Drinking water supply and management practices in British Columbia 1997-98. Fluoride

Background: Questions regarding control over a water fluoridation system in a British Columbia (BC) community led to a drinking water management survey in 1997-98. Method: A questionnaire was constructed based on published drinking water control and management criteria and was sent to 91 communities. Results: 73/91 surveys were returned (80 % response rate); 31 reported a protected water supply system, 40 reported logging and/or cattle grazing in watershed areas, 25 reported a lack of primary disinfection. Water fluoridation was reported in 12 locations, 3 of which did not monitor fluoride levels. Testing for protozoans was done routinely in 19 locations, 15 using approved laboratories. 15 water contamination events were reported, 9 of biolog-ical origin. Statistically significant associations were found between contamination events and: wooden delivery systems, lack of primary chlorination, increased number of proto-zoan tests, and increased number of personnel. Interpretation: At the time of the survey in British Columbia, a number of communities were vulnerable to preventable drinking water contamination