Mark Ledsom, 54, purchased the cottage of his dreams in Runcorn, Cheshire, with his wife, Lesley, 62, in 2021. 

The three bedroom cottage, built in 1737, has three bedrooms, a large garden and open-plan living downstairs. 

Soon after moving into the cottage in 2022, however, Mark, who lives with his wife and one of their sons, Tom, 25, discovered a problem in the back garden he had not anticipated. 

Mark, who works in retail, told the Daily Mail: 'About 12 months after moving into our dream cottage we noticed standing water in the garden. The smell by the house and in the garden was terrible. 

'There would be wet grass down the bottom of the garden, everything started to die, and we couldn’t understand why. It progressed and we'd just find black pools of water in the garden.'

He added: 'It got to a point where none of us, including our grandchildren, could use the garden as the smell was so bad.' 

After a spell of flooding, Mark contacted a local drainage company to conduct a drain survey and establish what was going on.

Mark said: 'The drain expert came out and told me, "You’ve got a septic tank, it’s not compliant and it’s a £50,000 fine".'

The discovery came as a shock to Mark, who had not been informed of the septic tank's existence when buying the property.  

After the drain survey was completed, Mark spent £8,000 on a new drainage field and £7,000 getting the garden landscaped in a bid to resolve the problem. He'd also spent £10,000 on new decking. Getting the old septic tank cleaned out every six months also cost £200 a time. 

Mark, when off work due to a knee replacement and bored last year, started searching for 'septic tank negligence' online on Google. 

He found a law firm called CEL Solicitors who he thought could assist with his case and explained the septic tank saga to them. 

Mark ended up winning £25,000 this year from the conveyancing solicitor involved, who the Daily Mail is not naming. 

Mark said: 'It was a relief to receive the £25,000. Using the money, I installed a legal and compliant septic tank.'

He added: 'It’s perfect as it’s a mini sewerage treatment plant. Since getting the new septic tank we have had our Easter party for 35 people in the garden, as well as our Halloween party for 45 people. There's no more bad smells or black stagnant water.' 

What are the rules around septic tanks?

A septic tank is an underground and watertight container, usually found in rural areas without connection to the public sewage system. 

It treats domestic waste by allowing solids to settle and liquids to drain to a drainage field, where bacteria break them down.

Before buying his cottage, Mark had paid around £700 for a Level Two Homebuyers Survey, which suggested the property was connected to the mains. Only an online search had been conducted as part of the survey and the old septic tank was missed. 

Septic tanks must comply with the General Building Rules 2015, which came into operation on 1 January 2020. 

Among others, rules include ensuring discharge does not pollute any surface water or groundwater, and ensuring the sewage receives treatment from a sewage treatment plant. 

The seller of Mark's property had correctly disclosed that a private septic tank served the home. 

But his solicitor believes the old septic tank in Mark's garden was probably originally installed as the cottage was not connected to the public foul sewer network, even but waste water still had to be serviced.  

The solicitor claims Mark's conveyancing solicitor failed to investigate the private septic tank further, mistakenly assuming the cottage was connected to the public sewer system and raising no concerns before completion. 

When looking at a property that is not connected to the mains and instead has a septic tank or other private drainage field, the conveyancing solicitor should make detailed enquiries about the system - its location, maintenance and whether it is compliant with current regulations.

The seller should have been asked to supply maintenance records and evidence that the system meets the Environment Agency’s General Binding Rules. Since 2020, it’s been illegal for a septic tank to discharge directly into a water course, so compliance is essential.

The solicitor has a duty not to inspect the tank themselves but to identify and evaluate risks, ask the right questions and ensure their client is adequately informed before they purchase the property.

Lucy McCallum, head of residential property at WSP Solicitors, told the Daily Mail that as well as the TA6 Property Information Form, title documents 'may refer to historic rights to use a septic tank or similar private drainage system'. She said standard solicitor searches should include a water and drainage search. 

McCallum added: 'A solicitor may be liable if there were clues in the paperwork, such as historic planning records, references to a private drainage system or an old map, and the solicitor failed to follow up with appropriate enquiries.'  

CEL urges buyers considering buying a property that is disconnected from the mains drainage system to seek advice as soon as the issue becomes apparent. 

Seeing the correct documentation is crucial, from the emptying records to maintenance contracts and the proof of compliance.

Inform your solicitor and ensure they carry out the right searches and enquiries. The septic tank’s compliance should be woven into any contracts the seller has to sign. 

This situation is much more likely in rural properties than anywhere else.

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