This guide is primarily intended for personnel with line management responsibility for Department of Energy (DOE)
environmental restoration projects conducted pursuant to the Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA) and the Resource Conservation and Recovery Act (RCRA). It describes techniques for managing project
uncertainty, including decision rules and contingency planning as outlined in the DOE/EPA "Principles of Environmental
Restoration" workshop. Additional written guidance is available in DOE's Remedial Investigation/Feasibility Study (RI/FS)
Process, Elements, and Techniques Guidance (DOE/EH-9400, December 1993) and DOE's Phased Response/Early Action
Guidance (DOE/EH-0256, November 1995).
DOE/EH/(CERCLA)-002

Ot
Uncertainty Management:	¦— ^ *
Expediting Cleanup	WP \ r\
Through Contingency Planning
Office of Environmental Management
Office of Environment, Safety & Health
February 1997
Introduction
Some degree of uncertainty in environmental restoration
projects always exists. This inherent uncertainty may
result from incomplete knowledge of the nature and
extent of contamination, an inability to predict a
technology's performance under site-specific conditions,
or new or changing regulatory requirements. Although
these inherent uncertainties present a significant
challenge to effective project management, recognizing
and planning for them helps to ensure that projects stay
on schedule and within budget.
In order to effectively reduce and manage uncertainty
prior to or during a response action, the project team
must first determine which uncertainties are significant
(i.e., can impact the implementation of the response
action(s) under consideration). Once significant
uncertainties are identified, the DOE, EPA and State
project managers (i.e., the core team), must decide
whether to reduce the uncertainty through data
collection, or reach consensus on how best to "manage"
the uncertainty through contingency planning. In short,
this decision will require a balance between the cost of
data collection (and decisional benefits gained) against
the cost of planning for a potential deviation (i.e.,
uncertainty), and the cost / schedule impacts of
modifying the design if the deviation occurs.
Outlined below are steps to follow once the core team
decides to pursue managing an uncertainty through
contingency planning.
Step One: Identify Expected Conditions and
Potential Deviations
The core team should use their conceptual model
developed for the site (or "problem") being addressed as
a basis for identifying and evaluating expected
conditions and potential deviations. An expected
condition is any physical, chemical, technical, or
regulatory condition that is expected to be encountered
during implementation of the response action. For
example, based on all available information [e.g.,
process history, preliminary assessment / site
investigation (PA/SI)], the core team expects that
contamination of Pu-238 greater than 75 pCi/g is
confined to the soil and sediment from zero to four feet
deep in the bed of an old, abandoned canal. However,
given the possible releases of Pu-238 that could have
occurred over a twenty year period, the core team
identifies the potential presence of Pu-238 greater than
75 pCi/g below four feet, as a deviation that has a
realistic probability of occurrence.
Step Two: Evaluate Deviations
Once potential deviations have been identified, the core
team should determine what level of "pre-response"
planning is appropriate by evaluating each deviation as
to its possible impact on the implementation of the likely
response(s), and its ability to negate achievement of
response objectives.

-------
Typically, a qualitative evaluation of the factors
discussed below is sufficient to determine how best to
proceed:
•	Probability deviation will occur: The core team
should rank deviations based on their likelihood
of occurrence (e.g., high, medium, low).1 Using
the example from above, the core team may
determine there is a low probability that
contamination of Pu-238 above 75 pCi/g
extends below four feet since the two PA/SI
samples taken did not exceed this level.
•	Potential impacts of the deviation: The core
team should evaluate each deviation in terms of
its potential impacts on the response action(s)
cost, schedule, and implementation
requirements (e.g., site preparation /
mobilization, material handling, transportation).
Typically, this requires bounding the range of
impacts and comparing this range to a tolerable
threshold2 around which the base design is being
constructed. For example, should contamination
of Pu-238 above 75 pCi/g extend below four
feet, soil volumes requiring excavation will
increase significantly. If the site's temporary
storage facility can only absorb a 25% increase
(the threshold) in soil volume before capacity is
exceeded, termination of field activities may be
necessary until additional temporary storage is
made available.
•	Time to respond: The core team should
estimate the "lead" time to respond between
occurrence of the deviation and the impact to the
project. As before, this may be done
qualitatively or quantitatively, depending on the
significance of the potential impact of the
deviation. The shorter the lead time to respond,
the less time available to implement the
contingent response if a deviation is detected.
Consequently, a greater level of contingency
plan development / design is usually required to
1	The core team needs to carefully consider whether a
deviation having a high probability of occurrence is better characterized
as an expected condition rather than a potential deviation.
2
This threshold is the maximum change in the expected
conditions that the base design (for the response action) can
accommodate before a contingent response(s) is required.
modify the base design in a timely manner (e.g.,
special equipment is procured and brought out
to the site in case deviation occurs).
Alternatively, if a long lead time is expected,
then a less detailed contingency plan may be
appropriate.
Step Three: Develop Appropriate Contingency
Plans
Once the core team determines the appropriate level of
"pre-response" contingency plan for each specified
deviation, development of contingency plans can begin.
Based on the required level of detail, a contingency plan
should include a strategy for what needs to be
accomplished to effectively manage and respond to a
deviation. Specifically, the core team should define the
necessary design modifications and / or actions required
in the field to manage the deviation (e.g., modify
excavation approach, provide higher level of personnel
protection equipment (PPE), construct short-term
storage area). Ultimately, the objective is to ensure the
required scope of the contingency plan can be
documented for procurement purposes and preplanning
is sufficient to allow rapid, effective responses to
deviations.
Additional considerations in developing contingency
plans are discussed below3:
• Implementabilitv: Based on the evaluation in
step two, the core team should determine the
necessary level of development / design to
ensure the contingency plan can be easily
implemented and will reliably address the
deviation. As the probability that a deviation
may occur increases, or as a shorter lead time to
respond is required, a more developed
contingency plan may be necessary to ensure
rapid implementation. [NOTE: In some cases,
the design of the contingency plan may need to
be integrated into the base design.] Likewise,
the greater the potential impacts of the deviation
(e.g., occurrence of the deviation will require
termination of field activities), the higher degree
of confidence required that the contingency plan
is implementable.
3
These same factors are useful to determine the most suitable
contingency plan in the case where several contingency options exist.

-------