Based on the information provided in this report, the following conclusions can be made about the risk the use of fertilizer presents to the Greater Nanaimo Watershed and the people of Nanaimo reliant upon it as a source of drinking water:
•There is no evidence that the drinking water supply has been effected to date by the use of fertilizers in the watershed.
•There is no evidence to date to support the fact that ongoing use of the fertilizer in the watershed will present a drinking water hazard, providing the type of fertilizer utilized and amount are the same as that currently utilized. The reduction in the amount of fertilizer used per seedling back to 30 grams from 50 by Weyerhaeuser will further reduce any potential there might be for contamination of the drinking water supply.
Based on the information presented in this report, the following recommendations are made to ensure to continued safety of the drinking water supply:
•All new fertilizers should be reviewed for their potential to adversely effect the watershed by Weyerhaeuser, in conjunction with the Greater Nanaimo Water District, before being used in the watershed. As a minimum, the contents of the fertilizer (including trace metals and other elements) should be reviewed, along with the locations the fertilizer is to be applied, the application method and the amount of fertilizer to be used.
•The Greater Nanaimo Water District and Weyerhaeuser should have in place a protocol to respond to increasing concentrations of ”fertilizer” parameters in the water samples. This protocol should include what corrective actions should be taken in the event that the concentration of a fertilizer parameter in the water samples starts to approach and or exceeds the recommended guideline values.
•The Greater Nanaimo Water District should continue to monitor the water quality on a regular basis (monthly is sufficient) for components of the fertilizer that could indicate that leaching is occurring. This monitoring should be undertaken to ensure that increases in water quality measures can be detected and corrective action can be implemented in a timely manner.
Conclusions and Recommendations
Based on the information provided in this report, the following conclusions can be made about the risk the use of fertilizer presents to the Greater Nanaimo Watershed and the people of Nanaimo reliant upon it as a source of drinking water:
•There is no evidence that the drinking water supply has been effected to date by the use of fertilizers in the watershed.
•There is no evidence to date to support the fact that ongoing use of the fertilizer in the watershed will present a drinking water hazard, providing the type of fertilizer utilized and amount are the same as that currently utilized. The reduction in the amount of fertilizer used per seedling back to 30 grams from 50 by Weyerhaeuser will further reduce any potential there might be for contamination of the drinking water supply.
Based on the information presented in this report, the following recommendations are made to ensure to continued safety of the drinking water supply:
•All new fertilizers should be reviewed for their potential to adversely effect the watershed by Weyerhaeuser, in conjunction with the Greater Nanaimo Water District, before being used in the watershed. As a minimum, the contents of the fertilizer (including trace metals and other elements) should be reviewed, along with the locations the fertilizer is to be applied, the application method and the amount of fertilizer to be used.
•The Greater Nanaimo Water District and Weyerhaeuser should have in place a protocol to respond to increasing concentrations of ”fertilizer” parameters in the water samples. This protocol should include what corrective actions should be taken in the event that the concentration of a fertilizer parameter in the water samples starts to approach and or exceeds the recommended guideline values.
•The Greater Nanaimo Water District should continue to monitor the water quality on a regular basis (monthly is sufficient) for components of the fertilizer that could indicate that leaching is occurring. This monitoring should be undertaken to ensure that increases in water quality measures can be detected and corrective action can be implemented in a timely manner.
Web Link: http://www.city.nanaimo.bc.ca/speed/gnwd/src/fertilizer.pdf