MOBILITY AND AQUATIC TOXICITY OF COPPER IN AN URBAN WATERSHED¹

Abstract

Abundant use of copper based products has resulted in increased violation of copper water quality criteria in runoff from urban storm water systems. The objectives of this work were to understand the mobility and toxicity of copper in an urban watershed and to apportion the amount of copper entering the freshwater receiving stream from different urban land covers using a mass balance approach. Sixteen rainfall events collected from the University of Connecticut study watershed between August 1998 and September 2000 were analyzed to assess copper flux in an urban storm water system. Mean flow weighted dissolved copper concentrations observed in the study for copper based architectural material runoff, pervious area runoff, impervious area runoff, and in the receiving stream were 1210 ± 840, 9 ± 3, 8 ± 2, and 14 ± 7 μg/L, respectively. Mean dissolved copper concentrations in the receiving stream exceeded Connecticut's water quality criteria. Despite exceeding the dissolved concentration based criteria, cupric ion concentrations at the system outlet remained below 0.05 μg/L for all storms analyzed, and no acute toxicity (using Daphnia pulex as the test organism) was measured in samples collected from the stream.

The interaction between concrete pavement and corrosion-induced copper runoff from buildings

“…Despite a high bioavailability at the immediate release situation, the total copper concentration in the runoff water and its bioavailable fraction undergo a vital and rapid reduction to background values upon environmental entry as a result of dilution, interaction with solid surfaces, organic matter and other complexing agents. This conclusion is supported by recent laboratory findings with soil (Bertling et al 2002(Bertling et al , 2006a and at field exposures when transport and changes in toxicity of coppercontaining runoff water were monitored from its source, the roof, to its recipient, a stream, distanced hundred meters away from the roof (Boulanger and Nikolaidis 2003).…”

“…Here the runoff water will be diluted with rainwater from other places such as roads, market places and roofs made of other materials. An approximate dilution with 100 times (Boulanger and Nikolaidis 2003) would reduce the cupric ion concentration in the runoff water to 0.0165 mg l −1 . The storm drains are often made of concrete and could end up in a lake or in a water purification plant.…”

Roof Runoff Water as Source of Pollution: A Case Study of Some Selected Roofs in Orlu Metropolis, Imo State, Nigeria

“…12 . The acidic nature of ambient rainwater may cause the chemical compounds (such as cadmium, copper, lead, zinc, and chromium) from roofing materials to leach into the harvested rainwater [30,31].…”

“…Roof runoff water has been identified as a major contributor to the pollution of streams, rivers and estuaries [3,4,5], resulting from increasing urbanization [6], since roof runoffs are discharged into the environment without being previously treated [7]. Roof surfaces in urban settlements contribute excess nutrients and toxic metals to receiving waters [8,9,10,11], and these surfaces could cover from 12% in residential areas to 21% in commercial areas [8,12]. This therefore increases the overall toxic burden of the environment [13].…”

Mobility of copper in greenhouse soils

“…However, both Cu deficiency and over-exposure may cause serious health disorders to humans [2]. The concentration upper limit of Cu in drinking water is 2 ppm and 2500 ppb in the soil [3]. The toxicity limits for a number of aquatic organisms are extremely low, in the order of 5 ppb [3]; therefore, any Cu concentrations above 5 ppb in groundwater may be responsible for * Corresponding author.…”