The use of control engineering in the case of wastewater treatment processes can be an effective measure in the improvement of the treatment plants' performance. This paper presents the implementation and evaluation of control solutions for wastewater treatment plants taking into consideration the hypothesis that the plant can be structured as having two operating lines: a water line and a sludge line. For the water line there are proposed four control strategies, and for the sludge line there are considered four control actions. After an initial evaluation of the control strategies used for the water line by comparison with a default closed-loop strategy, the paper shows the influence of each control action of the sludge line over the considered evaluation indicators. The evaluation is presented for all the water line control strategies, trying to check the generality of the initial hypothesis. The results are validated using the Benchmark Simulation Model No. 2. The simulation results showed that the control strategies implemented for the water line act mainly on the global integral indicators and the control actions implemented for the sludge line act mainly on the acute effects.