The City of Thunder Bay is required to have an approved Corrosion Control Plan in accordance with Drinking Water System Regulation O. Reg. 170/03.

The City moved ahead with the next phase of its Corrosion Control Plan and has added sodium hydroxide to its water supply to reduce the amount of lead found in tap water. The pH of the City’s drinking water has been increased to reduce lead levels at the tap by adding small amounts of sodium hydroxide to the water at the Bare Point Water Treatment Plant. Sodium hydroxide is a safe and approved water treatment chemical.

The removal of lead service pipes remains a key priority in the Plan. However, the full removal of lead service pipes will take many years to accomplish. In the short term, lead levels will be reduced in private plumbing systems across the City through the addition of sodium hydroxide for pH adjustment.

Studies have shown chronic exposure to lead, even at low levels, can have health impacts. Of particular concern are the neurodevelopmental effects impacting learning and memory on developing fetuses and young children. 

Learn how to Get the Lead Out. 

In addition, you should also routinely clean your faucet screens

*Below, the American Water Works explains where lead comes from, how it gets into water, and what households can do to keep their water lead-safe: 

 *Excepted by permission. Copyright © American Water Works Association. 

 Lead service replacement
 

Prior to a watermain being replaced (performed by a private contractor under a capital contract), the City notifies the homeowner to discuss the replacement of the private portion of their service line. Prior to the City portion being replaced under the capital contract, testing of the tap water in the private residence is requested to provide a baseline lead result. If a homeowner wishes to have the private portion of their service line (property line to meter) replaced at the same time as the City portion, they must arrange with the on-site contractor to do the work at their own expense. A plumbing permit must be obtained, and a plumber must complete the final connection. Once the service line is partially or completely replaced, it is recommended that the tap water be tested again to ensure lead levels are reduced. Testing is free and arranged through the City by calling 684-3568.

On streets not scheduled for watermain renewal, homeowners may arrange with a contractor to replace the private portion (property line to meter) of their lead service line and the City will fund and complete the work extending from the property line to the watermain. It is preferred that the homeowner contact the City to arrange for lead testing prior to the replacement of their private portion to obtain a baseline lead result. The homeowner must obtain the required plumbing permit, hire a plumber for the final connection and have all final inspections done. Once this is complete the homeowner will submit a Priority Lead Water Service Replacement, with all documentation to The City of Thunder Bay Engineering Division. The homeowner completes the final restoration of their property, and the City will restore City property. The City processes such requests in sequence, the priority given to cases of elevated lead levels according to drinking water testing.

In all cases, you will need a Building/Plumbing Permit from the City. Please print out the Building Permit, Plumbing Permit and Guide below

 Partial lead service replacement

Research indicates that when lead service lines are disturbed, the amount of lead found in consumer’s drinking water may increase for weeks to months. In the event a service line is partially replaced by the City or the homeowner, it is strongly recommended that private plumbing lines be flushed prior to consumption. After a partial replacement of a lead service line has been completed, the following steps should be taken prior to consuming the water from your tap.

  1. Remove and clean your faucet aerators from all cold water taps in the home.
  2. Beginning in the lowest level of the home, fully open the cold water taps throughout the home.
  3. Let the water run for at least 30 minutes at the last tap you opened (top floor).
  4. Turn off each tap starting with the taps in the highest level of the home. Be sure to run water in bathtubs and showers as well as faucets.
  5. Do not consume tap water, open hot water faucets or use icemaker or filtered water dispenser until flushing is complete.
  6. Replace cleaned aerators

In addition to the above instructions, a daily mini-flush consisting of a 5min displacement flush is recommended for 6 months post partial replacement of a lead service line. Aerators should be should be cleaned regularly to remove any particulate lead that may have accumulated.


It is also recommended that after a partial or full lead service line replacement, the water be tested to ensure lead levels at the tap are reduced. This testing is free and arranged through the City by calling 684-3568.

 How can you reduce your exposure to lead in drinking water

There are many steps you can take to reduce your exposure to lead in drinking water, but if you have a lead service line, the best step you can take is to have it replaced.
In addition you can:

  • Have your water tested for lead free of charge.
  • Run your water to flush the lead out – if it hasn’t been used for several hours, run the water for 3-5minutes to clear most of the lead from the water. 
  • Always use cold water for drinking, cooking and preparing food – never cook with or drink water from the hot water tap.
  • Do not boil water to remove lead – boiling does not reduce lead concentrations.
  • Periodically remove and clean faucet screens / aerators – while removed run water to eliminate debris.
  • Identify and replace plumbing fixtures containing lead. Brass faucets, fittings and valves may leach lead into drinking water.
  • You may consider investing in a home water treatment device (filter system). When purchasing a water treatment device, make sure it is certified under NSF/ANSI 53 to remove lead. Search for certified products at NSF International (800-NSF-8010) or Water Quality Association (630-505-0160).
 What the City is doing to reduce lead

The City of Thunder Bay strives to reduce overall lead service connections and fixtures, provide ongoing watermain flushing/cleaning, increase overall water quality awareness and provide free testing for lead at the tap. The piped water infrastructure is renewed by the watermain replacement program, which also replaces the individual service connection to the property line (partial replacement). In 2017, the City notified all consumers by mailing information inserts into their water bills that notified them of the change being made to the drinking water through the addition of sodium hydroxide for the purpose of reducing lead levels at the tap.

 How you can help

If you have a lead service, please contact the City to arrange for testing. A qualified licenced operator will come to your home and test your tap water free of charge. You will be provided with the results of the testing. You can also help by replacing your lead service line – reducing the amount of lead. If you replace your service line, follow the flushing instructions post replacement and contact the City for testing. Submit a priority lead replacement form through the Engineering Department so that the City can replace their portion of the service line. Once this full replacement is complete, arrange for testing through the City to ensure lead levels have been reduced. Free testing can be arranged by contacting the City at 684-3568.


The City is also looking for volunteers to help us in determining the effectiveness of the corrosion control plan. This would entail allowing one of our certified operators to take samples in your home on a monthly basis. We are requesting that homeowners with a known or suspected lead service line or lead solder contact us at 684-3568. Our certified operators will contact you and make arrangements to obtain samples at your convenience. You will be provided copies of all test results and there is no charge for the sampling and testing.

Public engagement and information materials

The City hosted a series of Public Information Session regarding the Corrosion Control Plan and also distributed public notices to customers with their water bills:

More information

Visit the Ministry of the Environment & Climate Change's Drinking Water Ontario website.

In addition, visit Health Canada's webpage on reducing your exposure to lead from drinking water.

For more information about Thunder Bay's drinking water, contact the Infrastructure & Operations Department at 625-2195.

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