It’s a scenario District of Muskoka staff are taking steps to ensure never happens again.
Gravenhurst’s drinking water system was shut down on November 27, 2021 out of concern that the water could be contaminated. It was not, but the actions taken to ensure the water was safe caused a three-and-a-half day disruption in water services for residents—first a complete shutdown followed by a do not use order and a boil water advisory.
At the District’s engineering and public works meeting on Jan. 19, staff presented a report outlining the cause of the shutdown, as well as subsequent corrective actions being taken.
It all started at just after 2 a.m. on Saturday November 27, 2021, when a low-fluoride level alarm sounded at the Gravenhurst plant. Responding staff couldn’t find an apparent explanation for the alarm, but did notice that the drum containing fluoride didn’t have the identifying label required by WHMIS (Workplace Hazardous Materials Information System). That raised concerns about the contents of the drum, despite the product bill of lading and supplier manifest indicating that the correct chemical had been received.
There had been no issues with maintaining fluoride levels with other drums from the same shipment.
At just after 5 a.m., given the possibility of contamination by an unknown chemical, the commissioner of engineering and public works directed that the drinking water system be turned off and that all drinking water taps be isolated from the water towers pending further investigation and chemical analysis of the fluoride drum.
By 9:00 a.m. Saturday morning, staff had determined a credible explanation for the alarm: the fluoride drum had increased in weight by 18 kg during the night, possibly due to backflow of treated water into the drum.
Officials from the Ministry of Environment, Conservation and Parks (MECP) and Simcoe Muskoka District Health Unit (SMDHU) allowed the system to be turned on in early afternoon, but with a do not use order, which meant residents could only flush toilets.
At just before 2:30 p.m., a lab test confirmed there had been no contamination of the drum and an hour later the do not use order was changed to a boil water advisory. The advisory permitted use of tap water for bathing, showering, washing dishes, and clothes, as well as drinking if boiled as directed.
The events had already set in motion requirements under the Safe Drinking Water Act for flushing the system and taking samples to test for bacterial contamination due to system depressurization and confirm chloride levels.
The boil water advisory was lifted at noon on Tuesday, November 30, almost three-and-a-half days after the system had been shutdown.
Although it was the missing label that caused concern, the cause of the alarm was a check valve failure that allowed water to flow into the drum.
Fred Jahn, commissioner of engineering and public works apologized to residents and Gravenhurst council for the District’s part in the shutdown.
“It is the chemical manufacturer’s responsibility to meet all requirements of the transportation of dangerous goods migrations and WHMIS regulations. And they did not do that. It was their duty to put a proper label on that drum and all the other parties in the chain of custody [to ensure regulations were met],” Jahn told committee. Although receiving procedures were followed, “under the District’s health and safety policies and under WHMIS regulations, it was our responsibility in operations before the drums were unpackaged and placed in the fluoride room, it was our responsibility to make sure that there was labels on those drums, and that did not happen. And we have to acknowledge that that was a failure of meeting the District procedures and WHMIS procedures.”
The District’s procedures have been updated so that when chemicals arrive at a District facility, if any requirements on their checklist are not met, including inadequate labelling, the drums will not be accepted and will be loaded back into the truck, said Jahn.
Mark Pringle, an area manager with the District, added that staff have also expanded procedures for chemical contamination in consultation with the MECP inspector, and are creating a dedicated standard operating procedure (SOP) for restoring the system after a shutdown. “There’s also a requirement here to look at an operating procedure for hauling water to another community.”
Jahn said that despite the disruption the shutdown caused, “I hope that the corrective action plan gives committee and the public confidence that we are continuing to do better and be prepared for any worst-case conditions.”
Councillor Rick Maloney wanted assurances that should another inadequately labelled product be found in the facility, it won’t be used.
“Every product we are using and every container that that product comes in within the water works will be labelled,” said Pringle. “If it’s [repackaged after arrival]then it will be labelled, I mean that follows the WHMIS legislation, but we’re going further to ensure that a signed copy of the manifest is on the products within the waterworks. And putting on additional security for our bulk systems, we’re locking the bulk fill lines so a key has to be obtained from a plant operator before a tanker driver unloads. So a number of checks and balances to control not just the receiving of the chemical but how it’s distributed through the facility.”
In response to a question from Councillor Robert Lacroix, Jahn added that on the day of the alarm, “I can confirm that my staff checked every chemical drum in every plant in Muskoka and these were the only drums that we found. We took immediate action to ensure that this wasn’t going to be a case elsewhere.”
Councillor Heidi Lorenz noted that restaurants couldn’t operate for the duration of the do not use and boil water advisory. “I mean talk about being kicked when you’re down during COVID, so what can we do so if that happens again that we can protect these people, it was I think three or four days that they couldn’t operate.”
“That direction comes from the medical officer of health,” said Jahn. “I think it’s highly unlikely that they would change that procedure because that is connected to the Safe Drinking Water Act. When you’re not providing safe drinking water to the public, then a restaurant simply cannot be open.”
Councillor Brian Thompson asked if the same procedure would apply to other substances used in the water treatment process. “What other chemicals are introduced into the water?”
All of Muskoka’s facilities use chlorine, some have fluoride, and the Port Sydney well also has a UV light for disinfection, said Pringle. Other chemicals added to process the water are: “a coagulant to help us remove the particles and the colour in the water that’s often alum based—aluminum sulfate. We also add lyme—our water’s soft so we add in some hardness [with]hydrated lyme. CO2 gas to adjust the pH, sodium hydroxide otherwise known as lye as a corrosion control, and also sodium permanganate in some cases where we have some taste and colour issues… The standard operating procedure does address all of them, it’s a blanket for any chemical we’re using, some of them come in drums, some of them come in bags, some are bulk shipped in tanker.”
The District is also conducting an emergency response review in connection with the incident.
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