EPA 540/G-87/006
OSWER DIRECTIVE 9355.3-03
February 1988
GUIDANCE DOCUMENT FOR PROVIDING
ALTERNATE WATER SUPPLIES
Office of Emergency and Remedial Response
U.S. Environmental Protection Agency
Washington, DC 20460
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NOTICE
The information in this document has been funded, wholly or in part, by the United States Environmental
Protection Agency under Contract No. 68-01-6939 to COM Federal Programs Corporation. It has been subject
to the Agency's peer and administrative review and has been approved for publication as an EPA document.
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FOREWORD
Section 118(a) of the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA) of
1980 was amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA) to "give a high
priority to facilities where the release of hazardous
substances or pollutants or contaminants has resulted in
the closing of drinking water wells or has contaminated a
principal drinking water supply." This guidance document
was prepared to assist Superfund contractors and on-
scene Federal, State, and local officials with the planning
and implementation of alternate water supplies at
uncontrolled hazardous waste sites. The term "alternate
water supplies" includes, but is not limited to, drinking
water and household water supplies.
Provision of an alternate water supply may be appropriate
when existing supplies are contaminated or are threatened
by contamination in the near future. The implementation of
alternate water supplies can be performed under the
removal program or the remedial program, depending on
the specific conditions of the site and whether it is on the
National Priorities List (NPL). The four implementation
options available are as follows:
1. Time-Critical Removal Actions - These actions
are performed at sites where numeric action levels
established by removal authority are exceeded or
site-specific factors indicate the presence of a
serious health threat. These actions are only taken in
cases where it is determined that action is required
within 6 months.
2. Non-Time-Critical Removal Actions - These
actions are performed at sites which meet the same
criteria as above (numeric levels exceeded or site-
specific factors) but do not require action within 6
months. These actions can be performed by
removal personnel using Emergency Response
Cleanup Services (ERCS) contractors or a site-
specific contractor. These actions may also be
performed as Expedited Response Actions (ERA).
ERAs are conducted under removal authority by
remedial contractors and personnel. ERAs are
limited to sites listed on the National Priorities List
(NPL).
3. Operable Unit Remedial Action - These actions
are performed at NPL sites where short-term
threats to the human population exist. These actions
are performed under remedial authority using an
abbreviated remedial investigation and feasibility
study (RI/FS) process and require State cost-
sharing. Operable units should be consistent with
the final remedy for the site.
4. Final Remedial Action - These actions are
performed at sites which may present a long-term
health threat but no immediate or short-term
threats. These actions are performed under the
remedial program as part of a final remedy and are
preceded by a full RI/FS.
This document provides guidance for those sites that do
not require a time-critical removal action but do require
provision of an alternate water supply as either a non-
time-critical removal action or a remedial action before
implementation of a final remedy can be achieved. Those
actions are described in items two and three above. Items
one and four are outside the scope of this guidance. The
ability to implement alternate water supplies as non-tirne
critical removal actions is subject to site-specific
considerations and available resources, particularly at
non-NPL sites. Further discussion of the appropriate
authority for proposed actions is presented in Section
3.1.5. It is important to emphasize that this guidance does
not provide direction for situations requiring an emergency
or time-critical response. Such activities should be
performed in accordance with Superfund Removal
Procedures (EPA 1987) guidance.
The guidance presented in this document was developed
using information from the National Oil and Hazardous
Substances Contingency Plan (NCP), other EPA guidance
documents, and experience gained in the implementation
of. the Superfund program.
in
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TABLE OF CONTENTS
Section Page
1.0 INTRODUCTION 1-1
2.0 APPROACH 2-1
3.0 ALTERNATE WATER SUPPLY SELECTION PROCESS 3-1
3.1 Site Characterization and Determination of Authority 3-1
3.1.1 Obtain Available Data 3-1
3.1.2 Review and Evaluate Available Data and Identify Data Gaps 3-1
3.1.3 Conduct Additional Sampling . 3-3
3.1.4 Determine Applicable or Relevant and Appropriate Requirements 3-4
3.1.5 Determine Appropriate Authority : 3-5
3.2 Determination of Response Scope 3-7
3.2.1 Evaluate Problem Extent 3-7
3.2.2 Develop Demand Requirements 3-7
3.2.3 Prepare Maps 3-9
3.2.4 Determine Appropriate Response 3-9
3.3 Preparation of Community Relations Plan 3-11
3.4 Identification, Screening and Analysis of Alternatives 3-11
3.4.1 Identify Alternatives 3-11
3.4.2 Preliminary Screening 3-16
3.4.3 Analysis of Selected Alternatives 3-16
3.4.4 Recommended Alternative 3-19
3.5 Prepare EE/CA or FS Report 3-19
3.6 Public Participation 3-19
3.7 Selection of Remedy 3-19
4.0 ALTERNATE WATER SUPPLY DESIGN AND IMPLEMENTATION 4-1
4.1 Design and Implementation Procedures 4-1
4.1.1 General Consideration 4-1
4.1.2 Treatment Processes and Facilities 4-1
4.1.3 Transmission and Distribution Facilities 4-2
4.1.4 Storage Facilities 4-2
4.2 Treatability Studies 4-2
4.2.1 Bench Scale 4-2
4.2.2 Pilot Scale 4-3
4.3 Contract Documents 4-4
4.4 Contracting Procedure 4-5
4.4.1 Lump Sum Contract 4-6
4.4.2 Unit Price Contract 4-6
4.5 Contract Provisions 4-6
4.5.1 Change Orders 4-6
4.5.2 Special Provision 4-7
5.0 POST IMPLEMENTATION ACTIVITIES 5-1
6.0 REFERENCES - - - 6-1
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APPENDIX PAGE
APPENDIX A LOCATIONS WHERE ALTERNATE SUPPLIES HAVE BEEN INSTALLED A - 1
APPENDIX B AN ANALYTICAL APPROACH TO DETERMINING A CONTAMINANT
TRANSPORT REGIME B - 1
APPENDIX C EPA AMBIENT STANDARDS AND CRITERIA C - 1
APPENDIX D INTERIM FINAL GUIDANCE ON REMOVAL ACTION
LEVELS AT CONTAMINATED DRINKING WATER SITES D - 1
APPENDIX E TREATABILITY CLASSIFICATION OF PRIORITY POLLUTANTS .. . . E-1
APPENDIX F GLOSSARY OF ACRONYMS F - 1
LIST OF FIGURES
Figure Page
1-1 Process for Selecting Alternate Water Supplies 1-2
2-1 Site Characterization and Determination of Authority 2-2
2-2 Determination of Response Scope 2-3
2-3 Screening and Analysis of Alternatives 2-4
3-1 Information Source Matrix 3-2
3-2 Availability of Usable Drinking Water Versus Time 3-8
3-3 Relation of Extreme Consumption on Maximum and Minimum Days
to the Average Daily Consumption of Potable Water 3-10
LIST OF TABLES
Table Page
3-1 Treatment Process Applicability Matrix 3-14
3-2 Example of Decision Matrix 3-20
4-1 Typical Table of Contents for Technical Specifications 4-4
VI
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ACKNOWLEDGMENTS
This document was prepared for the Office of Emergency and Remedial Response under EPA Contract 68-
01-6939 by the following individuals:
Douglas Sarno, Office of Emergency and Remedial Response, HSCD
Nancy Willis, Office of Emergency and Remedial Response, HSCD
Randall Kaltreider, Office of Emergency and Remedial Response, HSCD
Jean Schumann, Office of Emergency and Remedial Response, ERD
Karen Clark, Office of General Counsel
Dana C. Pedersen, Camp Dresser & McKee Inc.
William Swanson, Camp Dresser & McKee Inc.
Wendy L. Sydow, COM Federal Programs Corporation
Sidney F. Paige, C.C. Johnson & Malhbtra, P.C.
Steven D. Stinger, C.C. Johnson & Malhotra, P.C.
Thanks are also extended to the other EPA and COM staff who assisted in development of this guidance
document through providing technical reviews, editing, and production support.
vii
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1.0 INTRODUCTION
Non-time-critical removal actions, ERAs, and
operable unit remedial actions are used to provide
faster response than can be achieved with normal
remedial actions. In order to streamline the
implementation of an alternate water supply, first
operable unit remedial actions rely on an abbreviated
form of the remedial investigation/feasibility study
(RI/FS). For non-time-critical removal actions and
ERAs, the process used to evaluate alternatives is
referred to as the engineering evaluation/cost analysis
(EE/CA). Figure 1-1 illustrates the decision-making
process used in this guidance for determining
alternate water supply needs, screening and
evaluating alternatives, and designing and
implementing the remedy. This process uses
components of the EE/CA and RI/FS guidance
combined with knowledge of alternate water supplies
to provide the user with a complete and streamlined
approach to developing these actions in the field. This
guidance does not replace guidance on EE/CAs or
RI/FSs and should not be used as an absolute
reference.
This manual should be used in conjunction with other
EPA guidance documents, technical reports and
references. Selected applicable references are listed
below.
Superfund Amendments and Reauthorization
Act of 1986 (SARA).
Comprehensive Environmental Response,
Compensation and Liability Act of 1980
(CERCLA), 42 U.S.C. 9601-9657.
Revised National Oil and Hazardous
Substances Pollution Contingency Plan
(NCP), 40 CFR Part 300, 1985 (47 FR
31180).
Guidance Document for Remedial
Investigations under CERCLA. U.S. EPA
OERR, OWPE, OSWER EPA/540/G-85/002,
June 1985.
Superfund Remedial Design and Remedial
Action Guidance. U.S. EPA OERR, June
1986. OSWER Directive 9355.0-4A
Compendium of Field Operations Methods.
OERR, Planned August 1987. OSWER
Directive 9355.0-14
Superfund Removal Procedures, U.S. EPA
OERR, ERD. July 1987.
Engineering Evaluation/Cost Analysis
Guidance, U.S. EPA OERR, ERD. Draft, June
1987.
Guidance on Feasibility Studies under
CERCLA. U.S. EPA OSWER and ORD.
EPA/540/6-85/003. June 1985.
Community Relations in Superfund: A
Handbook. U.S. EPA, OSWER Directive
9230.0-3A. March 1986.
State Participation in the Superfund Remedial
Program, U.S. EPA, OERR, February 1984.
This manual serves as a planning and guidance tool
and should not be substituted for the services of
competent professionals.
1-1
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CHARACTERIZE
SITE; DETERMINE
RELEVANT
CRITERIA
DETERMINE
APPROPRIATE
AUTHORITY
EVALUATE SCOPE OF PROBLEM
AND DEMANDS OF THE AFFECTED
COMMUNITY; IDENTIFY
ALTERNATIVES
LIMITED
SCREENING OF
ALTERNATIVES
NO
DISCONTINUE EFFORT
OR CONSIDER ALTERNATE
WATER SUPPLY
AS PART OF
FINAL REMEDY
EVALUATE
ALTERNATIVES
TECHNICAL
ENVIRONMENTAL
PUBLIC HEALTH
COST
REGULATORY/
INSTITUTIONAL
FIGURE 1-1
PROCESS FOR SELECTING ALTERNATE WATER SUPPLIES
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2.0 APPROACH
This document provides guidance at two levels
of decision making. The first level is determining if an
alternate water supply is needed. If needed, then the
second level is selecting alternate water supplies and
implementing the selected alternative. The term
"alternate water supply" is used throughout this
document to refer to both provision of new supplies
and treatment or redistribution of existing supplies.
The term "existing water supply" is defined in this
document as any potable source, including a private
well, public wellfield, or surface supply such as a
lake, reservoir, or river, and the distribution system
which connects it with users. A water supply can
provide 200-300 gallons per day (for a small system)
up to 10-20 million gallons per day for an average
city or even more for a larger city.
This manual discusses techniques which have
been derived from removal and remedial actions
implemented under the Superfund program and
provides a systematic approach to selecting and
implementing these or other actions for sites with
contaminated water supplies. Appendix A presents a
list of sites where alternate supplies have been (or
will be) installed and identifies the type of system
selected. Based on the experience gained at these
sites, the following types of alternate drinking water
supplies have been identified and are given primary
consideration in this document:
Connection to existing public water supplies
or private supplies and distribution systems
Development of new water resources
Treatment at well head or at each point of
consumption
Oversized community storage facilities to
compensate for loss of existing system capacity
in emergency demand situations (storage will
not increase the actual capacity of the system)
Blending of new and existing water supplies
to achieve acceptable levels.
Figures 2-1, 2-2, and 2-3 illustrate the
detailed methodology developed for selecting
alternate water supplies. Figure 2-1 illustrates the
decision components corresponding to site
characterization and determination of response
authority. Figure 2-2 illustrates the components
corresponding to the determination of response
scope. Finally, Figure 2-3 provides the components
of the identification, screening, and analysis of
alternatives.
A detailed discussion on the decision process is
presented in Section 3.0. Once this process is
completed and an alternate water supply is selected,
the selected alternative will be designed and
implemented. This design and implementation
process is discussed in Section 4.0.
2-1
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to
DETERMINE
NEED FOR
ADOmONAL
DATA
DISCONTINUE EFFORT
TABULATE TYPES,
CONCENTRATIONS
FOUND IN OR NEAR
WATER SUPPLY
REMEDIAL PROGRAMS
DO
ANY SITE
SPECIFIC FACTORS
PRESENT A SERIOUS
HEALTH
THREAT?1
CURRENT
CONTAMINATION
EXCEED NUMERIC
ACTION LEVEL FO
REMOVALS
DO
CURRENT OR
EXPECTED VALUES
EXCEED MCL'S?
DOES RISK
ASSESSEMENT INDICATE
UNACCEPTABLE RISK
POPULATIONS
USING SITE-SPECIFIC
FACTORS AS DISCUSSED
PERFORM AS
FIRST OPERABLE
UNIT REMEDIAL
ACTION
DOES
RISK
ASSESSMENT INDICATE THAT
A SERIOUS THREAT
EXISTS?
WILL
ACTION MEET
REMOVAL COST/TIME
RESTRICTIONS OR
QUALIFY FOR
AIVER
PROCEED
DETERMINATION OF
RESPONSE SCOPE
IS
ACTION
REQUIRED
WITHIN 6
MONTHS?
AS NON TIME-CRITICAL
DRINKING WATER ACTION LEVELS DESCRIBED IN APPENDIX D
OUT OF THE SCOPE OF THIS DOCUMENT
Figure 2-1
Site Characterization And Determination Of Authority
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IDENTIFY THE
EXTENT OF CURRENT AND
FUTURE WATER SUPPLY
CONTAMINATION
IDENTIFY/ESTIMATE
THE DEMAND OF THE
AFFECTED COMMUNITY
PREPARE SITE MAPS
(AS APPROPRIATE)
NONNPL SITES
IS THE
UNCONTAMINATED
SUPPLY SUFFICIENT TO MEET
DEMAND UNTIL A FINAL
REMEDY IS
PLEMENTE
9
ADJUST CURRENT
USE CHARACTERISTICS
TO ELIMINATE
CONTAMINATED VOLUMES
FROM SUPPLY AND CONSIDER
ALTERNATE WATER SUPPLY
AS PART OF
FINAL REMEDY
PROCEED TO SCREENING AND
ANALYSIS OF ALTERNATIVES
©
Figure 2-2
Determination Of Response Scope
2-3
-------
DELETE
ALTERNATIVE
1
DELETE
ALTERNATIVE
i
CONSIDER
COMBINATION OF
ALTERNATIVES
i
CONSIDERACTION
IN FINAL EVALUATION
,
ARETHERE
UNCONTAMINATED
WATER SUPPUES IN OR
NEARTHE STUDY
AREA?
DELETE
ALTERNATIVE
i
DELETE
ALTERNATIVE
' i
CONSIDER
COMBINATION OF
ALTERNATIVES
CONSID
IN FINAL
1 \
DELETE
ALTERNATIVE
1
DELETE
ALTERNATIVE
1
CONSID
IN FINAL
\
COULD
USE OF
ESCONTRIBUT
TO PROVIDING
NECESSARY
LIES
ISTHERE
LAND AVAILABLE
FOR BUILDING SUCH
A STORAGE
FACILITY?
DELETE
ALTERNATIVE
i
DELETE
ALTERNATIVE
' i
CONSID
IN RNAL
\
IS
THERE ANY
COMBINATION OF
E ABOVE ALTERNA
NT TO MEET.
DEMANDS?
ARETH
ANY OTHER
AVAILABLE SOURCES
OF UNCONTAMINATED
WATER?
ARE
ANY BLENDING
COMBINATIONS
SUFFICIENTTODILUT
DES1R
LEVELS
CONDUCT ANALYSIS
OF REMAINING ALTERNATIVES
BASED ON THE FOLLOWING CRITERIA:
-COST
-TECHNICAL
-PUBLIC HEALTH
-ENVIRONMENTAL
-INSTITUTIONAL
_
FIGURE 2-3
SCREENING AND ANALYSIS OF ALTERNATIVES
2-4
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3.0 ALTERNATE WATER SUPPLY
SELECTION PROCESS
3.1 SITE CHARACTERIZATION AND
DETERMINATION OF AUTHORITY
The activities discussed in this section include
the collection and review of data to determine
the levels of contamination present and the
determination of which response authority, if
any, is appropriate. The information collected at
this stage will be used throughout the selection
and design processes to accurately define and
effectively remediate the problem.
3.1.1 OBTAIN AVAILABLE DATA
Available data are collected to define water
supply system conditions and provide a basis
for a preliminary water supply system
evaluation. Once collected and compiled,
these data will also serve as the foundation of
the data base that will eventually be
assembled for evaluation of potential
technologies and alternatives, and the design
of any removal and/or remedial actions during
the implementation phase. As part of this
activity, a brief site history should be
developed.
Information which may be needed is listed in
Figure 3-1, along with potential sources.
Although some information may need to be
collected in each area to provide an accurate,
broad perspective of site conditions, those
topics at the top of the list are more critical to
alternate water supply selection activities and
should be the focus at this stage. The On-
Scene Coordinator (OSC) or Remedial
Project Manager (RPM) will determine which
data are relevant depending on site-specific
conditions and time constraints. As another
important means of gathering information, the
OSC or RPM may want to set up personal
interviews with state or local authorities with
jurisdiction over the site as well as any public
or private water purveyors in the area. This is
particularly important because of institutional
concerns relating to water supplies.
Specific documents which may be
investigated are listed below:
Specifications, maps or other descriptions
of the water supply system in question (if
available)
Records of average, daily, monthly or
annual consumption and relationship
between demand and safe yield
Technical reports related to existing water
supply system characteristics and
contamination (including sample locations
and analytical results, if possible)
Results of previous surface and/or ground
water sampling and monitoring programs
Remedial Action Master Plan (RAMP) and
other initial planning documents (if
available, for NPL sites only)
Site history, ownership, operations, and
disposal practices (past and present) from
past owners, operators, and generators
RI/FS reports from prior site work (NPL
sites only)
Specifications or descriptions of other
uncontaminated water supply systems in
the vicinity of the study area (if present)
Listing of legal or institutional constraints
which may affect implementation of
alternative water supply options
Federal and State geological surveys
Base map of study area (could be
provided by local governmental agency)
Records from local health department
regarding complaints and testing of water
supply
Soil surveys or other published
documents such as university agricultural
extension soil data
Aerial photographs (sequential/dated).
3.1.2 REVIEW AND EVALUATE AVAILABLE
DATA AND IDENTIFY DATA GAPS
In this step, available data are summarized in
formats that will facilitate their use to meet
the objective of the project. In the process of
reviewing and evaluating the available data,
an understanding of study area conditions will
be developed and data gaps will be identified.
At this early stage it is important to compile
information which is relevant to the existing
3-1
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FIGURE 3-1
INFORMATION SOURCE MATRIX
Water Supply System Descriptions
System capacity
Contamination problems
Evaluation of water supply resource
Ease of integration with other regional supply systems
Contaminant Source
Wastes present
Quantities of each waste
Toxicity and persistence
Current contaminant migration
Othsr Regional Water Supply Systems
Distance from contaminated system
Available excess capacity
Ease of connection to contaminated supply's distribution system
Groundwater
Potential for water supply development
Flow direction and gradient
Location of recharge areas
Surface Water
Water quality, use and classification of area surface waters
Drainage area and flow potential
Potential for water supply development
Regional and Local Geology
Geologic history
Stratigraphy
Structure and characteristics of formations
Physiography/Topography
Study area slope orientation/drainage patterns
Study area topography
Soils
Soil types
Extent and thickness
Hydraulic properties
Climatology and Meteorology
Net precipitation and evapotransportation
One year 24-hour rainfall
Local temperature regime
Direction and magnitude of prevailing winds
Infiltration potential
LandUie
Study area land usa
Study area population density
Study area development density
Water Rights
Institutional and legal limitations
Local restrictions, agreements, etc.
Ecology
Ecologically sensitive areas in study area
Significant habitats in study area
Community Involvement
Community relations plan status
Level and nature of community concerns
EPA Region
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3-2
-------
water supply system, contamination problems
associated with the present system, and factors
affecting the applicability of alternate water
supply systems. The status of information on the
following areas should be determined:
Condition of currently used water supply
source including total capacity, existing
treatment facilities, contamination
problems, and potential for total or partial
rehabilitation
Condition of currently used water
distribution system including
contamination problems and potential for
connection to an alternate water supply
source
Location and present condition of
contamination source, if possible (e.g.,
are contaminants still leaving the source
and entering the water supply?)
Capabilities of other regional water supply
systems including available excess
capacity and ease of connection to the
distribution system of the contaminated
water supply system
Hydrogeology and hydrology of water
resources currently providing water
supply and those which could potentially
provide a water supply (ground water or
surface water)
Implications of continuing or discontinuing
pumping of wells in the site area on
plume movement.
Construction details of wells in the site
area (is there a potential for hydraulic
conductance between two aquifers due to
an existing well?)
Geology and soils in the study area, with
particular emphasis on areas between the
contaminant source and water supply
source.
An important part of reviewing and evaluating
the available data is an assessment of its
reliability (the extent to which the data
represent site conditions) and quality
(accuracy and precision). The dates of maps,
drawings, and plans should be checked;
sampling locations should be evaluated for
representativeness. Analytical data should be
checked, if possible, against internal
laboratory QA/QC criteria (blanks, duplicates,
spike/recovery) and the methods of sample
collection, preservation, handling, and
sampler decontamination should be examined
for conformance with quality control protocols.
If more than one laboratory tested samples
from the same location in the study area, the
results should be assessed for consistency
and variations in the identified methodology.
It may also be beneficial to examine
information relating to alternative response
actions to ensure that available data are
sufficient for the evaluation of each. Topics
for which data of questionable accuracy and
precision have been obtained may constitute
data gaps because of the lack of reliability of
the available data.
Summarizing data in graphical, tabular, or
matrix formats usually provides a convenient
means of evaluation. These formats are
compact and allow for efficient presentation,
comparison, and identification of gaps. Unless
the amount of available data is quite small,
some written documentation in the form of an
"executive summary" should also be
prepared. All summaries, whether graphical,
tabular, or written, should identify both what is
known, (e.g., conditions at the site), and what
is not known (i.e., evident data gaps).
Following identification of data gaps, an effort
should be made to evaluate the importance of
the gaps and to find additional information if it
is necessary for the decision making process.
If additional information is unavailable, study
area investigations may have to be
undertaken to provide the necessary
information, as discussed in the following
section.
3.1.3 CONDUCT ADDITIONAL SAMPLING
Due to time involved in conducting additional
sampling and analysis, existing data should
be thoroughly reviewed to determine its
sufficiency for use in evaluating the condition
of the water supply. In many cases, the
amount of available analytical data is not
sufficient for decision making. In such cases,
additional sampling will be necessary.
Whenever possible, this sampling should
include existing wells and taps in the affected
area. Screening of samples for contaminants
in the field or laboratory is an effective way to
achieve results rapidly. Obtaining full
laboratory results generally requires several
3-3
-------
weeks or more depending on the analyses
performed. However, 7-day turnaround for
analytical results is available through CLP
Special Analytical Services. For sampling of
private wells it is recommended to request
low detection levels so that values below the
Contract Required Detection Limits (CRDLs)
are reported. Designing a strategy for siting
new wells, drilling wells, sampling and
analysis will take much longer. Certain
portions of identifying and evaluating
alternatives could be conducted
simultaneously with sampling. It is important
that the need for additional sampling be
identified as early as possible in the selection
process so that the data can be collected,
analyzed, validated and interpreted with a
minimum delay.
If sampling is necessary, certain documents
must be prepared before initiating field
activities. These documents are:
Sampling and Analysis Plan (includes a
field sampling plan and a quality
assurance project plan)
Health and Safety Plan.
The required contents of these documents
may vary depending on the authority used.
Guidance on the preparation of these plans
has been published by EPA. The following
references provide further information:
U.S. EPA. Guidance Document for
Remedial Investigations under
CERCLA. OERR, OWPE, OSWER,
EPA/540/G-85/002, June 1985.
U.S. EPA. Data Quality Objectives for
Remedial Response Activities,
EPA/540/G-87/003 and EPA/540/G-
87/004, March 1987.
Sisk, S.W. NEIC Manual for Ground
Water/Subsurface Investigations at
Hazardous Waste Sites. EPA-330/9-
81-002. July 1981.
U.S. EPA. Interim Guidelines and
Specifications for Preparing Quality
Assurance Project Plans. QAMS-005/80.
Office of Research and Development.
December 1980.
U.S. EPA. Guidance for Phase I - Fluid
Quality Measurements. UIC Quality
Assurance Program, Ground Water
Protection Branch, Water Supply Branch.
July 1984.
U.S. EPA. Handbook for Sampling and
Sample Preservation of Water and
Wastewater. EPA-600/4-82-029.
September 1982.
U.S. EPA. Compendium of Field
Operation Methods, OSWER Directive
9355.0-14 Office of Emergency and
Remedial Response Planned August
1987.
U.S. EPA. Safety Manual for Hazardous
Waste Site Investigations (Draft), Office of
Occupational Investigation Center,
Denver, Colorado. 1979.
U.S. EPA. Standard Operating Safety
Guides, Office of Emergency and
Remedial Response, Washington, DC.
1984.
3.1.4 DETERMINE APPLICABLE OR
RELEVANT AND APPROPRIATE
REQUIREMENTS
Applicable or relevant and appropriate
requirements (ARARs) are determined on a
site-specific basis.
There are a number of Federal and State
standards which state specific hazard levels
for contaminants in drinking water. State laws
that are more stringent than Federal
requirements may be ARARS. Local
requirements are not potential ARARs but
may be taken into consideration. The numeric
values for the criteria discussed in this
section are presented in Appendix C.
Potentially applicable or relevant and
appropriate Federal standards are described
below.
In general, alternate water supplies are
subject to the requirements of the National
Environmental Policy Act (NEPA).
Specifically, NEPA requires the production of
an Environmental Impact Statement (EIS) and
opportunity for public comment. Only time-
critical removal actions qualify for a statutory
exemption from NEPA requirements.
However, providing alternate water supplies
as non-time-critical removal or remedial
actions may be exempt from NEPA based on
categorical exclusions. OSWER Directive No.
9318.0-05 on "Environmental Review
3-4
-------
Requirements for Removal Actions" (EPA
1987) contains more detailed guidance on the
applicability of NEPA requirements to removal
actions.
The EPA Office of Drinking Water has
developed a series of numeric Health
Advisory (HA) levels for contaminants in
drinking water. Separate levels are identified
for 1-day, 10-day, longer term, and lifetime
health advisories. The lifetime health advisory
is referred to as the drinking water equivalent
level (DWEL). Under the Safe Drinking Water
Act (SDWA) (P.L. 93-523) maximum
contaminant levels (MCLs) for public water
systems have been set for five classes of
contaminants: microbiological, turbidity,
inorganics, organics (including trihalo-
methanes) and radiological. MCLs are
enforceable standards [See EPA's Guidance
on Feasibility Studies under CERCLA (EPA
1985) for MCL calculations]. In addition to
MCLs, EPA has set maximum contaminant
level goals (MCLGs). MCLGs are health-
based goals set at levels at which no adverse
health effects may arise, with a margin of
safety. EPA has established water quality
criteria (WQC) for a number of metals and
organics, many of which are associated with
uncontrolled hazardous waste sites. In
contrast to MCLs, WQC do not establish
requirements, but instead provide guidance
on the human health effects of carcinogenic
and non-carcinogenic pollutants. WQC can
be used where;MCLs do not exist where
appropriate under the circumstances.
EPA has also developed toxicity values for
substances commonly found at Superfund
sites based on Health Effects Assessments
(HEAs). HEAs are not ARARs but are used to
establish site-specific engineering design
goals for remedial actions which involve
hazardous substances most frequently found
at CERCLA sites for which applicable or
relevant standards do not exist. Compounds
without HEAs will generally have a reference
dose which gives a maximum intake value.
A list of available drinking water standards are
presented in Appendix C. When MCLs, WQC,
HAs or HEAs are not available, contact the
Policy and Analysis Staff (PAS) of the Office
of Emergency and Remedial Response
(OERR) or the Toxics Integration Branch of
the Hazardous Site Evaluation Division at
OERR for guidance criteria or available
advisories.
3.1.5 DETERMINE APPROPRIATE
AUTHORITY
This section describes the process to be
used to determine the appropriate authority to
implement alternate water supplies. The
removal and remedial authorities use different
criteria for determining the need for action;
the application of these criteria will determine
which authority is to be used.
Removal Authority - The method used to
determine drinking water action levels for
removals is presented in Appendix D. The
removal program model includes consideration
of both numeric action levels and site-specific
factors. The numeric action level is based on
the Drinking Water Equivalent Level (DWEL)
and, for carcinogens, the 10-4 Lifetime Excess
Cancer Risk Level. Removal action can only be
taken if the numeric level is exceeded or if site
specific factors otherwise indicate that a serious
threat exists. In general, removal actions to
provide alternate water supplies can be
performed on the basis of a future threat, if it
can be determined that the numeric action level
will be exceeded within 6 months. It is important
to note that removal authority is invoked only in
cases where no other party can respond in a
timely manner. The appropriateness of using
removal authority to implement non-time
critical alternate water supplies will be judged
on a site-by-site basis, depending on the
priorities for removal resources in the region.
In general, removal actions are limited to $2
million and 12 months. Actions which will
exceed these limits may not be performed
under removal authority unless certain
findings are made by the EPA in accordance
with CERCLA 104(c), as amended by SARA.
Although performed by remedial contractors,
expedited response actions (ERAs) are
performed under removal authority and are
subject to the same requirements as all other
removal actions. These statutory limits may
be an important factor in determining whether
to use removal or remedial authority.
Responses lasting longer than 12 months and
responses to widespread areas of low-level
contamination may be too extensive for use
of removal authority and therefore, may be
more appropriately addressed by remedial
3-5
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authority. At non-NPL sites, removal
personnel should refer such sites to the
remedial program for further evaluation.
Remedial Authority - The criteria for taking
action under remedial authority are more
flexible than for removals; however, in order
to qualify for fund-financed action under
remedial authority, the site must be listed on
the National Priorities List (NPL). This is not a
constraint under removal authority. If an NPL
site does not satisfy the criteria for initiating a
removal action, it may still be possible to take
action under remedial authority. Non-NPL
sites, however, may not be considered for
action under remedial authority.
The remedial program primarily uses MCLs or
more stringent state standards where
available to determine the need for action and
these values are generally lower than the
numeric criteria under the removal authority.
In cases where these standards are not
available, remedial authority will also consider
reference doses, cancer potency factors,
MCLGs, water quality criteria, health
advisories, and state advisories. In addition,
remedial action may be taken based on the
threat of future contamination in cases where
these criteria are not yet exceeded. If potable
wells are not currently contaminated, it must
be determined if they will be threatened with
contamination before a final remedy
addressing ground water contamination can
be implemented. To make this determination,
the rate of plume movement can be
calculated (if the aquifer system is relatively
simple) using a form of Darcy's Law.
Appendix B describes the application of
Darcy's Law and an approach which can be
used to calculate ground water movement.
Sufficient data on ground water hydrology
may not be available to perform these
calculations at all sites. An easier method of
estimating future contamination and validating
results of contaminated transport modeling is
to monitor contamination levels in nearby
upgradient wells. It may be beneficial to install
new wells if suitable points do not exist. By
considering the rate of contamination increase
over time in these wells, it is possible to
estimate expected impacts on the threatened
water supply. In some cases, special
circumstances may exist where protection of
human health requires more stringent
standards than MCLs. Where multiple
contaminants or pathways of exposure
present extraordinary risks, more stringent
standards will be considered based on
appropriate risk ranges for carcinogens, levels
of quantification, and other pertinent
guidelines.
In many cases, sufficient numeric criteria are
not available and the need for remedial action
will be determined by performing a risk
assessment. As a rough estimate, the total
maximum risk that a person would incur by
drinking water contaminated with a number of
chemicals for a lifetime can be estimated by
calculating the excess carcinogenic risks
associated with each chemical and then
adding the risks together. This calculation
assumes that risks are additive and that there
are no synergistic or antagonistic effects. For
example, production wells are contaminated
with the following:
Compounds
trichloroethylene
1,1-dichloroethylene
1 ,2-dichloroethane
Concentration
15 U9/I
5 ng/l
2ng/l
10 -6 HEAorWQC
1.84iig/l
.033 jig/l
.51 iig/l
To calculate the excess cancer risk:
Trichloroethylene
X10-6=8.1X10~6
1,1 -dichloroethylene
X10~6= 151.5 X10 ~6
.033
1,2-dichloroethane
X10~6=
3.9X10
-6
0.51
TOTAL RISK =163.5X10-6 = 1.6 X 10"*
This example is presented as a possible
approach for a situation where only two or
three carcinogens are involved. For situations
involving multiple carcinogens and/or
noncarcinogens, consult the Superfund Public
Health Evaluation Manual (EPA 1986) and
3-6
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seek the assistance of a competent health
professional.
Direct ingestion is not the only pathway of
concern in providing alternate water supplies.
Other pathways such as inhaling volatile
organic compounds during showers and direct
dermal contact may also present risks. These
pathways should be investigated. Consult the
Superfund Public Health Evaluation Manual
or contact a health professional for more
information in calculating risk due to multiple
pathways of exposure.
EPA uses a risk range of 10"4 to 10'7
when determining an acceptable risk level.
For more detailed information on risk
assessment and criteria contact the Toxics
Integration Branch, OERR. For. enforcement
sites, refer to the Office of Waste Programs
Enforcement's Endangerment Assessment
Guidance (EPA 1985) as well as the SPHEM.
3.2 DETERMINATION OF RESPONSE SCOPE
Previous activities established the presence of a
health threat due to contamination of drinking
water supplies. The purpose of activities
described in this section is to determine the
extent of contamination and identify the quantity
of usable water available, if any. The volume of
usable water is compared to the demands of the
affected community to determine the need for
further action. Under both the removal and
remedial authority, the goal of cleanup will be to
achieve MCLs at the tap. In cases where MCLs
are not available, other criteria as described in
Section 3.1.5, will be used.
EE/CA and FS activities will be performed using
the available contractors under the removal and
remedial programs according to standard
contract procedures. Work will commence with
either an EE/CA approval memorandum
(removal) or an FS work plan (remedial).
3.2.1 EVALUATE PROBLEM EXTENT
The purpose of this task is to determine, over
time, how much of the water supply will be
contaminated beyond use and to what extent
good quality water will be available for use.
Determination of this information will involve
quantifying the present level of contamination
in the water supply. If ground water wells are
used, determine how many wells are
contaminated, how many wells are free from
contamination, how many have low enough
contamination for limited use, and what
quantities are available for each of these
categories.
In addition to the extent of current
contamination, the estimated levels of future
contamination need to be considered. It is
important to determine whether the amount of
available uncontaminated water will be
continually decreasing. The rate at which the
contamination will increase can be estimated
by contaminant transport modeling or
monitoring of nearby wells as discussed in
Section 3.1.5.
As a result of this task, a graph or table could
be developed to show the presently available
quantity of usable drinking water and the
expected rate of change in water quality over
time. An example is shown in Figure 3-2.
The result is a simple curve showing the
amount of usable water available over a given
period of time. By overlaying the expected
demand (as will be developed in the next
section), it is possible to estimate when the
usable supply of water will be insufficient.
This information will be critical to determining
the extent of alternate water supplies
necessary.
3.2.2 DEVELOP DEMAND REQUIREMENTS
It is important to know the quantity of water
which will have to be supplied to the affected
area and if the available usable water supply
can serve community needs. This information
will provide the basis for subsequent design
and cost criteria.
Water requirements can be calculated or
estimated based on average daily, maximum
daily, and peak hourly demand; however,
water supplies are normally sized based on
maximum instantaneous demand. These
demand estimates should not include
projection for future growth because
Superfund does not provide for the expansion
of a community and will only correct problems
within an existing system. Fire protection
provisions will comply with all Federal, State
and local fire codes. These provisions should
only require a small incremental cost, which
generally would allow for providing hydrants,
valves, and the means for providing adequate
pressure. The National Fire Protection
Association codes and Insurance Services
3-7
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USABLE
WATER
SUPPLY
(gallons)
DEMAND
I I I I ] I I
Expected Date Of
Insufficient Supply
I I I
I I I I I T
TIME (weeks)
Availability Of Usable Drinking Water Versus Time
FIGURE 3-2
3-8
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Office (ISO) rates and durations should be
considered during design. If an expanded
remedy is desired by the State or locality for
fund-financed remedial or removal actions,
the State will generally have to pay the
incremental cost and must have a defensible
basis for dividing costs; the remedy must
then be implemented as a State-lead action.
This determination should be made as early
as possible, usually prior to commencing the
EE/CA or FS. State Participation in the
Superfund Remedial Program (EPA 1984)
contains detailed information on coordinating
activities with States. Guidance for removal
sites are discussed in Appendix W, Guidance
for State Lead Removals (July 1987).
There are a number of methods which can be
used to estimate the water demand. These
include (in order of decreasing accuracy):
Obtain metered consumption data for the
community (both for residential and for
commercial/industrial) based on historical
usage
Extrapolate from data on per capita water
use rates observed by municipal supply
facilities in the general area
Estimate demand from general per capita
rates. For residential use, an average
daily consumption of 80-100 gallons per
day per capita can be used (these values
are inflated to account for system
leakage). For industrial/ commercial uses
the reader is .encouraged to interview
businesses in the area to obtain
consumption data. Commercial usage is
highly variable depending on the type of
business. If data are not available,
commercial/industrial usage can be
estimated to average 2500
gallons/connection/day.
Apply engineering judgment to estimate
demand from published water use
patterns and information on the size of
existing equipment (Figure 3-3 indicates
maximum and minimum consumption
values which can be obtained if average
daily consumption is known).
Metered consumption data is preferred
because it is the most accurate data.
However, in a small community using
individual private wells, such information may
not be available. In this situation, water use in
areas of similar development (i.e., rural,
suburban, urban) can be used to predict use
in the affected community.
3.2.3 PREPARE MAPS
In order to accurately characterize the site, it
may be beneficial to represent site conditions
using maps. In instances where little data are
available or where time is a constraint, the
development of maps may not be warranted.
They are intended only as an aid to
performing the site evaluation and remedy
selection.
Two types of maps may be useful in providing
an accurate depiction of site conditions and
the extent of contamination. Community base
maps are used to show all of the relevant
features of the study area that may affect
design and implementation of alternate water
supplies. The community base map should
show all major surface features and identify
areas of contamination. The map should show
the affected study area, including the
contaminant source and the horizontal extent
of the contaminated plume. It should also
show the relative location of potential sources
of uncontaminated water (either existing
public or private water systems and/or
uncontaminated aquifers). The needs of the
site should be considered in determining the
degree of detail that will be required and the
number and types of maps which should be
drafted. Subsurface cross-sections provide
an overview of soils and geology and a
schematic representation of the extent of
subsurface water contamination. Subsurface
maps can be developed from existing site
maps, soil and geologic publications, any
existing soil boring and monitoring well
installation reports, and analytical results of
soil sampling and ground water sampling.
3.2.4 DETERMINE
RESPONSE
APPROPRIATE
At this point the response authority has been
chosen and the health threat and amount of
contamination have been quantified. If
removal action criteria are met and removal
authority is selected to implement action at
the site, there is not a "no action" alternative.
Selection of removal authority implies that
timely response to the situation is required.
3-9
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O.I
!*....?....".?.. *.:?....? 7 a910 1S 2 2.5 3 4 5 6 7 8 9 10 15 2O 25 30 4O 5O 6O 7O8O 100'
z
o
w
o
o
>-
_l
<
Q
Ul
&
IT
U)
o
l-
<
PEAK ON MAXIMUM DAY
MAXIMUM 24 HR.
AVERAGE DAILY CONSUMPTION
MINIMUM 2* HR
EXTREME MINIMUM ON MINIMUM DAY
O.I
K>
9
8
7
5
4
3
2.5
1.5
I.O
.9
.8
7
6
,5
.4
.3
.25
.15
'4 5 6 7 8 9I° l5 22-53.4 5 6 7 8 9 10 15 20 25 30 4O 5O 60 TO 8O IOO
AVERAGE DAILY CONSUMPTION OF POTABLE WATER (MGD)
O.I
RELATION OF EXTREME CONSUMPTION ON MAXIMUM AND MINIMUM DAYS
TO THE AVERAGE DAILY CONSUMPTION OF POTABLE WATER
FIGURE 3-3
SOURCE: WPCF and ASCE, 1970
-------
Under remedial authority, however, no action
may be taken if it can be documented that
exposures to pollutants, as a result of
consuming contaminated water, does not
present a threat to public health. In cases
where pollutants are only detected in isolated
wells, an alternate water supply may not be
required. This decision will be contingent
upon the ability of the remaining supplies to
meet the community's water needs and the
assurance that these wells will not become
contaminated beyond safe use before a final
remedy can be implemented.
Even if no action with respect to alternate
water supplies is justified, other remedial
investigation and feasibility study activities
may be needed to provide long term
protection of public health. For example, other
activities being taken at the site such as
source or plume migration control may slow
or alleviate contamination of drinking water. If
an alternate water supply is necessary, the
FS should focus solely on the provision of
that water supply and not the complete
mitigation of the contaminant source.
3.3 PREPARATION OF COMMUNITY RELATIONS
PLAN
The details for producing a Community Relations
Plan (CRP) are described in Community Relations
in Superfund: A Handbook, (EPA 1986).
Preparation of the CRP will coincide with the
EE/CA or FS and should be completed prior to
release of these documents.
The CRP is the planning document for managing
the interaction between the community and the
technical aspects of the response actions at a site.
Community relations activities are an integral part
of Superfund response actions and must be closely
coordinated with all technical activities conducted
at the site. All site related activities, all statements
made to the public, and even statements not
made, have the potential to affect the technical
activities at the site and the community's
willingness to cooperate with these activities. To
expedite production of the CRP as well as to
assure consistent and clear communication with
the public and press, a community relations
coordinator should be designated. A good
community relations plan is particularly important to
work related to correcting drinking water problems
because such problems often involve significant
community interest and concern.
If a CRP has not been prepared for the entire site,
it will be necessary to prepare one which pertains
specifically to provision of an alternate water
supply. While this document is abbreviated, it must
be consistent with CERCLA community relations
policy.
3.4 IDENTIFICATION, SCREENING AND ANALYSIS
OF ALTERNATIVES
Previous efforts focused on gathering data and
assessing the existing contamination at the site.
This section describes procedures for assessing
the applicability of available alternate water supply
options to the specific set of site conditions. The
assessment includes, (1) the identification of the
alternatives, (2) preliminary screening of water
supply alternatives and (3) analysis of the
alternatives which survive the screening.
3.4.1 IDENTIFY ALTERNATIVES
While there may be other possibilities, the
following list covers the major categories of
alternatives that have survived screening at
other Superfund sites and that will be
considered in this guidance document:
No action (under remedial program only)
Connection with an existing municipal or
private supply
Develop new uncontaminated water
resources
Removal of contaminants via treatment
Oversized community storage facilities to
compensate for loss of existing system
capacity
Blending contaminated portion of water
supply with uncontaminated water
supplies to reduce contaminants to safe
levels.
In the development of each alternative, the
efficiency of the current system or a potential
existing system should be assessed. This
assessment may be available from the utility
or from previous work. In many cases,
additional capacity may be created by taking
steps to control leakage from the existing
system, thus eliminating the high costs of
implementing a new system. By such actions,
it may be possible to increase the volume of
safe water available from the current system
3-11
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or allow a neighboring system to provide the
capacity needed.
Connection To Existing Municipal Or Private
Supplies
If there is a public water supply with an
uncontaminated water supply in close
proximity, connection to the existing supply
may be a viable alternative. It is strongly
encouraged that existing supplies be used in
implementing alternate water supplies
wherever possible. In fact, some states have
coordinated Public Water Supply Master
Plans that discourage the proliferation of small
public water systems in areas where existing
systems have expansion capacity and a
willingness to service new developments.
In general, public water supplies can be
classified as publicly owned (municipally
owned) or privately owned (investor owned).
Private water suppliers are regulated by rates
and franchise (service area) in each State,
the District of Columbia, and the territories by
a Public Utility Commission (PUG). Public
water suppliers are generally not regulated by
State PUCs; in some States, if a public water
supplier sells water outside its corporate
boundaries, its rates and/or franchise areas
fall under the jurisdiction of PUCs.
Under the Safe Drinking Water Act, a
community water supply is defined as having
15 or more service connections or serving 25
or more people substantially all year long. In
general, all others are defined as non-
community water supplies. Community water
supplies are more strictly regulated under the
Safe Drinking Water Act. Non-community
water suppliers are required to monitor for
acute hazards but less frequently than
community suppliers. (For a complete
discussion, the reader should refer to 40 CFR
part 141.) Community water supplies may be
either publicly or privately owned, therefore,
the ownership of the water supply is not
relevant when classifying community or non-
community water supplies.
Depending on the type of water supply
available, a number of factors must be
considered to help determine the feasibility of
using existing sources as follows:
Connections to a Private, Community Water
Supply
The rates charged to the new homes will
be regulated by a PUC
The more complete monitoring and
reporting requirements for acute and
non-acute materials under the Safe
Drinking Water Act will be required
The water company's franchise may have
to be extended by the PUC.
Connections to a Private, Non-Community
Water Supply
The rates charged to the new houses will
be regulated by a PUC
The less stringent monitoring
requirements under the Safe Drinking
Water Act will apply (other criteria may
still be relevant and appropriate, however)
Too many new connections may cause
the non-community supplier to become
a community supplier
The water company's franchise may have
to be extended by the PUC.
Connections to a Public, Community Water
Supply
If the new connections are outside the
community's corporate boundaries, rates
may be regulated by the PUC. If the
community becomes regulated because
of the new connections, there may be
opposition from the community. A
wholesale supply arrangement where
water is supplied in bulk at the townline,
may preclude this problem. In addition,
the community may not want to extend its
system outside the corporate boundaries
because such a provision could foster
growth outside of the town, drawing
business away from the town.
If the community's rates to the new
homes would be unregulated, there is no
regulatory agency protecting the new
connections from unfair charges.
The more complete monitoring and
reporting requirements for acute and
non-acute materials under the Safe
Drinking Water Act will be required.
3-12
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Connections to a Public, Non-Community
Water Supply
If the new connections are outside the
community's corporate boundaries, rates
may be regulated by the PUC. If the
community becomes regulated because
of the new connections, there may be
opposition from the community. A
wholesale supply arrangement may
preclude this problem. The community
may not want to extend its system
outside the corporate boundaries to foster
outside growth.
If the community's rates to the new
homes would be unregulated, there is no
regulatory agency protecting the new
connections from unfair charges.
The less stringent monitoring
requirements under the Safe Drinking
Water Act will apply (other criteria may
still be relevant and appropriate,
however).
In addition to the factors presented above,
considerable institutional and political
resistence may result due to the loss of
autonomy caused by connection to another
existing supply.
Development of New Sources
New ground water sources which may be
available include shallow wells that can be
drilled upgradient of the contamination source
so that the ground water is unaffected by
pollutants from the source. Such an approach
may also serve to retard movement of the
contaminant plume downgradient of the
source if there is sufficient pumping. If an
aquifer is located below the contaminated
aquifer and is not hydraulically connected to
it, new wells can be drilled in this deeper
aquifer. It is difficult, however, to demonstrate
conclusively the absence of hydraulic
connections. Therefore, this option should
only be used in cases where no other water
supply is available. Finally, new wells can be
drilled away from the source so that, with
controls to prevent additional contaminant
migration, a safe water supply can be
guaranteed.
New surface water sources that may be
available include streams, rivers, ponds,
lakes, and reservoirs located upgradient from
this site. If these surface supply sources have
adequate watershed yield and quality, then
they may be located downgradient of the
source, provided that the surface supply is
not hydraulically connected to the
contaminated aquifer or, if downgradient, is a
safe distance from the source.
In cases where the location of the source is
unknown, it may be difficult to predict the
locations of potential water supplies and
detailed sampling and analysis may be
required.
Removal Of Contaminants Via Treatment
Depending on the contaminants present, a
treatment process can be designed to remove
contaminants and reduce levels to comply
with drinking water standards. Treatment of
contaminated water supplies is used to
provide drinkable water at the tap and not as
a source remediation. The SARA preference
for treatment in Section 121(b) is, therefore,
not a primary consideration in providing
alternate water supplies. Treatment should
generally not be selected in cases where
existing sources are available to meet the
demands of the affected community. The
treatment necessary to remove a variety of
contaminants can be complex and can involve
treatment trains consisting of various
processes in series. Processes used can be
physical, chemical, or a combination of these.
Treatment alternatives require additional
considerations to determine applicability to a
site depending on suitable space and facilities
to locate the treatment equipment.
Environmental and public health assessments
will need to be performed to assess any
potential dangers of the treatment process
itself. Many processes involve the release of
hazardous gases or vapors which must be
controlled as well as treatment media
requiring disposal as a hazardous waste.
Table 3-1 presents a matrix of potentially
applicable treatment processes for a variety
of pollutant types.
Physical Processes
Physical processes are those which separate
the contaminants from the water stream by
either applying physical forces or changing
the physical form of the contaminants. In
these processes, the chemical structure of
the contaminants remains the same, and the
3-13
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TABLE 3-1
TREATMENT PROCESS APPLICABILITY MATRIX
TREATMENT TECHNOLOGY
CHEMICAL TREATMENT
CHEMICAL OXIDATION
ALKALINE CHLORINATION
OXDATCN
CHEMICAL REDUCTION
NEUTRALIZATION
PRECIPITATION
ION EXCHANGE
WET AIR OXIDATION
PHYSICAL TREATMENT
CARBON ADSORPTION
DENSITY SEPARATION
SEDIMENTATION
FLOTATION
FILTRATION
REVERSE OSMOSIS
STRIPPING
EQUALIZATIONOETENTION
ALCOHOLS
E
E
N
G,E
N
-
X
V
V
-
ALIPHATICS
V
V
N
P
N
-
X
V
V
-
AMINES
V
V
N
N
N
-
X
V
-
AROMATICS
V
V
N
F,G
N
-
F
X
G,E
C
E
-
i
G
G
N
N
-
X
V
-
i
HALOCARBO
P
P
N
F,G
N
-
X
G,E
E
-
METALS
PiF
P.F
N
G
-
E
E
N,P
E
G
E
E
N
-
POLLUTANTTYPE
B
N
N
N
N
PHI
E
PESTICIDES
N,P
N,P
N
E
N
ONTRO
X
E
E
PHENOLS
G
G
N
E
N
X
E
V
PRETREATMENT -
PHTHALATES
G
G
N
N
-
G
X
E
-
5
POLYNUCLB
AROMATICS
N,P
N,P
N
G
N
-
R
G,E
-
CYANIDE
F,G
F.G
E
E
N
-
N
X
N
N
-
G,E
G,E
N
N
-
N
N
N
G
-
Q
j>
TOTAL DISSO
SOLIDS
N
N
N
N
.
N
E
N
N
E
N
-
s
o
TOTALSUSPE
SOLIDS
-
X
X
-
5
GREASE AND
_
X
-
KEY
E - Excellent Performance Likely
G - Good Performance Likely
F - Fair Performance Likely
P - Poor Performance Likely
SOURCE: Adapted from Shuokrow etal., 1980
R - Reported to be Removed
N-Not Applicable
V - Variable Performance Reported for Different
Compounds in the Class
X - Treatment is Applicable but not
Specified in the Source Reference
- A Blank Indicates no Data Available
-------
advantages of these systems are that the
processes are usually simple, relatively
inexpensive, and can be applied to a wide
range of wastes. Below is a summary of
these processes.
Air Stripping - a process which removes
volatile organic contaminants via mass
transfer from the water phase to the
gaseous (air) phase. This process is often
used in combination with a vapor phase
carbon system to remove the
contaminants from the air before it is
released.
Steam Stripping - a process similar to
air stripping used for less volatile
compounds where the gaseous phase is
water vapor
Activated Carbon Adsorption - a process
by which contaminated water is passed
through activated carbon and soluble
organic contaminants are removed from
the water stream by adsorption onto the
carbon
Filtration - the removal of suspended
solids from a fluid by passage through
porous media
Ion exchange - the process of
exchanging toxic ions in solution for
non-toxic ions using a solid ion
exchange resin
Membrane separation - the use of
specifically constructed membranes to
selectively reject contaminants as water
passes through the membrane
Phase Separation - physical separation
of components with a specific gravity
different from water, such as skimming oil
and grease constituents off the top or
settled solids sludge removal from the
bottom of a clarifier
Chemical Processes
Chemical treatment processes alter the
chemical structure of the contaminants to
facilitate removal of the contaminants from
the water stream. Below is a summary of
some of these processes.
Chemical reduction-oxidation (redox)
treatment - this process makes use of
oxidizing agents such as ozone, hydrogen
peroxide, or UV/ozone to induce the
oxidation of the contaminants in the water
stream and to reduce or eliminate the
toxicity of many toxic organics and heavy
metals
Neutralization - the additional of an acid
or base to adjust the pH of the water to 7
(neutral)
precipitation/Flocculation - the process
where coagulant chemicals such as lime
or ferrous sulfate are added to the water
to precipitate out dissolved solids and to
agglomerate suspended solids so that
they will settle out by gravity
Treatment processes are usually used in
combination to remove several types of
contaminants. For example, a typical
treatment process could involve
precipitation/flocculation with lime to remove
suspended solids and metals in the water, a
gravity filter to remove solids and colloidal
residual material, an air stripper to remove
volatile contaminants such as trichloro-
ethylene or tetrachloroethylene, and a final
polishing step with activated carbon to adsorb
any organic contaminants which may not
have been removed in the air stripper.
The decision on which treatment processes
should be used and design criteria should be
based on the type of contaminants present,
data available on effective treatment
processes, and (at times) on bench or pilot
scale studies. For some well known and
understood processes such as air stripping
and carbon adsorption, enough data are
available that a full bench and pilot scale
study may not be necessary. However, for
other lesser known processes, a properly
designed study should be used to obtain
removal efficiencies and design criteria.
Oversized Community Storage Facilities
If an alternate supply (or the portion of a
community's supply which is not
contaminated) does not have a sufficient yield
to meet maximum demand, round-the-
clock pumping and an oversized storage
facility may provide adequate flows. It should
be noted, however, that such facilities are
commonly used only for demand fluctuations,
fire flows, emergencies, or other situations in
which the demand exceeds normal daily
3-15
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demand and cannot be used alone to
overcome the loss of source capacity.
Excessive pumping of single or multiple wells
cannot be maintained for extended periods
without loss of source capacity.
Blending Uncontaminated Water with Portion
of Contaminated Water Supply to Achieve
Safe Levels
At times, water obtained from uncontaminated
or new sources (described above) may be
mixed with existing supplies which result in a
dilution of pollutants to levels within water
quality standards or criteria. Such an
approach requires daily monitoring and
specialized control equipment to assure the
quality of the contaminated supply remains
consistently within standards or criteria. This
alternative should only be used as a last
resort.
3.4.2 PRELIMINARY SCREENING
The screening and analysis process was
outlined in the flow chart shown in Figure
2-3. Preliminary screening indicates
which of the identified alternatives may be
suited for implementation, considering the
specific site conditions and surrounding
resources.
The alternatives in the flow chart are
ordered from most desirable to least
desirable. The flow chart is devised so
that the user can move directly to detailed
evaluation as soon as a feasible
alternative is identified. In cases where
time is very limited, a full scale evaluation
of all potential alternatives may not be
feasible. Generally, however, it is
recommended that the flow chart be
followed in its entirety. This is especially
important because alternatives other than
those considered in this guidance are not
given consideration until the end of the
process. The user should also note that
the hierarchy of these alternatives will not
be applicable to all sites and situations
and al! feasible alternatives should be
given equal analysis before a recom-
mendation is made.
3.4.3 ANALYSIS OF
ALTERNATIVES
SELECTED
An analysis is performed for each of the
alternate water supply alternatives which
have survived the preliminary screening.
The analysis is data intensive and should
only be performed for alternatives which
are viable candidates.
There are five major elements of the
alternative analysis:
Engineering analysis - timeliness,
performance, reliability,
implementability/constructibility, and
safety
Cost analysis
Environmental protection analysis
Public health analysis
Regulatory/institutional analysis.
Each of these topics is discussed briefly in
the following paragraphs, however, the user is
directed to the primary guidance documents
referenced in Section 1.0 for supplementary
information. The format presented in this
guidance does not match either the EE/CA or
FS process exactly. Rather, this document
focuses on the information needed to prepare
an EE/CA or FS specifically for alternate
water supplies. In preparing an EE/CA or FS
report, always use the format specified in
those guidance documents.
Engineering Analysis
The user should characterize each response
action alternative in terms of major equipment
required (including sizes and specifications),
personnel requirements, chemical and utility
requirements, and specific waste disposal
strategies. Using the information developed,
the user should next compare alternatives
using the following technical criteria:
Timeliness - the speed with which the
selected alternative can be implemented
Performance - effectiveness and
efficiency in accomplishing design
objectives over the system's useful life
including the ability to meet established
drinking water criteria
Reliability - operation and maintenance
requirements, demonstrated performance
of equipment over time, and level of
operator training required
3-16
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Implementibility/constructibility - (site
conditions and conditions external to the
site) and availability of adequately trained
operation and maintenance personnel
Safety - on-site personnel, nearby
communities, surrounding environment.
A significant degree of variation can exist
between the success of techniques when
applied for different wastes and in different
hydrogeological settings. A tabular summary
should be developed including a mechanism
for presenting positive and negative features
of each alternative according to engineering
evaluation criteria.
Additional guidance is available in the
literature on the details of potential
technologies for inclusion in remedial or
removal action alternatives and the use of
technical comparison criteria. Specific
information on particular technologies and
procedures can be obtained from vendors,
equipment manufacturers, and cleanup
contractors.
Case studies concerning the actions which
have been taken by other individuals who
have faced the problem of contaminated
water supplies should also provide information
on potential technologies and their track
records. Superfund sites with alternate water
supplies are noted in Appendix A.
Cosf Analysis
Costs consist of all capital outlays, general
and administrative expenses, and other costs
required for implementation of the
remedial/removal action including engineering,
design, and installation, as appropriate. Some
cost data may be developed during the
screening and analysis of remedial
technologies and would be very useful and
applicable for this more detailed analysis.
The cost analysis should take into
consideration the demand requirements
determined according to the guidelines
discussed in Section 3.2.2. If an alternative
includes a distribution system, the cost of
constructing the distribution system should be
included. The cost of connecting existing
households to the alternate water supplies will
also be included. EPA does not provide
specific consideration for future development
(e.g., while EPA will not preclude the owner
of an empty lot from extending a service
connection to buildings once the property is
developed, EPA will not consider the
possibility of such future connections in
determining the size of the mains to be
installed or the water supply necessary to
provide an alternate water supply). Whenever
possible EPA will use existing distribution
systems or work with the public utility to
provide new distribution systems so that the
cost of constructing the distribution system is
not borne by EPA.
The following list presents several costs that
should be considered and quantified
(discounted to present worth) during a cost
analysis:
Engineering expenses, such as technical
services related to drilling, sampling,
testing, designing, managing, and
reviewing the response action
Land-related expenses for the rent or
purchase of right-of-ways easements,
as well as expenditure for land/site
preparation (if no other options are
available for providing the distribution
system)
Construction costs including direct outlays
for equipment, hardware, materials, and
labor
Transportation and other costs associated
with the disposal of wastes (including soil
and sediments generated from drilling
operations if drilling occurs into
contaminated soils) at an approved off-
site facility
Start-up costs including operator
training, temporary professional services,
additional testing, monitoring, processing
contracts, and equipment and materials
transport.
All known costs associated with construction
should be included because these costs will
be used for budgeting purposes. EPA does
not provide the funds for operation and
maintenance of the system; however, these
costs should be included in preparing a
budget to provide a total cost of the system.
3-17
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The discount value for purposes of the
present worth analysis should be 10 percent.
Environmental Analysis
Provision of an alternate water supply would
generally not consider mitigation of
environmental risk; however, selected
technologies must be analyzed for possible
increased risk to the environment. The
analysis should focus on the adverse and
beneficial impacts of each response
alternative. Some alternatives involve
elements requiring significant construction
activities which may result in various negative
environmental impacts; however, these
.impacts are typically short-term in nature.
Other alternatives, such as operation of a
treatment facility, may require the handling of
hazardous materials. This situation may
increase the risk of exposure or accident and
these impacts are more long-term.
Potential adverse environmental impacts
which may preclude the use of each
alternative should be identified. Major actions
required to implement each alternative must
be identified and a determination made as to
whether any of these actions will or could
result in adverse environmental impacts.
Alternatives that cause significant adverse
impacts or do not adequately protect the
environment should be eliminated; the
reasons the alternatives were eliminated
should be documented. Beneficial impacts of
a response action alternative should be
balanced against any potential adverse
impacts. The following issues must be
considered:
Discharges of contaminants to the air,
land, ground water, or surface water
Disruption of normal community activities
due to construction- related impacts
(e.g., subsurface construction)
Characteristics of long-term system
operation which may create a disruption
or nuisance to the surrounding community
Failure of alternative system to effectively
and reliably remove contamination and
provide potable water of adequate quality
and quantity to the service area
Processes which increase the area and/or
level of contamination in the study area.
Public Health Analysis
Public health analyses must be addressed to
ensure that the alternative mitigates the actual
or potential threat to public health presented
by the contaminated supply. Remedial
alternatives are generally designed for risk
level in the 10-4 to 10-7 range, consistent
with 300.68(c) of the NCP revisions.
Impacts of the alternatives should also be
considered. For instance, in very small
communities, economies of scale may make
central treatment a high cost response
alternative. In such cases, use of home
treatment devices (e.g. granular activated
carbon) may represent a lower cost option.
This option, however, would need to be
considered with a centrally coordinated
maintenance and monitoring program which
complies with State and Federal policy, as
activated carbon requires regular regeneration
to provide adequate treatment and prevent
the growth of microbes. Improperly
constructed new wells can provide an
effective conduit for wastes to move from a
contaminated aquifer to an uncontaminated
aquifer. Safety considerations (worker health
and safety during construction and general
safety features associated with the site, e.g.,
protection of personnel from moving parts of
pumps) will include those that must be
implemented both during and after
implementation of the selected
strategy/technology.
Regulatory and Institutional Analysis
An analysis of Federal and State applicable or
relevant and appropriate requirements
(ARARs) is necessary to understand the
possible impacts of implementing the
response action alternatives. These statutes
and regulations may directly impact overall
feasibility, technical feasibility, engineering,
design, costs, and schedules associated with
any or all of the alternatives. Local regulations
may also require consideration. For example,
a certain water district may be forbidden from
selling water to an adjacent town. Thus, this
analysis must be completed as early as is
feasible so that regulatory constraints can be
identified and incorporated into subsequent
analyses. Any alternatives which would be
precluded or prohibited because of regulatory
restrictions may not warrant further
3-18
-------
consideration. It should be noted, however,
that Section 121 of SARA specifies six
situations in which ARARs may be waived.
These waivers should be investigated prior to
ruling out a desirable alternative. Appropriate
officials at the Federal, Regional, State, and
local levels should be contacted to review
response actions being considered for
providing the community with alternate water
supplies. ARARs must be determined on a
site-specific basis.
As described in Section 3.1.5, State
standards and criteria must be considered in
evaluating possible remedies for remedial
authority sites. Generally, the remedial action
selected will meet State standards that are
applicable or relevant and appropriate when
more strict than MCLs. If State standards are
waived, the action must fit one of the waivers
identified in section 121 of SARA. These
waivers will be discussed in more detail in the
proposed NCP. Removal actions will attain or
exceed ARARs or other Federal and State
environmental and public health laws to the
maximum extent practicable considering the
exigencies of the situation. Specific
information on ARARs is presented in the
CERCLA Compliance with Other Laws
Manual (EPA 1987).
Information on the responsibilities, authorities,
and potential roles of Federal agencies during
the planning and implementation of a remedial
action is presented in Guidance Document for
Feasibility Studies under CERCLA (EPA
1985). The document also includes an
extensive list of regulatory requirements
which potentially apply to the implementation
of a remedial action alternative.
Comparison of Alternatives.
A method for evaluating options is presented
in Table 3-2. Alternatives with high costs
and few public health or environmental
benefits should be eliminated. Those options
with unacceptable adverse environmental
impacts or public health risks would be
eliminated, (n addition, alternatives with
design limitations or which are marginally
proven would be given a low priority due to
the length of time generally required to
implement such remedies. This evaluation
process will result in selection of a
recommended alternative or range of
alternatives for presentation to EPA.
3.4.4 RECOMMENDED ALTERNATIVE
Based upon the results of the detailed
analysis, a potential remedial action/removal
action alternative will be selected by EPA that
can be implemented in a cost-effective,
technically feasible, and environmentally
acceptable manner.
3.5 PREPARE EE/CA OR FS REPORT
Actions performed under removal authority
(including ERAs) will require an EE/CA report;
remedial authority activities will require an FS
report. The purpose of the EE/CA and FS
reports is to present the results of the study and
to provide the community with an opportunity to
review and comment on the Agency's
alternatives and recommended response.
These reports should be consistent with the
appropriate guidance. The EE/CA and Feasibility
Study Guidance Documents contain information
on the appropriate report format and specific
contents of each report.
3.6 PUBLIC PARTICIPATION
Following completion of the EE/CA or FS report,
a 21-day public comment period is conducted
under both authorities. This is to provide the
public with an opportunity to comment on
proposed actions before the design and
construction process begins. This public input is
then considered in selecting the final remedy. A
public hearing may also be conducted for local
citizens to voice their concerns and opinions.
Under both authorities, all relevant information
pertaining to decisions made for the site is
placed into an administrative record and a local
information repository is established. Revisions
under consideration for the NCP may extend the
public comment period to 30 days.
3.7 SELECTION OF REMEDY
Following the public comment period, a remedy
will be selected from among the alternatives for
implementation at the site. The alternate water
supply remedy should be consistent with the
final remedy for the site and in accordance with
the guidelines in the NCP for the respective
program. The selected remedy should represent
the best balance across all of the engineering,
3-19
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Table 3-2 EXAMPLE OF DECISION MATRIX
Alternative
1. No action
2. Connection to
Minneapolis
water system
3. Drill deeper
wells to
underlying
formations
4. Aquifer treatment
A. Ozone
B. Granular
activated
carbon
(GAC)
Cost ($1,000)
Capital
250
1,870
374
459
709
633
633
633
Present
Worth
-_
8,102
2,916
1,618
2,109
2,434
2,150
2,263
24,050
Public Health
Concerns
Unacceptable exposure to
PAH during sunnier or
during fires.
Reduces public health
threat to less than
10 (migration).
Reduces public health
threat to less than
i
-------
protectiveness, and cost factors examined in the
analysis as presented in Section 3.4.3.
Under remedial authority, the selected remedy
will be developed and presented in the Record
of Decision (ROD). The ROD will contain an
accurate and complete summary of the site, the
threat it poses, the selected remedy, as well as
the relative strengths and weaknesses of each
alternative considered and a clear justification
for the final decision that is made. Under
removal authority, the selected remedy will be
developed and presented in an Action
Memorandum. The Action Memorandum also
provides a site description, threat
characterization, and justification for the final
removal action selected.
3-21
-------
-------
4.0 ALTERNATE WATER SUPPLY
DESIGN AND IMPLEMENTATION
This section outlines procedures for designing
and implementing an alternate water supply
system. The procedures and requirements for
selection, design, and implementation will vary
according to the lead agency involved. This
document discusses the general procedures
involved in Federal-lead cases. For more
complete guidance on developing State
Superfund contracts, cooperative agreements,
contract documents and implementing remedial
actions, the user should consult EPA's
Superfund Remedial Design and Remedial
Action Guidance (June 1986) and other
appropriate documents. For removal sites,
consult the Technical Assistance Team (TAT)
Contract Users Manual (Draft, August 1987) and
the Emergency Response Cleanup Services
(ERCS) Users' Manual (Draft, August 1987).
4.1 DESIGN AND
PROCEDURES
IMPLEMENTATION
Source, treatment, and distribution facilities are
the principal components of an alternate water
supply system. Previous sections have
discussed the identification and investigation of
potential new sources for an alternate water
supply. This section will discuss design and
implementation procedures.
4.1.1 GENERAL CONSIDERATION
Most states require the approval of plans and
specifications for public water supply facilities
before construction begins. System additions,
major alternations and new installations come
under this provision. Over the years, the
review agencies have established minimum
design requirements and standards. New
facilities should be in compliance with these
standards where possible.
The design engineers are advised to meet
with regulatory agencies in the early stages,
preferably during preparation of the predesign
reports. State or local engineers are often
able to contribute helpful information to assist
designers because of their experience and
knowledge of local conditions. Consultation
with agencies such as the U.S. Geological
Survey and U.S. Public Health Service is also
recommended to obtain as much basic
information concerning the proposed project
as possible.
A safety factor is usually considered on the
basis of system capacity. The rated or
nominal capacity of the water supply system
should exceed the maximum daily water
demand. For systems comprising more than
one system, the combined capacities should
exceed the maximum daily demand.
Careful survey work is recommended to
eliminate expensive changes and revisions in
the design stage, during construction, and
after completion. Investigation of soil
conditions is necessary to determine
protective coating requirements, excavation
procedures, permissible foundation pressures,
design of anchor or thrust blocks and level of
water tables.
4.1.2 TREATMENT PROCESSES AND
FACILITIES
The quality of the source, its variations and
possible future changes, and the cleanup
levels form the basis for selecting a treatment
process. The proven and simple processes
are preferred, especially for actions with time
constraints. Alternative and innovative
technologies, though preferred by SARA,
generally require longer periods of time for
implementation and are not as reliable as
proven technologies and thus may not be
appropriate for alternate water supplies. For
highly contaminated water, a more
conservative allowance for standby units
should be applied than might be required for
a single contaminant, as reliability becomes
more difficult to attain.
Site selection and acquisition for new
treatment and storage facilities are likely to be
time consuming. An accurate estimate of area
required is important. This can be determined
by a preliminary layout of tanks, buildings,
and pumping and storage structures. Physical
characteristics of new treatment facilities site
will affect construction. Flooding, foundation
conditions, ground water level, and site
preparation, including clearing, grading, and
drainage, are factors which directly influence
the cost of construction. Flood records should
4-1
-------
be carefully examined because protection
against flooding is essential.
The availability of electric power must be
ascertained. A site for treatment facilities
linked to more than one source of outside
power is favored with respect to continuity of
operation.
4.1.3 TRANSMISSION AND DISTRIBUTION
FACILITIES
Surveying and laying out of pipelines are
affected by both the size of the line and its
location. More details and care are necessary
as the size increases and as a line passes
from rural to urban areas.
In general, a plan and profile, together with
certain other details, are necessary for any
water pipeline. The AWWA Manual of Water
Supply Practices recommends including the
following:
Horizontal and vertical distances, either
directly or by survey station and elevation
Location of angles or bends, both
horizontal and vertical (point of
intersection preferred)
Degree of bends, degree or radius of
curves, tangent distances for curves, or
external distances if clearance is required
Points of intersection with pipe centerline
for tees, wyes, crosses, or other
branches, together with direction-right
or left hand, up or down--or angle of
flow, viewed from inlet end
Location and covering length of all valves,
pumps, meters or other fittings
Location of adjacent or interfering
installations or structures
Tie-ins with property lines, curb lines,
road or street centerlines, and other
pertinent features necessary to define
right-of-way and locate pipe centerline
clearly
Details or descriptions of all specials,
together with other data required to
supplement AWWA standards
Details, dimensions, and class
designation or other description of all
flanges and mechanical field joints
Any special requirements affecting the
manufacture of the pipe or installation
procedures.
4.1.4 STORAGE FACILITIES
Present and future storage requirements are
to be considered for the design of the storage
facilities. The required storage capacity must
provide for the following:
Hourly fluctuationstotal volume
required to meet hourly consumption
fluctuations on days of maximum
demands (generally taken to be a
percentage of the maximum daily
demand). Fluctuation volumes above the
maximum daily demand rate are
estimated using the projected peak hour
to maximum daily demand ratios. This
consideration helps to dampen hourly
demand fluctuations at pumping stations,
thus reducing operation costs.
Fire Flowbased on the rates and
durations established by the ISO. This
consideration helps to reduce pumping
station capacity and construction cost.
EmergenciesA volume of water for
emergencies in case of pipeline breaks,
mechanical equipment malfunctions, or
power failure. Emergency storage is not
required if full standby power and a
back-up water supply is provided.
However, if standby power is not
provided, and/or a back-up water supply
is not provided, the volume of active
storage that is generally recommended is
equivalent to the average daily demand
volume.
4.2 TREATABILITY STUDIES
Before designing an alternate water supply
system, treatability studies and pilot testing may
be required if water treatment is the selected
alternative. Performing treatability studies will
delay the implementation of alternate water
supplies and should only be performed if
necessary. Sites with standard types of
contaminants and using proven treatment
technologies will not generally require studies to
be performed. The following sections discuss
the purposes and procedures of bench-scale
and pilot-scale testing.
4-2
-------
4.2.1 BENCH SCALE
Treatability studies may be required to
evaluate the effectiveness of a treatment
scheme. If treatment is recommended,
studies should be conducted as soon as
practicable. Treatment of both toxic organic
and inorganic contaminants may be
considered. Appendix E (adapted from
Shuckrow et al. 1980) presents the
applicability of various treatment processes to
the hazardous substance list. For more
details, review Concentration Technologies for
Hazardous Aqueous Waste Treatment,
(Touhill 1981). Depending on the number and
type of pollutants found in the water supply,
two or three treatment technologies are
generally selected for possible use. The
process which will remove the worst
contaminants most effectively will be the first
examined during the bench-scale studies.
To monitor the effectiveness of the bench-
scale testing, representative compounds are
selected from each pollutant group and are
traced through the system. The
representative compound should generally be
the most difficult to remove by the selected
treatment process. For example, if carbon
adsorption is the chosen treatment process,
the compound with the lowest adsorbability
should be analyzed. The selection of
representative indicator compounds should be
made, however, on a site-by-site basis;
this will promote high quality response
activities.
Once the carbon adsorption system reaches
equilibrium, a complete priority pollutant scan
(if appropriate) can be run to determine if the
removal of contaminants was successful. If
the water is still above cleanup levels,
additional treatment may be required. Other
processes may also have to be tested.
4.2.2 PILOT SCALE
Before final design of a treatment process is
completed, pilot testing may be necessary.
Because of budget and schedule constraints,
proven conventional technologies are often
favored for alternate water supplies. There
may be sufficient data available on these
technologies that pilot testing would not be
required. The goal of such studies is to verify
the applicability of processes previously
tested on a bench scale, to refine the design
criteria, and to obtain an estimate of O&M
costs. If bench scale testing cannot be
conducted (e.g., air stripping of volatile
compounds), pilot studies may be required.
Data are usually available for predicting size
requirements without pilot testing for common
processes such as air stripping and GAC
treatment. Such data may be obtained by
consulting equipment manufacturers or EPA
personnel responsible for implementation of
treatment alternatives at previous sites (see
Appendix A).
Bench scale testing can provide adequate
data for conventional treatment plant design
and processes. A conventional treatment
process includes chemical addition, mixing,
flocculation, sedimentation and filtration. Pilot
testing is often appropriate for non-
conventional treatment processes or for
conventional plants which treat waters
containing multiple contami nants. The time
required to conduct pilot testing depends on
the selected process and the water quality.
The following requirements should be
considered for pilot studies.
Operating Conditions - Once a treatment
alternative is chosen, the purpose of a pilot
study is to collect operating data and to refine
the design parameters for full scale design of
the treatment system. Due to limitations in
time and money, a pilot test typically
investigates a small range of operating
conditions. These conditions are often chosen
based on previous bench scale test results,
on other full-scale plant operating data, or
on literature information. As a general rule, all
pilot processes should be tested at two
significant loading concentrations of the
influent water, at normal or "average"
conditions, and at high or "stressed"
conditions.
Design parameters typically refined in pilot
studies include chemical dosages for
precipitation/flocculation systems, air to water
ratios in air strippers, and carbon usage rates
for activated carbon adsorption. To save time
and money in the laboratory analyses, a few
compounds are selected as the indicator
compounds and are analyzed for during the
study, typically hose which are the most toxic
or the most difficult to remove by the
treatment process. However, extensive
analyses should be done for all known
4-3
-------
contaminants on occasion to confirm that the
effluent meets the drinking water standards.
Duration of Testing - The length of time
required to conduct a pilot study is dependent
on various factors. Certain processes require
time to stabilize before steady state operating
data can be collected. For example, an air
stripping process will stabilize after several
minutes (e.g., an air flotation process will
stabilize within 30-60 minutes). Once the
process is stable, data should be collected for
at least a few weeks to assure that the
process is achieving the desired results.
Another factor affecting the duration of the
test is the number of parameters studied. An
increase in the number of parameters which
are varied and analyzed will result in a longer
period of process stabilization and require
more time in which to collect data. A third
consideration is the variability of the
contaminants in the water source. This can
be accounted for by operating the pilot
facility, either continuously or intermittently,
as appropriate, for sufficient time to cover the
variation in raw water quality. State
requirements for duration and time of year for
pilot testing should be taken into
consideration.
It is possible, in some cases, such as in
carbon adsorption studies, to reduce the time
required to obtain test results by using small,
highly loaded units. This type of bench-scale
study can be done in a laboratory rather than
in the field.
Installation and Configuration - Since the
goal of a pilot study is to obtain design
parameters and to confirm process
effectiveness, the pilot plant should simulate
as closely as possible the full-scale process.
As a rule of thumb, a pilot plant should
operate at a flow of 5 percent of the full scale
plant. However, the actual flow of the pilot
plant may be determined by economics,
equipment availability, and the extent to which
scale up difficulties are present (i.e.,
processes which do not scale up well should
have pilot plant flow rates as high as
economically feasible).
It is also possible to have various units in a
pilot plant which do not treat the same flow.
In this case, the flows through the plant can
be split into various streams testing multiple
processes or operating conditions
simultaneously.
Mobile and Prepackaged Pilot Plants - For
many applications, it may be more
economical and feasible to lease a mobile
pilot plant. Various manufacturers offer mobile
treatment systems which include air strippers,
carbon adsorption, reverse osmosis, filtration,
metals removal, neutralization and biological
processes. Also, if a specialized or proprietary
process is being considered, it may be
necessary to use a manufacturer's pilot
system to determine the technology's
effectiveness.
The use of these services may include
sampling, analyses and report preparation, or
the manufacturer may just provide the
equipment and the contractor would design
and operate the entire pilot study.
4.3 CONTRACT DOCUMENTS
In general, an alternate water supply design will
contain the General Condition section which
contains contractual language similar to most
construction projects. The next section, the
Technical Specifications, outlines how the work
will be conducted. Table 4-1 represents a
typical table of contents in the Technical
Specifications section. Much of the material
under Division 1 presents the project
requirements. Divisions 2 through 17 focus on
the special conditions and detail how these
conditions are handled. The drawings for an
alternate water supply system have the same
purpose as drawings for construction-related
projects. These drawings include the following:
Cover sheet with project name, location
map, agency, engineer, etc.
Grading, landscaping, and drainage plan
around any major structures
Plan and profile of all pipelines
Structural, architectural, mechanical,
plumbing, HVAC, and electrical drawings,
detail sheets
Typical installation drawings for individual
home treatment devices.
4-4
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Table 4-1 TYPICAL TABLE OF CONTENTS FOR
TECHNICAL SPECIFICATIONS
Section No. Description
DIVISION 1 - GENERAL REQUIREMENTS
01010 Summary of Work
01030 Special Project Procedures
01060 Regulatory Requirements
01340 Submittals
01510 Temporary Facilities
01590 Support Area Facilities
01601 Control of Materials
01671 Temporary Site Utilities
01700 Contract Closeout
DIVISION 2 - SITE WORK
02100 Site Preparation
02221 Trenching, Backfilling, Compaction
and Grading
02223 Granular Fill and Clay Materials
02444 Chain Link Fence
02585 Learning and Hydroseeding
02596 Sheeting and Filter Fabric
02611 Concrete Pipe
02612 Reinforced Concrete Pipe
02615 Cast-Iron Pipe
02616 Ductile Iron Pipe and Fittings
02617 Steel Pipe
02618 Corrugated Metal Pipe
02622 High Density Polyethylene Pipe
and Fittings
02625 Concrete Cylinder Pipe Fittings
02640 Valves, Cocks and Hydrants
02660 Water Wells
02734 Groundwater Monitoring Wells
DIVISION 3 - CONCRETE
03200 Concrete Reinforcement
03250 Concrete Accessories
03300 Concrete
DIVISION 5 - METALS
05500 Miscellaneous Metal
DIVISION 6 - WOODS AND PLASTICS
06100 Carpentry Work
DIVISION 11 - EQUIPMENT
11201 Sluice Gates
11202 Slide Gates and Weir Gates
11240 Liquid Alum Feed System
11241 Liquid Alum Storage Tanks
11242 Polymer System
11312 Pumps
11313 Automatic Pump Assembly
11372 Compressed Air Supply Equipment
11373 Trench and Sump Ventilation and
Heating
DIVISION 13 - SPECIAL CONSTRUCTION
13122 Prefabricated Metal Building
13124 Treatment Trailer
13411 Steel Tanks
13416 Trailer Mounted Storage Tank
13573 Treatment Operation Protocol
13574 Bulking and Consolidation Protocol
13575 Waste Material
13576 Transport of Hazardous Materials
13577 Disposal of Chemical Wastes
13600 Instrumentation
Table 4-1
Section No.
13700
15061
15062
15064
15101
15102
15103
15107
15108
15113
15100
16000
16110
16310
16460
16470
16480
(Continued)
DIVISION 15
DIVISON 16
Description
Materials and Equipment
Decontamination
MECHANICAL
Steel Pipe and Fittings
Cast Iron Pipe
Plastic Pipe
Gate Valves
Butterfly Valves
Ball Valves
Pressure Regulating Valves
Solenoid Valves
Valve Operators
Valves and Appurtenances
ELECTRICAL
Electrical - General Provisions
Raceways and Fittings
Unit Substations
Tranformers
Panel Boards
Motor Control Center
4.4 CONTRACTING PROCEDURE
Design and construction of an alternate water
supply for a non-time critical removal action or
an operable unit remedial action is usually
performed by contractors who can successfully
compete with other firms during the selection
process. Removal authority may also use
Emergency Response Cleanup Services (ERGS)
in cases where there is not sufficient time to
perform site specific contracting. Site specific
contracts are encouraged whenever possible. A
contractor that meets the technical re
quirements of the job responsibly and cost-
effectively is selected. Sepa rate firms will be
selected for design and construction. The design
firm may provide construction management
services and perform the contracting functions
required to obtain a construction contractor. It is
essential that contract documents completely
and accurately define all the work required and
comply with the Construction Specification
Institute (CSI) format and any State
requirements.
The bidding and contract requirements define
the conditions under which the contractor must
perform the work. A number of financial options
may apply to a particular contract, such as lump
sums and unit prices. The contract bid may be
based upon one or a combination of these
options. The purpose of these contracting
options is to provide a mechanism by which
numerous bids may be compared.
4-5
-------
A brief discussion of these contract bid options
is presented below.
Lump Sum Contract - A lump sum contract
requires the bidder to determine project costs
and to undertake the services outlined in the
project plans. This method requires the
contractor to accurately interpret the plans
and specifications, as well as unusual
conditions. This will help estimate project
cost; one price covers all work involved. A
complete design is also required which
identifies project risks.
Unit Price - A unit price contract requires
bidders to estimate the materials required to
prepare the site, install pipelines and
appurtenances. The contractor then
determines the project costs on a per unit
basis; this number is extrapolated to the
estimated number of units. The sum of these
costs is the bid price. The contractor is paid
for the number of units completed during the
work assignment. This allows for flexibility and
insures that the contractor will be paid for all
work actually accomplished. This contract
balances the risk between the contractor and
EPA.
A combination of the described bid options
above can be used.
4.4.1 LUMP SUM CONTRACT
The lump sum contract, is most applicable for
pricing the well-defined elements of the
work. These elements include:
Mobilization - up front costs such as
insurance, bonding requirements,
obtaining project-specific licenses and
permits, and the development of site-
specific contingency and health and
safety plans.
Site Preparation - typical construction
related activities such as roadways,
clearing, and grading.
Structures and Equipment - building and
vault foundations, superstructures and
equipment including pumps, generators,
treatment units, electrical, and HVAC.
Temporary Facilities - support facilities
such as trailers, laboratory and utility
hook-ups.
Demobilization - payment for
decommissioning utilities, final grading
and reporting requirements.
4.4.2 UNIT PRICE CONTRACT
Unit pricing provides a fixed unit price (e.g.,
per linear foot, per cubic yard and/or tons), at
the time of bid. This unit price is determined
for an estimated quantity of units rather than
a set quantity, because specific conditions,
such as number of drums to be handled, may
not be known. The unit price system provides
contractors with a mechanism that will pay for
all work completed, regardless of original
estimates.
Unit pricing requires that the price quoted for
each unit include the cost for all required
labor and equipment. Typical unit cost items
include: excavations, piping (including trench
excavation), concrete, paving, hydrants,
individual home treatment units, wells, drilling
and associated piping, house connections,
and water treatment units. These price quotes
are generally considered firm unless there is
a significant change in conditions or if there is
a major increase or decrease in the original
estimate; a 15 percent margin around the
price quote is standard. Deviations above or
below this margin lead to renegotiation. The
unit price concept can accommodate changes
and provides a mechanism by which bids can
be compared.
4.5 CONTRACT PROVISIONS
The contract must contain provisions which
address the scope of the project. A "Change of
Conditions" refers to those activities which do
not coincide with the scope of project but are
still billable. In addition, the contract should
comply with State and local requirements.
4.5.1 CHANGE ORDERS
As discussed previously, different types of
contracts are available that divide the risk
between EPA and the contractor; this
provision modifies the terms of the contract
and lowers the risk to the owner and
contractor in order to obtain the best possible
price. When this occurs, the work is more
strictly defined. Therefore, a change of
conditions is defined as unspecified or
unanticipated additional work which is paid
separately. This method, called a change
order, is defined below:
4-6
-------
Without invalidating the Agreement and
without notice to any surety, OWNER
may, at any time from time to time, order
additions, deletions or revisions in the
Work; these will be authorized by a
Written Amendment, a Change Order, or
a Work Directive change. Upon receipt of
any such document, CONTRACTOR shall
promptly proceed with the Work involved
which will be performed under the
applicable conditions of the Contract
Document (except as otherwise
specifically provided).
General Conditions are the provisions
contained in the contract that outline change
order conditions and the accounting
procedures that apply.
4.5.2 SPECIAL PROVISION
Some aspects of the project are unique to the
site and are not necessarily unknown but fall
under the term "considerations." There are
"considerations" in each project that the
owner expects the contractor to consider
when preparing the bid. These could include
provisions for the following:
Coordination with government
agencies
Storage and handling of equipment
Coordination with utilities
Control of erosion and runoff
Services of manufacturers'
representatives for start-up, training,
operation manuals, lubrication schedules
Connections to existing systems
Disposal of materials
Providing adequate plant (i.e., support
equipment)
Inclement weather.
Experienced contractors will be familiar with
these and other standard operating
conditions. However, it is in the Agency's
best interest to include such items.
In addition, there may be conditions that are
not known during a particular stage of the
work. These conditions may be included in
the contract and priced on a unit basis in the
event that they occur. Such provisions are
referred to as "Control of Work" and may
include the following:
Relocation of existing utilities
Removal/replacement of unsuitable
materials
Removal/replacement of rocks and
boulders
Dewatering via well points
Wood or steel sheeting
Test pits.
If any of these conditions were encountered,
the contractor would be bound to the price
specified in the proposal.
4-7
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-------
5.0 POST IMPLEMENTATION
ACTIVITIES
Alternate water supplies may be installed to
provide an interim remedy until the existing
water supply is cleaned up or as a final remedy
to permanently replace the existing water
supply. At non-NPL sites and at most NPL
sites, alternate water supplies will be considered
a final remedy with regard to the drinking and
household water pathway. Further remedial
action may be needed at the NPL site.
EPA's responsibility for the alternate water
supply system ends upon completion of
construction, when responsibility for operation
and maintenance of the system is transferred to
the appropriate utility or State agency. EPA will
seek transfer of control as soon as construction
is complete. In cases where EPA implements an
alternate water supply and no utility exists, the
State Superfund contract must provide
assurances under Section 104 for provision of
operation and maintenance services for the
system. In cases where EPA or another party
implements the alternate water supply for
inclusion in an existing utility, the OSC or RPM
should work closely with OGC to develop means
for transfer of control.
5-1
-------
-------
6.0 REFERENCES
Comprehensive Environmental Response,
Compensation, and Liability Act of 1980
(CERCLA) as amended by Superfund
Amendments and Reauthorization Act.
1986, 42 U.S.C. 9601-9657.
Revised National Oil and Hazardous
Substances Pollution Contingency Plan
(NCP). 40 CFR Part 300. 1985. 47 FR
31180.
Sisk, S.W. July 1981. NEIC Manual for
Ground Water/Subsurface Investigations
at Hazardous Waste Sites. EPA-330/9-
81-002.
Touhill (Schuckrow and Assoc., Inc.). 1981.
Concentration Technologies for
Hazardous Aqueous Waste Treatment.
EPA-600/2-91-019.
U.S. Environmental Protection Agency. 1979.
Safety Manual for Hazardous Waste Site
Investigations (draft). Office of
Occupational Investigation Center.
Denver.
December 1980.
Interim Guidelines and Specifications for
Preparing Quality Assurance Project
Plans. Office of Research and
Development. QAMS-005/80.
. September 1982.
Handbook for Sampling and Sample
Preservation of Water and Wastewater.
EPA-600/4-82-029.
. October 1982. EPA
Descriptive Summary: Survey of
Operating and Financial Characteristics of
Community Water Systems. Office of
Drinking Water.
. 1984. Standard
Operating Safety Guides. Office of
Emergency and Remedial Response.
Washington, D.C.
. February 1984. State
Participation in the Superfund Remedial
Program. Office of Emergency and
Remedial Response. Washington, D.C.
. July 1984. Guidance
for Phase T - Fluid Quality
Measurements. UIC Quality Assurance
Program, Ground Water Protection
Branch, Water Supply Branch.
. June 1985. Guidance
Document for Remedial Investigations
Under CERCLA. Office of Emergency and
Remedial Response, Office of Waste
Programs Enforcement, Office of Solid
Waste and Emergency Response.
Washington, DC. EPA 540/G-85/002.
- June 1985. Guidance
Document for Feasibility Studies Under
CERCLA. Office of Emergency and
Remedial Response, Office of Waste
Programs Enforcement, Office of Solid
Waste and Emergency Response.
Washington, DC. EPA 540/G-85/003.
_. August 1985. The
Endangerment Assessment Handbook.
Office of Waste Programs Enforcement.
Washington, D.C. Prepared by Life
Systems, Inc. under EPA Contract 68-
01-7037.
. March 1986.
Community Relations in Superfund: A
Handbook. Office of Solid Waste and
Emergency Response. Washington, D.C.
OSWER Directive 9230.0-3A.
_. June 1986. Superfund
Remedial Design and Remedial Action
Guidance. Office of Emergency and
Remedial Response. Washington, D.C.
OSWER Directive 9355.0-4A.
. October 1986.
buperfund Public Health Evaluation
Manual. Office of Emergency and
Remedial Response. Washington, D.C.
OSWER Directive 9285.4-1. EPA
540/1-86/060.
. March 1987. Data
Quality Objectives for Remedial
Response Activities. Volume 1 -
Development Process. Office of
Emergency and Remedial Response and
Office of Waste Programs Enforcement.
Washington, D.C. OSWER Directive
9355.0-7B. EPA 540/G-87/003.
March 1987. Data
Quality Objectives for Remedial
Response Activities. Volume 2 -
6-1
-------
Example Scenario. Office of Emergency
and Remedial Response and Office of
Waste Programs Enforcement.
Washington, D.C. OSWER Directive
9355.0-7B. EPA 540/G-87/004.
.April 13, 1987.
Environmental Review Requirements for
Removal Actions. Office of Emergency
and Remedial Response. Washington,
D.C. OSWER Directive 9318.0-05.
. July 1987. Superfund
Removal Procedures. Office of
Emergency and Remedial Response.
Washington, D.C.
. Draft August 1987.
Compendium of Field Operations
Methods. Office of Emergency and
Remedial Response. Washington, D.C.
OSWER Directive 9355.0-14.
. Draft July September
1987. Engineering Evaluation/Cost
Analysis Guidance. Office of Emergency
and Remedial Response. Washington,
D.C.
Draft September 1987.
CERCLA Compliance with Other Laws
Manual. Office of Emergency and
Remedial Response. Washington, D.C.
OSWER Directive 9234.1-01.
. State Participation in
the Superfund Program, Appendix W,
Guidance for State-Lead Removals, July
10, 1987 (OSWER Directive 9375.1-4-
W).
Technical Assistance
Team (TAT) Contract User's Manual,
Draft, August 1987. (OSWER Directive
9242.4-01A). (Final expected
September, 1987).
. Emergency Response
Cleanup Services (ERGS) Users' Manual,
Draft, July, 1987 (OSWER Directive
9242.2-1 A). (Final expected September,
1987).
6-2
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APPENDIX A
LOCATIONS WHERE ALTERNATE SUPPLIES HAVE BEEN INSTALLED
Site
South Valley Site
New Brighton
Milltown
San Gabriel
Western Sand and Gravel
Charles George Landfill
TacomaWell 12A
Verona Weil Field
Charlevoix Municipal Well
Krysowaty Farm
Bridgeport
Price Landfill
Eau Claire
Caldwell Trucking
Location
Albuquerque, NM
New Brighton, MN
Milltown, MT
San Gabriel, CA
Burrillviile, Rl
Tyngsboro, MA
Tacoma, WA
Battle Creek, Ml
Charlevoix, Ml
Hillsborough, NJ
Bridgeport, NJ
Pleasantville, NJ
Eau Claire, Wl
Fairfield, NJ
Selected Remedy for Water Supply
New wells
Connection to existing system
New wells
Connection to existing system
Home treatment units, new wells
Connection to existing system
Extraction well, aeration towers
Barrier wells with air stripping, new
wells
New surface water supply
Connection to existing system
Connection to existing system
New well field
Packed tower air stripping
Ground water treatment, alternate
water supply
Combe Fill South Landfill
Chisman Creek
Heleva Landfill
Lehillier/Mankato Site
Main Street Well Field
Old Mill
Chester Township, NJ
York County, VA
North Whitehall Township, PA
Lehillier/Mankato, MN
Elkhart, IN
Rock Creek, OH
Ground water pump and treat,
alternate water supply
Ground water pump and treat, ground
water diversion, alternate water supply
Extension of existing water supply
Ground water extraction and
treatment, extension of municipal
water system
Ground water treatment with
discharge to municipal distribution
system
Ground water extraction and
treatment, alternate water supply
A-1
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APPENDIX B
AN ANALYTICAL APPROACH TO DETERMINING A CONTAMINANT TRANSPORT REGIME
It is necessary to assess the contamination rate
at a site to determine how quickly alternate water
supplies should be provided. Many factors must be
considered during an evaluation including defining the
local lithology and aquifer parameters. Complicated
lithologies which involve multiple aquifers require
digital modeling to approximate contaminant
movement. In less complex systems, however,
Darcy's equation may be adapted to provide an
estimate of contaminant transport.
It is necessary to establish the radius of the water
supply well; groundwater velocity may increase within
these areas. Therefore, it is important to know the
size of the water supply and the groundwater velocity
when pumping is not occurring.
The size of the well may be determined
graphically if there are existing observation wells
within the pumping well. This may be accomplished
by plotting drawdown(s) vs log r, where r equals the
distance between the pumping and observation well.
The zero drawdown intercept represents the radius of
the pumping well during the discharge rate test. If no
observation wells exist, the size of the well may be
estimated from a series of equations using known or
estimated aquifer parameters.
The average velocity of groundwater movement
may be estimated using a form of Darcy's Law:
where:
Kdhldl
9
v = average velocity (feet/day)
K = hydraulic conductivity (feet/day)
dh/dl = hydraulic gradient (dimensionless)
9 = effective porosity, as a decimal
fraction
Parameter Determination
Hydraulic Conductivity (K) - Pump test data for
the production well may be available. A hydraulic
conductivity may have been calculated for the aquifer
of concern. This value may be substituted into the
Darcy equation or a hydraulic conductivity may be
estimated based on the soil description. Tables
comparing hydraulic conductivity and soil type can be
found in Freeze and Cherry's (1979) text,
Groundwater. Aquifers capable of sustaining a
production well generally have K values ranging from
102 to 104 feet/day.
Hydraulic Gradient (dh/dl) - The regional
hydraulic gradient may be derived from potentiometric
surface maps developed for the site. The hydraulic
gradient must be established from data available
outside the area of influence of the pumping well. In
gently sloping areas the hydraulic gradient usually
ranges from 1 to 10 feet per 1,000 feet.
Porosity (9) - The porosity of an aquifer may be
determined from laboratory test or may be estimated
based on the soil type. Most aquifer materials have
porosities of 30 to 35%. Tables comparing soil type
and porosity can also be found in Freeze and
Cherry's (1979) Groundwater text.
Example
In this example, a landfill is located approximately
6,500 feet upgradient from a production well which is
releasing contaminants. If the production well was not
releasing contaminants, the distance from the edge of
the contaminant plume to the production well would
be used. An aquifer test was performed when the well
was put into service. The radius of the well was
approximately 1 ,500 feet. The aquifer is composed of
sand and gravel with a hydraulic conductivity of
feet/day and a porosity of 35%. The hydraulic
gradient is 10 feet/1,000 feet. Substituting these
values into the Darcy equation:
K dh/dl
v~~ 9
(350 (-0.01)
-= 10 feet/day
v
Groundwater is moving with a velocity of 10
feet/day. To calculate the travel time of contaminants
to intercept the radius of influence of the production
well the distance of travel in feet is divided by the
velocity in feet/day. Therefore:
5,000 (feet)
\Qfeetlday
= 500 days
The contaminant may be expected to intercept the
radius of influence of the production well in 500 days.
B-1
-------
Limitations and Considerations
This simplified model must be used with, caution.
It assumes that the aquifer is homogeneous and
isotropic. It does not consider contaminant
retardation, effects of contaminant dispersion or the
additional stresses placed on the aquifer system. The
fraction of the total discharge derived from the
direction of the contaminant plume would effect the
water quality in the production well. The source of
groundwater in the production well may be decreased
if surface water is close by. Complex aquifer systems
may require more sophisticated analytical or digital
modeling. However, a simplified analytical approach
may provide the necessary information required to
assess contaminant transport in groundwater. The
user is strongly encouraged to seek the assistance of
a competent hydrogeologist to determine an
appropriate modeling approach.
B-2
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APPENDIX C
EPA AMBIENT STANDARDS AND CRITERIA
Chemical
Acenaphthene
Acrolein
Acrylonitrile
Aldrin
Antimony
Arsenic
Asbestos
Barium
Benzene
Benzidine
Benzo(a)pyrene
Beryllium
Cadmium
Carbofuran
Carbon monoxide
Carbon tetrachloride
Chlordane
Chlorinated benzenes
Hexachlorobenzene
1,2,4,5-Tetra-
chlorobenzene
Pentachlorobenzene
Trichlorobenzene
Monochlorobenzene
Chlorinated ethanes
1 ,2-Di-chloro-
ethane
1,1,1 -Trichloroethane
1 ,1 ,2-Trichloroethane
1,1,2,2-Tetra-
chloroethane
Hexachloroethane
Monochloroethane
1,1-Dichloroethane
1,1,1,2-
Tetrachloroethane
1,1,1,2-
Tetrachloroethane
Clean Water
Safe Drinking Act, Water
Water Act, Quality
MCLs, (mg/L Criteria for
unless Human
otherwise Health
noted) Drinking
Water Only a)
20 yg/L (or-
ganoleptic)d>
540 ug/L
0 (63 ng/L)e)
0(1.2ng/L)
146 ug/L
0.05 0 (2.5 ng/L)
0 (30,000
fibers/L)
1
0 (0.67 ug/L)
0 (0.15 ng/L)
0 (3.9 ng/L)
0.01 10pg/L
0 (0.27
ug/L)f>
0 (22 ng/L)
0 (21 ng/L)
1 80 ng/L
570 ug/L
Insufficient
data
488 ug/L
0 (0.5 ug/L)f>
1 9 mg/L
0 (0.6 ug/L)
0 (0.17 ug/L)
0 (2.4 ug/L)
Insufficient
data
Insufficient
data
Insufficient
data
Insufficient
data
Health Effects Assessments b)
AlCc) Carcinogenic Potency
Intake Cone. Intake 10-6 risk
(mg/kg/day) (mg/L) (mg/kg-day)-i
2.9x1 0'4 0.01 0.045 0.77 ug/L
11.5 3.0 ng/L
0.13 0.27 ug/L
1.6 0.22 ug/L
1.7 0.21 ug/L
0.069 0.51 uQ/t-
0.54 19
0.057 0.61 U9/L
0.2 0.175 ug/L
C-1
-------
APPENDIX C (Continued)
Chemical
Safe Drinking
Water Act,
MCLs, (mg/L
unless
otherwise
noted)
Clean Water
Act, Water
Quality
Criteria for
Human
Health
Drinking
Water Only a)
. .
Health Effects Assessments W
.
AICO
intake Cone.
(mg/kg/day) (mg/L)
_ . . .
Carcmogemc Potency
Intake 10-6 risk
(mg/kg-day)-1
Pen tachloroe thane
Chlorinted naphthalenes
Chlorinated phenols
3-Chlorophenol
4-ChlorophenoI
2,3-Dichlorophenol
2,5-Dichtorophenol
2,6-Dichlorophenol
3,4-Dichlorophenol
2,3,4.6-
Tetrachlorophenol
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
2-Methyl-4-
chlorophenol
3-Methyl-4-
chlorophenol
3-Methyl-6-
chtorophenol
Chlorophenoxys
2,4-Dichloro-
phenoxyacetic acid
2,4,5-Trichloro-
phenoxy-propionic
(Silvex)
Chtoroalkyl ethers
bis-(Chloromethyl)
ether
bis-(2-Chloroethyl)
ether
bis-(2-
Chloroisopropyl) ether
Chloroform
2-Chlorophenol
Chromium Cr+6
Cr+3
TOTAL
0.1
0.01
0.1 g)
Insufficient
data
Insufficient
data
0.1 ng/L
(organoleptic)
0.1 ng/L
(organoleptic)
o.04 ng/L
(organoleptic)
0.5 n9/L
(organoleptic)
0.2 ng/L
(organoleptic)
0.3 ng/L
(organoleptic)
1.0 ng/L
(organoleptic)
2600 ng/L
0(1.8 ng/L)
1800 na/L
(organoleptic)
3000 ng/L
(organoleptic)
20 ng/L
(organoleptic)
0.05
1.8
0.02
1.75 ug/L
(0.0039 ng/L)
0 (30 ng/L)
34.7 ng/L
o (0.19 ng/L)
0.1 ng/L
(organoleptic)
50 ng/L
170 mg/L 1.6
.07
0.50 ng/L
56
0.05
C-2
-------
APPENDIX C (Continued)
Chemical
Copper
Cyanide
DDT
Dichlorobenzenes (all
isomers)
Dichlorobenzidines
Dichloroethylenes
1 , 1 -Dichloroethylene
1 ,2-Dichloroethylene
Dichloromethane
2,4-Dichlorophenol
Dichloropropanes/
Dichloropropenes
Dichloropropanes
Dichloropropenes
1 ,2-Dichloro-
propane
Dieldrin
2,4-Dimethylphenol
2,4-Dinitrotoluene
p-Dioxane
1 ,2-Diphenylhydrazine
Endosulfan
Endrin
Ethylbenzene
Ethylene glycol
Formaldehyde
Fluoranthene
Fluoride
Haloethers
Halomethanes
Heptachlor
Hexachlorobutadiene
Hexachlorocyclohexanes
Lindane (99% gamma-
HCH)
alpha-HCH
beta-HCH
gamma-HCH
Clean Water
Safe Drinking Act, Water
Water Act, Quality
MCLs, (mg/L Criteria for
unless Human
otherwise Health
noted) Drinking
Water Only a)
1 mg/L
(organoleptic)
200 ng/L
0 (>1,2
ng/L)
470
0 (20.7 ng/L)
0 (33 ng/L)
Insufficient
data
See
Halomethane
s
0.3 n9/L
(organoleptic)
Insufficient
data
87 ng/L
0(1.1 ng/L)
400 n9/L
(organoleptic)
0(0.11 ng/L)
0 (46 ng/L)
138 ng/L
0.0002 13 ng/L
2.4 mg/L
1 88 na/L
1.4-2.4
Insufficient
data
0(0.1 9 ng/L)
0 (1 1 ng/L)
0 (0.45 n9/L)
0.004
0 (13 ng/L)
0 (23.2 ng/L)
0 (26.4 ng/L)
Health Effects Assessments b>
AICC> Carcinogenic Potency
Intake Cone. Intake 1 __6 . .
(mg/kg/day) (mg/L) (mg/kg-day)-i
8.4 4.17 ng/L
0.097 3.4
0.078 0.45 ng/L
1.3 0.27 ng/L
C-3
-------
APPENDIX C (Continued)
Chemical
detta-HCH
epsilon-HCH
Technical-HCH
Hexachlorocyclopentadiene
n-Hexane
Clean Water . .
Safe Drinking Act, Water Health Effects Assessments b)
Water Act, Quality
MCun%(s7/L ^uman" A.CO Carcinogenic Potency
otherwise Health intake Cone. Intake 1Q.6 rjgk
noted) Drinking (mg/kg/day) (mg/L) (mg/kgvday)-1
Water Only a)
Insufficient
data
Insufficient
data
0 (17.4 ng/L)
206 ng/L
Hydrocarbons (non-
methane)
Isophorone
Kerosene
Lead 0.05
Mercury (inorganic) 0.002
Mercury (alkyl)
Methoxychlor 0.1
Methyl Ethyl Ketone
Naphthalene
Nickel
Nitrate (as N) 10
Nitrobenzene
Nitrogen dioxide
Nitre-phenols
2,4-Dinitro-o-cresol
5.3 mg/L
50
10 ug/L
Insufficient
data
15.4 ng/L
19.8 mg/L
0.0014 0.05
0.002 0.07
2.9x10-4 0.01
Dinitrophenol
Mononitrophenol
Trinitrophenol
Nitrosamines
n-Nitrosodimethylamine
n-Nitrosodiethylamine
n-Nitrosodi-n-butylamine
n-Nitrosodiphenylamine
n-Nitrosophyrrolidine
Ozone
Particulate Matter
Pentachlorophenol
Phenol
Phthalate esters
Dimethylphthalate
Diethylphthalate
DIbutylphthalate
Di-2-ethylhexyl-
phthalate
70 n9/L
Insufficient
data
Insufficient
data
0 (1.4 ng/L)
0 (0.8 ng/L)
0 (6.4 ng/L)
0 (7.0 ng/L)
0 (16 ng/L)
1.01 mg/L 0.03 1.05
3.5 mg/L 0.1 3.5
350 mg/L
434 mg/L
44 mg/L
21 mg/L
C-4
-------
APPENDIX C (Continued)
Clean Water
Safe Drinking Act, Water
Water Act, Quality
Health
Effects Assessments W
MCLs, (ma/L Criteria for
Chemical
unless
otherwise
noted)
Human
Health
Drinking
Water Only a)
AICO
Intake Cone.
(mg/kg/day) (mg/L)
Carcinogenic Potency
Intake
(mg/kg-day)-1
(PCBs)
Polynuclear aromatic
hydrocarbons (PAHs)
Radionuclides
Radium-226 and 228
Gross alpha activity
Tritium
Strontium-90
Other man-made
Selenium
Silver
Sulfur dioxide
2,3,7,8-TCDD
Tetrachloroethylene
Thallium
Toluene
Toxaphene
Trichloroethylene
Trihalomethanes (total)')
Vinyl chloride
Xylenes
Zinc
0 (> 12.6
ng/L)
0 (3.1 ng/L)
4.3
11.5
8.14 ng/L
3.0 ng/L
5 pCI/L
15 pCi/L
20,000 pCi/L
8 pCi/L
h
0.01
0.05
0.29
0.005
0.1
10 ug/L
50 ug/L
0 (0.00018
ng/L)
0(1.8ug/L)f)
17.8 ng/L
15 mg/L
0 (25.8 mg/L)
(2.8 ug/L)
(O.0l5ng/L)f)
5 mg/L 0.21
(organoleptic)
10
1.6x10-5 2.2x1 O^ng/L
0.04 0.88
0.019
5.8 ng/L
7.4
Footnotes:
a) These adjusted criteria, for drinking water ingestion only, were derived from published EPA Water Quality Criteria (45 FR
79318-79379, November 28, 1980) for combined fish and drinking water ingestion and for fish ingestion alone. These
adjusted values are not official EPA Water Quality Criteria, but may be appropriate for Superfund sites with contaminated
ground water. In the derivation of these values, intake was assumed to be 2 liters/day for drinking water and 6.5 grams/day
for fish; human body weight was assumed to be 70 kilograms.
b) Health Effects Assessments (HEA's) - interim toxicity values developed by EPA's Environmental Criteria and
Assessment office for substances commonly found at Superfund sites.
c) Acceptable Intake Chronic (AIC) - the highest long-term exposure level not expected to cause adverse effects.
d) Organoleptic criteria are based on taste and odor effects, not human health effects.
e) The criterion for all carcinogens is zero; the concentration given in parentheses corresponds to a carcinogenic risk of
10-6. Water Quality Criteria documents present concentrations resulting in risks from 10-5 to 10-7. To obtain
concentrations corresponding to risks of 10-4 and 10-5, the 10-6 concentrations should be multiplied by 100 and 10,
respectively. To obtain concentrations corresponding to risk of 10-7, 10-6 concentrations should be divided by 10.
f) These values are based on updated calculations performed by EPA's Carcinogen Assessment Group.
g) Chloroform is one of four trihalomethanes whose sum concentration must be less than 0.1 mg/L.
h) Activity corresponding to total body or any internal organ dose of 4 mrem/year.
i) Total trihalomethanes refers to the sum concentration of chloroform, bromodichloromethane, dibromochloromethane and
bromoform.
C-5
-------
-------
APPENDIX D
INTERIM FINAL GUIDANCE ON REMOVAL ACTION LEVELS AT CONTAMINATED DRINKING
WATER SITES
REMOVAL ACTION LEVELS FOR CONTAMINATED
DRINKING WATER SITES
Introduction
The purpose of this guidance is to establish "action
levels" for providing alternate water supplies under
Superfund removal authority at contaminated drinking
water sites. The action level is the primary criterion
that must be met for a site to qualify for removal
response. The action levels established in this
guidance must generally be satisfied before removal
authority can be used at either National Priorities List
(NPL) sites or non-NPL sites.
Under the 1982 National Contingency Plan (NCP),
removal actions were taken in response to
"immediate and significant" threats to human health
or the environment. The removal program used the
10-Day Health Advisory as the principal benchmark
to identify those drinking water contamination
incidents that posed the most acute threats to human
health. The November 1985 NCP broadened removal
authority by authorizing response in situations that
present a "threat" to human health or the
environment. Therefore, removal actions may now be
taken in less urgent situations than under the 1982
NCP.
In response to this expansion of removal authority,
the Office of Emergency and Remedial Response
(OERR) is revising removal program action levels for
contaminated drinking water sites. This guidance
expands the previous policy in a number of ways.
First, the numeric action levels are now based on
levels that are protective for a lifetime exposure rather
than a 10-day exposure. Second, both carcinogenic
and non-carcinogenic health effects are considered.
Third, a reduction factor is used for volatiles to
account for exposure due to inhalation. Finally,
additional guidance is provided on the use of site-
specific factors to trigger removal actions.
The action levels established in this guidance allow a
site to qualify for removal response if either: 1) the
numeric trigger is exceeded at the tap, or 2) site-
specific factors otherwise indicate that a significant
health threat exists. The guidance also discusses
information sources on health threats from drinking
water contamination, factors to consider in
determining the extent of action, action levels vs.
cleanup standards, prioritizing removal sites, and
obtaining exemptions to the statutory limits for
alternate water supply sites.
Action Level Based on Numeric Trigger
The numeric trigger is calculated using a model that
establishes four different action levels, depending on
whether the substance is also a potential human
carcinogen and/or volatile. The model is explained
below and summarized in Exhibit 1. Based on this
model, Exhibit 2 lists the numeric action level for
various substances that may be found in drinking
water at Superfund sites. A site may qualify for
removal response if the numeric trigger for the
drinking water contaminant is exceeded at the tap of
at least one residence ("residence" includes schools,
businesses, etc.). (Note that the decision to initiate a
removal action is based on other factors as well, such
as the availability of other response mechanisms to
initiate action in a timely manner.)
The first step in calculating the numeric trigger is
determining whether the substance of concern is also
a potential human carcinogen and/or volatile. For
purposes of this guidance, a substance is a
carcinogen if it falls into categories A, B, or C of
EPA's carcinogen classification guidelines. (A
substance should be considered a non-carcinogen if
it is in categories D or E.) Volatile organic chemicals
(VOCs) are generally of low molecular weight, high
vapor pressure, and low solubility. For purposes of
this guidance, VOCs include those chemicals
identified as volatiles in the following documents: Test
Methods for Evaluating Solid Waste, Vol. 1A, SW-
846, 3rd ed., November 1986 (Chapter 2); Contract
Lab Program Statement of Work, October 1986
(Exhibit C); Methods for the Determination of Organic
Compounds in Finished Drinking Water and Raw
Source Water, September 1986 (available from
Regional water program offices); and 40 CFR Part
264, Appendix IX (analytical methods 8010 and 8240
designate volatiles).
With the substance thus classified, the second step is
to determine the appropriate action level in
accordance with the categories below:
1. Non-volatile non-carcinogens -- Action
level equals the Drinking Water Equivalent Level
(DWEL).*
Volatile non-carcinogens -- Action level
equals 50 percent of the DWEL.
Non-volatile carcinogens - Action level is
determined by comparing the DWEL to the
10-4 Lifetime Upperbound Cancer Risk Level,
and choosing the lower of the two.
Volatile carcinogens -- Action level is
determined by comparing 50 percent of the
DWEL to the 10-4 Lifetime Upperbound Cancer
Risk Level, and choosing the lower of the two.
The action level for methylene chloride, for example,
is calculated as follows. Methylene chloride is a
"DWEL equals Reference Dose (RfD) times 70 kg * 2 liters/day
2.
3.
4.
D-1
-------
volatile and a potential human carcinogen- (classified
as a "82" under EPA guidelines). The DWEL for
methylene chloride equals 1750 ppb and the 10-4
Cancer Risk Level equals 48 ppb. The action level is
determined by comparing 50 percent of the DWEL, or
875 ppb, to the 10"4 Cancer Risk Level, or 48 ppb,
and choosing the lower of the two, which is 48 ppb. If
at least one residence has methylene chloride levels
that exceed 48 ppb at the tap, the site may qualify for
removal response.
This model will provide an action level for many of the
substances commonly encountered in drinking water
at Superfund sites, including many solvents.
However, OERR is still working on establishing an
appropriate action level for certain substances in the
two situations described below. Until action levels are
developed, most decisions regarding these
substances will be made in OERR. The modifications
discussed below have been incorporated into Exhibits
1 and 2.
The calculated action level for a substance is
lower than or equal to the Maximum
Contaminant Level (MCL) established under the
Safe Drinking Water Act (SDWA). For example,
for vinyl chloride, a volatile carcinogen, the
calculated action level under this model is 1.5
ppb (1.5 ppb is the 10'4 Cancer Risk Level,
which is lower than 50% of the DWEL).
However, 1.5 ppb is lower than the MCL for
vinyl chloride, which is 2 ppb. Given the limited
scope of the removal program, it may not be
appropriate for the removal program to trigger
removal action at levels equal to or below the
MCL. Therefore, OERR is currently examining
whether it would be appropriate to establish an
alternate action level for these substances that
is above the MCL. Until an action level is
established for these substances, removal action
may be initiated if contaminant levels exceed the
10-Day Health Advisory. However, if
contaminant levels are between the calculated
action level and the 10-Day Health Advisory,
OERR will review individual site conditions to
determine if removal action should be taken.
The calculated action level is based on the
DWEL, but the 10-Day Health Advisory is lower
than the DWEL. For most substances, the 10-
Day Health Advisory is higher than the DWEL. In
some cases, however, the 10-day advisory is
lower than.the DWEL. (This situation occurs
primarily where 10-day exposure data were not
available, so the 10-Day Health Advisories
were based on other studies.) For example, the
action level for barium (a non-volatile non-
carcinogen) is based on the DWEL of 1800 ppb,
but the 10-Day Health Advisory for barium is
1500 ppb. OERR is currently examining whether
it would be appropriate to use the lower 10-day
advisories as the removal action level. Until
OERR determines if an alternate action level is
appropriate for these substances, removal action
may be initiated if contaminant levels exceed the
DWEL. However, if contaminant levels are
between the (lower) 10-Day Health Advisory
and the DWEL, OERR will review individual site
conditions to determine if removal action should
be taken.
Action Level Based on Site-Specific Factors
A significant health threat may exist even though the
numeric action level has not been exceeded. A
removal action may be initiated if the health risk at a
site has been analyzed in detail and the analysis
indicates that a serious health risk is present due to
site-specific factors. Examples of such factors
include evidence that a contaminated groundwater
plume is moving, contaminant levels will likely
increase (e.g., increased pumping from an aquifer
anticipated during summer months), people have
been drinking contaminated water for a long period of
time, multiple contaminants are likely to result in
synergistic effects, there are sensitive members in
the population at risk, etc.
With regard to a threat based on future
contamination, as a general rule, removal action may
be warranted where it can be projected that the
numeric action level will be exceeded within 6
months. It is important to note that this 6 month
period is not related to the definition of time-
critical/non-time-critical removal actions. For
example, where contaminant levels will likely exceed
the DWEL by a significant amount within 6 months, a
time-critical removal action would be appropriate.
However, if contaminant levels will only exceed the
DWEL by a minimal amount within 6 months, a non-
time-critical removal action may be more
appropriate. Future threat may therefore warrant
either a time-critical or non-time-critical removal
action.
When conditions such as those described above are
present, the site may qualify for removal action even
though a numeric indicator has not been exceeded.
Decisions will be made on a case-by-case basis.
OERR concurrence must be obtained before
approving Action Memoranda for contaminated
drinking water sites where the removal action
decision is based solely on site-specific factors,
even where site cost or time projections do not
exceed the statutory limits on removal actions.
However, if an emergency exists based on site-
specific factors, action may be initiated immediately
and OERR should be contacted as soon as possible.
Information Sources
DWELS, as well as RfDs and other relevant
standards and advisories, are available to the Regions
through the Integrated Risk Information System
(IRIS). IRIS can be accessed on-line through E-
D-2
-------
mail; type in "IRIS" at the prompt rather than "mail."
The EPA Office of Drinking Water has also
established a Safe Drinking Water Hotline, which can
provide information about relevant standards and
criteria, and treatment techniques for contaminated
drinking water. The Hotline telephone number is
800-426-4791 (in the Washington D.C. area, 382-
5533).
Additional advice and information on health
assessments at drinking water contamination sites
may be obtained from the Agency for Toxic
Substances and Disease Registry (ATSDR) and the
Superfund Public Health Evaluation Manual Directive
#9285.4-01). ATSDR may be particularly helpful in
providing advice on threats posed by site-specific
factors.
OERR should be contacted if a substance of concern
does not have a DWEL, RfD, and/or cancer risk level.
Determining the Extent of Action
Once it has been determined that a site qualifies for
removal response based on a numeric trigger or
site-specific factors, the Region must determine how
many residences (including businesses, schools, etc.)
will receive alternate water supplies. First, the area of
impact should be estimated (both extent and
magnitude of the threat) by considering factors such
as the hydrogeology of the site, plume movement,
and the likelihood of contaminant levels increasing.
For sites where removal action is warranted because
the numeric trigger has been exceeded at certain
residences, the area of impact may be defined to
include neighboring residences which are at risk, but
do not exceed the numeric trigger.
After the area of impact fs defined, the number of
residences to be provided with alternate water
supplies must be determined by considering cost vs.
benefits received, the statutory limits on removal
actions, and the availability of other response
mechanisms. For example, response to widespread
low-level contamination may be too extensive for
removal action, and therefore, may be addressed
more appropriately by the remedial program. In
another case, a contaminated aquifer may affect a
public water supply system and private wells, but
Superfund resources may only be needed to address
the private wells.
Determining the appropriate extent of action therefore
involves analysis of both the area of impact and
programmatic factors.
Action Levels vs, Cleanup Standards
The numeric action levels established in this guidance
are not intended to be used as cleanup standards.
The MCL, if available, will generally be the
appropriate cleanup standard. (For guidance on the
use of MCLs and MCLGs as cleanup standards, see
"Interim Guidance on Compliance with Applicable or
Relevant and Appropriate Requirements," July 9,
1987, OSWER Directive 9234.0-05. Final guidance
will be issued in the CERCLA Compliance with
ARARs Manual.) This means that for any residence
provided with an alternate water supply, the goal will
generally be to meet MCLs. For example, if carbon
filter units will be provided to treat drinking water
contaminated with trichloroethylene (TCE), treated
water should achieve 5 ppb TCE, the MCL.
Prioritizing Removal Sites.
Sites may qualify for removal action under either the
numeric indicator or site-specific factor approaches.
For the purpose of prioritizing those site that qualify
for removal action, response should be initiated as
soon as possible if contaminant levels exceed the
10-Day Health Advisory or site-specific factors
ptherwise indicate that an emergency exists.
Exemption to the Statutory Limits
To obtain an exemption to the $2 million/12 month
limits on removal actions based on a continuing
emergency, it will generally not be adequate to show
that contaminant levels exceed the numeric action
level by some minimal amount. An exemption may be
justified if contaminant levels exceed the 10-Day
Health Advisory, significantly exceed the numeric
action level, or an emergency exists based on site-
specific factors. A finding that contaminant levels
exceed the numeric action level by a minimal amount
may be appropriate, however, in "non-emergency"
situations where an exemption is based on the new
consistency waiver.
Summary of Policy
A contaminated drinking water site may qualify for
removal response if: 1) the numeric action level
(based on the DWEL and/or the 10-4 Lifetime
Upperbound Cancer Risk Level) is exceeded, or
2) site-specific factors otherwise indicate the
presence of a serious health threat. In prioritizing
those sites that qualify for response under this model,
Regions should give priority to sites where
contaminant levels exceed the 10-Day Health
Advisory or site-specific factors otherwise indicate
that an emergency exists.
D-3
-------
Exhibit 1: Summary of Action Level Decision Model
Do contaminant levels exceed the NUMERIC action level?
Is the substance a volatile and/or potential human carcinogen?
Non-volatile non-carcinogens - Action level equals the DWEL.
Volatile non-carinogens - Action level equals 50% of the DWEL.
Non-volatile carcinogens - Action level is determined by
comparing the DWEL to the 10-4 Lifetime Upperbound Cancer
Risk Level, and choosing the lower of the two.
Volatile carcinogens - Action level is determined by comparing
50% of the DWEL to the 10"4 Lifetime Upperbound Cancer Risk
Level, and choosing the lower of the two.
Do either of the two modifications to the numeric action level
apply?
Is the numeric action level lower than or equal to the MCL, if available?
If yes:
If contaminant levels are between the numeric action level and the
10-day Health Advisory, contact OERR to determine appropriate
action.
If contaminant levels exceed the 10-Day Health Advisory, action be
taken if the site otherwise qualifies for removal response.
If the action level is based on the DWEL, is the 10-day Health Advisory
lower than the DWEL? If yes:
If contaminant levels are between the (lower) 10-day Health
Advisory and the DWEL, contact OERR to determine appropriate
action.
If contaminant levels exceed the DWEL, action may be taken if the
otherwise qualifies for removal response
If contaminant levels do not exceed the numeric trigger, can the
site quality for removal response based on SITE-SPECIFIC
FACTORS?
A site can qualify for removal response if the health risk at a site has
been analyzed in detail and the analysis indicates that a serious health
risk is present due to site-specific factors.
ATSDR may be particularly helpful in providing advice on health due
to site-specific factors.
OERR concurrence must be obtained before approving Action
Memoranda based on site-specific factors, even where the site will
not exceed the statutory limits on removal actions.
D-4
-------
Exhibit 2
Removal Numeric Action
Chemical
Alachlor
Barium
Benzene
Cadmium
Carbofuran
Carbon tetrachloride
Chlordane
Chlorobenzene
Chromium (total)
Cyanide
o-Dichlorobenzene
p-Dichlorobenzene
1 ,2-Dichloroethane
1,1-Dichloroethylene
Cis-1,2-
Dichloroethylene
Trans- 1,2-
Dichloroethylene
Dichloromethane/
Methylene chloride
Endrin
Ethylbenzene
Heptachlor
Lindane
Mercury (inorganic)
Methoxychlor
Methyl ethyl ketone
(MEK)
Nickel
Pentachlorophenol (PGP)
Styrene
Tetrachloroethylene
(PCE)
Toluene
Toxaphene
1 ,1 ,1 -Trichloroethane
Trichloroethylene
Vinyl chloride
Xylenes (total)
Levels for Contaminated Drinking Water Sites (pg/L)
EPA
Volatile Carcinogen 10-Day
(Y/N) Groupa MCL HA DWELb
N
N
Y
N
N
Y
N
Y
N
N
Y
Y
Y
Y
Y
Y
Y
N
Y
N
N
Ne
N
Y
N
Y
Y
Y
Y
N
Y
Y
Y
Y
B2
D
A
D
E
B2
B2
D
D
D
D
C
B2
C
D
D
B2
E
D
B2
C
D
D
D
D
D
C
B2/C
D
B2
D
B2
A
D
None
1000
5
10
None
5
None
None
50
None
None
75
5
7
None
None
None
0.2
None
None
4
2
100
None
None
None
None
None
None
5
200
5
2
None
100
1500C
235
43C
50C
160
63
4300C
1400
22QC
8930C
1070QC
74QC
1000C
1000C
1430C
1500
5
3200C
10
1200
1.6<=
2000
7500C
1000
300C
200QC
2000
3460C
40
35000C
None
2600
7800C
350
1800
NA
17
175
24
1.6
1505
168
770
3115
3500
None
350
350
350
1750
1.6
3395
17
10
5.5
1750
864
350
1050
7000
500
12100
None
1000
257
None
2157
10-4 Removal
Cancer Risk Action
Level Level
44
NA
120
NA
NA
27
2.7
NA
NA
NA
NA
175
38
None
NA
NA
480
NA
NA
7.6
None
NA
NA
NA
NA
NA
None
66
NA
3.1
NA
280
1.5
NA
44
1800d
120
17
175d
12
1.6
753
168
770d
1558
175
38
175
175
175
480
1.6
1698d
7.6
10
5.5f
1750
432
350
525d
3500d
66
6050d
409
500
128
1300h
1078
(Continued)
D-5
-------
Exhibit 2 (Continued)
Chemical
Volatile
(Y/N)
EPA
Carcinogen
Groupa
MCL
10-Day
HA
DWEL&
10-4
Cancer Risk
Level
Removal
Action
Level
a Carcinogen group designation is from EPA carcinogen classification guidelines for effects from ingestion.
b DWEL equals RfD times 70kg divided by 21/day. (Note that the DWEL in health advisory documents produced by
EPA's Office of Drinking Water may be slightly different due to rounding.)
c Because no suitable studies of appropriate duration were available, these 10-day Health Advisories were based
on Health Advisories of greater or lesser duration, e.g., 1 -Day, Longer-term, and lifetime Health Advisories.
d Removal action level is an interim value. OERR is examining whether it would be appropriate to use the lower
10-Day Health Advisory (50% for volatiles) as the action. Until that time, if contaminant levels exceed the action
level shown in the table, removal action may be taken. If contaminant levels exceed the 10-day advisory (50%
for volatiles), but not the DWEL (50% for volatiles), consult OERR.
e. Not soluble in water.
f. Removal action may be initiated if mercury levels exceed the DWEL of 5.5 ug/L. If mercury levels exceed the
10-day advisory of 1.6 ug/L, but not 5.5 ug/L, consult OERR.
Q Removal action may be initiated immediately if toxaphene levels exceed the 10-Day Health Advisory of 40 ug/L-
If toxaphene levels exceed the 10'4 Cancer Risk Level of 3.1 ug/L, but not 40 ug/L, consult OERR.
h Removal action may be initiated immediately if vinyl chloride levels exceed 1300 ug/L, which is 50% of the 10-
Day Health Advisory. If vinyl chloride levels exceed the 10-4 Cancer Risk Level of 1.5 ug/L, but not 1300 ug/L,
consult OERR.
NA = Not appropriate.
D-6
-------
APPENDIX E
TREATABILITY CLASSIFICATION OF PRIORITY
POLLUTANTS
NAME
Acenaphthene
Acenaphthlyene
Acetone
Acrolein
Acrylonitrile
Aldrin
Aluminum
Aniline
Anthracene
Antimony
Arsenic
Asbestos
Barium
Beryllium
Benzene
Benzidine
Benzo(a)anthracene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzole Acid
Benzo(ghi)perylene
Benzo(e)pyrene
Benzyl Alcohol
BHC-Alpha
BHC-Beta
BHC-Gamma
BHC-Delta
Bis (2-chloroethoxy)methane
Bis(2-chloroethyl)ether
Bis(chloromethyl)ether
Acenaphthene
Acenaphthlyene
Acetone
Acrolein
Acrylonitrile
Aldrin
Aluminum
Aniline
Anthracene
Antimony
Arsenic
Asbestos
Barium
Beryllium
Benzene
Benzidine
Benzo(a)anthracene
Benzo(b)fluoranthene
TREATABILITY CLASS
Aromatics
Aromatics
Ketones
Miscellaneous
Miscellaneous
Pesticides
Metals
Aromatics
Aromatics
Metals
Metals
Miscellaneous
Metals
Metals
Aromatics
Substitute Aromatics
Aromatics
Aromatics
Aromatics
Aromatics
Aromatics
Aromatics
Aromatics
Pesticides
Pesticides
Pesticides
Pesticides
Halocarbon
Chlorinated Ethers
Chlorinated Ethers
Aromatics
Aromatics
Ketones
Miscellaneous
Miscellaneous
Pesticides
Metals
Aromatics
Aromatics
Metals
Metals
Miscellaneous
Metals
Metals
Aromatics
Substitute Aromatics
Aromatics
Aromatics
SYNONYMS
1 ,2-Dihydroacenaphthylene
2 Propenal
2 Propenenitrile
Stibium
Amianthus
Benzol
Lindane
1 ,2-Dihydroacenaphthylene
2 Propenal
2 Propenenitrile
Stibium
Amianthus
Benzol
SOURCE: adapted, from Shuckrow et al. 1980
E-1
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NAME
APPENDIX E (Continued)
TREATABILITY CLASS
SYNONYMS
Benzo{k)fluoranthene
Benzoic Acid
Benzo(ghi)perylene
Benzo(e)pyrene
Benzyl Alcohol
BHC-Alpha
BHC-Beta
BHC-Gamma
BHC-Delta
Bis (2-chIoroethoxy)methane
Bis(2-chloroethyl)ether
Bis(chloromethyl)ether
Bis(2-chloroisopropyl)ether
Bis{2-ethylhexyl)phthalate
Bromoform
4-Bromophenyl Phenyl Ether
2-Butanone
Butyl Benzyl Phthalate
Cadmium
Calcium
Carbon disulfide
Carbon Tetrachloride
Chlordane
4-Chloroaniline
Chlorobenzene
Chlorodibromomethane
Chloroe thane
2-Chloroethyl Vinyl Ether
Chloroform1
2-Chlorophenol
4-Chlorophenyl Phenyl Ether
2-Chloronaphthalene
Chromium
Chrysene
Cobalt
Copper
Cyanide
4,4'-DDD
4,4'-DDE
4,4'-DDT
Dibenzo(a,h)anthracene
Dibenzofuran
1,3-dichlorobenzene
1,2-Dichlorobenzene
1,4-DichIorobenzene
3,3'-Dichlorobenzidine
Dichlorbromomethane,
Dichlorodifluromethane
Aromatics
Aromatics
Aromatics
Aromatics
Aromatics
Pesticides
Pesticides
Pesticides
Pesticides
Halocarbon
Chlorinated Ethers
Chlorinated Ethers
Chlorinated Ethers
Phthalate Esters
Halocarbon
Chlorinated Ethers
Ketones
Phthalate Esters
Metals
Metals
Miscellaneous
Halocarbon
Pesticides
Chlorated Aromatics
Chlorinated Aromatics
Chlorinated Alkanes
Chlorinated Alkanes
Chlorinated Ethers
Halocarbon1
Phenols
Chlorinated Ethers
Chlorinated Aromatics
Metals
Aromatics
Metals
Metals
Miscellaneous
Pesticides
Pesticides
Pesticides
Chlorinated Aromatics
Chlorinated Aromatics
Chlorinated Aromatics
Chlorinated Aromatics
Substitute Aromatics
Halocarbon
Halocarbon
Lindane
Tribromomethane
Methyl Ethyl Ketone
Tetrachloromethane
Monochlorobenzene
(2-Chloroethoxy)Ethane
Trichloromethane1
1,2-Benzphenanthrene
SOURCE: adapted, from Shuckrow et al. 1980
1Trihalomethanes can be found in a water supply either due to direct contamination, or formation during
treatment or distribution. The treatment approach for this latter situation strives for prevention of formation,
rather than removal via treatment.
E-2
-------
APPENDIX E (Continued)
NAME
TREATABILITY CLASS
SYNONYMS
1,1-Dichloroethane
1,2-Dichloroethane
1,1 -Dichloroethylene
2,4-Dichloro Phenol
1,2-Dichloropropane
1,3-Dichloropropylene
Dieldrin
Diethylphthalate
2,4-Dimethylphenol
Dimethyl Phthalate
Di-N-Butyl Phthalate
4,6-Dinitro-O-Cresol
4,6-Dinitro-2-methylphenol
2,4-Dinitrophenol
2,4-Dinitrotoluene
2,6-Dinitrotoluene
Di-N-Octyl Phthalate
1,2-Diphenyl Hydrazine
A-Endosulfan-Alpha
B-Endosulfan-Beta
Endosulfan Sulfate
Endrin
Endrin Ketone
Endrin Aldehyde
Ethylbenzene
Fluoranthene
Fluorene
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclopentadiene
Hexachloroethane
2-Hexanone
Indeno (1,2,3-c,d)Pyrene
Iron
Isophorone
Lead
Magnesium
Manganese
Mercury
Methoxychlor
Methyl Bromide
Methyl Chloride
Methylene Chloride
2-Methylnaphthalene
2-Methylphenol
4-Methylphenol
4-Methyl-2-pentanone
Nickel
Halocarbon
Halocarbon
Halocarbon
Phenolts
Halocarbon
Halocarbon
Pesticides
Phthalate Esters
Phenols
Phthalate Esters
Phthalate Esters
Phenols
Phenols
Phenols
Substituted Aromatics
Substituted Aromatics
Phthalate Esters
Substitute Aromatics
Pesticide
Pesticide
Pesticide
Pesticide
Pesiticide
Pesticide
Aromatics
Aromatics
Aromatics
Pesticides
Pesticides
Chlorinated Aromatics
Halocarbon
Halocarbon
Halocarbon
Ketones
Aromatics
Metals
Miscellaneous
Metals
Metals
Metals
Metals
Pesticides
Hafocarbon
Halocarbon
Halocarbon
Aromatics
Phenols
Phenols
Ketones
Metals
1,2-Benzenedicarboxylic Acid
2-Methyl-4, 6-Dinitrophenol
Aldifen
Perchlorobenzene
Hydrargyrum
Bromomethane; Monobromo-
methane; Embafume
Chloromethane
Dichloromethane
(Methyl Isobutyl Ketone)
SOURCE: adapted, from Shuckrow et al. 1980
E-3
-------
NAME
APPENDIX E (Continued)
TREATABILITY CLASS
SYNONYMS
2-Nitroaniline
3-Nitroaniline
4-Nitroaniline
Nitrobenzene
2-Nitrophenol
4-Nitrophenol
N-Nitrosodimethylamine
N-Nitrosodiphenylamine
N-Nitrosodipropylamine
Para-Chloro-Meta-Cresol
PCB-1016
PCB-1221
PCB-1232
PCB-1242
PCB-1248
PCB-1254
PCB-1260
Pentachlorophenol
Phenan thane
Phenol
Potassium
Pyrene
Selenium
Silver
Sodium
Styrene
2,3,7,8-Tetrachlorodibenzo-p-
Dioxin
1,1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Thallium
Tin
Toluene
Toxaphene
1 ,2-Trans-DichIoroethylene
1 ,2,4-Trichtofobenzene
1,1,1-Trichloroethane
1,1,2-Trichloroethane
Trichloroethylene
Trichlorofluoromethane
Aromatic
Aromatic
Aromatic
Substituted Aromatics
Phenols
Phenols
Miscellaneous
Miscellaneous
Miscellaneous
Phenols
Polychlorinated Biphenyls
Phenols
Aromatics
Phenols
Metals
Aromatics
Metals
Metals
Metals
Aromatic
Halocarbon
Halocarbon
Metals
Metals
Aromatics
Pesticides
Halocarbon
Chlorinated Aromatics
Halocarbon
Halocarbon
Halocarbon
Halocarbon
Nitrobenzol
Penta; PCP; Penchloro;
Santophen
Carbolic Acid; Phenic Acid
Benzo(def)Phenanthrene
Perchlorothylene; Ethylene
Tetrachloride
Methylbenzene
Vinyl Trichloride
Trichloroethene; Ethinyl
Trichloride
Fluorotrichloromethane
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
Vanadium
Vinyl Acetate
Vinyl Chloride
Xylenes
Zinc
Chlorinated Aromatics
Phenols
Metals
Halocarbons
Aromatics
Metals
Dowicide 25; Omal
Chloroethylene
SOURCE: adapted, from Shuckrow et al. 1980
E-4
-------
ACI
ARAR
CERCLA
CLP
CRDL
CRP
DWAL
DWEL
EE/CA
EIS
EPA
ERGS
ERA
FS
GAG
HA
HEA
ISO
MCL
MCLG
NCP
NEPA
NPL
OERR
OSC
PAS
RAMP
Rl
RPM
ROD
SARA
SDWA
USGS
USPHS
WQC
APPENDIX F
GLOSSARY OF ACRONYMS
Acceptable Chronic Intake, developed by EPA's Environmental Criteria and Assessment
office.
Applicable or Relevant and Appropriate Requirements
Comprehensive Environmental Response, Compensation and Liability Act of 1980.Also
known as Superfund.
Contract Laboratory Program
Contract Required Detection Limit
Community Relations Plan
Drinking Water Action Levels
Drinking Water Equivalent Levels
Engineering Evaluation and Cost Analysis
Environmental Impact Statement
Environmental Protection Agency
Emergency Response Cleanup Services
Expedited Response Action
Feasibility Study
Granular Activated Carbon
Health Advisory
Health Effects Assessment
Insurance Services Office
Maximum Contaminant Level, established under the Safe Drinking Water Act.
Maximum Contaminant Level Goal
National Oil and Hazardous Substance Contingency Plan
National Environmental Policy Act
National Priorities List
Office of Emergency and Remedial Response, U.S. EPA
On-Scene Coordinator
Policy Analysis Staff
Remedial Action Management Plan
Remedial Investigation
Remedial Project Manager
Record of Decision
Superfund Amendments Reauthorization Act
Safe Drinking Water Act
U.S. Geological Survey
U.S. Public Health Service
Water Quality Criteria
F-1
U. S. GOVERNMENT PRINTING OFFICE: 1988/548-158/87038
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