Evaluating property that relies on a groundwater well

There are two things that must be considered if you purchase a property with a groundwater well: Water quality and water quantity.

Water quality considerations 

Groundwater wellThe requirement for testing well water quality during a property transaction varies from location to location; therefore, it is important to check what your local requirements are for well testing. Most property sales that involve water wells include testing for bacteria (i.e. coliform and e.coli) as a minimum. If bacteria are found in test results, a qualified specialist should complete a further review of the well conditions. However, there are several wellhead conditions that can be visually inspected.

These include:

The well’s proximity to a septic field. Septic fields (if present) are areas of high bacteria concentrations. A minimum separation distance of typically 15m for cased wells and 30m for uncased wells is necessary. This distance should be provided between the well and the tile bed to prevent contamination of the well, from the bacteria in the vicinity of the tile bed.

The conditions around the wellhead. A low-lying well head that is not protected (with a casing that extends above ground surface) is vulnerable to contamination from surface water that may enter the well.

Livestock waste in the vicinity of the well. If livestock or agricultural fields that are treated with manure are close to the well, there is a potential for contamination.

Bacteria parameters are key in assessing if well water has been compromised at a rural property. However, bacteria is only one of the many parameters that can potentially impact well water quality. Three other potential sources of contamination might be: extensive use of pesticides/herbicides, leaks from former underground fuel storage tanks in the vicinity of the well, or the presence of lead supply piping.

If these conditions are a potential concern, water samples can be tested for parameters, such as pesticides/herbicides, petroleum, hydrocarbons, or lead. The results of such testing will either provide a little more piece of mind or indicate there may be a larger issue at hand.

If issues with compromised water quality are identified, there are a wide variety of water treatment/filtration systems that are available, such as water softeners, carbon filters, reverse osmosis/ultraviolet light systems, and chlorination.

Water quantity considerations

The two main water quantity considerations with wells are water availability and the condition of the supply system.

Water availability

The quantity of water available in a well is typically measured using a well flow/recovery test that is performed by well contractors. The first component of the test involves flowing a plumbing fixture at a constant flow rate for a set period of time (usually 1 hour minimum). If the flow is maintained at the specified rate over the duration of the test without decreasing, then this provides an indication of the available water in the well.

The second recovery component measures the level of water in the well during the flow test. If water levels remain consistent during testing, this indicates that the water in the area around the well is plentiful. If water levels lower significantly or the well goes dry, this indicates that there is a problem with water availability in the vicinity of the well. Water levels fluctuate both seasonally and annually, which could influence water availability.

Supply system

The condition of the pump, pressure tank and supply piping can influence the flow and pressure of water in a home. For example, an older, corroded pump or heavily rusted pressure tank may soon need replacement. Some older houses have galvanized steel plumbing. Galvanized plumbing rusts from the inside out, which decreases the pipe diameter over time. This results in low water pressure and will eventually require the replacement of the pipe.