Source tracking of Enterococcus moraviensis and E. haemoperoxidus.

Enterococci were detected occasionally in 100 L samples of water abstracted from a shallow aquifer in a natural dune infiltration area for drinking water production. Enterococcus moraviensis was the species most frequently identified in these samples. Because there are no existing reports of faecal sources of E.

Screening municipal wastewater effluent and surface water used for drinking water production for the presence of ampicillin and vancomycin resistant enterococci.

The emergence of clinical enterococcal isolates that are resistant to both ampicillin and vancomycin is a cause of great concern, as therapeutic alternatives for the treatment of infections caused by such organisms are becoming limited. Aquatic environments could play a role in the dissemination of antibiotic resistant enterococci. This study investigated the presence of ampicillin and vancomycin resistant enterococci in the treated effluent of six wastewater treatment plants (WWTPs) and in surface water used as a source for drinking water production in the Netherlands.

Improved biostability assessment of drinking water with a suite of test methods at a water supply treating eutrophic lake water.

Assessment of drinking-water biostability is generally based on measuring bacterial growth in short-term batch tests. However, microbial growth in the distribution system is affected by multiple interactions between water, biofilms and sediments. Therefore a diversity of test methods was applied to characterize the biostability of drinking water distributed without disinfectant residual at a surface-water supply.

Variability of invertebrate abundance in drinking water distribution systems in the Netherlands in relation to biostability and sediment volumes.

A survey of invertebrates in drinking water from treatment works, internal taps and hydrants on mains was carried out by almost all water companies in the Netherlands from September 1993 to August 1995. Aquatic sow bugs (Asellidae, 1-12 mm) and oligochaeta worms (Oligochaeta, 1-100 mm), both known to have caused rare though embarrassing consumer complaints, were found to form 98% of the mean biomass in water flushed from mains. Their numbers in the mains water ranged up to 1500 (mean 37) Asellidae m(-3) and up to 9900 (mean 135) Oligochaeta m(-3).