Purchase Credits or Request a Quote..... The Tye River Mitigation Bank (TRMB) of central Virginia is pleased to announce its final federal and state approvals by the Virginia Inter-Agency Review Team (IRT).  The fully permitted mitigation project occupies approximately 440 acres southeast of Arrington, in Nelson County, Virginia, and offers highest-quality stream mitigation credits. If you have any questions regarding current or future credit availability please feel free to contact us.