EEN3700 PROJECT 2026 |Environmental Engineering (Civil)| 2026

UNIVERSITY OF SOUTH AFRICA (UNISA)
College of Science, Engineering and Technology



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Assessment of Wastewater Treatment Works

Performance Under Population
Growth Pressure
Societal, Environmental and Ethical Implications


EEN3700 Project — 2026


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Module Code: EEN3700

Module Name: Environmental Engineering (Civil)

Assessment: Year Project

Semester: 2026

Referencing style: OSCOLA

, Declaration




I hereby declare that the project work entitled “Assessment of Wastewater Treatment Works
Performance Under Population Growth Pressure: Societal, Environmental and Ethical Implica-
tions” is a record of an original work done by me. The results embodied in this thesis have not
been submitted to any other University or Institute for the award of any degree or diploma.




NAME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SURNAME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .




STUDENT NUMBER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .




SIGNATURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

,UNISA | EEN3700 WWTW Performance Under Population Growth



Contents


1 Introduction and Background Research 4

1.1 Description of the Wastewater Treatment Works . . . . . . . . . . . . . . . . . . . 4

1.2 Catchment Area and Population Growth Trends . . . . . . . . . . . . . . . . . . . 4

1.3 Original Design Capacity versus Current Demand . . . . . . . . . . . . . . . . . . 5

1.4 Importance of the System to the Community . . . . . . . . . . . . . . . . . . . . . 5


2 Performance and Regulatory Compliance 7

2.1 Identification of Key Effluent Quality Parameters . . . . . . . . . . . . . . . . . . . 7

2.2 Comparison with DWS General Authorisation Limits . . . . . . . . . . . . . . . . . 7

2.3 Discussion of Performance Trends and Non-Compliance . . . . . . . . . . . . . . 8


3 Societal, Environmental and Ethical Implications 10

3.1 Impacts on Downstream Ecosystems and Communities . . . . . . . . . . . . . . 10

3.2 Public-Health Risks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3.3 Ethical Responsibilities of Environmental Engineers . . . . . . . . . . . . . . . . . 11

3.4 Consequences of Inaction or Poor Decision-Making . . . . . . . . . . . . . . . . . 12


4 Engineering Judgement and Sustainable Recommendations 13

4.1 Technical Feasibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.2 Cost and Affordability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4.3 Sustainability and Long-Term Impacts . . . . . . . . . . . . . . . . . . . . . . . . . 14

4.4 Social Equity and Regulatory Compliance . . . . . . . . . . . . . . . . . . . . . . . 14


5 Personal Professional Reflection 16


Table of Legislation 17



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,UNISA | EEN3700 WWTW Performance Under Population Growth


6 References 18


References 18




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, UNISA | EEN3700 WWTW Performance Under Population Growth



1 Introduction and Background Research


1.1 Description of the Wastewater Treatment Works


The study considers a hypothetical municipal wastewater treatment works (WWTW) situ-
ated within a rapidly developing town in South Africa. The treatment works receives domestic
wastewater from residential, commercial and institutional areas before treating the wastewa-
ter to meet regulatory discharge standards. Typical wastewater treatment processes include
preliminary screening, grit removal, primary sedimentation, biological treatment using acti-
vated sludge, secondary clarification, sludge handling and final disinfection before the treated
effluent is discharged into a nearby river.1 The overall purpose of the WWTW is to remove
suspended solids, biodegradable organic matter, nutrients and disease-causing microorgan-
isms, thereby protecting receiving water resources and safeguarding public health. Effective
wastewater treatment also reduces environmental pollution and supports sustainable wa-
ter resource management, which is particularly important in water-scarce countries such as
South Africa.


1.2 Catchment Area and Population Growth Trends


The wastewater treatment works serves a municipal catchment consisting of residential sub-
urbs, schools, healthcare facilities, businesses and light industrial developments. Like many
South African municipalities, the catchment has experienced continuous population growth
resulting from urbanisation, natural population increase and rural-to-urban migration. As the
population increases, greater volumes of wastewater are generated, placing additional pres-
sure on existing treatment infrastructure. Population growth frequently exceeds the rate at
which municipal infrastructure is upgraded, causing wastewater treatment facilities to oper-
ate beyond their intended capacity. Consequently, hydraulic overloading reduces treatment
efficiency, increases the risk of untreated or partially treated effluent entering receiving water
bodies and places greater strain on maintenance resources.2

1
Department of Water and Sanitation, General Authorisation in terms of Section 39 of the National Water Act 36
of 1998 (DWS 2013).
2
Department of Water and Sanitation, Green Drop Progress Assessment Report (DWS 2022).




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