Findings from the most recent surface water sampling event on November 18, 2025, conducted at 12
locations across the Upper Nine Mile River watershed situated north of the Five Bridge Lakes
Wilderness area show no apparent chemistry concerns from local industry, construction, or residential
/ commercial pollution. This event was the 6th sampling event conducted since 2014. The late
November sampling event was chosen because there was a prolonged drought period followed by
heavy rainfall on November 10-11 th (65.4mm) and lighter rain on November 12-14 th (7.4mm) and
November 16 th (12.2mm).
Typically, following a drought period, rainfall will then flush out any contaminants in the groundwater
into receiving watercourses. So on a positive note, most parameters analyzed in the November 18 th
samples were lower than in previous sample events. Aluminum once again exceeded the guideline at
nearly all locations; however, iron only exceeded the 300ug/L guideline at one location, where a value
of 316ug/L was reported at the SW3 Fraser’s Lake outlet to Mill Pond. Typically, aluminum and iron
are elevated across the province due to shallow permeable overburden and slightly acidic waters.
In the past, there were occasional guideline exceedances of cadmium, copper, lead and zinc across
the watershed. However, the November 18 th results only reported three guideline exceedances of
these metals, and that was for copper (8ug/L) at SW7 (Kingswood Subdivision discharge to Mill Pond)
compared to the guideline of 2ug/L and zinc (16ug/L at SW1 Mason’s Mill Pond outlet and 30ug/L at
SW6 Lakeside Industrial Park discharge to Governor Lake) compared to the guideline of 7ug/L. Field
measured pH was in the range of 6.15-7.14, and the lab reported pH in the range of 5.09-6.57, which
likely accounts for the reported lower metal concentrations.
It is noted that chloride once again exceeded the guideline of 120mg/L at the discharge from Lakeside
Industrial Park to Governor Lake, where a value of 181mg/L was reported at SW6. The outlet of
Governor Lake (SW4) also exceeded the chloride guideline, where a value of 173mg/L was reported.
The sodium concentrations were also highest at these two locations, with values of 81 and 87.7mg/L
reported. Elsewhere, sodium concentrations were less than 32.2mg/L.
A 12th sample location was added at Yankeetown Road because clearcutting/land grubbing
beginning in the spring of 2025 at a new development being constructed north of Hammonds Plains
Road was discharging silty water to Cox Lake. Aside from a slightly low pH of 5.28, turbidity and Total
Dissolved Solids were relatively low, with values of 69 NTU and 61 mg/L reported, respectively.
However, aluminum and iron were highest at this location, with values of 978ug/L and 914ug/L
reported, respectively. The remaining metal concentrations were below applicable guidelines.
It is noted, though, that during the summer months, past events reported low oxygen levels and high
temperatures exceeding 20 degrees C at all sampling locations. The oxygen levels on November 18 th
were above 90% at all but one location (82% at SW9 Half Mile Lake outlet at HWY 103), and
temperatures ranged from 3.1-7.5 degrees C.