Federal-provincial Subcommittee on Drinking Water - 28th Meeting, Ottawa, Ontario, June 4- 5, 2001

The twenty-eighth meeting of the Federal-Provincial-Territorial Subcommittee on Drinking Water (DWS) was held in Ottawa, Ontario, on June 4 and 5, 2001. The status of new guidelines being developed and the revision of existing guidelines was discussed for the following substances:

Arsenic

The Secretariat noted that the guideline value for arsenic in drinking water was established at 25 µg/L in 1989 because available treatment technology could not further remove the contaminant from water supplies. The technology for removing arsenic from water has improved over the past few years. If the guideline were to be re-assessed, the health aspects would likely stay the same though the attainable guideline value might change. The Secretariat will prepare a report reviewing the treatment technology and, based on this review, recommend whether to revise the existing the guideline value.

Cyanobacterial Toxins

(Microcystin-LR) - The member from Health Canada noted that the prototype field test kit is working well. The analytical method for identifying and quantifying cyanobacterial toxins is almost ready although some development work is still needed. Members will wait to vote on the guideline value until the analytical method is ready and is available for widespread use. Members reaffirmed their intention to use the proposed guideline of 1.5 µg/L in the event of a toxic bloom; they do not question the validity of the proposed guideline, only the lack of a routine monitoring method.

Haloacetic Acids

(HAAs) - The member from Health Canada noted that the supporting document for HAAs is being reviewed internally. It is expected to be sent out for peer review soon. The draft document, expected to be based on the five HAAs, will be ready for review and consultation in the fall.

Microbiological - Bacteriological

The member from Health Canada noted the guideline statement had been substantially revised. Members suggested further wording revisions. The Secretariat will modify the bacteriological supporting document for review by Members. Publication is anticipated this fall.

Microbiological - Protozoa

The protozoa document is now posted on the HC Water Quality website ( www.hc-sc.gc.ca/waterquality ). Members agreed by consensus to leave the guideline as is, without a numerical value attached.

Trichloroethylene

Members were updated on the status of the US EPA review of TCE. Health Canada will wait for the EPA's decision before re-examining the guideline.

Trihalomethanes (CDBPs Project)

Work on the Chlorinated Disinfection By-Products (CDBPs) project is on-going. The purpose of this project is to assess new research on the health effects associated with exposure to CDBPs in treated drinking water in order to determine whether the current guideline for Trihalomethanes (one group of CDBPs) should be revised.

Turbidity

Members asked that minor changes be made to the revised guideline statement and supporting documentation. Members approved the turbidity document in principle. The public consultation process for the revised turbidity document will likely begin in the fall.

Priority List

Members discussed the status of a number of substances currently on the priority list, including MtBE, nickel (moved to the suggested list), pharmaceuticals and hexachlorobenzene. The substance priority list will be up-dated.

Other Reports Given and Items Discussed Include:

• Development of a national drinking water strategy and framework by two Working Groups made up of Subcommittee members (Health Canada) and the Canadian Council of Ministers of the Environment -Water Quality Task Group (Environment Canada ). Each group will develop a framework relating to their areas of expertise; both documents will be joined to form a single national framework.
• Concerns related to the operation and maintenance of drinking water systems in small communities. These concerns will be considered by the Subcommittee Working Group when developing a national framework.
• Members were referred to comments in the agenda package about exposure to volatile organic compounds through inhalation. Members agreed with suggestions on how to modify the current development protocol to account for dermal and inhalation exposure; modifications will be made in the next version of the document. Members discussed the possibility of reassessing many of the Guidelines for Canadian Drinking Water Quality to take inhalation data into account.
• Concerns about the current lead sampling strategy for drinking water. These concerns will be reviewed by the Secretariat and a summary report will be prepared for the next meeting.
• Provincial regulations and policies related to drinking water quality. These will be summarized for the Subcommittee
• Reports from certification bodies regarding materials which come into contact with drinking water.