Susceptibility to pollution can be related to the flushing capacity of aquatic systems. Transport time scales constitute a useful tool for representing the water exchange and transport processes. A new transport time scale, recovery time, and a methodology to estimate it by means of numerical models is hereby developed.
View Article and Find Full Text PDFThe approval of the current Bathing Water Directive (Directive 2006/7/EC) set the necessity to define the bathing water profile. The goals established in the definition of the profile are: (i) to know the processes that determine the concentration of bacteriological indicators in the aquatic environment, (ii) to obtain relationships between the cause of pollution and its effects, and (iii) to evaluate the fulfilment of the Directive and to set the Quality Monitoring and Assessment Program, according to the bacteriological characteristics of the bathing water. In this paper an approach to elaborate the bathing water profile and its application to several bathing waters located in Santander municipality (North Spain) is shown.
View Article and Find Full Text PDFData on the 95th and 90th percentiles of bacteriological quality indicators are used to classify bathing waters in Europe, according to the requirements of Directive 2006/7/EC. However, percentile values and consequently, classification of bathing waters depend both on sampling effort and sample-size, which may undermine an appropriate assessment of bathing water classification. To analyse the influence of sampling effort and sample size on water classification, a bootstrap approach was applied to 55 bacteriological quality datasets of several beaches in the Balearic Islands (Spain).
View Article and Find Full Text PDFSince the flushing time is a physical descriptor used to distinguish between different types of heavily modified water bodies (HMWB), the establishment of a methodology for its calculation becomes important. In order to achieve this task, a methodological procedure involving the tide mean value and variable river flow values is proposed. The hydrodynamics were assessed using a two-dimensional model which integrates the depth-averaged mass and momentum equations in the time and space domains and includes a wet-dry point treatment method.
View Article and Find Full Text PDFThe city of Santander ceased the discharge of sewage effluents into the bay of Santander in June, 2001 and began discharging at a site 2.4 km offshore in the nearby coastal area (Virgen del Mar, Bay of Biscay) at a water depth of about 40 m. The present study investigates the effects of the new outfall discharges on the water quality of the high-energy coastal area and the recovery of the perturbed temperate estuarine area now only affected by combined sewer overflows (CSOs).
View Article and Find Full Text PDFAn investigation on the effects of deepwater outfall discharges on the status of rocky reef communities was carried out. The sanitation system was found to be an environmentally suitable option for the protection of those habitats situated in high energy coastal environments. Sediments occurring between the predominating rocky substrates showed low values of the fine fraction (<63microm) and organic matter content.
View Article and Find Full Text PDF