Jip 4 At-sea monitoring of surface dispersant effectiveness
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- Figure 3 Monitoring the effectiveness of dispersant using fluorometry
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not be easy in such circumstances, carrying out Tier II and Tier III fluorometry monitoring where it is possible can provide useful qualitative evidence of the environmental benefit of dispersant use, as demonstrated at the Sea Empress incident (Lunel et al., 1996). Tier III: additional monitoring Tier III uses the same methodology as Tier II, but with sampling occurring at additional depths to further define the shape and size of the dispersed oil cloud/plume. This is achieved by either taking additional readings to a depth of 10 metres in areas along the transect where there was a peak in readings at 1 metre, or by running the transect with fluorometers deployed at two different IPIECA-IOGP Oil Spill Response Joint Industry Project 12
readings, a transect should be followed through the slick: if there is an increase in readings of five times between the untreated oil (left) and the dispersed oil (right), the dispersant may be considered as effective. Figure 3 Monitoring the effectiveness of dispersant using fluorometry Sour
ce: US Coast Guar d
evaluate effectiveness Sour
ce: NOAA depths (for example, at 1 metre and 5 metres). Tier III monitoring may also include the measurement of the physical and chemical parameters of the water column, including temperature, dissolved oxygen, pH, turbidity, conductivity (surrogate for salinity), and any other parameters which may have an effect on the rate of dispersion. Field Guides on dispersant application monitoring have been produced by OSRL, based on the SMART Protocol. These are freely available at: http://www.oilspillresponse.com/technical- development/technical-field-guides . Monitoring prolonged dispersant application There may be circumstances where the surface application of dispersant is feasible and required for prolonged periods. Scenarios may arise involving ongoing oil releases from sources such as vessels, subsea pipelines or offshore platforms. This issue has been considered by the US National Response Team, and led to the publication of guidance for the monitoring of dispersant operations that are expected to exceed four days. The guidance supplements, but does not replace, the SMART protocol. Prolonged monitoring addresses estimations of the weathering characteristics and potential dispersibility of oil. In some cases these studies may have been undertaken as part of the contingency planning process, and relevant information would therefore be available to response managers at the commencement of an incident. Where this is not the case, it may be possible to undertake rapid laboratory analyses of the spilled oil to ascertain weathering characteristics (particularly increases in viscosity and emulsification) and how these may reduce the effectiveness of the dispersant. Such laboratory information can be verified in the field as the response progresses, by carefully-controlled and observed test spraying from vessels in the field on ageing areas of the spilled oil—assuming such areas remain and have not been prevented by the success of the response. The test sprays can be monitored with visual observation and fluorometry, and correlated with laboratory testing and, possibly, also with a shipboard field effectiveness test. One outcome of these various tests will be a better understanding of dispersant effectiveness in terms of the cut-off point for its application during prolonged operations. This will provide field operational teams with a heightened awareness of the likely success of ongoing operations, and of where particular attention may need to be given to ensure that dispersant operations remain effective, e.g. by recognizing the appearance of oil that is becoming non-dispersible, and the geographic areas where operations are unlikely to be viable. 13 At-sea monitoring of surface dispersant effectiveness All aspects of the potential use of dispersants require planning, which should include provision for mobilizing the appropriate resources for dispersant effectiveness monitoring. The emergency response phase (typically the initial few hours of an incident) is focused on Tier I SMART monitoring. More detailed monitoring capability associated with Tier II and Tier III monitoring is most likely to be held and deployed by specialized oil spill response organizations with dedicated dispersant application capability. Equipment Tier I monitoring equipment may be limited to ensuring the availability of resources, guidelines and procedures for the observation of oil and the appearance of dispersed oil. Digital camera(s) and video recorder(s), geo-referenced where possible, and in a ready-to-go condition, should be available to record observations. Camera systems mounted on aerostats are increasingly being used by oil spill response vessels. Unmanned aerial vehicles (UAVs) may also be available to responders. These aerial platforms may carry both visual and IR imaging. Where practical, and if considered necessary, an organization may maintain simple field effectiveness testing kits as part of the first-response equipment. More sophisticated monitoring tools such aerial remote sensing capability and fluorometry are likely to be held and deployed by specialized oil spill response organizations and scientific institutes. Response managers and decision makers are likely to request rapid communication of the initial results of dispersant test sprays. This may extend to requirements for live image feeds and voice communications from field supervisors and vessel/aerial-based observers to the Command centre. Personnel It is vital for first responders involved in supervising or observing test sprays or initial dispersant operations to be familiar with the required techniques for observation and verification of dispersant effectiveness. Training personnel for this role can be challenging, considering that the opportunities for real-time observation and monitoring of dispersant application are opportunistic and very limited. Supporting materials have been developed which assist with the correct implementation of protocols, including the following examples available from NOAA: http://response.restoration.noaa.gov/oil-and-chemical-spills/oil-spills/resources/dispersant- application-observer-job-aid.html http://response.restoration.noaa.gov/training-and-education/training/workshops/aerial- observation-training.html IPIECA-IOGP Oil Spill Response Joint Industry Project 14 Planning considerations Personnel from specialized oil spill response organizations will be expected to have undergone appropriate training and development as part of their organization’s internal training programmes, and to be competent to undertake monitoring associated with the dispersant capability mobilized by their organizations. It is recommended that the team undertaking monitoring includes representation from relevant authorities, agencies or regulators. This is to ensure that consensus on observations can be reached in the field and, where there is uncertainty about effectiveness, this can be raised and further monitoring undertaken to provide further data. Operational support and logistics All monitoring will require some degree of logistical support, and in all cases the basic transport of observers by vessel or aircraft to the site will be required. If spraying is from a vessel it may be possible for the observation to take place from the same vessel. At some larger spills there are likely to be demands from various at-sea response operations for vessels and aircraft. It is imperative that monitoring activities are highlighted in advance through contingency planning. The incident management team should therefore be prepared to integrate monitoring requirements into the response effort and allocate adequate resources. In many spill scenarios, vessels of opportunity (VOOs) can be used to support more advanced Tier II and Tier III monitoring. Operationally, the vessels need to be able to manoeuvre at slow speeds, tow fluorometers (which are typically towed at speeds up to 2 knots), and be sufficiently manoeuvrable to navigate the required path through the slick. A VOO also needs to be able to travel quickly between deployments to different slicks or operating bases as required. Practically, a VOO needs to have sufficient deck space and the means of securing a davit, if required, to deploy the fluorometer. Vessels with high sides will be difficult to work from due to the limitations in easily deploying and recovering the submersible equipment. Finally, dependent upon the location and type of the incident and the ongoing operations, suitable and sufficient accommodation may be required for the monitoring team. The short operational time horizons between vessel-borne spraying operations are compounded when aircraft are used to spray dispersant because, for safety reasons, the vessel is required to move off-station during the aerial spray operation and then return to the treated area on completion. While aerial dispersant spraying can prove extremely effective, attempting to establish numerical efficacy using vessel-borne equipment following an aerial spray operation can be fraught with difficulty. 15 At-sea monitoring of surface dispersant effectiveness The application of dispersants to floating oil slicks is one of the key at-sea response tools with the potential to reduce the overall ecological and socio-environmental damages caused by a spill. However, dispersants are not effective on all oils in all conditions; their effectiveness will vary depending on the prevailing environmental conditions, and the type of spilled oil and its weathering state. In all cases following shipping spills, the effectiveness will reduce with time, and there will usually be a ‘window of opportunity’ for the effective application of dispersant. This does not of course apply in the case of an ongoing release of oil from an offshore platform where fresh oil, which is amenable to dispersal, continues to be released over time. It is important to ensure that dispersant is only used on spilled oil in areas where this is appropriate and when there is a reasonable expectation of it being effective. Monitoring should be established to verify that the dispersant is effective. Initial estimations of likely effectiveness may be based on studying an oil’s properties (notably the viscosity and pour point) and on computer modelling predictions of the oil’s fate, or, in cases where operations are fixed and the oil type is known, on laboratory studies of oil weathering and dispersibility. It should be recognized that the behaviour of oil at sea means that estimations may not match the reality, and some weathering processes, such as emulsification, are difficult to predict accurately. It is typical for national regulations to include laboratory testing of dispersant effectiveness prior to a product being allowed for use; this is explained in detail in the IPIECA-IOGP document, Guidelines on oil characterization
products, but they cannot reproduce open sea conditions. The results of such laboratory testing (usually presented as ‘percentage effectiveness’) cannot, therefore, be extrapolated to likely performance in the field. The difficulties of calculating both the volume of floating oil slicks and the extent of oil naturally or chemically dispersed beneath a slick mean that it is not currently possible to quantify with any degree of precision the effectiveness of dispersant applied in the field. Monitoring effectiveness is therefore a qualitative exercise, which focuses on determining whether the application of dispersant has led to increased levels of dispersed oil coupled, where possible, with observations of a reduced area of surface slick. The use of field effectiveness tests coupled with initial test sprays can help decision makers to determine whether the full deployment of dispersant should go ahead. However, such tests need to be undertaken quickly so as to avoid unnecessary delays in the decision making process. The SMART protocol provides a suitable approach for practical monitoring of effectiveness in the field. In many cases monitoring will be limited to visual observations from vessel or aircraft, possibly supported by remote sensing. In larger spills it may be viable to utilize in-water monitoring using fluorometry, although this is difficult to deploy in relation to aerial dispersant application. In larger incidents where the primary application is aerial, limited application of dispersant by vessels may also be carried out to enable in-water monitoring to be undertaken. In all cases the monitoring should include representations from relevant authorities and be carried out on a regular basis to ensure that the dispersant remains effective on weathering oil. IPIECA-IOGP Oil Spill Response Joint Industry Project 16 Conclusions and recommendations AMSA (2012). National Plan Oil Spill Dispersant Effectiveness Field Test Kit (Nat-DET): Operational Guide. Revision: June 2012. Australian Maritime Safety Authority (AMSA). http://www.amsa.gov.au/forms-and-publications/Publications/NatDET_Guide_2012.pdf BenKinney, M., Pascal, B., Huler, C., Wood, B., Russell, M., Nevin, A. and Gass, M. (2011). Getting SMARTer: Recommendations for Improving SMART Monitoring Procedures Based on Experiences from the Deepwater Horizon Response: Scientific Support for Deepwater Horizon (DWH) Aerial Dispersant Operations. In International Oil Spill Conference Proceedings, March 2011, Vol. 2011, No. 1, pp. abs349. 2011. http://dx.doi.org/10.7901/2169-3358-2011-1-349 Fingas, M. F., Kyle, D. A., Laroche, N. D., Fieldhouse, B. G., Sergy, G. and Stoodley, R. G. (1995). The effectiveness testing of oil spill-treating agents. In The Use of Chemicals in Oil Spill Response, ASTM STP1252, P. Lane (Ed.). ASTM International, Philadelphia, PA, USA. pp. 286- 298.
www.astm.org/DIGITAL_LIBRARY/STP/SOURCE_PAGES/STP1252.htm IPIECA-IOGP (2013). Finding 19: Guidelines on oil characterization to inform spill response decisions. Finding 6 of the IOGP Global Industry Response Group (GIRG) response to the Deepwater Horizon incident in the Gulf of Mexico in April 2010. IPIECA-IOGP Oil Spill Response Joint Industry Project (OSR-JIP). http://oilspillresponseproject.org/completed-products IPIECA-IOGP (2015). Net environmental benefit analysis (NEBA). IPIECA-IOGP Good Practice Guide Series, Oil Spill Response Joint Industry Project (OSR-JIP). IOGP Report 517. http://oilspillresponseproject.org/completed-products IPIECA-IOGP (2015a). Dispersants: surface application. IPIECA-IOGP Good Practice Guide Series, Oil Spill Response Joint Industry Project (OSR-JIP). IOGP Report 532. http://oilspillresponseproject.org/completed-products Lunel T., Swannell R., Rusin J., Bailey N., Halliwell C., Davies L., Sommerville M., Dobie A., Mitchel D., McDonagh M. and Lee, K. (1996). Monitoring of the effectiveness of response options during the Sea Empress incident: a key component of the successful counter-pollution response. In Spill Science & Technology Bulletin, Vol. 2, Issues 2–3, 1995, pp. 99-112. (Published in 1996.) www.sciencedirect.com/science/article/pii/S1353256196000114 NRC (1989). Using Oil Spill Dispersants on the Sea. Committee on Effectiveness of Oil Spill Dispersants, US National Research Council (NRC). National Academy Press, Washington, D.C. http://www.nap.edu/openbook.php?record_id=736&page=R1 NRC (2005). Oil Spill Dispersants: Efficacy and Effects. Committee on Understanding Oil Spill Dispersants, US National Research Council (NRC). National Academy Press, Washington, D.C. http://www.nap.edu/openbook.php?record_id=11283 17 At-sea monitoring of surface dispersant effectiveness References and further reading NRT (2013). Environmental Monitoring for Atypical Dispersant Operations, Including Guidance for: Subsea Application; Prolonged Surface Application. U.S. National Response Team (NRT). www.nrt.org/production/NRT/NRTWeb.nsf/AllAttachmentsByTitle/SA-1086NRT_Atypical_ Dispersant_Guidance_Final_5-30-2013.pdf/$File/NRT_Atypical_Dispersant_Guidance_Final_5-30- 2013.pdf?OpenElement Oil Spill Response Limited, Technical Field Guides for Dispersant Application Monitoring. www.oilspillresponse.com/technical-development/technical-field-guides . S. L. Ross (2008). Updating the U.S. SMART Dispersant Efficacy Monitoring Protocol. A review of OHMSETT dispersant effectiveness test results, 2001–07. S. L. Ross Environmental Research Limited. Prepared for the USCG Research and Development Center, Groton, CT and U.S. Department of the Interior, Minerals Management Service. www.slross.com/publications/AMOP/2009_Updating_the_U.S._SMART_Dispersant_Efficacy_ Monitoring_Protocol.pdf USCG et al. (2006). Special Monitoring of Applied Response Technologies (SMART). U.S. Coast Guard (USCG), National Oceanic and Atmospheric Administration (NOAA), U.S. Environmental Protection Agency (U.S. EPA), Centers for Disease Control and Prevention (CDC), Minerals Management Service (MMS). http://response.restoration.noaa.gov/sites/default/files/SMART_protocol.pdf IPIECA-IOGP Oil Spill Response Joint Industry Project 18
This page is intentionally blank © IPIECA-IOGP 2015 All rights reserved. IOGP represents the upstream oil and gas industry before international organizations including the International Maritime Organization, the United Nations Environment Programme (UNEP) Regional Seas Conventions and other groups under the UN umbrella. At the regional level, IOGP is the industry representative to the European Commission and Parliament and the OSPAR Commission for the North East Atlantic. Equally important is IOGP’s role in promulgating best practices, particularly in the areas of health, safety, the environment and social responsibility. www.iogp.org IPIECA is the global oil and gas industry association for environmental and social issues. It develops, shares and promotes good practices and knowledge to help the industry improve its environmental and social performance; and is the industry’s principal channel of communication with the United Nations. Through its member led working groups and executive leadership, IPIECA brings together the collective expertise of oil and gas companies and associations. Its unique position within the industry enables its members to respond effectively to key environmental and social issues. www.ipieca.org Yüklə 143,73 Kb. Dostları ilə paylaş:
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