While some differences in scope and philosophy exist between the two, they are substantially similar. Finally, where necessary or desirable, contamination may be assessed against objectives developed specifically for the site using sophisticated risk assessment techniques and maximum information on site conditions. The CWS for PHC should provide information for all tiers. However, the phased nature and direct dependence of the second tier on the first tier means that developmental effort must initially focus on the first tier. Overview Major phases, events and milestones in the present PHC workplan are shown in Figure 1.
Scientific assessment is broken into two phases that overlap somewhat.
I includes such activities as retrieval and summarization of information on fate, behaviour and effects of PHC, review of approaches applied in Canada and other jurisdictions, and preliminary analysis of options for technical development. Multistakeholder Workshop I was largely aimed at confirming that an adequate overview of approaches had been attained and that all credible developmental directions had been identified. A workshop report issued in December 1997 confirmed that these objectives had been substantially met and provided some recommendations for a path forward. An important segment of Scientific Assessment I will be to receive and respond to TAG input on preliminary designs for PHC guidelines. This input is needed to confirm the number and type of tests and calculations for the development of draft guidelines.