Federal-Provincial-Territorial Committee on Drinking Water - Thirty-First Meeting October 24-25, 2002, Ottawa, Ontario

4.0 Parameters: Chemical, Under Assessment

S. Grant-Trusdale introduced Health Canada's Water Quality and Health Bureau's Chemical Assessment Section and noted who is working on which projects.

4.01 Arsenic

S. Grant-Trusdale gave an update on new studies which confirms that internal cancers are still the main health concern. The lowest practical detection of arsenic is 10 µg/L. Members discussed their provinces' procedures for dealing with arsenic contamination in groundwater and suggested the Secretariat add information to the guideline document about the health risks associated with drinking water with arsenic levels above and below the guideline, given that the households using private groundwater supplies will be making their own treatment decisions.

Decision/Action:

• Members to gather data on exposure to arsenic in their jurisdictions and cost data for removing arsenic from their water supplies. Data should be supplied to the Secretariat by January 6, 2003.
• Secretariat to complete a draft arsenic document by March 21, 2003. The document will be for discussion and public consultation approval at the next meeting.

4.02 Chloral Hydrate

S. Grant-Trusdale noted that a guideline for chloral hydrate is being developed and that health risks have been noted. The Secretariat is aiming for a draft document to be ready for the next meeting.

Decision/Action:

• Members to gather exposure and cost data on chloral hydrate and supply data to Secretariat by January 6, 2003.
• Secretariat to complete a draft chloral hydrate document by March 21, 2003. The document will be for discussion and public consultation approval at the next meeting.

4.03 Corrosion control

S. Benard presented information on corrosion control, including practices in other countries and a suggested method of sampling for Canada. Members discussed how often sampling should be conducted to verify the corrosion control program is working, the differences between high-rise residential buildings vs. high-rise offices, whether to test at the tap in consumers' homes or at a sampling site outside the home, how the US EPA defines a representative sample (how many houses per thousand, centre of cities vs. suburbs), and that the greatest benefit of controlling corrosion is related to maintaining the integrity of the infrastructure (e.g., plumbing). Members also discussed how to measure the success of control measures.

Decision/Action:

• Secretariat to complete a draft corrosion control document including different monitoring protocols for homes and buildings by March 21, 2003. The document will be for discussion and public consultation approval at the next meeting.
• Members to gather data and information on the impact of implementing an operational guideline by the next meeting.

4.04 Cyanobacterial Toxins (Microcystin-LR)

S. Grant-Trusdale noted that the Cyanobacterial Toxins document was approved by CEOH in July. M.Giddings noted that samples were taken this summer from a number of areas affected by cyanobacterial blooms and noted that other toxins are being detected in other jurisdictions which may need to be tracked in Canada. The field test kit is still waiting for funding for marketing. NSF has been asked to develop standard for drinking water treatment units related to the removal of Microcystin-LR from drinking water. The letter to health practitioners about concerns regarding these toxins in water used by dialysis patients has been sent out.

Decision/Action:

• Item dropped.

4.05 Cyanogen Chloride

S. Grant-Trusdale noted the draft guideline document for cyanogen chloride is under development. The World Health Organisation is recommending a guideline value of 70 µg/L.

Decision/Action:

• Members to gather exposure data and supply data to Secretariat by the next meeting.

4.06 Haloacetic Acids (HAAs)

S. Grant-Trusdale gave an update on the guideline for HAAs. It should be ready for external review at the end of 2002.

Decision/Action:

• Secretariat to complete a draft haloacetic acids document by March 21, 2003. The document will be for discussion and public consultation approval at the next meeting.
• Members to gather exposure and cost data on haloacetic acids and supply data to Secretariat by next meeting.

4.07 MTBE

S. Grant-Trusdale noted that an guideline has been drafted, based on odour considerations. Health concerns related to human carcinogenicity are insufficiently supported at this time even though these have shown up in rodent studies (i.e., rodent carcinogen). The proposed aesthetic guideline will be protective of human health.

Decision/Action:

• B.Boettger to send copy of BC report to the Secretariat for distribution by November 29, 2002.
• Secretariat to complete a draft MTBE document by March 21, 2003. The document will be for discussion and public consultation approval at the next meeting.
• Members to gather exposure and cost data on MTBE and supply data to Secretariat by next meeting.

4.08 Trichloroethylene (TCE)

S. Grant-Trusdale gave an update on this guideline, noting that toxicological studies are being assessed and the WHO will be coming out with a guideline for consultation. The Secretariat is planning an experts workshop or panel format, similar to the recent THMs panel, to help determine the best method of incorparating exposure from dermal and inhalation routes for volatiles, such as TCE, in drinking water.

Decision/Action:

• Members to provide names and contact information of potential experts to participate in the next workshop on risk assessment from dermal and inhalation exposure by November 8, 2002.
• Secretary to provide information to members on both Health Canada's and CCME's websites regarding TCE by November 29, 2002.

4.09 Trihalomethanes (CDBPs Project)

S. Grant-Trusdale gave an update on progress made by the sub-groups and talked about the conclusions raised by the expert panel convened to determine critical health end-points for the THMs re-evaluation. A.MacDonald from the CDBPs Task Group's economics subgroup gave a presentation on the application of economic evaluation to drinking water guidelines. Members were given timelines for completion of the Task Group's work. A.Socha updated members about the cancer prevention strategy of an organisation called Cancer Care Ontario.

Decision/Action:

• A. Socha to provide name of contact for Cancer Care Ontario by November 8, 2002.

4.10 Turbidity

The Secretary is preparing a summary of the comments received through the public consultation process. If some of the comments raise a major concern, a conference call will be held to deal with the issue before the next meeting. Members raised points for consideration in revising the turbidity document.

Decision/Action:

• All Members to submit to the Secretariat comments received by November 8, 2002, or before.
• Secretary to send all comments to members by November 8, 2002, and post on website.
• Secretary to prepare draft responses to comments received and send to members by January 6, 2003.
• Secretary to revise the Turbidity document and send to members by March 21, 2003.
• Members to review and approve the responses and the revised turbidity document and guideline before or at the next meeting.