; (iv) energy transfer; (v) enhanced nutrient recovery; (vi) material feedstocks; (vii) facility upgrades and retrofits necessary to create or improve waste-to-energy systems; and (viii) other emerging technologies that transform waste to energy; and (B) a project that is being carried out pursuant to an existing plan that, as determined by the Secretary, will assist in tran­si­tion­ing a wastewater treatment facility towards the use of energy-efficient technologies. (3) Covered costs A guarantee provided under this subsection may be used for— (A) predevelopment costs associated with the eligible project or existing water and wastewater systems that are part of the eligible project, including energy assessments; and (B) construction and equipment costs incurred in carrying out an eligible project under this subsection. (4) Additional activity In providing guarantees under this subsection, the Secretary shall promote technologies to reduce pollution in wastewater, including enhanced nutrient recovery and other innovative technologies. (f) Small-Scale Extension Services Program In carrying out the Program, the Secretary shall establish a small-scale extension services program to provide assistance to rural communities through grants, outreach, training, and technical assistance regarding energy-efficient technologies at wastewater treatment facilities in eligible municipalities and Tribes. (g) Administration (1) Effect on State, Tribal, and local permits The provision of a grant or guarantee for an eligible project under the Program shall not— (A) relieve any recipient of the grant or guarantee of any obligation to obtain any required State, local, or Tribal permit or approval with respect to the project; (B) limit the right of any unit of State, local, or Tribal government to approve or regulate any rate of return on private equity invested in the project