Maintenance and Operation of Sewage Disposal

When are sewage disposal systems used?

Any home or other building that is not connected to a municipal or city sewage system needs a method for getting rid of human wastes. Some people — usually in rural settings or camps — are content to use an outhouse or privy. However, all buildings with indoor plumbing need to have a sewage disposal system that is properly designed and approved by the local public health authority.

How does a septic tank/treatment plant work?

A typical sewage disposal system has two basic parts:

* A septic tank, or a package treatment plant, or an engineer-designed treatment plant, or a combination of these, and
* an appropriate disposal area - usually a series of underground pipes with holes in them, that let treated liquid from the septic tank soak into the ground below the surface. These pipes are connected to the tank by a distribution box.

Septic tank: A septic tank is a watertight, underground container for receiving, treating, and settling human wastes. The solids settle to the bottom of the tank and become sludge, while oils and other light material float to the surface, forming a scum layer. Within the tank, anaerobic bacteria (bacteria that do not need oxygen) break down the solid wastes. When the septic tank is working properly, these bacteria can reduce the solids by 50 or 60 per cent. The liquid between the sludge on the bottom of the tank and the scum on the top flows out of the tank into the disposal area, where further breakdown occurs within the soil, until the liquid effluent is harmless and inert. The sludge and surface oils remaining in the septic tank need to be pumped out every three or five years. This can be done by a septic system pump-out contractor. If you do not maintain your sewage disposal system properly, this can result in the premature failure of your system, and you will need to pay for costly repairs or replacement of your disposal area.

Treatment Plant: A typical treatment plant uses air (oxygen) to help break down the wastes. In some cases, the wastes are treated in a septic tank first, before they flow into the treatment plant. Other treatment plants may be multi-chambered, and not need any pre-settling of solid wastes. A treatment plant is used to treat liquid wastes to a higher quality, so it is cleaner and safer before it enters the disposal area than discharge from a regular septic tank. The net result for the home owner is a smaller disposal area. However, because these treatment plants are more complex than septic tanks, with various working parts, they need more maintenance to make sure they work properly.

Can a sewage disposal system be installed anywhere?

Everyone who wants to install an on-site sewage disposal system must apply for a permit and pay an administrative fee of $250 which includes the cost of one final inspection. (If a re-inspection is necessary, the fee is an extra $100.)

Remember that all sewage systems must conform to the Health Act and the 'Sewage Regulation' and must be approved by an Environmental Health Officer, from the local health authority.

Maintaining your sewage disposal system

It is important to keep an accurate drawing that shows the location of your septic tank, distribution box and disposal field. Make sure the drawing shows the system relative to a fixed point, such as your house or an outbuilding.

All access hatches should be water tight to keep surface water from getting in. Using a "Riser" over access ports will make access easier.

All advanced treatment systems (treatment plants) need ongoing, proper operation and maintenance. To make sure this is done, it is usually included as a condition of an operating permit. An owner of an advanced treatment system should contact a local service agent who has experience with your specific treatment plant and model, to set up an annual service contract.

Preventing possible problems

Sewage disposal systems can be damaged in a number of different ways, although most of these can be prevented. Sewage Disposal Systems are not pleasant to fix! So keep the following in mind:

* Do not let any vehicles (including snowmobiles) drive or park on any part of the disposal system;
* Do not flush paints, solvents or any kind of toxic chemicals down the toilet;
* Do not plant large trees or shrubs nearby because the roots may affect the disposal field;
* Do not allow roof or perimeter drains, or any surface water, to discharge on or near the sewage disposal system;
* Do not overload the system with too much water (for example by a continuously running toilet or a dripping faucet). This includes irrigating (watering) on or near the disposal area;
* Do not flush cigarette butts, filters, sanitary napkins, newspaper, disposable diapers, condoms, facial tissue (e.g. Kleenex®), paper towels, hair, metal or metal items, coffee grounds, tea leaves, fats or grease. These can all plug a septic tank or a drain field;
* Do not install a garborator without increasing the size of your tank and field;
* Use water sparingly (establish a water conservation strategy for the house);
* In areas where frost penetration is a problem, insulate the main pipe and disposal area with a generous layer of straw during winter months. Insulate the tank and pipe connection from the house as well;
* Do not leave the system inoperative for long periods during cold winter months;
* Use snow fences to promote maximum insulation from snow cover;
* If water pools up on a disposal area, seek advice from your Environmental Health Officer.

Servicing a septic tank/treatment plant

Septic tanks should be inspected every year, and they usually need servicing every two to three years (depending on the number of people using the system and the volume of daily sewage flow). Here are a few things to keep in mind:

Septic Tank

* Remove sludge in the spring rather than in the fall. This prevents leaving undigested solids in the tank during the cold winter months;
* Do not scrub a septic tank clean. A small amount of sludge should be left to renew bacterial activity;
* When it is time to service your system, check the Yellow Pages for firms equipped for this work.

Treatment Plant

* A treatment plant should only be serviced by the appropriate service agent (check with the manufacturer).