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Cryptospondium (part 1 of 2) Page 12 of 13 �• �� Centers for Disease Control and Prevention (CDC) In September 1994, CDC convened a meeting to address concerns over waterborne cryptosporidiosis involving representatives from regulatory and public health agencies, water utilities, and advocacy groups. The focus of the workshop was to avoid unnecessary alarm (i.e., premature or unwarranted boil water advisories) and preventing waterborne outbreaks. Four workgroups addressed the special topics: surveillance systems and epidemiological study designs, public health responses, immunocompromised persons, and water sampling methods and interpretation of results. A document published in 1995 noted that there was significant uncertainty regarding waterborne cryptosporidiosis and as such recommended increased surveillance and epidemiological investigations, methods development for Cryptosporidium detection in drinking water, and development of task forces for providing information to the immunocompromised as well as regional population. Canadian Authorities There are no current regulations for Cryptosporidium or Giardia, though Giardia has been identified as a public health concern. The only regulatory guidance on microbial water quality is for coliform levels in the distribution system. There are no current plans to regulate Cryptosporidium. Summary Of all the regulatory agencies contacted, EPA appears to be the most aggressive in pursuing a Cryptosporidium regulation, but is hampered by poor analytical methods. In the wake of the Las Vegas and Milwaukee outbreaks, EPA is continuing its efforts. Other organizations, due to the meagerness of available information, have decided not to regulate Cryptosporidium at this time. Current Activities of the Water Industry A number of water agencies in North America and Europe were contacted to determine their activities with respect to Cryptosporidium. There appears to be much interest in assessing Cryptosporidium levels and optimizing treatment practices to minimize its passage into the water supply.z Activities include: ■ Monitoring of source and treated waters for Cryptosporidium, ■ Optimizing coagulation practices, ■ Monitoring turbidity of individual filter cells, ■ Backwashing filters prior to restarting, ■ Evaluating filter washwater treatment (i.e., clarification and/or disinfection), ■ Setting limits for turbidity spikes occurring after �Iter restarts (i.e., ripening period), ■ Controlling filters in a manner to avoid sudden flow changes, ■ Optimizing disinfection, and ■ Watershed management. For unfiltered sources there has been a strong emphasis on watershed management,as http://sfwater.org/printContent.cfm/C_ID/446/ 10/19/2004 � .. . i _. _ _