A herder is a chemical product that contains a surface-active agent that acts on the water surrounding an oil slick and causes the oil to contract in size and so “thicken”. Herders essentially “round up” the oil when applied to the margins and thicken it so it can either be ignited via in-situ burning (ISB) or could be used as a chemical “boom” to deflect oil away from sensitive resources.

They have undergone extensive field and laboratory trials over the last 15 years and are pre-approved by the US regulator. However, their widespread use has been slow partly due to a misconception that they are an “ice-only” technique. This is not the case; their original testing was done off the ice-free east coast of the USA.

A relatively small amount of herder is required; for a comparable slick, orders of magnitude, less herder product are needed than required to disperse the same volume of oil with a chemical dispersant.

We have been focusing our attention on ‘Thickslick 6535’ which is already approved for use in the US. We spearheaded a Herder Working Group with OSRL members, other response cooperatives, ITOPF and a research laboratory. This has enabled us to leverage expertise, open doors, and work as a collective with a common goal.

Part of our project was to get ‘Thickslick 6535’ onto the UK Approved List, and we are proud to say that we’ve been able to achieve this following strict toxicity testing that meets the new UK requirements. A sample of herder was sent to a UK commercial testing laboratory where it underwent rigorous testing to meet the required criteria. The lab report was then submitted to the UK regulator for their approval. Thickslick 6535 is now on the UK Approved List which means it could potentially be used in a response should the NEBA case be justifiable and with authority approval at the time.

As part of our internal preparatory work to start using this technique, we evaluated the specific HSE requirements for storage, PPE, and Responder operational use. We evaluated specific herder application equipment and engaged with a cutting-edge ‘autonomous jet ski’ technology research project.

This jet-ski platform has been developed as an unmanned platform that is capable of herder application, ignition source and a platform for additional tasks such as surveillance. As part of the jet-ski testing, a recent set of trials at the Poker Flats (Alaska) was attended by OSRL staff for them to view the jet ski in action as it herded the oil. Then, it remotely ignited the oil and safely burned off the herded oil. They watched four tests of herding and burning and were very impressed with the capabilities of the jet ski and excited about possibilities for OSRL usage in monitoring oil scenarios remotely from a command centre.

During the Alaska exercise with the “autonomous jet ski” we understood that this piece of equipment could do multiple tasks while reducing personnel exposure to possible hazards. This technology has many capabilities, including safe zoning SWIS, gas monitoring, fluorometry, oil sampling, subsurface video recording, tethered drone video footage back to EOC, and more, which could be a massive positive for responding to oil spills effectively in the future.

What’s next?

In 2024 we plan to start building our operational capability for herders via product purchase, stock management, application equipment and most importantly HSE, Responder training, exercises and operational working procedures.