Composting
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In-vessel Composting System
The Lower East Side Ecology Center is using an aerobic compost process to turn fruit and vegetable peelings into rich compost using a custom-build setup that produces a finished product in approximately three months.

Our aerobic compost process consists of two distinct steps:

1.The initial phase is sometimes referred to as the "active phase" of decomposition, where the addition of oxygen and moisture is optimized to ensure sustained high temperature (150 Fahrenheit for at least 3 consecutive days) in the composting materials to ensure rapid decomposition and the destruction of any harmful pathogens. 

2.The second phase of composting is called the "curing" process, whereby compost is aged and matured to form a stable end product.

The term "in-vessel composting" refers to any type of composting done in a closed container. Here it refers to the first step or active phase of our composting process. The second step takes place in open bins, and will be described below. Our compost vessels were designed by Jim McNelly and comprise a one-of-a-kind small-scale system, consisting of 16 plastic containers, each measuring approximately one cubic yard. Each container can hold approximately 1,000 pounds of material. 

Our Special Recipe
To start the process of composting we unload organic waste, collected from New York City households and a small number of businesses, from our truck directly into our Bobcat bucket. From there the materials are dumped into a custom blender, where the kitchen scraps are blended together with sawdust and a small amount of active composting material, to inoculate the bin with the aerobic bacteria needed for composting.

To ensure optimum conditions for the aerobic organisms that break down the organic materials, the bins are equipped with a passive aeration system. This system depends on fresh, oxygen rich air to enter the in-vessel system through an opening on the bottom of the bin and a blower to remove hot air from the top. All bins are connected through tubing and a manifold to the blower. The blower in turn blows the exhaust air into a bio-filter. The bio-filter consist of a plastic bin, without the lid and contains a blend of compost and wood chips to ensure the biological degradation of odorous compounds found in the exhaust air.

The organic materials stay in the active phase of the in-vessel compost system for 15 to 20 days. After this initial active composting process, the mix has to be cured to turn into a stable finished product. We use a special kind of earthworm, Eisenia foetida - commonly called red wiggler worm - to help in the curing process and to create worm castings. The curing phase takes anywhere from two to three month (depending on the season) and we sandwich the composted mixture in between a bottom and top layer of finished worm castings, loaded with worms. The second step takes place in large metal trays that are also custom-fitted with aeration mats to keep the worms happy.

After the curing stage we empty the containers into a pile to prepare compost for screening and bagging. Screened materials are bagged for sale at our table at the Union Square Greenmarket. The courser material, which contains the majority of the worms, is reintroduced back into the process.

The Lower East Side Ecology Center developed this in-vessel compost system in 1998 with funding from the Empire State Development Corporation. We currently handle 60 tons of organic materials a year to produce 15 tons of finished compost. Through a license agreement with the Department of Parks & Recreation (Parks) the Lower East Side Ecology Center established this in-vessel compost system at an under-utilized 10,000 square foot area in East River Park, just south of the Williamsburg Bridge, in 1998.