The term efficiency in hydraulic transport system design and operation has several possible interpretations. Whether it may stand for energy consumption, it may also aim to the minimization of the water or the carbon footprint. All these tentative means of efficiency should meet project and operational goals, including throughput constraints. The consideration of these aspects altogether, seeking for best project and operational conditions, represents a major optimization problem which, on the other hand, depends on the evolution of input variables for slurry transport along with environmental, energy and water consumption costs. In this paper, an example of a long distance ore pipeline with plant demand-dependent inputs is studied in the light of the implementation of an optimization problem. Results have been compared with those corresponding to typical transport modes, and show that common operational conditions differ from those optimized in terms of system utilization, flow rate and slurry concentration. In particular, the optimal computed parameters include lower fractions of the total available times, lower flow rates and higher concentrations than in typical systems, thus suggesting a different design and operational rationale. (C) 2014 Elsevier Ltd. All rights reserved.