| occurrence of cryptosporidium oocysts and giardia cysts in norwegian groundwater wells in bedrock. | 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 f ... | 2008 | 19108559 |