1. Store enough clean water to meet household needs for the duration of the disinfection process (approximately 12 hours) as use of water is restricted.
2. Bypass or disconnect any carbon filters, water softeners or other water treatment devices otherwise any pipes located past these filters will not be disinfected. Replace the filters once chlorination is completed. Highly chlorinated water can damage treatment units. It is important to follow the manufacturer’s recommendations to ensure treatment systems are properly disinfected and not damaged. Be sure to turn off the hot water tank’s heat source.
3. Estimate the chlorine necessary to disinfect the water in the buildings plumbing including the hot water tank, and the chlorine necessary to disinfect the water in the well water column. Add them together.
   • Drilled well: 1 cup of normal household bleach for every 25 feet of water in the well.
   • Dug well: 1 liter of normal household bleach per every 5 feet of water.
   • A chlorine calculator is available at: Well Disinfection Tool
4. Pour the required amount of chlorine directly into your well.
5. If possible, mix the water in the well. This can be done by attaching a hose to a tap and running water from the well through the hose and back into the well.
6. Open all water taps one at a time, including outside hose and cold and hot water taps and laundry hook-ups. Allow the water to run until a chlorine smell is detected from each faucet then turn off each tap.
7. If a strong chlorine odour is NOT present, return to step 4 and add half the amount of chlorine used for the initial treatment, then repeat steps 5 and 6.
8. Let the chlorinated water stand in the system for a minimum of 12 hours, make every attempt to avoid water use during this process.
9. Run water through the outside hose away from vegetation until the strong smell of chlorine disappears. Make certain that the water does not enter any natural water source. Finally, open each and every indoor tap until the system is completely flushed. Since chlorinated water can damage the action in a septic system, chlorinated water should not be allowed into the building’s sewage system. Taps or fixtures should be temporarily diverted to an outside discharge point to avoid affecting the septic system.
10. Wait at least a couple of days after shocking the well water, then sample the water using official water testing bottle and instructions provided by Renfrew County and District Health Unit. Two clean water tests, performed over a period of one to three weeks, should indicate that the treatment was successful.
11. If the above steps do not fix the problem, you may want to speak with a public health inspector for assistance at 613-732-3629 ext. 505 or visit our safe water webpage.