MARCH 15th, 2019 – PRINCE RUPERT, B.C. – Northern Health has determined that the City has now met criteria to completely remove the Water Quality Advisory, which means that all Prince Rupert users may now drink the tap water without boiling it.
City staff, Northern Health, Health Canada as well as water quality professionals from across the country have worked closely together to determine the best protocol for evaluating drinking water safety from protozoa in our community, and parameters to move forward with continued monitoring.
Following accuracy testing of results initiated during the Notice it was also discovered through comparative testing that the original December test showing a result for Cryptosporidium is most likely a false positive. Initial test results were sent to the lab used by the City for many years, however this particular form of protozoa testing requires more advanced skill to identify. Under advice from the City’s engineering consultant, the City began sending additional samples to an accredited microbiology lab that specializes in Giardia and Cryptosporidium in Alberta for analysis shortly after the Notice was issued. This facility is known to Health Canada and nationwide for their advanced research equipment and highly skilled staff. Since initiating testing with this laboratory, the results from this facility showed no signs of Cryptosporidium and recorded levels of Giardia that are well-within treatable limits given the City’s available chlorination treatment system.
These test results aside, based on the reported levels of Cryptosporidium and understanding at the time regarding treatment effectiveness for Giardia, the Boil Water Notice was put into effect as a precaution to protect the health of residents.
“Although we now understand that there is reason to believe initial results for Cryptosporidium were false positives, we also know that putting the Boil Notice into effect was the best action to take from a public health perspective based on our understanding at the time,” said Mayor Lee Brain. “This incident has helped both us at the City and Northern Health better understand potential risk from protozoa, and has improved our standard for testing and monitoring water quality going ahead.”
Northern Health has directed the City to continue to monitor for protozoa at minimum on a monthly basis, which has been added as a condition of our Water Operating Permit. The Environmental Health Officer may also request greater testing frequency during times where there is higher risk to the water supply, for instance during periods of inclement weather or higher levels of recorded turbidity in the water supply.
“The shared intention of both the City and Northern Health is to protect residents’ health,” said Northern Health Medical Health Officer Dr. Rakel Kling. “We continue to work collaboratively with to ensure residents can have confidence in the municipal water supply.”
Northern Health confirms it has not recorded any instances of Giardia or Cryptosporidium-related illness related to Prince Rupert’s drinking water supply, leading up to, during or since the boil water notice and water quality advisories were implemented.
The City has released an After-Incident Report this week as well that details these findings, which was reviewed and approved by Northern Health. This information is also accompanied by an infographic that illustrates water test results for the public. The After Incident Report and Infographic are available on the City’s website, here: http://www.princerupert.ca/services/infrastructure/drinking_water, and at the front desk of City Hall.
Moving forward the City is awaiting notification regarding our grant application to complete the water treatment project. If successful in our grant application, we will be developing a Value Engineering program to ensure that water treatment is implemented as efficiently as possible, to explore options to reduce project costs while ensuring a high quality facility is developed. This process will produce the best overall value for the community, and is recommended by the Province. The City has invited Northern Health, as the regulator, to be a party to that process to ensure that our water treatment system is in line with Federal water quality objectives.
As mentioned when the Notice was downgraded to a Water Quality Advisory, the City and Northern Health are now using a new sophisticated statistical system called a Quantitative Microbial Risk Assessment (QMRA) provided by Health Canada. This QMRA model determines how effective our municipal water system is in deactivating Giardia if it is found to be present in our raw water supply (Woodworth/Shawatlan Lake). This program essentially identifies what level of Giardia is treatable with our available chlorination system. The model takes into account the specific parameters of our treatment system, including contact time water has with chlorine, the concentration of chlorine applied, temperature, and pH. Results from this statistical model show that since the Notice was issued on December 15th, Giardia has remained within treatable limits. However, at the time the Notice was issued, this model was not in place, and the Notice would have been issued as a precaution, regardless of results for Cryptosporidium.
The condition in place with Northern Health to meet treatable limits is also combined with a post treatment Giardia cyst viability/infectivity monitoring program approved by the Environmental Health Officer. The monitoring program, which tests for both Giardia and Cryptosporidium, will continue at a frequency of once a month, unless the frequency is increased by the Environmental Health Officer.
Veronika Stewart, Communications Manager
City of Prince Rupert
(778) 884 6285
Toll Free Media Line: 1 877 961 7724