(1) Initial written statements of position and written testimony with supporting affidavits on the admitted contentions. These materials must be filed on the dates set by the presiding officer;

(2) Written responses, rebuttal testimony with supporting affidavits directed to the initial statements and testimony of witnesses and other participants, and proposed written questions for the presiding officer to consider for submission to the persons sponsoring testimony under paragraph (a)(1) of this section. These materials must be filed within twenty (20) days of the service of the materials submitted under paragraph (a)(1) of this section unless the presiding officer directs otherwise;

(3) Written questions on the written responses and rebuttal testimony submitted under paragraph (a)(2) of this section, which the presiding officer may, in his or her discretion, require the persons offering the written responses and rebuttal testimony to provide responses. These questions must be filed within seven (7) days of service of the materials submitted under paragraph (a)(2) of this section unless the presiding officer directs otherwise; and

(4) Written concluding statements of position on the contentions. These statements shall be filed within twenty (20) days of the service of written responses to the presiding officer's questions to the participants or, in the absence of questions from the presiding officer, within twenty (20) days of the service of the materials submitted under paragraph (a)(2) of this section unless the presiding officer directs otherwise.