Vegetative Tertiary Filter

Biologically Advanced Onsite Wastewater Reclamation with a Type 3+ Vegetative Tertiary Filter

The most biologically sophisticated, yet mechanically simple, widely installed Type 3+ system utilized in British Columbia, is the Vegetative Tertiary Filter or VTF. The VTF incorporates the functionality of constructed wetlands by using peat for final polishing to remove trace contaminants such as endocrine disrupting compounds, pharmaceuticals, and personal care products (EDC/P/PCP). Invented in British Columbia by an applied wetland scientist who designs constructed wetlands for subdivisions, communities, commercial developments, and landfills, the VTF has been granted U.S. Patent 7,407,577, and second U.S. Patent 7,695,620, issued on April 13th, 2010. The Canadian Patent 2,481,956 was issued on February 10, 2011.

Residential/commercial wastewater can be effectively treated with a Vegetative Tertiary Filter onsite wastewater treatment system, when the VTF is coupled with an advanced secondary treatment system. The VTF is the most biologically sophisticated, yet mechanically simple, widely installed Type III+ system utilized in British Columbia. Over 200 have been installed in the most difficult sites from Vancouver Island to Alberta.

WetlandsPacific supplied and installed a VTF for the Crawford Bay School project. The school was built to gold standard in the LEED® points system, and one of the credits was awarded for the VTF in Innovative Wastewater Technologies in the Water Effeciency Category.

Depending upon application, we offer either long or square VTF constructed wetlands. The flowers are planted in the VTF treatment system. VTF Photo Gallery

Wastewater treatment for single and multi family home

Long Vegetative Tertiary Filter(VTF) for a single family home in Ladysmith, B.C.


Square VTF constructed wetland in the frontyard of a single family home.

A Made in British Columbia Solution to Water Pollution

Treatment Train:

  1. Primary treatment in a septic tank, where anaerobic (without oxygen) organisms liquefy solids
  2. Secondary treatment in a Nayadic, North America’s original fiberglass extended aeration treatment plant. It works aerobically (with oxygen) to remove up to 96% of the contaminants and 99.9% of the bacteriaConceptually when a plant grows it takes in water, minerals, and carbon dioxide and releases oxygen via photosynthesis. To break that plant material down again, the oxygen must be returned. Then via a combination of direct oxidation and suspended growth, microbes consume dissolved compounds breaking them down into their component molecules, i.e., water, carbon dioxide, and minerals.
  3. Tertiary - the now clear, odorless effluent then moves into the VTF for tertiary+ (nutrient and trace compound removal) peat filtration including aquatic plant bioremediationPeat can have 30,000 times more surface area than course sand. It is this vast surface area that provides attachment space for microbes to form a community that consumes the remaining dissolved compounds. Research has demonstrated that a single cubic centimeter can contain a billion microbes and a hundred thousand fungi. A VTF will typically have in excess of 3 million cubic centimeters of peat thus could have up to 3,000,000,000,000,000 or three quadrillion microbes. Microbes consume and break down the 100,000+ compounds found in domestic wastewater that would otherwise contaminate surface and ground waters and are causing ecological havoc in our lakes and oceans.
  4. Final dispersal by evapotranspiration and wicking into organically enriched soil

treatment train


  • VTF is the most compact system sold in BC: occupies a 3 m x 3 m area on flat ground or 1.5 m x 9 m on a slope
  • Removes contaminants down to non-detectable levels of BOD5 and coliform bacteria so protects environment from harmful substances such as pharmaceuticals, personal care products and endocrine disrupting compounds
  • Can be installed in the most difficult sites: impervious clay, hardpan, shallow or rocky soils, high water table and small lots
  • No unsightly sandmounds
  • Peat does not have to be replaced as it is replenished by decayed plant growth
  • When appropriately planted can be as aesthetically pleasing as any garden
  • Maintenance is a simple inspection
  • Provides wastewater reclamation for single family dwellings, subdivisions and commercial developments


A VTF constructed wetland installed in 2004 on an industrial site. By 2007 it is indistinguishable from the native vegetation background

  • Peat removes trace compounds even municipal treatment does not
  • Maintenance is a simple inspection
  • Plant tending as desired, no tending required in the above installation
  • Peat never has to be replaced
  • Robust plant growth replaces peat as it decays

Challenging Sites Are Our Specialty

Vegetative Tertiary Filters have been installed in the most difficult sites imaginable including soils that are impervious clay or hardpan, shallow or rocky, with high water tables, on small lots, and even a road.

A VTF installed on a logging road. Even poor soils can be used for wastewater dispersal.

A VTF literally installed on a road. Used as a logging road for 80 years, now decommissioned as a roadway; the property measures 20 m by 425+ m (66’ wide x 1400’+ long). It has 50 cm of well packed bed run gravel over homogenous silty clay that grades to weathered sedimentary rock.