CWWA Comments on PFOS and PFOA Guidance
CWWA and our Drinking Water Quality Committee have reviewed the new proposed Guidance documents for both PFOS and PFOA and provided Health Canada with comments.
Overall the document provided excellent background information on these substances and their impact on human health. Our Committee did have some concerns about the proposed MAC, however.
The proposed MAC of only 6ug/l, while perhaps a commendable goal from a health standpoint does pose some challenges from a laboratory and treatment perspective. At the present time very few if any analytical laboratories in Canada, public or private, seem to be able to measure to this level of MAC and be ISO 17025 accredited for it in drinking water. Consequently, we’re not sure what is being achieved by having such a stringent target, notwithstanding the ability of water utilites to obtain a representative drinking water sample and access a Canadian laboratory accredited for this analysis cost effectively.
While most utilities will likely have no difficulty meeting the proposed MACs for PFOS and PFOA in drinking water, for those that do, the cost to remove them will be substantial. These substances are resistant to most conventional treatment and even some advanced processes. In some cases a full system redesign or replacement may be necessary to meet the MAC, which could be beyond the financial capacity of a utility.
CWWA suggested that Health Canada consider a higher interim MAC, or delay the publication of this guideline until the treatment and standardized analytical technologies are less expensive, more readily available and, in the case of the treatment, more effective.