UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WSG66
Date Signed: August 25, 1992
MEMORANDUM
SUBJECT: Final Guidances for State Sampling Waiver Programs
FROM: Robert J. Blanco, Director
Enforcement and Program Implementation Division
TO: Drinking Water & Ground Water Protection Branch
Chiefs
Regions I - X
This is to distribute the final national and Region V Guidances for State Sampling
Waiver Programs. I would like to thank Regions IV, V, VI and VIII for their comments on the
draft national guidance. We have tried to address these comments, while keeping the detail and
length of this guidance to a minimum.
I hope these documents will be useful to you in reviewing State primacy applications. If
you have any further questions about the Region V guidance, please call Ed Walters at 312/353-
2151, or have your staff call Tom Matheson at 312/886-6204. If you have any questions about
the national guidance, please call me at 202/260-5522, or have your staff call Mike Muse at
202/260-3874.
cc: Drinking Water Section Chiefs
Regional Phase II/V Coordinators
Ramona Trovato, GWPD
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GUIDANCE TO REGIONS FOR REVIEW OF STATE WAIVER PROGRAMS
UNDER PHASE II & V PRIMACY REVISION APPLICATIONS
Introduction
The purpose of this document is to provide guidance to regional offices to help them
review State waiver programs for surface water and ground water systems established pursuant
to the Phase II and V National Primary Drinking Water Regulations (NPDWRs). This guidance
summarizes waiver provisions in the NPDWRs and then presents the criteria Regions should
consider in reviewing State requests to take advantage of these provisions.
Waiver Provision
The Phase II/V NPDWRs provide States the flexibility to grant waivers to systems. The
NPDWRs state that systems are responsible for submitting waiver requests to the States. The
States are responsible for acting on these waiver requests and deciding if the monitoring
requirements can be reduced. In the absence of a State decision, the water system is legally
responsible for performing full monitoring as though a waiver request had been denied. The
same is true in States conducting vulnerability assessments on behalf of their water systems;
failure by the State to complete a vulnerability assessment and issue a waiver does not excuse the
water system from its monitoring responsibilities.
Waivers are allowed for asbestos, lOCs, SOCs, and VOCs. They are not allowed for
nitrate or nitrite.1 Waivers for VOC monitoring in surface water can be used to reduce or
completely eliminate repeat monitoring, but waivers for VOC monitoring in ground water and all
IOC monitoring can be used only to reduce the repeat monitoring requirements. Waivers for
VOC monitoring and IOC monitoring can not alter the initial sampling requirements. Waivers
for SOC monitoring and asbestos monitoring can be used to reduce or eliminate all monitoring
requirements.
There are two basic types of waivers: use and susceptibility. States may also devise a
variety of combined use/susceptibility waivers. Use waivers may be granted where there is no
previous use (including transport, storage,.or disposal) of the contaminant within the watershed
or delineated area (VOC use waivers must include consideration of initial sampling results.).
Susceptibility waivers may be granted where the contaminant has been used or where the use is
unknown after considering several factors which would influence the probability of its
occurrence in the source water. These factors are:
For Asbestos - presence of asbestos in the source water and the potential for asbestos
contamination in the distribution system, including the use of unlined asbestos-cement
pipe and the corrosivity of finished water;
1 The regulation of sulfate an NPDWR will be decided at some future date.
2
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For IQCs - all previous analytical results, the variation in the concentration and other
factors affecting concentration e.g, changes in pumping rates, system configuration or
operating procedures, and stream flows or characteristics;
For SOCs - (1) previous analytical results, (2) environmental persistence and transport of
the chemical, (3) proximity of the system to a potential point or non-point source of
contamination, including: spills and leaks at or near the water system; from
manufacturing, distribution, or storage facilities; from hazardous and municipal waste
landfills and other waste handling facilities; and the use of pesticides on agricultural
areas, forest lands, home and gardens, and other land application uses, (4) elevated nitrate
levels as an indicator of potential for pesticide contamination, (5) aspects of source water
protection, including depth of the well and integrity of its casing, and type of soil in the
delineated area, and (6) for PCBs the proximity of water pumps, electrical transformers
or other equipment that may contain PCBS.
For VOCs - (1) previous analytical results, (2) environmental persistence and transport of
the compound, (3) proximity of the water system to potential sources of contamination,
including spills or leaks: at or near the water treatment facility; from commercial or
industrial use, disposal, or storage of contaminants; and from hazardous and municipal
waste landfills and other waste handling facilities, (4) number of persons served by the
system, and (5) the proximity of a small system to a larger system.
States can design their waiver programs in many different ways. Waivers can be given
on an individual system basis or on an area-wide basis. States could limit waivers to certain
groups of contaminants (e.g. pesticides). They may limit waivers to use waivers only; they may
wish to focus their resources on area-wide waivers only; or they may want to limit waivers to
ground water systems' or to systems serving certain population categories.
States should carefully evaluate their options to determine what type of program has the
greatest benefit for the resource investment, while providing an adequate level of public health
protection. Because waivers have a potentially significant long term payoff in terms of reducing
source water contamination, States should begin to establish waiver programs, even if they do
not yet have sufficient resources to implement vulnerability analyses for all contaminants.
Criteria for Reviewing/Approving State Waiver Programs
When reviewing State waiver programs, regions should be satisfied that the State
drinking water authority has thought through and adequately described: (1) the type of waiver
program it is adopting; (2) a sound method for meeting the minimum requirements (described
above) for granting waivers; (3) a sound way of coordinating its activities with its ground water
protection counterparts; and (4) adequate procedures for reviewing and approving waiver
applications and documenting the results. These criteria are described in greater detail below.
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(1) Type of waiver Program: The State should identify the kinds of waivers it intends to
issue (use/susceptibility; types of contaminants; area-wide /individual) and the types of
systems eligible for the program.
(2) Method of Meeting Minimum Requirements: The State Primacy Application should
adequately answer the following questions:
Does the State have a sound method for determining the monitoring waiver
review area and assuring that its time of travel equals or exceeds the term of the
waiver? Is this method the same or complementary to the area delineation
method used in the Wellhead Protection Program (WHPP)?
Has the State adequately considered all sources of information to meet the
requirement outlined above, e.g. source water quality, management of existing
and future contamination sites within the monitoring waiver review area,
pesticide programs, wellhead protection and well construction records, geology or
soil data?
Does the State present a reasonable plan for using this information to make sound
decisions, and is the plan easy to use and understand by field/county offices that
may help in making the determinations? Are the decision criteria and process
clearly explained i.e... would two reviewers come to the same conclusion using
the State's procedures?
(3) Coordination with Ground Water Program: The State should describe the
coordination between its waiver and ground water programs. If the State has adopted a
wellhead protection program, the waiver program should complement this effort by using
its area delineation methods and its contamination sites inventory. If the State has not yet
adopted a wellhead program, its ground water staff should participate in the waiver
program development, so that its future wellhead program is consistent with the waiver
program.
(4) Procedures for Reviewing/Approving/Documenting Waiver Decisions: The State
application should describe its overall procedures for granting, renewing and recording
waivers. The State should address who has authority to sign waivers, what the internal
review process is, and how it will document the decision. States should not allow their
field offices to grant verbal waivers to systems based on the "judgement" of the field
staff. The State should have a well documented and reasonably uniform process. State
waiver decisions are subject to EPA review, and future data verification efforts should
include a random sample of waivers.
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U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION 5
MONITORING WAIVERS GUIDANCE
Introduction
As part of the Phase 11 Regulatory package for 38 inorganic and organic contaminants, the U.S.
Environmental Protection Agency (U.S. EPA) established a standardized monitoring framework.
The U.S. EPA's use of a standard monitoring framework will apply to future monitoring
requirements for inorganics, Volatile Organic Chemicals (VOC), pesticides, and radionuclides.
Monitoring requirements for currently regulated contaminants will be integrated into the
framework when the existing regulations are revised.
The degree of variability among monitoring requirements poses both management and technical
barriers for States and water systems that are ultimately responsible for implementing and
complying with the regulations. In response, the U.S. EPA has attempted to standardize and
simplify monitoring requirements and synchronize monitoring schedules where possible. The
benefits of this action are:
1) Reduce the complexity of the
monitoring workload from a technical and
managerial perspective for both States and
water systems;
2) Level out resource expenditures for
monitoring and vulnerability assessments;
3) Reduce sampling and vulnerability
determination costs; and
4) Increase compliance with monitoring
requirements.
Standardized Monitoring Framework
To standardize monitoring, the U.S. EPA has
established nine-year compliance cycles (Figure
1). Each nine-year compliance cycle has 3 three-
year compliance periods. All compliance cycles
and periods run on a calendar year basis (January 1
to December 31). The first compliance cycle
begins on January 1, 1993 and ends on December Figure L A nine.year compiiance cycie with the
31, 2001. Within the first nine-year Cycle, the first three-year compliance periods.
compliance period begins January 1, 1993 and
ends December 31, 1995; the second compliance period begins January 1, 1996 and ends
December
Nine-Tear
Prinking Water Monitoring -
, Compliance Cycle
, ,
O Year
N 1'
E '
- ' Year
C 2. .
O
M Year
P 3
L
I ' Year
A- 4
N
c Year
E S
ft Year
Y' «..'
c
, . Year
E-'. 7"
. Year
8,
Year '
9
f
Initial
Monitoring
i
t
Repeat
Monitoring
, 41.
t
Repeat
Monitoring
4
First
3-Year
Compliance
Period
Second
3 -Tear *
Comp liance
Period
' Third
3 7 Year -
Compliance
, Period
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31, 1998; and the third compliance period begins on January 1, 1999 and ends December 31,
2001.
The U.S. EPA's requirement to phase-in monitoring by system size is eliminated in the Phase II
Regulations. However, phase-in of the Phase V Regulations will be based on system size
(systems with 150 or more service connections will be required to begin monitoring during the
first compliance period, whereas systems with less than 150 will be required to begin monitoring
in the second compliance period). The States are required to schedule approximately one-third
of the systems for monitoring during each year of the initial three-year compliance period. Each
State has the flexibility to establish its own monitoring plan.
Monitoring Frequency
The U.S. EPA has established base monitoring frequencies for all community and non-transient
water systems. In cases of detection or non-compliance, U.S. EPA has specified increased
monitoring from the base frequencies. Water systems may decrease monitoring frequencies by
obtaining waivers from the State.
Contaminant Detection Level
Inorganics
Nitrate
Nitrite
All Others
Volatile Organic .Chemicals
All
50% of MCL
50%'ofMCL
MGL
0,0005 mg/L
Pesticides/PCBs
All .
Method Detection Limit
Increased Monitoring
All systems that detect contamination must sample
quarterly, until the State determines that the analytical
results are "reliably and consistently" below the
maximum contaminant level (MCL). "Detection" is
defined as the MCL for inorganics, except nitrate and
nitrite; 50 percent of the MCL for nitrate and nitrite;
0.0005 mg/1 for the VOCS; and at the analytical Method
Detection Limit (MDL) for the pesticides and PCBs
(figure 2). "Reliably and consistently" below the MCL
means that though the system detects contaminants in its
water supply, it has sufficient knowledge of the source or
extent of the contamination to predict that the MCL will
not be exceeded. Wide variations in the analytical results
near the MCL will not meet the "reliably and consistently" test.
In some cases, monitoring requirements for an initial monitoring event may be more prescriptive
than the more routine repeat monitoring requirements. For example, initial VOC monitoring will
require one sample during each of four consecutive quarters. Following this initial monitoring
event, compliance with VOC requirements may be satisfied by one sample per year.
Figure 2. The various Phase II contaminant
"detection" levels for determining repeat
sampling requirements.
Grandfathered Data
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At the State's discretion, VOC sampling data collected after January 1, 1988 and SOC sampling
data collected after January 1, 1990, can be used to satisfy the initial sampling requirements.
Systems using this grandfather provision could then sample at the repeat frequencies that
generally may be lower than the initial frequencies.
Waivers
Provisions are available by which States may waive sampling requirements if certain conditions
are met. These provisions are discussed in further detail in the section on Waiver Types. All
systems may be considered for waivers. Waivers must be granted on a contaminant-by-
contaminant basis. Systems which do not receive waivers must comply with the minimum
sampling requirements. Waivers may be issued for a maximum of 3, 6, or 9 year periods,
depending on the contaminant and system specific conditions.
CONTAMINANT WAIVER TYPE LENGTH
.Inorganics
Asbestos
Nitrate
Nitrite
Eliminate
Not Available
Not Available
Volatile Organic Chemicals:
All Reduced
Pesticides/PCBs
All
Eliminate
Unregulated Gdntammants
All Eliminate
9 years,
6 years
3 years
3 years'
Three, six, or nine year waivers will reduce or
completely eliminate monitoring requirements during
the 9-year compliance cycle (Figure 3). Waivers
issued to ground water systems for VOCs reduce the
number of samples required to comply with the
regulations. Waivers issued for pesticides/PCBs and
the unregulated contaminants completely eliminate
sampling requirements. The waivers may be issued
at any time before the beginning of the monitoring
period in which the contaminant is to be monitored.
Waivers may be issued for a group of contaminants
analyzed under the same analytical method (Figure
4), in lieu of obtaining an individual waiver for each
contaminant in the group. An example of
contaminant grouping would be EPA analytical method 525.1. This analytical method is used
for Alachlor, Atrazine, Chlordane, Heptachlor, Methoxychlor, Pentachlorophenol and Lindane.
For a water supply system to apply for a group waiver, each contaminant in that group must be
eligible for the waiver.
Waiver Types
The types of waivers available to all systems are water system "use" waiver and "susceptibility"
waivers. In addition, States may choose to issue State-wide or region-wide waivers. These
"area-wide" waivers are based on "use" or "susceptibility" criteria specified in the Primary
Drinking Water Regulations.
Figure 3. Phase II contaminants with the type
and length of the waiver.
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1) "Use" Waiver:
"Use" waivers are
available for both
individual systems and
may be applied as an
"area wide" waiver.
The State or system
must determine if the
contaminant was used,
manufactured, stored,
transported, or
disposed of in the area.
For some
contaminants, an
assessment of the
contaminant's use in
the treatment or
distribution of water
also may be required.
"Area" is defined as
the watershed area for
a surface water system
or the area of recharge
for a ground water
system and includes
possible effects in the
distribution system,
such as the use of pipe
material, which may
allow certain VOCs to
permeate through the
pipe wall, or lack of an
effective back-flow
prevention program. If
the contaminant was
not used,
manufactured, stored,
transported, or
disposed of in the area,
then the system may obtain a "use" waiver. If the system or State cannot ascertain those factors,
the system will not receive a "use" waiver, but may apply for a "susceptibility" waiver. "Use"
waivers will apply mostly to pesticides and PCBs where use can more readily be determined than
for VOCS.
EPA ANALYTICAL METHODS FOR VOCs and SOCs
* * - " ,
Methods 502, 1,502.2, 503<15
524.1,*; 524.2
Benzene
Carbon tetrachloride
. 1,2-Diehloroethanfe
Ijl-Bichloroethylene
o-BichlorGbenzene4"
para-Dichlorobenzene
cia-l,2-Dichloroethylene^
trans- 1 ,1 - Bichioro ethyl en e^
Bichlorome thane*
lJ2-DIchioropropanei*?
Ethylbenzene^1
Monochlorobenzene^
Styrene^
, Tetrach,ioroethyiene4" '
I.(2j4-Triehlorobenzene*
Ijljl-Trichloro ethane
1 , 1 s2-Trichiof oethane* .
Toluene^1 -
Vinyl Chloride -
Xylenes'f',
Method 505
Alachlor^ ,
Aldrins* -
AtrazineT
Chlordane't' ," .
Die Idrin^l
Endtin*
HeptachloHl*
Heptachlor epoxide^
Hexachlorobenzene*
Hexachloroey elopentadi ene *
LindaneT1
Methoxyehlor^
PCBst
Simazine*
Toxaphene^,
Method 504
DibroniochloropropaneT'
Ethylene Dibromide'T
TPhase II Regulated Contaminants
4lPhase II Unregulated Contaminants
*Phase Y Contaminants
Method 508.
Aldrinfll
Chlordane5^'
Dieldrin^ - '
Endrin*
Heptachlor^
Heptaehlor epoxide^1
Hexachlorobenzene*
Hexachlorocyc.lopentadiene*
Lindane4"
MethoxychoHr
Metribuzin*!
PCBsf
Method 515:1
2?4-D^
2,3,5-fPtSilvex)^
Dalapoh* ,
Dicambra4*
Dinoseb*
Picloram*
Pentacliloropheriol4*
Method 531,1.' - ' ,
Aldicarb^
Aidicarb siilfone4*
Aldicarb sulfoxideT*
Carbaryl^
Carbofuxan^
'3-Hydroxycarbofuranlfe
Methomyl^ *
Oxamyl*(vydate)*
Method 550 & 550.-1
B,enzo{a)pyrene*
Method 50?
Alachlor^
AtrazineT
Butachlor^
Metolachlor1^
Metribti?in^.
Propachlor^
Simazine*
Method 525.1'
. Alachlor^
Aldrini
Atrazinev
Ben?o{a)pyrene*
Butachlor^
Chlordane4i'
.Dieldrinft
Di(2"ethylhexyl)adipate*
Di(2"ethylhexyl)phthalate^
Endrin
Heptaehlor^
Heptachlor epoxide^
Hexachlorobenzene*
Hexachlorocyclopentadiene
*
Lmdane^
'MethoxychlorT
Metolaclilor*^
Metribu-zin1?
Pentachlorophenol"^
Simazine*
Method 547 '
Glyphosate* . .
Method 548'
Endothall* -
' Method 549 ' ' ' '
Dlquat*
Method .161.2 & 1613
2,3 ,7,8-TCDD -{0 ioxin) * ,
Method 506
Bi(2-ethylhexyl)adipate*
' Dl{2-ethylhexyl)phthalate*
Figure 4. Contaminant groupings according to EPA analytical method.
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WSG66
2) "Susceptibility" Waiver: This type
of waiver may be issued for individual
systems or applied on a regional scale.
If a "use" waiver is not granted, a
system may apply for a susceptibility"
waiver. Susceptibility waivers may be
issued when the following
information is reviewed and
evaluated: previous monitoring
results; contaminant persistence and
transport; soil and aquifer properties
and/or confinement system geology;
well construction; and known
abandoned well history. Systems with
no known susceptibility to
contamination based on an assessment
of the above criteria may be granted a
waiver. If susceptibility cannot be
determined, the system is not eligible
for a waiver.
ITEMS TO EVALUATE IN ISSUING
"SUSCEPTIBILITY" WAIVERS ' '.
1, Previous monitoring data. If there are any detects In previous
monitoring, the system is normally not eligible for a'waiver.
2, ' Contaminant persistence and transport A contaminant such as
PCBs persists in the environment, but is generally not mobile,
3, Aquifer properties and geological setting. A shallow,
'unconfined aquifer is more susceptible to contamination than-a
deep, confined aquifer. If a system is located in, a ka.rst area,
the system is not normally eligible-fbr a "susceptibility**
.waiver. A ground water well under the direct influence of
surface water is considered susceptible to contamination.' '
4. Well construction and abandonment history. Wells that do not
comply with the State construction code would normally not
be eligible for a susceptibility waiver.
5. Location of a system relative to potential contamination
, sources-, e.g., waste sites, military installations, pesticide
storage or use areas. The system must demonstrate it is not
susceptible to contamination from nearby sources.
Figure 5. "Susceptibility" waiver consideration items.
General Approach in Issuing Waivers
A first step is to issue "area wide" waivers for those pesticides (or group of pesticides analyzed
under the same analytical method) not used in the State or a region of the State. States may
choose to exclude specific systems, such as those failing to meet State well construction codes.
Since pesticide use is the easiest to determine and pesticides are most expensive to monitor,
States should begin their waiver program by considering "area wide" pesticide "use" waivers.
Following "area wide" "use" waivers, "susceptibility" waivers should then be considered for
those eligible regions or areas of the State for those contaminants identified as unlikely to
contaminate the source water. Individual system waivers should then be pursued to the extent
that it is economically feasible. A "susceptibility" waiver may be issued to a system in the
process of initial quarterly monitoring, thereby reducing the initial monitoring requirement,
provided the system did not detect the contaminant and meets the other requirements for the
waiver.
"Area Wide" Waivers
A State may issue "area wide" waivers without an application from the water system. An "area
wide" waiver may be issued to ground water supplies for contaminants not used or not likely to
contaminate the source water. Region 5 strongly urges a system to complete an initial round of
sampling before an "area wide" waiver may be issued for surface water supplies or for volatile
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First Steps in Issuing "Area Wide" Waivers
Step 1: , Send the list of Phase II pesticides to the State
. 'Department of Agriculture, The Department will
determine which pesticides are not or have not 'been used
; in the State,'
Step 2: Have the State Department of Agriculture^ with
cooperation of other agricultural entities, determine
which pesticides are limited to certain regions or areas of
the State,, .. ' . '
Step 3:
Compile list of ''waste sites'*, SAHA Title III locations,
and military installations. Prohibit "area wide" waivers
, to those water systems within an area considered to be at
risk to contamination. ,
Figure 6. Steps to take for initial pesticides waivers
issued on an "Area Wide" basis.
organic chemicals (VOCS) (both ground
water and surface water supplies). Some
information that must be gathered and
evaluated includes: previous monitoring
data, geology type, aquifer depth and type
(confined or unconfined), well construction,
pesticide use, agricultural chemical sales
data, cropping patterns, previous aquifer
susceptibility studies, soil studies, and
pesticide persistence/transport. Locations of
the following sites must be identified:
military installations, pesticide mixing sites,
SARA Title III sites, proposed or current
NPL sites, and RCRA sites. Various State
and Federal groups must be contacted to
determine what pesticides are eligible for
"area wide" waivers and to delineate the area included in the waiver. Examples of the State and
Federal agencies that should be involved in the decision process are: State Department of
Agriculture, State Wellhead Protection Program, (WHPP), State Ground Water Division, Soil
Conservation Service, Department of Interior, State and/or Federal Geological Survey, State
and/or Federal Hazardous Waste programs, State and/or Federal Solid Waste Administration
program, State Pesticide Committees, and University Agricultural Schools.
In addition to the information obtained on the non-use of certain pesticides, a State must have a
compliance program within the State Agricultural Department to verify the information. The
Director of the State Agricultural Department must submit documentation of that Department's
pesticide compliance program. At a minimum, the compliance program must consist of an
inspection component and an enforcement component. In addition, the Director must submit
documentation certifying the non-use of those pesticides eligible for waivers. The procedures
for obtaining the information and the methods used to determine the pesticides that will be
eligible for "area wide" waivers must be outlined in the State's primacy application.
"Area wide" waivers should be issued using a multi-step approach. The first step would be for
the State Agricultural Department to review the list of contaminants. The Departments should
provide the most site specific information available on manufacture, storage, use, persistence,
and transport of each pesticide on the list. The second step is to use the information to locate
geographical areas where the potential for contamination is small and/or non-existent. Then a
survey must be conducted to identify the "waste sites", SARA Title III locations, and military
installations. The public water systems that are located within an area that may be influenced by
contamination from one of these waste sites are not eligible for an "area wide" waiver. By using
these steps, the total number of pesticides to be tested could be reduced.
"Dioxin Area Wide" Waivers
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All public water systems, except those located within one mile of any facility utilizing chlorine
in the manufacturing process; a Superfund or NPL site; or a military installation, where dioxin
may be suspected of being present, are considered non-vulnerable and will not be required to
monitor for 2,3,7,8,-TCDD (dioxin). States may choose to vary the one mile limit to
accommodate local geologic or hydrologic conditions.
Systems NOT Covered by "Area wide" Waivers
For those systems not covered by an "area wide" waiver, an individual system waiver may be
sought. The same criteria used to evaluate potential "area wide" waivers should be used to
evaluate potential waivers to individual systems. In addition to the "area wide" criteria, the
system must define a monitoring waiver review area around the wellhead, conduct a source
identification assessment, and use this data to conduct a vulnerability assessment. The approved
wellhead protection area (WHPA) would typically represent-the minimum acceptable
monitoring waiver review area. The Wellhead Protection Program has established technical
methods for delineating a wellhead protection area for use in developing a wellhead protection
program. The approaches established by the WHP program are considered technically valid in
delineating the monitoring waiver review area and should be used. In order to avoid confusion
with the terminology of the WHP program, the term monitoring waiver review area should be
used in describing the delineated area surrounding the well in which the system or State will be
required to identify contaminant sources for use in conducting a vulnerability assessment prior to
being granted a monitoring waiver. For the States with an EPA approved WHP Program,
systems must be expected to factor in the approved wellhead program delineation approach
(methods and criteria) to establish the monitoring waiver review area. It is recognized that in
some unusual cases the WHPA delineated under the State's approved wellhead protection
program may not be large enough to provide a sufficient margin of safety for the purpose of
issuing monitoring waivers. These unusual cases will be evaluated on an individual basis.
Where a State WHPP is not yet approved the State PWSS program and WHP Program would be
expected to develop joint delineation criteria and a method or methods that would serve the
objectives of both programs, understanding that sometimes threshold values may need to be
different.
Once the monitoring waiver review area has been delineated, a site assessment must be
undertaken to identify the contaminant sources within the monitoring waiver review area. The
source identification will identify the types of contaminants found in the delineated area. Those
contaminants not found in the area may be eligible for a "use" waiver. If any of the
contaminants are found or were used in this area, a "use" waiver cannot be issued for those
contaminants. For those contaminants that do not meet the criteria for "use" waivers, a
"susceptibility" waiver may be considered.
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To issue a "susceptibility" waiver, it must
be shown that the water system is not
susceptible to contamination. The items
listed in figure 7 are some of the
components that should be reviewed to
determine if a system is susceptible to
contamination. A system may be required
to complete an initial round of sampling
for the contaminants with potential to
leach into ground water before being
granted a susceptibility waiver. Once
these criteria are met, susceptibility
waivers may be issued in areas with
contamination sources that are adequately
managed. The State must identify the
process by which these determinations are
made and how the decisions are made to
grant a waiver.
Susceptibility waivers for VOCs may be
issued if after three consecutive annual
samples, the system has no detects.
Grandfathering Data
MONITORING WAIVER DECISION STRATEGY
1. Review all previous monitoring data.
2. If the system has any previous history of chemical detects, the
system is not eligible for waivers.
3. The system must delineate a monitoring waiver review area around
the water source.
4. The system must then identify all sources of contamination within
the delineated area through a source identification process.
5. If any of the contaminants are used, stored, manufactured, or
transported within the monitoring waiver area, the system is not
eligible for a "use" waiver. The system may be eligible for a
''susceptibility" waiver.
6. The geology of the area must be identified. If the water sources is
located in an area of cavernous limestone (karst), the system is not
normally eligible for a "susceptibility" waiver.
7. The system must determine the aquifer type. A ground water
system under the direct influence of surface water is not eligible for
a "susceptibility" waiver.
8. The well(s) must meet the State construction codes. Any well logs
must be reliable and accurate. If a well does not meet well
construction codes, a susceptibility waiver would normally not be
issued.
9.
The persistence and transport of each contaminant must be known.
Figure 7. Some of the items to consider in issuing individual
system susceptibility waivers.
The grandfathering provision allows
systems to substitute a single sample for the four consecutive quarterly samples required under
the initial base monitoring requirements of Phase II and Phase V. The VOC sampling must be
completed after January 1, 1988 and the SOC sampling must be completed after January 1, 1990,
to satisfy the initial monitoring requirements.
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