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Oil Detection and Delineation using Canine Detection (or K9-SCAT) Teams

By: Helen Dubach and Ed Owens, Owens Coastal Consultants

Current practice for the detection of surface oil on shorelines following a spill focuses on systematic visual aerial and/or ground-based observations. This is a straightforward process in which oil can be observed directly. Visual or video aerial survey techniques are suitable for Heavy and Moderate surface oiling categories but may not be able to identify Light, Very Light or Trace categories. Aerial or ground surveys (on foot or by boat) may not be able to locate surface oil that is hidden by vegetation in salt marshes, reed beds, river bank shrubs and trees, or in between boulders and rip-rap.

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Ground-based SCAT survey.

 

A large portion of the reconnaissance-level shoreline assessment survey effort is typically undertaken to ensure that oil is not present in the affected area. As examples, 75% of the 7,058 km of shoreline surveyed during the Deepwater Horizon response and 61% of the 5,459 km of shoreline surveyed during the Exxon Valdez response had No Observed Oil.

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Subsurface oil on a sandy beach. Using manual or mechanical practices for detection and deliniation is laber intensive and time consuming. However, canines are able to detect buried oil with impressive accuracy.

 

This type of “clearance” survey is a time-consuming effort for ground-based teams and may tie up resources that may be better deployed elsewhere, particularly during the early phase of a response. In addition, systematic ground-based surveys may be very slow and tiring in areas of difficult terrain, such as exposed bedrock, cobble or boulder substrates, and in snow conditions.

Current practice for the detection and delineation of subsurface oil in sediment shorelines, river banks and on land relies primarily on the use of manual or mechanical excavation of pits and trenches or auguring to allow visual examination and documentation of subsurface conditions and/or sampling for offsite analysis. These procedures are typically labor intensive and very time consuming. Other currently acceptable techniques include coring and water jetting. A range of other potential techniques has been reviewed, but these are either not proven or have a limited applicability.

Excavation with pits, auguring and trenches is a spot-sampling technique; therefore, there are limitations in the ability of the survey to accurately and efficiently delineate the three-dimensional (3D) extent of subsurface oiling, particularly in the horizontal dimension. The location of an excavation is based on a professional judgment, a random selection, or on a fixed sampling grid. In situations of discontinuous oiling, there is a high potential for non-detection where individual deposits or layers have a horizontal dimension less than the distance between pits or trenches. Even with an intensive excavation survey, pitting, trenching or auguring may only cover a small percentage (<0.01%) of the total survey area. Intensive sampling is atypical due to the high level of effort involved, and many locations would typically have No Observed Oil (NOO); for example, of the >180,000 pits excavated between May 2010 and December 2012 during the Deepwater Horizon response, 67% had NOO.

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Manual excavation of pits.

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Mechanical excavation of pits.

 

Dogs have an innate ability to analyze and recognize odors for which they have been imprinted, and a well-trained canine can be taught to communicate with the handler when the presence of a particular odor is detected. The scenting ability of canines has recently been used to detect oil that is difficult to find, for example, in crevices between boulders, oil that is under shallow water, or oil that has been buried by, or penetrated into sediment, snow or ice.

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Photo from 2008 Svalbard survey. Photo credit: P.J. Brandvik, SINTEF.

 

In Norway, SINTEF and the Trondheim Hundeskole (Trondheim Dog Training Academy) have verified, through a series of field tests and informal exercises that trained canines can detect oil residues in a range of situations. Field trials in Svalbard and western Norway in 2008 were designed to evaluate the ability of canines to detect oil hidden in snow and ice and in beach sediments.1

The results show that the canines were able to: detect a small amount of weathered oil (400ml) that had been buried 30 cm into ice and covered with snow and left for a week; determine the dimensions of large oil deposits by indicating the borders of clusters of smaller amounts of oil at a 10-m spacing; and find the location of a larger oil deposit (400 L) that had been laid down on top of ice and covered by snow based on the triangulation of detected plume dimensions; with oil detected up to 5 km downwind of the spill location.

In Svalbard, an IFO-30 that had been laid down in 1997 as part of a shoreline experiment was detected 11 years later in upper intertidal zone mixed sand-pebble beach sediments at a depth of 0.8 m. At Fedje in 2008, on challenging terrain with difficult bedrock and coarse-sediment shorelines, snow and winds gusting to 20 m/s, oil from the 2007 M/V Server spill was detected in mixed sand-pebble sediments and in bedrock crevices and cracks. Under these weather conditions, the teams worked in two 4 to 5 hr periods each day. A search speed of 1 to 5 km/hr was recorded on the challenging terrain with 3 to 5 km/hr on more favorable terrain. As one of several informal exercises, oil was buried in an intertidal zone at low tide and later detected at high tide from the adjacent beach in a water depth of approximately 40 cm.

More recently, field trials to demonstrate and evaluate the applicability of using oil detection canines were conducted in June 2015 as part of an American Petroleum Institute (API) Joint Industry Task Force (JITF) Oil Spill Preparedness and Response program study on subsurface oil detection and delineation technologies in support of inland and shoreline oil spill response.2 This study focused on evaluating the ability of a canine team to delineate the footprint of the oil odor, and therefore tell us the outline or shape of the subsurface oil deposit(s).

Two detection search strategies were used:
• Off-leash Wide Area Search (WAS) to locate surface or subsurface oil within an area; and
• On-leash Delineation Survey to inspect smaller areas; for subsurface oil, this typically is used after a site has been located by a WAS.

Wide Area Search
WAS patterns are used for rapid evaluation of large areas for surface or subsurface target materials. A WAS is a High Confidence-Low Risk survey in which the canine searches independently (off leash) by air scenting, by ground scenting if the air scent is not readily available, or a combination of both. The canine has sufficient appropriate direction from the handler to ensure adequate coverage of the search area through the use of visual (hand signals) and/or auditory (voice, canine collar sounds or other audible signals) direction and is typically trained to follow a sweeping pattern known as quartering or orbiting. The canine is fitted with a GPS tracking collar to record the trackline of the search. The tracking collar is linked to a handheld GPS unit or moving map display so that the survey team can ensure that the entire survey area is fully covered.

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GPS tracking collar with handheld GPS unit.

 

The team typically works at a scale of several acres (or hectares) with 100% coverage and can cover at a ground survey rate on the order of 2 km/hour. A WAS team is trained to thoroughly and rapidly cover extensive areas to detect plumes or targets that subsequently can be defined in greater detail using delineation search procedures. A WAS pattern can also rapidly clear areas that have no detectable odors or targets (No Detectable Oil [NDO]).

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Wide Area Search.Press.

 

Delineation Surveys
Delineation Surveys for subsurface oil are used to inspect smaller areas in detail, where the canine focuses on the ground odor in the footprint of the subsurface oil.

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Delineation Survey.

 

A Delineation Survey may be the next phase after a WAS has detected the presence of a target odor. During a Delineation Survey, the canine works on-leash as directed by the handler and involves “bouncing” around the odor footprint. The team can cover on the order of 100 m by 10 m (1,000 m2) in 10 minutes.

The 2015 API trials were conducted at the K2 Solutions Inc. K9 Training Center, Jackson Springs, North Carolina, and involved two detection canines imprinted with a West Texas Intermediate crude oil and a certified handler who had no knowledge of the target locations.

Seven off-leash WAS tests were conducted on open fields to evaluate the ability to rapidly survey a 0.5 ha (1.2 acre) area to either detect a single shallow target or to “clear” the area if no oiled sediment targets had been deployed. In terms of accuracy, the teams detected and located each WAS target during four tests and cleared (No Detectable Oil) the areas searched during the other three tests with no false alerts, equating to 100% accuracy. In terms of performance, the WAS tests were equivalent to a survey rate of 2 km/hr, or on the order of 15 to 25 linear km/day, for a High Confidence-Low Risk survey with 100% coverage of a 50-m wide shoreline or pipeline Right of Way.

Fourteen on-leash Delineation Survey tests involved a gridded layout within a 1,250-m2 area using six different target designs to represent continuous, discontinuous and isolated subsurface oil distributions as well as a linear pipeline scenario. Oiled sediment targets were “buried” at various depths between 30 and 90 cm (12 and 36 in.). Oil was detected at all depths up to 90 cm (36 in.). In terms of accuracy, 2 of the 700 oiled sediment and non-oiled targets that were deployed in the delineation tests were misidentified for undetermined reasons; 20 targets were misidentified due to survey or experimental issues that were not attributed to the canines, equating to 99.7% canine accuracy. In terms of performance, the average time for the 14, 1,250-m2 Delineation Surveys was 11 minutes for 100% ground coverage.

The proven ability of canines to detect oil targets, even in very small amounts, and to efficiently provide full survey coverage is a significant advantage over systematic ground, or vessel-based, surveys. Canines are, however, primarily a support tactic and do not replace the standard SCAT team surveys, although they may obviate the need for a ground survey in some areas when used in a “clearance” capacity. The positive attributes of excavation and canine detection do not overlap, but rather are complementary. If an alternative detection technique is used, excavation in some form is required for verification and vertical characterization.

Several applications for the use of oil detection canine teams have been identified:
→ Clearance Survey: During an initial SCAT reconnaissance phase where surface, hidden or subsurface oil is not anticipated, but confirmation is required—for example, a survey in an area not believed to have been oiled; or a routine pipeline inspection.

→ Oil Detection Survey: During an initial SCAT systematic survey phase where hidden or subsurface oil possibly exists, and where confirmation, location (detection) and delineation is required or the area is cleared as No Detectable Oil (NDO)—for example, a survey where oil is suspected to have penetrated into or been buried by sediment or snow, a survey where oil is suspected to be present in a wetland or scrub area or within boulders or riprap and cannot be directly observed from the air or ground, where human traffic in a wetland can be avoided, in difficult terrain, or a pipeline survey following a leak warning and/or pressure decrease.

→ Survey for the confirmation of endpoint achievement: As part of a post‐treatment survey where the location of oiling is known and either recommended treatment has been completed or a suitable period of natural recovery has transpired.

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2015 API Field Trials: Canine alerting detection of an oil odor.

 

There are some limitations to the use of canine teams to detect oil:
• Highly volatile odors, such as gasoline, can saturate the nasal passages so that a canine’s sense of smell is blocked for several minutes.
• Large volumes of oil can also saturate the odor, making it difficult to pinpoint and, therefore, delineate.
• Different oil sources may present multiple targets to confuse the canine, which can be avoided by discrimination between oils during imprinting.
• Snow can absorb vapor. Loose, dry snow is porous and allows vapors to rise to the surface, tightly packed snow less so. Wet snow could cause vapor components to go into solution and be aborted by the snow through capillary action, thus changing the overall scent.

K9 SCAT Article Draft 29 Jan 2016 RB2

 

 

The selection of the appropriate techniques and tool(s) to conduct a SCAT survey evaluates the advantages and disadvantages of each tactic:

A K9‐SCAT program has the potential to:
• Rapidly clear large shoreline/inland areas or pipeline corridors with a High‐Confidence, Low-Risk survey to ensure that oil is not present in those areas, something that otherwise would be time consuming for a traditional ground observation survey team.
• Be effective in areas that would be difficult or hazardous for a ground survey team, such as large sediment (boulder and riprap), bedrock, or vegetated terrain and deep snow and detect subsurface oil to depths of several feet with 100% coverage, versus spot sampling by manual or mechanical excavation.

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2015 API Field Trials: Ground scenting.

 

K9‐SCAT requires close interaction between the K9‐SCAT Team Lead and the Canine Handler, and requires a high level of understanding of each other’s roles, expectations, protocols, and skills in order to communicate effectively and develop a good working relationship. An effective and successful K9‐SCAT Team must fully integrate the two very different disciplines of SCAT and canine detection with inter‐disciplinary training, cooperation and calibration.

The subsurface oil detection field trials are part of ongoing R&D studies in which OCC has been involved since the 1980s to improve the understanding of the fate and behavior of spilled oil and to support the environmental and operational decisions on how to treat or clean spilled oil. K2 Solutions, similarly, has been at the forefront of R&D for imprinting canines to target odors and the utilization of detection teams in locating sub-surface targets as well as canine performance training and enhancement and certification standards. This partnership between OCC and K2 Solutions Inc. exemplifies how progress can be made by interaction and collaboration between disciplines.

Further Information
Further information and references can be found at www.K9SCAT.com. A report on the 2015 API canine field trials and Canine Oil Detection (K9-SCAT) Guidelines are currently in press and will be posted on the website once published.

Contacts
Ed Owens, Owens Coastal Consultants Ltd. (PST)
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Office: (206) 451-4818 / Cell: (206) 369-3679
Website: www.owenscoastal.com

Paul Bunker, K2 Solutions, Inc. (EST)
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Office: (910) 528-5412 / Cell: (910) 692-6898
Website: www.k2si.com

References:
1 Buvik, T. and Brandvik, P.J., 2009. Using dogs to detect oil hidden in beach sediments. Results from field training on Svalbard, September 2008 and on the west coast of Norway (Fedje/Austreheim), November 2008. SINTEF Report No. F12274, Trondheim, Norway, 20 pp.

2 API, 2016. Canine Oil Detection: Field Trials Report. American Petroleum Institute. Washington D.C. In Press.

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