Blog · 3 min read
Well Water Testing Before Buying: What to Test and Why
Tap water in a country home is often clear, cool and odourless. That says nothing about its quality. Before buying a property on a well, a lab analysis is the only way to know what you'll be drinking.
The owner is responsible for the water
A municipal system is monitored continuously. A private well is entirely its owner's responsibility: nobody else checks the water quality. By buying a house on a well, you become responsible for the water your family will drink.
Most contaminants of concern have no taste, odour or colour. Perfectly clear water can contain bacteria, nitrates or naturally occurring metals at excessive levels. Appearance and the seller's word don't replace an analysis.
That's why water testing should be part of every transaction on a property with a well, during the conditional period.
Water quality can also change over time. A well that tested fine ten years ago may have been affected since by nearby farming, a new septic system on a neighbouring lot, flooding or simple aging of the casing. An old result is useful history, but it isn't a substitute for a current analysis.
Parameters to have analyzed
Bacteriological analysis is the foundation: total coliforms, E. coli and, depending on recommendations, enterococci. Their presence indicates faecal contamination or surface water entering the well, which can make the water unsafe to drink without treatment.
Physicochemical analysis completes the picture: nitrites and nitrates, often linked to farming or septic systems, then, depending on the region and geology, arsenic, manganese, iron, uranium, fluorides or hardness. Some of these occur naturally and vary widely from one area to another.
Ask the accredited lab which parameters are recommended for your region. Regional public health authorities also publish useful recommendations.
- Bacteriological: total coliforms, E. coli
- Nitrites and nitrates
- By region: arsenic, manganese, uranium, fluorides
- Iron, hardness and other aesthetic parameters
Sampling correctly
A bad sample gives a bad result. Use the sterile bottles provided by the lab, follow its instructions to the letter and respect the delivery deadline, often very short for bacteriological analysis. A sample that arrives too late may be rejected.
Sampling is usually done at a cold-water tap without an aerator or filter, after letting the water run. If the house has a treatment system, specify whether the sample is taken before or after it, depending on what you want to assess.
During a transaction, it's best for sampling to be done by someone independent of the seller, to avoid any doubt about where the sample came from.
The well itself
Water quality also depends on the well's condition. The inspector looks at the well type, the casing above ground, the cap, the surrounding ground and the distance from the septic system, farm buildings or contamination sources. A shallow well is more vulnerable than a properly sealed drilled well.
They also examine the equipment: pump, pressure tank, gauge, and treatment systems like softeners, filters or UV lamps. A treatment system often means a quality problem was already found; ask why it was installed and whether it's maintained.
Finally, quantity matters: insufficient flow can make a house hard to live in. If in doubt, a well driller can perform a flow test.
Look at the ground around the wellhead too. The casing should rise above the surrounding soil, with ground sloping away from it, so that surface water, snowmelt and runoff don't pool around the top of the well and find their way down the outside of the casing.
Reading results and deciding
The lab compares results with applicable drinking water standards and recommendations. Bacterial contamination usually calls for disinfecting the well, fixing the cause, then follow-up tests. A naturally occurring metal above the standards calls for suitable treatment.
In most cases, solutions exist: disinfection, sealing the well, targeted treatment, sometimes a new well. Their cost should be known before waiving conditions, so you can decide knowingly or negotiate.
After buying, keep testing the water regularly, especially bacteriological parameters, and after any unusual event like a flood or work near the well.
Keep every lab report in one place, with dates. Over the years, this record shows how your water behaves across seasons and helps spot changes early, and it's exactly the kind of documentation a future buyer will ask for when you sell.
