Water Lice and Other Macroinvertebrates in Drinking Water Pipes: Diversity, Abundance and Health Risk

Abstract

Activities to ensure and maintain water quality in drinking water networks, including flushing, are presented after standardized hydrant sampling combined with a stainless-steel low pressure–high flow rate (NDHF) filter and a 100 µm mesh size was used to separate pipe inhabitants. A databank of more than 1000 hydrant samples in European lowland areas was developed and used to analyze the diversity and abundance of macroinvertebrates in drinking water networks. Load classes for water louse (Asellus aquaticus) and oligochaetes are given with three evaluation classes: normal colonization, increased colonization, and mass development. The response of Asellus aquaticus in drinking water networks to environmental conditions are presented as are their growth and reproduction, promotion of a third generation by climate change effects, food limitations, and the composition and stability of their feces. Finally, the health risks posed by dead water lice and water lice feces with bacterial regrowth and the promotion of microbe development on house filters are analyzed.

Passability of Chironomid Larvae in Granular Activated Carbon

“…In studies of benthic macroinvertebrates in drinking water systems in Europe, not only chironomid larvae, but also various macroinvertebrates such as water louse ( Asellus aquaticus ), cave water louse ( Proasellus cavaticus ), and detritus worms ( Oligochaeta spp.) were found [ 11 , 33 ]. However, in these studies, samples were collected from water reservoirs or pipes in drinking water supply networks [ 11 , 14 , 34 ].…”

“…were found [ 11 , 33 ]. However, in these studies, samples were collected from water reservoirs or pipes in drinking water supply networks [ 11 , 14 , 34 ]. In the current study, we confirmed the possibility of macroinvertebrates physically filtered from the GAC used in a water treatment facility, which is a stage before pipe inflow.…”

“…If chironomid larvae pass through GAC, they may enter the drinking water networks, where they might reproduce within the pipes and eventually enter the home water supply. A few species of Chironomidae, such as Limnophyes asquamatus and Paratanytarsus grimmii , which are widely distributed in North America, Australia, and Europe, can multiply parthenogenetically without reaching the adult stage [ 11 , 35 ]. Egg masses of Chironomidae have been found to serve as a reservoir for Vibrio cholera and Aeromonas spp., and Chironomidae may cause the spread of pathogenic bacteria into drinking water networks [ 36 ].…”

“…The problems associated with occurrence of invertebrates in drinking water have received increasing attention in recent years. The occurrence of visible invertebrates in tap water causes psychological discomfort to consumers and decreases consumer confidence in tap water quality [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. In addition, it can lead to indirect negative effects such as microbial regrowth [ 11 , 12 ].…”

“…The occurrence of visible invertebrates in tap water causes psychological discomfort to consumers and decreases consumer confidence in tap water quality [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. In addition, it can lead to indirect negative effects such as microbial regrowth [ 11 , 12 ]. In the case of benthic macroinvertebrates, most of these are eliminated during the filtration of the surface water, but it has been reported that some remain in the GAC or biological activated carbon (BAC) filter layer and can survive.…”