This is a Firm Fixed Price delivery order awarded by the Environmental Protection Agency's (EPA) Office of Research and Development to Tetra Tech, Inc., a global consulting and engineering firm. The $90,000.00 contract is for the development of a Biological Condition Gradient (BCG) for the Middle Rio Grande in New Mexico, which will be used to establish quantitative thresholds for the implementation of existing water quality criteria. This work is part of a larger effort to assess and set standards for non-wadeable rivers in New Mexico, which have been highly altered by dams, diversions, and channel modifications. The contract does not have a set-aside designation, reflecting Tetra Tech's status as a large business. As a prime contractor, Tetra Tech has extensive experience supporting the EPA across various environmental assessment, water quality, and climate change research programs through both contracts and grants.