Well Disinfection

HOW TO DISINFECT YOUR WELL

1. For safety – Shut off the power to your pump.  You can also shut off your hot water heater just to save heating water you’re not going to use. If you have a water filter, remove it and put the cover back on.  If you have a water softener, you must bypass it so the bleach does not go through the softener.  Contact your softener provider for instructions on how to bypass.

Once that is done, go outside to your well.  Remove the top half of your well cap by removing the bolts fastening the cap together.  It usually takes a half-inch wrench.  Take off the top half.  Pull out any excess wire and lay it outside the wellhead.

Note:  The average well on PEI ranges 80-100 ft deep with at least 50 ft of water in the well.  Depths can vary depending on the area that you are in.  If you are unsure of the depth of your well, contact the well drilling company that drilled it (the name is usually on the cap) or the Department of Environment for a Well Report.  This will tell you everything you need to know about your well, such as depth, water level, how much water the well will produce, etc.  

Disinfecting – Start pouring bleach down the well. The general rule of thumb is 1 gallon of bleach for every 20 gallons of water in the well.  An average 5-inch residential well holds approx. 1 gallon for every foot of water in the well.  For example, If your well is 100 ft deep and the water level is 20 ft.  You have 80 gallons of water sitting in the well.  So, 4 gallons of bleach would be needed.  However, as you start disinfecting, you may need a couple more gallons of bleach.

2. Hook up a garden hose to an outside tap, put the other end into the top of the well and open the tap.  Turn the power on to your pump.  When you can smell bleach from the hose, let it run down the well so the pump can pick it up and circulate through the system.  While the hose is running down the well, enter the house to start the disinfection.

3. When inside your home, take off any screens on the end of your taps (When the bleach comes through, the water will discolour and loosen built-up sediments and minerals in the well and water system. You may see some rust from the casing as the bleach is acidic and will create some minor corrosion that can plug up screens at the tap). 

Once screens are removed, run each tap (shower included) cold, then hot, one at a time, until you can smell bleach. (If you cannot smell any bleach, go outside and pour more bleach down the well until there is no doubt).

Shut off the tap and move on to the next step (remember to flush your toilet a few times to make sure the bleach got through).

For the washing machine, put it in a warm water setting and have it go through a rinse or wash cycle. Put the dishwasher through a quick cycle as well. (Make sure there is no clothing in the washer and no dishes in the dishwasher).

4. Once you are done disinfecting all taps, go outside and shut off your hose.  Pull it out of the wellhead and put your well cap back together.  Tighten the bolts and let the bleach sit in your water system for 12 hours.

5. Flushing the bleach – After 12 hours, turn on your outside tap with the attached hose and let it run until you cannot smell bleach (The more hoses you run, the sooner it will come out). Usually, it can take up to 8 hours or more to get the bleach out completely.

Once you cannot smell bleach from the hose, leave it running.  Go inside the house and start turning on all your taps. One at a time until you cannot smell the bleach.  

For a washing machine, put it through 2 wash cycles to ensure the bleach is completely out. The dishwasher should only need one cycle.

6. Once you’re done flushing out the bleach inside your home, you can move on to water sampling.  Make sure you leave the outside tap running until sampling is done.

HOW TO TAKE A SAMPLE FOR BACTERIA

1. Pick up a sample bottle for Bacteria from any Access PEI location.  

2. Turn on all your outside taps and let them run for at least 2 hours (The reason is to get the water directly from the aquifer in the well.  Not any standing water that has been sitting in your system) Then, while the hoses are running outside, go to a tap with no spray nozzle in your home, just a straightforward tap. Remove the screen, and disinfect the tap with rubbing alcohol inside and out (The best method is to spray it on; if you can’t spray, use a Q tip and swab generously inside and out). Turn on the tap and let it run for at least 10 minutes.  

3. Disinfect hands.  Slow tap down to a small trickle.  Open cap to sample bottle. (hold on to the cap, do not place it on the counter) Fill the bottle to the bottom of the neck (do not overfill). Place the cap back on the bottle.  

Note:   Most water samples that fail are from not taking the necessary steps when taking the sample from the tap.  And too often, the well gets the blame.

4. You can now shut off your hoses outside.  Place your sample in a small cooler to keep it cold, and drop it off at the nearest Access PEI location, usually before 3 pm Monday to Thursday and before 12 pm on Fridays.