## 3 Results and Discussion
### Optimization of the W2 WQMP - Results and Discussion
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt}} \hline \hline
**Actionable Tasks** & **Stations Submitted to the Tasks (IDSS would Lead to a Specific Series of Options to Comply with These Tasks)** \\ \hline Verify whether sufficient data is available during rain events & All stations \\ \hline Verify whether sufficient data is available during rain events & Ideally all stations, however, the analysis is time-consuming, therefore the following stations are suggested as being representative for different sections of W2: \\  & 1 – Witness station of the Rivière du Nord watershed. \\  & 12 – Station representing water quality upstream from the drinking water treatment plant of Saint-Jerome. \\  & 14 – Station with the longest history. \\  & 22 – Station the furthest downstream on Rivière du Nord (close to an integrative station of the entire watershed). \\  & 23 – Integrative station of a watershed with mostly agricultural activities (representative of the downstream portion of W2). \\  & 17 – Integrative station of a watershed with mostly recreational activities (representative of the upstream portion of W2) \\ \hline Verify mixing and representativity & LJER01 – sampling site is situated on a lakeshore. The site could be placed at the outflow of the lake – the goal of this site is to document the impact of downstream construction. \\  & 12 – the goal of the sampling site is to document water quality upstream of the drinking water intake of Saint-Jerome. A waterfall between this station and the intake probably contributes to oxygenation. Data from the raw water intake could be integrated into the WQMP. \\ Verify mixing and representativity & All other stations on Rivière du Nord, due to the width of the river. Verify whether the precise sampling site represents the water quality of the entire river section (e.g., through validating mixing at different flow regimes with the help of a probe (representative parameters are specific conductivity, pH and temperature on several spots on the river section - if they are similar or identical mixing is provided. If not, another sampling site or strategy may be considered (e.g., composite sampling or taking several samples). \\ \hline Verify whether additional water quality parameters should be taken according to the sampling site justification and new monitoring objectives & All stations. \\  & \(\bullet\) Stations M03 and 04010258 – can be removed unless more water quality parameters are monitored, such as specific conductivity (all stations) and road salts (on specific sections due to cost). These stations are downstream from Highway 15. \\ \hline Verify whether additional water quality parameters should be taken according to the sampling site justification and new monitoring objectives & All stations. \\  & \(\bullet\) Stations M03 and 04010258 – can be removed unless more water quality parameters are monitored, such as specific conductivity (all stations) and road salts (on specific sections due to cost). \\  & \(\bullet\) These stations are downstream from Highway 15. \\ \hline Verify whether additional stations should be added (or removed) (other than those presented in Figure 10B) & Add a station upstream from M08 (witness station for the watershed). \\  & \(\bullet\) Station M09 was a witness station but was replaced by M14 due to urban development upstream. Verify whether M09 can be kept as a section station to document the impact of this development. \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Summary of the actionable tasks to take final decisions to optimize the W2 WQMP. concentrations for each of these three water quality parameters are attained in rain event modality 3 (rainfall 24-48 h prior to sampling). The difference detected between modalities 2 and 3, as well as 3 and 4 supports this hypothesis. Therefore, rain events can be considered as defined in modality 3. The number of samples necessary to capture such a rain event can be estimated through a Power test.