How 20,000 Worms Transformed this Building [Interview]

We’re kicking off a new series of stories focusing on sustainable rooftops and initiatives in a dialogue with AMA Plaza’s Assistant Property Manager Yordanos Ghdey with Riverview Realty Property Management. Yordanos walks us through the ins and outs of the AMA Plaza’s worm composting program housed on the 48^th floor (20,000 worms, to be exact) – the city’s first large-scale commercial composting program.

How did the idea of worm composting originate?

Yordanos Ghdey: We began investigating the concept of composting in 2008, a time when commercial composting capability didn’t exist in the Chicago metropolitan area.  As our knowledge of sustainability increased, we discovered worm composting or vermicomposting through a worm composting consultant.  In 2009, we became the first large-scale commercial worm composting program in the City with 5,000 worms, which have since increased to 20,000.

What was involved in setting up a worm composting operation?

Yordanos Ghdey: We first had to understand the requirements to successfully host vermicomposting within the building, including the maintenance responsibilities, to ensure the worms’ environment is safe. We settled on a location in the 48^th floor mechanical room that provides a comfortable and consistent tempered environment. Because the worms are self-managing, we simply needed a container, bedding and waste material to serve as food and nutrients. The worms at AMA Plaza are Eisenia Fetida worms – also known as red worms.

What kind of maintenance is involved?

Yordanos Ghdey: The maintenance is minimal. The management staff, along with an employee from Café 330, checks on the worms once or twice per week to evaluate their food consumption as well as their environment. If too much food is provided, it may become moldy which can create a vulnerable system open to infestations from other microorganisms. If food has become anaerobic, it may begin to smell, but the food is still edible by the worms so we simply add a generous amount of damp cardboard or paper shreddings over it and adjust the feeding schedule accordingly. We also check on the compost level at this time. If the amount of compost produced is not efficient, that is a warning sign that additional care is needed in the health of the worms.

Additionally,  third party assistance is provided by a vermicomposting professional once or twice a year – or on an as needed basis – to check on the worms and confirm the compost level the worms are producing is sufficient. We also have the support of our management team members and one of our Café’s employees who feed the worms dinner from left-over food and ensure their bedding and moisture content of their environment is adequate.

What food do the worms eat?

Yordanos Ghdey: The worms can digest any compostable foods including fruits and vegetables that are broken down into smaller pieces as well as coffee grinds. Shredded paper and cardboard are added to the top of the bin to provide a source of fiber, and foster a dark and moist environment which discourages fruit flies. We also add coconut shreddings to provide additional nutrients in the event the compost is too thick or in need of supplementary moisture. They should not be fed meat, poultry, fish, dairy, junk food or any fruits that are high in citrus such as oranges, limes and lemons. Non–biodegradable materials should never enter the bin. The worms eat about 5,200 pounds of food a year.

Why is this initiative so important to the AMA Plaza?

Yordanos Ghdey: Not only does composting connect the office environment to the natural environment, it also promotes healthier plant growth in our plaza plant beds. The castings of the worms, which are essentially the     compost, have high water retention which is beneficial in the event of a dry spell. The compost also has a slow nutrition release meaning the nutrients are released slowly so the plants receive what they need over a period of time. In comparison, chemical fertilizers oversaturate plants with a large amount of nutrients at once. When it rains, the nutrients are washed out of the soil and chemicals can seep into drinking water pipes.

How do you use your compost?

Yordanos Ghdey: Compost is easily removed from the bottom of the bin because the worms are drawn towards the top where the food source is located. Once the compost falls to the bottom of the bin, we remove it and store it for our outdoor landscaping. When the flowers are replaced in the spring, summer, and fall, the compost is mixed with the soil to provide an organic soil conditioner as well as a natural fertilizer.

What other green features does your building feature?

Yordanos Ghdey: We have several green initiatives here at AMA Plaza and are proud to be leaders within the City of Chicago with many of them.  We offer a robust recycling program which includes complimentary battery and electronic waste recycling. Food composting is also offered within tenant spaces which we operate on a weekly schedule to make the concept much easier on the tenants and in return, increase participation.  Other features include a 6,500 square foot vegetated roof, green cleaning program; water conservation programs, closed-loop paper and product purchasing, traffic reduction initiatives and a materials re-use procedure.

What are some considerations for other buildings who want to implement worm composing?

Yordanos Ghdey: The initial set-up for the worms is minimal, and we were able to use food and other materials recycled from the building, so it is a very low-cost program.

The bin, which is self-contained and odorless, is well ventilated and the worms are very aware of the size of the bin they are in. Because worms are hermaphroditic and can produce a cocoon every 7 to 10 days, one would think they would quickly overpopulate, however, they have an innate ability to control their population. Availability of food, size of their bin and the fouling of their environment decreases reproduction.

Commercial composting does have additional costs for bio-bags (which hold the material and degrade along with the organic material) and for removal.  This cost is somewhat offset by a reduction in waste removed from the property.

How do you involve your tenants with composting?

Yordanos Ghdey: Due to the smaller scale of worm composting, tenants are not directly involved with that program. Tenants are made aware of the program and images are shared on social media and the lobby slides. In 2014, we hosted an event to introduce tenants to a larger scale food composting process and benefits, and invited them to participate. We also provided incentives in collaboration with Waste Management, which handles the food compost pick-up for the building. Once tenants realized how simple the process is and that it does not require much effort on their part, they were very open to the idea. We currently have eight companies composting within the building, including the management office and the hotel. We continue to engage our tenants through education, tours and presentations.