Water quality modelling and quantitative microbial risk assessment for uMsunduzi River in South Africa
Artikel i vetenskaplig tidskrift, 2022

South African rivers generally receive waste from inadequate wastewater infrastructure, mines, and farming activities, among others. The uMsunduzi River in KwaZulu-Natal, South Africa, is among these recipients with recorded poor to very poor water quality. To identify parts of the uMsunduzi River that are polluted by Cryptosporidium and Escherichia coli (E. coli), this study mapped out pollutants emanating from point and non-point sources using the Soil and Water Assessment Tool (SWAT). Streamflow calibration in the upper and lower reaches of the catchment showed good performance with R-2 of 0.64 and 0.58, respectively. SWAT water quality output data were combined with a Quantitative Microbial Risk Assessment (QMRA) to understand the microbial health implications for people using river water for drinking, recreational swimming, and non-competitive canoeing. QMRA results for Cryptosporidium and pathogenic E. coli showed that the probability of infection for most users exceeds the acceptable level for drinking and recreation as outlined in the South African water quality guidelines, and by the World Health Organisation (WHO). The results of this study can be used as a baseline to assess the economic and health implications of different management plans, resulting in better-informed, cost-effective, and impactful decision-making.


water quality modelling



uMsunduzi River

Escherichia coli (E. coli)


Zesizwe Ngubane

Durban University of Technology

Viktor Bergion


Bloodless Dzwairo

Durban University of Technology

Karin Troell

Statens veterinärmedicinska anstalt

Uppsala universitet

Isaac Dennis Amoah

Durban University of Technology

Thor Axel Stenstrom

Durban University of Technology

Ekaterina Sokolova

Uppsala universitet

Chalmers, Arkitektur och samhällsbyggnadsteknik, Vatten Miljö Teknik

Journal of Water and Health

1477-8920 (ISSN) 19967829 (eISSN)

Vol. In Press

Cryptosporidium and Giardia: Water quality modelling, microbial source tracking and risk assessment

STINT (SA2015-6274), 2016-03-01 -- 2019-08-31.

Modellering av klimatförändringars effekter på mikrobiologiska risker för ett säkert och hållbart dricksvattensystem

Formas (2017-01413), 2018-01-01 -- 2020-12-31.



Oceanografi, hydrologi, vattenresurser






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