; or (C) other similar practices, as determined by the Secretary. (3) Conversion to a solid separation system in which manure solids are separated prior to entry into a wet, anaerobic environment at a dairy or livestock operation, or installation of a new solid separation system with significantly higher separation efficiency than the existing solid separation system, in conjunction with one or more of the following practices: (A) Open solar drying or composting of manure onsite. (B) Solar drying in an enclosed environment. (C) Forced evaporation with natural-gas fueled dryers. (D) Storage of manure in unconfined piles or stacks. (E) Composting in an enclosed vessel, with forced aeration and continuous mixing. (F) Composting in piles with forced aeration but no mixing. (G) Composting in intensive windrows with regular turning for mixing and aeration. (H) Composting in passive windrows with infrequent turning for mixing and aeration. (4) Scrape conversion in conjunction with one of the practices listed in paragraph (3). (e) Term A contract under the program shall have a term that does not exceed 3 years. (f) Payments (1) Availability of payments Payments provided to an eligible producer under this section may be used to implement one or more practices described in subsection (d). (2) Payment amounts The Secretary may provide a payment to an eligible producer under the program for an amount that is up to 100 percent of the costs associated with planning, design, materials, equipment, installation, labor, management, maintenance, and training related to implementing a practice described in subsection (d). (3) Limitation on payments A person or legal entity (including a joint venture and a general partnership) may not receive, directly or indirectly, payments under the program that exceed $750,000 during any 5-year period. (4) Advanced payments The Secretary shall provide at least 50 percent of the amount of total payments to an eligible producer in advance for all costs related to purchasing materials and equipment