A field guide to oil spill response on freshwater shorelines: chapter 8

8.1 Response objectives and shoreline treatment criteria

Response objectives are broad statements of guidance necessary for the selection of appropriate response strategies and tactics (Sections 6.2, 6.3 and 6.4). These objectives and strategies must be realistic (i.e. feasible and practicable), measurable, and prioritized. They should be set early in the shoreline response planning stage (Section 1.2.2) and reviewed and revised as appropriate by spill management throughout the response.

At a more specific level of detail and precision, shoreline treatment criteria or standards are developed for each segment to facilitate treatment decision-making and guide operations during the response. Historically, treatment criteria were called endpoints or endpoint criteria, or treatment targets. The use of treatment criteria (i.e. endpoint criteria) in shoreline treatment operations has a long history of usage and is detailed in Sergy and Owens (2007; 2008) and ECCC (2018), and for submerged and sunken oil in Harper et al. (2018). The prime function of shoreline treatment criteria is to provide clear targets for response operations and subsequently provide an inspection team with measurable criteria and standards with which to evaluate the condition of the shoreline.

Treatment criteria are assigned to a specific segment, shoreline type or defined area of shoreline and are developed through collaboration with the various stakeholders, technical experts, and any affected Indigenous communities. This collaboration is key, and helps to ensure that the relevant environmental, socio-economic, and cultural considerations are incorporated into the overall decision-making process regarding shoreline treatment. It is important that both stakeholders and response personnel are calibrated to these treatment criteria so that expectations are managed and that everyone understands what the final goals for a given segment look like. As with the response objectives, treatment criteria must be realistic and measurable. An effective and successful response is far more likely when all parties share the same expectation of what must be accomplished.

There are no set shoreline treatment criteria, however there are guidelines available for selecting treatment criteria for oil spill response that can provide spill management with a framework for working through this process (Sergy and Owens 2007; 2008). It should be noted that while there are provincial and territorial regulations for contaminated sites, these standards are based on existing numerical guidelines (limits) or narrative statements for chemical parameters of concern (contaminants) and are not considered appropriate for the development of treatment criteria for shoreline activities.

There may be sequential stages of shoreline treatment defined in a plan, each of which may have treatment criteria, for example:

• The Emergency Response Phase may have interim criteria to guide field operations to focus on removal of bulk oil, oil that could be easily remobilized, and/or high-priority oiled segments.
• While the initial stage is in progress, the spill management team can develop the treatment criteria as part of the Planned Response Phase for those segments that require specific treatments.
• The Monitoring and Completion phase after completion of treatment may subsequently have its own set of criteria addressing residual oil left to naturally weather.
• Some segments may have progressive stages of treatment using different tactics, with each stage having its own criteria.
• Additionally, there may be a process of establishing phased treatment criteria for situations where there is difficulty or reluctance to setting final criteria in the initial stages of an oil spill. This flexible approach was used during a pipeline spill into the North Saskatchewan River (Section 9.1.10), during which No Further Treatment (NFT) criteria were established for the 2016 and 2017 phases of the response.

Whatever type and form treatment criteria take (i.e. interim or final, staged or phased), it is important that they be defined in advance of SCAT field surveys and response operations. For examples and additional discussion concerning shoreline treatment criteria, refer to ECCC (2018).

The following Tables 8.1 and 8.2 provide an example of shoreline treatment criteria for a lake environment and a riverine system, respectively.

8.2 Monitoring and follow-up

Throughout the response, there is a need for ongoing monitoring to provide information on changes in oiling conditions and to evaluate the effectiveness of treatment. This oversight is meant to complement the expertise that Operations has and ensure that response objectives and treatment criteria are being met. There may be a need for monitoring during treatment in specific areas due to a sensitive resource, ensuring that Best Management Practices are being upheld. These monitors would be experts in specific fields, available to guide and advise operations (e.g. cultural monitors, biologists, SCAT-Ops Liaisons).

Photo-monitoring can be used as a means of monitoring a specific site over time. Photo-monitoring sites are selected early in the response and a photo library is developed by taking photos at the same exact locations over specific time-intervals. Stakes or other natural markers provide a visual reference point that enable the photographer to relocate at the exact same location and to frame the image for comparison with earlier imagery (Figure 8.1).

Figure 8.1: View onshore of stakes (with tape flagging) and natural marker (dead tree in backshore) for monitoring location

Time-series photographs may illustrate changes in oil character and distribution and can help to visualize how a certain type of shoreline is responding to and recovering from either treatment or natural attenuation (Figure 8.2).

Figure 8.2: Monitoring location showing: shoreline oiling with mobile product on water surface in late July (left panel); no mobile oil on water surface in mid August (middle panel); erosion and slumping of bank with no oil observed in mid September (right panel)

Another means of monitoring shoreline is through shoreline profiling. Shoreline profile surveys are periodic or scheduled across-shore surveys used to monitor and document topographic changes to lake shores and channel banks as they undergo erosional-depositional processes associated with ice gouging, flooding, and other events. The Emery Method, a simple but accurate technique that relies upon two, centimetre-incremented profile rods and a measured distance between them, is easy to use, easy to train people on, and involves simple equipment (Emery 1961). Stakes are established in the backshore and near the water line (may be a geo-referenced location) and the positions are recorded. The elevation of the back stake is considered the reference point (benchmark) for the survey, as well as the profile’s location. The front and back profile rods are aligned with the water line and back stakes. The reader notes where the horizon (or another Table reference point if the horizon is not visible) intersects one of the profile rods (reading off back stake indicates an elevation drop and reading off the front stake indicates a rise in elevation). This type of monitoring is done to determine if there is erosion or deposition along a shoreline, which can in help in determining whether there is any potential for oil to become buried based on the timing of oil standing.

8.3 Inspection and completion

Considerations for terminating a response include ensuring that: sensitive areas are no longer threatened; there is no recoverable oil remaining on the water; only residual oil remains on the shorelines; and shoreline treatment criteria have been met. For treatment on a given segment of shoreline to be deemed complete, there must be a formal process for inspection and completion. This includes post-treatment surveys where SCAT teams determine if the segment meets the treatment criteria, gain consensus in the field, and generate a Shoreline Inspection Report (SIR) documenting the results. Treatment is completed when one of the following applies:

• No Observed Oil (NOO)
• Oiling meets criteria, therefore NFT
• Oiling does not meet criteria, but NFT is recommended with a specific reason(s):
  • Net Environmental Benefit (NFT-NEB);
  • Monitored Attenuation (NFT-MON);
  • As Low as Reasonably Practicable (NFT-ALARP);
  • Access (NFT-Access);
  • Safety Concerns (NFT-SAFETY)

Once a segment of shoreline is deemed complete and the pertinent stakeholders and Indigenous representatives agree, it passes to the Completion and Monitoring Phase. This includes post-incident assessments, evaluation of the effectiveness of the treatments, and monitoring the effects of oiling and subsequent treatment.

After spill response activities have terminated, additional activities may continue for some time. These may include investigations, legal challenges, financial claims, restoration, long–term monitoring, and human resource activities. Staging areas, roads and other access points, fences, etc. are restored or repaired. At this stage, a project team may continue long-term incident-related activities such as monitoring. After completion, spill managers should initiate an evaluation of the response. This evaluation is focused on how the response was managed, not the cause of the incident. All appropriate personnel and external responders that participated in the response may be asked to contribute to the evaluation through a formal or informal lessons-learned briefing. The evaluation may include, but is not limited to, the following items:

• general site characterization information
• description of incident type and circumstances
• immediate emergency actions undertaken
• notification and alert
• organization and efficiency of Incident Management Team
• resources utilized and their efficiency
• lessons learned

The final report may include, but is not limited to:

1. Initial event summary.
2. Key response activities.
3. Response resource use and efficacy.
4. Summary of lessons learned.
5. Recommended improvements in response planning or preparedness.
6. Financial consequence analysis.
7. Legal consequence analysis.
8. Future operational or business recommendations.

It is important for future response that the lessons learned from a given response are documented and shared with the response community so that everyone can benefit and improve their knowledge. End-of-Spill Reports and Lessons Learned Reports are required in some jurisdictions, such as BC, to ensure that these learnings are captured and shared, and that there is final, formal documentation of the incident details. This is an opportunity for response teams to re-evaluate their processes, procedures and training requirements.