Hertfordshire County Council is ensuring that it has three months' supply of fuel for the county's fire service, ahead of the UK's withdrawal from the EU.
Usually fire appliances are filled with fuel from a small number of petrol bunkers around the county, or by using fuel cards at local petrol stations.
But now fire fighters have been told NOT to use fuel from the bunkers, to ensure they can use the supply if there is a national fuel shortage after Brexit.
Fuel shortages are one of the key post-Brexit risks that the county council is already preparing for.
And it's estimated that the 'bunkered' fuel would keep the emergency vehicles running for an additional three months after routine supplies had dried up.
On Thursday (October 24) 'bunkered fuel' was one of the precautions that were highlighted to members of the county council's resources and performance cabinet panel, in the run-up to Brexit.
Among the catalogue of risks highlighted to councillors was the potential for widespread traffic disruption in the south east that could result in significant congestion at key locations in Hertfordshire, like the M25 and lorry parks.
And that congestion, in turn, it is said, could itself impact on the delivery of fuel - with further shortages impacted by panic-buying.
There could, it is said, be a reduction in the range of foods available, like fresh produce, or increases in food prices.
And the reduction on flow of goods between the UK and the EU could, it is said, impact on supply chains in Hertfordshire for up to six months
Although the NHS has stockpiled medicine and medical supplies for up to six months, the council's report says that if border disruption continued there could then be shortages.
And if the supply of chemicals to treat UK water is disrupted, there could be disruption to supplies - but this risk is said to be low.
As well as supplies, there are a number of risks to Hertfordshire associated with EU nationals leaving the UK, and with UK nationals returning.
Should EU nationals leave that, the report warns, could impact on the county's care sector - leading to even more care worker vacancies. And there could also be further shortages of engineers, nurses and planners.
Meanwhile UK nationals who have been living in Europe, t is suggested, may return to Hertfordshire. And they may require the support of health and social social care services.
There are also concerns that Brexit or the knock-on effects of Brexit - such as traffic congestion or fuel shortages - could lead to a rise in public order, which would have an impact on police resources.
In the case of 'no deal' it is believed the number of unaccompanied asylum seeking children in Hertfordshire would increase, who would need the support of the authority.
And it was reported to the cabinet panel there are also risks for the council related to contracts with EU-based companies for services such as waste recycling, as well as uncertainty around exchange rates, VAT rules and rising costs.
Presenting the report the county council's assistant director for strategic prevention and regulatory services Guy Pratt said the risks were higher if the UK left the EU with 'no deal'.
But, either way, the report makes it clear that Brexit is expected to have a significant financial impact to the county council.
The report states: "The financial implications of Brexit, whether in the event of a withdrawal agreement being reached or a no-deal scenario, is considered a significant risk facing the council."
The county council, it was reported, started preparations for a 'no deal' Brexit at the end of last year. And now the Brexit Incident Management Team is meeting daily.
But some questions from councillors suggested the plans included a lot of 'monitoring' - and questioned whether further actions should have been included.
Liberal Democrat Paul Zukowskyj said the best way to mitigate risk is to plan for that risk - but he said a number of responses suggested "close monitoring". And he suggested this was not the best way to deal with it.
Speaking after the meeting, a spokesman for Hertfordshire Fire Service said that the force was continuing to plan for Brexit alongside colleagues across the County Council, but that is "still operating under business as usual fashion".
Chief Fire Officer Darryl Keen added that he did not anticipate that shortages would be an issue, but that 'bunkered' fuel could keep the emergency vehicles running for up to three months.
He said: “During this current climate of uncertainty around Brexit we want to reassure our residents and local businesses that we are proactively prepared for the UK’s withdrawal from the European Union.
“This does include the business as usual storage of fuel in order to deliver critical services, such as for emergency vehicles. This is part of our normal preparations as we look to re-stock and maintain supplies."