Getting from 78 per cent landfill diversion to 97 was engineering: buy a granulator, build a water reclaim skid, start rebottling. Getting from 97 to 99.4 was detail work. Getting to 100 is a different kind of problem entirely, and I am not sure we can.
What the 0.6 per cent is
In 2024 we handled 2,994,000 pounds of inbound mass and sent 18,000 pounds to licensed disposal. Here is all of it, itemised, because naming it is the only way to shrink it.
| Stream | Mass | Why it is stuck |
|---|---|---|
| Dewatered wash sludge | 11,400 lb | Mixed organic and inorganic residue, no viable outlet |
| Fouled gasket rubber | 3,200 lb | Cross-linked elastomer carrying chemical residue |
| Mixed fasteners and pallet nails | 1,900 lb | Too small and too mixed for economic separation |
| Labels, liners and adhesive | 1,100 lb | Multi-material laminates |
| Contaminated PPE and absorbents | 400 lb | Regulated by contact rather than by material |
Wash sludge is nearly two thirds of it
Everything that comes off the inside of a container ends up in the settling tank, gets dewatered, and goes out as a cake. It is a genuine mixture — residues from hundreds of different cargoes, plus the solids that were already in our water.
There are two routes out and I do not like either. Thermal treatment moves the problem into an incinerator and lets us call it diversion, which is the kind of boundary redefinition this whole page exists to avoid. The other route is changing the wash chemistry so the residue is recoverable, which is a genuine research project and is what we are actually working on.
That is a 2027 line item, honestly stated. It may not work.
Gasket rubber is small and stubborn
We replace every gasket on every unit — reusing a flange gasket is the single most common cause of a leak, so it is not negotiable. That generates three thousand-odd pounds a year of cross-linked elastomer that has been in contact with chemistry we cannot always identify.
Cross-linked rubber does not remelt. Cryogenic grinding into crumb rubber is possible in principle and uneconomic at our volume, and the chemical contact history makes most buyers nervous. We are investigating it rather than claiming to have solved it.
Pallet nails, which are almost funny
Nineteen hundred pounds of nails, staples and assorted fasteners from wooden pallets. Individually trivial, collectively a real number, and genuinely difficult because they arrive embedded in wood fibre.
A magnetic sort trial is running on the chipper output. It should recover most of it, which would take the residual from 0.6 to roughly 0.54 per cent. Not a headline, but it is the only honest kind of progress left at this end of the curve.
This is also a small argument for composite and plastic pallets over wood, which we make on the pallets page for other reasons too.
Labels and liners, which are a supplier problem
Multi-material laminates — paper bonded to film bonded to adhesive — are not recoverable by any route available to us. The only real fix is upstream: single-material labels that survive a caustic wash and then recycle with the substrate.
We raise this with suppliers and it moves slowly. It is a classic case of a problem that is cheap to fix at design and expensive to fix at end of life.
Why we do not round it to zero
Plenty of operations describe themselves as zero waste at diversion rates below ours. They get there by redefining boundaries: counting waste-to-energy as recovery, excluding “non-process” waste, or measuring units instead of mass.
We measure inbound mass, we count incineration as disposal, and we include everything — including the PPE and the absorbents. That is why the number is 99.4 and not 100, and why it is going to stay honest even when it stops improving.
The full mass balance is published on the zero-landfill page, updated every January.
Why mass is the right denominator
Diversion rates can be computed several ways and the choice changes the headline substantially. Three common bases:
- By unit. Count containers diverted versus landfilled. Flattering, because the residual streams are not containers — they are sludge and rubber, which have no unit count.
- By volume. Also flattering, because a dewatered cake is dense and a reused tote is bulky.
- By mass. What we use. Every pound in, every pound accounted for.
Mass is the only basis where the answer cannot be improved by choosing a different measuring stick, which is why we use it and why our number is lower than some competitors' claims.
The waste-to-energy question
We count incineration as disposal. A great many diversion figures count it as recovery, and that single accounting choice is the difference between 99.4 per cent and a claim of zero waste.
There is a real argument on the other side: energy recovery displaces fossil generation and avoids landfill methane. We are not saying it is worthless. We are saying it destroys the material, and a company whose entire premise is keeping material in use should not count destroying material as a success.
It also conveniently solves our wash sludge problem on paper without solving it in fact, which is exactly the kind of boundary shift this page exists to avoid.
What we tried that did not work
Three dead ends, because the failures are more informative than the wins.
Composting the sludge
Attempted in 2022. The organic fraction is genuinely compostable; the inorganic fraction and the unpredictable chemical content are not, and no composter would take a feedstock they could not characterise. Abandoned.
Cryogenic grinding of gasket rubber
Technically feasible, economically absurd at 3,200 pounds a year. The capital cost would never be recovered and shipping it to somebody who already has the equipment runs into the same problem composting did: nobody wants a crumb rubber feedstock with an unknown chemical contact history.
Pallet wood to biomass fuel
Would have worked and we chose not to, because by our own accounting burning it is disposal rather than recovery. The wood now goes to chipping for landscaping and animal bedding markets, which is a genuine material use at slightly lower value.
What is actually in progress
- Magnetic fastener recovery on the chipper output. Should recover most of the 1,900 pounds of nails and take the residual to roughly 0.54 per cent.
- Wash chemistry reformulation so the residue is characterisable and therefore placeable. This is the big one and it is a genuine research project with no guaranteed outcome.
- Supplier pressure on labels. Single-material labels that survive a caustic wash and then recycle with the substrate. Slow, and the right fix.
- Gasket material review. If we can standardise on fewer elastomer types with better end-of-life routes, the stream becomes characterisable. Under evaluation.
The curve flattens, and that is the honest story
78 per cent to 97 took equipment: a granulator, a reclaim skid, a rebottling line. Each purchase moved the number several points.
97 to 99.4 took detail work: better sorting, the upcycle bay, tighter pallet handling. Each intervention moved it a fraction of a point.
99.4 to anything higher needs chemistry we do not have and markets that do not exist. That may take years, it may not happen, and saying so is more useful than announcing a target we cannot support.
The figures are reviewed every January against metered consumption and published on the zero-landfill page. When a number gets worse we leave it on the page with the miss written next to it, because removing it would defeat the point of publishing it at all.
