EXCLUSIVE: The NT Government’s latest attempt to have TIO Stadium certified has been bungled again, after documents show the company it re-hired to fix problems with the fire hydrant system it designed does not have a proper licence to carry out the works, the NT Independent can reveal.

Engineering firm Cardno was hired by the Department of Infrastructure in June to “investigate” the same fire hydrant system that it designed and certified in 2014, after numerous complaints and an independent audit that found the water flow did not meet national minimum standards and put people attending games and firefighters at risk.

Department chief executive Andrew Kirkman refused to explain to the NT Independent earlier this month why he would hire the same firm that designed and certified the system to assess its shortcomings and how the conflict of interest of a company investigating its own work was handled.

But he told the ABC last week that the department subsequently engaged Cardno after the “investigation” to undertake upgrades identified from the investigation – including installing fire booster pumps, water tanks and associated works – despite claiming Cardno’s “investigation” found no problems.

However, documents filed with the NT Building Practitioners Board show Cardno does not currently have a valid hydraulic engineer licence or a mechanical engineering licence.

Records show Cardno’s hydraulic engineer registration expired two and a half years ago and has not been renewed since February 2020. That document is needed to complete the works, and industry sources said the licence should have been valid before their “investigation” into the hydrant system.

“A hydraulic engineer may certify the design and/or construction of plumbing and draining works and hydraulic fire services servicing buildings or structures of all classes, including … fire hydrants, fire hose reels and fire sprinklers/suppression systems …” the BPB rules state.

That document shows Cardno’s licence is listed as “expired” as of February 2020. It appears the company was registered in 2014, when it originally engineered and certified the fire hydrant system.

Cardno NT manager Gerry Oorloff did not respond to the NT Independent’s questions, despite being provided a deadline extension, including why the company did not have a valid licence for works the company is reportedly undertaking.

Mr Kirkman and NT building controller Mark Meldrum also refused to answer questions, including if the department was checking registration statuses before awarding contracts for works.

It was unclear how the revelation that the company does not have the current licence will affect the works, which the government claimed has commenced. Cardno NT was recently taken over by Stantec, but the records show Stantec is also not registered for a hydraulic and mechanical engineering work.

The department told the ABC that it had hired Cardno through a select tender process in June to investigate their own works “due to their historical knowledge of the hydrant system”.

Mr Kirkman’s spokesperson then claimed the company was awarded “upgrade” works identified through the investigation, which they claimed showed the water pressure was “sufficient” and repeated claims the building was safe, despite not being able to be certified.

“During [Cardno’s review] process, it was confirmed that although the pressure at the supply hydrant assembly was sufficient, the department would upgrade the system, taking into consideration any future expansion at the facility, including in the general Marrara sporting complex,” the department told the ABC.

Mr Kirkman also refused to explain why fire booster pumps, water tanks and other associated works needed to be installed at the venue if the system was “sufficient”.

The ICAC is currently investigating the minister and the department’s handling of the stadium’s ongoing certification and safety issues. The stadium did not receive an occupancy permit when it was built in the early 1990s.

Infrastructure Minister Eva Lawler has repeatedly claimed the building is “safe” citing “advice” from unnamed advisers and used ministerial powers to exempt the building from requiring certification after being made aware of the ICAC investigation.

Ms Lawler has also repeatedly refused to explain why she and her department officials ignored the independent engineer’s report prepared by BCA Engineers last year that raised safety issues which it said could “impact life and safety” at the venue, including that the water flow and pressure did not meet national standards and highlighted other concerns including electrical issues and improper emergency exits.

NT firefighters raised concerns about the weak water pressure ahead of the AFL Gold Coast and North Melbourne match at the venue in June, with one saying there was a “catastrophic risk”, forcing the government to enact temporary mitigation measures including bringing in a water tanker and a larger fire truck on site for the game.