The septic tank is a buried, watertight container typically made of concrete, fibreglass, or plastic. The purpose of the tank is to let solids (sludge) settle to the bottom and oils and greases (scum) float to the top (the crusty layer you see when looking into the tank). It also allows partial breakdown of solid materials. Baffles or a pipe “T” are used in the tank to prevent sludge and scum from leaving the tank and travelling to the drainfield area. Only mostly clear water leaves the tank and continues to the drainfield for further treatment.
Regular Maintenance: To prevent buildup, sludge and floating scum, the septic tank should be pumped out periodically. Regular septic pumping in Manitoba, every 3 to 5 years, is the best and cheapest way to keep your septic system in good working order.
The Disposal Field: The disposal field (drainfield) disperses the effluent throughout the soil. The size and type of field depends on the volume of sewage produced, the type of soil, the slope of the lot, and other site conditions as well as regulations that were in effect at the time. A typical disposal field that would be installed today is shown in the cross section diagram.
- Do spread automatic washer use over the week rather than many loads on one day.
- Do make a permanent record of where the key parts of your system are located for future maintenance, such as tank pump outs or field repairs.
- Do have your septic tank pumped out regularly.
- Do keep records of pump outs and maintenance.
- Do use water conserving devices where possible. Low flush toilets and shower heads are commonly available.
- Do have manually cleaned lint traps on your automatic washer.
- Do check any pumps, siphons, or other moving parts of the system regularly.
- Do remove or prevent trees with large root systems growing near the disposal field.
- Do maintain a healthy grass cover over the disposal field to use some of the water and to prevent erosion.
- Do keep surface water from up slope or from roof drains away from the disposal field.
- Do check your interceptor drain regularly to ensure that it is free flowing.
- Do compost your kitchen waste.
- Do increase the size of your septic tank, and have it pumped more often, if a garbage grinder is to be installed.
- Don’t overload the system with high volumes of water.
- Don’t connect basement sump pumps to the on-site system.
- Don’t connect backwash from water treatment devices directly to the on-site system.
- Don’t allow large amounts of fats, chemicals, or solvents to enter the system; don’t allow any plastics to enter.
- Don’t enter a septic tank without proper ventilation, a second person (adult) above ground, and other requirements for confined spaces apply. Sewer gases can be fatal.
- Don’t allow vehicles or heavy equipment to drive over or park on the disposal field. This may compact the soil and crush the piping.
- Don’t plant anything over the disposal field except grass; especially, don’t cover the tank or field with asphalt or concrete or other impermeable material.
- Don’t put in a separate pipe to carry wash waters to a side ditch or woods. This ‘greywater’ also contains disease carrying organisms.
- Don’t wait for signs of failure. Check the system regularly.