A decision handed down by the ACT Civil and Administrative Tribunal this week said that between August 2015 and October 2018, Ian Cook was the tenant of a property owned by Jure and Mira Rezo.

After Mr Cook moved out, the Rezos made a claim on his bond for rent and water arrears. The claim was for $1974, according to tribunal senior member Allan Anforth's decision.

But Mr Cook lodged an application of his own, seeking $8000 compensation and the return of his bond.

Mr Anforth's decision said Mr Cook told the tribunal sewage regularly overflowed into the house through the bathroom, laundry and toilet.

"It seeped into the carpets in the hall and on two occasions covered the vinyl floor in the family room," the decision said.

"[Mr Cook] cleaned up the mess on each occasion and had to throw away bathmats and towels used for that purpose.

"The house permanently stunk.

"[Mr Cook] was forced to have access visits from his eight-year-old son at his grandmother's house."

According to the decision, the Rezos said in response that they did not dispute that "plumbers had attended the property approximately every six months to clear the pipes out".

But they said Mr Cook had not made any requests for the property to be cleaned following sewage overflows.

The Rezos alleged in the response that Mr Cook's application was made in retaliation after they had made a claim on his bond.

Mira Rezo also claimed she had gone to the property on an unspecified date following a complaint about a blocked toilet, and that the toilet had overflowed on that occasion because there was a nappy in it.

The tribunal's decision said at a hearing in October last year, Mr Cook estimated there had been seven sewage overflows.

Invoices provided by a real estate agent representing the Rezos at the hearing showed there had been eight visits from plumbers in response to call-outs.

Mr Cook's former partner Belinda and her mother Helen also gave evidence of having been at the house during sewage overflows.

"Belinda was concerned about her son living in what she saw as unhygienic conditions," the decision said.

"Helen recounted one occasion in which the water was over her foot in the family room."

Mr Anforth's decision said the evidence in this case was consistent.

"The carpets in the hall were affected and stank," the decision said.

"The overflow soaked through the walls into the kitchen and family room, but it seems the wall absorbed the faecal matter so that water in the kitchen and family room was relatively clear albeit smelly.

"The stench in the house was permanently present, even after the tenant's cleaning."

In his decision, Mr Anforth said each of the times a plumber attended, they had reported tree roots as the problem.

"There was no reference to other causes of blockages," the decision said.

"On two occasions the plumbers recommended CCTV exploration which did not occur.

"It seems [the Rezos] were content with a reactive mode of response to the problem."

The decision said blockages caused by tree roots were a common problem and there were known solutions available.

"It was difficult to understand why [the Rezos] would not have moved to a more permanent solution after the first overflow," the decision said.

Mr Anforth found the Rezos had breached their duties to Mr Cook by failing to take adequate action after the first sewage overflow, which meant the problem had been allowed to continue.

Mr Anforth settled on a compensation figure of $8000, but ordered that the Rezos need only pay Mr Cook $6000 because he owed them just under $2000 in rent and water arrears.

The tribunal also directed that the $1520 bond Mr Cook paid to rent the property must be released to him.