Septic Tanks
The septic tank is where solids settle and scum floats, so that only relatively clear liquid moves on to the disposal field.
17 questions in this section
- What standard must a septic tank meet?
- What is the minimum septic tank size in New Brunswick?
- What materials are allowed for septic tanks?
- Why does a septic tank have two compartments?
- Does the pump chamber count toward the tank capacity?
- What are baffles for?
- What is an effluent filter and is it required?
- How should the effluent filter be set up so I can service it?
- Does my tank have to be level?
- How deep can a septic tank be buried?
- What is the minimum liquid depth in a tank?
- What slope is required in the pipe from the house to the tank?
- Can I build a deck or shed over my septic tank?
- Can a septic tank float out of the ground?
- Can I drive over my septic tank?
- What happens if a two-piece tank arrives damaged?
- Do all the connections have to be watertight?
What standard must a septic tank meet?
Prefabricated septic tanks must conform to the most recent version of CSA Standard B66 and carry a visible stamp. If the stamp is unclear or missing, the licensee may have to prove the tank conforms.
What is the minimum septic tank size in New Brunswick?
A minimum liquid capacity of 3,410 litres.
What materials are allowed for septic tanks?
Concrete, fibreglass or polyethylene. Steel tanks are not permitted because they corrode at rates significantly higher than the alternatives and may have a much shorter life.
Why does a septic tank have two compartments?
To improve settling and prevent solids carrying over to the field. The Guidelines require two compartments, with the first compartment holding two-thirds of the total tank capacity.
Does the pump chamber count toward the tank capacity?
No. The capacity of a siphon or pump compartment is not included as part of the septic tank capacity.
What are baffles for?
Baffles at the inlet and outlet prevent short-circuiting, which is raw sewage flowing straight through the tank without settling.
What is an effluent filter and is it required?
Yes, it is required. Septic tanks must be equipped with an effluent filter meeting NSF Standard 46, easily accessible for maintenance. It catches solids that would otherwise reach and clog the disposal field.
How should the effluent filter be set up so I can service it?
Unless the manufacturer says otherwise, the filter should have a permanently attached handle extending to within 150 mm of the access riser rim, made of a material that allows easy removal and replacement.
Does my tank have to be level?
Yes. All septic tanks must be installed level, which means the bedding pad must be levelled before the tank is lowered in.
How deep can a septic tank be buried?
The tank must be designed to carry a minimum of 600 mm of earth cover, and the earth cover must not exceed the maximum burial depth the tank is designed for. Depth below grade must also stay within the suction elevation of vacuum trucks so it can still be pumped.
What is the minimum liquid depth in a tank?
0.9 metres (3 feet), as specified in the CSA standard.
What slope is required in the pipe from the house to the tank?
A minimum of 3 mm per 300 mm of length, which is 1 percent.
Can I build a deck or shed over my septic tank?
No. Decks or other structures that can limit access should not be built over septic tanks or pump chambers. Tanks must remain accessible for septage removal, service and maintenance, with access openings at or above grade.
Can a septic tank float out of the ground?
Yes. Empty septic tanks have been known to lift out of the ground under high water table conditions. Tanks in such areas must be secured against hydraulic uplift, and the manufacturer's placing and backfilling instructions - which may call for pea gravel - must be followed.
Can I drive over my septic tank?
No. Septic tanks should be protected from overhead loads or stresses greater than the tank's load-bearing capabilities.
What happens if a two-piece tank arrives damaged?
Two-piece septic tanks that arrive on site with damaged joining edges, or that are installed with improper caulking, will be rejected and must be removed from the installation.
Do all the connections have to be watertight?
Yes. All piping connections must be watertight and must not allow groundwater or surface water infiltration or wastewater leakage. This applies from the building to the tank and from the tank to and including the header.
Have a question about your own property? General answers only go so far — your soil, slope, water table and setbacks are specific to your lot. Call (506) 233-6272 or send us the details.
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