As specified above, this document focuses on a specialized subset of consequence management activities critical to chemical incident response and recovery: 1) characterization of potential contamination of the general area and specific sites impacted by the incident; 2) general area and site- specific remediation; and 3) clearance for re-entry/re-occupation of general areas or specific sites contaminated by chemical HAZMAT. The table below provides a synopsis of these key consequence management activities as they relate to the operational phases discussed above. Real-world case studies and additional references providing illustrative examples of chemical incident consequence management activities by operational phase are provided in Appendix B.
Table 1: Chemical Incident Consequence Management Activities by Operational Phase.15
Chemical Incident Consequence Management Activities
| Immediate Response (Phase 2a) | Deployment (Phase 2b) | Sustained Response (Phase 2c) | Recovery (Phase 3) | ||
|---|---|---|---|---|---|
| Characterization | Remediation | Clearance | |||
| Receive and assess initial chemical incident information Conduct initial notifications and ICS activations Establish key FSLTT and RP POCs Identify suspect release site(s) Conduct initial (rapid) release modeling and site security operations Relay key initial risk information to appropriate agencies Support initial public communications and messaging, focusing on warnings and recommended protective actions | Deploy specialized assets and teams with gross field level instrumentation Determine agent type, concentration, and viability (as able based on instrumentation available) Conduct initial area/site-specific incident characterization and initial risk assessment Conduct initial site containment Perform additional release modeling and analysis, including extended downwind impacts analysis Conduct initial screening sampling Support ongoing risk communication and updates to recommended protective actions and worker health and safety actions | Perform detailed characterization of hazardous chemical (s) involved in the incident Perform detailed characterization of affected area/site(s)Conduct extensive environmental sampling and analysis Conduct supplemental health and environmental risk assessments Develop procedures to manage investigation derived waste Support ongoing risk communication | Develop and implement site/area containment plan Effect source reduction, as practical Establish decontamination parameters Develop and implement remediation (decontamination and clean-up) plan Develop and implement waste management plan Support ongoing risk communication | Conduct clearance sampling and analysis Establish clearance goal and develop collaborative clearance courses of action Support continued risk communication | Implement re-use/re- occupancy decision Seal/cap, decommissi on, or demolish if necessary Conduct environment al and public health monitoring, as required Support ongoing risk communication |
Immediate Response (Phase 2a). The Immediate Response phase typically is characterized by the unknowns and/or uncertainties associated with the immediate aftermath of the release. The source of the release may still be active and may be covert. Covert release or chemicals whose presence is difficult to detect, may result in significant cross-contamination, which can lead to the need to perform more extensive remediation activities. In general, the priority focus in this phase is on lifesaving and first aid actions such as evacuations, sheltering-in-place, protecting emergency workers, patient decontamination, and emergency medical treatment.
Deployment (Phase 2b). In this phase, initial incident characterization is undertaken to define areas/sites that require decontamination. Initial characterization activities may be based on rough estimates (e.g., visibility of a plume, emergency response guidelines), plume models, or even information from visual or odor indicators or gross level field instrumentation results reported by first responders. If the hazardous chemical has been identified, the IC/UC may be able to use other field instrumentation and/or more precise chemical dispersion models that provide estimates of the extent of the spread of the hazardous chemical. However, field instruments may only be able to provide information on whether the hazardous chemical is present above a certain concentration, rather than providing the concentration itself.
Likewise, the detection limit of the instrument (the concentration at which the instrument can detect the hazardous chemical) may be quite high; in some cases, it may be higher than the concentration at which responders are likely to show symptoms of exposure.
During Phase 2b and 2c, the IC/UC and other senior leaders may be supported by a technical/environmental planning team(s) and/or executive committees comprised of FSLTT agencies and other organizations with authorities, roles, and responsibilities in chemical incident consequence management. Such groups typically are established to advise the IC/UC on technical issues brought to light during initial incident characterization and other assessment and initial decision-making activities (e.g., protective exposure level determinations). Such groups typically expand in size and focus to include additional expertise to address other issues and needs that arise as the response evolves (e.g., development of remediation strategies, methodologies, etc.).16 See Section 2 below for further detail.
Sustained Response (Phase 2c). This phase of the response encompasses the detailed characterization of the site including determining the extent of contamination and other impacts, decontamination and cleanup planning and plan implementation, determining appropriate clearance criteria, and conducting final restoration and remediation of the site for proper resumed use/re-occupancy.
During this phase, additional site and other incident data will be gathered through a variety of different site characterization activities. Examples of such activities include:
- Developing detailed description and dimensions of the areas affected (natural or man-made);
- Estimating the extent of potentially contaminated surface areas and the volume of potentially contaminated materials using maps, building blueprints (including HVAC systems and building interconnections), and water distribution system maps (including connections and components of water and wastewater distribution systems);
- Identifying material types: nonporous (e.g., glass, metals), semi-porous (e.g., walls, concrete), or porous (e.g., ceiling tile, carpet);
- Identifying populations exposed, potential human exposure pathways (e.g., inhaling contaminated air, skin contact with contaminated surfaces or water, drinking water) and exposure parameters (e.g., intake rates and time-activity patterns);
- Documenting environmental conditions during and after the contamination event (e.g., ambient temperature, humidity, exposure to sunlight, cloud cover, wind speed and direction, rate and directional flow of water, rainfall);
- Applying mathematical models to characterize the fate and transport of contamination (e.g., air, ground water, and surface water models); and
- Conducting waste management activities.
Based on the outcomes of the characterization activities identified above, in the areas affected by the release, the IC/UC may need to revise assessments of suspected areas of contamination as established during earlier phases of the response. Unlike in the case of the immediate response, in this phase the bounding of these areas is likely to be based upon the results of strategic sampling plans and precise, laboratory-based, analytical methods. Outputs of this process would not only indicate if a hazardous chemical was detected, but would also provide a quantitative estimate of the contamination present in the affected environmental materials and surfaces (e.g., building surfaces, soil, ground water, drinking water, surface water, air).
Regarding Phase 2c remediation activities, various decontamination technologies and procedures may be implemented to remediate the impacted sites. Such activities necessarily will be iterative in nature, with ongoing decontamination activities and re-characterization of the decontaminated areas to assess if additional measures must be implemented, until acceptable clearance levels are reached.
Decontamination technologies may use mechanical/physical, chemical, or natural degradation/natural attenuation methods to physically remove, chemically treat, degrade, or naturally dissipate the hazardous chemical contaminant(s).17 In addition, every decontamination technology produces waste, and the amount and character of waste is dependent on not only the contaminant, but also the specific decontamination technology employed. A partial listing of decontamination technologies for specific chemical warfare agents (CWAs) for surface “hot spots,” large volume spaces, and sensitive equipment is provided in Section 5.
Optimally, the following end-states are achieved when Phase 2C is completed:
- Contaminated facilities are identified and successfully decontaminated for safe re-use and re- occupancy;
- All hazardous and non-hazardous waste materials are removed and successfully managed in accordance with FSLTT environmental regulations;
- Facilities, equipment, and/or materials, unable to be safely decontaminated to established levels, due to a variety of factors, are demolished and corresponding waste streams properly disposed of in accordance with FSLTT environmental laws and regulations;
- Chemical incident remediation efforts are completed within a reasonable timeframe (as established by identified FSLTT senior leaders and stakeholders) to minimize economic and public health impacts to the affected communities; and
- Remediation personnel (both government and private entities) conducting cleanup and HAZMAT disposal activities are protected and show no signs of adverse health effects as a result of such activities.
Recovery (Phase 3). During this phase, final decisions are made regarding longer-term remediation issues and resumed use/re-occupancy of contaminated sites and facilities. Consideration should also be given to plans for determining if long-term environmental monitoring is required to ensure that clearance levels are maintained over time and whether it is necessary to institute longer-term site controls or restrictions. Continued risk communication is important during the remediation phase to inform the public and help them make decisions regarding themselves and their families and to maintain trust between the public and government decision-makers.