Levels of Norovirus and E. coli in Untreated, Biologically Treated and UV-Disinfected Sewage Effluent Discharged to a Shellfish Water


The efficacy of an activated sludge (modified Ludzack-Ettinger (MLE)) UV disinfection processes in removing human noroviruses and E. coli from sewage were compared with the prevalence of these microorganisms in a settled storm discharge from the same sewage treatment works. Both discharges impacted a designated oyster production area. The treatment process delivered average NoV and E. coli reductions of 2.9log10 and 5.2log10, respectively. Most E. coli reductions occurred during the UV disinfection process whereas the MLE process was comparatively more important in reducing NoV levels. A positive relationship was found between NoV removal and measured applied UV dose. The average levels of total NoV in the settled storm tank were of the same order of magnitude of those in screened raw influent at the works. These results highlight the importance of measures to reduce the impact of stormwater discharges to minimise the risk of NoV gastroenteritis associated with the consumption of oysters.

Share and Cite:

C. Campos, J. Avant, J. Lowther, D. Till and D. Lees, "Levels of Norovirus and E. coli in Untreated, Biologically Treated and UV-Disinfected Sewage Effluent Discharged to a Shellfish Water," Journal of Water Resource and Protection, Vol. 5 No. 10, 2013, pp. 978-982. doi: 10.4236/jwarp.2013.510101.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] P. G. Cantalupo, B. Calgua, G. Zhao, A. Hundesa, A. D. Wier, J. P. Katz, M. Grabe, R. W. Hendrix, R. Girones, D. Wang and J. M. Pipas, “Raw Sewage Harbors Diverse Viral Populations,” mBio, Vol. 2, No. 5, pp. e00180-11.
[2] D. Lees, “Viruses and Bivalve Shellfish,” International Journal of Food Microbiology, Vol. 59, No. 1-2, 2000, pp. 81-116. http://dx.doi.org/10.1016/S0168-1605(00)00248-8
[3] C. T. Zainazor, M. S. Noor Hidayah, L. C. Chai, R. Tunung, F. M. Ghazali and R. Son, “The Scenario of Norovirus Contamination in Food and Food Handlers,” Journal of Microbiology and Biotechnology, Vol. 20, No. 2, 2010, pp. 229-237.
[4] Environment Agency, “Efficacy and Effects of Wastewater Disinfection Phase 5 Review of Wastewater UV Disinfection Performance in England and Wales,” Environment Agency R&D Technical Report P2-036/TR, 2002.
[5] Environment Agency, “Water Discharge Permitting: Disinfection of Wastewater,” Operational Instruction 347_09 Issued 30/06/2010.
[6] Environment Agency, “Consenting Guidance to Achieve the requirements of the Shellfish Waters Directive (Microbial Quality),” Environment Agency Water Quality Consenting Guidance 169_01 Issued 30/01/2003.
[7] G. Berg, “Removal of Viruses from Sewage, Effluents, and Waters. 1. A Review,” Bulletin of the World Health Organization, Vol. 49, No. 5, 1973, pp. 451-460.
[8] L. J. Cross, “The Development and Application of Quantitative Methods for Norovirus Detection in Sewage Effluents and Seawater,” Ph.D. Thesis, School of Biomedical & Molecular Sciences, University of Surrey, Guildford, 2004.
[9] M. Puig, J. Jofre, F. Lucena, A. Allard, G. Wadell and R. Girones, “Detection of Adenoviruses and Enteroviruses in Polluted Waters by Nested PCR Amplification,” Applied and Environmental Microbiology, Vol. 60, No. 8, 1994, pp. 2963-2970.
[10] J. A. Lowther, N. E. Gustar, A. L. Powell, R. E. Hartnell and D. N. Lees, “Two-Year Systematic Study to Assess Norovirus Contamination in Oysters from Commercial Harvesting Areas in the United Kingdom,” Applied and Environmental Microbiology, Vol. 78, No. 16, 2012, pp. 5812-5817. http://dx.doi.org/10.1128/AEM.01046-12
[11] Environment Agency, “The Microbiology of Recreational and Environmental Waters. Methods for the Examination of Waters and Associated Materials,” Environment Agency, Bristol, 2000.
[12] D. Kay, J. Crowther, C. M. Stapleton, M. D. Wyer, L. Fewtrell, A. Edwards, C. A. Francis, A. T. McDonald, J. Watkins and J. Wilkinson, “Faecal Indicator Organism Concentrations in Sewage and Treated Effluents,” Water Research, Vol. 42, No. 1-2, 2008, pp. 442-454.
[13] C. P. Gerba, “Pathogen Removal,” In: M. Henze, M. C. M. van Loosdrecht, G. A. Ekama and D. Brdjanovic, Eds., Biological Wastewater Treatment: Principles, Modelling and Design, IWA Publishing, Cambridge University Press, London, 2008, pp. 221-242.
[14] R. Palfrey, M. Harman and R. Moore, “Impact of Waste Water Treatments on Removal of Noroviruses from Sewage,” WRc R&D Technical Report WT0924/TR to Defra, 2011.

Copyright © 2023 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.