Methods
In July 2025, BICA board members Ron Kivikink and Chris Redston took water samples in three locations in the Bay of Islands:
Four water sample bottles were filled at each location on July 16, 2025. Ron and Chris were travelling on personal watercraft. They waited a few minutes after turning off their machines to allow for the water to exchange before taking the samples and took the samples upwind or upstream of the machines.
Samples were sent to TESTMARK Laboratories in Garson, ON. They were evaluated on 58 parameters, including:
The 4 categories of hydrocarbons tested included:
In order to establish thresholds and evaluate whether contaminants were within accepted safe limits, we referred to provincial or federal water quality guidelines wherever possible. Thresholds weren’t available for every parameter tested, mostly because not every parameter is considered a safety concern.
There were 4 types of thresholds identified:
Results
In general, the results showed that contaminants in the water at the three testing sites were generally well below accepted thresholds, wherever those thresholds were available. Of the 48 elements tested, we were able to identify thresholds for 18.
The only element that was higher than the threshold was iron, which was the same or higher at all three locations (main channel: 100 ug/L, railway: 120 ug/L, Whitefish River: 130 ug/L) than the Guidelines for Canadian Drinking Water Quality aesthetic objective of 100 ug/L (Table 1). The rationale for this threshold for iron “is based on minimizing the occurrence of discoloured water and to improve consumer confidence in drinking water quality.”1 According to the province of Alberta, iron “levels as low as 0.2 to 0.3 mg/L [200 to 300 ug/L] will usually cause the staining of laundry and plumbing fixtures. The presence of iron bacteria in water supplies will often cause these symptoms at even lower levels. Iron gives water a metallic taste that may be objectionable to some at 1 to 2 mg/L [100 to 200 ug/L].”2
The table also shows all the results where no thresholds were available. Where there was divergence between sites, even if no threshold was identified, we highlighted those in yellow. For example, we noted that the levels of copper at the main channel were considerably higher than in the other two locations, although they were still well within safe thresholds.
We also tested for conductivity, pH, and turbidity, which were generally within accepted thresholds, with the exception of the turbidity in Whitefish River. Given the boat traffic and the movement of the water in the river, this isn’t a surprising result. The measured turbidity of 1.4 nephelometric turbidity units (NTU) was higher than the Guidelines for Canadian Drinking Water Quality threshold of 1.0 NTU. According to the province of Alberta, turbidity:
Table 1: Water testing results for elements, conductivity, pH, turbidity
*The Ontario AO for sulphate is 500 and the conversion to sulfur is 500mg/l x 1/3 = 166.7 mg/l = 166,700 ug/L; †The turbidity of treated water should be <0.1; AO, aesthetic objective; ALARA, as low as reasonably achievable; MAC, maximum acceptable concentration; MDL, method detection limit; OG, operational guidance; WHO, World Health Organization
Finally, we tested for hydrocarbons at all sites (Table 2). Unfortunately, it was difficult to find thresholds for any of the categories, but naturally we are hoping to find as little as possible of any of these contaminants. The good news is that for the F2, F3, and F4 categories, the levels were lower than even the lab’s method detection limit (MDL).
| Parameter | MDL | Main Channel Result | Railway Result | Whitefish River Result | Units |
| F1 (C6-C10) Incl. BTEX | 25 | 34 | <25 | 44 | ug/L |
| F1 (C6-C10) Less BTEX(Calc.) | 25 | 34 | <25 | 40 | ug/L |
| F2 (C10-C16) | 200 | <200 | <200 | <200 | ug/L |
| F3 (C16-C34) | 300 | <300 | <300 | <300 | ug/L |
| F4 (C34-C50) | 500 | <500 | <500 | <500 | ug/L |
BTEX, benzene, toluene, ethylbenzene, and xylene; MDL, method detection limit
The concerning category was the F1 category, which includes gasoline and volatile organic compounds such as benzene, toluene, ethylbenzene, and xylene (BTEX). The results by the railway were below the MDL, but in the main channel and in Whitefish River, the levels were 34 and 44 ug/L respectively. For this category, we were able to determine that Canadian Drinking Water Quality guideline threshold level for benzene is 5 ug/L.
Testmark was asked to perform additional analysis to better understand the F1 fraction of hydrocarbons, given the elevated values in our samples. Both the main channel and railway samples showed that the F1 values with BTEX included and F1 values with BTEX excluded remained the same. This is a good result, indicating no BTEX components in our samples at those sites. However, the Whitefish River result does indicate a 4 ug/L difference in values, and this means there were F1 hydrocarbons in our sample. This suggests that the significant boat traffic in the river is contributing to the F1 hydrocarbon fraction. The F1 values that exclude BTEX can be the result of other naturally occurring substances in the water such as isoprenes from decaying plants, other naturally decaying material in the water, fallout and runoff from forest fire smoke etc.
For more information about F1-F4 hydrocarbons, please refer to this “cheat sheet” from Testmark.
Conclusions
Overall, the levels of contaminants that we measured in the water in the Bay of Islands were within thresholds generally accepted to be safe. One exception was the iron level at all tested sites, which might result in a metallic taste, but is probably too low to cause staining.
Another exception was the turbidity in Whitefish River, which was higher than the aesthetic objective of some guidelines. Since the main concern with higher turbidity is that it can interfere with UV disinfection, it is reassuring that the turbidity in other areas of the Bay is well below the thresholds.
With respect to the hydrocarbons, although we tried to ensure the samples were taken in fresh water, there is a possibility that they were contaminated by our watercraft. We will continue to monitor these contaminants in future testing and will take additional steps to avoid contamination by our collection methods.
One key limitation of this project lies in the limited scope of water testing that we were able to undertake. There are several contaminants that we would like to measure in the future, such as per- and polyfluoroalkyl substances (PFAS), commonly known as forever chemicals and microplastics. Testing for these is expensive and we hope to collaborate with other local interested stakeholders, apply for grants where possible and highlight research studies. Forever chemicals and microplastics are endemic to Georgian Bay and beyond and will likely continue to be in our drinking water for the foreseeable future. This is why it’s so important to have adequate drinking water filtration.
We are happy to have a baseline available for the Bay so we can monitor changes over time.
Links
References
Bay Of Islands Community Association