How to Test Your Well Water in Wellington County

How often to test

Public Health recommends testing for bacteria at least three times a year, with spring the most important, when melting snow and runoff can carry bacteria toward the water table.

Test more often if you just bought the home, if the well has tested positive before, if you have a shallow dug well, and after any flooding or work on the well.

How to do it

Pick up a bottle. Free sample bottles and forms are available from Public Health offices, Wellington County Library branches and some participating municipal offices and hospitals.
Take the sample. Follow the instructions on the form: remove any aerator, run the cold tap, and fill the bottle without touching the inside of the cap.
Drop it off on time. Return it to a drop-off location within the posted times so it reaches the lab in Hamilton while still valid. Drop-off hours are limited, especially on Fridays.
Get your results. Results come from Public Health Ontario, which also has a phone line and an online portal.

What the results mean

Result	What to do
E. coli: 0 and total coliforms: 5 or less	No significant evidence of bacterial contamination
E. coli: any amount above 0	Stop drinking the water. Use bottled water, and resample
Total coliforms: above 5	Stop drinking the water and resample. The well may need disinfection

You cannot see, smell or taste E. coli, so water that looks fine can still be contaminated. Public Health inspectors can help interpret results.

What the free test does not cover

The free program tests for bacteria only. For nitrates, sodium, fluoride, metals or other chemicals, you need a private accredited lab. Hardness, iron and sulphur can be tested on site by a water treatment specialist.

If your well fails

Switch to bottled water for drinking and cooking
Check the well cap and casing for damage or gaps
Have the well shock chlorinated, then retest
If problems repeat, install a UV disinfection system with a sediment pre-filter

Common questions

Is the bacteria test really free?

Yes. Bacteria testing for private wells is provided free through Public Health Ontario, with bottles from Wellington-Dufferin-Guelph Public Health.

Can I drop off a sample on Friday afternoon?

Usually not. Friday drop-off windows are short so samples reach the lab in time. Check the posted times before you sample.

My test was clean. Do I still need a UV system?

Not necessarily. Keep testing on schedule. UV is the usual fix if a well tests positive more than once or is vulnerable, such as a shallow dug well.