THUNDER BAY -- The City of Thunder Bay has begun notifying residents of its plan to start adding sodium hydroxide to the water supply.
Residents can expect to see the details attached to their next water bill.
The city had indicated the addition of the chemical to reduce the lead content of the water would begin sometime after February 1, 2018.
About one-third of customers receive their water bills each month, so it's taking a total of three months to complete the mailouts.
Michelle Warywoda, director of the city's Environment Division, says when the program begins, "a very, very minute amount" of sodium hydroxide will be added at the Bare Point Water Treatment Plant, from where it will be distributed through the entire system.
The chemical will make the water less acidic, thereby reducing the risk that lead that may be present in water connections will leach into the water when a tap is opened.
"The amount (of lead) is going to vary depending on a person's home," Warywoda said in an interview Monday.
She said some homes have a very long service line that's all lead, and may have higher lead levels than houses that only have soldered joints.
Homes built before the mid 1950s are more likely to have lead pipes and service lines, while residences built from the mid 1950s to 1989 may have lead within some fixtures or in solder.
City officials have said that there is "a lead issue" in about 8,000 Thunder Bay homes, and that tap water in about 10 per cent of those homes has higher lead content than the prescribed limit for human health.
Despite the mitigation with sodium hydroxide, Warywoda said the city is still advising residents concerned about lead in their water supply to contact the city to request a free test.
"We encourage people to call us. We can check our records and let them know if they do indeed have a lead service connection."
She said the city will also dispatch a technician to take a water sample for testing.
Replacing pipe is the homeowner's responsibility within the property boundary, but the city will pay for simultaneously replacing the section from the property line to the watermain.
