Green Cones

Green Cones

Riverstone International School is going GREEN (cones)

Riverstone is not new to exploring alternative methods for waste disposal on campus. We have been using red wiggler worms for vermiculture for many years now. However, there are challenges when working with biological systems like worms – they have limited types of food that should be fed to them (no dairy, fat, citrus) and they need to be climate-controlled in the harsh winters & hot summers.

RIS has been composting for a long time in a small way, however, the inputs of compost are also limited…organic green and brown vegetable material are the preferred things to put in the pile. Composting is less restrictive than worm farming as you can add citrus but compost piles are not meant to digest fat, meat, dairy or other animal products.


The solution? How about a food digestion system that can handle all of the waste from the food stream we create on campus? Green Cone food digesters are a great way to dispose of food waste and divert it from the landfill and into our gardens without the maintenance of worms or the restrictions from vermiculture or composting. Food digesters can accommodate, meat, dairy, and small amounts of fat/oil without attracting pests or becoming a health hazard. The result? A much more complete diversion from our landfill bound waste stream than previously available to the students.

The Riverstone Parents Association became aware of the need to support school gardening, to provide a maintenance-free method of dealing with organic waste that can be successful in our harsh climate and that would scale to accommodate all of the waste that the Riverstone populace generates. The PA was amazing and purchased three cones for the students to build and install in each of the food production areas near where the majority of the organic waste is created (where the students eat lunch).

As part of our Earth Week festivities last year, a small group of students helped me and Ben Brock, RIS Sustainability Coordinator, do a pilot waste audit.


The amazing Riverstone Plant Club helped install and explain the uses for the cones. Currently we have two cones set up, one in the high-school and one in the elementary school veggie gardens. There is a group of students that have identified the gym lunchroom as the main place that we are missing organic waste diversion, but there is not an ideal place to bury a cone… the solution? They want to build raised beds near the gym lunch area to provide more food creation space and a home for the third cone to be placed!! We are excited to be able to get back together with students and continue our waste audit and diversion efforts more systemically over the next school year!