Environmental monitoring of the sanitation system of Santander(North Spain)

Field validation of modeling predictions for the new sanitation system of the Bay of Santander were carried out through the implementation of an objective-oriented Environmental Monitoring Program (EMP), which enclosed the control of water bodies, quality of sediments and ecological status of benthos communities in the areas affected by continuous (outfall) and sporadic (combined sewer overflows) discharges. Surveillance of salubrity of bathing waters, aesthetic deterioration, trophic status of the coastal and estuarine water bodies, benthic pollution effects and bioaccumulation were some of the preliminary environmental objectives adopted by the EMP. However, because of the adaptive design of the monitoring programs, case-specific modifications were introduced. In agreement with the predictions of the environmental design of the sanitation system, no significant effects of the outfall discharges in the quality of water, sediments and biological communities were detected and the recovery of estuarine ecosystems has already been initiated.