(1) Form. Changes to bid documents shall be accomplished by addenda. The bidder shall acknowledge receipt of all addenda issued, either with the bid or separately prior to bid opening.

(2) Distribution. Addenda shall be sent to all prospective bidders known to have obtained the bid documents or attending any mandatory pre-bid conferences.

(3) Timeliness. Addenda shall be issued within a reasonable time (preferably five days prior to bid closing) to allow prospective bidders to consider them in preparing their bids, but in no case less than 48 hours before the bid opening. If necessary, the manager may notify prospective bidders electronically or by telephone, followed by a confirming written addendum.