Ministry of Health Approved Onsite Sewage Treatment

Canwest Tanks manufactures various sewage treatment systems using activated sludge with aeration and suspended or attached growth media technology. Wastewater treatment plants of this type work by utilizing the microorganisms naturally occurring in wastewater to form colonies (biomass) which can grow suspended in the liquid or attached to a growth media in the reactor chamber.

By infusing air (oxygen) into the liquid, these microorganisms (aerobes) multiply at an accelerated rate, resulting in larger than normal populations of aerobes in the environment, causing an increased amount of nutrients to be digested. This process lowers the BOD and is continuous for as long as the reactor chamber is supplied with nutrients and oxygen. In addition to rapid absorption of the nutrients, the increased biomass contributes to better breakdown of solids resulting in lower total suspended solids (TSS).

The Whitewater® and ECOPOD systems were approved by the Ministry of Health, Public Health Protection Branch in 1994. Canwest Tanks began manufacturing them in 1996. Canwest has manufactured and sold more than 6,000 units in BC, Alberta, Ontario, Yukon, Saskatchewan, Manitoba, and parts of the US.

The BC Ministry of Health, Sewage System Standard Practice Manual (SPM) lists 3 types of systems approved for the disposal of domestic waste:


This is a conventional septic tank and dispersal field system. The sewerage regulation outlines the setback, ground, and soil conditions that determine whether a conventional septic tank and dispersal field can be used.


The on-site sewage regulation specifies the acceptable effluent quality for a Type 2 System as being:

BOD5 = 45 mg/l
TSS = 45 mg/l

Under this heading, a Whitewater® sewage treatment plant or ECOPOD system is installed as the primary receptacle and aerobic treatment unit for domestic wastewater.

This type of system generally consists of:

  • Trash tank (optional), however in most jurisdictions it is mandatory or strongly recommended
  • The Whitewater® sewage treatment plant or ECOPOD sewage treatment plant
  • Discharge pump package if other than gravity flow to field

A disposal field will still be required; however the field may be greatly reduced.


The Whitewater® Type 3 or ECOPOD Type 3 Systems are an extension of the basic Whitewater® or ECOPOD systems, and are used in applications where the effluent quality must meet specific criteria.

A Type 3 system must be designed by a professional (P.Eng.) with experience in environmental matters.

The on-site sewage regulation specifies the acceptable effluent quality for a Type 3 System as being:

BOD5 = 10 mg/l

TSS = 10 mg/l

Fecal Coliform = 400 CFU/100ml

The equipment required for this treatment method generally consists of:

  • Trash/pre-settling tank
  • Whitewater® sewage treatment unit
  • Clarifier/filtration unit
  • UV disinfection unit
  • Discharge pump package (if required)

Please note that design criteria may vary as influent strength and disposal method can have a bearing on the treatment process.

Created by

Legal notice