Pipecon pleaded not guilty to two charges of breaching the Occupational Health and Safety Act at the Ballarat Magistrates' Court on Wednesday.

The charges relate to Charlie Howkins, 34, and Jack Brownlee, 21, who died in the double workplace fatality in the Winterfield Estate on March 21 last year.

Howkins died at the scene while Brownlee died the next day in hospital.

Magistrate Gregory Robinson found there was sufficient evidence to support the conviction of Pipecon on both charges after a two day contested committal hearing.

READ MORE ABOUT IT HERE: PIPECON COMES UNDER FIRE FROM WORKSAFE | VIDEO

EARLIER, TUESDAY:

Protective shields were not in place to stop two men from being buried alive in a trench at a Ballarat housing estate, according to witnesses at the first day of a court hearing on Tuesday.

Ballarat-based construction company Pipecon is fighting charges and facing a contested committal hearing at the Ballarat Magistrates' Court this week related to the double workplace fatality in the Winterfield Estate on March 21 last year.

The charges relate to the deaths of Charlie Howkins, 34, and Jack Brownlee, 21.

Howkins died at the scene, while Brownlee died the next day in hospital.

During defence cross-examination, witness Lorne Heppeler, a subcontractor who was working on the same estate for Pipecon to install sewer pits, said he was surprised no shields were in place at the time the accident occurred.

In answering questions whether safe work procedures were always followed, Mr Heppeler said there were times individual assessments were made on each trench.

"I wouldn't say every time working in a trench above 1.5 metres it was done by textbook," he said.

READ MORE: PIPECON TO FIGHT CHARGES

Mr Heppeler, who arrived at the site after the accident, said some of the trenches at the Winterfield site had been open for more than two weeks because of a slow supply of foam to lay down and complete the job at the time the trench was dug.

"We were always behind. There were three or four pits open at a time," he said.

Another witness, Pipecon site foreman and Winterfield Estate development supervisor Shaun Mahar said there was a sufficient number of barriers, shields and cages at the Winterfield site to ensure appropriate protection of all workers.

Mr Mahar said all employees at the site had undergone a safety induction and signed a Safe Work Method Statement for trench work.

During defence questioning, Mr Mahar said he had spoken to Mr Howkins the day before the accident occurred about getting a manhole cage ready for Mr Heppeler to complete his work in manhole eight, where the accident occurred, the next day.

"I presumed they would have used the manhole cage," he said. "You can never assume a trench is secure."

The manhole cage was stored at the top of the Winterfield site where he was at the time but the accident occurred around 500 to 700 metres lower on the site.

Mr Mahar said it was a situation where he could have done with 'more people on site' and had put in a request to the office for more staff.

Expert witness geotechnical engineer Dr Chris Haberfield provided evidence shields available at the Winterfield site would have been sufficient in providing proper protection if used.

Dr Haberfield said he had come to the conclusion both Mr Howkins and Mr Brownlee were in the trench at the time of the collapse.

Another witness testified he had completed around 10 safety checks at the Winterfield site.

During the opening addresses, prosecuting barrister Andrew Palmer QC, acting on behalf of Worksafe, said trenching and pipe laying occurred without using appropriate safety measures to protect workers from the risk of engulfment and failing to provide appropriate supervision.

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"The first charge is about the system of work... and the second charge is about supervision - it is alleged supervision should have been as such they were not engaging in trench and pipe laying works without supervision in place," Mr Palmer said.

Defence barrister Stephen Russell told the court Pipecon disagreed with the allegations trenching work was undertaken without safe measures and supervision in place.

"There was a safe work statement signed," he said.

"Pipecon indicate at all times trenching work was conducted in a safe manner."

Pipecon company director Andrew Maher was present in the front row at court on Tuesday.

The family members of the Mr Brownlee and Mr Howkins and their supporters were also present wearing badges that featured photos of the men and the words 'Charlie and Jack, Justice'.

Pipecon is charged with two alleged breaches of the Occupational Health and Safety Act:

The charges carry 9000 penalty points each ($161.19 a point), and based on calculations carried out by The Courier, it means the company could be fined almost $3 million if found guilty and given the maximum penalty on both counts.

The contested committal hearing will continue before Magistrate Gregory Robinson at the Ballarat Magistrates' Court on Wednesday.

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