Walking Ireland's border – the new Brexit priority | Garrett Carr

I recently explored Ireland’s border from end-to-end. I wanted to get to know the border’s true character, to meet it on the ground. I also wanted to learn more about its past and what it might become in the future.

The Brexit vote brought much anxiety to the borderland, worries about how the United Kingdom’s only land frontier with the European Union would operate. A hard border, with mandatory stops for customs, would not just be bad for business but could threaten the peace process.

In 1993, when both the Republic of Ireland and the UK joined the single market, customs checks were no longer necessary

The anxiety was exacerbated by Downing Street’s refusal to commit to anything, apart from leaving the single market and the customs union. The European Council are no less intransigent but they are much more open about what they want from the divorce. Just over a week ago their operating guidelines were published and Ireland’s border was given emphasis: “In view of the unique circumstances on the island of Ireland, flexible and imaginative solutions will be required, including with the aim of avoiding a hard border.” Days later, the EU’s chief negotiator Michel Barnier said he would “pay particular attention to Ireland”.

On the ground, the first thing you notice about Ireland’s border is that you can’t see it. In 1993, when both the Republic of Ireland and the UK joined the single market, customs checks were no longer necessary. That layer of bureaucracy – manifested on the border by queues of traffic and customs facilities – disappeared. Then in 1998 the Good Friday Agreement set in motion the process of dismantling military installations along the frontier.

Garrett Carr, author of The Rule of the Land: Walking Ireland's Border.

Nowadays you must look for more subtle indications to locate the border, such as changes in the road surface or carriageway markings turning from yellow to white. Away from the roads there is even less to go by. The border corridor is almost entirely rural, fields and forests, although the invisible line is always hosted by something; a fence, an old stone wall, a hedgerow or, most commonly of all, a river. The most frequent sound along the border is trickling water, along with the coo of wood pigeons and puttering of tractor engines.

A common smell is the tang of diesel. One bright cold morning I was walking a narrow border lane in Armagh when I experienced this smell again. It was coming from a cube-shaped plastic tank sitting on a layby. It was about four feet tall and semi-transparent so I could see it was half-full of sludge that had settled into two layers. Liquid the colour of varnish was floating on top of something black and tar-like. Both layers looked poisonous. I walked around the tank a few times, wondering if it was what I thought it was. Whoever left the tank had wedged a couple of planks underneath to stop it tipping over. You could call this gesture considerate and it made me wonder if the tank was left for an official waste disposal scheme. This was too optimistic, as I found out when, a few minutes after me, a local council employee arrived in a car. “No, no, it’s just been dumped here,” she said. “We get a lot of them.” She took a photograph of it. I later learned some of this waste material is shipped to Holland to be disposed of properly. Having recorded the location of the illegal dump she drove off. Her electric car was a pleasing contrast to the toxic atmosphere around the tank.

Fuel is a product largely unaffected by the single market. In fact, diesel is currently one of the few things worth smuggling. Each jurisdiction has its own system of tariffs so price differentials appear, gaps that have been exploited by smugglers for years. “The border never disappeared for oilmen,” the writer Glenn Patterson was told recently by a fuel haulier. There are profits to be made by selling southern diesel in the north and, as there are no customs checks at the border, getting the stuff across is easy.

President of the European Council Donald Tusk and European Commission President Jean-Claude Juncker.

You might say the borderline has been relocated into the fuel itself: northern diesel is dyed red and southern dyed green. The dye must be removed from the diesel before it can be sold because customs officials visit farms and businesses to check they are not using illegally imported fuel. Laundering fuel is a messy business, producing toxic waste that has to be dumped, hence the tank I stumbled across.

Finding a single tank the way I did is unusual. They are more often found in threes, each holding a tonne of gunk. A couple of years ago an entire truck trailer of waste was abandoned on a roadside. In the haste to escape, the driver had not lowered the trailer’s jacks so it fell forward as the cab pulled away, tonnes of waste pooling at one end.

The only ones a hard border will suit are the smugglers

I reject any notion of smuggling gangs as Robin Hood-type figures. These are not victimless crimes; one victim is the environment. Thousands of tonnes of chemical waste have been dumped along Ireland’s border over the years. Sometimes it is even set alight; the black sludge can smoulder for days. Recently the authorities made a deft move in the battle against fuel smuggling. They have started using an invisible isotope to ‘mark’ diesel in a way that cannot be seen by the naked eye. Reports indicate this has been extremely effective and diesel smuggling has been reduced as a result. The smuggling gangs have hired chemists to find a way to remove the marker but without success. Some suggest the end of diesel smuggling is in sight.

It is likely gangs are seeking other things to smuggle and it is unfortunate Brexit is arriving just in time to help them. “The only ones a hard border will suit are the smugglers,” an Enniskillen businessman told me. “It’ll suit those boyos just fine.”

Gangs have been keeping in practice and have distribution systems in place; they are ready to begin exploiting price differences as soon as they appear. It is likely all sorts of smuggling operations will emerge when the UK leaves the single market and, presumably, price differentials will widen on all sorts of products: cement, milk, cigarettes, beef, bricks… you name it. Apart from the “boyos”, I think most people along the border consider this an unhappy story.

The border could soon see more and more smuggling. People here will once again have to get used to smugglers’ trucks rumbling by after dark and will continue to find their castoffs along laybys in the cold light of morning.

Garrett Carr’s book The Rule of the Land: Walking Ireland’s Border (Faber & Faber, £13.99) is out now