Benefits
In the medium to long term wetland/reedbed systems are, in most cases, more cost effective than any other wastewater treatment. They are robust and require little maintenance. They are naturally environmentally sound protecting groundwater, dams, creeks, rivers and estuaries. Wetlands are environmentally sustainable.
Benefits of Reedbeds
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Long term solution
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Easy maintenance
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Low on-going costs
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Clearest water for lowest energy input
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Natural processes
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Physical and biological filtration
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Reuse of nutrients and water
Other Advantages of Reedbeds
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Quality of final output
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System continues to treat wastewater if pump fails
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Emergency light and overflow provided for pump failure
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Natural living system
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Reliability
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Maintainable by user-no maintenance contract necessary
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Lowest medium and long term costs (installation and on-going) compared to any other system
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Improve with age
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Individual design for site and client needs
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Low operation costs
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No operational noise
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Aesthetically pleasing
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Can handle intermittent usage (eg holiday houses)
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Capable of treating shock loads
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Capable of treating flows from residents/businesses/schools/camping areas/holiday units/restaurants/nurseries not connected to main sewerage systems
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Environmentally friendly
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Provide effective and reliable wastewater treatment
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Can tolerate both large and small volumes of water and varying contamination levels
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Treatment reduces algal buildup in irrigation lines
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Sustainable
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constructed reedbeds
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Treatment results from Reedbeds (and Sandfilters)
Abbreviations: Biological Oxygen Demand (BOD), Total Suspended Solids (TSS), Total Nitrogen (TN), Total Phosphorus (TP), and Faecal Coliforms (FC).
NB- BOD (a measure of the oxygen used by microorganisms to decompose organic waste in effluent discharge) and TSS are below the maximum recommended levels for subsurface irrigation (20 and 30 mg/L). Nurtrients (TN and TP) are decreased to reduced irrigation area required. FC is indicative measure of potential pathogen concentration.
It is important to recover and reuse as much nutrient as possible whilst reducing pathogens and BOD and TSS for irrigation/dispersal. Nutrients can be recovered from the reedbed discharge and used in an irrigation area and by cropping the reeds. The latter are a useful mulching material. If nutrients are not reduced by treatment and reuse they can make their way into groundwater or overland flows to pollute waterways.
Reedbeds are cost competitive with any other secondary treatment system for initial installation. They are more economical in the medium to long term (no maintenance contract necessary - can be maintained by owner). Power costs are minimal. The treated wastewater is to Australian Standards and NSW Health Guidelines for sub-surface irrigation (unlike many worm based wastewater systems that have high BOD and TSS). Reedbeds do not use chemicals unlike Aerated Water Treatment Systems, which also generally have high power usage, and require a service contract for 3 monthly inspections.
Reedbeds reduce nutrient levels by 50% (not counting any nitrogen loss to atmosphere in primary tank) as part of the process before release into the environment.
A major part of the NSW Regulations and Guidelines is to reduce the risk of nutrient escaping into rivers, dams and streams resulting in algae blooms, unnatural weed growth, oxygen depletion and fish kills.
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Green lines showing even dispersal of
filtered water in poor quality soil.
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Approx. 12 months later, image showing soil is being
conditioned by microbial activity. Note - Also surrounding pasture in drought conditions.
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