asked Her Majesty's Government:

What consideration they have given to the usefulness of assessing the amount and proportion of waste that is recycled or reused, and that which goes to landfill, by volume instead of or in addition to by weight. [HL1131]

There are difficulties in assessing waste by volume rather than by weight, notably the level of compaction when collected and in landfill sites, which varies by material and may change over time. As set out in the England Waste Strategy 2007, the Government prefer to complement waste tonnage figures with estimates of the carbon effects of waste prevention, recycling and disposal practices. The Government are also considering developing a greenhouse gas emissions performance indicator for local authority performance on waste.