In contrast, glass companies place less value on green glass, which makes up 50% of glass collected, but only 16% of glass manufactured in the UK.
Bardon Aggregates, which has about 230 operations across the UK, set up collections of glass bottles from pubs and clubs in Devon in early 2003 through local collectors Quay Waste. The mixed glass collected was used a substitute for aggregate in asphalt production.
But when the company came to expand collections, it found that a number of pubs and clubs were already taking part in Berryman's national Recycle-More-Glass commercial collections.
Business development manager Jason Black said: "I realised that there were certain establishments we were unable to pick up glass from because they had national contracts with Berryman." Mr Black set up talks with Berryman in September 2003 and has now arranged to swap the mixed glass collected by Quay Waste for the excess green glass collected by Berryman.
He explained: "For every tonne of mixed glass we collect, Berryman replaces it with green. In return, Berryman gives us more outlets in Devon for us to collect from. Everybody gets something it's a straight swap with no cost difference." The glass collection charge is about £3 per 1,100 litre bin cheaper than compared to regular commercial waste collections, he said.
Berryman announced last month that it was investing £2.5 million in a sophisticated new colour separation plant. This will make it much easier than before to extract high quality clear cullet from mixed glass, which has been a difficult problem for container recyclers.
Quay Waste collects about 100 tonnes a month for Bardon, but Mr Black said he wanted to increase this 10 times to 1,000 tonnes a month. Bardon is looking into alternative uses of the glass such as use in concrete blocks and higher value products.