
125
175
250
350
450
5OO
PA TABLE 10: DISTANCE WEIGHTS AND CALCULATIONS
FOR AIR PATHWAY SECONDARY SENSITIVE ENVIRONMENTS
Distance
Oniito
0- 1 M nii
l/4-1/2mi
Distance
Weight
0.10
0.025
O.OOS4
Sensitive Environment Type and Value
(from PA Tfbb S or 91
X
X
X
X
X
X
X
X
X
Total Environments Score
Product
-------
\
Values for Secondary Target Populations
Distance
from Site
Onsite
0 to % mile
>% mile to V
>Vs mile to 1
>1 to 2 miles
>2 to 3 miles
>3 to 4 miles
Population Range:
Air Ground Water (nonkarst) I
(PA table 8) (PA table 2a) \
163
41 163
i mile 9 101
mile 3 52
1 29
1 21
1 13
1,001 to 3,000 OH 14
)
Likelihood of Release
No suspected release vs. suspected release
Primary targets
O Secondary targets
OH* 15
4/94
Air Pathway
page 7-11
-------
AIR PATHWAY SCORESHEET
Do you suspect a release Isee Air Patnway Criteria list, page 21)?
Distance to the nearest individual:
Yes No
LIKELIHOOD OF RELEASE
1. SUSPECTED RELEASE: II YOU susoect a release to air Isee page 211. assign a
score ol 550. Use only column A (or this patfiway.
2. NO SUSPECTED RELEASE: If you do not susoect a release to air. assign a
score ol 500. Use only column 8 lor this pathway.
LR -
TARGETS
3. PRIMARY TARGET POPULATION: Determine the number ol people subject
to exposure Irom a suspected release ol hazardous substances to the air.
people x 10
4. SECONDARY TARGET POPULATION: Determine the number ol people not
suspected to be exposed to a release to air, ana assign the total population
score using PA Table 8.
5. NEAREST INDIVIDUAL: If you have identified any Primary Target Population
for the an pathway, assign a score of 50: otnerwise, assign tne Nearest
Inoividual score from PA Table 8.
6. PRIMARY SENSITIVE ENVIRONMENTS: Sum the sensitive environment values
(PA Table 5) and wetland acreage values (PA Table 91 for environments subject
to exposure from a suspected release to the air.
Typ*
Sum -
7. SECONDARY SENSITIVE ENVIRONMENTS: Use PA Table 10 to determine
tne score tor secondary sensitive environments.
8. RESOURCES
T -
WASTE CHARACTERISTICS
9. A. If you have identified any Primary Target lor the air pathway, assign the waste
characteristics score calculated on page <. or a score of 32. whichever is
GREATER; do not evaluate part B of this factor.
B. II you nave NOT identified any Primary Target for the air pathway, assign the
waste characteristics score calculated on page *.
WC -
AIR PATHWAY SCORE:
LR x T x WC
82.500
Air Pathway
page 7-12
A-43
-------
AIR PATHWAY
CASE STUDY: ABC VACUUM SERVICE
AIR PATHWAY
OBJECTIVE
Using background information from file searches, site reconnaissance notes, and site maps,
complete the Air Pathway portion of the PA scoresheets.
METHOD
1. Review the existing site information, site reconnaissance notes, population data
base information, and map included with the exercise.
2. Read the instructions for the air pathway criteria list and complete the "Suspected
Release" evaluation. Determine whether you can hypothesize a suspected release.
Summarize the rationale for this decision in the space provided.
3. Using the existing site information and the scoresheet instructions, complete all
portions of the air pathway scoresheet. PA Table 8, Values for Secondary Air Target
Populations; PA Table 9, Air Pathway Values for Wetland Area; and PA Table 10,
Distance Weights and Calculations for Air Pathway Secondary Sensitive
Environments should be used to evaluate sensitive environments and secondary
targets. Remember to evaluate the nearest individual factor.
4. Calculate and record the air pathway score.
Air Pathway: GEMS Population Data for ABC Vacuum Service
North Latitude: 30° 30' 18" West Longitude: 91° 19' 16" Total Population: 6,489
Record
Number
1
2
3
4
5
6
Population
0
0
1096
1254
1733
2406
House
0
0
320
330
456
710
Distance
kilometers
0.40
0.81
1.60
3.20
4.80
6.40
miles
0.25
0.50
1
2
3
4
Sector
1
1
1
1
1
1
4/94
Mr Pathway
page 7-13
-------
"S =:
to "
! ABC Vacuum Service
Oxidation ::
Debris
Concrete
pads
Warehouse
Septic
tank Q
Private well
Property boundary
Rubbish
pile
Not to Scale
-------
AIR PATHWAY CRITERIA LIST
This "Criteria List" helps guide the process of developing a hypothesis as to whether a release to the
air is likely to be detected. The check-boxes record your professional judgment. Answers to all of the
listed questions may not be available during the PA. Also, the list is not all-inclusive; if other criteria
help shape your hypothesis, list them at the bottom of the page or attach an additional page.
The "Suspected Release" section identifies several conditions that could provide insight as to whether
a release from the site is likely to be detected. If a release is suspected, primary targets are any
residents, workers, students, and sensitive environments on or within '/« mile of the site.
Check the boxes to indicate a "yes," "no," or "unknown" answer to each question. If you check the
"Suspected Release" box as "yes," make sure you assign a Likelihood of Release value of 550 for the
pathway.
Air Pathway
A-40 page 7-15
-------
21
AIR PATHWAY CRITERIA LIST
SUSPECTED RELEASE
PRIMARY TARGETS
Y N U
eon
s k
c D a
C D u
C 2 C
G D IT
Are odors currently reported?
Has release of a hazardous substance to the air
been directly observed?
Are there reports of adverse health effects
(e.g., headaches, nausea, dizziness) potentially
resulting from migration of hazardous
substances through the air?
Does analytical or circumstantial evidence
suggest a release to the air?
Other criteria?
If you suspect a release to air, evaluate all populations and
sensitive environments within 1/4 mile (including those
onsite) as primary targets.
SUSPECTED RELEASE?
Summarize the rationale for Suspected Release (attach an additional page if necessary):
Air Pathway
page 7-16
A-41
-------
AIR PATHWAY SCORESHEET
Pathway Characteristics
Answer the questions at the top of the page. Refer to the Air Pathway Criteria List (page 21) to hypothesize whether
you suspect that a hazardous substance release to the air could be delected. Due to dispersion, releases to air are not
as persistent as releases to water migration pathways and are much more difficult to detect. Develop your hypothesis
concerning the release of hazardous substances to air based on "real time" considerations. Record the distance (in feetl
from any source to the nearest regularly occupied building.
Likelihood of Release (LR)
1. Suspected Release Hypothesize based on professional judgment guided by trie Air Pathway Criteria Lisi (page 21).
If you suspect a release to air, use only Column A for this pathway and do not evaluate factor 2.
2. No Suspected Release: If you do not suspect a release, enter 500 and use only Column B for this pathway.
Targets (T)
3. Primary Target Population: Evaluate populations subject to exposure from release of a hazardous substance from the
site. If you suspect a release, the resident, student, and worker populations on and within '/. mile of the sue are
considered primary target population. II only the number of residences is known, use the average county residents per
household (rounded up to the next integer) to determine the population. In the space provided, enter this population.
Multiply the population by 10 to determine the Primary Target Population score. Note that if you Oo not suspect a release.
there can be no primary target population.
4. Secondary Target Population: Evaluate populations in distance categories not suspected to be subject to exposure from
release of a hazardous substance from the site. If you suspect a release, residents, students, and workers in the '/ to
4-mile distance categories are secondary target population. If you do not suspect a release, all residents, students, and
workers onsite and within 4 miles are considered secondary target population.
Use PA Table 8 (page 23). Enter the population in each secondary target population distance category, circle the assigned
value, and record it on the far-right side of the table. Sum the far-right column and enter the total as the Secondary
Target Population factor score.
5. Nearest Individual represents the threat posed to the person most likely to be exposed to a hazardous substance release
from the site. If you have identified a primary target population, enter 50. Otherwise, assign the score from PA Table
8 (page 23) for the closest distance category in which you have identified a secondary target population.
6. Primary Sensitive Environments: If a release is suspected, all sensitive environments on or within '/« mile of the sue
are considered primary targets. List them and assign values for sensitive environment type (from PA Table 5, page 16)
and/or wetland acreage (from PA Table 9, page 23). Sum the values and enter the total as the factor score.
7. Secondary Sensitive Environments: If a release is suspected, sensitive environments in the '/« to '/7-mile distance
category are secondary targets; greater distances need not be evaluated because distance weighting greatly diminishes
the impact on site score. If you do not suspect a release, all sensitive environments on and within '/> mile of the site are
considered secondary targets. List each secondary sensitive environment on PA Table 10 (page 23) and assign a value
to each using PA Tables B and 9. Multiply each value by the indicated distance weight end record the product in the far-
right column. Sum the products and enter the total as the factor score.
8. Resources: A score of 5 can generally be assigned as a default measure. Assign zero only if there is no land resource
use within V> mile.
Sum the target scores in Column A (Suspected Release) or Column B (No Suspected Release).
Waste Characteristics (WCI
9.Waste Characteristics: Score is assigned from page 4. However, if you have identified any primary target for the air
pathway, assign either the score calculated on page 4 or a score of 32, whichever is greater.
Air Pathway Score: Multiply the scores for LR, T, end WC. Divide the product by 82.500. Round the result to the
nearest integer. If the result is greater than 100, assign 100.
Air Pathway
A-42 page 7-17
-------
AIR PATHWAY SCORESHEET
Do you suspect a release Isee Air Patrtway Criteria Lisi. page 211?
Outance to (he nearest individual:
LIKELIHOOD OF RELEASE
I. SUSPECTED RELEASE: II you suspect a release to air Isee page 211. assign a
score of 550. Use only column A (or this pathway.
2. NO SUSPECTED RELEASE: If you do not suspect a release to air. assign a
score ol 500. Use only column 8 for this pathway.
TARGETS
3. PRIMARY TARGET POPULATION: Determine the number of people subject
to exposure from a suspected release of hazardous substances to the air.
people x 10
4. SECONDARY TARGET POPULATION: Determine the number of people not
suspected to be exposed to a release to air. and assign the total population
score using PA Table 8.
5. NEAREST INDIVIDUAL: If you have identified any Primary Target Population
lor the air pathway, assign a score of 50; otherwise, assign the Nearest
Individual score from PA Table 8.
6. PRIMARY SENSITIVE ENVIRONMENTS: Sum the sensitive environment values
IPA Table 51 and wetland acreage values IPA Table 91 for environments subject
to exposure from a suspected release to the air.
7 SECONDARY SENSITIVE ENVIRONMENTS: Use PA Table 10 to determine
the score for secondary sensitive environments.
8. RESOURCES
WASTE CHARACTERISTICS
9. A. If you have identified any Primary Target for the air pathway, assign the waste
characteristics score calculated on page 4. or a score ol 32, whichever is
GREATER; do not evaluate pan B of this factor.
B. If you nave NOT identified any Primary Target for the air pathway, assign the
waste characteristics score calculated on page *.
WC -
AIR PATHWAY SCORE:
LR x T x WC
82.500
Air Pathway
page 7-18
A-43
-------
PA TABLE 8: VALUES FOR SECONDARY AIR TARGET POPULATIONS
Distance
from Site
Onaile
>0 lo X mila
> V. 10 H mil*
> H lo 1 mils
> 1 lo 2 n«le«
> 1 lo 3 nrulei
> 3 lo 4 miloi
Population
Nearest Individual «=
Nearest
Individual
(choose
highest!
20
20
2
1
O
0
O
Population Within Distinct Category
1
1C
to
1
. 1
0
0
O
0
O
n
lo
30
2
1
0
0
O
0
0
31
lo
100
5
I
1
0
O
0
0
101
It
300
10
4
1
1
0
0
0
301
lo
1.OOO
52
13
3
1
1
0
1.001
to
3.OOO
183
41
9
3
1
1
1
3.OOI
lo
10.OOO
521
130
28
8
3
1
1
10.001
lo
3O.OOO
1.A33
4O8
88
20
8
4
2
3O.OO1
Im
1OO.OOO
6,214
1.303
282
83
27
12
7
100.001
if
3OO.OOO
18.325
4.081
882
201
83
38
23
300.001
to
1. OOO.OOO
62.138
13.034
2.815
834
2S6
120
73
Qr*mtor
CAM
1. OOO.OOO
183.246
40,811
8.815
2.012
833
370
229
Score
Population
Vtlut
t*.
on
1*
CD Q)
-------
Section 8:
Completing the PA Investigation
Data
Summary
Form
Narrative
Report
Complete PA Package
PA
Scoresheets
-------
COMPLETING THE PA INVESTIGATION
Completing the PA Investigation
Site Scoring
and
Summary
T
Reporting
Requirements
Review
PA
Package
OH*1
Site Score
Combines scores for all four pathways
Uses a root-mean-square formula:
Site Score =
S 2 +S
QW t
+S
Calculate score using matrix provided in the PA
scoresheet (appendix A, site score calculation,
page A-47)
PA Guidance, section 3.7
OH* 2
Competing 0M A4 Investigition
page 8-2
-------
COMPLETING THE PA INVESTIGATION
Summary
Provides a qualitative evaluation of relative risk of targets
exposed to hazardous substances from the site
Cross-checks individual pathway scores
Identifies affected targets
Used as basis for site hypotheses
Summary table and instructions are found in appendix A,
pages A-46 and A-47
PA Guidance, Section 3.7 OH 3
V
Notes:
4194 Completing the RAInvgsttgitlon
page 8-3
-------
SITE SCORE CALCULATION
In the column labeled S, record the Ground Water Pathway score, the Surface Water Pathway score,
the Soil Exposure Pathway score, and the Air Pathway score. Square each pathway score and record
the result in the S2 column. Sum the squared pathway scores. Divide the sum by 4, and take the
square root of the result to obtain the Site Score.
SUMMARY
Answer the summary questions, which ask for a qualitative evaluation of the relative risk of targets
being exposed to a hazardous substance from the site. You may find your responses to these
questions a good cross-check against the way you scored the individual pathways. For example, if
you scored the ground water pathway on the basis of no suspected release and secondary targets
only, yet your response to question #1 is "yes," this presents apparently conflicting conclusions that
you need to reconsider and resolve. Your answers to the questions on page 24 should be consistent
with your evaluations elsewhere in the PA scoresheets package.
Completing the PA Investigation
page 8-4
A-46
-------
SITE SCORE CALCULATION
GROUND WATER PATHWAY
SCORE (Sow):
SURFACE WATER PATHWAY
SCORE (S,J:
SOIL EXPOSURE PATHWAY
SCORE (S,):
AIR PATHWAY
SCORE (S.):
SITE SCORE:
A
S
.
I s^+s^+s^+s^
\ 4
S3
SUMMARY
1.
2.
3.
4.
Is there a high possibility of a threat to any nearby drinking water well(s) by migration of a
hazardous substance in ground water?
A. If yes, identify the well(s).
8. If yes, how many people are served bv the threatened well(s)?
Is there a high possibility of a threat to any of the following by hazardous substance
migration in surface water?
A. Drinking.water intake
B. Fishery
C. Sensitive environment (wetland, critical habitat, others)
0. If yes, identify the target(s).
Is there a high possibility of an area of surficial contamination within 200 feet of any
residence, school, or daycare facility?
If yes, identify the property(ies) and estimate the associated population(s).
Are there public health concerns at this site that are not addressed by PA scoring
considerations? If yes, explain:
i
YES
D
D
a
a
a
a
NO
a
a
a
a
a
a
A-47
Completing the PA Investigation
page 8-5
-------
COMPLETING THE PA INVESTIGATION
Data
Summary
Form
Narrative
Report
PA
Scoresheets
PA Guidance, section 4
Reporting Requirements
Complete PA Package
OH* 4
Reporting Requirements
Potential hazardous waste site preliminary assessment form (PA
Guidance, appendix D)
Narrative report
- May be a letter report or a stand-alone document
- Factual statements must be keyed to a supporting reference
- References not available to general public are attached to report
- Must include latitude and longitude worksheet
- Table 4-1 (pages 145-147) contains PA report outline
PA Guidance, sections 4.1 and 4.2
OH* 6
Completing the PA Investigation
page 8-6
4/94
-------
Table 4-1
PA Narrative Report, Outline of Contents
INTRODUCTION
State that a PA was performed, name the agency or organization performing it, and
state the authority under which it was conducted (i.e., CERCLA as amended by SARA,
and EPA contract or cooperative agreement). Include the site name, CERCLIS
identification number, and location (street address, city, county, state).
Briefly state the purpose of the PA (i.e., to assess the immediate or potential threat
wastes at the site pose to human health and the environment and to collect information
to support a decision regarding the need for further action under CERCLA/SARA) and the
scope of the investigation (e.g., research and review file information, comprehensive
target survey, and an offsite or onsite reconnaissance).
SITE DESCRIPTION. OPERATIONAL HISTORY. AND WASTE CHARACTERISTICS
State brief directions to the site. Provide latitude/longitude coordinates. Identify the
type of site (e.g., plating facility, chemical plant), whether it is active or inactive, and
years of operation. Describe its physical characteristics (e.g., dimensions, size,
structures, buildings, borders, drainage patterns), and setting (e.g., topography, local
land uses). Include a USGS 7.5-minute base map locating the site and showing a 1-mile
radius. On the map, identify the surface water drainage route; nearest well, intake, and
residence; wetlands and other sensitive environments. Include a drafted site sketch
showing features on and around the site.
Provide an operational history of the site. Identify current and former owners and
operators, and describe site activities. Identify and describe wastes generated,
quantities, disposal practices, and source areas. Indicate source areas on the sketch.
Describe any removals, whether conducted by facility operators or regulatory authorities.
Describe past regulatory activities including permits, violations, and inspections by local,
state, or Federal authorities. Present available analytical data in a table and discuss.
PATHWAY AND ENVIRONMENTAL HAZARD ASSESSMENT
Ground Water
Describe the local geologic and hydrogeologic setting (e.g., stratigraphy, formations,
aquifers, karst features, depth and permeability to the shallowest aquifer).
On the basis of the site description, operational history, local geology and hydrogeology,
and any available analytical data, state whether release of a hazardous substance from
the site to ground water is suspected. If analytical data are available, summarize them
in a table.
Discuss ground water use within a 4-mile radius. Identify the nearest drinking water
well and state the distance to it. Quantify drinking water populations served by wells
within 4 miles. Differentiate between populations served by private wells and those
served by municipal wells; identify blended systems. Identify drinking water wells
suspected to be primary targets and quantify the populations associated with each.
Completing the PA Investigation
page 8-7
-------
Table 4-1 (continued)
PA, Narrative Report, Outline of Contents
PATHWAY AND ENVIRONMENTAL HAZARD ASSESSMENT (continued)
Surface Water
Describe the local hydrologic setting, including site location with respect to floodplains,
and the overland and downstream portions of the surface water migration path. State
the distance from the site to the probable point of entry (PPE) to surface water. Identify
the water bodies .within a 15-mile downstream distance, and state the length of reach
and flow characteristics of each. Include a drafted sketch of the surface water
migration path.
On the basis of the site description and operational history, local hydrology, and any
available analytical data, state whether release of a hazardous substance from the site to
surface water is suspected. If analytical data are available, summarize them in a table.
Indicate whether surface water within a 15-mile downstream distance supplies drinking
water. Identify each drinking water intake and state the distance from the PPE to the
nearest intake. Quantify the drinking water population served by surface water and
identify blended systems. Identify surface water intakes suspected to be primary targets
and quantify the populations served by each.
Indicate whether surface water along a 15-mile downstream distance supports fisheries.
Identify each fishery and state the distance from the PPE to the nearest fishery; identify
the fishery with the lowest flow characteristics. Identify fisheries suspected to be
primary targets.
Indicate whether sensitive environments are present in or adjacent to the surface water
migration path (overland and along a 15-mile downstream distance). Identify each
sensitive environment and state the distance from the PPE to the nearest; identify the
sensitive environment with the lowest flow characteristics. Identify sensitive
environments suspected to be primary targets.
Soil Exposure and Air
Indicate the number of onsite workers and the number of people who live onsite or
within 200 feet of areas of known or suspected contamination. Identify schools and day
care facilities onsite or within 200 feet of areas of known or suspected contamination,
and state the number of attendees. Quantify the populations (residents, students, and
workers) within 4 miles of the site; state the distance to the nearest regularly occupied
onsite or offsite building. Identify sensitive environments onsite and within 4 miles of
the site. Discuss the likelihood of a hazardous substance being released to the air. If
analytical data are available, summarize them in a table.
Completing the PA Investigation
page 8-8
-------
Table 4-1 (concluded)
PA Narrative Report, Outline of Contents
SUMMARY AND CONCLUSION
Briefly summarize the major aspects of the site and its history that relate to the potential
for releases of hazardous substances and the exposure of targets. Identify principal
pathways and targets of concern. Discuss additional qualitative considerations or
unusual circumstances that should be brought to the attention of Regional EPA site
assessment personnel.
PHOTODOCUMENTATION LOG
As an attachment, provide original photographs of the site and pertinent site features
(e.g., waste source areas, stained soil, stressed vegetation, drainage paths) taken during
the site reconnaissance. Provide a written description on the back of each photo, in
captions, or in an accompanying text. Key each photo to its location on the site sketch.
REFERENCES
Provide a numbered list, in bibliographic citation format, of all references cited in the PA
report.
Attach copies of references cited in the PA report. Include complete copies of site-
specific references (e.g., USGS topographic quads, records of communication, drinking
water population apportionment and calculation worksheets, GEMS and other database
printouts, waste handling records or shipping manifests). Include only the title page and
pertinent excerpts of general references (e.g., geologic reports, census reports, other
publicly available documents).
Completing the PA Investigation
page 8-9
-------
COMPLETING THE PA INVESTIGATION
Reporting Requirements
PA scoring
PA scoresheets
- Must be included
- Provide national consistency in reporting
- Found in PA Guidance, appendix A
- Also available from EPA
- Regional variations may exist
PA-Score
- Computer program developed by EPA
- Performs all factor value table look-ups and mathematical
calculations
- PA-print used to print scoresheets, references, and PA data
summary form
PA Guidance, section 4.3 OH 6
PA Guidance, section 5.1
Reviews
Chocking for internal consistency
Look at:
- Criteria lists
- Pathway characteristics boxes
- Scoring columns "A" and "B"
- PA tables 1-10
- Summary questions
Use Table 5-1, Checklist for Internal Consistency
(PA Guidance, pages 151-152)
OH«7
Completing the PA Investigation
page 8-10
4/94
-------
COMPLETING THE PA INVESTIGATION
Reviews
Review of PA hypotheses
Ensure hypotheses are reasonable and well-founded
Evaluate responses on criteria lists for appropriate
conclusions
Resolve any differences of opinion
Avoid inappropriate NFRAP recommendations
PA Guidance, section 5.2
OH* 8
The Next Step...
Site
Discovery
CERCLIS
Preliminary
Assessment
Site
Inspection
t Yes
PA
Score
> 28.5?
No
NFRAP
Recommen-
dation
OH* 9
4/94
Completing the PA Investigation
page 8-11
-------
APPENDIX A
Fact Sheets
-------
PB93-963341
United States
Environmental Protection
Agency
Office of
Solid Waste and
Emergency Response
Directive 9345.1-16FS
EPA540-F-93-038
September 1993
Integrating Removal and
Remedial Site Assessment
Investigations
Office of Emergency and Remedial Response
Hazardous Srte Evaluation Division (5204GL
Quick Reference Fact Sheet
Increased efficiency and shorter response times are the primary objectives of integrating removal and remedial site
assessment investigations under the Superfund Accelerated Cleanup Model (SACM). This is based on the
assumption that there is duplication of effort between the programs. A critical element of SACM is a continuous
and integrated approach to assessing sites. The concept of integrating removal and remedial site assessment
activities was introduced in Assessing Sites Under SACMInterim Guidance (OSWER Publication 9203.1-051,
Vonme 1, Number 4, December 1992). This fact sheet examines areas of duplication and key differences between
the two types of investigations, and describes some approaches for integrating assessments. The primary audience
for this information is the site assessment community which includes EPA On-Scene Coordinators (OSCs) and Site
Assessment Managers (SAMs), their counterparts in state or other federal agencies, and assessment contractors.
REMOVAL ASSESSMENTS AND
REMEDIAL SITE ASSESSMENTS
Figure 1 illustrates traditional assessment activities of
the removal and remedial programs prior to SACM.
Typically, when EPA is notified of a possible release
(under CERCLA Section 103), the removal program
determines whether there is a need for emergency
response by EPA. If a response is deemed
necessary, an OSC and/or a removal program
contractor will visit the site. If circumstances allow,
a file and telephone investigation should be initiated
prior to the site visit. The OSC may decide to take
samples during this initial visit or may postpone
sampling. EPA can initiate a removal action at any
point in the assessment process. If the OSC
determines that the site does not warrant a removal
action, he may refer the site to remedial site
assessment or the State for further evaluation, or
recommend no further federal response action.
The remedial site assessment process is similar to that
of the removal program. Once a site has been
discovered and entered into the CERCLIS data base,
the SAM directs that a preliminary assessment (PA)
be performed at the site. The focus of PA data
collection is the set of Hazard Ranking System (HRS)
factors that can be obtained without sampling (e.g.,
population within 1/4 mile). The PA includes a file
and telephone investigation, as well as a site visit (the
PA reconnaissance, or "recon"). The PA recon
differs from the typical removal site visit because
samples are not collected and observations are often
made from the perimeter of the site (although some
Regions prefer on-site PA recons). From the PA
information, the SAM determines if a site inspection
(SI) is needed (i.e., whether the site could score
greater than the 28.5 needed to qualify for inclusion
on the National Priorities List (NPL)). The SI would
include sufficient sampling and other information to
allow the SAM to determine whether the score is
above 28.5. Even in cases where SI data are
adequate for this decision, it may be necessary to
conduct an expanded site inspection (ESI) to obtain
legally defensible documentation.
In general, the remedial site assessment process is
more structured than the removal assessment and
operates on a less intensive schedule. The remedial
site assessment process is focused on collecting data
for the HRS, while Removal assessments are based
on whether site conditions meet National Contingency
Plan (NCP) criteria for a removal action.
-------
Figure 1: Traditional Assessment Processes
REMOVAL PROGRAM
Assess Whether Incident
Meets NCP Criteria (or a
Removal Action
YES
Prepare and Obtain Approval
of Action Memorandum
Initiate Removal
Action Site Actlvltes
NO
Terminate PA or Refer to Remedial
Program or Other Authorities,
If Appropriate
REMEDIAL PROGRAM
Removal Actions May Occur at any Stage
Discovery
CERCL1S
k
Prell
AflftOfl
,
s
tnspc
(£
^
Ie
')
r
r>
k
ESI (If necestary)
r1
Hazard Ranking
System (MRS)
National
Priorities List
(NPL)
^
Remedial
Investigation/
Feasibility Study
(RI/FS)
w
Record of
Decision
(ROD)
Remedial 1
Design/
Remedial |
Action
Site Evaluation Accomplished (SEA)
(Site Screened Out of Process)
-------
INTEGRATING ASSESSMENT ACTIVITIES
While there are differences in objectives between
removal and remedial assessments (i.e., NCP
removal criteria versus HRS), many of the same
factors are important to both programs: the potential
for human exposure through drinking water, soils,
and air pollution; and threats to sensitive
environments such as wetlands. Similarities in the
activities required by both assessmentstelephone
and file investigations, site visits or PA recons,
removal or SI sampling visitssuggest that the
activities can be consolidated. The challenge of
integrating assessments is to organize the activities to
enhance efficiency.
The basic goals of an integrated assessment program
under SACM are:
Eliminate duplication of effort.
Expedite the process. At a minimum, avoid
delays for time-critical removal actions or early
actions (see Early Action and Long-Term Action
Under SACM Interim Guidance, OSWER
Publication 9203.1-051, Volume 1, Number 2,
December 1992, for details on early and long-
term actions).
Minimize the number of site visits and other
steps in the process.
Collect only the data needed to assess the site
appropriately.
The last point is critical to enhancing efficiency since
not all sites need to be assessed in depth for both
removal and remedial purposes. Integrating
assessments does not mean simply adding together the
elements of both assessments for all sitesefficient
decision points must be incorporated into the
integration process. The elements deemed necessary
for an integrated assessment depend on the particular
needs of a specific site and could involve similar,
additional, or slightly different activities from
traditional removal or remedial site assessments.
Figure 2 shows an approach for integrating the two
assessments and indicates ways to eliminate
unnecessary data collection. The most important
features of the approach are the combined
notification/site discovery/screening function; the
single site visit for both programs; phased file
searches as appropriate; and integrated sample
planning and inspection. This approach is detailed
below.
Notification/Siie Discovery/Screening
This "one door" notification process is a combination
of the current removal and remedial program
notification/discovery. All remedial and removal
program discovered sites are screened for possible
emergency response. The screening step would
determine whether there is time for a Hie search prior
to the initial site visit.
(Classic) Emergency
If an emergency is identified, the response would be
implemented immediately. Emergency responses
require immediate sampling and removal actions and
allow little or no time for file or telephone
investigations prior to site activity.
File Search
The integrated file search includes all elements of the
current removal assessment file search. All file
search elements should be thoroughly documented to
serve the needs of both programs. Table 1 lists data
elements that are commonly a part of the file search.
The timing of the file search relative to the initial site
visit would be determined during the
notification/screening step.
Table 1: File Search and
Telephone Investigation
Elements Common to Both Programs
Regulatory program file search (e.g., RCRA,
water, state)
Site access information and property
ownership
Site history, industrial processes
Substances used at site
Past releases (substances, locations, impacts)
Latitude and longitude
Topographic maps
Generally Removal Assessment Only
Potentially responsible party (PRP) search
Treatment technology review
-------
Figure 2: Integrated Assessment
No Further Action
No Further Action
Sample (Optional)-
1
Report
Received/Release
Identified
Initial Screening
lor Emergency
Elglblllty
<28.S
Review
Data/Oeclclon on
Further Action
Definitely
May be
>28.S
Do Removal
No
Si/Removal
Assessment
Sampling Report
>28.S
Do Removal
-------
Initial Field Investigation/PA Recon
The integrated site visit combines elements of both
the removal assessment field visit and the remedial
PA recon. Because removal and remedial program
site visit activities are similar, only a small increase
in effort would be required to meet the needs of both
programs. Documentation needs of remedial site
assessment might require slight revision of removal
assessment procedures. For example, one might need
to document the distance to the nearest residence, in
addition to locating any contaminated residential
properties; for removal assessment needs, one might
need to assess the extent of contamination. The
assessment team will need to gain site access
approval for the site visit, in contrast with current
remedial PA recons performed from the perimeter in
some Regions. Table 2 lists elements that are
commonly part of the screening site visit.
Sample (Optional1)
Integrated assessment sampling should follow the
current removal assessment approach, except that
HRS data needs should be considered in selecting
sample locations and laboratory analyses. The
emphasis, however, is on removal assessment needs.
Review Data/Decide Further Action
Both removal and remedial programs would jointly
recommend a course of action, taking into
consideration any previous removal actions. A site
might undergo either a continuation of the removal
assessment, a remedial site assessment PA, or both
concurrently. Alternatively, a time-critical removal
action could be performed prior to deciding whether
the site should undergo a PA. Completing the PA
might be expedited in order to determine early in the
process whether remedial site assessment
requirements should be included in sampling plans.
When planning the site inspection, the Region may
also want to consider the effect of a removal action
on the HRS score (see The Revised Hazard Ranking
System: Evaluating Sites After Waste Removals,
OSWER Publication 9345.1-03FS, October 1991).
Complete the PA
Collect any information needed for the remedial site
assessment that was not part of the earlier file search,
and calculate the preliminary HRS score. For sites
assigned the SEA (site evaluation accomplished)
Table 2: Data Elements of the Site Visit
Elements Common to Both Programs
Current human exposure identification
Sources identification, including locations,
sizes, volumes
Information on substances present
Labels on drums and containers
Containment evaluation
Evidence of releases (e.g., stained soils)
Locations of wells on site and in immediate
vicinity
Runoff channels or pathways
Location of site or sources relative to surface
waters
Nearby wetlands identification
Nearby land uses (e.g., residential, schools,
parks, industrial)
Distance measurements or estimates for wells,
land uses (residences and schools), surface
waters, and wetlands
Public accessibility (e.g., site fence)
Blowing soils and air contaminants
Photodocumentation
Site sketch
Generally Removal Assessment Only
Petroleum releases (eligible)
Fire and explosion threat
Urgency of need for response
Response and treatment alternatives evaluation
Greater emphasis on specific pathways (e.g.,
direct contact)
Sampling
Generally Remedial Site Assessment Only
Perimeter survey (in some Regions)
Number of people within 200 feet
Some sensitive environments (e.g., endangered
species habitats)
Review all pathways
designation, also complete the PA report. Depending
on circumstances and the Region's approach, the PA
report might be included as part of a comprehensive
PA/SI report for sites scoring above 28.5. Table 3
lists typical data elements of this activity. If after the
PA it is evident that a site is likely to qualify for the
NPL, the site would be referred to the Regional
Decision Team (RDT). (See SACM Regional
Decision TeamsInterim Guidance, OSWER
Publication 9203.1-051, Volume 1, Number 5,
-------
Table 3: Data Elements Needed to Complete the PA
Population within 1 and 4 miles
All private and municipal wells within 4 miles
Depth to ground water (sometimes also collected for removal assessment)
Local or regional geology and climate
Distance to surface water measured (removal assessment only estimates distance)
Fisheries along a 15-mile surface water migration pathway
Sensitive environments along a 15-mile surface water migration pathway
Size of wetlands
Preliminary HRS score
December 1992, for details on the composition and
role of the RDT.)
Integrated Sampling Plan
This combines planning for the current screening
level SI (see section 2.1 of the Guidance for
Performing Site Inspections Under CERCLA, OS WER
Directive 9345.1-05, 1992) and any removal
sampling activities not already addressed by the initial
visit. When it appears that a remedial action will be
appropriate, and the site looks like a candidate for
NPL listing, a Remedial Project Manager (RPM)
should join the OSC and SAM in sample planning to
incorporate the objectives of any potential long-term
actions at the site. For applicable sites, this will
enhance the efficiency of progressing from
assessment to remediation, or starting a remedial
investigation prior to NPL proposal. Likewise,
sample planning should anticipate the needs of any
possible engineering evaluation/cost analysis (EE/C A)
that might be needed for subsequent non-time-critical
removal actions.
Si/Removal Assessment Sampling
This is a single sampling event designed to meet the
needs of both programs, where appropriate. Along
with the site visit and the file search, integrating
sampling would improve efficiency. Table 4
describes differences in emphasis between removal
and remedial site assessment sampling approaches
which need to be considered when developing a joint
sampling plan.
RDT Decisions
The RDT determines the course of action needed to
address a site, based on the outcome of the site
assessment PA, Si/removal assessment, and any time-
critical removal actions. This can include proposing
to list the site on the NPL; conducting an early
action; starting the remedial investigation (RI) early;
or combining the RI with the data collection needed
for listing.
ESI/RI
One option open to the RDT is to start the RI as soon
as it is apparent that the site will qualify for the NPL
(e.g., after a PA), even if further documentation is
needed for NPL rulemaking. The needs of NPL
listing and the RI can be integrated into a single
sampling plan to give a headstart to a long-term
action.
Flexibility in Approach
Figure 2 addresses the most likely approaches for
screening site assessments; in fact, the approach will
vary according to the site and other factors. Time-
critical removal actions can occur at any time.
Enforcement, community relations, and remedial
planning considerations can be factored into data
collection as needed at any point along the process.
OTHER CONSIDERATIONS
Methods of recording or documenting information
vary between programs. Documentation is a major
consideration for both programs, but the HRS
requires a specific data set. In order for a common
data element to be used by both programs, HRS
documentation needs to be addressed.
Timing and duration of the activities also need to be
considered by Regional personnel who are setting up
integrated assessments. One critical timing
consideration involves the step "complete the PA."
At some sites this can proceed on a routine schedule,
but if a Region decides that sampling is needed to
-------
Table 4: Site Inspection/Removal Assessment Sampling
Remedial Site Assessment Emphasis
Attribution to the site
Background samples
Ground water samples
Grab samples from residential soils
Surface water sediment samples
HRS factors related to surface water sample locations (e.g., floodplains, watershed area)
Fewer samples on average (10-30) than removal assessment
Strategic sampling for HRS
Contract Laboratory Program (CLP) usage (no separate funding for analytical services)
Full screening organics and inorganics analyses
Definitive analyses
Documentation, including targets and receptors (e.g., maps, census data)
Computing HRS scores
Standardized reports
Removal Assessment Emphasis
Sampling from containers
Physical characteristics of wastes
Treatability and other engineering concerns
On-site contaminated soils
Composite and grid sampling
Rapid turnaround on analytical services
Field/screening analyses
PRP-lead removal actions
Goal of characterizing site (e.g., defining extent of contamination)
Focus on NCP removal action criteria
determine whether to undertake a time-critical
removal action, the PA should be completed before
developing the integrated sampling plan. Otherwise,
the remedial site assessment sampling needs may not
be appropriately factored into the sampling plan. By
collecting enough data to develop a preliminary HRS
score, the Region can determine whether the site may
be eligible for the NPL and whether it is worthwhile
to collect HRS-related samples. The PA report can
be combined with an SI report at a later time, if
appropriate.
An integrated sampling approach implies the need for
a coherent approach to sample analysis. Some
general principles should be followed to avoid major
problems. Analytical data must be suitable for NPL
purposes. Analytical services should include the
appropriate reporting requirements to allow for data
validation at a later date, if necessary. Table 5 lists
some data quality considerations for analytical data
used to support an HRS score.
The focus of this fact sheet is on the technical
integration of assessments at sites where there is a
potential for no action, early actions, or long-term
actions. In some cases, the Region will rule out the
need for one of those, and the assessment process
under SACM will be similar to a traditional removal
or remedial site assessment.
Integration of assessments under SACM will reduce
duplication of effort at sites by addressing them with
a single assessment approach which incorporates the
objectives of both programs as applicable to each
site. Integration of assessments is an efficieni
blending of similar procedures which may be
appropriate at some sites and meets the objectives and
needs of both programs.
-------
Table 5: Analytical Data Quality Needs For MRS Observed Releases
Sampling procedures, location, and conditions documented in field log.
Chain of custody.
Field blanks for each parameter for each day of sampling. The concentration of contaminants detected must be at
least one order of magnitude below corresponding sample results.
Initial 2-point calibration. Low level standard at or below concentration level of concern. High concentration
standard no more than 2 orders of magnitude above the low concentration standard.
Continuing calibration using low level concentration standard after 10 to 15 sample analyses, or at the end of the
day/sampling event, whichever occurs first. (This step ensures consistent instrument response.)
Blanks run after high level samples to avoid cross contamination.
Specific examples of acceptable field methods:
X-ray fluorescence (XRF) for metals with site-specific standard matrix or with 10 percent lab confirmation by
accepted EPA atomic absorption (AA) method.
Field headspace or vadose zone VOC analysis with site specific standards, coupled with previous site information
such as spill composition, 10 percent split for verification by an accepted EPA method, or successful field
analysis of a PE or reference sample.
Additional copies can be obtained from:
Public EPA Employees
National Technical Information Service (NTIS) or Superfiind Documents Center
U.S. Department of Commerce U.S. Environmental Protection Agency
5285 Port Royal Road 401 M Street, SW (OS-245)
Springfield, VA 22161 Washington, DC 20460
(703) 487-4650 (202) 260-9760 or (202) 260-2596 (FAX)
Order #: PB93-963341
United States
Environmental Protection Agency
5204G
Washington, DC 20460
$300 Penalty for Private Use
-------
United States
Environmental Protection
Agency
Office of
Solid Waste and
Emergency Response
&EPA
Directive 9285.7-14FS
PB94-963311
EPA/540/F-94/028
July 1994
Using Qualified Data to
Document an Observed Release
Office of Emergency and Remedial Response
Hazardous Site Evaluation Division (5204G)
Quick Reference Fact Sheet
Abstract
Data validation checks the accuracy of analytical data, and qualifies results that fall outside performance criteria of
the Contract Laboratory Program (CLP). Results qualified with a "J" are estimated concentrations that may be
biased, but may be used to determine an observed release in Hazard Ranking System (HRS) evaluation. This fact
sheet explains the conditions for use of "J"-qualified data, and introduces factors which compensate for variability
and enable their use in HRS evaluation.
Why Qualify Data?
Chemical concentration data for environmental
decision-making are generated using analytical
methods. EPA analytical chemistry methods are
designed to provide the definitive analyte
identification and quantitation needed to establish an
observed release under the Hazard Ranking System
(HRS). Routine operational variations in sampling
and analysis inevitably introduce a degree of error
into the analytical data. Data validation checks the
usability of the analytical data for HRS evaluation and
identifies the error (bias) present. The validation
process qualifies the biased data. Certain types of
qualified data for release and background samples
may be used to determine an observed release.
EPA Data Qualifiers
EPA analytical methods (e.g., SW-846 and Contract
Laboratory Program [CLP]) introduce a number of
Quality Assurance/Quality Control (QA/QC)
mechanisms during the course of sample analysis to
measure qualitative and quantitative accuracy.3l
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guidelines' performance criteria are qualified to
indicate bias or QC deficiencies. The data validation
report usually explains why the data were qualified
and indicates the direction of bias when it can be
determined. Most EPA validation guidelines use the
data qualifiers presented below. u (Other data
qualifiers besides these are in use; always check the
validation report for the exact list of qualifiers and
their meanings.)
"U" qualifier -- the analyte was analyzed for,
but was not detected above the reported
sample quantitation limit. For practical
purposes, "U" means "not detected"; the result
is usable for characterizing background
concentrations for HRS eval'"»tion.5
"J" qualifier -- the analyte was positively
identified; the associated numerical value is
the approximate concentration of the analyte in
the sample. "J" data are biased, but provide
definitive analyte identification, and are usually
reliable. They may be used to determine an
observed release under conditions specified
later in this fact sheet. *
"N" qualifier -- the analysis indicates the
presence of an analyte for which there is
presumptive evidence to make a "tentative
identification." "N" data are not sufficiently
definitive for HRS evaluation.
"NJ" qualifier ~ the analysis indicates the
presence of an analyte that has been
"tentatively identified" and the associated
numerical value represents its approximate
concentration. "NJ" data are not sufficiently
definitive for HRS evaluation.
"UJ" qualifier -- the analyte was not detected
above the reported sample quantitation Limit.
However, the reported quantitation limit is
approximate and may or may not represent the
actual limit of quantitation necessary to
accurately and precisely measure the analyte in
the sample. "UJ" non-detects are not definite;
the analyte may be present. The result can be
used to document non-detects in background
samples under certain conditions.
"R" qualifier -- the sample results arc rejected
due to serious deficiencies in the ability to
analyze the sample and meet quality control
criteria. The presence or absence of the
analyte cannot be verified. EPA does not use
"R" data because they arc considered
unreliable.s
Validrted data that are not qualified are unbiased,
and can be used at their reported values for HRS
evaluation.
Criteria for Determining an Observed Release with
Chemical Data
Chemical data demonstrate an observed release when
all of the following are true:
1. The release of a hazardous substance is at least
partially attributable to the site under
investigation.
2. The release sample concentration is greater than
or equal to the appropriate detection limit (e.g.,
sample quantitation limit [SQL]).
3. If background levels are below detection limits,
the release sample concentration must be greater
than its detection limit, or, if background levels
are greater than or equal to detection limits, the
release sample concentration must be at least
three times the background concentration. 7
Direction of Bias in "J"-QuaIified Data
It is important to understand the bias associated with
"J"-qualified data when using them for HRS
evaluation. "J" data may have high, low, or
indeterminate bias. A low bias means that the
reported concentration is most likely an
underestimate of the true concentration. For
example, data may be biased low when sample
holding times for volatile organic compounds (VOCs)
are exceeded or when the recovery of QA/QC
compounds is significantly less than the true amount
originally introduced into the sample. A high bias
means that the reported concentration is most likely
an overestimate of the true concentration. A bias is
indeterminate when it is impossible to ascertain
whether the concentration is an overestimate or an
underestimate. For example, an indeterminate bias
could result when matrix effects obscure QA/QC
compounds.
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Qualified Data and Direction of Bias
Qualified data may be used when it can be
demonstrated that the data meet the HRS rule for
determining an observed release despite the bias in
the reported concentrations. This condition depends
on the direction of bias: low bias data may be used
for release samples, and high bias data may be used
for background samples. Low bias release samples
are underestimates of true concentration. Under-
estimated release concentrations that still meet the
HRS criteria (e.g., they are still three times
background level) clearly establish an observed
release. High bias background samples are
overestimates of background level. If the
concentration of unbiased release samples still
significantly exceeds an overestimated background
level according to HRS criteria, an observed release
is clearly established. Similarly, an observed release
is established when low bias release concentrations
significantly exceed high bias background
concentrations according to the HRS criteria.
These scenarios show that low bias "J-"qualificd data
may be used for release samples at their reported
concentrations, and that high bias "J-'qualified data
may be used for background samples at their
reported concentrations.
High bias release samples may not be used at their
reported concentrations because they are an
overestimate of true concentration; the true
concentration might be less than the HRS criteria for
an observed release. The reported concentration for
low bias background concentrations may not be
compared to release samples because it is most likely
an underestimate of background level; the release
sample concentration might not significantly exceed
the background concentiation. However, high bias
release data and low bias background data may be
used with factors which compensate for the variability
in the dat.a. The factors will enable these types of
biased data to meet HRS criteria for determining an
observed release.
Factors for Biased Data: Tables 1 through 4 (pages
6-13) present analvte-specific factors to address the
uncertainty when determining an observed release
using high bias release data and low bias background
data. The factors are derived from percent recoveries
of matrix spikes, surrogates, and laboratory control
samples in the CLP Analytical Results Database
(CARD) from January 1993 to March 1994.
The range of CARD data for each analyte includes 95
percent of all percent recoveries. Discarding outliers
left 95 percent of the CARD data available for
calculating factors. The factors are ratios of percent
recovery values at the 97.5 and 2.5 percentiles. The
ratios generally show a consistent pattern.
An attempt to "convert" a biased value to its true
concentration is not recommended because the
CARD data do not differentiate and quantify
individual sources of variation. The factors are
* o
applied as "safety factors" to ensure that biased data
can be used to meet HRS criteria for determining an
observed release. Dividing a high bias value by a
factor effectively deflates it from the high end of the
range to the low end (low bias alue). Multiplying a
low bias value by the factor effectively inflates it to a
high bias value. Use of the ratio of percentiles is a
"worst-case" assumption that the data are biased by
the extent of the range of CARD data considered.
The factors either inflate the values to the high end of
the range, or deflate the data to the low end, and thus
compensate for the apparent variability when
comparing a high bias value to a low bias value (see
Exhibit 1).
Factors have been selected for all analytes in the CLP
Target Compound List (organic analytes) and Target
Analyte List (inorganic analytes). Some organic
factors were derived from matrix spike percent
recoveries, and some from surrogate percent
recoveries, depending on availability of data. When
both matrix spike and surrogate data were available
for the same compound, the larger value
(representing more extreme high and low percent
recoveries) was used. Laborato.y control samples
were used to calculate some of the inorganic factors.
A default factor of 10 was used for analytes when
percent recovery data were unavailable.
Application of the Factors: Exhibit 1 shows how to
apply the factors to "J" qualified data. High bias
background data, low bias release data, and unbiased
data may be used at their reported concentrations.
Multiply low bias background sample data by the
analyte-specific factor to bring them to their new
value. The new background value -ffectively becomes
a high bias value that may be used to determine an
observed release. Divide high bias release sample
data by the analyte-specific factor to bring them to
their new value. The new release sample value
effectively becomes a low bias result that may be used
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Exhibit 1: Use of Factors for "J"-Qualified Data
Type of Sample
Background
Sample
Release
Sample
Type of Bias
No Bias
Low Bias
High Bias
Unknown Bias
No Bias
Low Bias
High Bias
Unknown Bias
Action Required
None: Use concentration without factor
Multiply concentration by factor
None: Use concentration without factor
Multiply concentration by factor
None: Use concentration without factor
None: Use concentration without factor
Divide concentration by factor
Divide concentration by factor
to determine an observed release. Note: Adjusted
release and background values must still meet HRS
criteria (e.g., release concentration must be at least
three times background level) to determine an observed
release.
Examples Using Trichloroethene in Soil:
1. Release sample data biased low, background
sample data biased high.
Release sample value:
Background sample value:
30 /xg/kg (J) low bias
10 pig/kg (J) high bias
In this instance, the direction of the bias indicates
that the release sample concentration exceeds
background by more than three times, so an observed
release is established (provided all other HRS criteria
are met). Use of the factors is not needed.
2. Release sample data unbiased, background sample
data biased low.
Release sample value:
Background sample value:
30 /xg/kg no bias
10 jig/kg (J) low bias
To use the data to establish an observed release,
multiply the background sample value by factor given
for trichloroethene (1.8). No factor is needed for the
release sample.
New background sample value:
(10 /xg/kg) x (1.8) = 18 Mg/kg (J) high bias
The release sample concentration does not exceed the
new background level by a factor of three, so an
observed release is not established.
3. Release sample data biased high, background
sample data unbiased.
Release sample value: 75 /ig/kg (J) high bias
Background sample value: 15 /ig/kg no bias
To use the data to establish an observed release,
divide the release sample value by the factor for
trichloroethene (1.8). No factor is needed for the
background sample.
New release sample value:
(75 /ig/kg) + (1.8) = 42 /ig/kg (J) low bias
The new release sample concentration does not
exceed background concentration by a factor of three,
so an observed release is not established.
4. Release sample data biased high, background
sample data biased low.
Release sample value: 100 /*gAg (J) high bias
Background sample value: 10 /ig/kg (J) low bias
To use the data to establish an observed release,
divide the release sample value and multiply the
background sample value by the factor given for
trichloroethene in soil (1.8).
-------
New release sample value:
(100 Mg/kg) + (1.8) = 56 /ig/kg (J) low bias
New background sample value:
(10 ,ig/kg) x (1.8) = 18 /ig/kg (J) high bias
The new release sample concentration is three times
the new background concentration, so an observed
release is established, provided all other HRS criteria
are met.
Documentation Requirements for Use of Qualified
Data: When using T-qualified data to determine an
observed release, include the "J"-qualifier commentary
from the data validation report in the HRS package.
This step will ensure that the direction of bias is
documented.
Use of Other Factors: EPA Regions may substitute
higher factor values other than the ones in this fact
sheet on a case-by-case basis when technically
justified. For example, other factors may be applied
to conform with site-specific Data Quality Objectives
(DQOs) or with Regional Standard Operating
Procedures (SOPs).10
Detection Limit Restrictions: Factors may only be
applied to "J" data with concentrations above the CLP
Contract Required Quantitation Limit (CRQL) or
Contract Required Detection Limit (CRDL). "J"-
qualified data with concentrations below CLP
detection limits cannot be used to document an
observed release.
Use of "UJ"-Quallfied Data
A combination of the "U" and "J" qualifiers indicates
that the reported value may not accurately represent
the concentration necessary to detect the analyte in
the sample. Under limited conditions, "UJ" data can
be used to represent background when determining
an observed release. These conditions include
instances when there is confidence that the
background concentration has not been detected and
the sample measurement that establishes the observed
release equals or exceeds the SQL or other
appropriate detection limit. This reasoning is based
on the presence of a high bias in the background
sample. Thus, UJ data can be used only when all of
the following conditions apply:
The "UJ" value applies to the background
sample and represents the detection limit,
The "UJ" value is biased high, and
The release sample concentration exceeds the
SQL (or applicable detection limit) and is
unbiased or biased low.
Summary
Data validation checks the usability of analytical data
and identifies certain errors (bias). "J"-qualified data
identify that analytes are present, but the reported
values represent estimated concentrations associated
with bias. Low bias release data and high bias
background data may be used at the reported values.
High bias release data and low bias background data
may not be used at their reported concentrations
because they do not establish an observed release
with certainty. Application of factors introduced in
this fact sheet compensate for this u icertainty, and
enable "J" data to be used to determine an observed
release.
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Table 1: Factors for Volatile Organic Analytes
VOLATILE
ORGANIC
ANALYTES
1,1,1-TRICHLOROETHANE
1 ,1 ,2,2-TETRACHLOROETHANE
1,1,2-TRICHLOROETHANE
1,1-DICHLOROETHANE
1,1-DICHLOROETHENE
1,2-DICHLOROETHANE
1,2-DICHLOROETHENE (TOTAL)
1,2-DICHLOROPROPANE
2-BUTANONE
2-HEXANONE
4-METHYL-2-PENTANONE
ACETONE
BENZENE
BROMODICHLOROMETHANE
BROMOFORM
BROMOMETHANE
CARBON DISULFIDE
SOIL MATRIX
Number of
CARD
Samples
Reviewed
..
11144
11144
2064
11144
11144
11144
11144
11144
11144
2060
11144
11144
Factor
10.0
1.5
10.0
1.4
2.4
1.4
1.4
10.0
1.4
1.5
1.5
1.4
1.7
10.0
10.0
1.4
1.4
WATER MATRIX
Number of
CARD
Samples
Reviewed
9180
-
9179
1484
9179
9179
-
9179
9180
9180
9179
1482
.
9179
9179
Factor
10.0
1.2
10.0
1.3
2.0
1.3
1.3
10.0
1.3
1.2
1.2
1.3
1.5
10.0
10.0
1.3
1.3
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Table 1: Factors for Volatile Organic Analytes (continued)
VOLATILE
ORGANIC
ANALYTES
CARBON TETRACHLORIDE
CHLOROBENZENE
CHLOROETHANE
CHLOROFORM
CHLOROMETHANE
CIS-1 ,3-DICHLOROPROPENE
DIBROMOCHLOROMETHANE
ETHYLBENZENE
METHYLENE CHLORIDE
STYRENE
TETRACHLOROETHENE
TOLUENE
TRANS-1 ,3-DICHLOROPROPENE
TRICHLOROETHENE
VINYL CHLORIDE
XYLENE (TOTAL)
SOIL MATRIX
Number of
CARD
Samples
Reviewed
-
2058
11144
11144
11144
11144
11144
11144
11144
2029
2046
11144
11144
Factor
10.0
1.6
1.4
1.4
1.4
10.0
10.0
1.5
1.4
1.5
1.5
2.0
10.0
1.8
1.4
1.5
WATER MATRIX
Number of
CARD
Samples
Reviewed
-
1480
9179
9179
9179
-
-
9180
9179
9180
9180
1468
-
1452
9179
9180
Factor
10.0
1.4
1.3
1.3
1.3
10.0
10.0
1.2
1.3
1.3
1.2
1.4
10.0
1.5
1.3
1.2
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Table 2: Factors for Semivolatile Organic Analytes
SEMIVOLATILE
ORGANIC
ANALYTES
1 ,2.4-TRICHLOROBENZENE
1,2-DICHLOROBENZENE
1.3-DICHLOROBENZENE
1,4-DICHLOROBENZENE
2.2'-OXYBIS(1 -CHLOROPROPANE)
2,4.5-TRICHLOROPHENOL
2,4,6-TRICHLOROPHENOL
2,4-DICHLOROPHENOL
2.4-DIMETHYLPHENOL
2.4-DINITROPHENOL
2,4-DINITROTOLUENE
2,6-DINITROTOLUENE
2-CHLORONAPHTHALENE
2-CHLOROPHENOL
2-METHYLNAPHTHALENE
2-METHYLPHENOL
2-NITROANILINE
2-NITROPHENOL
3.3'-DICHLOROBENZIDINE
3-NITROANILINE
4.6-DINITRO-2-METHYLPHENOL
4-BROMOPHENYL-PHENYL ETHER
4-CHLORO-3-METHVLPHENOL
4-CHLOROANILINE
4-CHLOROPHENYL-PHENYL ETHER
4-METHYLPHENOL
SOIL MATRIX
Number of
CARD
Samples
Reviewed
1978
11899
11899
1980
11899
11889
11889
11896
11896
11889
1979
11889
11889
1930
11896
118H9
11 "89
11896
11898
-
-
-
1927
11896
11899
11899
Factor
3.5
3.8
3.8
3.8
3.8
8.9
8.9
4.0
4.0
8.9
3.4
8.9
8.9
3.2
4.0
3.8
8.9
4.0
4.3
10.0
10.0
10.0
3.6
4.0
8.9
3.8
WATER MATRIX
Number of
CARD
Samples
Reviewed
1375
7951
7951
1-73
7951
7952
7952
7949
7949
7952
1375
7952
7952
1376
7949
79E.
7952
7949
7951
-
-
~
1375
7949
7952
7951
Factor
2.9
4.0
4.0
3.0
4.0
3.6
3.6
2.5
2.5
3.6
2.6
3.6
3.6
2.9
2.5
4.0
3.6
2.5
6.0
10.0
10.0
10.0
3.5
2.5
3.6
4.0
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Table 2: Factors for Semivolatile Organic Analytes (continued)
SEMIVOLATILE
ORGANIC
ANALYTES
4-NITROANIUNE
4-NITROPHENOL
ACENAPHTHENE
ACENAPHTHYLENE
ANTHRACENE
BENZO(A)ANTHRACENE
BENZO(A)PYRENE
BENZO(B)FLUORANTHENE
BENZO(G,H,I)PERYLENE
BENZO(K)FLUORANTHENE
BIS(2-CHLOROETHOXY)METHANE
BIS(2-CHLOROETHYL) ETHER
BIS(2-ETHYLHEXYL)PHTHALATE
BUTYLBENZYLPHTHALATE
CARBAZOLE
CHRYSENE
DI-N-BUTYLPHTHALATE
DI-N-OCTYLPHTHALATE
DIBENZ(A,H)ANTHRACENE
DIBENZOFURAN
DIETHYLPHTHALATE
DIMETHYLPHTHALATE
FLUORANTHENE
FLUORENE
HEXACHLOROBENZENE
HEXACHLOROBUTADIENE
HEXACHLOROCYCLOPENTADIENE
SOIL MATRIX
Number of
CARD
Samples
Reviewed
11889
1905
1965
11889
-
11898
-
--
-
-
11896
11899
11898
11898
-
11898
--
--
11889
11889
11889
11889
-
11889
--
11896
11889
Factor
8.9
4.8
3.1
8.9
10.0
4.3
10.0
10.0
10.0
10.0
4.0
3.8
4.3
4.3
10.0
4.3
10.0
10.0
8.9
8.9
8.9
8.9
10.0
8.9
10.0
4.0
8.9
WATER MATRIX
Number of
CARD
Samples
Reviewed
7952
1368
1361
7952
-
7951
-
-
--
-
7949
7951
7951
7951
-
7951
-
--
7952
7952
7952
7952
--
7952
--
7949
7952
Factor
3.6
4.5
3.0
3.6
10.0
6.0
10.0
10.0
10.0
10.0
2.5
4.0
6.0
6.0
10.0
6.0
10.0
10.0
3.6 '
3.6
3.6
3.6
10.0
3.6
10.0
2.5
3.6
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Table 2: Factors for Semivolatile Organic Analytes (continued)
SEMIVOLATILE
ORGANIC
ANALYTES
HEXACHLOROETHANE
4-NITROPHENOLINDENO(1,2,3-CD)PYRENE
ISOPHORONE
N-NITROSO-DI-N-PROPYLAMINE
N-NITROSODIPHENYLAMINE (1)
NAPHTHALENE
NITROBENZENE
PENTACHLOROPHENOL
PHENANTHRENE
PHENOL
PYRENE
SOIL MATRIX
Number of
CARD
Samples
Reviewed
11899
_
11896
1966
11896
11896
1895
1924
1901
Factor
3.8
10.0
4.0
3.7
10.0
4.0
4.0
18.8
10.0
3.2
8.3
WATER MATRIX
Number of
CARD
Samples
Reviewed
7951
7949
1345
7949
7949
1359
-
1368
1369
Factor
4.0
10.0
2.5
3.7
10.0
2.5
2.5
3.7
10.0
3.5
4.9
10
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Table 3: Factors for Pesticide/PCB Analytes
PESTICIDE/PCB
ANALYTES
4,4'-DDD
4,4'-DDE
4,4'-DDT
ALDRIN
ALPHA-BHC
ALPHA-CHLORDANE
AROCLOR-1016
AROCLOR-1221
AROCLOR-1232
AROCLOR-1242
AROCLOR-1248
AROCLOR-1254
AROCLOR-1260
BETA-BHC
DELTA-BHC
DIELDRIN
SOIL MATRIX
Number of CARD
Samples Reviewed
1801
1870
-
_
--
-
1886
Factor
10.0
10.0
7.4
7.9
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
6.2
WATER MATRIX
Number of CARD
Samples Reviewed
-
~
1353
1350
-
-
23305
23305
23305
23305
23305
23305
23305
-
-
1350
Factor
10.0
10.0
4.6
4.8
10.0
10.0
8.7
8.7
8.7
8.7
8.7
8.7
8.7
10.0
10.0
2.8
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Table 3: Factors for Pesticide/PCB Analytes (continued)
PESTICIDE/PCB
ANALYTES
ENDOSULFAN 1
ENDOSULFAN II
ENDOSULFAN SULFATE
ENDRIN
ENDRIN ALDEHYDE
ENDRIN KETONE
GAMMA-BHC (UNDANE)
GAMMA-CHLORDANE
HEPTACHLOR
HEPTACHLOR EPOXIDE
METHOXYCHLOR
TOXAPHENE
SOIL MATRIX
Number of CARD
Samples Reviewed
-
-
-
1866
1872
1877
-
Factor
10.0
10.0
10.0
8.5
10.0
10.0
4.5
10.0
4.5
10.0
10.0
10.0
WATER MATRIX
Number of CARD
Samples Reviewed
-
-
-
1348
-
-
1350
-
1351
-
-
-
Factor
10.0
10.0
10.0
3.4
10.0
" 10.0
3.1
10.0
3.6
10.0
10.0
10.0
12
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Table 4: Factors for Inorganic Analytes
INORGANIC
ANALYTES
1
ALUMINUM
ANTIMONY
ARSENIC
BARIUM
BERYLUUM
CADMIUM
CALCIUM
CHROMIUM
COBALT
COPPER
CYANIDE.
IRON
LEAD
MAGNESIUM
MANGANESE
MERCURY
NICKEL
POTASSIUM
SELENIUM
SILVER
SODIUM
THALLIUM
VANADIUM
ZINC
SOIL MATRIX
Number of CARD
Samples Reviewed
1147
1153
1208
1149
1150
1148
1163
1148
1153
1154
884
1149
1331
1143
1151
1563
1150
-
1190
1152 ..
-
1197
1152
1154
Factor
1.5
1.8
1.6
3.3
1.2
1.3
1.2
1.2
1.2
1.1
1.4
1.2
1.3
1.2
1.2
1.7
1.2
10.0
2.3
1.6
10.0
1.7
1.2
1.3
WATER MATRIX
Number of CARD
Samples Reviewed
1686
1688
1701
1686
1686
1685
1685
1686
1685
1683
--
1687
1727
1686
1685
--
1685
-
1695
1684
-
1691
1685
1689
Factor
1.2
1.2
1.2
1.1
1.2
1.2
1-1
1.2
1.2
1.2
10.0
1.2
1.2
1.1
1.2
10.0
1.2
10.0
1.3
1.3
10.0
1.2
1.1
1.2
13
If
-------
References
1. U.S. Environmental Protection Agency, 1994.
CLP National Functional Guidelines for Inorganic
Data Review. Office of Solid Waste and
Emergency Response. Publication 9240.1-05-01.
2. U.S. Environmental Protection Agency, 1993.
CLP National Functional Guidelines for Organic
Data Review. Office of Solid Waste and
Emergency Response. Publication 9240.1-05.
3. U.S. Environmental Protection Agency, 1991.
Contract Laboratory Program Statement of Work for
Inorganics Analysis. Document No. ILM02.0
4. U.S. Environmental Protection Agency, 1991.
Contract Laboratory Program Statement of Work for
Organics Analysis. Office of Solid Waste and
Emergency Response. Document No. OLM1.8
5. U.S. Environmental Protection Agency, 1992.
Hazard Ranking System Guidance Manual. Office
of Solid Waste and Emergency Response.
Directive 9345.1-07.
6. U.S. Environmental Protection Agency, 1991.
Guidance for Performing Preliminary Assessments
Under CERCLA. Office of Solid Waste and
Emergency Response. Publication 9345.0-01A.
7. U.S. Environmental Protection Agency, 1992.
Guidance for Performing Site Inspections under
CERCLA. Office of Solid Waste and Emergency
Response. Directive 9345.1-05.
8. U.S. Environmental Protection Agency, 1992.
Quality Assurance/Quality Control Samples.
Environmental Response Team Quality Assurance
Technical Information Bulletin.
9. U.S. Environmental Protection Agency, 198o. Test
Methods for Evaluating Solid Waste (SW-846):
Physical and Chemical Methods. Office of Solid
Waste and Emergency Response. Document No.
SW-846.
10. U.S. Environmental Protection Agency, 1993.
Data Quality Objectives Process for Superfund.
Office of Emergency and Remedial Response.
Directive 9355.9-01.
14
-------
15
-------
Additional copies can be obtained from:
National Technical Information Service (NTIS)
U.S. Department of Commerce
5285 Port Royal Road
Springfield, VA 22161
(703) 487-4650
Order #94-963311
United States
Environmental Protection Agency
5204G
Washington, DC 20460
$300 Penalty for Private Use
-------
United States
Environmental Protection
Agency
Office of
Solid Waste and
Emergency Response
Directive 9285.7-19FS
PB94-963313
EPA/540/F-94/030
October 1994
4*ER& Establishing Background Levels
Office of Emergency and Remedial Response
Hazardous Site Evaluation Division (5204G)
DRAFT
Quick Reference Fact Sheet
Abstract
The Hazard Ranking System (HRS) establishes criteria for documenting an observed release and observed contamination.
There must be evidence of a hazardous substance in the medium of concern at a concentration significantly above the
background level, and some portion of the release and the hazardous substance must be attributable to the site. This fact
sheet defines background, describes background level determination, and emphasises the necessity of strategic, efficient
sampling. Background considerations for each HRS pathway are presented.
Introduction
Background level is "the concentration of a hazardous
substance that provides a defensible reference point that
can be used to evaluate whether or not a release from
the site has occurred. The background level should
reflect the concentration of the hazardous substance in
the medium of concern for the environmental setting on
or near a site. Background level does not necessarily
represent pre-release conditions, nor conditions in the
absence of influence from source(s) at the site." '
Background levels do not have to reflect pristine
conditions; they define concentrations of contaminants
outside the influence of a release.
Background level determination, usually by chemical
analysis, is necessary to document an observed release
and to establish attribution of contaminants where
multiple sources or contaminant contributors exist.
When evaluating a release, the background level of a
substance is compared with the concentration of the
release sample(s). Background and release samples
generally should be collected during the same sampling
event and from the same geologic stratum or medium of
concern. Time differences between release and
background samples become critical when analytical
holding times are short (e.g., volatile organic analysis and
hexavalent chromium). Collect release and background
samples within the shortest time period possible,
preferably on the same day. Obtaining suitable
background samples can be challenging because of
varying media compositions and potentially false
assumptions regarding data representativeness. Consult
the Guidance for Performing Site Inspections Under
CERCLA, 1992, OSWER Directive 9345.1-05, for further
information on establishing background levels.
Resource Considerations
Determining a background level is important for
evaluating an observed release and attribution. Only a
few background samples are usually necessary. The
selection of strategic sampling locations is critical to the
success of the Site Inspection (SI), which is a limited-
scope biased sampling event. Evaluate the benefits of
sampling at specific locations and assess the validity of
available data to meet SI objectives and conserve
resources (see exhibits 1 and 2).
Background Level Determination Without Sampling
Establishing background level requires determining the
concentration level of a hazardous substance; it does not
always require sampling. Often, the contaminant of
concern is ubiquitous (e.g., lead), and sampling is
required to establish a background level However, some
man-made hazardous substances (e.g., chlorinated
organic solvents, pesticides, short-lived radioactive
substances) can be attributed only to a contaminant
source. In areas that are isolated or where no other
sources can be identified, the presence of these
substances in release samples is sufficient documentation
of contamination; a background sample is not needed.2
(However, certain low-level chlorinated organic com-
DELIVERED OCT 1 3 1994
-------
Exhibit 1: Direct Observation and Chemical
Analysis
The HRS documents an observed release in one
of two ways: by direct observation, or by
chemical analysis.
Direct Observation: Material containing a
hazardous substance from the site is observed
entering or is known to have been deposited
directly into or otherwise has come to be located
in the medium (e.g., an effluent discharge from
the site to surface water). No background
sampling is required if direct observation is
documented. However, the presence of a
hazardous substance in the release must be
documented, preferably by chemical analysis. A
demonstrated adverse effect also may be used to
document an observed release by direct
observation in the air and surface water
pathways.
Chemical Analysis: There is analytical evidence
of a hazardous substance in a medium, at a
concentration significantly above the background
level, and attributable wholly or in part to the
site or source.
Criteria for observed release by chemical
analysis (Refer to Table 2-3 in the Hazard
Ranking System, Final Rule, 40 CFR Part 300):
"If the background concentration is not
detected (or is less than the detection Emit),
an observed release is established when the
sample measurement equals or exceeds the
sample quantitation limit,"
"If the background concentration equals or
exceeds the detection limit, an observed
release is established when the sample
measurement is 3 times or more above the
background concentration."
-pounds in aqueous samples may be associated with
drinking water chlorination.)
In some cases, a sample location may serve as its own
background location. 2 For example, a ground water well
or surface water intake may have associated historical
analytical data. A release can be demonstrated when
historical data from a contaminated well or intake show
that it was previously uncontaminated or less
contaminated. Detailed historical data are useful to
define encroachment of a contaminant plume. Often,
historical data are available for wells and surface water
intakes at industrial sites or municipal water facilities
which have a regular monitoring program. l
Exhibit 2: Reasons for Collecting
Background Samples
A release cannot be determined by direct
observation
The source consists of contaminated soil
Historical data are unavailable or
insufficient
The substance of interest is ubiquitous
Some substances, such as metals in soils, may have
published background levels that can be applied to the
site locally. Consult the following published data sources:
Background sample results from other nearby
CERCLA site investigations
Local surveys by other Federal or State agencies
(e.g., U.S. Geological Survey (USGS), Soil
Conservation Service (SCS))
University studies (e.g., graduate theses)
Tables or databases with natural concentration
ranges and averages in local or regional soils 2
Note that in many cases published information may be
inappropriate. Published data may not account for
regional variations or unique site-specific characteristics.2
Background levels may vary with regional and local
geology (e.g., ore veins, soils with naturally high metals
content). It is difficult to demonstrate comparability
using published data because of the difficulty of
duplicating sample method and analysis. To be similar,
published or existing data should be generated under
quality assurance/quality control (QA/QC) measures
equivalent to EPA requirements for release samples.
Published data may be useful when selecting background
sampling locations. If published data are used, multiple
sources of information help to support a comparison
determination. The use of background level data without
sampling (e.g., published data) may be acceptable for SI
or HRS scoring activities. The analytical package for the
published data should be obtained whenever possible.2
Background Sample Selection Considerations
Collect at least one background sample per pathway or
medium collected outside the area believed to be
influenced by the site. The activities of the investigation
team should not introduce any non-attributable
contaminants to a release or background sample.
Sampling methodology can minimize thin error.
DELIVERED OC1
-------
Smart Sampling Example:
Advantages of CIS
For ground water contamination with multiple
sources or very large areas of contamination,
computer-based Geographic Information
Systems (GIS) are often used to store and
manage large quantities of water quality data,
as well as hydrogedogic and geographic data
and Potentially Responsible Party (PRP)
information. The advantage of a GIS over a
standard database management system is the
ability to relate data spatially. Sample data in
the GIS may contain historical background
concentrations or aid In the selection of
background sampling locations. In conjunction
with GIS, use existing data from CERCLA sites.
It is often necessary to collect more than one background
sample. The location and number of background
samples depend upon:
Hazardous substances present at the site and
expected concentrations
Availability and quality of existing information and
analytical data
Objectives of the investigation
Site hypotheses to be tested
Media variability
Size of the site, number, and type of sources
Pathway-specific considerations (e.g., geologic
formations, types of surface water bodies)
Other potential sources of contamination in the
vicinity of the site 2
The number of background samples collected may also
depend upon the type of investigation performed. At
times, a contaminated background sample can be
compared with a release sample to demonstrate that the
site under investigation contributes at least part of the
contamination in the release sample (refer to chapter 4
of the Guidance for Performing Site Inspections Under
CERCLA, for more information).
In general, the highest background sample concentration
can be used as a background level. In a non-industrial
area, average background concentrations may be used
when sufficient background samples are collected in a
relatively homogeneous environment and there are no
alternative sources of contamination nearby. Qualified
analytical data may also be used for background level
determination (refer to Using Qualified Data to
Document an Observed Release, 1994, OSWER Directive
9285.7-14FS, for more information).
In all evaluations, release and background samples must
be similar for comparison. In some situations, collection
of a comparable background sample is not possible (e.g.,
when there is no surface water sample similar to an
isolated pond, or when a surface water body originates
from a spring).2 If background sampling is not possible,
substitute'published data, as available.
Exhibit 3: Examples of Factors Affecting
Comparability
Filtered versus unfiltered aqueous samples,
including preservative added before or after
filtering
Depth of the ground water sample (i.e.,
screened interval). Note: Data may not be
available for household wells
Density of contaminants (floater or sinker)
Geologic strata, sorptive capacities, and soil
types
Plants that bioaccumulate certain substances
(consider cover vegetation types and density
between surface soil sample locations)
Factors within a water body
thermal or chemical stratification
sediments versus aqueous samples
coarse grain sediments in riffle or
scouring zones versus fine grain
sediments in depositional zones
mixing zones
Age, species, and gender (tissue samples and
portions analyzed)
Date, time, and weather conditions
Sample handling procedures1-3
Factors which determine sample similarity include
location, type, depth, medium, sampling method,
preservation, handling, timing1 and weather conditions
during sampling (see exhibit 3). Variability introduced by
sampling methods can be much greater than that
introduced by the analytical laboratory. Consider
variability factors for each HRS pathway under
investigation. The following are specific considerations
when selecting background samples for each HRS
pathway.
Ground Water Pathway
A direct observation of a release to ground water can be
documented if it is observed or known that a hazardous
substance has been deposited, or the source lies below
the water table of the aquifer of concern (e.g., injection
well, buried waste). A direct observation of a release to
ground water does not require establishing a background
level, but the presence of a hazardous substance in the
f.3
-------
release should be documented by manifest data or
chemical analysis. u
When establishing an observed release by chemical
analysis, background samples generally are needed.
Collect background samples from nearby wells that are
not expected to be influenced by the source of
contamination or by other sites. If there are other sites
or potential local sources of ground water contamination,
collect additional background samples, where possible, to
differentiate their contribution from that of the site under
investigation (refer to the Guidance for Performing Site
Inspections Under CERCLA, for more information).
Similarity of Aquifers
Where possible, aqueous release and background samples
should be collected during the same sampling event but
must be collected from comparable zones in the same
aquifer. Interconnected aquifers should not be
considered as one aquifer when comparing samples for
an observed release. When collecting background
samples, it is preferable not to use samples from a well
screened in two or more aquifers.2
Evaluate aquifer characteristics before selecting wells for
sampling, especially in areas of complex or variable
geology. Be aware of the existence of mines, faults, or
other aquifer intrusions which may affect sample
representativeness. (Note: Section 7.1 of the Hazard
Ranking System Guidance Manual, 1992, OSWER
Directive 9345.1-07, provides detailed guidance on
determining aquifers and aquifer boundaries.)
Note information on ground water flow direction if it is
known or can be easily determined. This information
may also be useful in selecting monitoring well
installation locations for Expanded Site Inspection (ESI)
and Remedial Investigation (RI) work. Obtain
information on flow direction by using piezometers, by
comparing static water levels in existing wells in the same
aquifer, and by using data from published reports. The
well used for background sampling should be out of the
influence of the site.:
Comparability of Wells
Samples from any two wells can be considered
comparable if both are collected from the same aquifer
and if the sample preparation is the same (i.e., compare
filtered release samples to filtered background samples,
and unfiltered release samples to unfiltered background
samples). Ideally, well completion techniques and usage
of background wells should be similar to those of the
well under investigation. It is best if sample methodology
is the same for both release and background wells.
Sampled wells generally should be screened at similar
zones within the same aquifer, depending on the site
hydrogeologic setting, because different depths may have
different contaminant levels and water chemistry.
Measure depth as elevation relative to a reference (e.g.,
mean sea level) instead of below ground surface for data
consistency. Where possible, duplicate purge parameters
and method, sampling method, and sampling equipment
for all well samples. Sample release and background
samples on the same day, if possible, but not more than
three days apart.2
In cases where a background well is not available, sample
a spring before it reaches the surface by inserting a pipe
or well point near the location where ground water
discharges at the spring.2 Thoroughly document this type
of sampling in a field logbook. Sampling data may be
supplemented with applicable published data. Springs
may be used for background sampling of surficial
aquifers only.
Surface Water Pathway
Direct observation of a release to surface water may be
documented if material containing a hazardous substance
is seen entering surface water; is known to have entered
surface water through direct deposition; or is present in
a source which is in contact with surface water through
flooding. Direct observation of a release to surface water
eliminates the need for background sampling, but the
presence of a hazardous substance in the release should
be documented analytically. No background sample is
required when sampling an effluent discharge from the
site into surface water, because the effluent is considered
a direct observation.
In non-tidal surface water bodies, sample downstream to
upstream. Background sediment samples should be from
a location comparable to that of the release samples
(e.g., fine sediments from quiescent zones).2 Sediment
samples are generally preferred over aqueous samples for
evaluation of the surface water pathway because
sediments are more likely to retain contaminants. In
general, aqueous samples might represent current release
conditions, whereas sediment samples might exhibit
historical release conditions.
Background tissue samples from essentially sessile,
benthic organisms (e.g., sponges, oysters) can be used in
support of similar (same species) release tissue samples.
Individuals selected for background tissue sampling
should be the same gender and approximate age,
wherever possible, of those selected for release tissue
sampling.2
DELIV
-------
Special Considerations for Tidal Water Bodies
Determine the need to collect aqueous and sediment
samples in cases where the surface water body is tidally
influenced. One approach for background sampling is to
collect outside of the zone of tidal influence (this can be
gauged by the level of the highest tide). Beware of tidal
flow picking up additional sources upstream. Consider
the effect of the tides on contaminant concentration
(upstream concentrations would be highest during the
rising tide and lowest at falling tide). Consider collecting
release and background samples at the same tidal level.1
Comparability of Water Bodies
Collect release and background samples from the same
type of water body. (Use flow characteristics to
determine similar water bodies.) For example, a
background sample from a small tributary usually is not
comparable to a release sample from a river. Consider
physical and chemical properties of the surface water,
such as lack of mixing in large, slow-flow segments of
rivers, physical transport mechanisms, and biological
influences. Where possible, collect release and
background samples during the same time period, since
thermal stratification and salt/freshwater stratification
vary with the time of year. Consider the thermoclines of
a pond or lake or measure them in the field prior to
sampling.1"2
Simple surface water pathway sampling generally consists
of a minimum of one Probable Point of Entry (PPE)
release sample and one upstream background sample. If
the surface water pathway has multiple PPEs, multiple
background samples may be needed. The number of
background samples collected depends on the complexity
of the path of the surface water body. The presence of
multiple tributaries upstream with multiple potential
sources requires multiple background samples because of
the potential contribution of contamination from other
off-site sources.1-2
For ponds and lakes, background samples may be
collected near the inflow to the water body if it is not
influenced by the source. A pond near the site may be
selected for background sampling if it exhibits similar
physical characteristics to the pond on site. For large
ponds and lakes, background samples may be collected
from the water body itself but as far away as possible
from the influence of the PPE and other potential
sources.l
Air Pathway
Direct observation of release to the air pathway can be
documented in two ways: a release containing hazardous
substances is seen entering the atmosphere directly (e.g.,
visually observing dust blowing off a pile known to
contain hazardous substances), or an adverse effect is
demonstrated (e.g., a documented health effect from a
reaction of incompatible substances). Background levels
need not be established when an observed release by
direct observation is documented.
Weather conditions are critical for evaluating the air
pathway. Throughout the sampling period, determine the
predominant wind direction and speed. Consider lack of
air movement, effects of low temperatures, existence of
flat, open terrain, and any atmospheric instability.
Perform background sampling upwind of site sources,
although cross-wind samples may be acceptable. Always
consider multiple samples for this pathway and collect
them from the same height and at the same time.
(Samples from great heights such as rooftops generally
are not useful because they do not represent target
conditions; very low heights are subject to potential
interference from particulates introduced by field
activities.) Dust, wipe, soil, and soil gas samples are not
acceptable for background sampling in the air pathway,
but these types of samples may be used, along with field
air monitoring equipment, to select release and
background sample locations. Always sample release and
background concurrently. A minimum 12-hour
monitoring period is recommended for sampling the air
pathway, particularly during hot and dry weather
conditions. u
Wind roses may be used to determine predominant wind
direction, or to document changes hi wind direction; this
is important when selecting sample stations.' The 'rose"
diagrams consist of bars on a compass face indicating the
frequency of each wind direction during the selected time
period, as well as the average high wind speed for the
period. If wind roses are utilized, determine the
elevation for which the wind rose was calculated; this
elevation should be representative of target exposure.
Weather stations and airports may provide information
on local wind direction at ground level and at various
elevations.
Soil Exposure Pathway
There is no direct observation of contamination in the
soil exposure pathway. Establishing background levels
for this pathway can be difficult, particularly if the
hazardous substances attributed to the site are naturally
occurring substances. Where possible, collect on-site
background soil samples from surficial soils not likely to
be affected by the source. Collect off-site background
soil samples from shallow soils which ideally should not
be affected by other sources and sites in the area.
However, if there are alternative sources of
contamination in the area, background levels should
account for these contributions. When possible, sample
release and background samples on the same day, or not
more than three days apart. (See Highlight 9-1 of the
DELIVERED PCT 1 3 1994
-------
HRS Guidance Manual for information on background
samples for non-soil sources in the soil exposure
pathway).
Carefully document location, depth, and appearance of
all soil samples. If depths and thicknesses of soil strata
vary with location, ensure that release and background
samples are from a similar stratum and soil type.
Samples should have similar texture, color, and grain
size. 2 During an SI, grab samples (as opposed to
composite) are preferred for determining soil
contamination. Obtain the background sample from an
undisturbed, unfilled area, because fill may have
contaminants which are not representative of background
conditions. If a site is located on fill, obtain the
background samples from a similarly filled area (where
the fill is not considered one of the areas of observed
contamination at the site).1
Select more than one background sample and location
for the soil exposure pathway. Do not collect
background soil samples from a drainage channel which
receives water from off site. * Where possible, collect
background samples from a higher elevation than the
sources to avoid the effect of potential surface drainage.
Avoid background sample locations that are subject to
airborne contamination from the site or other sources. u
Determining Background Levels in Industrial, Mining,
and Radioactive Areas
Industrial areas pose a special challenge to determining
background levels. Ambient conditions may include
elevated concentrations of common -contaminants from
alternative sources not associated with the site. Common
contaminants in background samples in industrial and
urban areas include:
Metals in soils (e.g., lead)
Trichloroethene (TCE) and perchloroethene (PCE)
in urban aquifers
Organic substances in harbor sediments 2
In industrial areas, the investigator often needs to
document that a release sample is above background
sample variability. Where potential alternative sources
exist and possibly interfere with background or release
samples, assess whether the interference affects
background samples and the site significantly, or whether
bias can be determined. Because industrial areas are
affected by increased levels of contaminants and greater
local variability, additional background samples may be
required to establish surrounding off-site conditions. Be
sure to collect a sufficient number of samples between
the site and all other potential sources of contamination
in order to attribute the increase to the site.2 In general,
it is inappropriate to average background samples in an
industrial area where more than one type of industry
existed. This probably will lead to unacceptable levels of
local variability (see Establishing Areas of Observed
Contamination, 1994, OSWER Directive 9285.7-18FS, for
more detailed information).
Mining areas, like industrial areas, pose a challenge to
determining background levels. Often the contaminants
associated with the mine are naturally occurring
elements. Surface water may originate from the mine,
presenting no upstream location for background
sampling. Surface water may pass through the mined
watershed; its nearest upstream location away from the
influence of the site may be in a different geologic
formation, with different water chemistry, producing
uncertainty about comparability. Mines are often located
in areas with aquifers that are highly fractured or
influenced by mine drainage tunnels. It is difficult to find
undisturbed areas in which to locate ground water wells.
Because it may be difficult to determine background
levels in mining areas, it is preferable to determine an
observed release by direct observation (e.g., evidence of
mining below the water table of the aquifer of concern,
tailings observed in surface water). Mine tailings
generally have a high concentration of minerals and are
considered waste; collecting background samples is not
necessary if tailings are analyzed and the mineral
concentrations are shown to be elevated well beyond
what might be expected under natural conditions.
When surface water originates in the source or when no
similar upstream location exists, select a water body with
similar physical characteristics (e.g., a similar stream on
the other side of a mined hill) for background sampling.
The similar water body should not be directly affected by
the site. Release concentrations may be so significantly
elevated (this is common with large-scale mining sites)
that published data may provide a more reasonable
background level for comparison. Establishing
background conditions at mining sites should be
addressed on a site-by-site basis.
To sample sites with radioactive wastes, follow sampling
strategies similar to those for other hazardous substances.
Criteria to establish an observed release through
chemical analysis for radioactive substances are available
for the following three groups:
Radionuclides that occur naturally, or ubiquitous
man-made radionuclides
Non-ubiquitous man-made radionuclides
External gamma radiation (soil exposure pathway
only)
Some portion of the release sample concentration must
be attributable to the site. For each group, compare
release concentrations against known background
radionuclide concentrations or against sample
quantitation limits for a sample medium. Section 4.9.4 of
the Guidance for Performing Site Inspections Under
-------
CERCLA provides details on establishing an observed
release for each group.
Summary
Collect samples to improve documentation for factors
that significantly affect HRS evaluation. If demonstrating
a release or establishing actual contamination is critical
to evaluating a site, do not limit background or QA/QC
samples unduly because of budgetary considerations
collecting these samples may prevent having to return
to the site. Thorough documentation of the locations of
the background samples and potential alternative sources
is necessary to assess the adequacy of the background
levels and to evaluate release and attribution. Evaluate
the benefits of sampling at specific locations and assess
the validity of existing analytical data. Meet SI objectives
while conserving Superfund resources when feasible.
Direct observation of a release does not require
background sampling if detectable concentrations of
hazardous substances are documented to be present in
the source. Background samples may not be necessary
for certain man-made compounds.
To establish background levels by chemical analysis,
thoroughly review on-site and off-site sources and their
locations. Collect background and release samples from
similar locations and media. Ground water samples are
similar when they come from the same zone within an
aquifer and undergo similar sample preparation. Collect
background samples for surface water upstream of the
PPE. Additional site reconnaissance and review are
often needed to select sampling locations in industrial
and mining areas and at complex sites.
References
1. U.S. Environmental Protection Agency, 1992.
Hazard Ranking System Guidance Manual. Office of
Solid Waste and Emergency Response. Directive
9345.1-07.
2. U.S. Environmental Protection Agency, 1992.
Guidance for Performing Site Inspections Under
CERCLA. Office of Solid Waste and Emergency
Response. Directive 9345.1-05.
3. U.S. Environmental Protection Agency, Hazard
Ranking System, Final Rule. 40 CFR Part 300.
DELIVERED OCT 1 3 1994
-------
Additional copies can be obtained from:
National Technical Information Service (NTIS)
Department of Commerce
5285 Port Royal Road
Springfield, VA 22161
(703) 487-4650
Order # 94-963313
United States
Environmental Protection Agency
5204G
Washington, DC 20460
$300 Penalty for Private Use
-------
United States
Environmental Protection
Agency
Office of
Solid Waste and
Emergency Response
Directive 9285.7-20FS
PB94-963314
EPA/540/F-94/031
October 1994
K>EPA Establishing an Observed Release
Office of Emergency and Remedial Response
Hazardous Site Evaluation Division (5204G)
DRAFT
Quick Reference Fact Sheet
Abstract
The Hazard Ranking System (HRS) establishes criteria for documenting an observed release and observed contamination.
This fact sheet describes an observed release and the data required to substantiate it for National Priorities List (NPL)
rule-making purposes. This fact sheet further describes the process documenting an observed release and emphasizes
strategic, efficient sampling.
Introduction
'nrce categories of sampling generally are performed
« uring a Site Inspection (SI):
Source sampling to establish the presence of
hazardous substances at a site
Sampling in the media of concern to establish an
observed release, with background sampling
corresponding to the source to establish attribution
Quality Assurance/Quality Control (QA/QC)
sampling (e.g., field blanks) to ensure data integrity
This fact sheet addresses the second category of
sampling, although each category is dependent upon the
others for site assessment.
Determining an Observed Release
An observed release is evidence that contaminants have
migrated from a site to a pathway or medium. Ground
water, surface water, and air constitute the migration
pathways for observed releases. The Hazard Ranking
System (HRS) establishes general criteria to document
an observed release: there must be evidence of a
hazardous substance in the medium of concern at a
concentration significantly above the background level,
and the release and the hazardous substance must be at
least partially attributable to the site under
investigation.1-2-3 In contrast, the soil exposure pathway is
evaluated for observed contamination, where targets
(human populations, resources, and sensitive
environments) may come into direct contact with
contaminants. For more information on the soil
exposure pathway, refer to the fact sheet Establishing
DELIVERED
OCT 1 3
Areas of Observed Contamination, 1994, OSWER
Directive 9285.7-18FS.
An observed release can be determined either hy
chemical analysis of samples, or by directly observing t *e
release of the hazardous substance (to be documented)
into the medium of concern (see figure 1).
Documenting an observed release by chemical analysis
cannot be accomplished without determining background
level and attribution. Determine background level by
sampling or by using other acceptable information such
as published or existing sample data. For example, a
ground water well or surface water intake with historical
monitoring data may show a change in contaminant levels
over time. If the change is attributable to the site or
source, the data may serve both as background and
release levels. Attribution requires documentation that
the hazardous substance detected in a medium resulted
from site activities. Background samples or existing data
should be as similar as possible to the release samples
for comparison.2 For more information on establishing
background levels, refer to the fact sheet Establishing
Background Levels, 1994, OSWER Directive 9285.7-19FS.
Documenting an observed release is a prerequisite for
evaluating actual contamination at targets. Actual
contamination is evidence that targets have contact with
the hazardous substance(s) resulting from an observed
release. The level of actual contamination is determined
by comparing the release sample concentration to health-
based or ecological benchmark values, where available.
Level I contamination is at or above media-specific
benchmarks; level n is a concentration less than
benchmark values. Note that the detection of
contamination at targets is not in itself sufficient to
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Figure 1: Flowchart for Establishing an Observed Release
Waa tha material
containing
a hazardous substance
observed entering or aeon
existing in
tha environmental
medium?
Is tha concentration of a
hazardous substance m
tha release sample
significantly above
background?
Is the
hazardous
substance
attributable to
the site?*
the hazardou
substance
attributable to
the site?
No observed
release
at the site
Is a portion of
the significant
increase
attributable to
the site?
^
YES
r
Observed release
established by
direct observation
* Not applicable to ground water plume sites with unknown sources
Figure adapted from reference 2 (p. 56)
Observed release
established by
chemical analysia
establish an observed release or actual contamination.2
Samples can be strategically collected to establish an
observed release and to include one or more targets
(dual purpose sampling). Analytical data with
appropriate and adequate quality assurance/quality
control (QA/QC) are needed, since benchmarks are
expressed in concentration units.
Resource Considerations
The SI is a limited-scope biased sampling event, and
selecting strategic sampling locations is critical to its
success. Evaluate the benefits of sampling at specific
locations. Use available data when possible to meet SI
objectives and conserve resources (see exhibit 1).
Observed Release by Direct Observation
To establish an observed release by direct observation, a
hazardous substance must be observed or known to have
been released into the medium of concern. Use existing
analytical data or other references, such as manifests, to
document that the hazardous substance is present or
known to have been released.2 See exhibit 2 for
examples of an observed release by direct observation.
For the ground water pathway, an observed release by
direct observation may be documented with information
that hazardous materials have come to be located or
deposited in the aquifer of concern.2
For the surface water pathway, direct observation to
establish an observed release can be documented by:
Documented hazardous substances seen entering the
water body through migration or known to have
entered through direct deposition
Flooding of a source area so that hazardous
substances come in direct contact with the water
Documented adverse effects (e.g., fish kill)
associated with the release of a hazardous substance
to surface water. Note that inference requires
extensive documentation and verified attribution.2
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Exhibit 1: Questions to Consider when Determining the Need for Sampling
1. Is there an imminent or current threat to human health or the environment? Is a removal action
warranted? Sample at targets if human or environmental exposure to contaminants is suspected. Sample
for public health concerns, where possible.
2. Does the pathway critically affect the site Hazard Ranking System (HRS) score (Si 28.50)? If yes, must
an observed release be documented for that pathway to achieve that site score? If no, evaluating the
pathway for potential contamination may be sufficient (particularly for less critical pathways).
3. What are the constraints of the pathway? Are targets nearby? Each HRS pathway has certain criteria
for determining and limiting target distance with respect to contaminants. For example, for the soil
exposure pathway, contamination must be documented within a zero to 2 foot depth of the surface, and
contamination must be on the property and within 200 feet of targets. For the surface water pathway,
the surface water body must be within two overland miles of the site or source.2 If release samples
cannot meet the pathway constraints, do not collect samples.
4. What are the objectives of the SI? Table 4-7 in Guidance for Performing Site Inspections Under
CERCLA provides guidelines on the number of samples recommended for a focused, expanded, or single
SI as part of an observed release sampling strategy.1
For an observed release by direct observation from
flooded contaminated soils to surface water, the presence
of a hazardous substance significantly above background
prior to flooding must be demonstrated.2 Historical data
may be sufficient to document flood levels, the presence
of a hazardous substance, and its direct contact with
flooded waters.
For the air pathway, direct observation may be
established by demonstrating adverse effects from a
release.2
Observed Release by Chemical Analysis
An observed release can be documented when samples
from the media of concern exhibit contamination
significantly above background levels, and the
contaminants are attributable to the source. Since
concentrations of contaminants usually decrease with
distance from a source, sampling near to sources will
better establish an observed release and attribution.1 At
minimum, one validated sample and a background level
are required to document a release, even if earlier or
later sampling fails to show a release. Varying results
could be due in part to intermittent releases.2
Background level determination usually is required to
attribute an observed release to the site.
To document an observed release by chemical analysis,
the following criteria must be met (except for
radionudides, which are discussed later in this fact
sheet):
1. The release of a hazardous substance must be
at least partially attributable to a source at the
site. (Note: This does not apply to ground
water plume sites with unknown sources.)
2. The release sample concentration must be
greater than or equal to the appropriate
detection limit (e.g., sample quantitation limit
[SQL]).U
3. If the background level is below its detection
limit, the release sample concentration must be
greater than or equal to the background
detection limit, or, if the background level is
greater than or equal to its detection limit, the
release sample concentration must be at least
three times the background concentration. 2
4. The detection limits must be calculated or
determined properly. The detection limit used
for comparison often depends on the source of
the analytical data. The SQL is the preferred
HRS measure, but other limits such as those
provided by the Contract Laboratory Program
(CLP) may be used.2 Note that detection limits
may be different for release and background
samples.
Observed release sampling issues vary according to the
medium, or pathway. These issues include temporal and
spatial variation, hazardous substances present, and
documentation of location and collection conditions. The
surface water pathway may use aqueous, effluent,
sediment, and tissue samples from sessile, benthic
organisms to document an observed release. The other
pathways generally are more limited (e.g., aqueous
samples for ground water, soil samples for soil exposure,
and air samples for the air pathway). Establishing an
observed release in the ground water pathway could be
further complicated by uncertainties about ground water
flow direction, and the resultant uncertainty about
background and attribution.
OCT I 3
894
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Exhibit 2: Examples of an Observed
Release by Direct
Observation
Ground water pathway-Hazardous
substances placed into an old quarry
where the water table has been
reestablished above the level of the
deposited materials.
Surface water pathwayAn
impoundment leachate seep seen
entering a stream. (Collect a sample
from the leachate to document
hazardous substances.) Also, effluent
known to contain hazardous substances
(through manifests) seen entering a
surface water body.
Air pathway-A field logbook entry and
photodocumentation of a dust cloud
originating from a tailings pile. A
sample of the fine particulate matter
from the pile showing the presence of
hazardous substances will verify the
release.1J
Ground Water Pathway
For the ground water pathway, certain types of wells,
including monitoring, irrigation, or drinking water wells,
may be used to establish an observed release, although
the same well may not necessarily serve to document
actual contamination of targets. For a target population,
actual contamination should be documented using a
drinking water well. To establish an observed release,
sample the well(s) closest to the contamination source,
where possible. Select background well(s) outside the
influence of a source and in the same aquifer being
evaluated. Either cross-gradient or upgradient
background sample-locations are preferred when flow
gradient information is available. (Ground water flow
gradient is not required for HRS purposes.) Be cautious
about using wells that are close to the site as background,
because some sources (e.g., landfills and impoundments)
interfere with natural ground water flow. Pumping also
may affect ground water direction and plume movement.
If available, pumping rates of nearby wells (including
those sampled) may serve as a useful source of
information for addressing both sample comparability
and contaminant effect.
Consider characteristics of suspected contaminants in
water when selecting sample locations and depths.
Contaminants in water may not be evenly dispersed. Oils
and organic substances lighter than water (light non-
aqueous phase liquids [LNAPLs]) tend to float on top of
the water table. Contaminants heavier than water (dense
DELIVERED OCT 1 3 J994
non-aqueous phase liquids [DNAPLs]) sink to the bottom
of the water column. u
Smart Sampling Example: Using Springs
to Gather Ground Water Data
Experience at several sites indicates that
springs are an underutilized source of
ground water quality data, which are usually
obtained from monitoring wells. Springs are
common, occur in most geological settings,
and are found at, or near, many hazardous
waste sites. They require no installation or
purging, and may be used to gather rapid
screening data upon site discovery and/or
later as part of an established sampling or
monitoring program. The spring sample
must be documented as ground water rather
than surface water. When properly
documented, spring sampling successfully
has identified surficial aquifer contamination
when well sampling did not. It also has
located reaches of streams into which
contaminated ground water plumes
discharge. Consider using springs as
surficial aquifer sampling points for
documenting either a background level or
an observed release.
Surface Water Pathway
A minimum of two samples (aqueous or sediment)
generally is required for documenting a release in the
surface water pathway: a background sample slightly
upstream of the Probable Point of Entry. (PPE) for
contaminants from the site or source, and a release
sample at or slightly downstream of the PPE. Beware of
tidal flow picking up additional sources upstream.
Exceptions to the two sample minimum are when the
surface water body originates at the site (no upstream
background exists) or when multiple PPEs exist. In the
first case, one sample may be sufficient to document a
release. In the second case, it may be advisable to
sample at or downstream of each PPE to establish an
observed release; similar background sample(s) should be
included.'1*
Proper sampling methods and sample handling are
critical for documenting an observed release, particularly
for the surface water pathway. Aqueous samples may be
used to document current releases to a surface water
body. Collect the downstream sample first, and aqueous
samples before sediments, to avoid the introduction of
any contaminants not associated with the site or medium.
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Minimize aeration of a sample to prevent reducing the
concentration of contaminants such as volatile organic
chemicals.
Consider seasonal and other potential variations such as
irrigation and flooding when sampling in this pathway.
Deep, slow-moving surface water bodies often exhibit
some chemical or thermal stratification. Stratification
also occurs where two streams converge. The absorption
or dilution of substances is affected by stream movement,
and depositional conditions vary within the riffles or close
to stream edges.2
Sediment samples may be used to document historical
releases to the water body. Ideally, the characteristics of
the suspected contaminant(s) should be known to select
the best sample medium, location, and sampling method.
Grain size, organic content, and structure can affect
adsorbance of substances to sediments. For example,
trichloroethylene (TCE) adsorbs to certain particles,
which may bias a sample.2 Sediments are scoured and
deposited in bends of streams and other flowing surface
water bodies. Sample from like areas (e.g., inside bend
deposition areas) for comparability.
Distinguish sediments from soils, especially when
sampling along the edge of a water body. Note that in
arid or semiarid locations (less than 20 inches mean
annual precipitation), "sediments" include areas with
intermittently flowing waters as well as contiguous
intermittently flowing ditches. Contamination in these
areas should be evaluated in the surface water pathway.3
Tissue sampling poses challenges - for comparability
because of differences between members of the same
species, differences between species, variations within a
study population, species mobility, and tissue
differentiation. The target sample species should be
examined for type of organism, approximate age, gender,
size of population, migratory nature, and seasonal,
feeding, spawning, or other periodic activities that
influence concentration of substances within the
organism.2 Tissue samples can be used to determine an
observed release only under Limited circumstances; they
are more readily used to document actual contamination.
It is prudent to collect tissue samples in concert with
other sampling activities when documenting an observed
release.
For tissue sampling, document both the rationale for the
tissue selection, and the accuracy of measurement.
Edible tissues from sessile, benthic organisms are
preferred for HRS evaluation. (Non-sessile benthic
organisms, finfish, amphibians, and reptiles generally
should not be used.)
DELIVERED OCT I 3 1994
Air Pathway
It is important to consider temporal variability in air
sampling because large variations in substance
concentration can occur over a very short time.
Emissions characteristics depend upon topography and
changeable atmospheric conditions, including
temperature, pressure, wind speed and direction,
precipitation, and atmospheric stability.
Monitoring wind direction is prudent to document
migration of hazardous substances from the source.
Wind roses, which detail the percentage of predominant
wind direction, should be developed for the sampling
period to document shifts in wind direction.2
For the air pathway, an air sample may be used to
document both an observed release and actual
contamination of targets within a certain radius from the
source. (In contrast, the ground water pathway requires
sampling at the target; the surface water pathway
requires sampling at or beyond the target to establish
actual contamination.)
An observed release by chemical analysis is not easy to
establish for the air pathway because of the difficulty of
obtaining comparable and verifiable samples. The HRS
evaluates outdoor ambient air conditions only, indoor air
samples are not evaluated for this pathway.1
Partial Attribution and Multiple Source Sites
Sources of contamination other than those found at the
site under investigation are often present. Where
attribution is questionable, sampling should produce
analytical data demonstrating that the contamination is at
least partially attributable to the site. Contributions from
sites sometimes can be isolated by identifying hazardous
substances unique to the site under investigation. This
may require special analytical services and close
evaluation of data. Knowledge of the nearby facilities'
disposal practices and wastes is helpful.'
Attribution may be established through the use of
manifests, labels, records, oral or written statements, or
other information regarding hazardous substances present
at the site or at alternative sources. If these references
confirm the presence of a hazardous substance in release
samples, attribution generally can be established even if
specific sources where the substance was deposited
cannot be documented.2
Establishing background levels is important when
attributing hazardous substances to varied sources.
Background and release sample data should be from the
same medium using similar sampling and analytical
methods. Background samples should be collected from
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outside the influence of contamination from the site
under investigation, but do not have to be free of
contamination. The data need only support that the
release sample concentration is beyond a reasonable
background level. Thoroughly review and document the
location of potential alternative sources so that the
appropriate background sampling locations can be
selected. Many hazardous substances may be widespread
in the vicinity of the site. Substances may originate from
non-point sources such as pesticides and lead.
Background levels for ubiquitous substances should
account for local variability; several samples may be
required to establish this variability.2
Obtain sufficient samples from the site under
investigation and from other known potential sources (or
other adjacent sites) to demonstrate that an increase in
contaminant levels is attributable to the site. Additional
information beyond analytical samples may be required
if the other sites release intermittently. To attribute
contamination sufficiently, collect the following data:
Concentration gradients (e.g., establish an observed
release and attribution with samples from multiple
wells or a series of samples between the site and
alternative sources)
Flow gradients and other information about the
media of concern
Data that associate the site with a unique substance
or unique ratios of different substances 2
Complex factors affecting attribution (e.g., soil
contamination in an industrial area) may require
conducting an expanded SI. In many cases, attribution
concerns may be addressed by fully characterizing all
sources at a site and those of neighboring sites. '
To establish attribution for the ground water pathway,
sample wells located between site sources and alternative
sources. Three wells generally are needed to define flow
direction and to verify the source versus an alternative
source(s). For surface water, a release sample may be
collected downstream of or at the confluence. Sample
background and attribution along each tributary if
multiple sources are located upstream.2
Transformation Products
Transformation products are substances found when a
hazardous substance is changed in the environment by
physical, chemical, or biological processes. Most
transformation products at hazardous waste sites are the
result of degradation.2
An observed release for transformation products must be
documented by chemical analysis and the transformation
product must be a hazardous substance.2
DELIVERED OCT 1 3 199-.
Document the presence of a transformation product in a
release sample at levels significantly above background
level to attribute the parent substance(s) and the
transformation product to the site. The following
references may be useful for documenting the parent
substance and transformation product relationship:
Site-specific studies on the transformation process by
qualified research organizations (e.g., U.S.
Government agencies, universities)
Technical reports on transformation from EPA's
Office of Research and Development
Databases containing EPA-reviewed information
Articles from peer-reviewed journals
Textbooks on soil, environmental microbiology,
biotechnology, and biotreatment processes and their
effectiveness 2
For determining an observed release, conditions at the
site must be conducive to, or must not impede,
transformation, and at least one source must be able to
release the substance to the pathway.2
Smart Sampling Example: Minimizing
Investigation Derived Wastes (IDW)
Solvents, equipment, and other materials
used in site investigation and cleanup may
themselves end up as hazardous waste.
Disposal of IDW at an approved facility
increases site costs and adds to the overall
waste disposal burden. Take precautions to
minimize waste generated on site. Solvents
should be recycled rather than incinerated,
whenever feasible. In many instances,
drums may be cleaned and reconditioned
instead of sent to a landfill. A series of
treatment steps may reduce the final volume
of hazardous waste for disposal. Consider
pollution prevention when planning response
actions.
Radionuclide Sites
The criteria for documenting an observed release by
direct observation apply to radionuclides. Table 7-1 in
the Hazard Ranking System, Final Rule provides the HRS
factor categories that are evaluated differently when
radionuclides are present.3
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For documenting an observed release by chemical
analysis, radionuclide sites are divided into three groups:
1. Radionuclides that exist naturally and
ubiquitous radionudides.
2. Man-made radionuclides which are not
ubiquitous.
3. External gamma radiation (for the soil
exposure pathway only).
Observed releases from a combination of radionuclides
and hazardous wastes (mixed waste) should be
documented separately.
Establishing an observed release requires:
Identification of the radionuclide of concern and the
physical and chemical properties of the radionuclide
On-site and background activities for that
radionuclide
SQL or other detection limit for the radionuclide
For gamma radiation, measure the exposure rate at one
meter above ground for the soil exposure pathway.
Specific requirements for establishing an observed release
for each of the three groups of radionuclides can be
found in Section 7.1 of the Hazard Ranking System, Final
Rule.
Summary
Documenting an observed release for NPL rule-making
purposes requires evidence that the concentration of the
hazardous substance of concern significantly exceeds the
background level. The hazardous substance must be
attributable at least in part to the site under investigation
(except for ground water plume sites with unknown
sources). Establishing an observed release requires
thorough documentation. The sampling design should
attempt to meet multiple HRS data needs with a limited
number of samples.
References
1. U.S. Environmental Protection Agency, 1992.
Guidance for Performing Site Inspections Under CERCLA.
Office of Solid Waste and Emergency Response.
Directive 9345.1-05.
2. U.S. Environmental Protection Agency, 1992. Hazard
Ranking System Guidance Manual. Office of Solid Waste
and Emergency Response. Directive 9345.1-07.
3. U.S. Environmental Protection Agency,
Ranking System, Final Rule. 40 CFR Part 300.
Hazard
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Additional copies can be obtained from:
National Technical Information Service (NTIS)
Department of Commerce
5285 Port Royal Road
Springfield, VA 22161
(703) 487-4650
Order # 94-963314
&EBV
United States
Environmental Protection Agency
5204G
Washington, DC 20460
$300 Penalty for Private Use
DELIVERED OCT t 3
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United States
Environmental Protection
Agency
Office of
Solid Waste and
Emergency Response
Directive 9285.7-18FS
PB94-963312
EPA/540/F-94/029
October 1994
&ER& Establishing Areas of Observed
Contamination
Office of Emergency and Remedial Response
Hazardous Site Evaluation Division (5204G)
DRAFT
Quick Reference Fact Sheet
Abstract
This fact sheet addresses the use of analytical data to establish areas of observed contamination at a hazardous waste site
when evaluating the soil exposure pathway under the Hazard Ranking System (HRS). The data may also be used to
evaluate hazardous waste quantity for some HRS source types. The soil exposure pathway is evaluated only if observed
contamination is established. Establishing observed contamination, defining the area of observed contamination, and
identifying areas of differing levels of contamination are critical in evaluating the soil exposure pathway.
Introduction
The Hazard Ranking System (HRS) establishes general
criteria to document an observed release of hazardous
substances to the migration pathways (ground water,
surface water, air) and to document observed
contamination in the soil exposure pathway. An observed
release is evidence that contaminants have migrated away
from a site to a migration pathway. In contrast, observed
contamination is evidence that targets (human
populations, resources, and sensitive environments) have
come into direct contact with the contaminants. Unlike
the migration pathways, the soil exposure pathway is
evaluated based on current, rather than historical, site
conditions. An exception occurs when a removal action
is performed under EPA oversight during or after a Site
Inspection (SI). In such a case, the soil exposure
pathway could be evaluated based on conditions prior to
the removal action (see the fact sheet The Revised
Hazard Ranking System: Evaluating Sites After Waste
Removals," OSWER 9345.1-03FS, for more information
on removal actions performed during or after an SI).
The HRS criteria for documenting an observed release
and observed contamination are: there must be evidence
of a hazardous substance in the medium of concern at a
concentration significantly above the background level
and at or above the appropriate detection limit, and the
hazardous substance must be at least partially
attributable to a release from the site under investigation
(see figure 1). (For more information on observed
releases, refer to the fact sheet "Establishing an Observed
Release," OSWER Directive 9285.7-20FS.)
Establishing Observed Contamination
When evaluating the soil exposure pathway, observed
contamination must be documented by chemical analysis
of samples from contaminated areas. The source
samples are compared to a background level. Most
samples consist of soil, but leachate, waste, sediment, and
other surficial samples may be collected. ' In
comparison, an observed release in the migration
pathways may be documented either by direct
observation or by chemical analysis of release samples
compared to a background level.
Three criteria must be met in order to document
observed contamination by chemical analysis:
1. The source sample concentration must be
greater than or equal to the appropriate
detection limit (e.g., sample quantitation limit
[SQL]). The detection limit must be properly
determined.
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Figure 1: Flowchart for Establishing Observed Contamination
li the concentration of a
hazardous substance in
the source sample
significantly above
(background?
YES
NO
No ob:
contam
at the
lerved NO
site
NO
* Direct observation ooes not apply to
the sol I exposure pathway
Figure aoapted from reference 2 CP 56}
Is the hazardous
substance
attributable to
the site?
Is a portion o
the significant
Increase
If the hazardous substance of concern is not
detected in the background samples (or its
concentration is less than the detection limit),
the source sample concentration must be
greater than or equal to its detection limit, if
both detection limits are the same. If
background levels are greater than or equal to
the detection limit, the source sample
concentration must be at least three times the
background level. Note that detection limits
may be different for source and background
samples.
The hazardous substance is present at the
surface or is covered by no more than two feet
of penetrable material (except for gamma
radiation emitters, which have no depth
restriction).1
Sampling to Meet the HRS Sampling Objective
In the soil exposure pathway, there is no acceptable
documentation of observed contamination based on
direct observation, and the potential for contamination is
not evaluated. Consider both the types and locations of
targets when selecting sampling locations. Establish an
area of observed contamination as close to targets as
possible. Evaluate targets under the HRS resident
population threat when an area of observed
contamination lies on the site property and within 200
feet of a residence, school, day care center, or workplace.
Evaluate sensitive environments and resources in the
resident population threat only if the area of observed
contamination lies within site boundaries. Evaluate
targets beyond 200 feet but within one mile of the area
of observed contamination under the HRS nearby
population threat.4 Collect samples no deeper than two
feet below the surface. Document the absence of a
maintained, essentially impenetrable cover material (e.g.,
asphalt, concrete) over any portion of an area of
observed contamination.J Since surficial contamination is
not limited to soil, sampling of other surface media, such
as leachate or waste, should be considered.
Attribute contamination to a site by collecting
appropriate background samples outside the influence of
sources. Obtain source samples from locations where the
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Exhibit 1: Background Samples for Areas of Observed Contamination
Source
Contaminated soil
Tanks/Drums filled with contaminated soil
Tanks/Drums containing liquid or solid wastes
Landfill'
Piles'
Surface Impoundment (liquid)*
Surface impoundment (sludges or backfilled)*
Other sources
Background Sample
Soil in vicinity of the site'
Same as for the soil at the site
Background is zero
Soil in vicinity of the site
Soil in vicinity of the site
Aqueous samples from vicinity of the site;
background may be zero
Soil in the vicinity of the site
Review on a site-specific basis
'See sections 5.1 and 5.2 of reference 2 for additional considerations.
'For these source types, the Indicated sample is likely to be the most appropriate background.
Figure adapted from Highlight 9-1 of reference 2 (p. 344)
substances are suspected to have been deposited (e.g.,
contaminated soil along the flood plain of a contaminated
surface water body). 2 Exhibit 1 suggests appropriate
locations for background samples by source type.
Evaluating Waste Quantity by Defining Areas of
Observed Contamination
Identify and delineate areas of observed contamination
for the following reasons:
1. The soil exposure pathway can be evaluated only if
there are areas of observed contamination.
2. Target values are assigned based on the distance of
targets from the area of observed contamination.
3. Waste quantity can be calculated based on the area
of observed contamination.
A site may have more than one area of observed
contamination. Each area of observed contamination
may be associated with its own targets. Assign a source
hazardous waste quantity value for each area. Sum the
source hazardous waste quantity values assigned to each
area of observed contamination to determine the waste
quantity factor value for the soil exposure pathway.2
Some soil areas cannot be included in evaluating an area
of observed contamination. Exclude the following sub-
areas:
Areas covered by permanent or otherwise
maintained and essentially impenetrable material
(e.g., asphalt, concrete)
Areas of higher ground not influenced by runoff
from the site, if contamination results from runoff
Areas where the types of operations at a facility
preclude the presence of hazardous substances (e.g.,
contamination at loading docks but not elsewhere on
site)
Contaminated areas covered by more than two feet
of fill or other material2
(Refer to specific examples in Highlights 9-3 through 9-6
in the Hazard Ranking System Guidance Manual, 1992,
OSWER Directive 9345.1-07.)
Areas of observed contamination can be established with
sampling locations and analytical data that meet the HRS
criteria for observed contamination, including
determination of background level2. A minimum of
three contaminated samples is sufficient to establish an
area of observed contamination for soil. The area of
-------
observed contamination includes the three sampling
points and the area within them, except excluded sub-
areas.1-2
Points and linear strips of observed contamination may
be evaluated as areas of observed contamination for the
soil exposure pathway, even though an actual "area"
cannot be delineated. For soils, one contaminated sample
denotes a point of observed contamination. Two
contaminated soil samples denote a linear strip of
observed contamination. Either a point or a linear strip
can be used to identify other targets and to demonstrate
a hazardous waste quantity value greater than zero. This
method, however, should not be used indiscriminately to
calculate waste quantity.
For non-soil sources, such as waste piles, observed
contamination at a single point generally is sufficient to
establish the entire source as an area of observed
contamination.
Inferring zn Area of Observed Contamination
For contaminated soil, an area of observed contamination
may be inferred within sampling locations that meet the
observed contamination criteria and have proper
documentation. Select sampling locations that will allow
maximum use of inferred areas of observed
contamination. This strategy may identify more targets
with fewer samples. Consider the following when
inferring an area of observed soil contamination:
*
Density of sampling points
Physiography
Topography and drainage patterns
Operational history
Transport and deposition of hazardous substances,
such as wind dispersion
Contamination in the downgradient portion of a
well-defined migration route
Data derived from other investigations (e.g.,
geophysical surveys)
Soil staining
Stressed vegetation patterns
Aerial and ground photography
Infrared satellite imagery indicating soil anomalies
Use of composite samples (Samples within one grid
cell may be combined; vertical samples from a single
point within a zero to two foot depth may be
combined. In general, do not use non-grid
horizontal composite samples to infer areas of
observed contamination.) u
Consider the modes of contaminant transportation and
deposition when inferring an area of observed
contamination. Contaminants dispersed by air would be
distributed differently than those transported by water;
take this into account when planning sampling. Do not
infer an area of observed contamination between soils in
the floodplain of a contaminated surface water body and
those contaminated from other modes of transportation
and deposition.
Determining Levels of Actual Contamination
Documentation of observed contamination is a
prerequisite for evaluating actual contamination at
targets. Actual contamination is evidence that targets
have contact with the hazardous substance(s) from
observed contamination. The level of actual
contamination is determined by comparing the release
sample concentration to media-specific benchmark
values, where available. Level I contamination is at or
above benchmarks; level II is below benchmarks. Note
that the presence of contamination at targets is not in
itself sufficient to establish observed contamination or
actual contamination.2 Observed contamination samples
can be strategically located to establish an area of
contamination and to include one or more targets (dual
purpose sampling). Analytical data with appropriate and
adequate quality assurance/quality control (QA/QC) are
needed since benchmarks are expressed in concentration
units. Analytical data should provide definitive
identification of the hazardous substances.3
Level I actual contamination concentrations cannot be
inferred between contaminated soil sampling points. The
inferred area of observed contamination is evaluated as
Level II, even if Level I concentrations are found at
sampling points.2
Use
Grid samples may consist of grab samples (from a single
point) or composite samples (from multiple points).
Either grab or composite grid samples may be used to
evaluate the area of observed contamination if the
following conditions apply.
Samples are obtained from a depth of two feet or
less from the source or soil surface, and the source
is not covered by impervious material
The available analytical data verify analyte identity
and quantitation with adequate QA/QC (this may
-------
consist of confirming 10 percent of screening
analyses by definitive methods)3
The verified analytical data meet the HRS definition
of observed contamination as defined in section 2.3
of the Hazard Ranking System, Final Rule
Contaminated grid cells are those with identified
hazardous substances that meet HRS criteria for depth,
attribution to the site, and significance above background
level. The area within these grid cells may be used to
define an area of observed contamination.
Contamination can be inferred at grid cells not sampled
if they lie between contaminated grid cells. Grid cells
lying within inferred contaminated cells are themselves
considered inferred contaminated cells. The area within
inferred contaminated grid cells may be included as part
of an area of observed contamination. (Refer to
Highlight 9-4 in the Hazard Ranking System Guidance
Manual, 1992, OSWER Directive 9345.1-07.)
The following guidelines should be used when
considering grid sampling data:
Exclude from the area of observed contamination
uncontaminated grid cells and unsampled grid cells
that do not lie between contaminated or inferred
contaminated ones.
Subtract from the defined area of observed
contamination any grid cells or sub-areas which are
covered with impervious materials, or meet other
criteria for exclusion.2
Use the same methods to define both the excluded
sub-areas and areas of observed contamination. All
samples should be of the same quality, and analyzed
by similar procedures. Exclude sub-areas from the
inferred area of observed contamination on a case-
by-case basis.
Composite grid samples may establish Level II
actual contamination; specific grab samples are
required to establish Level I actual contamination.
Determining an Area of Observed Contamination for
Sources Other Than Soil
Sources other than contaminated soil, such as waste piles,
impoundments, and containers, can be evaluated for the
soil exposure pathway. The entire source is considered
an area of observed contamination if a sample collected
from it meets the criteria for observed contamination.2
Determine an area of observed contamination as follows:
Impoundment, landfill, and land treatment
Use the surface area of the source i(
Pile Use the surface area of the pile
Ruptured tanks, drums, and other containers Use
the surface area of the container or the land area
under the container (Note: Do not evaluate
containers which have not leaked.)
Example Site
EPA conducted an Expanded Site Inspection (ESI) at a
scrap metal yard in an industrial area to assess inorganic
soil contamination. For a number of years, reclamation
of automotive batteries had taken place at the scrap yard,
which was surrounded by a residential area. A prior
removal action mitigated severe soil contamination and
secured the site from public access, but did not generate
enough data to allow HRS evaluation.
The removal action uncovered extensive lead
contamination within the property boundaries of the
scrap yard, but had not evaluated the residential area.
Eleven residences were situated on a tract adjacent to the
site; six residences abutted the scrap yard boundary.
The proximity of the residential area raised the possibility
that inhabitants could be exposed to lead from sources at
the scrap yard. A study of the area revealed that lead
could be deposited on the residential tract from surface
runoff, dispersion of participates from wind, and
vehicular movement. EPA hypothesized that these
modes of soil transport created an area of observed
contamination in the residential tract.
EPA collected soil samples at each residence and at
border areas to demonstrate attribution of lead
contamination by area! contiguity. Background samples
were collected at nearby areas that were outside the
influence of sources at the scrap yard. In an industrial
area, it is always possible that background concentration
is inflated from various sources. To account for this
possibility, seven spatially divergent sample locations
were selected within the background area to ensure
provision of at least one representative background level.
Soils in all sample locations were classified so that
release samples could be compared to background
samples of similar soil composition. All samples were
-------
Figure 2: Lead Concentrations in Residential Soils Related to Various Background Levels
r\
O
0
(J
0
ID
UJ
13
12
11
10
A - Level I Benchmark:
B - 3X Lowest Background
C - 3X Second Highest Background
D - 3X Highest Background
1 2 3 A 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Residential Sample Number
collected within six inches of the ground surface.
Analytical results from the area of suspected lead
contamination revealed lead concentrations ranging from
740 to 12,600 mg/kg (see figure 2). Lead concentrations
from the background area ranged from 448 to 1,410
mg/kg. Observed and actual contamination were clearly
established, since three residences had lead
concentrations greater than or equal to three times the
highest background level, and the lead was attributable to
the scrap yard. Data from local and regional health
agencies indicated that the highest background level,
which is usually the one selected for HRS evaluation, was
inflated. If this were the case, the number of residences
with actual contamination would be underestimated.
EPA decided to examine the background data more
closely.
According to data from the health agencies, background
levels of lead in area soils ranged from 500 to 1000
mg/kg. Statistical analysis of the background levels
showed that the highest value, 1,410 mg/kg, was not an
outlier, but did lie well above the upper quartile of the
data distribution. EPA suspected that the highest
background value was not a representative level, and
considered using a statistically derived concentration.
The use of the mean concentration was immediately
rejected because it was subject to inflation from the
highest value. In such a skewed data set, the median
would be a more stable estimator of typical background
value. The median background level of 625 mg/kg was
consistent with published data. It was, however, only an
inference of typical background level, not a real sample
concentration. The second highest background
concentration, 856 mg/kg, fell within the range of the
published data. EPA chose this value because a single
background sample is a sufficient, defensible
determination of background level under the HRS. Use
of the lowest background concentrations was not
considered because it could erroneously indicate observed
contamination in areas where lead concentrations were
below three times the reasonable background level. The
lowest concentration is not defensible in HRS evaluation
when there are higher background values obtained from
sampling
Samples from seven residences had lead concentrations
in excess of three times background level (i.e., 3 x 856
mg/kg = 2,568 mg/kg). The health-based benchmark
for lead in soil is 500 mg/kg. The ESI therefore
established an area of observed contamination beyond
the facility's boundaries and found seven residences with
Level I actual contamination.
-------
Smart Sampling Example: Use of Aerial
Photographs
The use of aerial photographs during early site
screening can provide valuable information for
optimal selection of sampling locations.
Further, photos can facilitate potentially
responsible party (PRP) searches and
enforcement activities. Recent aerial
photography may reveal burial outlines,
staining, or stressed vegetation. In one
Instance, aerial photos of a landfill pinpointed
locations of buried drums more precisely than
did borings. In another instance, aerial photos
of two adjacent oilfield-related sites revealed
the possibility of buried waste pits.
Subsequent samples from the locations
confirmed the existence of the waste pits.
Whenever possible, use aerial photographs to
help delineate site contamination, aid in
enforcement, and save money by narrowing
the areas that must be sampled.
Summary
Surfitial soil and other source samples may be used to
establish observed contamination for the soil exposure
pathway. Observed contamination can be documented
only by chemical analysis. Direct observation and the
potential for observed contamination are not evaluated
for this pathway. Sample on the property, within 200 feet
of targets, and within two feet of the source surface.
Multiple samples which meet the HRS criteria for
observed contamination may be used to delineate an area
of observed contamination by inferring contamination
between sampling points. The scope of the Site
Inspection generally does not warrant fully delineating
areas that are not subject to observed contamination.
The primary objective is to identify targets that may
come in contact with hazardous substances at the site.
Whenever possible, select sampling locations which serve
the dual purpose of establishing observed contamination
and identifying targets.
References
1. U.S. Environmental Protection Agency, 1992.
Guidance for Performing Site Inspections Under
CERCLA. Office of Solid Waste and Emergency
Response. Directive 9345.1-05.
2. U.S. Environmental Protection Agency, 1992.
Hazard Ranking System Guidance Manual. Office of
Solid Waste and Emergency Response. Directive
9345.1-07.
3. U.S. Environmental Protection Agency, 1993. Data
Quality Objectives Process for Superfund, Interim
Final Guidance. Office of Emergency and Remedial
Response. Directive 9355.9-01.
4. U.S. Environmental Protection Agency, 1990.
Hazard Ranking System, Final Rule. 40 CFR Part
300.
-------
Additional copies can be obtained from:
National Technical Information Service (NTIS)
U.S. Department of Commerce
5285 Port Royal Road
Springfield, VA 22161
(703) 487-4650
Order #94-963312
AEPA
United States
Environmental Protection Agency
5204G
Washington, DC 20460
$300 Penalty for Private Use
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APPENDIX B
Acronym List
and
Glossary
-------
ACRONYM LIST
AALAC ambient aquatic life advisory concentration
AOC area of observed contamination
AWQC ambient water quality criteria
BCF bioconcentration factor
BIA Bureau of Indian Affairs
BLM Bureau of Land Management
BPF bioaccumulation potential factor
BPFV bioaccumulation potential factor value
BTAG Biological Technical Assistance Group
CA cooperative agreement
CERCLA Comprehensive Environmental Response, Compensation and Liability Act
CERCLIS Comprehensive Environmental Response, Compensation and Liability Information
System
CERI Center for Environmental Research Information
CFR Code of Federal Regulations
CLP Contract Laboratory Program
CRDL contract-required detection limit
CRQL contract-required quantitation limit
ODD dichloro-diphenyl-dichloro-ethane
DDE dichloro-diphenyl-ethane
DDT dichloro-diphenyl-trichloroethane
DL detection limit
DNAPL dense nonaqueous phase liquid
DOE U.S. Department of Energy
DOT U.S. Department of Transportation
EECA engineering evaluation/cost analysis
EIS environmental impact statement
EP extraction procedure
EPA U.S. Environmental Protection Agency
ERCS Emergency Response Cleanup Services
ERD Emergency Response Division
ERT Environmental Response Team
FDAAL Food and Drug Administration advisory level
FRDS Federal Data Reporting System
FWRS Fish and Wildlife Reference Service
CIS Geographic Information System
GW ground water
HFC human food chain
MRS Hazard Ranking System
HRSGM Hazard Ranking System Guidance Manual
HWQ hazardous waste quantity
IAG interagency agreement
IDL instrument detection limit
LNAPL light nonaqueous phase liquid
LR likelihood of release
MCL maximum contaminant level
MCLG maximum contaminant level goal
MDL method detection limit
MMS Minerals Management Service
NAAQS National Ambient Air Quality Standards
NAWDEX National Water Data Exchange
NCP National Contingency Plan
Acronym List
page 1
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NESHAP National Emission Standard for Hazardous Air Pollutants
NMFS National Marine Fisheries Service
NOAA National Oceanic and Atmospheric Administration
NPDES National Pollutant Discharge Elimination System
NPL National Priorities List
NPS National Park Service
NRC Nuclear Regulatory Commission
NRT National Response Team
NSFF National Sport Fishing Federation
NWI National Wetlands Inventory
OSC Onscene Coordinator
OSM Office of Surface Mining
OSWER Office of Solid Waste and Emergency Response
OVA organic vapor analyzer
OWRS Office of Water Regulations and Standards
PA preliminary assessment
PCB polychlorinated biphenyl
PPE probable point of entry
PRP potentially responsible party
QA quality assurance
QC quality control
RA removal action
REAC Regional Engineering Analytical Contract
RCRA Resource Conservation and Recovery Act
RDT Regional Decision Team
RI/FS remedial investigation/feasibility study
RREL Risk Reduction Engineering Laboratory
RRT Regional Response Team
SACM Superfund Accelerated Cleanup Model
SARA Superfund Amendments and Reauthorization Act
SAV submerged aquatic vegetation
SC screening concentration
SCDM Superfund Chemical Data Matrix
SCS Soil Conservation Service
SDWA Safe Drinking Water Act
SF slope factor
SI site inspection
SQL sample quantitation limit
SW surface water
SWDA Solid Waste Disposal Act
TAT Technical Assistance Team
TCLP Toxic Characteristic Leaching Procedure
TDL target distance limit
TSCA Toxic Substances Control Act
TSDF treatment, storage, or disposal facility
USC U.S. Code
USDA U.S. Department of Agriculture
USFS U.S. Forest Service
USFWS U.S. Fish and Wildlife Service
USGS U.S. Geological Survey
UV ultraviolet
WC waste characteristics
WPA wellhead protection area
Acronym List
page 2
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GLOSSARY
Apportioned population: In the evaluation of drinking water target populations associated with a
blended system, that portion of the population evaluated as being served by an individual well or
intake within the system.
Aquifer: A saturated subsurface zone from which drinking water is drawn.
Blended system: A drinking water supply system which can or does combine (e.g., via connecting
valves) water from more than one well or surface water intake, or from a combination of wells and
intakes.
CERCLA: Comprehensive Environmental Response, Compensation, and Liability Act of 1980.
CERCLA Information System: CERCLIS, EPA's computerized inventory and tracking system for
potential hazardous waste sites.
CERCLIS: CERCLA Information System.
Coastal tidal waters: Surface water body type that includes embayments, harbors, sounds,
estuaries, back bays, etc. Such water bodies are in the interval seaward from the mouths of rivers
and landward from the 12-mile baseline marking the transition to the ocean water body type.
Comprehensive Environmental Response. Compensation, and Liability Act of 1980: Legislation that
established the Federal Superfund for response to uncontrolled releases of hazardous substances to
the environment.
Contaminated soil: Soil onto which available evidence indicates that a hazardous substance was
spilled, spread, disposed, or deposited.
Depth to aquifer: The vertical distance between the deepest point at which hazardous substances
are suspected and the top of the shallowest aquifer that supplies drinking water.
Distance to surface water: The shortest distance that runoff would follow from a source to surface
water.
Drinking water population: The number of residents, workers, and students who drink water drawn
from wells or surface water intakes located within target distance limits.
Drums: Portable containers designed to hold a standard 55-gallon volume of wastes.
Emergency response: See "removal."
Factor: The basic element of site assessment requiring data collection and evaluation for scoring
purposes.
Factor category: A set of related factors. Each pathway consists of three factor categories --
likelihood of release or exposure, targets, and waste characteristics.
Federal Register: Daily publication of the Government Printing Office; contains public notices,
rules, and regulations issued by the Federal Government. Cited as " FR ."
Glossary
page 1
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FEMA: Federal Emergency Management Agency.
Fishery: An area of a surface water body from which food chain organisms are taken or could be
taken for human consumption on a subsistence, sporting, or commercial basis. Food chain
organisms include fish, shellfish, crustaceans, amphibians, and amphibious reptiles.
FR: Federal Register.
GEMS: Geographical Exposure Modeling System.
Geographical Exposure Modeling System: Population database maintained by EPA's Office of Toxic
Substances; provides residential populations in specified distance rings around a point location.
Hazard Ranking System: EPA's principal mechanism for placing sites on the NPL.
Hazardous constituent: Hazardous substance.
Hazardous substance: Material defined as a hazardous substance, pollutant, or contaminant in
CERCLA Sections 101(14) and 101(33).
Hazardous waste: Any material suspected to contain a hazardous substance, pollutant, or
contaminant that is or was in a source.
HRS: Hazard Ranking System.
Karst: A kind of terrain with characteristics of relief and drainage arising from a high degree of
rock solubility. The majority of karst conditions occur in limestone areas, but karst may also occur
in areas of dolomite, gypsum, or sajt deposits. Features associated with karst terrain may include
irregular topography, abrupt ridges, sinkholes, caverns, abundant springs, disappearing streams,
and a general lack of a well-developed surface drainage system of tributaries and streams.
Lake: A type of surface water body which includes:
Natural and artificially-made lakes or ponds that lie along rivers or streams (but excluding
the Great Lakes).
Isolated but perennial lakes, ponds, and wetlands.
Static water channels or oxbow lakes contiguous to streams or rivers.
Streams or small rivers, without diking, that merge into surrounding perennially-inundated
wetlands.
Wetlands contiguous to water bodies defined as lakes are considered to be part of the lake.
Landfill: An engineered (by excavation or construction) or natural hole in the ground into which
wastes have been disposed by backfilling, or by contemporaneous soil deposition with waste
disposal, covering wastes from view.
Land treatment: Landfarming or other land treatment method of waste management in which liquid
wastes or sludges are spread over land and tilled, or liquids are injected at shallow depths into
soils.
Glossary
page 2
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National Contingency Plan: Regulation that establishes roles, responsibilities, and authorities for
responding to hazardous substance releases. The NCR established the HRS as the principal
mechanism for placing sites on the NPL.
National Priorities List: Under the Superfund program, the list of releases and potential releases of
hazardous substances, pollutants, and contaminants that appear to pose the greatest threat to
public health, welfare, and the environment.
NCR: National Oil and Hazardous Substances Pollution Contingency Plan, commonly known as the
National Contingency Plan.
NFRAP: No further remedial action planned; site disposition decision that further response under
the Federal Superfund is not necessary.
No suspected release: A professional judgement conclusion based on site and pathway conditions
indicating that a hazardous substance is not likely to have been released to the environment. (No
suspected release is the PA term analogous to the HRS "potential to release.")
NPL: National Priorities List.
Ocean: A type of surface water body which includes:
Ocean areas seaward from a baseline distance of 1 2 miles from shore.
The Great Lakes, along with wetlands contiguous to them.
PA: Preliminary assessment.
PA-Score: EPA's computer program that automates PA site scoring.
Pathway: The environmental medium through which a hazardous substance may threaten targets.
The PA evaluates the migration and threat potential through the ground water, surface water, air,
and soil exposure pathways.
Pile: Any non-containerized accumulation above the ground surface of solid, non-flowing wastes;
includes open dumps. Some types of piles are: Chemical Waste Pile -- consists primarily of
discarded chemical products, by-products, radioactive wastes, or used or unused feedstocks; Scrap
Metal or Junk Pile - consists primarily of scrap metal or discarded durable goods such as
appliances, automobiles, auto parts, or batteries, composed of materials suspected to contain or
have contained a hazardous substance; Tailings Pile -- consists primarily of any combination of
overburden from a mining operation and tailings from a mineral mining, beneficiation, or processing
operation; Trash Pile -- consists primarily of paper, garbage, or discarded non-durable goods which
are suspected to contain or have contained a hazardous substance.
PPE: Probable point of entry.
Preliminary assessment: Initial stage of site assessment under Superfund; designed to distinguish
between sites that pose little or no threat to human health and the environment and sites that
require further investigation.
PREscore: EPA's computer program that automates site scoring with the Hazard Ranking System.
Glossary
page 3
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Primary target: A target which, based on professional judgement of site and pathway conditions
and target characteristics, has a relatively high likelihood of exposure to a hazardous substance.
(Primary target is the PA term analogous to the MRS target expqsed to Level I or Level II actual
contamination.)
Probable point of entry: The point at which runoff from the site most likely enters surface water.
RCRA: Resource Conservation and Recovery Act of 1976.
Removal: An action taken to eliminate, control, or otherwise mitigate a threat posed to the public
health or environment due to release or threatened release of a hazardous substance. Removals
are relatively short-term actions to respond to situations requiring immediate action.
s
Resident: A person whose place of residence (full- or part-time) is within the target distance limit.
Resident individual: Under the soil exposure pathway, a resident or student within 200 feet of any
area of suspected contamination associated with the site.
Resident population: Under the soil exposure pathway, the number of residents and students
within 200 feet of any area of suspected contamination associated with the site.
Resource Conservation and Recovery Act of 1976: Legislation that established cradle-to-grave
accountability for hazardous wastes, from point of generation to point of ultimate disposal.
SARA: Superfund Amendments and Reauthorization Act of 1986.
Secondary target: A target which, based on professional judgement of site and pathway conditions
and target characteristics, has a relatively low likelihood of exposure to a hazardous substance.
(Secondary target is the PA term analogous to the MRS target exposed to potential contamination.)
Sensitive environment: A terrestrial or aquatic resource, fragile natural setting, or other area with
unique or highly-valued environmental or cultural features.
SI: Site inspection.
Site: The area consisting of the aggregation of sources, the areas between sources, and areas that
may have been contaminated due to migration from sources; site boundaries are independent of
property boundaries.
Site inspection: Second stage of site assessment under Superfund, conducted on sites that receive
a further action recommendation after the PA; builds on PA information and typically includes
sampling to identify hazardous substances, releases, and contaminated targets; identifies sites that
pose the greatest threats to human health and the environment.
Source: An area where a hazardous substance may have been deposited, stored, disposed, or
placed. Also, soil that may have become contaminated as a result of hazardous substance
migration. In general, however, the volumes of air, ground water, surface water, and surface
water sediments that may have become contaminated through migration are not considered
sources.
Stream flow: The average rate of flow of a water body, expressed in cubic feet per second (cfs).
Glossary
page 4
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Stream or river: A type of surface water body which includes:
Perennially-flowing waters from point of origin to the ocean or to coastal tidal waters,
whichever comes first, and wetlands contiguous to these flowing waters.
Aboveground portions of disappearing rivers.
Artificially-made ditches only insofar as they perennially flow into other surface water.
Intermittently-flowing waters and contiguous intermittently-flowing ditches in areas where
mean annual precipitation is less than 20 inches.
Student: A full- or part-time attendee of a daycare facility or educational institution located within
the target distance limit.
Superfund Amendments and Reauthorization Act of 1986: Legislation which extended the Federal
Superfund program and mandated revisions to the HRS.
Surface impoundment: A topographic depression, excavation, or diked area, primarily formed from
earthen materials (lined or unlined) and designed to hold accumulated liquid wastes, wastes
containing free liquids, or sludges that were not backfilled or otherwise covered during periods of
deposition; depression may be dry if deposited liquid has evaporated, volatilized or leached, or wet
with exposed liquid; structures that may be more specifically described as lagoon pond, aeration
pit, settling pond, tailings pond; sludge pit, etc.; also a surface impoundment that has been covered
with soil after the final deposition of waste materials (i.e., buried or backfilled).
Surface water: A naturally-occurring, perennial water body; also, some artificially-made and/or
intermittently-flowing water bodies. See "water body type" and subsequent definitions for more
detail.
Suspected release: A professional judgement conclusion based on site and pathway conditions
indicating that a hazardous substance is likely to have been released to the environment.
(Suspected release is the PA term analogous to the HRS "observed release.")
Tanks and non-drum containers: Any stationary device, designed to contain accumulated wastes,
constructed primarily of fabricated materials (such as wood, concrete, steel, or plastic) that provide
structural support; any portable or mobile device in which waste is stored or otherwise handled.
Target: A physical or environmental receptor that is within the target distance limit for a particular
pathway. Targets may include wells and surface water intakes supplying drinking water, fisheries,
sensitive environments, and resources.
Target distance limit: The maximum distance over which targets are evaluated. The target
distance limit varies by pathway: ground water and air pathways -- a 4-mile radius around the site;
surface water pathway -15 miles downstream from the probable point of entry to surface water;
soil exposure pathway - 200 feet (for the resident population threat) and 1 mile (for the nearby
population threat) from areas of known or suspected contamination.
Target population: The human population associated with the site and/or its targets. Target
populations consist of those people who use target wells or surface water intakes supplying
drinking water, consume food chain species taken from target fisheries, or are regularly present on
the site or within target distance limits.
Glossary
page 5
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Terrestrial sensitive environment: A terrestrial resource, fragile natural setting, or other area with
unique or highly-valued environmental or cultural features.
USF&WS: U.S. Fish and Wildlife Service.
USGS: U.S. Geological Survey.
Water body type: Classification of a surface water body. Water body types include: streams and
rivers; lakes; oceans (includes the Great Lakes); and coastal tidal waters. See the specific
definition of each water body type for more detail.
Wetland: A type of sensitive environment characterized as an area that is sufficiently inundated or
saturated by surface or ground water to support vegetation adapted for life in saturated soil
conditions. Wetlands generally include swamps, marshes, bogs, and similar areas.
Worker: Under the soil exposure pathway, a person who is employed on a full- or part-time basis
on the property on which the site is located. Under all other pathways, a person whose place of
full- or part-time employment is within the target distance limit.
Guidance for Performing Preliminary Assessments Under CERCLA, USEPA, Sept. 1991
Glossary
page 6
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APPENDIX C
Integrated Assessments
-------
Appendix C
Integrated Assessments
-------
INTEGRATED ASSESSMENTS
Lecture Overview:
Integrated Assessment
Integrated Assessments and SACM
Introduction to the Removal Program
Integrated Assessments Approach
OH*1
Integrated Assessments
filiS
Introduction to the Removal Program
Integrated Assessments Approach
OH* 2
Integrated Assessments
page C-2
4/94
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INTEGRATED ASSESSMENTS
"Integrated Assessments'
Integrating removal and remedial site assessment
investigation to achieve increased efficiency and shorter
response times
One of many programs associated with the implementation of
the Superfund Accelerated Cleanup Model (SACM)
OH* 3
SACM History
Developed to increase efficiency of the Superfund program by
streamlining cleanup efforts at all Superfund sites
Designed to combine immediate action with continuing study as
necessary
Should restore public confidence in Superfund process
Hazard Ranking System Guidance Manual,
EPA 540-R-92-026, November 1992
OH* 4
4/94
Integrated Assessment*
pageC-3
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INTEGRATED ASSESSMENTS
Traditional Approaches
Removal assessments are traditionally based on whether site
conditions meet National Contigency Plan (NCP) criteria for a
removal action
Remedial site assessments are focused on collecting data for
MRS
The need to integrate these programs is based on the
assumption that there is duplication of effort between the
programs
EPA Directive 9345.1-16FS (Fact Sheet), Integrating Removal and
Remedial Site Assessment Investigations, September 1993
OH* s
Integrated Assessments
Integrated Assessments and SACM
introduction to the Removal Pr<:>grarn
Integrated Assessments Approach
OH* 6
Integrated Assessments
pageC-4
4/94
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INTEGRATED ASSESSMENTS
What is the Removal Program?
Federal response capability for releases or threatened releases of:
Hazardous substances that present a threat to public health, welfare,
or the environment
Oil spills into or on navigable waters and shorelines
Petroleum releases from underground storage tanks
OH»7
/
What are the Removal Program Authorities?
Statutory
Clean Water Act (CWA) as amended by the Oil Pollution Act
of 1990
Comprehensive Environmental Response, Compensation
and Liability Act of 1980 (CERCLA)
Superfund Amendments and Reauthorization Act (SARA)
Oil Pollution Act
Regulatory
NCP
OH* 8
4/94 Integrated Assessments
pageC-5
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INTEGRATED ASSESSMENTS
Initiating Removal Actions
Authority to approve a removal Is generally based on estimated cost..
Less than 50K - onscene coordinator (OSC)
$50K to $2M - regional adminisrator
Over $2M - assistant administrator, OSWER
PRP search
NCR requirement
Action memorandum
Criteria for qualifying site
Proposed removal action
Estimated cost
Note: Cost criteria are under revision
OH* 9
J
What are Removal Actions?
Near-term response actions taken to prevent, minimize, or
mitigate threats to public health, welfare, or the environment
including, but not limited to:
Collection and analysis of samples
Provision of alternate water supplies
Onsite treatment
Source control/stabilization
Offsite storage, treatment, destruction, or disposal
Temporary relocation of threatened individuals
Installation of security fencing/guards
OH* 10
Integrated Assessments 4/94
pageC-6
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INTEGRATED ASSESSMENTS
Classification of Removal Actions
Classic emergency
33 percent of removal actions since 1985
Immediate action required
Time critical
Planning period of less than 6 months
Nontime critical
Planning period of greater than 6 months is available
Agency conducts an engineering evaluation/cost analysis
(EE/CA)
OH* 11
How is the Appropriate Response Selected?
Discovery or ^ Removal Site
Notification " Evaluation
^ No release
or threatened
release
^ Nonfederal party
* undertaking proper
response
Removal action
fr (removal action
memo to
document a
threat)
^ Remedial
" action
OH
12
4/94
Integrated Assessments
pageC-7
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INTEGRATED ASSESSMENTS
The Removal Evaluation
Removal preliminary assessments and site Inspections are
conducted to determine and evaluate:
Presence and magnitude of threat to health or environment
Source and nature of the release
Activities required to mitigate threat
Ability of nonfederal party(ies) to undertake response
Need for CERCLA-funded removal
OH '13
Removal Criteria
Actual or potential human or animal food chain exposure
Actual or potential drinking water contamination
Fire or explosion threat
Hazardous substance in containers that pose a threat of release
Highly contaminated soils at the surface direct contact threat
Weather conditions that may cause substances to migrate
Unavailability of other response or enforcement mechanisms
OH 14
JntegnrtecfAssassmonts 4/94
pageC-8
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INTEGRATED ASSESSMENTS
How are Removals Implemented?
Technical response support
Technical Assistance Team (TAT) - Contractor
U.S. Coast Guard (USCG)
Environmental Response Team (ERT)
Mitigation/cleanup response
Regional Emergency Response Cleanup Services (ERCS) -
Contractor
Site-specific contracts
Cooperative agreements (CAs) with states
OH 15
ERCS
Analytical services
Containment and countermeasures
Cleanup, mitigation, and disposal
Site restoration
OH* 16
4/94 Integrated Assessments
page C-9
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INTEGRATED ASSESSMENTS
EPA Emergency Notification Procedures
The National Response Center (NRC; 1-800-424-8802) alerts
regional EPA or USCG OSC about most spill notifications
OH-17
Integrated Assessments
Integrated Assessments and SACM
Introduction to the Removal Program
Integrated Assessments Approach
OH* 18
Integrated Assessments
page C-10
4/94
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INTEGRATED ASSESSMENTS
Removal and Remedial Assessments
Similarities in programs'goals
Evaluate potential for human exposure to drinking water, soil,
and airborne contaminants
Evaluate threats to sensitive environments (e.g., wetlands)
Similarities in activities
Telephone and file investigations
Site visits or PA recons
Sampling visits
Fact sheet, page 3 OH 19
SACM Goals: Integrated Assessment
Eliminate duplication of effort
Expedite the process
Minimize the number of site visits and other steps in the process
Collect only the data needed to assess the site appropriately
Fact sheet, page 3 OH 20
4/94 Integrated Assessments
pageC-11
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INTEGRATED ASSESSMENTS
Integrated Assessment Approach
Important features
Combined notification/site discovery/screening function
Single site visit for both programs
Phased file searches
Integrated sample planning and inspection
See Figure 2, Integrated Assessment, Integrating Removal
and Remedial Site Assessment Investigations Fact Sheet,
EPA 540-F-93-038, September 1993
Fact sheet, page 4
OH* 21
Integrated Assessment Approach
Notification/site discovery/screening
"One door" notification process
All sites screened for emergency response
Determine whether there is enough time for a file search before
initial site visit
Classic emergency
Respond immediately
Little or no time for file search or telephone
investigation
Fact sheet, page 3
OH* 22
Integrated Assessments
page C-12
4/94
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INTEGRATED ASSESSMENTS
Integrated Assessment Approach
File search
Includes all elements of a removal assessment file search
Table 1, File Search and Telephone Investigation, lists
elements
Document all elements for both programs
Fact sheet, page 3 OH 23
v y
Integrated Assessment Approach
Initial field investigation/PA reconnaissance:
Combines elements from removal field visit and remedial PA
reconnaissance
Documentation procedures for removal assessment may require
revision to meet remedial assessment needs
Would require onsite reconnaissance at all sites
Table 2, Data Elements of the Site Visit, lists data needs for both
programs
Fact sheet, page 5 OH 24
4/94 Integrated Assessments
pageC-13
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INTEGRATED ASSESSMENTS
Integrated Assessment Approach
Sample (optional)
Should follow current removal assessment approach
Should consider MRS data needs
Review data and decide further action
Both programs meet to decide next step(s)
May continue removal assessment, PA, or both concurrently
May expedite PA to determine whether remedial site assessment
requirements should be included in sampling plans
Fact sheet, page 5 OH 26
V
Integrated Assessment Approach
Complete the PA
Collect additional information needed to complete PA
Calculate preliminary MRS score
Prepare PA report
Table 3, Data Elements Needed to Complete the PA, should be
consulted
Refer site to regional decision team if score is greater than or
equal to 28.5
Fact sheet, page 5 OH 26
Integrated Assessments 4/94
page C-14
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INTEGRATED ASSESSMENTS
Integrated Assessment Approach
Integrated sampling plan
Combines screening level SI plans and remaining removal
sampling activities
For sites going to NPL, remedial project manager (RPM) should
be consulted
Could include sampling for long-term objectives
Si/removal assessment sampling
One event
Meet needs of both programs
See Table 4, Integrating Removal and Remedial Site
Assessment Investigations Fact Sheet, EPA 540-F-93-038,
September 1993
Fact sheet, page 6
OH* 27
Integrated Assessment Approach
Emergency site inspection/remedial investigation
Option allowing Rl to start as soon as site appears to qualify for
NPL
NPL listing needs and Rl needs can be incorporated into single
sampling plan
Fact sheet, page 6
OH* 28
4/94
Integrated Assessments
page C-15
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APPENDIX D
PA Data and Site Characteristics Form
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APPENDIX D
PA DATA AND SITE CHARACTERISTICS FORM
This form summarizes PA information and serves three functions:
Records administrative information to update and maintain CERCLIS
Records descriptive site information to update and maintain EPA's database of CERCLIS
site characteristics
Identifies and provides space to record technical data to evaluate PA sites
D-1
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OMB Approval Number: 2050-0095
Approved for Use Through: 1/92
VvEPA Potential Hazardous
Waste Site
Preliminary Assessment F
Identification
State: CERCLIS Number:
Orm CERCLIS Discovery Dale:
7. General Site Information
Ntmc: Street Address:
City: Stile:
Latitude: Longitude: Approximate Are. c
On . .. ^cr
Squ
Zip Code: County: Co. Code: Cong.
Dist:
f Site: Status of Site:
D Active D Not Specified
es D Inactive D NA (OW plume, elc.)
are Ft
2. Owner/Operator Information
Owner: Operator:
Street Address: Street Address:
City. City:
State: Zip Code: Telephone: State: Zip C
( )
Type of Ownership: How Initially I<
Q Private D County D Citizen
O Federal Agency D Municipal D PA Pe
Name D Not Specified D Slate/L
D State D Other O RCRA
Q Indian
ode: Telephone:
( )
entitled:
Complaint Q Federal Program
lition O Incidental
ocal Program O Not Specified
/CERCLA Notification D Other
3. Site Evaluator Information
Name of Evaluator: Agency/Organization:
Street Address: City
Name of EPA or Sute Agency Contact: Strce
City: State
Dale Prepared:
Slate:
t Address:
: Telephone:
( )
4. Site Disposition (for EPA use only)
Emergency Ruponse/Renioval CERCLIS Reconunendation: Signi
Assessment Recommendation: Q Higher Priority SI
D Ye» D Lower Priority SI
D No Q NFRAP Nam
Dale: D RCRA
D Other
Date: Posit
turc:
i (typed):
ion:
D-3
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Potential Hazardous Waste Site
Preliminary Assessment Form - Page 2 of 4
CERCLIS Number:
5. General Site Characteristics
Predominant Land U«ei Within 1 Mile of Site (check ill that apply):
O Industrial D Agriculture D DOI
D Commercial O Mining D Other Federal Facility
D Residential D DOD
D Forest/Fields D DOE
D Other
Site Setting:
D Urban
O Suburban
D Rural
Years of Operation:
Beginning Year _
Ending Year _
Q Unknown
Type of Site Operations (check all that apply):
D Manufacturing (must check subcalegory)
O Lumber and Wood Products
O Inorganic Chemicali
O Plastic and/or Rubber Products
O Paints, Varnishes
Q Industrial Organic Chemicals
Q Agricultural Chemicals
(e.g., pesticides, fertilizers)
O Miscellaneous Chemical Products
(e.g., adhesive*, explosives, ink)
D Primary Metals
Q MeUl Coating, Plating, Engraving
D MeUl Forging, Stamping
O Fabricated Structural Metal Products
O Electronic Equipment
D Other Manufacturing
D Mining
D Metals
D Coal
O Oil and Gas
O Non-metallic Minerals
D Retail
Q Recycling
Q Junk/Salvage Yard
D Municipal Landfill
Q Other Landfill
D DOD
D DOE
D DOI
D Other Federal Facility
D RCRA
D Treatment, Storage, or Disposal
Q Large Quantity Generator
O Small Quantity Generator
O Subtitle D
Q Municipal
D Industrial
D "Converter"
D "Protective Filer"
D "Non- or Late Filer"
D Not Specified
Q Other
Waste Generated:
O Onsite
Q Offsile
D Onsite and Offsile
Waste Deposition Authorized By:
D Present Owner
D Former Owner
D Present & Former Owner
O Unauthorized
Q Unknown
Waste Accessible to the Public:
D Yes
D No
Distance to Nearest Dwelling,
School, or Workplace:
Feet
6. Waste Characteristics Information
Source Waste Quantity:
(include units)
Source Type:
(check all that apply)
D Landfill
O Surface Impoundment
D Drums
D Tanks and Non-Drum Containers
Q Chemical Waste Pile
O Scrap MeUl or junk Pile
O Tailings Pile
O Trash Pile (open dump)
D Land Treatment
O Contaminated Ground Water Plume
(unidentified source)
D Contaminated Surface Water/Sediment
(unidentified source)
D Contaminated Soil
D Other
D No Sources
C = Constituent, W = Wastestream, V = Volume, A = Area
Tier
General Types of Waste (check all that apply)
D Metals
D Organics
D Inorganics
O Solvents
O Paints/Pigments
O Pesticides/Herbicides
O Acids/Bases
D Oily Waste
Q Municipal Waste
D Mining Waste
Q Laboratory/Hospital Waste D Explosives
D Radioactive Waste D Other
O Construction/Demolition
Waste
Physical State of Waste as Deposited (check all that
apply):
O Solid O Sludge D Powder
D Liquid O Gas
D-4
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Potential Hazardous Waste Site
Preliminary Assessment Form - Page 3 of 4
CERCLIS Number:
7. Ground Water Pathway
\) Ground Witcr Uacd Tor Drinking
Water Within 4 Miles:
D Yes
D No
Type of Drinking Water Wells
Within 4 Miles (check all thit
tpply):
D Municipal
. D Private
O None
Depth to Shallowest Aquifer:
Feel
Karat Terrain/Aquifer Present:
D Yes
D No
Is There a Suspected Release to Ground
Water:
D Yes
D No
Have Primary Target Drinking Water
Wells Been Identified:
D Yes
DNo
I/ Yes, Enter Primary Target Population:
People
Nearest Designated Wellhead Protection
Area:
O Underlies Site
D >0-4 Miles
D None Within 4 Miles
List Secondary Target Population Served by Ground Water
Withdrawn From:
0 - « Mile
> « - Vi Mile
> 'A - 1 Mile
> 1 - 2 Miles
>2-3 Miles
> 3 4 Miles
Total Within 4 Miles
5. Surface Water Pathway
Type of Surface Water Draining Site and 15 Miles Downstream (check all
that apply):
Q Stream D River D Pond D Lake
D Bay D Ocean D Other
Shortest Overland Distance From Any Source to Surface Water:
Feet
Miles
Is There a Suspected Release to Surface Water:
G Yes
D No
Site is Located in:
D Annual - 10 yr Floodplain
D > 10 yr - 100 yr Floodplain
D > 100 yr - 500 yr Floodplain
D > 500 yr Floodplain
Drinking Water Intakes Located Along the Surface Water Migration Path:
D Yes
D No
Have Primary Target Drinking Water Intakes Been Identified:
O Yes
D No
If Yes, Enter Population Served by Primary Target Intakes:
People
List All Secondary Target Drinking Water Intakes:
Name Water Body Flow (cfs) Population Served
Total within 15 Miles
Fisheries Located Along the Surface Water Migration Path:
D Yea
D No
Have Primary Target Fisheries Been Identi/ied:
D Yea
D No
List All Secondary Target Fisheries:
Water Body/Fishery Name
D-5
-------
iyCDA Potential Hazardous Waste Site - CERCLIS Number:
^^t-' » Preliminary Assessment Form - Page 4 of 4
5. Surface Water Pathway (continued)
Wetlands Located Along the Suffice Witer Migration Pith:
D Yes
D No
Hive Primary Target Wetlands Been Identified:
D Yea
D No
Lilt Secondary Target Wetlands:
Wiltr Body Flow (cfs) Frontage Miles
Other Sensitive Environments Located Along the Surface Water Migration Path:
D Yes
D No
Have Primary Target Sensitive Environments Been Identified:
Q Yes
DNo
List Secondary Target Sensitive Environment!:
Witer Body Flow (cfs) Sensitive Environment Type
9. Soil Exposure Pathway
Are People Occupying Residence) or Number of Workers Onsite: Have Terrestrial Sensitive Environments Been Identified on
Attending School or Diycare oo or Within 200 Q None or Within 200 Feet of Areas of Known or Suspected
Feel of Areas of Known or Suspected D 1 - 100 Contamination:
Contamination: D 101 - 1,000 D Yes
D Yes D > 1,000 D No
DNo
If Yes, List Each Terrestrial Sensitive Environment:
If Yes, Enter Total Resident Population:
People
10. Air Pathway
Is There a Suspected Release to Air:
Q Yes
D No
Enter Total Population on or Wilhin:
Oniile
0 - U Mile
> U - « Mile
> 1 2 Milu
> 2 3 Miles
> 3 - W - 'A Mile
D-6
U.S. GOVERNMENT PRINTING OFFICE: 1995-386-541/22018
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