must use their experience, judgment, lessons learned, and subject matter experts (SMEs)
to assist them in determining degrees of severity. The following examples of severity for
archaeological, historical, or cultural sites provide leaders with a frame of reference for
what may be included when estimating degrees of severity (see Table 1-3).
Catastrophic. Irreparable damage to or total loss of an irreplaceable site.
Commanders can anticipate widespread public concern. Such damage will require
notification of the higher HQ, public affairs, and outside agencies.
Critical. Major physical damage to a historical/cultural structure. Restoration will be
difficult, long-term, and costly and will require assistance and notification of the
higher HQ, public affairs, and outside agencies.
Marginal. Minor physical damage to historical/cultural structures, which can be
restored with outside assistance. Units must report damage to the higher HQ.
Negligible. Surrounding site damage from individual and vehicular activities will be
easily repaired or restored by the unit. There is no physical damage to structures;
however, the unit must report damage to the higher HQ.
Table 1-3. Hazard Severity Definitions
Loss of ability to accomplish the mission or near mission failure, death or
permanent total disability (accident risk), loss of or damage to major
property (facility) damage, severe (strategic) environmental damage,
mission-critical security failure, unacceptable collateral damage.
Significantly (severely) degraded mission capability or unit readiness,
permanent partial disability, temporary total disability exceeding 3 months
time (accident, risk), extensive (major) damage to equipment or systems,
significant damage to property or the environment, security failure,
significant collateral damage.
Degraded mission capability or unit readiness; minor damage to equipment,
systems, property, or the environment; lost days due to injury or illness, not
exceeding 3 months (accident risk).
Little or no adverse impact on mission capability, first aid or minor medical
treatment (accident risk), slight equipment or system damage but fully
functional and serviceable, little or no property or environmental damage.
A leader determines the risk level of each hazard. Then, using the defined degrees of
probability and severity and the risk assessment matrix, the leader determines the overall
environmental-related risk level. The risk categories are as follows:
Extremely high (E). Mission failure if hazardous incidents occur during mission.
There is a frequent or likely probability of catastrophic loss (IA or IB) or a frequent
probability of critical loss (IIA).
High (H). Significantly degraded mission capabilities in terms of the required
mission standards. Degradation of a mission includes not accomplishing all parts of
the mission, not completing the mission to standard (if hazards occur during the
mission), occasional to seldom probability of a catastrophic loss (IC or ID), a likely
to occasional probability of a critical loss (IIB or IIC) occurring with material and