in the most efficient manner practicable. (7) Facility operations costs The Secretary of Health and Human Services shall ensure that facilities utilized to provide care and custody of unaccompanied alien children are operated efficiently and at a rate of cost that is not greater than $500 per day for each child housed or detained at such facility, unless the Secretary certifies that compliance with this requirement is temporarily impossible due to emergency circumstances. . 325. Custody of unaccompanied alien children in formal removal proceeding (a) Custody of unaccompanied alien children Section 235(c) of the William Wilberforce Trafficking Victims Protection Reauthorization Act of 2008 ( 8 U.S.C. 1232(c) ) is amended— (1) in paragraph (2), by adding at the end the following: (C) Children in formal removal proceedings (i) Limitation on placement Notwithstanding any settlement or consent decree previously issued before date of enactment of the Building America’s Trust Act and section 236.3 of title 8, Code of Federal Regulations, or similar successor regulation, an unaccompanied alien child who has been placed in a proceeding under section 240 of the Immigration and Nationality Act ( 8 U.S.C. 1229a ) may not be placed in the custody of a nongovernmental sponsor or otherwise released from the immediate custody of the United States Government unless— (I) the nongovernmental sponsor is a biological or adoptive parent or legal guardian of the alien child