In a recent study carry out by Mosteo et al.
(2013) in 5 different WWTP inside the Ebro River Basin, a marked
improvement in the bacteriological quality of the effluent was
observed” in those WWTP which provided a tertiary treatment,
were these microorganisms are removed by natural processes.
Therefore, if water reuse for agricultural uses is intended,
implementing a tertiary treatment is suggested.