Emissions and release to the water column shall be quantified as follows:

CO2emittedt CO2=∑TStartTEnd L CO2t CO2∕d

Where:

L CO₂

the mass of CO₂ emitted or released per calendar day due to the leakage in accordance with all of the following:

1. (a)

   for each calendar day for which leakage is monitored, each operator shall calculate L CO₂ as the average of the mass leaked per hour [t CO₂/h] multiplied by 24;

2. (b)

   each operator shall determine the mass leaked per hour in accordance with the provisions in the approved monitoring plan for the storage site and the leakage;

3. (c)

   for each calendar day prior to commencement of monitoring, the operator shall take the mass leaked per day to equal the mass leaked per day for the first day of monitoring ensuring no under-estimation occurs;

T_start

the latest of:

1. (a)

   the last date when no emissions or release of CO₂ into the water column from the source under consideration were reported;

2. (b)

   the date the CO₂ injection started;

3. (c)

   another date such that there is evidence demonstrating to the satisfaction of the competent authority that the emission or release into the water column cannot have started before that date.

T_end

the date by which corrective measures in accordance with Article 16 of Directive 2009/31/EC have been taken and emissions or release of CO₂ into the water column can no longer be detected.

The competent authority shall approve and allow the use of other methods for the quantification of emissions or release of CO₂ into the water column from leakages where the operator can show to the satisfaction of the competent authority that such methods lead to a higher accuracy than the methodology set out in this subsection.

The operator shall quantify the amount of emissions leaked from the storage complex for each of the leakage events with a maximum overall uncertainty over the reporting period of 7,5 %. Where the overall uncertainty of the applied quantification methodology exceeds 7,5 %, each operator shall apply an adjustment, as follows:

CO_2,Reported [t CO₂] = CO_2,Quantified [t CO₂] * (1 + (Uncertainty_System [%]/100) – 0,075)

Where:

CO_2,Reported

the amount of CO₂ to be included in the annual emission report with regards to the leakage event in question;

CO_2,Quantified

the amount of CO₂ determined through the used quantification methodology for the leakage event in question;

Uncertainty_System

the level of uncertainty associated with the quantification methodology used for the leakage event in question.