Federal-Provincial-Territorial Committee on Drinking Water Thirty-Ninth Meeting October 25 - 27, 2006 Ottawa, Ontario

4.0 Parameters: Chemical & Radiological

4.01 Benzene

The Secretariat gave an update on the development of the guideline document for benzene. Members discussed the peer review comments, exposure assumptions, NSF standards, detection limits, and one-time incidents versus long term exposure. Members agreed that it would be good for the consultation document to include information on the differences in health risks between guideline values of 1 and 5 µg/L.

Decision/Action:

• Secretariat to include information on the differences between the old and proposed documents in the consultation document
• Secretariat to provide members with the finalised consultation document by December 1, 2006
• Members approved the document in principle for consultation. Members to provide impact paragraphs and approval by January 5, 2007

4.02 Carbon Tetrachloride

The draft guideline technical document will go to peer review soon. The science sections of the document have been updated since the chemical is now classified as possibly carcinogenic to humans. The guideline will likely remain at 5 µg/L.

Decision/Action:

• For information

4.03 Chlorine

The Secretariat updated the committee on the new chlorine guideline document. Members discussed concerns with chlorine, particularly high doses resulting from operational failures, the effectiveness of chlorine disinfection with changes to pH and temperature, and the recommended chlorine residual levels. No impact paragraphs are required from members because there is no guideline statement.

Decision/Action:

• Members approved the document in principle for consultation
• Secretariat to send members the revised document by December 1, 2006, for CDW approval for consultation, no impact paragraphs required
• Members to review the consultation package and provide written approval or reason for show stopper by January 5, 2007

4.04 Radiological

The Secretariat gave a presentation on the status of the radiological guidelines document. Members discussed the screening process recommended in the document. Nova Scotia noted major concerns with this process that will need to be addressed prior to approval.

Decision/Action:

• Secretariat to follow up with the Environmental Radiation Hazards Division to get details on why the alpha beta tests are unreliable as initial screening
• Secretariat to review the possibility of developing a generic guideline statement for radon rather than a guideline value
• Secretariat to prepare the post-consultation document by December 22, 2006
• The approval process for this guideline will be determined once the final version is ready and members have had an opportunity to review it

4.05 Fluoride

The Secretariat gave an update on the development process for this guideline. An expert committee is looking at this guideline and will be meeting in the new year. The committee noted receipt of a letter from K.Millership through the Secretariat and reviewed and approved a proposed draft response.

Decision/Action:

• Secretariat to post the web site of the American Dental Association on the CDW extranet site
• Members to provide questions and concerns by November 17 in order to have them addressed by the expert committee
• Two members to attend the expert committee meeting as observers

4.06 Other Chemical/ Radiological Work and Documents

Chlorite/chlorate:
The Secretariat gave a presentation on the draft chlorite/chlorate document. Members discussed whether chlorine dioxide should be included in the title.

Nitrate/nitrite:
Some forms of nitrogen have been listed as a possible human carcinogen, which could be an issue with nitrate-nitrite.

Microcystin-LR:
Microcystin-LR has been listed as a possible human carcinogen.

Pesticides:
PMRA has provided information on pesticide availability and use. In some cases the data are related to drinking water.

BDCM:
The member from Alberta raised the issue of a small exceedence of BDCM in the province. Authorities reacted by distributing point-of-use devices to consumers because the guideline is based on single exceedence. Members discussed changing the guideline to base it on an average rather than a single exceedence and decided that what was needed was actually better risk communication tools.

Corrosion control:
Members received the draft document. Quebec noted concerns about the feasibility of implementation and suggested modifications for consideration.

Iodinated by-products
The Secretariat requested monitoring data for iodinated by-products.

MCPA
Consultations on the MCPA guideline will start in late November and end on January 23, 2007. The consultations for potassium and chlorate hydrate will follow.

Hydrogen peroxide
Members discussed the use of hydrogen peroxide as a disinfectant and cleaning agent. Members noted occupational health and safety concerns with handling the chemical.

Decision/Action:
Chlorite/Chlorate

• Members agreed to not change the title of the document
• Secretariat to include in the document a generic statement that disinfection should not be compromised
• Members to review the document for approval by November 24, 2006, by email or teleconference

Corrosion control

• Members to review the final consultation package and provide written approval or show stoppers by November 24, 2006
• Members to review the need for an impact paragraph for this document

BDCM

• Secretariat to provide more direction on implementation of the guideline, including risk management / communication and Qs and As

Iodinated by-products

• Members to provide monitoring data

Hydrogen peroxide

• Members to provide information on the use of hydrogen peroxide as a disinfectant to Quebec and the Secretary