NWSS-M001 — Mass and recovery accounting
Provisional. Usable pending approval; a project-proposed concept only by the project that proposed it.
- Code: NWSS-M001
- Version: NWSS-2026-11-09
- Approval status: Provisional
Accounting for waste mass from facility weighing to destination. Weighed quantities on facility weighing records are summed into mass collected by material category and stream; weighings are counted; weighed quantities on material offtake, residual disposal and organic treatment records are summed by destination; and from these the share of collected mass recovered and the collected mass per household served are computed. Applies to every facility of a project at which collected waste is weighed or from which it leaves.
underlying principles and assumptions
The weighed quantity is the unit of observation: one mass of one material category, or of uncategorised material, on one record. A blank weight is absent, never zero. Uncategorised mass is its own value, never assigned to a stream and never counted toward recovery (ADR-0007). Collection is not recovery: mass counts as recovered only when an offtake or treatment record shows it reached a recovery destination and its category is in a stream the project design declares diverted (ADR-0008). The share recovered is a share of collected mass, never a rate on generated waste, and claims nothing about what would otherwise have been landfilled. Payment rules, exceptions and payable dates belong to bounties and never change mass. NWSS computes no emission reduction.
methods and procedures
At the facility, weigh each delivery by material category at the level the project design declares, or as uncategorised when it is weighed unsorted, and record the facility, the collector by tag, the observer and the observer role on a facility weighing record. When material leaves, record a material offtake with the offtaker, the destination and the weighed quantities by category, keeping the weighbridge ticket or receipt in the evidence store; record residual deliveries to a disposal site as residual disposal and composting or other treatment as organic treatment, each with destination and weighed quantities. Compute the indicators over the records of the reporting period.
data requirements and inputs
Facility weighing records with their weighed quantities (material category and mass in kg), facility, collector, observer, observer role and observedAt. Material offtake records with offtaker, destination and weighed quantities; residual disposal and organic treatment records with destination and weighed quantities; the evidence item behind each by content address. From the project design: the material category level weighed, any stream overrides, the streams declared diverted and the service period. For collected mass per household served, the households actively served and the service periods from NWSS-M003.
calculation and transformation rules
Let Q be the weighed quantities with a mass on facility weighing records dated in the reporting period, each with mass m, category c, facility and collector, and let s(c) be the stream of c: the project design’s override for c or its nearest broader category, else the default separation stream of c or of its nearest broader category; uncategorised has no stream. The collector of a record is the agent its collector tag resolves to at its observedAt under the scan resolution rule of ADR-0003, gaps included; a record whose tag resolves to no agent forms its own unresolved row, and a record with no facility stays in the service-area total as a row with no facility. (1) Waste mass collected C = sum of m over Q, by category, stream, facility, collector and service area. Uncategorised mass U = sum of m over Q with c uncategorised. (2) Facility weighing records = the number of facility weighing records dated in the period with at least one weighed quantity; those without one are reported alongside. (3) Let L be the weighed quantities on material offtake, residual disposal and organic treatment records dated in the period, each with destination d. Mass leaving by destination = sum of m over L, by d, category, stream and facility; reported alongside, per facility and stream, C minus the mass leaving, as information on stock. (4) Recovered mass R = sum of m over L with d in the recovery destinations (recycled, composted or treated) and s(c) in the project parameter diverted streams. Share of collected mass recovered = 100 × R / (C − U), undefined when C − U is zero; per stream, 100 × R_s / C_s. Reported alongside: R, U, the mass stockpiled and the diverted streams. Organic mass with no organic treatment or offtake record is not recovered. (5) Collected mass per household served, per service area = C / HD, where HD is the sum, over the service periods of the reporting period, of the households actively served in the period (NWSS-M003) times the days of the period. Every rate rolls up by summing its numerator and denominator over facilities, areas and periods.
outputs and units of measure
Waste mass collected (kg) by material category, stream, facility, collector and service area; facility weighing records (count, NUM); mass leaving facilities by destination (kg) by destination, material category, stream and facility, with the collected-minus-leaving difference alongside; share of collected mass recovered (PERCENT) with recovered, uncategorised and stockpiled mass in kg alongside; collected mass per household served (KiloGM-PER-HH-DAY) per service area.
validation and verification approach
Validation: a reviewer with Knowledge and Skills Reputation in material recovery and recyclate markets checks that the project design declares the weighing level, the diverted streams and every facility, and that its offtakers are named by role. Verification of a diversion claim: a reviewer holding that domain at the standard’s highest threshold (ADR-0012), who is neither the facility operator who recorded the offtake nor its offtaker, checks every recovery-destination record against its evidence item (weighbridge ticket or receipt), that the offtaker is an agent in the offtaker role, that organic recovery rests on a treatment record, and that recovered mass by stream does not exceed collected mass plus opening stock over the claim period; and samples weighing records against their scale evidence.
limitations and applicability boundaries
Collection and offtake are dated independently, so material held at a facility makes a single period’s share recovered too low or above 100 percent; claims should be read over windows long enough to clear stock. A recovery destination is evidenced by the offtaker’s receipt, not by what the offtaker then does with the material. Mass includes moisture and contamination as delivered. Collected mass is attributed to facilities and collectors, never to service points. Waste households take to a landfill or burn themselves is outside this accounting; only a characterisation baseline (NWSS-M008) reaches it.
rationale
Dashboards built on collected mass reported three incompatible diversion rates and counted unsorted batches as recyclable on some surfaces and not on others. One accounting from the weighed quantity to the recorded destination gives a single mass balance whose recovered part a verifier can trace to receipts, and whose quantities by material approved GHG methodologies can consume.
Indicators it serves
Activity types
- Facility weighing
- Material offtake
- Organic treatment
- Residual disposal
Knowledge domains a reviewer needs
- Data and evidence quality
- Landfill and residual disposal
- Material recovery and recyclate markets
- Organic waste treatment
Variables
| Variable | Role | Unit | Description |
|---|---|---|---|
| Collected mass per household served | DerivedOutput | KiloGM-PER-HH-DAY | C / HD per service area, HD from NWSS-M003. |
| Facility weighing records (N_w) | DerivedOutput | NUM | N_w = number of facility weighing records dated in the period with at least one weighed quantity. |
| 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. |
| Mass leaving by destination (L_d) | DerivedOutput | KiloGM | L_d = sum of m over weighed quantities on offtake, residual disposal and organic treatment records dated in the period with destination d. |
| 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. |
| Share of collected mass recovered | DerivedOutput | PERCENT | 100 x R / (C - U); undefined when C - U is zero. |
| 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. |
| Uncategorised mass (U) | DerivedOutput | KiloGM | U = sum of m over weighed quantities with c uncategorised; reported alongside, in neither side of the recovery share. |
| Waste mass collected (C) | DerivedOutput | KiloGM | C = sum of m over weighed quantities on facility weighing records dated in the period, by c, s(c), facility, collector and service area. |
| Collector (k) | MeasuredInput | UNITLESS | The agent in the collector role named on a record, resolved from the collector tag at observedAt under the scan resolution rule of ADR-0003. |
| 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. |
| Destination (d) | MeasuredInput | UNITLESS | Where material left a facility to, on an offtake, disposal or treatment record. |
| Facility (f) | MeasuredInput | UNITLESS | The facility a record was made at. |
| 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. |
| Offtaker | MeasuredInput | UNITLESS | The agent in the offtaker role that took the material. |
| Restated record | MeasuredInput | UNITLESS | The earlier record a record replaces; of a record and its restatements only the latest counts (ADR-0006). |
| Tag assigned to | MeasuredInput | UNITLESS | The entity a tag bore under an assignment; a scan resolves to it while the assignment is valid, and in a gap after it unless the code was next assigned to a different entity (ADR-0003). |
| Tag assignment valid from | MeasuredInput | UNITLESS | Start of a tag assignment’s validity window. |
| Tag assignment valid until | MeasuredInput | UNITLESS | End of a tag assignment’s validity window; open while the assignment is not superseded. |
| 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
- Destination recorded for every outflow: Every material leaving a facility is recorded as an offtake, residual disposal or organic treatment with its destination and weighed quantities, and its ticket or receipt kept in the evidence store; recovery is claimed for no other mass.