scholarly journals Intensive monitoring of conventional and surrogate quality parameters in a highly urbanized river affected by multiple combined sewer overflows

2018 ◽  
Vol 19 (3) ◽  
pp. 953-966 ◽  
Author(s):  
D. Copetti ◽  
L. Marziali ◽  
G. Viviano ◽  
L. Valsecchi ◽  
L. Guzzella ◽  
...  

Abstract The paper reports results of four intensive campaigns carried out on the Seveso River (Milan metropolitan area, Italy) between 2014 and 2016, during intense precipitation events. Laboratory analyses were coupled with on-site, continuous measurements to assess the impact of pollutants on water quality based on both conventional and surrogate parameters. Laboratory data included total suspended solids, caffeine, total phosphorus and nitrogen, and their dissolved forms. Screening of trace metals (Cr, Cu, Pb, Ni, Cd) and PBDEs (polybromodiphenylethers) was carried out. Continuous measurements included water level, physico-chemical variables and turbidity. Nutrient concentrations were generally high (e.g. average total phosphorus > 1,000 μg/L) indicating strong sewage contributions. Among monitored pollutants Cr, Cu, Pb, and Cd concentrations were well correlated to TSS, turbidity and discharge, being bound mostly to suspended particulate matter. A different behavior was found for Ni, that showed an early peak occurring before the flow peak, as a result of first flush events. PBDEs correlated well to nutrient concentrations, showing the highest peaks soon after activation of the combined sewer overflows, likely because of its accumulation in sewers. In addition to showing the existing correlations between quality parameters, the paper highlights the importance of surrogate parameters as indicators of anthropic pollution inputs.

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3425
Author(s):  
Marco Romei ◽  
Matteo Lucertini ◽  
Enrico Esposito Renzoni ◽  
Elisa Baldrighi ◽  
Federica Grilli ◽  
...  

Combined sewer overflows (CSOs) close to water bodies are a cause of grave environmental concern. In the past few decades, major storm events have become increasingly common in some regions, and the meteorological scenarios predict a further increase in their frequency. Consequently, CSO control and treatment according to best practices, the adoption of innovative treatment solutions and careful sewer system management are urgently needed. A growing number of publications has been addressing the quality, quantity and types of available water management and treatment options. In this study, we describe the construction of an innovative detention reservoir along the Arzilla River (Fano, Italy) whose function is to store diluted CSO wastewater exceeding the capacity of a combined drain system. River water sampling and testing for microbial contamination downstream of the tank after a heavy rain event found a considerable reduction of fecal coliform concentrations, which would have compounded the impact of stormwater on the bathing site. These preliminary results suggest that the detention tank exerted beneficial environmental effects on bathing water by lowering the microbial load.


2013 ◽  
Vol 51 (19-21) ◽  
pp. 4072-4080
Author(s):  
Hong Guo ◽  
Seungjae Oh ◽  
Sung Min Cha ◽  
Seung Won Lee ◽  
Aamir Alaud-din ◽  
...  

2021 ◽  
Vol 9 (12) ◽  
pp. 1415
Author(s):  
Fabio Di Nunno ◽  
Francesco Granata ◽  
Francesco Parrino ◽  
Rudy Gargano ◽  
Giovanni de Marinis

One of the main sources of microplastics inside surface waters is represented by combined sewer overflows (CSOs), involving severe risks for the environment. The entry of microplastics into water bodies also depends on the characteristics of sewer diversion structures used as flow control devices. In this work, an experimental investigation was carried out to evaluate the outflow of microplastic particles, consisting of different types of nylon fibers, from a side weir located on a channel with a rectangular section. A specific methodology was developed for the fiber sampling and outflow assessment after the tests were performed. For the tested configurations, an increase in fibers discharged up to 196.15% was measured as the water flow rate increased by 62.75%, combined with an increase in the side weir length up to 40% and a decrease in the crest height up to 20%. The size and weight of the different fibers showed a low impact due to their low inertia, and their motion was governed by the water flow. An empirical equation to evaluate the fiber outflow as a function of water flow rate and side weir geometric characteristics was also proposed and calibrated for the experimentally tested ranges of the dimensionless lateral water outflow Q* = 0.51–0.83 and of the dimensionless geometric parameter S* = 0.114–0.200. These first experimental results make it possible to carry out a preliminary assessment of the impact of CSOs in terms of microplastics spilled into water bodies.


2021 ◽  
Vol 3 ◽  
Author(s):  
Andrew Roseboro ◽  
Maria Nariné Torres ◽  
Zhenduo Zhu ◽  
Alan J. Rabideau

Combined sewer overflows (CSOs) release pollutants collected in urban runoff into local waterways, impacting both aquatic life and human health. The impact of climate change on precipitation may result in an increase in the frequency and magnitude of heavy precipitation events, with a corresponding increase in CSO discharges. The installation of Green Infrastructure (GI) such as Porous Pavements (PP) is a resilient approach to mitigate CSO events. However, an understanding of the impact of climate change on CSO events and the effectiveness of GI practices is crucial for designing sustainable urban stormwater management systems. Using the Storm Water Management Model (SWMM), the performance of PP as a CSO abatement strategy was studied for the city of Buffalo, New York, USA. This paper used the Intensity-Duration-Frequency (IDF) curves for current (1970–1999) and future (2070–2099) design rainfall scenarios, with four rainfall durations (1, 6, 12, and 24 hours) and four return periods (2, 10, 50, and 100 years). The simulation results show that (1) current 100-year events generate CSO volumes similar to predicted 50-year events; (2) CSO volumes could increase by 11–73% in 2070–2099 compared to 1970–1999 when no GI intervention is performed; and (3) the installation of PP can reduce 2–31% of future CSO volume. This case study demonstrates the regional CSO challenges posed by climate change and supports the use of GI as a mitigation strategy.


Author(s):  
Bruce Petrie

AbstractEmerging contaminants such as pharmaceuticals, illicit drugs and personal care products can be released to the environment in untreated wastewater/stormwater mixtures following storm events. The frequency and intensity of combined sewer overflows (CSOs) has increased in some areas due to increasing urbanisation and climate change. Therefore, this review provides an up-to-date overview on CSOs as an environmental source of emerging contaminants. Other than compounds with high removal, those chiral species subject to enantioselective changes (i.e. degradation or inversion) during wastewater treatment can be effective markers of CSO discharge in the environment. A proposed framework for the selection of emerging contaminants as markers of CSOs is outlined. Studies have demonstrated that CSOs can be the main source of emerging contaminants with high removal efficiency during wastewater treatment (e.g. > 90%). However, the impact of CSOs on the environment is location specific and requires decision-making on their appropriate management at catchment level. This process would be aided by further studies on CSOs which incorporate the monitoring of emerging contaminants and their effects in the environment with those more routinely monitored pollutants (e.g. pathogens and priority substances). Mitigation and treatment strategies for emerging contaminants in CSOs are also discussed.


2011 ◽  
Vol 59 (2) ◽  
pp. 85-94 ◽  
Author(s):  
Petra Hnaťuková

Geochemical distribution and mobility of heavy metals in sediments of urban streams affected by combined sewer overflowsThis study was undertaken to assess the impact of combined sewer overflows (CSOs) on distribution and potential mobility of heavy metals in sediments of urban streams in Prague, Czech Republic. Contents of total and extractable heavy metals (Cu, Zn, Pb, Cd, Cr and Ni), mineralogical phases and other sediment properties were measured in 44 surficial sediment samples. Total metal concentrations were obtained after microwave-assisted digestion whilst extractable metal contents were obtained following a sequential extraction scheme (acid soluble, reducible, oxidisable and residual fraction). The multivariate statistics of cluster analysis was used to identify specific areas of contamination and to evaluate the impact of CSOs. The observed mobility order of metals was Cd > Zn > Ni > Cu > Pb > Cr. There was a considerable increase in Zn mobility and increase of Cu associated with the oxidisable fraction in the sediments below CSO discharges. Cd was revealed as the most mobile heavy metal with percentages of extraction of approximately 40-60% in acid soluble fraction. Pb was mainly found in reducible fraction associated with Fe/Mn (oxi)hydroxides, which is indicative of anthropogenic pollution. In terms of environmental significance, Cd and Zn can be particularly mobile and bioavailable under acidic conditions, because they are predominantly bound in labile fractions. However, potential changes of redox state and pH may remobilize the metals bound to carbonates, reducible, and/or organic matter.


1994 ◽  
Vol 29 (1-2) ◽  
pp. 245-254 ◽  
Author(s):  
Govert Geldof ◽  
Per Jacobsen ◽  
Shoichi Fujita

In urban areas there are many problems with water management: combined sewer overflows, peak flows, man-induced droughts, consolidation of the soil, damage from frost penetration, etc. It is preferable to look at all these problems in relation to each other, according the concept of integrated water management. This paper focuses on the possibilities for urban stormwater infiltration. The results of three studies are presented. The first study concerns the flooding of the Shirako River in Tokyo. It is shown that with the help of stormwater infiltration the floods can be reduced remarkably. The second study concerns combined sewer overflows and the discharge from treatment plants for catchments in Denmark and the Netherlands. When looking at the total yearly discharge from the combined sewer and the treatment plant, it is shown that infiltration is more effective than detention. The third study shows the impact of urban stormwater infiltration on the ground water flux in an area in the south of the Netherlands. To relate the different results from the three studies an analogy is introduced with the human body. The combination of problems results in a so-called urban hang-over. It is shown that the positive effects of urban stormwater infiltration within an integrated approach are more significant than looking at all the effects separately.


1996 ◽  
Vol 31 (3) ◽  
pp. 453-472 ◽  
Author(s):  
M. Stirrup

Abstract The Regional Municipality of Hamilton-Wentworth operates a large combined sewer system which diverts excess combined sewage to local receiving waters at over 20 locations. On average, there are approximately 23 combined sewer overflows per year, per outfall. The region’s Pollution Control Plan, adopted by Regional Council in 1992, concluded that the only reasonable means of dealing with large volumes of combined sewer overflow in Hamilton was to intercept it at the outlets, detain it and convey it to the wastewater treatment plant after the storm events. The recommended control strategy relies heavily on off-line storage, with an associated expansion of the Woodward Avenue wastewater treatment plant to achieve target reductions of combined sewer overflows to 1–4 per year on average. The region has begun to implement this Pollution Control Plan in earnest. Three off-line detention storage tanks are already in operation, construction of a fourth facility is well underway, and conceptual design of a number of other proposed facilities has commenced. To make the best possible use of these facilities and existing in-line storage, the region is implementing a microcomputer-based real-time control system. A number of proposed Woodward Avenue wastewater treatment plant process upgrades and expansions have also been undertaken. This paper reviews the region's progress in implementing these control measures.


Sign in / Sign up

Export Citation Format

Share Document