Sewage treatment in a greenhouse

An on-site wastewater treatment system, which treats sewage using a series of engineered ecologies, is now operational at a Vermont ski resort, treating up to 30,000GPD (114m3/d) of raw sewage.

The Living Machine treats sewage using a system of microbes, plants, snails and insects, and has provided the additional wastewater treatment capacity needed for the Smuggler’s Notch Resort in Jeffersonville to build new residential and commercial facilities.

The Living Machine has enabled the resort to handle more waste and, at the same time, complete construction of a new condominium project and a base lodge facility for a ski lift and trail network.

The Living Machine is housed in a concentric tank with a central clarifier and an outer tank forming a ring around the clarifier. The outer tank is divided into anaerobic, anoxic, aerobic, and sludge holding compartments. The compartments provide environments for different ecologies to thrive and breakdown waste in the water. The planted aerobic reactors are covered by tropical, sub-tropical, and native plants including iris, willows, bluebells, calla lillies and monkey flowers that help with the treatment process.

The Smuggler’s Notch Living Machine is housed in a 15m2 greenhouse, replacing a dilapidated wooden structure that covered the former package plant. All odour-producing processes are under cover in the greenhouse and any odorous compounds are removed.

The Living Machine retrofit does not include effluent polishing of the wastewater after it is treated in the clarifier, usually part of the Living Machine treatment process. Instead effluent is pumped to the resort’s lagoons for second stage polishing before being piped to a nearby site for irrigation.

BOD influent entering the greenhouse at around 300mg/l leaves at <20mg/l while TSS, entering the Living Machine at around 250mg/l leave at <20mg/l also. The Living Machine removes nitrogen using a natural denitrification process. Effluent total N should be less than 10mg/l, although there are currently no final effluent requirements for nitrogen.

What is a Living Machine?

Living Machines are on-site wastewater treatment systems that incorporate and accelerate natural processes to treat sewage. With the help of sunlight and a managed environment, a range of organisms — including bacteria, plants, zooplankton and other invertebrates – breakdown and digest organic pollutants.

Depending on climate, Living Machines can be housed in a protective greenhouse, under light shelter, or in the open air. With effluent polishing, Living Machines produce high quality effluent that is suitable for reuse or a number of disposal alternatives, a useful feature for communities unable to connect to a municipal sewerage network or where water is scarce.

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