Onsite Systems

When used in accordance with the design parameters and properly maintained, an onsite sewerage system will provide effective treatment and will minimize risks to human health and the environment. 


This is the new term for what used to be called a “septic system.” Provincial regulations define it as “a system for treating domestic sewage that uses one or more treatment methods and a discharge area, but does not include a holding tank or privy. ” The term “wastewater” is often used interchangeably with “sewage.”

Most B.C. homes outside major urban areas do not have access to a public sanitary sewer system – a city sewer hook-up, in other words. That means it is up to the home owner to treat and disperse wastewater on her or his property in accordance with Provincial Regulations.

These systems are designed to match the expected usage of the building, the number of occupants, the size and type of the planned or existing building, along with the limitations of the property and soil type. The goal is to treat and disperse wastewater in a manner that does not cause, or contribute to a health hazard, and minimizes risk to the environment.

Installation of a gravity seepage bed

A system typically includes a septic tank for a physical separation of solids from liquids, and may include a treatment plant or process to promote additional biological treatment. Although septic tanks provide some treatment, the microbiology found in those conditions is not as efficient at breaking down the contents of wastewater as conditions within a treatment plant.

From the septic tank or treatment plant/process, the effluent is directed to a soil dispersal area which could be one of many styles including standard trenches, a sand mound or even drip irrigation. The physical and biological characteristics of the soil continue the treatment process and break down or use the nutrients and otherwise harmful components of the wastewater. When functioning as designed and maintained properly, a system will return water into the environment that is safe.

Many older styles of systems used a simple gravity-based means to transport fluids from the home to the final soil treatment area. Today many systems require a pump set into a separate chamber with a control panel and alarms for monitoring its operation. These more advanced methods can improve the lifespan of the system, often substantially, but with these components comes an added cost over the older, simpler styles. Simple gravity dispersal systems are allowed on some sites with substantial depth of favourable soil, but many sites are not suitable for these simpler systems.  More advanced systems that provide uniform dispersal to the entire dispersal field are often a requirement rather than an option.