Fertiliser loads applied (AR: nitrate, phosphate), with the percentage (α) that reaches the natural water bodies (WFIA-FS), and the concentrations of pollutants considered (ceff: nitrate, phosphate) in the irrigation returns (WFIA-ES).

Maximum acceptable pollutant concentrations (cmax) specified in the Spanish law (WFIA-FS and WFIA-ES). Natural concentrations (cnat) are the measurements in the unaltered water bodies in the SRB.