1. AQ Review System Calculation Overview
Compiled By xoserve AQ Team
Version 6

2. Presentation Overview
AQ System Calculation:
DM Calculation
NDM Calculation
Backstop Date
Important Points

3. Section 1: AQ System Calculation Methodology Daily Metered (DM) AQ Calculation
UNWC Section: G.1.6.2
System Calculation Date
DM Consumption: 1 YEAR
Consumption 1
Start Read
Consumption 2
End Read
1 Years Consumption for DM sites is 365 Days (or 366 days for Leap Years)
Reads on a day denote the end of the previous days consumption, therefore consumption 365 (End Read) will be derived from the read on day 366
DM AQs are NOT Adjusted to seasonal normal temperature (NDM AQs are)

4. Read 1 (Start Read) OR Read 1 (Start Read)
1: AQ System Calculation Methodology Non-Daily Metered (NDM) AQ Calculation
UNWC Section: H.3
(After October 2002)
Target Read Date
System
Calculation
Date
NDM Consumption
Read 2 minus 42 / 50 Weeks
Read 2 (End Read)
Read 1 (Start Read) OR Read 1 (Start Read)
Read 2 minus 6 Months & 1 Day
All Reads used in System AQ Calculation have to be after the Backstop of October 2002.
Read 2 (End Read) is the latest dated valid read prior to the system calculation
Target Read Date (Start Read) is Read 2 minus 50 weeks for Monthly Read Meters, 42 Weeks for Non-Monthly Read Meters
Read 1 (Start Read) is the latest valid read prior to Target Read Date OR if no valid read exists before the Target Read Date, the earliest dated read after the Target Read Date BUT before Read 2 minus 6 months & 1 day
If no valid read exists earlier than the Read 2 minus 6 months and 1 day, no AQ calculation will take place, current AQ will be carried forward

5. 1: AQ System Calculation Methodology Backstop Date
UNWC Section: H.3
System Calculation Date
New Backstop Date
Start Read 01/07/05
End Read 01/07/06
Shipper Amendment / Appeal AQ 2003
Read 1 Start Read 01/03/05
AQ 2003 System Calculation
Read 2 End Read 12/02/06
Backstop Date
BACKSTOP DATE: Earliest date that can be used in the AQ Calculation
EXAMPLE: System Calculation (2006) used 01/03/05 & 12/02/06 as Start and End Read
Backstop Date for FUTURE calculations will be 12/02/06 – No future calculation will use reads prior to this date
BUT: A Shipper Amendment or Appeal has used 01/07/05 and 01/07/06 as Start and End Read
New Backstop date of 01/07/06 will now be applied – No FUTURE calculation will use reads prior to this date (earliest read used in 2007 calculation will be 02/07/06)

6. 1: AQ System Calculation Methodology Backstop Date (Continued)
UNWC Section: H.3
System Calculation Date
Target Read Date
01/07/05
Read 2 minus 42 / 50 Weeks
Read 2 End Read 01/04/06
Read 1 has to fall between these two dates
Backstop Date
6 Months & 1 Day
AQ Review 2006 – System Calculation uses 01/04/06 as Read 2 (End Read)
If there is no read on the Target Read Date the system will search back to the backstop date + 1 day
If Read 1 (Start Read) is still not found then the system will search forward to 6 months & 1 day before Read 2 (End Read)
The System will never use a read on or prior to the Backstop Date

7. 1: AQ Calculation Methodology Important Points
AQ System Calculation will use any valid read on our system
System Calculation takes place in April each year
If system is unable to determine 2 reads within specified parameters, AQ will be Carried Forward – same AQ Value for previous Gas Year will be applied in next Gas Year
Manual Analysis will take place on:
Threshold Crossers
LSP AQ Calculation
WC Calculation
Primes & Subs
Aim to identify erroneous AQ calculations