A Norfolk–based energy firm has unveiled plans for a £1m expansion of its offshore waste treatment plant that will nearly double its size and create three new jobs.

Enviroco is ploughing fresh investment into its site on Denes Road as part of a modernisation project that will create new offices, larger work premises and new facilities to meet the demands of the emerging offshore decommissioning sector.

And as well as improving the site for workers, bosses are hopeful that the investment, which will increase the site by 40pc to 7,000sq m, will boost output and attract future contracts. It comes as Enviroco, which employs 35 people in Yarmouth and has sites in Aberdeen and Sheffield, saw turnover rise to £43m last year from £38m in 2011.

Dominic Travis, UK facilities manager for Enviroco, said: 'It remains business as usual while we complete the works, so the service delivered to customers is undisturbed.

'On completion, our turnaround times will improve as will our capacity for handling increased volumes of waste. We will be in a better position to cope with peaks in demand and attract more clients, which can only be good news for the local economy.'

The site takes waste from the offshore oil and gas sector and processes hazardous and non-hazardous materials such as contaminated water, drilling fluids, batteries, paints and aerosols.

Great Yarmouth MP Brandon Lewis said: 'I was very pleased to hear about the refurbishment of Enviroco's offshore-waste recycling centre. Yarmouth is the number-one place for offshore energy companies.

'This investment will make the area even more attractive to energy businesses, creating further growth and jobs for local people.'

Simon Gray, chief executive of the East of England Energy Group (EEEGR), said: 'It is heartening for EEEGR to see a successful major UK company like Enviroco remaining loyal to the area, prepared to commit its future here and to invest and expand to meet the increasing business opportunities ahead – particularly in the oil and gas sector.'