NWSS-M008 — Waste characterisation baseline
Provisional. Usable pending approval; a project-proposed concept only by the project that proposed it.
- Code: NWSS-M008
- Version: NWSS-2026-11-09
- Approval status: Provisional
Measurement of how much waste households generate and what it is made of, by sampling service points, collecting all the waste they set out over a declared accumulation period, sorting it by material category and weighing it; with the waste generation rate per household per day by material category and, read against recovered mass, the recovery rate on generated waste.
underlying principles and assumptions
A generation baseline is measured, never assumed. The sample is drawn from the project’s service points by a declared design and is representative of the service area it is used for. All the waste set out in the accumulation period is weighed, uncategorised fines included. Generation is per household per day, from the household count in force at the sampled service point. A recovery rate on generated waste uses the baseline of its own service area, or one the project design declares representative of it, and is never pooled across baselines.
methods and procedures
Draw a sample of occupied service points, stratified as the project design declares. On day zero ask each sampled household to keep all its waste, in bags provided, for the accumulation period. At its end collect the bags, sort each sample into material categories at the project’s declared level or finer, weigh each category and the uncategorised remainder, and record the household and person count at the service point, on a waste characterisation record per sampled service point.
data requirements and inputs
Waste characterisation records, one per sampled service point, with weighed quantities by material category (uncategorised included), the start and end dates of the accumulation period, and a household and person count observation; the sample design. For the recovery rate on generated waste: recovered mass by service area from NWSS-M001 and households actively served per period from NWSS-M003. From the project design: the accumulation period, the sample size and strata, and which characterisation serves as baseline for each service area.
calculation and transformation rules
Let X be the sampled service points of a characterisation, each with weighed quantities m_c by material category c, household count H and accumulation period of A days (the project parameter accumulation period, default 7 days). (1) Waste generation rate = (sum over X of all m_c) / (sum over X of H × A), in kg per household per day; by category, the same with m_c of category c (and its narrower categories) only; composition share of c = rate for c / total rate; persons per household = (sum of persons) / (sum of H) reported alongside, with the sample size and dates. Service points with no household count are left out of both sums and counted alongside. (2) Recovery rate on generated waste, for a service area and stream s = 100 × R_s / (G_s × HD), where R_s is the recovered mass of stream s in the area and reporting period (NWSS-M001), G_s the generation rate of the categories in s from the area’s baseline, and HD the sum over the service periods of the reporting period of the households actively served times the days of the period; for all streams, sum R over the diverted streams and G over all categories.
outputs and units of measure
Waste generation rate per household (KiloGM-PER-HH-DAY) by material category and stream, with composition shares, persons per household and sample size alongside; recovery rate on generated waste (PERCENT) per service area and stream, with the baseline used alongside.
validation and verification approach
Validation: a reviewer with Knowledge and Skills Reputation in waste characterisation and sampling checks the sample design, size and strata, the accumulation period and the declared baseline per service area. Verification: a reviewer in that domain, who did not sort the samples, checks the sorting and weighing records against their photographs and scale evidence and that every sampled service point is either weighed or reported as lost from the sample.
limitations and applicability boundaries
A characterisation describes the season and the period sampled; generation varies by season, income and household size. Households may change what they set out while observed. Waste burnt, buried or fed to animals during the accumulation period is not in the sample. The recovery rate on generated waste applies a baseline to households served, so it is only as representative as the baseline.
rationale
The dashboard behind this standard reported mass per service point and per household as if it were generation, and its owner left the generation rate open. A measured baseline by material category is the only basis for a recovery rate on generated waste and gives approved GHG methodologies the composition they start from.
Indicators it serves
Activity types
- Waste characterisation
Knowledge domains a reviewer needs
- Survey and monitoring design
- Waste characterisation and sampling
Variables
| Variable | Role | Unit | Description |
|---|---|---|---|
| Household-days served (HD) | DerivedOutput | NUM | Sum over the service periods of the reporting period of households actively served in the period times the days of the period. |
| Recovered mass (R) | DerivedOutput | KiloGM | R = sum of m over weighed quantities on offtake and treatment records dated in the period with d a recovery destination and s(c) a declared diverted stream. |
| Recovery rate on generated waste | DerivedOutput | PERCENT | 100 x R_s / (G_s x HD) per service area and stream. |
| Stream of category s(c) | DerivedOutput | UNITLESS | s(c) = the project design’s stream override for c or its nearest broader category, else the default separation stream of c or its nearest broader category; undefined for uncategorised. |
| Waste generation rate (G) | DerivedOutput | KiloGM-PER-HH-DAY | G = sum of m over sampled service points / sum of H x A, in kg per household per day; by category likewise. |
| Accumulation days (A) | MeasuredInput | DAY | Days over which a sampled service point’s waste was kept for a characterisation. |
| Default separation stream | MeasuredInput | UNITLESS | On a material category: the stream it belongs to unless the project design overrides it; inherited by narrower categories; uncategorised has none. |
| Household count (H) | MeasuredInput | NUM | Households at a service point as observed; the latest valid count is in force. |
| Material category (c) | MeasuredInput | UNITLESS | The category of a weighed quantity at the declared level, or uncategorised. |
| Observed at (t) | MeasuredInput | UNITLESS | The instant the observation or record was made; its local date in the project’s time zone is the record’s date. |
| Person count | MeasuredInput | NUM | People in the households at a service point as observed. |
| Restated record | MeasuredInput | UNITLESS | The earlier record a record replaces; of a record and its restatements only the latest counts (ADR-0006). |
| Service point (x) | MeasuredInput | UNITLESS | The service point a record or observation is about. |
| Weighed mass (m) | MeasuredInput | KiloGM | Mass of one weighed quantity in kg; a blank weight is absent, never zero. |
| Withdrawn record | MeasuredInput | UNITLESS | The record a withdrawal declares never happened; a withdrawn record never counts (ADR-0006). |
Monitoring requirements
- A baseline for each service area claimed against: A recovery rate on generated waste is reported for a service area only when the project design names the characterisation that serves as its baseline.