From a water resource to a point pollution source: the daily journey of a coastal urban stream

Abstract

The aim of this study was to understand how a stream ecosystem that flows from its fountainhead to its mouth inside a city, changes from a water resource to a point pollution source. A multidisciplinary descriptive approach was adopted, including the short-term temporal and spatial determination of physical, chemical, biological and ecotoxicological variables. Results showed that water quality rapidly decreases with increasing urbanization, leading the system to acquire raw sewage attributes even in the first hundred meters after the fountainheads. Despite the tidal circulation near the stream mouth being restricted by shallowness, some improvement of the water quality was detected in this area. The multidisciplinary evaluation showed to be useful for obtaining a more realistic understanding of the stream degradation process, and to forecast restoration and mitigation measures.

Contamination from an affluent of Furnas reservoir by trace metals

“…The United States Environment Protection Agency (USEPA) states that besides Pb, Cd and Zn, sewage discharges originated in urban areas can contain high concentrations of metals such as Cu, Cr, Ar, Ni, Sb and Se, as well as a serial organic pollutant (Rörig et al, 2007). However, metals can also be sourced in surface runoff, given that stormwater carries these contaminants from the urban environment to the drainage catchments, increasing its concentration (Rocha and Martin, 2005;Krissanakriangkrai et al, 2009).…”

“…However, metals can also be sourced in surface runoff, given that stormwater carries these contaminants from the urban environment to the drainage catchments, increasing its concentration (Rocha and Martin, 2005;Krissanakriangkrai et al, 2009). In literature were found several studies reporting high concentrations of Pb, Cd and Zn in water and sediment samples taken from water bodies located near urban and industrial regions (Rörig et al, 2007;Peres et al, 2009;Sekabira et al, 2010;Chiba et al, 2011).…”

Hidrologia do Saco da Fazenda, Itajaí, SC

“…Além do aspecto de balanço de massa de água para o saco, outro elemento importante de nota é quanto à qualidade da água aportada pelos pequenos tributários do saco. Rörig et al (2006) apresentam uma análise aprofundada do estado da qualidade ambiental da bacia hidrográfica do ribeirão Schneider. Neste trabalho onde foram levantadas diversas variáveis ambientais, constata-se o elevado estado de degradação ambiental na bacia, o que somado a inexistência de um sistema de captação e tratamento de esgotos torna estes cursos de água como cloacas urbanas.…”

“…Neste trabalho onde foram levantadas diversas variáveis ambientais, constata-se o elevado estado de degradação ambiental na bacia, o que somado a inexistência de um sistema de captação e tratamento de esgotos torna estes cursos de água como cloacas urbanas. Mais dos que tributários para o Saco da Fazenda, estes pequenos cursos de água atualmente são fontes poluidoras, segundo Rörig et al (2006).…”

Aquatic life protection index of an urban river Bacanga basin in northern Brazil, São Luís - MA

“…It reports water quality scenarios based on the trophic status of the environment, determine the degree of toxicity for the aquatic biota, and indicates deficiency in essential parameters for the protection of the aquatic life. Hence, the joint use of those methods helps understand degradation process of aquatic ecosystems and leads to more accurate conclusions (Rörig et al, 2007).…”