Author(s): E. Arasaki; J. P. Ortiz; C. C. Lamparelli; J. E. Bevilacqua; H. J. And Bressan
Linked Author(s): Jayme P. Ortiz
Keywords: Submarine outfalls; Monitoring; Plume visualization; Sao Paulo State; Brazil
Abstract: The coast of Sao Paulo State has a set of seven submarine outfalls operated by SABESP (Sao Paulo State Basic Sanitation Company), mainly discharging domestic wastewater. The effluent is previously treated in preconditioning plants, receiving preliminary treatment and clorination dosage before the discharge. Each submarine outfall has an operation license, but its renovation depends on the performance in relation with water quality standard. Actually, CETESB (Environmental Sanitation Technology Company) attached to the State Environmental Secretariat, intends monitoring these discharges in the ocean, and is developing with Polytechnic School, University of Sao Paulo, technologies for detect and visualize the plume. The present paper shows preliminary results obtained with two oceanographic campaigns realized by CETESB. The first sampling was made during the summer (February/2002), period with maximum sewage flows, in the area of Praia Grande outfall, using sounding equipment. The second sampling was carried out in Santos Bay (August/2002) with conductivimetry, around the visible plume discharged by the submarine outfall. For each area, some water samples was taken to verify faecal coliform and salinity profile in each station. Salinity data was used to verify the plume format, through the software Tecplot. Initial results demonstrate that it is possible to draw the plume, since the data had been sampled in regular grid (with few gaps), permitting utilize as tool for decision makers.
Year: 2003