scholarly journals Impact of roof surface runoff on urban water quality

2012 ◽  
Vol 66 (7) ◽  
pp. 1527-1533 ◽  
Author(s):  
P. Egodawatta ◽  
N. S. Miguntanna ◽  
A. Goonetilleke

The pollutant impacts of urban stormwater runoff on receiving waters are well documented in research literature. However, it is road surfaces that are commonly identified as the significant pollutant source. This paper presents the outcomes of an extensive program of research into the role of roof surfaces in urban water quality with particular focus on solids, nutrients and organic carbon. The outcomes confirmed that roof surfaces play an important role in influencing the pollutant characteristics of urban stormwater runoff. Pollutant build-up and wash-off characteristics for roads and roof surfaces were found to be appreciably different. The pollutant wash-off characteristics exhibited by roof surfaces show that it influences the first flush phenomenon more significantly than road surfaces. In most urban catchments, as roof surfaces constitute a higher fraction of impervious area compared with road surfaces, it is important that the pollutant generation role of roof surfaces is specifically taken into consideration in stormwater quality mitigation strategies.

2021 ◽  
Author(s):  
Katherine Purdy ◽  
Jason K Reynolds ◽  
Ian Alexander Wright

Abstract Riparian vegetation along urban streams and wetlands is frequently dominated by invasive weeds. Elevated nitrogen and phosphorous in urban waters and soils are well-known to encourage invasive urban weeds, but this research demonstrates that other urban geochemical contaminants may also be influential. Previous studies have demonstrated that the dissolution of urban concrete is a poorly recognised source of modified water and soil geochemistry, which may enhance the growth of some invasive weeds. This study investigated the relationship between urban water quality and the growth of an invasive urban riparian weed, willow (Salix spp.) to examine the contribution of concrete materials. The study used water from a wetland in the Greater Blue Mountains World Heritage Area. These wetlands have a unique biodiversity but are fragile and susceptible to degradation from human activity. Many are in urban catchments and are frequently dominated by invasive weeds, including Salix spp. In this study, willow cuttings were grown in a laboratory using four water treatments: pristine, urban, and pristine water exposed to two different concrete materials. The urban and concrete water treatments had higher pH, salinity, calcium, potassium, and higher concentration of several metals and were associated with increased growth of Salix spp. We suggest that the modification of urban water and riparian soil chemistry by urban concrete materials may contribute to the success of invasive species in urban wetlands and riparian zones. Some metals (barium, strontium) were present in urban water and in pristine water exposed to concrete and bioaccumulated in plant tissue.


2013 ◽  
Vol 68 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Bastian Johann Manz ◽  
Juan Pablo Rodríguez ◽  
Čedo Maksimović ◽  
Neil McIntyre

A key control on the response of an urban drainage model is how well the observed rainfall records represent the real rainfall variability. Particularly in urban catchments with fast response flow regimes, the selection of temporal resolution in rainfall data collection is critical. Furthermore, the impact of the rainfall variability on the model response is amplified for water quality estimates, as uncertainty in rainfall intensity affects both the rainfall-runoff and pollutant wash-off sub-models, thus compounding uncertainties. A modelling study was designed to investigate the impact of altering rainfall temporal resolution on the magnitude and behaviour of uncertainties associated with the hydrological modelling compared with water quality modelling. The case study was an 85-ha combined sewer sub-catchment in Bogotá (Colombia). Water quality estimates showed greater sensitivity to the inter-event variability in rainfall hyetograph characteristics than to changes in the rainfall input temporal resolution. Overall, uncertainties from the water quality model were two- to five-fold those of the hydrological model. However, owing to the intrinsic scarcity of observations in urban water quality modelling, total model output uncertainties, especially from the water quality model, were too large to make recommendations for particular model structures or parameter values with respect to rainfall temporal resolution.


1993 ◽  
Vol 28 (3-5) ◽  
pp. 231-240 ◽  
Author(s):  
G. Fred Lee ◽  
Anne Jones-Lee

Water pollution control agencies are implementing control programs for chemical contaminants in urban stormwater runoff because concentrations of total forms of some contaminants in receiving water exceed numeric water quality standards. While some assert that stormwater-associated contaminants are causing water quality problems (impairment of beneficial uses), there are significant reasons to question the reliability of that claim. While urban stormwater runoff frequently contains many chemicals in sufficient concentrations to cause exceedance of numeric US EPA water quality criteria in receiving waters, exceedance of a water quality criterion/standard applied to total concentrations is not a demonstration of water quality impairment The US EPA water quality criteria were developed for worst-case or near-worst-case exposure to available forms of the contaminants. Such exposure conditions would not be expected with short-term, episodic runoff events. Substantial portions of many of the chemical contaminants in stormwater runoff are associated with particulates and would hence be expected to be largely unavailable to affect aquatic life-related beneficial uses of receiving waters. Furthermore, evidence of beneficial use impairment caused by urban stormwater runoff has not been forthcoming to document the claims. It is concluded that many of the contaminants associated with urban stormwater runoff from residential and commercial areas do not impair beneficial uses of receiving waters. The current US EPA water quality criteria have limited applicability to assessing potential water quality concerns for stormwater runoff. Guidance is presented on how urban stormwater runoff-associated contaminants should be evaluated and regulated to control use impairment without significant unnecessary expenditures for contaminant control.


2021 ◽  
Vol 18 (4) ◽  
pp. 248-256
Author(s):  
Monique Cerqueira Araujo ◽  
Adriano Souza Leão ◽  
Thiago Barbosa de Jesus ◽  
Eduardo Cohim

2015 ◽  
Vol 40 (3) ◽  
pp. 480-492 ◽  
Author(s):  
Geoff J. Vietz ◽  
Christopher J. Walsh ◽  
Tim D. Fletcher

The urban stream syndrome is an almost universal physical and ecological response of streams to catchment urbanization. Altered channel geomorphology is a primary symptom that includes channel deepening, widening and instability. While the common approach is to treat the symptoms (e.g. modifying and stabilizing the channel), many stream restoration objectives will not be achieved unless the more vexing problem, treating the cause, is addressed in some way. Research demonstrates that the dominant cause of geomorphic change in streams in urban catchments is an altered flow regime and increase in the volume of stormwater runoff. Thus, managers can choose to treat the symptoms by modifying and controlling the channel to accommodate the altered flow regime, or treat the cause by modifying the flow regime to reduce the impact on channel morphology. In both cases treatments must, at the least, explicitly consider hydrogeomorphology—the science of the linkages between various hydrologic and geomorphic processes—to have a chance of success. This paper provides a review of recent literature (2010 to early 2015) to discuss fluvial hydrogeomorphology in the management of streams subject to urbanization. We suggest that while the dominant approach is focused on combating the symptoms of catchment urbanization (that we refer to as channel reconfiguration), there is increasing interest in approaches that attempt to address the causes by using stormwater control measures at a range of scales in the catchment (e.g. flow-regime management). In many settings in the oft-constrained urban catchment, effective management of stream morphology may require multiple approaches. To conclude, we identify five research areas that could inform urban hydrogeomorphology, one of the most challenging of which is the extent to which the volume of excess urban stormwater runoff can be reduced to mitigate the impact on stream geomorphology.


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