A self-employed builder who says he almost died while putting up fencing after hitting an underground power mains has been hit with a £24,000 bill.

Mark Staples was working at his sister’s house in Hextable, near Swanley, last year when he struck the cable – leading to a village-wide blackout.

Now, nine months on, he has received an invoice from UK Power Networks for the damage caused.

The 53-year-old said: “We had dug a post hole just below a foot on the boundary where an old garden wall exists when I used my breaker to go through some footings to make it a little bit deeper for the concrete fence post.

"I had gone barely four inches with the chisel when there was a loud bang, flames and smoke and the deafening sound of electricity buzzing.

“I let go of the breaker’s handle instantly. They were plastic and I have been told that is what saved my life.

“We had struck a power main on my sister's property without any clear warning of its presence. It was not very deep. You would have expected there to be some warning.”

Mark, along with his brother-in-law, were putting in a fence with concrete posts around the garden in the same position as the previous wall after it was knocked down when a car crashed into it.

The property, in Herbert Road, is powered by overhead cables, so they had no reason to believe they would strike a mains.

Mark said there was no hazard tape around the cable, which had around 11,000 volts running through it, to alert him of its presence before hitting it.

“I have never come across this before,” said Mark, who lives in Swanscombe.

“It all happened so quickly, I was just in shock. My brother-in-law came back outside and his face was just horror.

“I did not know what had happened. I thought my Kango had blown up but when we realised what had happened we knew it was serious.”

According to the Health and Safety Executive, most underground cables are laid in trenches between 450 mm and 1m deep.

In its guidance, it adds cables may have a layer of tile, slab or coloured plastic marking tape above them but this protection can be disturbed and moved so should not be relied upon solely to give an accurate indication of a cable’s position.

Damage was caused to a high voltage underground cable which interrupted power to 1,368 UK Power Network customers in the area and took around 10 hours for engineers to restore.

A spokesman from the network operator said its workers had to reconfigure the electricity network and connect generators to reconnect the final properties to get the power back.

They said the incident also caused damage to the overhead network and extensive work was needed to restore it to normal.

Mark added: “I could have died in the front garden, it is unbelievable I did not. I went to the hospital and spoke to a doctor who was one of many to state how incredibly lucky I was.

“I have been told countless times that it was a miracle I had no physical injury or even worse was lucky not to have been killed.”

Although the married man did not have any physical injuries, he has since been diagnosed by his GP with PTSD and still suffers from nightmares.

He said he did not hear anything following the incident on December 1, 2022, from UK Power Networks until a few weeks ago when he received an invoice through the post.

It read: “This is our claim for compensation following our attendance... to repair damage to our equipment as detailed on the attached invoice.

“The reason we are alleging fault is that the damage was caused by you or your employee or agent’s negligence.

“This includes failure to adhere to the safe working practices outlined by the Health and Safety Executive in their publication HS(G)47 Avoiding Danger from Underground Services.”

In a second letter, it states negligence as there was a failure to adequately obtain location plans, locate electrical apparatus and use locating scanners.

The invoice of £23,970.29 breaks down the cost as £13,445.08 for direct labour, £470.40 for materials and £10,054.81 for indirect labour.

Mark, who is seeking legal advice, said: “It opened up old wounds. At first, I thought it was a joke. It was an accident and now they have decided to come after me with a bill.

“I just wanted to forget about it. I did not go out that morning to hit the power main and try and kill myself, cause damage or shut the village down. It was the last thing I wanted to do.

“Would they have still sent the bill if I had been killed?”

He has since replied to the letter which he has branded an insult due to the impact it has had on his and his family’s life.

A UK Power Networks spokesman said: “We were concerned to hear of this accident and our first thoughts were for the welfare of the customer. Our engineer who attended was a trained first aider and also advised him to attend the hospital.

“This incident underlines the importance of planning ahead before you dig, as electricity cables and other utilities can run underground. We recommend that all works of this type are undertaken after consulting cable plans and use of a CAT scanning tool.

“We do claim costs for cable repairs after third party damage, and did so within the required timescales.

“We have not received a claim from the customer in connection with this incident and would review that if we received one.”

Mark said he did not use a CAT – cable avoidance tool – scan as he had no reason to believe the power cables would be in the garden.

The HSE does advise using detection tools but its guidance adds some cables may not be detected using a locator, but people should still be wary as that does not meant live cables are not present.