Methods for Calculation of Annual and Extreme Overflow Events from Combined Sewer Systems

1984 ◽  
Vol 16 (8-9) ◽  
pp. 311-325 ◽  
Author(s):  
N B Johansen ◽  
P Harremoës ◽  
M Jensen
Keyword(s):  
Extreme Event ◽  
Short Term ◽  
Sewer Systems ◽  
Extreme Load ◽  
Combined Sewer ◽  
Receiving Waters ◽  
Water Problems ◽  
Source Of Pollution ◽  
Receiving Water

Overflow from combined systems constitute an increasing source of pollution of receiving waters, as compared to daily wastewater discharges which undergo treatment to a still higher extent. The receiving water problems from overflows are significant both in a long term scale (mean annual load) and in a short term scale (extreme event load). A method for computation of both annual and extreme load is presented. It is based on historical rain series and the use of a time-area model and simple pollutant mixing model in runoff calculation. Statistical calculations for both mean annual load and extreme events have been applied to the computed overflow series. Based on the computerized method simple manual calculations methods have been developed, resulting in graphs and tables for annual load and extreme load.

Occurrence and fate of organic pollutants in combined sewer systems and possible impacts on receiving waters

2007 ◽  
Vol 56 (10) ◽  
pp. 141-148 ◽  
Author(s):  
A. Welker
Keyword(s):  
Organic Pollutants ◽  
Wastewater Treatment Plants ◽  
Combined Sewer Overflows ◽  
Sewer Systems ◽  
Flow Surface ◽  
Combined Sewer ◽  
Polycyclic Aromatic ◽  
Receiving Waters ◽  
First Time ◽  
Receiving Water

Selected organic pollutants are classified based on an intensive literature survey. Two wastewater parameters (COD and ammonium) and six selected organic pollutants (polycyclic aromatic hydrocarbons (PAH), diethylhexylphthalate (DEHP), estradiol (E2), ethinylestradiol (EE2), ethylenediamine tetraacetic acid (EDTA) and nitrilo triaceticacid (NTA)) are specified. As a result, for the first time representative concentrations in dry weather flow, surface runoff and effluent of wastewater treatment plants (WWTPs) in combined sewer systems (CSS) are stated. The second part of the paper presents a first estimation of main emission out of a combined sewer system and possible receiving water impacts in terms of (1) annual discharged loads calculated by pollution load simulations in a hypothetical catchment and (2) concentrations calculated in combined sewer overflows (CSO) discharges and resulting receiving water concentrations.

Urban Storm Water Discharges: Effects upon Communities of Sessile Diatoms and Macro-Invertebrates

1990 ◽  
Vol 22 (10-11) ◽  
pp. 147-154 ◽  
Author(s):  
G. D. Willemsen ◽  
H. F. Gast ◽  
R. O. G. Franken ◽  
J. G. M. Cuppen
Keyword(s):  
Organic Pollution ◽  
Constant Flow ◽  
Combined Sewer Overflows ◽  
Sewer System ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Receiving Waters ◽  
Sewer Overflows ◽  
Urban Storm

From 1985 to 1987, long-term and more or less permanent effects of discharges from combined or separate sewer systems on communities of sessile diatoms and macro-invertebrates in receiving waters have been studied. Sessile diatoms and/or macro-invertebrates have been investigated on 46 locations, spread all over The Netherlands. The results were related to the type of sewer system, the discharges, and the characteristics of the receiving water, and compared with results from sample(s) taken from a corresponding water not influenced by sewer overflows, the reference water. In general, communities of sessile diatoms and macro-invertebrates indicate a more severe organic pollution and disturbance of receiving waters compared with reference waters. In the immediate vicinity of the overflows these communities were more disturbed than at some distance. In small ditches, effects were more pronounced compared with large waterbodies and waters with a constant flow regime. Finally, effects of combined sewer overflows were more pronounced than effects of discharges from separate sewer systems, except for locations in industrial areas.

Predicting the Long Term Distribution of Extreme Loads From Limited Duration Data: Comparing Full Integration and Approximate Methods

2002 ◽  
Author(s):  
LeRoy M. Fitzwater ◽  
Steven R. Winterstein ◽  
C. Allin Cornell
Keyword(s):  
Load Distribution ◽  
Robust Methods ◽  
Short Term ◽  
Approximate Methods ◽  
Wind Speeds ◽  
Extreme Loads ◽  
Long Run ◽  
Extreme Load ◽  
Limited Duration

In this paper we present a methodology for proceeding from the short-term observations of extreme loads to the long-run load distribution of these extreme events, for both flap and edge loading in both operating and parked wind turbine conditions. First a general approach utilizing full integration, where numerical routines are used to directly integrate the conditional short-term load distribution over the annual occurrence of wind speeds and turbulence intensities, is presented. Then starting from this general approach, a qualitative analysis is undertaken to explore the extent of the contribution of each of the three variables, in the governing equation, to the variability in the long-term extreme load distribution. From this analysis, lower order models are considered, where instead of using the entire distribution of the variables, a constant fractile of the short-term extreme load distribution, turbulence intensity distribution, or both are used. Finally recommendations are given to guide the analyst to decide when simpler, yet robust, methods which account for sufficient variability in extreme load event may be employed with confidence.

Settleable Solids from Combined Sewers: Settling, Stormwater Treatment, and Sedimentation Rates in Rivers

1994 ◽  
Vol 29 (1-2) ◽  
pp. 95-102
Author(s):  
S. Michelbach ◽  
C. Wöhrle
Keyword(s):  
River Sediments ◽  
Oxygen Demand ◽  
Stormwater Treatment ◽  
Organic Micropollutants ◽  
Sewer Systems ◽  
Settling Behaviour ◽  
Combined Sewer ◽  
Important Pathway ◽  
Receiving Waters ◽  
The Relationship

Settleable solids are an important pathway for pollutants found in river sediments. To study settling behaviour of settleable solids, settling velocity was measured by a settling apparatus. Special measurements were undertaken to determine the relationship between the settling distribution of settleable solids and their pollutant load - organic mass, chemical oxygen demand, heavy metals and organic micropollutants. To calculate where settleable solids from combined sewer systems will settle in receiving waters, the settling distribution is also useful. The results of a three-year research indicate that stormwater treatment by settling is effective in preventing adverse environmental impacts of combined sewage pollutants.

scholarly journals Evaluating three commonly used infiltration methods for permeable surfaces in urban areas using the SWMM and STORM

2021 ◽  
Author(s):  
Frida E. Å. Parnas ◽  
Elhadi M. H. Abdalla ◽  
Tone M. Muthanna
Keyword(s):  
Urban Areas ◽  
Sandy Soils ◽  
High Sensitivity ◽  
Field Measurements ◽  
Infiltration Rate ◽  
Infiltration Capacity ◽  
Infiltration Process ◽  
Sewer Systems ◽  
Combined Sewer

Abstract Climate change and urbanization increase the pressure on combined sewer systems in urban areas resulting in elevated combined sewer overflows, degraded water quality in receiving waters, and changing stream flows. Permeable surfaces offer infiltration potential, which can contribute to alleviate the runoff to combined sewer systems. The variation in urban soil characteristics and the initial moisture conditions before a rainfall event are important factors affecting the infiltration process and consequently runoff characteristics. In this study, the urban hydrological models SWMM and STORM are used to evaluate the Green-Ampt, Horton, and Holtan infiltration methods for three urban sandy soils. A sensitivity analysis was carried out on a set of key parameter values. In addition, long-term simulations were conducted to evaluate the ability to account for initial soil moisture content. The results showed that the Holtan method's ability to account for both available storage capacity and maximum infiltration rate, as well as evapotranspiration in the regeneration of infiltration capacity, gave the best result with regards to runoff behaviour, especially for long-term simulations. Furthermore, the results from the urban sandy soils with different infiltration rate at saturation, together with a high sensitivity to the degree of sensitivity for maximum infiltration rate under dry conditions and minimum infiltration rate under wet conditions, indicate that field measurements of infiltration rate should be carried out at saturation for these soils.

scholarly journals Ecological aspect in combined sewer overflows chamber design

2013 ◽  
Vol 8 (3-4) ◽  
pp. 409-416
Author(s):  
J. Pollert
Keyword(s):  
Ecological Engineering ◽  
Combined Sewer Overflows ◽  
Reinforced Plastic ◽  
Combined Sewer ◽  
New Type ◽  
Receiving Waters ◽  
Sewer Overflows ◽  
The Cost ◽  
Floating Objects ◽  
Receiving Water

In 2005 one of major Czech manufacturers of glass reinforced plastic pipes asked the Department of Sanitary and Ecological Engineering to develop a new type of combined sewer overflows (CSO) chamber that could become a part of their manufacturing programme. The main requirements were economy of production, easy and fast installation on the field and increased protection of receiving waters. A simple object consisting of a pipe placed above another one was designed. The object begins with a stilling chamber formed by a conical expansion of the inlet pipe. It is separated from the overflow object itself by a downflow baffle designed to trap floating objects. The CSO chamber is equipped by a flow regulation device (e.g. vortex valve or throttle pipe) at the end. Excess water flows through a slit in the top of the bottom pipe into the upper pipe and from there to the receiving water. More than 15 prototypes were already installed in the Czech and Slovak Republics and more than 20 are planned to be built in Europe. We hope this type of CSO CHAMBER will help to decrease the cost of construction of new sewers and reconstruction of old ones. Its higher efficiency of separation of suspended particles might also contribute to the improvement of the quality of receiving water bodies according to Water Framework Directive 2000/60/EC.

Urban Storm Water Discharges: Effects upon Plankton Communities

1990 ◽  
Vol 22 (10-11) ◽  
pp. 155-162 ◽  
Author(s):  
H. F. Gast ◽  
R. E. M. Suykerbuyk ◽  
R. M. M. Roijackers
Keyword(s):  
Storm Water ◽  
Running Waters ◽  
Sewer System ◽  
Combined Sewer ◽  
Receiving Waters ◽  
Zooplankton Communities ◽  
Plankton Communities ◽  
Urban Storm ◽  
Receiving Water

From 1985 to 1987, effects of sewer discharges on communities of phyto- and Zooplankton in receiving waters have been studied. Locations all over The Netherlands have been selected. The results were related to the type of sewer system, the discharges and the characteristics of the receiving water. Results were compared with those from samples taken from a corresponding water not influenced by sewer discharges, the reference water. Often either phyto- or Zooplankton communities could be used succesfully to describe the short-and medium-term effects of the discharges on the quality of the involved habitats. Plankton communities could also indicate permanent effects due to higher saprobic levels in the receiving water compared to the reference water: an obvious result of urban storm water discharges. In small and medium-sized stagnant waters, particularly in the immediate vicinity of the overflows, effects on plankton communities were more pronounced compared to large and running waters. Combined sewer system overflows (CSO) often proved to affect plankton communities more severely than separate sewer system discharges (SSD), except for some locations in industrial areas.

Predicting the Long Term Distribution of Extreme Loads From Limited Duration Data: Comparing Full Integration and Approximate Methods

2002 ◽  
Vol 124 (4) ◽  
pp. 378-386 ◽  
Author(s):  
LeRoy M. Fitzwater ◽  
C. Allin Cornell
Keyword(s):  
Load Distribution ◽  
Robust Methods ◽  
Short Term ◽  
Approximate Methods ◽  
Wind Speeds ◽  
Extreme Loads ◽  
Long Run ◽  
Extreme Load ◽  
Limited Duration

In this paper, we present a methodology for proceeding from the short-term observations of extreme loads to the long-run load distribution of these extreme events, for both flap and edge loading in both operating and parked wind turbine conditions. First, a general approach utilizing full integration, where numerical routines are used to directly integrate the conditional short-term load distribution over the annual occurrence of wind speeds and turbulence intensities, is presented. Then starting from this general approach, a qualitative analysis is undertaken to explore the extent of the contribution of each of the three variables in the governing equation to the variability in the long-term extreme load distribution. From this analysis, lower-order models are considered, where instead of using the entire distribution of the variables, a constant fractile of the short-term extreme load distribution, turbulence intensity distribution, or both are used. Finally recommendations are given to guide the analyst to decide when simpler, yet robust, methods which account for sufficient variability in extreme load events may be employed with confidence.

Urban Drainage Systems: Design and Operation

1993 ◽  
Vol 27 (12) ◽  
pp. 31-70 ◽  
Author(s):  
J. Marsalek ◽  
T. O. Barnwell ◽  
W. Geiger ◽  
M. Grottker ◽  
W. C. Huber ◽  
...  
Keyword(s):  
Sewage Treatment ◽  
Systems Design ◽  
Urban Drainage ◽  
Sewer System ◽  
Drainage Systems ◽  
Planning And Design ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Urban Drainage Systems ◽  
Receiving Waters

Design and operation of urban drainage systems are addressed in the context of the urban water system comprising drainage, sewage treatment plants and receiving waters. The planning and design of storm sewers are reviewed with reference to planning objectives, design objectives, flows and pollutant loads, sewer system structures and urban runoff control and treatment. The discussion of combined sewers focuses on hydraulic design of combined sewer systems, including combined sewer overflow (CSO) structures, and the use of CSO structures and storage in control of CSOs. The section on operation of sewer systems focuses on real time control, its feasibility, planning, design, operation and applications. Sewer system planning and design are generally conducted using computer modelling tools and procedures which are reviewed in the last section. A brief listing of selected models focuses on internationally used models. Finally, it was concluded that further improvements in environmental and ecological protection of urban waters is feasible only by consideration of urban drainage systems in conjunctions with sewage treatment and water quality in the receiving waters.

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