Biogas Tanks in Guizhou Province in China

Integrity

The verification report confirms additionality through a combined test and says there were no material findings, which supports the project’s core integrity. At the same time, leakage is not addressed, buffer pool coverage is not stated, and the report notes a broken biodigester diagnosed in May 2013 without a clear reversal resolution. The project also relies on a project baseline last reassessed in 2008, which is dated and weakens confidence in baseline validity.

Transparency

Transparency is moderate because the record includes a named verifier, a clear monitoring period, and a verification report with claimed and verified reductions both shown as 2,977. However, usage monitoring is based on self-reporting, the usage rate is not stated, and leakage treatment is missing. The documentation is therefore usable but not especially robust.

Claim Safety

Claim safety is weakened by the project-specific baseline and the absence of quantified leakage treatment. The record does not provide enough information on usage rates or eligibility status to rule out over-crediting or dual-claim concerns. The matching claimed and verified reductions help, but the contradictions in the extracted record reduce confidence.

Documentation

The evidence base is broader than minimal, with a PDD, verification report, and monitoring report all used, and extraction confidence is medium rather than low. Still, several important items are not stated in available documents, including buffer pool coverage, leakage deduction, and verified usage rate. That leaves the documentation adequate but incomplete for a high-confidence assessment.

Overall

I privileged the 2013 verification report over the earlier 2011 figures because it is the more recent and project-verification-specific source, so I used 2,977 tCO2e as the verified and claimed amount. I also privileged the later PDD entry for the combined additionality test over the earlier investment-test wording because it appears to be the updated project design document. The contradictions on reversal events and emission reductions indicate some extraction or reporting inconsistency, so I reduced confidence and did not score the project as highly robust.