A Software Monitor for Intermittent Bacterial Contamination in Urban Rivers

• Published in: Water science and technology Vol. 47; no. 2; p. 165
• Main Authors: Mietzel, T, Frehmann, T, Geiger, W F, Schilling, W
• Format: Journal Article
• Language: English
• Published: 01.01.2003
• ISSN: 0273-1223

Data from the Leirelva River in Trondheim, Norway, were used to search for correlations between bacterial contamination and other parameters that could be measured online. Effluents from 13 combined sewer overflows and three stormwater outfalls are discharged into the river. The online data included flow, pH, conductivity, temperature, the spectral absorption coefficient, and turbidity. Weekly water samples were collected and analyzed for thermotolerant bacteria and fecal streptococci. Strong correlations were found between thermotolerant bacteria and fecal streptococci. The spectral absorption coefficient was deemed the parameter best suited for predicting bacterial contamination. However, only by classifying the water samples into those exceeding and not exceeding the bathing water standard, respectively, was the method found to be applicable. Using this classification, rainfall-runoff simulation was also effective.