I-DEV0432: Request for deviation on the monitoring of the Chemical Oxygen Demand (COD) for untreated and treated wastewater

The request for deviation is for a registered CDM project activity “Methane Recovery in Wastewater Treatment, Project AIN07-W-04, Sumatera Utara, Indonesia” (project reference number 2130), which was registered against AMS-III.H version 7 on 16/01/2009. During the second periodic verification, as per the requirement of VVM para 210, SIRIM QAS Intl. found that the project participant (PP) had deviated from the provisions of the registered monitoring plan. The deviation was as follows:

In the Monitoring Plan of the registered PDD (page 25 and 26), for the monitoring of CODuntreated and CODtreated, the following additional statement has been included under the QA/QC procedure to be applied : “In addition, internal sampling on a monthly basis will be conducted to ensure proper digester operation”.

During the second monitoring period i.e 1 March 2010 to 28 February 2011, the internal sampling was not carried out for the months of April, June, July, August and December 2010.

The deviation do not require revision of the monitoring plan or change from the project activity, as the internal monthly sampling has being carried out as specified in the plan beginning from 1 March 2011.

The internal monthly samplings were meant for the monitoring of the digester operation. According to the Monitoring Plan, only the COD analysed semi annually by a third party laboratory was to be used in the calculation of the ER, hence the monthly samplings shall not bear any impact to the estimates of the emissions reductions for the project activity.

Since the analysis of the samples were also sent to external accredited laboratory, PP had decided to include the COD values monitored in the calculation of the average COD for the monitoring period. This is found to be conservative as more average of more data would results in a more accurate average value of the COD, and hence would give a more accurate ER estimation. Furthermore, the internal monthly samplings analyses were also carried out by the external accredited laboratory.

The methodology (AMS-III.H version 7) did not specify the QA/QC procedure for the monitoring of the digester operation. Therefore, this deviation does not change the applicability of the methodology.