30 C.F.R. § 778.22
The plans of a facility or structure that is to be shared by two or more separately permitted mining operations may be included in one permit application and referenced in the other applications. In accordance with part 800 of this chapter, each permittee shall bond the facility or structure unless the permittees sharing it agree to another arrangement for assuming their respective responsibilities. If such agreement is reached, then the application shall include a copy of the agreement between or among the parties setting forth the respective bonding responsibilities of each party for the facility or structure. The agreement shall demonstrate to the satisfaction of the regulatory authority that all responsibilities under this chapter for the facility or structure will be met.
30 C.F.R. § 778.22