scholarly journals Analysis of the Inflow Characteristics of Separate Sewer Systems for Rainfall Using an XP-SWMM Model and the SSOAP Toolbox

2021 ◽  
Vol 21 (5) ◽  
pp. 271-280
Author(s):  
Young Jun Lee ◽  
Chae Young Lee
Keyword(s):  
Urban Areas ◽  
Volume Data ◽  
Sewer System ◽  
Rainfall Events ◽  
Rainfall Characteristics ◽  
Sanitary Sewer ◽  
Sewer Systems ◽  
Sanitary Sewer Overflow ◽  
Sampling Intervals ◽  
Swmm Model

Even after the sewer system rehabilitation project, sewer system-related problems caused by inflow still persist. However, analysis of the characteristics of the inflow has been limited to specific rainfall events and monitoring points. This study analyzed inflow characteristics according to rainfall events using an XP-SWMM model and the Sanitary Sewer Overflow Analysis and Planning (SSOAP) Toolbox. In this study, the XP-SWMM model was built for sewers and collecting pipes in urban areas where classification projects were completed. The R, T, and K parameters were calculated using the SSOAP tool based on the sewer volume data of the study area. The calculated parameters were inputted into the XP-SWMM model and used to analyze R, T, and K of unmeasured sampling intervals. The amount of rainfall-derived inflow and infiltration (RDII) increased according to the amount of rainfall, and the correlation coefficient between the amount of rainfall and the amount of RDII was 0.9352, indicating a high correlation. The results of this study can support efficient facility planning that reflects the rainfall characteristics of specific areas, including areas where actual survey of sewage data is not possible.

Performance of partially separate sewer systems and impacts on receiving waters

2002 ◽  
Vol 45 (3) ◽  
pp. 273-279 ◽  
Author(s):  
F.M. Ferreira ◽  
J.S. Matos ◽  
A.C. Rodigues ◽  
H.M. do Monte
Keyword(s):  
Urban Areas ◽  
Oxygen Demand ◽  
First Flush ◽  
Drainage Basins ◽  
Sewer System ◽  
Sanitary Sewer ◽  
Sewer Systems ◽  
Receiving Waters ◽  
The Village ◽  
Bacteriological Contamination

The aim of this document is to present and discuss the results of the experimental work undertaken in Laje stream, in a section near the village of Oeiras in Portugal. The work was developed with the main objective of characterising stormwater quality in Portuguese drainage systems, and to predict the effects of the performance of partially separate sewer systems on receiving waters. For this purpose, volume and characteristics of stormwater carried by a partially separated sewer system were estimated, both in terms of flow and Chemical Oxygen Demand (COD) loads. The study also analyses the eventual implementation of non-conventional solutions, as a way of reducing problems of bacteriological contamination of seawaters. This aspect is particularly important in Portugal, where the population is mainly concentrated in urban areas located down-stream of important drainage basins, close to the coastline. Therefore, sanitary sewer overflows discharging directly into receiving waters are frequent, with possible consequences in terms of bacteriological contamination of bathing areas. Based on experimental research and available data it was possible to collect informations regarding stormwater average COD and overflow coliform loads, and the occurrence of first flush effects.

Origins and characteristics of urban wet weather pollution in combined sewer systems: the experimental urban catchment “Le Marais” in Paris

1998 ◽  
Vol 37 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Marie-Christine Gromaire-Mertz ◽  
Ghassan Chebbo ◽  
Mohamed Saad
Keyword(s):  
Waste Water ◽  
Sewer System ◽  
Urban Catchment ◽  
Rainfall Events ◽  
Sources Of Pollution ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Wet Weather ◽  
Wet Weather Flow ◽  
Different Sources

An experimental urban catchment has been created in the centre of Paris, in order to obtain a description of the pollution of urban wet weather flows at different levels of the combined sewer system, and to estimate the contribution of runoff, waste water and sewer sediments to this pollution. Twenty-two rainfall events were studied from May to October 1996. Dry weather flow was monitored for one week. Roof, street and yard runoff, total flow at the catchment outlet and waste water were analysed for SS, VSS, COD and BOD5, on both total and dissolved fraction. Results show an evolution in the characteristics of wet weather flow from up to downstream: concentrations increase from the catchment entry to the outlet, as well as the proportion of particle-bound pollutants and the part of organic matter. A first evaluation of the different sources of pollution establishes that a major part of wet weather flow pollution originates from inside the combined sewer, probably through erosion of sewer sediments.

Estimating rainfall-induced inflow and infiltration in a sanitary sewer system based on water quality modelling: which parameter to use?

2018 ◽  
Vol 4 (3) ◽  
pp. 385-393 ◽  
Author(s):  
Mingkai Zhang ◽  
Yanchen Liu ◽  
Qian Dong ◽  
Yi Hong ◽  
Xia Huang ◽  
...  
Keyword(s):  
Public Health ◽  
Water Quality ◽  
Water Quality Modelling ◽  
Sewer System ◽  
Sanitary Sewer ◽  
Sewer Systems ◽  
Management Issues

Rainfall-derived inflow and infiltration (RDII) of urban sanitary sewer systems poses serious challenges for public health and management issues.

scholarly journals Modeling the quality of sewage during the leaking of stormwater surface runoff to the sanitary sewer system using SWMM: a case study

2021 ◽  
Author(s):  
Maryam Hassan Mohammed ◽  
Haider M. Zwain ◽  
Waqed Hammed Hassan
Keyword(s):  
Surface Runoff ◽  
Low Impact Development ◽  
Maximum Level ◽  
Return Periods ◽  
Sewer System ◽  
Statistical Validation ◽  
Rainfall Events ◽  
Storm Water Management Model ◽  
Sanitary Sewer

Abstract This paper describes the application of the storm water management model (SWMM) for predicting the sewage quality in the sanitary sewer system of the study area resulting from the leaking of stormwater surface runoff to the system during rainfall events at different return periods. The concentrations of major pollutants were assessed in the sanitary sewer system at different rainfall intensities. Then, a solution to mitigate the problem was proposed using low impact development (LID) technology. The results of sensitivity analysis indicated that maximum build-up possible was the most sensitive parameter for model calibration. The model was calibrated using actual rainfall events, and statistical validation coefficients of R (0.81–0.82) and NMSE (0.0173–0.022) proved that the model is valid. The sewage quality assessment results showed that pollutants concentration increased to its maximum level at 20 min and gradually decreased to a slightly constant minimum value after 2 h. The proposed solution of LID reduced the pollutants concentrations by 82–88, 75–77, 52–55, and 7–10% for all pollutants at return periods of 2, 5, 10, and 25 years, respectively. To conclude, SWMM simulation successfully predicted the concentration of the pollutants, and leaking of stormwater surface runoff has changed the sewage quality.

scholarly journals Disaggregation of Future Regional Climate Model Data to Generate Future Rainfall Intensity-Duration-Frequency Curves to Assess Climate Change Impacts

2021 ◽  
Author(s):  
Hüsamettin Tayşi ◽  
Mehmet Ozger
Keyword(s):  
Climate Change ◽  
Urban Areas ◽  
Climate Model ◽  
Regional Climate ◽  
Rainfall Data ◽  
Rainfall Events ◽  
Rainfall Characteristics ◽  
Hourly Data ◽  
Idf Curves ◽  
Intensity Duration Frequency

Heavy increase in urbanization, industrialization and population is causing an increase in emissions of greenhouse gases (GHG) and this causes variations in atmosphere. Climate change causes extreme rainfall events and these events are expected to be enhanced in the future. Since flooding is influencing urban areas, controlling and management of flooding is a major necessity. Intensity-Duration-Frequency (IDF) curves play a huge role in representing rainfall characteristics by linking intensity, duration, and frequency of rainfall. Analysing short-duration rainfall is crucial for urban areas due to fast responses of drainage systems against heavy rainfall events. IDF curves were generated via the Gumbel method for rainfalls from 5-min to 24-h in this study. However, providing short-duration rainfall data is challenging due to the low capacity, costs and geographic conditions. Therefore, the HYETOS disaggregation model was applied to obtain sub-hourly data. IDF curves are stationary since they only consider historical events. However, IDF curves must be non-stationary and time varying based on preparation for upcoming extreme events. This study aims to generate IDF curves under climate change scenarios. The Regional Climate Model (RCM) HadGEM2-ES generated under Representative Concentration Pathways (RCP) 4.5 and 8.5 scenarios and was used in the study to represent future rainfalls. Future daily rainfalls were disaggregated into sub-hourly using disaggregation parameters of corresponding station’s historical rainfall data since it is impossible to estimate parameters when hourly data is not available. With this new approach, future daily rainfall data is disaggregated into 5-min data by complying with historical rainfall patterns rather than complying with randomly selected rainfall characteristics. The study concluded that future rainfall intensities increases compared to historical IDF curves. RCP8.5 scenarios have higher rainfall intensities for all return periods compared to RCP4.5 scenarios for all stations except a station. In addition, the accuracy of the selected disaggregation model was verified.

scholarly journals Comparative Study of AI-Based Methods—Application of Analyzing Inflow and Infiltration in Sanitary Sewer Subcatchments

2020 ◽  
Vol 12 (15) ◽  
pp. 6254
Author(s):  
Zhe Zhang ◽  
Tuija Laakso ◽  
Zeyu Wang ◽  
Seppo Pulkkinen ◽  
Suvi Ahopelto ◽  
...  
Keyword(s):  
Situation Awareness ◽  
Structural Condition ◽  
Sewer System ◽  
Important Indicator ◽  
Inference System ◽  
Sanitary Sewer ◽  
Sewer Systems ◽  
Pumping Stations ◽  
Spatial Decision Making ◽  
Using Data

Inflow and infiltration (I/I) is a common problem in sanitary sewer systems. The I/I rate is also considered to be an important indicator of the operational and structural condition of the sewer system. Situation awareness in sanitary sewer systems requires accurate wastewater-flow information at a fine spatiotemporal scale. This study aims to develop artificial intelligence (AI)-based models (adaptive neurofuzzy inference system (ANFIS) and multilayer perceptron neural network (MLPNN)) and to compare their performance for identifying the potential inflow and infiltration of the sanitary sewer subcatchment of two pumping stations. We tested the performance of these AI models by using data gathered from two pumping stations through a supervisory control and data acquisition (SCADA) system. As a result, these two AI models produced similar inflow and infiltration patterns—both subcatchments experienced inflow and infiltration. On the other hand, the ANFIS had overall higher performance than that of the MLPNN model for modelling the I/I situation for the catchments. The results of the research can be used to support spatial decision making in sewer system maintenance.

Application of a leakage model to assess exfiltration from sewers

2005 ◽  
Vol 52 (5) ◽  
pp. 225-231 ◽  
Author(s):  
C. Karpf ◽  
P. Krebs
Keyword(s):  
Surface Water ◽  
Urban Areas ◽  
Unsaturated Zone ◽  
Specific Model ◽  
Model Parameters ◽  
Sewer System ◽  
Leakage Model ◽  
Sewer Systems ◽  
Potential Impact ◽  
The City

The exfiltration of wastewater from sewer systems in urban areas causes a deterioration of soil and possibly groundwater quality. Beside the simulation of transport and degradation processes in the unsaturated zone and in the aquifer the analysis of the potential impact requires the estimation of quantity and temporal variation of wastewater exfiltration. Exfiltration can be assessed by the application of a leakage model. The hydrological approach was originally developed to simulate the interactions between the groundwater and surface water, it was adapted to allow for modelling of interactions between groundwater and sewer system. In order to approximate the exfiltration specific model parameters infiltration specific parameters were used as a basis. Scenario analysis of the exfiltration in the City of Dresden from 1997 to 1999 and during the flood event in August 2002 shows the variation and the extent of exfiltration rates.

Design of self-cleansing sanitary sewer systems with the use of flushing devices

2009 ◽  
Vol 60 (4) ◽  
pp. 901-908 ◽  
Author(s):  
T. Goormans ◽  
D. Engelen ◽  
R. Bouteligier ◽  
P. Willems ◽  
J. Berlamont
Keyword(s):  
Surface Waters ◽  
Sewer System ◽  
Sewer Pipes ◽  
Hydrodynamic Simulations ◽  
Sanitary Sewer ◽  
Sewer Systems ◽  
Increased Risk ◽  
Combined Sewer ◽  
Maintenance Requirements

Many European countries tend to shift from constructing combined sewer systems to separate ones, in order to optimise wastewater treatment efficiency and reduce CSO impact on surface waters. An economic design minimises maintenance requirements by aiming at self-cleansing pipes. However, providing the necessary slopes for self-cleansing sanitary sewer pipes often is unfeasible in flat regions, resulting in an increased risk of loss of hydraulic capacity or blocking. To reduce these risks, flushing tanks can be installed in the sewer system. Where most other researchers contribute to a better understanding of the hydraulics of flushing, this paper rather tries to formulate a methodology to design and test flushing devices in sanitary sewer systems using standards and hydrodynamic simulations. Therefore, several aspects that require consideration when incorporating flushing devices into a sanitary sewer system are discussed. For instance, when flushing sanitary sewers the increase in discharge has to be explicitly considered. A Belgian case study is used to investigate the suitability of the developed methodology. Although the pipe slopes in the methodology are derived assuming uniform flow, the simulation results comply with it. Furthermore, pressurisation of the conduits due to multiple flushing waves remains within acceptable limits.

scholarly journals River water intrusion as a source of inflow into the sanitary sewer system

2020 ◽  
Vol 82 (11) ◽  
pp. 2472-2481
Author(s):  
Shuai Guo ◽  
Xiang Shi ◽  
Xujia Luo ◽  
Haoming Yang
Keyword(s):  
River Water ◽  
Field Experiments ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Sewer System ◽  
Water Intrusion ◽  
Sanitary Sewer ◽  
Sewer Systems ◽  
Water Problem ◽  
Groundwater Infiltration

Abstract Previous studies on the extraneous water problem (or infiltration/inflow) in sanitary sewer systems assumed that the wastewater flow is mainly composed of foul sewage (FS), groundwater infiltration (GWI) and rainfall-derived inflow and infiltration (RDII). Most existing assessment methods are based on this assumption. In 2018, China initiated the ‘Protection of the Yangtze River Program’, and the two-year research data showed that it was neither the GWI nor the RDII but the direct surface water intrusion (DSWI), which has rarely been reported in literatures, that serves as the main source of the extraneous water in many local sewer systems. The discovery has enriched the understanding of the extraneous water in sewer systems. Meanwhile, it brings new challenges for the assessment of extraneous water. In this study, starting from the analysis of the low influent concentration of chemical oxygen demand (COD) of the wastewater treatment plant in a southeastern city in China, a river water intrusion point was successfully localized and the volume of river water intrusion was quantified by a series of field experiments. The methodology used in this study can also be applied in other areas with DSWI.

scholarly journals The efficiency of urban combined sewer systems during wet weather

2018 ◽  
Vol 45 ◽  
pp. 00017 ◽  
Author(s):  
Ewa Burszta-Adamiak ◽  
Justyna Stańczyk ◽  
Janusz Łomotowski ◽  
Tomasz Konieczny
Keyword(s):  
Urban Areas ◽  
Hydraulic Parameters ◽  
Test Results ◽  
Sewer System ◽  
Transient Flows ◽  
Sewer Systems ◽  
Hydraulic Conditions ◽  
Combined Sewer ◽  
Artificial Neural ◽  
Accuracy Of Prediction

The intensive development of urban areas results in the sealing of increasingly large areas. In such conditions the existing sewer systems are quite often unable to simultaneously collect sewage along with the additional volume of rainwater. These systems require control of the hydraulic parameters in order to recognize the hydraulic conditions that occur in different operational states. Nowadays, such control may be exercised through the use of models that are capable of prediction as a result of the process of learning from a database of historical events. The study presents the possibilities of using Artificial Neural Networks (ANNs) for the analyses of the time series of waste-water depth and flows in a combined sewer system. The measurement campaign organized in Wrocław (Poland) enabled obtaining data on the hydraulic parameters of the flow of sewage in the sewer systems, and rainfall of various characteristics. The test results demonstrate that algorithms of the MLP (Multi-Layered Perceptron) Artificial Neural Network may be implemented to predict the flow rate in the system. The method presented in the paper may be applied to the daily operation of sewer systems to predict transient flows. The obtained results demonstrate a good and very good accuracy of prediction model.

Sign in / Sign up

Export Citation Format

Share Document