# How do we count the alum, PAC and polyelectrolyte our water plant buys?

Canonical: https://senseible.earth/answers/water-treatment-chemicals-scope-3

Coagulants and flocculants you buy are Scope 3 Category 1. Use kilograms bought from invoices and a supplier or named database factor for each. They are often small next to the plant's electricity, but auditors still expect them listed or a reason for leaving them out.

## List

- Alum and poly aluminium chloride (PAC).
- Polyelectrolyte.
- Hypochlorite, lime and acid for pH.

## Leaving them out

If they are below your exclusion threshold, say so and show the estimate behind that decision.

## What Senseible does here

Senseible reads bills, fuel invoices and production records into dated, fingerprinted records, so the figure you send a buyer can be traced to its documents.

- [ETP electricity per kl](https://senseible.earth/answers/etp-electricity-per-kl-effluent)
- [Exclusion threshold](https://senseible.earth/answers/carbon-footprint-exclusion-threshold)

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 2026-10-22.