What a diversion rate
actually measures

What the number is

In its ordinary form, a diversion rate is the weight of material kept out of landfill and incineration divided by the total weight of material leaving the site, expressed as a percentage.

Every part of that is a choice. What counts as diverted, what counts in the total, and which sites and streams are included all vary between organizations, which is why two companies reporting the same rate may not be measuring the same thing.

Weight flatters some programs and penalizes others

Weight is the only unit that can be summed across every material, and it is also the reason the number can mislead. A site generating large volumes of cardboard will post a high rate almost automatically, because cardboard is heavy and recycles easily.

A site handling smaller quantities of difficult regulated material can do genuinely excellent work and post a lower number, because the material that is hardest to divert weighs the least. The rate rewards the easy win and understates the difficult one.

What usually gets left out

Several things commonly sit outside the calculation without anyone deciding they should. Material handled under a separate contract. Construction debris from a project. Streams that leave as product rather than waste. Anything a tenant or contractor removes directly.

None of those exclusions are necessarily wrong. What matters is that they are deliberate and written down, because the first hard question anyone asks about a diversion rate is what is not in it.

Where the figure actually comes from

A diversion rate is only as good as its weight data, and weight data arrives from several places at once: scale tickets, hauler reports, estimated container weights and occasionally someone's reasonable guess.

Estimated weights are not disqualifying, and most programs contain some. They do need to be identified as estimates, with the basis recorded. A rate built on a mixture of measured and estimated weights with no distinction between them will not survive a serious review.

Reporting it so it holds up

Four things make a diversion rate hold up under scrutiny: state what is included, state what counts as diverted, state what is left out and why, and say which figures were weighed and which were estimated.

That is a more modest claim than a bare percentage, and a far stronger one. A rate presented with its method attached invites a conversation. A rate presented alone invites someone to go looking for what is behind it.

What to track alongside it

The rate on its own cannot tell you whether a program is improving, because it moves when production volume moves. Two things make it readable: total weight generated, which shows whether you are producing less material rather than just handling it better, and the rate broken out by stream.

The second is where decisions get made. A network-level rate tells you where you are. The rate for one material at one site tells you what to do on Monday.