Stormwater Pollution Management Research Articles

Temporal variations in micropollutant inlet concentrations matter when planning the design and compliance assessment of stormwater control measures

Stormwater Control Measures (SCMs) contribute to reducing micropollutant emissions from separate sewer systems. SCM planning and design are often performed by looking at the hydrological performance. Assessment of pollutant removal and the ability to comply with discharge concentration limits is often simplified due to a lack of data and limited monitoring resources. This study analyses the impact of using different time resolutions of input stormwater concentrations when assessing the compliance of SCMs against water quality standards. The behaviour of three indicator micropollutants (MP - Copper, Diuron, Benzo[a]pyrene) was assessed in four SCM archetypes, which were defined to represent typical SCM removal processes. High resolution MP data were extrapolated by using high resolution (2 min) measurements of TSS over a long period (343 events). The compliance assessment showed that high resolution input concentrations can result in a different level of compliance with water quality standards, especially when discharged concentrations are close to the limit values. This study underlines the importance of considering the high temporal variability of stormwater micropollutants when planning and designing SCMs to identify the most effective solutions for stormwater pollution management and to ensure a thorough consideration of all the environmental implications.

Accelerating the adoption of water sensitive innovations: community perceptions of practices and technologies to mitigate urban stormwater pollution

Water management increasingly focuses on tackling stormwater pollution to improve waterway health. Community members have a role in adopting pollution-reduction practices and supporting technologies such as water sensitive urban design. However, because communities are unfamiliar with these practices and technologies, little is known about how they make sense of these ‘water sensitive innovations’. Drawing on Diffusion of Innovations theory, we conduct focus groups across different regions of Australia. Our findings indicate that key barriers to adoption included poor understanding of the relative advantage of these practices and technologies, and perceived poor compatibility with community members’ lifestyle and local geography. In turn, appraisals of relative advantage were constrained by limited observability of stormwater pollution and the benefits that innovations generate for people and the environment. Our findings suggest engagement strategies should emphasize the relevance and advantages of water sensitive innovations, and help individuals visualize the intangible elements of stormwater pollution management.

Management of stormwater pollution using green infrastructure: The role of rain gardens

AbstractMajor modifications are needed in existing stormwater management practices to control floods in urban landscapes, protect natural ecosystems, and minimize infrastructural destruction due to stormwater hazards. Stormwater management combined with urban design can be the best solution to minimize urban flooding risks and promote a clean natural environment. Green infrastructure (GI) is an environmentally sustainable alternative to traditional methods of stormwater management. Rain gardens, a GI, play a vital role in reducing rainwater volume and flow, prevent asset's destruction, remove pollutants from urban runoff, and recharge groundwater. Rain gardens can remove sediments, heavy metals, pathogens, nutrients, hydrocarbons from stormwater via several mechanisms. Various amendments in soil media help in delayed saturation, low sorption capacity, limited pollutant mobility, and bioaccumulation/biotransformation of metals/organic compounds in rain gardens. Soil media and plants play a vital role in the pollutant removal processes of rain gardens. Various plant‐based mechanisms and chemical processes like adsorption, reduction, sedimentation, cation‐exchange capacity, complexation, and so forth are involved in the removal of contaminants from stormwater. Construction and design considerations; different models of rain gardens; working mechanisms; performance assessment tools like capacity tests and synthetic runoff tests; removal of stormwater pollutants, and biphasic rain gardens have been critically discussed in this review. The state‐of‐the‐art review approaches to provide fundamental knowledge of rain gardens and in‐depth analyzes its potential as a stormwater management tool. Future directions on improving efficiencies of rain gardens have also been discussed for prospective researchers.This article is categorized under: Engineering Water

Nutrients transport in the bare urban redeveloped soil system during runoff process

ABSTRACTStormwater pollution in redeveloped soils mixed with construction wastes imposes a serious impact to receiving waters. The transport and distribution of rainfall water and nutrients in the surface-flow and subsurface-flow (including side-flow and down-flow) of bare redeveloped soil runoff system were determined. Results indicated that the flow patterns and pollutants transport of surface-flow were different from those in subsurface-flow. The flowrate of surface-flow increased at the beginning and reached to a stable state, and then disappeared immediately after the rainfall stopped. While the flow rate of subsurface-flow was persisted and decreased gradually artery the rainfall. Most of the pollutants were carried in the surface-flow, which directly results in polluting the surface-receiving waters. And the pollutants distribution percent in side-flow was higher than that in down-flow. Results obtained in this study will provide information for the management of stormwater pollution in the bare redeveloped soil mixed with construction wastes.

Calculation of intercepted runoff depth based on stormwater quality and environmental capacity of receiving waters for initial stormwater pollution management.

While point source pollutions have gradually been controlled in recent years, the non-point source pollution problem has become increasingly prominent. The receiving waters are frequently polluted by the initial stormwater from the separate stormwater system and the wastewater from sewage pipes through stormwater pipes. Consequently, calculating the intercepted runoff depth has become a problem that must be resolved immediately for initial stormwater pollution management. The accurate calculation of intercepted runoff depth provides a solid foundation for selecting the appropriate size of intercepting facilities in drainage and interception projects. This study establishes a separate stormwater system for the Yishan Building watershed of Fuzhou City using the InfoWorks Integrated Catchment Management (InfoWorks ICM), which can predict the stormwater flow velocity and the flow of discharge outlet after each rainfall. The intercepted runoff depth is calculated from the stormwater quality and environmental capacity of the receiving waters. The average intercepted runoff depth from six rainfall events is calculated as 4.1mm based on stormwater quality. The average intercepted runoff depth from six rainfall events is calculated as 4.4mm based on the environmental capacity of the receiving waters. The intercepted runoff depth differs when calculated from various aspects. The selection of the intercepted runoff depth depends on the goal of water quality control, the self-purification capacity of the water bodies, and other factors of the region.

Metals, nutrients and total suspended solids discharged during different flow conditions in highly urbanised catchments

Stormwater discharged from highly urbanised catchments on the southern shore of Sydney estuary, Australia, has been identified as the primary source of contaminants responsible for ecological degradation and reduction in recreational value of the waterway. Effective management of this pollution requires knowledge of contaminant loads associated with various stormwater flow conditions in three highly urbanised catchments in Sydney estuary catchment. The majority (>90%) of metal (Cu, Pb and Zn) and total suspended solid annual loads were contributed during high-flow conditions (>50 mm rainfall day(t1)), whereas ≤55% of TN and ≤21% of total phosphorus were contributed to annual loading by dry weather base-flow conditions. All flow conditions posed an in-stream ecological threat because contaminant concentrations exceeded water quality guidelines for all analytes measured, except Pb. Irregular, temporal variability in contaminant concentrations associated with base-flow (within day and amongst days), high-flow (amongst events) and irregular discharges indicated that contaminant contributions in stormwater were strongly controlled by human activity in the three catchments. Significant variation in contaminant concentrations under all flow conditions revealed unique chemical signatures for each catchment despite similarities in land uses, location and geology amongst catchments. These characteristics indicate that assessment and management of stormwater pollution needs to be conducted on an individual-catchment basis for highly urbanised regions of Sydney estuary catchment.

The development of a novel approach for assessment of the first flush in urban stormwater discharges

The management of stormwater pollution has placed particular emphasis on the first flush phenomenon. However, definition and current methods of analyses of the phenomena contain serious limitations, the most important being their inability to capture a possible impact of the event size (total event volume) on the first flush. This paper presents the development of a novel approach in defining and assessing the first flush that should overcome these problems. The phenomenon is present in a catchment if the decrease in pollution concentration with the absolute cumulative volume of runoff from the catchment is statistically significant. Using data from seven diverse catchments around Melbourne, Australia, changes in pollutant concentrations for Total Suspended Solids (TSS) and Total Nitrogen (TN) were calculated over the absolute cumulative runoff and aggregated from a collection of different storm events. Due to the discrete nature of the water quality data, each concentration was calculated as a flow-weighted average at 2 mm runoff volume increments. The aggregated concentrations recorded in each increment (termed as a 'slice' of runoff) were statistically compared to each other across the absolute cumulative runoff volume. A first flush is then defined as the volume at which concentrations reach the 'background concentration' (i.e. the statistically significant minimum). Initial results clearly highlight first flush and background concentrations in all but one catchment supporting the validity of this new approach. Future work will need to address factors, which will help assess the first flush's magnitude and volume. Sensitivity testing and correlation with catchment characteristics should also be undertaken.

Federalism at the 'Cathedral': Property Rules, Liability Rules, and Inalienability Rules in Tenth Amendment Infrastructure

As the climate crisis, war in the Middle East, and the price of oil focus American determination to move beyond fossil fuels, nuclear power has resurfaced as a possible alternative. But heady plans for energy reform may be stalled by an unlikely policy deadlock stemming from a structural technicality in an aging Supreme Court decision: New York v. United States, which set forth the Tenth Amendment anti-commandeering rule in 1992. The same dry technicality has also threatened the effective management of storm water pollution, contributed to the failed response to Hurricane Katrina, and poses ongoing regulatory obstacles in such critical interjurisdictional contexts as national security and counter-terrorism efforts. Such is the enormous power hidden in the infrastructure of legal rules, parts of which we know better as property, liability, and inalienability remedy rules. Federalism at the Cathedral explores the consequences for good governance of poorly constructed legal infrastructure in the Tenth Amendment context, and recommends a simple jurisprudential fix: exchanging a property rule for the inalienability remedy rule that the Court used to protect the anti-commandeering entitlement. Grounded in a values-based theory of American federalism, it shows how the New York inalienability rule unnecessarily removes tools for resolving interjurisdictional quagmires - exemplified by the radioactive waste capacity problem at the heart of the New York litigation - by prohibiting novel forms of state-federal bargaining. In New York, the Court held that Congress lacked the authority to bind a state's participation in a regulatory scheme even if state officials had effectively waived Tenth Amendment-based objections during consensual negotiations with the federal government. In so doing, the Court articulated a reasonable entitlement to federal noninterference protected by an unreasonable inalienability rule. It is an inalienability rule, because any number of collective action problems would prevent the negotiated transfer of the entitlement except through elected representation. It is unreasonable, because the intergovernmental partnerships thus thwarted would help resolve pressing interjurisdictional problems without offending the constitution. Indeed, underlying values of federalism that give meaning to the Tenth Amendment would be better served by allowing a state to decide for itself whether to hold or trade its entitlement. Focusing on the facts and legacy of the New York decision, the Article concludes that although its inalienability rule is defensible in exclusively state or federal jurisdictional contexts, it is dubious in contexts that require regulatory attention at both the local and national level. A property rule that would enable states to bargain with their anti-commandeering entitlement would not offend the touchstone of Tenth Amendment jurisprudence, which has always been the prevention of federal coercion of the states. A pro-bargaining property rule would be more consistent with the rest of the Court's federalism jurisprudence, more faithful to the full panoply of values that under gird American federalism, and better for state and federal governance in difficult interjurisdictional contexts.

Stormwater Pollution Management at a Foundry Site

Stormwater Pollution Management at a Foundry Site

Stormwater Pollution Management at a Foundry Site – Monitoring, Modeling, and Design

Stormwater Pollution Management at a Foundry Site – Monitoring, Modeling, and Design

Using satellite imagery for stormwater pollution management with Bayesian networks

Urban stormwater runoff is the primary source of many pollutants to Santa Monica Bay, but its monitoring and modeling is inherently difficult and often requires land use information as an intermediate process. Many approaches have been developed to estimate stormwater pollutant loading from land use. This research investigates an alternative approach, which estimates stormwater pollutant loadings directly from satellite imagery. We proposed a Bayesian network approach to classify a Landsat ETM + image of the Marina del Rey area in the Santa Monica Bay watershed. Eight water quality parameters were examined, including: total suspended solids, chemical oxygen demand, nutrients, heavy metals, and oil and grease. The pollutant loads for each parameter were classified into six levels: very low, low, medium low, medium high, high, and very high. The results provided spatial estimates of each pollutant load as thematic maps from which the greatest pollutant loading areas were identified. These results may be useful in developing best management strategies for stormwater pollution at regional and global scales and in establishing total maximum daily loads in the watershed. The approach can also be used for areas without ground-survey land use data.

A stochastic approach to designing wetlands for stormwater pollution control

Central to wetland design for stormwater pollution management is the proper control of the hydrologic regime of these wetlands and wet detention basins. The paper proposes a stochastic approach in determining the appropriate wetland size for stormwater treatment in recognition of the inherent variability of stormwater runoff and pollutant load generation within a storm event and between storm event. The determination of wetland size would include the use of stochastic generation of stormwater runoff and continuous wetland behaviour simulation. A typical design chart summarising the interaction between wetland size, prescribed retention period of stormwater and wetland hydrologic effectiveness for Melbourne is presented. The chart enables the selection of the appropriate storage volume and outlet characteristics on the basis of long-term average effectiveness of the wetland to retain stormwater over a desired minimum period rather than a prescribed level of performance for an individual probablistic event.

A stochastic approach to designing wetlands for stormwater pollution control

Central to wetland design for stormwater pollution management is the proper control of the hydrologic regime of these wetlands and wet detention basins. The paper proposes a stochastic approach in determining the appropriate wetland size for stormwater treatment in recognition of the inherent variability of stormwater runoff and pollutant load generation within a storm event and between storm event. The determination of wetland size would include the use of stochastic generation of stormwater runoff and continuous wetland behaviour simulation. A typical design chart summarising the interaction between wetland size, prescribed retention period of stormwater and wetland hydrologic effectiveness for Melbourne is presented. The chart enables the selection of the appropriate storage volume and outlet characteristics on the basis of long-term average effectiveness of the wetland to retain stormwater over a desired minimum period rather than a prescribed level of performance for an individual probablistic event.