scholarly journals A Detention Reservoir Reduced Combined Sewer Overflows and Bathing Water Contamination Due to Intense Rainfall

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3425
Author(s):  
Marco Romei ◽  
Matteo Lucertini ◽  
Enrico Esposito Renzoni ◽  
Elisa Baldrighi ◽  
Federica Grilli ◽  
...  
Keyword(s):  
Environmental Concern ◽  
Treatment Options ◽  
Heavy Rain ◽  
Rain Event ◽  
Storm Events ◽  
Combined Sewer Overflows ◽  
Bathing Water ◽  
Combined Sewer ◽  
Sewer Overflows ◽  
The Impact

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.

scholarly journals A review of combined sewer overflows as a source of wastewater-derived emerging contaminants in the environment and their management

2021 ◽  
Author(s):  
Bruce Petrie
Keyword(s):  
Wastewater Treatment ◽  
Illicit Drugs ◽  
Emerging Contaminants ◽  
Treatment Strategies ◽  
Storm Events ◽  
Combined Sewer Overflows ◽  
Untreated Wastewater ◽  
Combined Sewer ◽  
Sewer Overflows ◽  
The Impact

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.

Implementation of Hamilton-Wentworth Region’s Pollution Control Plan

1996 ◽  
Vol 31 (3) ◽  
pp. 453-472 ◽  
Author(s):  
M. Stirrup
Keyword(s):  
Wastewater Treatment ◽  
Pollution Control ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Control Measures ◽  
Storm Events ◽  
Combined Sewer Overflows ◽  
Control Plan ◽  
Combined Sewer ◽  
Sewer Overflows

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.

Pilot-Scale Study of Satellite Treatment Options for the Control of Combined Sewer Overflows

1997 ◽  
Vol 32 (1) ◽  
pp. 169-184 ◽  
Author(s):  
J. SCHMIDT ◽  
P. SETO ◽  
D. Averill
Keyword(s):  
Treatment Options ◽  
Cost Effective ◽  
Pilot Scale ◽  
Combined Sewer Overflows ◽  
International Joint Commission ◽  
Pollution Problem ◽  
Combined Sewer ◽  
Vortex Separator ◽  
Sewer Overflows ◽  
Screen Performance

Abstract Combined sewer overflows (CSOs) have been recognized for many years as a pollution problem within the Great Lakes ecosystem. CSOs were identified as a source of contamination in 10 of the 17 Canadian “Areas of Concern” designated by the International Joint Commission, and were considered a major problem in Hamilton Harbour and the Metropolitan Toronto Waterfront. Satellite treatment systems (located upstream in the sewerage system) were identified as being significantly more cost effective than other CSO control options in a feasibility study conducted for Metropolitan Toronto. Consequently, a multi-agency initiative was established in 1993 to examine the treatment of CSOs at a pilot-scale facility in the City of Scarborough. The technologies evaluated during two experimental seasons in 1994 and 1995 included a vortex separator, a circular clarifier, a horizontal-flow plate clarifier and an inclined rotary drum screen. Performance of the technologies is being assessed against a draft policy proposed by the Ontario Ministry of Environment and Energy. Results to date have indicated that the vortex separator and the plate clarifier under “best conditions” were capable of 50% TSS removal and 30% BOD5 removal and should be capable of satisfying the policy.

Priority substances in combined sewer overflows: case study of the Paris sewer network

2011 ◽  
Vol 63 (5) ◽  
pp. 853-858 ◽  
Author(s):  
J. Gasperi ◽  
S. Garnaud ◽  
V. Rocher ◽  
R. Moilleron
Keyword(s):  
Hazardous Substances ◽  
Local Source ◽  
Rain Event ◽  
Combined Sewer Overflows ◽  
Limit Of Quantification ◽  
Seine River ◽  
Pollutant Loads ◽  
Sewer Network ◽  
Combined Sewer ◽  
Sewer Overflows

This study was undertaken to supply data on both priority pollutant (PP) occurrence and concentrations in combined sewer overflows (CSOs). A single rain event was studied on 13 sites within the Paris sewer network. For each sample, a total of 66 substances, including metals, polycyclic aromatic hydrocarbons (PAHs), pesticides, organotins, volatile organic compounds, chlorobenzenes, phthalates and alkylphenols were analyzed. Of the 66 compounds analyzed in all, 40 PPs including 12 priority hazardous substances were detected in CSOs. As expected, most metals were present in all samples, reflecting their ubiquitous nature. Chlorobenzenes and most pesticides were never quantified above the limit of quantification, while the majority of the other organic pollutants, except DEHP (median concentration: 22 μg.l−1), were found to lie in the μg.l−1 range. For the particular rain event studied, the pollutant loads discharged by CSOs were evaluated and then compared to pollutant loads conveyed by the Seine River. Under the hydraulic conditions considered and according to the estimations performed, this comparison suggests that CSOs are potentially significant local source of metals, PAHs and DEHP. Depending on the substance, the ratio between the CSO and Seine River loads varied from 0.5 to 26, underscoring the important local impact of CSOs at the scale of this storm for most pollutants.

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 ◽  
...  
Keyword(s):  
Total Phosphorus ◽  
Laboratory Data ◽  
Quality Parameters ◽  
Nutrient Concentrations ◽  
Combined Sewer Overflows ◽  
Continuous Measurements ◽  
Combined Sewer ◽  
Early Peak ◽  
Sewer Overflows ◽  
The Impact

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.

scholarly journals The Role of Sewer Network Structure on the Occurrence and Magnitude of Combined Sewer Overflows (CSOs)

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2675
Author(s):  
Julian Reyes-Silva ◽  
Emmanuel Bangura ◽  
Björn Helm ◽  
Jakob Benisch ◽  
Peter Krebs
Keyword(s):  
Network Structure ◽  
Mitigation Strategies ◽  
Mitigation Measures ◽  
Storm Events ◽  
Combined Sewer Overflows ◽  
Untreated Wastewater ◽  
Intense Storm ◽  
Combined Sewer ◽  
Sewer Overflows

Combined sewer overflows (CSOs) prevent surges in sewer networks by releasing untreated wastewater into nearby water bodies during intense storm events. CSOs can have acute and detrimental impacts on the environment and thus need to be managed. Although several gray, green and hybrid CSO mitigation measures have been studied, the influence of network structure on CSO occurrence is not yet systematically evaluated. This study focuses on evaluating how the variation of urban drainage network structure affects the frequency and magnitude of CSO events. As a study case, a sewer subnetwork in Dresden, Germany, where 11 CSOs are present, was selected. Scenarios corresponding to the structures with the lowest and with the highest number of possible connected pipes, are developed and evaluated using long-term hydrodynamic simulation. Results indicate that more meshed structures are associated to a decrease on the occurrence and magnitude of CSO. Event frequency reductions vary between 0% and 68%, while reduction of annual mean volumes and annual mean loads ranged between 0% and 87% and 0% and 92%. These rates were mainly related to the additional sewer storage capacity provided in the more meshed scenarios, following a sigmoidal behavior. However, increasing network connections causes investment costs, therefore optimization strategies for selecting intervention areas are needed. Furthermore, the present approach of reducing CSO frequency may provide a new gray solution that can be integrated in the development of hybrid mitigation strategies for the CSO management.

scholarly journals Microplastics in Combined Sewer Overflows: An Experimental Study

2021 ◽  
Vol 9 (12) ◽  
pp. 1415
Author(s):  
Fabio Di Nunno ◽  
Francesco Granata ◽  
Francesco Parrino ◽  
Rudy Gargano ◽  
Giovanni de Marinis
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Water Bodies ◽  
Combined Sewer Overflows ◽  
Side Weir ◽  
Combined Sewer ◽  
Sewer Overflows ◽  
Water Outflow ◽  
The Impact

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.

scholarly journals The Impacts of Climate Change and Porous Pavements on Combined Sewer Overflows: A Case Study of the City of Buffalo, New York, USA

2021 ◽  
Vol 3 ◽  
Author(s):  
Andrew Roseboro ◽  
Maria Nariné Torres ◽  
Zhenduo Zhu ◽  
Alan J. Rabideau
Keyword(s):  
Climate Change ◽  
New York ◽  
Combined Sewer Overflows ◽  
Aquatic Life ◽  
Impact Of Climate Change ◽  
Combined Sewer ◽  
Sewer Overflows ◽  
The Impact ◽  
The City

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.

Temporal analysis of E. coli, TSS and wastewater micropollutant loads from combined sewer overflows: implications for management

2015 ◽  
Vol 17 (5) ◽  
pp. 965-974 ◽  
Author(s):  
Madoux-Humery Anne-Sophie ◽  
Sarah M. Dorner ◽  
Sébastien Sauvé ◽  
Khadija Aboulfadl ◽  
Martine Galarneau ◽  
...  
Keyword(s):  
Treatment Options ◽  
Temporal Analysis ◽  
Combined Sewer Overflow ◽  
Combined Sewer Overflows ◽  
E Coli ◽  
Snowmelt Period ◽  
Combined Sewer ◽  
Different Seasons ◽  
Mass Loads ◽  
The Impact

A combined sewer overflow (CSO) outfall was monitored during different seasons (including the snowmelt period) to assess the impact ofE. coli, TSS and WWMP temporal mass loads on the appropriateness of treatment options.

Influence of changes of the wastewater composition on the applicability of UV-absorption measurements at combined sewer overflows

2003 ◽  
Vol 47 (2) ◽  
pp. 73-78 ◽  
Author(s):  
K. Stumwöhrer ◽  
N. Matsché ◽  
S. Winkler
Keyword(s):  
Calibration Procedure ◽  
Uv Absorption ◽  
Storm Water ◽  
Poor Correlation ◽  
Storm Events ◽  
Combined Sewer Overflows ◽  
Rainfall Events ◽  
Combined Sewer ◽  
Sewer Overflows ◽  
Absorption Measurements

The applicability of UV-absorption measurements at combined sewer overflows was investigated under different storm water conditions. Three specific rainfall events of different intensity, different duration and different intervals between the events were investigated. An individual evaluation of each single event resulted in an acceptable correlation between the UV absorption and the pollution measured as COD. A combined evaluation of the different events exhibited a very poor correlation which could not be used as pollution control parameter. Since the calibration procedure of the spectrometer used was not flexible enough to distinguish between different wastewater matrices from the different storm events the applicability of this type of spectrometer for the control of storm water overflows is questionable.

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