Workers building a water bottling plant in suburban Christchurch are allegedly sleeping on boxes and involved in a daily litany of unsafe work practices.

Some local contractors left work on the site, citing safety risks, and multiple investigations have been launched to look into the allegations.

The water bottling plant is one of two independently under construction in Belfast. Together, the plants have permission to extract around 9 billion litres of water per year, the equivalent water usage of 70,000 people.

SUPPLIED A worker standing on a forklift beneath a scissor-lift. If the scissor lift failed, the worker would be crushed.

The lightly regulated water bottling industry allows water to be extracted and bottled for a negligible cost. The new Government has pledged to put a charge on bottled water exports.

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One of the plants, owned by China-based Cloud Ocean Water, is being built in what used to be the Kaputone Wool Scour, which closed in 2015.

SUPPLIED Workers regularly stood on forks whilst undergoing construction work, a witness said.

The company is associated with the Ling Hai Group, which has winery interests in New Zealand and links to a Chinese sugar giant.

It bought the site earlier this year from developer Phil Burmester, who is constructing a much larger water bottling plant of his own next door.

Several people Stuff spoke with raised safety concerns about practices at the Cloud Ocean Water construction site. Cloud Ocean Water's director declined to comment on the allegations.

A former contractor on the site, who asked not to be identified so he could speak freely, said the breaches were unlike anything he'd seen on a New Zealand building site.

These included workers cooking on-site and sleeping on dust-covered mattresses. He shared photos with Stuff, which appear to show one worker balancing on a forklift while welding, as another worker watches on directly underneath. Metadata from the images confirm they were taken at the site.

Other pictures appear to show workers dangling from bungee cords, and a short video shows chunks of wood falling from a beam holding up the roof.

He said he and many other contractors were in disbelief at the unsafe practices.

"I ended up leaving the site because it is just so dangerous, I don't want to be accountable for hurting someone," he said. "I'd shut that site down, have it inspected... It's just so unsafe."

Few of the workers appeared to know how to operate the heavy machinery they were using, he said. Structural aspects of the building were dangerously rusted.

"You'll be working there and you'll see people sleeping on cardboard boxes with bubble wrap over them, and you're just like what the hell's going on here?"

Another person with knowledge of the site said workers appeared to be living in "squalid conditions".

Both the Christchurch City Council and WorkSafe said they were investigating alleged breaches at the Cloud Ocean Water site.

Cloud Ocean Water director Feng Liang said he was "unable to comment" on the investigations. When asked to respond to specific allegations about the alleged workplace practices, he again declined to comment.

A WorkSafe spokesperson confirmed notices had been issued "relating to a mobile scaffolding system, [an] untested and untagged welding plant and failings of the employer to provide a safe and healthy work environment."

A city council spokeswoman said an investigation into allegations workers were living at the site was ongoing.

The company had hoped to begin extracting water this week, according to resource consent documents filed to Environment Canterbury (ECan).

The site's resource consent allows it to take 4.3 million litres a day, the equivalent daily usage of around 12,000 people.

The consent was granted to the wool scour in 1997, and is still active. Cloud Ocean Water has applied for a consent to use the water for bottling, which is being processed by ECan.

ECan can only consider the environmental effects of using the water for bottling, not the effects of taking the water as that had already been consented, principal consents advisor Dr Philip Burge said.

The neighbouring water-bottling plant is also under construction, on a former Silver Fern Farms site.

It has permission to take around 7 billion litres per year. Burmester recently set up a company named Southern Alps Artesian Water, which appears to be linked to the plant, which has yet to begin pumping.

The prospect of two large water bottling plants taking water from the aquifer has raised concern among some in the community, particularly as the city is in the midst of a record dry spell.

A petition opposing the plant had obtained more than 22,000 signatures since Sunday.

Some 46 consecutive dry days in Christchurch have beaten a record set in 1954. The city council has urged residents to conserve water, recommending residents do not water their lawns. It has stopped short of imposing water restrictions.

Because water cannot be priced, the public recoups little from water bottling operations, other than minor administration costs.

Cloud Ocean Water, for example, paid $2277 for its resource consent application allowing access to billions of litres of water. It would likely pay hundreds of dollars per year in monitoring costs.

The site is well placed for immediate export: a rail siding goes directly into the building.

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