ANNEX VII p77/90 Data Field No. 4b Type of Event – It would appear that we can only select one value. As a SSO where we have a TOTAL outage, does this mean that we have to report the loss of injection and withdrawal capacity separately? Hence we would have 2 UMMs for the same event detailing loss in both directions?
In the case of bidirectional sites we would expect to see loss of capacity in both directions on a single UMM however we have interpreted the Data field above as 2 UMMs reporting loss of availability, one for injection and one for withdrawal.
Answer: In case of a total outage of a gas storage facility when a loss of both injection and withdrawal capacity occurs, the value ‘Storage unavailability’ shall be provided in the (4/b) Type of Event field. The value ‘Storage unavailability’ represents a combination of both ‘Injection unavailability’ and ‘Withdrawal unavailability’ and hence only 1 UMM is reportable for a total outage.