Earth Flow Site-Built Composting System

unspecified-7The Earth Flow™ Site-Built System is an automated composting system that mixes, aerates and adds moisture with little labor required beyond loading and unloading. Instead of composting inside a steel vessel, the Site-Built Earth Flow™ mixing system is integrated into a locally-built vessel of your choice. Typically, the vessel has a concrete pad and concrete or stainless-lined wood walls and some type of enclosure. This design allows us to significantly reduce capital costs and provide convenient accessibility to the compost for materials handling and process control. The Site-Built System provides excellent control over moisture, odors, vectors, and leachate. The system is an innovative solution since it combines the low-cost and flexibility of pile-based systems with the containment and control of in-vessel systems.

The Earth Flow In-Vessel Composting System can be operated as either a batch or a continuous flow composting system:

  • Batch Process: the system is fully loaded with feedstocks. These materials are composted as a batch and then fully discharged. This approach works well for materials such as biosolids, where it is necessary  to isolate material for pathogen reduction.
  • Continuous Flow Process: feedstocks are added into the load end of the vessel and compost is discharged from the other end. In this process, the auger moves the compost slowly toward the discharge end of the vessel. Once materials arrive at the discharge end, the compost is ready to be removed from the system.




1. Feedstock Loading

An organic “recipe” (for example, a mixture of food waste and wood chips) is loaded into the Earth Flow through the load doors via a                      variety of means including manual emptying of containers, using a front-end loader, using tote tipper or chute.

Plastic contamination should be limited. Hard foods such as pineapples, hard crusted loaves of bread, etc. should be chopped up prior to       addition. Since food scraps are wet, a dry bulking agent such as wood shavings must be added to create a balanced compost recipe.

Prohibited materials in an Earth Flow include: long-fiber materials such as tall weeds, rope, clothing, tree branches, bioplastic bags(these get wrapped around the auger) as well as large rocks and sand.

2. Mixing and Active Composting

Once the new material has been added, the traveling auger system blends the new feedstock with existing compost mass. A complete mix can take 30 minutes or more. The auger is programmed to mix automatically one to four times per day.

Thermophilic composting at temperatures above 115° F occurs rapidly in the insulated bin. The food wast “slow cooks” at this temperature and is easily shredded by the auger. Continue adding feedstocks until the bin is filled to the top of the auger screw.

3. Unloading and Curing the Compost

Once the active composting cycle is complete (approximately 14-21 days), composted material can be removed through the discharge end of the vessel. There should be no residual food waste and the material should have a pleasant odor and a black or dark brown color.

The composted material can be discharged automatically using the auger into a bin, rolling cart, truck or conveyor. Alternatively, a front end loader can enter the system to remove compost directly.

This compost can be used immediately as a cover mulch or can be cured in a pile for 30-60 days before being used as a soil amendment. Screening will eliminate residuals (for example, bones and large wood chips) and plastic contaminants, making the finished product even finer.

The Earth Flow Site-Built Composting System can process 1,000 pounds to 10 tons of material per day.

  • Colleges and Universities
  • Farms
  • Equine Facilities
  • Resorts
  • Commercial Facilities


  • Utilizes the same traveling auger technology as our Earth Flow In-Vessel Composting System.
  • Side walls that are either concrete or wood with a stainless steel liner with coated concrete floor.
  • Optional gasketed stainless-steel-lined end doors for complete containment of leachate.
  • State-of-the-art aeration technology on the floor pad to provide optimal in-vessel aeration and curing.
  • The hoop house can be completely enclosed for total odor control and biofiltration.
  • The hoop house can cover the Earth Flow vessel or be enlarged to provide covered storage for bulking agent and curing.
  • Configurations allows a front-end loader or dump truck to drive straight into the Earth Flow composting vessel to load or unload materials.


  • Lower Capital Costs.  Roughly half the cost of in-vessel systems.
  • Increased Capacity.  Up to 5 tons per day.
  • Lower Labor Costs.  Less turning of compost required after exiting the system.
  • Reduced Shipping Costs.  Ships on pallets.  No crane required for placing equipment.
  • Flexible/Scalable.  Can be installed on existing pads and in existing buildings.  Can be sized and configured to meet your project needs.
  • Odor and Leachate Control.  Hoop house can be completely enclosed and process air treated with a biofilter.

Mixing Auger Specifications

Mixing Auger 14″ 304 Stainless Steel (13″ on EF-12)
Gear Motor 5hp 3ph (3hp on EF-12, 208/230/460V – 50/60Hz)
Gear Box Helical bevel synthetic lube
Carriage Drive VS 1/4 hp motor (1/2 hp for EF-30 and up)
Rail Drive VS 1/4 hp motor (1/2 hp for EF-30 and up)
Control Panel Programmable PLC in NEMA 4X panel
Power Requirements (Motors) 30A 220V single or 208V 3 phase
Site Built Earth Flow Spec
Site Built Earth Flow Spec
Earth Flow Business Case White Letter
Earth Flow Business Case White Letter