The report very briefly describes an intra-tidal-time, deterministic, one-dimensional, non-isothermal, multi-state-variable, water quality model for the Upper Delaware River Estuary system between Trenton and Wilmington. The unique features of the proposed model are associated with its time and space scales, which are of the order of 30 minutes and one mile, respectively, and its simultaneous state equation format, which included an ad hoc tidal velocity equation and conservation balances on dissolved oxygen, BOD, and thermal energy. Numerical routines using central differences for the space derivatives in combination with a fourth-order, Runge-Kutta expression for the time derivatives provided stable and accurate results for the integration of the system equations. (Modified author abstract)