; and (B) in which the livestock spend all or a substantial portion of time grazing on fields in which some or all of the manure is deposited and left in the field to decompose aerobically. (5) Solid separation system The term solid separation system means a system that is designed to separate liquid components of manure from mineral and organic solid components of such manure. (b) Establishment The Secretary shall establish an alternative manure management program to award contracts to eligible producers to support carbon sequestration and greenhouse gas emissions reductions by implementing covered management measures. (c) Submission of individual contract offers To be eligible to participate in the alternative manure management program, an eligible producer shall submit to the Secretary a contract offer that details any covered management measure to be used on the operation of such eligible producer. (d) Cluster contract offers The Secretary shall establish procedures under which— (1) a group of producers may submit a joint contract offer for a shared composting facility; and (2) the Secretary will allocate payments to each eligible producer associated with such joint contract. (e) Duties of Secretary (1) Evaluation criteria The Secretary shall develop criteria for evaluating and ranking contract offers to prioritize contract offers that will maximize— (A) carbon sequestration; (B) greenhouse gas emissions reductions