Page 30 - Council Journal Winter 2019

FEATURE Integrated Constructed Wetlands
elements provided (depending on the particular treatment process at the plant) up front of the reedbed wetland pond or ponds, which can be surface flow and/or sub-surface flow, generally with a single plant species within a gravel media and lined with polyethylene barriers.
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ensure even flow across the wetland area is being achieved; keep pipe inlets/outlets to/ from wetland free from plant and vegetation overgrowth; monitor discharge from primary (and secondary treatment – especially for the reedbed system to prevent sludge carry over) into wetland pond;
Integrated Constructed Wetlands (ICWs) are a sustainable wastewater treatment system constructed with natural materials and designed to integrate into the landscape with the purpose of treating wastewater by using a series of ponds with a variety of wetland plants to clean the water before allowing it return safely to the environment.
monitor & test discharge from wetland to discharge point of system;
remove weeds and tree saplings;
These systems generally have a
engineered reedbed systems will be Other operations activities for the greatly influenced by the type of ICW systems:
primary settlement tank or primary
process units provided at any • particular site with the major
operations and maintenance activities • predominated by the primary and secondary elements of the treatment system. The operations activities
desludge primary settlement tanks, as required; control/remove overly dominant plants and replant wetlands plants where required;
ponds followed by a series of
vegetated wetland ponds. The
Department of the Environment,
Heritage & Local Government
Integrated Constructed Wetlands
Guidance Document for Farmyard
opportunities for enhancing existing wastewater treatment plants.
Good design and correct
construction is paramount for the
effective and efficient operation and maintenance of wetland treatment
systems, to ensure system robustness,
to maximise the service provisions of
the treatment plant, to extend the
useful life of the assets, to facilitate operations activities and to keep
ongoing operating costs to a
minimum. •
How Reedbeds & ICW’s Work
Soiled Water & Domestic Wastewater required for the Engineered Reedbed •
trim and cut grass and vegetation to maintain access along pathways and embankments around ponds, as required by with periodic maintenance this can be on monthly frequency or more during the growing season; remove sediment and organic debris build up in wetland pond, 10-20 years after the establishment of an ICW. This nutrient rich material is a potential future source of phosphorous and is expected to become a more valued resource in future when natural rock phosphorous reserves are depleted.
Applications, published in 2010, wetlands are relatively easy due to the explains that the ICW concept was absence of mechanical, electrical or developed to: process equipment in that element of
• integrate water flow and water the treatment system.
quality management with Operations activities for the
landscape fit and biodiversity Integrated Constructed Wetland enhancement; systems require regular periodic
The operations activities for
maintain access.
• deliver enhanced treatment inspections with minimal follow up • with emphasis on phosphorous interventions to maintain surface
removal; flows within ponds, maintain access
• provide greater system to and from the ponds and the
robustness and sustainability. removal of sediment and organic Wetlands are adaptable and debris that builds up over a period
versatile systems that can be utilised years.
for primary, secondary and/or Regular operations activities for the
polishing processes for the treatment Reedbed and ICW systems include:
of wastewater effluent. These systems • monitor and maintain water have gained recognition for providing levels in the wetland;
a sustainable treatment option for • monitor condition of plants, small rural settlements and provide minimise need for replanting of
30 Council Journal wetland plants;