# How does a paper mill count sludge and rejects in its footprint?

Canonical: https://senseible.earth/answers/paper-mill-sludge-and-rejects-emissions

Burnt in your own boiler, they are Scope 1, with biogenic CO2 from fibre reported separately and CO2 from plastic rejects counted in full. Sent to a landfill or another company, they are Scope 3 category 5, waste generated in operations.

## Where each goes

- Own boiler: fossil share of rejects, mainly plastics, in Scope 1; fibre share biogenic.
- Landfill: Scope 3 category 5, using a factor for the waste type and disposal route.
- Sold to a cement kiln or brick maker: category 5 only for any treatment you pay for.

## Measure the tonnes

Weighbridge slips for sludge and rejects leaving the site, and moisture content, because wet tonnes overstate the mass.

## Plastic in rejects

Plastic is fossil carbon. Burning it raises your Scope 1 even if the rest of the fuel is biomass.

## What Senseible does here

Senseible reads the energy invoices behind the making stage into a fingerprinted Scope 1 and 2 record, and keeps material invoices on the Scope 3 trail. Material factors come from your supplier or a named database and are labelled with their source, so the product figure can be traced line by line.

- [ETP sludge in Scope 3](https://senseible.earth/answers/etp-sludge-and-wastewater-scope-3-textiles)
- [Plastic waste co processing in kilns](https://senseible.earth/answers/plastic-waste-coprocessing-cement-kiln-emissions)
- [Recycled paper mill waste paper](https://senseible.earth/answers/recycled-paper-mill-waste-paper-scope-3)

Sources: [GHG Protocol Corporate Value Chain (Scope 3) Standard](https://ghgprotocol.org/corporate-value-chain-scope-3-standard), [GHG Protocol Corporate Standard](https://ghgprotocol.org/corporate-standard)

Last reviewed 2026-10-21.