^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

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Regional Center for Environmental Information
            US EPA Region III
               1650 Arch St.
           Philadelphia, PA 19103

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                                         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

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                                                                          9285 .<-27
                                                                          EPA5-  -1-94-099
                                                                          PB95-<  >:212
                                      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

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	, 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


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                               • 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
                        Section S • Reviews
                        References
                        Glossary
                        Appendixes
         PA Guidance, section 1.1
OH*1
                    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 • 8
         Notes:
Mr
page 1-4
                                                                           10/94

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                             • INTRODUCTION  •
             Superfund 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
Ust







RVF3
Record of
Decision






Remedial
Design

Remedial


                                                      OlM
                                                              Deletion
                                                                 OH* 6
10/94
Introduction
  page 1-5

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                               • INTRODUCTION •
V
/"
                           "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* 7
                              Site Assessment Goals
            Screen
                Determine the nation's priorities for remediation
            Evaluate
                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

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                              •  INTRODUCTION •
                       CERCUS
                        8KM
                                  PA
                                 Sites
                                         Sl/HRS
                                          SitM
                                                   NPL
                                                   Sites
                      Site Assessment Screening Process
         PA Guidance, section 1.3
 OH»t
                        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

• PA-,;, •;

*
HRS
SI

*

HRS
Score

        PA Guidance, sections 1.3 and 1.4
OH* 10
10/94
   Introduction
     page 1-7

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                               •  INTRODUCTION •
                        The SKe 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
SI

*

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
Scot*

      PA Guidance, section 1.3
OH* 12
                                                                           10/94
page 1-8

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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
                     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 an the foundation of MRS

               Evaluate:

                  • Waste characteristics
                  • Likelihood of release
                  • Targets
                                                                       OH* IS
                             MRS Factor Categories
               Wast*
            Characteristics
            What are the
           properties of the
             hazardous
           substances, and
          how much is likely
             to migrate?
  Likelihood
  of Release
  What is the
likelihood that a
  hazardous
 substance has
 been or will be
   released
    to the
 environment?
    Targets
 Who or what is
threatened by the
   hazardous
  substances?
                                                                       OH* 16
page 1-10
                                                                              10/94

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                              INTRODUCTION •
                   MRS Pathways and Factor Categories





we


LR


T

Waste
Characteristics
Likelihood of
Release
Targets
eLji
Ground
Water



Lr^l
Surface
Water




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

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                         ss    «  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
                                 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                                              „ t,
10/94                                                                       Introduction
                                                                             page 1-13

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                                    INTRODUCTION
                          PA Activities:  The Big Picture
                                                   Data collection
                                                   Reporting
                                                   Reconnaissance
                                                   Scoring
                                                          Typical Ranof
                                                           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
Mr
page 1-14
                                                                                  10/94

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                                 INTRODUCTION
                                  PA Strategy

               • Focus on critical factors—ones 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" factors—weigh heavily
                - No target - no site
               • A comprehensive target survey is possible at PA stage
      PA Guidance, section 1.5
                                            OH* 25
                                 PA Terminology

               • Sources
               • Suspected release vs. no suspected release
               • Primary targets vs. secondary targets
                     Yes
               J_
             Primary
             Targets
                                    Suspected
                                    Release?
1
                                       1
 Secondary
  Targets
                                                        No
Secondary
 Targets
         PA Guidance, section 1.6
                                             OH* 26
Mr
page 1-16
                                                    10/94

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                                                                                                                          8
                                GROUND WATER PATHWAY SCORESHEET
ftlAwiy CtlirtctfritticM
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 71.
   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.
                                                                        Lfl -
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, artach 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  (WHPAI: 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 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
fiub)*ct to • n
uxWnum el 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:
                                                                            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
                                       Site
                                   Racomuluanai
         PA Guidance, section 1.4, figure 1-2 (modified)
                                                    Data collection
                                                    Reporting
                                                    Reconnaissance
                                                    Scoring
TVplcal Range
 60-80 hours
 20-30 hours
 10-20 hours
  5-15 hours
                                                    AVERAGE PA = 120 hours
        OH-1
Conducting the 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
                                                                                J
                      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 th9 PA Investigation
                                                                             page 2-3

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                                                   Figure 2-1
                                       Checklist of PA Information Needs
                                           GENERAL SITE INFORMATION
           _ Site Name and Location                            O Owner/Operator Information
           1. CERCLIS ID Number                               O Operational History
           !Z! Type of Facility                                   O Environmental Setting
           d Type of Ownership                                O Approximate Size of Site
           \2 Site Status (active/inactive)                         O Latitude/Longitude
           12 Years of Operation                                D Site Sketch
                                     SOURCE AND WASTE CHARACTERISTICS
           D Source Types and Locations                        D Waste Types and Quantities
           ~1 Size of Sources (dimensions)                       O Hazardous Substances Present
                                    GROUND WATER USE AND CHARACTERISTICS
           C! General Stratigraphy and Hydrogeology              O Municipal Wells Within 4 Miles
           O Presence of Karst Terrain                               (locations, populations served,
           O Depth to Shallowest Aquifer                            blended systems)
           O Private Wells  Within 4 Miles                        D Distance to Nearest Drinking
              (locations, populations served)                         Water Well
                                                              O Wellhead Protection Areas
                                   SURFACE WATER USE AND CHARACTERISTICS
           O Flood Frequency at Site
           D Distance to Nearest Surface Water
           O Surface Water Body Types Within 16 Downstream Miles
           D Surface Water Flow Characteristics Within 15 Downstream Miles
           O Drinking  Water Intakes Within 15 Downstream Miles (locations, populations served, blended systems)
           D Fisheries Within  15 Downstream Miles
           D Sensitive Environments and Wetlands Within 15 Downstream Miles
                                         SOIL EXPOSURE CHARACTERISTICS
           D Number of People Living Within 20O 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 PATHWAY 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 tfi« 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 tfra PA (nvestyatfon
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 the 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, sections 2.5.2 end 2.5.3
OH* 10
                        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 btwUga
page 2-8
                                                                               4/94

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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


                                         9  Photodocumentation
                                         • Site sketch
                                            Logbook
                                                                  OH* 13
4/04                                                   Conducting 0i«flA(nv«*tfgaff on
                                                                      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
                   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 • 18
Conducting the 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 the PA Inwstigttlon                                                       4/94
page 2-12

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            WASTE MANAGEMENT INSPECTION REPORT
DATE
                   10   1^85"
 FACILITY    A*SC-  vA&uurn
 LOCATION
 FACILITY TYPE   VCLCuam SeTUtTlg. tf^A  dlrllUcc,
      07 OPERATION


FACILITY size   VropcrVt-y
                             4o
                                  f5
WASTE MANAGEMEliT UHIT3
WASTE TTIEJ
RCSA WASTE COOES
                                         Conducting the PA Investigation
                                                       page 2-13

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           WASTE MANAGEMENT INSPECTION REPORT - PAGE 2
WASTE QUANTITIES
           OAMTIT
             O
                                    .
                                   r«o*AeA
    NOHCOMPLIAHCB
                                   dQ
    COKKIMTS
Conducting the PA Investigation
page 2-14

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    9
    A
    2
(t> (Q

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 j3  £if"ra.-fpd \p  W-  3
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I


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ABC Vicuun SERVICE
     no-* 4° sca/e

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                           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

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                                 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 9345.1-1 1). 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.
   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

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                                 GENERAL INFORMATION
Site Description and Operational History:
Probable Substances of Concern:
(Previous investigations, analytical data)
                                                                Conducting the PA Investigation
                                                                                   page 2-21
                                           A-.1

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                               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 environments, etc.
Conducting the PA Investigation
page 2-22                                      A.4

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                            GENERAL INFORMATION (continued)
Site Sketch:
(Show all pertinent features, indicate sources and closest targets, indicate north)
                                           A-S
                                                                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

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             CASE STUDY SUPPLEMENT: ABC VACUUM SERVICE

                               WORKSHEET
Identify data gaps:
List at least eight PA site reconnaissance objectives:

1	

2	__

3	

4	
6	

7	

8	


Outline the steps necessary to obtain site access:
Conducting the PA Investigation
page2a-2

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                                    SITE SAFETY PLAN
She Name:
Site Address:
                     She 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:
Hazard evaluation: (check all that apply)

waste types:  liquid:  	   solid: 	
unknown:
              sludge:
              vapor:
waste characteristics:
              corrosive:
              toxic:	
       ignitable:
       reactive: .
              volatile: _
              unknown:
Identification of expected hazards (chemical/physical):
       reactive:
       other: _
Hazard assessment:   low _

Work tasks to be performed:
       moderate
              high
unknown
Protective equipment/clothing:
                  Respiratory     Clothing       Gloves         fififite        Modifications
                   (A.B,C,D)      (T,S,F,0)      
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                     EQUIPMENT UST: SITE RECONNAISSANCE VISIT

                            (Check off those items that apply)
Expendable Protective Equipment




butyl rubber boots (M 	 , L_
boot covers (S 	 , M 	 , L 	 ,
_, XL_)
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, XXLJ
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_J
XL_, XXL_J
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

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                      EQUIPMENT UST: SITE RECONNAISSANCE VISIT

                            (Check off those Herns that apply)
Cameras/Film






SX70 Polaroid
35mm Pentax
Kodamatic
12/24/36 print film (rolls )
12/24/36 slide film (rolls 	 )
other
Decontamination








Indian Tank
hand sprayer
eyewash bottles
scrub brushes
Alconox
buckets
paper towels
other
Tape






clear plastic
duct tape
masking tape
strapping tape/fiber tape
flagging tape
other
Surveying Equipment






optical rangefinder
Brunton compass
compass
binoculars
300-foot steel tape
wooden stakes
Hand Tools








hacksaw
bolt cutter
wire cutter
pliers
rake
shovel
trowel
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
1
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     Section 3:
ite, Source, and Waste
  Characterization

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                • 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 once—use for alt 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
Slto, SOUK*, and Mfeste Characterization
page 3-2
                                                                             4/94

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                •  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                                                 Stt», Source, and Waste Characterization
                                                                            page 3-3

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               •  SITE, SOURCE, AND WASTE CHARACTERIZATION •
                      Mini Exercise:  Defining the Site
                                                   « »  FT » »
                                                   . 3  I I « .
                                                    New
                                                 Residential
                                                 Community
             XYZ
          Corporation
CumntXYZ
property boundary
                                                                 OH* 8
Sfta, Source and Wttto Chinctorinrtton
                                                                       4/94

                            •


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                • 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                                                Sto,SouK9, and Wast* Characterization
                                                                            page 3-5

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                   SITE, SOURCE, AND WASTE CHARACTERIZATION •
                      HRS 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.
Sit* Sourer, utd W*st« Chtnctorlzrton                                                 4/94
page 3-6

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                   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/B4
                                                                              page 3-7

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                 •  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
                       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
Sfte, Source, and Waste Characterization                                                4/94
page 3-8

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                •  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, section3.2.2, page47                                  OH* 10
V	
      Notes:
4/94                                               Site, Source, tnd Mfesfa Chenctertzation
                                                                         page 3-9

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                 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
SK9, Souica, and Wuto Characterization
page 3-10
4/94

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                • 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 1b to determine WC score for site
      PA Guidance, section 3.2.2, page 47                                      OH • 12
   	
      Notes:
4/94                                                 Site, Source, MdWutoCtunctsrizatton
                                                                           page 3-11

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                •  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 squar^
        feet.

S/fe, Source, and Waste C/iaracteffzaffon                                                4/94
page 3-12

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ABC Vacuum Service
                                        Shed on
                                        top of
                                        mixing
                                        tanks
                   Drainage ditches

                   Drainage direction
                                           Warehouse complex road
                                            Not to Scale

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                                           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  of 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 1a and 1b.  Identify waste quantity tier and waste characteristics (WQ 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.
                                            Sourc* Type Description*

   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.

   Surface Impoundment: a topographic depression, excavation, or diked area, primarily formed  Irom 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).

   Drum«: 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.

   Pll«: any non-containerized  accumulation above the ground surface of solid, non-flowing wastes; includes open
   dumps. Some types of piles ere:  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 end 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 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.

   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.6

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                                       SOURCE EVALUATION
Source
  No.:
Source Name:
Source Description:
Source Waste Quantity (WO) 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

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                                 WASTE CHARACTERISTICS (WC) SCORES

    WC,  based  on waste quantity, may  be determined by  one or  alt  of  four  measures called  "tiers'-
    constituent quantity, wastestream quantity, source volume,  and source area.  PA Table  la (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 100); column 6 provides  formulas to
    obtain source waste quantity (WQ) values at sites  with multiple sources.

    To dale/mine WC for jrtes wHh only one source:

       1.   Identify source type /see descriptions opposite page 41.

      2.   Examine all wests quantity  data 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 lor the source.

      6.   Identify the range into which the total quantity falls for  each tier  evaluated (PA Table la).

       7.   Determine the highest WC score obtained for any tier 118,  32, or  1OO, at top of PA Table la columns 3, 4, and
           5, respectivelyl.

      8.   Use this WC score for all pathways. '

    To determine WC for sites with muHiple sources:

       J.   Identify each source type [see descriptions opposite page  4).

      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 1a 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 a/I 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 all 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 o( 32, whichever is
         greater, as the WC score for that pathway.

Site, Source, and Waste Characterization
page 3-16                                             A_8

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                              PA TABLE 1:  WASTE CHARACTERISTICS (WC) SCORES
  w
  A
  v
  o
  I
  u
  M
  E
  A
  fl
  E
  A
        SOURCE TYPE
             N/A
             N/A
Landfill

Surface
impoundment

Drums

Tanks and non-
drum containers

Contaminated soil
      Pile
      Other
Landfill

Surface
impoundment

Contaminaied soil


Pile*


Land treatment
                            PA Table  1a:  WC Secret lor Single Sourci Situ »nd FormuUi
                                             for Multiple Sourc* Site*
SINGLE SOURCE SfTES (anlgned WC «coru)
WC - IB
*\OO Ib
sSOO.OOOIb
S6.75 million rH
s25o.ooo yd'
SS.750 fr1
S250 yd1
S l.OOO dnjmi
5 50. OOO c«iloni
S6.75 million fr*
S250.OOO yd1
S6.750 ft"
S250 yd'
S8.7SO fr1
s250 yd'
S34O.OOO fr1
27.8 ecr«i
St. 300 fr*
$0.029 «cr«t
S3. 4 million fr1
S78 »c/«i
Si. 300 ft*
£0.029 4crt>
527. OOO Ir1
SO. 62 «cr«i
WC - J2
> 10O lo 10.0OO Ib
> SOO.OOO (o SO million Ib
> 6.75 million lo 675 million fr3
> 250.OOO lo 25 million yd'
> 8.750 to 875. OOO fr3
>2SO lo 25. OOO yd1
> 1 ,OOO lo 1 0O.OOO drumt
> SO. OOO 10 5 million o*"oni
> 8. 75 million lo 67S million rr"
> 25O.OOO 10 25 million yd1
>«.750 lo 675. OOO rr1
> 250 to 25.OOO yd1
>6.750 to 675.000 fr1
>25O lo 25.OOO v^3J
>3*O.OOO 10 3* million rr1
> 7.8 10 780 «cr.i
> 1.300 lo 130. OOO rr1
>0.029 10 2.9 •£'•!
> 3.4 million 10 34O million rr*
> 78 lo 7. BOO «ci«i
> 1.300 to 130. OOO fr1
>0.029 lo 2.9 «cr«t
> 27, OOO lo 2.7 million tr1
>0.02 10 62 >cr<«
WC - JOO
> 10. OOO Ib
>SO million Ib
> 675 million fr1
> 25 million yd'
>875.OOO fr"
> 25, OOO yd1
? 100. OOO dnjm«
> S million o*'loni
>875 nrvillion fr3
> 25 million ydj
> 675. OOO rr"
> 25. OOO yd1
>675.OOO fr1
> 25, OOO yd1
> 3* million fr1
> 78O »cr«i
> 130. OOO rr1
> 2.9 3*O million fr1
>7.8OO  130. OOO fr1
> 2.9 KKI
>2.7 million fr1
>62 >cr»i
                                                                                             MULTIPLE SOURCE
                                                                                                   SITES
                                                                                                Formula for
                                                                                              Auigning Source
                                                                                                WQ Valuei
                                                                                                  It)
                                                                                                Ib
                                                                                                     5.000
                                                                                               fr1 -

                                                                                                 fr1
    - 67,500
    - 2,500

     -t- 57.5
    1  •»• 2.5
                                                                                                dnjms
                                                                                                         ;o
gallons •*•  500

fr'  + 57,500
 yo0 •+• 2,500

  fr3 - 67.5
  yff> -t- 2.5

  /T1 f 57.5
  y-  13
                                                                                              acres  •*• 0.00023
                                                                                                  (V
         0. 7fl
                                                                                                      0.00023

                                                                                                     • 270
                                                                                                     •  0.0062
1 ion
       2.000 Ib - 1 yd' - 4 drumi
                       - 200 o«lloni                         '  Ui> •!•• ol Und >url>c« undti pil«. not lurttci •'•• ol Dili.

                           PA Table Ib: WC Secret for Multiple Sourci  Sites
WO Tor*/
>0 lo 100
> 1OO lo 10.0OO
> 10.0OO
WC Soon
18
32
10O
                                                                        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
         Resource*
            /
                             Ground Water Pathway
                                       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 W*t*rPtthw»y
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
                       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
            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
                      82,500
3.  Who and what are
   likely to be impacted
   by contaminated
   ground water?
                        Ground
                         Water
                        Pathway
                         Score
                                                                  OH* 5
                     Ground Water Pathway Evaluation

                   Waste characteristics (WC)
                     • Determined during source characterization
                   Likelihood of release (LR)
                     • Suspected release
                     • No suspected release
                   Targets (T)
                     • Primary targets
                     • Secondary targets
        PA Guidance, section 3.3
                                       OH* 6
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 Aquifer
                                                     22 feet -5 feet = 17 feet
     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
 feterPrfiway
    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
v	;	'
                              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
                                                                                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 Vtotw
                                                                       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
                              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 Wataf Pathway                                                               4/94
page 4-8

-------
                            GROUND WATER PATHWAY •
                             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* 16
                             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
V.

4/94
     OH* 16
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,
                 14 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 Water 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
                             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 Watar 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
         Notes:
QmundWttarPtthwty                                                             4/94
page 4-12

-------
                         GROUND WATER PATHWAY
                Mini Exercise:  Blended Municipal Well System
                             The 40-Percent Rule
                                           DW-1
                 DW-2
                                     QDW-3


                      Water from DW-1, DW-2, and DW-3
                   is blended together and serves 10,000 people
     SCENARIO
          ONE
Well
DW-1
DW-2
DW-3
Percent Contribution
30
35
35
Population Served



     SCENARIO
          TWO
Well
DW-1
DW-2
DW-3
Percent Contribution
50
20
30
Population Served



                                                              OH* 22
4/94
Ground Water Pathway
        page 4-13

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                             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
                              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
QroundWftarPitthwiy                                                              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 • 26
                               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                                                                GroundWatarPathway
                                                                             page 4-15

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                             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
                              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

  s^_            	                                                             •   -*^


Grwnd Water Pathway                                                               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
            Do you suspect a release (see Ground Water Pathway Criteria List, page 7)7
            Is the site located in karst terrain?
            Oepth to aquifer:
            Distance to the nearest drinking water well:
              Yes.
              Yes
No
No
  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.
                                                                          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 pan 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
      IU.KLIM.O.I. >a
                                                                            T -
  WASTE CHARACTERISTICS
     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 B of this factor.

     8. 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
(•ub)*ct to * maximum of
1001
Ground Water Path way
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 K milo
> K to K mile
> Vt to 1 milo
> 1 to 2 miles
> 2 to 3 milei
> 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
11
10
30
2
1
1
1
1
1
31
to
too
5
3
2
1
1
1
101
to
300
16
10
5
3
2
1
301
to
1.OOO
52
32
17
9
7
4
1.001
to
3.000
163
101
52
29
21
13
3.001
(0
10.000
521
323
167
94
68
42
10.001
to
30.000
1.633
1.012
522
294
212
131
t
30.OO1
to
IOO.OOO
5.214
3.233
1.668
939
678
417
Qrmmtmt
ttitn
IOO.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
> K to h mile
> K to 1 mile
> 1 lo 2 milai
> 2 to 3 mile*
>3 10 4 mile*
Population






Nearest Well -
Nearest
Well
(use 20
for karstl
2O
20
20
20
20
20

Population Served by Wells Within Distance Category
i
to
JO
1
1
1
1
1
1
;;
to
3O
2
1
1
1
1
1
31
to
100
5
3
3
3
3
3
101
to
300
16
10
8
8
8
8
307
to
1.0OO
52
32
26
26
26
26
1.001
to
3.000
163
101
82
82
82
82
3.001
to
10.000
521
323
261
261
261
261
10.001
to
30. OOO
1.633
1.012
816
816
816
816
f
30.0O1
to
IOO.OOO
5.214
3.233
2.6O7
2.6O7
2.607
2.607
Orfttfr
thmn
IOO.OOO
16.325
10.121
8.162
8.162
8,162
8.162
Score —

Population
Vaiue





	


-------
                            GROUND WATER PATHWAY
         Mini Exercise:  Secondary Ground Water Target Population
         iOW-1
          10 miles torn source,
          serves 1,500 people
     DW-2
     0.0 mites from source.
     serves 842 people
                       Q DW-5
                          5.2 mites from source,
                          serves town of Baker
          Town of Bator has 3 walla
          of aqual capacity serving
          2,700 people
                                                         DW-4
                                                         2.5 miles from source,
                                                         serves town or Baker
         o DW-3
            04 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
page 4-20
                                                                             4/94

-------
                             GROUND WATER PATHWAY
                Mini Exercise:  Ground Water Target Population
            DW-3
            2.4 miles from source:
            serves 842 people
      O DW-1
        0.3 miles from source;
        serves 25 people
                                 (Contaminant plume)
                   (Not to scale)
DW-2
1.3 miles from 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
                                                                             page 4-21

-------
                     GROUND WATER PATHWAY
                     Ground Water Scoring
                                      Ground
           WC  x   LR   x  T   _  Water

                 82,500         =  Pathway
                                      Score
    Notes:
                                                   OH* 34
Ground Water Pathway                                             4/94

page 4-22

-------
                          • 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 nules)
4,000 feet
(0.76 miles)
4,000 feet
(0.76 miles)
PERCENT ANNUAL
PRODUCTION
30
35
35
Ground W*arP*hw*y
page 4-24
                                                                                  4/94

-------
ABC Vacuum Service

                                                     £; Stained soil $
                                      Oxidation
                              i—i  pads
                                       11 > i
       i \ Vw.wa
        .VvftS&VaJi
                                                   Private well

                                                   Property boundary
                              Rubbish
                                pile
                                         Not to Scale


-------
                ABC Vacuum Service
                                                  Residential
                                                    Area
  vis-
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

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       HYDROGEOLOGIC SETTING

             Atlas Parish is situated in the subtropical zone along the borders of the
       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   VV
                                                Hi. |3L  /   Jfl/ 41
                                               Tim.
 Company

 Address
               I O J**ii T<»  ^« W^H i A i
                                                    injtor Placed CaJI
                                              C Originator Received Call
                                              w.o. NO.
                                                                               ET
rftlt*
  Tickle FiJe
  Follow-Up By:
  Copy/Rout* To:
                                              Follow-Up-Acton:.
                                               Originator's Initials.
                                                                     , Ground Water Pathway
                                                                                page 4-29

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                                      GROUND WATER PATHWAY


  Ground Water Us* 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 apportionmrnt calculations lor blended supply
  systems.
Ground Water Pathway
page 4-30                                        A-10

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                               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-n

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                             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

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                              GROUND WATER PATHWAY CRITERIA LIST
                SUSPECTED RELEASE
                                                                        PRIMARY TARGETS
Y  N   U
a  o   n
s      k
ODD

a a  a
ODD

ODD

ODD
D D

•i a  a

a o  a

ODD

a D  a

a a

a a
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 e 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
ODD

ODD


ODD


ODD


ODD



ODD



ODD


D D

D 'D
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?

Ooea any naarby 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?

Does any drinking water  well  warrant
sampling?

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

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                                  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 feetl: the difference between the deepest occurrence of a hazardous
    substance and the depth of the top of.the shallowest aquifer at (or  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 Oo
    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 (WC1

    8. Waste Characteristics: Score is assigned  from page 4. However,  if you have identified any primary targe:
    for ground water, assign either the score calculated 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 100,  assign  TOO.
Ground Water Pathway
page 4-34                                           A-14

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                                GROUND WATER PATHWAY SCORESHEET
          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.
TARGETS
3. PRIMARY TARGET POPULATION: Determine the number ot 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
                                                                         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
(iub)*ct to • maximum of
100)
                                                    A-15
                   Ground Water Pathway
                                  page 4-35

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3
sr
4
PA TABLE 2: VALUES FOR SECONDARY GROUND WATER TARGET POPULATIONS




                     PA Table 2o:  Non-Karst Aquifers
Distance
from Site
0 to K mile
> X to K mile
>Vi to 1 miia
> 1 to 2 miles
> 2 lo 3 milas
> 3 to 4 milaa
Population







Nearest Well =
Nearest
Watt
Ichoose
highest)
20
18
9
S
3
2

Copulation Served by Wells Within Distance Category
i
lo
10
1
1
1
1
1
1
11
lo
30
2
1
1
1
1
1
31
to
100
5
3
2
1
1
1
101
to
300
16
10
5
3
2
1
30 1
to
1.00O
52
32
17
9
7
4
1.001
to
3.OOO
163
101
52
29
21
13
3.001
to
10.000
521
323
167
94
68
42
1O.OO1
to
3O.OOO
1,633
1.012
522
294
212
131
u-
30,001
lo
1OO.OOO
5.214
3.233
1.668
939
678
417
Q/mmtot
Ihmn
1OO.OOO
16.325
10.121
5,224
2.938
2.122
1.3O6
Score =
Population
Value








                                                   PA Table 2b: Karst Aquifers
Distance
from Site
0 to K (tula
> K lo K mila
> K to 1 mila
> 1 to 2 milaa
> 2 to 3 milaa
> 3 to 4 milaa
Population






Nearest Well -
Nearest
Wen
(use 20
for karstl
20
20
20
20
20
20

Population Served by Wells Within Distance Categor\
i
to
10
1
1
1
1
1
1
11
to
3O
2
1
1
1
1
1
31
to
too
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,OOO
163
101
82
82
82
82
3.001
to
10.000
S21
323
261
261
261
261
10.001
to
30.000
1.633
1,012
816
816
816
816
f
JO,OOT
to
1OO.OOO
5.214
3.233
2.6O7
2,607
2.607
2.6O7
Oromtof
thmn
100.000
16,325
10,121
8,162
8.162
8.162
8.162
Score -
Population
Value








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             5:
Surface Water Pathway


-------
                           •  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
V	
         Notes:
Surface Water Pathway                                                              11/94
page 5-2

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                         •  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
        PA Guidance, section 3.4
                     Surface
                      Water
                    Pathway
                      Score
                                       OHO
11/94
                                Surface Water Pathway
                                          page 5-3


-------
                           SURFACE WATER PATHWAY
                      Surface Water Pathway Evaluation
                                                      Drinking
                                                     Water Threat
                   Waste
               Characteristics
H Likelihood of  I
  Release    |
                                                         I
Human Food
Chain Threat
                                                    Environmental
                                                       Threat
         PA Guidance, section 3.4
                                    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
SurfMe Wafer Patnway
page £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, section 3.4.1                                           OH • 6
V
                            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
                                                                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:
Surffect WMtrPtt/nray
page 5-6
                                                                               11/94

-------
                               SURFACE WATER  PATHWAY CRITERIA LIST
                 SUSPECTED RELEASE
                                                                PRIMARY TARGETS
Y  N   U
ton
s      k
ODD

ODD

000

ODD

ODD

ODD


O O  O


ODD


000

ODD

0 O  O


O O  O


000


O O

O O
Is surface water nearby?

Is waste quantity particularly large?

Is ihe 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., dilch 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
O O  Q  Is any target nearby?  If yes:

          O Drinking water intake
          O Fishery
          O Sensitive environment

O O  O  Has  any intake, fishery, or recreational area
          been closed?

O O  O  Does analytical or circumstantial evidence
          suggest surface water contamination at or
          downstream of a target?

O O  O  Does any target warrant sampling?  II yes:

          O Drinking water intake
          O Fishery
          O Sensitive environment
O  O

O  0

O  O

o  a
Other criteria?
PRIMARY INTAKEIS) IDENTIFIED?

PRIMARY FISHERY(IES) 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 an
                                               additional page il 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
        	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 W*t9r Pathway                                                              11/94
page 54

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                           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
11/94
SurfK* M/ttwPMftway
           page 5-9



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                           • 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.
                              Target Distance Limit
  /
ftunoff
                     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
                                                                                  11/04
page 5-10

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                          •  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 • 16
         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
                                     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
Su/ftce Water Pathway
page 5-12
                                                                              11/94

-------
                           •  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
StirfK* W
page 5-14
                                                                              11/94

-------
                                         SURFACE WATER PATHWAY
                   LIKELIHOOD OF  RELEASE AND DRINKING WATER THREAT SCORESHEET
          Do you suspect a release (see Surface Waiei Pathway Criteria List, page 1 II?
          Distance to surface water:
          Flood frequency:
          What is the downstream distance to the nearest drinking water intake?  	
          Nearest fishery?
         Yes
                                 miles   Nearest sensitive environment?
miles
                       yr$
                                                                            miles
LIKELIHOOD  OF RELEASE
1. SUSPECTED RELEASE:  I' you suspect a release to surface water (see page 1 1|.
   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 surlace
   water and flood frequency.  Use only column B lor this pathway.
          Distance to surface water f.  2.500 feet
          Distance to surface water >  2.500 leet. and
               Site in annual or 10-year lloodplam
               Site in 100-year Moodplain
               Site in 500-year lloodplam
               v)nc ii > «j wy CQI ' 'uwyiqit t
               Site outside 500-year lloodplam
                                                     500
                                                     500
                                                     300
DRINKING WATER THREAT TARGETS
   Record the water body rype. Mow (if applicable), and number ol people served
   by each drinking water intake within the target distance limit. II there is no
   drinking water intake within the target distance limit, (actors 4. 5. and 6
   each receive zero scores.
tnttJCf N»m* W«rw AooY 7"yp*
flow Pmopt* S*rv*d
. cfs
cfs
els
   PRIMARY TARGET POPULATION: If you suspect any drinking water intake listed
   aoove has been exposed to a hazardous substance from the site Isee Surface Water
   Pathway Criteria List, page 1 1|. 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 ol people served by
   drinking water intakes that you do NOT suspect have been exposed to a hazardous
   substance from the sue. and assign the total population score from PA Table 3.

          Are any  intakes pan ol a blended  system?   Yes	   No	
          If yes. artach a page to show apportionment calculations.

6. NEAREST INTAKE: If you have identified a primary target population for the
   drinking water threat (factor *l. assign a  score of 50: otherwise, assign the
   Nearest Intake score Irom PA Table 3. If no drinking water intake  exists within
   me target distance limn, assign a score of zero.

7  RESOURCES
                                                                            T -
                                                                                               Surface Water Pathway
                                                                                                              page 5-15
                                                        A-23

-------
                             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 01                                   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, section 3.4.2, pages 103 and 104                           OH • 24
                                                                               11/94
page 5-16

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                                 SURFACE WATER PATHWAY (continued)
                               HUMAN FOOD CHAIN THREAT SCORESHEET
LIKELIHOOD OF RELEASE
Enter Surface Water Likelihood of Release score from page 12. LR -



1MD.400.JaO . 103
HUMAN FOOD CHAIN THREAT TARGETS
8. Record the water body type and (low (il applicable) for each fishery within
   the target distance limit. II there is no fishery within the target
   distance limit, assign a Tatgeis score of 0 at  the bonom of the page.
                                                               Raw
                                                                      _cfs
                                                                      _cfs
                                                                       cfs
9. PRIMARY FISHERIES: If you susoect any fishery listed above has been exposed
   to a hazardous substance from the site (see Surface Water Criteria List, page 11)
   assign a score of 300 and do not evaluate Factor  10.  List the primary fisheries:
10. SECONDARY FISHERIES

 A. II 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 susoect a release, assign a Secondary Fisheries score from the table
   below using the  lowest flow at any fisher/ within the target distance limit.
ton-Mr flow
< 10 els
10 to 100 cfs
> 100 cts. coastal
tidal waters, oceans,
or Great Lakes
£«CCVM/J/V Rthffit? Soon
210
30
12
                                                                           T  -
                                                        A-27
                                                                                                 Surface Water Pathway
                                                                                                                page 5-17

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                             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
        	J
                                     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
page 5-18

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                                  SURFACE WATER PATHWAY (continued)
                                  ENVIRONMENTAL THREAT SCORESHEET
LIKELIHOOD OF RELEASE
Enter Surface Water Likelihood of Release score from page 12. LR —
Sv,p~x^
/?•<*•••
tua
H» SutpmalmJ
*•<•«••
iM*iea_XB. IOQ
ENVIRONMENTAL THREAT TARGETS
1 1. Record the water body type and flow (if applicable) lor each surface water
    sensitive environment within the target distance limit (see PA Tables 4
    and SI.  If there is no sensitive environment within the  target distance
    lima, assign a Targets score of 0 at the bonom of the page.
&.Wn>~n.rM *,m. W.f-r t^Y TYP»
«ow
cfs
cfs
cfs
els
cfs
1 2. PfllMARY SENSITIVE ENVIRONMENTS: II you suspect any sensitive environ-
    ment listed above has been exposed to a hazardous substance from the site (see
    Surface Water Criteria List, page 1 1), assign a score of 300 and do not evaluate
    factor 13.  List the primary sensitive environments:
13. SECONDARY SENSITIVE ENVIRONMENTS: If 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 cfs or less, assign scores as follows, and do not evaluate part B of
       this factor:
Oow
cfs
els
CIS
els
cfs
Ofc/txwi WWy/if
IP A r.W. ft
x
X
X
X
X
£/rwwvn mfrt Typf «*W Wu«
If A 7"«A/«/ S tnd SI
.
-
_
_
-
Tot*





    8.  If all secondary sensitive environments are located on surface water bodies
       with flows > 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
             WCxLRx
             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:
                                                                             11/94
page 5-20

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                          • 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

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                             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.
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



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                                       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

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                              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

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                                  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

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                               SURFACE WATER PATHWAY CRITERIA LIST
                 SUSPECTEO RELEASE
Y  N   U
eon
s      k
D a  a
a a  a
a a  a
a a  a
ODD
aaa

ODD

D D  a

a D  a
c D  a
aaa

oca

c a  a

a a
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 elong the probable run-
off route?

Are bedimenis 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?
SUSPECTED RELEASE?
                                                                           PRIMARY TARGETS
Y  N   U
eon
s      k
O O  a  Is any target nearby?  If yes:

          a Drinking weler inteke
          O Fishery
          a Sensitive environment

aaa  Has  any intake, fishery, or recreational area
          been closed?

aaa  Does analytical or circumstantial evidence
          suggest surface weter contamination at or
          downstream of a target?

aaa  Does any target warrant sampling? If yes:

          a Drinking water intake
          a Fishery
          a Sensitive environment
a a
a a
a a
a a
Other criteria?
PRIMARY INTAKEIS) IDENTIFIED?

PRIMARY FISHERYIIESI IDENTIFIED?

PRIMARY SENSITIVE ENVIRONMENT(S)
IDENTIFIED?
Summarize the rationale for Suspected Release (attach an
additional page if necessary):
                                               Summarize the rationale for Primary Targets (attach an
                                               additional page il necessary):
                                                     A-21
                                                                                          Surface Water Pathway
                                                                                                        page 5-27

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         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 sue 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 tne sue (e.g.,  100-yr, 200-yr). if the sue is
      located in more than one floodplam, 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 (LR)

      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  target
      distance limit that you do not suspect have been exposed to a hazardous substance.  Use PA Table 3 (page 13)
      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
      withm 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

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                                                                                                                            12
                                         SURFACE WATER PATHWAY
                   LIKELIHOOD OF RELEASE AND DRINKING WATER THREAT SCORESHEET
          Oo you susotct a release (see Surface Water Pathway Criteria List, page Mi?
          Distance to surface water:
          Flood frequency:
          What is the downstream distance to me nearest drinking water intake? 	miles
          Nearest fishery' 	miles   Nearest sensitive environment? 	miles
Yes
         No
LIKELIHOOD OF RELEASE
 I.  SUSPECTED RELEASE:  I' you Susoect a release to surface water (see page 1 II.
    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 oaseo on distance to surface
    water and flood  frequency.  Use only column B lor this pathway.
          Distance to surlace water ^ 2.500 feet
          Distance to surface water > 2.500 ftet. and
               Sue m annual or 10-year tloodpum
               Sue in 100-year floodpiam
               Site m SOO-year
               ^nc n» jw yea' "uvjuutoiii

               Sue outsiOt 500-year (looopiain
                                                     500
                                                     500
                                                     440
                                                     300
                                                     100
DRINKING WATER THREAT TARGETS
3. Record the water body ryot, flow (if aoplicaoie). and number of people served
   Py each drinking water intake within the target distance limit.  If there is no
   onnking water intake within me target distance limit, factors 4. 5. and 6
   each receive zero scores.
Inttkm Hum*
W,itf tatty TYP* flow Poeptf Str**d
cfs
cfs
cts
   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 1II, 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
   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 part of a blended system?   Yes	  No	
          if yes. anach a page to  snow apportionment calculations.

6.  NEAREST INTAKE:  if you nave identified a primary target pdpuianon  for the
   onnking water threat (factor 4). assign a score pi SO: otherwise, assign me
   Nearest intake score Irom PA Table 3.  If no drinking water intake exists within
   me target distance limn, assign a score o' zero.

7  RESOURCES
                                                                           T -
                                                       A-23
                                                                                              Surface Water Pathway
                                                                                                              page 5-29

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  "2 «*
   Ul O
   I  A

   «•» _.
                                PA TABLE 3: VALUES FOR SECONDARY SURFACE WATER TARGET POPULATIONS
Siritc* W»tf(
Body Flow
(*•• PA Tabi» 4)
<10 cl.
10 to IOO clt
> IOO 10 l.OOO cl.
> 1.000 lo 10.0OO clt
> 10.OOO clt 01
Gieel Lakei
3 mil* Miiing Zone
Population
	
	


Nearest Intake =
Nttrtit
Intfka
(c boost
hlghait)
20
2
1
0
0
10

Population Servfd by Intakes WHhIn Flow Ctttoofy
1
t*
30
2
1
0
0
0
1
ji
la
IOO
5
1
0
0
0
3
101
lo
30O
16
2
1
0
0
8
Ml
lo
l.OOO
52
6
1
0
0
26
1.OOI
!•
J.OOO
163
16
2
1
0
82
3.001
l»
IO.OOO
521
52
5
1
0
261
10.0O1
i*
JO. 000
1.633
163
16
2
1
816
30.OO1
1*
1OO.OOO
6.214
521
52
5
1
2.607
r 00.00 1
u
30O.OOO
16,325
1.633
163
16
2
8.162
30O.OO 1
(•
l.OOO. OOO
52.136
5.214
521
52
5
26.068
QA»«tar
MM
l.OOO. OOO
163.246
16.325
1.633
163
16
81.663
Score -
PopuUHon
Vf.'iv
	
	



    s
ro
in
                                     PA TABLE 4: SURFACE WATER TYPE / FLOW CHARACTERISTICS

                           WITH DILUTION WEIGHTS FOR SECONDARY SURFACE WATER SENSITIVE ENVIRONMENTS
Typo of Surface
Watar Body Type OR
minim*! flrcam
•mall lo moderate iti*am
mod*r«t« lo Urg* «li*«m
larga ttraam lo rival
Urga river
3-mile mixing lone of
quiet /lowing etream* or riven
coailal lidal walx (haiboti.
loundi, bay*, etc.), ocaan.
or Great Lakai
Water Body
Flow
< lOcfa
10 10 100 cl.
> 100 to l.OOO el*
> l.OOO to IO.OOO cl*
> 10.000 cf*

10 clt or greater

N/A

Dilution
Wtlght
1
0.1
N/A
N/A
N/A

N/A

N/A

                                                                                                                     Co

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           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).
                                                                    Surface Water Pathway
                                                                                page 5-31
                                            A-26

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                                  SURFACE WATER PATHWAY (continued)
                                HUMAN FOOD CHAIN THREAT SCORESHEET
LIKELIHOOD OF RELEASE
Enter Surface Water Likelihood of Release score from page 12. LR -
t'ttfCtf*
«*•*••

H* £M»MfW
«*••••

 HUMAN FOOD CHAIN THREAT TARGETS
    Record the water body rype 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.
                                                       Type
                                                               flaw
                                                                      _cfs
                                                                      _cfs
                                                                      _cfs
                                                                      _cts
                                                                       cfs
    PRIMARY FISHERIES:  If you susoect any fishery listed above has been exoosed
    to a hazardous substance from the site Isee Surface Water Criteria List, page 11).
    assign a score of 300 and do not evaluate Factor 10.  List the primary fisheries:
10. SECONDARY FISHERIES

 A. if you susoect 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  susoect a release, assign a Secondary Fisheries score from the table
    below using tne lowest flow at any fishery within the target distance limit.
t»...r «cw
< lOcts
5«a>fl 100 cts. coastal
tidal waters, oceans.
or Great Lakes
12
Surface Water Pathway
page 5-32
                                                        A-27

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             SURFACE WATER PATHWAY ENVIRONMENTAL THREAT SCORESHEET

Likelihood of Release (LR)

LR is the same for all surface water pathway threats. Eater 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 sue.
Use  professional judgment guided by the Surface  Water Pathway Criteria List (page 1 1) 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 witrf 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 lengtn
       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 8 (No Suspected Release).


                                                                    Surface Water Pathway
                                            A.28

-------
                                     SURFACE WATER PATHWAY (continued)
                                     ENVIRONMENTAL THREAT SCORESHEET
LIKELIHOOD OF RELEASE
Enter Surface Water Likelihood of Release score from gage 12. LR -
Sumf*al*4
£•!•*••
IMA
ft* 5<*«*o>w
**Mf.
ix*r
IP A TttiJf 41
x
X
X
X
Esnvwvn*f* Typ* *fid VtJum
IPA Tfbl»i $ *nd SI
.
.
.
.
«l
To,*





                                                                            Sum -
       B. If all secondary sensitive environments are located on surface water bodies
          with flows > 100 els. 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
StnsHlvt Envirorvntm	
Critical hatmet lor Federally designate*} endangered or threetened species
                     Assigned v»lu
Manna Sanctuary
National Park
Designated Federal Wildarnaai Araa
Ecologically important araaa identified under the Coastal Zone Wilderness Act
Sensitive Areee identified under tha Nauonal Estuary Program or Naar Coastal Watar Program of tha Claan Watar Act
Critical Araas Identified undar tha Claan Lakaa Program of tha Claan Watar Act Isubereas in lakes or antira small Isieel
Nauonal Monumant (air pathway only)
Nauonal Saashora Racraaoon Araa
National laksshore Racraaoon Araa
                                                                                                            100
Habitat known to ba used by Federally dastgnatad or proposed sndangared or thraatanad spaciaa
National Prasarva
Nauonal or Stala Wildlifa Refuge
Unit ol Coastal Barriar Raaourcas Systam
Federel land deeignated  for tha protaction of natural ecosystems
Administrauvaly Proposad Fadaral Wilderness Araa
Spawning araaa critical  lor tha maintananca of fish/shellfish ipacias within a rivar systam, bay, or aacuary
Migratory pathways and feeding ereas cntical lor tha maintananca of anadromoua fiah spaciaa in a rivar syatam
Tarrastnal trial uuliiad for braading by larga or dansa aggragations of vanabrata animals lair pathway) or
     sami-aguatic foragara durtaca watar pathway)
National rivar raech dasignatad as Racreational
                           75
Habitat known to ba uaad by Slata dasignatad andangaraa or tnreatanad.spacias
Habitat known to ba uaad by a apaciaa undar reviaw as to its Fadaral andangarad or thraatanad atatua
Coastal Barnar IpamaJly davalopad)
Fadarally dasignatad Scanie or Wild Rivar
                           50
Slata land daaignatad for wildlife or gome managamant
Slata dasignatad Scamc or Wild Rivar
Stata designated Natural Araa
Particular areas, relatively  small in size, important to maintenance of uniaue biotic communitiea
                            25
Slats designated areas tor protection/maintenance of aquatic lila under the Claan Water Act
Wetlands
See PA Table 6 (Surface Water Pathway!
                  or
       PA Table 9 (Air Pathway!
                                  PA TABLE 6:  SURFACE WATER PATHWAY
                                         WETLANDS FRONTAGE VALUES
Total Lgngrh of Wetlands
Lees than 0.1 mile
0.1 to 1 mile
Greater than 1 to 2 miles
Greater than 2 to 3 miles
Greater than 3 to 4 miles
Greater than 4 to 8 mile*
Greater than 8 to 1 2 miles
Greater than 1 2 10 16 rrvlei
Greater than 18 to 20 mles
Greeter than 2C miles
Assignad Valut
0
25
50
75
10O
150
250
350
450
500
                                                         A-31
                                                                                              Surface Wat«r 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)
         WAST! CHARACTERISTICS. THREAT. AND PATHWAY SCORE SUMMARY
WASTE CHARACTERISTICS
14. A. If YOU have identified any primary target for surface water (pages 12. 14,
      or 1 51, assign the waste characteristics score calculated on page 4, or a scoie
      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.
                                                               WC -
SURFACE WATER PATHWAY THREAT SCORES
Threat
Drinking Water
Human Food Chain
Environmental
Uktiihoed of
R*J***» ILK) Seer*
/from otf* 121



Ttfftu (Tl Soon
/pi?** 12. 14. 151



PttAwty w*ft*
Ctiincleniac* (WCI Soon
ld*l*finirmd itx>**>



TVirMr Soar*
LK t T * WC
/ 82.500
1 " ' 	 " "**
'"•*"" " ' 	 " " <001
1 " " ^ "" " ""
                                            SURFACE WATER PATHWAY SCORE
       (Drinking Water Threat -t-  Human Food Chain Threat -t- Environmental Threat)
                                             A-33
                                                                                Surface Water Pathway
                                                                                             page 5-37

-------
       Section 6:
Soil Exposure Pathway

            F«nc«
      Inline*
         H   H
             200 M
     I
            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
                                                                              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
SoU Exposure Ptthwty                                                             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
                                                                    OH* 3
                     Likelihood of Exposure and Targets

                                       Fence
                                  H     H
                                         200 to*
                                       XYZ
                                    Corporation
                                                                     OH* 4
4/94
                      Sotf Exposure Pitfiway
                                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
        	__	J
                            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. f                                           OH • 6
Soil Exposure PHhway                                                              4/94
page

-------
                          • 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* I
4/94
Soil Exposure Pithway
          page 6-5

-------
                            SOIL EXPOSURE PATHWAY
                             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                                          OH • 9
                             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

            Resident population is identified using the Soil Exposure Pathway
            Criteria List
                      Turn to appendix A, Soil Exposure Pathway
                              Criteria List, page A-35
      PA Guidance, section 3.5.2                                             OH • 10
Soil Exposun Pathway
page 6-6

-------
                               SOIL EXPOSURE PATHWAY CRITERIA LIST
             SUSPECTED CONTAMINATION
                                                                        RESIDENT POPULA TION
    Surficiel contamination can generally be assumed.
Y  N   U
son
9      k.
O O  G  Is any residence, school. 01 daycare (acilny on
          or within 200 laet ol an area of suspected
          contamination?

O O  G  Is any residence, school, or daycare facility
          located on adjacent land previously ownad or
          leased by the sue ownet/operetot?

O O  O  Is thare a migration route that might spread
          hazardous substances near residences,
          schools,  or daycare facilities?

G G  G  Have onsita or adjacent residents or students
          reported  adverse health effects, exclusive of
          apparent drinking water or air contamination
          problems?

GOG  Does any neighboring property warrant
          sampling?
                                                        D  G
                                                        D  O
           Other criteria?
          RESIDENT POPULATION IDENTIFIED?
Summarize the rationale for Resident Population (attach an additional page if necessary):
                                                                                         Soil Exposure Pathway
                                                                                                         page 6-7

-------



Soil Exposure Targets:
Resident Population Threat
•
:illl
/ 101

fflSt
I 150 ft
m n ^^
>>*j>j> • • •
lOOflXfc H
School
Ptaygreund
V


OH* 11
J

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
J
SoiExootunPtihww 4/94
page 6-8

-------
   PA TABLE 7:  SOIL EXPOSURE PATHWAY
TERRESTRIAL SENSITIVE ENVIRONMENT VALUES
Ttrrastrif/ StniHIv* fnvironmtrrt • Asiiqntij Vilu*
Terrestrial critical habitat lor Federally designated endangered or threatened species
National Park
Designated Federal Wilderness Area
National Monument
Terrestrial haonai known to De used by Federally designated or O'oposea threatened or enoangered species
National Preserve (terrestrial)
National or Slate terrestrial Wildlife Refuge
Federal land designated lor protection of natural ecosystems
Administratively proposed Federal Wilderness Area
Terrestrial areas utilized by large or dense aggregations of animals (vertebrate species! for breeding
Terrestrial habitat used by State designated endangered or threatened species
Terrestrial habitat used by soecies under review lor Federal designated endangered or threatened status
Stale lands 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                                     pa0e 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
Nearty 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
SoU Exposure Pathway
page 6-10
                                                                             4/94

-------
                                SOIL EXPOSURE PATHWAY SCORESHEET
'.<*-. y Ol~.er.rf.Kc.
Do any people live on or within 200 It of areas of suspected contamination?
Do any people anend school or daycare on or within 200 It of areas
of suspected contamination? •
Is the facility active? Yes No If yes. estimate Ihe number of workers:
Yes 	
Yes 	
No 	
No 	
LIKELIHOOD OF EXPOSURE
1. SUSPECTED CONTAMINATION: Surficial contamination can
and a score o< 550 assigned. Assign zero only il the absence
contamination can be confidently demonstrated.
generally be assumed.
of surficial
LE -
5U1PMTW
Corn * /TV/I* Von

RESIDENT POPULATION THREAT TARGETS
2.  RESIDENT POPULATION:  Determine the number ol people occupying residences
   or attending school or daycare on or within 200 leet of areas of suspected
   contamination (see Soil Exposure Pathway Criteria List, page 181.
                                                	people x 10  -

3.  RESIDENT INDIVIDUAL: If you have identified a resident population (factor 21,
   assign a score of SO; otherwise, assign a score of 0.

4.  WORKERS: Use the following taole to assign a score based on the total number of
   workers at the facility and nearby facilities with suspected contamination:
M/m»v at Wor*OT
0
1 to 100
101 to 1,000
> 1 .000
Scon
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:
                                                                Sum
6.  RESOURCES
                                                                 T  -
WASTE CHARACTERISTICS
RESIDENT POPULATION THREAT SCORE:
NEARBY POPULATION THREAT SCORE:
LE  X T  X  WC
    82.500.
SOIL EXPOSURE PATHWAY SCORE:
Resident Population Threat  - Nearby Population Threat
7.
Assign the waste characteristics score calculated on page «.
WC -
not. n. • • *
                                               A-37
                                                                               Soil 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
                                                    ~ Lagoon c;
                                         Shed on
                                         lop of
                                         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                                Pfl9e

-------
                                 SOIL EXPOSURE PATHWAY CRITERIA  LIST
              SUSPECTED CONTAMINA TION
                                                                          RESIDENT PQPULA TION
      Surficial contamination can generally be assumed.
                                                           Y  N
                                                           e   o
                                                           s
                                                           n  a
D D


D D


D D



D D

D D

D a
u
n
k
G  Is eny residence, school, or daycare facility on
    or within 200 feet of an erea of suspected
    contamination?

G  Is any residence, school, or daycare facility
    located on adjacent land previously owned or
    leased by the site owner/operetor?

G  Is there a migration route that might spread
    hazardous  substances near residences.
    schools, or daycare facilities?

O  Have onsite or adjacent residents or students
    reported adverse health effects, exclusive of
    apparent drinking weter or air conteminetion
    problems?

G  Does any neighboring property warrant
    sampling?

    Other criteria?	
                                                                     RESIDENT POPULATION IDENTIFIED?
  Summarize the rationale lor 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 pan-time workers.  Note thai
evaluation of targets  is based on current site conditions.

Likelihood of Exposure  ILEI

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 furthe'
consideration, only if  there is no surficial contamination; reliable analytical data are generally necessary to make
this determination.

Resident Population Threat Targets (T)

2.  Resident Population corresponds to "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 lane
resource use on an area of suspected contamination.

Sum the target scores.

Waste Characteristics 1WC1

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 TOO.

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                               T
                           10,000 to 50,000                           2
                             >50,000                                4

Soil Exposure Pathway Score:  Sum the Resident Population Threat score and the Nearby Population Threa:
score, subject to  a maximum of  100.
                                                                                    Soil Exposure Pathway
                                                A-36

-------
                                      SOIL EXPOSURE PATHWAY SCORESHEET
        Do any people live on or within 200 It ol areas o< suspected contamination?              Yes	  No
        Do any people anend school or daycare on or within 200 It of areas
           o( suspected contamination?                                   •              Yes	  No
        Is the facility active?  Yes	  No	   H yes, estimate the number ol workers: 	
LIKELIHOOD OF EXPOSURE
1. SUSPECTED CONTAMINATION: Surticial contamination can generally be assumed.
and a score of 550 assigned. Assign zero only if the absence of surficial
contamination can be confidently demonstrated. LE -
fuipccfW
. C0/Tf«m//MOO/t

     RESIDENT POPULATION THREAT TARGETS
     2. RESIDENT POPULATION:  Determine the number o( 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; omen-vise, 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 nearby facilities with suspected contamination:
Numb* tl WankOT
0
1 to 100
101 to 1.000
Seen
0
5
10
> 1.000 | 15
     5. TERRESTRIAL SENSITIVE ENVIRONMENTS:  Use PA Table 7 to assign a value
        lor each terrestrial sensitive environment on an area of suspected
        contamination:
                                                                      .Sum
     6. RESOURCES
                                                                        T -
     WASTE CHARACTERISTICS
     RESIDENT POPULATION THREAT SCORE:
      NEARBY POPULATION THREAT SCORE:
  LE X T  X  WC
      82.500.
      SOIL EXPOSURE PATHWAY SCORE:
      Resident Population Threat * Nearby Population Threat
7. Assign the *
vane characteristics score calculated on page 4.
WC -
noo. a. • in
Soil Exposure Pathway
page 6-18
A-37

-------
   PA TABLE 7: SOIL EXPOSURE PATHWAY
TERRESTRIAL SENSITIVE .ENVIRONMENT VALUES
Ttrrtstritl Stnsrtlvt fnvironmtm • Auigned Vi/u*
Terrestrial critical natmat tor Federally designated endangered or inreatened species
National Pare.
Designated Federal Wilderness Area
National Monument
Terrestrial naoitat known to be used by Federally designated or proposed threatened or endangered species
National Preserve (terrestrial)
National or State terrestrial Wildlife Refuge
Fede'ai lana 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 f.aoitat used by species under review for Federal designated endangered or threatened status
State lands cesignated 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
of • ralMM to ilr
         Rr»
    Bum OpMDOR (OOOfB,
        . pvtteuMM)
     Waste water
       lagoon
                                             Targets)
             Cortamtwl
               i on buldngi or

      viromiMnl
(• B.. rMbtat, p«K or
 rtcTMbon in*} .,.,..--
                                        OywddtNty
                                      eondWorw nwy
                          Mine tailings
                                        blown ofMte
              vapora/Bun that an>
           Contaminated
              soils

-------
                                  • AIR PATHWAY*
              T»WMt
                Bum operation (odore,
                 «•••. pvttouMM)
                 Wi
                                     Air Pathway
                                                                   anbuMngsor
                                                                  M* onto taM
                                                    (•.». (MMMt. p»K or
                                                  DryanddMty
                                                                           OH*1
                              Air Pathway Evaluation
                  Waste
              Characteristics
 Ukelihood
of Exposure
                                                              Human
                                                             Population
                                                              Target*
                                                             S«nsitiv«
                                                            Environment
                                                              Target*
            Guidance, section 3.6
                                       OH* 2
AlrPtthwty
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
"  J
                              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
4/94                                                                       Mr Pathway
                                                                             page 7-3

-------
                                          AIR PATHWAY  CRITERIA LIST
                     SUSPECTED RELEASE
                                                                PRIMARY TARGETS
    Y  N   U
    eon
    $      k
    COG  Are odors currently reported?

    O  Q  LJ  Has release of a hazardous substance to the air
              bean directly observed?

    G  —  C  Are there reports of adverse  health effects
              (e.g., headaches, nausea, dizziness) potentially
              resulting from migration of hazardous
              substances through the air?
                                              If you suspect a release to air.  evaluate all populations and
                                              sensitive environments within 1/4 mile (including those
                                              onsite) as primary targets.
    c  a  c
    a  a
    c  G
Does analytical or circumstantial evidence
suggest a release to the air?

Other criteria?         	
              SUSPECTED RELEASE?
    Summarize the rationale for Suspected Release (attach an additional page if 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 V& mile
                 Resources
         PA Guidance, section 3.6.2
             OH* 6
                                     Air Targets:
                            Target Distance Categories
                           (Not to scale)
         PA Guidance, section 3.6.2
                                                          0   - % mile
                                                           1
                                                           2
                                                           3
-  1 mile
- 2 miles
- 3 miles
- 4 miles
             OH'6
4/94
               Mr 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 3.0.2                                           OH • 8
AlrPtthwiy
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, % mile)
         PA Guidance, section 3.6.2, page 131
 OH* 9
v.
4/94
                                     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 1/i mile
         R4 Guidance, section 3.6.2, page 132
OH* 10
   AlrPtthwty
     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 Y* 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
      Notes:
4/94
   AlrPtthwiy
     page 7-9

-------
                                   PA TABLE 8: VALUES FOR SECONDARY AIR TARGET POPULATIONS
Distance
front Site
Onaila
>0 lo X milo
>V. to K mil*
> H lo 1 m'la
> 1 lo 2 nvloi
> 2 10 3 rrvlot
> 3 lo 4 milat
Population







Nearest Individual •=
Nearest
Individual
(choose
highest)
20
20
2
1
0
0
0

Population Within Distance Category
1
i*
10
1
1
0
0
0
0
0
11
if
30
2
1
0
0
0
0
0
31
If
100
s
1
1
0
o
0
0
101
If
3OO
IB
4
\
1
0
0
0
301
If
I.OOO
52
13
3
t
1
1
0
1.001
If
3.000
103
41
9
3
1
1
1
3.OOI
It
10.OOO
521
130
28
8
3
1
10.001
If
3O.OOO
1.633
4OB
88
28
8
4
2
jo.oor
if
100.000
6.214
1.303
282
83
27
12
7
100.00 i
if
3OO.OOO
18.325
4.081
882
201
83
38
23
3OO.O0 1
ff
1.OOO.OOO
52.130
13.034
2.815
834
200
120
73
£/••(•/
CAM
l.OOO.OOO
103.240
4O.811
8.815
2.012
833
370
229
Score -
Population
Value








>
en
                 PA TABLE 9: AIR PATHWAY VALUES
                       FOR WETLAND AREA
Wetland Area
{.*•• than 1 aoa
1 to SO >ci»
Assigned Value


GronKM than SO lo 1OO aciot
Gfaalei than 10O
Giaalar lhan ISO
Ciaalai than 2OO
Giaalar lhan 3OO
Giaalai lhan 4OO
Giaaloi lhan SOO
to 150 acraa
10 20O aciai
lo 3OO acrai
lo 4OO aciaa
lo SOO aciai
aciai
0
25
75
125
175
2SO
3 SO
450
SOO
  PA TABLE 10: DISTANCE WEIGHTS AND CALCULATIONS
FOR AIR PATHWAY SECONDARY SENSITIVE ENVIRONMENTS
Distance
Oniilo
0-1/4 mi
1/4-1/2mi
Distance
Weight
0.10
0.025
0.0054
SeniHIve Environment Typ* and Value
/from PA Table 5 or 31
X
X
X
X
X
X
X
X
X
Total Environments Scorn —
Product











-------
                               AIR PATHWAY
                  Values for Secondary Target Populations
Distance
from Site
Onsite
0 to % mile
>% mile to V& mile
>V£ mile to 1 mile
>1 to 2 miles
>2 to 3 miles
>3 to 4 miles
Population Range: 1,001 to 3,000
Air
f R4 table 8)
163
41
9
3
1
1
1

Ground Water (nonkarst) 1
(PA table 2a) |
—
163
101
52
29
21
13
OH* 14

                           Likelihood of Release
                  No suspected release vs. suspected release
                             • Primary targets
                             O Secondary targets
                                                                 OH* 15
4/94
AJr Path way
  page 7-11

-------
                                             AIR PATHWAY SCORESHEET
^«CAw»y Ch*r»clmri*dc*
Oc you suspect 3 release (see Air Pathway Criteria List, page 21H
Distance to the nearest individual:
Yes 	 No
li
      LIKELIHOOD OF RELEASE
      l.  SUSPECTED RELEASE: II YOU susoect a release to air (see page 21). assign a
         score ol 550.  Use only column A lor this patnway.

      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.
      TARGETS
      3.  PRIMARY TARGET POPULATION:  Determine the number ol people subject
         to exposure from a suspected release of hazardous substances to the air.
                                                               	 peoole  x  10

      A.  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
         for tne air pathway, assign a score ol 50: 'otherwise, assign tne Nearest
         Individual score from PA Table 8.

      6.  PRIMARY SENSITIVE ENVIRONMENTS:  Sum the sensitive environment values
         (PA Table 51 and wetland acreage values IPA Taole 91 for environments subject
         to exposure from a suspected release to  the air
                         S*"vc/DV*
                                           Typ*
                                                                         VWu.
      7   SECONDARY SENSITIVE ENVIRONMENTS:  Use PA Table 10 to Determine
         the score for secondary sensitive environments.

      8.  RESOURCES
                                                                              Sum -
                                                                                T  -
      WASTE  CHARACTERISTICS
      9.  A. If you nave identified any Primary Target lor the air pathway, assign the waste
            characteristics score calculated on page 4. or a score of 32. whichever is
            GREATER; do not evaluate pan B ol this factor.

         B. If you nave NOT identified any Primary Target lor the air pathway, assign the
            waste characteristic! score calculated on  page 4
                                                                              WC
      AIR PATHWAY SCORE:
LR  x  T
                                                                           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 o
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
AlrPtthway
  page 7-13

-------
II ABC Vacuum Service
                                                           ..;>Stained soil :».
                                                           '
                                  Debris
                                     Concrete
                                      pads
                                    Warehouse
                                                Doors
                                                7 \
                                                         Private well

                                                         Property boundary
                                                       Standing
                                                       rainwater
                                   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  Z)  G  Are odors currently reported?
    C  D
    C  2
    CDC
Has release of a hazardous substance to the air
bean 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 ana
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 Characteristic
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" consioerauons.  Recotd the distance 1m teet)
from any source to the nearest  regularly occupied building.

Likelihood of Release (LRI

1. Suspected Release  Hypothesize based on professional judgment guided by tne Air Pathway Criteria List (page  21).
II you suspect a release to air. use only Column A lor this pathway and do not  evaluate (actor 2.

2. No Susp«ct»d Release:  II you do  not suspect a release, enter 500 and use only Column B for  mis pathway.

Targets 1T|

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  V. mile of  the sue are
considered primary target population. If 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 pnmery  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 m 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 eech 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) lor the closest distance  category in which you have identified a  secondary target poaulation.

6. Primary  Sensitive  Environments:  If a release is  suspected,  all sensitive environments on or within '/. mile of the site
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 '/i 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 and record the product in the far-
right column. Sum the products and enter the total as the factor  score.
8. R«sourc«: A score of 5 can generally be assigned as a default measure.  Assign zero only if there is no land resource
use within !4  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.  and WC.  Divide the product by 82.500.  Round the  result to the
 nearest integer.  II the result is greater than  100, assign  100.


                                                                                                  Air Pathway
                                                      A-42

-------
                                            AIR PATHWAY SCORESHEET
filAwiy CXirtctmrtittct
Do you suspect a release (see Air Pathway Criteria List, page 211?
Distance to the nearest individual:
Yes 	 No
M
      LIKELIHOOD OF RELEASE
      l   SUSPECTED RELEASE:  II you suspect i release to air [see page 211. assign a
         score ol 550.  Use only column A lor this pathway.

      2.  NO SUSPECTED RELEASE:  ll you do not suspect  a release to air. assign a
         score of 500.  Use only column 8 lor this pathway.
                                                                              LR -
     TARGETS
      3.  PRIMARY TARGET POPULATION:   Determine the number ol people subiect
         to exposure Irom a suspected release o> nazaraous 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. and assign the total peculation
         score using PA Table 8.

      5.  NEAREST INDIVIDUAL: II you have identified any Primary Target Population
         for the air pathway, assign a score ol 50: otherwise, assign the Nearest
         Individual score from PA Table 8.

      S.  PRIMARY SENSITIVE ENVIRONMENTS: Sum the sensitive environment values
         (PA Table 51 and wetland acreage values IPA Table 91 lor environments  subiect
         to exposure Irom a suspected release to me air.
                                           Typ*
                                                                              Sum
      7   SECONDARY SENSITIVE ENVIRONMENTS:  Use PA Table '.0 to determine
         the score tor secondary sensitive environments.

      8.  RESOURCES
                                                                               T  -
      WASTE CHARACTERISTICS
      9.  A.  II you have identified any Primary Target lor the air pathway, assign the waste-
            characteristics score calculated on page *; or a score ol 32. whichever is
            GREATER; do not evaluate pan B ol this (actor.

         B.  II you nave NOT identified any Primary Target lor the a
-------
                                    PA TABLE 8:  VALUES FOR SECONDARY AIR TARGET POPULATIONS
Dlsttnct
tram SJte
Oneile
>0 lo X mila
> K 10 K mile
> H lo 1 mile
> 1 lo 2 nuloi
> 2 lo 3 miles
> 3 lo 4 milei
Population








Nearest Individual «•
Metres t
Individual
(choose
hlghetll
20
20
2
t
O
0
0

Population Within Distance Category
i
<•
10
1
1
0
0
0
0
0
it
to
30
2
1
0
0
O
0
0
31
lo
100
5
1
1
0
0
O
0
101
lo
300
18
4
1
1
0
0
0
3OI
lo
1.OOO
52
13
3
1
1
0
1.001
to
3,OOO
163
41
9
3
1
1
1
J.oot
lo
10.000
521
130
28
8
3
1
1
10.OO1
lo
3O.OOO
I.S33
408
88
26
a
4
2
30.001
lo
1OO.OOO
6.214
1.303
282
83
27
12
7
1OO.O0 1
i»
3OO.OOO
16.325
4.081
882
261
83
38
23
30O.OO 1
to
1.OOO.OOO
62.136
13.O34
2.815
834
266
120
73
Ofooto/
1»M
t. 000.000
163.246
4O.811
8. BIS
2.612
833
376
229
Score -
Population
Value









-fc.
tn
                 PA TABLE 9: AIR PATHWAY VALUES
                        FOR WETLAND AREA
Wetland Area
L<» lh«n 1 «c<«
1 lo SO acrei
Assigned Value


denial than SO to 10O acfoi
dealer then 1OO
dealer Ihen ISO
daaloi limn 2OO
dealer than 3OO
deamr then 4OO
GIO«IOI llxn SOO
lo ISO acrea
to 20O acree
lo 3OO eoee
to 4OO acree
10 SOO acrel
acre*
0
25
75
125
175
2 SO
350
450
SOO
  PA TABLE 10: DISTANCE WEIGHTS AND CALCULATIONS
FOR AIR PATHWAY SECONDARY SENSITIVE ENVIRONMENTS
Distance
Oniile
0-1/4 mi
1/4-l/2mi
Distance
Weight
0.10
0.025
O.OOS4
Sensitive Environment Type and Value
(from PA Table S or S)
X
X
X
X
•
X
X
M
X
Total Environments Score -
Product










                                                                                                                          K.
                                                                                                                          C

-------
             Section 8:
Completing the PA Investigation
     Data
   Summary
     Form
    Narrative
    Report
     PA
  Scoresheets
Complete PA Package

-------
                      COMPLETING THE PA INVESTIGATION
                       Completing the PA Investigation
                                  Site Scoring
                                     and
                                   Summary
                                   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  2 + S2 +S2
                                     gw    tw     •     •
                      Calculate score using matrix provided in the PA
                      scoresheet (appendix A, site score calculation,
                      page A-47)
        PA Guidance, section 3.7
OH* 2
Completing the /M InvesHgeVon
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
         Notes:
4/94
Competing th* PA Invntigttion
                  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 (S0J:
SURFACE WATER PATHWAY
SCORE (S.J:
SOIL EXPOSURE PATHWAY
SCORE (S,):
AIR PATHWAY
SCORE (S.):
SITE SCORE:
\
S
.




| S^+S^+Ss'+S*'
\ 4
S2





SUMMARY
                                                                                              YES
       NO
  1.   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).
D
      B.  If yes, how many people are served by the threatened well(s)?
  2.   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).
O
D
D
D
O
Q
 3.   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).
D
D
 4.   Are there public health concerns at this site that are not addressed by PA scoring
      considerations?  If yes, explain:
        a
                                                                                Completing the PA Investigation
                                                                                                        page 8-5
                                                    A-47

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                     •  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

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                                         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

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                                     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 on site 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

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                                   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

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                       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-tips and mathematical
                     calculations
                   -  PA-print used to print scoresheets, references, and PA data
                     summary form
         PA Guidance, section 4.3                                            OH • •
         PA Guidance, section 5. f
        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
CompMng tfw «Investigation
page 8-10
                                                                              4/94

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                       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

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APPENDIX A
  Fact Sheets

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                                                                         PB93-963341
                      United States
                      Environmental Protection
                      Agency
Office of
Solid Waste and
Emergency Response
Directive 9345. M6FS
EPA540-F-93-038
September 1993
                      Integrating  Removal  and
                      Remedial  Site  Assessment
                      Investigations
  Office of Emergency and Remedial Response
  Hazardous Site Evaluation Division (5204G)
                    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
ac'"vines was introduced  in Assessing Sites Under SACM—Interim  Guidance (OSWER Publication 9203.1-051,
Vo -me 1, Number 4, December 1992). This fact sheet examines areas of duplication and key differences between
ih* ;wo types of investigations, and describes some approaches for integrating assessments. The primary audience
f >r this information is the site assessment community which includes EPA On-Scene Coordinators (OSCs) and Site
. ssessment 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.

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                 Figure 1:  Traditional Assessment Processes
                           REMOVAL PROGRAM
                       Access Whether Incident
                       Meels NCP Criteria (or a
                           Removal Action
                             YES
Prepare and Obtain Approval
  ol Action Memorandum
                                  NO
                       Terminate PA or Refer to Remedial
                          Program or Other Authorities,
                                If Appropriate
                          REMEDIAL PROGRAM
                         Removal Actions May Occur at any Stage
    Preliminary
    Assessment}
       (PA)
   Site
Inapectlonj
   (SI)
                                ESI (II necaitary)
^T
Hazard Ranking
Syitem (HRS)

— w
National
(NPL)
k

Remedial
Investigation/
Feasibility Study
(RI/FS)
— b

Record ol
Decision
(ROD)


Remedial
Design/
Remedial
Action
Site Evaluation Accomplished (SEA)
  (Site Screened Out of Process)

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INTEGRATING ASSESSMENT ACTIVITIES

While  there are differences  in  objectives between
removal   and   remedial  assessments  (i.e.,  NCR
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 assessments—telephone
and  file investigations,  site visits or PA  recons,
removal  or SI  sampling  visits—suggest  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 sites—efficient
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/Site 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 Tile 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

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                                              Figure 2:  Integrated Assessment
                                                                                                  No Further Action
                    No Further Action
                                                      Sample (Optional)
                          I
     Report
Received/Release
    Identified
Initial  Screening
 lor Emergency
   Elglblllty

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Initial Field Investigation/?A 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 (Optional)

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-Q3FS, 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  SA CM. Regional
Decision   Teams—Interim    Guidance,    OSWER
 Publication  9203.1-051,  Volume  1,  Number  5,

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                     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, OSWER
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/G 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 (Rl) early;
or combining the  Ri with the data collection needed
for listing.

ESI/RI

One option open to the RDT is  to start the Rl 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

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                  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
      MRS 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
      Cm-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  efficient
blending of similar  procedures  which  may  be
appropriate at some sites and meets the objectives and
needs of both programs.

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            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            Superfund 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) 487^650                                                     (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

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                        United States
                        Environmental Protection
                        Agency
Office of
Solid Waste and
Emergency Response
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
  Ha2ardous 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.3<4A9
Such mechanisms include matrix spikes, matrix spike
duplicates, laboratory control samples, surrogates,
blanks, laboratory  duplicates, and  quarterly  blind
performance evaluation (PE)  samples..  Surrogates
and spikes are chemically similar to the analytes of
interest   and   thus  behave  similarly  during the
analytical process.  They are  introduced or "spiked"
at a known concentration into  the  field  samples
before   analysis.     Comparison  of  the   known
concentrations of the surrogates and spikes with their
analytical results measures accuracy, and may indicate
bias caused by interferences from the sample medium
(matrix  effect).li9    Laboratory  control  samples
contain known concentrations of target analytes and
are analyzed in the same batch  as field samples.
Their  results  are   used  to  measure  laboratory
accuracy.   Blanks  are   analyzed to  detect any
extraneous contamination  introduced either in  the
field or in the laboratory.   Laboratory duplicates
consist of  one sample that undergoes two  separate
analyses; the  results are  compared  to determine
laboratory precision. Quarterly blind PE samples also
evaluate lab precision.

CLP and  other  EPA  analytical methods  include
specifications  for  acceptable  identification,  and
minimum  and maximum  percent recovery of  the
target analytes and QA/QC compounds.  Data are
validated   according  to   guidelines  which  set
performance  criteria  for instrument calibration,
analyte identification, and  identification and recovery
of  the  QA/QC compounds. J<4#   The  National
Functional Guidelines for  Data Review used in EPA
validation  were designed for data generated under the
CLP organic and inorganic analytical protocols.1'13'4
The guidelines do not preclude the validation of field
and non-CLP data;  many EPA Regions have adapted
the National Functional Guidelines for Data Review to
validate non-CLP data. Data which do not meet the

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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'"Uion.3

   •  "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. s

   •  "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 are 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  are  considered
      unreliable. *

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"-Qualified Data

It is important to understand the bias associated with
T-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 concenti ation.   However, high bias
release data and low bias background data  may be
used with factors which compensate for the variability
in the  data.   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-spccific 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
 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../ 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 (or "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 /xg/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 /xgAg CO l°w 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 /ig/kg) x (1.8) = 18 /xg/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 /xg/kg (J)  high bias
Background sample value: 15 /xgAg  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 /xg/kg) +  (1.8) =  42 /xg/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 /tg/kg (J) high bias
Background sample value: 10 /xg/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).
                                                                                                  IF

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New release sample value:
(100 jig/kg) -  (1.8)  =  56 Mg/kg (J) low bias

New background sample value:
(10 ^g/kg) x (1.8)  = 18 MgAg (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 "J"-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).  T-
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 ot
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-METHYLPHENOL
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
11809
11Q89
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
DIETHYLPHTtHALATE
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(1,2l3-CD)PYRENE
ISOPHORONE
N-NITROSO-DI-N-PROPYLAMINE
N-N1TROSOD1PHENYLAMINE (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
11

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Table 3: Factors for Pesticide/PCB Analytes (continued)
PESTIC1DE/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
ALUMINUM
ANTIMONY
ARSENIC
BARIUM
BERYLLJUM
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
IT

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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
   Organic*  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

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15

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                                      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

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                    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
  &BR&      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 emphasizes 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 rhr.miral
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

         F<;fahli<;ning 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

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   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 limit),
       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.1 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.'
   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 *

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.'
 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 fhU error.
       DELIVERED

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            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
   abUity 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 accessary 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
92&S.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). * 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 procedures'"2
Factors  which  determine  sample  similarity  include
location,  type,  depth,  medium,  sampling  method,
preservation, handling, timing, 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.&, 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
                    OCT I 3 1994

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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.2

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.&,
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).1  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
          DEL"/™'

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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.'

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  participates 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 in wind direction; this
is important when selecting sample stations.l 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 suriicial 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
          BEUVf!&£D OCT  I 3

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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. l  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.J  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 radionudides
   •  Non-ubiquitous man-made radionudides
   •  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

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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

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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 # 94-963313
United States
Environmental Protection Agency
5204G
Washington, DC 20460

$300 Penalty for Private Use

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                       United States
                       Environmental Protection
                       Agency
Office Of              Directive 9285.7-2QFS
Solid Waste and       PB94-963314
Emergency Response  EPA/540/F-94/031
                      October 1994
    &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.                                          	
Infc eduction

• hree 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 «ig^fir?nf»y above  the background level,
and the release and the hazardous substance must be at
least  partially   attributable  to   the   site   under
investigation.1-"  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
                            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 .c
   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
   BackgroundLevels, 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
                         Was the material
                            containing
                       a hazardous substance
                     observed entering or seen
                            existing in
                         the environmental
                             medium?
                              Is the concentration of a
                              hazardous substance in
                                the release sample
                                significantly above
                                   background?
                                                                                            Is the
                                                                                          hazardous
                                                                                          substance
                                                                                         attributable to
                                                                                           the site?*
 s the hazardou
   substance
  attributable to
    the site?
No observed
  release
 at the site
                                                                                         Is a portion of
                                                                                         (he significant
                                                                                           increase
                                                                                         attributable to
                                                                                           the site?
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 analysis
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
                                                    .••• ft 
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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 (^ 28.50)7 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.1  If release samples
       cannot meet the pathway constraints, do not collect samples.
       4. What an 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
radionuclides,  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]).1J

   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

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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 pathway—An
         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 participate matter
         from the pile showing the presence of
         hazardous substances will verify the
         release. u
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  1994
non-aqueous phase liquids [DNAPLs]) sink to Che 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.1-2

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. l  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  1  3  J994
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.2
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 faculties'
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.a

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
                                                   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
DELIVERED
                       OCT  1  3

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. For  documenting  an  observed release  by  chemical
 analysis, radionuclide sites are divided into three groups:

   1.      Radionudides  that  exist   naturally  and
          ubiquitous radionudides.
   2.      Man-made  radionudides  which   are   not
          ubiquitous.
   3.      External  gamma   radiation  (for  the   soil
          exposure pathway only).

 Observed releases from a combination of radionudides
 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 radionudides 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
United States
Environmental Protection Agency
5204G
Washington, DC 20460

$300 Penalty for Private Use
  DELIVERED OCT  1 3 199
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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
                    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.  l    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
                                   concentration
                              hazardous substance
                                trie source sample
                                 gnificantly abc
                                  Background?
                                                            YES
                                        NO
No ob
contam
at the

lerved NO
site
NO
                    " Direct ooservatlon does not apply to
                           tne sol I exposure pathway

                    Figure  oaaotea from reference 2 CP   553
                                                                           Is the hazardous
                                                                              substance
                                                                            attributable to
                                                                              the site?
         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).l
Sampling to Meet toe 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 dose  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. * Since surficial contamination is
not limited to soil, sampling of other surface media, such
as leacbate 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 site1
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.'
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  materialJ

(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

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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.
Inferrirg a," 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 downgradicnt 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 n 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.}

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.1
 Use of  ri
 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 01
     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 ma;

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     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.1

   •  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.J
Determine an area of observed contamination as follows:

  • Impoundment, landfill, and land treatment
    — Use the  surface area of the source w

  • 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

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         Figure 2:  Lead Concentrations in Residential Soils Related to Various Background Levels
  13'

  12'

  11

  10-


C  Q_|
          o
          o
   5-


   3-

   2-

   1 -
                                         A - Level  I  Benchmark
                                         B - 3X  Lowest Background
                                         C - 3X  Second Highest  Background
                                         0 - 3X  Highest Background
                   1  2   3  45   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 MRS 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.

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   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

Suificial 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  MRS 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.

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                                   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
United States
Environmental Protection Agency
5204G
Washington, DC 20460

$300 Penalty for Private Use

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APPENDIX B
  Acronym List
     and
   Glossary

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                                  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
DOE          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
HRS          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
       ROT          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.

    ifer:  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 salt 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 NCP 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.

NCP:  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; Tailinos 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 taroet: 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 HRS target exposed 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.

    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 HRS 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.

    SJ: 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 MRS.

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

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     Appendix C
Integrated Assessments

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                      • INTEGRATED ASSESSMENTS •
                          Lecture Overview:
                        Integrated Assessment
                   Integrated Assessments and SACM
                  Introduction to the Removal Program
                    Integrated Assessments Approach
                                                           OH«1
                        Integrated Assessments
                  Integrated Assessments and SACIVI
                   Introduction to the Removal Program
                    Integrated Assessments Approach
                                                            OH* 2
Integrated Assessments
pageC-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 S40-R-92-026, November 1992
                                                                       OH* 4
4/04
                                                                           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 Program
                       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 re/nova/ 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 ore wider revision
                                                                        OH* 9
                           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
Integnted Assessments
pageC-6
                                                                                4/94

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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?













	 ^ No release





Discovery or ^ Removal Site ^_^
Notification Evaluation





or threatened
release
w Nonfederal party
* undertaking proper
response
Removal action
fr (removal action
memo to
document a
threat)
	 ^ Remedial
^ action













OH* 12
                                                   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
       ! Assessments
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 Assossmants
           pageC-9

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                        INTEGRATED ASSESSMENTS •
                 EPA Emergency Notification Procedures
             The National Response Center (NRC; 1-600-424-8802) 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
pageC-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
V    '
                     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
                       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* 28
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
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
          pageC-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
4>EPA Potential Hazardous
Waste Site
Preliminary Assessment Form
Identification
Sute: CERCLIS Number:
CERCLIS Discovery Date:
1. General Site Information
Name: Street Address:
City: Stile: Zip Code: C
Utitude: Longitude: Approximate Are. of Site: S
0 0 Acres
' . " ' . •'
Square Fl
2. Owner/Operator Information

:ouniy: Co. Code: Cong.
Disc
latus of Site:
O Active D Not Specified
D Inactive D NA (GW plume, etc.)

Owner: Operator:
Street Address: Street Address:
City: City:
Slate: Zip Code: Telephone: State: Zip Code: Teleph
(
Type of Ownership: How Initially Identified:
O Private O County Q Citizen Complaint
D Federal Agency O Municipal O PA Petition
Name D Not Specified D State/Local Program

ane:
( )
D Federal Program
D Incidental
Q Not Specified
Q Slate D Other D RCRA/CERCLA Notification D Other
D Indian
3. Site Evaluator Information
Name of Evaluator: Agency/Organization: Due Pre
Street Address: City:
Name of EPA or Slate Agency Contact: Si/eel Address:
City: Sute: Telephoi
pared:
Slate:

ic:
( )
4. Site Disposition (for EPA use only)
Emergency Response/Removal CERCUS Recommendation: Signature:
Assessment Recommendation: D Higher Priority SI
D Yes D Lower Priority SI
D No Q NFRAP Name (typed):
Date: O RCRA
O Other
Dale: Position:

D-3

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&EPA
                  Potential Hazardous Waste  Site
                  Preliminary Assessment  Form - Page 2 of 4
                                                CERCLIS Number:
 5.  General Site  Characteristics
  Predominant Land Uses Within 1 Mile of Site (check lU thai apply):
    Q Industrial       O Agriculture    D DOI
    D Commercial     O Mining        O Other Federal Facility
    D Residential      Q DOD          	
    O Forest/Fields
                     Q DOE
                                  Q Other
                                                              Site Setting:
                                                                        D Urban
                                                                        Q Suburban
                                                                        O Rural
                                              Years of Operation:
                                                 Beginning Year _

                                                 Ending Year   _

                                                 Q Unknown
 Type of Site Operations (check all that apply):

    Q Manufacturing (must check subcategory)
           O Lumber and Wood Products
           D Inorganic Chemicals
           O Plastic and/or Rubber Products
           O Paints, Varaishe*
           O Industrial Organic Chemicals
           D Agricultural Chemicals
               (e.g., pesticides, fertilizers)
           Q Miscellaneous Chemical Products
               (e.g., adhesives, explosives, ink)
           D Primary  Metals
           O Metal Coating, Plating, Engraving
           D Metal Forging, Stamping
           D Fabricated Structural Metal Products
           O Electronic Equipment
           O Other Manufacturing
    D Mining
           D Metais
           D Coal
           D Oil and Gas
           O Non-metallic Minerals
                                                Q Retail
                                                Q Recycling
                                                D Junk/Salvage Yard
                                                Q Municipal Landfill
                                                O Other Landfill
                                                D DOD
                                                D DOE
                                                O DOI
                                                D Other Federal Facility
                                                D RCRA
                                                     Q Treatment, Storage, or Disposal
                                                     D Large Quantity Generator
                                                     O Small Quantity Generator
                                                     O Subtitle D
                                                           Q Municipal
                                                           Q Industrial
                                                         Converter"
                                                         Protective Filer"
                                                         'Non- or Late Filer"
      D
      D
      D
Q Not Specified
D Other	
                                              Waste Generated:
                                                  O Onsile
                                                  O Offsile
                                                  D Onsite and Offsile
                                               Waste Deposition Authorized By:
                                                  O Present Owner
                                                  D Former Owner
                                                  D Present & Former Owner
                                                  Q Unauthorized
                                                  Q Unknown
                                               Waste Accessible to the Public:
                                                  O Yes
                                                  Q No
Distance to Nearest Dwelling.
School, or Workplace:

                    Feet
 6.  Waste  Characteristics Information"
                                       Source Waste Quantity:
                                         (include units)
                                                                  Tier*
Source Type:
(check all that apply)

 D Landfill
 Q Surface Impoundment
 O Drums
 Q Tanks and Non-Drum Containers
 O Chemical Waste Pile
 O Scrap Metal or Junk Pile
 O Tailings Pile
 D Trash Pile (open dump)
 D Land Treatment
 Q Contaminated Ground Water Plume
     (unidentified source)
 O Contaminated Surface Water/Sediment
     (unidentified source)
 O Contaminated Soil
 D Other	
 O No Sources
               C = Constituent, W = Wasteitream,  V = Volume, A = Area
                                                                          General Types of Waste (check all that apply)
                                                                              D Metals
                                                                              O Organics
                                                                              Q Inorganics
                                                                              Q Solvents
                                                                              D Paints/Pigments
                                                     O Pesticides/Herbicides
                                                     Q Acids/Bases
                                                     D Oily Waste
                                                     Q Municipal Wisle
                                                     O Mining Waste
                                                                              O Laboratory/Hospital Waste O Explosives
                                                                              Q Radioactive Waste        D Other	
                                                                              O Construction/Demolition
                                                                                Waste
                                                                              Physical Stale of Waste as Deposited (check all that
                                                                              apply):
                                                                                        O Solid   D Sludge   O Powder
                                                                                        O 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
\i Ground Wiier Used for Drinking
Witcr Wilhin 4 Miles:
          Q Yes
          O No

Type of Drinking Wiier Wells
Wilhin 4 Milei (check «U Uut
•ppiy);
          Q Municipal
          D Priviie
          Q None
Depth to Shallowest Aquifer:

          	Feet

Kant Temin/Aquifer Present:
          CD Ye.
          D No
Is There i Suspected Release to Ground
Wiier:
          Q Yes
          D No
Hive Primary Target Drinking Wiler
WeUs Been Identified:
          D Yes
          D No
If Yes, Enter Primiry Tirgcl Populition:

          	People
Neirest Designiled Wellhead Protection
Aru:
          Q Underlies Site
          Q >0-4 Miles
          D None Wilhin 4 Miles
List Secondary Tirget Population Served by Ground Witer
Wilhdriwo From:
          0 •  U Mile

          >*- vi - 1 Mile

          > 1 - 2 Miles

          >2-3 Milei

          > 3 - 4 Milei

          Total Wilhin 4 Miles
8.  Surface  Water Pathway
Type of Suffice Witer Driining Site and IS Miles Downstream (check all
that apply):
          O Stream  D River   D Pond   Q Lake
          D Bay    D Ocean   D Other	
                                 Shortest Overland Distance From Any Source to Surface Water:

                                           	Feel

                                                     Miles
Is There a Suspected Release to Surface Water:
          D Yes
          D No
                                 Site is Located in:
                                           Q Annual - 10 yr Floodplain
                                           D > 10 yr - 100 yr Floodplain
                                           D > 100 yr - 500 yr Floodplain
                                           Q > 500 yr Floodplain
Drinking Wiier Intakes Located Along the Surface Water Migration Path:
          D Yes
          D No

Have Primary Target Drinking Water Intakes Been Identified:
          Q Yes
          D No

If Yes, Enter Population Served by Primary Target Intakes:

                    	People
                                 List All Secondary Tirget Drinking Water Intakes:
                                 Name      Water Body          Flow (cfs) Populition Served
                                                     Total within 15 Miles
Fisheries Located Along the Surface Water Migration Path:
          D Yes
          D No

Have Primary Target Fisheries Been Identified:
          D Yes
          DNo
                                 List All Secondary Target Fisheries:
                                    Water Body/Fishery Name               Flow (cfs)
                                                             D-5

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                   Potential Hazardous Waste Site
                   Preliminary Assessment Form  - Page 4 of 4
                                                                                            CERCLIS Number:
8.  Surface Water Pathway (continued)
Wetlands Located Moot U»e Surface Water Migration Path:
         O Ye.
         D No

Hive Primary Targe* Wellind! Been Identified:
         D Yea
         O No

Litt Secondary Target Wetlands:
   Wiier Body                 Flow (cfs)  Frontage Milci
             Other Sensitive Environment] Lociled Along the Surface Witer Migration Pith:
                      D Yei
                      D No

             Have Primary Target Sensitive Environment* Been Identified:
                      D Yes
                      D No

             List Secondary Target Sensitive Environments:
                Wittr Body                 Flow (cfs) Sensitive Environment Type
3. So/7 Exposure Pathway
Are People Occupying Residences or
Attending School or Daycarc on or Within 200
Feel of Areas of Known or Suspected
Contamination:
          D Yea
          DNo

If Yes, Enter ToUl Resident Population:

          	People
Number of Workers Onsite:
         D None
         O 1 - 100
         D 101 - 1,000
         O >1,000
Have Terrestrial Sensitive Environment* Been Identified on
or Within 200 Feet of Areas of Known or Suspected
Contamination:
          Q Yes
          DNo

If Yea, List Each Terrestrial Sensitive Environment:
 10. Air Pathway
Is There a Suspected Releaae to Air:
          Q Yea
          D No

Enter Total Population on or Within:

          Onsite

          0 • VI  Mile

          > « • Vi Mile

          > V» - I  Mile

          > 1 - 2 Milu

          > 2 - 3 Miles

          > 3 • 4 Miles

          Toul Within 4 Miles
            Wetlands Located Within 4 Miles of the Site:

                     D Ye»
                     DNo
            Other Sensitive Environments Located Within 4 Miles of the Site:

                     D Yei
                     DNo
            Lilt All Sensitive Environments Within V> Mile of the Site:
               Distance         Sensitive Environment Type/Wetlands Area (acres)
               Onsite

                0- U Mile

                > « - '/i Mile
                                                           D-6
                                                                       • O.S. GOVERNMENT PRINTING OFFICE: 1995-386-541/22018

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