Analysis of three-weekly household bin collections suggests that councils can expect significant improvements in recycling performance and reductions in residual waste if such a regime was implemented.
Research by the consultancy Eunomia, published on the Isomonia blogging site, concludes: “As the data on three-weekly collections starts to become more robust, it appears that in most cases the expectation that it would meaningfully improve recycling performance and reduce residual waste has been borne out.”
The blog is written by Maxine von Eye and Tanguy Tomes, who acknowledge there is limited evidence from the dozen or so authorities which have either implemented three-weekly collections or announced they are planning to do so.
There are only three – Fife, Gwynedd and Conwy – where there is said to be both detailed predictions and clearly reported outcomes. Gwynedd was one of the first adopters, starting to roll out three-weekly collections in early 2014.
The blog states: “Although its predictions overestimated the increase in collected food waste, [Gwynedd] underestimated the decrease in landfill tonnage, with an observed reduction of more than 3,000 tonnes a year.”
Gwynedd predicted that its recycling rate would increase by 5.2 percentage points. In 2013-14, the recycling rate was 54%. By 2015-16, when the switch to three-weekly collections had been fully rolled out, it had risen to 58.7% and a year later it was 61.1%, an overall increase of 7.1 percentage points.
Three-weekly systems in Conwy achieved nearly double the predicted benefit in terms of residual, food and garden wastes.
But the record in Fife was less successful. According to a committee report in January 2018, the business case had been based on recycling growing by six percentage points. In the event, the rate increased by barely one point where three-weekly trials had been carried out.
Von Eye and Tomes say a number of factors, including the trial areas already having a high baseline recycling rate of more than 60%, account for the lower increase.
Concerns such as householders putting non-recyclable materials in the dry recycling bin or increased fly-tipping did not appear to have materialised.
The blog concludes: “As the evidence builds to show the scale of the savings and performance improvements, it is reasonable to expect that an increasing number of councils will opt for less frequent residual waste collections.”