Sainsbury's and Waitrose's apples and pears will have improved environmental credentials after a leading supplier to the stores completed an £8.5m storage and grading facility.

FW Mansfield & Son's one hectare complex in Chartham, Kent, combines modern fruit handling and storage technology with strong environmental credentials. The site was formally opened last week and is expected to be operational this month.

The facility includes 33 chilled stores with a capacity to hold 20,000 bulk bins, and a computerised grader that can operate at 15 tonnes per hour, sorting fruit by both colour and size. Rainwater is collected and stored and used for trickle irrigation on crops.

Mansfield, the largest independent fruit grower in the UK, supplies fruit through producer organisation Fruition, which handles much of Sainsbury's and Waitrose's English apples and pears and all Waitrose's top fruit imports. Mansfield received £1m of funding from the South East England Development Agency for the project and plans to spend a further £3.5m in the next 18 months on extra storage and equipment.

The new facility would make the production of premium apples such as Jazz more efficient and lead to higher overall fruit quality, said owner Paul Mansfield. "Quality is paramount, because production only accounts for a third of the total cost, which can make anything other than Class I an expensive undertaking."

Developments such as Mansfield's supported retailer demands for English fruit produced in an environmentally sensitive way, said Adrian Barlow, chief executive of English Apples & Pears. "The industry is already seeing a tremendous revival offering huge opportunities, as more and more consumers want home-grown fruit because of its superior taste."

However Barlow warned the momentum would only continue if growers could see returns that were both profitable and allowed reinvestment to continue.