10.4122/1.1000001666
Rueedi, J.
J.
Rueedi
Cronin, A.A.
A.A.
Cronin
Morris, B.L.
B.L.
Morris
Daily patterns of micro-organisms in the foul sewer system of Doncaster, United Kingdom
DTU Library, Technical University of Denmark (DTU)
2005
Conference full text
Urban water
Daily pattern
Micro-organisms
Sewage
Seasonal trend
Enterovirus
University Of Surrey, Robens Centre For Public
Robens Centre For Public
University Of Surrey
Cronwnmarsh Guifford, British Geological Survey
British Geological Survey
Cronwnmarsh Guifford
2005
en
10.4122/1.1000001665
application/pdf
Much is known about short-term changes in sewage volumes because they are often measured in pipeline design studies. Usually, sewage volumes peak in the morning and again in the evening, and leakage rates are expected to change correspondingly. To assess the contaminant load leaking into the subsurface, however, it is important to know the daily evolution of contaminant concentrations. These data are scarce, particularly for pathogenic micro-organisms. This study describes results of raw sewage sampling at three pumping stations for total coliforms, faecal coliforms, faecal streptococci, sulphite-reducing clostridia, coliphage and enteric viruses. The results show that all analysed micro-organisms follow a similar daily pattern, namely high concentrations during the morning, dropping around noon, rising again during the afternoon and then falling again in the evening and nighttime. Concurrent measurement of sewage volumes enabled assessment of total contaminant loads leaving the urban area, estimation of likely daily patterns of toilet/grey water contribution to raw sewage and calculation of daily average loads for urban mass balance modeling. The paper shows how important it is to measure not only daily patterns of sewage volumes but also sewage concentrations because both vary significantly during the day due to different household usage patterns.