GREC Unit 2 to Unit 1 IPB Interconnection for Grand River Energy Center Amendment 2 to Solicitation RFP 8634 U1 U2 ISO Phase changes the following Q&A from 11 March 2026 10:00 AM CST to 19 March 2026 12:00 PMCST. ALL QUESTIONS MUST BE PROCESSED THROUGH BID EXPRESS. NONE WILL BE ACCEPTED THROUGH EMAIL, FAX, PHONE, OR TEXT SINCE THIS IS A SEALED BID PROCESS. Bid Due date from 18 March 2026 8:00 AM CST to 1 Apr 2026 2:00 PM CST. ALL BIDS MUST BE PROCESSED THROUGH BID EXPRESS. NONE WILL BE ACCEPTED THROUGH EMAIL, FAX, PHONE, OR TEXT SINCE THIS IS A SEALED BID PROCESS. You must register with Bid Express to view the RFP Packet. It costs $50.00 to upload a proposal. No other changes at this time. Amendment 1 to Solicitation RFP 8634 U1 U2 ISO Phase changes the following A new Non-Mandatory Site Visit is being added for 5 March 2026 1:00 PM CST. LOCATION: Grand River Energy Center – TSE Building – 8142 Hwy 412B Chouteau, OK 74337. Please procced to check in at South Gate Entrance. Procurement Officer will meet attendees at the South Gate Entrance and escort attendees to the TSE Building. Please wear appropriate PPE i.e. FR clothing, Safety Toe Shoes, Ear Protection, and Hard Hats. A Sign In Sheet will be provided and Required. Please respond that you will be or your company will be sending someone to attend. Q&A from 10 February 2026 10:00 AM CST to 11 March 2026 12:00 PMCST. ALL QUESTIONS MUST BE PROCESSED THROUGH BID EXPRESS. NONE WILL BE ACCEPTED THROUGH EMAIL, FAX, PHONE, OR TEXT SINCE THIS IS A SEALED BID PROCESS. Bid Due date from 16 February 2026 8:00 AM CST to 18 March 2026 2:00 PM CST. ALL BIDS MUST BE PROCESSED THROUGH BID EXPRESS. NONE WILL BE ACCEPTED THROUGH EMAIL, FAX, PHONE, OR TEXT SINCE THIS IS A SEALED BID PROCESS. You must register with Bid Express to view the RFP Packet. It costs $50.00 to upload a proposal. No other changes at this time. ***PLEASE NOTE*** There will be a Non-Mandatory Pre-Bid Meeting/Site Visit on Thursday, February 5, 2026, 12:00pm Central Time—LOCATION: Grand River Energy Center – TSE Building – 8142 Hwy 412B Chouteau, OK 74337.  Please procced to check in at South Gate Entrance.  Procurement Officer will meet attendees at the South Gate Entrance and escort attendees to the TSE Building.  Please wear appropriate PPE i.e. FR clothing, Safety Toe Shoes, Ear Protection, and Hard Hats. A Sign In Sheet will be provided and Required.

Rental - GREC Mobile Demineralization/Reverse Osmosis Trailer (as needed) A mandatory job site examination / pre-bid meeting for prospective Bidders will be held on April 7, 2026 at the Grand River Energy Center (GREC), 8142 Hwy 412B Chouteau, OK 74337, at 10:30 AM Central Time. Failure of a prospective Bidder to attend will disqualify them from being able to submit a bid. All statements made by GRDA at the job site examination meeting are informational only, and the terms of the final Contract (if any) between GRDA and the prevailing Bidder will control.