title: Occurrence of Cryptosporidium oocysts and Giardia cysts in Norwegian groundwater wells in bedrock.
abstract: The occurrence of Cryptosporidium oocysts and Giardia cysts in Norwegian groundwater wells in bedrock has been investigated for the first time. Wells close to risk areas such as farming and septic tanks were chosen. In all, 20 water samples from 20 different waterworks were collected. The samples were analysed for Cryptosporidium and Giardia, using US EPA Method 1623. Turbidity was also measured. Water samples from 10 of the waterworks were also analysed for Clostridium perfringens by membrane filtration. Cryptosporidium was detected in the groundwater samples from 3 of the waterworks. Giardia and Clostridium perfringens were not detected. Too few samples were analysed to verify whether Giardia is indeed absent from bedrock wells, and further studies are recommended to give more reliable data.
authors.affiliation: Department of Groundwater, Geological Survey of Norway, 7491 Trondheim, Norway. sylvi.gaut@ngu.no
authors.forename: Sylvi
authors.initials: S
authors.lastname: Gaut
authors.forename: Lucy
authors.initials: L
authors.lastname: Robertson
authors.forename: Bjørn
authors.initials: B
authors.lastname: Gjerde
authors.forename: Atle
authors.initials: A
authors.lastname: Dagestad
authors.forename: Bjørge
authors.initials: B
authors.lastname: Brattli
mesh_terms: D000818:Animals; D003458:Cryptosporidium / Q000302:isolation & purification*; D005618:Fresh Water / Q000469:parasitology*; D005844:Geology; D005872:Giardia / Q000302:isolation & purification*; D006801:Humans; D009664:Norway; D033661:Oocysts; D014881:Water Supply