Up to 300 new jobs will be coming to rural Somerset after councillors backed plans for a new concrete factory near one of the area's main quarries.

Porr UK Ltd. applied for permission to build the factory on the former Trinidad Works on the A361 near the small village of Wanstrow, between Frome and Shepton Mallet.

The company intends to use the site, located near the Torr Works quarry, to manufacture numerous concrete products for major UK infrastructure projects – including railway bed slabs for the construction of the High Speed 2 (HS2) railway line.

Mendip District Council's planning board gave the green light to these proposals when it met in Shepton Mallet on Wednesday evening (October 12), despite concerns about the environmental impact of the new facility.

The site lies on Haygrove Lane to the south of the A361, opposite the Leighton Business Park, and has been largely underused since Permanite Asphalt Ltd. ceased operation there in the 1990s.

The land – which is not allocated for development within the council's Local Plan – is bordered to the south by Haygrove Wood and the freight railway line connecting Torr Works to mainline rail services.

Porr UK intends to bring the site back into use to manufacture trackbed slabs and other concrete-based components, using materials from the neighbouring quarry (operated by Aggregate Industries) wherever possible.

The new factory will be built at the southern end of the site (on the old factory's footprint), with the northern end being used for storing the slabs and other products before they are transported off-site.

Richard Arnott, Porr UK's contracts manager, told the board on Wednesday evening (October 12) that a new railhead would be created to link the factory directly to the existing freight route, reducing the amount of extra vehicles on the already busy A361.

He said: "The proposed railhead will clearly reduce the volume of highway traffic when the transportation of the slabs begins.

"The location will also substantially reduce the CO2 emissions when transporting the raw materials due to the close proximity of the two sites.

"Aggregate Industries has applied to Network Rail for permission to lease a further 170 metres of track [for the railhead].

"We will have an area of 5,100 sq m of solar panels on the site, significantly reducing our requirements of power from the National Grid.

"All positions will be advertised locally. Our plan is to train in-house, and we currently anticipate that the majority of employees will result in or around Shepton Mallet and Frome.

"Employees who live further afield will be encouraged to travel by train to Frome, and from there they will board buses supplied by our company."

Councillor Michael Gay – whose Postlebury ward includes the site – said Porr had not provided sufficient information on how the factory would "provide a carbon betterment" for the district.

Mr Gay – who leads the Green Party opposition group on the council – said: "In an authority with the well-being of its residents in mind, that would have been the end of the application, I guess.

"The envisaged development does not meet our core policies regarding development in this location or development in open countryside. This clearly increases the use of private transport due to staff journeys.

"There is no long-term commitment which is possible for Porr to make for this facility, and this district should be looking for long-term green jobs."

Somerset County Council confirmed in its local aggregates assessment (LAA), made public in late-September, that the planning permission for the Torr Works quarry was currently due to expire in 2040.

Councillor Philip Ham – who represents the Mendip Central and East division on the county council – said the development was "very positive" in light of the current difficult economic conditions.

In a statement read out on his behalf, he said: "We should be proud of our links to the national economy and projects like Hinkley Point C, Crossrail, major new roads and now HS2."

Councillor Simon Carswell, the district council's portfolio holder for economic development, added: "It is important to ensure our communities continue to be able to access a variety of local job opportunities, particularly those which offer decent wages and the chance to learn new skills.

"Young people also require apprenticeships and traineeships with the certainty of completion – and furthermore, we would wish these young people to continue to live and work in this area."

Councillor Helen Kay – whose Frome Keyford ward has seen significant interest from housing developers in recent times – said she was sceptical as to how many of the new employees would actually be sourced from the local area.

She said: "I am not convinced that this is going to necessarily benefit rural people living in the villages. Can the commitment to recruit local people be put into a legal agreement, or do we have to take it on trust?"

Planning officer Anna Clark responded: "Market forces will determine that local people will be used wherever possible. I don't think this is something we can secure through planning conditions."

 Councillor Matt Martin broadly welcomed the plans, but warned any increase in HGV traffic would affect the entire district, not just the settlements nearest the factory site.

He said: "We can't do anything about the way that HGV drivers drive – they go where they want, and they pay road tax the same as the rest of us.

"Unfortunately, they do end up barrelling through my villages at 45mph – and that's when people start bashing on my door, and rightly so.

"The legal side may say we can't do anything, but that doesn't help people in Westhay and Meare. It's not human error – they do it every day."

After around an hour's debate, the board voted to approve the plans by a margin of eight votes to one, with one councillor (Adam Boyden) being unable to vote for technical reasons.