Alberta Electric System Operator
Long Term Critical Transmission Outages > 10 days (Revised 2014-03-05)

The table below contains the critical transmission maintenance outages submitted as tentative to the AESO.
These Outages have not yet necessarily been approved, but are listed for awareness and coordination purposes.
An Outage has been considered critical for this table if it affects:
  • A 500 kV Line, Breaker, Bus or Transformation,
  • A 240 kV Line, Breaker, Bus or Transformation,
  • The interconnection of the AIES to an external transmission system, specifically the BC intertie, the Saskatchewan intertie or the Montana intertie,
  • A significant component of the AIES, is an interconnecting element between transmission facility owners, or connects a generating units to the AIES,
  • Elements which impact cutplane operating limits,
  • Requires curtailing generation to facilitate the outage
Note: Where a transmission outage requires generation curtailments, the adjustments to generation will typically happen in the hours before the scheduled transmission outage and in the hour after the element is returned to service.

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Owner From To Duration Element Scheduled Activity Affected Intertie
ATCO 21-Nov-13 08:00 30-Jun-14 16:00 222 Days
Continuous		 732s 503R (732s Mitsue) Forced Outage  
ALTALINK 18-Dec-13 08:00 31-May-14 16:00 165 Days
Continuous		 89s 1852 (89s Ellerslie) Heartland project  
ALTALINK 01-Feb-14 08:00 28-Apr-14 08:00 86 Days
Continuous		 102s R7 (102s Langdon) move reactors from 102s to 520s - affects 1201L reclosing - WATL  
ALTALINK 03-Feb-14 10:30 25-Mar-14 17:30 51 Days
Continuous		 935L (324s Cassils - 356s Milo) re conductor STR’s #87 to #104  
ALTALINK 24-Feb-14 09:00 20-Mar-14 17:00 25 Days
Continuous		 310p 1952 (310p Sundance) replace breaker, CTs, breaker fail relay  
ENMAX 01-Mar-14 08:00 31-Mar-14 16:00 31 Days
Continuous		 38.1C (ENMAX 38) low SF6 (forced outage) AB-BC
ENMAX 01-Mar-14 08:00 31-Mar-14 16:00 31 Days
Continuous		 14.1C (ENMAX 14), 14.2C (ENMAX 14) forced outage AB-BC
ALTALINK 05-Mar-14 07:00 15-Apr-14 17:00 42 Days
Continuous		 1003L (74s Janet - ENMAX 25) L to J: 1003L rebuild L9 diameter - new switchs, CT, CVT - P&C, SCADA & Telecom.  
ALTALINK 05-Mar-14 07:30 15-May-14 17:00 72 Days
Continuous		 1071L (103s Goose Lake - 205s Castle Rock Ridge) string new 1071L & 994L to 312s Fidler.  
ALTALINK 06-Mar-14 07:30 17-Mar-14 19:00 12 Days
Continuous		 903L (17s Benalto - 320p Keephills) string 1325L over 903L & 190L - WATL AB-BC
ALTALINK 12-Mar-14 08:00 28-Mar-14 12:00 17 Days
Continuous		 1036L (370s North Lethbridge - 356s Milo) Re-terminate at 554s Travers - BSR  
ALTALINK 15-Mar-14 06:30 15-Mar-14 15:00 8.5 Hours
Daily		 74s C3 (74s Janet), 74s C4 (74s Janet), 74s T2 (74s Janet) L to J project. De- energize: Create open point for bus construction expansion and re-energize T2. AB-BC
ENMAX 17-Mar-14 08:00 19-Mar-14 16:00 3 Days
Continuous		 25s Bus SW/MD Mtce (151, 150, 149, 145, 137, 131)  
ALTALINK 17-Mar-14 13:00 18-Mar-14 14:00 25 Hours
Continuous		 89s1552 - GOI 240kV Breaker Maintenance  
ALTALINK 19-Mar-14 08:00 19-Mar-14 12:00 4 Hours
Daily		 250p11 (250s Bighorn) maintenance  
ALTALINK 19-Mar-14 08:00 19-Mar-14 17:00 9 Hours
Daily		 74s2252 - GOI oil leak on grading caps  
ALTALINK 19-Mar-14 12:00 19-Mar-14 16:00 4 Hours
Daily		 250p22 (250p Bighorn) maintenance  
ALTALINK 20-Mar-14 08:30 20-Mar-14 09:00 30 Mins
Daily		 310p2552 Advice Trip test from 310p1952 new breaker fail relay  
ALTALINK 20-Mar-14 10:00 20-Mar-14 10:30 30 Mins
Daily		 310p2252 Advice Trip test from 310p1952 new breaker fail relay  
ALTALINK 20-Mar-14 11:00 20-Mar-14 11:30 30 Mins
Daily		 310p1652 Advice Trip test from 310p1952 new breaker fail relay  
ALTALINK 20-Mar-14 12:00 20-Mar-14 12:30 30 Mins
Daily		 310p1352 Advice Trip test from 310p1952 new breaker fail relay  
ALTALINK 20-Mar-14 13:00 20-Mar-14 13:30 30 Mins
Daily		 310p1052 Advice Trip test from 310p1952 new breaker fail relay  
ALTALINK 20-Mar-14 14:00 20-Mar-14 14:30 30 Mins
Daily		 310p752 Advice Trip test from 310p1952 new breaker fail relay  
ALTALINK 20-Mar-14 15:00 20-Mar-14 15:30 30 Mins
Daily		 310p452 Advice Trip test from 310p1952 new breaker fail relay  
ALTALINK 20-Mar-14 16:00 20-Mar-14 16:30 30 Mins
Daily		 310p152 Advice Trip test from 310p1952 new breaker fail relay  
ALTALINK 20-Mar-14 17:00 20-Mar-14 17:30 30 Mins
Daily		 310p2852 Advice Trip test from 310p1952 new breaker fail relay  
ALTALINK 20-Mar-14 17:30 20-Mar-14 19:00 90 Mins
Daily		 922L (310p Sundance - 17s Benalto) Trip test to 310p2052, energize new 310p1952 & CTs AB-BC
EPCOR 24-Mar-14 08:00 28-Mar-14 16:00 5 Days
Continuous		 805S Trans #3 CVT Replacement  
ALTALINK 24-Mar-14 10:00 27-Mar-14 15:00 4 Days
Continuous		 905L (19s - 37s) GOI Conductor Repair  
ALTALINK 25-Mar-14 08:00 27-Mar-14 17:00 3 Days
Continuous		 17s6 - GOI 240kV breaker maintenance  
ALTALINK 27-Mar-14 08:00 27-Mar-14 14:00 6 Hours
Daily		 283s31 (C1) - GOI 138kV Breaker Maintenance  
ALTALINK 27-Mar-14 08:00 27-Mar-14 17:00 9 Hours
Daily		 77s T2 TX18521 - GOI T2 Maintenance  
ALTALINK 30-Mar-14 08:00 31-Mar-14 16:00 2 Days
Continuous		 1005L (120s - 356s) GOI Remove temporary bypass - BSR  
ALTALINK 31-Mar-14 08:00 11-Apr-14 16:00 12 Days
Continuous		 83s T1 & 25kV Bus 1 GOI Replace various switches, LAs, insualtors  
ENMAX 01-Apr-14 08:00 02-Apr-14 16:00 2 Days
Continuous		 162B240-RB136 Dashpot maint on 162B240-RB136  
ALTALINK 01-Apr-14 09:00 01-Apr-14 17:00 8 Hours
Daily		 650s70 & T3 - GOI 650s70 Replace Latch  
ATCO 02-Apr-14 08:00 06-Apr-14 18:00 5 Days
Continuous		 9L57 CONNECT LINES9L57 TOBIRCHWOOD (LINES WILL NOT BE CONNECTED INTO BIRCHWOOD A BYPASS WILLBE INSTALLED)  
ENMAX 03-Apr-14 08:00 03-Apr-14 16:00 8 Hours
Continuous		 1080L Maint 65MD240-1080, SW 133, SW134  
ENMAX 05-Apr-14 08:00 07-Apr-14 16:00 3 Days
Continuous		 917L Activity  
ALTALINK 07-Apr-14 08:00 08-Apr-14 17:00 2 Days
Continuous		 305s 138kV West Bus (712L, C1) & 739L GO Replace 305s1, create open point 'A', repair 305s24 hotspot  
ALTALINK 07-Apr-14 14:00 07-Apr-14 17:00 3 Hours
Daily		 72s852 - GOI 240kV Breaker Maintenance  
ALTALINK 08-Apr-14 08:00 10-Apr-14 17:00 3 Days
Continuous		 28s41 - GOI 240kV breaker maintenance  
ALTALINK 08-Apr-14 08:00 10-Apr-14 17:00 3 Days
Continuous		 17s9 - GOI 240kV breaker maintenance  
ALTALINK 09-Apr-14 08:00 14-Apr-14 17:00 6 Days
Continuous		 305s 138kV East Bus & 739L (C1) GOI Replace 305s3 & 305s4, repair 305s23 hotspot  
ALTALINK 09-Apr-14 09:00 09-Apr-14 17:00 8 Hours
Daily		 818s17 (C1) - GOI Investigate C2 Alarm  
ALTALINK 10-Apr-14 08:00 10-Apr-14 12:00 4 Hours
Daily		 405s17 (C1)- GOI Cap Bank Blown Fuse  
ALTALINK 10-Apr-14 09:00 10-Apr-14 17:00 8 Hours
Daily		 149s 858L & T1 - GOI T1 Bushing Check & 149s1 Mech Repairs  
ALTALINK 12-Apr-14 08:00 13-Apr-14 17:00 2 Days
Continuous		 38sT4 (Tx18247) GOI Replace breaker control module on 38s18  
ALTALINK 15-Apr-14 08:00 15-Apr-14 17:00 9 Hours
Daily		 59s952 - GOI 240kV breaker maintenance  
ALTALINK 15-Apr-14 08:00 15-Apr-14 17:00 9 Hours
Daily		 305s 138kV West Bus (712L, 739L, C1) GOI Close open point 'A'  
ALTALINK 15-Apr-14 08:01 15-Apr-14 17:00 9 Hours
Daily		 74s C3 (74s Janet), 74s C4 (74s Janet), 74s T2 (74s Janet) L to J project. De-enrgize T2: Close open point for B2 bus construction expansion and re-energize AB-BC
ALTALINK 16-Apr-14 08:00 16-Apr-14 13:00 5 Hours
Daily		 151s C1 (151s Strathmore) 151s44: Migrate breaker control, status, alarms to new SCADA RTU system  
ALTALINK 17-Apr-14 07:30 02-May-14 09:00 16 Days
Continuous		 937L (102s Langdon - 74s Janet) Move line from old 102s 240 kV Bus to new 102s 240 kV Bus - WATL AB-BC
ALTALINK 22-Apr-14 10:00 24-Apr-14 17:00 3 Days
Continuous		 89s452 - GOI 240kV Breaker Maintenance  
ALTALINK 23-Apr-14 07:30 24-Apr-14 18:00 2 Days
Continuous		 1201L (102s Langdon - BCH), 1113L & 102s SVC (affects 1201L) GOI affects 1201L; connect new 102s 240 kV bus to 1113AL - WATL AB-BC
ALTALINK 26-Apr-14 08:00 27-Apr-14 17:00 2 Days
Continuous		 38s 240kV Bus 1, 138kV Bus 1& T1 GOI Replace 38s31, repair 38s98, maintain T1  
ALTALINK 26-Apr-14 08:00 27-Apr-14 17:00 2 Days
Continuous		 648s Partial 138kV Bus & 954L - GOI Breaker and Switch Maintenance  
ALTALINK 28-Apr-14 07:30 01-May-14 18:00 4 Days
Continuous		 1201L (102s Langdon - BCH) Re-terminate 1201L at 520s (permanent) - WATL AB-BC
ALTALINK 28-Apr-14 08:00 30-Apr-14 17:00 3 Days
Continuous		 37s T6 (Tx18309) GOI Replace 138 & 240kV Tx bushings  
ALTALINK 28-Apr-14 12:00 01-May-14 17:00 4 Days
Continuous		 89s852 - GOI 240kV Breaker Maintenance  
ALTALINK 01-May-14 08:00 01-May-14 14:00 6 Hours
Daily		 69s45 & 913L - GOI 69s45 Hot Spot  
ALTALINK 01-May-14 09:00 01-May-14 17:00 8 Hours
Continuous		 217s 138kV 1/2 Bus (80L, 768L, C1, T7) - TX and cap bank maintenance  
ALTALINK 02-May-14 08:00 09-May-14 18:00 8 Days
Continuous		 924L (102s - 356s) GOI Move line from old 102s 240 kV Bus to new 102s 240 kV Bus - WATL  
ALTALINK 05-May-14 07:30 05-May-14 13:00 5.5 Hours
Daily		 914L (86s Bigstone - 89s Ellerslie) SCADA Equipment Upgrade AB-BC
ALTALINK 05-May-14 07:30 16-May-14 18:00 12 Days
Continuous		 1209L (89s Ellerslie - 330p Genesee) Epcor Sunnybrook Project; ***outage duration is under review with the TFO’s and may be shortened as we get closer to the date*** AB-BC
ALTALINK 06-May-14 07:30 06-May-14 13:00 5.5 Hours
Daily		 914L (86s Bigstone - 89s Ellerslie) SCADA Equipment Upgrade AB-BC
ALTALINK 10-May-14 08:00 16-May-14 18:00 7 Days
Continuous		 927L (102s - 356s) GOI Move line from old 102s 240 kV Bus to new 102s 240 kV Bus - WATL  
ALTALINK 13-May-14 08:00 13-May-14 14:00 6 Hours
Daily		 86s T1(TX18491) - GOI SCADA Equipment Upgrade  
ALTALINK 17-May-14 08:00 04-Jun-14 18:00 19 Days
Daily		 1212L(89s-12s) G.O.I. EATL Interface: Line move.  
ALTALINK 20-May-14 07:30 27-May-14 18:00 8 Days
Continuous		 936L (102s Langdon - 74s Janet) Move line from old 102s 240 kV Bus to new 102s 240 kV Bus - WATL AB-BC
ALTALINK 26-May-14 13:00 29-May-14 17:00 4 Days
Continuous		 902L (19s-310P) - GOI 138kV Breaker Maintenance & Hot Spots  
ALTALINK 29-May-14 07:00 29-May-14 19:00 12 Hours
Daily		 1053L (132s Ware Junction - 324s Cassils) EATL interface: ATCO installing 13L50 Str # 1327.  
ALTALINK 31-May-14 07:00 15-Jun-14 18:00 16 Days
Daily		 1206L(89s-12s) G.O.I. EATL Interface:  
ATCO 01-Jun-14 07:00 02-Jun-14 18:00 2 Days
Continuous		 9L27 9L27 GOI TO SET RIDER POLES FOR EATL XING AT NW 8 40 14 W4  
ATCO 09-Jun-14 07:00 10-Jun-14 18:00 2 Days
Continuous		 9L27 9L27 GOI TO REMOVE RIDER POLES FOR EATL XING AT NW 8 40 14 W4W4  
ALTALINK 10-Jun-14 08:00 10-Jun-14 14:00 6 Hours
Daily		 650s T1(TX18691) - GOI SCADA Equipment Upgrade  
ALTALINK 14-Jun-14 07:00 19-Jul-14 18:00 36 Days
Continuous		 1034L(324s-244s)GOI EATL Interface: Line cut in and out.  
ALTALINK 14-Jun-14 07:00 25-Jul-14 18:00 42 Days
Continuous		 1088L(OLD 1035L)(324s-Newell)GOI EATL Interface: Line cut into Newell and commission.  
ALTALINK 14-Jun-14 07:00 07-Aug-14 18:00 55 Days
Continuous		 1035L(324s-244s)GOI EATL Interface: Line cut in and out.  
ALTALINK 15-Jun-14 07:00 20-Jun-14 18:00 6 Days
Continuous		 925L (63s Red Deer - 74s Janet) L to J : Replace 74s21N, PTs, CTs and footings. AB-BC
ALTALINK 21-Jun-14 07:00 26-Jun-14 18:00 6 Days
Continuous		 901L (63s Red Deer - 74s Janet) L to J : Replace 74s24N, PTs, CTs and footings. AB-BC
ENMAX 26-Jun-14 08:00 30-Jun-14 16:00 5 Days
Continuous		 5sT2 Tie into 138KV GIS @ 2s  
ALTALINK 14-Jul-14 08:00 14-Jul-14 13:00 5 Hours
Daily		 77s14 - GOI SCADA Equipment Upgrade  
ALTALINK 15-Jul-14 08:00 15-Jul-14 13:00 5 Hours
Daily		 275s1752 - GOI SCADA Equipment Upgrade  
ALTALINK 15-Jul-14 08:00 15-Jul-14 13:00 5 Hours
Daily		 77s48 - GOI SCADA Equipment Upgrade  
ALTALINK 15-Jul-14 13:00 15-Jul-14 14:00 60 Mins
Daily		 919L (77s-310p) - Advice SCADA Equipment Upgrade  
ALTALINK 16-Jul-14 08:00 16-Jul-14 13:00 5 Hours
Daily		 77s40 - GOI SCADA Equipment Upgrade  
ALTALINK 16-Jul-14 08:00 16-Jul-14 13:00 5 Hours
Daily		 275s1852 - GOI SCADA Equipment Upgrade  
ALTALINK 16-Jul-14 13:00 16-Jul-14 14:00 60 Mins
Daily		 938L (77s-A809s) - Advice SCADA Equipment Upgrade  
ALTALINK 16-Jul-14 13:30 16-Jul-14 14:30 60 Mins
Daily		 951L (275s-132s) - Advice SCADA Equipment Upgrade  
ALTALINK 19-Jul-14 07:00 22-Jul-14 18:00 4 Days
Continuous		 935L(356s-324s)GOI EATL Interface: Relocate to original tower.  
ALTALINK 21-Jul-14 08:00 21-Jul-14 13:00 5 Hours
Daily		 77s29 - GOI SCADA Equipment Upgrade  
ALTALINK 22-Jul-14 08:00 22-Jul-14 13:00 5 Hours
Daily		 77s26 - GOI SCADA Equipment Upgrade  
ALTALINK 22-Jul-14 08:00 22-Jul-14 13:00 5 Hours
Daily		 275s1952 - GOI SCADA Equipment Upgrade  
ALTALINK 22-Jul-14 13:00 22-Jul-14 14:00 60 Mins
Daily		 989L (77s-310p) - Advice SCADA Equipment Upgrade  
ALTALINK 22-Jul-14 13:30 22-Jul-14 14:30 60 Mins
Daily		 1002L (275s-163s) - Advice SCADA Equipment Upgrade  
ALTALINK 23-Jul-14 07:00 28-Jul-14 18:00 6 Days
Continuous		 923L(356s-324s)GOI EATL Interface: Line cut in.  
ALTALINK 23-Jul-14 07:00 31-Jul-14 18:00 9 Days
Continuous		 1087L(OLD 923L)(324s-Newell)GOI EATL Interface: Line cut in and commission.  
ALTALINK 23-Jul-14 08:00 23-Jul-14 13:00 5 Hours
Daily		 77s51 - GOI SCADA Equipment Upgrade  
ALTALINK 23-Jul-14 08:00 23-Jul-14 13:00 5 Hours
Daily		 275s2 - GOI SCADA Equipment Upgrade  
ALTALINK 28-Jul-14 08:00 28-Jul-14 13:00 5 Hours
Daily		 77s54 - GOI SCADA Equipment Upgrade  
ALTALINK 29-Jul-14 08:00 29-Jul-14 13:00 5 Hours
Daily		 275s5 - GOI SCADA Equipment Upgrade  
ALTALINK 29-Jul-14 08:00 29-Jul-14 13:00 5 Hours
Daily		 77s57 - GOI SCADA Equipment Upgrade  
ALTALINK 29-Jul-14 13:00 29-Jul-14 14:00 60 Mins
Daily		 907L (77s-122s) - Advice SCADA Equipment Upgrade  
ALTALINK 29-Jul-14 13:30 29-Jul-14 14:30 60 Mins
Daily		 944L (275s-132s) - Advice SCADA Equipment Upgrade  
ALTALINK 29-Jul-14 14:00 29-Jul-14 15:00 60 Mins
Daily		 939L (77s-A809s) - Advice SCADA Equipment Upgrade  
ALTALINK 30-Jul-14 08:00 30-Jul-14 13:00 5 Hours
Daily		 275s8 - GOI SCADA Equipment Upgrade  
ALTALINK 30-Jul-14 13:30 30-Jul-14 14:30 60 Mins
Daily		 945L (275s-562s) - Advice SCADA Equipment Upgrade  
ALTALINK 03-Aug-14 07:00 10-Aug-14 18:00 8 Days
Continuous		 942L (71s Lamoureux - 13s Deerland) EATL interface: ATCO deadline crossing for 13L50  
ALTALINK 03-Aug-14 07:00 10-Aug-14 18:00 8 Days
Continuous		 943L (13s Deerland - 108s Amelia) EATL interface: ATCO deadline crossing for 13L50  
ALTALINK 06-Aug-14 08:00 06-Aug-14 15:00 7 Hours
Daily		 275s T1(TX18457) - GOI SCADA Equipment Upgrade  
ALTALINK 12-Aug-14 08:00 12-Aug-14 13:00 5 Hours
Daily		 77s552 - GOI SCADA Equipment Upgrade  
ALTALINK 12-Aug-14 08:00 12-Aug-14 15:00 7 Hours
Daily		 275s T2(TX18458) - GOI SCADA Equipment Upgrade  
ENMAX 14-Aug-14 08:00 27-Aug-14 16:00 14 Days
Continuous		 917L 23s flyover with 2-240 ccts.  
ALTALINK 19-Aug-14 08:00 19-Aug-14 14:00 6 Hours
Daily		 77s T1(TX18372) - GOI SCADA Equipment Upgrade  
ALTALINK 20-Aug-14 08:00 20-Aug-14 14:00 6 Hours
Daily		 77s T2(TX18521) - GOI SCADA Equipment Upgrade  
ATCO 25-Aug-14 08:30 29-Aug-14 15:30 5 Days
Continuous		 840S McNeill Station McNeill 2014 FALL Turn Around. AB-SK
ENMAX 01-Sep-14 08:00 01-Feb-15 16:00 154 Days
Continuous		 65.1TR FATD, Check reversing sw, Doble, Oil sample LTC  
ALTALINK 05-Sep-14 08:00 02-Oct-14 16:00 28 Days
Continuous		 5s C1 (5s East Calgary), 5s C2 (5s East Calgary) ECTP 2s, Swap AIS to GIS AB-BC
ALTALINK 16-Sep-14 07:30 30-Sep-14 18:00 15 Days
Continuous		 74s C3 (74s Janet), 74s C4 (74s Janet), 74s T2 (74s Janet) Janet to Langdon project. Tie in South Bus Extension. AB-BC
ALTALINK 17-Sep-14 08:00 17-Sep-14 14:00 6 Hours
Daily		 473c102 (C1) - GOI SCADA Equipment Upgrade  
ALTALINK 28-Sep-14 07:30 09-Oct-14 18:00 12 Days
Continuous		 1203L (320p Keephills - 330p Genesee) Cut in/out of 510s - WATL. ***outage duration is under review with the TFO’s and may be shortened as we get closer to the date*** AB-BC
ALTALINK 29-Sep-14 08:00 05-Jan-15 18:00 99 Days
Continuous		 5s T1 and 240KV Bus GOI East Calgary 5S – Replace existing TXMER with new.  
ALTALINK 01-Oct-14 08:00 15-Oct-14 18:00 15 Days
Continuous		 74s T1 and 240 kV Bus 1 GOI Janet to Langdon project. Tie in North Bus Extension.  

AB-BC, AB-SK & AB-MATL: refer to AESO web posting: http://itc.aeso.ca/itc/public/atcQueryInit.do
Also,
AB-BC, AB-SK & AB-MATL: refer to ISO Rule 203.6: http://www.aeso.ca/rulesprocedures/18592.html

Prepared On: 2014-03-05   4:51:00 PM


This document and the information contained herein are based upon information and data which by their nature contain a degree of uncertainty and are subject to change. In addition, this document may contain information and data from public sources and/or third parties, which have been assumed to be accurate and complete and have not been verified. Accordingly, the Independent System Operator, operating as the Alberta Electric System Operator (the "AESO") makes no warranty, representation or guarantee, express or implied, with respect to this document or the information contained herein, including, but not limited to, any warranty, representation or guarantee of accuracy, completeness, timeliness, reliability, availability, absence of computer virus, non- infringement, merchantability or suitability for any purpose. Under no circumstances will the AESO, its members, officers, employees, contractors or agents, or any of their respective affiliates, be liable for any errors or omissions in, or any losses, damages or claims whatsoever, whether in contract, tort or otherwise, arising from use of or reliance upon, this document or any information contained herein.

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