Reed Bed Systems

Traditionally, all wastewater generated from the household was treated on-site by a septic tank or released into the storm water systems. Recent studies on the operating performance of on-site sewage management systems have revealed that a significant number of systems are failing to meet environmental standards and community expectations.

A reed bed or waste water garden is essentially a channel, lined with an impermeable membrane, that is filled with gravel and planted with macrophytes i.e. reeds, rushes and other plants that are used to treat the wastewater. Wastewater, black or grey, is passed through the root zone of the plants where it undergoes treatment. Inlet and outlet pipes are positioned below the gravel surface, so that the water always remains below the gravel surface, thus excluding human exposure to the wastewater, mosquito breeding and unpleasant odors.

Reed beds can be used after septic or grey water tanks and are usually installed on sites on bad soils i.e. sand, clays, or steep slopes, allowing the wastewater to be treated to an acceptable standard prior to land application.

Vertical flow reed bed filters

The filters are excavations made to be impermeable, filled with successive layers of gravel or sand with a grading that varies according to the quality of the wastewater to be treated. The raw effluent is distributed directly, without prior settling, onto the surface of the filter. During flow through it is subject to a physical (filtering), chemical (absorption, complexing, etc.) and biological (biomass attached to small media) treatment. The treated water is drained. The filters are fed with raw effluent via surface discharge pipes. Within the same system, the filtering surfaceis separated into several units which makes it possible to establish periods of treatment and inactivity.

Horizontal flow reed bed filters

In horizontal flow reed bed filters, the filter pack is almost totally saturated with water. The effluent is spread out over the entire horizontal cross-section of the bed by a distributor system located at one end of the bed; it then flows in a direction that is practically horizontal through the substrate. Most of the time, nutrient absorption via the plants takes place continuously since the supplied organic load is low. Discharge of the treated water takes place via a drain positioned at the opposite end of the bed, at the bottom and buried in a trench of drainage stones. This pipe is connected to a siphon which allows the height of the overflow to be adjusted, and thus the level of the water in the bed. The water level must be maintained at approximately 5cm under the surface of the material. In fact, water will not circulate above the surface, so as to avoid shortcircuiting of treatment; therefore there is no free water surface and no risk of insect proliferation.

The reed bed is the central component of our waterrecycling system.

It uses natural processes including biological activity, chemical reactions, mechanical filtration and absorption to clean your wastewater. We can recycle enough water here to irrigate the whole garden and lawn area.

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