Assessment of attenuation of flows and diffuse pollution of detention pond at Guará II - DF

Abstract

The growth of urbanization results in an increase in diffuse pollution, which is difficult to measure. The runoff carries all the pollutants from anthropogenic activities to the receiving water, deteriorating the quality of it. As a compensatory technique to reduce the impacts of pollution and flow rates are the detention ponds, these are widely used in the Federal District. This research sought to analyze the efficiency of one of these urban drainage structures located in Guará II- DF, through quantitative and qualitative monitoring, collecting samples for the analysis of nutrients (nitrogen and phosphorus), organic matter and coliforms. Therefore, samples were collected at the entrance and outfall of the basin of a rainy event of March 2019, and these were analyzed in several parameters of water quality. The pond had a flow damping with efficiency greater than 96%, but it was not as efficient in reducing pollutants, which showed a small reduction in concentration between the entrance and the exit of the structure. It is concluded that the detention pond is a good alternative for the preservation of the support capacity of the water body that receives stormwater, however it could be more efficient in reducing the concentration of pollutants if it worked as a retention.