# What emissions must a composting project deduct under CCTS tool BM-T-013?

Canonical: https://senseible.earth/answers/ccts-tool-bm-t-013-composting-emissions

Methane and nitrous oxide from the compost, power and fuel used, and methane from run-off in co-composting. Without measurements, BM-T-013 sets 0.002 t of methane and 0.0002 t of nitrous oxide per tonne of wet waste, 0.01 MWh of power and 0.0207 t CO2 from fuel.

## What is counted

- Methane and nitrous oxide from the composting process.
- CO2 from fossil fuel and electricity used for composting.
- Methane from run-off wastewater in co-composting. It is zero if run-off is collected and recirculated, as in tunnel co-composting.
- Leakage if compost is dumped or stored anaerobically, worked out with BM-T-011. Compost used as landfill cover is not leakage, and transport is not counted.

## Weighing the waste

Use a calibrated weighbridge or belt scale. Without one, add up the nameplate carrying capacity of every truck delivering waste. For household, community and SME projects, a weighbridge gap of up to 30 consecutive days in six months can be filled from truck capacities or the highest figure for the same period in earlier years.

## Measuring instead of defaults

Measure at least three composting cycles a year. In closed halls, measure the exhaust pipe or use BM-T-005. For windrows, use a flux box at at least 10 sites per windrow, two cross sections of five points, with at least five measurement events per site, so 50 or more readings per cycle.

## Run-off defaults

Methane = COD in the run-off x 0.25 t methane per t COD x the treatment system's methane conversion factor x 1.12. If you only monitor the wastewater you co-compost, run-off COD can be taken as 0.02 of its COD. The conversion factor is 0 for well managed aerobic treatment, 0.8 for anaerobic reactors or deep lagoons without recovery, and 1 if unknown.

## Worked example: 10,000 t of wet waste a year

- Methane: 10,000 x 0.002 = 20 t x 29.8 = 596 t CO2e
- Nitrous oxide: 10,000 x 0.0002 = 2 t x 273 = 546 t CO2e
- Fuel: 10,000 x 0.0207 = 207 t CO2
- Power: 10,000 x 0.01 = 100 MWh, at the grid factor BM-T-003 sets
- Total before power: 1,349 t CO2e a year to deduct

BM-T-013 leaves the GWP blank; 29.8 is the methane value BEE applies in BM-T-008 and 273 is the IPCC AR6 value for nitrous oxide. Use what your methodology version sets.

## What Senseible does here

Senseible gives carbon credit eligibility signals from your records; it does not register projects or issue credits. It keeps dated, fingerprinted fuel and electricity invoices that a project's monitoring records can draw on.

- [Methane from dump sites BM-T-011](https://senseible.earth/answers/ccts-tool-bm-t-011-waste-disposal-methane)
- [Landfill vs compost vs biogas](https://senseible.earth/answers/food-waste-landfill-vs-compost-vs-biogas-emissions)
- [Approved CCTS methodologies](https://senseible.earth/answers/ccts-offset-approved-methodologies)

Sources: [BEE, BM-T-013 Project and leakage emissions from composting (CCTS Offset Mechanism, version 1.0, 27 March 2025): data and parameter tables 1 to 14](https://beeindia.gov.in/WriteReadData/RTF1984/RTF-PDF-5f949cdf849d668d_1776061649.pdf), [IPCC AR6 Working Group I, global warming potentials](https://www.ipcc.ch/report/ar6/wg1/), [BEE, Methodologies and Tools under the CCTS Offset Mechanism](https://beeindia.gov.in/view_content.php?lid=571&lang=1)

Last reviewed 2026-10-25.