Urban Runoff Research Articles

Shallow floating treatment wetland capable of sulfate reduction in acid mine drainage impacted waters in a northern climate

Floating treatment wetlands (FTW)s that can uptake nutrients and metals from water, and/or trap suspended solids in their roots, are becoming viable options to treat urban, agriculture and sewage runoffs. However, current FTW designs favor aerobic processes and short-term storage of metals, which are ineffective in acid mine drainage (AMD) environments. Many also function poorly in northern latitudes with strong seasonality and several months of sub-zero temperatures. In this study, we designed a novel FTWs with 20 cm soil profile to test its ability to sustain anaerobic microbial processes, such as iron and sulfate reduction and remain functional after freezing conditions of winter months. Three different plants, Carex lacustris, Typha latifolia, and Juncus canadensis were used to test in our FTWs, which were deployed in a mining-impacted water in Sudbury, ON, Canada. Porewater samples were acquired using built-in porewater peepers. Low to moderately reducing conditions, along with presence of ferrous iron and hydrogen sulfide in the porewater of all FTWs was prevalent, irrespective of the constituent vegetation type. Moreover, as well as a ~30% increase in sulfate-reducing bacteria (SRB) richness and ~100% increase in SRB abundance between years, was the evidence that anaerobic processes were occurring in these shallow FTWs. From this study we estimated that during its lifetime, one shallow FTW can treat ~61 m3 of sulfate-rich water, thus offering an alternative way to capture sulfate and other metals from mining-impacted waters.

A Combination Model for Quantifying Non-Point Source Pollution Based on Land Use Type in a Typical Urbanized Area

Water pollution poses threats to urban environments and subsequently impacts the ecological health and sustainable development of urban areas. Identifying the spatiotemporal variation in non-point sources (NPS) pollution is a prerequisite for improving water quality. This paper aimed to assess the NPS pollution load and then recognized the spatiotemporal characteristics of the pollution sources in a typical urbanized area. A combination model based on land use type was used to simulate the NPS pollution load. The results showed the following: (1) ponds and farmlands had higher pollution production intensities than other land use types, but the intensity and magnitude of pollution emissions were generally greater in urban areas; (2) monthly and annual total nitrogen (TN) and total phosphorus (TP) emissions had the same pattern as rainfall, and TN and TP emissions accounted for 56.2% and 58.0%, respectively, of the total in summer; (3) TN pollution was more serious than TP pollution in the study area, especially in farmlands; (4) urban runoff (UR) and livestock and poultry breeding (LPB) were the main sources of NPS, TN and TP emissions in the study area. If these NPS pollutants cannot be removed from this area, a large amount of freshwater is needed to dilute the current rivers to meet the requirement of the fourth category of China national environmental quality standards for surface water. This problem is serious in the control of polluted rivers in many cities throughout China.

Cerucuk Filter Modified (CFM) Design as Sediment Traps to Reduce Total Suspended Solids (TSS) Concentration in the Drainage Mine Reclamation Area: An Field Experiment

One of the environmental issues for the physical components of soil and water, is the potential risk of carrying soil particles by runoff. However, sedimentation and high TSS concentrations still occur in settling ponds before flowing into river, lake or sea. Transfer of such pollutants from solid to aqueous phase at the interface of sediments/particles facilitates their entry into the food chain and further bio accumulation in neighboring fauna and flora. A vast variety of geogenic (rocks weathering and soil erosion) and anthropogenic sources (mining activities, urban and agricultural run-offs, industrial and municipal sewer overflows, etc.) may cause toxic metals discharge into water bodies. The metals can be dissolved in the water column, absorbed/adsorbed to the sediments/particulates or accumulated in biota. In comparison with other media, river bed and suspended sediments play a more significant role in overall pollution and environmental risks. This research is improvement of USEPA recommendations for the installation of sediment traps in drainage channel. The advantage of using this additional modification is that it can significantly reduce TSS concentration. The results of the water samples test and statistical test show that this research provides significant result in reducing TSS concentrations.

A Generalized Automated Framework for Urban Runoff Modeling and Its Application at a Citywide Landscape

This research presents a fully automated framework for runoff estimation, applied to Philadelphia, Pennsylvania, a major urban area. Trends in global urbanization are exacerbating stormwater runoff, making it an increasingly critical challenge in urban areas. Understanding the fine-scale spatial distribution of local flooding is difficult due to the complexity of the urban landscape and lack of measured data, but it is critical for urban management and development. A one-meter resolution Digital Elevation Model (DEM) was used in conjunction with a model developed by using ArcGIS Pro software to create urban micro-subbasins. The DEM was manipulated to account for roof drainage and stormwater infrastructure, such as inlets. The generated micro-subbasins paired with 24-h storm data with a 10-year return period taken from the National Resources Conservation Service (NRCS) for the Philadelphia area was used to estimate runoff. One-meter land-cover and land-use data were used to estimate pervious and impervious areas and the runoff coefficients for each subbasin. Peak runoff discharge and runoff depth for each subbasin were then estimated by the rational and modified rational methods and the NRCS method. The inundation depths from the NRCS method and the modified rational method models were compared and used to generate percent agreement, maximum, and average of inundation maps of Philadelphia. The outcome of this research provides a clear picture of the spatial likelihood of experiencing negative effects of excessive precipitation, useful for stormwater management agencies, city managers, and citizen.

Treatment Assessment of Road Runoff Water in Zones filled with ZVI, Activated Carbon and Mineral Materials

Reducing the discharge of contaminants present in runoff water is important for a clean environment. This paper analyses field test results of three pilot-scale horizontal runoff water treatment zones filled with mixtures of zero valent iron (ZVI), activated carbon (AC), silica spongolite (SS), zeolite (Z), and limestone (LS). The investigated systems were (S1) ZVI/AC/SS, (S2) ZVI/AC/Z and (S3) ZVI/AC/LS. The efficiency of the three systems in the removal of Cd, Cu, Ni, Pb, Zn, COD and ammonium ions from runoff water was compared and the factors (temperature, pH, redox potential, hydraulic conductivity) and relationships affecting treatment effectiveness were determined. A statistical analysis of effluent contaminant concentrations and physicochemical parameters of effluent solutions included descriptive statistics, analysis of variance (ANOVA), a multidimensional analysis using a Principal Component Analysis (PCA), a factor analysis (FA) and a cluster analysis (CA). The ANOVA and cluster analyses indicated similarities between systems containing SS and LS. As a consequence, using cheaper SS can reduce investment costs. In addition, there were no significant differences between the three systems regarding Cd and Ni removal, while Cu and Pb were removed to almost 100%. The results indicate that all the tested materials supported ZVI and AC in the removal of heavy metals in a similar way. However, runoff water was enriched with nitrogen oxides and sulfates while flowing through treatment zones with SS and LS. The enrichment increased with increasing temperature and redox potential. The conducted analyses indicate that the most suitable mixture is ZVI/AC/Z. It should be emphasized that the ongoing processes (precipitation and ZVI corrosion) reduced the hydraulic conductivity of the filters up to two orders of magnitude. Expansive iron corrosion was the most limiting factor in ZVI filtration systems. In the future, applications decreasing the percentage of ZVI in the mixture are suggested.

Research on Pollution Characteristic of Urban Runoff in Storm Sewer

Taking urban roof as the catchment area in Xinxiang City, researching on the hydrology and water quality process of each rainfall event in storm sewer can provide the basis for effectively using urban rainfall and controlling non-point source pollution, and so on. The samples were taken to analyze the contents of SS, COD and TN. The results show that the variation trend of pollutant index SS, COD in runoff is similar and tends to be a steady value. TN decreased with the accumulation of rainfall, but rebounded before the end of rainfall. The standard deviation rate of water quality indicator is SS > COD > TN. The roof flush effect is obvious at the initial stage of runoff, and the initial runoff amount can be defined as the first 1-3mm rainfall. The correlation of SS, COD and TN is good in runoff, and measures can be taken to remove them simultaneously in controlling the runoff pollution. The runoff pollutants flow into the receiving water directly through urban drainage pipe network, and have a great effect on its water quality, especially the changes of SS and COD are the most obvious.

Overview of the analysis, occurrence and ecological effects of hormones in lake waters in Asia

Hormones are natural and synthetic compounds that are now being detected in the aquatic environment. Many lakes in Asia are important water sources that may be affected by these emerging contaminants. Lakes are drains and reservoirs of watersheds that are altered by changing land use and environmental conditions. While there are several studies on the detection of hormones in lakes, these studies were mostly done in China. Limited information is available on the presence of these contaminants in the lakes in other Asian countries. Hormones in the lake water come from discharge waters in urban areas, farm runoffs, and effluents of wastewater and sewage treatment plants. Hormones contamination in water has been shown to affect the reproduction and growth of certain aquatic organisms. In this review, a background on the chemical nature and physiological functions of hormones is provided and the existing knowledge on the occurrence and ecological impacts of hormones in lakes is described. The available analytical methods for sampling, analyte extraction and instrumental analysis are outlined. This overview provides insights on the current conditions of lakes that may be impacted by hormones contamination. Understanding the levels and possible ecological consequences will address the issues on these emerging contaminants especially in the Asian environment. This will elicit discussions on improving guidelines on wastewater discharges and will drive future research directions.

Application of Bio-pore Infiltration Hole as an Urban Runoff Management

The application of bio-pore infiltration holes (BIH) can be one solution for urban runoff management by reducing surface runoff to the ground. But, the difference in soil types and characteristics could affect the runoff reduction that can be achieved by BIH. This research aims to determine the runoff reduction can be achieved by bio-pore infiltration hole (BIH) from different soil types and conditions. The methods in this study mainly focus on hydraulic conductivity calculations using Porchet method and the implementation of Minister of Environment Regulation Numb. 12/2009 for the BIH installations. Based on the implementation of Minister of Environment Regulation Numb. 12/2009, the required BIHs for the area of 500 m2 are 1,000, both for silt and clay soils. The runoff reductions that can be achieved with the application of BIHs are 38.98 - 95.73% for silt soils and 20.67 - 54.28% for clay soils, depends on the soil conditions

Urban Spatial Configuration and Functional Runoff Connectivity: Influence of Drainage Grid Density and Landscape Metrics

Due to changing precipitation patterns induced by climate change, urban planners are confronted with new challenges to effectively mitigate rainfall runoff. An important knowledge gap that needs to be addressed before tackling these challenges is how and to which extent street/drainage grid density and spatial land use configuration influence the amount of runoff. Therefore, a virtual experiment was conducted to assess the influence of grid density and spatial land use configuration on the functional runoff connectivity (Fc), which is a measure of the easiness by which water flows through the landscape. Through the use of a design of experiments approach in combination with the SCS—Curve Number runoff model, a wide variety of neutral landscape models with a fixed percentage of pervious- and impervious cover were generated that maximized the variance of Fc. Correlations between landscape metrics and neutral landscape models were calculated. Our results indicated that, out of the 17 landscape metrics tested, the average impervious cluster area, the number of impervious clusters, the standard deviation of the cluster size, two proximity indexes and the effective impervious area were strongly correlated with Fc throughout all grid scenarios. The relationship between Fc on the one hand and the average impervious cluster area and the effective impervious area on the other hand, was modelled. The average impervious cluster area models showed a relationship with Fc that closely approximated a logarithmic function (R2: 0.49–0.73), while the effective impervious area models were found to have a linear relationship with Fc (R2: 0.63–0.99). A dense grid was shown to cause a strong increase in Fc, demonstrating the effectiveness of an urban grid in channeling and removing runoff. Our results further indicate that fine-grained landscapes with a lot of small impervious clusters are preferred over course-grained landscapes when the goal is to reduce Fc. In highly urbanized landscapes, where the percentage of impervious area is high, small changes in landscape pattern could significantly reduce Fc. By using a downward hydrological modeling approach this research aims to bring more clarity to the underlying variables influencing Fc, rather than trying to generate realistic prediction values.

Analysis of the Effect of Low Impact Development on Urban Runoff Control Based on the SWMM Model

Zhang, J.; Zhang, Y.; Sun, S.-J.; Zhang, W.-W., and Zhang, S.-H., 2019. Analysis of the effect of low impact development on urban runoff control based on the SWMM model. In: Yu, T.-s. (ed.), Environmental Sustainability: Water Resources Integrated Management and the Development of Coastal Environments. Journal of Coastal Research, Special Issue No. 96, pp. 62-67. Coconut Creek (Florida), ISSN 0749-0208.In order to solve the problems of frequent urban flood disasters and the continuous deterioration of the water environment in the process of urbanization, the urban storm flood management method centered on Low Impact Development (LID) has become a new concept in urban construction. Taking one residential area in Beijing as the research object, and on the basis of the Storm Water Management Model (SWMM), this paper simulates and analyzes the effect of LID measures on runoff control under different rainfall conditions, and deduces the functional relationship between the LID scale and runoff reduction. The results show that the runoff reduction rate decreases with the increase in rainfall level, and LID measures have the most obvious effect on runoff quantity reduction while having a small effect on the peak time delay. The research methods and results of this paper can provide a reference for sponge city construction, flood control and drainage management.

Evaluation of Stormwater Treatment Vault with Coanda-Effect Screen for Removal of Solids and Phosphorus in Urban Runoff

AbstractCatch basins commonly are used by cities as part of a stormwater management plan to remove sediment and associated contaminants from stormwater, keeping them in compliance with regulations....

Effect of Urban Stormwater Road Runoff of Different Land Use Types on an Urban River in Shenzhen, China

Urban storm runoff is a major source of pollutants in receiving water bodies. To assess the impact of urban stormwater runoff on an urban river, the runoff process of total suspended solids (TSS), chemical oxygen demand (COD), ammonium (NH4), and total phosphorus (TP) were investigated on road surfaces classified as arterial road (AR), residential area (RA), and industrial area (IA) in the Pingshan River (PSR) watershed in Shenzhen, China. Event mean concentration (EMC) was calculated to analyze the water quality of road runoff, and the dimensionless M(V) cumulative curves were used to estimate the course of decreasing concentration of runoff pollutants during each rainfall event. Multicriteria decision making methods (PROMETHEE-GAIA) were used to identify the linkage between runoff pollutants, land use types, and rainfall intensity. The EMCs of COD and TP in runoff exceeded the class IV level of the water quality standard for surface water (China). RA was a major potential source for NH4, COD, and TP in the river. Controlling the first flush is critical to decrease the effect of road runoff on receiving water bodies, as most runoff pollutants in AR, RA, and IA had a first flush effect during heavy rainfall. The specific management measure for runoff pollution varied with land use type. Reducing road TSS concentrations was effective for controlling runoff pollution in AR and RA because NH4, TP, and COD attached to particulate matter. In IA, the collection and reuse of stormwater in the initial rainfall period were effective for reducing the effect of soluble pollutants in runoff on receiving water bodies. This study provides new information for managing urban road stormwater runoff in different land use types.

Wastewater bioremediation by mangrove ecosystems impacts crab ecophysiology: In-situ caging experiment

Mangroves are tidal wetlands that are often under strong anthropogenic pressures, despite the numerous ecosystem services they provide. Pollution from urban runoffs is one such threats, yet some mangroves are used as a bioremediation tool for wastewater (WW) treatment. This practice can impact mangrove crabs, which are key engineer species of the ecosystem. Using an experimental area with controlled WW releases, this study aimed to determine from an ecological and ecotoxicological perspective, the effects of WW on the red mangrove crab Neosarmatium africanum. Burrow density and salinity levels (used as a proxy of WW dispersion) were recorded, and a 3-week caging experiment was performed. Hemolymph osmolality, gill Na+/K+-ATPase (NKA) activity and gill redox balance were assessed in anterior and posterior gills of N. africanum. Burrow density decreased according to salinity decreases around the discharged area. Crabs from the impacted area had a lower osmoregulatory capacity despite gill NKA activity remaining undisturbed. The decrease of the superoxide dismutase activity indicates changes in redox metabolism. However, both catalase activity and oxidative damage remained unchanged in both areas but were higher in posterior gills. These results indicate that WW release may induce osmoregulatory and redox imbalances, potentially explaining the decrease in crab density. Based on these results we conclude that WW release should be carefully monitored as crabs are key players involved in the bioremediation process.

Planning for spatial equity - A performance based approach for sustainable urban drainage systems

There is a rising demand to use nature and natural processes to address a different range of urban issues, especially when looking at the risk of pluvial flood associated with climate changes and urbanization processes. Among the set of Nature-Based Solutions used in urban planning, Sustainable Urban Drainage Systems (SUDS) represent promising solutions to reduce the negative effects of urban water run-offs and to increase urban Ecosystem Services.However, SUDS can impact differently in the urban fabric and generate positive effects only on particular portions of cities. Planning of SUDS should try to consider not only the number of potential beneficiaries but also where beneficiaries are located in the city, as water sensitive approaches to urban planning must deal with distributive, procedural and contextual dimensions of equity.In this paper, we simulate different spatially explicit planning scenarios of SUDS for densely populated catchments in Sicily. Particularly, we evaluate the relation between the quantitative performance of SUDS in terms of reduction of hazard/risk of pluvial flooding and the number and location of beneficiaries -intended here as residents of different social groups. Results suggest that scenarios of SUDS generate benefits that are not equally distributed within the city.

A Review of Nitrogen Removal for Urban Stormwater Runoff in Bioretention System

One of the best management practices (BMPs) for stormwater quality and quantity control is a bioretention system. The removal efficiency of different pollutants under this system is generally satisfactory, except for nitrogen which is deficient in certain bioretention systems. Nitrogen has a complex biogeochemical cycle, and thus the removal processes of nitrogen are typically slower than other pollutants. This study summarizes recent studies that have focused on nitrogen removal for urban stormwater runoff and discusses the latest advances in bioretention systems. The performance, influencing factors, and design enhancements are comprehensively reviewed in this paper. The review of current literature reveals that a bioretention system shows great promise due to its ability to remove nitrogen from stormwater runoff. Combining nitrification and denitrification zones with the addition of a carbon source and selecting different plant species promote nitrogen removal. Nevertheless, more studies on nitrogen transformations in a bioretention system and the relationships between different design factors need to be undertaken.

A Comparison of Three Types of Permeable Pavements for Urban Runoff Mitigation in the Semi-Arid South Texas, U.S.A

This study examines the hydrologic and environmental performance of three types of permeable pavement designs: Porous Concrete Pavement (PCP), Permeable Interlocking Concrete (PICP), and Interlocking Block Pavement with Gravel (IBPG) in the semi-arid South Texas. Outflow rate, storage, Normalized Volume Reduction (NVR), Normalized Load Reductions (NLR) of Total Suspended Solids (TSS), and Biochemical Oxygen Demand (BOD5) were compared to results obtained from adjacent traditional pavements at different regional parking lots. A notable percentage of peak flow attenuation of approximately 31–100% was observed when permeable pavements were constructed and implemented. IBPG was capable to hold runoff from rainfall depths up to 136 mm prior to flooding. PCP was the most satisfactory in reducing surface runoff (NVR: 2.81 × 10−3 ± 0.67 × 10−3 m3/m2/mm), which was significantly (p < 0.05) higher (98%) than the traditional pavement. PCP was also very effective in TSS removal (NLR: 244 × 10−5 ± 143 × 10−5 kg/m2/mm), which was an increase of over 80% removal than traditional pavement. IBPG (NLR: 7.14 × 10−5 ± 7.19 × 10−5 kg/m2/mm) showed a significantly (p < 0.05) higher (46%) BOD5 removal over traditional pavement. These results demonstrate that the type of permeable pavement and the underlying media can significantly influence the runoff reduction and infiltration in this climatic region.

A Framework for Assessing Modeling Performance and Effects of Rainfall-Catchment-Drainage Characteristics on Nutrient Urban Runoff in Poorly Gauged Watersheds

Protection of surface water quality plays a crucial role for sustainable urban watershed management since the wash-off from impervious contaminated surfaces generates transport phenomena from a range of pollutants (like nutrients, such as total nitrogen (Ntot) and total phosphorus (Ptot)). This leads to the consequent reduction of water quality, and to phenomena, such as eutrophication and the presence of algae blooms. For this reason, a comprehensive understanding of nutrient build-up and wash-off is essential for efficient stormwater treatment design. However, data scarcity could represent one of the main limitations in this context. This manuscript presents a methodological framework able to tackle such limitations by an in-depth investigation of the main factors that influence the build-up and wash-off from impervious surfaces, including rainfall, watershed, and drainage-network characteristics. The outcomes highlight the key role played by the antecedent dry period, among the rainfall characteristics, and the width of the overland flow path, among the catchment/drainage characteristics. It is also confirmed as appropriate to use suspended solids as a surrogate for the investigation of the behavior of other pollutant species. Additionally, the capability of this approach in assessing modeling performance was successfully tested. The results of the present study are expected to contribute valuable knowledge for defining effective management strategies to minimize stream pollution and protect the health of aquatic ecosystems in urban watersheds characterized by data scarcity.

Phytoremediation of Three Herbaceous Plants to Remove Metals from Urban Runoff.

Phytoremediation experiments were carried out to assess the ability of different herbaceous buffer strips to absorb metals. Results revealed the Medicago sativa buffer strip had the best removal capacity for copper, lead, and cadmium in the runoff and seepage flow. Copper and lead content in M. sativa were significantly higher than in Lolium perenne and Poa pratensis (p < 0.05). Cadmium content in P. pratensis was significantly higher than in L. perenne and M. sativa(p < 0.05). Total accumulation of copper and lead in M. sativa buffer strips was 13.45mgkg-1 and 1.01mgkg-1, respectively. Total cadmium accumulation was approximately 0.50mgkg-1 in both M. sativa and P. pratensis. Overall, results indicated that using M. sativa in the buffer strips was optimal for the remediation of copper, lead, and cadmium in sewage water.

Analysis of Urban Runoff Discharge Characteristics Affected by Climate Change and Urbanization: Case on Bokdae-dong Basin

Analysis of Urban Runoff Discharge Characteristics Affected by Climate Change and Urbanization: Case on Bokdae-dong Basin

Street Tree Pits as Bioretention Units: Effects of Soil Organic Matter and Area Permeability on the Volume and Quality of Urban Runoff

The quantity, intensity, and quality of urban stormwater runoff are changing as a consequence of urbanization and climate change. Low impact development (LID) techniques (e.g., bioretention systems) are emerging to manage runoff quantity and quality. Street tree pits were used as bioretention units in Montreal, Canada. The concentration and mass flux of contaminants (Na, Cr, Ni, Cu, Zn, Cd, Pb) and dissolved organic carbon (DOC) were measured in soil solution samples from the tree pits. The soil organic matter (SOM) and the permeability of the area nearby the tree pit (sidewalk and front lawn) were tested. The SOM did not affect contaminant concentrations. However, tree pits with higher SOM reduced the mass flux of contaminants more than tree pits with lower SOM. Sidewalk permeability decreased the concentration and mass flux of contaminants observed (e.g., Na and Cr). The estimated water flux in the open part of the tree pit changed from 6.15 to 1.64 mm week−1 from the less permeable units (absence of lawn + impermeable sidewalk) to the more permeable units (presence of lawn + permeable sidewalk). Urban runoff quality and quantity were locally affected by the tree pits. This indicates that the increase in surface permeability and SOM in street tree pits is advisable. Street tree pits have the potential as bioretention units to locally mitigate some of the impacts of urbanization. City planners could consider the use of street tree pits as bioretention units to help the management of urban runoff.