Water quality in rural Australia

Thurman, Robert B.; Faulkner, B.; Veal, Duncan; Cramer, George H.; Meiklejohn, M.

doi:10.1046/j.1365-2672.1998.00390.x

Cited by 48 publications

(34 citation statements)

References 6 publications

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“…The concentrations of E. coli, coliform bacteria, and enterococci, as well as turbidity, increased after rainfall (1,9,10,28,31). The concentrations of Cryptosporidium oocysts were found to be lower during dry periods, such as summer (14,28).…”

Section: Vol 68 2002mentioning

confidence: 92%

“…Only moderate correlations between parasites and other parameters, such as fecal microorganisms, especially C. perfringens (1,6,9,27,28), turbidity (1, 9), or rainfall and runoff, which increased the concentrations of several feces-borne microorganisms (1,9,20), have been reported. Many studies did not detect any statistically significant correlations between parasites and other microbial, chemical, and hydrological parameters (4,16,29,31). No significant correlation was found between Cryptosporidium oocyst concentrations and rainfall or river flow at 10 sites in the United Kingdom (3).…”

Section: Vol 68 2002mentioning

confidence: 99%

“…Hsu et al investigated small water systems in Taiwan for correlations with altitude and water quality parameters but found significant correlations only between Giardia and Cryptosporidium concentrations (16). Thurman et al analyzed reservoirs and creeks at different sites in Australia for interactions among land use, rainfall, and water quality parameters but found no significance even though parasite and E. coli concentrations peaked after heavy rainfall (31).…”

Section: Vol 68 2002mentioning

confidence: 99%

“…Additional loading from non-point-source runoff (5,7,10), as well as from river bottom resuspension, was determined to be responsible for the increases (6,9,13,23,25). As most of the Giardia cysts observed had a nonviable morphology, resuspension of stream bottom sediment or suspension of soil and aged fecal material was assumed to be the major contributor to rainfall-induced increases in parasite concentrations (1,31). However, because of combined sewage overflows and reduced treatment of discharged wastewater during extreme runoff situations, sewage plants should not be excluded as point sources of parasite contamination (1,5,9,14,20,21,29).…”

Section: Vol 68 2002mentioning

confidence: 99%

“…Some studies have shown that there are correlations between microbial loads of stream water and the conditions mentioned above (1,9,10,28,31), and the question is whether dry-weather sampling provides representative data for microbial contamination of reservoir tributaries throughout the year (5,17,31), since the (Enhanced) Surface Water Treatment Rule of the U.S. Environmental Protection Agency includes an action level of 30 parasites per 100 liters of raw water and no parasites per 100 liters of finished water (17,20,28). In this study we investigated the association of several parasitic and bacterial parameters with rainfall, runoff, and specific conditions in catchment areas of drinking water reservoirs in order to understand what factors are associated with peaks of contamination (4,20).…”

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confidence: 99%

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Microbial Load of Drinking Water Reservoir Tributaries during Extreme Rainfall and Runoff

Kistemann

Claßen

Koch

et al. 2002

Appl Environ Microbiol

365

239

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Hygienic and microbiological examinations of watercourses are usually not carried out during heavy rainfall and runoff events. After rainfall or snowmelt, there are often massive increases in turbidity in flooding creeks in mountain ranges, which are frequently interpreted as an indication of microbial contamination. The aim of this study was to quantify the microbial loads of watercourses during such runoff events and to compare these loads with loads occurring during regular conditions. In a 14-month monitoring period we investigated the microbial loads of three tributaries of different drinking water reservoirs. A total of 99 water samples were taken under different runoff conditions and analyzed to determine physical, chemical, bacterial, and parasitic parameters. Thirty-two water samples were considered event samples during nine measuring series. The criteria for events, based on duration and intensity of precipitation, water depth gauge measurements, and dynamics, had been fixed before the investigation for each creek individually. Of the physical and chemical parameters examined, only the turbidity, pH, and nitrate values differed clearly from the values obtained for regular samples. Most of the bacteriological parameters investigated (colony, Escherichia coli, coliform, fecal streptococcal, and Clostridium perfringens counts) increased considerably during extreme runoff events. If relevant sources of parasitic contamination occurred in catchment areas, the concentrations of Giardia and Cryptosporidium rose significantly during events. The results show that substantial shares of the total microbial loads in watercourses and in drinking water reservoirs result from rainfall and extreme runoff events. Consequently, regular samples are considered inadequate for representing the microbial contamination of watercourse systems. The procedures for raw water surveillance in the context of multiple-barrier protection and risk assessment ought to include sampling during extreme runoff situations.In some regions of Germany surface reservoirs are the main source of drinking water. In the state of North Rhine-Westphalia, 60% of the drinking water production in 1999 was based on surface water resources (2). Surface water bodies are presumed to be more vulnerable to fecal contamination than groundwater reservoirs due to the absence of natural soil protection and filtration and the possibly short distances between the occurrence of contamination and water extraction. It is argued that especially in the case of heavy rainfall the microbial loads of running waters may suddenly increase substantially and reach reservoir bodies very quickly (18,19). For this reason monitoring microbiological raw water quality is an essential component of the protection strategy in catchment areas of surface drinking water reservoirs (8). In Germany, catchment areas of surface water supplies are usually protected by buffer zones, and the intensity of protection increases with proximity to the water body. Protection of entire catchment areas i...

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Section: Vol 68 2002mentioning

confidence: 92%

Section: Vol 68 2002mentioning

confidence: 99%

Section: Vol 68 2002mentioning

confidence: 99%

Section: Vol 68 2002mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Microbial Load of Drinking Water Reservoir Tributaries during Extreme Rainfall and Runoff

Kistemann

Claßen

Koch

et al. 2002

Appl Environ Microbiol

365

239

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Is E. Coli an appropriate surrogate for Cryptosporidium occurrence in water?

Nieminski¹,

Durrant²,

Hoyt³

et al. 2010

Journal AWWA

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This study evaluated the validity of monitoring for Escherichia coli in lieu of Cryptosporidium to assess the vulnerability of source waters to the presence of Cryptosporidium oocysts. Over a period of seven years, four large water systems in Utah collected Cryptosporidium, E. coli, and turbidity data from seven water treatment plants that treat both reservoir and stream sources. The data represented analyses completed by two US Environmental Protection Agency‐approved protozoan laboratories and local state‐certified laboratories for E. coli. Results of the statistical analyses indicated poor correlation between Crypto sporidium and E. coli and between Cryptosporidium and turbidity in all monitored water sources throughout the entire monitoring period. The analyses indicate that elevated concentrations of E. coli are not indicative of the presence of Cryptosporidium in surface water. Both E. coli and turbidity are poor surrogates for occurrence of Cryptosporidium at treatment plant intakes. Further investigation is needed to establish appropriate surrogates for Cryptosporidium occurrence.

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