An exploratory study of urban runoff toxicity

Abstract

An exploratory study of urban runoff toxicity was undertaken at 14 urban sites, including two sites receiving runoff from major multi-lane divided highways (>100,000 vehicles·day−1). To assess various types of toxicity, a battery of tests was used including Daphnia magna, Microtox™, sub-mitochondrial particles, and the SOS Chromotest (for genotoxicity). The whole data set comprised almost 70 samples and 350 test results, which were reduced to toxicity point values using a toxicity scale. About two fifths of all data did not show any toxic responses, one fifth indicated severe toxicity, one fifth confirmed toxicity, and one fifth potential toxicity. When comparing urban stormwater toxicity to that of multi-lane divided highway (MLDH) runoff, the main difference was noted for the severe toxicity level; almost 20% of MLDH samples were severely toxic compared to 1% of urban stormwater samples. The MLDH data were obtained at the edge of the pavement, and although attenuation of runoff toxicity during transport can be expected, particularly in grassed swales, additional research is required.

Heavy metal concentrations and toxicity in water and sediment from stormwater ponds and sedimentation tanks

“…The toxic effects of stormwater have been studied by e.g. [15][16][17][18]. Depending on the drainage area and design, season, characteristics of the storm and time during a storm, stormwater can show both acute toxicity and genotoxicity [18].…”

“…[15][16][17][18]. Depending on the drainage area and design, season, characteristics of the storm and time during a storm, stormwater can show both acute toxicity and genotoxicity [18]. Highway runoff demonstrates the highest toxicity, particularly during the first flush stage and during winter conditions [18,19], with mixed land use showing lower toxicity [3,20].…”

“…Depending on the drainage area and design, season, characteristics of the storm and time during a storm, stormwater can show both acute toxicity and genotoxicity [18]. Highway runoff demonstrates the highest toxicity, particularly during the first flush stage and during winter conditions [18,19], with mixed land use showing lower toxicity [3,20]. Pitt et al [3] studied, under laboratory conditions, the reduction of stormwater toxicity by different treatment processes and found that settling, screening and aeration and/or photodegradation processes were the most efficient in reducing the toxicity.…”

“…Pitt et al [3] studied, under laboratory conditions, the reduction of stormwater toxicity by different treatment processes and found that settling, screening and aeration and/or photodegradation processes were the most efficient in reducing the toxicity. Studies of stormwater ponds have shown mixed results regarding the removal of toxicity with Collins et al [21] finding no significant toxicity reduction while Marsalek et al [18,19] found minor reduction of toxicity. However, Marsalek et al [19] observed that the sediment in the pond was very toxic and demonstrated a spatial decrease from the inlet to the outlet [22].…”

“…plankton (Daphnia magna) [18,19], water flea (Ceriodaphia dubia) [20], rotifers (Brachionus calyciflorus) [17], algae [24], fish [25] and SOS chromotest [18,19]. One of the most common test organisms is the luminescent bacteria Vibrio fischeri, because the test is rapid, easy to perform and cost-effective and there are no ethical implications [26,27].…”