Buying a House with a Well and Septic System
In rural areas, many homes do not have connections to municipal water and sewer lines. Homeowners rely upon privately owned or communal (shared) wells as their drinking water source, and individual septic systems to treat and discharge their wastewater. Homeowners must ensure that their well water is safe to drink, and that their well and septic system are properly maintained. A malfunctioning well or septic system can pose a health risk to your family and neighbours, and can be expensive to repair or replace. It is therefore very important to conduct a detailed inspection of both the well and septic systems prior to purchasing a home.
When you are purchasing a home with a private water supply (a well), there are three key items to consider:
- well system
- water quantity
- water quality
There are three common types of wells: dug, bored and drilled.
Dug and bored wells (60 – 120 cm/24 – 48 in. diameter) are commonly used to produce water from shallow surface aquifers (less than 15 m/50 ft. deep). They are prone to contamination from surface water infiltration and to water shortages.
Drilled wells (10 – 20 cm/4 – 8 in. diameter) are commonly used to penetrate deeper aquifers (15 to greater than 60 m/50 to greater than 200 ft. deep). They are more costly to construct, but generally provide a safer source of drinking water.
The well should be inspected for issues, well water tested and quantity of well water verified before the house is purchased. If there is a problem with the physical state of the well (for example, cracked seals, settled casing) contact a licensed well contractor to estimate the cost to correct the problem. Your Realtor and lawyer will assist with any amendments required to the Offer to Purchase and Sale as a result of issues.
Quantity of Water
There are three sources of information to help determine if a well can produce a sufficient quantity of water:
- local knowledge
- well record
- water recovery test
Local Knowledge: The best indication of whether there is sufficient water supply is to ask the owner, neighbours or local well drillers if there have been any problems with wells running dry on the property and in the area. Generally, shallow wells are more likely to have problems with water shortages than deep wells, as shallow wells draw water from surface aquifers, which can fluctuate greatly depending upon the amount of precipitation.
Well Record: Obtain a copy of the well record from the previous owner or the Ministry of the Environment. The pumping water level indicates if the well is shallow or deep (less than 15 m/50 ft. is considered a shallow well). The recommended pumping rate should be greater than 14 L/min (3.6 US gal/min).
Water Recovery Test: A licensed contractor can be hired to conduct a recovery test which involves pumping water out of a well and then giving it time to recharge. This can help you determine how much water you can draw from the well. A well should be able to pump 14 L/min (3.6 US gal/min) for 120 minutes or 450 L/person/day (119 US gal/person/day)
The quality of the well water is very important. Poor water quality can lead to health problems, unpleasant taste and odour, and costly treatment systems and/or the costly use of bottled water. Well water can be contaminated with bacteria and chemicals. Common sources of contamination include infiltration from septic systems, manure runoff, pet waste, or road chemicals as well as dissolved chemicals naturally present in the groundwater such as calcium, sulphur, chloride or iron.
Your offer of purchase should always include a requirement that closing is conditional upon an acceptable water quality evaluation. If possible, take the water samples yourself or have a qualified well water technician, well inspector or well contractor conduct the test. The three samples should be analyzed for: total coliform, E. coli, and nitrate (~ $30 each time) while one of the samples should also be analyzed for: sodium, hardness, sulphate, chloride, lead, iron, manganese and pH (~ 80). If possible, samples should be taken from a tap between the well pump and any water treatment units and/or pressure tank.
Test Results — What They Mean?
If concentrations are higher than the limits prescribed by the province, consult a water treatment systems supplier to determine if a water treatment technology is appropriate. It is preferable to get several quotations.
Above all, the best insurance for a buyer is to have a qualified inspector complete an inspection of the well, it’s water quality and quantity!
The septic system accepts wastewater from the home (sinks, shower, toilets, dishwasher, washing machine), treats the wastewater and returns the treated effluent to the groundwater. A conventional septic system is comprised of two components: a septic tank and a leaching bed.
A septic tank is a buried, watertight container, which accepts wastewater from your house. Septic tanks can be made from concrete, polyethylene or fibreglass and in the past were sometimes made from steel (if the property has a steel tank, it is likely rusted through and needs replacing). Older tanks may be smaller than those found today. Current tanks have two compartments, while older tanks may only have one compartment. Solids settle to the bottom of the tank to form a sludge layer, and oil and grease float to the top to form a scum layer. The tank should be pumped out every two to five years or when 1/3 of the tank volume is filled with solids (measured by a service provider such as a pumper). Bacteria, which are naturally present in the tank, work to break down the sewage over time.
The wastewater exits the septic tank into the leaching bed — a system of perforated pipes in gravel trenches on a bed of unsaturated soil (minimum 0.9 m/3 ft) The wastewater percolates through the soil where microbes in the soil remove additional harmful bacteria, viruses and nutrients before returning the treated effluent to the groundwater. In cases where there is more than 0.9 m (3 ft.) of unsaturated soil from the high water table or bedrock, a conventional system is used, where the network of perforated drainage piping is installed either directly in the native soil or in imported sand if the native soil is not appropriate for treatment. In cases where the groundwater or bedrock is close to the surface, the leaching bed must be raised 0.9 m (3 ft.) above the high water table or bedrock. This is called a raised bed system.
Under certain site conditions such as limited lot area, high groundwater table or poor soil conditions (clay or bedrock for example), a conventional system will not provide sufficient treatment of the wastewater. Under these conditions, it is often possible to install an alternative treatment unit. The two most common types of alternative treatment units are trickling filters, where the effluent from the septic tank trickles through an unsaturated filter media (such as peat or a textile filter), and aeration systems, where the effluent from the septic tank passes through an aerated tank.
Alternative treatment units provide a higher level of wastewater treatment, allowing the effluent to be discharged to a smaller area than in a conventional leaching bed. Effluent from an alternative treatment unit can also be discharged to a shallow buried trench, which is a pressurized pipe system 15 cm (6 in.) below the ground surface. In most provinces homeowners with alternative treatment units are required to have a maintenance contract with a service provider to inspect and maintain their systems.
Inspecting the Septic System
You should have the septic system inspected by a certified on-site system professional (such as a certified installer or engineer) prior to purchasing the home. Call your local municipal office, public health office or Ministry of Environment office for a list of qualified professionals. Inspections can cost anywhere from $50 for a simple file search to $500 for a complete inspection of the tank and leaching bed.
The inspection should include: a discussion with the homeowner, a review of the system permit, a tank inspection, a leaching bed inspection and a house inspection.
System Replacement or Repair
A septic system should last anywhere from 20 – 25 years, or even longer, if it is properly installed and maintained with regular pump-outs every three to five years. The cost of system replacement can vary between $12,000 to over $20,000 depending upon site conditions and local market conditions. The cost of system repair can vary from $500 for line lushing to $1,000 for a new septic tank to over $6,000 to replace clogged leaching bed lines (tile lines).
Above all, the best insurance for a buyer is to have a qualified inspector complete an inspection of the entire septic system!!
The above is a shortened excerpt from the CMHC website. For more information review the website in detail at cmhc-schl.gc.ca/en/co/buho/buho_003.cfm Source: CMHC Website.