The Eco-Machine is an on-site sanitary sewage system

This Eco Machine is an on-site natural wastewater treatment and recycling system that processes all wastewater from the buildings at the Roosevelt Operations Center.

The Eco-Machine is a system of tanks and plants that remove suspended solids and neutralize toxins. The clean water that comes out of the Eco-Machine is then used to flush the toilets or to irrigate upland vegetation. This helps reduce the demand for treated water from the municipal system, reserving it for uses that require cleaner water.

Eco-machine components include:
  • Influent pump
    Wastewater is collected from sinks and toilets at the Roosevelt Operations Center and is pumped into the septic tanks by an underground pump.
  • Septic tanks
    Suspended soils, which are heavier than water, settle to the bottom of two 15,000 gallon tanks, while lighter substances like grease and detergents rise to the top.
  • Equalization tank
    The volume of wastewater from the buildings rises and falls as activity levels change. This tank holds the water until it is needed, equalizing the flow into the Eco-Machine.
  • Wetland cells
    The plants in the planters grow in a bed of gravel. Wastewater is pumped into pipes running through the gravel beds, where it flows through the plants' roots. Organisms that live in the root hairs reduce the water's biochemical oxygen demand (BOD). BOD is a measure of the uptake rate of dissolved oxygen by the biological organisms in a body of water. In general, lower levels of BOD mean cleaner water. Suspended solids are also removed as water passes through the tanks.
  • Aquatic aeration cells
    Bacteria and other organisms in the roots of the suspended plants help to clean the wastewater in a process known as "nitrification." In this process, ammonia in the wastewater is converted into a nitrate form. This reduces toxicity and odor.
  • Sand filter
    Water passes through the sand and plant roots as a "polishing step" that removes fine suspended solids. Some water is then returned to the septic tank.
  • Cartridge Filter and UV disinfection unit
    The Cartridge Filter mechanically removes the smallest suspended particles and dust. The UV disinfection unit then uses ultraviolet light to kill pathogens.
  • Recycled water
    Treated water is recycled to flush toilets in the Operations and Engineering Building.
  • Landscape irrigation
    Extra water not needed for toilets is used for landscape irrigation.
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