Biologic Design Ltd
Archenhills
Stanford Bishop
Bringsty
Herefordshire WR6 5TZ
Tel: 01886 884 721
Email: jay@biologicdesign.co.uk
Website: www.biologicdesign.co.uk
Wetland Ecosystem Treatment
(WET) Systems
• WET Systems function by harnessing the innate
ability of natural wetland ecosystems to absorb
and transform the organic nutrients found in
wastewater, converting them into plant biomass
and soil.
• Each WET System design is site specific, and
is based upon good ecological practice and
Permaculture design principles.
Background
• Biologic Design was formed in 1993 and aims to
create multi-species constructed wetlands for
sustainable wastewater purification, biodiversity
enhancement and resource production.
• We are a family-run company working with a
wide range of clients and specialise in the
creation of WET Systems for ecologically
minded people and organisations, sustainable
housing developments, low input/organic
farmers and food producers as well as
environmental, educational and Permaculture
projects.
The main aims of a WET System
1. The purification of wastewater with
minimal non-renewable energy use.
The main aims of a WET System
2.The creation of a beautiful, species-rich
ecosystem/wildlife habitat which gives greatly
enhanced biodiversity.
The WET System provides a refuge for frogs,
toads and newts, as well as a large variety of
insects and pond life which in turn attracts
many species of bird.
The main aims of a WET System
3. The generation of a biomass
resource; the willow can be coppiced
and the wands harvested can be
used for a range of traditional and
contemporary crafts.
Basis of the WET System
• A WET System is made up of a series of
specially designed and constructed earth banks
and ponds. As the wastewater flows through
these soil banks it is both purified by microbial
action and transpired by growing plants.
• The WET System is planted with a wide range of
aquatic and marginal plants and a variety of
willow types and wetland tree species.
Established WET Systems
• WET Systems have been created for
domestic sewage;
• Systems for full time populations from one
person up to 380 people
• An environmental education centre, which
now has around 250,000 visitors/year
• Field Studies Centre with a maximum
seasonal population of around 200.
Established WET Systems
WET Systems purify a wide variety of other effluents as
well, including:
• Piggery and dairy farm yard runoff
• Waste process water from an organic creamery
producing cheese and another producing sheeps
milk ice cream
• Kennel yard washdown water
• Westons Cider Mill in Herefordshire
• The Otter Brewery in Devon
WET Systems
Sustainable wastewater purification
technology
• WET Systems are ‘low-entropy systems’ in that
they use no fossil fuels or electricity to purify the
wastewater.
• WET Systems are ‘solar powered’ by the ability
of plants to absorb solar energy during
photosynthesis.
• Micro-organisms in the root-zone mineralise the
nutrients found in wastewater making them
available to the plants.
Low embedded energy
• Unlike conventional Reedbed Treatment
Systems, no gravel or plastic aeration pipes
are used in their construction.
• Gravel does not need to be quarried and
transported to site.
• Plastics are not routinely used in our designs
• WET Systems have a very low embedded
energy - soil in the root-zone, not imported
gravel, is the filtration medium and this is
already on-site
Biomass Yield of the WET
System
• The biomass yield from a well managed WET
System can include one-year old coppiced
willow wands for basketry.
• Two-year old willow wands for hurdle making or
living willow domes and tunnels, as well as
binders used for hedge-laying.
• Three-year old willow wands which are used for
the construction of living willow structures and
garden furniture.
Biomass Yield of the WET
System
• Rapidly growing, large, biomass willow
types can also be planted and when
harvested and seasoned these can be
used to fuel simple woodstoves, ceramic
stoves or combined heat and power (CHP)
boilers and so contribute to the energy
needs of the site.
Integrated Resource Recovery
Systems
• In some instances where the wastewater has a
very large BOD it is beneficial to consider
preceding the WET System with an Anaerobic
Digestor
• This reduces the organic load entering the WET
System and also creates methane which can
then be used as a fuel gas for the generation of
electricity, process steam and/or hot water.
Biologic Design Ltd
Archenhills
Stanford Bishop
Bringsty
Herefordshire WR6 5TZ
Tel: 01886 884 721
Email: jay@biologicdesign.co.uk
Website: www.biologicdesign.co.uk