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Water Mission Tanzania: market access, honestly ledgered

Virridy's role here is offtake: buying CORSIA-eligible credits from Water Mission's certified systems and selling them on.

Water Mission finances, builds, and operates the water systems. Claiming their health impact on Virridy's ledger would double-count another organization's impact, so this page publishes no $/DALY. The honest Virridy-attributable metrics are climate value and margin integrity.

PRELIMINARY · v1 · AUGUST 2026 · NOT YET THROUGH ADVERSARIAL REVIEW
01The Role

An intermediary model, priced as one

The contract is a deliberate loss-leader: 458,000 credits through 2030, including a 112,000-credit issued backlog bought above its resale price to bring the portfolio's largest certified partner into the platform.

810,000 t
credits modeled 2026–2033: the 458,000-credit contract plus continued offtake at current system growth (18 Gold Standard certified communities, RUWASA partnership, in Tanzania since 2013)
−$504K
the 2026 backlog year margin: 112,000 credits bought at $18 and sold at $13.50. The loss-leader is priced, on the page, not buried.
$3.63/t
average margin per tonne across the window: $2.94M on a $10.39M outlay, all of it contingent on CORSIA labeling

Structural protection: Virridy neither pays nor takes delivery until credits are CORSIA-labeled, so labeling failure is a revenue risk, not a cash-loss risk.

02The Worksheet

The model, cell by cell

Provenance key: Proforma input Judgment · flagged Formula
↓ Download the workbook (.xlsx)
A · Trade series, 2026–2033
Series20262027202820292030203120322033Total
Credits (tCO₂e)112,00074,00084,00094,000104,000114,000114,000114,000810,000
Buy price ($/cr)18.0012.0012.0012.0012.0012.0012.0012.00
Sell price ($/cr)13.5014.5015.0015.5018.0018.0018.0018.00
Virridy outlay ($)2,016,000888,0001,008,0001,128,0001,248,0001,368,0001,368,0001,368,00010,392,000
Virridy revenue ($)1,512,0001,073,0001,260,0001,457,0001,872,0002,052,0002,052,0002,052,00013,330,000
Margin ($)−504,000185,000252,000329,000624,000684,000684,000684,0002,938,000

All prices and volumes are proforma inputs: the 2026 backlog trades at $18 buy / $13.50 sell; subsequent vintages at $12 buy against a rising CORSIA sell curve, with the offtake channel to Louis Dreyfus.

B · Cost basis and integrity
Single denominator$10,392,000Virridy-attributable cost is the credit purchase outlay only. Water Mission's system capex and operations are excluded from BOTH sides of the ledger: no cost claimed, no health claimed.
Residual baseline factor0.80Judgment · flagged The 0.2 credits-per-person-year yield is booked but NOT yet reconstructed to the 2026 SDWS V2.0 methodology; this is the model's most decision-relevant pending item.
Delivery factor0.90remote-monitored systems, 18 certified communities
Credit integrity ratio0.72Formula 0.80 × 0.90 × 1.00
$ / tonne, outlay basis$12.8314.4× below the $185 social cost of carbon
$ / tonne, integrity-adjusted$17.8210.4× below the SCC
C · Scenarios (one-way; a preliminary model carries no Monte Carlo by design)
ScenarioCreditsMargin$/t outlayReading
Base · contract + expansion to 2033810,000$2,938,000$12.83as above
S1 · contracted-only, 458,000 to 2030458,000$826,000$13.4713.7× below the SCC; margin concentrated in later vintages
S2 · sell flat at $13.50 all years810,000$543,000$12.83the commercial finding is price-fragile; the climate finding is not
S3 · CORSIA labeling fails0$0no payment and no delivery until labeled: revenue risk, not cash-loss risk
03Critique

The model's critique of itself

DimensionRatingAssessment
Effect-size qualityFLAGNo health effect modeled, by design. The climate quantity rests on the booked 0.2 yield, not yet reconstructed to SDWS V2.0; the 0.80 baseline residual prices that risk and the reconstruction gates v2.
Counterfactual robustnessMODERATEThe systems operate regardless of Virridy; what Virridy adds is CORSIA market access and the revenue it returns. Another offtaker could plausibly fill this role: the carbon-side funging probability is the highest in the portfolio.
Moral-weight transparencyFLAGNot applicable: no units of value are computed. Stated so the omission cannot be reintroduced silently.
Attribution and integrityMODERATE-STRONGThe model refuses the welfare frame precisely because attribution is thin, and keeps costs and claims on the same outlay basis.
Excluded factorsFLAGExcluded: system capex and operations (both sides), any health valuation, overhead allocation, and the working-capital cost of the 2026 backlog year ($2.0M out against $1.5M in).
Ranking stabilityMODERATEThe climate finding is stable, above 13× the SCC in every modeled case. The commercial finding is price-fragile: flat $13.50 selling compresses the margin to about $0.5M.