TDOT followed most applicable laws, regulations, and terms and conditions of the cooperative agreement in the procurement and monitoring of contracts for the TSE facilities-with the exception of the Buy American requirements of the Recovery Act. TDOT did not determine whether trusses used in the construction of TSE facilities by one contractor qualify as substantial transformation as defined in 2 CFR 176.160. This occurred because subsequent to the contract awards, EPA incorrectly determined that the Buy American requirements did not apply to the project. Consequently, there is no assurance that all iron, steel, or manufactured goods incorporated into the project were manufactured or substantially transformed in the United States, as required by Section 1605 of the Recovery Act. TDOT complied with the cooperative agreement requirements and satisfied Region 4 requirements for projecting results. However, TDOT overstated its results. This occurred because TDOT utilized significantly overestimated usage assumptions in its projections rather than current usage. As a result, TDOT does not have reasonable assurance that the TSE project will achieve projected emissions reductions, and the expected environmental results and human health benefits. Quarterly reporting of diesel emissions reductions by the DERA program may also be overstated."