|Monitoring of β-D-Galactosidase Activity as a Surrogate Parameter for Rapid Detection of Sewage Contamination in Urban RecreationalWater
Abstract: The activity of the enzyme β-D-galactosidase (GAL) can rapidly (<2 h) be measured by field instruments, or a fully automated instrument, and was evaluated as a potential surrogate parameter for estimating the level of fecal contamination in urban waters. The GAL-activity in rivers, affected by combined sewer overflows, increased significantly
rainfall, and the increase in GAL-activity correlated well with the increase in fecal indicator bacteria. Furthermore, the GAL-activity per gram feces from birds, sheep and cattle was 2–3 LOG10 lower than the activity from human feces, indicating that high GAL-activity in water may reflect human fecal pollution more than the total fecal pollution.
|On-Line Monitoring of Escherichia coli in Raw Water at Oset
Abstract: The fully automated Colifast ALARMTM has been used for two years for daily monitoring of the presence/absence of Escherichia coli in 100 mL raw water at Oset drinking water treatment plant in Oslo, Norway. The raw water is extracted from 35 m depth from the Lake Maridalsvannet. E. coli was detected in 18% of the daily samples. In general, most samples positive for E. coli were observed during the autumn turnover periods, but even in some samples taken during warm and dry days in July, with stable temperature stratification in the lake, E. coli was detected. The daily samples gave useful additional information compared with the weekly routine samples about the hygienic raw water quality and the hygienic barrier efficiency of the lake under different weather conditions and seasons. The winter 2013/2014 was much warmer than the winter 2012/2013. The monitoring supported the hypothesis that warmer winters with shorter periods with ice cover on lakes, which may be a consequence of climate changes, may reduce the hygienic barrier efficiency in deep lakes used as drinking water sources.
|New methods for on-line detection of coliform bacteria in drinking water
|Vurdering av metoder for overvåkning av hygienisk badevannskvalitet
|Gothenburg raw water – Göta river monitoring