Co-mingled waste collections are helping to boost overall recycling rates, according to recycling firm Greenstar.

Concerns over quality of recyclate have led for calls for greater kerbside separation, but Greenstar chief executive Ian Wakelin said data from five local authorities showed improvement in recycling tonnages when they switched to co-mingled collections.

"Greenstar collects recyclables from around 1.2 million homes, many of which have converted from a kerbsite-sort to a single-stream system. An average improvement of 78% is massively significant," he said.

Greenstar said co-mingled collections were easier for householders, and more efficient and safer for collection crews. While reject rates can be higher than for source-separated, Wakelin said it was an acceptable trade of for higher volumes.

"If our smart processing and quality control identifies recurring contamination, we can alert the supplying local authorities and help them tighten up their collections so as to drive up quality," said Wakelin.

Greenstar collected data from Walsall, Stratford-upon-Avon, Blackburn with Darwen Borough, South Oxfordshire and the London Borough of Waltham Forest.

Wakelin echoes the view of Veolia Environmental Services deputy chief executive Paul Levett on the need for co-mingled collections.

COUNCIL COLLECTION DATA
(Average tonnes per month)

Walsall
Introduced co-mingled in February 2009
Before 769
After 2,224

Stratford-upon-Avon District
Introduced co-mingled in August 2008
Before 648
After 1,171

Blackburn with Darwen Borough
Introduced co-mingled in October 2008
Before 964
After 1,036