(a) For each registration submitted, the Executive Director shall determine the grandfathered quantity for each withdrawal source and consumptive use.

(b) In making a determination, the following factors should be considered:

(1) The withdrawal and use data and the peak consecutive 30-day average shown by the data;

(2) The reliability and accuracy of the data and/or the meters or measuring devices;

(3) Determination of reasonable and genuine usage of the project, including any anomalies in the usage;

(4) Whether the grandfathered amount includes an operational margin of safety; and

(5) Other relevant factors.

(c) The Executive Director, in lieu of a determination under paragraph (b) of this section, may accept a previous grandfathering determination by the Commission at the request of the project sponsor.