(a)Time allowed. Except as provided in § 228.61(f) , § 228.62(b) , and elsewhere in this paragraph, a contract or permit may not exceed 1 year from the effective date of the contract or permit unless a written extension is obtained. For those mineral materials sold under a duration of production contract or under a contract for the sale of all mineral material within a specified area, or under a construction contract where removal cannot reasonably take place before completion of other work under the same contract, the authorized officer will establish a reasonable time period for removal.(b)Extension of time. If it is shown that a delay in removal was due to causes beyond the control of the purchaser or permittee, the authorized officer may grant an extension, not to exceed 1 year, upon written request. Written requests for extensions of contracts must be received between 30 and 90 days before the expiration date of the contract. Written requests for extensions of permits must be received between 15 and 90 days before the permit expiration date. The authorized officer may grant a total of two extensions for contracts and permits.