The methodology caps the MCF for suppressed-demand (open defecation) populations at 0.5 and applies a further 5% deduction (ADJSD). This is based on the assumption that the counterfactual is a basic pit latrine. For many MWA member contexts in Sub-Saharan Africa, this cap significantly reduces creditable emissions. Consider whether the 0.5 cap is overly conservative for wet/tropical environments where pit latrines with high water tables (MCF = 0.7) would be the realistic counterfactual.

The 0.66 UAF is applied to the entire unadjusted baseline. Combined with the suppressed-demand cap, MCF conservativeness, the 5% SD deduction, and the DAF, the cumulative conservativeness may reduce creditable volumes to the point where projects become financially unviable. The methodology should clarify how these multiple layers interact and whether double-discounting occurs.

The methodology requires a Baseline Scenario Survey (BSS) at 90/10 precision to determine pathway proportions. For organisations operating across diverse geographies (e.g., multiple cities or countries), conducting a compliant BSS for each area is resource-intensive. Clarity is needed on whether existing sector studies (e.g., JMP data, government WASH surveys) can supplement or replace primary BSS data collection.

CC_y requires a mass-balance chain-of-custody assessment reconciling volumes collected at containment against volumes received at treatment. This is operationally challenging for many FSM service providers, particularly those using manual emptying or operating in informal settlements. The alternative — a flat 5% market-leakage deduction — may be more practical, but the methodology positions CC_y as the primary mechanism.

OF_y must be determined via a statistically representative field survey confirming that containment units are active, functional, and in regular use. Units that are abandoned, destroyed, or where users have reverted to open defecation are counted as non-operational (OF = 0). The sample frame must include all distributed units on record, not just active users, and units that cannot be located are conservatively coded as non-operational.

If a treated batch fails pathogen limits, the entire batch's emission reductions are forfeit (ER_y = 0 for that fraction). This binary gate is an important safeguard, but raises questions about proportionality: a minor exceedance on one parameter results in the same penalty as a major failure. It also means the methane avoidance (which did occur) goes uncredited because of a downstream treatment quality issue.

The IPCC 2019 default BOD values are applied by broad region (Africa = 0.037 kg/person/day). This relatively low value may underestimate organic load in some sub-regions. The methodology allows developers to use measured values but does not specify the protocol for doing so. For projects seeking to demonstrate higher-than-default BOD, clearer guidance on acceptable measurement methodologies would be beneficial.

At crediting period renewal, if a state-funded municipal sewer network has expanded into the activity boundary providing safely managed waterborne sanitation, those households' baselines shift to zero-methane and credits stop. This is appropriate in principle, but the trigger definition could be problematic: many municipal sewer expansions in LMICs are partial, non-functional, or lack treatment. Clarity is needed on what constitutes "reasonable access to a functional municipal sewer system."

Pooled sampling across VPAs is limited to 10 unless homogeneity is demonstrated and validated. For large-scale service providers operating uniform CBS systems across 20+ cities, this cap could be unnecessarily restrictive and increase MRV costs. The requirement to demonstrate homogeneity across technology type, geography, and system age is reasonable, but the hard cap of 10 seems arbitrary.

Annex 2 provides indicative cradle-to-gate embodied-carbon factors from the ICE database (UK-centric). For projects manufacturing containers or infrastructure in LMICs (e.g., HDPE containers made in East Africa), actual embodied carbon may differ. The methodology allows project-specific EPDs, but obtaining these is expensive. Consider whether the UK-based defaults are appropriate for projects operating in different manufacturing contexts.

The DAF is applied per GS4GG Tool 05 to encourage ambition over time. While the concept is sound, sanitation services already face thin margins. The DAF compounds with the UAF, SD cap, and other deductions. The methodology should clarify whether any of these conservativeness measures are considered sufficient to satisfy the ambition function, potentially allowing a reduced or waived DAF for sanitation.

Annex 1, which should contain the detailed monitoring schedule and requirements, is listed as "To be added in the final version." This is a significant gap in the public consultation draft, as it prevents stakeholders from reviewing the practical implementation timeline for monitoring activities.

The additionality test requires demonstrating that safe sanitation is "not yet the norm" in the target area. However, the methodology does not define quantitative thresholds for common practice. In rapidly urbanising LMIC contexts, some form of pit latrine emptying may be common, but safe treatment of collected sludge is extremely rare. The methodology should distinguish between the prevalence of emptying services (which may be common but unsafe) and truly safely managed sanitation chains (which are almost universally non-common practice in target geographies).

At crediting period renewal, developers must demonstrate "ongoing financial need" for carbon finance. The methodology does not define how OFN is assessed or what level of financial dependency qualifies. For sanitation services that have grown partly due to carbon revenue, does their improved financial position at renewal risk disqualifying them — even though withdrawing carbon finance would collapse the service?