Abstract
In Norway, placement of the water treatment plant intake within the lake hypolimnion is considered a hygienic barrier against pathogens of fecal origin. It is unclear, however, whether this practice provides a barrier against opportunistic pathogens such as Legionella. In this study, water samples were collected at 10 m depth intervals near the drinking water intakes of two lakes. Legionella and one of their common hosts, Acanthamoeba spp., were quantified using culture-based assays (Legionella pneumophila only) and real-Time quantitative PCR (qPCR). L. pneumophila and Acanthamoeba spp. were never detected by qPCR; Legionella spp., however, were present in all samples at concentrations ranging from 2.33 to 4.14 log10[copies/L] in lake A and from 2.69 to 4.27 log10[copies/L] in lake B. For most sampling months in both lakes, there was no significant difference between total bacteria and Legionella spp. concentrations at the intake depth versus those on the lake surface. The results of this limited investigation of two Norwegian water supplies suggest that placement of water treatment plant intakes within the hypolimnion may not afford a sufficient hygienic barrier against Legionella.
| Original language | English (US) |
|---|---|
| Journal | ACS Environmental Science and Technology Water |
| DOIs | |
| State | Published - Apr 14 2022 |
Bibliographical note
Funding Information:This research was made possible with support from the INTPART project funded by the Research Council of Norway (275062). The authors thank the municipality for giving access to two drinking water sources and their assistance in sample collection.
Publisher Copyright:
© 2022 The Authors. Published by American Chemical Society.
Keywords
- Legionella
- amoebas
- drinking water sources
- hygienic barrier
- opportunistic pathogens
- thermocline
