How to prepare for a well inspection

A well inspection has two halves: the mechanical system that gets water into the house and the quality of the water itself. Both halves depend on what happens in the week before the inspector arrives. A chlorinated well, a softener that was bypassed, or a house that has sat empty can all produce a report that looks better or worse than the truth. This guide covers what to do, what not to do, what the inspection involves, and how to read the results.

Written by John Hansen, Registered Home Inspector, Past President of the Ontario Association of Home Inspectors, WETT certified, BCIN qualified for septic systems. Inspecting since 2011.

Before the inspection: paperwork

Every well drilled in Ontario since the 1950s should have a water well record filed with the Ministry of the Environment, Conservation and Parks. It gives the depth, the casing length, the static water level and the pumping rate when the well was drilled, and the geology the driller went through. The record is searchable online by lot and concession or by the well tag number, a small metal plate on the casing of newer wells. Ask the seller for it, and for anything else on file: pump replacement receipts, water test results, treatment equipment manuals, and any notes about shortages in dry summers.

Before the inspection: access

What not to do

The single most important instruction is not to chlorinate the well in the two to three weeks before the inspection. Shock chlorination temporarily kills the bacteria the test is looking for and masks a well that is actually contaminated. If the well was chlorinated recently, tell us, and we will note it and recommend a follow-up sample. Equally, do not bypass or shut off treatment equipment, do not swap filters on the day, and do not leave taps running for days to clear the lines; we want to see the water the household drinks.

If the seller has chlorinated the well, the first bacteria result is of limited value. Ask for a second sample at least two weeks later, and make the purchase condition depend on it.

On the day: the wellhead

The inspection starts outside. Ontario Regulation 903 requires the casing to extend at least 40 cm above grade, with a vermin-proof cap, sealed electrical entry, and ground sloping away so surface water cannot pool around it. We check the cap, the vent screen, the casing for corrosion or damage, the grading, and the distance to the septic system, barns, fuel tanks, and roads. A well in a pit, a well with the top below grade, or a well with a loose cap is a direct route for contamination and will be reported as such. Dug wells and bored wells with concrete tile get particular attention because they are shallow and more exposed.

On the day: the flow test

The flow test tells you whether the well can keep up with your household. We run water at a measured rate for a sustained period, typically an hour, while monitoring the pressure and, where the wellhead allows, the water level in the well. The result is a sustained yield in litres or gallons per minute and a note on how the level recovered. A well that delivers well for ten minutes and then fades is a very different thing from one that holds steady, and the difference is only visible under a sustained draw. We relate the yield to the size of the house and the number of bathrooms, and to the storage that a cistern or large pressure tank adds.

On the day: the pump and pressure system

On the day: treatment and sampling

We identify each piece of treatment equipment, confirm it is working, and note the maintenance it needs. A UV unit with a lamp past its life, a softener with no salt, or a sediment filter that has not been changed in a year is common and is an indication of how the water has actually been treated. We test the water on site for pH, hardness, iron, nitrate, and other basic parameters, and take a bacteria sample using the bottle and procedure of the Public Health Ontario laboratory, which tests private well water for total coliform and E. coli at no charge. The sample has to reach the lab within its holding time, so timing the inspection to the lab’s intake days matters.

Reading the results

The lab report gives counts of total coliform and E. coli per 100 mL. The Ontario standard for drinking water is zero for both. Any E. coli means the water is unsafe to drink until the source is fixed and the well is disinfected and retested. Total coliform without E. coli means surface water or soil is getting in somewhere, most often at the cap, the casing, or a pit, and the fix is usually at the wellhead. On-site chemistry explains the rest: hardness and iron drive the staining and the softener; nitrate above the guideline points to agricultural or septic influence; low pH is hard on copper pipe. Our report puts the lab result and the physical findings side by side so you can see cause and effect.

After the inspection

1. If bacteria are present, get quotes to correct the wellhead and have the well disinfected, then retest before closing.
2. If the yield is marginal, consider storage, a lower-flow fixture strategy, or in persistently poor areas a cistern, and price it into the deal.
3. Budget for treatment maintenance: UV lamps yearly, softener salt, filter changes, and a bacteria test two or three times a year, which Public Health Ontario recommends for every private well.
4. Confirm any unused wells on the property have been properly decommissioned by a licensed well contractor, which is a legal requirement in Ontario and a frequent gap on farm properties.
5. Keep the well record, the report, and the lab result together for the next test and the next owner.