&EPA
68-01-6425
APPROACH TO MIDCOURSE EVALUATION
OF
MECHANICAL INTEGRITY TESTING
SUBMITTED TO
DR. JENTAI YANG
OFFICE OF DRINKING WATER
U.S. ENVIRONMENTAL PROTECTION AGENCY
JANUARY 1983
BOOZ ALLEN & HAMILTON, INC.
UNDER THE DIRECTION OF
GERAGHTY & MILLER, INC.
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&EPA
68-01-6425
APPROACH TO MIDCOURSE EVALUATION
OF
MECHANICAL INTEGRITY TESTING
SUBMITTED TO
DR. JENTAI YANG
OFFICE OF DRINKING WATER
U.S. ENVIRONMENTAL PROTECTION AGENCY
JANUARY 1983
BOOZ-ALLEN & HAMILTON, INC.
UNDER THE DIRECTION OF
GERAGHTY & MILLER, INC.
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ACKNOWLEDGEMENT
This report was prepared by Booz, Allen & Hamilton, Inc., under
the direction of Geraghty & Miller, Inc. The Booz, Allen project
manager was Dr. Joanne Wyman. She was assisted by Mr. Walter Mardis
of Booz, Allen. The Geraghty & Miller project manager was Mr.
William Thompson, and Mr. Roger Anzzolin was the EPA task monitor.
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TABLE OF CONTENTS
Page
Number
1. OVERVIEW OF MECHANICAL INTEGRITY 1
DEMONSTRATION REQUIREMENT
2. OBJECTIVES OF THE MIT MID-COURSE EVALUATION 2
3. APPROACH TO THE CONDUCT OF THE MIT 3
MID-COURSE REVIEW
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APPROACH TO MIDCOURSE EVALUATION OF
MECHANICAL INTEGRITY TESTING
On June 24, 1980 the U.S. Environmental Protection
Agency (EPA) issued final regulations for the Underground
Injection Control (UIC) program. These rules require a
more extensive midcourse program evaluation than EPA had
set forth in the proposed rules. Accordingly, EPA's
Office of Drinking Water (ODW) asked Geraghty and Miller,Inc.
(G&M) and Booz, Allen & Hamilton, Inc. (BA&H) to expand
our initial analysis on the conduct of the midcourse eval-
uation to include the mechanical integrity testing (MIT)
requirement for Class II wells.^ In response to ODW1s re-
quest, we developed baseline information for the MIT re-
view similar to that we prepared for the AOR midcourse
evaluation.3 This information is summarized in Exhibit 1
and the accompanying narrative.
1. OVERVIEW OF THE MECHANICAL INTEGRITY DEMONSTRATION
REQUIREMENT
The principal purpose of requiring well operators to
demonstrate mechanical integrity is to ensure:
The absence of significant leaks in the well
casing, tubing, or packer
The absence of significant fluid movement into
an underground source of drinking water through
vertical channels adjacent to the injection well
bore.
The rules EPA proposed in April 1979 required a midcourse evaluation only
of the costs and benefits of the Area of Review requirement
for Class II wells. The final rules, however, extend the midcourse
evaluation to the AOR for Class I and III and to the mechanical
integrity testing program for Class II.
Prior to promulgating final rules, EPA asked us to assist in de-
signing the midcourse evaluation of AOR. After issuance of the
final rules, EPA asked us to extend our initial analysis of
alternative study methodologies to mechanical integrity testing
in lieu of preparation of an AOR midcourse evaluation study manual.
See Geraghty & Miller, Inc. and Booz, Allen & Hamilton, Inc.,
Development of Midcourse Evaluation Methodology ( Task I Report:
Evaluation of Alternatives), June 17, 1980 pp. 1-5.
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In its April 1979 version of the proposed rules, EPA called
for the use of eight tests to determine the likelihood of
leaks and the use of either well records or tests to determine
the existence of fluid movement. The requirements covered
Class Ir II, and III well operations.
In the preamble to the final regulations, EPA indicates
that it now has serious doubts about the reliability of well
records as indicators of the absence of fluid movement.
Accordingly, for Class I and III operations the Agency now
requires the use of formal tests. For Class II operations,
however, because of the large number of wells and the Safe
Drinking Water Act (SDWA) requirement that regulations not
interfere with oil and gas production, EPA continues to allow
the use of well records to demonstrate mechanical integrity.
At the same time, under a modified Section 146.08, EPA requires
a sample of Class II wells to conduct mechanical integrity
tests. Wells in the sample are to be ones which initially use .
well records in place of temperature or noise logs to
determine the likelihood of fluid movement.
2. OBJECTIVES OF THE MIT MIDCOURSE 'EVALUATION
The purpose and objectives of the AOR and MIT midcourse
reviews differ markedly. The purpose of the AOR review is
to ascertain whether EPA regions and the states have imple-
mented the requirements effectively. By contrast, the pur-
pose of the MIT review is to establish a mechanical integrity
demonstration procedure which is more economical and less
time consuming than universal formal testing, while still
guaranteeing a high degree of accuracy.
Establishment of a screening procedure would be one
possible approach. EPA believes that it may be possible
to identify certain well characteristics (such as depth, age
and type of cementing) which are reliable indicators of
well integrity. For each well, well records will indicate
whether the well has the characteristics indicative of mechani-
cal integrity. Wells not having those characteristics will
have to perform formal tests.
In order to determine the feasibility of this approach,
EPA intends to compare the mechanical integrity demonstration
results from the well record reviews with those from the
formal tests. Key questions the Agency needs to consider
in analyzing the data are:
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How accurate are Class II well records in identi-
fying mechanical integrity problems?
What savings to well owners/operators result from
the use of well records instead of noise and tem-
perature logs?
What are the administrative impacts on state
regulatory agencies of substituting well records
for log data?
In addition, the Agency is interested in examining the
applicability of any Class II screening procedure to Classes
I and III. For each of these key study questions, Exhibit 1
displays five specific study objectives for answering the key
questions. For each-objective, it discusses the study
rationale, the data needed to respond to each question, and
methodological or procedural problems in conducting the
analyses.
3. APPROACH TO THE CONDUCT OF THE MIT MIDCOURSE REVIEW
EPA's planning activities for the MIT evaluation must
differ from those for the AOR review in order to be consistent
with differences in:
Measurement of objectives
Level of regulatory detail.
Unlike the AOR review, in which measuring administrative
effectiveness must serve as a surrogate for measuring
achievement of substantive program objectives, the MIT
review directly measures substantive and administrative
objectives. Thus, the MIT review will require a more de-
tailed, but less extensive in scope, collection and analysis
of program organization, activity, and resource data. In
addition, unlike the proposed rules for .the AOR midcourse
review, the final regulations for the MIT evaluation contain
specific guidance on the midcourse review design. Whereas
EPA had the opportunity for the AOR review to consider three
alternatives (two of which involved sampling), EPA must
evaluate sampling data for the MIT. Furthermore, the
regulations require the states to comply with the following
in drawing the sample:
For an explanation of the difficulties, see Geraghty & Miller, Inc.
and Booz, Allen & Hamilton, Ibid, pp. 5-6.
•«
A substantive objective is to determine well record reliability;
an administrative one is to determine changes in the administrative
burden resulting from use of well record data instead of log data.
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EXHIBIT 1
Overview of Study Objectives For MIT Midcourse Review
STUDY OBJECTIVES
BASIS OF ANALYSIS
NECESSARY DATA FOR THE ANALYSIS
ADDITIONAL QUESTIONS
1. Determine if reviews of
well records are suitable
substitutes for tempera-
ture or noise logs in
identifying mechanical
integrity problems in
outer casings or well
bores.
A comparison will be made of
the results of well record
analyses for a sample of Class
II wells compared to results
of noise and temperature logs
conducted for the same sample.
The key concern is the precent
of variation between the
findings of the two analyses
and the characteristics of
wells for which variation
occurs.
Relevant data on a random
sample of Class II wells as
required in Section 146.25
of the UIC regulations
including:
results of well record
reviews
characteristics of
wells
characteristics of well
record data
Type of state regulations and
requirements for injection
wells in effect prior to the
implementation of the UIC
program.
What constitutes an
acceptable level of error?
Do the variations in accuracy
differ based on certain
characteristics of the sub-
ject well such as:
age?
location?
past state regulatory
practices?
condition and detail of
well records?
type of cementing
techniques employed?
other factors?
For how many wells were well
records incomplete or in-
adequate, thus necessitating
use of temperature or noise logs?
2. Determine if there are any
technical factors which
might preclude reliance on
well records as an indica-
tor of well integrity.
The analysis will identify any
technical problems which appear
to cause variations between the
results of record reviews and
the results of formal mechani-
cal integrity testing. The
significance of these factors
will be assessed and an
attempt will be made to iden-
tify means for avoiding or
overcoming them.
Examples of well integrity
problems found in formal
mechanical integrity tests
which were not identified
in well record reviews.
Evidence on how well records
could be improved so as to
provide necessary informa-
tion.
Is there sufficient capacity
on the part of well testing
firms to manage all of the
potential need for mechanical
integrity testing?
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EXHIBIT 1 (Continued)
STUDY OBJECTIVES
Determine if major cost or
time differences exist for
well operators between well
integrity analyses based on
record reviews and those
based on mechanical integ-
rity tests.
4. Determine if the adminis-
trative burden for state
regulatory agencies varies
depending upon the type of
review conducted by Class
II well operator/owners.
BASIS OF ANALYSIS
The analysis will attempt
to determine if reliance on
record reviews rather than
on formal mechanical inte-
grity testing will result in
any time or cost savings to
well operators/owners and
lence any reductions in the
overall cost/production
Impact of the DIG regulations.
NECESSARY DATA FOR THE ANALYSIS
ADDITIONAL QUESTIONS
The analysis will assess state
agency review procedures for
owner/operator submittals
Qased on well record reviews
and for submittals based on
temperature or noise logs to
determine:
- The length of time
associated with the state
evaluation
- The types of additional
supporting information
which the state agency
must obtain
The types of personnel
required to conduct the
evaluation
Numbers of on-site in-
spections of wells.
Empirical data on costs of
reviewing well records and
costs of performing tempera-
ture and/or noise logs for
the sample of wells covered in
the survey.
Analyses of time involved in
both types of reviews in-
cluding:
Overall time from start
to finish of each type of
review
Actual well down-time
attributable to each type
of review
- Time spent in administra-
tive analyses of data
supplied to state regula-
tions for each type of
review.
Can downtime attributed to mechani
cal integrity listing delays be
distinguished from delays associ-
ated with other factors?
Do time delays or cost increases
related to mechanical integrity
testing appear to vary according
to:
The state in which they are
performed
The conditions of existing well
records
- The age of the well
- Other factors.
Review calendar time frames
Number and skills of individ-
uals involved in reviews
Manhours spent on collecting
supporting information
Number and types of site
inspections.
Does not having log data on
well integrity adversely effect
any other aspect of the state's
UIC program?
Do states typically have or can
they acquire the skills necessary
to interpret mechanical integrity
testing data?
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EXHIBIT 1 (Continued)
STUDY OBJECTIVES
BASIS OF ANALYSIS
NECESSARY DATA FOR THE ANALYSIS
ADDITIONAL QUESTIONS
Determine if the use of
well records as a sub-
stitute for log data
could be acceptable for
other classes of wells.
If there is a strong correla-
tion between the conclusions
reached by reviewing well
records and those resulting
from temperature and noise
logs. EPA may wish to allow
Class I and III well owner/
operators to also use well
records. This analysis will
assess the feasability of
doing this. In part, it will
entail a comparison of any
technical differences be-
tween Class II wells and I
and III wells.
Number of Class I arid III
wells which would be affected
Potential cost and time
savings of expanding use of
well record reviews
Percentage of Class I and II
wells which have adequate and
complete well records.
Are there any factors which
would increase the likelihood
that well records would be
less accurate in determining
mechanical integrity for
Class I or III wells than for
Class II wells.
Would there be a greater risk
from having misjudged Class I
or III wells than for mid-
judging Class II wells.
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Sampling must be formal, random selection.
It must be done on a field or pool basis and be
statistically representative of the fields or pools,
At least 50% of the wells tested must be existing
ones.
Consequently, EPA is in a position to begin detailed planning
Some of the principal issues it must address during this
planning phase include the format of data submittals; system
of data storage, retrieval and analysis; frequency of data
analysis and aggregation;^ and lead office/work group for
conducting the analysis.
For example, EPA must determine whether to conduct the analysis
after each six month reporting period or after 12 months, 18 months,
or 24 months.
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