Reliable estimation of sewage flow rates is essential for the proper design of sewers, pumping stations, and treatment plants. The widely used design peaking factors for sewerage systems are usually related to the population served or the average sewage flow rate ignoring the difference between communities having same population but different socio-economic conditions and water use practice. In this study, a simulation model is developed to generate synthetic wastewater flow hydrographs resulting from a community with specific socio-economic conditions. The synthetic hydrographs are developed while retaining their commonly observed random behavior. The socioeconomic characteristics of a community are accounted for by the composition of the community and its social categories, the water use pattern of every category during the various daily activities (weekday and weekend), and the water use facilities (fixtures and appliances) available to the community. The model utilizes different water use patterns by every social group for every appliance during the different day types e.g. weekday and weekend. The use patterns account for the stochastic nature of use in terms of number of uses, duration of use and times of use in the day. Randomly generated hydrographs are generated for weekdays and weekends. The daily sewer hydrographs are transformed by hydraulic routing through the sump --pump to daily pumped flow hydrographs conveying wastewater to the treatment plant. One year of generated record of both hydrographs is statistically analyzed to derive two sets of flow factor curves to be used for the design of sewers, and the various components of the treatment plant. The flow factors are given in terms of the duration when the flow factor is sustained and the probability that the flow is not- . The proposed model was applied to a small community with certain socio-economic conditions and population and the resulting design peaking factors were obtained and compared to flow factors derived from a limited measurement program of the wastewater hydrographs generated by the community. The results indicate the usefulness of the proposed model in predicting probable flow hydrographs from selected communities with specific socio-economic setting and population. A parametric study is carried out to investigate the effect of the community population, class and socio-economic conditions on the design flow factors.


Environmental Engineering Program

Degree Name

MS in Environmental Engineering

Graduation Date


Submission Date

July 2012

First Advisor

Imam, Emad



Document Type

Master's Thesis

Library of Congress Subject Heading 1

Sewerage -- Design and construction.

Library of Congress Subject Heading 2

Sanitary engineering.


The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy.

Institutional Review Board (IRB) Approval

Not necessary for this item


I would like to thank my family for their constant and relentless support. It is a must to highly appreciate my great advisor, Dr. Emad Imam who always supported me and taught me far beyond the written words and numbers of these pages. His advice will always guide me in life, and I am really honored of always being his student. He is always believing in me and giving me the confidence to conquer and advance. I would like also to extend my gratitude to Dr. Khaled ssar for giving me the sincere guidance through developing the model of this thesis. He has given me a lot of his valuable time and patience that I really appreciate. My professors who taught me at the Environmental Engineering program have strengthen my engineering wise and helped me a lot in opening my mind. I would like here to highly appreciate Dr. Edward Smith, Director of Environmental Engineering Program, who believed in me from the beginning of my working at AUC. Last but not least, I would like acknowledge that this thesis was supported by award No. UK-C0015 made by King Abdullah University of Science and Technology (KAUST)