Modelling of Combined Sewer Overflow Impacts on the Receiving Water Quality: Case Studies Hron and Drava

2017 ◽  
Author(s):  
Marek Sokáč ◽  
Marta Jerković
Keyword(s):  
Water Quality ◽  
Case Studies ◽  
Slovak Republic ◽  
Treatment Plant ◽  
Combined Sewer Overflows ◽  
Combined Sewer ◽  
Sewer Overflows ◽  
The Town ◽  
Receiving Water

Paper analyses the influences of combined sewer overflows (CSO’s), on the receiving water quality, but generally deals also with various types of storm water management in urban areas. The first case study analyses the impacts of the continuous (wastewater treatment plant in the town Osijek) and discontinuous pollution sources (CSO’s in the town Osijek) on the quality of the receiving water – the Drava river (Croatia). The second modelling case study was performed on the river Hron (Slovak republic). In this study, the impacts on the water quality from combined sewer overflows form the biggest town on Hron River – Banská Bystrica were studied, as well as four feasible alternatives of storm sewer management (different mixing ratio, different size of storm tanks) were analysed. For both case studies, the mathematical simulation model MIKE11 (Danish Hydraulic Institute, DHI) was used.

Toxicity and pollutant impact analysis in an urban river due to combined sewer overflows loads

2010 ◽  
Vol 61 (1) ◽  
pp. 207-215 ◽  
Author(s):  
A. Casadio ◽  
M. Maglionico ◽  
A. Bolognesi ◽  
S. Artina
Keyword(s):  
Water Quality ◽  
Impact Analysis ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Quality Data ◽  
Waste Water Treatment Plant ◽  
Combined Sewer Overflows ◽  
Water Quality Data ◽  
Combined Sewer ◽  
Sewer Overflows

The Navile Channel (Bologna, Italy) is an ancient artificial water course derived from the Reno river. It is the main receiving water body for the urban catchment of Bologna sewer systems and also for the Waste Water Treatment Plant (WWTP) main outlet. The aim of this work is to evaluate the Combined Sewer Overflows (CSOs) impact on Navile Channel's water quality. In order to collect Navile flow and water quality data in both dry and wet weather conditions, two measuring and sampling stations were installed, right upstream and downstream the WWTP outflow. The study shows that even in case of low intensity rain events, CSOs have a significant effect on both water quantity and quality, spilling a considerable amount of pollutants into the Navile Channel and presenting also acute toxicity effects. The collected data shown a good correlations between the concentrations of TSS and of chemical compounds analyzed, suggesting that the most part of such substances is attached to suspended solids. Resulting toxicity values are fairly high in both measuring points and seem to confirm synergistic interactions between heavy metals.

Emission-immission based design of combined sewer overflows and treatment plant - the dresden case study

1997 ◽  
Vol 36 (8-9) ◽  
pp. 355-359
Author(s):  
L. Fuchs ◽  
D. Gerighausen ◽  
S. Schneider
Keyword(s):  
Treatment Plant ◽  
Combined Sewer Overflows ◽  
Quality Model ◽  
Combined Sewer ◽  
Receiving Waters ◽  
Sewer Overflows ◽  
Set Up ◽  
The City

For the city of Dresden a general master plan was set up based on investigations of the hydraulic capacity of the sewer system, the loads from combined sewer overflow and the treatment plant. The total emission from combined sewer overflows and treatment plant was the main criteria for the analysis of the efficiency of different renovation alternatives. The effect of the different alternatives on the quality of the receiving waters was investigated with a water quality model and evaluated with different approaches.

River Water Quality Model no. 1 (RWQM1): Case study I. Compartmentalisation approach applied to oxygen balances in the River Lahn (Germany)

2001 ◽  
Vol 43 (5) ◽  
pp. 41-49 ◽  
Author(s):  
D. Borchardt ◽  
P. Reichert
Keyword(s):  
Water Quality ◽  
Water Column ◽  
River Water ◽  
Water Quality Model ◽  
River Water Quality ◽  
Combined Sewer Overflows ◽  
Quality Model ◽  
Combined Sewer ◽  
Sewer Overflows

A case study on the application of the River Water Quality Model No. 1 (RWQM1) is presented in order to illustrate the importance of modelling a sediment compartment for an ecologically meaningful assessment of the impact of wastewater effluents and combined sewer overflows. The focus of this case study is on the compartmentalisation approach of the RWQM1 that makes such a description possible. In contrast to this, a strongly simplified biochemical submodel is used that considers only oxygen and dissolved substrate. The object of the case study is the River Lahn, a moderately polluted 5th order stream in Germany, for which the connectivity of surface/subsurface flows and mass fluxes within river sediments have been intensively investigated. The hyporheic flow between a downwelling and upwelling zone of a riffle-pool sequence has been studied with the aid of tracer experiments and continuous records of water constituents. High diurnal fluctuations of oxygen travelled to considerable depth of the sediment and oxygen in the interstitial water decreased considerably while travelling through the riffle. Starting with the implementation of a strongly simplified version of the biochemical part of the RWQM1, but with the consideration of a sediment pore water compartment in addition to the water column compartment, a calibration procedure is performed using tracer data from the water column and the sediment. The calibrated model is then used to study the system response to wastewater treatment plant effluent and combined sewer overflow emissions. The modelling approach makes it possible to quantify the sediment oxygen demand and the spatial and temporal extent of sediment zones with oxygen depletion. However, the spatially averaged approach does not account for inhomogeneities in the sediment. It is shown that for this river with its alluvial coarse sediments even moderate emissions from sewerage systems may be high enough to drop sediment oxygen concentrations to low levels while those in the surface flow remain close to saturation. Similarly, it is demonstrated that combined sewer overflows may cause anoxic sediment oxygen conditions for extended time periods. The implications for ecologically sound river water quality modelling and for specific quality objectives are 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.

An application of Austrian legal requirements for CSO emissions

2011 ◽  
Vol 64 (5) ◽  
pp. 1081-1088 ◽  
Author(s):  
Manfred Kleidorfer ◽  
Wolfgang Rauch
Keyword(s):  
Model Calibration ◽  
Model Building ◽  
Treatment Plant ◽  
Cost Effective ◽  
Combined Sewer Overflows ◽  
Sewer System ◽  
Legal Requirements ◽  
Innovative Methods ◽  
Combined Sewer

The Austrian standard for designing combined sewer overflow (CSO) detention basins introduces the efficiency of the combined sewer overflows as an indicator for CSO pollution. Additionally criteria for the ambient water quality are defined, which comprehend six kinds of impacts. In this paper, the Austrian legal requirements are described and discussed by means of hydrological modelling. This is exemplified with the case study Innsbruck (Austria) including a description for model building and model calibration. Furthermore an example is shown in order to demonstrate how – in this case – the overall system performance could be improved by implementing a cost-effective rearrangement of the storage tanks already available at the inflow of the wastewater treatment plant. However, this guideline also allows more innovative methods for reducing CSO emissions as measures for better usage of storage volume or de-centralised treatment of stormwater runoff because it is based on a sewer system simulation.

Model-based comparison of two ways to enhance WWTP capacity under stormwater conditions

2009 ◽  
Vol 60 (7) ◽  
pp. 1875-1883 ◽  
Author(s):  
M. Ahnert ◽  
J. Tränckner ◽  
N. Günther ◽  
S. Hoeft ◽  
P. Krebs
Keyword(s):  
Treatment Plant ◽  
Combined Sewer Overflows ◽  
Worst Case ◽  
Wwtp Effluent ◽  
Combined Sewer ◽  
Total Ammonia ◽  
Rain Events ◽  
Simulated Time ◽  
Simulated Time Series ◽  
Receiving Water

Two different approaches to increase the fraction of combined water treated in the wastewater treatment plant (WWTP) which would otherwise contribute to combined sewer overflows (CSO) are presented and compared based on modelling results with regard to their efficiencies during various rain events. The first option is to generally increase the WWTP inflow according to its actual capacity rather than pre-setting a maximum that applies to worst case loading. In the second option the WWTP inflow is also increased, however, the extra inflow of combined water is bypassing the activated sludge tank and directly discharged to the secondary clarifier. Both approaches have their advantages. For the simulated time series with various rain events, the reduction of total COD load from CSOs and WWTP effluent discharged to the receiving water was up to 20% for both approaches. The total ammonia load reduction was between 6% for the bypass and 11% for inflow increase. A combination of both approaches minimises the adverse effects and the overall emission to the receiving water.

XAI tools in the public sector: a case study on predicting combined sewer overflows

2021 ◽  
Author(s):  
Nicholas Maltbie ◽  
Nan Niu ◽  
Matthew Van Doren ◽  
Reese Johnson
Keyword(s):  
Public Sector ◽  
Combined Sewer Overflows ◽  
The Public ◽  
Combined Sewer ◽  
Sewer Overflows
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